Description Of Business, Basis Of Presentation, And Changes In Significant Accounting Policies ResCap Bankruptcy Information (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	May 14, 2012
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash Contribution to ResCap	$ 750,000,000
RMBS Investors Holding More Than 25% in One Class of Securitizations			25.00%
Securitizations Agreed to Settle			290
Allowed Claim in Debtors' Bankruptcy Cases			8,700,000,000
Securitizations Agreed to RMBS Settlements			336
Aggregate Original Principal Balance of Outstanding Securitizations			189,000,000,000
Total Number of Outstanding Residential Mortgage-Backed Securitizations			392
Original Principal Balance of Outstanding Securitizations			221,000,000,000
ResCap settlement accrual	750,000,000	750,000,000
Total Charge Recorded Related to ResCap Bankruptcy	1,200,000,000
Impairment of Investment in ResCap	442,000,000
Finance Receivable Due from ResCap	$ 1,100,000,000