Properties And Equipment (Narrative) (Details) a in Millions		3 Months Ended		6 Months Ended
	Jun. 01, 2023 USD ($) a ft²	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	May 31, 2023 USD ($)
Property, Plant and Equipment [Line Items]
Depreciation expense for operating property		$ 4,700,000	$ 5,300,000	$ 9,300,000	$ 10,600,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | 2483 Trenton Avenue Williamsport Pennsylvania [Member]
Property, Plant and Equipment [Line Items]
Acre Of Land Announced To Be Sold | a	26.6
Book value	$ 460,000,000,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | 2483 Trenton Avenue Williamsport Pennsylvania [Member] | Land [Member]
Property, Plant and Equipment [Line Items]
Area of Land | ft²	18,000
Property book value adjustment				$ 0
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Culver City Los Angeles [Member]
Property, Plant and Equipment [Line Items]
Book value						$ 11,200,000
Sale price						$ 8,500,000