Derivative Instruments and Hedging Activities Disclosure [Abstract] Schedule of Interest Rate Derivatives Schedule of Interest Rate Derivatives [Table Text Block] Schedule of the Fair Value of Derivative Instruments Recorded in the Consolidated Balance Sheets Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Schedule of the Pre-Tax Impact of Derivative Instruments Recorded in the Consolidated Statement of Operations Derivative Instruments, Gain (Loss) [Table Text Block] Segment Reporting [Abstract] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] HBB HBB [Member] HBB [Member] NACoal NACoal [Member] NACoal [Member] Geographical [Axis] Geographical [Axis] Segment, Geographical [Domain] Geographical [Domain] United States UNITED STATES Other Other Countries [Member] Other Countries [Member] Revenues from External Customers and Long-Lived Assets [Line Items] Revenues from External Customers and Long-Lived Assets [Line Items] Revenues Revenues Long-lived assets Long-Lived Assets Valuation and Qualifying Accounts [Abstract] Valuation and Qualifying Accounts Disclosure [Table] Valuation and Qualifying Accounts Disclosure [Table] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves [Domain] Valuation Allowances and Reserves [Domain] Allowance for doubtful accounts Allowance for Doubtful Accounts [Member] Allowance for discounts, adjustments and returns Allowance for Discounts, Adjustments and Returns [Member] Allowance for Discounts, Adjustments and Returns [Member] Valuation and Qualifying Accounts Disclosure [Line Items] Valuation and Qualifying Accounts Disclosure [Line Items] Valuation allowances and reserves [Roll Forward] Movement in Valuation Allowances and Reserves [Roll Forward] Balance at Beginning of Period Valuation Allowances and Reserves, Balance Charged to Costs and Expenses Valuation Allowances and Reserves, Charged to Cost and Expense Charged to Other Accounts Valuation Allowances and Reserves, Charged to Other Accounts Deductions Valuation Allowances and Reserves, Deductions Balance at End of Period Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] KC KC [Member] KC [Member] NACCO and Other NACCO and Other [Member] NACCO and Other [Member] Eliminations Eliminations [Member] Eliminations [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Total assets Assets Depreciation, depletion and amortization Depreciation, Depletion and Amortization Capital expenditures, excluding acquisitions of business Payments to Acquire Property, Plant, and Equipment Statement of Comprehensive Income [Abstract] Net income (loss) Net Income (Loss) Attributable to Parent Other comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Foreign currency translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Deferred gain on available for sale securities Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Current period cash flow hedging activity, net of $838 tax benefit in 2014, $477 tax expense in 2013 and $2,471 tax expense in 2012 Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Reclassification of hedging activities into earnings, net of $489 tax benefit in 2014, $95 tax benefit in 2013 and $2,630 tax expense in 2012 Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Current period pension and postretirement plan adjustment, net of $3,292 tax benefit in 2014, $5,531 tax expense in 2013 and $1,553 tax benefit in 2012 Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax Curtailment gain into earnings, net of $718 tax expense in 2013 Other Comprehensive Income (Loss), Finalization of Pension and Other Postretirement Benefit Plan Valuation, Net of Tax Reclassification of pension and postretirement adjustments into earnings, net of $313 tax benefit in 2014, $740 tax benefit in 2013 and $2,056 tax benefit in 2012 Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), Net of Tax Total other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Attributable to Parent Compensation and Retirement Disclosure [Abstract] Effect of one-percentage point change in assumed health care cost rrend rates Defined Benefit Plan, Effect of One-Percentage Point Change in Assumed Health Care Cost Trend Rates [Abstract] Effect on total of service and interest cost of 1-percentage point increase Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components Effect on total of service and interest cost of 1-percentage point decrease Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components Effect on postretirement benefit obligation of 1-percentage point increase Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation Effect on postretirement benefit obligation of 1-percentage point decrease Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation Organization, Consolidation and Presentation of Financial Statements [Abstract] Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Camino Real Camino Real [Member] Camino Real [Member] Coyote Creek Coyote Creek [Member] Coyote Creek [Member] Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Number of wholly owned subsidiaries Number of Wholly Owned Subsidiaries Number of Wholly Owned Subsidiaries Production capacity in 2015 Production Capacity, Next Fiscal Year Production Capacity, Next Fiscal Year Production capacity, mid 2016 Production Capacity, Two Fiscal Years Production Capacity, Two Fiscal Years Variable interest entity, ownership percentage by parent Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage Provision for doubtful accounts Provision for Doubtful Accounts Condensed Financial Information of Parent Company Only Disclosure [Abstract] Condensed Financial Statements [Table] Condensed Financial Statements [Table] Parent Company Parent Company [Member] Condensed Financial Statements, Captions [Line Items] Condensed Financial Statements, Captions [Line Items] Unrestricted investment Investments in Subsidiaries, Unrestricted Investment Investments in Subsidiaries, Unrestricted Investment Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Income Tax Disclosure [Abstract] Schedule of Income Tax Expense (Benefit) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Summary of Tax Credit Carryforwards Summary of Tax Credit Carryforwards [Table Text Block] Unrecognized Tax Benefits Roll Forward Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Defined contribution plan, total costs Defined Contribution Plan, Cost Recognized Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plans and Other Postretirement Benefit Plans [Axis] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] Defined Benefit Plan and Other Postretirement Benefit Plan [Domain] U.S. Pension Plan United States Pension Plan of US Entity [Member] Non-U.S. Pension Plan Foreign Pension Plan [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Expected pension contributions, next fiscal year Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year Increase projected benefit obligation Defined Benefit Plan, Actuarial Gain (Loss) Other Postretirement Benefit Plans, Defined Benefit Other Postretirement Benefit Plan [Member] Actuarial loss Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, before Tax Amortization of actuarial loss Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax Prior-service credit Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax Amortization of prior service (cost) credit Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), before Tax Curtailment gain Other Comprehensive Income (Loss), Finalization of Pension and Other Postretirement Benefit Plan Valuation, before Tax Total recognized in other comprehensive (income) loss Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax Statement of Stockholders' Equity [Abstract] Cash dividends on Class A and Class B common stock Common Stock, Dividends, Per Share, Declared Asset Retirement Obligation Disclosure [Abstract] Bellaire Bellaire Corporation [Member] Bellaire Corporation [Member] Fair value of trust assets Asset Retirement Obligation, Legally Restricted Assets, Fair Value Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] Balance at beginning of period Asset Retirement Obligation Liabilities acquired during the period Asset Retirement Obligation, Liabilities Incurred Liabilities settled during the period Asset Retirement Obligation, Liabilities Settled Accretion expense Asset Retirement Obligation, Accretion Expense Revision of estimated cash flows Asset Retirement Obligation, Revision of Estimate Balance at end of period Accounting Policies [Abstract] Significant Accounting Policies Significant Accounting Policies [Text Block] Inventory Disclosure [Abstract] Inventories Inventory Disclosure [Text Block] Statement of Financial Position [Abstract] Parent Company Condensed Balance Sheets Condensed Financial Information of Parent Company Only Disclosure [Text Block] Defined Benefit Pension Plans Pension Plan [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Defined Benefit Plan, Asset Categories [Axis] Defined Benefit Plan, Asset