Name:	gnk_TimeCharterFutureMinimumRevenueAbstract
Namespace Prefix:	gnk_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Represents the expected future minimum charter revenue, based on vessels committed to noncancellable time charter contracts during the second fiscal year following the latest fiscal year ended.

No definition available.

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

Represents the expected future minimum charter revenue, based on vessels committed to noncancellable time charter contracts for the remainder of the fiscal year following the latest fiscal year ended.

No definition available.

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

Represents the assumed offhire days for a vessel which has a scheduled drydocking.

No definition available.

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

Represents the profit sharing revenue included in time charter revenues.

No definition available.

Name:	gnk_TimeChartersProfitSharingRevenue
Namespace Prefix:	gnk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Revenue from transporting cargo and freight between locations.

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(d))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688