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Represents the aggregate fair value of the mortgaged vessels actual as a percentage of aggregate outstanding principal amount as per the terms of the credit facilities' covenants.

No definition available.

Name:	gnk_LineOfCreditFacilityCovenantFairMarketValueOfMortgagedVesselsAsPercentageOfAggregateOutstandingPrincipalAmountActual
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Data Type:	num:percentItemType
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Represents the number of quarterly installments in which the line of each credit facility shall be repaid.

No definition available.

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Represents the period after latest vessel delivery date for first periodic repayment of the line of credit facility.

No definition available.

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Represents the maximum delivered cost per vessel allowed under the credit facility.

No definition available.

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Represents the maximum percentage of delivered cost per vessel allowed under the credit facility.

No definition available.

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Represents the maximum percentage of fair market value per vessel at delivery allowed under the credit facility.

No definition available.

Name:	gnk_MaximumPercentageOfFairMarketValueOfVesselAllowedUnderCreditFacility
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Represents the percentage of each facility amount due as balloon payment at final maturity.

No definition available.

Name:	gnk_PercentageOfFacilityAmountDueAsBalloonPaymentAtMaturity
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Data Type:	num:percentItemType
Balance Type:	na
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Represents percentage of facility amount due per installment.

No definition available.

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Represents the percentage of outstanding principal plus interest insured by China Export & Credit Insurance Corporation (Sinosure) to cover political and commercial risks.

No definition available.

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

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
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Data Type:	num:percentItemType
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The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

No definition available.

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Data Type:	xbrli:stringItemType
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Period Type:	duration

Period remaining on line of credit facility before it terminates, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	us-gaap_LineOfCreditFacilityExpirationPeriod
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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.

No definition available.

Name:	us-gaap_LineOfCreditFacilityLineItems
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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.

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

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Amount of the required periodic payments of both interest and principal.

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

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. 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 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 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 20, 22
-Article 5

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of long-term debt, after unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. 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
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-Name Accounting Standards Codification
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Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
-Paragraph 14
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-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3255-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 235
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-Section S99
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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Name:	us-gaap_DebtInstrumentAxis=gnk_BalticTradingTermLoanFacility2014Member
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Namespace Prefix:
Data Type:	na
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Name:	gnk_VesselsByNameAxis=gnk_BalticHornetMember
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