Segment Reporting Identifiable Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Segment Reporting, Asset Reconciling Item [Line Items]
Investment property, net	$ 7,288,401	$ 7,232,620
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	394,740	34,830	$ 34,175	$ 62,262
Marketable securities	55,602	94,727
Inventory of manufactured homes	64,436	62,061
Notes and other receivables, net	186,692	157,926
Other assets	219,176	219,896
Total Assets	8,209,047	7,802,060
Real Property Operations Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Investment property, net	6,689,866	6,651,275
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	348,470	(8,346)
Marketable securities	55,602	94,727
Inventory of manufactured homes	128	0
Notes and other receivables, net	170,569	142,509
Other assets	163,864	167,804
Total Assets	7,428,499	7,047,969
Home Sales and Home Rentals Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Investment property, net	598,535	581,345
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	46,270	43,176
Marketable securities	0	0
Inventory of manufactured homes	64,308	62,061
Notes and other receivables, net	16,123	15,417
Other assets	55,312	52,092
Total Assets	$ 780,548	$ 754,091