- Earnings Per Share Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share, Basic and Diluted [Abstract]
Net income	$ 34,920	$ 40,366
Net loss attributable to noncontrolling interests	67	37
Net income attributable to The GEO Group, Inc.	$ 34,987	$ 40,403
Basic earnings per share attributable to The GEO Group, Inc.:
Weighted average shares outstanding (in shares)	121,768	113,599
Per share amount (USD per share)	$ 0.29	$ 0.36
Diluted earnings per share attributable to The GEO Group, Inc.:
Weighted average shares outstanding (in shares)	121,768	113,599
Dilutive effect of equity incentive plans (shares)	536	879
Weighted average shares assuming dilution	122,304	114,478
Income from continuing operations (USD per share)	$ 0.29	$ 0.35