Earnings Per Share (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
Earnings Per Share, Basic and Diluted [Abstract]
Net Income	$ 36,263	$ 38,453	$ 30,942	$ 40,366	$ 49,342	$ 43,674	$ 23,156	$ 32,326	$ 146,024	$ 148,498	$ 139,315
Loss attributable to noncontrolling interests									217	217	123
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 attributable to The GEO Group, Inc.:
Weighted average shares outstanding (in shares)									120,095,000	111,065,000	110,544,000
Net income per share — basic (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 attributable to The GEO Group, Inc.:
Weighted average shares outstanding (in shares)									120,095,000	111,065,000	110,544,000
Dilutive effect of equity incentive plans (in shares)									719,000	420,000	449,000
Weighted average shares assuming dilution (in shares)									120,814,000	111,485,000	110,993,000
Net income per share — diluted (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
Stock Options
Diluted earnings per share attributable to The GEO Group, Inc.:
Antidilutive securities excluded from computation of earnings per share									617,025	862,964	360,693
Restricted Stock Award
Diluted earnings per share attributable to The GEO Group, Inc.:
Antidilutive securities excluded from computation of earnings per share									719,204	267,045	315,111