Debt Covenant, Asset Proceeds, Excess Proceeds

No definition available.

Name:	geo_DebtCovenantAssetProceedsExcessProceeds
Namespace Prefix:	geo_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Debt Covenant, Indenture Agreement, Period After Notice

+ References

No definition available.

+ Details

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

- Definition

Debt Instrument, Notice Period Prior to Redemption

+ References

No definition available.

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

Debt Instrument, Redemption Period, Percentage of Principal Amount Redeemable

+ References

No definition available.

+ Details

Name:	geo_DebtInstrumentRedemptionPeriodPercentageOfPrincipalAmountRedeemable
Namespace Prefix:	geo_
Data Type:	num:percentItemType
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 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: 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=64930785&loc=d3e28551-108399

+ 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

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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

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

Name:	us-gaap_DebtInstrumentRedemptionPricePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629

Reference 2: 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=66902209&loc=d3e3602-108585

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=49170532&loc=d3e12355-112629

+ Details

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

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ 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(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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

- 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

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=geo_FivePointEightSevenFivePercentSeniorNotesDue2024Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=geo_FivePointEightSevenFivePercentSeniorNotesDue2022Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodThreeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentRedemptionPeriodAxis=us-gaap_DebtInstrumentRedemptionPeriodFiveMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=geo_FivePointOneTwoFivePercentSeniorNotesDue2023Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

Debt (5.875% Senior Notes) (Details) - USD ($)		12 Months Ended
Debt (5.875% Senior Notes) (Details) - USD ($)	Sep. 25, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Oct. 03, 2013	Mar. 19, 2013
Debt Instrument [Line Items]
Line of Credit, amount outstanding		$ 515,000,000	$ 485,000,000
Capitalized loan costs		48,900,000	50,500,000
Loss on extinguishment of debt		$ 15,885,000	$ 0	$ 0
5.875% Senior Notes due 2024
Debt Instrument [Line Items]
Capitalized loan costs	$ 4,600,000
5.875% Senior Notes \| Redemption, Period 2017
Debt Instrument [Line Items]
Redemption price percentage		104.406%
5.875% Senior Notes \| Redemption, Period 2018
Debt Instrument [Line Items]
Redemption price percentage		102.938%
5.875% Senior Notes \| Redemption, Period 2019
Debt Instrument [Line Items]
Redemption price percentage		101.469%
5.875% Senior Notes \| 2020 and thereafter
Debt Instrument [Line Items]
Redemption price percentage		100.00%
Senior Notes \| 5.875% Senior Notes due 2024
Debt Instrument [Line Items]
Debt instrument, face amount	$ 250,000,000.0
Stated interest rate	5.875%	5.875%	5.875%
Senior Notes \| 5.875% Senior Notes due 2024 \| Redemption, Period 2017
Debt Instrument [Line Items]
Redemption price percentage	100.00%
Senior Notes \| 5.875% Senior Notes due 2024 \| Redemption, Period 2019
Debt Instrument [Line Items]
Redemption price percentage	102.938%
Senior Notes \| 5.875% Senior Notes due 2024 \| 2020 and thereafter
Debt Instrument [Line Items]
Redemption price percentage	101.958%
Senior Notes \| 5.125% Senior Notes
Debt Instrument [Line Items]
Debt instrument, face amount						$ 300,000,000.0
Stated interest rate		5.125%	5.125%			5.125%
Percentage of principal amount redeemable		101.00%
Redemption price percentage		105.125%
Redemption period, principal amount redeemable		35.00%
Debt covenant, asset proceeds, excess proceeds		$ 25,000,000
Debt covenant, indenture agreement, period after notice		60 days
Capitalized loan costs		$ 6,800,000
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 \| 2020 and thereafter
Debt Instrument [Line Items]
Redemption price percentage		100.854%
Senior Notes \| 5.125% Senior Notes \| Maximum
Debt Instrument [Line Items]
Notice period prior to redemption		60 days
Senior Notes \| 5.125% Senior Notes \| Minimum
Debt Instrument [Line Items]
Notice period prior to redemption		30 days
Senior Notes \| 5.875% Senior Notes
Debt Instrument [Line Items]
Debt instrument, face amount					$ 250,000,000.0
Stated interest rate		5.875%	5.875%
Percentage of principal amount redeemable		101.00%
Redemption price percentage		100.00%
Debt covenant, asset proceeds, excess proceeds		$ 25,000,000
Debt covenant, indenture agreement, period after notice		60 days
Capitalized loan costs		$ 5,900,000
Senior Notes \| 5.875% Senior Notes \| Maximum
Debt Instrument [Line Items]
Notice period prior to redemption		60 days
Senior Notes \| 5.875% Senior Notes \| Minimum
Debt Instrument [Line Items]
Notice period prior to redemption		30 days
Senior Notes \| 7.75% Senior Notes
Debt Instrument [Line Items]
Stated interest rate		7.75%