Accounting Policies [Abstract]
Regulatory Assets And Liabilities Table [Abstract]
Regulatory Assets And Liabilities Table [Abstract]
-- None. No documentation exists for this element. --
Regulatory assets and liabilities table
Schedule Of Regulatory Assets And Liabilities [Table Text Block]
Tabular disclosure of regulatory assets and liabilities, including current and noncurrent assets created when regulatory agencies permit the deferral of costs to the balance sheet that would otherwise be required to appear on the company's income statement and would be charged against current expenses or revenues, as well as current and noncurrent liabilities that result from rate actions of a regulator.
Debt Disclosure [Abstract]
Debt Instruments [Table]
Schedule of Long-term Debt Instruments [Table]
Debt Instrument [Axis]
Debt Instrument [Axis]
Debt Instrument, Name [Domain]
Debt Instrument, Name [Domain]
Unsecured Senior Notes Due 2014 [Member]
Unsecured Senior Notes Due 2014 [Member]
Unsecured 4.95% Senior Notes, due 2014
Unsecured Senior Notes Due 2017 [Member]
Unsecured Senior Notes Due 2017 [Member]
Unsecured 6.35% Senior Notes, due 2017
Unsecured Senior Notes Due 2019 [Member]
Unsecured Senior Notes Due 2019 [Member]
Unsecured 8.50% Senior Notes, due 2019
Unsecured Senior Notes Due 2034 [Member]
Unsecured Senior Notes Due 2034 [Member]
Unsecured 5.95% Senior Notes, due 2034
Unsecured Senior Notes Due 2041 [Member]
Unsecured Senior Notes Due 2041 [Member]
Unsecured 5.50% Senior Notes, due 2041
Unsecured Senior Notes Due 2043 [Member]
Unsecured Senior Notes Due 2043 [Member]
Unsecured 4.15% Senior Notes, due 2043
Medium Term Notes Due 2025 [Member]
Medium Term Notes Due 2025 [Member]
Series A, 1995-1, 6.67%, due 2025
Unsecured Debentures Due 2028 [Member]
Unsecured Debentures Due 2028 [Member]
Unsecured 6.75% Debentures, due 2028
Debt Instrument [Line Items]
Debt Instrument [Line Items]
Debt Instrument Carrying Amount
Long-term Debt, Gross
Debt Instrument, Interest Rate, Stated Percentage
Debt Instrument, Interest Rate, Stated Percentage
Debt Instrument, Maturity Date
Debt Instrument, Maturity Date
Debt Instrument, Unamortized Discount
Debt Instrument, Unamortized Discount
Current maturities of long-term debt
Long-term Debt, Current Maturities
Long-term debt
Long-term Debt, Excluding Current Maturities
Line Of Credit Facility [Abstract]
Line of Credit Facility [Abstract]
Line Of Credit Facility [Table]
Line of Credit Facility [Table]
Lender Name [Axis]
Lender Name [Axis]
Line of Credit Facility, Name [Domain]
Line of Credit Facility, Name [Domain]
The name for the particular credit facility that distinguishes it from other credit facilities.
First Facility Regulated Operations [Member]
First Facility Regulated Operations [Member]
Five-Year $950 Million Unsecured Facility held by the Regulated Operations
Second Facility Regulated Operations [Member]
Second Facility Regulated Operations [Member]
$25 Million Unsecured Facility held by the Regulated Operations
Third Facility Regulated Operations [Member]
Third Facility Regulated Operations [Member]
$14 Million Revolving Facility held by the Regulated Operations
Intercompany Facility Regulated Operations [Member]
Intercompany Facility Regulated Operations [Member]
Intercompany Revolving Credit Facility held by the Regulated Operations
Committed Facility Nonregulated Operations [Member]
Committed Facility Nonregulated Operations [Member]
Committed Revolving Credit Facility held by the Nonregulated Operations
Uncommitted Facility Nonregulated Operations [Member]
Uncommitted Facility Nonregulated Operations [Member]
Uncommitted Revolving Credit Facility held by the Nonregulated Operations
Intercompany Facility Nonregulated Operations [Member]
Intercompany Facility Nonregulated Operations [Member]
Intercompany Revolving Credit Facility held by the Nonregulated Operations
Nonregulated Facilities [Member]
Nonregulated Facilities [Member]
Total Revolving Credit Facilities held by the Nonregulated Operations
Regulated Facilities [Member]
Regulated Facilities [Member]
Total Revolving Credit Facilities held by the Regulated Operations
Range [Axis]
Range [Axis]
Range [Domain]
Range [Domain]
Minimum [Member]
Minimum [Member]
Maximum [Member]
Maximum [Member]
Line Of Credit Facility [Line Items]
Line of Credit Facility [Line Items]
Line Of Credit Facility Maximum Borrowing Capacity
Line of Credit Facility, Maximum Borrowing Capacity
Line of Credit Facility, Current Available Borrowing Capacity
Line of Credit Facility, Current Available Borrowing Capacity
Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets) and the amount, if any, currently outstanding under the facility.
Line of Credit Facility, Maximum Borrowing Capacity with Accordion Feature
Line of Credit Facility, Maximum Borrowing Capacity with Accordion Feature
Maximum available borrowing capacity under the credit facility with consideration of any additional commited line portions under the accordion feature that could be borrowed against with the approval of the issuing banks.
Line of Credit Facility, Amended Maximum Borrowing Capacity
Line of Credit Facility, Amended Maximum Borrowing Capacity
Amended temporary maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.
Line Of Credit Facility Description
Line of Credit Facility, Description
Debt Instrument, Covenant, Excess Debt Trigger
Debt Instrument, Covenant, Excess Debt Trigger
Debt Instrument, Covenant, Excess Debt Trigger
Long Term Debt Other Disclosures [Abstract]
Long-term Debt, Other Disclosures [Abstract]
Authorized Commercial Paper
Authorized Commercial Paper
Authorized commercial paper, an unsecured promissory note that provides creditworthy institutions, typically finance companies or holding companies of banks and savings institutions with short-term funds. Commercial paper is generally short-term (at most 270 days, but usually much less) and negotiable.
Commercial Paper
Commercial Paper
Debt and Equity Securities Authorized for Issuance
Debt and Equity Securities Authorized for Issuance
The total dollar amount of debt and equity securities authorized to be issued.
Debt And Equity Securities Available For Issuance
Debt And Equity Securities Available For Issuance
The total dollar amount of debt and equity securities available to be issued.
Regulated Operations Line of Credit Facilities, Covenant Terms
Regulated Operations Line of Credit Facilities, Covenant Terms
Description of the conditions for borrowing under the regulated operations' credit facilities including the nature of any restrictions.
Ratio of Total Debt to Total Capital
Ratio of Total Debt to Total Capital
For covenant purposes, total debt divided by total capitalization including original issue discount, short-term debt, capital leases, operating leases and guaranty obligations.
