F.N.B. (FNB) 10-Q 4 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Oct. 31, 2021
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	001-31940
Entity Registrant Name	FNB CORP/PA/
Entity Incorporation, State or Country Code	PA
Entity Tax Identification Number	25-1255406
Entity Address, Address Line One	One North Shore Center,
Entity Address, Address Line Two	12 Federal Street,
Entity Address, City or Town	Pittsburgh,
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	15212
City Area Code	800
Local Phone Number	555-5455
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		318,927,908
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Central Index Key	0000037808
Current Fiscal Year End Date	--12-31
New York Stock Exchange | Common Stock, par value $0.01 per share
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	FNB
Security Exchange Name	NYSE
New York Stock Exchange | Depositary Shares each representing 1/40th interest in a share of Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock, Series E
Entity Information [Line Items]
Title of 12(b) Security	Depositary Shares each representing 1/40th interest in a share of Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock, Series E
Trading Symbol	FNBPrE
Security Exchange Name	NYSE

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions		Sep. 30, 2021	Dec. 31, 2020
Assets
Cash and due from banks		$ 402	$ 369
Interest-bearing deposits with banks		3,708	1,014
Cash and Cash Equivalents		4,110	1,383
Debt securities available for sale (amortized cost of $3,162 and $3,380; allowance for credit losses of $0 and $0)		3,208	3,463
Debt securities held to maturity (fair value of $3,267 and $2,973; allowance for credit losses of $0 and $0)		3,202	2,868
Loans held for sale (includes $227 and $144 measured at fair value)	[1]	253	154
Loans and leases, net of unearned income of $51 and $77		24,716	25,459
Allowance for credit losses on loans and leases		(349)	(363)
Net Loans and Leases		24,367	25,096
Premises and equipment, net		342	332
Goodwill		2,262	2,262
Core deposit and other intangible assets, net		45	54
Bank owned life insurance		545	549
Other assets		1,027	1,193
Total Assets		39,361	37,354
Liabilities
Non-interest-bearing demand		10,502	9,042
Interest-bearing demand		14,360	13,157
Savings		3,537	3,261
Certificates and other time deposits		3,045	3,662
Total Deposits		31,444	29,122
Short-term borrowings		1,563	1,804
Long-term borrowings		886	1,095
Other liabilities		370	374
Total Liabilities		34,263	32,395
Stockholders’ Equity
Preferred stock - $0.01 par value; liquidation preference of $1,000 per share Authorized - 20,000,000 shares Issued - 110,877 shares		107	107
Common stock - $0.01 par value Authorized - 500,000,000 shares Issued - 329,449,382 and 328,057,368 shares		3	3
Additional paid-in capital		4,106	4,087
Retained earnings		1,051	869
Accumulated other comprehensive loss		(52)	(39)
Treasury stock – 10,527,766 and 6,427,839 shares at cost		(117)	(68)
Total Stockholders’ Equity		5,098	4,959
Total Liabilities and Stockholders’ Equity		$ 39,361	$ 37,354
[1]	Amount represents loans for which we have elected the fair value option. See Note 18.

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)		Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Debt securities available for sale, amortized cost		$ 3,162,000,000	$ 3,380,000,000
Debt securities available for sale, allowance for credit losses		0	0
Debt securities held-to-maturity, fair value		3,267,000,000	2,973,000,000
Debt securities held to maturity, allowance for credit losses		60,000	40,000
Loans held for sale, fair value	[1]	227,000,000	144,000,000
Unearned income on loans		$ 51,000,000	$ 77,000,000
Preferred stock, par value (in dollars per share)		$ 0.01	$ 0.01
Preferred stock, liquidation preference per share (in dollars per share)		$ 1,000	$ 1,000
Preferred stock, shares authorized (in shares)		20,000,000	20,000,000
Preferred stock, shares issued (in shares)		110,877	110,877
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
Common stock, shares authorized (in shares)		500,000,000	500,000,000
Common stock, shares issued (in shares)		329,449,382	328,057,368
Treasury stock, shares (in shares)		10,527,766	6,427,839
[1]	Amount represents loans for which we have elected the fair value option. See Note 18.

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Interest Income
Loans and leases, including fees	$ 226	$ 239	$ 671	$ 750
Securities:
Taxable	22	25	65	84
Tax-exempt	7	8	22	24
Other	1	1	2	2
Total Interest Income	256	273	760	860
Interest Expense
Deposits	11	27	38	111
Short-term borrowings	7	9	21	31
Long-term borrowings	6	10	18	30
Total Interest Expense	24	46	77	172
Net Interest Income	232	227	683	688
Provision for credit losses	(2)	27	3	105
Net Interest Income After Provision for Credit Losses	234	200	680	583
Non-Interest Income
Service charges	31	24	89	78
Trust services	10	8	28	23
Insurance commissions and fees	7	7	20	19
Securities commissions and fees	5	5	17	13
Capital markets income	12	8	27	32
Mortgage banking operations	8	18	31	34
Dividends on non-marketable equity securities	2	2	7	10
Bank owned life insurance	3	4	11	11
Loss on debt extinguishment	0	(4)	0	(4)
Other	10	8	21	10
Total Non-Interest Income	88	80	251	226
Non-Interest Expense
Salaries and employee benefits	105	100	314	298
Net occupancy	13	14	45	49
Equipment	18	17	52	49
Amortization of intangibles	3	3	9	10
Outside services	18	16	54	50
FDIC insurance	4	4	13	15
Bank shares and franchise taxes	3	4	11	12
Merger-related	1	0	1	0
Other	19	22	52	68
Total Non-Interest Expense	184	180	551	551
Income Before Income Taxes	138	100	380	258
Income taxes	27	17	74	44
Net Income	111	83	306	214
Preferred stock dividends	2	2	6	6
Net income available to common stockholders	$ 109	$ 81	$ 300	$ 208
Earnings per Common Share
Basic (in dollars per share)	$ 0.34	$ 0.25	$ 0.94	$ 0.64
Diluted (in dollars per share)	$ 0.34	$ 0.25	$ 0.93	$ 0.64

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 111	$ 83	$ 306	$ 214
Securities available for sale:
Unrealized gains (losses) arising during the period, net of tax expense (benefit) of $(3), $(1), $(8) and $18	(10)	(3)	(29)	63
Derivative instruments:
Unrealized gains (losses) arising during the period, net of tax expense (benefit) of $0, $2, $1 and $(9)	(1)	8	3	(32)
Reclassification adjustment for gains included in net income, net of tax expense of $1, $1, $3 and $2	4	4	11	7
Pension and postretirement benefit obligations:
Unrealized gains arising during the period, net of tax expense of $1, $0, $1 and $0	1	0	2	1
Other Comprehensive Income (Loss)	(6)	9	(13)	39
Comprehensive Income	$ 105	$ 92	$ 293	$ 253

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Unrealized gains (losses) arising during the period, tax expense (benefit)	$ (3)	$ (1)	$ (8)	$ 18
Unrealized gains (losses) arising during the period, tax expense (benefit)	0	2	1	(9)
Reclassification adjustment for gains included in net income, tax of expense	1	1	3	2
Unrealized gains arising during the period, tax expense	$ 1	$ 0	$ 1	$ 0

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) $ in Millions	Total	Adoption of New Accounting Standard [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member]Adoption of New Accounting Standard [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Balance at beginning of period at Dec. 31, 2019	$ 4,883	$ (50)	$ 107	$ 3	$ 4,067	$ 798	$ (50)	$ (65)	$ (27)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	253					214		39
Dividends declared:
Preferred stock	(6)					(6)
Common stock	(118)					(118)
Issuance of common stock	1				4				(3)
Repurchase of common stock	(25)								(25)
Restricted stock compensation	13				13
Balance at end of period at Sep. 30, 2020	4,951		107	3	4,084	838		(26)	(55)
Balance at beginning of period at Jun. 30, 2020	4,897		107	3	4,081	796		(35)	(55)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	92					83		9
Dividends declared:
Preferred stock	(2)					(2)
Common stock	(39)					(39)
Issuance of common stock	1				1
Restricted stock compensation	2				2
Balance at end of period at Sep. 30, 2020	4,951		107	3	4,084	838		(26)	(55)
Balance at beginning of period at Dec. 31, 2020	4,959		107	3	4,087	869		(39)	(68)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	293					306		(13)
Dividends declared:
Preferred stock	(6)					(6)
Common stock	(117)					(117)
Issuance of common stock	(4)				3	(1)			(6)
Repurchase of common stock	(43)								(43)
Restricted stock compensation	16				16
Balance at end of period at Sep. 30, 2021	5,098		107	3	4,106	1,051		(52)	(117)
Balance at beginning of period at Jun. 30, 2021	5,037		107	3	4,101	981		(46)	(109)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	105					111		(6)
Dividends declared:
Preferred stock	(2)					(2)
Common stock	(39)					(39)
Issuance of common stock	(1)								(1)
Repurchase of common stock	(7)								(7)
Restricted stock compensation	5				5
Balance at end of period at Sep. 30, 2021	$ 5,098		$ 107	$ 3	$ 4,106	$ 1,051		$ (52)	$ (117)

CONSOLIDATED STATEMENTS OF ST_2

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Stockholders' Equity [Abstract]
Preferred stock dividends per share (in dollars per share)	$ 18.13	$ 18.13	$ 54.39	$ 54.39
Common stock dividends per share (in dollars per share)	$ 0.12	$ 0.12	$ 0.36	$ 0.36

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating Activities
Net income	$ 306	$ 214
Adjustments to reconcile net income to net cash flows provided by (used in) operating activities:
Depreciation, amortization and accretion	(1)	5
Provision for credit losses	3	105
Deferred tax expense (benefit)	8	(24)
Loans originated for sale	(1,593)	(1,351)
Loans sold	1,533	1,258
Net gain on sale of loans	(39)	(28)
Net change in:
Interest receivable	14	18
Interest payable	(5)	(7)
Bank owned life insurance, excluding purchases	4	(6)
Other, net	154	(265)
Net cash flows provided by (used in) operating activities	384	(81)
Investing Activities
Net change in loans and leases, excluding sales and transfers	800	(2,809)
Debt securities available for sale:
Purchases	(1,207)	(1,168)
Maturities/payments	1,415	1,429
Debt securities held to maturity:
Purchases	(993)	(163)
Maturities/payments	652	469
Increase in premises and equipment	(43)	(33)
Other, net	0	1
Net cash flows provided by (used in) investing activities	624	(2,274)
Financing Activities
Demand (non-interest bearing and interest bearing) and savings accounts	2,939	4,753
Time deposits	(617)	(702)
Short-term borrowings	(240)	(1,316)
Proceeds from issuance of long-term borrowings	18	322
Repayment of long-term borrowings	(227)	(266)
Repurchases of common stock	(43)	(25)
Cash dividends paid:
Preferred stock	(6)	(6)
Common stock	(117)	(118)
Other, net	12	14
Net cash flows provided by financing activities	1,719	2,656
Net Increase in Cash and Cash Equivalents	2,727	301
Cash and cash equivalents at beginning of period	1,383	599
Cash and Cash Equivalents at End of Period	$ 4,110	$ 900

NATURE OF OPERATIONS

NATURE OF OPERATIONS	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
NATURE OF OPERATIONS	NATURE OF OPERATIONS F.N.B. Corporation, headquartered in Pittsburgh, Pennsylvania, is a diversified financial services company operating in seven states and the District of Columbia. Our market coverage spans several major metropolitan areas including: Pittsburgh, Pennsylvania; Baltimore, Maryland; Cleveland, Ohio; Washington, D.C.; and Charlotte, Raleigh, Durham and the Piedmont Triad (Winston-Salem, Greensboro and High Point) in North Carolina. As of September 30, 2021, we had 332 banking offices throughout Pennsylvania, Ohio, Maryland, West Virginia, North Carolina, South Carolina, Washington D.C. and Virginia. We provide a full range of commercial banking, consumer banking and wealth management solutions through our subsidiary network which is led by our largest affiliate, FNBPA, founded in 1864. Commercial banking solutions include corporate banking, small business banking, investment real estate financing, government banking, business credit, capital markets and lease financing. Consumer banking provides a full line of consumer banking products and services, including deposit products, mortgage lending, consumer lending and a complete suite of mobile and online banking services. Wealth management services include asset management, private banking and insurance.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation Our accompanying Consolidated Financial Statements and these Notes to Consolidated Financial Statements (unaudited) include subsidiaries in which we have a controlling financial interest. We own and operate FNBPA, First National Trust Company, First National Investment Services Company, LLC, F.N.B. Investment Advisors, Inc., First National Insurance Agency, LLC, Bank Capital Services, LLC, F.N.B. Capital Corporation, LLC and Waubank Securities, LLC, and include results for each of these entities in the accompanying Consolidated Financial Statements. Companies in which we hold a controlling financial interest, or are a VIE in which we have the power to direct the activities of an entity that most significantly impact the entity’s economic performance and have an obligation to absorb losses or the right to receive benefits which could potentially be significant to the VIE, are consolidated. For a voting interest entity, a controlling financial interest is generally where we hold more than 50% of the outstanding voting shares. VIEs in which we do not hold the power to direct the activities of the entity that most significantly impact the entity’s economic performance or an obligation to absorb losses or the right to receive benefits which could potentially be significant to the VIE are not consolidated. Investments in companies that are not consolidated are accounted for using the equity method when we have the ability to exert significant influence or the cost method when we do not have the ability to exert significant influence. Investments in private investment partnerships that are accounted for under the equity method or the cost method are included in other assets and our proportional interest in the equity investments’ earnings are included in other non-interest income. Investment interests accounted for under the cost and equity methods are periodically evaluated for impairment. The accompanying interim unaudited Consolidated Financial Statements include all adjustments that are necessary, in the opinion of management, to fairly reflect our financial position and results of operations in accordance with GAAP. All significant intercompany balances and transactions have been eliminated. Events occurring subsequent to September 30, 2021 have been evaluated for potential recognition or disclosure in the Consolidated Financial Statements through the date of the filing of the Consolidated Financial Statements with the SEC. Certain information and Note disclosures normally included in Consolidated Financial Statements prepared in accordance with GAAP have been condensed or omitted pursuant to the rules and regulations of the SEC. The interim operating results are not necessarily indicative of operating results FNB expects for the full year. These interim unaudited Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and Notes thereto included in our 2020 Annual Report on Form 10-K filed with the SEC on February 25, 2021. Use of Estimates Our accounting and reporting policies conform with GAAP. The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the amounts reported in the Consolidated Financial Statements and accompanying Notes to Consolidated Financial Statements (unaudited). Actual results could materially differ from those estimates. Material estimates that are particularly susceptible to significant changes include the ACL, fair value of financial instruments, goodwill and other intangible assets, income taxes and deferred tax assets and litigation reserves, which are listed in the critical accounting estimates. For a detailed description of our significant accounting policies and critical accounting estimates, see Note 1, "Summary of Significant Accounting Policies" and the "Application of Critical Accounting Policies" section in the MD&A, both in our 2020 Annual Report on Form 10-K .

NEW ACCOUNTING STANDARDS

NEW ACCOUNTING STANDARDS	9 Months Ended
	Sep. 30, 2021
Accounting Changes and Error Corrections [Abstract]
NEW ACCOUNTING STANDARDS	NEW ACCOUNTING STANDARDS The following table summarizes accounting pronouncements issued by the FASB that we recently adopted. TABLE 2.1 Standard Description Financial Statements Impact Reference Rate Reform ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting ASU 2021-01, Reference Rate Reform (Topic 848): Scope These Updates provide temporary optional expedients and exceptions for applying GAAP to financial contracts, hedging relationships and other transactions affected by RRR if certain criteria are met. The following optional expedients, exceptions and elections are permitted for certain contracts that are modified because of RRR and meet certain scope guidance: • Contract modifications may be accounted for prospectively as a continuation of existing contracts rather than a new contract without re-measurement or reassessment of significant contract amendments • modifications of leases to be accounted for as a continuation of the existing contracts without reassessment of lease classification and discount rate or re-measurement of lease payments • to not reassess the original conclusion about whether a contract contains an embedded derivative that is clearly and closely related to the host contract • changes to critical terms of hedging relationships, on a hedge-by-hedge basis, without designation of the hedging relationship and various practical expedients and elections designed to allow hedge accounting to continue uninterrupted • modifications of certain derivatives modified to change the rate used for margining, discounting or contract price alignment. For securities affected by RRR that were classified as HTM before January 1, 2020, the Updates also allow an entity to make a one-time election to sell and/or transfer these securities to AFS or Trading. RRR Updates are effective for all entities from the beginning of an interim period that includes or is subsequent to March 12, 2020 and terminates on December 31, 2022 on a full retrospective or prospective basis. Although we do not expect RRR to have a material accounting impact on our consolidated financial position or results of operations, the Updates will ease the administrative burden in accounting for the effects of RRR. We adopted these updates on October 1, 2020 by retrospective application. The adoption did not have a material impact on our consolidated financial position or results of operations. We will continue to assess the impact of adoption through the termination date of these Updates on December 31, 2022.

SECURITIES

SECURITIES	9 Months Ended
	Sep. 30, 2021
Investments, Debt and Equity Securities [Abstract]
SECURITIES	SECURITIES The amortized cost and fair value of AFS debt securities are presented in the table below. There was no ACL in the AFS portfolio at September 30, 2021 and December 31, 2020. Accrued interest receivable on AFS debt securities totaled $5.8 million and $6.2 million at September 30, 2021 and December 31, 2020, respectively, and is excluded from the estimate of credit losses and assessed separately in other assets in the Consolidated Balance Sheets. Accordingly, we have excluded accrued interest receivable from both the fair value and the amortized cost basis of AFS debt securities. TABLE 3.1 (in millions) Amortized Gross Gross Fair Debt Securities AFS: September 30, 2021 U.S. Treasury $ 49 $ — $ — $ 49 U.S. government agencies 152 2 — 154 U.S. government-sponsored entities 170 1 (1) 170 Residential mortgage-backed securities: Agency mortgage-backed securities 1,286 26 (1) 1,311 Agency collateralized mortgage obligations 1,171 18 (6) 1,183 Commercial mortgage-backed securities 299 8 (1) 306 States of the U.S. and political subdivisions (municipals) 33 — — 33 Other debt securities 2 — — 2 Total debt securities AFS $ 3,162 $ 55 $ (9) $ 3,208 (in millions) Amortized Gross Gross Fair Debt Securities AFS: December 31, 2020 U.S. Treasury $ 600 $ — $ — $ 600 U.S. government agencies 172 — — 172 U.S. government-sponsored entities 160 1 — 161 Residential mortgage-backed securities: Agency mortgage-backed securities 959 35 — 994 Agency collateralized mortgage obligations 1,094 31 (1) 1,124 Commercial mortgage-backed securities 361 17 — 378 States of the U.S. and political subdivisions (municipals) 32 — — 32 Other debt securities 2 — — 2 Total debt securities AFS $ 3,380 $ 84 $ (1) $ 3,463 The amortized cost and fair value of HTM debt securities are presented in the table below. The ACL for the HTM municipal bond portfolio was $0.06 million and $0.04 million at September 30, 2021 and December 31, 2020, respectively. Accrued interest receivable on HTM debt securities totaled $10.9 million and $12.5 million at September 30, 2021 and December 31, 2020, respectively, and is excluded from the estimate of credit losses and assessed separately in other assets in the Consolidated Balance Sheets. Accordingly, we have excluded accrued interest receivable from both the fair value and the amortized cost basis of HTM debt securities. TABLE 3.2 (in millions) Amortized Gross Gross Fair Debt Securities HTM: September 30, 2021 U.S. Treasury $ 1 $ — $ — $ 1 U.S. government agencies 1 — — 1 U.S. government-sponsored entities 20 — — 20 Residential mortgage-backed securities: Agency mortgage-backed securities 1,174 21 (2) 1,193 Agency collateralized mortgage obligations 690 9 (4) 695 Commercial mortgage-backed securities 284 5 (2) 287 States of the U.S. and political subdivisions (municipals) 1,032 39 (1) 1,070 Total debt securities HTM $ 3,202 $ 74 $ (9) $ 3,267 (in millions) Amortized Gross Gross Fair Debt Securities HTM: December 31, 2020 U.S. Treasury $ 1 $ — $ — $ 1 U.S. government agencies 1 — — 1 U.S. government-sponsored entities 120 1 — 121 Residential mortgage-backed securities: Agency mortgage-backed securities 769 29 — 798 Agency collateralized mortgage obligations 562 17 — 579 Commercial mortgage-backed securities 307 10 — 317 States of the U.S. and political subdivisions (municipals) 1,108 48 — 1,156 Total debt securities HTM $ 2,868 $ 105 $ — $ 2,973 There were no significant gross gains or gross losses realized on securities during the nine months ended September 30, 2021 or 2020. As of September 30, 2021, the amortized cost and fair value of debt securities, by contractual maturities, were as follows: TABLE 3.3 Available for Sale Held to Maturity (in millions) Amortized Fair Amortized Fair Due in one year or less $ 45 $ 46 $ 21 $ 21 Due after one year but within five years 194 194 22 22 Due after five years but within ten years 103 103 122 125 Due after ten years 64 65 889 924 406 408 1,054 1,092 Residential mortgage-backed securities: Agency mortgage-backed securities 1,286 1,311 1,174 1,193 Agency collateralized mortgage obligations 1,171 1,183 690 695 Commercial mortgage-backed securities 299 306 284 287 Total debt securities $ 3,162 $ 3,208 $ 3,202 $ 3,267 Actual maturities may differ from contractual terms because security issuers may have the right to call or prepay obligations with or without penalties. Periodic principal payments are received on residential mortgage-backed securities based on the payment patterns of the underlying collateral. Following is information relating to securities pledged: TABLE 3.4 (dollars in millions) September 30, December 31, Securities pledged (carrying value): To secure public deposits, trust deposits and for other purposes as required by law $ 5,714 $ 5,384 As collateral for short-term borrowings 412 402 Securities pledged as a percent of total securities 95.6 % 91.4 % At September 30, 2021, there were no holdings of securities of any one issuer, other than the U.S. government and its agencies, in any amount greater than 10% of stockholders’ equity. Following are summaries of the fair values of AFS debt securities in an unrealized loss position for which an ACL has not been recorded, segregated by security type and length of continuous loss position: TABLE 3.5 Less than 12 Months 12 Months or More Total (dollars in millions) # Fair Unrealized # Fair Unrealized # Fair Unrealized Debt Securities AFS September 30, 2021 U.S. Treasury 1 $ 49 $ — — $ — $ — 1 $ 49 $ — U.S. government agencies — — — 9 9 — 9 9 — U.S. government-sponsored entities 3 74 (1) — — — 3 74 (1) Residential mortgage-backed securities: Agency mortgage-backed securities 9 428 (1) — — — 9 428 (1) Agency collateralized mortgage obligations 14 534 (6) — — — 14 534 (6) Commercial mortgage-backed securities 3 91 (1) — — — 3 91 (1) States of the U.S. and political subdivisions (municipals) 5 11 — — — — 5 11 — Other debt securities — — — 1 2 — 1 2 — Total 35 $ 1,187 $ (9) 10 $ 11 $ — 45 $ 1,198 $ (9) Less than 12 Months 12 Months or More Total (dollars in millions) # Fair Unrealized # Fair Unrealized # Fair Unrealized Debt Securities AFS December 31, 2020 U.S. government agencies 1 $ 13 $ — 16 $ 69 $ — 17 $ 82 $ — U.S. government-sponsored entities 1 25 — — — — 1 25 — Residential mortgage-backed securities: Agency collateralized mortgage obligations 5 130 (1) — — — 5 130 (1) Other debt securities — — — 1 2 — 1 2 — Total 7 $ 168 $ (1) 17 $ 71 $ — 24 $ 239 $ (1) We evaluated the AFS debt securities that were in an unrealized loss position at September 30, 2021. Based on the credit ratings and implied government guarantee for these securities, we concluded the loss position is temporary and caused by the movement of interest rates and does not reflect any expected credit losses. We do not intend to sell the AFS debt securities and it is not more likely than not that we will be required to sell the securities before the recovery of their amortized cost basis. Credit Quality Indicators We use credit ratings and the most recent financial information to help evaluate the credit quality of our credit-related AFS and HTM securities portfolios. Management reviews the credit profile of each issuer on a quarterly basis. Based on the nature of the issuers and current conditions, we have determined that securities backed by the UST, Fannie Mae, Freddie Mac, FHLB, Ginnie Mae, and the SBA have zero expected credit loss. Our municipal bond portfolio, with a carrying amount of $1.1 billion as of September 30, 2021 is highly rated with an average rating of AA and 100% of the portfolio having an A or better rating. All of the securities in the municipal portfolio are general obligation bonds. Geographically, municipal bonds support our primary footprint as 63% of the securities are from municipalities located in the primary states within which we conduct business. The average holding size of the securities in the municipal bond portfolio is $3.5 million. In addition to the strong stand-alone ratings, 60% of the municipal bonds have some formal credit enhancement (e.g., insurance) that strengthens the creditworthiness of the bond. The ACL on the HTM municipal bond portfolio is calculated on each bond using: • The bond’s underlying credit rating, time to maturity and exposure amount; • Credit enhancements that improve the bond’s credit rating (e.g., insurance); and • Moody’s U.S. Bond Defaults and Recoveries, 1970-2020 study. By using these components, we derive the expected credit loss on the HTM general obligation bond portfolio. We further refine the expected credit loss by factoring in economic forecast data using our Commercial and Industrial Non-Manufacturing loan portfolio forecast adjustment as derived through our assessment of the loan portfolio as a proxy for our municipal bond portfolio. For the year-to-date periods ending September 30, 2021 and 2020, we had no significant provision expense and no charge-offs or recoveries. The ACL on the HTM portfolio was $0.06 million and $0.04 million as of September 30, 2021 and December 31, 2020, respectively. No other securities portfolios had an ACL. At September 30, 2021 and December 31, 2020, there were no securities that were past due or on non-accrual.

