Fair Value (Fair Value of Financial Instruments) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held-for-sale, net	$ 43	$ 35
Total finance receivables and loans, net	98,432	99,120
Nonmarketable equity securities	236	337
Deposit liabilities	55,367	53,350
Short-term borrowings	5,163	8,545
Long-term debt	68,295	69,465
Deferred interest for zero coupon bonds	370	359
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held-for-sale, net	43	35
Total finance receivables and loans, net	98,432	99,120
Nonmarketable equity securities	236	337
Deposit liabilities	55,367	53,350
Short-term borrowings	5,163	8,545
Long-term debt	68,665	69,824
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held-for-sale, net	43	35
Total finance receivables and loans, net	99,440	100,090
Nonmarketable equity securities	249	346
Deposit liabilities	56,085	54,070
Short-term borrowings	5,163	8,545
Long-term debt	72,243	73,364
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	0
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	43	17
Total finance receivables and loans, net	0	0
Nonmarketable equity securities	205	308
Deposit liabilities	0	0
Short-term borrowings	0	0
Long-term debt	27,852	31,067
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held-for-sale, net	0	18
Total finance receivables and loans, net	99,440	100,090
Nonmarketable equity securities	44	38
Deposit liabilities	56,085	54,070
Short-term borrowings	5,163	8,545
Long-term debt	$ 44,391	$ 42,297