Debt Instrument Covenant Description
Debt Instrument, Covenant Description
Debt Instrument Covenant Compliance
Debt Instrument, Covenant Compliance
Stock Issued During Period, Shares, New Issues
Stock Issued During Period, Shares, New Issues
Net proceeds from equity offering
Proceeds from Issuance of Common Stock
General Discussion of Pension and Other Postretirement Benefits [Abstract]
Interim Pension and Postretirement Benefit Plans
Pension and Other Postretirement Benefits Disclosure [Text Block]
Schedule Of Defined Benefit Plans Disclosures [Table]
Schedule of Defined Benefit Plans Disclosures [Table]
Defined Benefit Plans Disclosures Defined Benefit Plans [Axis]
Defined Benefit Plans and Other Postretirement Benefit Plans [Axis]
Defined Benefit Plans [Domain]
Defined Benefit Plan and Other Postretirement Benefit Plan [Domain]
Pension Benefits [Member]
Pension Plan, Defined Benefit [Member]
Supplemental Employee Retirement Plan, Defined Benefit [Member]
Supplemental Employee Retirement Plan, Defined Benefit [Member]
Other Benefits [Member]
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Disclosure [Line Items]
Components of net periodic pension cost [Abstract]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service Cost
Defined Benefit Plan, Service Cost
Interest Cost
Defined Benefit Plan, Interest Cost
Expected return on assets
Defined Benefit Plan, Expected Return on Plan Assets
Amortization of transition (asset)/obligation
Defined Benefit Plan, Amortization of Transition Obligations (Assets)
Amortization of prior service (credit)/cost
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)
Amortization of actuarial (gain) loss
Defined Benefit Plan, Amortization of Gains (Losses)
Settlement loss
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements
Net periodic pension cost
Defined Benefit Plan, Net Periodic Benefit Cost
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Net Periodic Benefit Cost Abstract
Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract]
Discount Rate
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate
Rate of compensation increase
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase
Expected return on plan assets
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets
Current Year Benefit Plan Contributions [Abstract]
Current Year Benefit Plan Contributions [Abstract]
-- None. No documentation exists for this element. --
Contributions Actual
Defined Benefit Plan, Contributions by Employer
Defined Benefit Plan, Expected Contributions in Current Fiscal Year
Defined Benefit Plan, Expected Contributions in Current Fiscal Year
Benefit Payment
Defined Benefit Plan, Settlements, Benefit Obligation
Effect on Net Periodic Cost Due To Discount Rate Change, Remaining Fiscal Year
Effect on Net Periodic Cost Due To Discount Rate Change, Remaining Fiscal Year
The net increase or (decrease) in net periodic cost in the remaining fiscal year due to a change in the discount rate.
Unaudited Financial Information
Significant Accounting Policies [Text Block]
Debt
Debt Disclosure [Text Block]
Derivative Instruments and Hedging Activities Disclosure [Abstract]
General Discussion Of Derivative Instruments And Hedging Activities [Abstract]
General Discussion of Derivative Instruments and Hedging Activities [Abstract]
Minimum Hedge Percentage Of Anticipated Heating Season Gas
Minimum Hedge Percentage Of Anticipated Heating Season Gas
Minimum anticipated percentage of heating season gas purchases hedged using financial instruments.
Maximum Hedge Percentage Of Anticipated Heating Season Gas
Maximum Hedge Percentage Of Anticipated Heating Season Gas
Maximum anticipated percentage of heating season gas purchases hedged using financial instruments.
Hedge Percentage Of Actual Heating Season Gas
Hedge Percentage Of Actual Heating Season Gas
Actual percentage of heating season gas purchases hedged using financial instruments.
Hedge Volume Of Actual Heating Season Gas
Hedge Volume Of Actual Heating Season Gas
Actual volume of heating season gas purchases hedged using financial instruments.
Minimum Length Of Time Hedged In Cash Flow Hedge
Minimum Length Of Time Hedged In Cash Flow Hedge
Minimum length of time over which the entity is hedging its exposure to the variability in future cash flows for forecasted transactions, excluding those forecasted transactions related to the payment of variable interest on existing financial instruments, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
Maximum Length Of Time Hedged In Cash Flow Hedge
Maximum Length of Time Hedged in Cash Flow Hedge
Gain (Loss) On Hedge Ineffectiveness
Gain Loss On Hedge Ineffectiveness
Gain or loss recognized in earnings during the reporting period representing the amount of the hedges' ineffectiveness for fair value and cash flow hedges.
Regulated Segments Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate
Regulated Segments Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate
The domestic federal statutory tax rate applicable under enacted tax laws to the Regulated operations pretax income from continuing operations for the period. The "statutory" tax rate shall be the regular tax rate if there are alternative tax systems.
Nonregulated Segment Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate
Nonregulated Segment Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate
The domestic federal statutory tax rate applicable under enacted tax laws to the Nonregulated operations pretax income from continuing operations for the period. The "statutory" tax rate shall be the regular tax rate if there are alternative tax systems.
Gain (Loss) On Derivative Instruments Not Designated Hedges Net Pretax
Gain (Loss) On Derivative Instruments Not Designated Hedges, Net, Pretax
Aggregate net gain (loss) on all derivative instruments not designated as hedges recognized in gross profit during the period, before tax effects.
Interest Rate Cash Flow Hedges [Abstract]
Interest Rate Cash Flow Hedges [Abstract]
Derivative [Table]
Derivative [Table]
Derivative, by Nature [Axis]
Derivative, by Nature [Axis]
Derivative, Name [Domain]
Derivative, Name [Domain]
Interest Rate Hedges, Senior Notes 2015 Issuance [Member]
Interest Rate Hedges, Senior Notes 2015 Issuance [Member]
Interest rate cash flow hedges entered into to fix the Treasury yeild component of the interest cost associated with the anticipated issuance of $500 million unsecured senior notes in fiscal 2015.
Interest Rate Hedges, Senior Notes 2017 Issuance [Member]
Interest Rate Hedges, Senior Notes 2017 Issuance [Member]
Interest rate cash flow hedges entered into to fix the Treasury yeild component of the interest cost associated with the anticipated issuance of $250 million unsecured senior notes in fiscal 2017.
Interest Rate Hedges, Senior Notes 2019 Issuance [Member]
Interest Rate Hedges, Senior Notes 2019 Issuance [Member]
Interest rate cash flow hedges entered into to fix the Treasury yeild component of the interest cost associated with the anticipated issuance of $450 million unsecured senior notes in fiscal 2019.
Derivative [Line Items]
Derivative [Line Items]
Notional Amount of Interest Rate Cash Flow Hedge Derivatives
Derivative, Notional Amount
Anticipated Debt Issuance, Amount
Anticipated Debt Issuance, Amount
Anticipated debt issuance amount of future debt issuance.
Derivative, Average Forward Interest Rate
Derivative, Average Forward Interest Rate
Statement of Financial Position [Abstract]
Common Stock, Par Value Per Share
Common Stock Par Value Per Share
Par value of common stock per share; generally not indicative of the fair market value per share
Common Stock, Stated Value Per Share
Common Stock, Par or Stated Value Per Share
Common Stock, Shares Authorized
Common Stock, Shares Authorized
Common Stock, Shares, Issued
Common Stock, Shares, Issued
Common Stock, Shares, Outstanding
Common Stock, Shares, Outstanding
Income Statement [Abstract]
Discontinued Operation Tax Effect Of Income Loss From Discontinued Operation During Phase Out Period
Discontinued Operation, Tax Effect of Income (Loss) from Discontinued Operation During Phase-out Period
Discontinued Operation, Tax Effect of Income (Loss) from Disposal of Discontinued Operation
Discontinued Operation, Tax Effect of Income (Loss) from Disposal of Discontinued Operation
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]
Commitments and Contingencies Disclosure [Abstract]
Loss Contingency Information About Litigation Matters Abstract
Loss Contingency, Information about Litigation Matters [Abstract]
Description of Pending Litigation
Description of Pending Litigation
Describes the current status of significant pending litigation
Loss Contingency, Compensatory Damages Awarded, Value
Loss Contingency, Compensatory Damages Awarded, Value
Loss Contingency, Compensatory Damages Awarded, Value
Business License Tax [Abstract]
Business License Tax [Abstract]
Business License Tax [Abstract]
Business License Tax Examination, Description
Business License Tax Examination, Description
A brief description of status of the tax examination, significant findings to date, and the entity's position with respect to the findings.
