Condensed Consolidated Statement of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Income (Loss) Attributable to Parent	$ 466	$ 610
Depreciation, Amortization and Accretion, Net	1,003	1,241
Provision for Loan Losses Expensed Including Discontinued Operations	540	392
Gain Loss on Sales of Loans Net Including Discontinued Operations	50	4
Availableforsale Securities Gross Realized Gain Loss Excluding Otti Including Disc Ops	(50)	(93)
Gain (Loss) on Extinguishment of Debt	(2)	(4)
Payments for Origination and Purchases of Loans Held-for-sale	202	44
Proceeds from Sale of Loans Held-for-sale	187	144
Increase (Decrease) in Deferred Income Taxes	(203)	(193)
Increase (Decrease) in Interest Payable, Net	48	76
Increase (Decrease) in Other Operating Assets	94	(17)
Increase (Decrease) in Other Operating Liabilities	(50)	(55)
Increase (Decrease) in Other Operating Assets and Liabilities, Net	(67)	45
Net Cash Provided by (Used in) Operating Activities	2,070	2,436
Net Cash (Used in) Provided by Investing Activities [Abstract]
Payments to Acquire Available-for-sale Securities	(5,853)	(8,657)
Proceeds from sales of available-for-sale securities	2,162	6,584
Proceeds from maturities and repayment of available-for-sale securities	1,230	1,536
Payments to Acquire Held-to-maturity Securities	(313)	(571)
Proceeds from Sale and Maturity of Held-to-maturity Securities	17	0
Payments for (Proceeds from) Loans and Leases	(1,817)	(2,442)
Proceeds from Sale of Loans Held-for-investment	1,280	4,156
Originations and repayments of loans held-for-investment and other	1,588	3,211
Purchases of operating lease assets	(1,965)	(1,472)
Disposals of operating lease assets	3,043	3,047
Payments to Acquire Interest in Subsidiaries and Affiliates	0	288
Increase (Decrease) in Restricted Cash	474	482
Increase (Decrease) in Non marketable equity securities	107	(354)
Payments for (Proceeds from) Other Investing Activities	(93)	(69)
Net cash provided by investing activities	(3,316)	(1,259)
Net Cash Used in Financing Activities [Abstract]
Proceeds from (Repayments of) Short-term Debt	(1,962)	(2,112)
Increase (Decrease) in Deposits	7,133	6,308
Proceeds from issuance of long-term debt	9,330	9,020
Repayments of long-term debt	(14,366)	(14,305)
Payments for Repurchase of Preferred Stock and Preference Stock	0	696
Payments for Repurchase of Common Stock	(373)	(14)
Payments of Dividends	(75)	(30)
Net cash (used in) provided by financing activities	(313)	(1,829)
Effect of exchange-rate changes on cash and cash equivalents	2	3
Cash and Cash Equivalents, Period Increase (Decrease)	(1,557)	(649)
Cash and Cash Equivalents, at Carrying Value	5,934	6,380
Cash and Cash Equivalents, at Carrying Value	4,377	5,731
Supplemental Cash Flow Information [Abstract]
Interest Paid	1,331	1,234
Income Taxes Paid	28	12
Held-to-maturity securities received in consideration for loans sold	56	0
Transfer of Portfolio Loans and Leases to Held-for-sale	1,298	4,174
Proceeds from sales and repayments of mortgage loans held-for-investment originally designated as held-for-sale	$ 20	$ 18