Real Estate (Schedule of Real Estate Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	May 31, 2019	Dec. 31, 2018
Real Estate Properties [Line Items]
Real estate, net	$ 1,527,219		$ 1,771,019
Real estate available and held for sale	8,650		22,551
Total real estate	1,535,869		1,793,570
Net investment in leases	418,915	$ 424,100	0
Real estate assets derecognized at inception of sales-type lease		$ 193,400
Net Lease
Real Estate Properties [Line Items]
Land, at cost	199,710		336,740
Buildings and improvements, at cost	1,347,321		1,487,270
Less: accumulated depreciation	(219,949)		(287,516)
Real estate, net	1,327,082		1,536,494
Real estate available and held for sale	0		1,055
Total real estate	1,327,082		1,537,549
Operating Properties
Real Estate Properties [Line Items]
Land, at cost	106,187		133,599
Buildings and improvements, at cost	107,861		118,724
Less: accumulated depreciation	(13,911)		(17,798)
Real estate, net	200,137		234,525
Real estate available and held for sale	8,650		21,496
Total real estate	208,787		256,021
Real Estate Properties
Real Estate Properties [Line Items]
Land, at cost	305,897		470,339
Buildings and improvements, at cost	1,455,182		1,605,994
Less: accumulated depreciation	(233,860)		(305,314)
Real estate, net	1,527,219		1,771,019
Real estate available and held for sale	8,650		22,551
Total real estate	1,535,869		1,793,570
Residential Operating Properties
Real Estate Properties [Line Items]
Real estate available and held for sale	$ 8,600		$ 20,600

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