Goodwill (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Goodwill		$ 1,242	$ 1,607	$ 1,607
Accumulated impairment loss		1,035	670
Goodwill impairment charge	$ 365	$ 365	0	$ 0
RBWM [Member]
Goodwill [Line Items]
Goodwill			$ 737

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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