Schedule III - Real Estate Assets and Accumulated Depreciation Summary of Transactions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2014
SEC Schedule III, Real Estate Assets and Accumulated Depreciation [Line Items]
Investment in Real Estate, balance at beginning of period	$ 3,542,023		$ 3,071,094	$ 3,078,902
Additions through capital expenditures	54,678		433,481	45,929
Acquisitions	36,199		131,348
Sale of real estate for cash				(4,368)
Asset impairments				(49,247)
Reclassifications and other	4,035		(93,900)	(122)
Investment in Real Estate, balance at end of period	3,636,935	[1]	3,542,023	3,071,094
Accumulated Depreciation, balance at beginning of period	(834,558)		(815,980)	(755,761)
Depreciation	(125,913)		(113,611)	(79,745)
Disposals/Other	117		95,033	118
Asset impairments				19,408
Accumulated Depreciation, balance at end of period	$ (960,354)	[2]	$ (834,558)	$ (815,980)

[1] The aggregate cost of properties for federal income tax purposes is approximately $3.6 billion at December 31, 2016.

[2] Depreciation is calculated using estimated useful lives of depreciable assets up to 50 years for prison facilities.