Fair Value Measurements and Derivatives - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Recurring [Member] - Fair Value, Inputs, Level 2 [Member] - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Marketable securities	$ 20	$ 21
Foreign Exchange Forward [Member] | Not Designated as Hedging Instrument [Member] | Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Currency contracts asset value	1	2
Foreign Exchange Forward [Member] | Not Designated as Hedging Instrument [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Currency contracts liability value	1	1
Foreign Exchange Forward [Member] | Cash Flow Hedging [Member] | Other Current Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Currency contracts asset value	8	6
Foreign Exchange Forward [Member] | Cash Flow Hedging [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Currency contracts liability value	6	5
Interest Rate Contract [Member] | Cash Flow Hedging [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Interest rate contracts	5
Currency Swap [Member] | Cash Flow Hedging [Member] | Other Noncurrent Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Currency contracts liability value	$ 42	$ 118