Earnings Per Share - Earnings Per Share Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share, Basic and Diluted [Abstract]
Net income	$ 30,942	$ 23,156	$ 71,308	$ 55,482
Net loss attributable to noncontrolling interests	50	53	87	77
Net income attributable to The GEO Group, Inc.	$ 30,992	$ 23,209	$ 71,395	$ 55,559
Basic earnings per share attributable to The GEO Group, Inc.:
Weighted average shares outstanding (in shares)	122,125	111,066	117,885	110,940
Per share amount (USD per share)	$ 0.25	$ 0.21	$ 0.61	$ 0.50
Diluted earnings per share attributable to The GEO Group, Inc.:
Weighted average shares outstanding (in shares)	122,125	111,066	117,885	110,940
Dilutive effect of equity incentive plans (shares)	770	413	817	441
Weighted average shares assuming dilution	122,895	111,479	118,702	111,381
Income from continuing operations (USD per share)	$ 0.25	$ 0.21	$ 0.60	$ 0.50