2.4.0.8037 - Disclosure - Note 7 - Derivative Financial Instruments (Details)truefalseIn Millions, unless otherwise specifiedfalse1false USDfalsefalse$c76_From1Dec2009To31Dec2009http://www.sec.gov/CIK0001030749duration2009-12-01T00:00:002009-12-31T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$c77_From1Jan2012To31Dec2012http://www.sec.gov/CIK0001030749duration2012-01-01T00:00:002012-12-31T00:00:00usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3false USDfalsefalse$c0_AsOf30Jun2013http://www.sec.gov/CIK0001030749instant2013-06-30T00:00:000001-01-01T00:00:00pureStandardhttp://www.xbrl.org/2003/instancepurexbrli0usdStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$4false EURfalsefalse€c0_AsOf30Jun2013http://www.sec.gov/CIK0001030749instant2013-06-30T00:00:000001-01-01T00:00:00eurStandardhttp://www.xbrl.org/2003/iso4217EURiso42170EUREUR€1true 1glf_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlockAbstractglf_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Derivative Instruments and Hedging Activities Disclosure [Text Block]2false 2us-gaap_DerivativeAssetNotionalAmountus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4truefalsefalse70000007.0EUR€falsetruefalsexbrli:monetaryItemTypemonetaryNominal or face amount used to calculate payments on the derivative asset.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5579245-113959 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Notional Amount -URI http://asc.fasb.org/extlink&oid=6519104 false2Derivative Asset, Notional Amount (in Euro)3false 2us-gaap_DerivativeAmountOfHedgedItemus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse100000000100.0falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of the hedged item as of the balance sheet date related to the derivative. For example, the hedged balance on a debt instrument.No definition available.false2Derivative, Amount of Hedged Item4false 2us-gaap_NumberOfForeignCurrencyDerivativesHeldus-gaap_truenainstantfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalse3truefalsefalse11falsefalsefalse4truefalsefalse11falsefalsefalsexbrli:integerItemTypeintegerNumber of foreign currency exchange rate derivatives held by the entity at the reporting date.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5580258-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5579245-113959 false0Number of Foreign Currency Derivatives Held5false 2glf_CashPaidForInterestRateSwapsSettlementglf_falsecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse64000006.4falsefalsefalse2falsefalsefalse00falsefalsefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryCash paid for interest rate swaps settlement.No definition available.false2Cash Paid For Interest Rate Swaps Settlement6false 2glf_ReclassifiedAmountFromAccumulatedOciAssociatedWithInterestRateSwapsglf_falsedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2truefalsefalse3000000.3USD$falsetruefalse3falsefalsefalse00falsefalsefalse4falsefalsefalse00falsefalsefalsexbrli:monetaryItemTypemonetaryReclassified amount from accumulated OCI associated with interest rate swaps.No definition available.false2Reclassified Amount From Accumulated Oci Associated With Interest Rate SwapsfalseNote 7 - Derivative Financial Instruments (Details)HundredThousandsUnKnownUnKnownUnKnowntruefalsetrueSheethttp://www.gulfmark.com/role/Note7DerivativeFinancialInstrumentsDetails46