Accumulated Other Comprehensive Income (Loss) (Schedule of Accumulated Other Comprehensive Income (Loss)) (Details) (USD $) In Millions				6 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010	Jun. 30, 2011 Accumulated Net Unrealized Gains on Investment Securities Available-For-Sale [Member]	Jun. 30, 2010 Accumulated Net Unrealized Gains on Investment Securities Available-For-Sale [Member]	Jun. 30, 2011 Accumulated Net Gains on Cash Flow Hedges [Member]	Jun. 30, 2010 Accumulated Net Gains on Cash Flow Hedges [Member]	Jun. 30, 2011 Accumulated Defined Benefit Pension and Other Postretirement Plans Adjustment [Member]	Jun. 30, 2010 Accumulated Defined Benefit Pension and Other Postretirement Plans Adjustment [Member]
Balance at beginning of period, net of tax				$ 14	$ 11
Net unrealized holding gains arising during the period				106	149
Less: Reclassification adjustment for net gains included in net income				6	3
Change in net unrealized gains before income taxes				100	146
Less: Provision for income taxes				37	54
Change in net unrealized gains on investment securities available-for-sale, net of tax				63	92
Balance at end of period, net of tax				77	103
Balance at beginning of period, net of tax						2	18
Net cash flow hedge gains (losses) arising during the period						(2)	7
Less: Reclassification adjustment for net gains included in net income						1	17
Change in net cash flow hedge gains (losses) before income taxes						(3)	(10)
Less: Provision (benefit) for income taxes						(1)	(4)
Change in net cash flow hedge gains, net of tax						(2)	(6)
Balance at end of period, net of tax							12
Balance at beginning of period, net of tax								(405)	(365)
Net defined benefit pension and other postretirement adjustment arising during the period								7
Less: Adjustment for amounts recognized as components of net periodic benefit cost during the period								(24)	(16)
Change in defined benefit pension and other postretirement plans adjustment before income taxes								31	16
Less: Provision for income taxes								11	6
Change in defined benefit pension and other postretirement plans adjustment, net of tax								20	10
Balance at end of period, net of tax								(385)	(355)
Total accumulated other comprehensive loss at end of period, net of tax	$ (308)	$ (389)	$ (240)