LOANS AND LEASES

LOANS AND LEASES	9 Months Ended
	Sep. 30, 2021
Receivables [Abstract]
LOANS AND LEASES	LOANS AND LEASES Accrued interest receivable on loans and leases, which totaled $51.4 million at September 30, 2021 and $62.9 million at December 31, 2020, is excluded from the estimate of credit losses and assessed separately in other assets in the Consolidated Balance Sheets for both periods and not included in the tables below. Upon adoption of CECL on January 1, 2020, PCD assets were adjusted to reflect the addition of a $50.3 million ACL and a remaining noncredit discount of $110.0 million included in the amortized cost. The remaining noncredit discount was $34.2 million and $50.9 million at September 30, 2021 and December 31, 2020, respectively. Loans and Leases by Portfolio Segment Following is a summary of total loans and leases, net of unearned income: TABLE 4.1 (in millions) September 30, 2021 December 31, 2020 Commercial real estate $ 9,871 $ 9,731 Commercial and industrial 5,960 7,214 Commercial leases 489 485 Other 81 40 Total commercial loans and leases 16,401 17,470 Direct installment 2,250 2,020 Residential mortgages 3,588 3,433 Indirect installment 1,230 1,218 Consumer lines of credit 1,247 1,318 Total consumer loans 8,315 7,989 Total loans and leases, net of unearned income $ 24,716 $ 25,459 The loans and leases portfolio categories are comprised of the following types of loans, where in each case the LGD is dependent on the nature and value of the respective collateral: • Commercial real estate includes both owner-occupied and non-owner-occupied loans secured by commercial properties where operational cash flows on owner-occupied properties or rents received by our borrowers from their tenant(s) on both a property and global basis are the primary default risk drivers, including rents paid by stand-alone business customers for owner-occupied properties; • Commercial and industrial includes loans to businesses that are not secured by real estate where the borrower's leverage and cash flows from operations are the primary default risk drivers. PPP loans are included in the commercial and industrial category and comprise $0.7 billion and $2.2 billion of this category's outstanding balance at September 30, 2021 and December 31, 2020, respectively. The PPP loans are 100% guaranteed by the SBA, which provides a reduced risk of loss to us on these loans; • Commercial leases consist of leases for new or used equipment where the borrower's cash flow from operations is the primary default risk driver; • Other is comprised primarily of credit cards and mezzanine loans where the borrower's cash flow from operations is the primary default risk driver; • Direct installment is comprised of fixed-rate, closed-end consumer loans for personal, family or household use, such as home equity loans and automobile loans where the primary default risk driver is the borrower's employment status and income; • Residential mortgages consist of conventional and jumbo mortgage loans for 1-4 family properties where the primary default risk driver is the borrower's employment status and income; • Indirect installment is comprised of loans originated by approved third parties and underwritten by us, primarily automobile loans where the primary default risk driver is the borrower's employment status and income; and • Consumer lines of credit include home equity lines of credit and consumer lines of credit that are either unsecured or secured by collateral other than home equity where the primary default risk driver is the borrower's employment status and income. The loans and leases portfolio consists principally of loans to individuals and small- and medium-sized businesses within our primary market in seven states and the District of Columbia. Our primary market coverage spans several major metropolitan areas including: Pittsburgh, Pennsylvania; Baltimore, Maryland; Cleveland, Ohio; Washington, D.C.; and Charlotte, Raleigh, Durham and the Piedmont Triad (Winston-Salem, Greensboro and High Point) in North Carolina. The following table shows occupancy information relating to commercial real estate loans: TABLE 4.2 (dollars in millions) September 30, December 31, Commercial real estate: Percent owner-occupied 28.2 % 28.1 % Percent non-owner-occupied 71.8 71.9 Credit Quality Management monitors the credit quality of our loan portfolio using several performance measures based on payment activity and borrower performance. We use an internal risk rating assigned to a commercial loan or lease at origination, summarized below. TABLE 4.3 Rating Category Definition Pass in general, the condition of the borrower and the performance of the loan is satisfactory or better Special Mention in general, the condition of the borrower has deteriorated, requiring an increased level of monitoring Substandard in general, the condition of the borrower has significantly deteriorated and the performance of the loan could further deteriorate if deficiencies are not corrected Doubtful in general, the condition of the borrower has significantly deteriorated and the collection in full of both principal and interest is highly questionable or improbable The use of these internally assigned credit quality categories within the commercial loan and lease portfolio permits management’s use of transition matrices to establish a basis which is then impacted by quantitative inputs from our econometric model forecasts over the R&S period. Our internal credit risk grading system is based on past experiences with similarly graded loans and leases and conforms to regulatory categories. In general, loan and lease risk ratings within each category are reviewed on an ongoing basis according to our policy for each class of loans and leases. Each quarter, management analyzes the resulting ratings, as well as other external statistics and factors such as delinquency, to track the migration performance of the commercial loan and lease portfolio. Loans and leases within the Pass credit category or that migrate toward the Pass credit category generally have a lower risk of loss compared to loans and leases that migrate toward the Substandard or Doubtful credit categories. Accordingly, management applies higher risk factors to Substandard and Doubtful credit categories. The following tables summarize the designated loan rating category by loan class including term loans on an amortized cost basis by origination year: TABLE 4.4 September 30, 2021 2021 2020 2019 2018 2017 Prior Revolving Loans Amortized Cost Basis Total (in millions) COMMERCIAL Commercial Real Estate: Risk Rating: Pass $ 1,290 $ 1,817 $ 1,706 $ 964 $ 797 $ 2,385 $ 148 $ 9,107 Special Mention 15 16 45 111 115 175 2 479 Substandard — 8 34 38 44 158 3 285 Total commercial real estate 1,305 1,841 1,785 1,113 956 2,718 153 9,871 Commercial and Industrial: Risk Rating: Pass 1,500 980 788 422 200 293 1,335 5,518 Special Mention — 31 15 5 18 64 35 168 Substandard 2 6 22 61 65 21 97 274 Total commercial and industrial 1,502 1,017 825 488 283 378 1,467 5,960 Commercial Leases: Risk Rating: Pass 139 124 107 58 43 2 — 473 Special Mention — — — 2 3 2 — 7 Substandard — 4 3 2 — — — 9 Total commercial leases 139 128 110 62 46 4 — 489 Other Commercial: Risk Rating: Pass 23 — — — — 9 49 81 Substandard — — — — — — — — Total other commercial 23 — — — — 9 49 81 Total commercial 2,969 2,986 2,720 1,663 1,285 3,109 1,669 16,401 CONSUMER Direct Installment: Current 707 585 240 141 106 458 — 2,237 Past due — — 1 1 — 11 — 13 Total direct installment 707 585 241 142 106 469 — 2,250 Residential Mortgages: Current 996 986 445 167 240 715 2 3,551 Past due — 2 4 4 3 24 — 37 Total residential mortgages 996 988 449 171 243 739 2 3,588 Indirect Installment: Current 415 290 180 210 80 45 — 1,220 Past due 2 2 2 2 1 1 — 10 Total indirect installment 417 292 182 212 81 46 — 1,230 Consumer Lines of Credit: Current 13 3 4 6 3 126 1,078 1,233 Past due — — — — — 12 2 14 Total consumer lines of credit 13 3 4 6 3 138 1,080 1,247 Total consumer 2,133 1,868 876 531 433 1,392 1,082 8,315 Total loans and leases $ 5,102 $ 4,854 $ 3,596 $ 2,194 $ 1,718 $ 4,501 $ 2,751 $ 24,716 December 31, 2020 2020 2019 2018 2017 2016 Prior Revolving Loans Amortized Cost Basis Total (in millions) COMMERCIAL Commercial Real Estate: Risk Rating: Pass $ 1,879 $ 1,854 $ 1,135 $ 927 $ 888 $ 1,911 $ 163 $ 8,757 Special Mention 9 30 80 158 70 163 4 514 Substandard 4 32 29 81 116 192 6 460 Total commercial real estate 1,892 1,916 1,244 1,166 1,074 2,266 173 9,731 Commercial and Industrial: Risk Rating: Pass 3,286 1,007 590 304 120 311 1,095 6,713 Special Mention 30 23 13 28 10 35 79 218 Substandard 8 26 65 44 6 37 97 283 Total commercial and industrial 3,324 1,056 668 376 136 383 1,271 7,214 Commercial Leases: Risk Rating: Pass 178 134 83 56 5 3 — 459 Special Mention 1 1 4 4 1 2 — 13 Substandard 7 2 2 1 1 — — 13 Total commercial leases 186 137 89 61 7 5 — 485 Other Commercial: Risk Rating: Pass — — — — — 4 35 39 Substandard — — — — — 1 — 1 Total other commercial — — — — — 5 35 40 Total commercial 5,402 3,109 2,001 1,603 1,217 2,659 1,479 17,470 CONSUMER Direct Installment: Current 706 337 200 143 171 442 1 2,000 Past due — 1 2 1 2 14 — 20 Total direct installment 706 338 202 144 173 456 1 2,020 Residential Mortgages: Current 1,079 707 283 378 330 603 1 3,381 Past due 1 5 7 4 6 29 — 52 Total residential mortgages 1,080 712 290 382 336 632 1 3,433 Indirect Installment: Current 372 260 332 147 67 27 — 1,205 Past due 1 3 4 2 2 1 — 13 Total indirect installment 373 263 336 149 69 28 — 1,218 Consumer Lines of Credit: Current 4 7 8 3 5 127 1,146 1,300 Past due — — — — — 15 3 18 Total consumer lines of credit 4 7 8 3 5 142 1,149 1,318 Total consumer 2,163 1,320 836 678 583 1,258 1,151 7,989 Total loans and leases $ 7,565 $ 4,429 $ 2,837 $ 2,281 $ 1,800 $ 3,917 $ 2,630 $ 25,459 We use delinquency transition matrices within the consumer and other loan classes to establish the basis for the R&S forecast portion of the credit risk. Each month, management analyzes payment and volume activity, Fair Isaac Corporation (FICO) scores and Debt-to-Income (DTI) scores and other external factors such as unemployment, to determine how consumer loans are performing. Non-Performing and Past Due The following tables provide an analysis of the aging of loans by class. TABLE 4.5 (in millions) 30-89 Days > 90 Days Past Due and Still Accruing Non- Total Current Total Non-accrual with No ACL September 30, 2021 Commercial real estate $ 6 $ — $ 55 $ 61 $ 9,810 $ 9,871 $ 20 Commercial and industrial 13 — 23 36 5,924 5,960 4 Commercial leases 4 — 1 5 484 489 — Other — — 1 1 80 81 — Total commercial loans and leases 23 — 80 103 16,298 16,401 24 Direct installment 4 1 8 13 2,237 2,250 — Residential mortgages 18 5 14 37 3,551 3,588 — Indirect installment 8 — 2 10 1,220 1,230 — Consumer lines of credit 6 2 6 14 1,233 1,247 — Total consumer loans 36 8 30 74 8,241 8,315 — Total loans and leases $ 59 $ 8 $ 110 $ 177 $ 24,539 $ 24,716 $ 24 (in millions) 30-89 Days > 90 Days Past Due and Still Accruing Non- Total Current Total Non-accrual with No ACL December 31, 2020 Commercial real estate $ 13 $ — $ 85 $ 98 $ 9,633 $ 9,731 $ 36 Commercial and industrial 8 — 44 52 7,162 7,214 16 Commercial leases 2 — 2 4 481 485 — Other — — 1 1 39 40 — Total commercial loans and leases 23 — 132 155 17,315 17,470 52 Direct installment 7 2 11 20 2,000 2,020 — Residential mortgages 23 11 18 52 3,381 3,433 — Indirect installment 10 1 2 13 1,205 1,218 — Consumer lines of credit 9 2 7 18 1,300 1,318 — Total consumer loans 49 16 38 103 7,886 7,989 — Total loans and leases $ 72 $ 16 $ 170 $ 258 $ 25,201 $ 25,459 $ 52 Following is a summary of non-performing assets: TABLE 4.6 (dollars in millions) September 30, December 31, Non-accrual loans $ 110 $ 170 Total non-performing loans 110 170 Other real estate owned 8 10 Total non-performing assets $ 118 $ 180 Asset quality ratios: Non-performing loans / total loans and leases 0.45 % 0.67 % Non-performing assets + 90 days past due + OREO / total loans and leases + OREO 0.51 0.77 The carrying value of residential-secured consumer OREO held as a result of obtaining physical possession upon completion of a foreclosure or through completion of a deed in lieu of foreclosure amounted to $1.1 million at September 30, 2021 and $2.5 million at December 31, 2020. The recorded investment of residential-secured consumer OREO for which formal foreclosure proceedings are in process at September 30, 2021 and December 31, 2020 totaled $6.3 million and $8.2 million, respectively. During 2020 and 2021, we extended the residential mortgage foreclosure moratorium beyond the requirements for government-backed loans, under the CARES Act, to all residential mortgage loan customers. Approximately $40 million of commercial loans are collateral dependent at September 30, 2021. Repayment is expected to be substantially through the operation or sale of the collateral on the loan. These loans are primarily secured by business assets or commercial real estate. Troubled Debt Restructurings TDRs are loans whose contractual terms have been modified in a manner that grants a concession to a borrower experiencing financial difficulties. TDRs typically result from loss mitigation activities and could include the extension of a maturity date, interest rate reduction, principal forgiveness, deferral or decrease in payments for a period of time and other actions intended to minimize the economic loss and to avoid foreclosure or repossession of collateral. Consistent with the CARES Act and interagency bank regulatory guidance which allows temporary relief for current borrowers affected by COVID-19, we are working with borrowers and granting certain modifications through programs related to COVID-19 relief. As of September 30, 2021, we had $54 million in loans that have been granted short-term modifications as a result of financial disruptions associated with the COVID-19 pandemic, compared to $397 million as of December 31, 2020 and $2.4 billion as of June 30, 2020, the highest point during the pandemic. Also, consistent with the CARES Act and the interagency bank regulatory guidelines, such modifications are not included in our TDR totals. Following is a summary of the composition of total TDRs: TABLE 4.7 (in millions) September 30, December 31, Accruing $ 58 $ 58 Non-accrual 35 33 Total TDRs $ 93 $ 91 TDRs that are accruing and performing include loans that met the criteria for non-accrual of interest prior to restructuring for which we can reasonably estimate the timing and amount of the expected cash flows on such loans and for which we expect to fully collect the new carrying value of the loans. During the nine months ended September 30, 2021, we returned to accruing status $7.8 million in restructured residential mortgage loans that have consistently met their modified obligations for more than six months. TDRs that are on non-accrual are not placed on accruing status until all delinquent principal and interest have been paid and the ultimate collectability of the remaining principal and interest is reasonably assured. Some loan modifications classified as TDRs may not ultimately result in the full collection of principal and interest, as modified, and may result in potential incremental losses which are factored into the ACL. Commercial loans over $1.0 million whose terms have been modified in a TDR are generally placed on non-accrual, individually analyzed and measured based on the fair value of the underlying collateral. Our ACL includes specific reserves for commercial TDRs of $1.4 million at September 30, 2021 compared to $2.8 million at December 31, 2020, and pooled reserves for individual loans of $1.8 million and $2.5 million for those same periods, respectively, based on loan segment LGD. Upon default, the amount of the recorded investment in the TDR in excess of the fair value of the collateral, less estimated selling costs, is generally considered a confirmed loss and is charged-off against the ACL. All other classes of loans whose terms have been modified in a TDR are pooled and measured based on the loan segment LGD. Our ACL included pooled reserves for these classes of loans of $3.8 million for September 30, 2021 and $4.1 million for December 31, 2020. Upon default of an individual loan, our charge-off policy is followed for that class of loan. Following is a summary of TDR loans, by class, for loans that were modified during the periods indicated: TABLE 4.8 Three Months Ended September 30, 2021 Nine Months Ended September 30, 2021 (dollars in millions) Number Pre- Post- Number Pre- Post- Commercial real estate 5 $ 2 $ 2 21 $ 20 $ 20 Commercial and industrial 3 — — 8 1 — Other 1 — — 1 — — Total commercial loans 9 2 2 30 21 20 Direct installment 8 — — 26 1 1 Residential mortgages 12 2 2 15 2 2 Consumer lines of credit 7 — — 31 2 2 Total consumer loans 27 2 2 72 5 5 Total 36 $ 4 $ 4 102 $ 26 $ 25 Three Months Ended September 30, 2020 Nine Months Ended September 30, 2020 (dollars in millions) Number Pre- Post- Number Pre- Post- Commercial real estate 7 $ 2 $ 2 23 $ 8 $ 6 Commercial and industrial 4 — — 19 3 2 Other — — — 1 — — Total commercial loans 11 2 2 43 11 8 Direct installment 14 1 1 50 3 3 Residential mortgages 2 1 1 18 3 2 Consumer lines of credit 9 — — 36 1 1 Total consumer loans 25 2 2 104 7 6 Total 36 $ 4 $ 4 147 $ 18 $ 14 The year-to-date items in the above tables have been adjusted for loans that have been paid off and/or sold. Following is a summary of TDRs, by class, for which there was a payment default, excluding loans that have been paid off and/or sold. Default occurs when a loan is 90 days or more past due and is within 12 months of restructuring. TABLE 4.9 Three Months Ended Nine Months Ended (dollars in millions) Number of Recorded Number of Recorded Commercial and industrial — $ — 1 $ — Total commercial loans — — 1 — Direct installment 1 — 1 — Residential mortgages — — 1 — Total consumer loans 1 — 2 — Total 1 $ — 3 $ — Three Months Ended Nine Months Ended (dollars in millions) Number of Recorded Number of Recorded Commercial real estate — $ — 8 $ 3 Commercial and industrial 1 — 3 — Total commercial loans 1 — 11 3 Direct installment 4 — 12 1 Residential mortgages — — 2 — Consumer lines of credit 1 — 3 — Total consumer loans 5 — 17 1 Total 6 $ — 28 $ 4

ALLOWANCE FOR CREDIT LOSSES ON

ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES	9 Months Ended
	Sep. 30, 2021
Receivables [Abstract]
ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES	ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES Beginning January 1, 2020, the former incurred loss method was replaced with the CECL method to calculate estimated loan losses. The CECL model takes into consideration the expected credit losses over the expected life of the loan compared to the incurred loss model under the prior standard. At the time of CECL adoption, we recorded a one-time cumulative-effect adjustment of $50.6 million as a reduction to Retained Earnings. The ACL balance increased by $105 million and included a “gross-up" to purchased credit impaired (PCD under CECL) loan balances and the ACL of $50 million. Included in the CECL adoption impact was a Day 1 increase to our AULC of $10 million. The ACL addresses credit losses expected in the existing loan and lease portfolio and is presented as a reserve against loans and leases on the Consolidated Balance Sheets. Loan and lease losses are charged off against the ACL, with recoveries of amounts previously charged off credited to the ACL. Provisions for credit losses are charged to operations based on management’s periodic evaluation of the appropriate level of the ACL. Included in Table 5.1 is the impact to the ACL from our CECL (ASC 326) adoption on January 1, 2020. Following is a summary of changes in the ACL, by loan and lease class: TABLE 5.1 (in millions) Balance at Charge- Recoveries Net Provision for Credit Losses Balance at Three Months Ended September 30, 2021 Commercial real estate $ 176 $ (3) $ 2 $ (1) $ (14) $ 161 Commercial and industrial 81 (2) 2 — 6 87 Commercial leases 16 — — — — 16 Other 1 — — — 1 2 Total commercial loans and leases 274 (5) 4 (1) (7) 266 Direct installment 27 (1) — (1) — 26 Residential mortgages 33 — — — — 33 Indirect installment 12 — — — 1 13 Consumer lines of credit 11 (1) 1 — — 11 Total consumer loans 83 (2) 1 (1) 1 83 Total allowance for credit losses on loans and leases 357 (7) 5 (2) (6) 349 Allowance for unfunded loan commitments 14 — — — 4 18 Total allowance for credit losses on loans and leases and allowance for unfunded loan commitments $ 371 $ (7) $ 5 $ (2) $ (2) $ 367 Nine Months Ended September 30, 2021 Commercial real estate $ 181 $ (9) $ 5 $ (4) $ (16) $ 161 Commercial and industrial 81 (11) 4 (7) 13 87 Commercial leases 17 — 1 1 (2) 16 Other 1 (2) 1 (1) 2 2 Total commercial loans and leases 280 (22) 11 (11) (3) 266 Direct installment 26 (1) — (1) 1 26 Residential mortgages 34 — — — (1) 33 Indirect installment 11 (3) 2 (1) 3 13 Consumer lines of credit 12 (1) 1 — (1) 11 Total consumer loans 83 (5) 3 (2) 2 83 Total allowance for credit losses on loans and leases 363 (27) 14 (13) (1) 349 Allowance for unfunded loan commitments 14 — — — 4 18 Total allowance for credit losses on loans and leases and allowance for unfunded loan commitments $ 377 $ (27) $ 14 $ (13) $ 3 $ 367 (in millions) Balance at Charge- Recoveries Net Provision ASC 326 Adoption Impact Initial ACL on PCD Loans Balance at Three Months Ended September 30, 2020 Commercial real estate $ 163 $ (3) $ 1 $ (2) $ 23 $ — $ — $ 184 Commercial and industrial 98 (17) 1 (16) 11 — — 93 Commercial leases 17 — — — — — — 17 Other 1 (1) — (1) 1 — — 1 Total commercial loans and leases 279 (21) 2 (19) 35 — — 295 Direct installment 25 — — — (1) — — 24 Residential mortgages 33 (1) 1 — (2) — — 31 Indirect installment 17 (1) 1 — (5) — — 12 Consumer lines of credit 11 — — — — — — 11 Total consumer loans 86 (2) 2 — (8) — — 78 Total allowance for credit losses on loans and leases 365 (23) 4 (19) 27 — — 373 Allowance for unfunded loan commitments (1) 15 — — — — — — 15 Total allowance for credit losses on loans and leases and allowance for unfunded loan commitments $ 380 $ (23) $ 4 $ (19) $ 27 $ — $ — $ 388 Nine Months Ended September 30, 2020 Commercial real estate $ 60 $ (8) $ 6 $ (2) $ 48 $ 38 $ 40 $ 184 Commercial and industrial 53 (25) 3 (22) 50 8 4 93 Commercial leases 11 — — — 6 — — 17 Other 9 (3) — (3) 4 (9) — 1 Total commercial loans and leases 133 (36) 9 (27) 108 37 44 295 Direct installment 13 (1) — (1) 1 10 1 24 Residential mortgages 22 (1) 1 — (1) 6 4 31 Indirect installment 19 (6) 3 (3) (6) 2 — 12 Consumer lines of credit 9 (2) — (2) 3 — 1 11 Total consumer loans 63 (10) 4 (6) (3) 18 6 78 Total allowance for credit losses on loans and leases 196 (46) 13 (33) 105 55 50 373 Allowance for unfunded loan commitments (1) 3 — — — 2 10 — 15 Total allowance for credit losses on loans and leases and allowance for unfunded loan commitments $ 199 $ (46) $ 13 $ (33) $ 107 $ 65 $ 50 $ 388 (1) The net benefit of $0.3 million for the quarter and $2 million for the year-to-date provision for the AULC is included in other non-interest expense on the Consolidated Statements of Income. Following is a summary of changes in the AULC by portfolio segment: TABLE 5.2 Three Months Ended Nine Months Ended 2021 2020 2021 2020 (in millions) Balance at beginning of period $ 14 $ 15 $ 14 $ 3 Provision for unfunded loan commitments and letters of credit: Commercial portfolio 4 — 4 — Consumer portfolio — — — — Other adjustments: Commercial portfolio — — — 2 ASC 326 adoption impact: Commercial portfolio — — — 8 Consumer portfolio — — — 2 Balance at end of period $ 18 $ 15 $ 18 $ 15 The model used to calculate the ACL is dependent on the portfolio composition and credit quality, as well as historical experience, current conditions and forecasts of economic conditions and interest rates. Specifically, the following considerations are incorporated into the ACL calculation: • a third-party macroeconomic forecast scenario; • a 24-month R&S forecast period for macroeconomic factors with a reversion to the historical mean on a straight-line basis over a 12-month period; and • the historical through-the-cycle mean was calculated using an expanded period to include a prior recessionary period. COVID-19 Impacts on the ACL Beginning in March 2020, the broader economy experienced a significant deterioration in the macroeconomic environment driven by the COVID-19 pandemic resulting in notable adverse changes to forecasted economic variables utilized in our ACL modeling process. Based on these changes, we utilized a third-party pandemic recessionary scenario from the first quarter of 2020 through the third quarter of 2020 for ACL modeling purposes. At September 30, 2021 and December 31, 2020, we utilized a third-party consensus macroeconomic forecast due to the improving macroeconomic environment. Macroeconomic variables that we utilized from this scenario for our ACL calculation as of December 31, 2020 included, but were not limited to: (i) gross domestic product, which reflects growth of 4% in 2021, (ii) the Dow Jones Total Stock Market Index, which grows steadily throughout the R&S forecast period, (iii) unemployment, which steadily declines and averages 6% over the R&S forecast period and (iv) the Volatility Index, which remains stable over the R&S forecast period. For our ACL calculation at September 30, 2021, the macroeconomic variables that we utilized included, but were not limited to: (i) the purchase only Housing Price Index, which reflects growth of 6.1% over our R&S forecast period, (ii) a Commercial Real Estate Price Index, which reflects growth of 9.5% over our R&S forecast period, (iii) S&P Volatility, which increases 7.7% in 2022 before declining 2.7% in 2023 and (iv) bankruptcies, which increase steadily over the R&S forecast period but average below historical levels. While we have not changed our ACL modeling methodology, we continually assess our key macroeconomic variables and their correlation to our historical and expected portfolio performance. During the quarter, we changed certain macroeconomic variables used for ACL modeling purposes as the new variables better correlate to our historical performance over the economic cycles. The ACL of $349.3 million at September 30, 2021 decreased $13.9 million, or 3.8%, from December 31, 2020 due to the improving macroeconomic environment and positive credit quality trends. Our ending ACL coverage ratio at September 30, 2021 was 1.41%, compared to 1.43% at December 31, 2020. Total provision for credit losses for the three months ended September 30, 2021 was a net benefit of $1.8 million. Net charge-offs were $1.6 million during the three months ended September 30, 2021, compared to $19.3 million during the three months ended September 30, 2020, reflecting COVID-19 impacts on certain segments of the loan portfolio. Total provision for credit losses for the nine months ended September 30,

LOAN SERVICING

LOAN SERVICING	9 Months Ended
	Sep. 30, 2021
Transfers and Servicing [Abstract]
LOAN SERVICING	LOAN SERVICING Mortgage Loan Servicing We retain the servicing rights on certain mortgage loans sold. The unpaid principal balance of mortgage loans serviced for others is listed below: TABLE 6.1 (in millions) September 30, December 31, Mortgage loans sold with servicing retained $ 4,797 $ 4,653 The following table summarizes activity relating to mortgage loans sold with servicing retained: TABLE 6.2 Three Months Ended Nine Months Ended (in millions) 2021 2020 2021 2020 Mortgage loans sold with servicing retained $ 382 $ 466 $ 1,406 $ 1,142 Pretax net gains resulting from above loan sales (1) 10 25 36 47 Mortgage servicing fees (1) 3 3 9 9 (1) Recorded in mortgage banking operations on the Consolidated Statements of Income. Following is a summary of activity relating to MSRs: TABLE 6.3 Three Months Ended Nine Months Ended (in millions) 2021 2020 2021 2020 Balance at beginning of period $ 40.5 $ 34.0 $ 35.6 $ 42.6 Additions 4.4 4.5 15.3 11.0 Payoffs and curtailments (2.8) (4.6) (10.4) (10.5) (Impairment charge) / recovery 1.0 0.5 3.8 (7.5) Amortization (0.6) (0.6) (1.8) (1.8) Balance at end of period $ 42.5 $ 33.8 $ 42.5 $ 33.8 Fair value, beginning of period $ 40.8 $ 34.0 $ 35.6 $ 45.0 Fair value, end of period 43.2 33.8 43.2 33.8 We had a $3.5 million valuation allowance for MSRs as of September 30, 2021, compared to $7.3 million at December 31, 2020. The fair value of MSRs is highly sensitive to changes in assumptions and is determined by estimating the present value of the asset’s future cash flows utilizing market-based prepayment rates, discount rates and other assumptions validated through comparison to trade information, industry surveys and with the use of independent third-party valuations. Changes in prepayment speed assumptions have the most significant impact on the fair value of MSRs. Generally, as interest rates decline, mortgage loan prepayments accelerate due to increased refinance activity, which results in a decrease in the fair value of MSRs and as interest rates increase, mortgage loan prepayments decline, which results in an increase in the fair value of MSRs. Measurement of fair value is limited to the conditions existing and the assumptions utilized as of a particular point in time, and those assumptions may not be appropriate if they are applied at a different time. Following is a summary of the sensitivity of the fair value of MSRs to changes in key assumptions: TABLE 6.4 (dollars in millions) September 30, December 31, Weighted average life (months) 74.3 66.6 Constant prepayment rate (annualized) 11.8 % 13.4 % Discount rate 9.5 % 9.5 % Effect on fair value due to change in interest rates: +0.25% $ 3 $ 2 +0.50% 5 4 -0.25% (3) (2) -0.50% (6) (3) The sensitivity calculations above are hypothetical and should not be considered to be predictive of future performance. Changes in fair value based on adverse changes in assumptions generally cannot be extrapolated because the relationship of the changes in assumptions to fair value may not be linear. Also, in this table, the effects of an adverse variation in a particular assumption on the fair value of MSRs is calculated without changing any other assumptions, while in reality, changes in one factor may result in changing another, which may magnify or contract the effect of the change.

LEASES

LEASES	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
LEASES	LEASES We have operating leases primarily for certain branches, office space, land and office equipment. We have finance leases for certain branches. Our operating leases expire at various dates through the year 2046 and generally include one or more options to renew. Our finance leases expire at various dates through the year 2051 and generally include one or more options to renew. The exercise of lease renewal options is at our sole discretion. As of September 30, 2021, we had operating lease right-of-use assets operating lease liabilities Our operating lease agreements do not contain any material residual value guarantees or material restrictive covenants. As of September 30, 2021, we have certain operating lease agreements, primarily for administrative office space, that have not yet commenced. At commencement, it is expected that these leases will add approximately $69.2 million and $109.8 million in right-of-use assets and other liabilities, respectively. These operating leases are currently expected to commence in 2021 - 2023 with lease terms up to 16 years. These operating leases include the lease, with a related party, of the future new FNB headquarters building in Pittsburgh, Pennsylvania. The related party operating the lease is accounted for in a manner consistent with all other leases on the basis of the legally enforceable terms and conditions of the lease and represents a VIE for which we are not the primary beneficiary. The components of lease expense were as follows: TABLE 7.1 Three Months Ended Nine Months Ended (dollars in millions) 2021 2020 2021 2020 Operating lease cost $ 7 $ 7 $ 21 $ 20 Short-term lease cost — 1 — 1 Variable lease cost 1 1 3 3 Total lease cost $ 8 $ 9 $ 24 $ 24 Other information related to leases is as follows: TABLE 7.2 Nine Months Ended (dollars in millions) 2021 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 7 $ 19 Operating cash flows from finance leases $ — $ — Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 7 $ 5 Finance leases $ — $ — Weighted average remaining lease term (years): Operating leases 9.05 9.51 Finance leases 24.13 0 Weighted average discount rate: Operating leases 2.5 % 2.8 % Finance leases 1.9 % — % Maturities of lease liabilities were as follows: TABLE 7.3 (in millions) Operating Leases Finance Leases Total Leases September 30, 2021 2021 $ 7 $ — $ 7 2022 23 — 23 2023 19 — 19 2024 17 — 17 2025 13 — 13 Later years 67 12 79 Total lease payments 146 12 158 Less: imputed interest (15) (2) (17) Present value of lease liabilities $ 131 $ 10 $ 141 As a lessor we offer commercial leasing services to customers in need of new or used equipment primarily within our market areas of Pennsylvania, Ohio, Maryland, North Carolina, South Carolina and West Virginia. Additional information relating to commercial leasing is provided in Note 4, “Loans and Leases” in the Notes to Consolidated Financial Statements.
LEASES	LEASES We have operating leases primarily for certain branches, office space, land and office equipment. We have finance leases for certain branches. Our operating leases expire at various dates through the year 2046 and generally include one or more options to renew. Our finance leases expire at various dates through the year 2051 and generally include one or more options to renew. The exercise of lease renewal options is at our sole discretion. As of September 30, 2021, we had operating lease right-of-use assets operating lease liabilities Our operating lease agreements do not contain any material residual value guarantees or material restrictive covenants. As of September 30, 2021, we have certain operating lease agreements, primarily for administrative office space, that have not yet commenced. At commencement, it is expected that these leases will add approximately $69.2 million and $109.8 million in right-of-use assets and other liabilities, respectively. These operating leases are currently expected to commence in 2021 - 2023 with lease terms up to 16 years. These operating leases include the lease, with a related party, of the future new FNB headquarters building in Pittsburgh, Pennsylvania. The related party operating the lease is accounted for in a manner consistent with all other leases on the basis of the legally enforceable terms and conditions of the lease and represents a VIE for which we are not the primary beneficiary. The components of lease expense were as follows: TABLE 7.1 Three Months Ended Nine Months Ended (dollars in millions) 2021 2020 2021 2020 Operating lease cost $ 7 $ 7 $ 21 $ 20 Short-term lease cost — 1 — 1 Variable lease cost 1 1 3 3 Total lease cost $ 8 $ 9 $ 24 $ 24 Other information related to leases is as follows: TABLE 7.2 Nine Months Ended (dollars in millions) 2021 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 7 $ 19 Operating cash flows from finance leases $ — $ — Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 7 $ 5 Finance leases $ — $ — Weighted average remaining lease term (years): Operating leases 9.05 9.51 Finance leases 24.13 0 Weighted average discount rate: Operating leases 2.5 % 2.8 % Finance leases 1.9 % — % Maturities of lease liabilities were as follows: TABLE 7.3 (in millions) Operating Leases Finance Leases Total Leases September 30, 2021 2021 $ 7 $ — $ 7 2022 23 — 23 2023 19 — 19 2024 17 — 17 2025 13 — 13 Later years 67 12 79 Total lease payments 146 12 158 Less: imputed interest (15) (2) (17) Present value of lease liabilities $ 131 $ 10 $ 141 As a lessor we offer commercial leasing services to customers in need of new or used equipment primarily within our market areas of Pennsylvania, Ohio, Maryland, North Carolina, South Carolina and West Virginia. Additional information relating to commercial leasing is provided in Note 4, “Loans and Leases” in the Notes to Consolidated Financial Statements.

