Represents the number of prior credit facilities refinanced during the period.

No definition available.

Name:	gnk_NumberOfCreditFacilitiesRefinanced
Namespace Prefix:	gnk_
Data Type:	xbrli:integerItemType
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.

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+ Details

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

- Definition

Period remaining on line of credit facility before it terminates, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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+ Details

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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow for the settlement of obligation drawn from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

+ References

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+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	credit
Period Type:	duration

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=gnk_TermLoanFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

DEBT - 450 Million Credit Facility (Details) $ in Thousands		3 Months Ended		9 Months Ended
DEBT - 450 Million Credit Facility (Details) $ in Thousands	Aug. 03, 2021 USD ($) facility	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)
Debt
Repayment of secured debt				$ 26,250	$ 66,250
$450 Million Credit Facility \| Secured Debt
Debt
Maximum borrowing capacity	$ 450,000
Term of facilities	5 years
Number of prior credit facilities refinanced into one facility \| facility	2
Remaining borrowing capacity		$ 198,770		198,770
Repayment of secured debt		$ 8,750	$ 8,750	$ 26,250	$ 66,250
Revolving credit facility \| Secured Debt
Debt
Maximum borrowing capacity	$ 300,000
Term loan facility \| Secured Debt
Debt
Maximum borrowing capacity	$ 150,000