Business License Tax Examination, Settlement Amount
Business License Tax Examination, Settlement Amount
Amount of settlement of tax examination agreed upon between the Company and the Tennessee Department of Revenue (TDOR).
Long Term Commitment Excluding Unconditional Purchase Obligation Abstract
Long-term Commitment (Excluding Unconditional Purchase Obligation) [Abstract]
Long Term Purchase Commitment [Table]
Long-term Purchase Commitment [Table]
Long Term Purchase Commitment By Category Of Item Purchased [Axis]
Category of Item Purchased [Axis]
Long Term Purchase Commitment Category Of Item Purchased Domain
Long-term Purchase Commitment, Category of Item Purchased [Domain]
Inventories Under Indexed Contracts [Member]
Inventories Under Indexed Contracts [Member]
Contractual obligation to purchase inventory such as raw and packaging materials, finished goods, supplies and other types of materials under indexed contracts.
Inventories Under Fixed Price Contracts [Member]
Inventories Under Fixed Price Contracts [Member]
Contractual obligation to purchase inventory such as raw and packaging materials, finished goods, supplies and other types of materials under fixed price contracts.
Long Term Purchase Commitment [Line Items]
Long-term Purchase Commitment [Line Items]
Long Term Purchase Commitment Minimum Quantity Required Within One Year
Long Term Purchase Commitment Minimum Quantity Required Within One Year
Volume that must be purchased within one year of the balance sheet date to avoid penalties or unfavorable effects on pricing, among other adverse consequences.
Long Term Purchase Commitment Minimum Quantity Required One To Three Years
Long Term Purchase Commitment Minimum Quantity Required One To Three Years
Volume that must be purchased within one to three years following the balance sheet date to avoid penalties or unfavorable effects on pricing, among other adverse consequences.
Long Term Purchase Commitment Minimum Quantity Required After Three Years
Long Term Purchase Commitment Minimum Quantity Required After Three Years
Volume that must be purchased after three years following the balance sheet date to avoid penalties or unfavorable effects on pricing, among other adverse consequences.
Purchase Commitment Amount Minimum
Purchase Commitment Amount Minimum
The minimum per-unit amount the entity agreed to spend under fixed price purchase commitment arrangements.
Purchase Commitment Amount Maximum
Purchase Commitment Amount Maximum
The maximum per-unit amount the entity agreed to spend under fixed price purchase commitment arrangements.
Significant Purchase Commitment Amount
Significant Purchase Commitment, Amount
Purchases made during the period under arrangements in which the entity has agreed to expend funds to procure goods or services from one or more suppliers.
Equity [Abstract]
Reclassification out of Accumulated Other Comprehensive Income [Table]
Reclassification out of Accumulated Other Comprehensive Income [Table]
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 [Member]
Reclassification out of Accumulated Other Comprehensive Income [Member]
Equity Components [Axis]
Equity Components [Axis]
Equity Component [Domain]
Equity Component [Domain]
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Net Gain (Loss) from Interest Rate Hedges [Member] [Member]
Accumulated Net Gain (Loss) from Interest Rate Hedges [Member] [Member]
Changes to accumulated comprehensive income resulting from gains and losses from derivative instruments designated and qualifying as the effective portion of interest rate hedges.
Accumulated Net Gain (Loss) from Commodity Contracts Cash Flow Hedges [Member] [Member]
Accumulated Net Gain (Loss) from Commodity Contracts Cash Flow Hedges [Member] [Member]
Changes to accumulated comprehensive income resulting from gains and losses from derivative instruments designated and qualifying as the effective portion of commodity contract cash flow hedges.
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Operation and maintenance
Other Selling, General and Administrative Expense
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest
Income Tax Expense
Income Tax Expense (Benefit)
Income (loss) from continuing operations
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest
Interest charges
Interest Expense
Purchased gas cost
Cost of Natural Gas Purchases
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Interest rate agreements fair value
Other Comprehensive Income Unrealized Gain Loss On Treasury Locks Arising During Period Net Of Tax
Change in accumulated gains and losses from interest rate agreements designated and qualifying as the effective portion of cash flow hedges, net of tax effect. The after tax effect change includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.
Forward commodity contracts fair value
Other Comprehensive Income Unrealized Gain Loss On Forward Commodity Contracts Arising During Period Net Of Tax
Change in accumulated gains and losses from forward commodity contracts designated and qualifying as the effective portion of cash flow hedges, net of tax effect. The after tax effect change includes an entity's share of an equity investee's Increase or Decrease in deferred hedging gains or losses.
Interest rate agreements
Other Comprehensive Income Reclassification Adjustment On Treasury Locks Included In Net Income Net Of Tax
Net of tax effect of the reclassification adjustment for accumulated gains and losses from interest rate agreements designated and qualifying as the effective portion of cash flow hedges included in accumulated comprehensive income that was realized in net income during the period.
Forward commodity contracts
Other Comprehensive Income Reclassification Adjustment On Forward Commodity Contracts Included In Net Income Net Of Tax
Net of tax effect of the reclassification adjustment for accumulated gains and losses from forward commodity contracts designated and qualifying as the effective portion of cash flow hedges included in accumulated comprehensive income that was realized in net income during the period.
Total other comprehensive income (loss) from hedging, net of tax
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax
Expected Recognition in Earnings of Deferred Gain (Losses) Financial Instruments [Table]
Expected Recognition in Earnings of Deferred Gain Losses Financial Instruments [Table]
-- None. No documentation exists for this element. --
Expected Recognition in Earnings of Deferred Gain (Losses) Financial Instruments [Axis]
Expected Recognition in Earnings of Deferred Gain Losses Financial Instruments [Axis]
-- None. No documentation exists for this element. --
Expected Recognition in Earnings of Deferred Gain (Losses) Financial Instruments [Domain]
Expected Recognition in Earnings of Deferred Gain Losses Financial Instruments [Domain]
-- None. No documentation exists for this element. --
Next Twelve Months [Member]
Next Twelve Months [Member]
-- None. No documentation exists for this element. --
Thereafter [Member]
Thereafter [Member]
-- None. No documentation exists for this element. --
Expected Earnings [Line Items]
Expected Earnings [Line Items]
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
Interest Rate Agreement Gain (Loss) Reclassified To Earnings
Interest Rate Agreement Gain Loss Reclassified To Earnings
The expected amount of gain or loss on interest rate agreement transaction(s) reclassified in the period to earnings from accumulated other comprehensive income.
Commodity Contract Gain (Loss) Reclassified To Earnings
Commodity Contract Gain Loss Reclassified To Earnings
The expected amount of gain or loss on commodity contract hedges reclassified in the period to earnings from accumulated other comprehensive income.
