F.N.B. (FNB) 10-Q 3 Nov 20 2020 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2020	Oct. 31, 2020
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	001-31940
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		322,634,816
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Entity Registrant Name	FNB CORP/PA/
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, 2020	Dec. 31, 2019
Assets
Cash and due from banks		$ 396	$ 407
Interest-bearing deposits with banks		504	192
Cash and Cash Equivalents		900	599
Debt securities available for sale (amortized cost of $3,006 and $3,275; allowance for credit losses of $0)		3,101	3,289
Debt securities held to maturity (fair value of $3,072 and $3,305; allowance for credit losses of $0)		2,966	3,275
Loans held for sale (includes $138 and $41 measured at fair value)	[1]	680	51
Loans and leases, net of unearned income of $111 and $1		25,689	23,289
Allowance for credit losses		(373)	(196)
Net Loans and Leases		25,316	23,093
Premises and equipment, net		335	333
Goodwill		2,262	2,262
Core deposit and other intangible assets, net		57	67
Bank owned life insurance		548	544
Other assets		1,276	1,102
Total Assets		37,441	34,615
Liabilities
Non-interest-bearing demand		8,741	6,384
Interest-bearing demand		13,063	11,049
Savings		3,007	2,625
Certificates and other time deposits		4,025	4,728
Total Deposits		28,836	24,786
Short-term borrowings		1,899	3,216
Long-term borrowings		1,397	1,340
Other liabilities		358	390
Total Liabilities		32,490	29,732
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 - 328,004,096 and 327,242,364 shares		3	3
Additional paid-in capital		4,084	4,067
Retained earnings		838	798
Accumulated other comprehensive loss		(26)	(65)
Treasury stock – 4,791,698 and 2,227,804 shares at cost		(55)	(27)
Total Stockholders’ Equity		4,951	4,883
Total Liabilities and Stockholders’ Equity		$ 37,441	$ 34,615
[1]	Amount represents loans for which we have elected the fair value option. See Note 19.

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($)		Sep. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Debt securities available for sale, amortized cost		$ 3,006,000,000	$ 3,275,000,000
Debt securities available for sale, allowance for credit losses		0
Debt securities held-to-maturity, fair value		3,072,000,000	3,305,000,000
Debt securities held to maturity, allowance for credit losses		50,000
Loans held for sale, fair value	[1]	138,000,000	41,000,000
Unearned income on loans		$ 111,000,000	$ 1,000,000
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		20,000,000	20,000,000
Preferred stock, shares issued		110,877	110,877
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
Common stock, shares authorized		500,000,000	500,000,000
Common stock, shares issued		328,004,096	327,242,364
Treasury stock, shares		4,791,698	2,227,804
[1]	Amount represents loans for which we have elected the fair value option. See Note 19.

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Interest Income
Loans and leases, including fees	$ 239	$ 274	$ 750	$ 819
Securities:
Taxable	25	30	84	95
Tax-exempt	8	8	24	24
Other	1	2	2	3
Total Interest Income	273	314	860	941
Interest Expense
Deposits	27	56	111	161
Short-term borrowings	9	18	31	66
Long-term borrowings	10	10	30	23
Total Interest Expense	46	84	172	250
Net Interest Income	227	230	688	691
Provision for credit losses	27	12	105	37
Net Interest Income After Provision for Credit Losses	200	218	583	654
Non-Interest Income
Service charges	24	33	78	95
Trust services	8	7	23	21
Insurance commissions and fees	7	6	19	15
Securities commissions and fees	5	4	13	13
Capital markets income	8	9	32	25
Mortgage banking operations	18	9	34	21
Dividends on non-marketable equity securities	2	5	10	14
Bank owned life insurance	4	3	11	9
Other	4	4	6	7
Total Non-Interest Income	80	80	226	220
Non-Interest Expense
Salaries and employee benefits	100	93	298	279
Net occupancy	14	13	49	44
Equipment	17	15	49	45
Amortization of intangibles	3	4	10	11
Outside services	16	16	50	47
FDIC insurance	4	6	15	18
Bank shares and franchise taxes	4	4	12	10
Other	22	27	68	65
Total Non-Interest Expense	180	178	551	519
Income Before Income Taxes	100	120	258	355
Income taxes	17	17	44	63
Net Income	83	103	214	292
Preferred stock dividends	2	2	6	6
Net Income Available to Common Stockholders	$ 81	$ 101	$ 208	$ 286
Earnings per Common Share
Basic (in USD per share)	$ 0.25	$ 0.31	$ 0.64	$ 0.88
Diluted (in USD per share)	$ 0.25	$ 0.31	$ 0.64	$ 0.88

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 83	$ 103	$ 214	$ 292
Securities available for sale:
Unrealized gains (losses) arising during the period, net of tax expense (benefit) of $(1) and $1, $18 and $17	(3)	6	63	60
Derivative instruments:
Unrealized gains (losses) arising during the period, net of tax expense (benefit) of $2 and $(1), $(9) and $(7)	8	(4)	(32)	(24)
Reclassification adjustment for gains (losses) included in net income, net of tax expense (benefit) of $(1) and $0, $(2) and $0	4	0	7	(1)
Pension and postretirement benefit obligations:
Unrealized gains arising during the period, net of tax expense of $0 and $0, $0 and $0	0	1	1	2
Other Comprehensive Income	9	3	39	37
Comprehensive Income	$ 92	$ 106	$ 253	$ 329

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Unrealized gains (losses) arising during the period, tax expense (benefit)	$ (1)	$ 1	$ 18	$ 17
Unrealized gains (losses) arising during the period, tax expense (benefit)	2	(1)	(9)	(7)
Reclassification adjustment for (gains) losses included in net income, tax of expense (benefit)	(1)	0	(2)	0
Unrealized gains arising during the period, tax expense	$ 0	$ 0	$ 0	$ 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, 2018	$ 4,608		$ 107	$ 3	$ 4,049	$ 576		$ (106)	$ (21)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	329					292		37
Dividends declared:
Preferred stock	(6)					(6)
Common stock	(118)					(118)
Issuance of common stock	(1)				5				(6)
Restricted stock compensation	8				8
Balance at end of period at Sep. 30, 2019	4,820		107	3	4,062	744		(69)	(27)
Balance at beginning of period at Jun. 30, 2019	4,753		107	3	4,057	683		(72)	(25)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income	106					103		3
Dividends declared:
Preferred stock	(2)					(2)
Common stock	(40)					(40)
Issuance of common stock	1				3				(2)
Restricted stock compensation	2				2
Balance at end of period at Sep. 30, 2019	4,820		107	3	4,062	744		(69)	(27)
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)

CONSOLIDATED STATEMENTS OF ST_2

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Stockholders' Equity [Abstract]
Preferred stock dividends per share (in USD per share)	$ 18.13	$ 18.13	$ 54.39	$ 54.39
Common stock dividends per share (in USD 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, 2020	Sep. 30, 2019
Operating Activities
Net income	$ 214	$ 292
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion	5	33
Provision for Credit Losses	105	37
Deferred tax expense (benefit)	(24)	36
Loans originated for sale	(1,351)	(983)
Loans sold	1,258	984
Net gain on sale of loans	(28)	(17)
Net change in:
Interest receivable	18	(8)
Interest payable	(7)	2
Bank owned life insurance, excluding purchases	(6)	(5)
Other, net	(265)	(234)
Net cash flows (used in) provided by operating activities	(81)	137
Investing Activities
Net change in loans and leases, excluding sales and transfers	(2,809)	(1,200)
Debt securities available for sale:
Purchases	(1,168)	(395)
Maturities/payments	1,429	543
Debt securities held to maturity:
Purchases	(163)	(264)
Maturities/payments	469	323
Increase in premises and equipment	(33)	(31)
Loans sold, not originated for sale	0	262
Other, net	1	(9)
Net cash flows used in investing activities	(2,274)	(771)
Financing Activities
Demand (non-interest bearing and interest bearing) and savings accounts	4,753	1,286
Time deposits	(702)	(145)
Short-term borrowings	(1,316)	(984)
Proceeds from issuance of long-term borrowings	322	947
Repayment of long-term borrowings	(266)	(232)
Repurchases of common stock	(25)	0
Other, net	14	7
Cash dividends paid:
Preferred stock	(6)	(6)
Common stock	(118)	(118)
Net cash flows provided by financing activities	2,656	755
Net Increase in Cash and Cash Equivalents	301	121
Cash and cash equivalents at beginning of period	599	488
Cash and Cash Equivalents at End of Period	$ 900	$ 609

