Reportable Segments- Consolidated Net Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Depreciation on real estate assets and rental homes	$ (31,322)	$ (30,109)
Amortization of in-place leases	(1,052)	(1,032)
Reconciliation to Consolidated net income:
Income from other investments, net	940	757
General and administrative	(8,038)	(7,373)
Other expenses	(343)	(219)
Interest and related amortization	(25,703)	(24,879)
Equity in income of unconsolidated joint ventures	1,195	1,150
Consolidated net income	64,177	63,075
Total assets	3,690,083	3,471,041	$ 3,610,032
Capital improvements	31,316	24,354
Property Operations
Reconciliation to Consolidated net income:
Total assets	3,547,466	3,247,523
Capital improvements	21,267	13,198
Home Sales and Rentals Operations
Reconciliation to Consolidated net income:
Total assets	142,617	223,518
Capital improvements	10,049	11,156
Operating Segments
Segment Reporting Information [Line Items]
Operations revenues	243,135	229,862
Operations expenses	(116,585)	(106,852)
Income from segment operations	126,550	123,010
Interest income	1,715	1,767
Depreciation on real estate assets and rental homes	(31,322)	(30,109)
Amortization of in-place leases	(1,052)	(1,032)
Income (loss) from operations	95,891	93,636
Operating Segments | Property Operations
Segment Reporting Information [Line Items]
Operations revenues	231,016	218,988
Operations expenses	(105,512)	(97,257)
Income from segment operations	125,504	121,731
Interest income	808	729
Depreciation on real estate assets and rental homes	(28,822)	(27,410)
Amortization of in-place leases	(1,052)	(1,032)
Income (loss) from operations	96,438	94,018
Operating Segments | Home Sales and Rentals Operations
Segment Reporting Information [Line Items]
Operations revenues	12,119	10,874
Operations expenses	(11,073)	(9,595)
Income from segment operations	1,046	1,279
Interest income	907	1,038
Depreciation on real estate assets and rental homes	(2,500)	(2,699)
Amortization of in-place leases	0	0
Income (loss) from operations	(547)	(382)
Segment Reconciling Items
Reconciliation to Consolidated net income:
Corporate interest income	235	3
Income from other investments, net	940	757
General and administrative	(8,038)	(7,373)
Other expenses	(343)	(219)
Interest and related amortization	(25,703)	(24,879)
Equity in income of unconsolidated joint ventures	1,195	1,150
Consolidated net income	$ 64,177	$ 63,075