Statement of Financial Position [Abstract] Cash and cash equivalents Cash and cash equivalents at beginning of the period Cash and cash equivalents at end of period Trade accounts receivable, net of allowance for doubtful accounts of $2,504 and $448, respectively Allowance for doubtful accounts of trade accounts receivable (in Dollars) Other accounts receivable Prepaid expenses and other current assets Total current assets Vessels, equipment, and other fixed assets at cost, net of accumulated depreciation of $453,880 and $420,355, respectively Accumulated depreciation of vessels and equipment (in Dollars) Construction in progress Goodwill Intangibles, net of accumulated amortization of $18,018 and $15,858, respectively Accumulated amortization of intangibles (in Dollars) Cash held in escrow Escrow Deposit Deferred costs and other assets Total assets Accounts payable Income and other taxes payable Accrued personnel costs Accrued interest expense Other accrued liabilities Total current liabilities Long-term debt Deferred tax liabilities Other income taxes payable Other liabilities Preferred stock, shares authorized Preferred stock, shares issued Preferred stock, par value (in Dollars per share) Class A Common Stock, $0.01 par value; 60,000 shares authorized; 27,276 and 27,165 shares issued and 26,723 and 26,616 outstanding, respectively; Class B Common Stock $0.01 per value; 60,000 shares authorized; no shares issued Class of Stock [Axis] Common Class A [Member] Common Stock, par value (in Dollars per share) Common Stock, shares authorized Common Stock, shares issued Common Stock, shares outstanding Common Class B [Member] Additional paid-in capital Retained earnings Accumulated other comprehensive income Treasury stock, at cost Deferred compensation expense Total stockholders' equity Balance Balance Total liabilities and stockholders' equity Statement of Comprehensive Income [Abstract] Revenue Direct operating expenses Drydock expense General and administrative expenses Depreciation and amortization Depreciation and amortization expense Impairment charge Gain on sale of assets and other Gain on sale of assets Gain (Loss) on Disposition of Assets Total costs and expenses Operating income Operating income (loss) Interest expense Interest income Foreign currency loss and other Total other expense Income before income taxes Income tax provision Net income Net income Net income Net income attributable to common stockholders Basic (in Dollars per share) Basic (in Dollars per share) Diluted (in Dollars per share) Diluted (in Dollars per share) Basic (in Shares) Weighted-average common shares outstanding (in Shares) Diluted (in Shares) Foreign currency gain (loss) Translation adjustment Total comprehensive income (loss) Statement of Stockholders' Equity [Abstract] Balance (in Shares) Balance (in Shares) Dividends Dividends Declared (in thousands) Issuance of common stock Treasury stock Treasury stock (in Shares) Total Number of Common Shares Repurchased Treasury Stock, Shares, Acquired (in Shares) Deferred compensation plan Deferred compensation plan (in Shares) Equity Components [Axis] Common Stock [Member] Additional Paid-in Capital [Member] Retained Earnings [Member] Accumulated Other Comprehensive Income (Loss) [Member] Treasury Stock [Member] Deferred Compensation Expense [Member] Amortization of stock-based compensation Amortization of deferred financing costs Provision for doubtful accounts receivable, net of write-offs Provision for Doubtful Accounts Deferred income tax provision (benefit) Foreign currency transaction loss Accounts receivable Prepaids and other Accounts payable Other accrued liabilities and other Net cash provided by operating activities Purchases of vessels, equipment and other fixed assets Release of deposits held in escrow Proceeds from disposition of vessels and equipment Net cash used in investing activities Proceeds from borrowings under revolving credit facilities Repayments of borrowings under revolving credit facilities Cash dividends Stock repurchases Payments for Repurchase of Common Stock Debt issuance costs Proceeds from issuance of stock Proceeds from exercise of common stock options Net cash used in financing activities Effect of exchange rate changes on cash Net decrease in cash and cash equivalents Interest paid, net of interest capitalized Income taxes paid, net Disclosure Text Block [Abstract] Earnings Per Share [Abstract] Basic Diluted Dilutive effect of stock options and restricted stock awards (in Shares) Reserves And Impairment [Text Block] [Abstract] Property, Plant and Equipment [Abstract] Property, Plant and Equipment, Type [Axis] Asset under Construction [Member] Vessels Under Construction [Abstract] Large Platform Supply Vessel Two [Member] Name of Property [Axis] Thoma Sea [Member] Geographical [Axis] Americas [Member] Expected Delivery Length (feet) Length (feet) Highland Duke Length (feet) (in Feet) BHP BHP Highland Duke BHP (in Horsepower) DWT DWT Highland Duke DWT (in US tons) Expected Cost Large Platform Supply Vessel One [Member] BAE Systems [Member] Simek [Member] North Sea [Member] Additions [Member] Vessel Additions [Abstract] Large Platform Supply Vessel [Member] North Cruys [Member] Year Built Highland Duke Year Built Month Delivered Highland Princess [Member] Polaris [Member] Acquired [Member] Vessels Acquired [Abstract] Unique Name [Axis] Highland Duke [Member] Highland Duke Disposed [Member] Vessels Disposed [Abstract] Highland Piper [Member] Southeast Asia [Member] Month Disposed Highland Legend [Member] Platform Supply Vessel [Member] Long-term Debt, Unclassified [Abstract] Long-term Debt, Type [Axis] Senior Notes Due 2022 [Member] Long-term debt Long-term Debt Credit Facility [Axis] Multicurrency Credit Facility [Member] Norwegian Facility [Member] Debt Premium Total Maturities of Long-term Debt [Abstract] Income Tax Disclosure [Abstract] Stockholders' Equity Note [Abstract] Repurchase of Equity Securities [Abstract] Total Number of Common Shares Purchased as Part of Publicly Announced Plans or Programs Average Price Paid Per Common Share (in Dollars per share) Dividends Declared [Abstract] Dividend per share Commitments and Contingencies Disclosure [Abstract] New Accounting Pronouncements and Changes in Accounting Principles [Abstract] Segment Reporting [Abstract] Operating Income (Loss) by Operating Segment [Abstract] Other [Member] ASSETS Current assets: LIABILITIES AND STOCKHOLDERS' EQUITY Current liabilities: Long-term income taxes: Stockholders' equity: Costs and expenses: Other income (expense): Earnings per share: Weighted average shares outstanding: Comprehensive income: Cash flows from operating activities: Adjustments to reconcile net income to net cash provided by operations: Change in operating assets and liabilities: Cash flows from investing activities: Cash flows from financing activities: Supplemental cash flow information: Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Shares: Basic Income per common share: Reserves And Impairment [Text Block] Property, Plant and Equipment Disclosure [Text Block] Property, Plant and Equipment, Schedule of Significant Acquisitions and Disposals [Table Text Block] Long-term Debt [Text Block] Schedule of Long-term Debt Instruments [Table Text Block] Schedule of Maturities of Long-term Debt [Table Text Block] Income Tax Disclosure [Text Block] Stockholders' Equity Note Disclosure [Text Block] Class of Treasury Stock [Table Text Block] Maximum Number (or Approximate Dollar Value) of Common Shares that May Yet Be Purchased Under the Plans or Programs (in Dollars) Schedule of Dividends Payable [Table Text Block] Commitments and Contingencies Disclosure [Text Block] New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Segment Reporting Disclosure [Text Block] Schedule of Segment Reporting Information, by Segment [Table Text Block] Quarter Ended September 30, 2013 Nine Months Ended September 30, 2013 Income Statement Location [Axis] General and Administrative Expense [Member] Vessel [Member] Segments [Axis] Subsequent Event Type [Axis] Subsequent Event [Member] Additional PSV [Member] Scenario [Axis] Scenario, Forecast [Member] Accounting Policies [Abstract] Impairment of Long-Lived Assets to be Disposed of Property, Plant and Equipment, Additions Number of Vessel Sold Interest Costs Capitalized Number of Shipyards Use in Agreements Number of Vessels Under Construction Estimated Cost of Building Vessels Number of Vessels Expected to Operate Number of Vessels Delivered Number of Vessels, Expected To Be Delivered Increase (Decrease) in Restricted Cash Debt Instrument, Face Amount Debt Instrument, Interest Rate, Stated Percentage Redemption Price as Percentage of Principal Amount Premium and Interest Debt Instrument, Basis Spread on Variable Rate Debt Issuance Cost Long-term Debt, Fair Value Long-term Debt, Gross Line of Credit Facility, Maximum Borrowing Capacity Line of Credit Facility, Current Borrowing Capacity Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Percent Stock Repurchase Program, Authorized Amount Number of Operating Segments Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Earnings Per Share, Policy [Policy Text Block] Class of Stock [Domain] Equity Component [Domain] Property, Plant and Equipment, Type [Domain] Note 3 - Vessel Acquisitions and Dispositions (Tables) [Table] Note 3 - Vessel Acquisitions and Dispositions (Tables) [Line Items] Name of Property [Domain] Geographical [Domain] Schedule of Significant Acquisitions and Disposals [Table] Significant Acquisitions and Disposals [Line Items] Noncash or Part Noncash Divestiture, Name [Domain] Long-term Debt, Type [Domain] Credit Facility [Domain] Schedule of Long-term Debt Instruments [Table] Debt Instrument [Line Items] Dividends Payable [Table] Dividends Payable [Line Items] Schedule of Segment Reporting Information, by Segment [Table] Segment Reporting Information [Line Items] Income Statement Location [Domain] Note 2 -Reserves and Impairment (Details) [Table] Note 2 -Reserves and Impairment (Details) [Line Items] Subsequent Event Type [Domain] Segments [Domain] Note 3 - Vessel Acquisitions and Dispositions (Details) [Table] Note 3 - Vessel Acquisitions and Dispositions (Details) [Line Items] Scenario, Unspecified [Domain] Note 4 - Long-Term Debt (Details) [Table] Note 4 - Long-Term Debt (Details) [Line Items] Note 6 - Stockholders' Equity (Details) [Table] Note 6 - Stockholders' Equity (Details) [Line Items] The brake horse power of vessels produced by the company. The weight of a vessel or vessels in deadweight tons. The expense associated with drydockings. The estimated cost of building a vessel or