NATURE OF OPERATIONS

NATURE OF OPERATIONS	9 Months Ended
	Sep. 30, 2020
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, 2020, we had 355 banking offices throughout Pennsylvania, Ohio, Maryland, West Virginia, North Carolina, South Carolina and Virginia.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	9 Months Ended
	Sep. 30, 2020
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 and F.N.B. Capital Corporation, 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. 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. Certain prior period amounts have been reclassified to conform to the current period presentation. Such reclassifications had no impact on our net income and stockholders’ equity. Events occurring subsequent to September 30, 2020 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 Securities and Exchange Commission. 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 2019 Annual Report on Form 10-K filed with the SEC on February 27, 2020. 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, accounting for loans acquired in a business combination prior to January 1, 2020, fair value of financial instruments, goodwill and other intangible assets, income taxes and deferred tax assets. Adoption of New Accounting Standards On January 1, 2020, we adopted ASU 2016-13, Financial Instruments-Credit Losses (Topic 326), which replaces the incurred credit loss impairment methodology with a methodology that reflects lifetime current expected credit losses (commonly referred to as CECL) for most financial assets measured at amortized cost, including loans, HTM debt securities, net investment in leases and certain off-balance sheet credit exposure. We adopted CECL using the modified retrospective method for financial assets measured at amortized cost, net investments in leases and off-balance sheet credit exposures. As a result, we recorded a reduction of $50.6 million in retained earnings as of January 1, 2020 for the cumulative effect of the adoption. The transition adjustment was primarily driven by longer duration commercial and consumer real estate loans. Results for reporting periods prior to January 1, 2020 continue to be reported in accordance with previously applicable GAAP. We used the prospective transition method for PCD financial assets that were previously classified as PCI and accounted for under ASC 310-30, including loans accounted for by analogy under ASC 310-30. In accordance with the transition guidance, we did not reassess whether PCI assets met the criteria for PCD assets nor did we reassess whether modifications to individual acquired financial assets previously accounted for in pools were TDRs as of the date of adoption. We discontinued the use of pools beyond transition accounting and account for these loans on an individual loan basis. After transition, loans previously accounted for in pools are grouped with other loans with similar risk characteristics for purposes of estimating expected credit losses. As a result, beginning in 2020 certain credit metrics and ratios which previously excluded PCI loans now include PCD loans. On January 1, 2020, the amortized cost basis of the PCD assets was adjusted to reflect the addition of an ACL for $50.3 million. The net noncredit discount, after the adjustment for the ACL, will be accreted into interest income at the loan’s effective interest rate over the remaining contractual life. We made an accounting policy election to write-off accrued interest receivable balances by reversing interest income in accordance with our non-accrual policies instead of measuring an ACL for accrued interest receivable for all classes of financing receivables and major security types. We do not hold any securities at adoption for which other-than-temporary impairment had been recognized prior to January 1, 2020. The following table illustrates the impact of the adoption of ASC 326: TABLE 1.1 January 1, 2020 (in millions) As Reported Under ASC 326 Pre-ASC 326 Adoption Impact of ASC 326 Adoption Assets: Allowance for credit losses on debt securities held-to-maturity States of the U.S. and political subdivisions (municipals) $ — $ — $ — Loans Commercial real estate $ 138 $ 60 $ 78 Commercial and industrial 65 53 12 Commercial leases 11 11 — Commercial other — 9 (9) Direct installment 24 13 11 Residential mortgages 32 22 10 Indirect installment 21 19 2 Consumer lines of credit 10 9 1 Allowance for credit losses on loans $ 301 $ 196 $ 105 Liabilities: Allowance for credit losses on off-balance sheet credit exposures $ 13 $ 3 $ 10 For a detailed description of our significant accounting policies, see Note 1 "Summary of Significant Accounting Policies" in our 2019 Annual Report on Form 10-K . The accounting policies presented below have been added or amended for newly material items or the adoption of new accounting standards. Debt Securities Debt securities comprise a significant portion of our Consolidated Balance Sheets. Such securities can be classified as trading, HTM or AFS. As of September 30, 2020 and December 31, 2019, we did not hold any trading debt securities. Interest income on debt securities includes amortization of purchase premiums or accretion of discounts. Premiums and discounts on debt securities are generally amortized on the level-yield method without anticipating prepayments, except for mortgage-backed securities where prepayments are anticipated. Premiums on callable debt securities are amortized to their earliest call date. A debt security is placed on non-accrual when principal or interest becomes greater than 90 days delinquent. Interest accrued but not received for a security placed on non-accrual is reversed against interest income. Gains and losses on the sale of securities are recorded on the trade date and are determined using the specific identification method. HTM debt securities are securities that management has the positive intent and ability to hold until their maturity. Such securities are carried at amortized cost. Beginning in 2020, for certain HTM securities we have an expectation of zero expected credit losses. Based on a long history with no credit losses, high credit ratings, guarantees, and/or implied risk-free characteristics, we expect the nonpayment of our UST, Fannie Mae, Freddie Mac, FHLB, Ginnie Mae, and the SBA securities to be zero, and accordingly, have no ACL on those securities. We believe that these qualitative factors are indicators that historical credit loss information should be nominally impacted, if at all, by current conditions and reasonable and supportable forecasts. As such, we believe that without a change in these indicators, we may continue to assume zero credit losses on securities concluded to exhibit those factors. We also have a portfolio of HTM debt securities where we do not expect credit losses to be zero. This portfolio consists of high-grade municipal securities. To calculate the expected credit losses on these securities we group securities by major security type, rating and maturity and apply respective cumulative default rates from a third party data provider. The baseline credit loss estimate is adjusted using a qualitative approach to account for potential variability in probabilities of default data for current conditions and reasonable and supportable forecasts. Where available, expected credit losses take into consideration any enhancement a security has such as insurance or state aid. Debt securities that are not classified as trading or HTM are classified as AFS and are carried at fair value. AFS debt securities in unrealized loss positions are evaluated for impairment related to credit losses at least quarterly. Impairment may result from credit deterioration of the issuer or collateral underlying the security. In performing an assessment of whether any decline in fair value is due to a credit loss, all relevant information is considered at the individual security level. Beginning in 2020, for AFS debt securities in an unrealized loss position, we first determine whether we have the intent to sell, or it is more likely than not that we will be required to sell, the security before recovery of its amortized cost basis. If the criteria for intent or requirement to sell is met, the security’s amortized cost is written down to fair value and the write down is charged against the ACL with any incremental impairment reported in earnings in the Provision for Credit Losses line on the Consolidated Statements of Income. For AFS debt securities that do not meet the criteria for intent or requirement to sell, we evaluate whether the decline in fair value has resulted from credit losses or other factors. We first qualitatively evaluate each security to assess whether a potential credit loss exists. If as a result of this qualitative analysis we expect to get all of our principal back, then we conclude that the present value of expected cash flows equals or exceeds its amortized cost and no credit loss exists. If it was determined a potential credit loss exists, we compare the present value of cash flows expected to be collected with our amortized cost basis to measure its value. The credit loss is recorded through the ACL and limited to the amount the fair value is less than the amortized cost basis. We have made an accounting policy election for each major security type of AFS debt securities to adjust the effective interest rate used to discount expected cash flows to consider the timing of expected cash flows resulting from expected prepayments. Impairment for noncredit-related factors is recorded in OCI, net of income taxes. Changes in the ACL are recorded as a provision for credit loss expense. Losses are charged against the ACL when an AFS debt security is not collectible or when we believe the criteria regarding the intent or requirement to sell is met. Loans and Leases Loans we intend to hold for the foreseeable future or until maturity or payoff are reported at amortized cost, net of the ACL. Amortized cost primarily consists of the principal balances outstanding, deferred origination fees or costs and premiums or discounts on purchased loans. Interest income on loans is computed over the term of the loans using the effective interest method. Loan origination fees or costs, premiums or discounts are deferred and amortized over the term of the loan or loan commitment period as an adjustment to the related loan yield. Non-performing Loans We place loans on non-accrual status and discontinue interest accruals on loans generally when principal or interest is due and has remained unpaid for a certain number of days, unless the loan is both well secured and in the process of collection. Commercial loans and leases are placed on non-accrual at 90 days, installment loans are placed on non-accrual at 120 days and residential mortgages and consumer lines of credit are generally placed on non-accrual at 180 days, though we may place a loan on non-accrual prior to these past due thresholds as warranted. When a loan is placed on non-accrual status, all unpaid accrued interest is reversed against interest income and the amortization of deferred fees and costs is suspended. Non-accrual loans may not be restored to accrual status until all delinquent principal and interest have been paid and the ultimate ability to collect the remaining principal and interest is reasonably assured. Loans are charged-off against the ACL and recoveries of amounts previously charged-off are credited to the ACL when realized. Prior to 2020, PCI loans were not classified as non-performing assets as the loans were considered to be performing. Beginning in 2020, PCI loans previously accounted for in pools are grouped with other loans with similar risk characteristics for purposes of estimating expected credit losses and non-performing classification. Troubled Debt Restructured Loans Debt restructurings or loan modifications for a borrower occur in the normal course of business and do not necessarily constitute TDRs. In general, the modification or restructuring of a debt constitutes a TDR, including reasonably expected TDR, if, for economic or legal reasons related to the borrower’s financial difficulties, we grant a concession to the borrower that we would not otherwise consider under current market conditions or once we have determined that a loan modification for a financially troubled borrower is the most appropriate strategy. Additionally, a loan designated as a TDR does not necessarily result in the automatic placement of the loan on non-accrual status. When the full collection of principal and interest is reasonably assured on a loan designated as a TDR and where the borrower would not otherwise meet the criteria for non-accrual status, we will continue to accrue interest on the loan. Prior to 2020, we did not consider a restructured acquired loan as a TDR if the loan was accounted for as a component of a pool. TDR classification does not include short-term assistance to borrowers who are current at the time of a natural disaster or other extreme event (e.g. floods, hurricanes and pandemics). These borrowers are considered to not be experiencing financial difficulty at the time of modification, therefore not meeting the criteria for determining TDR status. For modifications of leases related to the effects of the COVID-19 pandemic that do not result in a substantial increase in our rights as lessor or the obligations of the lessee, we elected to account for these lease concessions as though enforceable rights and obligations for those concessions existed in the original contracts. We will account for these concessions as if no changes were made to the lease contract. Allowance for Credit Losses on Loans and Leases We estimate the ACL on loans and leases using relevant available information, from internal and external sources, relating to past events, current conditions, and reasonable and supportable forecasts under the CECL methodology effective January 1, 2020. The ACL is measured on a collective (pool) basis when similar risk characteristics exist. Our portfolio segmentation is characterized by similarities in initial measurement, risk attributes, and the manner in which we monitor and assess credit risk and is comprised of commercial real estate, commercial and industrial, commercial leases, commercial - other, direct installment, residential mortgages, indirect installment and consumer lines of credit. The ACL on loans and leases represents our current estimate of lifetime credit losses inherent in our loan portfolio at the balance sheet date. In determining the ACL, we estimate expected future losses for the loan's entire contractual term adjusted for expected prepayments when appropriate. The contractual term excludes expected extensions, renewals, and modifications. The ACL is the sum of three components: quantitative (formulaic or pooled) reserves; asset specific / individual loan reserves; and qualitative (judgmental) reserves. Quantitative Component We use a non-discounted cash flow factor-based approach to estimate expected credit losses that include component PD/LGD/EAD models as well as less complex estimation methods for smaller loan portfolios. • PD: This component model is used to estimate the likelihood that a borrower will cease making payments as agreed. The major contributors to this are the borrower credit attributes and macro-economic trends. • LGD: This component model is used to estimate the loss on a loan once a loan is in default. • EAD: Estimates the loan balance at the time the borrower stops making payments. For all term loans, an amortization based formulaic approach is used for account level EAD estimates. We calculate EAD using a portfolio specific method in each of our revolving product portfolios. Asset Specific / Individual Component Loans that do not share risk characteristics are generally evaluated on an individual basis. Loans evaluated individually are not included in the collective evaluation. We have elected to apply the practical expedient to measure expected credit losses of a collateral dependent asset using the fair value of the collateral, less any costs to sell. Individual reserves are determined as follows: • For commercial loans in default which are greater than or equal to $1.0 million, individual reserves are determined based on an analysis of the present value of the loan's expected future cash flows, the loan's observable market value, or the fair value of the collateral less costs to sell. • For commercial and consumer loans in default which are below $1.0 million, an established LGD percentage is multiplied by the loan balance and the results are aggregated for purposes of measuring specific reserve impairment. Qualitative Component The ACL also includes identified qualitative factors related to idiosyncratic risk factors, changes in current economic conditions that may not be reflected in quantitatively derived results, and other relevant factors to ensure the ACL reflects our best estimate of current expected credit losses. While our reserve methodologies strive to reflect all relevant risk factors, there continues to be uncertainty associated with, but not limited to, potential imprecision in the estimation process due to the inherent time lag of obtaining information and normal variations between estimates and actual outcomes. We provide additional reserves that are designed to provide coverage for losses attributable to such risks. The ACL also includes factors that may not be directly measured in the determination of individual or collective reserves. Such qualitative factors may include: • Lending policies and procedures, including changes in policies and underwriting standards and practices for collections, write-offs, and recoveries; • The experience, ability, and depth of lending, investment, collection, and other relevant personnel; • The quality of the institution’s credit review function; • Concentrations of credit or changes in the level of such concentration; • The effect of other external factors such as the regulatory, legal and technological environments; competition; and events such as natural disasters (e.g., pandemics); and • Forecast uncertainty and imprecision. Liability for Credit Losses on Unfunded Lending-Related Commitments The AULC, such as letters of credit, is included in other liabilities on the Consolidated Balance Sheets. Expected credit losses are estimated over the contractual period in which we are exposed to credit risk via a contractual obligation including home equity lines of credit. We do not reserve for other obligations which are unconditionally cancellable by us. The estimate includes consideration of the likelihood that funding will occur and an estimate of expected credit losses on commitments expected to be funded over its estimated useful life. Consistent with our estimation process on our loan and lease portfolio, we use a non-discounted cash flow factor-based approach to estimate expected credit losses that include component PD/LGD/EAD models as well as less complex estimation methods for smaller portfolios. Purchased Credit Deteriorated Loans and Leases We have purchased loans and leases, some of which have experienced more than insignificant credit deterioration since origination. Beginning in 2020, we have established criteria to assess whether a purchased financial asset, or group of assets, should be accounted for as PCD on the acquisition date. The selection of which criteria to apply, or the addition of new criteria, to a specific acquisition will be based on the facts and circumstances at the time of review, as well as the availability of information supplied by the acquiree. Generally, more-than-insignificant deterioration in credit quality since origination would include risk ratings of special mention or below, inconsistency of loan payments, non-accrual status at the time of acquisition, or loans modified in a TDR, in bankruptcy or for regulatory purposes.