Categories [Axis] Plan Asset Categories [Domain] Plan Asset Categories [Domain] U.S. equity securities US Equity Securities [Member] US Equity Securities [Member] Non-U.S. equity securities Non-US Equity Securities [Member] Non-US Equity Securities [Member] Fixed income securities Fixed Income Securities [Member] Money market Money Market Funds [Member] Fair value of each major category of U.S. plan assets Defined Benefit Plan, Fair Value of Plan Assets Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Name of Property [Axis] Name of Property [Axis] Name of Property [Domain] Name of Property [Domain] Reed Minerals Reed Minerals [Member] Reed Minerals [Member] Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Finite-Lived Intangible Assets Finite-Lived Intangible Assets [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Weston Products, LLC Weston Products, LLC [Member] Weston Products, LLC [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Customer Relationships Customer Relationships [Member] Trademarks Trademarks [Member] Other Intangible Assets Other Intangible Assets [Member] Coal Supply Agreement Coal Supply Agreements [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets, Net [Abstract] Finite-Lived Intangible Assets, Net [Abstract] Gross Carrying Amount Finite-Lived Intangible Assets, Gross Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Net Balance Finite-Lived Intangible Assets, Net Preliminary purchase price Business Combination, Consideration Transferred Intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Amount allocated to identifiable intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Goodwill Goodwill Amortization of intangible assets Amortization of Intangible Assets Reed Minerals long-lived asset impairment charge Asset Impairment Charges Expected annual amortization expense, 2015 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months Expected annual amortization expense, 2016 Finite-Lived Intangible Assets, Amortization Expense, Year Two Expected annual amortization expense, 2017 Finite-Lived Intangible Assets, Amortization Expense, Year Three Expected annual amortization expense, 2018 Finite-Lived Intangible Assets, Amortization Expense, Year Four Expected annual amortization expense, 2019 Finite-Lived Intangible Assets, Amortization Expense, Year Five Coal supply agreement amortization period Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Schedule of Change in Asset Retirement Obligation Schedule of Change in Asset Retirement Obligation [Table Text Block] Income Statement [Abstract] Cost of sales Cost of Goods Sold Gross profit Gross Profit Earnings of unconsolidated mines Earnings of unconsolidated mines This item represents the entity's proportionate share for the period of the pre-tax earnings of the unconsolidated mines to which the equity method of accounting is applied. Income tax amounts are included in the income tax provision line. Operating expenses Operating Expenses [Abstract] Selling, general and administrative expenses Selling, General and Administrative Expense Reed Minerals long-lived asset impairment charge Impairment of Long-Lived Assets Held-for-use Reed Minerals goodwill impairment charge Goodwill, Impairment Loss Gain on sale of assets Gain (Loss) on Disposition of Property Plant Equipment, Excluding Oil and Gas Property and Timber Property Operating Expenses Operating Expenses Operating profit (loss) Operating Income (Loss) Other expense (income) Nonoperating Income (Expense) [Abstract] Interest expense Interest Expense Income from other unconsolidated affiliates Income (Loss) from Equity Method Investments Closed mine obligations Nonoperating Income (Expense), Closed Mine Obligations Nonoperating Income (Expense), Closed Mine Obligations Other, net, including interest income Other Nonoperating Income (Expense) Other (income) expense Nonoperating Income (Expense) Income (loss) from continuing operations before income tax (benefit) provision Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest Income tax provision (benefit) Income Tax Expense (Benefit) Income (loss) from continuing operations, net of tax Income (Loss) from Continuing Operations Attributable to Parent Income from discontinued operations, net of tax expense of $7,599 in 2012 Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Net income (loss) Basic earnings (loss) per share: Earnings Per Share, Basic [Abstract] Continuing operations Income (Loss) from Continuing Operations, Per Basic Share Discontinued operations Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share Basic earnings (loss) per share Earnings Per Share, Basic Diluted earnings (loss) per share: Earnings Per Share, Diluted [Abstract] Continuing operations (in dollars per share) Income (Loss) from Continuing Operations, Per Diluted Share Discontinued operations (in dollars per share) Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share Diluted earnings (loss) per share (in dollars per share) Earnings Per Share, Diluted Basic weighted average shares outstanding Weighted Average Number of Shares Outstanding, Basic Diluted weighted average shares outstanding Weighted Average Number of Shares Outstanding, Diluted Debt Disclosure [Abstract] Line of Credit Facility [Table] Line of Credit Facility [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Private Placement Notes Private Placement Notes [Member] Private Placement Notes [Member] Note Payable to Coteau Note Payable to Coteau [Member] Note Payable to Coteau [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] Base Rate Base Rate [Member] LIBOR Rate London Interbank Offered Rate (LIBOR) [Member] Currency [Axis] Currency [Axis] All Currencies [Domain] All Currencies [Domain] US Dollar United States of America, Dollars Canadian Dollar Canada, Dollars Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Interest paid Interest Paid Interest capitalized Interest Costs Capitalized Line of credit facility, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Assets held as collateral Debt Instrument, Collateral Amount Basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Line of credit facility, unused capacity, commitment fee percentage Line of Credit Facility, Unused Capacity, Commitment Fee Percentage Long-term Debt, Weighted Average Interest Rate Long-term Debt, Weighted Average Interest Rate Line of credit facility, current borrowing capacity Line of Credit Facility, Current Borrowing Capacity Line of credit facility, amount outstanding Long-term Line of Credit Line of credit facility, remaining borrowing capacity Line of Credit Facility, Remaining Borrowing Capacity Amount of letters of credit outstanding Letters of Credit Outstanding, Amount Weighted average interest rate Debt, Weighted Average Interest Rate Interest rate at period end Debt Instrument, Interest Rate, Effective Percentage Line of credit facility, minimum excess availability Line Of Credit Facility, Minimum Excess Availability Line Of Credit Facility, Minimum Excess Availability Dividend restriction from closing date Debt Instrument, Dividend Restriction From Closing Date Debt Instrument, Dividend Restriction From Closing Date Dividend restriction credit facility excess availability requirement Debt Instrument, Dividend Restriction, Credit Facility Excess Availability Requirement Debt Instrument, Dividend Restriction, Credit Facility Excess Availability Requirement Minimum fixed charge coverage ratio Debt Instrument, Minimum Fixed Charge Coverage Ratio Debt Instrument, Minimum Fixed Charge Coverage Ratio Loan processing fee Loan Processing Fee Dividend restriction from closing date including minimum fixed charge coverage ratio Debt Instrument, Dividend Restriction From Closing Date Including Minimum Fixed Charge Coverage Ratio Debt Instrument, Dividend Restriction From Closing Date Including Minimum Fixed Charge Coverage Ratio Dividend restriction period following closing date of credit facility Debt Instrument, Dividend Restriction, Period Following Closing Date of Credit Facility Debt Instrument, Dividend Restriction, Period Following Closing Date of Credit Facility Dividend restriction credit facility excess availability requirement as defined within the agreement Debt Instrument, Dividend Restriction, Credit Facility Excess Availability Requirement As Defined Within the Agreement Debt Instrument, Dividend Restriction, Credit Facility Excess Availability Requirement As Defined Within the Agreement Minimum interest coverage ratio Debt Instrument, Minimum Interest Coverage Ratio Debt Instrument, Minimum Interest Coverage Ratio Line of credit facility, availability required to pay dividends Line of Credit Facility, Availability Required to Pay Dividends Line of Credit Facility, Availability Required to Pay Dividends Maximum EBITDA ratio Debt Instrument, Earnings Before Interest Taxes Depreciation and Amortization Ratio Debt Instrument, Earnings Before Interest Taxes Depreciation and