CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue:
Rental and other income	$ 2,154,481	$ 2,039,656	$ 1,846,081
Management, development and other fees	4,147	5,599	9,947
Total revenue	2,158,628	2,045,255	1,856,028
Expenses:
Operating expenses, excluding property taxes	503,946	478,437	448,747
Property taxes	221,375	204,837	193,499
Interest expense, net	199,661	187,510	175,615
Loss (gain) on extinguishment of debt, net	25,472	7,075	(26,736)
Depreciation expense	584,150	531,434	477,923
General and administrative expense	50,673	45,771	42,774
Expensed acquisition, development and other pursuit costs, net of recoveries	2,736	9,922	6,822
Casualty and impairment loss (gain), net	6,250	(3,935)	(10,542)
Total expenses	1,594,263	1,461,051	1,308,102
Income before equity in income of unconsolidated real estate entities, gain on sale of communities, (loss) gain on other real estate transactions, and income taxes	564,365	584,204	547,926
Equity in income of unconsolidated real estate entities	70,744	64,962	70,018
Gain on sale of communities	252,599	374,623	115,625
(Loss) gain on other real estate transactions	(10,907)	10,224	9,647
Income before income taxes	876,801	1,034,013	743,216
Income tax expense	141	305	1,483
Net income	876,660	1,033,708	741,733
Net loss attributable to noncontrolling interests	261	294	305
Net income attributable to common stockholders	876,921	1,034,002	742,038
Other comprehensive income (loss):
(Loss) income on cash flow hedges	(13,979)	(5,556)	5,354
Cash flow hedge losses reclassified to earnings	7,070	6,433	5,774
Comprehensive income	$ 870,012	$ 1,034,879	$ 753,166
Earnings per common share—basic:
Net income per common share - basic (in dollars per share)	$ 6.36	$ 7.53	$ 5.54
Earnings per common share—diluted:
Net income per common share - diluted (in dollars per share)	$ 6.35	$ 7.52	$ 5.51