vessels during the period. The expected costs associated with a vessel or vessels during the period. The expected delivery date of a vessel or vessels. The gain (loss) associated with foreign currencies. The increase (decrease) during the reporting period in the aggregate amount of expenses incurred but not yet paid and other expenses. The length of a vessel or vessels. The maximum value of common shares that may be purchased under the plan or programs. The month that a vessel or vessels were acquired. The month that a vessel or vessels were delivered. The month that a vessel or vessels were disposed. The number of shipyards that were used in agreements. Number of vessel sold. The number of vessels delivered during the period. The number of vessels that are expected to operate. The umber of vessels that are under construction. The number of vessels that are expected to be delivered at a specific point in time. Tax liabilities not otherwise defined. The redemption price of notes expressed as a percentage of the principal amount premium and interest. The entire disclosure for the details of allowances and the entire disclosure for the details of the charge against earnings resulting from the aggregate write down of all assets from their carrying value to their fair value. Disclosure may also include a description of the impaired asset and facts and circumstances leading to the impairment, amount of the impairment loss and where the loss is located in the income statement, method(s) for determining fair value, and the segment in which the impaired asset is reported. The number of shares that are issuable under a deferred compensation plan. Equity impact of the value of treasury stock (units) reissued during the period, used to satisfy equity-based compensation obligations exercised by the holders of such rights. Total number of common shares purchased as part of a publicly announced plan or program during the period. The year that a vessel or vessels were built. Acquired [Member] Vessels acquired during the period. Additional PSV [Member] Shipyard to build an additional vessel. Additions [Member] Vessel additions during the period. Bae Systems [Member] The U.S. shipyard BAE Systems. Deferred Compensation Expense [Member] An expense for compensation which is deferred. Disposed [Member] Vessels Disposed of Highland Duke [Member] The Highland Duke vessel. Highland Legend [Member] The Highland Legend Platform Supply Vessel. Highland Piper [Member] Highland Piper Large Platform Vessel Highland Princess [Member] The Highland Princess vessel. Large Platform Supply Vessel [Member] A vessel designated as a large platform supply vessel. Large Platform Supply Vessel One [Member] The first of two large platform supply vessels. Large Platform Supply Vessel Two [Member] The second of two large platform supply vessels. Multicurrency Credit Facility [Member] A multi-currency type of credit facility. North Cruys [Member] The North Cruys vessel. North Sea [Member] The North Sea segment. Norwegian Facility [Member] The Norwegian credit facility. Other 1 [Member] An operating segment not otherwise defined. Platform Supply Vessel [Member] A vessel designated as a platform supply vessel. Polaris [Member] Name of the vessel. Senior Notes Due 2022 [Member] senior notes which are due in 2022. Simek [Member] The Simek construction yard. Southeast Asia [Member] The Southeast Asia segment. Thoma Sea [Member] The Thoma-Sea construction yard. Vessel [Member] This item represents a Vessel. Document and Entity Information [Abstract] StockRepurchasedDuringPeriodSharesAsPartOfPubliclyAnnouncedPlansOrPrograms BasicAbstract SharesIssuableUnderDeferredCompensationPlan Cash and Cash Equivalents, Period Increase (Decrease) Assets, Current Shares, Outstanding Weighted Average Number of Shares Outstanding, Diluted Payments to Acquire Property, Plant, and Equipment Liabilities, Current Net Cash Provided by (Used in) Operating Activities Long-term Debt, Excluding Current Maturities Comprehensive Income (Loss), Net of Tax, Attributable to Parent Long-term Debt, Maturities, Repayments of Principal in Year Four Entity Common Stock, Shares Outstanding Assets Entity Well-known Seasoned Issuer Entity Registrant Name Entity Voluntary Filers Treasury Stock Acquired, Average Cost Per Share Entity Filer Category Entity Public Float Document Fiscal Period Focus Common Stock, Dividends, Per Share, Declared Current Fiscal Year End Date Interest Expense Costs and Expenses Amendment Flag Increase (Decrease) in Accounts Receivable Document Period End Date Net Cash Provided by (Used in) Investing Activities Payments of Dividends Increase (Decrease) in Accounts Payable Increase (Decrease) in Prepaid Expense and Other Assets Entity Central Index Key Net Cash Provided by (Used in) Financing Activities Long-term Debt, Maturities, Repayments of Principal after Year Five Entity Current Reporting Status Nonoperating Income (Expense) Payments of Financing Costs Document Fiscal Year Focus Liabilities and Equity Treasury Stock, Value Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Foreign Currency Transaction Gain (Loss), Unrealized Repayments of Long-term Lines of Credit Amendment Description Document Type Stockholders' Equity Attributable to Parent Income Tax Expense (Benefit) Statement [Table] Statement [Line Items]