Amortization Ratio Long-term debt Long-term Debt Debt instrument, amount outstanding Debt Instrument, Amount Outstanding Debt Instrument, Amount Outstanding Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Customer concentration risk Customer Concentration Risk [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Sales revenue, net Sales Revenue, Net [Member] Customer [Axis] Customer [Axis] Customer [Domain] Customer [Domain] Choctaw Generation Limited Partnership Choctaw Generation Limited Partnership [Member] Choctaw Generation Limited Partnership [Member] Alabama Coal Cooperative Alabama Coal Cooperative [Member] Alabama Coal Cooperative [Member] Wal-Mart Wal-Mart [Member] Wal-Mart [Member] Five Largest Customers Five Largest Customers [Member] Five Largest Customers [Member] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Groups, Including Discontinued Operations, Name [Domain] Disposal Groups, Including Discontinued Operations, Name [Domain] Hyster-Yale Hyster-Yale [Member] Hyster-Yale [Member] Revenue from major customer, percentage Concentration Risk, Percentage Management fees expense Management Fee Expense Leases [Abstract] Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Restructuring Type [Axis] Restructuring Type [Axis] Type of Restructuring [Domain] Type of Restructuring [Domain] Contract Termination Contract Termination [Member] Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Early lease termination penalties Loss Contingency, Accrual, Current Future minimum capital lease payments Capital Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2015 Capital Leases, Future Minimum Payments Due, Next Twelve Months 2016 Capital Leases, Future Minimum Payments Due in Two Years 2017 Capital Leases, Future Minimum Payments Due in Three Years 2018 Capital Leases, Future Minimum Payments Due in Four Years 2019 Capital Leases, Future Minimum Payments Due in Five Years Subsequent to 2019 Capital Leases, Future Minimum Payments Due Thereafter Total minimum lease payments Capital Leases, Future Minimum Payments Due Amounts representing interest Capital Leases, Future Minimum Payments, Interest Included in Payments Present value of net minimum lease payments Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments Current maturities Capital Lease Obligations, Current Long-term capital lease obligation Capital Lease Obligations, Noncurrent Future minimum operating lease payments Operating Leases, Future Minimum Payments, Due in Four and Five Years [Abstract] 2015 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2016 Operating Leases, Future Minimum Payments, Due in Two Years 2017 Operating Leases, Future Minimum Payments, Due in Three Years 2018 Operating Leases, Future Minimum Payments, Due in Four Years 2019 Operating Leases, Future Minimum Payments, Due in Five Years Subsequent to 2019 Operating Leases, Future Minimum Payments, Due Thereafter Total minimum lease payments Operating Leases, Future Minimum Payments Due Rental expense for all operating leases Operating Leases, Rent Expense, Net [Abstract] Rental expense for all operating leases Operating Leases, Rent Expense, Net Rental income on subleases of equipment Operating Leases, Rent Expense, Sublease Rentals Assets recorded under capital leases Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract] Plant and equipment Capital Leased Assets, Gross Less accumulated depreciation Capital Leases, Lessee Balance Sheet, Assets by Major Class, Accumulated Depreciation Assets recorded under capital leases Capital Leases, Balance Sheet, Assets by Major Class, Net Capital lease obligations with lease agreements to acquire plant and equipment Capital Lease Obligations Incurred Coal supply agreement amortization period Finite-Lived Intangible Asset, Useful Life Equity [Abstract] Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Loss (gain) on cash flow hedging Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member] Pension and postretirement plan Accumulated Defined Benefit Plans Adjustment [Member] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of accumulated other comprehensive income Reclassification out of Accumulated Other Comprehensive Income [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Foreign exchange contract Foreign Exchange Contract [Member] Interest rate contract Interest Rate Contract [Member] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Cost of sales Interest expense Income tax expense (benefit) Net of tax Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Other Events and Transactions [Abstract] Other Events and Transactions Other Transactions Other Events and Transactions [Text Block] Other Events and Transactions Derivative [Table] Derivative [Table] Derivative [Line Items] Derivative [Line Items] Interest rate derivative assets, at fair value Interest Rate Derivative Assets, at Fair Value Interest rate derivative liabilities, at fair value Interest Rate Derivative Liabilities, at Fair Value Notional amount of foreign currency derivatives Derivative, Notional Amount Derivative, fair value, net Derivative, Fair Value, Net Cash flow hedge gain (loss) to be reclassified within twelve months Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Interest rate cash flow hedge gain (loss) to be reclassified during next twelve months Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Designated as hedging instrument Designated as Hedging Instrument [Member] Not designated as hedging instrument Not Designated as Hedging Instrument [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Prepaid expenses and other Prepaid Expenses and Other Current Assets [Member] Other current liabilities Other Current Liabilities [Member] Other noncurrent assets Other Noncurrent Assets [Member] Other long-term liabilities Other Noncurrent Liabilities [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Interest rate swap agreements, asset derivatives Interest Rate Fair Value Hedge Asset at Fair Value Foreign currency exchange contracts, asset derivatives Foreign Currency Fair Value Hedge Asset at Fair Value Total derivatives designated as hedging instruments, asset derivatives Derivative Instruments in Hedges, Assets, at Fair Value Total derivatives no designated as hedging instruments, asset derivatives Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value Total derivatives, asset derivatives Derivative Asset, Fair Value, Gross Asset Interest rate swap agreements, liability derivatives Interest Rate Fair Value Hedge Liability at Fair Value Foreign currency exchange contracts, liability derivatives Foreign Currency Fair Value Hedge Liability at Fair Value Total derivatives designated as hedging instruments, liability derivatives Derivative Instruments in Hedges, Liabilities, at Fair Value Total derivatives no designated as hedging instruments, liability derivatives Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value Total derivatives, liability derivatives Derivative Liability, Fair Value, Gross Liability Operating Loss Carryforwards [Table] Operating Loss Carryforwards [Table] Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] Foreign tax authority Foreign Tax Authority [Member] State and local jurisdiction State and Local Jurisdiction [Member] Operating Loss Carryforwards [Line Items] Operating Loss Carryforwards [Line Items] Net deferred tax asset, net operating loss Deferred Tax Assets, Operating Loss Carryforwards Valuation allowance, net operating loss Operating Loss Carryforwards, Valuation Allowance Net deferred tax asset, tax credit Tax Credit Carryforward, Deferred Tax Asset Valuation allowance, tax credit Tax Credit Carryforward, Valuation Allowance Total net deferred tax asset Operating Loss Carryforwards and Tax Credit Carryforward, Net Deferred Tax Asset, Amount Operating Loss Carryforwards and Tax Credit Carryforward, Net Deferred Tax Asset, Amount Total valuation allowance Operating Loss Carryforwards and Tax Credit Carryforward, Valuation Allowance, Amount Operating Loss Carryforwards and Tax Credit Carryforward, Valuation Allowance, Amount 2015 Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months 2016 Defined Benefit Plan, Expected Future Benefit Payments, Year Two 2017 Defined Benefit Plan, Expected Future Benefit Payments, Year Three 2018 Defined Benefit Plan, Expected Future Benefit Payments, Year Four 2019 Defined Benefit Plan, Expected Future Benefit Payments, Year Five 2019 - 2023 Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter Total Defined Benefit Plan, Expected Future Benefit Payments Defined Benefit Plan, Expected Future Benefit Payments Income (loss) from continuing operations before income tax provision (benefit) Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest [Abstract] Domestic Income (Loss) from Continuing Operations before Income Taxes, Domestic Foreign Income (Loss) from Continuing Operations before Income Taxes, Foreign Total Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Current