Shareholders' Equity - Components of Accumulated Other Comprehensive Income (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($)
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 1,199,241
Current-period other comprehensive (loss) income	(783)
Ending balance	1,093,435
Foreign currency translation adjustments, net of tax attributable to The GEO Group, Inc.
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(7,470)
Current-period other comprehensive (loss) income	(4,527)
Ending balance	(11,997)
Change in fair value of derivatives, net of tax
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(11,892)
Current-period other comprehensive (loss) income	3,014
Ending balance	(8,878)
Pension adjustments, net of tax
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(5,084)
Current-period other comprehensive (loss) income	730
Ending balance	(4,354)
Total
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(24,446)
Ending balance	$ (25,229)