2.4.0.8001 - Statement - Unaudited Condensed Consolidated Balance SheetstruefalseIn Thousands, unless otherwise specifiedfalse1false USDfalsefalse$c0_AsOf30Jun2013http://www.sec.gov/CIK0001030749instant2013-06-30T00:00:000001-01-01T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$c1_AsOf31Dec2012http://www.sec.gov/CIK0001030749instant2012-12-31T00:00:000001-01-01T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 5glf_CurrentAssetsAbstractglf_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Current assets:2false 6us-gaap_CashAndCashEquivalentsAtCarryingValueus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse7270100072701USD$falsetruefalse2truefalsefalse185175000185175USD$falsetruefalsexbrli:monetaryItemTypemonetaryAmount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash -URI http://asc.fasb.org/extlink&oid=6506951 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash Equivalents -URI http://asc.fasb.org/extlink&oid=6507016 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.1) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6676-107765 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3044-108585 false2Cash and cash equivalents3false 6us-gaap_AccountsReceivableNetCurrentus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse115184000115184falsefalsefalse2truefalsefalse8570600085706falsefalsefalsexbrli:monetaryItemTypemonetaryAmount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.3-4) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a(1) -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 4 -Article 5 false2Trade accounts receivable, net of allowance for doubtful accounts of $2,624 and $3,250, respectively4false 6us-gaap_OtherReceivablesus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse96720009672falsefalsefalse2truefalsefalse85060008506falsefalsefalsexbrli:monetaryItemTypemonetaryCarrying amounts due as of the balance sheet date from parties or arising from transactions not otherwise specified in the taxonomy.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.8) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false2Other accounts receivable5false 6us-gaap_PrepaidExpenseAndOtherAssetsCurrentus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse2391000023910falsefalsefalse2truefalsefalse2518600025186falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of asset related to consideration paid in advance for costs that provide economic benefits in future periods, and amount of other assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6676-107765 false2Prepaid expenses and other current assets6false 7us-gaap_AssetsCurrentus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalsetotalLabel1truefalsefalse221467000221467falsefalsefalse2truefalsefalse304573000304573falsefalsefalsexbrli:monetaryItemTypemonetarySum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.9) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6801-107765 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6676-107765 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 9 -Article 5 true2Total current assets7false 5us-gaap_PropertyPlantAndEquipmentNetus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse10915290001091529falsefalsefalse2truefalsefalse11363600001136360falsefalsefalsexbrli:monetaryItemTypemonetaryAmount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.13) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 13 -Subparagraph a -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 7 false2Vessels, equipment, and other fixed assets at cost, net of accumulated depreciation of $400,035 and $389,469, respectively8false 5us-gaap_ConstructionInProgressGrossus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse258157000258157falsefalsefalse2truefalsefalse169429000169429falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229 false2Construction in progress9false 5us-gaap_Goodwillus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse3066500030665falsefalsefalse2truefalsefalse3343800033438falsefalsefalsexbrli:monetaryItemTypemonetaryAmount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 false2Goodwill10false 5us-gaap_IntangibleAssetsNetExcludingGoodwillus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse2018200020182falsefalsefalse2truefalsefalse2162400021624falsefalsefalsexbrli:monetaryItemTypemonetarySum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16212-109274 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph ((a)(1),(b)) -URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275 false2Intangibles, net of accumulated amortization of $14,417 and $12,975, respectively11false 5us-gaap_EscrowDepositus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse3225800032258falsefalsefalse2truefalsefalse4702800047028falsefalsefalsexbrli:monetaryItemTypemonetaryThe designation of funds furnished by a borrower to a lender to assure future payments of the borrower's real estate taxes and insurance obligations with respect to a mortgaged property. Escrow deposits may be made for a variety of other purposes such as earnest money and contingent payments. This element excludes replacement reserves which are an escrow separately provided for within the US GAAP taxonomy.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.10) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 false2Cash held in escrow12false 5us-gaap_DeferredCostsAndOtherAssetsus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse3070900030709falsefalsefalse2truefalsefalse3322200033222falsefalsefalsexbrli:monetaryItemTypemonetaryAggregate carrying amount of deferred costs and other assets not separately disclosed.No definition available.false2Deferred costs and other assets13false 6us-gaap_Assetsus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsefalsetotalLabel1truefalsefalse16849670001684967falsefalsefalse2truefalsefalse17456740001745674falsefalsefalsexbrli:monetaryItemTypemonetarySum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.18) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 12 -Article 7 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 true2Total assets14true 5glf_CurrentLiabilitiesAbstractglf_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Current liabilities:15false 6us-gaap_AccountsPayableCurrentus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse2380100023801falsefalsefalse2truefalsefalse2908900029089falsefalsefalsexbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(a)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 false2Accounts payable16false 6us-gaap_TaxesPayableCurrentus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse43100004310falsefalsefalse2truefalsefalse62620006262falsefalsefalsexbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date of obligations incurred and payable for statutory income, sales, use, payroll, excise, real, property and other taxes. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19,20) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Article 5 false2Income and other taxes payable17false 6us-gaap_EmployeeRelatedLiabilitiesCurrentus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse1959100019591falsefalsefalse2truefalsefalse2365600023656falsefalsefalsexbrli:monetaryItemTypemonetaryTotal of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.20) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 false2Accrued personnel costs18false 6us-gaap_InterestPayableCurrentus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse98300009830falsefalsefalse2truefalsefalse93270009327falsefalsefalsexbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date of [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Current Liabilities -URI http://asc.fasb.org/extlink&oid=6509677 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6935-107765 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.20) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e7018-107765 false2Accrued interest expense19false 6us-gaap_OtherAccruedLiabilitiesCurrentus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse1263000012630falsefalsefalse2truefalsefalse1140200011402falsefalsefalsexbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date of obligations incurred through that date and payable arising from transactions not otherwise specified in the taxonomy. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Current Liabilities -URI http://asc.fasb.org/extlink&oid=6509677 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6935-107765 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.20) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6911-107765 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e7018-107765 false2Other accrued liabilities20false 7us-gaap_LiabilitiesCurrentus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalsetotalLabel1truefalsefalse7016200070162falsefalsefalse2truefalsefalse7973600079736falsefalsefalsexbrli:monetaryItemTypemonetaryTotal obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.21) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 21 -Article 5 true2Total current liabilities21false 5us-gaap_OtherLongTermDebtNoncurrentus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse500933000500933falsefalsefalse2truefalsefalse500999000500999falsefalsefalsexbrli:monetaryItemTypemonetaryCarrying value as of the balance sheet date of debt not otherwise defined (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 false2Long-term debt22true 5glf_LongTermIncomeTaxesAbstractglf_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Long-term income taxes:23false 6us-gaap_DeferredTaxLiabilitiesNoncurrentus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse105059000105059falsefalsefalse2truefalsefalse105867000105867falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of deferred tax liability attributable to taxable temporary differences, net of deferred tax asset attributable to deductible temporary differences and carryforwards net of valuation allowances expected to be realized or consumed after one year (or the normal operating cycle, if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=21917399&loc=d3e31917-109318 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=21917399&loc=d3e31931-109318 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=21917399&loc=d3e31958-109318 false2Deferred tax liabilities24false 6glf_OtherTaxLiabilitiesglf_falsecreditinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse2244400022444falsefalsefalse2truefalsefalse2366500023665falsefalsefalsexbrli:monetaryItemTypemonetaryOther tax liabilities.No definition available.false2Other income taxes payable25false 5us-gaap_OtherLiabilitiesNoncurrentus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse82570008257falsefalsefalse2truefalsefalse75250007525falsefalsefalsexbrli:monetaryItemTypemonetaryAggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the balance sheet. Noncurrent liabilities are expected to be paid after one year (or the normal operating cycle, if longer).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.24) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 24 -Article 5 false2Other liabilities26true 5us-gaap_StockholdersEquityAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Stockholders' equity:27false 6us-gaap_CommonStockValueus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse269000269falsefalsefalse2truefalsefalse266000266falsefalsefalsexbrli:monetaryItemTypemonetaryAggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 false2Class A Common Stock, $0.01 par value; 60,000 shares authorized; 27,153 and 26,941 shares issued and 26,796 and 26,906 outstanding, respectively; Class B Common Stock $0.01 per value; 60,000 shares authorized; no shares issued28false 5us-gaap_AdditionalPaidInCapitalus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse396565000396565falsefalsefalse2truefalsefalse389881000389881falsefalsefalsexbrli:monetaryItemTypemonetaryExcess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of additional paid-in capital associated with common and preferred stock. For additional paid-in capital associated with only common stock, use the element additional paid in capital, common stock. For additional paid-in capital associated with only preferred stock, use the element additional paid in capital, preferred stock.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 31 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.30(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 false2Additional paid-in capital29false 5us-gaap_RetainedEarningsAccumulatedDeficitus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse578605000578605falsefalsefalse2truefalsefalse579062000579062falsefalsefalsexbrli:monetaryItemTypemonetaryThe cumulative amount of the reporting entity's undistributed earnings or deficit.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 31 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.31(a)(3)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 false2Retained earnings30false 5us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTaxus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalselabel1truefalsefalse1538600015386falsefalsefalse2truefalsefalse5987500059875falsefalsefalsexbrli:monetaryItemTypemonetaryAccumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=28358780&loc=SL7669686-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e637-108580 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=28358780&loc=d3e681-108580 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 31 -Article 5 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 false2Accumulated other comprehensive income31false 5us-gaap_TreasuryStockValueus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1truefalsefalse-19982000-19982falsefalsefalse2truefalsefalse-11533000-11533falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount allocated to treasury stock. Treasury stock is common and preferred shares of an entity that were issued, repurchased by the entity, and are held in its treasury.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6405834&loc=d3e23315-112656 false2Treasury stock, at cost32false 5us-gaap_DeferredCompensationEquityus-gaap_truedebitinstantfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1truefalsefalse72690007269falsefalsefalse2truefalsefalse1033100010331falsefalsefalsexbrli:monetaryItemTypemonetaryValue of stock issued under share-based plans to employees or officers which is the unearned portion, accounted for under the fair value method.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 35 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415241&loc=d3e4534-113899 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.30) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 false2Deferred compensation expense33false 6us-gaap_StockholdersEquityus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalsetotalLabel1truefalsefalse978112000978112falsefalsefalse2truefalsefalse10278820001027882falsefalsefalsexbrli:monetaryItemTypemonetaryTotal of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB TOPIC 4.E) -URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section E Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29-31) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 true2Total stockholders' equity34false 7us-gaap_LiabilitiesAndStockholdersEquityus-gaap_truecreditinstantfalsefalsefalsefalsefalsefalsefalsefalsetotalLabel1truefalsefalse16849670001684967USD$falsetruefalse2truefalsefalse17456740001745674USD$falsetruefalsexbrli:monetaryItemTypemonetaryAmount of liabilities and equity items, including the portion of equity attributable to noncontrolling interests, if any.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.32) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 25 -Article 7 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 32 -Article 5 true2Total liabilities and stockholders' equityfalseUnaudited Condensed Consolidated Balance Sheets (USD $)ThousandsUnKnownUnKnownUnKnowntruefalsefalseSheethttp://www.gulfmark.com/role/ConsolidatedBalanceSheet234