Total Hedge Gain (Loss) Reclassified To Earnings
Total Hedge Gain Loss Reclassified To Earnings
The expected amount of gains or losses on hedges reclassified in the period to earnings from accumulated other comprehensive income.
Commitments and Contingencies [Abstract]
Commitments and Contingencies [Abstract]
Long-term Purchase Commitment [Table Text Block]
Long-term Purchase Commitment [Table Text Block]
Document And Entity Information [Abstract]
-- None. No documentation exists for this element. --
Entity Registrant Name
Entity Central Index Key
Current Fiscal Year End Date
Entity Filer Category
Document Type
Document Period End Date
Document Fiscal Year Focus
Document Fiscal Period Focus
Amendment Flag
Entity Common Stock, Shares Outstanding
Entity Well-known Seasoned Issuer
Entity Voluntary Filers
Entity Current Reporting Status
Earnings Per Share [Abstract]
Shares Issued At Overallotment Option
Shares Issued At Overallotment Option
The number of shares issued to underwriters at the overallotment option.
Share Price
Share Price
Earnings Per Share Basic Two Class Method [Abstract]
Earnings Per Share, Basic, Two Class Method [Abstract]
Basic Earnings per Share from Continuing Operations
Earnings Per Share, Basic [Abstract]
Income from continuing operations
Less: Income from continuing operations allocated to participating securities
Undistributed Earnings Allocated to Participating Securities
Income from continuing operations available to common shareholders
Net Income (Loss) Available to Common Stockholders, Basic
Basic weighted average shares outstanding
Weighted Average Number of Shares Outstanding, Basic
Income from continuing operations per share - Basic
Income (Loss) from Continuing Operations, Per Basic Share
Basic Earnings per Share from Discontinued Operations
Earnings Per Share Basic Discontinued Operations [Abstract]
-- None. No documentation exists for this element. --
Income from discontinued operations, net of tax
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest
Less: Income from discontinued operations allocated to participating securities
Undistributed Earnings From Discontinued Operations Allocated To Participating Securities
Earnings from discontinued operations allocated (not distributed) to participating securities under the two-class method to the extent that participating securities may share in earnings as if all of the earnings for the period had been distributed.
Income from discontinued operations available to common shareholders
Net Income Loss From Discontinued Operations Available To Common Stockholders Basic
Earnings from discontinued operations allocated (not distributed) to participating securities under the two-class method to the extent that participating securities may share in earnings as if all of the earnings for the period had been distributed.
Income from discontinued operations per share - Basic
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share
Net income per share - Basic
Earnings Per Share, Basic
Net Income Loss Available To Common Stockholders Diluted Abstract
Net Income (Loss) Available to Common Stockholders, Diluted [Abstract]
Diluted Earnings per Share from Continuing Operations
Earnings Per Share, Diluted [Abstract]
Income from continuing operations available to common shareholders
Effect of dilutive stock options and other shares
Dilutive Securities, Effect on Basic Earnings Per Share, Options and Restrictive Stock Units
Income from continuing operations available to common shareholders
Net Income (Loss) Available to Common Stockholders, Diluted
Additional dilutive stock options and other shares
Incremental Common Shares Attributable to Participating Nonvested Shares with Non-forfeitable Dividend Rights
Diluted weighted average shares outstanding
Weighted Average Number of Shares Outstanding, Diluted
Income from continuing operations per share - Diluted
Income (Loss) from Continuing Operations, Per Diluted Share
Diluted Earnings per Share from Discontinued Operations
Earnings Per Share Diluted Discontinued Operations [Abstract]
-- None. No documentation exists for this element. --
Income from discontinued operations available to common shareholders
Effect of dilutive stock options and other shares
Amount Of Dilutive Securities Stock Options And Restrictive Stock Units Discontinued Operations
The amount resulting from the "as if" assumption that stock options or restrictive stock units were exercised for purposes of computing the dilutive effect of convertible securities for discontinued operations.
Net Income Loss From Discontinued Operations Available To Common Stockholders Diluted
Net Income Loss From Discontinued Operations Available To Common Stockholders Diluted
Net Income or Loss from Discontinued Operations Available to Common Stockholders plus adjustments resulting from the assumption that dilutive convertible securities were converted, options or warrants were exercised, or that other shares were issued upon the satisfaction of certain conditions.
Income from discontinued operations per share - Diluted
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share
Net income per share - Diluted
Earnings Per Share, Diluted
Earnings Per Share Diluted Other Disclosures Abstract
Earnings Per Share, Diluted, Other Disclosures [Abstract]
Anti-dilutive stock options excluded from computation of diluted earnings per share (in shares)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount
Share Repurchase Program - Shares Purchased
Stock Repurchased During Period, Shares
Share Repurchase Program - Amount Purchased
Stock Repurchased During Period, Value
Financial Instruments
Derivative Instruments and Hedging Activities Disclosure [Text Block]
Fair Value Disclosures [Abstract]
Fair value measurements table
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]
Schedule of Available-for-sale Securities Reconciliation [Table Text Block]
Schedule of Available-for-sale Securities Reconciliation [Table Text Block]
Other fair value measurements table
Schedule Of Other Fair Value Measures [Table Text Block]
Tabular disclosure of the fair value and carrying value of debt.
Segment Reporting [Abstract]
Schedule Of Segment Reporting Information By Segment [Table]
Schedule of Segment Reporting Information, by Segment [Table]
Statement Business Segments [Axis]
Segments [Axis]
Segment [Domain]
Segments [Domain]
Natural Gas Distribution Segment [Member]
Natural Gas Distribution Segment [Member]
The reportable segment, a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements, comprised of the regulated natural gas distribution and related sales operations.
Regulated Transmission and Storage Segment [Member]
Regulated Transmission and Storage Segment [Member]
The reportable segment, a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements, comprised of the regulated pipeline and storage operations.
Nonregulated Segment [Member]
Nonregulated Segment [Member]
The reportable segment, a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements, comprised of nonregulated natural gas management, nonregulated natural gas transmission, storage and other services.
Intersegment Elimination [Member]
Intersegment Eliminations [Member]
Subsegments Consolidation Items [Axis]
Subsegments Consolidation Items [Axis]
Subsegments Consolidation Items [Domain]
Subsegments Consolidation Items [Domain]
Reportable Subsegments [Member]
Reportable Subsegments [Member]
Intersubsegment Eliminations [Member]
Intersubsegment Eliminations [Member]
Segment Reporting Information [Line Items]
Segment Reporting Information [Line Items]
Number of operating segments
Number of Operating Segments
Segment Reporting Information Profit Loss [Abstract]
Segment Reporting Information, Profit (Loss) [Abstract]
Revenues from external customers
Revenues
Total operating revenues
Regulated and Unregulated Operating Revenue
Purchased gas cost
Gross profit
Gross Profit
Operating expenses
Operating Expenses [Abstract]
Operation and maintenance
Depreciation and amortization
Depreciation, Depletion and Amortization, Nonproduction
Taxes, other than income
Taxes, Other
Total operating expenses
Operating Expenses
Operating income
Operating Income (Loss)
Miscellaneous income (expense)
Other Nonoperating Income (Expense)
Interest charges
Income (loss) before income taxes
Income tax expense (benefit)
Income (loss) from continuing operations
Income from discontinued operations, net of tax
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax
Gain (loss) on sale of discontinued operations, net of tax
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax
Net income (loss)
Net Income (Loss) Attributable to Parent
Capital expenditures
Payments to Acquire Productive Assets
Segment Reporting Information, Balance Sheet [Abstract]
Segment Reporting Information, Balance Sheet [Abstract]
-- None. No documentation exists for this element. --
ASSETS
Assets [Abstract]
Net property, plant and equipment
Property, Plant and Equipment, Net
Investment in subsidiaries
Investment in subsidaries
The cost of investments in securities issued or assumed by subsidiary companies and investment advances to such companies attributed to the reportable segment, including interest accrued thereon when such interest is not subject to current settlement plus the equity in undistributed earnings or losses of such subsidiary companies since acquisition.
