GENERAL INFORMATION (Details) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2022 USD ($) item t segment	Dec. 31, 2021 USD ($)
Segment reporting
Number of reportable segments \| segment	1
Drybulk Vessels
Segment reporting
Number of vessels in fleet	44
Capacity of vessels \| t	4,636,000
Average age of vessels	10 years 3 months 18 days
Capesize Drybulk Carriers
Segment reporting
Number of vessels in fleet	17
Ultramax Vessels
Segment reporting
Number of vessels in fleet	15
Supramax Vessels
Segment reporting
Number of vessels in fleet	12
GSSM \| Variable Interest Entity
Segment reporting
Ownership percentage	50.00%	50.00%
Investments used directly for operations \| $	$ 50	$ 50
GSSM \| Synergy
Segment reporting
Ownership by synergy	50.00%	50.00%
Investments used directly for operations \| $	$ 50	$ 50

Average age of vessels.

No definition available.

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Balance Type:	na
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- Definition

Represents the capacity of vessels expressed in deadweight tonnage (dwt), a measure of weight a ship is carrying or can safely carry.

+ References

No definition available.

+ Details

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Namespace Prefix:	gnk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the number of vessels in the fleet.

+ References

No definition available.

+ Details

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Namespace Prefix:	gnk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Variable interest entity ownership percentage held by third party.

+ References

No definition available.

+ Details

Name:	gnk_VariableInterestEntityOwnershipPercentageHeldByThirdParty
Namespace Prefix:	gnk_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of investment in equity method investee and investment in and advance to affiliate.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8672-108599

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=123419778&loc=SL6759159-111685

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	gnk_VesselByTypeAxis=gnk_DrybulkVesselsMember
Namespace Prefix:
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Balance Type:
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- Details

Name:	gnk_VesselByTypeAxis=gnk_CapesizeDrybulkVesselsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	gnk_VesselByTypeAxis=gnk_UltramaxDrybulkVesselsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	gnk_VesselByTypeAxis=gnk_SupramaxDrybulkVesselsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_OwnershipAxis=gnk_GsShipmanagementPte.LtdMember
Namespace Prefix:
Data Type:	na
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- Details

Name:	srt_ConsolidatedEntitiesAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix:
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- Details

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Namespace Prefix:
Data Type:	na
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Period Type: