Earnings Per Share - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share Basic And Diluted [Abstract]
Net income	$ 39,172	$ 45,885	$ 100,947	$ 128,370
Net loss attributable to noncontrolling interests	48	47	174	181
Net income attributable to The GEO Group, Inc.	$ 39,220	$ 45,932	$ 101,121	$ 128,551
Basic earnings per share attributable to The GEO Group, Inc.:
Weighted average shares outstanding (in shares)	119,826	119,209	119,677	119,052
Per share amount (in dollars per share)	$ 0.33	$ 0.39	$ 0.84	$ 1.08
Diluted earnings per share attributable to The GEO Group, Inc.:
Weighted average shares outstanding (in shares)	119,826	119,209	119,677	119,052
Dilutive effect of equity incentive plans (in shares)	206	73	287	262
Weighted average shares assuming dilution (in shares)	120,032	119,282	119,964	119,314
Per share amount (in dollars per share)	$ 0.33	$ 0.39	$ 0.84	$ 1.08