Condensed Consolidating Financial Information (Statements of Cash Flows) (Details) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended	12 Months Ended
	Jan. 31, 2018	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flow from Operating Activities:
Net cash provided by operating activities			$ 274,475	$ 381,042	$ (28,028)
Cash Flow from Investing Activities:
Proceeds from sale of property and equipment			2,077	3,460	2,030
Acquisition of CEC, cash consideration, net of cash acquired			0	(353,556)	0
Insurance proceeds - damaged property			1,438	2,754	4,733
Proceeds from sale of assets held for sale	$ 4,000	$ 3,797	3,797	0	0
Change in restricted cash and investments			(129)	(4,507)	(2,892)
Capital expenditures			(195,666)	(148,406)	(81,565)
Net cash used in investing activities			(188,483)	(500,255)	(77,694)
Cash Flow from Financing Activities:
Payments on long-term debt			(282,358)	(1,140,788)	(934,006)
Proceeds from long term debt			502,998	1,389,084	1,012,945
Payments on non-recourse debt			(18,544)	(307,414)	(10,064)
Proceeds from non-recourse debt			0	181,658	266,835
Taxes paid related to net share settlements of equity awards			(3,820)	(4,142)	(2,336)
Payments for purchase of treasury shares			(95,175)	0	0
Tax benefit (deficiency) related to equity compensation			0	0	(1,626)
Debt issuance costs			(990)	(9,542)	(21,115)
Proceeds from stock options exercised			1,887	6,962	3,347
Dividends paid			(229,498)	(227,463)	(194,748)
Proceeds from issuance of common stock in connection with ESPP			534	497	436
Issuance of common stock in connection with public offering			0	275,867	0
Net cash (used in) provided by financing activities			(124,966)	164,719	119,668
Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash and Cash Equivalents			(10,099)	(2,318)	1,119
Net(Decrease) Increase in Cash Cash Equivalents and Restricted Cash and Cash Equivalents			(49,073)	43,188	15,065
Cash, Cash Equivalents and Restricted Cash and Cash Equivalents, beginning of period	133,545	133,545	133,545	90,357	75,292
Cash, Cash Equivalents and Restricted Cash and Cash Equivalents, end of period			84,472	133,545	90,357
The GEO Group Inc.
Cash Flow from Operating Activities:
Net cash provided by operating activities			156,754	118,018	154,125
Cash Flow from Investing Activities:
Proceeds from sale of property and equipment			0	3,436	2,030
Acquisition of CEC, cash consideration, net of cash acquired				(353,556)
Insurance proceeds - damaged property			0	2,754	0
Proceeds from sale of assets held for sale		0
Change in restricted cash and investments			0	0	0
Capital expenditures			(104,034)	(53,030)	(14,040)
Net cash used in investing activities			(104,034)	(400,396)	(12,010)
Cash Flow from Financing Activities:
Payments on long-term debt			(276,000)	(1,140,788)	(934,006)
Proceeds from long term debt			502,998	1,389,084	1,012,945
Payments on non-recourse debt			0	0	0
Proceeds from non-recourse debt				0	0
Taxes paid related to net share settlements of equity awards			(3,820)	(4,142)	(2,336)
Payments for purchase of treasury shares			(95,175)
Tax benefit (deficiency) related to equity compensation					(844)
Debt issuance costs			(990)	(8,701)	(16,980)
Proceeds from stock options exercised			1,887	6,962	2,367
Dividends paid			(229,498)	(227,463)	(194,748)
Proceeds from issuance of common stock in connection with ESPP			534	497	0
Issuance of common stock in connection with public offering				275,867
Net cash (used in) provided by financing activities			(100,064)	291,316	(133,602)
Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash and Cash Equivalents			0	0	0
Net(Decrease) Increase in Cash Cash Equivalents and Restricted Cash and Cash Equivalents			(47,344)	8,938	8,513
Cash, Cash Equivalents and Restricted Cash and Cash Equivalents, beginning of period	54,666	54,666	54,666	45,728	37,215
Cash, Cash Equivalents and Restricted Cash and Cash Equivalents, end of period			7,322	54,666	45,728
Combined Subsidiary Guarantors
Cash Flow from Operating Activities:
Net cash provided by operating activities			86,974	91,174	66,009
Cash Flow from Investing Activities:
Proceeds from sale of property and equipment			268	0	0
Acquisition of CEC, cash consideration, net of cash acquired				0
Insurance proceeds - damaged property			1,438	0	0
Proceeds from sale of assets held for sale		3,797
Change in restricted cash and investments			(129)	(4,507)	(2,892)
Capital expenditures			(89,310)	(86,336)	(61,811)
Net cash used in investing activities			(83,936)	(90,843)	(64,703)
Cash Flow from Financing Activities:
Payments on long-term debt			0	0
Proceeds from long term debt			0	0	0
Payments on non-recourse debt			0	0	0
Proceeds from non-recourse debt				0	0
Taxes paid related to net share settlements of equity awards			0	0	0
Payments for purchase of treasury shares			0
Tax benefit (deficiency) related to equity compensation					0
Debt issuance costs			0	0	0
Proceeds from stock options exercised			0	0	0
Dividends paid			0	0	0
Proceeds from issuance of common stock in connection with ESPP			0		0
Issuance of common stock in connection with public offering				0
Net cash (used in) provided by financing activities			0	0	0
Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash and Cash Equivalents			0	0	0
Net(Decrease) Increase in Cash Cash Equivalents and Restricted Cash and Cash Equivalents			3,038	331	1,306
Cash, Cash Equivalents and Restricted Cash and Cash Equivalents, beginning of period	4,952	4,952	4,952	4,621	3,315
Cash, Cash Equivalents and Restricted Cash and Cash Equivalents, end of period			7,990	4,952	4,621
Combined Non-Guarantor Subsidiaries
Cash Flow from Operating Activities:
Net cash provided by operating activities			30,747	171,850	(248,162)
Cash Flow from Investing Activities:
Proceeds from sale of property and equipment			1,809	24	0
Acquisition of CEC, cash consideration, net of cash acquired				0
Insurance proceeds - damaged property			0	0	4,733
Proceeds from sale of assets held for sale			0
Change in restricted cash and investments			0	0	0
Capital expenditures			(2,322)	(9,040)	(5,714)
Net cash used in investing activities			(513)	(9,016)	(981)
Cash Flow from Financing Activities:
Payments on long-term debt			(6,358)	0	0
Proceeds from long term debt			0	0	0
Payments on non-recourse debt			(18,544)	(307,414)	(10,064)
Proceeds from non-recourse debt				181,658	266,835
Taxes paid related to net share settlements of equity awards			0	0	0
Payments for purchase of treasury shares			0
Tax benefit (deficiency) related to equity compensation					(782)
Debt issuance costs			0	(841)	(4,135)
Proceeds from stock options exercised			0	0	980
Dividends paid			0	0	0
Proceeds from issuance of common stock in connection with ESPP			0	0	436
Issuance of common stock in connection with public offering				0
Net cash (used in) provided by financing activities			(24,902)	(126,597)	253,270
Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash and Cash Equivalents			(10,099)	(2,318)	1,119
Net(Decrease) Increase in Cash Cash Equivalents and Restricted Cash and Cash Equivalents			(4,767)	33,919	5,246
Cash, Cash Equivalents and Restricted Cash and Cash Equivalents, beginning of period	$ 73,927	$ 73,927	73,927	40,008	34,762
Cash, Cash Equivalents and Restricted Cash and Cash Equivalents, end of period			$ 69,160	$ 73,927	$ 40,008