Fair Value Measurements Fair Value, Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, Assets	$ 86	$ 76
Derivatives, Liabilities	(11)	(69)
Fair Value, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	2,007	2,230
Commercial Paper, at Carrying Value	297	149
Available for sale debt instruments	187	333
Available for Sale Securities, Government Agencies	32	114
Investments, Fair Value Disclosure	12	54
Derivatives, Assets	86	76
Total assets	2,621	2,956
Derivatives, Liabilities	(11)	(69)
Total liabilities	(11)	(69)
Fair Value, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	2,007	2,230
Investments, Fair Value Disclosure	12	54
Total assets	2,019	2,284
Fair Value, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commercial Paper, at Carrying Value	297	149
Available for sale debt instruments	187	333
Available for Sale Securities, Government Agencies	32	114
Derivatives, Assets	86	76
Total assets	602	672
Derivatives, Liabilities	(11)	(69)
Total liabilities	$ (11)	$ (69)