NEW ACCOUNTING STANDARDS

NEW ACCOUNTING STANDARDS	9 Months Ended
	Sep. 30, 2020
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 Credit Losses ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments ASU 2018-19, Codification Improvements to Topic 326, Financial Instruments - Credit Losses Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments Financial Instruments-Credit Losses, (Topic 326): Targeted Transition Relief Codification Improvements to Topic 326, Financial Instruments - Credit Losses These Updates replace the current long-standing incurred loss impairment methodology with a methodology that reflects current expected credit losses (commonly referred to as CECL) for most financial assets measured at amortized cost and certain other instruments, including loans, HTM debt securities, net investments in leases and off-balance sheet credit exposures except for unconditionally cancellable commitments. CECL requires loss estimates for the remaining life of the financial asset at the time the asset is originated or acquired, considering historical experience, current conditions and reasonable and supportable forecasts. In addition, the Update will require the use of a modified AFS debt security impairment model and eliminate the current accounting for PCI loans and debt securities. On January 1, 2020, we adopted CECL using the modified retrospective method for financial assets measured at amortized cost, net investments in leases and off-balance sheet credit exposures. While these Updates change the measurement of the ACL, it does not change the credit risk of our lending portfolios or the ultimate losses in those portfolios. However, the CECL ACL methodology will produce higher volatility in the quarterly provision for credit losses than our prior reserve process. We created a cross-functional management steering group to govern implementation and the Audit and Risk Committees and the Board of Directors received regular updates. For financial assets measured at amortized cost we have implemented a new modeling platform and integrated other auxiliary models to support a calculation of expected credit losses under CECL. We have made decisions on segmentation, a reasonable and supportable forecast period, a reversion method and period and a historical loss forecast covering the remaining contractual life, adjusted for prepayments as well as other criteria. Based on our portfolio composition and forecasts of relatively stable macroeconomic conditions over the next two years at the adoption date, we recorded an overall ACL of $301 million. This reflected an increase on the originated portfolio of $55 million, primarily driven by our longer duration commercial and consumer real estate loans and a "gross-up" for PCI loans of $50 million. There is no capital impact related to the PCI loans at adoption. The impact for the adoption of CECL was a reduction to retained earnings of $51 million, which included a $10 million increase to the AULC. The impact upon adoption was dependent on the portfolio composition and credit quality, as well as historical experience, current conditions and forecasts of economic conditions and interest rates at the time of adoption. The impact to our AFS and HTM debt securities was immaterial. Model development, as well as the development of policies and procedures and, internal controls were complete at the time of adoption.

