Variable Interest Entities - VIEs of Which we are the Primary Beneficiary (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Assets and liabilities [Abstract]
Cash and cash equivalents	$ 13,362,000,000	$ 15,101,000,000	$ 13,362,000,000	$ 15,101,000,000	$ 15,659,000,000	$ 17,148,000,000
Debt	107,857,000,000		107,857,000,000		105,058,000,000
Derivative Instruments related exposure [Abstract]
Fair Value of Assets	1,400,000,000		1,400,000,000
Variable Interest Entity, Primary Beneficiary [Member]
Assets and liabilities [Abstract]
Cash and cash equivalents	2,838,000,000		2,838,000,000		2,911,000,000
Debt	39,426,000,000		39,426,000,000		40,245,000,000
Financial Services [Member]
Assets and liabilities [Abstract]
Cash and cash equivalents	7,887,000,000	7,921,000,000	7,887,000,000	7,921,000,000	9,412,000,000	9,183,000,000
Debt	92,040,000,000		92,040,000,000		90,802,000,000
Derivative Instruments related exposure [Abstract]
Fair Value of Assets	818,000,000		818,000,000		1,300,000,000
Fair Value of Liabilities	386,000,000		386,000,000		381,000,000
Financial Performance [Abstract]
Interest expense	705,000,000	798,000,000	1,411,000,000	1,624,000,000
Financial Services [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Cash contribution for collateral to support Wholesale Securitization Program	7,000,000		7,000,000		0
Assets and liabilities [Abstract]
Cash and cash equivalents	2,800,000,000		2,800,000,000		2,900,000,000
Finance Receivables Net And Net Investment In Operating Leases	51,200,000,000		51,200,000,000		53,800,000,000
Debt	39,400,000,000		39,400,000,000		40,200,000,000
Footnote information [Abstract]
Variable Interest Entities Liabilities Excluded					145,000,000
Financial Services [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Finance Receivables [Member]
Assets and liabilities [Abstract]
Cash and cash equivalents	2,400,000,000		2,400,000,000		2,500,000,000
Finance Receivables Net And Net Investment In Operating Leases	44,900,000,000		44,900,000,000		47,500,000,000
Debt	35,100,000,000		35,100,000,000		36,000,000,000
Financial Services [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Retail [Member]
Assets and liabilities [Abstract]
Cash and cash equivalents	2,100,000,000		2,100,000,000		2,200,000,000
Finance Receivables Net And Net Investment In Operating Leases	24,100,000,000		24,100,000,000		27,000,000,000
Debt	21,300,000,000		21,300,000,000		23,200,000,000
Financial Services [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Wholesale [Member]
Assets and liabilities [Abstract]
Cash and cash equivalents	300,000,000		300,000,000		300,000,000
Finance Receivables Net And Net Investment In Operating Leases	20,800,000,000		20,800,000,000		20,500,000,000
Debt	13,800,000,000		13,800,000,000		12,800,000,000
Financial Services [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Net Investment in Operating Leases [Member]
Assets and liabilities [Abstract]
Cash and cash equivalents	400,000,000		400,000,000		400,000,000
Finance Receivables Net And Net Investment In Operating Leases	6,300,000,000		6,300,000,000		6,300,000,000
Debt	4,300,000,000		4,300,000,000		4,200,000,000
Minimum [Member] | Financial Services [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Cash contribution for collateral to support Wholesale Securitization Program	0		0
Maximum [Member] | Financial Services [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Cash contribution for collateral to support Wholesale Securitization Program	70,000,000		70,000,000
Securitization Transactions [Member] | Financial Services [Member]
Derivative Instruments related exposure [Abstract]
Fair Value of Assets	75,000,000		75,000,000		78,000,000
Fair Value of Liabilities	80,000,000		80,000,000		197,000,000
Financial Performance [Abstract]
Derivative expense/(income)	6,000,000	29,000,000	(83,000,000)	136,000,000
Securitization Transactions [Member] | Financial Services [Member] | Related to the VIEs [Member]
Derivative Instruments related exposure [Abstract]
Fair Value of Assets	39,000,000		39,000,000		74,000,000
Fair Value of Liabilities	40,000,000		40,000,000		63,000,000
Financial Performance [Abstract]
Derivative expense/(income)	7,000,000	(27,000,000)	10,000,000	(15,000,000)
Securitization Transactions [Member] | Financial Services [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Financial Performance [Abstract]
Interest expense	145,000,000	201,000,000	296,000,000	428,000,000
Securitization Transactions [Member] | Financial Services [Member] | Variable Interest Entity, Primary Beneficiary [Member] | VIEs [Member]
Derivative Instruments related exposure [Abstract]
Fair Value of Assets	36,000,000		36,000,000		4,000,000
Fair Value of Liabilities	40,000,000		40,000,000		134,000,000
Financial Performance [Abstract]
Derivative expense/(income)	$ (1,000,000)	$ 56,000,000	$ (93,000,000)	$ 151,000,000