Reportable Segments - Consolidated Net Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Depreciation and amortization	$ (37,776)	$ (34,345)	$ (75,753)	$ (66,719)
Gain on sale of real estate, net	0	0	52,507	0
Reconciliation to Consolidated net income:
Income from other investments, net	10,265	12,536	20,635	25,572
General and administrative	(9,225)	(9,669)	(19,134)	(17,707)
Other expenses	(540)	(367)	(967)	(710)
Interest and related amortization	(26,024)	(26,285)	(52,417)	(51,988)
Equity in income of unconsolidated joint ventures	3,226	1,613	4,759	2,808
Early debt retirement	(1,491)	0	(1,491)	0
Consolidated net income	49,085	49,169	169,620	113,346
Total assets	4,014,478	3,700,189	4,014,478	3,700,189	$ 3,925,808
Capital improvements	69,003	50,061	121,444	81,377
Property Operations
Reconciliation to Consolidated net income:
Total assets	3,766,573	3,477,455	3,766,573	3,477,455
Capital improvements	28,501	26,602	52,906	47,870
Home Sales and Rentals Operations
Reconciliation to Consolidated net income:
Total assets	247,905	222,734	247,905	222,734
Capital improvements	40,502	23,459	68,538	33,507
Operating Segments
Segment Reporting Information [Line Items]
Operations revenues	245,684	235,227	502,037	478,362
Operations expenses	(127,451)	(122,280)	(245,340)	(238,865)
Income from segment operations	118,233	112,947	256,697	239,497
Interest income	1,796	1,856	3,540	3,571
Depreciation and amortization	(37,776)	(34,345)	(75,753)	(66,719)
Gain on sale of real estate, net			52,507
Income (loss) from operations	82,253	80,458	236,991	176,349
Operating Segments | Property Operations
Segment Reporting Information [Line Items]
Operations revenues	233,848	222,167	479,864	453,183
Operations expenses	(116,893)	(110,046)	(225,863)	(215,558)
Income from segment operations	116,955	112,121	254,001	237,625
Interest income	950	823	1,844	1,631
Depreciation and amortization	(35,197)	(31,954)	(70,740)	(56,029)
Gain on sale of real estate, net			52,507
Income (loss) from operations	82,708	80,990	237,612	183,227
Operating Segments | Home Sales and Rentals Operations
Segment Reporting Information [Line Items]
Operations revenues	11,836	13,060	22,173	25,179
Operations expenses	(10,558)	(12,234)	(19,477)	(23,307)
Income from segment operations	1,278	826	2,696	1,872
Interest income	846	1,033	1,696	1,940
Depreciation and amortization	(2,579)	(2,391)	(5,013)	(10,690)
Gain on sale of real estate, net			0
Income (loss) from operations	(455)	(532)	(621)	(6,878)
Segment Reconciling Items
Reconciliation to Consolidated net income:
Corporate interest income	7	6	14	241
Income from other investments, net	879	3,413	1,865	4,353
General and administrative	(9,225)	(9,669)	(19,134)	(17,707)
Other expenses	(540)	(367)	(967)	(710)
Interest and related amortization	(26,024)	(26,285)	(52,417)	(51,988)
Equity in income of unconsolidated joint ventures	3,226	$ 1,613	4,759	$ 2,808
Early debt retirement	$ (1,491)		$ (1,491)