Number of consecutive trading days.

No definition available.

Name:	gsl_NumberOfConsecutiveTradingDays
Namespace Prefix:	gsl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of members.

+ References

No definition available.

+ Details

Name:	gsl_NumberOfMembers
Namespace Prefix:	gsl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of tranches.

+ References

No definition available.

+ Details

Name:	gsl_NumberOfTranches
Namespace Prefix:	gsl_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award earliest vesting date.

+ References

No definition available.

+ Details

Name:	gsl_ShareBasedCompensationArrangementByShareBasedPaymentAwardEarliestVestingDate
Namespace Prefix:	gsl_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum number of shares that may be granted to any non-employee director in any one calendar year, under the equity-based compensation plan.

+ References

No definition available.

+ Details

Name:	gsl_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsMaximumNumberOfGrantsInPeriod
Namespace Prefix:	gsl_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum value of shares that may be granted to any non-employee director in any one calendar year, under the equity-based compensation plan.

+ References

No definition available.

+ Details

Name:	gsl_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsMaximumValueOfGrantsInPeriod
Namespace Prefix:	gsl_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award shares issued in period notional value per share.

+ References

No definition available.

+ Details

Name:	gsl_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriodNotionalValuePerShare
Namespace Prefix:	gsl_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award shares issued percentage of directors fee.

+ References

No definition available.

+ Details

Name:	gsl_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedPercentageOfDirectorsFee
Namespace Prefix:	gsl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award vesting stock price.

+ References

No definition available.

+ Details

Name:	gsl_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingStockPrice
Namespace Prefix:	gsl_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of share instruments newly issued under a share-based compensation plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TitleOfIndividualAxis=us-gaap_ManagementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=gsl_TwoThousandAndFifteenEquityIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TitleOfIndividualAxis=us-gaap_DirectorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VestingAxis=us-gaap_ShareBasedCompensationAwardTrancheTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=gsl_TwoThousandNineteenIncentivePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Share-Based Compensation (Details) $ / shares in Units, $ in Thousands				11 Months Ended	12 Months Ended
	Mar. 01, 2018 Unit $ / shares shares	Jan. 08, 2018 Member Tranche $ / shares shares	Mar. 03, 2016 Member Tranche $ / shares shares	Nov. 15, 2018 shares	Dec. 31, 2018 USD ($) shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized share based compensation expenses \| $					$ 50	$ 272	$ 283
Restricted Stock Units [Member] \| Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation, Grants in Period							25,000
2015 Plan [Member] \| Director [Member] \| Common Class A [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued				60,425		4,266	4,266
Shares issued as percentage of directors base fee						20.00%	20.00%
Shares issued notional value per share \| $ / shares						$ 32	$ 32
2015 Plan [Member] \| Restricted Stock Units [Member] \| Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of members granted with restricted stock units	5	5	4
Number of tranches	2	2	2
2015 Plan [Member] \| Restricted Stock Units [Member] \| First Tranche [Member] \| Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting date	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2016
Share-based Compensation, Grants in Period	12,500	12,500	12,500
2015 Plan [Member] \| Restricted Stock Units [Member] \| Second Tranche [Member] \| Management [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting date	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2016
Share-based Compensation, Grants in Period	12,500	12,500	12,500
Number of consecutive trading days	20 days	20 days	20 days
2015 Plan [Member] \| Restricted Stock Units [Member] \| Second Tranche [Member] \| Management [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price \| $ / shares	$ 24.00	$ 24.00	$ 40.00
2019 Plan [Member] \| Common Class A [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of Equity Incentive Plan					10 years
Maximum number of shares approved under Equity Incentive Plan					1,812,500
2019 Plan [Member] \| Maximum [Member] \| Common Class A [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum Number of shares granted in any one calendar year					12,500
Maximum Value of shares granted in any one calendar year \| $					$ 100,000