Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Company's quarterly financial data
Revenues	$ 621,710	$ 631,579	$ 613,966	$ 610,667	$ 599,430	$ 583,530	$ 583,509	$ 564,917	$ 2,477,922	$ 2,331,386	$ 2,263,420
Operating Income	66,302	78,159	81,175	74,777	63,484	69,780	66,951	64,450	300,413	264,665	248,285
Net Income	38,042	45,885	41,836	40,649	33,353	39,229	37,325	34,920	166,412	144,827	146,024
Net income attributable to The GEO Group, Inc.	$ 38,052	$ 45,932	$ 41,914	$ 40,705	$ 33,392	$ 39,289	$ 37,421	$ 34,987	$ 166,603	$ 145,089	$ 146,241
Basic earnings per share
Net income per share — basic (in dollars per share)	$ 0.32	$ 0.39	$ 0.35	$ 0.34	$ 0.28	$ 0.33	$ 0.31	$ 0.29	$ 1.40	$ 1.21	$ 1.22
Diluted earnings per share
Net income per share — diluted (in dollars per share)	$ 0.32	$ 0.39	$ 0.35	$ 0.34	$ 0.28	$ 0.33	$ 0.31	$ 0.29	$ 1.40	$ 1.20	$ 1.21