Idled Facilities and Respective Carrying Values Excluding Equipment and Other Assets (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($) Bed	Dec. 31, 2017 USD ($)
Prairie Correctional Facility
Facility Activations Developments And Closures [Line Items]
Design Capacity | Bed	1,600
Date Idled	2010
Net Carrying Value | $	$ 15,330	$ 16,118
Huerfano County Correctional Center
Facility Activations Developments And Closures [Line Items]
Design Capacity | Bed	752
Date Idled	2010
Net Carrying Value | $	$ 16,803	16,980
Diamondback Correctional Facility
Facility Activations Developments And Closures [Line Items]
Design Capacity | Bed	2,160
Date Idled	2010
Net Carrying Value | $	$ 40,702	41,370
Southeast Kentucky Correctional Facility
Facility Activations Developments And Closures [Line Items]
Design Capacity | Bed	656
Date Idled	2012
Net Carrying Value | $	$ 21,233	21,864
Marion Adjustment Center
Facility Activations Developments And Closures [Line Items]
Design Capacity | Bed	826
Date Idled	2013
Net Carrying Value | $	$ 11,878	12,058
Kit Carson Correctional Center
Facility Activations Developments And Closures [Line Items]
Design Capacity | Bed	1,488
Date Idled	2016
Net Carrying Value | $	$ 55,952	57,095
Eden Detention Center
Facility Activations Developments And Closures [Line Items]
Design Capacity | Bed	1,422
Date Idled	2017
Net Carrying Value | $	$ 38,741	39,707
Torrance County Detention Facility
Facility Activations Developments And Closures [Line Items]
Design Capacity | Bed	910
Date Idled	2017
Net Carrying Value | $	$ 35,752	36,882
Idle Facilities
Facility Activations Developments And Closures [Line Items]
Design Capacity | Bed	9,814
Net Carrying Value | $	$ 236,391	$ 242,074