Current assets
Assets, Current [Abstract]
Cash and cash equivalents
Cash and Cash Equivalents, at Carrying Value
Assets from risk management activities
Derivative Asset, Current
Other current assets
Segment Reporting Information, Other Current Assets
Aggregate carrying amount, as of the balance sheet date, of current assets not separately disclosed in the segment balance sheet. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer).
Intercompany receivables
Intercompany receivables
Amounts due from other operating segments of the same entity attributed to the reportable segment.
Total current assets
Assets, Current
Goodwill
Goodwill
Noncurrent assets from risk management activities
Derivative Asset, Noncurrent
Deferred charges and other assets
Segment Reporting Information, Other Noncurrent Assets
Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the segment balance sheet. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer).
Total Assets
Assets
CAPITALIZATION AND LIABILITIES
Liabilities and Equity [Abstract]
Shareholders' equity
Stockholders' Equity Attributable to Parent
Total capitalization
Capitalization, Long-term Debt and Equity
Current liabilities
Liabilities, Current [Abstract]
Short-term debt
Short-term Debt
Liabilities from risk management activities
Derivative Liability, Current
Other current liabilities
Segment Reporting Information, Other Current Liabilities
Aggregate carrying amount, as of the balance sheet date, of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered and of liabilities not separately disclosed in the segment balance sheet. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).
Intercompany payables
Intercompany payables
Amounts due to other operating segments of the same entity attributed to the reportable segment.
Total current liabilities
Liabilities, Current
Deferred income taxes
Deferred Tax Liabilities, Gross
Derivative Liability, Noncurrent
Derivative Liability, Noncurrent
Regulatory cost of removal obligation
Regulatory cost of removal obligation
Reflects the total obligation as of the balance sheet date to remove regulatory assets from service.
Pension and postretirement liabilities
Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent
Deferred credits and other liabilities
Segment Reporting Information, Other Noncurrent Liabilities
Aggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the segment balance sheet. Noncurrent liabilities are expected to be paid after one year (or the normal operating cycle, if longer).
Total Equity and Liabilities
Liabilities and Equity
Regulatory assets and liabilities
Regulatory Assets and Liabilities, Recognition Criteria
Segment Reporting
Segment Reporting, Policy [Policy Text Block]
Earnings Per Share
Earnings Per Share, Policy [Policy Text Block]
Fair Value Measurements
Fair Value Measurements [Policy Text Block]
Describes an entity's accounting policy for determining the fair value of its financial and nonfinancial items.
Earnings per share table
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Schedule of Operating Revenues and Purchased Gas Cost, by Segment [Table]
Schedule of Operating Revenues and Purchased Gas Cost, by Segment [Table]
Operating revenues and purchased gas cost reported by segment in the consolidated income statement.
Operating Revenues and Purchased Gas Cost [Line Items]
Operating Revenues and Purchased Gas Cost [Line Items]
-- None. No documentation exists for this element. --
Operating revenues
Revenues [Abstract]
Operating revenues
Purchased gas cost
Cost of Revenue [Abstract]
Gross profit
Total operating expenses
Operating income
Income (loss) before income taxes
Gain on sale of discontinued operations, net of tax
Net income (loss)
Income (Loss) From Continuing Operations Per Basic Share
Income (Loss) From Discontinued Operations Net Of Tax Per Basic Share
Basic net income (loss) per share
Income (Loss) From Continuing Operations Per Diluted Share
Income (Loss) From Discontinued Operations Net Of Tax Per Diluted Share
Diluted net income (loss) per share
Cash dividends per share
Common Stock, Dividends, Per Share, Cash Paid
Weighted average shares outstanding:
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Diluted weighted average shares outstanding
Accumulated Other Comprehensive Income (Loss) [Abstract]
Accumulated Other Comprehensive Income (Loss) [Abstract]
-- None. No documentation exists for this element. --
Accumulated Other Comprehensive Income (Loss) [Table]
Accumulated Other Comprehensive Income (Loss) [Table]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), beginning balance
Accumulated Other Comprehensive Income (Loss), Net of Tax
Other comprehensive income (loss) before reclassifications
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax
Amounts reclassified from accumulated other comprehensive income
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax
Net current-period other comprehensive income (loss)
Other Comprehensive Income (Loss), Net of Tax
Accumulated other comprehensive income (loss), ending balance
Components of net periodic pension cost table
Schedule of Net Benefit Costs [Table Text Block]
Schedule of assumptions used table text block
Schedule of Assumptions Used [Table Text Block]
Discontinued operations income statement detail table
Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block]
Schedule of Available For Sale Securities [Abstract]
Available-for-sale Securities [Abstract]
Schedule of Available for Sale Securities [Table]
Schedule of Available-for-sale Securities [Table]
Major Types of Debt and Equity Securities [Axis]
Major Types of Debt and Equity Securities [Axis]
Major Types of Debt and Equity Securities [Domain]
Major Types of Debt and Equity Securities [Domain]
Equity Funds Domestic [Member]
Equity Funds Domestic [Member]
An investment that pools funds from many investors to invest in a combination of underlying domestic investments, primarily equity investments.
Equity Funds Foreign [Member]
Equity Funds Foreign [Member]
An investment that pools funds from many investors to invest in a combination of underlying foreign investments, primarily equity investments.
Debt Securities [Member]
Debt Securities [Member]
Money Market Funds [Member]
Money Market Funds [Member]
Schedule Of Available For Sale Securities [Line Items]
Schedule of Available-for-sale Securities [Line Items]
Available For Sale Securities Amortized Cost
Available-for-sale Securities, Amortized Cost Basis
Gross Unrealized Gain
Available For Sale Securities Gross Unrealized Gain Accumulated In Investments
Amount of accumulated pre-tax unrealized gains before deducting pre-tax unrealized losses on investments in available-for-sale securities impacting investments.
Gross Unrealized Loss
Available For Sale Securities Gross Unrealized Loss Accumulated In Investments
Amount of accumulated pre-tax unrealized loss before deducting pre-tax unrealized gain on investments in available-for-sale securities impacting investments.
Fair value
Available-for-sale Securities
Available-for-sale Securities, Other Disclosure Items [Abstract]
Available-for-sale Securities, Other Disclosure Items [Abstract]
Available-for-sale Securities, Supplemental Executive Benefit Plans
Available-for-sale Securities, Supplemental Executive Benefit Plans
Investments in debt and equity securities which are categorized neither as held-to-maturity nor trading held in separate rabbi trusts for the supplemental executive benefit plans.
