Benefit Plans - Components of Company Plan Benefit Expense (Parenthetical) (Details)	9 Months Ended
Sep. 30, 2021
Compensation And Retirement Disclosure [Abstract]
Age limit for a lump sum payment	55 years

Minimum age to be eligible to receive lump sum payment upon benefit.

No definition available.

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