Long-Term Debt (Financial Debt Covenants) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2017 USD ($)
Debt Instrument [Line Items]
Annual Operating Lease Commitment, Requirement	$ 50.0
Minimum [Member]
Debt Instrument [Line Items]
Leverage Ratio (Consolidated Indebtedness/Consolidated Adj. EBITDA), Requirement	1.00
Fixed Charge Coverage Ratio (Consolidated Free Cash Flow/Consolidated Fixed Charges), Requirement	1.00
Maximum [Member]
Debt Instrument [Line Items]
Leverage Ratio (Consolidated Indebtedness/Consolidated Adj. EBITDA), Requirement	3.50
Fixed Charge Coverage Ratio (Consolidated Free Cash Flow/Consolidated Fixed Charges), Requirement	1.50