income tax provision (benefit): Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Current Federal Tax Expense (Benefit) State Current State and Local Tax Expense (Benefit) Foreign Current Foreign Tax Expense (Benefit) Total current Current Income Tax Expense (Benefit) Deferred income tax provision (benefit): Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Federal Deferred Federal Income Tax Expense (Benefit) State Deferred State and Local Income Tax Expense (Benefit) Foreign Deferred Foreign Income Tax Expense (Benefit) Total deferred Deferred Income Tax Expense (Benefit) Income tax provision Condensed Balance Sheet Condensed Balance Sheet [Table Text Block] Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Schedule of earnings per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Deferred tax assets Components of Deferred Tax Assets [Abstract] Tax carryforwards Inventories Deferred Tax Assets, Inventory Accrued expenses and reserves Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Reserves Other employee benefits Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits Asset impairment Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Impairment Losses Other Deferred Tax Assets, Other Total deferred tax assets Deferred Tax Assets, Gross Less: Valuation allowance Deferred Tax Assets, Valuation Allowance Deferred tax assets, net of valuation allowance Deferred Tax Assets, Net of Valuation Allowance Deferred tax liabilities Components of Deferred Tax Liabilities [Abstract] Depreciation and depletion Deferred Tax Liabilities, Depreciation and Depletion Deferred Tax Liabilities, Depreciation and Depletion Partnership investment - development costs Deferred Tax Liabilities, Deferred Expense, Capitalized Research and Development Costs Accrued pension benefits Deferred Tax Liabilities, Accrued Pension Benefits Deferred Tax Liabilities, Accrued Pension Benefits Unremitted foreign earnings Deferred Tax Liabilities, Undistributed Foreign Earnings Total deferred tax liabilities Deferred Tax Liabilities, Gross Net deferred asset (liability) Deferred Tax Assets, Net Product Warranties Disclosures [Abstract] Schedule of Product Warranty Liability Schedule of Product Warranty Liability [Table Text Block] Statement [Table] Statement [Table] Total Stockholders' Equity Parent [Member] Common Stock Common Stock [Member] Capital in Excess of Par Value Additional Paid-in Capital [Member] Retained Earnings Retained Earnings [Member] Foreign Currency Translation Adjustment Accumulated Translation Adjustment [Member] Deferred Gain (Loss) on Available for Sale Securities Accumulated Net Unrealized Investment Gain (Loss) [Member] Deferred Gain (Loss) on Cash Flow Hedging Pension and Postretirement Plan Adjustment Noncontrolling Interest Noncontrolling Interest [Member] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Shares Outstanding Class A Common Class A [Member] Shares Outstanding Class B Common Class B [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Stockholders’ equity Stockholders' Equity Attributable to Parent [Abstract] Balance, beginning of period Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Stock-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Purchase of treasury shares Treasury Stock, Value, Acquired, Par Value Method Conversion of Class B to Class A shares Stock Issued During Period, Value, Conversion of Convertible Securities Cash dividends Dividends, Common Stock, Cash Stock dividend Dividends, Common Stock, Stock Current period other comprehensive income (loss) Other Comprehensive Income (Loss), before Reclassifications, Net of Tax Current period curtailment gain Other Comprehensive Income (Loss), Net of Tax Reclassification adjustment to net income Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax Balance, end of period ASSETS Assets [Abstract] Current assets Assets, Current [Abstract] Accounts receivable, net of allowances of $17,327 in 2014 and $13,705 in 2013 Accounts Receivable, Net Accounts receivable from affiliates Due from Affiliates Inventories, net Inventory, Net Deferred income taxes Deferred Tax Assets, Net of Valuation Allowance, Current Prepaid expenses and other Prepaid Expense and Other Assets Total current assets Assets, Current Property, plant and equipment, net Property, Plant and Equipment, Net Other intangibles, net Deferred income taxes Deferred Tax Assets, Net, Noncurrent Other non-current assets Other Assets, Noncurrent Total assets LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Current liabilities Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Revolving credit agreements of subsidiaries — not guaranteed by the parent company Line of Credit, Current Current maturities of long-term debt of subsidiaries — not guaranteed by the parent company Long-term Debt, Current Maturities Accrued income taxes Accrued Income Taxes, Current Accrued payroll Accrued Salaries, Current Other current liabilities Other Liabilities, Current Total current liabilities Liabilities, Current Long-term debt of subsidiaries — not guaranteed by the parent company Long-term Debt, Excluding Current Maturities Mine closing reserves Mine Reclamation and Closing Liability, Noncurrent Pension and other postretirement obligations Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Deferred income taxes Deferred Tax Liabilities, Net, Noncurrent Other long-term liabilities Other Liabilities, Noncurrent Total liabilities Liabilities Common stock: Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract] Common stock Common Stock, Value, Outstanding Capital in excess of par value Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Total stockholders’ equity Stockholders' Equity Attributable to Parent Total liabilities and equity Liabilities and Equity Tax effect of discontinued operations Discontinued Operation, Tax Effect of Discontinued Operation Quarterly Financial Information Disclosure [Abstract] Quarterly Results of Operations (Unaudited) Quarterly Financial Information [Text Block] Document and Entity Information [Abstract] DEI [Abstract] Entities [Table] Entities [Table] Entity Information [Line Items] Entity Information [Line Items] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Shares Outstanding Entity Common Stock, Shares Outstanding Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Public Float Entity Public Float Statement of Cash Flows [Abstract] Operating Activities Net Cash Provided by (Used in) Operating Activities [Abstract] Net income (loss) Income (Loss) from Operations before Extraordinary Items Income from discontinued operations Income (loss) from continuing operations Adjustments to reconcile net income (loss) to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Amortization of deferred financing fees Amortization of Financing Costs Deferred income taxes Reed Minerals long-lived asset impairment charge Reed Minerals goodwill impairment charge Gain on sale of assets Other Other Noncash Income (Expense) Working capital changes, excluding the effect of business acquisitions: Increase (Decrease) in Operating Capital [Abstract] Accounts receivable Increase (Decrease) in Accounts Receivable Inventories Increase (Decrease) in Inventories Other current assets Increase (Decrease) in Other Operating Assets Accounts payable Increase (Decrease) in Accounts Payable Other current liabilities Increase (Decrease) in Other Operating Liabilities Net cash provided by operating activities of continuing operations Net Cash Provided by (Used in) Operating Activities, Continuing Operations Net cash provided by operating activities of discontinued operations Cash Provided by (Used in) Operating Activities, Discontinued Operations Investing Activities Net Cash Provided by (Used in) Investing Activities [Abstract] Expenditures for property, plant and equipment Acquisition of business Payments for (Proceeds from) Businesses and Interest in Affiliates Proceeds from the sale of assets Proceeds from Sale of Property, Plant, and Equipment Proceeds from note receivable Proceeds from Sale of Notes Receivable Cash payment for cost method investment Increase (Decrease) in Restricted Cash Other Payments for (Proceeds from) Other Investing Activities Net cash used for investing activities of continuing operations Net Cash Provided by (Used in) Investing Activities, Continuing Operations Net cash used for investing activities of discontinued operations Cash Provided by (Used in) Investing Activities, Discontinued Operations Financing Activities Net Cash Provided by (Used in) Financing Activities [Abstract] Reductions of long-term debt Repayments of Long-term Debt Net additions to revolving credit agreements Line of Credit Facility, Increase (Decrease), Net Cash dividends paid Payments of Dividends Cash dividends received from Hyster-Yale Cash Dividends Paid to Parent Company by Discontinued Operation Cash Dividends Paid to Parent Company by Discontinued Operation Purchase of treasury shares