Shareholders' Equity - Components of Accumulated Other Comprehensive Income (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($)
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 975,056
Current-period other comprehensive income	4,757
Ending balance	1,214,310
Foreign currency translation adjustments, net of tax attributable to The GEO Group, Inc.
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(11,284)
Current-period other comprehensive income	2,026
Ending balance	(9,258)
Unrealized (loss)/gain on derivatives, net of tax
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(15,877)
Current-period other comprehensive income	2,556
Ending balance	(13,321)
Pension adjustments, net of tax
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(3,664)
Current-period other comprehensive income	175
Ending balance	(3,489)
Total
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(30,825)
Ending balance	$ (26,068)