Consolidated Statements Of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Statement of Cash Flows [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 411	$ 435
Provision for Loan, Lease, and Other Losses	25	(35)
Depreciation, Depletion and Amortization, Nonproduction	93	92
Share-based Payment Arrangement, Noncash Expense	18	18
Deferred Income Tax Expense (Benefit)	3	2
Increase (Decrease) in Debt Securities, Trading, and Equity Securities, FV-NI	42	59
Increase (Decrease) in Loans Held-for-sale	39	34
Increase (Decrease) in Operating Liabilities	(73)	85
Increase (Decrease) in Other Operating Assets	166	52
Other Noncash Income (Expense)	10	14
Net cash provided by (used in) operating activities	220	438
Payments for (Proceeds from) Short-term Investments	(827)	(40)
Proceeds from Maturities, Prepayments and Calls of Held-to-maturity Securities	239	114
Payments to Acquire Held-to-maturity Securities	160	222
Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-sale	1,345	1,404
Payments to Acquire Available-for-sale Securities	1,028	1,176
Payments for (Proceeds from) Other Loans and Leases	1,877	431
Net change in other noninterest-bearing investments	(5)	(4)
Payments to Acquire Property, Plant, and Equipment	60	54
Payments for (Proceeds from) Other Investing Activities	(4)	0
Net Cash Provided by (Used in) Investing Activities, Total	(715)	(329)
Increase (Decrease) in Deposits	232	965
Proceeds from (Repayments of) Short-term Debt	371	1,181
Repayments of debt over 90 days and up to one year	0	2,000
Proceeds from (Repayments of) Debt	497	0
Proceeds from Issuance of Common Stock	7	17
Payments for Repurchase of Common Stock	551	248
Payments of Dividends	127	104
Proceeds from (Payments for) Other Financing Activities	(10)	0
Net Cash Provided by (Used in) Financing Activities, Total	419	(189)
Net increase (decrease) in cash and due from banks	(76)	(80)
Cash and Due from Banks	538	468
Interest Paid, Including Capitalized Interest, Operating and Investing Activities	199	100
Income Taxes Paid, Net	132	91
Real Estate Owned, Transfer to Real Estate Owned	6	6
Transfer of Portfolio Loans and Leases to Held-for-sale	$ 0	$ 39