Payments for Repurchase of Common Stock Financing fees paid Payments of Financing Costs Other Proceeds from (Payments for) Other Financing Activities Net cash provided by (used for) financing activities of continuing operations Net Cash Provided by (Used in) Financing Activities, Continuing Operations Net cash used for financing activities of discontinued operations Cash Provided by (Used in) Financing Activities, Discontinued Operations Effect of exchange rate changes on cash of continuing operations Effect of Exchange Rate on Cash and Cash Equivalents, Continuing Operations Effect of exchange rate changes on cash of discontinued operations Effect of Exchange Rate on Cash and Cash Equivalents, Discontinued Operations Decrease for the year Cash and Cash Equivalents, Period Increase (Decrease) Net increase related to discontinued operations Net Cash Provided by (Used in) Discontinued Operations Balance at the beginning of the year Balance at the end of the year Commitments and Contingencies Disclosure [Abstract] Contingencies Commitments and Contingencies Disclosure [Text Block] Schedule of Debt Schedule of Debt [Table Text Block] Schedule of Maturities of Total Debt, Excluding Capital Leases Schedule of Maturities of Long-term Debt [Table Text Block] Income (loss) from continuing operations before income tax provision (benefit) Statutory taxes (benefit) at 35.0% Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount State and local income taxes Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount NACoal valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Non-deductible expenses Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amount Percentage depletion Effective Income Tax Rate Reconciliation, Nondeductible Expense, Depletion, Amount R&D and other federal credits Income Tax Reconciliation Research and Development and Other Federal Credits Income Tax Reconciliation, Research and Development and Other Federal Credits Other, net Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Tax settlements Effective Income Tax Rate Reconciliation, Tax Settlement, Amount Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Statutory tax rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Cumulative unremitted earnings of foreign subsidiaries Undistributed Earnings of Foreign Subsidiaries Cumulative deferred tax liabilities of unremitted foreign earnings Business Combinations [Abstract] Acquisition Business Combination Disclosure [Text Block] Gross profit (loss) Selling, general and administrative expenses, including Amortization of intangible assets Selling, General and Administrative Expense and Amortization of Intangible Assets Selling, General and Administrative Expense and Amortization of Intangible Assets Operating profit Interest income Interest Income, Other Other (income) expense, including closed mine obligations Segment Reporting Information, Other Income (Expense) Segment Reporting Information, Other Income (Expense) Income (loss) from continuing operations, net of tax Movement in Standard Product Warranty Accrual [Roll Forward] Movement in Standard Product Warranty Accrual [Roll Forward] Balance at beginning of period Product Warranty Accrual Warranties issued Product Warranty Accrual, Warranties Issued Settlements made Product Warranty Accrual, Payments Balance at end of period Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Selling, general and administrative expenses Selling, General and Administrative Expenses [Member] Nature of Error [Axis] Nature of Error [Axis] Nature of Error [Domain] Nature of Error [Domain] Increase in estimated liability for certain frozen deferred compensation plans Increase In Estimated Liability For Certain Frozen Deferred Compensation Plans [Member] Increase In Estimated Liability For Certain Frozen Deferred Compensation Plans [Member] Gross profit Basic earnings per share Diluted earnings per share Immaterial error correction Quantifying Misstatement in Current Year Financial Statements, Amount Curtailment gain Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments Investments in and Advances to Affiliates Categorization [Axis] Investments in and Advances to Affiliates Categorization [Axis] Investments in and Advances to Affiliates Categorization [Domain] Investments in and Advances to Affiliates Categorization [Domain] Other Other Subsidiaries [Member] Other Subsidiaries [Member] Other current assets Other Assets, Current Investment in subsidiaries Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Total Assets Current liabilities Current intercompany accounts payable, net Accounts Payable, Related Parties, Current Note payable to Bellaire Notes Payable Stockholders’ equity Liabilities and Equity Schedule of Inventory Schedule of Inventory, Current [Table Text Block] Site Contingency [Table] Site Contingency [Table] Environmental Remediation Site [Axis] Environmental Remediation Site [Axis] Environmental Remediation Site [Domain] Environmental Remediation Site [Domain] Picton, Ontario Facility Picton, Ontario Facility [Member] Picton, Ontario Facility [Member] Site Contingency [Line Items] Site Contingency [Line Items] Accrual for environmental loss contingencies Accrual for Environmental Loss Contingencies Loss contingency, range of possible loss, minimum Loss Contingency, Range of Possible Loss, Minimum Loss contingency, range of possible loss, maximum Loss Contingency, Range of Possible Loss, Maximum Increase due to charge to establish a liability for environmental investigation and remediation activities Accrual for Environmental Loss Contingencies, Provision for New Losses Receivable from a third party Recorded Third-Party Environmental Recoveries Receivable Schedule II - Valuation and Qualifying Accounts Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Table] Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Table] Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items] Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items] Income tax payments Income Taxes Paid Income tax refunds Proceeds from Income Tax Refunds Net (benefit) expense in interest and penalties related to uncertain tax positions Unrecognized Tax Benefits, Income Tax Penalties Expense Interest and penalties accrued Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] National Coal of Alabama, Inc. National Coal of Alabama, Inc. [Member] National Coal of Alabama, Inc. [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Purchase consideration Cash paid at closing Payments to Acquire Businesses, Gross Net working capital and EBITDA adjustment Business Combination Provisional Information, Initial Accounting Incomplete, Adjustment, Net Working Capital and EBITDA Adjustment Business Combination Provisional Information, Initial Accounting Incomplete, Adjustment, Net Working Capital and EBITDA Adjustment Acquisition related costs Business Combination, Acquisition Related Costs Liabilities incurred Business Combination, Consideration Transferred, Liabilities Incurred Other noncurrent assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets Other noncurrent liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other Reclamation obligations Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Reclamation Obligations Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed Reclamation Obligations Acquisition cost Business Combination, Separately Recognized Transactions, Additional Disclosures, Acquisition Cost Expensed Recognized identified assets acquired and liabilities assumed Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract] Accounts receivable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Inventory Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory Other current assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other Property, plant and equipment (including mineral rights) Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Total assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Other current liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other Total liabilities assumed Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Net assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Purchase price Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Results of National Coal of Alabama included in the Company's Consolidated Statements of Operations Business Acquisition, Pro Forma Information [Abstract] Accounts receivable, net of allowances of $17,327 in 2014 and $13,705 in 2013 Allowance for Doubtful Accounts Receivable, Current Common stock, par value Common Stock, Par or Stated Value Per Share Common stock, shares outstanding Common Stock, Shares, Outstanding Common stock, convertible conversion ratio Common Stock, Convertible Conversion Ratio Common Stock, Convertible Conversion Ratio Income (loss) from continuing operations Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest Equity in earnings of subsidiaries Equity in Earnings of Subsidiaries Equity