Earnings Per Share - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2020		Sep. 30, 2020		Jun. 30, 2020		Mar. 31, 2020		Dec. 31, 2019		Sep. 30, 2019		Jun. 30, 2019		Mar. 31, 2019		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share Basic And Diluted [Abstract]
Net Income	$ 11,884		$ 39,172		$ 36,654		$ 25,121		$ 38,042		$ 45,885		$ 41,836		$ 40,649		$ 112,831	$ 166,412	$ 144,827
Loss Attributable to Noncontrolling Interests																	201	191	262
Net income attributable to The GEO Group, Inc.	$ 11,911		$ 39,220		$ 36,720		$ 25,181		$ 38,052		$ 45,932		$ 41,914		$ 40,705		$ 113,032	$ 166,603	$ 145,089
Basic earnings per share
Weighted average shares outstanding																	119,719	119,097	120,241
Per share amount	$ 0.09		$ 0.33		$ 0.31		$ 0.21		$ 0.32		$ 0.39		$ 0.35		$ 0.34		$ 0.94	$ 1.40	$ 1.21
Diluted:
Weighted average shares outstanding																	119,719	119,097	120,241
Dilutive effect of equity incentive plans																	272	214	506
Weighted average shares assuming dilution																	119,991	119,311	120,747
Per share amount - diluted	$ 0.09	[1]	$ 0.33	[1]	$ 0.31	[1]	$ 0.21	[1]	$ 0.32	[1]	$ 0.39	[1]	$ 0.35	[1]	$ 0.34	[1]	$ 0.94	$ 1.40	$ 1.20

[1] Earnings per share table may contain slight summation differences due to rounding.