SECURITIES

SECURITIES	9 Months Ended
	Sep. 30, 2020
Investments, Debt and Equity Securities [Abstract]
SECURITIES	SECURITIES The amortized cost and fair value of AFS debt securities for the current period are as follows. There was no ACL in the AFS portfolio during the nine months ended September 30, 2020. Accrued interest receivable on AFS debt securities totaled $5.8 million at September 30, 2020 and is excluded from the estimate of credit losses and recorded 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, 2020 U.S. Treasury $ 300 $ — $ — $ 300 U.S. government agencies 161 — (1) 160 U.S. government-sponsored entities 135 2 — 137 Residential mortgage-backed securities: Agency mortgage-backed securities 1,057 39 — 1,096 Agency collateralized mortgage obligations 941 35 — 976 Commercial mortgage-backed securities 396 20 — 416 States of the U.S. and political subdivisions (municipals) 14 — — 14 Other debt securities 2 — — 2 Total debt securities AFS $ 3,006 $ 96 $ (1) $ 3,101 The amortized cost and fair value of debt securities AFS for December 31, 2019 are as follows: TABLE 3.2 (in millions) Amortized Gross Gross Fair Debt Securities AFS: December 31, 2019 U.S. government agencies $ 152 $ — $ (1) $ 151 U.S. government-sponsored entities 225 1 — 226 Residential mortgage-backed securities: Agency mortgage-backed securities 1,310 7 (3) 1,314 Agency collateralized mortgage obligations 1,234 10 (4) 1,240 Commercial mortgage-backed securities 341 6 (2) 345 States of the U.S. and political subdivisions (municipals) 11 — — 11 Other debt securities 2 — — 2 Total debt securities AFS $ 3,275 $ 24 $ (10) $ 3,289 The amortized cost and fair value of HTM debt securities for the current period are presented in the table below. The ACL for the HTM municipal bond portfolio was $0.05 million at September 30, 2020. Accrued interest receivable on HTM debt securities totaled $12.2 million at September 30, 2020 and is excluded from the estimate of credit losses and recorded separately in other assets in the Consolidated Balance Sheets. TABLE 3.3 (in millions) Amortized Gross Gross Fair Debt Securities HTM: September 30, 2020 U.S. Treasury $ 1 $ — $ — $ 1 U.S. government agencies 1 — — 1 U.S. government-sponsored entities 160 1 — 161 Residential mortgage-backed securities: Agency mortgage-backed securities 811 32 — 843 Agency collateralized mortgage obligations 571 19 — 590 Commercial mortgage-backed securities 278 12 — 290 States of the U.S. and political subdivisions (municipals) 1,144 42 — 1,186 Total debt securities HTM $ 2,966 $ 106 $ — $ 3,072 The amortized cost and fair value of HTM debt securities for December 31, 2019 are as follows: TABLE 3.4 (in millions) Amortized Gross Gross Fair Debt Securities HTM: December 31, 2019 U.S. Treasury $ 1 $ — $ — $ 1 U.S. government agencies 1 — — 1 U.S. government-sponsored entities 175 — — 175 Residential mortgage-backed securities: Agency mortgage-backed securities 949 8 (2) 955 Agency collateralized mortgage obligations 721 5 (6) 720 Commercial mortgage-backed securities 308 3 (2) 309 States of the U.S. and political subdivisions (municipals) 1,120 26 (2) 1,144 Total debt securities HTM $ 3,275 $ 42 $ (12) $ 3,305 There were no significant gross gains or gross losses realized on securities during the nine months ended September 30, 2020 or 2019. As of September 30, 2020, the amortized cost and fair value of debt securities, by contractual maturities, were as follows: TABLE 3.5 Available for Sale Held to Maturity (in millions) Amortized Fair Amortized Fair Due in one year or less $ 343 $ 343 $ 142 $ 143 Due after one year but within five years 107 108 41 41 Due after five years but within ten years 69 69 144 148 Due after ten years 93 93 979 1,017 612 613 1,306 1,349 Residential mortgage-backed securities: Agency mortgage-backed securities 1,057 1,096 811 843 Agency collateralized mortgage obligations 941 976 571 590 Commercial mortgage-backed securities 396 416 278 290 Total debt securities $ 3,006 $ 3,101 $ 2,966 $ 3,072 Maturities may differ from contractual terms because borrowers may have the right to call or prepay obligations with or without penalties. Periodic 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 3.6 (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 $ 5,427 $ 4,494 As collateral for short-term borrowings 390 285 Securities pledged as a percent of total securities 95.9 % 72.8 % At September 30, 2020, 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 surety type and length of continuous loss position: TABLE 3.7 Less than 12 Months 12 Months or More Total (dollars in millions) # Fair Unrealized # Fair Unrealized # Fair Unrealized Debt Securities AFS September 30, 2020 U.S. Treasury 1 $ 100 $ — — $ — $ — 1 $ 100 $ — U.S. government agencies 1 13 — 17 74 (1) 18 87 (1) Residential mortgage-backed securities: Agency collateralized mortgage obligations 2 5 — — — — 2 5 — Other debt securities — — — 1 2 — 1 2 — Total 4 $ 118 $ — 18 $ 76 $ (1) 22 $ 194 $ (1) Less than 12 Months 12 Months or More Total (dollars in millions) # Fair Unrealized # Fair Unrealized # Fair Unrealized Debt Securities AFS December 31, 2019 U.S. government agencies 5 $ 48 $ — 15 $ 61 $ (1) 20 $ 109 $ (1) U.S. government-sponsored entities — — — 6 130 — 6 130 — Residential mortgage-backed securities: Agency mortgage-backed securities 13 200 (1) 24 314 (2) 37 514 (3) Agency collateralized mortgage obligations 11 323 (1) 32 205 (3) 43 528 (4) Commercial mortgage-backed securities 3 114 (2) — — — 3 114 (2) Other debt securities — — — 1 2 — 1 2 — Total temporarily impaired debt securities AFS 32 $ 685 $ (4) 78 $ 712 $ (6) 110 $ 1,397 $ (10) We evaluated the AFS debt securities that were in an unrealized loss position at September 30, 2020. 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. 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 to help evaluate the credit quality of our HTM municipal bond portfolio. The ratings are updated quarterly with the last update on September 30, 2020. The remainder of the HTM portfolio is backed by the UST, Fannie Mae, Freddie Mac, FHLB, Ginnie Mae, and the SBA and we have designated these securities as having zero expected credit loss, and therefore, are not subject to an estimate of expected credit loss under CECL. Our municipal bond portfolio with a carrying amount of $1.2 billion as of September 30, 2020 is highly rated with an average rating of AA and 100% of the portfolio rated A or better, while 99% have stand-alone ratings of A or better. All of the securities in the municipal portfolio are general obligation bonds. Geographically, municipal bonds support our primary footprint as 67% 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, 63% of the municipalities have some formal credit enhancement insurance that strengthens the creditworthiness of their issue. Management reviews the credit profile of each issuer on a quarterly basis. The credit analysis on the municipal bond portfolio is completed on each bond using: • The bond’s credit rating; • Credit enhancements that improve the bond’s credit rating, for example insurance; and • Moody’s U.S. Bond Defaults and Recoveries, 1970-2019. By using these components, we derive the expected credit loss on the general obligation bond portfolio. We further refine the expected credit loss by factoring in economic forecast data using our Commercial and Industrial Non-Manufacturing PD adjustment as derived through our assessment of the loan portfolio. For the year-to-date period ending September 30, 2020, we had a provision expense of $0.01 million, with no charge-offs or recoveries. The ACL on the HTM portfolio as of September 30, 2020 was $0.05 million. No other securities portfolios had an ACL. At September 30, 2020, there were no securities that were past due or on non-accrual.

