Segment Reporting Identifiable Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Investment property, net	$ 5,517,139	$ 5,469,481
Cash and cash equivalents	241,646	8,164	$ 31,441	$ 45,086
Inventory of manufactured homes	25,582	21,632
Notes and other receivables, net	110,499	81,179
Collateralized receivables, net	138,696	143,870
Other assets	145,151	146,450
TOTAL ASSETS	6,178,713	5,870,776
Real Property Operations Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Investment property, net	5,057,937	5,019,165
Cash and cash equivalents	235,860	3,705
Inventory of manufactured homes	0	0
Notes and other receivables, net	97,362	68,901
Collateralized receivables, net	138,696	143,870
Other assets	141,213	143,650
TOTAL ASSETS	5,671,068	5,379,291
Home Sales and Home Rentals Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Investment property, net	459,202	450,316
Cash and cash equivalents	5,786	4,459
Inventory of manufactured homes	25,582	21,632
Notes and other receivables, net	13,137	12,278
Collateralized receivables, net	0	0
Other assets	3,938	2,800
TOTAL ASSETS	$ 507,645	$ 491,485