Fair Value Measurements Fair Value Measurement Recurring Basis (Details) - USD ($)		Dec. 31, 2019	Dec. 31, 2018
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Derivative Asset		$ 25,000,000	$ 72,000,000
Derivative Liability		43,000,000	21,000,000
Fair Value, Inputs, Level 2 [Member]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Long-term Debt, Fair Value		114,000,000	5,775,000,000
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Cash equivalents and restricted cash equivalents	[1]	1,293,000,000	1,221,000,000
Marketable securities		5,000,000	5,000,000
Total assets at fair value		1,323,000,000	1,298,000,000
Long-term Debt, Fair Value	[2]	119,000,000	6,100,000,000
Liabilities at fair value		162,000,000	6,121,000,000
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Foreign Exchange Contract [Member]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items]
Derivative Asset	[3]	25,000,000	72,000,000
Derivative Liability	[3]	$ 43,000,000	$ 21,000,000

[1] Time deposits included in cash and cash equivalents and money market funds included in other current assets in the Consolidated Balance Sheets are held at amortized cost, which approximates fair value.

[2] See Note 17 - Short-Term Borrowings, Long-Term Debt and Available Credit Facilities, for information on fair value measurements of long-term debt.

[3] See Note 22 - Financial Instruments, for the classification of derivatives in the Consolidated Balance Sheets.