LOANS AND LEASES

LOANS AND LEASES	9 Months Ended
	Sep. 30, 2020
Receivables [Abstract]
LOANS AND LEASES	LOANS AND LEASES The loan and lease portfolio categories were generally unchanged with the CECL adoption. Accrued interest receivable on loans and leases, which totaled $64.5 million at September 30, 2020, is excluded from the estimate of credit losses and recorded separately in other assets in the Consolidated Balance Sheets for both periods and not included in the tables below. Upon adoption of CECL, 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. 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, 2020 December 31, 2019 Commercial real estate $ 9,521 $ 8,960 Commercial and industrial 7,547 5,308 Commercial leases 487 432 Other 65 21 Total commercial loans and leases 17,620 14,721 Direct installment 1,977 1,821 Residential mortgages 3,531 3,374 Indirect installment 1,219 1,922 Consumer lines of credit 1,342 1,451 Total consumer loans 8,069 8,568 Total loans and leases, net of unearned income $ 25,689 $ 23,289 The loans and leases portfolio categories are comprised of the following types of loans, where in each case the loss given default 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 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; • 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. During September 2020, $508 million of indirect installment loans were transferred to loans held for sale in anticipation of a loan sale expected to close in the fourth quarter of 2020. The following table shows certain information relating to commercial real estate loans: TABLE 4.2 (dollars in millions) September 30, December 31, Commercial real estate: Percent owner-occupied 28.3 % 30.6 % Percent non-owner-occupied 71.8 69.4 Paycheck Protection Program The CARES Act included an allocation of $349 billion for loans to be issued by financial institutions through the SBA, utilizing the PPP. The Paycheck Protection Program and Health Care Enhancement Act (PPP/HCE Act) was passed by Congress on April 23, 2020 and signed into law on April 24, 2020. The PPP/HCE Act authorized an additional $320 billion of funding for PPP loans. PPP loans are forgivable, in whole or in part, if the proceeds are used for payroll and other permitted purposes in accordance with the requirements of the PPP. Loans closed prior to June 5 2020, carry a fixed rate of 1.00% and a term of two years, if not forgiven, in whole or in part. Payments are deferred until after a forgiveness determination is made, if submitted within ten months of the end of the loan forgiveness covered period. The loans are 100% guaranteed by the SBA. The SBA pays the originating bank a processing fee ranging from 1% to 5%, based on the size of the loan. This fee is recognized in interest income over the contractual life of the loan under the effective yield method. On June 5, 2020, the President signed the Paycheck Protection Program Flexibility Act (Flexibility Act) which extended the term for new PPP loans to 5 years and permitted a lender to extend a 2-year PPP loan up to a 5-year term by mutual agreement of the lender and borrower. The Flexibility Act also gives the borrower the option of 24 weeks to distribute the funds, and a borrower can remain eligible for loan forgiveness by using at least 60% of the funds for payroll costs. The SBA announced that lenders will have 60 days to review PPP loan forgiveness applications and that the SBA will remit the forgiveness payments within 90 days of receipt of approved forgiveness applications. The SBA has also stated that it will commence the loan forgiveness process in October 2020. As of September 30, 2020, we had approximately $2.5 billion of PPP net loans outstanding. PPP loan balances are included in the commercial and industrial category. Loan origination fees or costs, premiums or discounts are deferred and amortized over the contractual term of the loan or loan commitment period as an adjustment to the related loan yield. Given the 100% guarantee by the SBA, there is reduced risk of loss to us on these loans. 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 the basis for the reasonable and supportable forecast portion of the credit risk. 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. During the first quarter of 2020, the World Health Organization declared COVID-19 a pandemic. Subsequent to that declaration, the U.S. declared a national emergency concerning the COVID-19 contagion and certain states and local governments within our market footprint have likewise declared emergency conditions that have resulted in orders and guidelines that prohibited or imposed significant restriction on the operations of non-essential businesses. Interagency guidance was released to encourage bankers to work with their customers to provide some relief through loan modifications or other temporary concessions. We have been working with borrowers throughout 2020 to provide them with certain relief that falls within this guidance and within our underwriting standards. Therefore, for any payment or interest deferrals and modifications relating to COVID-19 for borrowers who were in good standing before COVID-19, they are not included in any TDR data presented in the following tables. The following table summarizes the designated loan rating category by loan class including term loans on an amortized cost basis by origination year: TABLE 4.4 September 30, 2020 2020 2019 2018 2017 2016 Prior Revolving Loans Amortized Cost Basis Total (in millions) COMMERCIAL Commercial Real Estate: Risk Rating: Pass $ 1,343 $ 1,810 $ 1,194 $ 1,086 $ 936 $ 2,071 $ 144 $ 8,584 Special Mention 10 31 58 74 60 166 3 402 Substandard 1 25 32 87 133 252 5 535 Total commercial real estate 1,354 1,866 1,284 1,247 1,129 2,489 152 9,521 Commercial and Industrial: Risk Rating: Pass 3,355 1,092 655 363 138 422 1,052 7,077 Special Mention 5 26 40 38 12 28 59 208 Substandard 4 31 55 40 7 46 79 262 Total commercial and industrial 3,364 1,149 750 441 157 496 1,190 7,547 Commercial Leases: Risk Rating: Pass 114 179 94 61 7 4 — 459 Special Mention — 1 5 4 1 2 — 13 Substandard 8 3 2 1 1 — — 15 Total commercial leases 122 183 101 66 9 6 — 487 Other Commercial: Risk Rating: Pass 21 — — — — 3 40 64 Substandard — — — — — 1 — 1 Total other commercial 21 — — — — 4 40 65 Total commercial 4,861 3,198 2,135 1,754 1,295 2,995 1,382 17,620 CONSUMER Direct Installment: Current 525 370 226 160 188 489 — 1,958 Past due — 1 1 1 2 14 — 19 Total direct installment 525 371 227 161 190 503 — 1,977 Residential Mortgages: Current 862 803 344 437 367 661 2 3,476 Past due 1 5 5 6 6 32 — 55 Total residential mortgages 863 808 349 443 373 693 2 3,531 Indirect Installment: Current 249 273 364 169 83 69 — 1,207 Past due — 1 2 2 1 6 — 12 Total indirect installment 249 274 366 171 84 75 — 1,219 Consumer Lines of Credit: Current 3 8 9 4 5 133 1,166 1,328 Past due — — — — 1 12 1 14 Total consumer lines of credit 3 8 9 4 6 145 1,167 1,342 Total consumer 1,640 1,461 951 779 653 1,416 1,169 8,069 Total loans and leases $ 6,501 $ 4,659 $ 3,086 $ 2,533 $ 1,948 $ 4,411 $ 2,551 $ 25,689 We use delinquency transition matrices within the consumer and other loan classes to establish the basis for the reasonable and supportable 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. The following tables present the December 31, 2019 summary of our commercial loans and leases by credit quality category segregated by loans and leases originated and loans acquired: TABLE 4.5 Commercial Loan and Lease Credit Quality Categories (in millions) Pass Special Substandard Doubtful Total Originated Loans and Leases December 31, 2019 Commercial real estate $ 6,821 $ 171 $ 121 $ 1 $ 7,114 Commercial and industrial 4,768 149 144 2 5,063 Commercial leases 423 3 6 — 432 Other 20 — 1 — 21 Total originated commercial loans $ 12,032 $ 323 $ 272 $ 3 $ 12,630 Loans Acquired in a Business Combination December 31, 2019 Commercial real estate $ 1,603 $ 116 $ 127 $ — $ 1,846 Commercial and industrial 201 19 25 — 245 Total commercial loans acquired in a business combination $ 1,804 $ 135 $ 152 $ — $ 2,091 Following is a table showing the December 31, 2019 consumer loans by payment status: TABLE 4.6 Consumer Loan Credit Quality (in millions) Performing Non- Total Originated Loans December 31, 2019 Direct installment $ 1,745 $ 13 $ 1,758 Residential mortgages 2,978 17 2,995 Indirect installment 1,919 3 1,922 Consumer lines of credit 1,086 6 1,092 Total originated consumer loans $ 7,728 $ 39 $ 7,767 Loans Acquired in a Business Combination December 31, 2019 Direct installment $ 63 $ — $ 63 Residential mortgages 379 — 379 Consumer lines of credit 358 1 359 Total consumer loans acquired in a business combination $ 800 $ 1 $ 801 Non-Performing and Past Due The following tables provide an analysis of the aging of loans by class. TABLE 4.7 (in millions) 30-89 Days > 90 Days Past Due and Still Accruing Non- Total Current Total Non-accrual with No ACL September 30, 2020 Commercial real estate $ 16 $ — $ 90 $ 106 $ 9,415 $ 9,521 $ 29 Commercial and industrial 8 — 55 63 7,484 7,547 14 Commercial leases 1 — 2 3 484 487 — Other — 1 1 2 63 65 — Total commercial loans and leases 25 1 148 174 17,446 17,620 43 Direct installment 8 2 9 19 1,958 1,977 — Residential mortgages 31 13 11 55 3,476 3,531 — Indirect installment 9 — 3 12 1,207 1,219 — Consumer lines of credit 5 2 7 14 1,328 1,342 — Total consumer loans 53 17 30 100 7,969 8,069 — Total loans and leases $ 78 $ 18 $ 178 $ 274 $ 25,415 $ 25,689 $ 43 (in millions) 30-89 Days > 90 Days Past Due and Still Accruing Non- Total Current Total Originated Loans and Leases December 31, 2019 Commercial real estate $ 10 $ — $ 26 $ 36 $ 7,078 $ 7,114 Commercial and industrial 9 — 28 37 5,026 5,063 Commercial leases 5 — 1 6 426 432 Other — — 1 1 20 21 Total commercial loans and leases 24 — 56 80 12,550 12,630 Direct installment 7 1 7 15 1,743 1,758 Residential mortgages 12 2 8 22 2,973 2,995 Indirect installment 15 1 3 19 1,903 1,922 Consumer lines of credit 5 1 3 9 1,083 1,092 Total consumer loans 39 5 21 65 7,702 7,767 Total originated loans and leases $ 63 $ 5 $ 77 $ 145 $ 20,252 $ 20,397 (in millions) 30-89 > 90 Days Past Due and Still Accruing Non- Total Current (Discount) Premium Total Loans Acquired in a Business Combination December 31, 2019 Commercial real estate $ 12 $ 28 $ 3 $ 43 $ 1,942 $ (139) $ 1,846 Commercial and industrial 2 3 — 5 259 (19) 245 Total commercial loans 14 31 3 48 2,201 (158) 2,091 Direct installment 3 — — 3 60 — 63 Residential mortgages 8 4 — 12 382 (15) 379 Consumer lines of credit 7 2 1 10 357 (8) 359 Total consumer loans 18 6 1 25 799 (23) 801 Total loans acquired in a business combination $ 32 $ 37 $ 4 $ 73 $ 3,000 $ (181) $ 2,892 (1) Prior to the adoption of CECL on January 1, 2020, loans acquired in a business combination were considered performing upon acquisition, regardless of whether the customer was contractually delinquent, if we could reasonably estimate the timing and amount of expected cash flows on such loans. In these instances, we did not consider acquired contractually delinquent loans to be non-accrual or non-performing and continued to recognize interest income on these loans using the accretion method. After the adoption of CECL on January 1, 2020, loans acquired in a business combination are considered non-accrual or non-performing when, due to credit deterioration or other factors, we determine we are no longer able to reasonably estimate the timing and amount of expected cash flows on such loans. We do not recognize interest income on loans acquired in a business combination considered non-accrual or non-performing. (2) Past due information for loans acquired in a business combination is based on the contractual balance outstanding at December 31, 2019. Following is a summary of non-performing assets: TABLE 4.8 (dollars in millions) September 30, December 31, Non-accrual loans $ 178 $ 81 Troubled debt restructurings — 22 Total non-performing loans 178 103 Other real estate owned 20 26 Total non-performing assets $ 198 $ 129 Asset quality ratios: Non-performing loans / total loans and leases 0.69 % 0.44 % Non-performing assets + 90 days past due + OREO / total loans and leases + OREO 0.84 % 0.73 % 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 $2.9 million at September 30, 2020 and $3.3 million at December 31, 2019. The recorded investment of residential-secured consumer OREO for which formal foreclosure proceedings are in process at September 30, 2020 and December 31, 2019 totaled $10.7 million and $9.2 million, respectively. Approximately $112 million of commercial loans are collateral dependent at September 30, 2020. 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 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, 2020, we had $792 million in loans that have been granted short-term modifications as a result of financial disruptions associated with the COVID-19 pandemic. Also, consistent with the CARES Act and the interagency guidelines, such modifications are not included in our TDR totals. Following is a summary of the composition of total TDRs: TABLE 4.9 (in millions) September 30, December 31, Accruing $ 61 $ 41 Non-accrual 33 15 Total TDRs $ 94 $ 56 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, 2020, we returned to accruing status $6.9 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 $1.6 million at September 30, 2020 compared to less than $0.5 million at December 31, 2019, and pooled reserves for individual loans of $3.4 million and $0.8 million for those same periods, respectively, based on loan segment loss given default. 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 loss given default. Our ACL included pooled reserves for these classes of loans of $4.6 million for September 30, 2020 and $4.1 million for December 31, 2019. 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 4.10 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 Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 (dollars in millions) Number Pre- Post- Number Pre- Post- Commercial real estate 4 $ — $ — 16 $ 4 $ 4 Commercial and industrial 1 — — 14 5 3 Total commercial loans 5 — — 30 9 7 Direct installment 15 1 1 47 2 2 Residential mortgages 4 1 1 14 1 1 Consumer lines of credit 7 — — 20 1 1 Total consumer loans 26 2 2 81 4 4 Total 31 $ 2 $ 2 111 $ 13 $ 11 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 4.11 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 Following is a summary of originated TDRs, by class, for which there was a payment default, excluding loans that have been paid off and/or sold. TABLE 4.12 Three Months Ended Nine Months Ended (dollars in millions) Number of Recorded Number of Recorded Commercial real estate 1 $ — 5 $ 1 Commercial and industrial — — 1 — Total commercial loans 1 — 6 1 Direct installment 1 — 4 — Residential mortgages — — 1 — Consumer lines of credit 1 — 1 — Total consumer loans 2 — 6 — Total 3 $ — 12 $ 1 Loans Acquired in a Business Combination Prior to January 1, 2020, all loans acquired in a business combination were initially recorded at fair value at the acquisition date with no associated ACL. Refer to the Loans Acquired in a Business Combination section in Note 1 to the Consolidated Financial Statements included in our 2019 Annual Report on Form 10-K

