Intangible Assets (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Amortized intangible assets:
Gross carrying value	$ 20,489	$ 20,357
Accumulated amortization	(16,957)	(16,242)
Net carrying value	3,532	4,115
Unamortized intangible assets:
Mortgage servicing rights	12,789	12,959
Goodwill	26,573	26,693	$ 26,963	$ 25,529
Trademark	14	14
MSRs [Member]
Amortized intangible assets:
Gross carrying value	3,721	3,595
Accumulated amortization	(2,322)	(2,189)
Net carrying value	1,399	1,406
Core deposit intangibles [Member]
Amortized intangible assets:
Gross carrying value	12,834	12,834
Accumulated amortization	(11,641)	(11,214)
Net carrying value	1,193	1,620
Customer relationship and other intangibles [Member]
Amortized intangible assets:
Gross carrying value	3,934	3,928
Accumulated amortization	(2,994)	(2,839)
Net carrying value	$ 940	$ 1,089