Condensed Consolidated Balance Sheet & Mini Balance Sheet - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Assets [Abstract]
Cash and Due from Banks	$ 1,514	$ 1,547
Interest-bearing Deposits in Banks and Other Financial Institutions	2,863	4,387
Cash and Cash Equivalents, at Carrying Value	4,377	5,934
Available-for-sale securities	21,764	18,926
Held-to-maturity securities	1,189	839
Loans Receivable Held-for-sale, Net, Not Part of Disposal Group	17	0
Finance receivables and loans, net [Abstract]
Loans and Leases Receivable, Gross	120,528	118,944
Financing Receivable, Allowance for Credit Losses	1,225	1,144
Loans and Leases Receivable, Net Amount	119,303	117,800
Property Subject to or Available for Operating Lease, Net	9,717	11,470
Premiums receivable and other insurance assets	2,025	1,905
Other Assets	5,953	6,854
Assets	164,345	163,728
Liabilities and Equity [Abstract]
Noninterest-bearing deposit liabilities	107	84
Interest-bearing Deposit Liabilities	86,076	78,938
Deposits	86,183	79,022
Short-term Debt	10,712	12,673
Long-term Debt	49,145	54,128
Interest payable	399	351
Unearned Premiums	2,541	2,500
Accounts Payable and Accrued Liabilities	1,892	1,737
Liabilities	150,872	150,411
Equity [Abstract]
Common Stocks, Including Additional Paid in Capital, Net of Discount	21,208	21,166
Retained Earnings (Accumulated Deficit)	(6,760)	(7,151)
Accumulated Other Comprehensive Income (Loss), Net of Tax	(245)	(341)
Treasury stock, Value	(730)	(357)
Stockholders' Equity Attributable to Parent, Total	13,473	13,317
Liabilities and Equity	164,345	163,728
Variable Interest Entity, Primary Beneficiary [Member]
Finance receivables and loans, net [Abstract]
Loans and Leases Receivable, Gross	22,035	24,630
Financing Receivable, Allowance for Credit Losses	140	173
Loans and Leases Receivable, Net Amount	21,895	24,457
Property Subject to or Available for Operating Lease, Net	907	1,745
Other Assets	827	1,390
Assets	23,629	27,592
Liabilities and Equity [Abstract]
Long-term Debt	12,499	13,259
Accounts Payable and Accrued Liabilities	12	12
Liabilities	$ 12,511	$ 13,271