Finance Assets, net (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance assets, net	$ 1,295		$ 1,295		$ 1,614
Investments in finance leases	1,337		1,337		1,656
Allowance for credit losses	42		42	$ 42	42	$ 52
Decrease to unguaranteed residual values	0	$ (35)		0
(Decrease) increase to allowance			0	(10)
Finance Leases Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Investments in finance leases	1,337		$ 1,337		$ 1,656
Decrease in Unguaranteed Residual Value Resulting in Reduction to Net Revenues [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reduction in net revenue	$ 0	$ 29		$ 0