Derivatives and Hedging Activities (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Derivatives and Hedging Activities (Textual)
Derivative assets after effects of bilateral collateral and master netting agreements	$ 213,000,000
Derivative liabilities after effects of bilateral collateral and master netting agreements	94,000,000
Derivative assets not designated as hedging instruments after effects of bilateral collateral and master netting agreements, and a reserve for potential future losses	732,000,000
Derivative liabilities not designated as hedging instruments after effects of bilateral collateral and master netting agreements, and a reserve for potential future losses	932,000,000
Reclassification of net losses on derivative instruments from AOCI	11,000,000
Length of time hedged in cash flow hedge	Next twelve months
Reclassification of net gains related to terminated cash flow hedges from AOCI to income	11,000,000
Maximum length of time over which forecasted transactions are hedged, years	16 years
Cash collateral netted against derivative assets	486,000,000	331,000,000
Cash collateral netted against derivative liabilities	11,000,000	2,000,000
Gross exposure on derivatives, after taking into account the effects of bilateral collateral and master netting agreements	994,000,000,000
Net exposure on derivatives, after taking into account, the effects of bilateral collateral and master netting agreements	238,000,000
Additional collateral held in the form of securities	206,000,000
Net exposure on derivatives to broker-dealers and banks, after the application of master netting agreements and collateral	32,000,000
Default reserve associated with the uncollateralized contracts	22,000,000	48,000,000
Gross exposure on derivatives, after taking into account the effects of master netting agreements	791,000,000
Net exposure on derivatives with clients, after the application of master netting agreements, collateral and the related reserve	707,000,000
Net liability position total	889,000,000
Derivative assets included in net liability position	613,000,000
Derivative liabilities included in net liability position	1,500,000,000
Cash and securities collateral posted	879,000,000
Payments to terminate contracts	$ 18,000,000