Debt Covenant, Asset Proceeds, Excess Proceeds

No definition available.

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Period Type:	duration

- Definition

Debt Covenant, Indenture Agreement, Period After Notice

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Notice Period Prior to Redemption

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Redemption Period, Change in Control, Percentage of Principal Amount Redeemable

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Debt Instrument, Redemption Period, Percentage of Principal Amount Redeemable

+ References

No definition available.

+ Details

Name:	geo_DebtInstrumentRedemptionPeriodPercentageOfPrincipalAmountRedeemable
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Period Type:	duration

- Definition

Debt Instrument, Redemption Price Calculation Contributor, Percentage

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Redemption Price, Percentage of Principal Remaining After Redemption

+ References

No definition available.

+ Details

Name:	geo_DebtInstrumentRedemptionPricePercentageOfPrincipalRemainingAfterRedemption
Namespace Prefix:	geo_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Redemption Period After Closing of Offering

+ References

No definition available.

+ Details

Name:	geo_RedemptionPeriodAfterClosingOfOffering
Namespace Prefix:	geo_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Details

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Period Type:	duration

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 470

-Section 50

-Paragraph 3

-Subparagraph e

-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Amount of debt issuance costs (for example, but not limited to, legal, accounting, broker, and regulatory fees).

+ References

No definition available.

+ Details

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

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 50

-Section 40

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6850294&loc=d3e12317-112629

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 50

-Section 40

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6850294&loc=d3e12355-112629

+ Details

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

- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.17)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=geo_CreditFacilityMember
Namespace Prefix:
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Period Type:

- Details

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Namespace Prefix:
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Debt (5.125% Senior Notes) (Details) (USD $)	12 Months Ended			0 Months Ended
Debt (5.125% Senior Notes) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Apr. 03, 2013	Aug. 31, 2010	Aug. 27, 2014	Sep. 25, 2014	Mar. 19, 2013
Debt Instrument [Line Items]
Stated interest rate					8.47%
Capitalized loan costs	$ 53,900,000us-gaap_UnamortizedDebtIssuanceExpense	$ 33,100,000us-gaap_UnamortizedDebtIssuanceExpense
Loss on extinguishment of debt	0	20,657,000	8,462,000
Credit Facility
Debt Instrument [Line Items]
Capitalized loan costs						4,600,000
Senior Notes \| 5.125% Senior Notes
Debt Instrument [Line Items]
Debt instrument, face amount							250,000,000.0	300,000,000.0
Stated interest rate	5.125%	5.125%						5.125%
Debt covenant, asset proceeds, excess proceeds	25,000,000
Debt covenant, indenture agreement, period after notice	60 days
Percentage of principal amount redeemable	101.00%
Redemption period, principal amount redeemable	35.00%
Capitalized loan costs	6,800,000
Redemption period after closing of offering	0 years 0 months 90 days
Redemption price percentage	105.125%
Percentage of principal remaining after redemption	65.00%
Redemption price calculation contributor, percentage	100.00%
Senior Notes \| 5.125% Senior Notes \| Redemption, Period 2018
Debt Instrument [Line Items]
Redemption price percentage	102.563%
Senior Notes \| 5.125% Senior Notes \| Redemption, Period 2019
Debt Instrument [Line Items]
Redemption price percentage	101.708%
Senior Notes \| 5.125% Senior Notes \| Redemption, Period 2020
Debt Instrument [Line Items]
Redemption price percentage	100.854%
Senior Notes \| 5.125% Senior Notes \| 2020 and thereafter
Debt Instrument [Line Items]
Redemption price percentage	100.00%
Senior Notes \| 5.125% Senior Notes \| Minimum
Debt Instrument [Line Items]
Notice period prior to redemption	0 years 0 months 30 days
Senior Notes \| 5.125% Senior Notes \| Maximum
Debt Instrument [Line Items]
Notice period prior to redemption	0 years 0 months 60 days
Senior Notes \| Credit Facility
Debt Instrument [Line Items]
Loss on extinguishment of debt				4,400,000
Senior Notes \| Credit Agreement
Debt Instrument [Line Items]
Debt issuance cost				$ 1,100,000