Commitments and Guarantees (Other Commitments) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Other Commitments [Line Items]
Commitments	$ 156,755	$ 155,141
Commitments to extend credit [Member]
Other Commitments [Line Items]
Commitments	143,958	142,489
Commitments to extend credit [Member] | Total commercial lending [Member]
Other Commitments [Line Items]
Commitments	101,434	101,252
Commitments to extend credit [Member] | Home Equity Lines of Credit [Member]
Other Commitments [Line Items]
Commitments	17,311	17,268
Commitments to extend credit [Member] | Credit Card [Member]
Other Commitments [Line Items]
Commitments	20,814	19,937
Commitments to extend credit [Member] | Other [Member]
Other Commitments [Line Items]
Commitments	4,399	4,032
Standby letters of credit [Member]
Other Commitments [Line Items]
Commitments	8,969	8,765
Standby letters of credit [Member] | Remarketing Programs [Member]
Other Commitments [Line Items]
Commitments	4,600	4,700
Reinsurance Agreements [Member]
Other Commitments [Line Items]
Commitments	1,968	2,010
Reinsurance Agreements [Member] | Accidental Death and Dismemberment [Member]
Other Commitments [Line Items]
Maximum Exposure	1,600	1,600
Reinsurance Agreements [Member] | Credit Life Accident and Health [Member]
Other Commitments [Line Items]
Maximum Exposure	400	400
Standby bond purchase agreements [Member]
Other Commitments [Line Items]
Commitments	891	911
Other commitments [Member]
Other Commitments [Line Items]
Commitments	969	966
Other commitments [Member] | Investments in qualified affordable housing projects [Member]
Other Commitments [Line Items]
Commitments	$ 500	$ 500