Business Combinations - Additional Information (Detail)	Oct. 28, 2015 USD ($) Bed Facility	Aug. 27, 2015 Bed Facility	Sep. 30, 2015 USD ($) Bed	Dec. 31, 2014 USD ($)
Business Acquisition [Line Items]
Number of beds at the facility | Bed		600	83,000
Number of facilities acquired | Facility		4
Revolving Credit Facility | $900.0 Million Revolving Credit Facility
Business Acquisition [Line Items]
Line of credit facility maximum borrowing capacity			$ 900,000,000	$ 900,000,000
Subsequent Event | Revolving Credit Facility | $900.0 Million Revolving Credit Facility
Business Acquisition [Line Items]
Line of credit facility maximum borrowing capacity	$ 900,000,000
Subsequent Event | Avalon Correctional Services, Inc
Business Acquisition [Line Items]
Business acquisition, acquisition date	Oct. 28, 2015
Business acquisition, percentage of acquired stock	100.00%
Number of beds at the facility | Bed	3,000
Number of facilities acquired | Facility	11
Aggregate purchase price	$ 157,500,000
Subsequent Event | Avalon Correctional Services, Inc | The achievement of certain utilization milestones over the next 12 months
Business Acquisition [Line Items]
Amounts due under earn-outs business combinations	2,000,000
Subsequent Event | Avalon Correctional Services, Inc | The completion of and transition to a newly constructed facility that will deliver the contracted services currently provided at the Dallas Transitional Center
Business Acquisition [Line Items]
Amounts due under earn-outs business combinations	$ 5,500,000