Borrowings and Contractual Commitments Borrowings and Contractual Commitments - Additional Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012
Debt Instrument [Line Items]
Loans Pledged as Collateral	$ 27,100,000,000		$ 23,800,000,000
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	9,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Two	817,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Three	1,137,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Four	4,700,000,000
Long-term Debt, Maturities, Repayments of Principal in Year Five	1,600,000,000
Long-term Debt, Maturities, Repayments of Principal after Year Five	2,400,000,000
Long-term Debt	10,700,000,000	[1]	9,357,000,000	[1]
Long-term Federal Home Loan Bank Advances	3,000,000,000
Federal Home Loan Bank, Advances, Short-term	4,000,000,000		1,500,000,000
Tier two risk based capital [Member]
Debt Instrument [Line Items]
Long-term Debt	1,100,000,000		1,500,000,000
Subsidiaries [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Senior Long-term Debt	600,000,000
Long-term Debt	6,589,000,000		6,108,000,000
Parent Company [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Senior Long-term Debt	750,000,000
Long-term Debt	4,111,000,000		3,249,000,000
Parent Company [Member] | Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Amount			627,000,000
Parent Company [Member] | Tier one risk based capital [Member] | Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Amount			627,000,000
Federal Reserve Bank Advances [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity	20,800,000,000		18,000,000,000
Federal Home Loan Bank Advances [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity	$ 12,300,000,000

[1] 3 Includes debt of consolidated VIEs of $597 million and $666 million at December 31, 2013 and 2012, respectively, of which $256 and $286 are carried at fair value at December 31, 2013 and 2012, respectively.