Significant Accounting Policies Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012
Accounting Policies [Abstract]
Performing Second Lien Loans Classified As Nonaccrual Due to Regulatory Guidance Issued	$ (81)
Incremental Charge-offs Recognized Due to Change in Policy	$ 65	$ (65)