Finance Assets, net (Schedule of PMCC Leveraged Lease Charge) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended					12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2011	Dec. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net Revenues	$ 0	$ 0	$ 7	$ 0		$ 7	$ 490
Benefit for Income Taxes						(75)	137
Total		(68)			627	(68)	627
Reduction To Cumulative Lease Earnings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net Revenues						7	490
Benefit for Income Taxes						(2)	(175)
Total					315	5	315
Interest On Tax Underpayments [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Benefit for Income Taxes					312	(73)	312
Total						$ (73)	$ 312