Business Combinations - Additional Information (Detail)					3 Months Ended									12 Months Ended
	Nov. 01, 2017 USD ($) Facility Bed	Jun. 01, 2017 USD ($) Bed	Apr. 08, 2016 USD ($) Facility Bed Entity Lease	Aug. 27, 2015 Facility	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) Facility Bed	Dec. 31, 2017 USD ($) Transaction	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) Bed
Business Acquisition [Line Items]
Number of facilities acquired | Facility				4
Revenue					$ 440,576,000	$ 442,845,000	$ 436,393,000	$ 445,684,000	$ 464,134,000	$ 474,935,000	$ 463,331,000	$ 447,385,000		$ 1,765,498,000	$ 1,849,785,000	$ 1,793,087,000
Number of purchase price transactions | Transaction														2
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					$ 900,000,000	$ 900,000,000
Avalon Correctional Services, Inc
Business Acquisition [Line Items]
Business acquisition, percentage of acquired stock													100.00%			100.00%
Number of additional facilities | Facility													2
Number of facilities acquired | Facility													11
Number of beds at the center | Bed													3,000			3,000
Aggregate purchase price													$ 157,500,000
Revenue										$ 2,000,000
Avalon Correctional Services, Inc | 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
Avalon Correctional Services, Inc | The achievement of certain utilization milestones over 12 months following the acquisition | Maximum
Business Acquisition [Line Items]
Amounts due under earn-outs business combinations													2,000,000			2,000,000
Avalon Correctional Services, Inc | The completion of and transition to a newly constructed facility that delivers the contracted services provided at the Dallas Transitional Center
Business Acquisition [Line Items]
Amounts due under earn-outs business combinations													$ 5,500,000			$ 5,500,000
Correctional Management, Inc
Business Acquisition [Line Items]
Business acquisition, percentage of acquired stock			100.00%
Number of facilities acquired | Facility			6
Number of beds at the center | Bed			600
Aggregate purchase price			$ 35,000,000
Number of entities affiliated | Entity			2
Number of facilities | Facility			7
Number of facilities leased | Lease			1
Correctional Management, Inc | Revolving Credit Facility | $900.0 Million Revolving Credit Facility
Business Acquisition [Line Items]
Line of credit facility maximum borrowing capacity			$ 900,000,000
Center Point, Inc.
Business Acquisition [Line Items]
Number of beds at the center | Bed		200
Aggregate purchase price		$ 5,300,000
Center Point, Inc. | Maximum
Business Acquisition [Line Items]
Business combination consideration excluding transaction related expense and potential earn-out		$ 1,700,000
Time to Change, Inc.
Business Acquisition [Line Items]
Number of beds at the center | Bed	422
Aggregate purchase price	$ 22,000,000
Number of facilities | Facility	3