Representations and Warranties Obligations and Corporate Guarantees (Details Textuals) (USD $)	3 Months Ended		6 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Jun. 30, 2011	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2010	Apr. 14, 2011
Covered Trust Origination Period [Line Items]
Number of Payments Made By Borrower	25			25
Original principal balance of covered trusts			$ 424,000,000,000
Unpaid principal balance of covered trusts			220,000,000,000
Provision for representations and warranties and corporate guarantees	278,000,000	872,000,000		15,328,000,000	2,646,000,000
New Purchase Claims				10,900,000,000
Private Label Securitization Trust Related Repurchase Claims	325,000,000			711,000,000
Representations and Warranties Obligations and Corporate Guarantees (Textuals) [Abstract]
Percentage of loans underlying outstanding repurchase demands	28.00%			28.00%		25.00%
Number of institutional investors involved in settlement agreement with BNY Mellon			22
Cash payment on settlement to the trustee for distribution to the covered trusts			8,500,000,000
Payment on attorneys fees, costs and expenses in connection with settlement agreement			100,000,000
Private Placements From Which Plaintiffs Purchased Mortgage Backed Securities Issued By Country Wide Financial Corporation Related Entities				6
Number of Groups With Opportunity to Dispute Legal Settlement				44
Amount paid to resolve repurchase claims for first-lien mortgages and home equity loans	2,200,000,000	920,000,000		4,400,000,000	2,800,000,000
Unpaid principle balance of repurchase claims for first-lien mortgages and home equity loans from the investor or securitization trust	2,600,000,000	1,100,000,000		5,200,000,000	3,200,000,000
Loss on repurchase or reimbursement of repurchase claims for first-lien mortgages and home equity loans from the investor or securitization trust	1,600,000,000	524,000,000		3,000,000,000	1,700,000,000
Payments for assured guaranty settlement				964,000,000
Timeframe to provide final response to repurchase request	90 to 120 days			90 to 120
Timetable to reach a settlement once a breach of representations and warranties is confirmed	60 to 90 days			60 to 90
The percentage of claims that the Corporation initially denied that have been subsequently resolved with monolines				30.00%
Percentage of claim resolved through repurchase	10.00%			10.00%
Unpaid principal balance of loans related to unresolved repurchase requests previously received from monolines that have been reviewed by the corporation	3,000,000,000			3,000,000,000
Unpaid principal balance of loans without repurchase requests				6,100,000,000
Original collateral exposure of first-lien and second-lien RMBS trusts							35,800,000,000
Principal at risk of first-lien and second-lien RMBS trusts							20,200,000,000
Cash payment to assured guaranty, net							1,100,000,000
Loss sharing reinsurance arrangement to assured guaranty settlement							470,000,000
Cash payment to assured guaranty, paid	57,000,000		57,000,000	57,000,000			850,000,000
Estimated cost of Assured Guaranty Settlement agreement for representation and warranties in liabilities			1,600,000,000
Consumer loans and related trust debt included in balance sheet as a result of Assured Guaranty Settlement agreement	4,700,000,000			4,700,000,000
Agreement reached to resolve repurchase claims for residential mortgage loans sold to GSEs related to legacy countrywide entities						2,800,000,000
Percentage of the voting rights of outstanding securities required to investigate loans files and demand repurchase of loans				25.00%
Percentage of loans resolved through repurchase or make-whole payments				16.00%
Percentage of loans resolved through rescission or payment in full by borrower				48.00%
New claim demands received from private-label securitization investors		1,700,000,000		1,700,000,000		1,700,000,000
Adjustment to reduce the range of possible loss for the presentation threshold for all private label securitizations				5,000,000,000
Percentage of claim resolved through rescission	1.00%			1.00%
Number of first and second lien RMBS trusts							29
Number of first lien RMBS trusts	525			525			21
Number of second lien RMBS trusts	5			5			8
2004 and 2008 [Member]
Covered Trust Origination Period [Line Items]
Original principal balance of covered trusts			409,000,000,000
Unpaid principal balance of covered trusts			217,000,000,000
Bank of New York Mellon [Member]
Covered Trust Origination Period [Line Items]
Provision for representations and warranties and corporate guarantees				8,600,000,000
Government sponsored enterprise obligations [Member]
Covered Trust Origination Period [Line Items]
Provision for representations and warranties and corporate guarantees				$ 6,700,000,000