Letters of credit outstanding relating to performance guarantees.

No definition available.

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- Definition

Maximum loan amount under SACS shareholder's loan.

+ References

No definition available.

+ Details

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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_
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Balance Type:	na
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- Definition

Potential estimated exposure of tax obligations.

+ References

No definition available.

+ Details

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

- Definition

Working capital line of credit.

+ References

No definition available.

+ Details

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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

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amounts due from an entity in which the reporting entity shares joint control with another party or group, due within 1 year (or 1 business cycle).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39599-107864

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.3(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864

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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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=82913245&loc=d3e12069-110248

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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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=77990344&loc=SL6759159-111685

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Balance Type:	na
Period Type:	duration

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Debt (Guarantees) (Details) £ in Millions, CAD in Millions, AUD in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) guarantee	Dec. 31, 2017 GBP (£) guarantee	Dec. 31, 2017 AUD guarantee	Dec. 31, 2017 CAD guarantee	Dec. 31, 2017 ZAR guarantee	Dec. 31, 2016 USD ($)
Debt Instrument [Line Items]
Variable interest entity ownership percentage in joint venture	50.00%
GEO Amey
Debt Instrument [Line Items]
Lines of credit	$ 12,000,000
Ravenhall
Debt Instrument [Line Items]
Number of letters of guarantee outstanding under separate international facilities relating to performance guarantees \| guarantee	10	10	10	10	10
Letters of guarantee outstanding relating to performance guarantees	$ 15,900,000
SACS
Debt Instrument [Line Items]
Maximum exposure, undiscounted	200,000				ZAR 2,400,000
Maximum loan amount under stand by facility to SACS	1,600,000.0				ZAR 20,000,000
Canada Facility
Debt Instrument [Line Items]
Potential estimated exposure of tax obligations \| CAD				CAD 1.1
Revolver \| Letter of credit \| Ravenhall
Debt Instrument [Line Items]
Maximum exposure, undiscounted			AUD 100			$ 78,100,000
Other Noncurrent Assets \| GEO Amey
Debt Instrument [Line Items]
Due from joint venture, current	$ 1,700,000	£ 1.3