Fair Value (Fair Value of Financial Instruments) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held-for-sale, net	$ 82	$ 2,576
Total finance receivables and loans, net	94,083	97,885
Nonmarketable equity securities	184	303
Deposit liabilities	52,031	47,915
Short-term borrowings	6,015	7,461
Long-term debt	60,701	74,561
Deferred interest for zero coupon bonds	349	321
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held-for-sale, net	82	2,576
Total finance receivables and loans, net	94,083	97,885
Nonmarketable equity securities	184	303
Deposit liabilities	52,031	47,915
Short-term borrowings	6,015	7,461
Long-term debt	61,050	74,882
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held-for-sale, net	82	2,576
Total finance receivables and loans, net	95,037	98,907
Nonmarketable equity securities	189	306
Deposit liabilities	52,750	48,752
Short-term borrowings	6,015	7,460
Long-term debt	63,914	78,551
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held-for-sale, net	0	0
Total finance receivables and loans, net	0	0
Nonmarketable equity securities	0	0
Deposit liabilities	0	0
Short-term borrowings	0	6
Long-term debt	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held-for-sale, net	63	2,490
Total finance receivables and loans, net	0	0
Nonmarketable equity securities	155	272
Deposit liabilities	0	0
Short-term borrowings	0	0
Long-term debt	31,055	36,018
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held-for-sale, net	19	86
Total finance receivables and loans, net	95,037	98,907
Nonmarketable equity securities	34	34
Deposit liabilities	52,750	48,752
Short-term borrowings	6,015	7,454
Long-term debt	$ 32,859	$ 42,533