ALLOWANCE FOR CREDIT LOSSES ON

ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES	9 Months Ended
	Sep. 30, 2020
Receivables [Abstract]
ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES	ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASESBeginning January 1, 2020, the former incurred loss method was replaced with the CECL method to calculate estimated loan loss. 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. All prior periods are presented using the incurred loss method which was the accounting method in place at the time of the respective financial statements. 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, 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 (in millions) Balance at Charge- Recoveries Net Provision for Credit Losses ASC 326 Adoption Impact Initial ACL on PCD Loans Balance at 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 on loans and leases $ 196 $ (46) $ 13 $ (33) $ 105 $ 55 $ 50 $ 373 This expected loss model takes into consideration the expected 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 PCI loan balances and the ACL of $50 million. Included in the CECL adoption impact was an increase to our AULC of $10 million. 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 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 are utilizing a third-party recessionary macroeconomic forecast scenario for ACL modeling purposes. This scenario captures forecasted macroeconomic variables as of mid-September to ensure our ACL calculation considers the most recently available macroeconomic data in a quickly evolving environment at quarter-end. Macroeconomic variables that we utilized from this scenario include but are not limited to: (i) gross domestic product, which reflects a contraction of up to 7.0% from the beginning of 2020 with average annual increases not occurring until mid-2021, (ii) the Dow Jones Industrial Average, which remains below peak levels throughout the R&S forecast period, (iii) unemployment, which averages 10% over the R&S forecast period and (iv) the Volatility Index, which remains elevated in the fourth quarter of 2020 before declining to pre-pandemic levels in mid-2021. The ACL of $373.0 million at September 30, 2020 increased $177.1 million, or 90.4%, from December 31, 2019 and reflects the Day 1 CECL adoption increase to the ACL of $105.3 million on January 1, 2020. Our ending ACL coverage ratio at September 30, 2020 was 1.45%. Total provision for credit losses for the three months ended September 30, 2020 was $27.2 million. Net charge-offs were $19.3 million during the three months ended September 30, 2020, compared to $6.4 million during the three months ended September 30, 2019, with the increase primarily due to commercial charge-offs taken against credits that were somewhat impacted by COVID-19. Total provision for credit losses for the nine months ended September 30, 2020 was $105.2 million. Net charge-offs were $33.4 million during the nine months ended September 30, 2020, compared to $23.0 million during the nine months ended September 30, 2019, with the increase primarily due to the aforementioned commercial charge-offs that occurred during the third quarter, which was partially offset by higher commercial recoveries in the current period as compared to the prior year. Following is a summary of changes in the ACL, by loan and lease class: TABLE 5.2 (in millions) Balance at Charge- Recoveries Net Provision Balance at Three Months Ended September 30, 2019 Commercial real estate $ 61 $ (1) $ — $ (1) $ (2) $ 58 Commercial and industrial 52 (3) 1 (2) 7 57 Commercial leases 9 — — — 1 10 Other 1 — — — 1 2 Total commercial loans and leases 123 (4) 1 (3) 7 127 Direct installment 13 — — — (1) 12 Residential mortgages 20 — — — 3 23 Indirect installment 18 (3) 1 (2) 2 18 Consumer lines of credit 9 — — — — 9 Total consumer loans 60 (3) 1 (2) 4 62 Total allowance for credit losses on originated loans and leases 183 (7) 2 (5) 11 189 Purchased credit-impaired loans 1 — — — — 1 Other acquired loans 4 (2) 1 (1) 1 4 Total allowance for credit losses on acquired loans 5 (2) 1 (1) 1 5 Total allowance for credit losses $ 188 $ (9) $ 3 $ (6) $ 12 $ 194 Nine Months Ended September 30, 2019 Commercial real estate $ 55 $ (3) $ 1 $ (2) $ 5 $ 58 Commercial and industrial 49 (7) 3 (4) 12 57 Commercial leases 8 — — — 2 10 Other 2 (2) — (2) 2 2 Total commercial loans and leases 114 (12) 4 (8) 21 127 Direct installment 14 (1) — (1) (1) 12 Residential mortgages 20 (1) — (1) 4 23 Indirect installment 15 (8) 3 (5) 8 18 Consumer lines of credit 10 (1) — (1) — 9 Total consumer loans 59 (11) 3 (8) 11 62 Total allowance on originated loans and leases 173 (23) 7 (16) 32 189 Purchased credit-impaired loans 1 — — — — 1 Other loans acquired in a business combination 6 (9) 2 (7) 5 4 Total allowance on loans acquired in a business combination 7 (9) 2 (7) 5 5 Total allowance for credit losses $ 180 $ (32) $ 9 $ (23) $ 37 $ 194 Following is a summary of the individual and collective ACL and corresponding loan and lease balances by class: TABLE 5.3 Allowance for Credit Losses Loans and Leases Outstanding (in millions) Individually Collectively Loans and Individually Collectively December 31, 2019 Commercial real estate $ 2 $ 58 $ 7,114 $ 13 $ 7,101 Commercial and industrial 2 51 5,063 17 5,046 Commercial leases — 11 432 — 432 Other — 2 21 — 21 Total commercial loans and leases 4 122 12,630 30 12,600 Direct installment — 13 1,758 — 1,758 Residential mortgages — 22 2,995 — 2,995 Indirect installment — 19 1,922 — 1,922 Consumer lines of credit — 9 1,092 — 1,092 Total consumer loans — 63 7,767 — 7,767 Total $ 4 $ 185 $ 20,397 $ 30 $ 20,367 The above table excludes loans acquired in a business combination that were pooled into groups of loans for evaluating impairment.

