Name:	glf_LineOfCreditFacilityCovenantMandatoryPrepaymentCashThreshold
Namespace Prefix:	glf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the market value of the vessels securing the credit facility as a percentage of outstanding unpaid loans which, if less than this percentage, will trigger a mandatory prepayment under the credit facility unless certain additional security is provided.

No definition available.

Name:	glf_LineOfCreditFacilityCovenantMandatoryPrepaymentMarketValueOfVesselsThresholdPercentageOfOutstandingUnpaidLoans
Namespace Prefix:	glf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the required maximum capitalization ratio, as defined, under a line of credit facility.

No definition available.

Name:	glf_LineOfCreditFacilityCovenantMaximumCapitalizationRatio
Namespace Prefix:	glf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the minimum collateral to commitments ratio, as defined, required to be maintained under a line of credit facility.

No definition available.

Name:	glf_LineOfCreditFacilityCovenantMinimumCollateralToCommitmentsRatio
Namespace Prefix:	glf_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

Represents the minimum collateral to debt ratio, as defined, required to be maintained under a line of credit facility.

No definition available.

Name:	glf_LineOfCreditFacilityCovenantMinimumCollateralToDebtRatio
Namespace Prefix:	glf_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

Represents the minimum consolidated adjusted EBITDA required to be maintained under a line of credit facility.

No definition available.

Name:	glf_LineOfCreditFacilityCovenantMinimumConsolidatedAdjustedEBITDA
Namespace Prefix:	glf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Represents the minimum consolidated interest coverage ratio, as defined, under the line of credit facility.

No definition available.

Name:	glf_LineOfCreditFacilityCovenantMinimumConsolidatedInterestCoverageRatio
Namespace Prefix:	glf_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

Represents the minimum liquidity under the terms of a financial covenant in connection with a line of credit facility.

No definition available.

Name:	glf_LineOfCreditFacilityCovenantMinimumLiquidity
Namespace Prefix:	glf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the number of vessels by which the line of credit facility is secured.

No definition available.

Name:	glf_LineOfCreditFacilityNumberOfVesselsSecuringTheFacility
Namespace Prefix:	glf_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

The number of vessels added as collateral to an existing credit agreement entered into by the company.

No definition available.

Name:	glf_NumberOfVesselsAddedAsCollateral
Namespace Prefix:	glf_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The number of vessels whose flag and ownership has changed and is now reflected in a credit agreement entered into by the company.

No definition available.

Name:	glf_NumberOfVesselsChangeOfOwnership
Namespace Prefix:	glf_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

Redemption price on the principal amount , stated in percentage.

No definition available.

Name:	glf_RedemptionPriceAsPercentageOfPrincipalAmountPremiumAndinterest
Namespace Prefix:	glf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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(22))
-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 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: 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(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Face (par) amount of debt instrument at time of issuance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Paragraph 2
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Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Contractual interest rate for funds borrowed, under the debt agreement.

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Face (par) amount of the original debt instrument that was repurchased.

No definition available.

Name:	us-gaap_DebtInstrumentRepurchasedFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount, after accumulated amortization, of debt issuance costs related to line of credit arrangements. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section S45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=68176171&loc=SL68176184-208336

Name:	us-gaap_DebtIssuanceCostsLineOfCreditArrangementsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Weighted average interest rate of debt outstanding.

No definition available.

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

Name:	us-gaap_DeferredFinanceCostsGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399

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 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_DeferredFinanceCostsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Amount of gain (loss) from the difference between the repurchase price of a debt instrument initially issued by the entity and the net carrying amount of the debt at the time of its repurchase.

No definition available.

Name:	us-gaap_GainLossOnRepurchaseOfDebtInstrument
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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.

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

No definition available.

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: 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(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

No definition available.

Name:	us-gaap_LongTermDebtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Name:	us-gaap_LongtermDebtTypeAxis=glf_SeniorNoteDue2022Member
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_LineOfCreditFacilityAxis=glf_MulticurrencyCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_LineOfCreditFacilityAxis=glf_NorwegianFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_CreditFacilityAxis=glf_SwinglineLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_VariableRateAxis=glf_NorwegianInterBankOfferedRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_LegalEntityAxis=glf_GulfmarkUkMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	dei_LegalEntityAxis=glf_GulfmarkRederiAsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_CreditFacilityAxis=glf_MulticurrencyCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: