Real Estate Transactions - Additional Information (Detail) $ in Thousands						3 Months Ended		9 Months Ended
	Sep. 15, 2017 USD ($) Bed Property	Aug. 01, 2017 USD ($) Bed	Jun. 01, 2017 USD ($) Bed	Feb. 10, 2017 USD ($) Bed	Jan. 02, 2017 USD ($)	Sep. 30, 2017 USD ($) Facility Bed	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) Facility Bed Acquisition	Sep. 30, 2016 USD ($)	Jan. 01, 2017 Bed
Facility Activations Developments And Closures [Line Items]
Aggregate purchase price paid	$ 8,700
Number of properties acquired in portfolio | Property	4
Purchase price, net tangible assets								$ 24,300
Purchase price, identifiable intangible assets								2,300
Purchase price, goodwill								$ 600
Number of acquisitions | Acquisition								5
Operating Expense						$ 316,865	$ 326,349	$ 940,065	$ 956,713
Idled Correctional Facilities
Facility Activations Developments And Closures [Line Items]
Number of facility | Facility								8
Idled Non-Core Facilities
Facility Activations Developments And Closures [Line Items]
Net Carrying Value						$ 4,100		$ 4,100
Number of beds at the facility | Bed						440		440
Number of facility | Facility								2
Idle Facilities
Facility Activations Developments And Closures [Line Items]
Operating Expense						$ 3,300	$ 2,500	$ 8,600	$ 6,600
Georgia
Facility Activations Developments And Closures [Line Items]
Number of properties leased | Property	1
North Carolina and Georgia
Facility Activations Developments And Closures [Line Items]
Number of properties leased | Property	1
North Carolina
Facility Activations Developments And Closures [Line Items]
Number of properties leased | Property	1
Purchase price, tenant improvements						300		300
Residential Reentry Centers
Facility Activations Developments And Closures [Line Items]
Number of beds at the center | Bed	230
Eden Detention Center
Facility Activations Developments And Closures [Line Items]
Net Carrying Value						$ 40,100		$ 40,100
Number of beds at the facility | Bed						1,422		1,422
Torrance County Detention
Facility Activations Developments And Closures [Line Items]
Number of beds at the facility | Bed						910		910
Carrying value of facility						$ 37,000		$ 37,000
Cibola County Corrections Center
Facility Activations Developments And Closures [Line Items]
Number of beds at the facility | Bed						1,129		1,129
Number of facility | Facility						1
Arapahoe Community Treatment Center
Facility Activations Developments And Closures [Line Items]
Number of beds at the center | Bed										135
Consideration paid					$ 5,500
Stockton Female Community Corrections Facility
Facility Activations Developments And Closures [Line Items]
Number of beds at the center | Bed				100
Consideration paid				$ 1,600
Lease expiration date				2021-04
Lease extension period				5 years
Center Point, Inc.
Facility Activations Developments And Closures [Line Items]
Number of beds at the center | Bed			200
Consideration paid			$ 5,300
Center Point, Inc. | Maximum
Facility Activations Developments And Closures [Line Items]
Business combination consideration excluding transaction related expense and potential earn-out			$ 1,700
New Beginnings Treatment Center, Inc.
Facility Activations Developments And Closures [Line Items]
Number of beds at the center | Bed		92
Aggregate purchase price paid		$ 6,400