LOAN SERVICING

LOAN SERVICING	9 Months Ended
	Sep. 30, 2020
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 $ 4,626 $ 4,686 The following table summarizes activity relating to mortgage loans sold with servicing retained: TABLE 6.2 Three Months Ended Nine Months Ended (in millions) 2020 2019 2020 2019 Mortgage loans sold with servicing retained $ 466 $ 354 $ 1,142 $ 937 Pretax net gains resulting from above loan sales (1) 25 10 47 23 Mortgage servicing fees (1) 3 3 9 8 (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) 2020 2019 2020 2019 Balance at beginning of period $ 34.0 $ 38.0 $ 42.6 $ 36.8 Additions 4.5 3.5 11.0 9.8 Payoffs and curtailments (4.6) (0.5) (10.5) (1.8) (Impairment) / recovery 0.5 (0.3) (7.5) (2.9) Amortization (0.6) (1.9) (1.8) (3.1) Balance at end of period $ 33.8 $ 38.8 $ 33.8 $ 38.8 Fair value, beginning of period $ 34.0 $ 39.8 $ 45.0 $ 41.1 Fair value, end of period 33.8 40.5 33.8 40.5 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) 62.3 78.9 Constant prepayment rate (annualized) 14.5 % 10.6 % Discount rate 9.6 % 9.7 % Effect on fair value due to change in interest rates: +0.25% $ 2 $ 3 +0.50% 5 5 -0.25% (2) (3) -0.50% (3) (5) 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. We had a $9.1 million valuation allowance for MSRs as of September 30, 2020, compared to $1.5 million at December 31, 2019.

GOODWILL AND OTHER INTANGIBLE A

GOODWILL AND OTHER INTANGIBLE ASSETS	9 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND OTHER INTANGIBLE ASSETS	GOODWILL AND OTHER INTANGIBLE ASSETS In performing our quarterly goodwill impairment assessment, we first assess qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying value. Qualitative factors include, among other things, macroeconomic conditions, industry and market considerations, financial performance of the respective reporting unit and other relevant entity- and reporting-unit specific considerations. If we conclude it is more likely than not that the fair value of a reporting unit is less than its carrying value, a quantitative assessment is performed. If the quantitative assessment results in the fair value of the reporting unit exceeding its carrying value, goodwill of the reporting unit is considered not impaired; however, if the carrying value of the reporting unit exceeds its fair value an impairment charge is recorded for the excess, limited to the amount of goodwill assigned to a reporting unit. In connection with the preparation of the third quarter 2020 financial statements, we concluded that it was more likely than not that the fair value of our Community Banking reporting unit was below its carrying amount due to a sustained decline in bank stock valuations, which was primarily attributable to the systemic near-term uncertainty of COVID-19 and its full impact on the global economy which caused an unprecedented shock in interest rates and equity valuations. Therefore, we performed an interim quantitative assessment of our Community Banking reporting unit as of September 30, 2020. Factors considered in the interim quantitative analysis included: the uncertainty due to the COVID-19 pandemic on our customers and our businesses and revisions to our 2020 annual operating plan due to the COVID-19 pandemic, which established revised expectations and priorities for the remainder of 2020 in response to current market factors, such as lower revenue growth and net interest margin expectations. The September 30, 2020 interim quantitative assessment for our Community Banking reporting unit, with $2.2 billion of allocated goodwill, resulted in an excess fair value over its carrying amount of less than 5%, which is stable from June 30, 2020. Based on the results of the interim quantitative impairment assessments, there were no impairments for the periods presented. Although not impaired, the fair value of our Community Banking reporting unit remains relatively close to carrying value. As margins for fair value over carrying amount decline, the risk of future impairment increases if any assumptions, estimates, or market factors change in the future. The annual test for impairment is performed in the fourth quarter each year and will include an update to our long-range forecast. Other intangible assets are tested annually for impairment, and more frequently if events or changes in circumstances indicate the carrying value may not be recoverable. We completed this annual test in 2019 and determined that our other intangible assets are not impaired. There were no impairment indicators for other intangible assets as of September 30, 2020.

