Financial Instruments And Fair Value Measurements (Nonfinancial Assets Measured on a Nonrecurring Basis) (Details) - USD ($)	3 Months Ended		12 Months Ended
	Jun. 30, 2021	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain/(Loss) on goodwill impairment			$ 0	$ (318,300,000)	$ 0
Equity investment			56,700,000	50,000,000
Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain/(Loss) on goodwill impairment		$ (318,300,000)	0	(318,300,000)
Gain/(loss) on franchise rights and other			0	(59,900,000)
Gain/(Loss) on equity investment	$ 3,400,000			0
Gain/(loss) on right-of-use assets			(100,000)	(3,100,000)
Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill			0	457,500,000
Franchise rights and other			0	26,200,000
Equity investment			53,400,000	0
Right of Use Asset			0	5,000,000.0
Continuing Operations [Member] | Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain/(Loss) on assets long-lived assets held and used			(3,100,000)	(9,200,000)
Continuing Operations [Member] | Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-lived assets held and used			$ 10,400,000	$ 1,800,000