VARIABLE INTEREST ENTITIES

VARIABLE INTEREST ENTITIES	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
VARIABLE INTEREST ENTITIES	VARIABLE INTEREST ENTITIESWe evaluate our interest in certain entities to determine if these entities meet the definition of a VIE and whether we are the primary beneficiary and required to consolidate the entity based on the variable interest we held both at inception and when there is a change in circumstances that requires a reconsideration. Unconsolidated VIEs The following table provides a summary of the assets and liabilities included in our Consolidated Financial Statements, as well as the maximum exposure to losses, associated with our interests related to VIEs for which we hold an interest, but are not the primary beneficiary, at September 30, 2021 and December 31, 2020. TABLE 8.1 (in millions) Total Assets Total Liabilities Maximum Exposure to Loss September 30, 2021 Trust preferred securities (1) $ 1 $ 67 $ — Affordable housing tax credit partnerships 113 37 113 Other investments 26 4 26 Total $ 140 $ 108 $ 139 December 31, 2020 Trust preferred securities (1) $ 1 $ 66 $ — Affordable housing tax credit partnerships 119 45 119 Other investments 26 8 26 Total $ 146 $ 119 $ 145 (1) Represents our investment in unconsolidated subsidiaries. Trust-Preferred Securities We have certain wholly-owned trusts whose assets, liabilities, equity, income and expenses are not included within our Consolidated Financial Statements. These trusts have been formed for the sole purpose of issuing TPS, from which the proceeds are then invested in our junior subordinated debentures, which are reflected in our Consolidated Balance Sheets as subordinated notes. The TPS are the obligations of the trusts, and as such, are not consolidated within our Consolidated Financial Statements. For additional information relating to our TPS, see Note 9, “Borrowings” in the Notes to Consolidated Financial Statements. Each issue of the junior subordinated debentures has an interest rate equal to the corresponding TPS distribution rate. We have the right to defer payment of interest on the debentures at any time, or from time-to-time for a period not exceeding five years provided that no extension period may extend beyond the stated maturity of the related debentures. During any such extension period, distributions to the TPS will also be deferred and our ability to pay dividends on our common stock will be restricted. Periodic cash payments and payments upon liquidation or redemption with respect to TPS are guaranteed by us to the extent of funds held by the trusts. The guarantee ranks subordinate and junior in right of payment to all of our indebtedness to the same extent as the junior subordinated debt. The guarantee does not place a limitation on the amount of additional indebtedness that may be incurred by us. Affordable Housing Tax Credit Partnerships We make equity investments as a limited partner in various partnerships that sponsor affordable housing projects utilizing the LIHTC pursuant to Section 42 of the Internal Revenue Code. The purpose of these investments is to support initiatives associated with the Community Reinvestment Act while earning a satisfactory return. The activities of these LIHTC partnerships include the development and operation of multi-family housing that is leased to qualifying residential tenants. These partnerships are generally located in communities where we have a banking presence and meet the definition of a VIE; however, we are not the primary beneficiary of the entities, as the general partner or managing member has both the power to direct the activities that most significantly impact the economic performance of the entities and the obligation to absorb losses beyond our own equity investment. We record our investment in LIHTC partnerships as a component of other assets. We use the proportional amortization method to account for a majority of our investments in LIHTC partnerships. Investments that do not meet the requirements of the proportional amortization method are recognized using the equity method. Amortization related to investments under the proportional amortization method is recorded on a net basis as a component of the provision for income taxes on the Consolidated Statements of Income, while write-downs and losses related to investments under the equity method are included in non-interest expense. The following table presents the balances of our affordable housing tax credit investments and related unfunded commitments: TABLE 8.2 (in millions) September 30, December 31, Proportional amortization method investments included in other assets $ 74 $ 71 Equity method investments included in other assets 2 3 Total LIHTC investments included in other assets $ 76 $ 74 Unfunded LIHTC commitments $ 37 $ 45 The following table summarizes the impact of these LIHTC investments on specific line items of our Consolidated Statements of Income: TABLE 8.3 Three Months Ended Nine Months Ended (in millions) 2021 2020 2021 2020 Non-interest income: Amortization of tax credit investments under equity method, net of tax benefit $ — $ — $ 1 $ 1 Provision for income taxes: Amortization of LIHTC investments under proportional method $ 3 $ 2 $ 10 $ 8 Low-income housing tax credits (4) (3) (11) (9) Other tax benefits related to tax credit investments — — (2) (2) Total impact on provision for income taxes $ (1) $ (1) $ (3) $ (3) Other Investments Other investments we also consider to be unconsolidated VIE’s include investments in Small Business Investment Companies, Historic Tax Credit Investments, and other equity method investments.

BORROWINGS

BORROWINGS	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
BORROWINGS	BORROWINGS Following is a summary of short-term borrowings: TABLE 9.1 (in millions) September 30, December 31, Securities sold under repurchase agreements $ 407 $ 403 Federal Home Loan Bank advances 1,030 1,280 Subordinated notes 126 121 Total short-term borrowings $ 1,563 $ 1,804 Borrowings with original maturities of one year or less are classified as short-term. Securities sold under repurchase agreements are comprised of customer repurchase agreements, which are sweep accounts with next-day maturities utilized by larger commercial customers to earn interest on their funds. Securities are pledged to these customers in an amount at least equal to the outstanding balance. We did not have any short-term FHLB advances with overnight maturities as of September 30, 2021 or December 31, 2020. At September 30, 2021, $1.0 billion, or 100.0%, of the short-term FHLB advances were swapped to fixed rates with various maturities through 2024. This compares to $1.3 billion, or 100.0%, as of December 31, 2020. Following is a summary of long-term borrowings: TABLE 9.2 (in millions) September 30, December 31, Federal Home Loan Bank advances $ 200 $ 400 Senior notes 299 299 Subordinated notes 72 81 Junior subordinated debt 67 66 Other subordinated debt 248 249 Total long-term borrowings $ 886 $ 1,095 Our banking affiliate has available credit with the FHLB of $8.3 billion, of which $1.2 billion was utilized as of September 30, 2021. These advances are secured by loans collateralized by residential mortgages, home equity lines of credit, commercial real estate and FHLB stock and are scheduled to mature in various amounts periodically through the year 2021. Effective interest rates paid on the long-term advances ranged from 0.26% to 0.29% for the nine months ended September 30, 2021 and 0.30% to 0.34% for the year ended December 31, 2020. The following table provides information relating to our senior debt and other subordinated debt as of September 30, 2021. These debt issuances are fixed-rate, with the exception of the Subordinated Notes due in 2029, which are fixed-rate and become floating-rate after February 14, 2024. The subordinated notes are eligible for treatment as tier 2 capital for regulatory capital purposes. TABLE 9.3 (dollars in millions) Aggregate Principal Amount Issued Net Proceeds (2) Carrying Value Stated Maturity Date Interest 2.20% Senior Notes due February 24, 2023 $ 300 $ 298 $ 299 2/24/2023 2.20 % 4.95% Fixed-To-Floating Rate Subordinated Notes due 2029 120 118 119 2/14/2029 4.95 % 4.875% Subordinated Notes due 2025 100 98 99 10/2/2025 4.875 % 7.625% Subordinated Notes due August 12, 2023 (1) 38 46 30 8/12/2023 7.625 % Total $ 558 $ 560 $ 547 (1) Assumed from a prior acquisition and adjusted to fair value at the time of acquisition. (2) After deducting underwriting discounts and commissions and offering costs. For the debt assumed from a prior acquisition, this is the fair value of the debt at the time of the acquisition. The junior subordinated debt is comprised of the debt securities issued by FNB in relation to our unconsolidated subsidiary trusts (collectively, the Trusts), which are unconsolidated VIEs, and are included on the Consolidated Balance Sheets in long-term borrowings. Since third-party investors are the primary beneficiaries, the Trusts are not consolidated in our Financial Statements. We record the distributions on the junior subordinated debt issued to the Trusts as interest expense. The following table provides information relating to the Trusts as of September 30, 2021: TABLE 9.4 (dollars in millions) Trust Common Junior Stated Interest Rate Rate Reset Factor F.N.B. Statutory Trust II $ 22 $ 1 $ 22 6/15/2036 1.77 % LIBOR + 165 basis points (bps) Yadkin Valley Statutory Trust I 25 1 22 12/15/2037 1.44 % LIBOR + 132 bps FNB Financial Services Capital Trust I 25 1 23 9/30/2035 1.59 % LIBOR + 146 bps Total $ 72 $ 3 $ 67

DERIVATIVE INSTRUMENTS AND HEDG

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES We are exposed to certain risks arising from both our business operations and economic conditions. We principally manage our exposures to a wide variety of business and operational risks through management of our core business activities. We manage economic risks, including interest rate risk, primarily by managing the amount, source, and duration of our assets and liabilities, and through the use of derivative instruments. Derivative instruments are used to reduce the effects that changes in interest rates may have on net income and cash flows. We also use derivative instruments to facilitate transactions on behalf of our customers. All derivatives are carried on the Consolidated Balance Sheets at fair value and do not take into account the effects of master netting arrangements we have with other financial institutions. Credit risk is included in the determination of the estimated fair value of derivatives. Derivative assets are reported in the Consolidated Balance Sheets in other assets and derivative liabilities are reported in other liabilities. Changes in fair value are recognized in earnings except for certain changes related to derivative instruments designated as part of a cash flow hedging relationship. The following table presents notional amounts and gross fair values of our derivative assets and derivative liabilities which are not offset in the Consolidated Balance Sheets: TABLE 10.1 September 30, 2021 December 31, 2020 Notional Fair Value Notional Fair Value (in millions) Amount Asset Liability Amount Asset Liability Gross Derivatives Subject to master netting arrangements: Interest rate contracts – designated $ 1,580 $ 2 $ — $ 1,430 $ 3 $ — Interest rate swaps – not designated 5,332 2 25 4,791 — 37 Total subject to master netting arrangements 6,912 4 25 6,221 3 37 Not subject to master netting arrangements: Interest rate swaps – not designated 5,332 211 16 4,791 349 — Interest rate lock commitments – not designated 524 13 — 531 24 — Forward delivery commitments – not designated 575 2 — 500 — 2 Credit risk contracts – not designated 390 — — 437 — 1 Total not subject to master netting arrangements 6,821 226 16 6,259 373 3 Total $ 13,733 $ 230 $ 41 $ 12,480 $ 376 $ 40 Certain derivative exchanges have enacted a rule change which in effect results in the legal characterization of variation margin payments for certain derivative contracts as settlement of the derivatives mark-to-market exposure and not collateral. Accordingly, we have changed our reporting of certain derivatives to record variation margin on trades cleared through these exchanges as settled. The daily settlement of the derivative exposure does not change or reset the contractual terms of the instrument. We adopted RRR on October 1, 2020, and the guidance will be followed until the Update terminates on December 31, 2022. As of October 16, 2020, we changed our valuation methodology to reflect changes made by central clearinghouses that changed the discounting methodology and interest calculation of cash migration from overnight index swap (OIS) to SOFR for U.S. dollar cleared interest rate swaps to better reflect prices obtainable in the markets in which we transact. Certain of these valuation methodology changes were applied to eligible hedging relationships. Accordingly, we have updated our hedge documentation to reflect the election of certain expedients and exceptions related to our cash flow hedging programs. The change in valuation methodology was applied prospectively as a change in accounting estimate and did not have a material impact on our consolidated financial position or results of operations. Derivatives Designated as Hedging Instruments under GAAP Interest Rate Contracts. We entered into interest rate derivative agreements to modify the interest rate characteristics of certain commercial loans and certain of our FHLB advances from variable rate to fixed rate in order to reduce the impact of changes in future cash flows due to market interest rate changes. These agreements are designated as cash flow hedges, hedging the exposure to variability in expected future cash flows. The derivative’s gain or loss, including any ineffectiveness, is initially reported as a component of other comprehensive income and subsequently reclassified into earnings in the same line item associated with the forecasted transaction when the forecasted transaction affects earnings. The following table shows amounts reclassified from AOCI: TABLE 10.2 Amount of Gain (Loss) Recognized in OCI on Derivatives Location of Gain (Loss) Reclassified from AOCI into Income Amount of Gain (Loss) Reclassified from AOCI into Income Nine Months Ended Nine Months Ended (in millions) 2021 2020 2021 2020 Derivatives in cash flow hedging relationships: Interest rate contracts $ 3 $ (42) Interest income (expense) $ (14) $ (9) Other income — (9) The following table represents gains (losses) recognized in the Consolidated Statements of Income on cash flow hedging relationships: TABLE 10.3 Nine months ended September 30, 2021 2020 (in millions) Interest Income - Loans and Leases Interest Expense - Short-Term Borrowings Interest Income - Loans and Leases Interest Expense - Short-Term Borrowings Total amounts of income and expense line items presented in the Consolidated Statements of Income (the effects of cash flow hedges are included in these line items) $ 671 $ 21 $ 750 $ 31 The effects of cash flow hedging: Gain (loss) on cash flow hedging relationships: Interest rate contracts: Amount of gain (loss) reclassified from AOCI into net income 1 (15) 2 (11) As of September 30, 2021, the maximum length of time over which forecasted interest cash flows are hedged is 4.0 years. In the twelve months that follow September 30, 2021, we expect to reclassify from the amount currently reported in AOCI net derivative losses of $14.5 million ($11.3 million net of tax), in association with interest on the hedged loans and FHLB advances. This amount could differ from amounts actually recognized due to changes in interest rates, hedge de-designations, and the addition of other hedges subsequent to September 30, 2021. During the third quarter of 2020, we terminated $225.0 million of notional value of interest rate contracts - designated subject to master netting arrangements. There were no components of derivative gains or losses excluded from the assessment of hedge effectiveness related to these cash flow hedges. Also, during the nine months ended September 30, 2021 and 2020, there were no gains or losses from cash flow hedge derivatives reclassified to earnings because it became probable that the original forecasted transactions would not occur. Derivatives Not Designated as Hedging Instruments under GAAP A description of interest rate swaps, interest rate lock commitments, forward delivery commitments and credit risk contracts can be found in Note 15, "Derivative Instruments and Hedging Activities" in the Consolidated Financial Statements included in our 2020 Annual Report on Form 10-K filed with the SEC on February 25, 2021. Interest rate swap agreements with loan customers and with the offsetting counterparties are reported at fair value in other assets and other liabilities on the Consolidated Balance Sheets with any resulting gain or loss recorded in current period earnings as other income or other expense. Risk participation agreements sold with notional amounts totaling $261.8 million as of September 30, 2021 have remaining terms ranging from nine months to twenty years. Under these agreements, our maximum exposure assuming a customer defaults on their obligation to perform under certain derivative swap contracts with third parties would be $0.3 million at September 30, 2021 and $0.6 million at December 31, 2020. The fair values of risk participation agreements purchased and sold were $0.1 million and $0.3 million, respectively, at September 30, 2021 and $0.2 million and $0.6 million, respectively at December 31, 2020. The following table presents the effect of certain derivative financial instruments on the Consolidated Statements of Income: TABLE 10.4 Nine Months Ended (in millions) Consolidated Statements of Income Location 2021 2020 Interest rate swaps Non-interest income - other $ — $ — Interest rate lock commitments Mortgage banking operations — — Forward delivery contracts Mortgage banking operations 2 (1) Credit risk contracts Non-interest income - other — — Counterparty Credit Risk We are party to master netting arrangements with most of our swap derivative dealer counterparties. Collateral, usually marketable securities and/or cash, is exchanged between FNB and our counterparties, and is generally subject to thresholds and transfer minimums. For swap transactions that require central clearing, we post cash to our clearing agency. Collateral positions are settled or valued daily, and adjustments to amounts received and pledged by us are made as appropriate to maintain proper collateralization for these transactions. Certain master netting agreements contain provisions that, if violated, could cause the counterparties to request immediate settlement or demand full collateralization under the derivative instrument. If we had breached our agreements with our derivative counterparties we would be required to settle our obligations under the agreements at the termination value and would be required to pay an additional $0.5 million and $0.3 million as of September 30, 2021 and December 31, 2020, respectively, in excess of amounts previously posted as collateral with the respective counterparty. The following table presents a reconciliation of the net amounts of derivative assets and derivative liabilities presented in the Consolidated Balance Sheets to the net amounts that would result in the event of offset: TABLE 10.5 Amount Not Offset in the (in millions) Net Amount Financial Cash Net September 30, 2021 Derivative Assets Interest rate contracts: Designated $ 2 $ — $ 2 $ — Not designated 2 — 2 — Total $ 4 $ — $ 4 $ — Derivative Liabilities Interest rate contracts: Not designated $ 25 $ — $ 24 $ 1 Total $ 25 $ — $ 24 $ 1 December 31, 2020 Derivative Assets Interest rate contracts: Designated $ 3 $ — $ 3 $ — Total $ 3 $ — $ 3 $ — Derivative Liabilities Interest rate contracts: Not designated $ 37 $ — $ 37 $ — Total $ 37 $ — $ 37 $ —

COMMITMENTS, CREDIT RISK AND CO

COMMITMENTS, CREDIT RISK AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS, CREDIT RISK AND CONTINGENCIES	COMMITMENTS, CREDIT RISK AND CONTINGENCIES We have commitments to extend credit and standby letters of credit that involve certain elements of credit risk in excess of the amount stated in the Consolidated Balance Sheets. Our exposure to credit loss in the event of non-performance by the customer is represented by the contractual amount of those instruments. The credit risk associated with commitments to extend credit and standby letters of credit is essentially the same as that involved in extending loans and leases to customers and is subject to normal credit policies. Since many of these commitments expire without being drawn upon, the total commitment amounts do not necessarily represent future cash flow requirements. Following is a summary of off-balance sheet credit risk information: TABLE 11.1 (in millions) September 30, December 31, Commitments to extend credit $ 11,015 $ 9,285 Standby letters of credit 200 158 At September 30, 2021, funding of 70.7% of the commitments to extend credit was dependent on the financial condition of the customer. We have the ability to withdraw such commitments at our discretion. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. Based on management’s credit evaluation of the customer, collateral may be deemed necessary. Collateral requirements vary and may include accounts receivable, inventory, property, plant and equipment and income-producing commercial properties. Standby letters of credit are conditional commitments issued by us that may require payment at a future date. The credit risk involved in issuing letters of credit is actively monitored through review of the historical performance of our portfolios. Our AULC for commitments that are not unconditionally cancellable, which is included in other liabilities on the Consolidated Balance Sheets, was $18.0 million at September 30, 2021 and $13.7 million at December 31, 2020. Additional information relating to the AULC is provided in Note 5, "Allowance for Credit Losses on Loans and Leases" in the Notes to Consolidated Financial Statements. In addition to the above commitments, subordinated notes issued by FNB Financial Services, LP, a wholly-owned finance subsidiary, are fully and unconditionally guaranteed by FNB. These subordinated notes are included in the summaries of short-term borrowings and long-term borrowings in Note 9, “Borrowings” in the Notes to Consolidated Financial Statements. Other Legal Proceedings In the ordinary course of business, we may assert claims in legal proceedings against another party or parties, and we are routinely named as defendants in, or made parties to, pending and potential legal actions. Also, as regulated entities, we are subject to governmental and regulatory examinations, information-gathering requests, and may be subject to investigations and proceedings (both formal and informal). Such threatened claims, litigation, investigations, regulatory and administrative proceedings typically entail matters that are considered incidental to the normal conduct of business. Claims for significant monetary damages may be asserted in many of these types of legal actions, while claims for disgorgement, reimbursement, restitution, penalties and/or other remedial actions or sanctions may be sought in regulatory matters. In these instances, if we determine that we have meritorious defenses, we will engage in an aggressive defense. However, if management determines, in consultation with counsel, that settlement of a matter is in the best interest of FNB and our shareholders, we may do so. It is inherently difficult to predict the eventual outcomes of such matters given their complexity and the particular facts and circumstances at issue in each of these matters. However, on the basis of current knowledge and understanding, and advice of counsel, we do not believe that judgments, sanctions, settlement resolutions, regulatory actions, investigations, settlements or orders, if any, that have or may arise from these matters (either individually or in the aggregate, after giving effect to applicable reserves and insurance coverage) will have a material adverse effect on our financial position or liquidity, although they could potentially have a material effect on net income in a given period. In view of the inherent unpredictability of outcomes in litigation and governmental and regulatory matters, particularly where (i) the damages sought are indeterminate, (ii) the proceedings are in the early stages, or (iii) the matters involve novel legal theories or a large number of parties, as a matter of course, there is considerable uncertainty surrounding the timing or ultimate resolution of litigation and governmental and regulatory matters, including a possible eventual loss, fine, restitution, penalty, business or adverse reputational impact, if any, associated with each such matter. In accordance with applicable accounting guidance, we establish accruals for litigation and governmental and regulatory matters when those matters proceed to a stage where they present loss contingencies that are both probable and reasonably estimable. In such cases, there may be a possible exposure to loss in excess of any amounts accrued. We will continue to monitor such matters for developments that could affect the amount of the accrual, and will adjust the accrual amount as appropriate. If the loss contingency in question is not both probable and reasonably estimable, we do not establish an accrual and the matter will continue to be monitored for any developments that would make the loss contingency both probable and reasonably estimable. We believe that our accruals for legal proceedings are appropriate and, in the aggregate, are not material to our consolidated financial position, although future accruals could have a material effect on net income in a given period.

STOCK INCENTIVE PLANS

STOCK INCENTIVE PLANS	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
STOCK INCENTIVE PLANS	STOCK INCENTIVE PLANS Restricted Stock We issue restricted stock awards to key employees under our Incentive Compensation Plan (Plan). We issue time-based awards and performance-based awards under this Plan, both of which are based on a three-year vesting period. The grant date fair value of the time-based awards is equal to the price of our common stock on the grant date. The fair value of the performance-based awards is based on a Monte-Carlo simulation valuation of our common stock as of the grant date. The assumptions used for this valuation include stock price volatility, risk-free interest rate and dividend yield. We issued 1,113,314 and 2,004,895 restricted stock units during the nine months ended September 30, 2021 and 2020, respectively, including 325,284 and 571,932 performance-based restricted stock units during those same periods, respectively. As of September 30, 2021, we had available up to 4,137,909 shares of common stock to issue under this Plan. The unvested restricted stock unit awards are eligible to receive cash dividends or dividend equivalents which are ultimately used to purchase additional shares of stock and are subject to forfeiture if the requisite service period is not completed or the specified performance criteria are not met. These awards are subject to certain accelerated vesting provisions upon retirement, death, disability or in the event of a change of control as defined in the award agreements. The following table summarizes the activity relating to restricted stock units during the periods indicated: TABLE 12.1 Nine Months Ended September 30, 2021 2020 Units Weighted Units Weighted Unvested units outstanding at beginning of period 4,322,115 $ 9.46 2,858,357 $ 12.56 Granted 1,113,314 12.65 2,004,895 5.95 Net adjustment due to performance 412,540 11.72 47,290 13.00 Vested (1,309,476) 12.10 (592,602) 14.50 Forfeited/expired/canceled (112,002) 10.94 (169,552) 13.05 Dividend reinvestment 134,600 12.26 173,990 6.99 Unvested units outstanding at end of period 4,561,091 9.74 4,322,378 9.45 The following table provides certain information related to restricted stock units: TABLE 12.2 (in millions) Nine Months Ended 2021 2020 Stock-based compensation expense $ 17 $ 13 Tax benefit related to stock-based compensation expense 4 3 Fair value of units vested 16 4 As of September 30, 2021, there was $11.7 million of unrecognized compensation cost related to unvested restricted stock units, including $1.0 million that is subject to accelerated vesting under the Plan’s immediate vesting upon retirement. The components of the restricted stock units as of September 30, 2021 are as follows: TABLE 12.3 (dollars in millions) Service- Performance- Total Unvested restricted stock units 2,933,219 1,627,872 4,561,091 Unrecognized compensation expense $ 10 $ 2 $ 12 Intrinsic value $ 34 $ 19 $ 53 Weighted average remaining life (in years) 1.86 0.88 1.51 Stock Options All outstanding stock options were assumed from acquisitions and are fully vested. Upon consummation of our acquisitions, all outstanding stock options issued by the acquired companies were converted into equivalent FNB stock options. We issue shares of treasury stock or authorized but unissued shares to satisfy stock options exercised. As of September 30, 2021, we had 170,529 stock options outstanding and exercisable at a weighted average exercise price per share of $8.75, compared to 207,030 stock options outstanding and exercisable at a weighted average exercise price per share of $8.42 as of September 30, 2020. The intrinsic value of outstanding and exercisable stock options at September 30, 2021 was $0.5 million. The aggregate intrinsic value represents the amount by which the fair value of underlying stock exceeds the option exercise price.

INCOME TAXES

INCOME TAXES	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES Income Tax Expense Federal and state income tax expense and the statutory tax rate and the actual effective tax rate consist of the following: TABLE 13.1 Three Months Ended Nine Months Ended (dollars in millions) 2021 2020 2021 2020 Current income taxes: Federal taxes $ 22 $ 16 $ 62 $ 62 State taxes 1 1 4 6 Total current income taxes 23 17 66 68 Deferred income taxes: Federal taxes 4 — 7 (24) State taxes — — 1 — Total deferred income taxes 4 — 8 (24) Total income taxes $ 27 $ 17 $ 74 $ 44 Statutory tax rate 21.0 % 21.0 % 21.0 % 21.0 % Effective tax rate 19.7 17.0 19.5 17.0 The effective tax rates for the nine months ended September 30, 2021 and 2020 were lower than the statutory federal tax rate primarily due to tax benefits resulting from tax-exempt income on investments and loans, tax credits and income from BOLI. The lower tax effective tax rate in 2020 is primarily due to lower pre-tax income levels and the impact from renewable energy investment tax credits. Deferred Income Taxes Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and tax purposes. Deferred tax assets and liabilities are measured based on the enacted tax rates that will apply in the years in which the temporary differences are expected to be recovered or paid. Net deferred tax assets were $47.4 million and $51.0 million at September 30, 2021 and December 31, 2020, respectively.

OTHER COMPREHENSIVE INCOME

OTHER COMPREHENSIVE INCOME	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
OTHER COMPREHENSIVE INCOME	OTHER COMPREHENSIVE INCOME The following table presents changes in AOCI, net of tax, by component: TABLE 14.1 (in millions) Unrealized Unrealized Unrecognized Total Nine Months Ended September 30, 2021 Balance at beginning of period $ 65 $ (40) $ (64) $ (39) Other comprehensive (loss) income before reclassifications (29) 3 2 (24) Amounts reclassified from AOCI — 11 — 11 Net current period other comprehensive (loss) income (29) 14 2 (13) Balance at end of period $ 36 $ (26) $ (62) $ (52) The amounts reclassified from AOCI related to debt securities AFS are included in net securities gains on the Consolidated Statements of Income, while the amounts reclassified from AOCI related to derivative instruments in cash flow hedge programs are generally included in interest income on loans and leases on the Consolidated Statements of Income. The tax (benefit) expense amounts reclassified from AOCI in connection with the debt securities AFS and derivative instruments reclassifications are included in income taxes on the Consolidated Statements of Income.

