Financial Instruments And Fair Value Measurements (Narrative) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Franchise rights impairment	$ 0	$ 0
Goodwill [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Date of Annual Goodwill and Indefinite Lived Intangible Assets Impairment Test	April 30	April 30
Franchise Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Date of Annual Goodwill and Indefinite Lived Intangible Assets Impairment Test	April 30	April 30