Variable Interest Entities - Third-party Sponsored VIEs (Details 2c) (Federal Reserve Bank of New York [Member], USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2010
Federal Reserve Bank of New York [Member]
Variable Interest Entity [Line Items]
Quantitative Information, Variable Interest Entity, Principal Amount Outstanding		$ 30,000,000,000
Variable Interest Term Loan Contract Amount		28,850,000,000
Variable Interest Subordinated Loan Contract Amount		1,150,000,000
Gain on Expected Recovery of Subordinated Loan, Pre-tax	$ 665,000,000