Derivative And Credit-Related Financial Instruments (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Fair value of securities pledged as collateral for derivative assets	$ 245,000,000
Cash received as collateral for derivative assets	264,000,000
Available-for-sale securities pledged as collateral	2,000,000
Aggregate fair value of all derivative instruments with credit-risk contingent features that were in a liability position	6,000,000
Collateral pledged for aggregate fair value of all derivative instruments with credit-risk contingent features that were in a liability position	2,000,000
Additional required overnight collateral on derivatives with credit-risk contingent features at period end should the credit-risk contingent features be triggered	4,000,000
Net interest income generated by risk management fair value interest rate swaps	72,000,000	72,000,000
Interest rate fair value hedge ineffectiveness	an insignificant amount	an insignificant amount
Net gain on open foreign currency positions	1,000,000	1,000,000
Allowance for credit losses on lending-related commitments	41,000,000	36,000,000
Allowance for credit losses on lending-related commitments, unused commitments to extend credit	30,000,000	28,000,000
Final year of expiration of all outstanding letters of credit		2022
Risk participation agreements covering standby and commercial letters of credit	316,000,000	259,000,000
Standby and commercial letters of credit	4,000,000,000	4,400,000,000
Carrying value of standby and commercial letters of credit included in accrued expenses and other liabilities	55,000,000	59,000,000
Deferred fees	44,000,000	51,000,000
Allowance for credit losses on lending-related commitments, standby and commercial letters of credit	11,000,000	8,000,000
Notional Amount of Derivative Credit Risk Participation Agreements	598,000,000	614,000,000
Maximum estimated exposure to credit risk participation agreements assuming 100% default	7,000,000	7,000,000
Weighted average remaining maturity of credit risk participation agreements, in years	2 years 11 months 0 days
Fair value of derivative liability	661,000,000	249,000,000
Visa derivative contract
Notional amount of the derivative contract equivalent to Visa Class B shares	780,000
Fair value of derivative liability	$ 1,000,000	$ 2,000,000