Summary of Significant Accounting Policies (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) class	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Class of Stock [Line Items]
Operating lease income	$ 67,667	$ 72,340	$ 72,071
Number of classes of common stock | class	1
Income taxes paid	$ 100	100	100
Percentage Rent
Class of Stock [Line Items]
Operating lease income	$ 300	$ 3,800	$ 4,300
Facilities
Class of Stock [Line Items]
Facilities useful life	40 years