Guarantee Arrangements and Pledged Assets (Details 2) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	$ 298,277
Investment Grade [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	251,379
Non-Investment Grade [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	46,898
Standby Letters of Credit [Member]
Summary of the credit ratings of credit risk related guarantees
Average Life in years	1 year 3 months 18 days
Credit Ratings of the Obligors or the Transactions	7,876
Standby Letters of Credit [Member] | Investment Grade [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	7,063
Standby Letters of Credit [Member] | Non-Investment Grade [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	813
Sell-protection Credit Derivatives [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	290,401
Sell-protection Credit Derivatives [Member] | Investment Grade [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	244,316
Sell-protection Credit Derivatives [Member] | Non-Investment Grade [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	46,085
Sell-protection Credit Derivatives [Member] | Single name CDS [Member]
Summary of the credit ratings of credit risk related guarantees
Average Life in years	2 years 6 months
Credit Ratings of the Obligors or the Transactions	188,999
Sell-protection Credit Derivatives [Member] | Single name CDS [Member] | Investment Grade [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	150,501
Sell-protection Credit Derivatives [Member] | Single name CDS [Member] | Non-Investment Grade [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	38,498
Sell-protection Credit Derivatives [Member] | Structured CDS [Member]
Summary of the credit ratings of credit risk related guarantees
Average Life in years	1 year 7 months 6 days
Credit Ratings of the Obligors or the Transactions	58,024
Sell-protection Credit Derivatives [Member] | Structured CDS [Member] | Investment Grade [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	53,932
Sell-protection Credit Derivatives [Member] | Structured CDS [Member] | Non-Investment Grade [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	4,092
Sell-protection Credit Derivatives [Member] | Index credit derivatives [Member]
Summary of the credit ratings of credit risk related guarantees
Average Life in years	3 years 3 months 18 days
Credit Ratings of the Obligors or the Transactions	29,301
Sell-protection Credit Derivatives [Member] | Index credit derivatives [Member] | Investment Grade [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	28,618
Sell-protection Credit Derivatives [Member] | Index credit derivatives [Member] | Non-Investment Grade [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	683
Sell-protection Credit Derivatives [Member] | Total return swaps [Member]
Summary of the credit ratings of credit risk related guarantees
Average Life in years	7 years 7 months 6 days
Credit Ratings of the Obligors or the Transactions	14,077
Sell-protection Credit Derivatives [Member] | Total return swaps [Member] | Investment Grade [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	11,265
Sell-protection Credit Derivatives [Member] | Total return swaps [Member] | Non-Investment Grade [Member]
Summary of the credit ratings of credit risk related guarantees
Credit Ratings of the Obligors or the Transactions	$ 2,812