Real Estate (Impairments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Lessor, Lease, Description [Line Items]
Real estate impairments, net of recoveries	$ 37,442	$ 31,992	$ 28,211
Minimum
Lessor, Lease, Description [Line Items]
Initial lease terms	10 years
Initial lease terms	10 years
Maximum
Lessor, Lease, Description [Line Items]
Initial lease terms	20 years
Initial lease terms	20 years