Letters of credit outstanding relating to performance guarantees.

No definition available.

Name:	geo_LettersofCreditOutstandingRelatingtoPerformanceGuarantees
Namespace Prefix:	geo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum loan amount under SACS shareholder's loan.

+ References

No definition available.

+ Details

Name:	geo_MaximumLoanAmountunderSACSShareholdersLoan
Namespace Prefix:	geo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Number of letters of guarantee outstanding under separate international facilities relating to performance guarantees.

+ References

No definition available.

+ Details

Name:	geo_NumberOfLettersOfGuaranteeOutstandingUnderSeparateInternationalFacilitiesRelatingToPerformanceGuarantees
Namespace Prefix:	geo_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Working capital line of credit.

+ References

No definition available.

+ Details

Name:	geo_WorkingCapitalLineOfCredit
Namespace Prefix:	geo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12069-110248

+ Details

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

- Definition

Fair value of the amount outstanding under the credit facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13433-108611

+ Details

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

- 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=121559654&loc=SL6759159-111685

+ Details

Name:	us-gaap_VariableInterestEntityOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	srt_ConsolidatedEntitiesAxis=geo_GeoAmeyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=geo_RavenhallMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_LetterOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=geo_SouthAfricanCustodialServicesPtyLimitedMember
Namespace Prefix:
Data Type:	na
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Period Type:

Debt (Guarantees) (Details) £ in Millions	12 Months Ended
Debt (Guarantees) (Details) £ in Millions	Dec. 31, 2020 USD ($) Guarantee	Dec. 31, 2020 GBP (£) Guarantee	Dec. 31, 2020 AUD ($) Guarantee	Dec. 31, 2020 ZAR (R) Guarantee
Debt Instrument [Line Items]
Variable interest entity ownership percentage in joint venture	50.00%
GEO Amey
Debt Instrument [Line Items]
Lines of credit \| £		£ 12.0
Ravenhall
Debt Instrument [Line Items]
Number of letters of guarantee outstanding under separate international facilities relating to performance guarantees \| Guarantee	7	7	7	7
Letters of guarantee outstanding relating to performance guarantees	$ 10,300,000
Ravenhall \| Letter of credit \| Revolver
Debt Instrument [Line Items]
Maximum exposure, undiscounted	45,500,000		$ 59,000,000
SACS
Debt Instrument [Line Items]
Maximum loan amount under stand by facility to SACS	1,400,000			R 20,000,000.0
Line of credit facility, amount outstanding	$ 0