Representations and Warranties Obligations and Corporate Guarantees (Details) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Outstanding Claims by Counterparty and Product
Total outstanding claims by counterparty	$ 11,580	$ 10,687
Total outstanding claims by product type	11,580	10,687
Home Equity [Member]
Outstanding Claims by Counterparty and Product
Total outstanding claims by product type	2,853	3,658
GSE's [Member]
Outstanding Claims by Counterparty and Product
Total outstanding claims by counterparty	5,081	2,821
Monoline [Member]
Outstanding Claims by Counterparty and Product
Total outstanding claims by counterparty	3,533	4,799
Whole loan sale, private-label securitizations and other [Member]
Outstanding Claims by Counterparty and Product
Total outstanding claims by counterparty	2,966	3,067
Prime loans [Member]
Outstanding Claims by Counterparty and Product
Total outstanding claims by product type	3,421	2,040
Alt-A [Member]
Outstanding Claims by Counterparty and Product
Total outstanding claims by product type	1,938	1,190
Pay option [Member]
Outstanding Claims by Counterparty and Product
Total outstanding claims by product type	2,478	2,889
Subprime [Member]
Outstanding Claims by Counterparty and Product
Total outstanding claims by product type	663	734
Other Product Type [Member]
Outstanding Claims by Counterparty and Product
Total outstanding claims by product type	$ 227	$ 176