Goodwill and other intangible assets - Mortgage Fees and Related Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Risk management:
All other	$ 1	$ 1	$ 2	$ 1
Mortgage fees and related income	783	1,291	1,488	1,805
Consumer & Community Banking
CCB mortgage fees and related income
Net production revenue	233	323	470	612
Operating revenue:
Loan servicing revenue	707	867	1,456	1,737
Changes in MSR asset fair value due to collection/realization of expected cash flows	(228)	(237)	(442)	(482)
Total operating revenue	479	630	1,014	1,255
Risk management:
Changes in MSR asset fair value due to market interest rates and other	815	(368)	339	(730)
Other changes in MSR asset fair value due to inputs or assumptions in model	(22)	220	(124)	(240)
Change in derivative fair value and other	(723)	485	(213)	907
Total risk management	70	337	2	(63)
Total CCB net mortgage servicing revenue	$ 549	$ 967	$ 1,016	$ 1,192