Fair Value Measurements - Recurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	$ 258	$ 141
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	205	142
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	22	20
Fair value on a recurring basis \| Foreign currency forward/option contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	187	125
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	22	20
Fair value on a recurring basis \| Interest rate contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	18	17
Fair value on a recurring basis \| Commercial paper
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	194	85
Fair value on a recurring basis \| Certificates of deposit/time deposits
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	6	10
Fair value on a recurring basis \| U.S. municipal securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	58	46
Fair value on a recurring basis \| Investments
Assets and Liabilities Measured on Recurring Basis
Investments	18	25
Fair value on a recurring basis \| Level 1 \| Investments
Assets and Liabilities Measured on Recurring Basis
Investments	18	25
Fair value on a recurring basis \| Level 2 \| Foreign currency forward/option contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	187	125
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	22	20
Fair value on a recurring basis \| Level 2 \| Interest rate contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	18	17
Fair value on a recurring basis \| Level 2 \| Commercial paper
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	194	85
Fair value on a recurring basis \| Level 2 \| Certificates of deposit/time deposits
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	6	10
Fair value on a recurring basis \| Level 2 \| U.S. municipal securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	21
Fair value on a recurring basis \| Level 3 \| U.S. municipal securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	$ 37	$ 46

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