Shareholders' Equity - Components of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 1,040,503
Current-period other comprehensive (loss) income	2,252	$ 1,354
Ending balance	1,027,559
Foreign currency translation adjustments, net of tax attributable to The GEO Group, Inc.
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(14,573)	(7,470)
Current-period other comprehensive (loss) income	1,736	513
Ending balance	(12,837)	(6,957)
Change in fair value of derivatives, net of tax
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(5,746)	(11,892)
Current-period other comprehensive (loss) income	1,164	736
Ending balance	(4,582)	(11,156)
Pension adjustments, net of tax
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(3,299)	(5,084)
Current-period other comprehensive (loss) income	(648)	105
Ending balance	(3,947)	(4,979)
Total
Components of Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(23,618)	(24,446)
Ending balance	$ (21,366)	$ (23,092)