Borrowings (Minetta And Orpheum Theatres Loan) (Narrative) (Details) - USD ($) $ in Thousands		9 Months Ended		12 Months Ended
	Oct. 12, 2018	Sep. 30, 2021		Dec. 31, 2020
Debt Instrument [Line Items]
Loan amount		$ 269,953		$ 300,449
Minetta And Orpheum Theatres Loan [Member]
Debt Instrument [Line Items]
Loan amount	$ 7,500	$ 8,000	[1]	$ 8,000	[1]
Minetta And Orpheum Theatres Loan [Member] | Santander Bank [Member]
Debt Instrument [Line Items]
Loan amount	$ 8,000
Debt instrument term		5 years

[1] The interest rate derivative associated with the Minetta & Orpheum loan provides for an effective fixed rate of 5.15%.