in Earnings of Subsidiaries Parent company only net loss Income (Loss) before Equity of Subsidiaries Income (Loss) before Equity of Subsidiaries Net changes related to operating activities Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities Net cash provided by (used for) operating activities Net Cash Provided by (Used in) Operating Activities Investing Activities Net cash used for investing activities Net Cash Provided by (Used in) Investing Activities Financing Activities Cash dividends received from subsidiaries Cash Dividends Paid to Parent Company by Consolidated Subsidiaries Notes payable to Bellaire Repayments of Notes Payable Capital contributions to subsidiaries Capital Contributions to Subsidiaries Capital Contributions to Subsidiaries Net cash provided by financing activities Net Cash Provided by (Used in) Financing Activities Cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) [Abstract] Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract] Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return on Plan Assets Amortization of actuarial loss Defined Benefit Plan, Amortization of Gains (Losses) Amortization of prior service credit Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Curtailment gain Net periodic pension benefit expense (income) Defined Benefit Plan, Net Periodic Benefit Cost Schedule of Finite-Lived Intangible Assets Schedule of Finite-Lived Intangible Assets [Table Text Block] Fair Value Disclosures [Abstract] Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument [Line Items] Debt Instrument [Line Items] Total outstanding borrowings: Capital lease obligations and other term loans: Long-term Debt and Capital Lease Obligations Private Placement Notes — NACoal Other borrowings Other Borrowings Total debt outstanding Debt and Capital Lease Obligations Current portion of borrowings outstanding: Long-term Debt and Capital Lease Obligations, Current Long-term portion of borrowings outstanding: Total available borrowings, net of limitations, under revolving credit agreements: Unused revolving credit agreements: Weighted average stated interest rate on total borrowings: Related Party Transactions [Abstract] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] Unconsolidated mines Unconsolidated Mines [Member] Unconsolidated Mines [Member] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Investments in unconsolidated mines and related tax assets Equity Method Investments Maximum loss Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount Dividends from unconsolidated mines Proceeds from Equity Method Investment, Dividends or Distributions Statement of Operations Revenues Equity Method Investment, Summarized Financial Information, Revenue Gross profit Equity Method Investment, Summarized Financial Information, Gross Profit (Loss) Income before income taxes Equity Method Investment, Summarized Financial Information, Income (Loss) from Continuing Operations before Income Taxes Equity Method Investment, Summarized Financial Information, Income (Loss) from Continuing Operations before Income Taxes Net income Equity Method Investment, Summarized Financial Information, Net Income (Loss) Balance Sheet Current assets Equity Method Investment, Summarized Financial Information, Current Assets Non-current assets Equity Method Investment, Summarized Financial Information, Noncurrent Assets Current liabilities Equity Method Investment, Summarized Financial Information, Current Liabilities Non-current liabilities Equity Method Investment, Summarized Financial Information, Noncurrent Liabilities 2015 Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months 2016 Long-term Debt, Maturities, Repayments of Principal in Year Two 2017 Long-term Debt, Maturities, Repayments of Principal in Year Three 2018 Long-term Debt, Maturities, Repayments of Principal in Year Four 2019 Long-term Debt, Maturities, Repayments of Principal in Year Five Thereafter Long-term Debt, Maturities, Repayments of Principal after Year Five Long-term debt Property, Plant and Equipment, Net [Abstract] Property, Plant and Equipment, Net Property, Plant and Equipment Disclosure [Text Block] Advertising expense Advertising Expense Product development costs Research and Development Expense Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Award Type [Domain] Equity Award [Domain] Stock Compensation Plan [Member] Stock Compensation Plan [Member] Restricted stock Restricted Stock [Member] Voluntary shares Voluntary Shares [Member] Voluntary Shares [Member] Share-based Compensation Arrangement BY Share-based Payment Award, Restriction Category [Axis] Share-based Compensation Arrangement BY Share-based Payment Award, Restriction Category [Axis] Share-based Compensation Arrangement BY Share-based Payment Award, Restriction Category [Axis] Share-based Compensation Arrangement BY Share-based Payment Award, Restriction Category [Domain] Share-based Compensation Arrangement BY Share-based Payment Award, Restriction Category [Domain] [Domain] for Share-based Compensation Arrangement BY Share-based Payment Award, Restriction Category [Axis] Participant's Retirement Date Participant's Retirement Date [Member] Participant's Retirement Date [Member] Date of award Award Date [Member] Award Date [Member] Participants retirement from board of directors Participants Retirement From Board Of Directors [Member] Participants Retirement From Board Of Directors [Member] Minimum age of director upon retirement from board Minimum Age Of Director Upon Retirement From Board [Member] Minimum Age Of Director Upon Retirement From Board [Member] Title of Individual [Axis] Title of Individual [Axis] Title of Individual with Relationship to Entity [Domain] Relationship to Entity [Domain] Executives Executive Officer [Member] Non-employee directors Director [Member] Schedule of Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Duration of restrictions on stock assignment, pledges or transfers Share-based Compensation Arrangement By Share-based Payment Award, Restriction Period Share-based Compensation Arrangement By Share-based Payment Award, Restriction Period Shares issued during the year under the Company's stock compensation plans (shares) Stock Issued During Period, Shares, Share-based Compensation, Gross Class A common stock available for issuance under the plan (shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Compensation expense related to share awards Allocated Share-based Compensation Expense Compensation expense related to share awards, net of tax Allocated Share-based Compensation Expense, Net of Tax Amount of directors, annual retainer paid in restricted shares Non-employee Directors Annual Retainer, Amount Paid Non-employee Directors Annual Retainer, Amount Paid Annual non-employee directors retainer amount Share-based Compensation Arrangement By Share-based Payment Award, Non-employee Directors Annual Retainer Share-based Compensation Arrangement By Share-based Payment Award, Non-employee Directors Annual Retainer Percentage of annual retainer that may be received in shares of Class A stock (percent) Share-based Compensation Arrangement By Share-based Payment Award, Annual Retainer Convertible To Class A Common Stock, Percentage Share-based Compensation BY Share-based Payment Awrd, Annual Retainer Convertible To Class A Common Stock, Percentage Derivatives qualifying as hedges tax expense (benefit) Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Reclassification adjustment from AOCI on derivatives tax expense (benefit) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Pension and other postretirement benefit plans tax expense (benefit) Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax Finalization of pension and non pension postretirement plan valuation tax expense Other Comprehensive Income (Loss), Finalization of Pension and Other Postretirement Benefit Plan Valuation, Tax Amortization adjustment from AOCI pension and other post retirement plans, tax expense (benefit) Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), Tax Stockholders' Equity and Earnings Per Share Stockholders' Equity Note Disclosure [Text Block] Schedule of Recognized Identified Assets Acquired and Liabilities Assumed Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Results of Weston Brands Included in the Company's Consolidated Statements of Operations Schedule of Business Acquisitions, by Acquisition [Table Text Block] Asset Retirement Obligations Asset Retirement Obligation Disclosure [Text Block] Fair Value Disclosures Fair Value Disclosures [Text Block] Schedule of Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Building and building improvements Building and Building Improvements [Member] Machinery and equipment Machinery and Equipment [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Property, plant and equipment useful life Property, Plant and Equipment, Useful Life Leasing Arrangements Leases of Lessee Disclosure [Text Block] Permanent