Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Company's quarterly financial data
Revenues	$ 568,977	$ 566,759	$ 577,070	$ 550,614	$ 566,579	$ 554,376	$ 548,350	$ 510,185	$ 2,263,420	$ 2,179,490	$ 1,843,307
Operating Income	66,458	62,902	54,553	64,372	68,008	72,452	65,957	59,167	248,285	265,584	235,729
Net Income	36,263	38,453	30,942	40,366	49,342	43,674	23,156	32,326	146,024	148,498	139,315
Net income attributable to The GEO Group, Inc.	$ 36,357	$ 38,489	$ 30,992	$ 40,403	$ 49,436	$ 43,720	$ 23,209	$ 32,350	$ 146,241	$ 148,715	$ 139,438
Basic earnings per share
Net income per share (in dollars per share)	$ 0.30	$ 0.31	$ 0.25	$ 0.36	$ 0.44	$ 0.39	$ 0.21	$ 0.29	$ 1.22	$ 1.34	$ 1.26
Diluted earnings per share
Net income per share (in dollars per share)	$ 0.30	$ 0.31	$ 0.25	$ 0.35	$ 0.44	$ 0.39	$ 0.21	$ 0.29	$ 1.21	$ 1.33	$ 1.25