EARNINGS PER COMMON SHARE

EARNINGS PER COMMON SHARE	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
EARNINGS PER COMMON SHARE	EARNINGS PER COMMON SHARE Basic earnings per common share is calculated by dividing net income available to common stockholders by the weighted average number of shares of common stock outstanding net of unvested shares of restricted stock. Diluted earnings per common share is calculated by dividing net income available to common stockholders by the weighted average number of shares of common stock outstanding, adjusted for the dilutive effect of potential common shares issuable for stock options and restricted shares, as calculated using the treasury stock method. Adjustments to the weighted average number of shares of common stock outstanding are made only when such adjustments dilute earnings per common share. The following table sets forth the computation of basic and diluted earnings per common share: TABLE 15.1 Three Months Ended Nine Months Ended ( dollars in millions, except per share data) 2021 2020 2021 2020 Net income $ 111 $ 83 $ 306 $ 214 Less: Preferred stock dividends 2 2 6 6 Net income available to common stockholders $ 109 $ 81 $ 300 $ 208 Basic weighted average common shares outstanding 319,512,598 323,379,720 320,023,695 323,642,925 Net effect of dilutive stock options, warrants and restricted stock 3,348,329 2,283,060 3,611,960 2,051,221 Diluted weighted average common shares outstanding 322,860,927 325,662,780 323,635,655 325,694,146 Earnings per common share: Basic $ 0.34 $ 0.25 $ 0.94 $ 0.64 Diluted $ 0.34 $ 0.25 $ 0.93 $ 0.64 The following table shows the average shares excluded from the above calculation as their effect would have been anti-dilutive: TABLE 15.2 Three Months Ended Nine Months Ended 2021 2020 2021 2020 Average shares excluded from the diluted earnings per common share calculation — 44,755 — 22,263

CASH FLOW INFORMATION

CASH FLOW INFORMATION	9 Months Ended
	Sep. 30, 2021
Supplemental Cash Flow Elements [Abstract]
CASH FLOW INFORMATION	CASH FLOW INFORMATION Following is a summary of supplemental cash flow information: TABLE 16.1 Nine Months Ended (in millions) 2021 2020 Interest paid on deposits and other borrowings $ 82 $ 179 Income taxes paid 53 34 Transfers of loans to other real estate owned 3 2 Loans transferred to held for sale from portfolio — 508

BUSINESS SEGMENTS

BUSINESS SEGMENTS	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
BUSINESS SEGMENTS	BUSINESS SEGMENTS We operate in three reportable segments: Community Banking, Wealth Management and Insurance. • The Community Banking segment provides commercial and consumer banking services. Commercial banking solutions include corporate banking, small business banking, investment real estate financing, business credit, capital markets and lease financing. Consumer banking products and services include deposit products, mortgage lending, consumer lending and a complete suite of mobile and online banking services. • The Wealth Management segment provides a broad range of personal and corporate fiduciary services including the administration of decedent and trust estates. In addition, it offers various alternative products, including securities brokerage and investment advisory services, mutual funds and annuities. • The Insurance segment includes a full-service insurance brokerage service offering all lines of commercial and personal insurance through major carriers. The Insurance segment also includes a reinsurer. The following tables provide financial information for these segments of FNB. The information provided under the caption “Parent and Other” represents operations not considered to be reportable segments and/or general operating expenses of FNB, and includes the parent company, other non-bank subsidiaries and eliminations and adjustments to reconcile to the Consolidated Financial Statements. TABLE 17.1 (in millions) Community Wealth Insurance Parent and Consolidated At or for the Three Months Ended September 30, 2021 Interest income $ 255 $ — $ — $ 1 $ 256 Interest expense 20 — — 4 24 Net interest income 235 — — (3) 232 Provision for credit losses (2) — — — (2) Non-interest income 68 15 6 (1) 88 Non-interest expense (1) 164 10 5 2 181 Amortization of intangibles 3 — — — 3 Income tax expense (benefit) 27 1 — (1) 27 Net income (loss) 111 4 1 (5) 111 Total assets 39,238 43 34 46 39,361 Total intangibles 2,271 9 27 — 2,307 At or for the Three Months Ended September 30, 2020 Interest income $ 273 $ — $ — $ — $ 273 Interest expense 41 — — 5 46 Net interest income 232 — — (5) 227 Provision for credit losses 27 — — — 27 Non-interest income 63 12 7 (2) 80 Non-interest expense (1) 162 8 5 2 177 Amortization of intangibles 3 — — — 3 Income tax expense (benefit) 18 1 1 (3) 17 Net income (loss) 85 3 1 (6) 83 Total assets 37,315 36 36 54 37,441 Total intangibles 2,282 9 28 — 2,319 (1) Excludes amortization of intangibles, which is presented separately. (in millions) Community Wealth Insurance Parent and Consolidated At or for the Nine Months Ended September 30, 2021 Interest income $ 759 $ — $ — $ 1 $ 760 Interest expense 67 — — 10 77 Net interest income 692 — — (9) 683 Provision for credit losses 2 — — 1 3 Non-interest income 191 45 19 (4) 251 Non-interest expense (1) 491 30 15 6 542 Amortization of intangibles 8 — 1 — 9 Income tax expense (benefit) 75 3 1 (5) 74 Net income (loss) 307 12 2 (15) 306 Total assets 39,238 43 34 46 39,361 Total intangibles 2,271 9 27 — 2,307 At or for the Nine Months Ended September 30, 2020 Interest income $ 859 $ — $ — $ 1 $ 860 Interest expense 155 — — 17 172 Net interest income 704 — — (16) 688 Provision for credit losses 105 — — — 105 Non-interest income 180 36 18 (8) 226 Non-interest expense (1) 495 26 14 6 541 Amortization of intangibles 9 — 1 — 10 Income tax expense (benefit) 47 2 1 (6) 44 Net income (loss) 228 8 2 (24) 214 Total assets 37,315 36 36 54 37,441 Total intangibles 2,282 9 28 — 2,319 (1) Excludes amortization of intangibles, which is presented separately.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Refer to Note 25 "Fair Value Measurements" to the Consolidated Financial Statements included in our 2020 Annual Report on Form 10-K filed with the SEC on February 25, 2021 for a description of additional valuation methodologies for assets and liabilities measured at fair value on a recurring and non-recurring basis. The following table presents the balances of assets and liabilities measured at fair value on a recurring basis: TABLE 18.1 (in millions) Level 1 Level 2 Level 3 Total September 30, 2021 Assets Measured at Fair Value Debt securities available for sale U.S. Treasury $ 49 $ — $ — $ 49 U.S. government agencies — 154 — 154 U.S. government-sponsored entities — 170 — 170 Residential mortgage-backed securities: Agency mortgage-backed securities — 1,311 — 1,311 Agency collateralized mortgage obligations — 1,183 — 1,183 Commercial mortgage-backed securities — 306 — 306 States of the U.S. and political subdivisions (municipals) — 33 — 33 Other debt securities — 2 — 2 Total debt securities available for sale 49 3,159 — 3,208 Loans held for sale — 227 — 227 Derivative financial instruments Trading — 213 — 213 Not for trading — 4 13 17 Total derivative financial instruments — 217 13 230 Total assets measured at fair value on a recurring basis $ 49 $ 3,603 $ 13 $ 3,665 Liabilities Measured at Fair Value Derivative financial instruments Trading $ — $ 41 $ — $ 41 Not for trading — — — — Total derivative financial instruments — 41 — 41 Total liabilities measured at fair value on a recurring basis $ — $ 41 $ — $ 41 (in millions) Level 1 Level 2 Level 3 Total December 31, 2020 Assets Measured at Fair Value Debt securities available for sale U.S. Treasury $ 600 $ — $ — $ 600 U.S. government agencies — 172 — 172 U.S. government-sponsored entities — 161 — 161 Residential mortgage-backed securities: Agency mortgage-backed securities — 994 — 994 Agency collateralized mortgage obligations — 1,124 — 1,124 Commercial mortgage-backed securities — 378 — 378 States of the U.S. and political subdivisions (municipals) — 32 — 32 Other debt securities — 2 — 2 Total debt securities available for sale 600 2,863 — 3,463 Loans held for sale — 144 — 144 Derivative financial instruments Trading — 349 — 349 Not for trading — 3 24 27 Total derivative financial instruments — 352 24 376 Total assets measured at fair value on a recurring basis $ 600 $ 3,359 $ 24 $ 3,983 Liabilities Measured at Fair Value Derivative financial instruments Trading $ — $ 37 $ — $ 37 Not for trading — 3 — 3 Total derivative financial instruments — 40 — 40 Total liabilities measured at fair value on a recurring basis $ — $ 40 $ — $ 40 The following table presents additional information about assets measured at fair value on a recurring basis and for which we have utilized Level 3 inputs to determine fair value: TABLE 18.2 (in millions) Interest Total Nine Months Ended September 30, 2021 Balance at beginning of period $ 24 $ 24 Purchases, issuances, sales and settlements: Issuances 13 13 Settlements (24) (24) Balance at end of period $ 13 $ 13 Year Ended December 31, 2020 Balance at beginning of period $ 3 $ 3 Purchases, issuances, sales and settlements: Issuances 24 24 Settlements (3) (3) Balance at end of period $ 24 $ 24 We review fair value hierarchy classifications on a quarterly basis. Changes in the observability of the valuation attributes may result in reclassification of certain financial assets or liabilities. Such reclassifications are reported as transfers in/out of Level 3 at fair value at the beginning of the period in which the changes occur. There were no transfers of assets or liabilities between the hierarchy levels during the first nine months of 2021 or 2020. From time to time, we measure certain assets at fair value on a non-recurring basis. These adjustments to fair value usually result from the application of the lower of cost or fair value accounting or write-downs of individual assets. Valuation methodologies used to measure these fair value adjustments were described in Note 25, "Fair Value Measurements" to the Consolidated Financial Statements included in 2020 Annual Report on Form 10-K . For assets measured at fair value on a non-recurring basis still held at the Balance Sheet date, the following table provides the hierarchy level and the fair value of the related assets or portfolios: TABLE 18.3 (in millions) Level 1 Level 2 Level 3 Total September 30, 2021 Collateral dependent loans $ — $ — $ 9 $ 9 Other assets - MSRs — — 15 15 Other assets - SBA servicing asset — — 4 4 Other real estate owned — — 1 1 December 31, 2020 Collateral dependent loans $ — $ — $ 45 $ 45 Other assets - MSRs — — 36 36 Other assets - SBA servicing asset — — 3 3 Other real estate owned — — 3 3 The fair value amounts for collateral dependent loans and OREO in the table above were estimated at a date during the nine months or twelve months ended September 30, 2021 and December 31, 2020, respectively. Consequently, the fair value information presented is not necessarily as of the period’s end. Collateral dependent loans measured or re-measured at fair value on a non-recurring basis during the nine months ended September 30, 2021 had a carrying amount of $9.5 million, which includes an allocated ACL of $8.2 million. The ACL includes a provision applicable to the current period fair value measurements of $2.1 million, which was included in provision for credit losses for the nine months ended September 30, 2021. MSRs measured at fair value on a non-recurring basis had a carrying value of $15.5 million, which included a valuation allowance of $3.5 million, as of September 30, 2021. The valuation allowance includes a recovery of $3.8 million included in earnings for the nine months ended September 30, 2021. SBA servicing assets measured at fair value on a non-recurring basis had a carrying value of $5.3 million, which included a valuation allowance of $0.9 million, as of September 30, 2021. The valuation allowance includes a recovery of $0.2 million included in earnings for the nine months ended September 30, 2021. OREO measured at fair value on a non-recurring basis during 2021 had a carrying amount of $1.1 million, which included a valuation allowance of $0.3 million, as of September 30, 2021. The valuation allowance includes a loss of $0.3 million, which was included in earnings for the nine months ended September 30, 2021. Fair Value of Financial Instruments Refer to Note 25, "Fair Value Measurements" to the Consolidated Financial Statements included in our 2020 Annual Report on Form 10-K filed with the SEC on February 25, 2021 for a description of methods and assumptions that were used to estimate the fair value of each financial instrument. The fair values of our financial instruments are as follows: TABLE 18.4 Fair Value Measurements (in millions) Carrying Fair Level 1 Level 2 Level 3 September 30, 2021 Financial Assets Cash and cash equivalents $ 4,110 $ 4,110 $ 4,110 $ — $ — Debt securities available for sale 3,208 3,208 49 3,159 — Debt securities held to maturity 3,202 3,267 1 3,266 — Net loans and leases, including loans held for sale 24,620 24,224 — 227 23,997 Loan servicing rights 46 47 — — 47 Derivative assets 230 230 — 217 13 Accrued interest receivable 76 76 76 — — Financial Liabilities Deposits 31,444 31,456 28,399 3,057 — Short-term borrowings 1,563 1,565 1,565 — — Long-term borrowings 886 906 — — 906 Derivative liabilities 41 41 — 41 — Accrued interest payable 8 8 8 — — December 31, 2020 Financial Assets Cash and cash equivalents $ 1,383 $ 1,383 $ 1,383 $ — $ — Debt securities available for sale 3,463 3,463 600 2,863 — Debt securities held to maturity 2,868 2,973 — 2,973 — Net loans and leases, including loans held for sale 25,250 25,012 — 144 24,868 Loan servicing rights 39 39 — — 39 Derivative assets 376 376 — 352 24 Accrued interest receivable 90 90 90 — — Financial Liabilities Deposits 29,122 29,158 25,460 3,698 — Short-term borrowings 1,804 1,809 1,809 — — Long-term borrowings 1,095 1,068 — — 1,068 Derivative liabilities 40 40 — 40 — Accrued interest payable 13 13 13 — —

MERGERS AND ACQUISITIONS

MERGERS AND ACQUISITIONS	9 Months Ended
	Sep. 30, 2021
Business Combination and Asset Acquisition [Abstract]
MERGERS AND ACQUISITIONS	MERGERS AND ACQUISITIONSPending Acquisition – Howard Bancorp, Inc.On July 12, 2021, the Corporation entered into a definitive merger agreement to acquire Howard, a bank holding company based in Baltimore, Maryland with approximately $2.6 billion in total assets. The transaction is valued at approximately $418 million. Under the terms of the merger agreement, Howard voting common shareholders will be entitled to receive 1.8 shares of the Corporation’s common stock for each share of Howard common stock. The Corporation expects to issue approximately 33.8 million shares of its common stock in exchange for approximately 18.8 million shares of Howard common stock. Howard’s banking affiliate, Howard Bank, will be merged into FNBPA. We have received all regulatory clearances for the proposed merger to occur. The transaction is expected to be completed in early 2022, pending satisfaction of certain routine and customary closing conditions and approval by Howard's shareholders.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Our accompanying Consolidated Financial Statements and these Notes to Consolidated Financial Statements (unaudited) include subsidiaries in which we have a controlling financial interest. We own and operate FNBPA, First National Trust Company, First National Investment Services Company, LLC, F.N.B. Investment Advisors, Inc., First National Insurance Agency, LLC, Bank Capital Services, LLC, F.N.B. Capital Corporation, LLC and Waubank Securities, LLC, and include results for each of these entities in the accompanying Consolidated Financial Statements. Companies in which we hold a controlling financial interest, or are a VIE in which we have the power to direct the activities of an entity that most significantly impact the entity’s economic performance and have an obligation to absorb losses or the right to receive benefits which could potentially be significant to the VIE, are consolidated. For a voting interest entity, a controlling financial interest is generally where we hold more than 50% of the outstanding voting shares. VIEs in which we do not hold the power to direct the activities of the entity that most significantly impact the entity’s economic performance or an obligation to absorb losses or the right to receive benefits which could potentially be significant to the VIE are not consolidated. Investments in companies that are not consolidated are accounted for using the equity method when we have the ability to exert significant influence or the cost method when we do not have the ability to exert significant influence. Investments in private investment partnerships that are accounted for under the equity method or the cost method are included in other assets and our proportional interest in the equity investments’ earnings are included in other non-interest income. Investment interests accounted for under the cost and equity methods are periodically evaluated for impairment. The accompanying interim unaudited Consolidated Financial Statements include all adjustments that are necessary, in the opinion of management, to fairly reflect our financial position and results of operations in accordance with GAAP. All significant intercompany balances and transactions have been eliminated. Events occurring subsequent to September 30, 2021 have been evaluated for potential recognition or disclosure in the Consolidated Financial Statements through the date of the filing of the Consolidated Financial Statements with the SEC. Certain information and Note disclosures normally included in Consolidated Financial Statements prepared in accordance with GAAP have been condensed or omitted pursuant to the rules and regulations of the SEC. The interim operating results are not necessarily indicative of operating results FNB expects for the full year. These interim unaudited Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and Notes thereto included in our 2020 Annual Report on Form 10-K filed with the SEC on February 25, 2021.
Use of Estimates	Use of Estimates Our accounting and reporting policies conform with GAAP. The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the amounts reported in the Consolidated Financial Statements and accompanying Notes to Consolidated Financial Statements (unaudited). Actual results could materially differ from those estimates. Material estimates that are particularly susceptible to significant changes include the ACL, fair value of financial instruments, goodwill and other intangible assets, income taxes and deferred tax assets and litigation reserves, which are listed in the critical accounting estimates. For a detailed description of our significant accounting policies and critical accounting estimates, see Note 1, "Summary of Significant Accounting Policies" and the "Application of Critical Accounting Policies" section in the MD&A, both in our 2020 Annual Report on Form 10-K .
New Accounting Standards	The following table summarizes accounting pronouncements issued by the FASB that we recently adopted. TABLE 2.1 Standard Description Financial Statements Impact Reference Rate Reform ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting ASU 2021-01, Reference Rate Reform (Topic 848): Scope These Updates provide temporary optional expedients and exceptions for applying GAAP to financial contracts, hedging relationships and other transactions affected by RRR if certain criteria are met. The following optional expedients, exceptions and elections are permitted for certain contracts that are modified because of RRR and meet certain scope guidance: • Contract modifications may be accounted for prospectively as a continuation of existing contracts rather than a new contract without re-measurement or reassessment of significant contract amendments • modifications of leases to be accounted for as a continuation of the existing contracts without reassessment of lease classification and discount rate or re-measurement of lease payments • to not reassess the original conclusion about whether a contract contains an embedded derivative that is clearly and closely related to the host contract • changes to critical terms of hedging relationships, on a hedge-by-hedge basis, without designation of the hedging relationship and various practical expedients and elections designed to allow hedge accounting to continue uninterrupted • modifications of certain derivatives modified to change the rate used for margining, discounting or contract price alignment. For securities affected by RRR that were classified as HTM before January 1, 2020, the Updates also allow an entity to make a one-time election to sell and/or transfer these securities to AFS or Trading. RRR Updates are effective for all entities from the beginning of an interim period that includes or is subsequent to March 12, 2020 and terminates on December 31, 2022 on a full retrospective or prospective basis. Although we do not expect RRR to have a material accounting impact on our consolidated financial position or results of operations, the Updates will ease the administrative burden in accounting for the effects of RRR. We adopted these updates on October 1, 2020 by retrospective application. The adoption did not have a material impact on our consolidated financial position or results of operations. We will continue to assess the impact of adoption through the termination date of these Updates on December 31, 2022.

NEW ACCOUNTING STANDARDS (Table

NEW ACCOUNTING STANDARDS (Tables)	9 Months Ended
	Sep. 30, 2021
Accounting Changes and Error Corrections [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The following table summarizes accounting pronouncements issued by the FASB that we recently adopted. TABLE 2.1 Standard Description Financial Statements Impact Reference Rate Reform ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting ASU 2021-01, Reference Rate Reform (Topic 848): Scope These Updates provide temporary optional expedients and exceptions for applying GAAP to financial contracts, hedging relationships and other transactions affected by RRR if certain criteria are met. The following optional expedients, exceptions and elections are permitted for certain contracts that are modified because of RRR and meet certain scope guidance: • Contract modifications may be accounted for prospectively as a continuation of existing contracts rather than a new contract without re-measurement or reassessment of significant contract amendments • modifications of leases to be accounted for as a continuation of the existing contracts without reassessment of lease classification and discount rate or re-measurement of lease payments • to not reassess the original conclusion about whether a contract contains an embedded derivative that is clearly and closely related to the host contract • changes to critical terms of hedging relationships, on a hedge-by-hedge basis, without designation of the hedging relationship and various practical expedients and elections designed to allow hedge accounting to continue uninterrupted • modifications of certain derivatives modified to change the rate used for margining, discounting or contract price alignment. For securities affected by RRR that were classified as HTM before January 1, 2020, the Updates also allow an entity to make a one-time election to sell and/or transfer these securities to AFS or Trading. RRR Updates are effective for all entities from the beginning of an interim period that includes or is subsequent to March 12, 2020 and terminates on December 31, 2022 on a full retrospective or prospective basis. Although we do not expect RRR to have a material accounting impact on our consolidated financial position or results of operations, the Updates will ease the administrative burden in accounting for the effects of RRR. We adopted these updates on October 1, 2020 by retrospective application. The adoption did not have a material impact on our consolidated financial position or results of operations. We will continue to assess the impact of adoption through the termination date of these Updates on December 31, 2022.

SECURITIES (Tables)

SECURITIES (Tables)	9 Months Ended
	Sep. 30, 2021
Investments, Debt and Equity Securities [Abstract]
Schedule of Amortized Cost and Fair Value of Securities Available for Sale	The amortized cost and fair value of AFS debt securities are presented in the table below. There was no ACL in the AFS portfolio at September 30, 2021 and December 31, 2020. Accrued interest receivable on AFS debt securities totaled $5.8 million and $6.2 million at September 30, 2021 and December 31, 2020, respectively, and is excluded from the estimate of credit losses and assessed separately in other assets in the Consolidated Balance Sheets. Accordingly, we have excluded accrued interest receivable from both the fair value and the amortized cost basis of AFS debt securities. TABLE 3.1 (in millions) Amortized Gross Gross Fair Debt Securities AFS: September 30, 2021 U.S. Treasury $ 49 $ — $ — $ 49 U.S. government agencies 152 2 — 154 U.S. government-sponsored entities 170 1 (1) 170 Residential mortgage-backed securities: Agency mortgage-backed securities 1,286 26 (1) 1,311 Agency collateralized mortgage obligations 1,171 18 (6) 1,183 Commercial mortgage-backed securities 299 8 (1) 306 States of the U.S. and political subdivisions (municipals) 33 — — 33 Other debt securities 2 — — 2 Total debt securities AFS $ 3,162 $ 55 $ (9) $ 3,208 (in millions) Amortized Gross Gross Fair Debt Securities AFS: December 31, 2020 U.S. Treasury $ 600 $ — $ — $ 600 U.S. government agencies 172 — — 172 U.S. government-sponsored entities 160 1 — 161 Residential mortgage-backed securities: Agency mortgage-backed securities 959 35 — 994 Agency collateralized mortgage obligations 1,094 31 (1) 1,124 Commercial mortgage-backed securities 361 17 — 378 States of the U.S. and political subdivisions (municipals) 32 — — 32 Other debt securities 2 — — 2 Total debt securities AFS $ 3,380 $ 84 $ (1) $ 3,463
Schedule of Amortized Cost and Fair Value of Securities Held to Maturity	The amortized cost and fair value of HTM debt securities are presented in the table below. The ACL for the HTM municipal bond portfolio was $0.06 million and $0.04 million at September 30, 2021 and December 31, 2020, respectively. Accrued interest receivable on HTM debt securities totaled $10.9 million and $12.5 million at September 30, 2021 and December 31, 2020, respectively, and is excluded from the estimate of credit losses and assessed separately in other assets in the Consolidated Balance Sheets. Accordingly, we have excluded accrued interest receivable from both the fair value and the amortized cost basis of HTM debt securities. TABLE 3.2 (in millions) Amortized Gross Gross Fair Debt Securities HTM: September 30, 2021 U.S. Treasury $ 1 $ — $ — $ 1 U.S. government agencies 1 — — 1 U.S. government-sponsored entities 20 — — 20 Residential mortgage-backed securities: Agency mortgage-backed securities 1,174 21 (2) 1,193 Agency collateralized mortgage obligations 690 9 (4) 695 Commercial mortgage-backed securities 284 5 (2) 287 States of the U.S. and political subdivisions (municipals) 1,032 39 (1) 1,070 Total debt securities HTM $ 3,202 $ 74 $ (9) $ 3,267 (in millions) Amortized Gross Gross Fair Debt Securities HTM: December 31, 2020 U.S. Treasury $ 1 $ — $ — $ 1 U.S. government agencies 1 — — 1 U.S. government-sponsored entities 120 1 — 121 Residential mortgage-backed securities: Agency mortgage-backed securities 769 29 — 798 Agency collateralized mortgage obligations 562 17 — 579 Commercial mortgage-backed securities 307 10 — 317 States of the U.S. and political subdivisions (municipals) 1,108 48 — 1,156 Total debt securities HTM $ 2,868 $ 105 $ — $ 2,973
Amortized Cost and Fair Value of Securities, by Contractual Maturities	As of September 30, 2021, the amortized cost and fair value of debt securities, by contractual maturities, were as follows: TABLE 3.3 Available for Sale Held to Maturity (in millions) Amortized Fair Amortized Fair Due in one year or less $ 45 $ 46 $ 21 $ 21 Due after one year but within five years 194 194 22 22 Due after five years but within ten years 103 103 122 125 Due after ten years 64 65 889 924 406 408 1,054 1,092 Residential mortgage-backed securities: Agency mortgage-backed securities 1,286 1,311 1,174 1,193 Agency collateralized mortgage obligations 1,171 1,183 690 695 Commercial mortgage-backed securities 299 306 284 287 Total debt securities $ 3,162 $ 3,208 $ 3,202 $ 3,267
Schedule of Securities Pledged as Collateral	Following is information relating to securities pledged: TABLE 3.4 (dollars in millions) September 30, December 31, Securities pledged (carrying value): To secure public deposits, trust deposits and for other purposes as required by law $ 5,714 $ 5,384 As collateral for short-term borrowings 412 402 Securities pledged as a percent of total securities 95.6 % 91.4 %
Summaries of Fair Values and Unrealized Losses of Impaired Securities, Segregated by Length of Impairment	Following are summaries of the fair values of AFS debt securities in an unrealized loss position for which an ACL has not been recorded, segregated by security type and length of continuous loss position: TABLE 3.5 Less than 12 Months 12 Months or More Total (dollars in millions) # Fair Unrealized # Fair Unrealized # Fair Unrealized Debt Securities AFS September 30, 2021 U.S. Treasury 1 $ 49 $ — — $ — $ — 1 $ 49 $ — U.S. government agencies — — — 9 9 — 9 9 — U.S. government-sponsored entities 3 74 (1) — — — 3 74 (1) Residential mortgage-backed securities: Agency mortgage-backed securities 9 428 (1) — — — 9 428 (1) Agency collateralized mortgage obligations 14 534 (6) — — — 14 534 (6) Commercial mortgage-backed securities 3 91 (1) — — — 3 91 (1) States of the U.S. and political subdivisions (municipals) 5 11 — — — — 5 11 — Other debt securities — — — 1 2 — 1 2 — Total 35 $ 1,187 $ (9) 10 $ 11 $ — 45 $ 1,198 $ (9) Less than 12 Months 12 Months or More Total (dollars in millions) # Fair Unrealized # Fair Unrealized # Fair Unrealized Debt Securities AFS December 31, 2020 U.S. government agencies 1 $ 13 $ — 16 $ 69 $ — 17 $ 82 $ — U.S. government-sponsored entities 1 25 — — — — 1 25 — Residential mortgage-backed securities: Agency collateralized mortgage obligations 5 130 (1) — — — 5 130 (1) Other debt securities — — — 1 2 — 1 2 — Total 7 $ 168 $ (1) 17 $ 71 $ — 24 $ 239 $ (1)

LOANS AND LEASES (Tables)

