Reportable Segments- Consolidated Net Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Operations revenues	$ 216,764	$ 205,475
Operations expenses	(101,152)	(96,478)
Income from segment operations	115,612	108,997
Interest income	1,636	1,798
Depreciation on real estate assets and rental homes	(28,656)	(28,116)
Amortization of in-place leases	(335)	(665)
Income (loss) from operations	88,257	82,014
Reconciliation to Consolidated net income:
Corporate interest income	24	22
Income from other investments, net	1,723	1,119
General and administrative	(7,407)	(7,406)
Property rights initiatives and other	(654)	(553)
Early Debt Retirement	0	(16,991)
Interest and related amortization	(25,634)	(27,276)
Equity in income of unconsolidated joint ventures	881	884
Consolidated net income	57,190	31,813
Total assets	3,415,125	3,447,785	$ 3,400,400
Capital improvements	22,495	16,260
Operating Segments | Property Operations
Segment Reporting Information [Line Items]
Operations revenues	204,726	194,689
Operations expenses	(90,512)	(87,280)
Income from segment operations	114,214	107,409
Interest income	718	709
Depreciation on real estate assets and rental homes	(25,965)	(25,356)
Amortization of in-place leases	(335)	(665)
Income (loss) from operations	88,632	82,097
Reconciliation to Consolidated net income:
Total assets	3,176,748	3,186,088
Capital improvements	9,783	8,887
Operating Segments | Home Sales and Rentals Operations
Segment Reporting Information [Line Items]
Operations revenues	12,038	10,786
Operations expenses	(10,640)	(9,198)
Income from segment operations	1,398	1,588
Interest income	918	1,089
Depreciation on real estate assets and rental homes	(2,691)	(2,760)
Amortization of in-place leases	0	0
Income (loss) from operations	(375)	(83)
Reconciliation to Consolidated net income:
Total assets	238,377	261,697
Capital improvements	$ 12,712	$ 7,373