Summary of Business Organization, Operations and Significant Accounting Policies - Components of Accumulated Other Comprehensive Loss (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Components of Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	$ 996,830,000
Current-period other comprehensive income (loss) before reclassifications	(2,254,000)	$ (568,000)
Amounts reclassified from other comprehensive income into earnings	0	3,851,000
Net current-period comprehensive income (loss)		3,283,000
Ending balance	913,102,000	996,830,000
Foreign currency translation adjustments, net of tax attributable to The GEO Group, Inc.
Components of Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	(12,314,000)	(14,573,000)
Current-period other comprehensive income (loss) before reclassifications	3,107,000	2,259,000
Amounts reclassified from other comprehensive income into earnings		0
Net current-period comprehensive income (loss)		2,259,000
Ending balance	(9,207,000)	(12,314,000)
Unrealized loss on derivatives, net of tax
Components of Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	(1,476,000)	(5,746,000)
Current-period other comprehensive income (loss) before reclassifications	(3,276,000)	419,000
Amounts reclassified from other comprehensive income into earnings		3,851,000
Net current-period comprehensive income (loss)		4,270,000
Ending balance	(4,752,000)	(1,476,000)
Pension adjustments, net of tax
Components of Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	(6,545,000)	(3,299,000)
Current-period other comprehensive income (loss) before reclassifications	(2,085,000)	(3,246,000)
Amounts reclassified from other comprehensive income into earnings		0
Net current-period comprehensive income (loss)		(3,246,000)
Ending balance	(8,630,000)	(6,545,000)
Accumulated Other Comprehensive Income (Loss)
Components of Accumulated Other Comprehensive Loss [Roll Forward]
Beginning balance	(20,335,000)	(23,618,000)
Ending balance	$ (22,589,000)	$ (20,335,000)