LOANS AND LEASES (Tables)	9 Months Ended
	Sep. 30, 2021
Receivables [Abstract]
Summary of Loans and Leases, Net of Unearned Income	Following is a summary of total loans and leases, net of unearned income: TABLE 4.1 (in millions) September 30, 2021 December 31, 2020 Commercial real estate $ 9,871 $ 9,731 Commercial and industrial 5,960 7,214 Commercial leases 489 485 Other 81 40 Total commercial loans and leases 16,401 17,470 Direct installment 2,250 2,020 Residential mortgages 3,588 3,433 Indirect installment 1,230 1,218 Consumer lines of credit 1,247 1,318 Total consumer loans 8,315 7,989 Total loans and leases, net of unearned income $ 24,716 $ 25,459
Certain Information Relating to Commercial Real Estate Loans	The following table shows occupancy information relating to commercial real estate loans: TABLE 4.2 (dollars in millions) September 30, December 31, Commercial real estate: Percent owner-occupied 28.2 % 28.1 % Percent non-owner-occupied 71.8 71.9
Summary of Loan, Credit Quality Indicators	We use an internal risk rating assigned to a commercial loan or lease at origination, summarized below. TABLE 4.3 Rating Category Definition Pass in general, the condition of the borrower and the performance of the loan is satisfactory or better Special Mention in general, the condition of the borrower has deteriorated, requiring an increased level of monitoring Substandard in general, the condition of the borrower has significantly deteriorated and the performance of the loan could further deteriorate if deficiencies are not corrected Doubtful in general, the condition of the borrower has significantly deteriorated and the collection in full of both principal and interest is highly questionable or improbable
Schedule of Financing Receivables, Originated Year	The following tables summarize the designated loan rating category by loan class including term loans on an amortized cost basis by origination year: TABLE 4.4 September 30, 2021 2021 2020 2019 2018 2017 Prior Revolving Loans Amortized Cost Basis Total (in millions) COMMERCIAL Commercial Real Estate: Risk Rating: Pass $ 1,290 $ 1,817 $ 1,706 $ 964 $ 797 $ 2,385 $ 148 $ 9,107 Special Mention 15 16 45 111 115 175 2 479 Substandard — 8 34 38 44 158 3 285 Total commercial real estate 1,305 1,841 1,785 1,113 956 2,718 153 9,871 Commercial and Industrial: Risk Rating: Pass 1,500 980 788 422 200 293 1,335 5,518 Special Mention — 31 15 5 18 64 35 168 Substandard 2 6 22 61 65 21 97 274 Total commercial and industrial 1,502 1,017 825 488 283 378 1,467 5,960 Commercial Leases: Risk Rating: Pass 139 124 107 58 43 2 — 473 Special Mention — — — 2 3 2 — 7 Substandard — 4 3 2 — — — 9 Total commercial leases 139 128 110 62 46 4 — 489 Other Commercial: Risk Rating: Pass 23 — — — — 9 49 81 Substandard — — — — — — — — Total other commercial 23 — — — — 9 49 81 Total commercial 2,969 2,986 2,720 1,663 1,285 3,109 1,669 16,401 CONSUMER Direct Installment: Current 707 585 240 141 106 458 — 2,237 Past due — — 1 1 — 11 — 13 Total direct installment 707 585 241 142 106 469 — 2,250 Residential Mortgages: Current 996 986 445 167 240 715 2 3,551 Past due — 2 4 4 3 24 — 37 Total residential mortgages 996 988 449 171 243 739 2 3,588 Indirect Installment: Current 415 290 180 210 80 45 — 1,220 Past due 2 2 2 2 1 1 — 10 Total indirect installment 417 292 182 212 81 46 — 1,230 Consumer Lines of Credit: Current 13 3 4 6 3 126 1,078 1,233 Past due — — — — — 12 2 14 Total consumer lines of credit 13 3 4 6 3 138 1,080 1,247 Total consumer 2,133 1,868 876 531 433 1,392 1,082 8,315 Total loans and leases $ 5,102 $ 4,854 $ 3,596 $ 2,194 $ 1,718 $ 4,501 $ 2,751 $ 24,716 December 31, 2020 2020 2019 2018 2017 2016 Prior Revolving Loans Amortized Cost Basis Total (in millions) COMMERCIAL Commercial Real Estate: Risk Rating: Pass $ 1,879 $ 1,854 $ 1,135 $ 927 $ 888 $ 1,911 $ 163 $ 8,757 Special Mention 9 30 80 158 70 163 4 514 Substandard 4 32 29 81 116 192 6 460 Total commercial real estate 1,892 1,916 1,244 1,166 1,074 2,266 173 9,731 Commercial and Industrial: Risk Rating: Pass 3,286 1,007 590 304 120 311 1,095 6,713 Special Mention 30 23 13 28 10 35 79 218 Substandard 8 26 65 44 6 37 97 283 Total commercial and industrial 3,324 1,056 668 376 136 383 1,271 7,214 Commercial Leases: Risk Rating: Pass 178 134 83 56 5 3 — 459 Special Mention 1 1 4 4 1 2 — 13 Substandard 7 2 2 1 1 — — 13 Total commercial leases 186 137 89 61 7 5 — 485 Other Commercial: Risk Rating: Pass — — — — — 4 35 39 Substandard — — — — — 1 — 1 Total other commercial — — — — — 5 35 40 Total commercial 5,402 3,109 2,001 1,603 1,217 2,659 1,479 17,470 CONSUMER Direct Installment: Current 706 337 200 143 171 442 1 2,000 Past due — 1 2 1 2 14 — 20 Total direct installment 706 338 202 144 173 456 1 2,020 Residential Mortgages: Current 1,079 707 283 378 330 603 1 3,381 Past due 1 5 7 4 6 29 — 52 Total residential mortgages 1,080 712 290 382 336 632 1 3,433 Indirect Installment: Current 372 260 332 147 67 27 — 1,205 Past due 1 3 4 2 2 1 — 13 Total indirect installment 373 263 336 149 69 28 — 1,218 Consumer Lines of Credit: Current 4 7 8 3 5 127 1,146 1,300 Past due — — — — — 15 3 18 Total consumer lines of credit 4 7 8 3 5 142 1,149 1,318 Total consumer 2,163 1,320 836 678 583 1,258 1,151 7,989 Total loans and leases $ 7,565 $ 4,429 $ 2,837 $ 2,281 $ 1,800 $ 3,917 $ 2,630 $ 25,459
Age Analysis of Past Due Loans, by Class	The following tables provide an analysis of the aging of loans by class. TABLE 4.5 (in millions) 30-89 Days > 90 Days Past Due and Still Accruing Non- Total Current Total Non-accrual with No ACL September 30, 2021 Commercial real estate $ 6 $ — $ 55 $ 61 $ 9,810 $ 9,871 $ 20 Commercial and industrial 13 — 23 36 5,924 5,960 4 Commercial leases 4 — 1 5 484 489 — Other — — 1 1 80 81 — Total commercial loans and leases 23 — 80 103 16,298 16,401 24 Direct installment 4 1 8 13 2,237 2,250 — Residential mortgages 18 5 14 37 3,551 3,588 — Indirect installment 8 — 2 10 1,220 1,230 — Consumer lines of credit 6 2 6 14 1,233 1,247 — Total consumer loans 36 8 30 74 8,241 8,315 — Total loans and leases $ 59 $ 8 $ 110 $ 177 $ 24,539 $ 24,716 $ 24 (in millions) 30-89 Days > 90 Days Past Due and Still Accruing Non- Total Current Total Non-accrual with No ACL December 31, 2020 Commercial real estate $ 13 $ — $ 85 $ 98 $ 9,633 $ 9,731 $ 36 Commercial and industrial 8 — 44 52 7,162 7,214 16 Commercial leases 2 — 2 4 481 485 — Other — — 1 1 39 40 — Total commercial loans and leases 23 — 132 155 17,315 17,470 52 Direct installment 7 2 11 20 2,000 2,020 — Residential mortgages 23 11 18 52 3,381 3,433 — Indirect installment 10 1 2 13 1,205 1,218 — Consumer lines of credit 9 2 7 18 1,300 1,318 — Total consumer loans 49 16 38 103 7,886 7,989 — Total loans and leases $ 72 $ 16 $ 170 $ 258 $ 25,201 $ 25,459 $ 52
Summary of Non-Performing Assets	Following is a summary of non-performing assets: TABLE 4.6 (dollars in millions) September 30, December 31, Non-accrual loans $ 110 $ 170 Total non-performing loans 110 170 Other real estate owned 8 10 Total non-performing assets $ 118 $ 180 Asset quality ratios: Non-performing loans / total loans and leases 0.45 % 0.67 % Non-performing assets + 90 days past due + OREO / total loans and leases + OREO 0.51 0.77
Summary of the Composition of Total TDRs	Following is a summary of the composition of total TDRs: TABLE 4.7 (in millions) September 30, December 31, Accruing $ 58 $ 58 Non-accrual 35 33 Total TDRs $ 93 $ 91
Summary of Troubled Debt Restructurings by Class of Loans	Following is a summary of TDR loans, by class, for loans that were modified during the periods indicated: TABLE 4.8 Three Months Ended September 30, 2021 Nine Months Ended September 30, 2021 (dollars in millions) Number Pre- Post- Number Pre- Post- Commercial real estate 5 $ 2 $ 2 21 $ 20 $ 20 Commercial and industrial 3 — — 8 1 — Other 1 — — 1 — — Total commercial loans 9 2 2 30 21 20 Direct installment 8 — — 26 1 1 Residential mortgages 12 2 2 15 2 2 Consumer lines of credit 7 — — 31 2 2 Total consumer loans 27 2 2 72 5 5 Total 36 $ 4 $ 4 102 $ 26 $ 25 Three Months Ended September 30, 2020 Nine Months Ended September 30, 2020 (dollars in millions) Number Pre- Post- Number Pre- Post- Commercial real estate 7 $ 2 $ 2 23 $ 8 $ 6 Commercial and industrial 4 — — 19 3 2 Other — — — 1 — — Total commercial loans 11 2 2 43 11 8 Direct installment 14 1 1 50 3 3 Residential mortgages 2 1 1 18 3 2 Consumer lines of credit 9 — — 36 1 1 Total consumer loans 25 2 2 104 7 6 Total 36 $ 4 $ 4 147 $ 18 $ 14
Summary of Troubled Debt Restructurings by Class of Loans and Leases, Payment Default	Following is a summary of TDRs, by class, for which there was a payment default, excluding loans that have been paid off and/or sold. Default occurs when a loan is 90 days or more past due and is within 12 months of restructuring. TABLE 4.9 Three Months Ended Nine Months Ended (dollars in millions) Number of Recorded Number of Recorded Commercial and industrial — $ — 1 $ — Total commercial loans — — 1 — Direct installment 1 — 1 — Residential mortgages — — 1 — Total consumer loans 1 — 2 — Total 1 $ — 3 $ — Three Months Ended Nine Months Ended (dollars in millions) Number of Recorded Number of Recorded Commercial real estate — $ — 8 $ 3 Commercial and industrial 1 — 3 — Total commercial loans 1 — 11 3 Direct installment 4 — 12 1 Residential mortgages — — 2 — Consumer lines of credit 1 — 3 — Total consumer loans 5 — 17 1 Total 6 $ — 28 $ 4

ALLOWANCE FOR CREDIT LOSSES O_2

ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES (Tables)	9 Months Ended
	Sep. 30, 2021
Receivables [Abstract]
Summary of Changes in Allowance for Credit Losses by Loan and Lease Class	Following is a summary of changes in the ACL, by loan and lease class: TABLE 5.1 (in millions) Balance at Charge- Recoveries Net Provision for Credit Losses Balance at Three Months Ended September 30, 2021 Commercial real estate $ 176 $ (3) $ 2 $ (1) $ (14) $ 161 Commercial and industrial 81 (2) 2 — 6 87 Commercial leases 16 — — — — 16 Other 1 — — — 1 2 Total commercial loans and leases 274 (5) 4 (1) (7) 266 Direct installment 27 (1) — (1) — 26 Residential mortgages 33 — — — — 33 Indirect installment 12 — — — 1 13 Consumer lines of credit 11 (1) 1 — — 11 Total consumer loans 83 (2) 1 (1) 1 83 Total allowance for credit losses on loans and leases 357 (7) 5 (2) (6) 349 Allowance for unfunded loan commitments 14 — — — 4 18 Total allowance for credit losses on loans and leases and allowance for unfunded loan commitments $ 371 $ (7) $ 5 $ (2) $ (2) $ 367 Nine Months Ended September 30, 2021 Commercial real estate $ 181 $ (9) $ 5 $ (4) $ (16) $ 161 Commercial and industrial 81 (11) 4 (7) 13 87 Commercial leases 17 — 1 1 (2) 16 Other 1 (2) 1 (1) 2 2 Total commercial loans and leases 280 (22) 11 (11) (3) 266 Direct installment 26 (1) — (1) 1 26 Residential mortgages 34 — — — (1) 33 Indirect installment 11 (3) 2 (1) 3 13 Consumer lines of credit 12 (1) 1 — (1) 11 Total consumer loans 83 (5) 3 (2) 2 83 Total allowance for credit losses on loans and leases 363 (27) 14 (13) (1) 349 Allowance for unfunded loan commitments 14 — — — 4 18 Total allowance for credit losses on loans and leases and allowance for unfunded loan commitments $ 377 $ (27) $ 14 $ (13) $ 3 $ 367 (in millions) Balance at Charge- Recoveries Net Provision ASC 326 Adoption Impact Initial ACL on PCD Loans Balance at Three Months Ended September 30, 2020 Commercial real estate $ 163 $ (3) $ 1 $ (2) $ 23 $ — $ — $ 184 Commercial and industrial 98 (17) 1 (16) 11 — — 93 Commercial leases 17 — — — — — — 17 Other 1 (1) — (1) 1 — — 1 Total commercial loans and leases 279 (21) 2 (19) 35 — — 295 Direct installment 25 — — — (1) — — 24 Residential mortgages 33 (1) 1 — (2) — — 31 Indirect installment 17 (1) 1 — (5) — — 12 Consumer lines of credit 11 — — — — — — 11 Total consumer loans 86 (2) 2 — (8) — — 78 Total allowance for credit losses on loans and leases 365 (23) 4 (19) 27 — — 373 Allowance for unfunded loan commitments (1) 15 — — — — — — 15 Total allowance for credit losses on loans and leases and allowance for unfunded loan commitments $ 380 $ (23) $ 4 $ (19) $ 27 $ — $ — $ 388 Nine Months Ended September 30, 2020 Commercial real estate $ 60 $ (8) $ 6 $ (2) $ 48 $ 38 $ 40 $ 184 Commercial and industrial 53 (25) 3 (22) 50 8 4 93 Commercial leases 11 — — — 6 — — 17 Other 9 (3) — (3) 4 (9) — 1 Total commercial loans and leases 133 (36) 9 (27) 108 37 44 295 Direct installment 13 (1) — (1) 1 10 1 24 Residential mortgages 22 (1) 1 — (1) 6 4 31 Indirect installment 19 (6) 3 (3) (6) 2 — 12 Consumer lines of credit 9 (2) — (2) 3 — 1 11 Total consumer loans 63 (10) 4 (6) (3) 18 6 78 Total allowance for credit losses on loans and leases 196 (46) 13 (33) 105 55 50 373 Allowance for unfunded loan commitments (1) 3 — — — 2 10 — 15 Total allowance for credit losses on loans and leases and allowance for unfunded loan commitments $ 199 $ (46) $ 13 $ (33) $ 107 $ 65 $ 50 $ 388 (1) The net benefit of $0.3 million for the quarter and $2 million for the year-to-date provision for the AULC is included in other non-interest expense on the Consolidated Statements of Income. Following is a summary of changes in the AULC by portfolio segment: TABLE 5.2 Three Months Ended Nine Months Ended 2021 2020 2021 2020 (in millions) Balance at beginning of period $ 14 $ 15 $ 14 $ 3 Provision for unfunded loan commitments and letters of credit: Commercial portfolio 4 — 4 — Consumer portfolio — — — — Other adjustments: Commercial portfolio — — — 2 ASC 326 adoption impact: Commercial portfolio — — — 8 Consumer portfolio — — — 2 Balance at end of period $ 18 $ 15 $ 18 $ 15

LOAN SERVICING (Tables)

LOAN SERVICING (Tables) - Mortgage Servicing Rights [Member]	9 Months Ended
	Sep. 30, 2021
Servicing Assets at Fair Value [Line Items]
Servicing Asset at Amortized Cost	The unpaid principal balance of mortgage loans serviced for others is listed below: TABLE 6.1 (in millions) September 30, December 31, Mortgage loans sold with servicing retained $ 4,797 $ 4,653 The following table summarizes activity relating to mortgage loans sold with servicing retained: TABLE 6.2 Three Months Ended Nine Months Ended (in millions) 2021 2020 2021 2020 Mortgage loans sold with servicing retained $ 382 $ 466 $ 1,406 $ 1,142 Pretax net gains resulting from above loan sales (1) 10 25 36 47 Mortgage servicing fees (1) 3 3 9 9 (1) Recorded in mortgage banking operations on the Consolidated Statements of Income. Following is a summary of activity relating to MSRs: TABLE 6.3 Three Months Ended Nine Months Ended (in millions) 2021 2020 2021 2020 Balance at beginning of period $ 40.5 $ 34.0 $ 35.6 $ 42.6 Additions 4.4 4.5 15.3 11.0 Payoffs and curtailments (2.8) (4.6) (10.4) (10.5) (Impairment charge) / recovery 1.0 0.5 3.8 (7.5) Amortization (0.6) (0.6) (1.8) (1.8) Balance at end of period $ 42.5 $ 33.8 $ 42.5 $ 33.8 Fair value, beginning of period $ 40.8 $ 34.0 $ 35.6 $ 45.0 Fair value, end of period 43.2 33.8 43.2 33.8
Schedule of Assumptions for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement	Following is a summary of the sensitivity of the fair value of MSRs to changes in key assumptions: TABLE 6.4 (dollars in millions) September 30, December 31, Weighted average life (months) 74.3 66.6 Constant prepayment rate (annualized) 11.8 % 13.4 % Discount rate 9.5 % 9.5 % Effect on fair value due to change in interest rates: +0.25% $ 3 $ 2 +0.50% 5 4 -0.25% (3) (2) -0.50% (6) (3)

LEASES (Tables)

LEASES (Tables)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Lease, Cost	The components of lease expense were as follows: TABLE 7.1 Three Months Ended Nine Months Ended (dollars in millions) 2021 2020 2021 2020 Operating lease cost $ 7 $ 7 $ 21 $ 20 Short-term lease cost — 1 — 1 Variable lease cost 1 1 3 3 Total lease cost $ 8 $ 9 $ 24 $ 24
Leases, Other Information	Other information related to leases is as follows: TABLE 7.2 Nine Months Ended (dollars in millions) 2021 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 7 $ 19 Operating cash flows from finance leases $ — $ — Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 7 $ 5 Finance leases $ — $ — Weighted average remaining lease term (years): Operating leases 9.05 9.51 Finance leases 24.13 0 Weighted average discount rate: Operating leases 2.5 % 2.8 % Finance leases 1.9 % — %
Lessee, Operating Lease, Liability, Maturity	Maturities of lease liabilities were as follows: TABLE 7.3 (in millions) Operating Leases Finance Leases Total Leases September 30, 2021 2021 $ 7 $ — $ 7 2022 23 — 23 2023 19 — 19 2024 17 — 17 2025 13 — 13 Later years 67 12 79 Total lease payments 146 12 158 Less: imputed interest (15) (2) (17) Present value of lease liabilities $ 131 $ 10 $ 141
Finance Lease, Liability, Fiscal Year Maturity	Maturities of lease liabilities were as follows: TABLE 7.3 (in millions) Operating Leases Finance Leases Total Leases September 30, 2021 2021 $ 7 $ — $ 7 2022 23 — 23 2023 19 — 19 2024 17 — 17 2025 13 — 13 Later years 67 12 79 Total lease payments 146 12 158 Less: imputed interest (15) (2) (17) Present value of lease liabilities $ 131 $ 10 $ 141

VARIABLE INTEREST ENTITIES (Tab

VARIABLE INTEREST ENTITIES (Tables)	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Variable Interest Entities, Assets and Liabilities	The following table provides a summary of the assets and liabilities included in our Consolidated Financial Statements, as well as the maximum exposure to losses, associated with our interests related to VIEs for which we hold an interest, but are not the primary beneficiary, at September 30, 2021 and December 31, 2020. TABLE 8.1 (in millions) Total Assets Total Liabilities Maximum Exposure to Loss September 30, 2021 Trust preferred securities (1) $ 1 $ 67 $ — Affordable housing tax credit partnerships 113 37 113 Other investments 26 4 26 Total $ 140 $ 108 $ 139 December 31, 2020 Trust preferred securities (1) $ 1 $ 66 $ — Affordable housing tax credit partnerships 119 45 119 Other investments 26 8 26 Total $ 146 $ 119 $ 145 (1) Represents our investment in unconsolidated subsidiaries.
Low Income Housing Tax Credits, Balances Of Affordable Housing Tax Credit Investments And Related Unfunded Commitments	The following table presents the balances of our affordable housing tax credit investments and related unfunded commitments: TABLE 8.2 (in millions) September 30, December 31, Proportional amortization method investments included in other assets $ 74 $ 71 Equity method investments included in other assets 2 3 Total LIHTC investments included in other assets $ 76 $ 74 Unfunded LIHTC commitments $ 37 $ 45
Low Income Housing Tax Credits, Income Statement Effect	The following table summarizes the impact of these LIHTC investments on specific line items of our Consolidated Statements of Income: TABLE 8.3 Three Months Ended Nine Months Ended (in millions) 2021 2020 2021 2020 Non-interest income: Amortization of tax credit investments under equity method, net of tax benefit $ — $ — $ 1 $ 1 Provision for income taxes: Amortization of LIHTC investments under proportional method $ 3 $ 2 $ 10 $ 8 Low-income housing tax credits (4) (3) (11) (9) Other tax benefits related to tax credit investments — — (2) (2) Total impact on provision for income taxes $ (1) $ (1) $ (3) $ (3)

BORROWINGS (Tables)

BORROWINGS (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Summary of Short-Term Borrowings	Following is a summary of short-term borrowings: TABLE 9.1 (in millions) September 30, December 31, Securities sold under repurchase agreements $ 407 $ 403 Federal Home Loan Bank advances 1,030 1,280 Subordinated notes 126 121 Total short-term borrowings $ 1,563 $ 1,804
Summary of Long-Term Borrowings	Following is a summary of long-term borrowings: TABLE 9.2 (in millions) September 30, December 31, Federal Home Loan Bank advances $ 200 $ 400 Senior notes 299 299 Subordinated notes 72 81 Junior subordinated debt 67 66 Other subordinated debt 248 249 Total long-term borrowings $ 886 $ 1,095
Schedule of Other Subordinated Debt	The subordinated notes are eligible for treatment as tier 2 capital for regulatory capital purposes. TABLE 9.3 (dollars in millions) Aggregate Principal Amount Issued Net Proceeds (2) Carrying Value Stated Maturity Date Interest 2.20% Senior Notes due February 24, 2023 $ 300 $ 298 $ 299 2/24/2023 2.20 % 4.95% Fixed-To-Floating Rate Subordinated Notes due 2029 120 118 119 2/14/2029 4.95 % 4.875% Subordinated Notes due 2025 100 98 99 10/2/2025 4.875 % 7.625% Subordinated Notes due August 12, 2023 (1) 38 46 30 8/12/2023 7.625 % Total $ 558 $ 560 $ 547 (1) Assumed from a prior acquisition and adjusted to fair value at the time of acquisition. (2) After deducting underwriting discounts and commissions and offering costs. For the debt assumed from a prior acquisition, this is the fair value of the debt at the time of the acquisition.
Schedule of Junior Subordinated Debt Trusts	The following table provides information relating to the Trusts as of September 30, 2021: TABLE 9.4 (dollars in millions) Trust Common Junior Stated Interest Rate Rate Reset Factor F.N.B. Statutory Trust II $ 22 $ 1 $ 22 6/15/2036 1.77 % LIBOR + 165 basis points (bps) Yadkin Valley Statutory Trust I 25 1 22 12/15/2037 1.44 % LIBOR + 132 bps FNB Financial Services Capital Trust I 25 1 23 9/30/2035 1.59 % LIBOR + 146 bps Total $ 72 $ 3 $ 67

DERIVATIVE INSTRUMENTS AND HE_2

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Tables)	9 Months Ended
	Sep. 30, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts and Gross Fair Values of Derivative Assets and Derivative Liabilities	The following table presents notional amounts and gross fair values of our derivative assets and derivative liabilities which are not offset in the Consolidated Balance Sheets: TABLE 10.1 September 30, 2021 December 31, 2020 Notional Fair Value Notional Fair Value (in millions) Amount Asset Liability Amount Asset Liability Gross Derivatives Subject to master netting arrangements: Interest rate contracts – designated $ 1,580 $ 2 $ — $ 1,430 $ 3 $ — Interest rate swaps – not designated 5,332 2 25 4,791 — 37 Total subject to master netting arrangements 6,912 4 25 6,221 3 37 Not subject to master netting arrangements: Interest rate swaps – not designated 5,332 211 16 4,791 349 — Interest rate lock commitments – not designated 524 13 — 531 24 — Forward delivery commitments – not designated 575 2 — 500 — 2 Credit risk contracts – not designated 390 — — 437 — 1 Total not subject to master netting arrangements 6,821 226 16 6,259 373 3 Total $ 13,733 $ 230 $ 41 $ 12,480 $ 376 $ 40
Summary of Amounts Reclassified from Accumulated Other Comprehensive Income (AOCI)	The following table shows amounts reclassified from AOCI: TABLE 10.2 Amount of Gain (Loss) Recognized in OCI on Derivatives Location of Gain (Loss) Reclassified from AOCI into Income Amount of Gain (Loss) Reclassified from AOCI into Income Nine Months Ended Nine Months Ended (in millions) 2021 2020 2021 2020 Derivatives in cash flow hedging relationships: Interest rate contracts $ 3 $ (42) Interest income (expense) $ (14) $ (9) Other income — (9)
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss)	The following table represents gains (losses) recognized in the Consolidated Statements of Income on cash flow hedging relationships: TABLE 10.3 Nine months ended September 30, 2021 2020 (in millions) Interest Income - Loans and Leases Interest Expense - Short-Term Borrowings Interest Income - Loans and Leases Interest Expense - Short-Term Borrowings Total amounts of income and expense line items presented in the Consolidated Statements of Income (the effects of cash flow hedges are included in these line items) $ 671 $ 21 $ 750 $ 31 The effects of cash flow hedging: Gain (loss) on cash flow hedging relationships: Interest rate contracts: Amount of gain (loss) reclassified from AOCI into net income 1 (15) 2 (11)
Schedule of Derivative Financial Instruments on the Consolidated Statements of Income	The following table presents the effect of certain derivative financial instruments on the Consolidated Statements of Income: TABLE 10.4 Nine Months Ended (in millions) Consolidated Statements of Income Location 2021 2020 Interest rate swaps Non-interest income - other $ — $ — Interest rate lock commitments Mortgage banking operations — — Forward delivery contracts Mortgage banking operations 2 (1) Credit risk contracts Non-interest income - other — —
Schedule of Offsetting Assets and Liabilities	The following table presents a reconciliation of the net amounts of derivative assets and derivative liabilities presented in the Consolidated Balance Sheets to the net amounts that would result in the event of offset: TABLE 10.5 Amount Not Offset in the (in millions) Net Amount Financial Cash Net September 30, 2021 Derivative Assets Interest rate contracts: Designated $ 2 $ — $ 2 $ — Not designated 2 — 2 — Total $ 4 $ — $ 4 $ — Derivative Liabilities Interest rate contracts: Not designated $ 25 $ — $ 24 $ 1 Total $ 25 $ — $ 24 $ 1 December 31, 2020 Derivative Assets Interest rate contracts: Designated $ 3 $ — $ 3 $ — Total $ 3 $ — $ 3 $ — Derivative Liabilities Interest rate contracts: Not designated $ 37 $ — $ 37 $ — Total $ 37 $ — $ 37 $ —

COMMITMENTS, CREDIT RISK AND _2

COMMITMENTS, CREDIT RISK AND CONTINGENCIES (Tables)	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Summary of Off-Balance Sheet Credit Risk Information	Following is a summary of off-balance sheet credit risk information: TABLE 11.1 (in millions) September 30, December 31, Commitments to extend credit $ 11,015 $ 9,285 Standby letters of credit 200 158

STOCK INCENTIVE PLANS (Tables)

STOCK INCENTIVE PLANS (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Summary of Activity Relating to Restricted Stock Units	The following table summarizes the activity relating to restricted stock units during the periods indicated: TABLE 12.1 Nine Months Ended September 30, 2021 2020 Units Weighted Units Weighted Unvested units outstanding at beginning of period 4,322,115 $ 9.46 2,858,357 $ 12.56 Granted 1,113,314 12.65 2,004,895 5.95 Net adjustment due to performance 412,540 11.72 47,290 13.00 Vested (1,309,476) 12.10 (592,602) 14.50 Forfeited/expired/canceled (112,002) 10.94 (169,552) 13.05 Dividend reinvestment 134,600 12.26 173,990 6.99 Unvested units outstanding at end of period 4,561,091 9.74 4,322,378 9.45
Schedule of Certain Information Related to Restricted Stock Units	The following table provides certain information related to restricted stock units: TABLE 12.2 (in millions) Nine Months Ended 2021 2020 Stock-based compensation expense $ 17 $ 13 Tax benefit related to stock-based compensation expense 4 3 Fair value of units vested 16 4
Components of Restricted Stock Units	The components of the restricted stock units as of September 30, 2021 are as follows: TABLE 12.3 (dollars in millions) Service- Performance- Total Unvested restricted stock units 2,933,219 1,627,872 4,561,091 Unrecognized compensation expense $ 10 $ 2 $ 12 Intrinsic value $ 34 $ 19 $ 53 Weighted average remaining life (in years) 1.86 0.88 1.51

INCOME TAXES (Tables)

INCOME TAXES (Tables)	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	Federal and state income tax expense and the statutory tax rate and the actual effective tax rate consist of the following: TABLE 13.1 Three Months Ended Nine Months Ended (dollars in millions) 2021 2020 2021 2020 Current income taxes: Federal taxes $ 22 $ 16 $ 62 $ 62 State taxes 1 1 4 6 Total current income taxes 23 17 66 68 Deferred income taxes: Federal taxes 4 — 7 (24) State taxes — — 1 — Total deferred income taxes 4 — 8 (24) Total income taxes $ 27 $ 17 $ 74 $ 44 Statutory tax rate 21.0 % 21.0 % 21.0 % 21.0 % Effective tax rate 19.7 17.0 19.5 17.0

OTHER COMPREHENSIVE INCOME (Tab

OTHER COMPREHENSIVE INCOME (Tables)	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Changes in AOCI, Net of Tax, by Component	The following table presents changes in AOCI, net of tax, by component: TABLE 14.1 (in millions) Unrealized Unrealized Unrecognized Total Nine Months Ended September 30, 2021 Balance at beginning of period $ 65 $ (40) $ (64) $ (39) Other comprehensive (loss) income before reclassifications (29) 3 2 (24) Amounts reclassified from AOCI — 11 — 11 Net current period other comprehensive (loss) income (29) 14 2 (13) Balance at end of period $ 36 $ (26) $ (62) $ (52)

EARNINGS PER COMMON SHARE (Tabl

EARNINGS PER COMMON SHARE (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Common Share	The following table sets forth the computation of basic and diluted earnings per common share: TABLE 15.1 Three Months Ended Nine Months Ended ( dollars in millions, except per share data) 2021 2020 2021 2020 Net income $ 111 $ 83 $ 306 $ 214 Less: Preferred stock dividends 2 2 6 6 Net income available to common stockholders $ 109 $ 81 $ 300 $ 208 Basic weighted average common shares outstanding 319,512,598 323,379,720 320,023,695 323,642,925 Net effect of dilutive stock options, warrants and restricted stock 3,348,329 2,283,060 3,611,960 2,051,221 Diluted weighted average common shares outstanding 322,860,927 325,662,780 323,635,655 325,694,146 Earnings per common share: Basic $ 0.34 $ 0.25 $ 0.94 $ 0.64 Diluted $ 0.34 $ 0.25 $ 0.93 $ 0.64
Schedule of Average Shares Excluded from Diluted Earnings Per Common Share Calculation	The following table shows the average shares excluded from the above calculation as their effect would have been anti-dilutive: TABLE 15.2 Three Months Ended Nine Months Ended 2021 2020 2021 2020 Average shares excluded from the diluted earnings per common share calculation — 44,755 — 22,263

CASH FLOW INFORMATION (Tables)

CASH FLOW INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2021
Supplemental Cash Flow Elements [Abstract]
Summary of Supplemental Cash Flow Information	Following is a summary of supplemental cash flow information: TABLE 16.1 Nine Months Ended (in millions) 2021 2020 Interest paid on deposits and other borrowings $ 82 $ 179 Income taxes paid 53 34 Transfers of loans to other real estate owned 3 2 Loans transferred to held for sale from portfolio — 508

BUSINESS SEGMENTS (Tables)

BUSINESS SEGMENTS (Tables)	9 Months Ended
	Sep. 30, 2021
Segment Reporting [Abstract]
Financial Information for Segments of FNB	The following tables provide financial information for these segments of FNB. The information provided under the caption “Parent and Other” represents operations not considered to be reportable segments and/or general operating expenses of FNB, and includes the parent company, other non-bank subsidiaries and eliminations and adjustments to reconcile to the Consolidated Financial Statements. TABLE 17.1 (in millions) Community Wealth Insurance Parent and Consolidated At or for the Three Months Ended September 30, 2021 Interest income $ 255 $ — $ — $ 1 $ 256 Interest expense 20 — — 4 24 Net interest income 235 — — (3) 232 Provision for credit losses (2) — — — (2) Non-interest income 68 15 6 (1) 88 Non-interest expense (1) 164 10 5 2 181 Amortization of intangibles 3 — — — 3 Income tax expense (benefit) 27 1 — (1) 27 Net income (loss) 111 4 1 (5) 111 Total assets 39,238 43 34 46 39,361 Total intangibles 2,271 9 27 — 2,307 At or for the Three Months Ended September 30, 2020 Interest income $ 273 $ — $ — $ — $ 273 Interest expense 41 — — 5 46 Net interest income 232 — — (5) 227 Provision for credit losses 27 — — — 27 Non-interest income 63 12 7 (2) 80 Non-interest expense (1) 162 8 5 2 177 Amortization of intangibles 3 — — — 3 Income tax expense (benefit) 18 1 1 (3) 17 Net income (loss) 85 3 1 (6) 83 Total assets 37,315 36 36 54 37,441 Total intangibles 2,282 9 28 — 2,319 (1) Excludes amortization of intangibles, which is presented separately. (in millions) Community Wealth Insurance Parent and Consolidated At or for the Nine Months Ended September 30, 2021 Interest income $ 759 $ — $ — $ 1 $ 760 Interest expense 67 — — 10 77 Net interest income 692 — — (9) 683 Provision for credit losses 2 — — 1 3 Non-interest income 191 45 19 (4) 251 Non-interest expense (1) 491 30 15 6 542 Amortization of intangibles 8 — 1 — 9 Income tax expense (benefit) 75 3 1 (5) 74 Net income (loss) 307 12 2 (15) 306 Total assets 39,238 43 34 46 39,361 Total intangibles 2,271 9 27 — 2,307 At or for the Nine Months Ended September 30, 2020 Interest income $ 859 $ — $ — $ 1 $ 860 Interest expense 155 — — 17 172 Net interest income 704 — — (16) 688 Provision for credit losses 105 — — — 105 Non-interest income 180 36 18 (8) 226 Non-interest expense (1) 495 26 14 6 541 Amortization of intangibles 9 — 1 — 10 Income tax expense (benefit) 47 2 1 (6) 44 Net income (loss) 228 8 2 (24) 214 Total assets 37,315 36 36 54 37,441 Total intangibles 2,282 9 28 — 2,319 (1) Excludes amortization of intangibles, which is presented separately.

