Financial Instruments - Recurring Fair Value Measurements (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Assets
Investment securities	$ 101	$ 283
Total assets	109	58
Liabilities
Total liabilities	(63)	(27)
Fair value, measurements, recurring
Assets
Derivatives	109	58
Investment securities	101	283
Total assets	210	341
Liabilities
Derivatives	(63)	(27)
Total liabilities	(63)	(27)
Fair value, measurements, recurring | Level 1
Assets
Derivatives	0	0
Investment securities	2	24
Total assets	2	24
Liabilities
Derivatives	0	0
Total liabilities	0	0
Fair value, measurements, recurring | Level 2
Assets
Derivatives	109	58
Investment securities	1	0
Total assets	110	58
Liabilities
Derivatives	(63)	(27)
Total liabilities	(63)	(27)
Fair value, measurements, recurring | Level 3
Assets
Derivatives	0	0
Investment securities	98	259
Total assets	98	259
Liabilities
Derivatives	0	0
Total liabilities	$ 0	$ 0