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Goodwill and Other Long-lived Assets - Goodwill (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Line Items]
Goodwill	$ 458		$ 1,242	$ 458	$ 1,242	$ 1,242
Accumulated impairment loss	1,819			1,819		$ 1,035
Goodwill impairment charge	$ 0	$ 784	$ 365	$ 784	$ 365
RBWM [Member]
Goodwill [Line Items]
Goodwill							$ 737