Goodwill and Intangible Assets - Components (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Intangible Assets by Major Class [Line Items]
Goodwill, Gross	$ 14,519	$ 14,480
Goodwill	14,519	14,480	$ 13,978
Intangible Assets, Gross (Excluding Goodwill)	3,856	4,305
Accumulated Amortization	(3,191)	(3,264)
Intangible Assets, Net (Excluding Goodwill)	665	1,041
Intangible Assets Gross Including Goodwill	18,375	18,785
Total goodwill and other intangible assets, Net Carrying Value	15,184	15,521
Commercial MSRs, Gross	276	212
Commercial MSR, Accumulated Amortization	(82)	(51)
Consumer MSRs	80	68
Total MSRs, Gross	356	280
Servicing Asset at Amortized Cost	194	161
Total MSRs, Net	274	229
Servicing Asset at Amortized Cost, Amortization	$ 31	$ 27
Finite-Lived Intangible Assets, Remaining Amortization Period	5 years 5 months 6 days	5 years 10 months 24 days
PCCR intangibles
Schedule of Intangible Assets by Major Class [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 2,151	$ 2,156
Accumulated Amortization	(1,715)	(1,467)
Intangible Assets, Net (Excluding Goodwill)	$ 436	$ 689
Finite-Lived Intangible Assets, Remaining Amortization Period	4 years 5 months 6 days	5 years 1 month 6 days
Core deposit intangibles
Schedule of Intangible Assets by Major Class [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 1,391	$ 1,771
Accumulated Amortization	(1,345)	(1,662)
Intangible Assets, Net (Excluding Goodwill)	$ 46	$ 109
Finite-Lived Intangible Assets, Remaining Amortization Period	2 years 6 days	2 years 10 months 24 days
Other Intangible Assets [Member]
Schedule of Intangible Assets by Major Class [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$ 314	$ 378
Accumulated Amortization	(131)	(135)
Intangible Assets, Net (Excluding Goodwill)	$ 183	$ 243
Finite-Lived Intangible Assets, Remaining Amortization Period	8 years 8 months 6 days	9 years 7 months 6 days