Commitments, Contingencies and Other (Details) $ in Millions		3 Months Ended
	Mar. 06, 2017 USD ($) bed	Mar. 31, 2017 USD ($) facility bed	Feb. 08, 2017 USD ($)	Oct. 22, 2014 detainees
Commitments and Contingencies [Line Items]
Number of current and former civil immigration detainees | detainees				9
Estimate of possible loss		$ 19.6
Estimated construction capital project cost		168.6
Cost already spent on existing capital projects		26.7
Remaining capital required for capital projects		$ 141.9
Number of vacant beds at idle facilities marketed to potential customers | bed		3,600
Number of marketed idle facilities | facility		4
Property and Equipment
Commitments and Contingencies [Line Items]
Carrying values of idle facilities marketed to potential customers		$ 49.5
Pending Litigation | Attorney General of Mississippi vs Company, Cornell Companies, Inc., Christopher B Epps And Cecil McCrory
Commitments and Contingencies [Line Items]
Contracts disputed			$ 256.0
Maverick County Detention Center
Commitments and Contingencies [Line Items]
Number of beds in detention facility | bed	688
Cash payments to acquire business	$ 15.0