Derivatives and Financial Instruments (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Estimated percentage of derivative contract volume expiring within twelve months	98.00%	98.00%
Payment terms of receivables	30 days or less
Cash Flow Hedging | Interest rate derivatives
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative, notional amount	$ 650,000,000
Cash Flow Hedging | Interest rate derivatives | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative, fair value	$ 1,000,000	$ 15,000,000
Facilities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Lessee leasing arrangements, operating leases (up to)	5 years
Selling, General and Administrative Expenses [Member] | Cash Flow Hedging | Interest rate derivatives | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative instruments, gain reclassified from AOCI into income in next twelve months	$ 1,000,000