SCHEDULE III - REAL ESTATE AND ACCUMULATED DEPRECIATION (Narrative) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
SEC Schedule III, Reconciliation of Carrying Amount of Real Estate Investments [Roll Forward]
Balance at beginning of period	$ 7,655,960	$ 7,566,358	$ 6,743,958
Acquisitions through foreclosure			25,000
Acquisitions	294,202	419,333	1,017,761
Impairment	(35,014)	(98,672)	(53,717)
Improvements	187,408	116,786	95,807
Disposals/other	(356,146)	(347,845)	(262,451)
Balance at close of period	7,746,410	7,655,960	7,566,358
Reconciliation of real estate accumulated depreciation
Balance at beginning of period	1,376,828	1,240,336	1,019,150
Provisions for depreciation	280,871	287,189	266,904
Dispositions/other	(95,080)	(150,697)	(45,718)
Balance at close of period	$ 1,562,619	$ 1,376,828	$ 1,240,336