Fair Value Measurements - Assets and Liabilities at Fair Value, Recurring (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Derivatives	$ 23	$ 11
Derivatives	83	74
Recurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Marketable Securities	59	63
Derivatives	23	11
Total Assets at Fair Value	82	74
Derivatives	83	74
Total Liabilities at Fair Value	83	74
Recurring Basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Marketable Securities	59	63
Derivatives	14	1
Total Assets at Fair Value	73	64
Derivatives	32	26
Total Liabilities at Fair Value	32	26
Recurring Basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Marketable Securities	0	0
Derivatives	9	10
Total Assets at Fair Value	9	10
Derivatives	51	48
Total Liabilities at Fair Value	51	48
Recurring Basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Marketable Securities	0	0
Derivatives	0	0
Total Assets at Fair Value	0	0
Derivatives	0	0
Total Liabilities at Fair Value	$ 0	$ 0