Real Estate Transactions - Additional Information (Detail) $ in Thousands					3 Months Ended			6 Months Ended
	Aug. 04, 2017 USD ($) Bed	Jun. 01, 2017 USD ($) Bed	Feb. 10, 2017 USD ($) Bed	Jan. 02, 2017 USD ($)	Sep. 30, 2017 Facility Bed	Jun. 30, 2017 USD ($) Bed	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) Facility Bed Acquisition	Jun. 30, 2016 USD ($)	Jan. 01, 2017 Bed
Facility Activations Developments And Closures [Line Items]
Purchase price, net tangible assets								$ 10,800
Purchase price, identifiable intangible assets								1,000
Purchase price, goodwill								$ 2,300
Number of acquisitions | Acquisition								3
Number of beds at the facility | Bed						87,400		87,400
Operating Expense						$ 307,897	$ 316,446	$ 623,200	$ 630,364
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						$ 3,900		$ 3,900
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						$ 2,500	$ 2,000	$ 5,400	$ 4,100
Eden Detention Center
Facility Activations Developments And Closures [Line Items]
Net Carrying Value						$ 40,500		$ 40,500
Number of beds at the facility | Bed						1,422		1,422
Torrance County Detention
Facility Activations Developments And Closures [Line Items]
Carrying value of facility						$ 37,300		$ 37,300
Torrance County Detention | Scenario Forecast
Facility Activations Developments And Closures [Line Items]
Number of beds at the facility | Bed					910
Cibola County Corrections Center | Scenario Forecast
Facility Activations Developments And Closures [Line Items]
Number of beds at the facility | Bed					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		$ 7,000
New Beginnings Treatment Center, Inc. | Subsequent Event
Facility Activations Developments And Closures [Line Items]
Number of beds at the center | Bed	92
Aggregate purchase price paid	$ 6,400