Leases (Components of Lease Income) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Operating Lease Income [Line Items]
Sales-type and Direct Financing Leases, Lease Income		$ 6,304	$ 6,034	$ 12,662	$ 11,896
Operating Lease, Lease Income	[1]	2,160	1,926	4,221	3,832
Lease Income		8,464	7,960	16,883	15,728
Operating Lease Income from Related Party [Member]
Operating Lease Income [Line Items]
Operating Lease, Lease Income		$ 19	$ 18	$ 38	$ 37

[1] (a) Includes rent of $19 thousand and $18 thousand, respectively, from Tower Properties Company, a related party, for the three month periods ended June 30, 2020 and 2019, and $38 thousand and $37 thousand, respectively, for the six months ended June 30, 2020 and 2019.