Fair Value Measurements - Recurring Basis (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	$ 281	$ 141
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	149	142
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	32	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	133	125
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	32	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	16	17
Fair value on a recurring basis \| Commercial paper
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	195	85
Fair value on a recurring basis \| Certificates of deposit/time deposits
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	27	10
Fair value on a recurring basis \| U.S. municipal securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	59	46
Fair value on a recurring basis \| Investments
Assets and Liabilities Measured on Recurring Basis
Investments	21	25
Fair value on a recurring basis \| Level 1 \| Investments
Assets and Liabilities Measured on Recurring Basis
Investments	21	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	133	125
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	32	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	16	17
Fair value on a recurring basis \| Level 2 \| Commercial paper
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	195	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	27	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	22
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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