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Balances of Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table presents the balances of assets and liabilities measured at fair value on a recurring basis: TABLE 18.1 (in millions) Level 1 Level 2 Level 3 Total September 30, 2021 Assets Measured at Fair Value Debt securities available for sale U.S. Treasury $ 49 $ — $ — $ 49 U.S. government agencies — 154 — 154 U.S. government-sponsored entities — 170 — 170 Residential mortgage-backed securities: Agency mortgage-backed securities — 1,311 — 1,311 Agency collateralized mortgage obligations — 1,183 — 1,183 Commercial mortgage-backed securities — 306 — 306 States of the U.S. and political subdivisions (municipals) — 33 — 33 Other debt securities — 2 — 2 Total debt securities available for sale 49 3,159 — 3,208 Loans held for sale — 227 — 227 Derivative financial instruments Trading — 213 — 213 Not for trading — 4 13 17 Total derivative financial instruments — 217 13 230 Total assets measured at fair value on a recurring basis $ 49 $ 3,603 $ 13 $ 3,665 Liabilities Measured at Fair Value Derivative financial instruments Trading $ — $ 41 $ — $ 41 Not for trading — — — — Total derivative financial instruments — 41 — 41 Total liabilities measured at fair value on a recurring basis $ — $ 41 $ — $ 41 (in millions) Level 1 Level 2 Level 3 Total December 31, 2020 Assets Measured at Fair Value Debt securities available for sale U.S. Treasury $ 600 $ — $ — $ 600 U.S. government agencies — 172 — 172 U.S. government-sponsored entities — 161 — 161 Residential mortgage-backed securities: Agency mortgage-backed securities — 994 — 994 Agency collateralized mortgage obligations — 1,124 — 1,124 Commercial mortgage-backed securities — 378 — 378 States of the U.S. and political subdivisions (municipals) — 32 — 32 Other debt securities — 2 — 2 Total debt securities available for sale 600 2,863 — 3,463 Loans held for sale — 144 — 144 Derivative financial instruments Trading — 349 — 349 Not for trading — 3 24 27 Total derivative financial instruments — 352 24 376 Total assets measured at fair value on a recurring basis $ 600 $ 3,359 $ 24 $ 3,983 Liabilities Measured at Fair Value Derivative financial instruments Trading $ — $ 37 $ — $ 37 Not for trading — 3 — 3 Total derivative financial instruments — 40 — 40 Total liabilities measured at fair value on a recurring basis $ — $ 40 $ — $ 40
Additional Information about Assets Measured at Fair Value on Recurring Basis	The following table presents additional information about assets measured at fair value on a recurring basis and for which we have utilized Level 3 inputs to determine fair value: TABLE 18.2 (in millions) Interest Total Nine Months Ended September 30, 2021 Balance at beginning of period $ 24 $ 24 Purchases, issuances, sales and settlements: Issuances 13 13 Settlements (24) (24) Balance at end of period $ 13 $ 13 Year Ended December 31, 2020 Balance at beginning of period $ 3 $ 3 Purchases, issuances, sales and settlements: Issuances 24 24 Settlements (3) (3) Balance at end of period $ 24 $ 24
Additional Information about Assets Measured at Fair Value on Non-Recurring Basis	For assets measured at fair value on a non-recurring basis still held at the Balance Sheet date, the following table provides the hierarchy level and the fair value of the related assets or portfolios: TABLE 18.3 (in millions) Level 1 Level 2 Level 3 Total September 30, 2021 Collateral dependent loans $ — $ — $ 9 $ 9 Other assets - MSRs — — 15 15 Other assets - SBA servicing asset — — 4 4 Other real estate owned — — 1 1 December 31, 2020 Collateral dependent loans $ — $ — $ 45 $ 45 Other assets - MSRs — — 36 36 Other assets - SBA servicing asset — — 3 3 Other real estate owned — — 3 3
Fair Values of Financial Instruments	The fair values of our financial instruments are as follows: TABLE 18.4 Fair Value Measurements (in millions) Carrying Fair Level 1 Level 2 Level 3 September 30, 2021 Financial Assets Cash and cash equivalents $ 4,110 $ 4,110 $ 4,110 $ — $ — Debt securities available for sale 3,208 3,208 49 3,159 — Debt securities held to maturity 3,202 3,267 1 3,266 — Net loans and leases, including loans held for sale 24,620 24,224 — 227 23,997 Loan servicing rights 46 47 — — 47 Derivative assets 230 230 — 217 13 Accrued interest receivable 76 76 76 — — Financial Liabilities Deposits 31,444 31,456 28,399 3,057 — Short-term borrowings 1,563 1,565 1,565 — — Long-term borrowings 886 906 — — 906 Derivative liabilities 41 41 — 41 — Accrued interest payable 8 8 8 — — December 31, 2020 Financial Assets Cash and cash equivalents $ 1,383 $ 1,383 $ 1,383 $ — $ — Debt securities available for sale 3,463 3,463 600 2,863 — Debt securities held to maturity 2,868 2,973 — 2,973 — Net loans and leases, including loans held for sale 25,250 25,012 — 144 24,868 Loan servicing rights 39 39 — — 39 Derivative assets 376 376 — 352 24 Accrued interest receivable 90 90 90 — — Financial Liabilities Deposits 29,122 29,158 25,460 3,698 — Short-term borrowings 1,804 1,809 1,809 — — Long-term borrowings 1,095 1,068 — — 1,068 Derivative liabilities 40 40 — 40 — Accrued interest payable 13 13 13 — —

NATURE OF OPERATIONS - Addition

NATURE OF OPERATIONS - Additional Information (Details)	Sep. 30, 2021Statebank
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of states, company operating financial services | State	7
Number of banking offices | bank	332

SECURITIES - Additional Informa

SECURITIES - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Schedule Of Securities [Line Items]
Debt securities available for sale, allowance for credit losses	$ 0	$ 0
Debt securities held to maturity, allowance for credit losses	60,000	40,000
Municipal bond portfolio, value	$ 1,100,000,000
Percentage of formal credit enhancement insurance of municipalities	60.00%
Municipal Bonds [Member] | Weighted Average [Member]
Schedule Of Securities [Line Items]
Average holding size of securities in bond portfolio	$ 3,500,000
Municipal Bonds [Member] | Credit Concentration Risk [Member] | General Obligation Bonds [Member] | A Rating or Better [Member] | Minimum [Member]
Schedule Of Securities [Line Items]
Percentage of portfolio	100.00%
Municipal Bonds [Member] | Geographic Concentration Risk [Member] | Pennsylvania, Ohio and Maryland [Member]
Schedule Of Securities [Line Items]
Percentage of portfolio	63.00%
Available-for-sale Debt Securities [Member]
Schedule Of Securities [Line Items]
Accrued investment income receivable	$ 5,800,000	6,200,000
Municipal Portfolio [Member]
Schedule Of Securities [Line Items]
Debt securities held to maturity, allowance for credit losses	60,000	40,000
Held-to-maturity Securities [Member]
Schedule Of Securities [Line Items]
Accrued investment income receivable	$ 10,900,000	$ 12,500,000

SECURITIES - Amortized Cost and

SECURITIES - Amortized Cost and Fair Value of Securities Available for Sale (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 3,162	$ 3,380
Gross Unrealized Gains	55	84
Gross Unrealized Losses	(9)	(1)
Debt securities, available for sale	3,208	3,463
U.S. Treasury [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	49	600
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Debt securities, available for sale	49	600
US Government Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	152	172
Gross Unrealized Gains	2	0
Gross Unrealized Losses	0	0
Debt securities, available for sale	154	172
U.S. Government-Sponsored Entities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	170	160
Gross Unrealized Gains	1	1
Gross Unrealized Losses	(1)	0
Debt securities, available for sale	170	161
Agency Mortgage-Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,286	959
Gross Unrealized Gains	26	35
Gross Unrealized Losses	(1)	0
Debt securities, available for sale	1,311	994
Agency Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,171	1,094
Gross Unrealized Gains	18	31
Gross Unrealized Losses	(6)	(1)
Debt securities, available for sale	1,183	1,124
Commercial Mortgage-Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	299	361
Gross Unrealized Gains	8	17
Gross Unrealized Losses	(1)	0
Debt securities, available for sale	306	378
States of the U.S. and Political Subdivisions (municipals) [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	33	32
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Debt securities, available for sale	33	32
Other Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2	2
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Debt securities, available for sale	$ 2	$ 2

SECURITIES - Amortized Cost a_2

SECURITIES - Amortized Cost and Fair Value of Securities Held to Maturity (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Investment Securities Held To Maturity [Line Items]
Amortized Cost	$ 3,202	$ 2,868
Gross Unrealized Gains	74	105
Gross Unrealized Losses	(9)	0
Fair  Value	3,267	2,973
U.S. Treasury [Member]
Investment Securities Held To Maturity [Line Items]
Amortized Cost	1	1
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair  Value	1	1
US Government Agencies [Member]
Investment Securities Held To Maturity [Line Items]
Amortized Cost	1	1
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair  Value	1	1
U.S. Government-Sponsored Entities [Member]
Investment Securities Held To Maturity [Line Items]
Amortized Cost	20	120
Gross Unrealized Gains	0	1
Gross Unrealized Losses	0	0
Fair  Value	20	121
Agency Mortgage-Backed Securities [Member]
Investment Securities Held To Maturity [Line Items]
Amortized Cost	1,174	769
Gross Unrealized Gains	21	29
Gross Unrealized Losses	(2)	0
Fair  Value	1,193	798
Agency Collateralized Mortgage Obligations [Member]
Investment Securities Held To Maturity [Line Items]
Amortized Cost	690	562
Gross Unrealized Gains	9	17
Gross Unrealized Losses	(4)	0
Fair  Value	695	579
Commercial Mortgage-Backed Securities [Member]
Investment Securities Held To Maturity [Line Items]
Amortized Cost	284	307
Gross Unrealized Gains	5	10
Gross Unrealized Losses	(2)	0
Fair  Value	287	317
States of the U.S. and Political Subdivisions (municipals) [Member]
Investment Securities Held To Maturity [Line Items]
Amortized Cost	1,032	1,108
Gross Unrealized Gains	39	48
Gross Unrealized Losses	(1)	0
Fair  Value	$ 1,070	$ 1,156

SECURITIES - Amortized Cost a_3

SECURITIES - Amortized Cost and Fair Value of Securities, by Contractual Maturities (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Schedule Of Securities [Line Items]
Available for sale, due in one year or less, amortized cost	$ 45
Available for sale, due after one year but within five years, amortized cost	194
Available for sale, due after five years but within ten years, amortized cost	103
Available for sale, due after ten years, amortized cost	64
Available for sale, with contractual maturities, amortized cost	406
Amortized Cost	3,162	$ 3,380
Available for sale, due in one year or less, fair value	46
Available for sale, due after one year but within five years, fair value	194
Available for sale, due after five years but within ten years, fair value	103
Available for sale, due after ten years, fair value	65
Available for sale, with contractual maturities, fair value	408
Total securities available for sale, fair value	3,208	3,463
Held to maturity, due in one year or less, amortized cost	21
Held to maturity, due after one year but within five years, amortized cost	22
Held to maturity, due after five years but within ten years, amortized cost	122
Held to maturity, due after ten years, amortized cost	889
Held to maturity, with contractual maturities, amortized cost	1,054
Amortized Cost	3,202	2,868
Held to maturity, due in one year or less, fair value	21
Held to maturity, due after one year but within five years, fair value	22
Held to maturity, due after five years but within ten years, fair value	125
Held to maturity, due after ten years, fair value	924
Held to maturity, with contractual maturities, fair value	1,092
Held to maturity, fair value	3,267	2,973
Agency Mortgage-Backed Securities [Member]
Schedule Of Securities [Line Items]
Available-for-sale, amortized cost	1,286
Amortized Cost	1,286	959
Available for sale, fair value	1,311
Total securities available for sale, fair value	1,311	994
Held to maturity, amortized cost	1,174
Amortized Cost	1,174	769
Held to maturity, fair value	1,193
Held to maturity, fair value	1,193	798
Agency Collateralized Mortgage Obligations [Member]
Schedule Of Securities [Line Items]
Available-for-sale, amortized cost	1,171
Amortized Cost	1,171	1,094
Available for sale, fair value	1,183
Total securities available for sale, fair value	1,183	1,124
Held to maturity, amortized cost	690
Amortized Cost	690	562
Held to maturity, fair value	695
Held to maturity, fair value	695	579
Commercial Mortgage-Backed Securities [Member]
Schedule Of Securities [Line Items]
Available-for-sale, amortized cost	299
Amortized Cost	299	361
Available for sale, fair value	306
Total securities available for sale, fair value	306	378
Held to maturity, amortized cost	284
Amortized Cost	284	307
Held to maturity, fair value	287
Held to maturity, fair value	$ 287	$ 317

SECURITIES - Schedule of Securi

SECURITIES - Schedule of Securities Pledged as Collateral (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Investments, Debt and Equity Securities [Abstract]
Securities pledged (carrying value), to secure public deposits, trust deposits and for other purposes as required by law	$ 5,714	$ 5,384
Securities pledged (carrying value), as collateral for short-term borrowings	$ 412	$ 402
Securities pledged as a percent of total securities	95.60%	91.40%

SECURITIES - Fair Values and Un

SECURITIES - Fair Values and Unrealized Losses of Impaired Securities, by Length of Impairment (Details) $ in Millions	Sep. 30, 2021USD ($)Security	Dec. 31, 2020USD ($)Security
Schedule Of Securities [Line Items]
Number of temporarily impaired available for sale securities, Less than 1 year | Security	35	7
Number of temporarily impaired available for sale securities, Greater than 1 year | Security	10	17
Number of temporarily impaired available for sale securities, total | Security	45	24
Temporarily impaired securities available for sale, less than 12 months, fair value	$ 1,187	$ 168
Temporarily impaired securities available for sale, 12 months or more, fair value	11	71
Temporarily impaired securities available for sale, fair value, total	1,198	239
Temporarily impaired securities available for sale, less than 12 months, unrealized losses	(9)	(1)
Temporarily impaired securities available for sale, 12 months or more, unrealized losses	0	0
Temporarily impaired securities available for sale, unrealized losses, total	$ (9)	$ (1)
U.S. Treasury [Member]
Schedule Of Securities [Line Items]
Number of temporarily impaired available for sale securities, Less than 1 year | Security	1
Number of temporarily impaired available for sale securities, Greater than 1 year | Security	0
Number of temporarily impaired available for sale securities, total | Security	1
Temporarily impaired securities available for sale, less than 12 months, fair value	$ 49
Temporarily impaired securities available for sale, 12 months or more, fair value	0
Temporarily impaired securities available for sale, fair value, total	49
Temporarily impaired securities available for sale, less than 12 months, unrealized losses	0
Temporarily impaired securities available for sale, 12 months or more, unrealized losses	0
Temporarily impaired securities available for sale, unrealized losses, total	$ 0
US Government Agencies [Member]
Schedule Of Securities [Line Items]
Number of temporarily impaired available for sale securities, Less than 1 year | Security	0	1
Number of temporarily impaired available for sale securities, Greater than 1 year | Security	9	16
Number of temporarily impaired available for sale securities, total | Security	9	17
Temporarily impaired securities available for sale, less than 12 months, fair value	$ 0	$ 13
Temporarily impaired securities available for sale, 12 months or more, fair value	9	69
Temporarily impaired securities available for sale, fair value, total	9	82
Temporarily impaired securities available for sale, less than 12 months, unrealized losses	0	0
Temporarily impaired securities available for sale, 12 months or more, unrealized losses	0	0
Temporarily impaired securities available for sale, unrealized losses, total	$ 0	$ 0
U.S. Government-Sponsored Entities [Member]
Schedule Of Securities [Line Items]
Number of temporarily impaired available for sale securities, Less than 1 year | Security	3	1
Number of temporarily impaired available for sale securities, Greater than 1 year | Security	0	0
Number of temporarily impaired available for sale securities, total | Security	3	1
Temporarily impaired securities available for sale, less than 12 months, fair value	$ 74	$ 25
Temporarily impaired securities available for sale, 12 months or more, fair value	0	0
Temporarily impaired securities available for sale, fair value, total	74	25
Temporarily impaired securities available for sale, less than 12 months, unrealized losses	(1)	0
Temporarily impaired securities available for sale, 12 months or more, unrealized losses	0	0
Temporarily impaired securities available for sale, unrealized losses, total	$ (1)	$ 0
Agency Mortgage-Backed Securities [Member]
Schedule Of Securities [Line Items]
Number of temporarily impaired available for sale securities, Less than 1 year | Security	9
Number of temporarily impaired available for sale securities, Greater than 1 year | Security	0
Number of temporarily impaired available for sale securities, total | Security	9
Temporarily impaired securities available for sale, less than 12 months, fair value	$ 428
Temporarily impaired securities available for sale, 12 months or more, fair value	0
Temporarily impaired securities available for sale, fair value, total	428
Temporarily impaired securities available for sale, less than 12 months, unrealized losses	(1)
Temporarily impaired securities available for sale, 12 months or more, unrealized losses	0
Temporarily impaired securities available for sale, unrealized losses, total	$ (1)
Agency Collateralized Mortgage Obligations [Member]
Schedule Of Securities [Line Items]
Number of temporarily impaired available for sale securities, Less than 1 year | Security	14	5
Number of temporarily impaired available for sale securities, Greater than 1 year | Security	0	0
Number of temporarily impaired available for sale securities, total | Security	14	5
Temporarily impaired securities available for sale, less than 12 months, fair value	$ 534	$ 130
Temporarily impaired securities available for sale, 12 months or more, fair value	0	0
Temporarily impaired securities available for sale, fair value, total	534	130
Temporarily impaired securities available for sale, less than 12 months, unrealized losses	(6)	(1)
Temporarily impaired securities available for sale, 12 months or more, unrealized losses	0	0
Temporarily impaired securities available for sale, unrealized losses, total	$ (6)	$ (1)
Commercial Mortgage-Backed Securities [Member]
Schedule Of Securities [Line Items]
Number of temporarily impaired available for sale securities, Less than 1 year | Security	3
Number of temporarily impaired available for sale securities, Greater than 1 year | Security	0
Number of temporarily impaired available for sale securities, total | Security	3
Temporarily impaired securities available for sale, less than 12 months, fair value	$ 91
Temporarily impaired securities available for sale, 12 months or more, fair value	0
Temporarily impaired securities available for sale, fair value, total	91
Temporarily impaired securities available for sale, less than 12 months, unrealized losses	(1)
Temporarily impaired securities available for sale, 12 months or more, unrealized losses	0
Temporarily impaired securities available for sale, unrealized losses, total	$ (1)
States of the U.S. and Political Subdivisions (municipals) [Member]
Schedule Of Securities [Line Items]
Number of temporarily impaired available for sale securities, Less than 1 year | Security	5
Number of temporarily impaired available for sale securities, Greater than 1 year | Security	0
Number of temporarily impaired available for sale securities, total | Security	5
Temporarily impaired securities available for sale, less than 12 months, fair value	$ 11
Temporarily impaired securities available for sale, 12 months or more, fair value	0
Temporarily impaired securities available for sale, fair value, total	11
Temporarily impaired securities available for sale, less than 12 months, unrealized losses	0
Temporarily impaired securities available for sale, 12 months or more, unrealized losses	0
Temporarily impaired securities available for sale, unrealized losses, total	$ 0
Other Debt Securities [Member]
Schedule Of Securities [Line Items]
Number of temporarily impaired available for sale securities, Less than 1 year | Security	0	0
Number of temporarily impaired available for sale securities, Greater than 1 year | Security	1	1
Number of temporarily impaired available for sale securities, total | Security	1	1
Temporarily impaired securities available for sale, less than 12 months, fair value	$ 0	$ 0
Temporarily impaired securities available for sale, 12 months or more, fair value	2	2
Temporarily impaired securities available for sale, fair value, total	2	2
Temporarily impaired securities available for sale, less than 12 months, unrealized losses	0	0
Temporarily impaired securities available for sale, 12 months or more, unrealized losses	0	0
Temporarily impaired securities available for sale, unrealized losses, total	$ 0	$ 0

LOANS AND LEASES - Additional I

LOANS AND LEASES - Additional Information (Details) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)State	Dec. 31, 2020USD ($)	Jun. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Dec. 31, 2019USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accrued interest receivable	$ 51.4	$ 62.9
Purchased with credit deterioration included with allowance for credit losses, amount	50.3
Purchased with credit deterioration, discount	110
Discount remaining	$ 34.2	50.9
Number of states, company operating financial services | State	7
Loans granted short-term modification due to COVID-19	$ 54	397			$ 2,400
Restructured loans returned to performing status	7.8
Total loan on allowance	349	363
Pooled reserves for all other classes of loans	$ 3.8	4.1
Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due period for loan to be in default	90 days
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due period for loan to be in default	12 months
SBA-Guaranteed Loan Servicing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Guaranteed percentage	100.00%
Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value of OREO through foreclosure	$ 1.1	2.5
Mortgage loans on real estate, foreclosure	6.3	8.2
Total Commercial Loans and Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loan on allowance	266	280	$ 274	$ 295	279	$ 133
Total Commercial Loans and Leases [Member] | Specific Reserves for Commercial Troubled Debt Restructurings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loan on allowance	1.4	2.8
Total Commercial Loans and Leases [Member] | Pooled Reserves For Commercial Troubled Debt Restructurings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loan on allowance	1.8	2.5
Total Commercial Loans and Leases [Member] | Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loan on allowance	87	81	$ 81	$ 93	$ 98	$ 53
Total Commercial Loans and Leases [Member] | Commercial and Industrial [Member] | Paycheck Protection Program Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to customers	700	$ 2,200
Total Commercial Loans and Leases [Member] | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, collateral dependent	40
Total Commercial Loans and Leases [Member] | Commercial Loan [Member] | Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Threshold for loans whose terms have been modified in a trouble debt restructuring, non accrual	$ 1

LOANS AND LEASES - Net of Unear

LOANS AND LEASES - Net of Unearned Income (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	$ 24,716	$ 25,459
Total Commercial Loans and Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	16,401	17,470
Total Commercial Loans and Leases [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	9,871	9,731
Total Commercial Loans and Leases [Member] | Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	5,960	7,214
Total Commercial Loans and Leases [Member] | Commercial Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	489	485
Total Commercial Loans and Leases [Member] | Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	81	40
Total Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	8,315	7,989
Total Consumer Loan [Member] | Direct Installment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	2,250	2,020
Total Consumer Loan [Member] | Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	3,588	3,433
Total Consumer Loan [Member] | Indirect Installment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	1,230	1,218
Total Consumer Loan [Member] | Consumer Lines of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	$ 1,247	$ 1,318

LOANS AND LEASES - Commercial R

LOANS AND LEASES - Commercial Real Estate Loans (Details) - Loan Portfolio Diversification Risk [Member] - Commercial Real Estate Loans [Member]	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Owner-Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Percent of total loans and leases	28.20%	28.10%
Non-Owner-Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Percent of total loans and leases	71.80%	71.90%

LOANS AND LEASES - Origination

LOANS AND LEASES - Origination Year (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	$ 5,102	$ 7,565
Fiscal year before current fiscal year	4,854	4,429
Two years before current fiscal year	3,596	2,837
Three years before current fiscal year	2,194	2,281
Four years before current fiscal year	1,718	1,800
Prior	4,501	3,917
Revolving Loans Amortized Cost Basis	2,751	2,630
Total Loans and Leases	24,716	25,459
Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	24,539	25,201
Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	177	258
Total Commercial Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	2,969	5,402
Fiscal year before current fiscal year	2,986	3,109
Two years before current fiscal year	2,720	2,001
Three years before current fiscal year	1,663	1,603
Four years before current fiscal year	1,285	1,217
Prior	3,109	2,659
Revolving Loans Amortized Cost Basis	1,669	1,479
Total Loans and Leases	16,401	17,470
Total Commercial Loans [Member] | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	16,298	17,315
Total Commercial Loans [Member] | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	103	155
Total Commercial Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	1,305	1,892
Fiscal year before current fiscal year	1,841	1,916
Two years before current fiscal year	1,785	1,244
Three years before current fiscal year	1,113	1,166
Four years before current fiscal year	956	1,074
Prior	2,718	2,266
Revolving Loans Amortized Cost Basis	153	173
Total Loans and Leases	9,871	9,731
Total Commercial Loans [Member] | Commercial Real Estate [Member] | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	9,810	9,633
Total Commercial Loans [Member] | Commercial Real Estate [Member] | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	61	98
Total Commercial Loans [Member] | Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	1,290	1,879
Fiscal year before current fiscal year	1,817	1,854
Two years before current fiscal year	1,706	1,135
Three years before current fiscal year	964	927
Four years before current fiscal year	797	888
Prior	2,385	1,911
Revolving Loans Amortized Cost Basis	148	163
Total Loans and Leases	9,107	8,757
Total Commercial Loans [Member] | Commercial Real Estate [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	15	9
Fiscal year before current fiscal year	16	30
Two years before current fiscal year	45	80
Three years before current fiscal year	111	158
Four years before current fiscal year	115	70
Prior	175	163
Revolving Loans Amortized Cost Basis	2	4
Total Loans and Leases	479	514
Total Commercial Loans [Member] | Commercial Real Estate [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	4
Fiscal year before current fiscal year	8	32
Two years before current fiscal year	34	29
Three years before current fiscal year	38	81
Four years before current fiscal year	44	116
Prior	158	192
Revolving Loans Amortized Cost Basis	3	6
Total Loans and Leases	285	460
Total Commercial Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	1,502	3,324
Fiscal year before current fiscal year	1,017	1,056
Two years before current fiscal year	825	668
Three years before current fiscal year	488	376
Four years before current fiscal year	283	136
Prior	378	383
Revolving Loans Amortized Cost Basis	1,467	1,271
Total Loans and Leases	5,960	7,214
Total Commercial Loans [Member] | Commercial and Industrial [Member] | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	5,924	7,162
Total Commercial Loans [Member] | Commercial and Industrial [Member] | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	36	52
Total Commercial Loans [Member] | Commercial and Industrial [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	1,500	3,286
Fiscal year before current fiscal year	980	1,007
Two years before current fiscal year	788	590
Three years before current fiscal year	422	304
Four years before current fiscal year	200	120
Prior	293	311
Revolving Loans Amortized Cost Basis	1,335	1,095
Total Loans and Leases	5,518	6,713
Total Commercial Loans [Member] | Commercial and Industrial [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	30
Fiscal year before current fiscal year	31	23
Two years before current fiscal year	15	13
Three years before current fiscal year	5	28
Four years before current fiscal year	18	10
Prior	64	35
Revolving Loans Amortized Cost Basis	35	79
Total Loans and Leases	168	218
Total Commercial Loans [Member] | Commercial and Industrial [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	2	8
Fiscal year before current fiscal year	6	26
Two years before current fiscal year	22	65
Three years before current fiscal year	61	44
Four years before current fiscal year	65	6
Prior	21	37
Revolving Loans Amortized Cost Basis	97	97
Total Loans and Leases	274	283
Total Commercial Loans [Member] | Commercial Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	139	186
Fiscal year before current fiscal year	128	137
Two years before current fiscal year	110	89
Three years before current fiscal year	62	61
Four years before current fiscal year	46	7
Prior	4	5
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	489	485
Total Commercial Loans [Member] | Commercial Leases [Member] | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	484	481
Total Commercial Loans [Member] | Commercial Leases [Member] | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	5	4
Total Commercial Loans [Member] | Commercial Leases [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	139	178
Fiscal year before current fiscal year	124	134
Two years before current fiscal year	107	83
Three years before current fiscal year	58	56
Four years before current fiscal year	43	5
Prior	2	3
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	473	459
Total Commercial Loans [Member] | Commercial Leases [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	1
Fiscal year before current fiscal year	0	1
Two years before current fiscal year	0	4
Three years before current fiscal year	2	4
Four years before current fiscal year	3	1
Prior	2	2
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	7	13
Total Commercial Loans [Member] | Commercial Leases [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	7
Fiscal year before current fiscal year	4	2
Two years before current fiscal year	3	2
Three years before current fiscal year	2	1
Four years before current fiscal year	0	1
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	9	13
Total Commercial Loans [Member] | Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	23	0
Fiscal year before current fiscal year	0	0
Two years before current fiscal year	0	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	0
Prior	9	5
Revolving Loans Amortized Cost Basis	49	35
Total Loans and Leases	81	40
Total Commercial Loans [Member] | Other [Member] | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	80	39
Total Commercial Loans [Member] | Other [Member] | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	1	1
Total Commercial Loans [Member] | Other [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	23	0
Fiscal year before current fiscal year	0	0
Two years before current fiscal year	0	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	0
Prior	9	4
Revolving Loans Amortized Cost Basis	49	35
Total Loans and Leases	81	39
Total Commercial Loans [Member] | Other [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Fiscal year before current fiscal year	0	0
Two years before current fiscal year	0	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	0
Prior	0	1
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	0	1
Total Consumer Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	2,133	2,163
Fiscal year before current fiscal year	1,868	1,320
Two years before current fiscal year	876	836
Three years before current fiscal year	531	678
Four years before current fiscal year	433	583
Prior	1,392	1,258
Revolving Loans Amortized Cost Basis	1,082	1,151
Total Loans and Leases	8,315	7,989
Total Consumer Loan [Member] | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	8,241	7,886
Total Consumer Loan [Member] | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	74	103
Total Consumer Loan [Member] | Direct Installment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	707	706
Fiscal year before current fiscal year	585	338
Two years before current fiscal year	241	202
Three years before current fiscal year	142	144
Four years before current fiscal year	106	173
Prior	469	456
Revolving Loans Amortized Cost Basis	0	1
Total Loans and Leases	2,250	2,020
Total Consumer Loan [Member] | Direct Installment [Member] | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	707	706
Fiscal year before current fiscal year	585	337
Two years before current fiscal year	240	200
Three years before current fiscal year	141	143
Four years before current fiscal year	106	171
Prior	458	442
Revolving Loans Amortized Cost Basis	0	1
Total Loans and Leases	2,237	2,000
Total Consumer Loan [Member] | Direct Installment [Member] | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Fiscal year before current fiscal year	0	1
Two years before current fiscal year	1	2
Three years before current fiscal year	1	1
Four years before current fiscal year	0	2
Prior	11	14
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	13	20
Total Consumer Loan [Member] | Residential Mortgages [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	996	1,080
Fiscal year before current fiscal year	988	712
Two years before current fiscal year	449	290
Three years before current fiscal year	171	382
Four years before current fiscal year	243	336
Prior	739	632
Revolving Loans Amortized Cost Basis	2	1
Total Loans and Leases	3,588	3,433
Total Consumer Loan [Member] | Residential Mortgages [Member] | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	996	1,079
Fiscal year before current fiscal year	986	707
Two years before current fiscal year	445	283
Three years before current fiscal year	167	378
Four years before current fiscal year	240	330
Prior	715	603
Revolving Loans Amortized Cost Basis	2	1
Total Loans and Leases	3,551	3,381
Total Consumer Loan [Member] | Residential Mortgages [Member] | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	1
Fiscal year before current fiscal year	2	5
Two years before current fiscal year	4	7
Three years before current fiscal year	4	4
Four years before current fiscal year	3	6
Prior	24	29
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	37	52
Total Consumer Loan [Member] | Indirect Installment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	417	373
Fiscal year before current fiscal year	292	263
Two years before current fiscal year	182	336
Three years before current fiscal year	212	149
Four years before current fiscal year	81	69
Prior	46	28
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	1,230	1,218
Total Consumer Loan [Member] | Indirect Installment [Member] | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	415	372
Fiscal year before current fiscal year	290	260
Two years before current fiscal year	180	332
Three years before current fiscal year	210	147
Four years before current fiscal year	80	67
Prior	45	27
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	1,220	1,205
Total Consumer Loan [Member] | Indirect Installment [Member] | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	2	1
Fiscal year before current fiscal year	2	3
Two years before current fiscal year	2	4
Three years before current fiscal year	2	2
Four years before current fiscal year	1	2
Prior	1	1
Revolving Loans Amortized Cost Basis	0	0
Total Loans and Leases	10	13
Total Consumer Loan [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	13	4
Fiscal year before current fiscal year	3	7
Two years before current fiscal year	4	8
Three years before current fiscal year	6	3
Four years before current fiscal year	3	5
Prior	138	142
Revolving Loans Amortized Cost Basis	1,080	1,149
Total Loans and Leases	1,247	1,318
Total Consumer Loan [Member] | Consumer Lines of Credit [Member] | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	13	4
Fiscal year before current fiscal year	3	7
Two years before current fiscal year	4	8
Three years before current fiscal year	6	3
Four years before current fiscal year	3	5
Prior	126	127
Revolving Loans Amortized Cost Basis	1,078	1,146
Total Loans and Leases	1,233	1,300
Total Consumer Loan [Member] | Consumer Lines of Credit [Member] | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Current fiscal year	0	0
Fiscal year before current fiscal year	0	0
Two years before current fiscal year	0	0
Three years before current fiscal year	0	0
Four years before current fiscal year	0	0
Prior	12	15
Revolving Loans Amortized Cost Basis	2	3
Total Loans and Leases	$ 14	$ 18

