Represents the amount of bankruptcy claim to be settled.

No definition available.

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 amount of bankruptcy claim to be 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 period of Payment plan.

+ References

No definition available.

+ Details

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

- Definition

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.

+ References

No definition available.

+ Details

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

- Definition

Amount of judgment or settlement awarded to (against) the entity in respect of litigation.

+ References

No definition available.

+ Details

Name:	us-gaap_LitigationSettlementAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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=63488584&loc=d3e20235-122688

+ Details

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

- Details

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

- Details

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

COMMITMENTS AND CONTINGENCIES - Settlements (Details) - USD ($) $ in Thousands				12 Months Ended
	Oct. 27, 2016	May 02, 2016	Apr. 08, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Bankruptcy settlement
Other operating income				$ 0	$ 960	$ 0
Bankruptcy settlement due \| Samsun
Bankruptcy settlement
Cash to be received to settle bankruptcy claim as percentage of total settlement			26.00%
Amount of bankruptcy claim to be settled following the rehabilitation process			$ 3,979
Cash to be received to settle bankruptcy claim			$ 1,035
Tenure of Payment plan			10 years
Bankruptcy claims settled by conversion into shares of entity (as a percent)			74.00%
Amount Received	$ 777	$ 157
Other operating income					$ 934