items Unrecognized Tax Benefits that Would Impact Effective Tax Rate Reconciliation of Unrecognized Tax Benefits [Roll Forward] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Balance at beginning of period Unrecognized Tax Benefits Additions based on tax positions related to prior years Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Additions based on tax positions related to the current year Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Reductions due to lapse of the applicable statute of limitations Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities Reductions due to lapse of the applicable statute of limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Balance at end of period Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] 2011 Stock Repurchase Program 2011 Stock Repurchase Program [Member] 2011 Stock Repurchase Program [Member] 2013 Stock Repurchase Program 2013 Stock Repurchase Program [Member] 2013 Stock Repurchase Program [Member] 2011 and 2013 Stock Repurchase Program 2011 and 2013 Stock Repurchase Program [Member] 2011 and 2013 Stock Repurchase Program [Member] Stock option Employee Stock Option [Member] Class of Stock [Line Items] Class of Stock [Line Items] Votes per share Common Stock, Voting Rights, Votes Common Stock, Voting Rights, Votes Common stock, shares authorized Common Stock, Shares Authorized Treasury sock, shares Treasury Stock, Shares Stock repurchase program authorized amount Stock Repurchase Program, Authorized Amount Purchase of shares Treasury shares acquired Treasury Stock, Shares, Acquired Average cost per share (in dollars per share) Treasury Stock Acquired, Average Cost Per Share Options exercisable, contractual term Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Options exercisable, expiration date Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period Common stock available for grant, shares Options granted in period, shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures Options outstanding, shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Notional amount of interest rate derivatives Average fixed interest rate of interest rate derivatives Derivative, Average Fixed Interest Rate Remaining term Remaining Maturity, Derivative The time remaining until the derivative matures. Weighted average discount rates for pension benefit obligation Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Weighted average discount rates for net periodic benefit cost Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Expected long-term rate of return on assets for pension benefit obligation Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Expected Long-term Return on Assets Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Expected Long-term Return on Assets Expected long-term rate of return on assets for net periodic benefit cost Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets Rate of increase in compensation levels Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Changes in plan assets and benefit obligations recognized in comprehensive income (loss) Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block] Actual allocation percentage and target allocation percentage for pension plan assets Schedule of Allocation of Plan Assets [Table Text Block] Fair value of pension plan assets Schedule of Defined Benefit Plans Disclosures [Table Text Block] Assumptions used in accounting for the defined benefit plan Schedule of Assumptions Used [Table Text Block] Net periodic benefit income and expense for the defined benefit plan Schedule of Net Benefit Costs [Table Text Block] Changes in benefit obligations during the year and funded status of defined benefit plan Schedule of Net Funded Status [Table Text Block] Effect of one-percentage-point change in assumed health care cost trend rates Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates [Table Text Block] Future benefit payments Schedule of Expected Benefit Payments [Table Text Block] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Balance at beginning of period Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value Change in estimate Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Estimate Increase (Decrease) Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Estimate Increase (Decrease) Accretion expense Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings Balance at end of period Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Table] Major Property Class [Axis] Major Property Class [Axis] Major Property Class [Domain] Major Property Class [Domain] Assets Held-for-sale [Member] Assets Held-for-sale [Member] Dragline Dragline [Member] Dragline [Member] Land Land [Member] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Gain on sale of property Gain (Loss) on Disposition of Property Plant Equipment Cash in escrow from investment Number of draglines sold Number of Draglines Sold Number of Draglines Sold Proceeds from the sale of assets Number of draglines sold for a gain Number of Draglines Sold for a Gain Number of Draglines Sold for a Gain Distributed shares Disposal Group, Including Discontinued Operation, Distributed Shares Disposal Group, Including Discontinued Operation, Distributed Shares Other recognized expenses of spin-off Business Disposition, Cost of Spin-Off, Transaction Costs Amount of direct costs of the spin-off including legal, accounting and other costs incurred to consummate the spin-off. Other recognized expenses of spin-off, net of tax Business Disposition, Cost of Spin-Off, Transaction Costs, Net of Tax Amount of direct costs of the spin-off including legal, accounting and other costs incurred to consummate the spin-off, net of tax. Property, Plant and Equipment Property, Plant and Equipment [Table Text Block] Income Taxes Income Tax Disclosure [Text Block] Standard Product Warranty, Policy [Policy Text Block] Standard Product Warranty, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Accounts Receivable, Net of Allowances Receivables, Policy [Policy Text Block] Inventories Inventory, Policy [Policy Text Block] Property, Plant and Equipment, Net Property, Plant and Equipment, Policy [Policy Text Block] Long-Lived Assets Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Coal Supply Agreement and Other Intangibles, Net Goodwill and Intangible Assets, Policy [Policy Text Block] Self-insurance Liabilities Self Insurance Reserve [Policy Text Block] Revenue Recognition Revenue Recognition, Policy [Policy Text Block] Advertising Costs Advertising Costs, Policy [Policy Text Block] Product Development Costs Research and Development Expense, Policy [Policy Text Block] Shipping and Handling Costs Shipping and Handling Cost, Policy [Policy Text Block] Tax Collected from Customers and Remitted to Governmental Authorities Value Added Tax [Policy Text Block] Value Added Tax [Policy Text Block] Stock Compensation Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block] Foreign Currency Foreign Currency Transactions and Translations Policy [Policy Text Block] Financial Instruments and Derivative Financial Instruments Derivatives, Policy [Policy Text Block] Fair Value Measurements Fair Value of Financial Instruments, Policy [Policy Text Block] Recently Issued Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Future Minimum Capital and Operating Lease Payments Contractual Obligation, Fiscal Year Maturity Schedule [Table Text Block] Assets recorded under capital leases are included in property Schedule of Capital Leased Assets [Table Text Block] Intercompany interest expense Intercompnay Interest Expenses Intercompnay Interest Expenses Other, net Administrative and general expenses Loss before income taxes Income tax benefit Net loss before equity in earnings of subsidiaries Discontinued operations, net of tax Schedule of Quarterly Financial Information Schedule of Quarterly Financial Information [Table Text Block] Derivative Financial Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Condensed Financial Statements Equity Method Investments [Table Text Block] Fixed income securities Fixed Income Funds [Member] Canadian equity securities Canadian Equity Securities [Member] Canadian Equity Securities [Member] Non-Canadian equity securities Non-Canadian Equity Securities [Member] Non-Canadian Equity Securities [Member] Cash and cash equivalents Cash and Cash Equivalents [Member] Actual allocation Defined Benefit Plan, Target Plan Asset Allocations Target allocations range, minimum Defined Benefit Plan, Target Plan Asset Allocations Range Minimum Target allocations range, maximum Defined Benefit Plan, Target Plan Asset Allocations Range Maximum Change in benefit obligation Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Benefit obligation at beginning of year Defined Benefit Plan, Benefit Obligation Actuarial (gain) loss Benefits paid Defined Benefit Plan, Benefits Paid Plan amendments Defined Benefit Plan, Plan Amendments Foreign currency exchange rate