Revenues and NOI for Reportable Segment (Detail) - Parent Company [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Information
Total operating revenues	$ 384,550	$ 276,898	$ 1,146,249	$ 818,150
Net Operating Income	235,371	170,252	709,828	507,668
Depreciation and amortization	(117,928)	(76,959)	(374,285)	(227,829)
Acquisition expense	0	(1,033)	0	(2,167)
Property management expense	(10,281)	(7,908)	(32,007)	(25,221)
General and administrative expense	(8,361)	(6,661)	(30,735)	(20,257)
Merger related expenses	(128)	(3,901)	(3,977)	(3,901)
Business Combination, Integration Related Costs	(4,002)	0	(10,521)	0
Interest and other non-property (expense) income	4,303	64	7,632	159
Interest expense	(39,940)	(32,168)	(115,005)	(96,418)
Loss on debt extinguishment	828	0	3,168	3
Gain on sale of depreciable real estate assets excluded from discontinued operations	58,844	47,749	59,045	48,572
Net casualty loss after insurance and other settlement proceeds	564	(75)	233	738
Income tax expense	(641)	(454)	(1,910)	(1,200)
Gain on sale of non-depreciable real estate assets	(6)	0	42	2,170
Gain (loss) from real estate joint ventures	335	0	1,021	27
Net income attributable to noncontrolling interests	(4,249)	(4,627)	(7,600)	(9,508)
Preferred Stock Dividends, Income Statement Impact	(922)	0	(2,766)	0
Net Income (Loss) Available to Common Stockholders, Basic	113,787	84,279	202,163	172,836
Large Market Same Store
Segment Information
Total property revenues	169,105	165,046	503,076	487,725
Net Operating Income	104,574	101,595	313,419	302,230
Secondary Market Same Store
Segment Information
Total property revenues	87,895	85,822	261,272	254,685
Net Operating Income	53,836	53,124	162,617	159,263
Non-Same Store and Other
Segment Information
Total property revenues	127,550	26,030	381,901	75,740
Net Operating Income	$ 76,961	$ 15,533	$ 233,792	$ 46,175