Summary of Business Organization, Operations and Significant Accounting Policies - Variable Interest Entities (Details) £ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Feb. 28, 2011 GBP (£) director £ / shares shares	Dec. 31, 2017 USD ($)	Dec. 31, 2017 GBP (£)	Dec. 31, 2016 USD ($)
Variable Interest Entity [Line Items]
Variable interest entity ownership percentage in joint venture		50.00%
Partnership interest share amount | £	£ 100
Units of partnership interest, amount	100
Value per partnership interest shares | £ / shares	£ 1
Directors appointed to board by each party | director	3
Line of Credit, amount outstanding | $		$ 270,559		$ 515,000
GEO Amey
Variable Interest Entity [Line Items]
Units of partnership interest, amount	50
Line of Credit, amount outstanding		$ 16,200	£ 12,000,000
SACS
Variable Interest Entity [Line Items]
Life term of contract		25 years
Reduction of government guarantee in case of default		80.00%
Investment in joint venture | $		$ 18,100		$ 11,800
GEO UK
Variable Interest Entity [Line Items]
Variable interest entity ownership percentage in joint venture		50.00%
Units of partnership interest, amount	50
Kensani Corrections
Variable Interest Entity [Line Items]
Variable interest entity ownership percentage in joint venture		50.00%
Other Noncurrent Assets | GEO Amey
Variable Interest Entity [Line Items]
Due from joint venture, current		$ 1,700	£ 1,300,000