CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
OPERATING ACTIVITIES
Net income		$ 2,319	$ 1,057	$ 1,791
Adjustments to reconcile net income to net change in cash due to operating activities:
Provision for credit losses		(411)	1,616	393
Net change in loans held for sale		1,085	32	(672)
Depreciation, amortization and accretion		625	578	633
Deferred income taxes		(429)	(238)	64
Share-based compensation		59	48	41
Net gain on sale of assets		(11)	(4)	(31)
Net (increase) decrease in other assets		(1,719)	(3,979)	(853)
Net increase (decrease) in other liabilities		757	1,001	331
Net change due to operating activities		2,275	111	1,697
Investment securities:
Purchases of debt securities available for sale		(12,406)	(9,271)	(8,422)
Proceeds from maturities and paydowns of debt securities available for sale		7,810	6,943	3,946
Proceeds from sales of debt securities available for sale		790	585	5,016
Proceeds from maturities and paydowns of debt securities held to maturity		1,006	897	398
Net (increase) decrease in interest-bearing deposits in banks		(10)	(9)	(149)
Acquisitions, net of cash acquired		(165)	(3)	(129)
Purchases of loans		(3,778)	(3,315)	(1,592)
Sales of loans		934	3,014	1,082
Net (increase) decrease in loans and leases		(3,177)	(4,794)	(3,824)
Capital expenditures, net		(124)	(118)	(95)
Purchases of bank-owned life insurance		(1,050)	0	0
Other		(316)	(65)	(106)
Net change due to investing activities		(10,486)	(6,136)	(3,875)
FINANCING ACTIVITIES
Net increase (decrease) in deposits		7,197	21,851	5,738
Net increase (decrease) in short-term borrowed funds		(154)	(39)	(1,048)
Proceeds from issuance of long-term borrowed funds		0	8,323	12,850
Repayments of long-term borrowed funds		(1,352)	(14,022)	(14,857)
Treasury stock purchased		(295)	(270)	(1,220)
Net proceeds from issuance of preferred stock		296	395	730
Redemption of preferred stock		(250)	0	0
Dividends declared and paid to common stockholders		(670)	(672)	(617)
Dividends declared and paid to preferred stockholders		(113)	(98)	(65)
Premium paid to exchange debt		(1)	(80)	0
Payments of employee tax withholding for share-based compensation		(22)	(16)	(21)
Net change due to financing activities		4,636	15,372	1,490
Net change in cash and cash equivalents		(3,575)	9,347	(688)
Cash and cash equivalents at beginning of period	[1]	12,733	3,386	4,074
Cash and cash equivalents at end of period	[1]	9,158	12,733	3,386
Supplemental disclosures:
Interest paid		347	837	1,560
Income taxes paid		1,247	261	326
Non-cash items:
Transfer of securities from available for sale to held to maturity		0	813	192
Transfer of securities from held to maturity to available for sale		0	0	734
Loans securitized and transferred to securities available for sale		260	956	150
Loans securitized and transferred to securities held to maturity		0	111	0
Stock issued for share-based compensation plans		43	30	59
Stock issued for Employee Stock Purchase Plan		$ 22	$ 19	$ 17

[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