Loans - by Portfolio Segment and Class (Details) (USD $)	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	$ 717,086,000,000	$ 718,997,000,000	$ 692,944,000,000
Loans Receivable Held-for-Sale Excluding Loans at Fair Value	2,111,000,000	2,626,000,000
Loans Receivable at Fair Value	2,750,000,000	2,097,000,000
Loans and Leases Receivable, Net of Deferred Income, Total	721,947,000,000	723,720,000,000
Loans And Leases Receivable Deferred Costs	2,700,000,000	2,700,000,000
Wholesale
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	297,576,000,000	278,395,000,000	255,799,000,000
Loans Receivable Held-for-Sale Excluding Loans at Fair Value	2,005,000,000	2,524,000,000
Loans Receivable at Fair Value	2,750,000,000	2,097,000,000
Loans and Leases Receivable, Net of Deferred Income, Total	302,331,000,000	283,016,000,000
Consumer Excluding Credit Card
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	295,079,000,000	308,427,000,000	310,104,000,000
Loans Receivable Held-for-Sale Excluding Loans at Fair Value	0	0
Loans Receivable at Fair Value	0	0
Loans and Leases Receivable, Net of Deferred Income, Total	295,079,000,000	308,427,000,000
Consumer Excluding Credit Card | Consumer Loan Excluding Credit Card [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	295,079,000,000	308,427,000,000
Consumer Excluding Credit Card | Residential Real Estate, Excluding Purchased Credit-Impaired [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	153,874,000,000	163,660,000,000
Consumer Excluding Credit Card | Home Equity Senior Lien [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	19,990,000,000	21,765,000,000
Consumer Excluding Credit Card | Home Equity Junior Lien [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	49,696,000,000	56,035,000,000
Consumer Excluding Credit Card | Prime Mortgages, Including Option ARMs [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	75,636,000,000	76,196,000,000
Consumer Excluding Credit Card | Subprime Mortgages [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	8,552,000,000	9,664,000,000
Consumer Excluding Credit Card | Other Consumer [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	80,009,000,000	79,221,000,000
Consumer Excluding Credit Card | Auto Loans [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	48,920,000,000	47,426,000,000
Consumer Excluding Credit Card | Business Banking Loans [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	18,568,000,000	17,652,000,000
Consumer Excluding Credit Card | Student And Other Loans [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	12,521,000,000	14,143,000,000
Consumer Excluding Credit Card | Purchased Credit-Impaired [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	61,196,000,000	65,546,000,000
Consumer Excluding Credit Card | PCI Home Equity [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	21,432,000,000	22,697,000,000
Consumer Excluding Credit Card | PCI Prime Mortgage [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	14,038,000,000	15,180,000,000
Consumer Excluding Credit Card | PCI Subprime Mortgage [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	4,702,000,000	4,976,000,000
Consumer Excluding Credit Card | PCI Option ARMs [Member]
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	21,024,000,000	22,693,000,000
Credit Card
Loans by Portfolio Segment and Class [Line Items]
Loans Receivable Held for Investment, Net of Deferred Income	124,431,000,000	132,175,000,000	127,041,000,000
Loans Receivable Held-for-Sale Excluding Loans at Fair Value	106,000,000	102,000,000
Loans Receivable at Fair Value	0	0
Loans and Leases Receivable, Net of Deferred Income, Total	$ 124,537,000,000	$ 132,277,000,000