Guarantees and Contingent Liabilities - Summary of Other Guarantees and Contingent Liabilities (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014
Standby letters of credit [Member]
Guarantor Obligations [Line Items]
Collateral Held
Carrying Amount	66
Maximum Potential Future Payments	15,913
Third-party borrowing arrangements [Member]
Guarantor Obligations [Line Items]
Collateral Held
Carrying Amount
Maximum Potential Future Payments	14
Securities lending indemnifications [Member]
Guarantor Obligations [Line Items]
Collateral Held	4,957
Carrying Amount
Maximum Potential Future Payments	4,824
Asset sales [Member]
Guarantor Obligations [Line Items]
Collateral Held
Carrying Amount	172
Maximum Potential Future Payments	3,931
Merchant processing [Member]
Guarantor Obligations [Line Items]
Collateral Held	796
Carrying Amount	80
Maximum Potential Future Payments	93,179
Contingent consideration arrangements [Member]
Guarantor Obligations [Line Items]
Collateral Held
Carrying Amount	2
Maximum Potential Future Payments	2
Tender option bond program guarantee [Member]
Guarantor Obligations [Line Items]
Collateral Held	4,470
Carrying Amount
Maximum Potential Future Payments	4,293
Minimum revenue guarantees [Member]
Guarantor Obligations [Line Items]
Collateral Held
Carrying Amount	8
Maximum Potential Future Payments	9
Other [Member]
Guarantor Obligations [Line Items]
Collateral Held
Carrying Amount
Maximum Potential Future Payments	$ 466