Goodwill and other intangible assets - Mortgage Fees and Related Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Risk management:
All other	$ 0	$ 1	$ 2	$ 2
Mortgage fees and related income	469	903	1,957	2,708
Consumer & Community Banking
CCB mortgage fees and related income
Net production revenue	176	253	646	865
Operating revenue:
Loan servicing revenue	648	787	2,104	2,524
Changes in MSR asset fair value due to collection/realization of expected cash flows	(232)	(214)	(674)	(696)
Total operating revenue	416	573	1,430	1,828
Risk management:
Changes in MSR asset fair value due to market interest rates and other	(677)	(101)	(338)	(831)
Other changes in MSR asset fair value due to inputs or assumptions in model	(88)	44	(212)	(196)
Change in derivative fair value and other	642	133	429	1,040
Total risk management	(123)	76	(121)	13
Total net mortgage servicing revenue	293	649	1,309	1,841
Mortgage fees and related income	$ 469	$ 902	$ 1,955	$ 2,706