Discontinued and Held-for-sale Operations (Select Balance Sheet Information for Held-for-sale Operations) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and Due from Banks	$ 1,292	$ 1,073
Interest-bearing Deposits in Banks and Other Financial Institutions	6,482	6,440
Total cash and cash equivalents	7,774	7,513	16,126	13,035
Available-for-sale Securities	17,015	14,178
Finance receivables and loans, net	96,993	99,055	119,913
Loans and Leases Receivable, Allowance	(1,183)	(1,170)
Total finance receivables and loans, net	95,810	97,885
Investment in operating leases, net	16,085	13,550
Premiums receivable and other insurance assets	1,611	1,609
Other Assets	6,701	11,908
Total assets	150,627	182,347	178,560
Interest-bearing deposit liabilities	50,053	45,938
Short-term borrowings	4,197	7,461
Long-term debt	64,534	74,561
Interest payable	999	932
Unearned insurance premiums and service revenue	2,301	2,296
Accrued expenses and other liabilities	5,043	6,585
Total liabilities	131,462	162,449
Insurance Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and Due from Banks		8
Interest-bearing Deposits in Banks and Other Financial Institutions		119
Total cash and cash equivalents		127
Available-for-sale Securities		576
Finance receivables and loans, net		0
Loans and Leases Receivable, Allowance		0
Total finance receivables and loans, net		0
Investment in operating leases, net		0
Premiums receivable and other insurance assets		277
Other Assets		94
Impairment on assets of held-for-sale operations		(53)
Total assets		1,021
Interest-bearing deposit liabilities		0
Short-term borrowings		0
Long-term debt		0
Interest payable		0
Unearned insurance premiums and service revenue		506
Accrued expenses and other liabilities		297
Total liabilities		803
Automotive finance operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and Due from Banks	30	100
Interest-bearing Deposits in Banks and Other Financial Institutions	174	1,918
Total cash and cash equivalents	204	2,018
Available-for-sale Securities		424
Finance receivables and loans, net	3,953	25,835
Loans and Leases Receivable, Allowance	(90)	(208)
Total finance receivables and loans, net	3,863	25,627
Investment in operating leases, net		144
Premiums receivable and other insurance assets		0
Other Assets	1,462	2,942
Impairment on assets of held-for-sale operations		0
Total assets	5,529	31,155
Interest-bearing deposit liabilities		3,907
Short-term borrowings	379	2,800
Long-term debt	3,299	13,514
Interest payable	106	177
Unearned insurance premiums and service revenue		0
Accrued expenses and other liabilities	479	1,498
Total liabilities	4,263	21,896
Discontinued Operation Or Assets Disposal [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and Due from Banks		108
Interest-bearing Deposits in Banks and Other Financial Institutions		2,037
Total cash and cash equivalents		2,145
Available-for-sale Securities		1,000
Finance receivables and loans, net		25,835
Loans and Leases Receivable, Allowance		(208)
Total finance receivables and loans, net		25,627
Investment in operating leases, net		144
Premiums receivable and other insurance assets		277
Other Assets		3,036
Impairment on assets of held-for-sale operations		(53)
Total assets		32,176
Interest-bearing deposit liabilities		3,907
Short-term borrowings		2,800
Long-term debt		13,514
Interest payable		177
Unearned insurance premiums and service revenue		506
Accrued expenses and other liabilities		1,795
Total liabilities		$ 22,699