Consolidated Statement of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Net Cash Provided by (Used in) Operating Activities [Abstract]
Net Income (Loss) Attributable to Parent	$ 819	$ 1,026
Depreciation, Amortization and Accretion, Net	1,807	2,130
Provision for Loan Losses Expensed Including Discontinued Operations	650	467
Gain Loss on Sales of Loans Net Including Discontinued Operations	(4)	(45)
Availableforsale Securities Gross Realized Gain Loss Excluding Otti Including Disc Ops	(145)	(106)
Gain (Loss) on Extinguishment of Debt	4	354
Payments for Origination and Purchases of Loans Held-for-sale	(141)	(1,594)
Proceeds from Sale of Loans Held-for-sale	184	1,580
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	0	(452)
Increase (Decrease) in Deferred Income Taxes	322	406
Increase (Decrease) in Interest Payable, Net	112	(40)
Increase (Decrease) in Other Operating Assets	16	528
Increase (Decrease) in Other Operating Liabilities	(65)	(212)
Increase (Decrease) in Other Operating Assets and Liabilities, Net	30	(72)
Net cash provided by (used in) operating activities	3,589	3,970
Net Cash Provided by Investing Activities [Abstract]
Payments to Acquire Available-for-sale Securities	(11,027)	(10,011)
Proceeds from sales of available-for-sale securities	8,546	4,408
Proceeds from maturities and repayment of available-for-sale securities	2,411	3,141
Payments to Acquire Held-to-maturity Securities	(650)	0
Payments for (Proceeds from) Loans and Leases	(8,308)	(9,175)
Proceeds from Sale of Loans Held-for-investment	4,221	2,665
Purchases of operating lease assets	(2,360)	(3,423)
Disposals of operating lease assets	4,631	3,855
Payments to Acquire Interest in Subsidiaries and Affiliates	(309)	0
Proceeds from Divestiture of Businesses	0	1,049
Increase (Decrease) in Restricted Cash	622	489
Increase (Decrease) in Non marketable equity securities	(401)	(42)
Payments for (Proceeds from) Other Investing Activities	(157)	25
Net cash provided by investing activities	(2,781)	(7,019)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from (Repayments of) Short-term Debt	(1,673)	(1,692)
Increase (Decrease) in Deposits	9,240	5,797
Proceeds from issuance of long-term debt	11,229	23,866
Repayments of long-term debt	(20,758)	(23,454)
Payments for Repurchase of Redeemable Preferred Stock	(696)	(442)
Payments for Repurchase of Common Stock	(173)	(16)
Payments of Dividends	(70)	(1,356)
Net cash (used in) provided by financing activities	(2,901)	2,703
Effect of exchange-rate changes on cash and cash equivalents	2	(3)
Cash and Cash Equivalents, Period Increase (Decrease)	(2,091)	(349)
Cash and Cash Equivalents, at Carrying Value	6,380	5,576
Cash and Cash Equivalents, at Carrying Value	4,289	5,227
Supplemental Cash Flow Information [Abstract]
Interest Paid	1,860	1,825
Income Taxes Paid	16	95
Transfer of Portfolio Loans and Leases to Held-for-sale	4,231	777
Proceeds from sales and repayments of mortgage loans held-for-investment originally designated as held-for-sale	$ 28	$ 61