changes Defined Benefit Plan, Foreign Currency Exchange Rate Gain (Loss) Intercompany transfers Defined Benefit Plan, Intercompany Transfers Defined Benefit Plan, Intercompany Transfers Benefit obligation at end of year Accumulated benefit obligation at end of year Defined Benefit Plan, Accumulated Benefit Obligation Change in plan assets Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Fair value of plan assets at beginning of year Actual return on plan assets Defined Benefit Plan, Actual Return on Plan Assets Employer contributions Defined Benefit Plan, Contributions by Employer Foreign currency exchange rate changes Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Plan Assets Intercompany transfers Defined Benefit Plan, Intercompany Transactions, Plan Assets Defined Benefit Plan, Intercompany Transactions, Plan Assets Fair value of plan assets at end of year Funded status at end of year Defined Benefit Plan, Funded Status of Plan Amounts recognized in the balance sheets consist of: Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract] Noncurrent assets Defined Benefit Plan, Assets for Plan Benefits, Noncurrent Current liabilities Pension and Other Postretirement Defined Benefit Plans, Current Liabilities Noncurrent liabilities Amount recognized in the balance sheets Defined Benefit Plan, Amounts Recognized in Balance Sheet Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), after Tax [Abstract] Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax [Abstract] Actuarial loss Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax Prior service credit Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Prior Service Cost (Credit), before Tax Deferred taxes Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Deferred Tax Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Deferred Tax Currency differences and other Defined Benefit Plan Accumulated Other Comprehensive Income Currency Differences and Other Defined Benefit Plan Accumulated Other Comprehensive Income Currency Differences and Other Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax Amounts that will be amortized from accumulated other comprehensive income (loss) in next fiscal year Defined Benefit Plan, Amount to be Amortized from Accumulated Other Comprehensive Income (Loss) Next Fiscal Year [Abstract] Actuarial loss included in accumulated other comprehensive income (loss) expected to be recognized in net periodic benefit cost in 2014, before tax Defined Benefit Plan, Amortization of Net Gains (Losses), before Tax Defined Benefit Plan, Amortization of Net Gains (Losses), before Tax Actuarial loss included in accumulated other comprehensive income (loss) expected to be recognized in net periodic benefit cost in 2014, net of tax (less than $0.1 million) Defined Benefit Plan, Future Amortization of Gain (Loss) Prior service cost (credit) included in accumulated other comprehensive income (loss) expected to be recognized in net periodic benefit cost in 2014, before tax (less than $0.1 million) Defined Benefit Plan, Amortization of Net Prior Service Cost (Credit), before Tax Defined Benefit Plan, Amortization of Net Prior Service Cost (Credit), before Tax Prior service cost (credit) included in accumulated other comprehensive income (loss) expected to be recognized in net periodic benefit cost in 2014, net of tax (less than $0.1 million) Defined Benefit Plan, Future Amortization of Prior Service Cost (Credit) Schedule I - Condensed Financial Information of the Parent Coal Lands and Real Estate Coal Lands and Real Estate [Member] Coal Lands and Real Estate [Member] Plant and Equipment Plant and Equipment [Member] Plant and Equipment [Member] Property, plant and equipment, at cost Property, Plant and Equipment, Gross Less allowances for depreciation, depletion and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Property, plant and equipment, net Depreciation, depletion and amortization Depreciation, Depletion and Amortization, Production Depreciation, Depletion and Amortization, Production Tangible asset impairment charges Tangible Asset Impairment Charges Proved and probable reserves (tons) Coal Mining Reserves, Proved and Probable Reserves, Quantity Proven and Probable Coal Reserves Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Quoted prices in active markets for identical assets (level 1) Significant other observable inputs (level 2) Significant unobservable inputs (level 3) Fair Value, Inputs, Level 3 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Assets: Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Available for sale securities Available-for-sale Securities Interest rate swap agreements Foreign currency exchange contracts Foreign Currency Contract, Asset, Fair Value Disclosure Assets: Assets, Fair Value Disclosure Liabilities: Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Interest rate swap agreements Foreign currency exchange contracts Foreign Currency Contracts, Liability, Fair Value Disclosure Contingent consideration Guarantees, Fair Value Disclosure Liabilities: Financial and Nonfinancial Liabilities, Fair Value Disclosure Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Derivative Instruments, Gain (Loss) [Table] Interest expense Interest Expense [Member] Cost of sales Cost of Sales [Member] Costs of sales or other Costs of sales or other [Member] Costs of sales or other income (expense) Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Amount of Gain or (Loss) Recognized in AOCI on Derivative (Effective Portion) Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net Amount of Gain or (Loss) Reclassified from AOCI into Income (Effective Portion) Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Amount of Gain or (Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing) Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments Amount of Gain or (Loss) Recognized in Income on Derivative Not Designated as Hedging Instruments Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net Dilutive effect of restricted stock awards Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Diluted weighted average shares outstanding Segment Reporting Information Schedule of Segment Reporting Information, by Segment [Table Text Block] Revenue From External Customers and Long-Lived Assets, by Geographical Areas Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block] Product Warranties Product Warranty Disclosure [Text Block] Current and Long-Term Financing Debt Disclosure [Text Block] Plant and Equipment Property, Plant and Equipment, Other Types [Member] Valuation Technique [Axis] Valuation Technique [Axis] Valuation Technique [Domain] Valuation Technique [Domain] Market approach Market Approach Valuation Technique [Member] Income approach Income Approach Valuation Technique [Member] Accounts receivable Accounts Receivable [Member] Credit concentration risk Credit Concentration Risk [Member] Purchase price Contingent consideration Change in estimate, decrease Tons of coal sold from reserves covered in earn-out period for earn-out calculation Business Combination, Tons of Coal Sold from Reserves Covered in Earn-out Period for Earn-out Calculation Business Combination, Tons of Coal Sold from Reserves Covered in Earn-out Period for Earn-out Calculation Valuation technique weighting Fair Value Measurement, Valuation Technique Weighting, Percentage Fair Value Measurement, Valuation Technique Weighting, Percentage Gross Carrying Amount Long-term debt fair value Long-term Debt, Fair Value Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Jones Day Jones Day [Member] Jones Day [Member] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Legal services Related Party Transaction, Expenses from Transactions with Related Party Business Segments Segment Reporting Disclosure [Text Block] Health care cost trend rate assumed for next year Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year Rate to which the cost trend rate is assumed to decline (ultimate trend rate) Defined Benefit Plan, Ultimate Health Care Cost Trend Rate Year that the rate reaches the ultimate trend rate Defined Benefit Plan, Year that Rate Reaches Ultimate Trend Rate Related Party Transactions Related Party Transactions Disclosure [Text Block] Principles of Consolidation and Nature of Operations Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Coal - NACoal Energy Related Inventory, Coal Mining supplies - NACoal Other Inventory, Supplies, Gross Total inventories at weighted average cost Weighted Average Cost Inventory Amount Sourced inventories - HBB Other Inventory, Purchased Goods, Gross Retail inventories - KC Retail Related Inventory Total inventories at FIFO FIFO Inventory Amount Inventories, net Retirement Benefit Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Other current assets Total Liabilities and Stockholders’ Equity Restricted investments Investments in Subsidiaries, Restricted Investment Investments in Subsidiaries, Restricted Investment