Segment Reporting (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Reconciliation of NOI to net income
Net income	$ 254,543	$ 165,194	$ 396,133	$ 400,975
Indirect operating expenses, net of corporate income	18,913	16,423	36,996	32,720
Investments and investment management expense	1,529	1,455	3,172	2,776
Expensed acquisition, development and other pursuit costs, net of recoveries	889	570	1,689	1,298
Interest expense, net	56,585	50,102	111,698	99,397
Loss on extinguishment of debt, net	642	24,162	1,039	24,162
General and administrative expense	14,444	13,947	28,108	27,153
Equity in income of unconsolidated real estate entities	(789)	(1,146)	(2,529)	(17,819)
Depreciation expense	156,685	141,439	315,743	282,060
Income tax expense	58	58	58	78
Casualty and impairment (gain) loss, net	0	0	(58)	11,688
Gain on sale of communities	(105,201)	(44,067)	(105,201)	(132,016)
Gain on other real estate transactions, net	(370)	0	(323)	(366)
Net operating income from real estate assets sold or held for sale	(4,442)	(9,727)	(9,900)	(21,493)
Net operating income	$ 393,486	$ 358,410	$ 776,625	$ 710,613