Fair Value Measurements (Assets and Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs (Level 3)) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Due in one year or less	$ 46	$ 50
Due after one year through three years	38	38
Fair Value, Inputs, Level 2 | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency exchange forward contracts	62	0
Fair Value, Inputs, Level 2 | Foreign Exchange Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency exchange forward contracts	$ 29	$ 23