Represents the amounts received as a banckruptcy claim due in past two years.

No definition available.

Name:	gnk_BanckruptcyClaimsDueTwoYearsPastReceived
Namespace Prefix:	gnk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the amounts received under banckruptcy claims.

+ References

No definition available.

+ Details

Name:	gnk_BanckruptcyClaimsReceived
Namespace Prefix:	gnk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the amount of bankruptcy claim converted into shares of the entity.

+ References

No definition available.

+ Details

Name:	gnk_BankruptcyClaimsAmountOfClaimsSettledByConvertingIntoSharesOfEntity
Namespace Prefix:	gnk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the amount of bankruptcy claim to be settled.

+ References

No definition available.

+ Details

Name:	gnk_BankruptcyClaimsAmountOfClaimsToBeSettled
Namespace Prefix:	gnk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the amount to be received in cash settle bankruptcy claim.

+ References

No definition available.

+ Details

Name:	gnk_BankruptcyClaimsAmountToBeReceivedInCashToSettleClaims
Namespace Prefix:	gnk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the percentage of settlement of bankruptcy claim to be received in cash as percentage of total settlement.

+ References

No definition available.

+ Details

Name:	gnk_BankruptcyClaimsAmountToBeReceivedInCashToSettleClaimsAsPercentageOfTotalSettlement
Namespace Prefix:	gnk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the amounts received as a banckruptcy claim due in past twelve months.

+ References

No definition available.

+ Details

Name:	gnk_BankruptcyClaimsDueTwelveMonthsPastReceived
Namespace Prefix:	gnk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Represents the amount of bankruptcy claim converted into shares of the entity expressed as percentage.

+ References

No definition available.

+ Details

Name:	gnk_BankruptcyClaimsPercentageOfAmountOfClaimsSettledByConvertingIntoSharesOfEntity
Namespace Prefix:	gnk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the percentage of bankruptcy claim due that was remitted.

+ References

No definition available.

+ Details

Name:	gnk_BankruptcyClaimsPercentageOfPaymentsDueRemitted
Namespace Prefix:	gnk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of total cash settlement to be received annually in bankruptcy claim.

+ References

No definition available.

+ Details

Name:	gnk_BankruptcyClaimsPercentageOfTotalCashSettlementToBeReceivedAnnually
Namespace Prefix:	gnk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The fair value of shares received in lieu of cash in the payment of a settlement.

+ References

No definition available.

+ Details

Name:	gnk_FairValueOfSharesReceived
Namespace Prefix:	gnk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Share received pursuant to the rehabilitation plan approved by the South Korean courts.

+ References

No definition available.

+ Details

Name:	gnk_NumberOfSharesReceivedRelatedToRehabilitationPlan
Namespace Prefix:	gnk_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Final revised rehabilitation plan approved by the South Korean courts which resulted in a settlement payment.

+ References

No definition available.

+ Details

Name:	gnk_SettlementPayment
Namespace Prefix:	gnk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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

- Definition

The total amount of other operating income, the components of which are not separately disclosed on the income statement, from items that are associated with the entity's normal revenue producing operation.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

+ Details

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

- Details

Name:	dei_LegalEntityAxis=gnk_KoreaLineCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=gnk_SamsunLogixCorporationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_GainContingenciesByNatureAxis=gnk_BankruptcySettlementDueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_PredecessorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

COMMITMENTS AND CONTINGENCIES (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended		12 Months Ended			0 Months Ended
	Dec. 31, 2014	Jul. 09, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Oct. 04, 2013	Feb. 05, 2010
Bankruptcy settlement
Other operating income recognized	$ 530us-gaap_OtherOperatingIncome
Predecessor
Bankruptcy settlement
Other operating income recognized		0	121	265
Samsun
Bankruptcy settlement
Other operating income recognized	530
Samsun \| Predecessor
Bankruptcy settlement
Percentage of bankruptcy claim due remitted				50.00%
Banckruptcy claims received			0	263
Other operating income recognized			0	263	530
Korea Line Corporation
Bankruptcy settlement
Other operating income recognized					0
Korea Line Corporation \| Predecessor
Bankruptcy settlement
Other operating income recognized			21	2
Settlement Payment				2		21
Number of shares received related to the rehabilitation plan (in shares)			3,355			3,355
Korea Line Corporation \| Predecessor \| Other Income
Bankruptcy settlement
Fair value of shares received			100			100
Bankruptcy settlement due \| Samsun
Bankruptcy settlement
Percentage of bankruptcy claim due remitted					50.00%
2013 Banckruptcy claims received					234
2012 Banckruptcy claims received					296
Bankruptcy settlement due \| Samsun \| Predecessor
Bankruptcy settlement
Amount of bankruptcy claim to be settled following the rehabilitation process							17,212
Cash to be received to settle bankruptcy claim as percentage of total settlement							34.00%
Cash to be received to settle bankruptcy claim							5,852
Bankruptcy claims settled by conversion into shares of entity (as a percent)							66.00%
Amount of bankruptcy claim settled through conversion into shares of entity							$ 11,360
Bankruptcy settlement due \| Samsun \| Predecessor \| Minimum
Bankruptcy settlement
Percentage of total cash settlement to be received annually							8.00%
Bankruptcy settlement due \| Samsun \| Predecessor \| Maximum
Bankruptcy settlement
Percentage of total cash settlement to be received annually							17.00%