Reportable Segments - Income from Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Community base rental income	$ 128,579	$ 121,964	$ 255,318	$ 242,656
Rental home income	3,561	3,632	7,076	7,237
Total revenues	240,502	221,312	486,527	453,701
Expenses:
Property operating and maintenance	80,091	72,901	154,999	140,955
Real estate taxes	13,440	13,943	27,575	27,980
Sales and marketing, gross	3,305	2,894	6,117	5,584
Right-to-use contract commissions, deferred, net	(262)	(112)	(286)	(196)
Home selling expenses	973	929	2,048	1,854
Rental home operating and maintenance	1,629	1,657	3,053	3,208
Total expenses	192,946	177,889	375,989	348,354
Income before equity in income of unconsolidated joint ventures	47,556	43,423	110,538	105,347
Property Operations
Revenues:
Community base rental income	128,579	121,964	255,318	242,656
Rental home income	55,231	50,055	119,485	111,123
Utility and other income	24,320	20,650	49,841	42,776
Total revenues	222,167	206,594	453,183	425,582
Expenses:
Property operating and maintenance	80,091	72,901	154,999	140,955
Real estate taxes	13,440	13,943	27,575	27,980
Sales and marketing, gross	3,305	2,894	6,117	5,584
Right-to-use contract commissions, deferred, net	(262)	(112)	(286)	(196)
Total expenses	110,046	102,649	215,558	199,906
Income before equity in income of unconsolidated joint ventures	112,121	103,945	237,625	225,676
Home Sales and Rentals Operations
Revenues:
Rental home income	3,561	3,632	7,076	7,237
Total revenues	13,060	11,811	25,179	22,685
Expenses:
Home selling expenses	973	929	2,048	1,854
Rental home operating and maintenance	1,629	1,657	3,053	3,208
Total expenses	12,234	10,481	23,307	20,076
Income before equity in income of unconsolidated joint ventures	826	1,330	1,872	2,609
Gross revenues from home sales
Revenues:
Contract revenue	9,105	7,833	17,414	14,860
Expenses:
Cost of home sales	9,632	7,895	18,206	15,014
Gross revenues from home sales | Home Sales and Rentals Operations
Revenues:
Contract revenue	9,105	7,833	17,414	14,860
Expenses:
Cost of home sales	9,632	7,895	18,206	15,014
Brokered resale revenues, net | Home Sales and Rentals Operations
Revenues:
Contract revenue	369	346	651	588
Right-to-use annual payments
Revenues:
Contract revenue	11,891	11,350	23,410	22,602
Right-to-use annual payments | Property Operations
Revenues:
Contract revenue	11,891	11,350	23,410	22,602
Right-to-use contracts current period, gross
Revenues:
Contract revenue	3,944	3,798	7,106	7,004
Right-to-use contracts current period, gross | Property Operations
Revenues:
Contract revenue	3,944	3,798	7,106	7,004
Right-to-use contract upfront payments, deferred, net
Revenues:
Contract revenue	(2,021)	(1,321)	(3,306)	(2,096)
Right-to-use contract upfront payments, deferred, net | Property Operations
Revenues:
Contract revenue	(2,021)	(1,321)	(3,306)	(2,096)
Ancillary services | Property Operations
Revenues:
Contract revenue	223	98	1,329	1,517
Ancillary services | Home Sales and Rentals Operations
Revenues:
Contract revenue	25	0	38	0
Property management
Expenses:
Cost of home sales	13,472	13,023	27,153	25,583
Property management | Property Operations
Expenses:
Cost of home sales	$ 13,472	$ 13,023	$ 27,153	$ 25,583