Finance Receivables - Credit Risk Profile by Dealer grouping of Commercial Finance Receivables (Details) (Commercial Finance Receivables [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	$ 8,072	$ 6,700	$ 560
Group I [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	1,062	598
Group II [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	2,090	1,588
Group III [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	2,856	2,174
Group IV [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	1,250	1,622
Group V [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	559	488
Group VI [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Gross	$ 255	$ 230