Fair Value Measurements - Recurring Basis (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	$ 532	$ 434
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	84	44
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	63	106
Fair value on a recurring basis | Foreign currency exchange contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	79	37
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	63	106
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	5	7
Fair value on a recurring basis | Corporate debt securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	7	7
Fair value on a recurring basis | Commercial paper
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	384	237
Fair value on a recurring basis | Certificates of deposit/time deposits
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	7	31
Fair value on a recurring basis | U.S. treasury securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	100	125
Fair value on a recurring basis | U.S. municipal securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	34	34
Fair value on a recurring basis | Level 1 | U.S. treasury securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	100	125
Fair value on a recurring basis | Level 2 | Foreign currency exchange contracts
Assets and Liabilities Measured on Recurring Basis
Gross Amounts of Derivative Assets Presented in the Consolidated Balance Sheet	79	37
Gross Amounts of Derivative Liabilities Presented in the Consolidated Balance Sheet	63	106
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	5	7
Fair value on a recurring basis | Level 2 | Corporate debt securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	7	7
Fair value on a recurring basis | Level 2 | Commercial paper
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	384	237
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	7	31
Fair value on a recurring basis | Level 3 | U.S. municipal securities
Assets and Liabilities Measured on Recurring Basis
Available-for-sale marketable securities	$ 34	$ 34