Commitments and Guarantees (Narrative) (Details) (USD $)		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012 Financial Standby Letter of Credit [Member] yr	Jun. 30, 2012 Total Repurchase and Indemnification Claims [Member]	Jun. 30, 2012 Recourse Obligations [Member]	Dec. 31, 2011 Recourse Obligations [Member]
Loss Contingencies [Line Items]
Unfunded commitments - private equity investments	$ 215,000,000
Unfunded commitments - other investments	3,000,000
Standby letters of credit and risk participations in standby letters of credit and bankers' acceptances - Terms outstanding - Minimum		1
Standby letters of credit and risk participations in standby letters of credit and bankers' acceptances - Terms outstanding - Maximum		7
Maximum Exposure		14,800,000,000		3,900,000,000	4,000,000,000
Standby letters of credit and risk participations in standby letters of credit and bankers' acceptances - remarketing programs		7,300,000,000
Standby letters of credit and risk participations in standby letters of credit and bankers' acceptances - Assets securing certain specifically identified standby letters of credit		1,700,000,000
Standby letters of credit and risk participations in standby letters of credit and bankers' acceptances - recourse provisions from third parties		3,500,000,000
Standby letters of credit and risk participations in standby letters of credit and bankers' acceptances - Liability carrying amount		250,000,000
Standby bond purchase agreements to support municipal bond obligations	635,000,000
Other liquidity facilities commitments	145,000,000
Commercial mortgage recourse obligations - Unpaid principal balance of loans sold				12,900,000,000	13,000,000,000
Repurchase Potential Excess Loss Range Maxmium			$ 350,000,000