Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Company's quarterly financial data
Revenues	$ 599,430	$ 583,530	$ 583,509	$ 564,917	$ 568,977	$ 566,759	$ 577,070	$ 550,614	$ 2,331,386	$ 2,263,420	$ 2,179,490
Operating Income	63,484	69,780	66,951	64,450	66,458	62,902	54,553	64,372	264,665	248,285	265,584
Net Income	33,353	39,229	37,325	34,920	36,263	38,453	30,942	40,366	144,827	146,024	148,498
Net income attributable to The GEO Group, Inc.	$ 33,392	$ 39,289	$ 37,421	$ 34,987	$ 36,357	$ 38,489	$ 30,992	$ 40,403	$ 145,089	$ 146,241	$ 148,715
Basic earnings per share
Net income per share (in dollars per share)	$ 0.28	$ 0.33	$ 0.31	$ 0.29	$ 0.30	$ 0.31	$ 0.25	$ 0.36	$ 1.21	$ 1.22	$ 1.34
Diluted earnings per share
Net income per share (in dollars per share)	$ 0.28	$ 0.33	$ 0.31	$ 0.29	$ 0.30	$ 0.31	$ 0.25	$ 0.35	$ 1.20	$ 1.21	$ 1.33