Schedule III - Real Estate Assets and Accumulated Depreciation (Parenthetical) (Detail) $ in Billions	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2015 Bed	Jun. 10, 2016 Bed	Aug. 27, 2015 Bed
SEC Schedule III, Real Estate Assets and Accumulated Depreciation [Line Items]
Aggregate cost of properties for federal Income Tax purposes | $	$ 3.6
Number of beds at the facility			112	600
San Diego Correctional Facility
SEC Schedule III, Real Estate Assets and Accumulated Depreciation [Line Items]
Number of beds at the facility		1,154
Lease expiration date		Dec. 31, 2015
Otay Mesa Detention Center
SEC Schedule III, Real Estate Assets and Accumulated Depreciation [Line Items]
Number of beds at the facility		1,482
Maximum
SEC Schedule III, Real Estate Assets and Accumulated Depreciation [Line Items]
Prison facilities, estimated useful lives of depreciable assets	50 years