Represents the number of interest rate derivative instruments held by the entity which have been expired.

No definition available.

Name:	gnk_NumberOfInterestRateDerivativesExpired
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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The term of interest periods when the Company is in default under the covenants of its 2007 Credit Facility.

+ References

No definition available.

+ Details

Name:	gnk_TermOfInterestPeriodsWhenInDefaultUnderCovenantsOfCreditFacility
Namespace Prefix:	gnk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

-Section 13

-Sentence Column B

+ Details

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Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of bankruptcy claim filed with bankruptcy court.

+ References

No definition available.

+ Details

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

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

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

- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DerivativeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of interest rate derivative instruments held by the entity at the reporting date.

+ References

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=35706170&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=35706170&loc=SL5579245-113959

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	gnk_ReorganizationAxis=gnk_Chapter11OfUSBankruptcyCodeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=gnk_CreditFacility2007Member
Namespace Prefix:
Data Type:	na
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Period Type:

- Details

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Namespace Prefix:
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- Details

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- Details

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- Details

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Data Type:	na
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- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_PredecessorMember
Namespace Prefix:
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INTEREST RATE SWAP AGREEMENTS (Details) (USD $) In Thousands, unless otherwise specified	0 Months Ended
	Apr. 30, 2014	Jul. 09, 2014	Dec. 31, 2014 item	Dec. 31, 2013 derivative
INTEREST RATE SWAP AGREEMENTS
Number of interest rate swaps			0
Predecessor
INTEREST RATE SWAP AGREEMENTS
Number of interest rate swaps				4
Interest rate swaps designated as cash flow hedges
Number of expired interest rate swap agreements		3
Notional amount outstanding				$ 306,233
Interest Rate Swap, 4.485% \| Predecessor
Interest rate swaps designated as cash flow hedges
Fixed rate (as a percent)				4.485%
Notional amount outstanding				106,233
Interest Rate Swap, 5.25% \| Predecessor
Interest rate swaps designated as cash flow hedges
Fixed rate (as a percent)				5.25%
Notional amount outstanding				50,000
Interest Rate Swap, 2.05% \| Predecessor
Interest rate swaps designated as cash flow hedges
Fixed rate (as a percent)				2.05%
Notional amount outstanding				100,000
Interest Rate Swap, 2.45% \| Predecessor
Interest rate swaps designated as cash flow hedges
Fixed rate (as a percent)				2.45%
Notional amount outstanding				50,000
Chapter 11 \| DNB Bank ASA \| Predecessor
Interest rate swaps designated as cash flow hedges
Secured claim issued with the Bankruptcy Court	$ 5,622
2007 Credit Facility \| Predecessor
Interest rate swaps designated as cash flow hedges
Term of interest periods when Company is in default under covenants of 2007 Credit Facility		1 month