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

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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

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

- Definition

Working Capital Line of Credit Issue to GEO Amey

+ References

No definition available.

+ Details

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

- Definition

Amount of receivables due from an entity that is affiliated with the reporting entity by means of direct or indirect ownership, due after 1 year (or 1 business cycle).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

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

- 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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
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+ Details

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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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
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+ Details

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Namespace Prefix:	us-gaap_
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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

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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

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Period Type:	duration

- Details

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- Details

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- Details

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- Details

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- Details

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Debt - Guarantees (Details) £ in Millions, $ in Millions	9 Months Ended
Debt - Guarantees (Details) £ in Millions, $ in Millions	Sep. 30, 2018 USD ($) guarantee	Sep. 30, 2018 AUD ($) guarantee	Sep. 30, 2018 GBP (£) guarantee	Sep. 30, 2018 ZAR (R) guarantee
Geo Amey
Line of Credit Facility [Line Items]
Ownership percentage in South African Custodial Services Pty. Limited	50.00%
Working capital line of credit issued to GEOAmey	$ 15,600,000		£ 12.0
Note receivable for GEOAmey	$ 1,700,000		£ 1.3
Ravenhall
Line of Credit Facility [Line Items]
Number of letters of guarantee outstanding under separate international facilities relating to performance guarantees \| guarantee	10	10	10	10
Letters of credit outstanding relating to performance guarantees	$ 14,700,000
Ravenhall \| Letter of Credit \| Revolver
Line of Credit Facility [Line Items]
Guaranteed obligations	72,200,000	$ 100.0
SACS
Line of Credit Facility [Line Items]
Maximum loan amount under standby facility	1,500,000.0			R 20,000,000
Amount funded	$ 0