Reportable Segments - Income from Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenues:
Other income	$ 9,680	$ 10,265	$ 20,739	$ 20,635
Total revenues	254,090	248,366	534,566	507,456
Expenses:
Real estate taxes	16,668	15,107	33,509	30,430
Sales and marketing, gross	4,276	4,214	8,254	7,623
Membership sales commissions, deferred, net	(481)	(389)	(697)	(580)
Total expenses	206,301	202,507	416,260	395,102
Income before equity in income of unconsolidated joint ventures	47,789	45,859	118,306	164,861
Property Operations
Revenues:
Rental income	213,885	208,375	449,249	428,357
Other income	9,680	10,265	20,739	20,635
Total revenues	238,155	233,848	500,629	479,864
Expenses:
Property operating and maintenance	84,020	83,576	166,311	160,320
Real estate taxes	16,668	15,107	33,509	30,430
Sales and marketing, gross	4,276	4,214	8,254	7,623
Membership sales commissions, deferred, net	(481)	(389)	(697)	(580)
Total expenses	119,296	116,893	237,194	225,863
Income before equity in income of unconsolidated joint ventures	118,859	116,955	263,435	254,001
Home Sales and Rentals Operations
Revenues:
Rental home income	4,078	3,632	8,060	7,216
Total revenues	13,122	11,836	28,674	22,173
Expenses:
Property operating and maintenance	1,245	1,292	2,588	2,496
Home selling expenses	1,081	1,102	2,294	2,185
Total expenses	11,176	10,558	25,643	19,477
Income before equity in income of unconsolidated joint ventures	1,946	1,278	3,031	2,696
Annual membership subscriptions
Revenues:
Contract revenue	12,961	12,586	26,034	24,902
Annual membership subscriptions | Property Operations
Revenues:
Contract revenue	12,961	12,586	26,034	24,902
Membership upgrade sales current period, gross
Revenues:
Contract revenue	5,048	5,041	9,891	8,879
Membership upgrade sales current period, gross | Property Operations
Revenues:
Contract revenue	5,048	5,041	9,891	8,879
Membership upgrade sales upfront payments, deferred, net
Revenues:
Contract revenue	(2,666)	(2,912)	(5,208)	(4,683)
Membership upgrade sales upfront payments, deferred, net | Property Operations
Revenues:
Contract revenue	(2,666)	(2,912)	(5,208)	(4,683)
Gross revenues from home sales
Revenues:
Contract revenue	8,866	7,825	20,175	14,300
Expenses:
Cost of home sales	8,850	8,164	20,761	14,796
Gross revenues from home sales | Home Sales and Rentals Operations
Revenues:
Contract revenue	8,866	7,825	20,175	14,300
Expenses:
Cost of home sales	8,850	8,164	20,761	14,796
Brokered resale revenues, net | Home Sales and Rentals Operations
Revenues:
Contract revenue	178	379	439	657
Ancillary services | Property Operations
Revenues:
Contract revenue	(753)	493	(76)	1,774
Ancillary services | Home Sales and Rentals Operations
Revenues:
Contract revenue	0	0	0	0
Property management
Expenses:
Cost of home sales	14,813	14,385	29,817	28,070
Property management | Property Operations
Expenses:
Cost of home sales	$ 14,813	$ 14,385	$ 29,817	$ 28,070