Financial Instruments - Recurring Fair Value Measurements (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Assets
Investment securities	$ 552	$ 1,532
Total assets	40	118
Liabilities
Total liabilities	(35)	(52)
Fair value, measurements, recurring
Assets
Derivatives	40	118
Investment securities	552	1,532
Total assets	592	1,650
Liabilities
Derivatives	(35)	(52)
Total liabilities	(35)	(52)
Fair value, measurements, recurring \| Level 1
Assets
Derivatives	0	0
Investment securities	544	1,502
Total assets	544	1,502
Liabilities
Derivatives	0	0
Total liabilities	0	0
Fair value, measurements, recurring \| Level 2
Assets
Derivatives	40	118
Investment securities	0	0
Total assets	40	118
Liabilities
Derivatives	(35)	(52)
Total liabilities	(35)	(52)
Fair value, measurements, recurring \| Level 3
Assets
Derivatives	0	0
Investment securities	8	30
Total assets	8	30
Liabilities
Derivatives	0	0
Total liabilities	$ 0	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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Fair value of financial and nonfinancial obligations.

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