Available-for-sale Securities, Gross Realized Gains
Available-for-sale Securities, Gross Realized Gains
Statement of Cash Flows [Abstract]
Cash Flows From Operating Activities
Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract]
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax
Adjustments to reconcile net income to net cash provided by operating activities:
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and amortization:
Depreciation, Depletion and Amortization [Abstract]
Charged to depreciation and amortization
Depreciation And Amortization Cash Flow
The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production. Includes depreciation recorded for discontinued operations.
Charged to other accounts
Other Depreciation and Amortization
Other
Other [Abstract]
-- None. No documentation exists for this element. --
Deferred income taxes
Deferred Income Tax Expense (Benefit)
Other
Other Noncash Income (Expense)
Net Assets Liabilities From Risk Management Activities
Increase (Decrease) in Commodity Contract Assets and Liabilities
Net change in operating assets and liabilities
Increase (Decrease) in Operating Assets
Net cash provided by operating activities
Net Cash Provided by (Used in) Operating Activities
Cash Flows From Investing Activities
Net Cash Provided by (Used in) Investing Activities [Abstract]
Capital expenditures
Proceeds from Sale of Productive Assets
Proceeds from Sale of Productive Assets
Other, net
Payments for (Proceeds from) Other Investing Activities
Net cash used in investing activities
Net Cash Provided by (Used in) Investing Activities
Cash Flows From Financing Activities
Net Cash Provided by (Used in) Financing Activities [Abstract]
Net decrease in short-term debt
Proceeds from (Repayments of) Short-term Debt
Net proceeds from issuance of long-term debt
Proceeds from Issuance of Long-term Debt
Settlement of Treasury lock agreements
Payments for (Proceeds from) Hedge, Financing Activities
Repayments of Long-term Debt
Repayments of Long-term Debt
Cash dividends paid
Payments of Ordinary Dividends, Common Stock
Repurchase of equity awards
Payments for Repurchase of Other Equity
Issuance of Common Stock
Proceeds from Issuance or Sale of Equity
Net cash provided by (used in) financing activities
Net Cash Provided by (Used in) Financing Activities
Net increase (decrease) in cash and cash equivalents
Cash and Cash Equivalents, Period Increase (Decrease)
Cash and cash equivalents at beginning of period
Cash and cash equivalents at end of period
Effect of Fair Value Hedges on Results of Operations [Abstract]
Commodity contracts
Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments
Fair value adjustment for natural gas inventory designated as the hedged item
Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge
Total (increase) decrease to purchased gas cost
Gain (Loss) on Fair Value Hedges Recognized in Earnings
Basis ineffectiveness
Fair Value Hedge Basis Ineffectiveness
Gain (loss) recognized in earnings during the reporting period representing the amount of the fair value hedges' ineffectiveness due to a difference in basis.
Timing ineffectiveness
Fair Value Hedge Timing Ineffectiveness
Gain (loss) recognized in earnings during the reporting period representing the amount of the fair value hedges' ineffectiveness due to a difference in timing.
Summary of Cash Flow Hedge Activity [Abstract]
Cash Flow Hedge [Table]
Cash Flow Hedge [Table]
Summary of Cash Flow Hedge activity.
Cash Flow Hedge [Line Items]
Cash Flow Hedge [Line Items]
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
Gain (loss) reclassified from AOCI into purchased gas cost for effective portion of commodity contracts
Cash Flow Hedge Gain (Loss) Reclassified to Purchased Gas Cost, Net
The amount of net gains or losses on a cash flow hedge reclassified in the period to purchased gas cost from accumulated other comprehensive income
Gain (loss) arising from ineffective portion of commodity contracts
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net
Total impact on purchased gas cost
Cash Flow Hedge Gain Loss Included In Cost of Sales Net
The amount of net gains or losses on a cash flow hedge reclassified to purchased gas cost from accumulated other comprehensive income or representing the ineffective portion of the hedge.
Loss on settled Treasury Lock agreements reclassified from AOCI into interest expense
Interest Rate Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net
Total Impact from Cash Flow Hedges
Cash Flow Hedge Gain (Loss) Impact on Earnings
The amount of net gains or losses on a cash flow hedge reclassified in the period to earnings from accumulated other comprehensive income.
Components of Debt
Schedule of Long-term Debt Instruments [Table Text Block]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table]
Fair Value Measurements, Recurring and Nonrecurring [Table]
Fair Value By Fair Value Hierarchy Level [Axis]
Fair Value, Hierarchy [Axis]
Fair Value Measurements Fair Value Hierarchy [Domain]
Fair Value Hierarchy [Domain]
Fair Value Inputs Level 1 [Member]
Fair Value, Inputs, Level 1 [Member]
Fair Value Inputs Level 2 [Member]
Fair Value, Inputs, Level 2 [Member]
Fair Value Inputs Level 3 [Member]
Fair Value, Inputs, Level 3 [Member]
Netting And Collateral [Member]
Netting [Member]
Equity Securities [Member]
Equity Securities [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]
Financial instruments, assets
Financial Instruments, Owned, at Fair Value
Hedged portion of gas stored underground
Hedged Portion Of Gas Stored Underground Fair Value Disclosure
Fair value amount as of the balance sheet date of the hedged portion of natural gas stored underground in depleted gas reservoirs, aquifers, or salt caverns to meet seasonal and peak load demands, and also as insurance against unforeseen supply disruptions, and deemed to be a current asset because it is expected to be used within twelve months or in the normal operating cycle.
Available-for-sale Securities
Total assets
Assets, Fair Value Disclosure
Financial instruments, liabilities
Financial and Nonfinancial Liabilities, Fair Value Disclosure
Fair Value [Abstract]
Fair Value [Abstract]
-- None. No documentation exists for this element. --
Derivative, Cash Collateral
Derivative, Cash Collateral
Amount of cash pledged as collateral against derivative liabilities.
Cash Held In Margin Accounts Classified Current Risk Management Asset
Derivative, Collateral, Right to Reclaim Cash
Cash Held In Margin Accounts Offset Current Risk Management Liabilities
Derivative Liability, Collateral, Right to Reclaim Cash, Offset
Debt Instrument Fair Value
Debt Instrument, Fair Value Disclosure
Discontinued Operation, Cash Price Received from Disposal of Discontinued Operation
Discontinued Operation, Cash Price Received from Disposal of Discontinued Operation
Amount of cash received resulting from the sale of a business component.
Discontinued Operation, Income (Loss) from Discontinued Operation Disclosures [Abstract]
Discontinued Operation, Income (Loss) from Discontinued Operation Disclosures [Abstract]
Operating revenues
Disposal Group, Including Discontinued Operation, Revenue
Purchased gas cost
Discontinued Operations Purchased Gas Cost
Cost of natural gas purchased and associated transportation and storage costs during the period for discontinued operations.
Gross profit
Disposal Group, Including Discontinued Operation, Gross Profit (Loss)
Operating expenses
Disposal Group, Including Discontinued Operation, Operating Expense
Operating income
Disposal Group, Including Discontinued Operation, Operating Income (Loss)
Miscellaneous income (expense)
Discontinued Operations Miscellaneous Income Expense
Amount, if any, of interest and miscellaneous expenses attirbuted to the discontinued operations during the reporting period.