LOANS AND LEASES - Age Analysis

LOANS AND LEASES - Age Analysis of Past Due Loans (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	$ 24,716	$ 25,459
90 Days Past Due and Still Accruing	8	16
Non-accrual loans	110	170
Non-accrual with No ACL	24	52
30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	59	72
Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	177	258
Current [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	24,539	25,201
Total Commercial Loans [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	16,401	17,470
90 Days Past Due and Still Accruing	0	0
Non-accrual loans	80	132
Non-accrual with No ACL	24	52
Total Commercial Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	9,871	9,731
90 Days Past Due and Still Accruing	0	0
Non-accrual loans	55	85
Non-accrual with No ACL	20	36
Total Commercial Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	5,960	7,214
90 Days Past Due and Still Accruing	0	0
Non-accrual loans	23	44
Non-accrual with No ACL	4	16
Total Commercial Loans [Member] | Commercial Leases [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	489	485
90 Days Past Due and Still Accruing	0	0
Non-accrual loans	1	2
Non-accrual with No ACL	0	0
Total Commercial Loans [Member] | Other [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	81	40
90 Days Past Due and Still Accruing	0	0
Non-accrual loans	1	1
Non-accrual with No ACL	0	0
Total Commercial Loans [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	23	23
Total Commercial Loans [Member] | 30-89 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	6	13
Total Commercial Loans [Member] | 30-89 Days Past Due [Member] | Commercial and Industrial [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	13	8
Total Commercial Loans [Member] | 30-89 Days Past Due [Member] | Commercial Leases [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	4	2
Total Commercial Loans [Member] | 30-89 Days Past Due [Member] | Other [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	0	0
Total Commercial Loans [Member] | Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	103	155
Total Commercial Loans [Member] | Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	61	98
Total Commercial Loans [Member] | Past Due [Member] | Commercial and Industrial [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	36	52
Total Commercial Loans [Member] | Past Due [Member] | Commercial Leases [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	5	4
Total Commercial Loans [Member] | Past Due [Member] | Other [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1	1
Total Commercial Loans [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	16,298	17,315
Total Commercial Loans [Member] | Current [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	9,810	9,633
Total Commercial Loans [Member] | Current [Member] | Commercial and Industrial [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	5,924	7,162
Total Commercial Loans [Member] | Current [Member] | Commercial Leases [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	484	481
Total Commercial Loans [Member] | Current [Member] | Other [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	80	39
Total Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	8,315	7,989
90 Days Past Due and Still Accruing	8	16
Non-accrual loans	30	38
Non-accrual with No ACL	0	0
Total Consumer Loan [Member] | Direct Installment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	2,250	2,020
90 Days Past Due and Still Accruing	1	2
Non-accrual loans	8	11
Non-accrual with No ACL	0	0
Total Consumer Loan [Member] | Residential Mortgages [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	3,588	3,433
90 Days Past Due and Still Accruing	5	11
Non-accrual loans	14	18
Non-accrual with No ACL	0	0
Total Consumer Loan [Member] | Indirect Installment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,230	1,218
90 Days Past Due and Still Accruing	0	1
Non-accrual loans	2	2
Non-accrual with No ACL	0	0
Total Consumer Loan [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,247	1,318
90 Days Past Due and Still Accruing	2	2
Non-accrual loans	6	7
Non-accrual with No ACL	0	0
Total Consumer Loan [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	36	49
Total Consumer Loan [Member] | 30-89 Days Past Due [Member] | Direct Installment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	4	7
Total Consumer Loan [Member] | 30-89 Days Past Due [Member] | Residential Mortgages [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	18	23
Total Consumer Loan [Member] | 30-89 Days Past Due [Member] | Indirect Installment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	8	10
Total Consumer Loan [Member] | 30-89 Days Past Due [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	6	9
Total Consumer Loan [Member] | Past Due [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	74	103
Total Consumer Loan [Member] | Past Due [Member] | Direct Installment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	13	20
Total Consumer Loan [Member] | Past Due [Member] | Residential Mortgages [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	37	52
Total Consumer Loan [Member] | Past Due [Member] | Indirect Installment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	10	13
Total Consumer Loan [Member] | Past Due [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	14	18
Total Consumer Loan [Member] | Current [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	8,241	7,886
Total Consumer Loan [Member] | Current [Member] | Direct Installment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	2,237	2,000
Total Consumer Loan [Member] | Current [Member] | Residential Mortgages [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	3,551	3,381
Total Consumer Loan [Member] | Current [Member] | Indirect Installment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,220	1,205
Total Consumer Loan [Member] | Current [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	$ 1,233	$ 1,300

LOANS AND LEASES - Non-Performi

LOANS AND LEASES - Non-Performing Assets (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 110	$ 170
Non-Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	110	170
Total non-performing loans	110	170
Other real estate owned	8	10
Non Performing Assets	$ 118	$ 180
Non-performing loans / total loans and leases	0.45%	0.67%
Non-performing assets + 90 days past due + OREO / total loans and leases + OREO	0.51%	0.77%
Past due	90 days	90 days

LOANS AND LEASES - Summary of P

LOANS AND LEASES - Summary of Payment Status of TDRs (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	$ 93	$ 91
Performing [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	58	58
Non-Accrual [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	$ 35	$ 33

LOANS AND LEASES - Troubled Deb

LOANS AND LEASES - Troubled Debt Restructurings (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)Contract	Sep. 30, 2020USD ($)Contract	Sep. 30, 2021USD ($)Contract	Sep. 30, 2020USD ($)Contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	36	36	102	147
Pre- Modification Outstanding Recorded Investment	$ 4	$ 4	$ 26	$ 18
Post- Modification Outstanding Recorded Investment	$ 4	$ 4	$ 25	$ 14
Total Commercial Loans and Leases [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	9	11	30	43
Pre- Modification Outstanding Recorded Investment	$ 2	$ 2	$ 21	$ 11
Post- Modification Outstanding Recorded Investment	$ 2	$ 2	$ 20	$ 8
Total Commercial Loans and Leases [Member] | Commercial Real Estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	5	7	21	23
Pre- Modification Outstanding Recorded Investment	$ 2	$ 2	$ 20	$ 8
Post- Modification Outstanding Recorded Investment	$ 2	$ 2	$ 20	$ 6
Total Commercial Loans and Leases [Member] | Commercial and Industrial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	3	4	8	19
Pre- Modification Outstanding Recorded Investment	$ 0	$ 0	$ 1	$ 3
Post- Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 2
Total Commercial Loans and Leases [Member] | Other [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	1	0	1	1
Pre- Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Post- Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Total Consumer Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	27	25	72	104
Pre- Modification Outstanding Recorded Investment	$ 2	$ 2	$ 5	$ 7
Post- Modification Outstanding Recorded Investment	$ 2	$ 2	$ 5	$ 6
Total Consumer Loan [Member] | Direct Installment [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	8	14	26	50
Pre- Modification Outstanding Recorded Investment	$ 0	$ 1	$ 1	$ 3
Post- Modification Outstanding Recorded Investment	$ 0	$ 1	$ 1	$ 3
Total Consumer Loan [Member] | Residential Mortgages [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	12	2	15	18
Pre- Modification Outstanding Recorded Investment	$ 2	$ 1	$ 2	$ 3
Post- Modification Outstanding Recorded Investment	$ 2	$ 1	$ 2	$ 2
Total Consumer Loan [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	7	9	31	36
Pre- Modification Outstanding Recorded Investment	$ 0	$ 0	$ 2	$ 1
Post- Modification Outstanding Recorded Investment	$ 0	$ 0	$ 2	$ 1

LOANS AND LEASES - Originated T

LOANS AND LEASES - Originated Troubled Debt Restructurings, Payment Default (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)Contract	Sep. 30, 2020USD ($)Contract	Sep. 30, 2021USD ($)Contract	Sep. 30, 2020USD ($)Contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	1	6	3	28
Recorded Investment | $	$ 0	$ 0	$ 0	$ 4
Total Commercial Loans and Leases [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	0	1	1	11
Recorded Investment | $	$ 0	$ 0	$ 0	$ 3
Total Commercial Loans and Leases [Member] | Commercial Real Estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract		0		8
Recorded Investment | $		$ 0		$ 3
Total Commercial Loans and Leases [Member] | Commercial and Industrial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	0	1	1	3
Recorded Investment | $	$ 0	$ 0	$ 0	$ 0
Total Consumer Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	1	5	2	17
Recorded Investment | $	$ 0	$ 0	$ 0	$ 1
Total Consumer Loan [Member] | Direct Installment [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	1	4	1	12
Recorded Investment | $	$ 0	$ 0	$ 0	$ 1
Total Consumer Loan [Member] | Residential Mortgages [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	0	0	1	2
Recorded Investment | $	$ 0	$ 0	$ 0	$ 0
Total Consumer Loan [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract		1		3
Recorded Investment | $		$ 0		$ 0

ALLOWANCE FOR CREDIT LOSSES O_3

ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES - Additional Information (Details) - USD ($) $ in Millions	Jan. 01, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Stockholders' equity attributable to parent		$ 5,098	$ 4,951	$ 5,098	$ 4,951	$ 4,959	$ 5,037	$ 4,897	$ 4,883
Financing receivable, allowance for credit loss, period increase (decrease)	$ 105					(13.9)
Allowance for credit loss		$ 349		$ 349		$ 363
Percentage of growth, gross domestic product						4.00%
Percentage of unemployment						6.00%
Percentage of growth, housing price index		6.10%		6.10%
Percentage of growth, commercial real estate price index		9.50%		9.50%
Percentage of growth, S&P volatility in next fiscal year		7.70%		7.70%
Percentage of decline, S&P volatility in next second year		2.70%		2.70%
Financing receivable, allowance for credit loss, period increase (decrease), percentage						(3.80%)
Financing receivable, allowance for credit loss, ratio		1.41%		1.41%		1.43%
Provision (benefit) for credit losses		$ (1.8)		$ 3
Financing receivable, allowance for credit loss, write-off, after recovery		(1.6)	(19.3)	(12.5)	(33.4)
Allowance For Credit Losses on Loans and Leases [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit loss		349.3	373	349.3	373	$ 363	357	365	196
Financing receivable, allowance for credit loss, write-off, after recovery		(2)	(19)	(13)	(33)
Impact of ASC 326 Adoption [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Stockholders' equity attributable to parent									(50)
Retained Earnings [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Stockholders' equity attributable to parent		$ 1,051	$ 838	$ 1,051	$ 838	$ 869	$ 981	$ 796	798
Retained Earnings [Member] | Impact of ASC 326 Adoption [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Stockholders' equity attributable to parent									$ (50)
Accounting Standards Update 2016-13 [Member] | Retained Earnings [Member] | Impact of ASC 326 Adoption [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Stockholders' equity attributable to parent	(50.6)
Longer Duration Loans and Gross Up [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, period increase (decrease)	50
Unfunded Loan Commitment [Member] | Accounting Standards Update 2016-13 [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit loss	$ 10

ALLOWANCE FOR CREDIT LOSSES O_4

ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES - Changes in Allowance for Credit Losses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2019
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			$ 363
Net Charge- Offs	$ (1.6)	$ (19.3)	(12.5)	$ (33.4)
Provision for Credit Losses	(2)	27	3	105
Balance at End of Period	349		349
Unfunded Loan Commitment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	14	15	14	3
Charge- Offs	0	0	0	0
Recoveries	0	0	0	0
Net Charge- Offs	0	0	0	0
Provision for Credit Losses	4	0	4	2
Initial ACL on PCD Loans					$ 0
Balance at End of Period	18	15	18	15
Unfunded Loan Commitment [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					10
Unfunded Loan Commitment [Member] | Other Non-interest Expense
Allowance for Loan and Lease Losses [Roll Forward]
Provision for Credit Losses		(0.3)		2
Total Commercial Loans and Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	274	279	280	133
Charge- Offs	(5)	(21)	(22)	(36)
Recoveries	4	2	11	9
Net Charge- Offs	(1)	(19)	(11)	(27)
Provision for Credit Losses	(7)	35	(3)	108
Initial ACL on PCD Loans					44
Balance at End of Period	266	295	266	295
Total Commercial Loans and Leases [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					37
Total Commercial Loans and Leases [Member] | Commercial Real Estate [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	176	163	181	60
Charge- Offs	(3)	(3)	(9)	(8)
Recoveries	2	1	5	6
Net Charge- Offs	(1)	(2)	(4)	(2)
Provision for Credit Losses	(14)	23	(16)	48
Initial ACL on PCD Loans					40
Balance at End of Period	161	184	161	184
Total Commercial Loans and Leases [Member] | Commercial Real Estate [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					38
Total Commercial Loans and Leases [Member] | Commercial and Industrial [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	81	98	81	53
Charge- Offs	(2)	(17)	(11)	(25)
Recoveries	2	1	4	3
Net Charge- Offs	0	(16)	(7)	(22)
Provision for Credit Losses	6	11	13	50
Initial ACL on PCD Loans					4
Balance at End of Period	87	93	87	93
Total Commercial Loans and Leases [Member] | Commercial and Industrial [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					8
Total Commercial Loans and Leases [Member] | Commercial Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	16	17	17	11
Charge- Offs	0	0	0	0
Recoveries	0	0	1	0
Net Charge- Offs	0	0	1	0
Provision for Credit Losses	0	0	(2)	6
Initial ACL on PCD Loans					0
Balance at End of Period	16	17	16	17
Total Commercial Loans and Leases [Member] | Commercial Leases [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					0
Total Commercial Loans and Leases [Member] | Other [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	1	1	1	9
Charge- Offs	0	(1)	(2)	(3)
Recoveries	0	0	1	0
Net Charge- Offs	0	(1)	(1)	(3)
Provision for Credit Losses	1	1	2	4
Initial ACL on PCD Loans					0
Balance at End of Period	2	1	2	1
Total Commercial Loans and Leases [Member] | Other [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					(9)
Total Commercial Loans and Leases [Member] | Unfunded Loan Commitment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Provision for Credit Losses	4	0	4	0
Other adjustments:	0	0	0	2
Total Commercial Loans and Leases [Member] | Unfunded Loan Commitment [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					8
Total Consumer Loan [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	83	86	83	63
Charge- Offs	(2)	(2)	(5)	(10)
Recoveries	1	2	3	4
Net Charge- Offs	(1)	0	(2)	(6)
Provision for Credit Losses	1	(8)	2	(3)
Initial ACL on PCD Loans					6
Balance at End of Period	83	78	83	78
Total Consumer Loan [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					18
Total Consumer Loan [Member] | Direct Installment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	27	25	26	13
Charge- Offs	(1)	0	(1)	(1)
Recoveries	0	0	0	0
Net Charge- Offs	(1)	0	(1)	(1)
Provision for Credit Losses	0	(1)	1	1
Initial ACL on PCD Loans					1
Balance at End of Period	26	24	26	24
Total Consumer Loan [Member] | Direct Installment [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					10
Total Consumer Loan [Member] | Residential Mortgages [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	33	33	34	22
Charge- Offs	0	(1)	0	(1)
Recoveries	0	1	0	1
Net Charge- Offs	0	0	0	0
Provision for Credit Losses	0	(2)	(1)	(1)
Initial ACL on PCD Loans					4
Balance at End of Period	33	31	33	31
Total Consumer Loan [Member] | Residential Mortgages [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					6
Total Consumer Loan [Member] | Indirect Installment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	12	17	11	19
Charge- Offs	0	(1)	(3)	(6)
Recoveries	0	1	2	3
Net Charge- Offs	0	0	(1)	(3)
Provision for Credit Losses	1	(5)	3	(6)
Initial ACL on PCD Loans					0
Balance at End of Period	13	12	13	12
Total Consumer Loan [Member] | Indirect Installment [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					2
Total Consumer Loan [Member] | Consumer Lines of Credit [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	11	11	12	9
Charge- Offs	(1)	0	(1)	(2)
Recoveries	1	0	1	0
Net Charge- Offs	0	0	0	(2)
Provision for Credit Losses	0	0	(1)	3
Initial ACL on PCD Loans					1
Balance at End of Period	11	11	11	11
Total Consumer Loan [Member] | Consumer Lines of Credit [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					0
Total Consumer Loan [Member] | Unfunded Loan Commitment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Provision for Credit Losses	0	0	0	0
Total Consumer Loan [Member] | Unfunded Loan Commitment [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					2
Allowance For Credit Losses on Loans and Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	357	365	363	196
Charge- Offs	(7)	(23)	(27)	(46)
Recoveries	5	4	14	13
Net Charge- Offs	(2)	(19)	(13)	(33)
Provision for Credit Losses	(6)	27	(1)	105
Initial ACL on PCD Loans					50
Balance at End of Period	349.3	373	349.3	373
Allowance For Credit Losses on Loans and Leases [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					55
Allowance For Credit Losses on Loans and Leases and Unfunded Loans Commitments [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	371	380	377	199
Charge- Offs	(7)	(23)	(27)	(46)
Recoveries	5	4	14	13
Net Charge- Offs	(2)	(19)	(13)	(33)
Provision for Credit Losses	(2)	27	3	107
Initial ACL on PCD Loans					50
Balance at End of Period	$ 367	$ 388	$ 367	$ 388
Allowance For Credit Losses on Loans and Leases and Unfunded Loans Commitments [Member] | Impact of ASC 326 Adoption [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Allowance for credit loss					$ 65

LOAN SERVICING - Activity in MS

LOAN SERVICING - Activity in MSR (Details) - Mortgage Servicing Rights [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Servicing Assets at Fair Value [Line Items]
Mortgage loans sold with servicing retained	$ 4,797		$ 4,797		$ 4,653
Mortgage loans sold with servicing retained	382	$ 466	1,406	$ 1,142
Pretax net gains resulting from above loan sales	10	25	36	47
Mortgage banking operations	3	3	9	9
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Balance at beginning of period	40.5	34	35.6	42.6
Additions	4.4	4.5	15.3	11
Payoffs and curtailments	(2.8)	(4.6)	(10.4)	(10.5)
(Impairment charge) / recovery	1	0.5	3.8	(7.5)
Amortization	(0.6)	(0.6)	(1.8)	(1.8)
Balance at end of period	42.5	33.8	42.5	33.8
Loan servicing rights, fair value, start	40.8	34	35.6	45
Loan servicing rights, fair value, end	43.2	$ 33.8	43.2	$ 33.8
Valuation allowance for servicing rights	$ 3.5		$ 3.5		$ 7.3

LOAN SERVICING - Sensitivity of

LOAN SERVICING - Sensitivity of Fair Value to Changes in key Assumptions (Details) - Mortgage Servicing Rights [Member] - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Assumption for Fair Value as of Balance Sheet Date of Assets or Liabilities that relate to Transferor's Continuing Involvement [Line Items]
Weighted average life (months)	74 months 10 days	66 months 17 days
Constant prepayment rate (annualized)	11.80%	13.40%
Discount rate	9.50%	9.50%
Sensitivity analysis of fair value, change in interest rates, plus .25%	$ 3	$ 2
Sensitivity analysis of fair value, change in interest rates, plus .50%	5	4
Sensitivity analysis of fair value, change in interest rates, minus .25%	(3)	(2)
Sensitivity analysis of fair value, change in interest rates, minus .50%	$ (6)	$ (3)

LEASES - Additional Information

LEASES - Additional Information (Details) $ in Millions	Sep. 30, 2021USD ($)
Leases [Abstract]
Operating lease, right-of-use asset, statement of financial position [extensible enumeration]	Other assets
Operating lease, liability, statement of financial position [extensible enumeration]	Other liabilities
Operating lease, right-of-use asset	$ 122.6
Operating lease, liability	130.8
Present value of lease liabilities	9.6
Lessee, operating lease, right-of-use asset, lease not yet commenced	69.2
Lessee, operating lease, lease not yet commenced, liability	$ 109.8
Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, operating lease, lease not yet commenced, term of contract	16 years

LEASES - Lease Expense (Details

LEASES - Lease Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Operating lease cost	$ 7	$ 7	$ 21	$ 20
Short-term lease cost	0	1	0	1
Variable lease cost	1	1	3	3
Total lease cost	$ 8	$ 9	$ 24	$ 24

LEASES - Other Information (Det

LEASES - Other Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Leases [Abstract]
Operating cash flows from operating leases	$ 7	$ 19
Operating cash flows from finance leases	0	0
Operating lease, right-of-use assets obtained in exchange for lease obligations	7	5
Finance lease, right-of-use assets obtained in exchange for lease obligations	$ 0	$ 0
Operating lease, weighted average remaining lease term (in years)	9 years 18 days	9 years 6 months 3 days
Finance lease, weighted average remaining lease term (in years)	24 years 1 month 17 days	0 years
Operating lease, weighted average discount rate, percent	2.50%	2.80%
Finance lease, weighted average discount rate, percent	1.90%	0.00%

LEASES - Maturities (Details)

LEASES - Maturities (Details) $ in Millions	Sep. 30, 2021USD ($)
Operating Leases
2021	$ 7
2022	23
2023	19
2024	17
2025	13
Later years	67
Total lease payments	146
Less: imputed interest	(15)
Present value of lease liabilities	130.8
Finance Leases
2021	0
2022	0
2023	0
2024	0
2025	0
Later years	12
Total lease payments	12
Less: imputed interest	(2)
Present value of lease liabilities	9.6
Total Leases
2021	7
2022	23
2023	19
2024	17
2025	13
Later years	79
Total lease payments	158
Less: imputed interest	(17)
Present value of lease liabilities	$ 141

VARIABLE INTEREST ENTITIES - As

VARIABLE INTEREST ENTITIES - Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Variable Interest Entity [Line Items]
Assets	$ 39,361	$ 37,354	$ 37,441
Liabilities	34,263	32,395
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Assets	140	146
Liabilities	108	119
Maximum Exposure to Loss	139	145
Trust Preferred Securities [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Assets	1	1
Liabilities	67	66
Maximum Exposure to Loss	0	0
Affordable Housing Tax Credit Partnerships [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Assets	113	119
Liabilities	37	45
Maximum Exposure to Loss	113	119
Other Investments [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Assets	26	26
Liabilities	4	8
Maximum Exposure to Loss	$ 26	$ 26

VARIABLE INTEREST ENTITIES - Tr

VARIABLE INTEREST ENTITIES - Trust-Preferred Securities (Details)	9 Months Ended
	Sep. 30, 2021
Trust Preferred Securities [Member] | Maximum [Member]
Variable Interest Entity [Line Items]
Deferral period for payment of interest	5 years

VARIABLE INTEREST ENTITIES - Af

VARIABLE INTEREST ENTITIES - Affordable Housing Tax Credit Investments And Related Unfunded Commitments (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Proportional amortization method investments included in other assets	$ 74	$ 71
Equity method investments included in other assets	2	3
Total LIHTC investments included in other assets	76	74
Unfunded LIHTC commitments	$ 37	$ 45

VARIABLE INTEREST ENTITIES - In

VARIABLE INTEREST ENTITIES - Income Statement Effect (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Non-Interest Income
Amortization of tax credit investments under equity method, net of tax benefit	$ 0	$ 0	$ 1	$ 1
Provision for income taxes:
Amortization of LIHTC investments under proportional method	3	2	10	8
Low-income housing tax credits	(4)	(3)	(11)	(9)
Other tax benefits related to tax credit investments	0	0	(2)	(2)
Total impact on provision for income taxes	$ (1)	$ (1)	$ (3)	$ (3)

BORROWINGS - Summary of Short-T

BORROWINGS - Summary of Short-Term Borrowings (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Securities sold under repurchase agreements	$ 407	$ 403
Federal Home Loan Bank advances	1,030	1,280
Subordinated notes	126	121
Total short-term borrowings	$ 1,563	$ 1,804

BORROWINGS - Additional Informa

BORROWINGS - Additional Information (Details) - USD ($) $ in Billions	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Short-term advances	$ 1	$ 1.3
Short-term advances, percentage bearing fixed interest rate	100.00%	100.00%
FHLB [Member]
Debt Instrument [Line Items]
Credit available with FHLB	$ 8.3
Credit with FHLB utilized	$ 1.2
Minimum [Member] | FHLB [Member]
Debt Instrument [Line Items]
Effective interest rates	0.26%	0.30%
Maximum [Member] | FHLB [Member]
Debt Instrument [Line Items]
Effective interest rates	0.29%	0.34%

BORROWINGS - Summary of Long-Te

BORROWINGS - Summary of Long-Term Borrowings (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Federal Home Loan Bank advances	$ 200	$ 400
Senior notes	299	299
Subordinated notes	72	81
Junior subordinated debt	67	66
Other subordinated debt	248	249
Total long-term borrowings	$ 886	$ 1,095

BORROWINGS - Schedule of Subord

BORROWINGS - Schedule of Subordinated Debt (Details)	9 Months Ended
	Sep. 30, 2021USD ($)
Debt Instrument [Line Items]
Aggregate Principal Amount Issued	$ 558,000,000
Net Proceeds	560,000,000
Carrying Value	$ 547,000,000
2.20% Senior Notes due February 24, 2023 [Member]
Debt Instrument [Line Items]
Interest Rate	2.20%
Aggregate Principal Amount Issued	$ 300,000,000
Net Proceeds	298,000,000
Carrying Value	$ 299,000,000
4.95% Fixed-To-Floating Rate Subordinated Notes due 2029 [Member]
Debt Instrument [Line Items]
Interest Rate	4.95%
Aggregate Principal Amount Issued	$ 120,000,000
Net Proceeds	118,000,000
Carrying Value	$ 119,000,000
4.875% Subordinated Notes due 2025 [Member]
Debt Instrument [Line Items]
Interest Rate	4.875%
Aggregate Principal Amount Issued	$ 100,000,000
Net Proceeds	98,000,000
Carrying Value	$ 99,000,000
7.625% Subordinated Notes due August 12, 2023 [Member] | Yadkin Financial Corporation (YDKN) [Member]
Debt Instrument [Line Items]
Interest Rate	7.625%
Aggregate Principal Amount Issued	$ 38,000,000
Net Proceeds	46,000,000
Carrying Value	$ 30,000,000

