Commitments and Contingencies (Details) $ in Millions	3 Months Ended	6 Months Ended
	Dec. 19, 2017 claim	Jun. 30, 2019 USD ($) bed facility
Commitments and Contingencies [Line Items]
Estimate of possible loss		$ 18.6
Estimated construction capital project cost		173.0
Cost already spent on existing capital projects		129.0
Remaining capital required for capital projects		$ 44.0
Number of vacant beds at idle facilities marketed to potential customers | bed		2,300
Number of marketed idle facilities | facility		3,000
Property and Equipment
Commitments and Contingencies [Line Items]
Carrying values of idle facilities marketed to potential customers		$ 27.5
Pending Litigation | Immigration Detainees Against Company
Commitments and Contingencies [Line Items]
New claims filed, number | claim	3
WASHINGTON | Pending Litigation | Immigration Detainees Against Company
Commitments and Contingencies [Line Items]
New claims filed, number | claim	2
CALIFORNIA | Pending Litigation | Immigration Detainees Against Company
Commitments and Contingencies [Line Items]
New claims filed, number | claim	1