Debt - Short Term and Long Term Debt (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Short Term and Long Term Debt [Line Items]
Secured debt	$ 34,338	$ 30,689
Unsecured debt	30,162	23,657
Revolving Credit Facility [Member]
Short Term and Long Term Debt [Line Items]
Secured debt	7,914	7,548
Unsecured debt	3,333	2,759
Securitization Notes Payable [Member] \| Retail Finance Receivables [Member]
Short Term and Long Term Debt [Line Items]
Secured debt	26,424	23,141
Senior Notes [Member]
Short Term and Long Term Debt [Line Items]
Unsecured debt	24,402	18,973
Retail Customer Deposits [Member]
Short Term and Long Term Debt [Line Items]
Unsecured debt	1,795	1,260
Other Unsecured Debt [Member]
Short Term and Long Term Debt [Line Items]
Unsecured debt	$ 632	$ 665

Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.16)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.16)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 20, 22
-Article 5

Name:	us-gaap_SecuredDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant