Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share, Basic and Diluted [Abstract]
Net Income	$ 33,353	$ 39,229	$ 37,325	$ 34,920	$ 36,263	$ 38,453	$ 30,942	$ 40,366	$ 144,827	$ 146,024	$ 148,498
Loss attributable to noncontrolling interests									262	217	217
Net Income Attributable to The GEO Group, Inc.	$ 33,392	$ 39,289	$ 37,421	$ 34,987	$ 36,357	$ 38,489	$ 30,992	$ 40,403	$ 145,089	$ 146,241	$ 148,715
Basic earnings per share attributable to The GEO Group, Inc.:
Weighted average shares outstanding (in shares)									120,241,000	120,095,000	111,065,000
Net income per share — basic (in dollars per share)	$ 0.28	$ 0.33	$ 0.31	$ 0.29	$ 0.30	$ 0.31	$ 0.25	$ 0.36	$ 1.21	$ 1.22	$ 1.34
Diluted earnings per share attributable to The GEO Group, Inc.:
Weighted average shares outstanding (in shares)									120,241,000	120,095,000	111,065,000
Dilutive effect of equity incentive plans (in shares)									506,000	719,000	420,000
Weighted average shares assuming dilution (in shares)									120,747,000	120,814,000	111,485,000
Net income per share — diluted (in dollars per share)	$ 0.28	$ 0.33	$ 0.31	$ 0.29	$ 0.30	$ 0.31	$ 0.25	$ 0.35	$ 1.20	$ 1.21	$ 1.33
Stock Options
Diluted earnings per share attributable to The GEO Group, Inc.:
Antidilutive securities excluded from computation of earnings per share									931,476	617,025	862,964
Restricted Stock Award
Diluted earnings per share attributable to The GEO Group, Inc.:
Antidilutive securities excluded from computation of earnings per share									680,062	719,204	267,045