Summary Of Significant Accounting Policies (Schedule Of Estimated Useful Lives Of Assets) (Details)	12 Months Ended
	Dec. 31, 2020
Building And Improvements [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	15 years
Building And Improvements [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	60 years
Theater Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	7 years
Furniture And Fixtures [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	3 years
Furniture And Fixtures [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life	10 years