Shareholders' Equity - Components of Accumulated Other Comprehensive Income (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 1,199,241
Current-period other comprehensive income	1,354
Ending balance	1,138,953
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 income	513
Ending balance	(6,957)
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 income	736
Ending balance	(11,156)
Pension adjustments, net of tax
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(5,084)
Current-period other comprehensive income	105
Ending balance	(4,979)
Total
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(24,446)
Ending balance	$ (23,092)