Goodwill and Intangible Assets - Components (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Schedule of Intangible Assets by Major Class [Line Items]
Goodwill, gross	$ 14,652	$ 14,653
Goodwill	14,652	14,653
Intangible assets, gross (excluding Goodwill)	212	396
Accumulated amortization	(124)	(306)
Intangible assets, net (excluding Goodwill)	88	90
Intangible assets gross including Goodwill	14,864	15,049
Total goodwill and other intangible assets, net carrying value	14,740	14,743
Commercial MSRs, gross	609	542
Commercial MSR, accumulated amortization	(199)	(175)
Total commercial MSRs	410	367
PCCR intangibles
Schedule of Intangible Assets by Major Class [Line Items]
Intangible assets, gross (excluding Goodwill)	29	148
Accumulated amortization	(8)	(138)
Intangible assets, net (excluding Goodwill)	21	10
Other intangible assets
Schedule of Intangible Assets by Major Class [Line Items]
Intangible assets, gross (excluding Goodwill)	183	248
Accumulated amortization	(116)	(168)
Intangible assets, net (excluding Goodwill)	$ 67	$ 80