Investments in Real Estate Entities (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Combined summary of the operating results of the accounted for using the equity method
Revenues	$ 2,301,261	$ 2,324,626	$ 2,284,535
Operating and other expenses	(1,826,659)	(1,696,904)	(1,700,067)
Gain on sale of communities	340,444	166,105	374,976
Interest expense, net	(214,151)	(203,585)	(220,974)
Depreciation expense	(707,331)	(661,578)	(631,196)
Net income	827,706	786,103	974,175
Company's share of net income	8,538	10,779	17,519
Amortization of excess investment and other	(2,116)	(2,127)	(2,249)
Equity in income from unconsolidated real estate investments	6,422	8,652	15,270
Equity Method Investment, Nonconsolidated Investee or Group of Investees
Combined summary of the operating results of the accounted for using the equity method
Revenues	118,474	144,431	92,533
Operating and other expenses	(49,509)	(55,732)	(35,840)
Gain on sale of communities	18,450	21,748	54,202
Interest expense, net	(31,982)	(33,896)	(22,500)
Depreciation expense	(34,606)	(58,387)	(26,706)
Net income	$ 20,827	$ 18,164	$ 61,689