Earnings Per Share - Earnings Per Share Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share, Basic and Diluted [Abstract]
Net income	$ 38,453	$ 43,674	$ 109,761	$ 99,156
Net loss attributable to noncontrolling interests	36	46	123	123
Net income attributable to The GEO Group, Inc.	$ 38,489	$ 43,720	$ 109,884	$ 99,279
Basic earnings per share attributable to The GEO Group, Inc.:
Weighted average shares outstanding (in shares)	122,251	111,162	119,356	111,015
Per share amount (USD per share)	$ 0.31	$ 0.39	$ 0.92	$ 0.89
Diluted earnings per share attributable to The GEO Group, Inc.:
Weighted average shares outstanding (in shares)	122,251	111,162	119,356	111,015
Dilutive effect of equity incentive plans (shares)	636	342	758	410
Weighted average shares assuming dilution	122,887	111,504	120,114	111,425
Income from continuing operations (USD per share)	$ 0.31	$ 0.39	$ 0.91	$ 0.89