BORROWINGS - Junior Subordinate

BORROWINGS - Junior Subordinated Debt Trusts (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 67	$ 66
Trust Preferred Securities [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debt	72
Common Securities [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debt	3
F.N.B. Statutory Trust II [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 22
Interest Rate	1.77%
F.N.B. Statutory Trust II [Member] | London Interbank Offered Rate (LIBOR) [Member]
Subordinated Borrowing [Line Items]
Basis spread on variable rate	1.65%
F.N.B. Statutory Trust II [Member] | Trust Preferred Securities [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 22
F.N.B. Statutory Trust II [Member] | Common Securities [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debt	1
Yadkin Valley Statutory Trust I [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 22
Interest Rate	1.44%
Yadkin Valley Statutory Trust I [Member] | London Interbank Offered Rate (LIBOR) [Member]
Subordinated Borrowing [Line Items]
Basis spread on variable rate	1.32%
Yadkin Valley Statutory Trust I [Member] | Trust Preferred Securities [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 25
Yadkin Valley Statutory Trust I [Member] | Common Securities [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debt	1
FNB Financial Services Capital Trust I [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 23
Interest Rate	1.59%
FNB Financial Services Capital Trust I [Member] | London Interbank Offered Rate (LIBOR) [Member]
Subordinated Borrowing [Line Items]
Basis spread on variable rate	1.46%
FNB Financial Services Capital Trust I [Member] | Trust Preferred Securities [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 25
FNB Financial Services Capital Trust I [Member] | Common Securities [Member]
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 1

DERIVATIVE INSTRUMENTS AND HE_3

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Notional Amounts and Gross Fair Values (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Notional amount	$ 13,733	$ 12,480
Derivative asset, not offset against collateral	4	3
Derivative liability, not offset against collateral	25	37
Derivative asset, not subject to master netting arrangement	226	373
Derivative liability, not subject to master netting arrangement	16	3
Fair value, asset	230	376
Fair value, liability	41	40
Interest rate contracts - designated [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, not offset against collateral	2	3
Derivative liability, not offset against collateral	0	0
Interest rate swaps - not designated [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, not offset against collateral	2	0
Derivative liability, not offset against collateral	25	37
Derivative asset, not subject to master netting arrangement	211	349
Derivative liability, not subject to master netting arrangement	16	0
Interest rate lock commitments – not designated [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, not subject to master netting arrangement	13	24
Derivative liability, not subject to master netting arrangement	0	0
Forward delivery commitments – not designated [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, not subject to master netting arrangement	2	0
Derivative liability, not subject to master netting arrangement	0	2
Credit risk contracts - not designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	261.8
Derivative asset, not subject to master netting arrangement	0	0
Derivative liability, not subject to master netting arrangement	0	1
Subject to Master Netting Arrangements [Member]
Derivatives, Fair Value [Line Items]
Notional amount	6,912	6,221
Subject to Master Netting Arrangements [Member] | Interest rate contracts - designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	1,580	1,430
Subject to Master Netting Arrangements [Member] | Interest rate swaps - not designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	5,332	4,791
Not Subject to Master Netting Arrangements [Member]
Derivatives, Fair Value [Line Items]
Notional amount	6,821	6,259
Not Subject to Master Netting Arrangements [Member] | Interest rate swaps - not designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	5,332	4,791
Not Subject to Master Netting Arrangements [Member] | Interest rate lock commitments – not designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	524	531
Not Subject to Master Netting Arrangements [Member] | Forward delivery commitments – not designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	575	500
Not Subject to Master Netting Arrangements [Member] | Credit risk contracts - not designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	$ 390	$ 437

DERIVATIVE INSTRUMENTS AND HE_4

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Amounts Reclassified from AOCI (Details) - Interest rate contracts [Member] - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	$ 3,000,000	$ (42,000,000)
Amount of Gain (Loss) Reclassified from AOCI into Income	0	0
Interest Income (Expense) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Amount of Gain (Loss) Reclassified from AOCI into Income	(14,000,000)	(9,000,000)
Other Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Amount of Gain (Loss) Reclassified from AOCI into Income	$ 0	$ (9,000,000)

DERIVATIVE INSTRUMENTS AND HE_5

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Effect of Cash Flow Hedging on Income Statement (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Derivative [Line Items]
Interest Income - Loans and Leases	$ 226,000,000	$ 239,000,000	$ 671,000,000	$ 750,000,000
Interest Expense - Short-Term Borrowings	$ 7,000,000	$ 9,000,000	21,000,000	31,000,000
Interest rate contracts [Member]
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into net income			0	0
Interest Income - Loans and Leases [Member] | Interest rate contracts [Member]
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into net income			1,000,000	2,000,000
Interest Expense - Short-Term Borrowings [Member] | Interest rate contracts [Member]
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into net income			$ (15,000,000)	$ (11,000,000)

DERIVATIVE INSTRUMENTS AND HE_6

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Derivative [Line Items]
Notional amount	$ 13,733,000,000		$ 12,480,000,000
Additional amount in excess of posted collateral required in case of breached agreements	500,000		300,000
Subject to Master Netting Arrangement [Member]
Derivative [Line Items]
Notional amount	$ 6,912,000,000		6,221,000,000
Interest rate contracts [Member]
Derivative [Line Items]
Maximum length of time hedged in interest rate cash flow hedge	4 years
Period to reclassification of cash flow hedge gain loss	12 months
Derivative gains to be reclassified within twelve months	$ 14,500,000
Derivative gains to be reclassified within twelve months, net of tax	11,300,000
Derivative gain or losses excluded from assessment of hedge effectiveness	0
Amount of gain (loss) reclassified from AOCI into net income	0	$ 0
Interest rate contracts [Member] | Subject to Master Netting Arrangement [Member]
Derivative [Line Items]
Termination of derivative contract, notional amount		$ 225,000,000
Notional amount	1,580,000,000		1,430,000,000
Credit risk contracts - not designated [Member]
Derivative [Line Items]
Notional amount	261,800,000
Maximum exposure under credit risk agreement assuming customer default	300,000		600,000
Credit risk derivatives, purchased at fair value	100,000		200,000
Credit risk derivatives, sold at fair value	$ 300,000		$ 600,000
Credit risk contracts - not designated [Member] | Minimum [Member]
Derivative [Line Items]
Risk participation agreements, term	9 months
Credit risk contracts - not designated [Member] | Maximum [Member]
Derivative [Line Items]
Risk participation agreements, term	20 years

DERIVATIVE INSTRUMENTS AND HE_7

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Effect of Derivative Financial Instruments on Income Statement (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Interest Rate Swap [Member] | Non-interest income - other [Member]
Derivative [Line Items]
Derivative financial instrument, net	$ 0	$ 0
Interest Rate Lock Commitments [Member] | Mortgage banking operations [Member]
Derivative [Line Items]
Derivative financial instrument, net	0	0
Forward Delivery Contracts [Member] | Mortgage banking operations [Member]
Derivative [Line Items]
Derivative financial instrument, net	2	(1)
Credit Risk Contract [Member] | Non-interest income - other [Member]
Derivative [Line Items]
Derivative financial instrument, net	$ 0	$ 0

DERIVATIVE INSTRUMENTS AND HE_8

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Derivative Assets (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Net Amount Presented in the Balance Sheet	$ 4	$ 3
Financial Instruments	0	0
Cash Collateral	4	3
Net Amount	0	0
Interest rate contracts - designated [Member]
Derivative [Line Items]
Net Amount Presented in the Balance Sheet	2	3
Financial Instruments	0	0
Cash Collateral	2	3
Net Amount	0	0
Interest rate swaps - not designated [Member]
Derivative [Line Items]
Net Amount Presented in the Balance Sheet	2	$ 0
Financial Instruments	0
Cash Collateral	2
Net Amount	$ 0

DERIVATIVE INSTRUMENTS AND HE_9

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Derivative Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Derivative [Line Items]
Net Amount Presented in the Consolidated Balance Sheets	$ 25	$ 37
Financial Instruments	0	0
Cash Collateral	24	37
Net Amount	1	0
Interest rate contracts - designated [Member]
Derivative [Line Items]
Net Amount Presented in the Consolidated Balance Sheets	0	0
Interest rate swaps - not designated [Member]
Derivative [Line Items]
Net Amount Presented in the Consolidated Balance Sheets	25	37
Financial Instruments	0	0
Cash Collateral	24	37
Net Amount	$ 1	$ 0

COMMITMENTS, CREDIT RISK AND _3

COMMITMENTS, CREDIT RISK AND CONTINGENCIES - Off-Balance Sheet Credit Risk (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Standby Letters of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Extended credit and standby letters of credit	$ 200	$ 158
Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Extended credit and standby letters of credit	$ 11,015	$ 9,285

COMMITMENTS, CREDIT RISK AND _4

COMMITMENTS, CREDIT RISK AND CONTINGENCIES - Additional Information (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Percentage of commitments to extend credit dependent upon the financial condition of the customers	70.70%
Allowance for credit losses on loan commitments that are not unconditionally cancellable	$ 18	$ 13.7

STOCK INCENTIVE PLANS - Additio

STOCK INCENTIVE PLANS - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares available up to (in shares)	4,137,909
Unrecognized compensation expense	$ 12
Shares, options outstanding and exercisable (in shares)	170,529	207,030
Weighted average exercise price, options outstanding (in dollars per share)	$ 8.75	$ 8.42
Intrinsic value of outstanding and exercisable stock options	$ 0.5
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of units issued, years	3 years
Restricted stock awards issued (in shares)	1,113,314	2,004,895
Unrecognized compensation expense	$ 11.7
Amount subject to accelerated vesting under Incentive Compensation Plan	1
Performance-based Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 2
Performance-based Units [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards issued (in shares)	325,284	571,932

STOCK INCENTIVE PLANS - Restric

STOCK INCENTIVE PLANS - Restricted Stock Units Activity (Details) - $ / shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares, unvested units outstanding at end of period (in shares)	4,561,091
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Shares, unvested units outstanding at beginning of period (in shares)	4,322,115	2,858,357
Shares, granted (in shares)	1,113,314	2,004,895
Shares, net adjustment due to performance (in shares)	412,540	47,290
Shares, vested (in shares)	(1,309,476)	(592,602)
Shares, forfeited/expired/canceled (in shares)	(112,002)	(169,552)
Shares, dividend reinvestment (in shares)	134,600	173,990
Shares, unvested units outstanding at end of period (in shares)	4,561,091	4,322,378
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted average grant price, invested units outstanding at beginning of period (in dollars per share)	$ 9.46	$ 12.56
Weighted average grant price, granted (in dollars per share)	12.65	5.95
Weighted average grant price, net adjusted due to performance (in dollars per share)	11.72	13
Weighted average grant price, vested (in dollars per share)	12.10	14.50
Weighted average grant price, forfeited/expired/canceled (in dollars per share)	10.94	13.05
Weighted average grant price, dividend reinvestment (in dollars per share)	12.26	6.99
Weighted average grant price, invested units outstanding at end of period (in dollars per share)	$ 9.74	$ 9.45

STOCK INCENTIVE PLANS - Schedul

STOCK INCENTIVE PLANS - Schedule of Certain Information Related to Restricted Stock Units (Details) - Restricted Stock [Member] - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 17	$ 13
Tax benefit related to stock-based compensation expense	4	3
Fair value of units vested	$ 16	$ 4

STOCK INCENTIVE PLANS - Compone

STOCK INCENTIVE PLANS - Components of Restricted Stock Units (Details) $ in Millions	9 Months Ended
	Sep. 30, 2021USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock units (in shares) | shares	4,561,091
Unrecognized compensation expense	$ 12
Intrinsic value	$ 53
Weighted average remaining life (in years)	1 year 6 months 3 days
Service-Based Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock units (in shares) | shares	2,933,219
Unrecognized compensation expense	$ 10
Intrinsic value	$ 34
Weighted average remaining life (in years)	1 year 10 months 9 days
Performance-based Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock units (in shares) | shares	1,627,872
Unrecognized compensation expense	$ 2
Intrinsic value	$ 19
Weighted average remaining life (in years)	10 months 17 days

INCOME TAXES - Income Tax Expen

INCOME TAXES - Income Tax Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Current income taxes: Federal taxes	$ 22	$ 16	$ 62	$ 62
Current income taxes: State taxes	1	1	4	6
Total current income taxes	23	17	66	68
Deferred income taxes: Federal taxes	4	0	7	(24)
Deferred income taxes: State taxes	0	0	1	0
Total deferred income taxes	4	0	8	(24)
Income taxes	$ 27	$ 17	$ 74	$ 44
Statutory tax rate	21.00%	21.00%	21.00%	21.00%
Effective tax rate	19.70%	17.00%	19.50%	17.00%

INCOME TAXES - Additional Infor

INCOME TAXES - Additional Information (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Deferred tax assets	$ 47.4	$ 51

OTHER COMPREHENSIVE INCOME - Ch

OTHER COMPREHENSIVE INCOME - Changes in AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 5,037	$ 4,897	$ 4,959	$ 4,883
Other comprehensive (loss) income before reclassifications			(24)
Amounts reclassified from AOCI			11
Other Comprehensive Income (Loss)	(6)	9	(13)	39
Balance at end of period	5,098	4,951	5,098	4,951
Unrealized Net Gains (Losses) on Debt Securities Available for Sale [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			65
Other comprehensive (loss) income before reclassifications			(29)
Amounts reclassified from AOCI			0
Other Comprehensive Income (Loss)			(29)
Balance at end of period	36		36
Unrealized Net Gains (Losses) on Derivative Instruments [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			(40)
Other comprehensive (loss) income before reclassifications			3
Amounts reclassified from AOCI			11
Other Comprehensive Income (Loss)			14
Balance at end of period	(26)		(26)
Unrecognized Pension and Postretirement Obligations [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			(64)
Other comprehensive (loss) income before reclassifications			2
Amounts reclassified from AOCI			0
Other Comprehensive Income (Loss)			2
Balance at end of period	(62)		(62)
Accumulated Other Comprehensive Income (Loss) [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(46)	(35)	(39)	(65)
Balance at end of period	$ (52)	$ (26)	$ (52)	$ (26)

EARNINGS PER COMMON SHARE - Com

EARNINGS PER COMMON SHARE - Computation of Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Net income	$ 111	$ 83	$ 306	$ 214
Less: Preferred stock dividends	2	2	6	6
Net income available to common stockholders	109	81	300	208
Net income available to common stockholders	$ 109	$ 81	$ 300	$ 208
Basic weighted average common shares outstanding (in shares)	319,512,598	323,379,720	320,023,695	323,642,925
Net effect of dilutive stock options, warrants and restricted stock (in shares)	3,348,329	2,283,060	3,611,960	2,051,221
Diluted weighted average common shares outstanding (in shares)	322,860,927	325,662,780	323,635,655	325,694,146
Earnings per common share:
Basic (in dollars per share)	$ 0.34	$ 0.25	$ 0.94	$ 0.64
Diluted (in dollars per share)	$ 0.34	$ 0.25	$ 0.93	$ 0.64

EARNINGS PER COMMON SHARE - Ave

EARNINGS PER COMMON SHARE - Average Shares Excluded from Earnings Per Common Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Average shares excluded from the diluted earnings per common share calculation (in shares)	0	44,755	0	22,263

CASH FLOW INFORMATION - Summary

CASH FLOW INFORMATION - Summary of Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Supplemental Cash Flow Elements [Abstract]
Interest paid on deposits and other borrowings	$ 82	$ 179
Income taxes paid	53	34
Transfers of loans to other real estate owned	3	2
Loans transferred to held for sale from portfolio	$ 0	$ 508

BUSINESS SEGMENTS - Additional

BUSINESS SEGMENTS - Additional Information (Details)	9 Months Ended
	Sep. 30, 2021Segment
Segment Reporting [Abstract]
Number of reportable segments	3

BUSINESS SEGMENTS - Financial I

BUSINESS SEGMENTS - Financial Information for Segments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Interest income	$ 256	$ 273	$ 760	$ 860
Interest expense	24	46	77	172
Net Interest Income	232	227	683	688
Provision for credit losses	(2)	27	3	105
Non-interest income	88	80	251	226
Non-interest expense	181	177	542	541
Amortization of intangibles	3	3	9	10
Income tax expense (benefit)	27	17	74	44
Net income (loss)	111	83	306	214
Total assets	39,361	37,441	39,361	37,441	$ 37,354
Total intangibles	2,307	2,319	2,307	2,319
Operating Segments [Member] | Community Banking [Member]
Segment Reporting Information [Line Items]
Interest income	255	273	759	859
Interest expense	20	41	67	155
Net Interest Income	235	232	692	704
Provision for credit losses	(2)	27	2	105
Non-interest income	68	63	191	180
Non-interest expense	164	162	491	495
Amortization of intangibles	3	3	8	9
Income tax expense (benefit)	27	18	75	47
Net income (loss)	111	85	307	228
Total assets	39,238	37,315	39,238	37,315
Total intangibles	2,271	2,282	2,271	2,282
Operating Segments [Member] | Wealth Management [Member]
Segment Reporting Information [Line Items]
Interest income	0	0	0	0
Interest expense	0	0	0	0
Net Interest Income	0	0	0	0
Provision for credit losses	0	0	0	0
Non-interest income	15	12	45	36
Non-interest expense	10	8	30	26
Amortization of intangibles	0	0	0	0
Income tax expense (benefit)	1	1	3	2
Net income (loss)	4	3	12	8
Total assets	43	36	43	36
Total intangibles	9	9	9	9
Operating Segments [Member] | Insurance [Member]
Segment Reporting Information [Line Items]
Interest income	0	0	0	0
Interest expense	0	0	0	0
Net Interest Income	0	0	0	0
Provision for credit losses	0	0	0	0
Non-interest income	6	7	19	18
Non-interest expense	5	5	15	14
Amortization of intangibles	0	0	1	1
Income tax expense (benefit)	0	1	1	1
Net income (loss)	1	1	2	2
Total assets	34	36	34	36
Total intangibles	27	28	27	28
Parent and Other [Member]
Segment Reporting Information [Line Items]
Interest income	1	0	1	1
Interest expense	4	5	10	17
Net Interest Income	(3)	(5)	(9)	(16)
Provision for credit losses	0	0	1	0
Non-interest income	(1)	(2)	(4)	(8)
Non-interest expense	2	2	6	6
Amortization of intangibles	0	0	0	0
Income tax expense (benefit)	(1)	(3)	(5)	(6)
Net income (loss)	(5)	(6)	(15)	(24)
Total assets	46	54	46	54
Total intangibles	$ 0	$ 0	$ 0	$ 0

FAIR VALUE MEASUREMENTS - Asset

FAIR VALUE MEASUREMENTS - Assets and Liabilities on Recurring Basis (Details) - USD ($) $ in Millions		Sep. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		$ 3,208	$ 3,463
Loans held for sale	[1]	227	144
Derivative assets		230	376
Derivative liabilities		41	40
U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		49	600
US Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		154	172
U.S. Government-Sponsored Entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		170	161
Agency Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		1,183	1,124
Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		306	378
States of the U.S. and Political Subdivisions (municipals) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		33	32
Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		2	2
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		49	600
Derivative assets		0	0
Derivative liabilities		0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		3,159	2,863
Derivative assets		217	352
Derivative liabilities		41	40
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Derivative assets		13	24
Derivative liabilities		0	0
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		3,208	3,463
Loans held for sale		227	144
Derivative assets		230	376
Total assets measured at fair value on a recurring basis		3,665	3,983
Derivative liabilities		41	40
Total liabilities measured at fair value on a recurring basis		41	40
Fair Value, Recurring [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		49	600
Fair Value, Recurring [Member] | US Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		154	172
Fair Value, Recurring [Member] | U.S. Government-Sponsored Entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		170	161
Fair Value, Recurring [Member] | Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		1,311	994
Fair Value, Recurring [Member] | Agency Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		1,183	1,124
Fair Value, Recurring [Member] | Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		306	378
Fair Value, Recurring [Member] | States of the U.S. and Political Subdivisions (municipals) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		33	32
Fair Value, Recurring [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		2	2
Fair Value, Recurring [Member] | Trading Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		41	37
Fair Value, Recurring [Member] | Not for Trading Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0	3
Fair Value, Recurring [Member] | Trading Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		213	349
Fair Value, Recurring [Member] | Non Trading Account Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		17	27
Fair Value, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		49	600
Loans held for sale		0	0
Derivative assets		0	0
Total assets measured at fair value on a recurring basis		49	600
Derivative liabilities		0	0
Total liabilities measured at fair value on a recurring basis		0	0
Fair Value, Recurring [Member] | Level 1 [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		49	600
Fair Value, Recurring [Member] | Level 1 [Member] | US Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 1 [Member] | U.S. Government-Sponsored Entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 1 [Member] | Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 1 [Member] | Agency Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 1 [Member] | Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 1 [Member] | States of the U.S. and Political Subdivisions (municipals) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 1 [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 1 [Member] | Trading Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0	0
Fair Value, Recurring [Member] | Level 1 [Member] | Not for Trading Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0	0
Fair Value, Recurring [Member] | Level 1 [Member] | Trading Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Fair Value, Recurring [Member] | Level 1 [Member] | Non Trading Account Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Fair Value, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		3,159	2,863
Loans held for sale		227	144
Derivative assets		217	352
Total assets measured at fair value on a recurring basis		3,603	3,359
Derivative liabilities		41	40
Total liabilities measured at fair value on a recurring basis		41	40
Fair Value, Recurring [Member] | Level 2 [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 2 [Member] | US Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		154	172
Fair Value, Recurring [Member] | Level 2 [Member] | U.S. Government-Sponsored Entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		170	161
Fair Value, Recurring [Member] | Level 2 [Member] | Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		1,311	994
Fair Value, Recurring [Member] | Level 2 [Member] | Agency Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		1,183	1,124
Fair Value, Recurring [Member] | Level 2 [Member] | Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		306	378
Fair Value, Recurring [Member] | Level 2 [Member] | States of the U.S. and Political Subdivisions (municipals) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		33	32
Fair Value, Recurring [Member] | Level 2 [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		2	2
Fair Value, Recurring [Member] | Level 2 [Member] | Trading Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		41	37
Fair Value, Recurring [Member] | Level 2 [Member] | Not for Trading Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0	3
Fair Value, Recurring [Member] | Level 2 [Member] | Trading Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		213	349
Fair Value, Recurring [Member] | Level 2 [Member] | Non Trading Account Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		4	3
Fair Value, Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Loans held for sale		0	0
Derivative assets		13	24
Total assets measured at fair value on a recurring basis		13	24
Derivative liabilities		0	0
Total liabilities measured at fair value on a recurring basis		0	0
Fair Value, Recurring [Member] | Level 3 [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 3 [Member] | US Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 3 [Member] | U.S. Government-Sponsored Entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 3 [Member] | Agency Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 3 [Member] | Agency Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 3 [Member] | Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 3 [Member] | States of the U.S. and Political Subdivisions (municipals) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 3 [Member] | Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities, available for sale		0	0
Fair Value, Recurring [Member] | Level 3 [Member] | Trading Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0	0
Fair Value, Recurring [Member] | Level 3 [Member] | Not for Trading Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		0	0
Fair Value, Recurring [Member] | Level 3 [Member] | Trading Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0	0
Fair Value, Recurring [Member] | Level 3 [Member] | Non Trading Account Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		$ 13	$ 24
[1]	Amount represents loans for which we have elected the fair value option. See Note 18.

FAIR VALUE MEASUREMENTS - Rollf

FAIR VALUE MEASUREMENTS - Rollforward on Recurring Basis (Details) - Fair Value, Recurring [Member] - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 24	$ 3
Purchases, issuances, sales and settlements:
Issuances	13	24
Settlements	(24)	(3)
Balance at end of period	13	24
Interest Rate Lock Commitments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	24	3
Purchases, issuances, sales and settlements:
Issuances	13	24
Settlements	(24)	(3)
Balance at end of period	$ 13	$ 24

FAIR VALUE MEASUREMENTS - Addit

FAIR VALUE MEASUREMENTS - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Fair Value Measurements Disclosure [Line Items]
Transfer of equity security to non-marketable equity securities, included in other assets	$ 0	$ 0
Collateral dependent loans, allowance for credit loss	8,200,000
Provision for fair value measurements included in allowance for loan losses	2,100,000
Carrying amount of OREO	1,100,000
Valuation allowance of OREO	300,000
Loss from OREO included in earnings	300,000
Fair Value, Nonrecurring [Member]
Fair Value Measurements Disclosure [Line Items]
Collateral dependent loans carrying value	9,500,000
Mortgage Servicing Rights [Member] | Fair Value, Nonrecurring [Member]
Fair Value Measurements Disclosure [Line Items]
Servicing asset	15,500,000
Valuation allowance for impairment of recognized servicing assets, additions (deductions) for expenses (recoveries)	3,500,000
Mortgage Servicing Rights [Member] | Fair Value, Nonrecurring [Member] | Provision Expense [Member]
Fair Value Measurements Disclosure [Line Items]
Valuation allowance for impairment of recognized servicing assets, provision recovery	3,800,000
SBA-Guaranteed Loan Servicing [Member] | Fair Value, Nonrecurring [Member]
Fair Value Measurements Disclosure [Line Items]
Servicing asset	5,300,000
Valuation allowance for impairment of recognized servicing assets, additions (deductions) for expenses (recoveries)	900,000
Valuation allowance for impairment of recognized servicing assets, provision recovery	$ 200,000

FAIR VALUE MEASUREMENTS - Non-R

FAIR VALUE MEASUREMENTS - Non-Recurring Basis Assets (Details) - USD ($) $ in Millions	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other asset	$ 0		$ 0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other asset	0		0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other asset	47		39
Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans	9		45
Other real estate owned	1		3
Fair Value, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans	0		0
Other real estate owned	0		0
Fair Value, Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans	0		0
Other real estate owned	0		0
Fair Value, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans	9		45
Other real estate owned	1		3
Mortgage Servicing Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other asset	43.2	$ 40.8	35.6	$ 33.8	$ 34	$ 45
Mortgage Servicing Rights [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other asset	15		36
Mortgage Servicing Rights [Member] | Fair Value, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other asset	0		0
Mortgage Servicing Rights [Member] | Fair Value, Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other asset	0		0
Mortgage Servicing Rights [Member] | Fair Value, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other asset	15		36
SBA-Guaranteed Loan Servicing [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other asset	4		3
SBA-Guaranteed Loan Servicing [Member] | Fair Value, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other asset	0		0
SBA-Guaranteed Loan Servicing [Member] | Fair Value, Nonrecurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other asset	0		0
SBA-Guaranteed Loan Servicing [Member] | Fair Value, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other asset	$ 4		$ 3

FAIR VALUE MEASUREMENTS - Finan

FAIR VALUE MEASUREMENTS - Financial Instruments (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt securities, available for sale	$ 3,208	$ 3,463
Debt securities held to maturity	3,267	2,973
Derivative assets	230	376
Long-term borrowings	547
Derivative liabilities	41	40
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	4,110	1,383
Debt securities, available for sale	3,208	3,463
Debt securities held to maturity	3,202	2,868
Net loans and leases, including loans held for sale	24,620	25,250
Loan servicing rights	46	39
Derivative assets	230	376
Accrued interest receivable	76	90
Deposits	31,444	29,122
Short-term borrowings	1,563	1,804
Long-term borrowings	886	1,095
Derivative liabilities	41	40
Accrued interest payable	8	13
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	4,110	1,383
Debt securities, available for sale	3,208	3,463
Debt securities held to maturity	3,267	2,973
Net loans and leases, including loans held for sale	24,224	25,012
Loan servicing rights	47	39
Derivative assets	230	376
Accrued interest receivable	76	90
Deposits	31,456	29,158
Short-term borrowings	1,565	1,809
Long-term borrowings	906	1,068
Derivative liabilities	41	40
Accrued interest payable	8	13
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	4,110	1,383
Debt securities, available for sale	49	600
Debt securities held to maturity	1	0
Net loans and leases, including loans held for sale	0	0
Loan servicing rights	0	0
Derivative assets	0	0
Accrued interest receivable	76	90
Deposits	28,399	25,460
Short-term borrowings	1,565	1,809
Long-term borrowings	0	0
Derivative liabilities	0	0
Accrued interest payable	8	13
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Debt securities, available for sale	3,159	2,863
Debt securities held to maturity	3,266	2,973
Net loans and leases, including loans held for sale	227	144
Loan servicing rights	0	0
Derivative assets	217	352
Accrued interest receivable	0	0
Deposits	3,057	3,698
Short-term borrowings	0	0
Long-term borrowings	0	0
Derivative liabilities	41	40
Accrued interest payable	0	0
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Debt securities, available for sale	0	0
Debt securities held to maturity	0	0
Net loans and leases, including loans held for sale	23,997	24,868
Loan servicing rights	47	39
Derivative assets	13	24
Accrued interest receivable	0	0
Deposits	0	0
Short-term borrowings	0	0
Long-term borrowings	906	1,068
Derivative liabilities	0	0
Accrued interest payable	$ 0	$ 0

MERGERS AND ACQUISITIONS (Detai

MERGERS AND ACQUISITIONS (Details) - Howard Bancorp, Inc. [Member] shares in Millions, $ in Millions	Jul. 12, 2021USD ($)shares
Business Acquisition [Line Items]
Assets acquired as a result of merger | $	$ 2,600
Fair value of consideration paid | $	$ 418
Common Stock [Member]
Business Acquisition [Line Items]
Conversion rate	1.8
Number of shares (in shares) | shares	33.8
Entity shares converted per acquirer share (in shares) | shares	18.8