- Earnings Per Share Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share, Basic and Diluted [Abstract]
Net income	$ 37,325	$ 30,942	$ 72,245	$ 71,308
Net loss attributable to noncontrolling interests	96	50	163	87
Net income attributable to The GEO Group, Inc.	$ 37,421	$ 30,992	$ 72,408	$ 71,395
Basic earnings per share attributable to The GEO Group, Inc.:
Weighted average shares outstanding (in shares)	120,274	122,125	121,017	117,885
Per share amount (USD per share)	$ 0.31	$ 0.25	$ 0.60	$ 0.61
Diluted earnings per share attributable to The GEO Group, Inc.:
Weighted average shares outstanding (in shares)	120,274	122,125	121,017	117,885
Dilutive effect of equity incentive plans (in shares)	385	770	444	817
Weighted average shares assuming dilution (in shares)	120,659	122,895	121,461	118,702
Income from continuing operations (USD per share)	$ 0.31	$ 0.25	$ 0.60	$ 0.60