Loans - Residential RealEstate - PCI Loans, FICO and LTV (Details 8b) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011
Purchased Credit Impaired [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	$ 71,855	$ 74,492
Purchased Credit Impaired [Member] | Current Estimated LTV Greater Than 125% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	10,781	11,210
Purchased Credit Impaired [Member] | Current Estimated LTV Greater Than 125% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	11,484	12,165
Purchased Credit Impaired [Member] | Current Estimated Ltv Between 101% And 125% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	12,668	13,114
Purchased Credit Impaired [Member] | Current Estimated Ltv Between 101% And 125% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	9,617	10,012
Purchased Credit Impaired [Member] | Current Estimated LTV Between 80% To 100% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	9,015	9,223
Purchased Credit Impaired [Member] | Current Estimated LTV Between 80% To 100% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	6,695	6,953
Purchased Credit Impaired [Member] | Current Estimated LTV Less Than 80% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	5,962	6,072
Purchased Credit Impaired [Member] | Current Estimated LTV Less Than 80% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	5,633	5,743
PCI Home Equity [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	24,330	25,064	25,064
PCI Home Equity [Member] | Current Estimated LTV Greater Than 125% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	5,683	5,915
PCI Home Equity [Member] | Current Estimated LTV Greater Than 125% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	3,235	3,299
PCI Home Equity [Member] | Current Estimated Ltv Between 101% And 125% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	5,178	5,393
PCI Home Equity [Member] | Current Estimated Ltv Between 101% And 125% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	2,223	2,304
PCI Home Equity [Member] | Current Estimated LTV Between 80% To 100% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	3,392	3,482
PCI Home Equity [Member] | Current Estimated LTV Between 80% To 100% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	1,265	1,264
PCI Home Equity [Member] | Current Estimated LTV Less Than 80% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	2,358	2,409
PCI Home Equity [Member] | Current Estimated LTV Less Than 80% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	996	998
PCI Prime Mortgage [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	15,462	16,060	16,060
PCI Prime Mortgage [Member] | Current Estimated LTV Greater Than 125% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	2,236	2,313
PCI Prime Mortgage [Member] | Current Estimated LTV Greater Than 125% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	2,206	2,319
PCI Prime Mortgage [Member] | Current Estimated Ltv Between 101% And 125% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	3,211	3,328
PCI Prime Mortgage [Member] | Current Estimated Ltv Between 101% And 125% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	2,248	2,314
PCI Prime Mortgage [Member] | Current Estimated LTV Between 80% To 100% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	1,601	1,629
PCI Prime Mortgage [Member] | Current Estimated LTV Between 80% To 100% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	1,340	1,457
PCI Prime Mortgage [Member] | Current Estimated LTV Less Than 80% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	1,237	1,276
PCI Prime Mortgage [Member] | Current Estimated LTV Less Than 80% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	1,383	1,424
PCI Subprime Mortgage [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	6,965	7,229	7,229
PCI Subprime Mortgage [Member] | Current Estimated LTV Greater Than 125% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	468	473
PCI Subprime Mortgage [Member] | Current Estimated LTV Greater Than 125% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	1,870	1,939
PCI Subprime Mortgage [Member] | Current Estimated Ltv Between 101% And 125% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	443	434
PCI Subprime Mortgage [Member] | Current Estimated Ltv Between 101% And 125% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	1,419	1,510
PCI Subprime Mortgage [Member] | Current Estimated LTV Between 80% To 100% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	357	372
PCI Subprime Mortgage [Member] | Current Estimated LTV Between 80% To 100% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	1,129	1,197
PCI Subprime Mortgage [Member] | Current Estimated LTV Less Than 80% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	202	198
PCI Subprime Mortgage [Member] | Current Estimated LTV Less Than 80% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	1,077	1,106
PCI Option ARMs [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	25,098	26,139
PCI Option ARMs [Member] | Current Estimated LTV Greater Than 125% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	2,394	2,509
PCI Option ARMs [Member] | Current Estimated LTV Greater Than 125% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	4,173	4,608
PCI Option ARMs [Member] | Current Estimated Ltv Between 101% And 125% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	3,836	3,959
PCI Option ARMs [Member] | Current Estimated Ltv Between 101% And 125% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	3,727	3,884
PCI Option ARMs [Member] | Current Estimated LTV Between 80% To 100% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	3,665	3,740
PCI Option ARMs [Member] | Current Estimated LTV Between 80% To 100% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	2,961	3,035
PCI Option ARMs [Member] | Current Estimated LTV Less Than 80% [Member] | Refreshed FICO Scores Equal to or greater than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	2,165	2,189
PCI Option ARMs [Member] | Current Estimated LTV Less Than 80% [Member] | Refreshed FICO Scores Less than 660 [Member]
Residential RealEstate - PCI Loans, by Class, by FICO and LTV [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance	$ 2,177	$ 2,215