Derivative Instruments and Other Financial Instruments Used For Hedging (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Cash Flow Hedges
Amount and location of net gains and losses
Amount of Gain or (Loss) Recognized in OCI on Derivative Instruments (Effective Portion)	$ 70	$ 3	$ 78	$ 9
Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	29	7	52	14
Cash Flow Hedges | Interest rate derivative contracts
Amount and location of net gains and losses
Amount of Gain or (Loss) Recognized in OCI on Derivative Instruments (Effective Portion)	70	3	78	9
Cash Flow Hedges | Interest rate derivative contracts | Interest income
Amount and location of net gains and losses
Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	27	8	49	15
Cash Flow Hedges | Interest rate derivative contracts | Interest expense
Amount and location of net gains and losses
Gain or (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	2	(1)	3	(1)
Cash Flow Hedges | Interest rate derivative contracts | Noninterest expense | Maximum
Amount and location of net gains and losses
Gain or (Loss) Recognized in Income on Derivative Instruments (Ineffective Portion and Amount Excluded from Effectiveness Testing)	(1)	(1)	(1)	(1)
Fair value hedges | Interest rate derivative contracts
Amount and location of net gains and losses
Derivative	3		3
Hedged Item	$ (3)		$ (3)