Income from discontinued operations before income taxes
Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, before Income Tax
Income tax expense
Income (loss) from discontinued operations
Net income (loss) from discontinued operations
Statement of Comprehensive Income [Abstract]
Other comprehensive income (loss), net of tax
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Net unrealized holding gains (losses) on available-for-sale securities, net of tax
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax
Amortization and unrealized gains (losses) on interest rate agreements, net of tax
Other Comprehensive Income Reclassification Adjustment And Unrealized Gain Loss On Derivatives Included In Net Income And Arising During Period Net Of Tax
Net of tax effect of the reclassification adjustment for accumulated gains and losses from derivative instrument designated and qualifying as the effective portion of interest rate agreements included in accumulated other comprehensive income that was realized in net income during the period. Also includes change in accumulated gains and losses from derivative instrument designated and qualifying as the effective portion of interest rate agreements, net of tax effect.
Net unrealized gains (losses) on commodity cash flow hedges, net of tax
Other Comprehensive Income Loss Commodity Cash Flow Hedges Net Of Tax
Net of tax and reclassification adjustments amount of the change in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of commodity cash flow hedges. Also includes an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).
Total other comprehensive income (loss)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent
Total comprehensive income (loss)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Schedule of Segment Reporting Information, by Segment
Schedule of Segment Reporting Information, by Segment [Table Text Block]
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income Disclosure [Text Block]
The entire disclosure for accumulated other comprehensive income. Includes, but is not limited to, the components of accumulated other comprehensive income (loss) allocated to each component of comprehensive income and reclassifications out of accumulated other comprehensive income.
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business
Nature of Operations [Text Block]
Number of Customers, Natural Gas Distribution
Number Of Customers, Natural Gas Distribution
Represents the approximate number of customers in our natural gas distribution segment.
Number of Divisions, Natural Gas Distribution
Number Of Divisions, Natural Gas Distribution
Represents the number of natural gas distribution divisions.
Number of States in which Entity Operates
Number of States in which Entity Operates
Number of Customers, discontinued operations
Number Of Customers, Discontinued Operations
Represents the approximate number of customers in our discontinued operations.
Earnings Per Share
Earnings Per Share [Text Block]
Other Comprehensive Income Loss Tax Portion Attributable To Parent Abstract
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent, Parenthetical Disclosures [Abstract]
Unrealized holding gains (losses) on available-for-sale securities, tax
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax
Amortization and unrealized gains (losses) on interest rate agreements, tax
Other Comprehensive Income Reclassification Adjustment And Unrealized Gain Loss On Derivatives Included In Net Income And Arising During Period Tax
Tax effect on reclassification adjustment for accumulated gains and losses from derivative instrument designated and qualifying as the effective portion of interest rate agreements included in accumulated comprehensive income that was realized in net income during the period. Also includes tax effect on the change in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of interest rate agreements.
Net unrealized gains (losses) on commodity cash flow hedging transactions, tax
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax
Regulatory Assets And Liabilities Disclosure Abstract
Regulatory Assets and Liabilities Disclosure [Abstract]
Schedule Of Regulatory Assets [Table]
Schedule of Regulatory Assets [Table]
Regulatory Asset [Axis]
Regulatory Asset [Axis]
Regulatory Asset [Domain]
Regulatory Asset [Domain]
Pension And Postretirement Benefit Costs [Member]
Pension And Postretirement Benefit Costs [Member]
Discloses the amount of regulatory asset arising from the difference between net periodic pension and postretirement cost, according to US GAAP, and the amount of pension and postretirement cost considered for rate-making purposes, according the actions of the regulator.
Merger And Integration Costs Net [Member]
Merger And Integration Costs Net [Member]
Costs incurred for acquired assets or services that would otherwise be charged to expense. These costs are included in allowable costs for rate making purposes and future revenue will be provided to permit recovery of such incurred costs.
Deferred Gas Costs Asset [Member]
Deferred Gas Costs Asset [Member]
Gas costs incurred that would otherwise be charged to expense. These costs are included in allowable costs for rate making purposes and future revenue will be provided to permit recovery of such incurred costs.
Regulatory Cost of Removal Asset [Member]
Regulatory Cost of Removal Asset [Member]
Costs associated with the removal of certain long-lived assets that would otherwise be charged to expense. Regulatory asset is recognized for differences in the timing of recognition of the period costs for financial reporting and rate-making purposes.
Rate Case Costs [Member]
Rate Case Costs [Member]
Costs incurred during the rate making process that would otherwise be charged to expense. These costs are included in allowable costs for rate making purposes and future revenue will be provided to permit recovery of such incurred costs.
Texas 8.209 [Member]
Texas 8.209 [Member]
Costs associated with capital expenditures incurred pursuant to the risk-based program for the renewal or replacement of distribution facilities, including steel service lines, per the Railroad Commission of Texas Division of Public Safety Rule 8.209 that would otherwise be charged to expense. These costs are included in allowable costs for rate making purposes and future revenue will be provided to permit recovery of such incurred costs.
APT Annual Adjustment Mechanism [Member]
APT Annual Adjustment Mechanism [Member]
Asset associated with our regulated transmission and storage segment's annual adjustment mechanism, which was approved by the Railroad Commission of Texas, that will adjust regulated rates up to a pre-defined percentage of the difference between Atmos Pipeline Texas' non-regulated annual revenue and a pre-defined base credit.
Recoverable Loss On Reacquired Debt [Member]
Recoverable Loss On Reacquired Debt [Member]
Recoverable Loss On Reacquired Debt [Member]
Other [Member]
Deferred Miscellaneous Costs [Member]
Costs incurred for miscellaneous items that would otherwise be charged to expense. These costs are included in allowable costs for rate making purposes and future revenue will be provided to permit recovery of such incurred costs.
Regulatory Asset [Line Items]
Regulatory Assets [Line Items]
Regulatory assets
Regulatory Assets
Schedule Of Regulatory Liabilities [Table]
Schedule of Regulatory Liabilities [Table]
Regulatory Liability [Axis]
Regulatory Liability [Axis]
Regulatory Liability [Domain]
Regulatory Liability [Domain]
Deferred Gas Costs [Member]
Deferred Gas Costs Liability [Member]
Amount received from customers for the delivery of gas above the cost of gas. These costs will be refunded to customers through the rate making process in future periods.
Deferred Franchise Fees [Member]
Deferred Franchise Fees Liability [Member]
Costs incurred for franchise fees that are reasonably expected to be recovered in rates charged to customers. Regulatory asset or liability is recognized for differences in the timing of recognition of the period costs for financial reporting and rate-making purposes.
Regulatory Cost of Removal Obligation [Member]
Asset Retirement Obligation Costs [Member]
Other [Member]
Miscellaneous Regulatory Liabilities [Member]
Miscellanous costs incurred that are reasonably expected to be recovered in rates charged to customers. Regulatory asset or liability is recognized for differences in the timing of recognition of the period costs for financial reporting and rate-making purposes.
