Long-Term Debt (Committed Funding Facilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Committed Funding Facilities [Member]
Debt Instrument [Line Items]
Outstanding	$ 17,909	$ 27,526
Unused capacity	6,747	15,535
Total capacity	24,656	43,061
Committed funding reliant upon origination of future automotive receivables [Member]
Debt Instrument [Line Items]
Unused capacity		2,200
Bank Funding Member | Committed Funding Facilities [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Outstanding	2,750	3,800
Unused capacity	250	4,700
Total capacity	3,000	8,500
Nonbank Funding Member | Committed Funding Facilities [Member]
Debt Instrument [Line Items]
Outstanding	15,159	22,572
Unused capacity	6,497	7,864
Total capacity	21,656	30,436
Nonbank Funding Member | Committed Funding Facilities [Member] | Secured Debt [Member]
Debt Instrument [Line Items]
Outstanding	15,159	22,454
Unused capacity	6,497	7,839
Total capacity	21,656	30,293
Nonbank Funding Member | Committed Funding Facilities [Member] | Secured Debt [Member] | International Businesses [Member]
Debt Instrument [Line Items]
Outstanding		9,600
Total capacity		12,000
Nonbank Funding Member | Committed Funding Facilities [Member] | Unsecured Debt [Member]
Debt Instrument [Line Items]
Outstanding	0	118
Unused capacity	0	25
Total capacity	0	143
Shared Capacity Member | Committed Funding Facilities [Member]
Debt Instrument [Line Items]
Outstanding	0	1,154
Unused capacity	0	2,971
Total capacity	0	4,125
Shared Capacity Member | Committed Funding Facilities [Member] | International Businesses [Member]
Debt Instrument [Line Items]
Outstanding		100
Total capacity		100
Revolving secured funding facilities [Member] | Committed Funding Facilities [Member]
Debt Instrument [Line Items]
Total capacity	22,400
Revolving secured funding facilities 1 year or greater [Member] | Committed Funding Facilities [Member]
Debt Instrument [Line Items]
Total capacity	$ 11,500