Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Weighted average remaining lease term	29 years 4 months 24 days			29 years 4 months 24 days
Weighted average discount rate	5.70%			5.70%
Rent expense	$ 0.2		$ 0.4	$ 0.9	$ 1.3
Percentage of contractual base rents and monthly tenant reimbursements collected	97.00%	97.00%
Lease rent deferred	$ 3.5			3.5
Lease rent waived				$ 2.4
Weighted average payback period for remaining deferred rent receivable				10 months