Regulatory Liabilities [Line Items]
Regulatory Liabilities [Line Items]
Regulatory liabilities
Regulatory Liabilities
Regulatory asset - future recoverable pension costs
Regulatory Asset - Future Recoverable Pension Costs
The difference between a gas utilitys actual pension and postretirement expense and the level of such expense recoverable in its existing rates. The deferred amount will become eligible for inclusion in the utilitys rates in its next rate proceeding
Regulatory noncurrent asset, amortization period
Regulatory Noncurrent Asset, Amortization Period
Segment Information
Segment Reporting Disclosure [Text Block]
Commitments and Contingencies
Commitments and Contingencies Disclosure [Text Block]
Oustanding commodity contracts volumes table
Schedule Of Commodity Derivative Volumes [Table Text Block]
Tabular disclosure of net long/short commodity contract derivative volumes by hedge designation.
Financial instruments on the balance sheet
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]
Fair value hedges table
Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]
Cash flow hedges
Schedule of Cash Flow Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block]
Other comprehensive income from hedging table
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block]
Expected recognition in earnings of deferred gains/(losses) in AOCI table
Schedule Of Expected Deferred Gains (Losses) Recognition Table [Text Block]
Tabular disclosure of the expected recognition in earnings of the deferred losses recorded in accumulated other comprehensive gains/(losses) associated with cash flow hedges.
Fair Value Measurements
Fair Value Disclosures [Text Block]
Risks and Uncertainties [Abstract]
Concentration of Credit Risk
Concentration Risk Disclosure [Text Block]
Commodity Contract Outstanding Volumes [Table]
Commodity Contract Outstanding Volumes [Table]
Schedule that discloses the oustanding volumes for commodity derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments).
Hedging Relationship [Axis]
Hedging Relationship [Axis]
Hedging Relationship [Domain]
Hedging Relationship [Domain]
Fair Value Hedging [Member]
Fair Value Hedging [Member]
Cash Flow Hedging [Member]
Cash Flow Hedging [Member]
Hedging Designation [Axis]
Hedging Designation [Axis]
Hedging Designation [Domain]
Hedging Designation [Domain]
Nondesignated [Member]
Not Designated as Hedging Instrument [Member]
Commodity Contract Outstanding Volumes [Line Items]
Commodity Contract Outstanding Volumes [Line Items]
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
Investment Contract Volume
Investment Contract Volume
Unrecorded Unconditional Purchase Obligation [Table]
Unrecorded Unconditional Purchase Obligation [Table]
Unrecorded Unconditional Purchase Obligation by Category of Item Purchased [Axis]
Unrecorded Unconditional Purchase Obligation by Category of Item Purchased [Axis]
Unconditional Purchase Obligation, Category of Goods or Services Acquired [Domain]
Unconditional Purchase Obligation, Category of Goods or Services Acquired [Domain]
Public Utilities, Inventory, Fuel [Member]
Public Utilities, Inventory, Fuel [Member]
Mid-Tex Division [Member]
Mid-Tex Division [Member]
Mid Tex reportable segment, a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statement.
Unrecorded Unconditional Purchase Obligation [Line Items]
Unrecorded Unconditional Purchase Obligation [Line Items]
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year
Unrecorded Unconditional Purchase Obligation, Due in Remainder of Fiscal Year
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months
Unrecorded Unconditional Purchase Obligation, Due in Next Twelve Months
Unrecorded Unconditional Purchase Obligation, Due within Two Years
Unrecorded Unconditional Purchase Obligation, Due within Two Years
Unrecorded Unconditional Purchase Obligation, Due within Three Years
Unrecorded Unconditional Purchase Obligation, Due within Three Years
Unrecorded Unconditional Purchase Obligation, Due within Four Years
Unrecorded Unconditional Purchase Obligation, Due within Four Years
Unrecorded Unconditional Purchase Obligation, Due within Five Years
Unrecorded Unconditional Purchase Obligation, Due within Five Years
Unrecorded Unconditional Purchase Obligation, Due after Five Years
Unrecorded Unconditional Purchase Obligation, Due after Five Years
Unrecorded Unconditional Purchase Obligation
Unrecorded Unconditional Purchase Obligation
Property, plant and equipment
Property, Plant and Equipment, Gross
Less accumulated depreciation and amortization
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment
Net property, plant and equipment
Accounts receivable, net
Accounts Receivable, Net, Current
Gas stored underground
Energy Related Inventory, Gas Stored Underground
Other current assets
Other Assets, Current
Total current assets
Deferred charges and other assets
Other Assets, Noncurrent
Total assets
Shareholders' equity
Stockholders' Equity Attributable to Parent [Abstract]
Common stock, no par value (stated at $.005 per share)
Common Stock, Value, Issued
Additional paid-in capital
Additional Paid in Capital, Common Stock
Retained earnings
Retained Earnings (Accumulated Deficit)
Accumulated other comprehensive income (loss)
Shareholders' equity
Total capitalization
Accounts payable and accrued liabilities
Accounts Payable and Accrued Liabilities, Current
Other current liabilities
Other Liabilities, Current
Total current liabilities
Regulatory cost of removal obligation
Regulatory Cost Of Removal Liability
Reflects the total obligation as of the balance sheet date to remove regulatory assets from service
Deferred credits and other liabilities
Other Liabilities, Noncurrent
Total shareholders' equity and liabilities
Schedule of Accumulated Other Comprehensive Income (Loss)
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]
Reclassification out of Accumulated Other Comprehensive Income
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]
Fair Values Derivatives Balance Sheet Location By Derivative Contract Type By Hedging Designation [Table]
Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table]
Designated As Hedging Instrument [Member]
Designated as Hedging Instrument [Member]
Balance Sheet Location [Axis]
Balance Sheet Location [Axis]
Balance Sheet Location [Domain]
Balance Sheet Location [Domain]
Other Current Assets [Member]
Other Current Assets [Member]
Deferred Charges And Other Assets [Member]
Deferred Charges And Other Assets [Member]
Line item in the statement of financial position in which the fair value amounts of the derivative instruments are included.
Other Current Liabilities [Member]
Other Current Liabilities [Member]
Deferred Credits And Other Liabilities [Member]
Deferred Credits And Other Liabilities [Member]
Line item in the statement of financial position in which the fair value amounts of the derivative instruments are included.
Derivative Instrument [Axis]
Derivative Instrument [Axis]
Derivative Contract [Domain]
Derivative Contract [Domain]
Interest Rate Contract [Member]
Interest Rate Contract [Member]
Commodity Contract [Member]
Commodity Contract [Member]
Derivatives Fair Value [Line Items]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset
Derivative Asset, Fair Value, Gross Asset
Derivative Asset, Contract Netting
Derivative Asset, Contract Netting
The amount as of the balance sheet date of the fair value of derivative assets that in accordance with a master netting arrangement was offset against derivative liabilities.
Derivative Asset, Net of Contract Netting
Derivative Asset, Net of Contract Netting
Fair value, after the effects of contract netting under the master netting arrangements and prior to the offset of cash collateral, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.
Derivative, Collateral, Right to Reclaim Cash
Derivative Asset
Derivative Asset
Derivative Liability, Fair Value, Gross Liability
Derivative Liability, Fair Value, Gross Liability
Derivative Liability, Contract Netting
Derivative Liability, Contract Netting
The amount as of the balance sheet date of the fair value of derivative liabilities that in accordance with a master netting arrangement was offset against derivative assets.
Derivative Liability, Net of Contract Netting
Derivative Liability, Net of Contract Netting
Fair value, after the effects of contract netting under the master netting arrangements and prior to the offset of cash collateral, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.
Derivative Liability, Collateral, Right to Reclaim Cash, Offset
Derivative Liability
Derivative Liability