CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
OPERATING ACTIVITIES
Net income		$ 1,791	$ 1,721	$ 1,652
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for credit losses		393	326	321
Originations of mortgage loans held for sale		(21,188)	(8,036)	(2,911)
Proceeds from sales of mortgage loans held for sale		20,430	8,149	3,161
Purchases of commercial loans held for sale		(1,979)	(1,944)	(2,057)
Proceeds from sales of commercial loans held for sale		2,065	1,857	1,963
Depreciation, amortization and accretion		633	489	487
Mortgage servicing rights valuation charge-off (recovery)		1	(3)	(2)
Debt securities impairment		2	3	7
Deferred income taxes		64	97	(136)
Share-based compensation		41	41	48
Net gain on sales of:
Debt securities		(25)	(19)	(11)
Equity securities		0	0	(1)
Premises and equipment		(6)	0	0
Other loans held for sale		0	0	(17)
Increase in other assets		(856)	(1,217)	(502)
Increase (decrease) in other liabilities		331	303	(119)
Net cash provided by operating activities		1,697	1,767	1,883
Investment securities:
Purchases of securities available for sale		(8,422)	(4,270)	(5,394)
Proceeds from maturities and paydowns of debt securities available for sale		3,946	3,258	3,470
Proceeds from sales of debt securities available for sale		5,016	998	1,257
Purchases of debt securities held to maturity		0	0	(171)
Proceeds from maturities and paydowns of debt securities held to maturity		398	522	561
Purchases of equity securities, at fair value		(717)	(162)	(326)
Proceeds from sales of equity securities, at fair value		851	150	253
Purchases of equity securities, at cost		(511)	(754)	(400)
Proceeds from sales of equity securities, at cost		538	642	637
Net (increase) decrease in interest-bearing deposits in banks		(149)	44	247
Purchases of mortgage servicing rights		0	(16)	(28)
Acquisitions, net of cash acquired		(129)	(533)	0
Net increase in loans and leases		(4,334)	(6,445)	(3,634)
Net increase in bank-owned life insurance		(27)	(42)	(44)
Premises and equipment:
Purchases		(126)	(232)	(253)
Proceeds from sales		31	0	0
Capitalization of software		(240)	(237)	(159)
Net cash used in investing activities		(3,875)	(7,077)	(3,984)
FINANCING ACTIVITIES
Net increase in deposits		5,738	4,486	5,285
Net (decrease) increase in federal funds purchased and securities sold under agreements to repurchase		(891)	341	(333)
Net decrease in other short-term borrowed funds		(157)	(5,211)	(4,959)
Proceeds from issuance of long-term borrowed funds		12,850	22,503	15,363
Repayments of long-term borrowed funds		(14,857)	(14,837)	(12,751)
Treasury stock purchased		(1,220)	(1,025)	(820)
Net proceeds from issuance of preferred stock		730	593	0
Dividends declared and paid to common stockholders		(617)	(471)	(322)
Dividends declared and paid to preferred stockholders		(65)	(14)	(14)
Payments of employee tax withholding for share-based compensation		(21)	(13)	(20)
Net cash provided by financing activities		1,490	6,352	1,429
(Decrease) increase in cash and cash equivalents		(688)	1,042	(672)	[1]
Cash and cash equivalents at beginning of period	[1]	4,074	3,032	3,704
Cash and cash equivalents at end of period	[1]	3,386	4,074	3,032
Supplemental disclosures:
Interest paid		1,560	1,184	716
Income taxes paid		326	241	371
Non-cash items:
Transfer of securities from available for sale to held to maturity		192	0	0
Transfer of securities from held to maturity to available for sale		734	0	0
Loans securitized and transferred to securities available for sale		150	142	134
Stock issued for share-based compensation plans		59	20	22
Stock issued for Employee Stock Purchase Plan		17	14	12
Due from broker for securities sold but not settled		$ 0	$ 0	$ 6

[1] Cash and cash equivalents include cash and due from banks and interest-bearing cash and due from banks as reflected on the Consolidated Balance Sheets.