Leases (Components of Lease Income) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Operating Lease Income [Line Items]
Sales-type and Direct Financing Leases, Lease Income		$ 6,358	$ 5,862
Operating Lease, Lease Income	[1]	2,061	1,906
Lease Income		8,419	7,768
Operating Lease Income from Related Party [Member]
Operating Lease Income [Line Items]
Operating Lease, Lease Income		$ 19	$ 19

[1] (a) Includes rent of $19 thousand from Tower Properties Company, a related party, for the three months ended March 31, 2020 and 2019.