Discontinued Operations (Summary Of Income (Loss) Of Discontinued Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Loss) income from discontinued operations before income taxes	$ (91)	$ (9,434)
MOD Pizza [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues		6,148
Depreciation, amortization and accretion, net		691
Impairment losses	71	6,749
Selling, general and administrative expenses	20	6,139
Total costs and expenses	91	15,591
Other revenue		9
(Loss) income from discontinued operations before income taxes	$ (91)	(9,434)
MOD Pizza [Member] | Trade Sales [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues		6,044
Costs and expenses		2,012
MOD Pizza [Member] | Other Revenue [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues		$ 104