Goodwill and Intangible Assets - Components (Detail) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Schedule of Intangible Assets by Major Class [Line Items]
Goodwill, Gross	$ 14,495	$ 14,480
Goodwill	14,495	14,480
Intangible Assets, Gross (Excluding Goodwill)	3,917	4,305
Accumulated Amortization	(3,069)	(3,264)
Intangible Assets, Net (Excluding Goodwill)	848	1,041
Intangible Assets Gross Including Goodwill	18,412	18,785
Total goodwill and other intangible assets, Net Carrying Value	15,343	15,521
Commercial MSRs, Gross	235	212
Commercial MSR, Accumulated Amortization	(65)	(51)
Consumer MSRs	53	68
Total MSRs, Gross	288	280
Servicing Asset at Amortized Cost	170	161
Total MSRs, Net	223	229
PCCR intangibles
Schedule of Intangible Assets by Major Class [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	2,148	2,156
Accumulated Amortization	(1,596)	(1,467)
Intangible Assets, Net (Excluding Goodwill)	552	689
Core deposit intangibles
Schedule of Intangible Assets by Major Class [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	1,391	1,771
Accumulated Amortization	(1,317)	(1,662)
Intangible Assets, Net (Excluding Goodwill)	74	109
Other Intangible Assets [Member]
Schedule of Intangible Assets by Major Class [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	378	378
Accumulated Amortization	(156)	(135)
Intangible Assets, Net (Excluding Goodwill)	$ 222	$ 243