Consolidated Statements of Operations (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Income tax provision on equity in earnings of affiliates	$ 200	$ 77	$ 636	$ 1,785

The sum of the current income tax expense (benefit) and the deferred income tax expense (benefit) pertaining the earnings from its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied.

No definition available.

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