Fair Value (Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	$ 571	$ 0
Loans held-for-sale, net	15	105
Total finance receivables and loans, net	111,564	110,546
Nonmarketable equity investments	772	418
Deposit liabilities	72,802	66,478
Short-term borrowings	5,994	8,101
Long-term debt	61,040	66,234
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	571
Loans held-for-sale, net	15	105
Total finance receivables and loans, net	111,564	110,546
Nonmarketable equity investments	772	418
Deposit liabilities	72,802	66,478
Short-term borrowings	5,994	8,101
Long-term debt	61,040	66,234
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	0
Loans held-for-sale, net	0	0
Total finance receivables and loans, net	0	0
Nonmarketable equity investments	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]
Held-to-maturity securities	579
Loans held-for-sale, net	0	0
Total finance receivables and loans, net	0	0
Nonmarketable equity investments	745	391
Deposit liabilities	0	0
Short-term borrowings	0	0
Long-term debt	23,407	23,018
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	0
Loans held-for-sale, net	15	105
Total finance receivables and loans, net	112,632	110,737
Nonmarketable equity investments	43	42
Deposit liabilities	73,528	66,889
Short-term borrowings	5,996	8,102
Long-term debt	39,574	45,157
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity securities	579
Loans held-for-sale, net	15	105
Total finance receivables and loans, net	112,632	110,737
Nonmarketable equity investments	788	433
Deposit liabilities	73,528	66,889
Short-term borrowings	5,996	8,102
Long-term debt	$ 62,981	$ 68,175