OPERATING LEASES

OPERATING LEASES	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
OPERATING LEASES	OPERATING LEASES We have operating leases primarily for certain branches, office space, land, and office equipment. Our operating leases expire at various dates through the year 2046 and generally include one or more options to renew. The exercise of lease renewal options is at our sole discretion. As of September 30, 2020, we had operating lease right-of-use assets and operating lease liabilities of $116.6 million and $124.2 million, respectively. Our operating lease agreements do not contain any material residual value guarantees or material restrictive covenants. As of September 30, 2020, 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 $28 million in right-of-use assets and other liabilities. These operating leases are currently expected to commence in 2020 with lease terms of 11 years to 16 years. The components of lease expense were as follows: TABLE 8.1 Three Months Ended Nine Months Ended (dollars in millions) 2020 2019 2020 2019 Operating lease cost $ 7 $ 6 $ 20 $ 20 Short-term lease cost 1 1 1 1 Variable lease cost 1 1 3 3 Total lease cost $ 9 $ 8 $ 24 $ 24 Other information related to leases is as follows: TABLE 8.2 Nine Months Ended (dollars in millions) 2020 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 19 $ 19 Right-of-use assets obtained in exchange for lease obligations: Operating leases 5 22 Weighted average remaining lease term (years): Operating leases 9.51 9.78 Weighted average discount rate: Operating leases 2.8 % 3.0 % Maturities of operating lease liabilities were as follows: TABLE 8.3 (in millions) September 30, 2020 $ 6 2021 24 2022 19 2023 15 2024 13 Later years 67 Total lease payments 144 Less: imputed interest (20) Present value of lease liabilities $ 124 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, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
VARIABLE INTEREST ENTITIES	VARIABLE INTEREST ENTITIES We 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 hold both at inception and when there is a change in circumstances that requires a reconsideration. Unconsolidated VIEs The following tables provide a summary of the assets and liabilities included in our Consolidated Financial Statements, as well as the maximum exposure to losses, associated with its interests related to unconsolidated VIEs for which we hold an interest, but are not the primary beneficiary, at September 30, 2020 and December 31, 2019. TABLE 9.1 (in millions) Total Assets Total Liabilities Maximum Exposure to Loss September 30, 2020 Trust preferred securities (1) $ 1 $ 66 $ — Affordable housing tax credit partnerships 121 51 121 Other investments 32 8 32 Total $ 154 $ 125 $ 153 December 31, 2019 Trust preferred securities (1) $ 1 $ 66 $ — Affordable housing tax credit partnerships 120 60 120 Other investments 33 10 33 Total $ 154 $ 136 $ 153 (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. See the Borrowings footnote for additional information relating to our TPS. 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 are recorded on a net basis as a component of the provision of 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 9.2 (in millions) September 30, December 31, Proportional amortization method investments included in other assets $ 67 $ 55 Equity method investments included in other assets 3 5 Total LIHTC investments included in other assets $ 70 $ 60 Unfunded LIHTC commitments $ 51 $ 60 The following table summarizes the impact of these LIHTC investments on specific line items of our Consolidated Statements of Income: TABLE 9.3 Three Months Ended Nine Months Ended (in millions) 2020 2019 2020 2019 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 $ 2 $ 2 $ 8 $ 6 Low-income housing tax credits (3) (3) (9) (7) Other tax benefits related to tax credit investments — — (2) (1) Total provision for income taxes $ (1) $ (1) $ (3) $ (2) 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, 2020
Debt Disclosure [Abstract]
BORROWINGS	BORROWINGS Following is a summary of short-term borrowings: TABLE 10.1 (in millions) September 30, December 31, Securities sold under repurchase agreements $ 405 $ 278 Federal Home Loan Bank advances 1,380 2,255 Federal funds purchased — 575 Subordinated notes 114 108 Total short-term borrowings $ 1,899 $ 3,216 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, 2020 or December 31, 2019. At September 30, 2020, $1.4 billion, or 100.0%, of the short-term FHLB advances were swapped to a fixed rate with maturities ranging from 2020 through 2024. This compares to $1.5 billion, or 64.5%, as of December 31, 2019. Following is a summary of long-term borrowings: TABLE 10.2 (in millions) September 30, December 31, Federal Home Loan Bank advances $ 700 $ 935 Senior notes 298 — Subordinated notes 84 90 Junior subordinated debt 66 66 Other subordinated debt 249 249 Total long-term borrowings $ 1,397 $ 1,340 Our banking affiliate has available credit with the FHLB of $8.4 billion, of which $2.1 billion was utilized as of September 30, 2020. 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 2022. Effective interest rates paid on the long-term advances ranged from 0.30% to 2.45% for the nine months ended September 30, 2020 and 1.62% to 2.71% for the year ended December 31, 2019. During the third quarter of 2020, we reduced higher rate outstanding FHLB borrowings by $415.0 million, which resulted in a loss on debt extinguishment and related hedge termination costs of $13.3 million reported in other non-interest income on the Consolidated Statements of Income. During the first quarter of 2020, we completed a debt offering in which we issued $300 million aggregate principal amount of senior notes due in 2023. The net proceeds of the debt offering after deducting underwriting discounts and commissions and offering costs were $297.9 million. These proceeds were used for general corporate purposes, which included investments at the holding company level, capital to support the growth of FNBPA, repurchase of our common shares and refinancing of outstanding indebtedness. The following table provides information relating to our senior debt and other subordinated debt as of September 30, 2020. These debt issuances are fixed-rate, with the exception of the debt offering in 2019, which is fixed-to-floating rate after February 14, 2024. The subordinated notes are eligible for treatment as tier 2 capital for regulatory capital purposes. TABLE 10.3 (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 $ 298 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 31 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, 2020: TABLE 10.4 (dollars in millions) Trust Common Junior Stated Interest Rate F.N.B. Statutory Trust II $ 22 $ 1 $ 22 6/15/2036 1.90 % LIBOR + 165 basis points (bps) Yadkin Valley Statutory Trust I 25 1 22 12/15/2037 1.57 % LIBOR + 132 bps FNB Financial Services Capital Trust I 25 1 22 9/30/2035 1.68 % LIBOR + 146 bps Total $ 72 $ 3 $ 66

DERIVATIVE INSTRUMENTS AND HEDG

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	9 Months Ended
	Sep. 30, 2020
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 the Consolidated Balance Sheets 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 11.1 September 30, 2020 December 31, 2019 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 $ 3 $ — $ 1,655 $ 1 $ — Interest rate swaps – not designated 4,601 — 42 3,640 — 23 Total subject to master netting arrangements 6,181 3 42 5,295 1 23 Not subject to master netting arrangements: Interest rate swaps – not designated 4,601 397 — 3,640 149 1 Interest rate lock commitments – not designated 532 22 — 163 3 — Forward delivery commitments – not designated 479 1 2 195 1 1 Credit risk contracts – not designated 445 — 1 265 — — Total not subject to master netting arrangements 6,057 420 3 4,263 153 2 Total $ 12,238 $ 423 $ 45 $ 9,558 $ 154 $ 25 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. The fair value of interest rate swaps - not designated has increased from December 31, 2019 primarily due to the significantly lower interest rate environment since year-end. 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. Prior to 2019, any ineffective portion of the gain or loss was reported in earnings immediately. The following table shows amounts reclassified from AOCI: TABLE 11.2 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) 2020 2019 2020 2019 Derivatives in cash flow hedging relationships: Interest rate contracts $ (42) $ (31) Interest income (expense) $ (9) $ 2 Other income (expense) (9) $ — The following table represents gains (losses) recognized in the Consolidated Statements of Income on cash flow hedging relationships: TABLE 11.3 Nine months ended September 30, 2020 2019 (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) $ 750 $ 31 $ 819 $ 66 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 2 (11) (1) 3 Amount of gain (loss) reclassified from AOCI into income as a — — — — As of September 30, 2020, the maximum length of time over which forecasted interest cash flows are hedged is 4.1 years. In the twelve months that follow September 30, 2020, we expect to reclassify from the amount currently reported in AOCI net derivative losses of $18.7 million ($14.5 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, 2020. During the third quarter of 2020, we terminated $225.0 million 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, 2020 and 2019, 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 14 "Derivative Instruments and Hedging Activities" in the Consolidated Financial Statements included in our 2019 Annual Report on Form 10-K filed with the SEC on February 27, 2020. 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 $302.5 million as of September 30, 2020 have remaining terms ranging from one month 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 $0.7 million at September 30, 2020 and $0.3 million at December 31, 2019. The fair values of risk participation agreements purchased and sold were $0.3 million and $0.7 million, respectively, at September 30, 2020 and $0.1 million and $0.3 million, respectively at December 31, 2019. The following table presents the effect of certain derivative financial instruments on the Consolidated Statements of Income: TABLE 11.4 Nine Months Ended (in millions) Consolidated Statements of Income Location 2020 2019 Interest rate swaps Non-interest income - other $ — $ — Interest rate lock commitments Mortgage banking operations — — Forward delivery contracts Mortgage banking operations (1) (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 $0.3 million and $0.1 million as of September 30, 2020 and December 31, 2019, 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 11.5 Amount Not Offset in the (in millions) Net Amount Financial Cash Net September 30, 2020 Derivative Assets Interest rate contracts: Designated $ 3 $ — $ 3 $ — Total $ 3 $ — $ 3 $ — Derivative Liabilities Interest rate contracts: Not designated $ 42 $ — $ 42 $ — Total $ 42 $ — $ 42 $ — December 31, 2019 Derivative Assets Interest rate contracts: Designated $ 1 $ 1 $ — $ — Total $ 1 $ 1 $ — $ — Derivative Liabilities Interest rate contracts: Not designated $ 23 $ 23 $ — $ — Total $ 23 $ 23 $ — $ —

COMMITMENTS, CREDIT RISK AND CO

COMMITMENTS, CREDIT RISK AND CONTINGENCIES	9 Months Ended
	Sep. 30, 2020
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 12.1 (in millions) September 30, December 31, Commitments to extend credit $ 9,121 $ 8,089 Standby letters of credit 156 150 At September 30, 2020, funding of 75.5% 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 $14.8 million at September 30, 2020. 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 10. 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, 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, settlements or orders, if any, that 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 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, 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, 2020
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 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 13.1 Nine Months Ended September 30, 2020 2019 Units Weighted Units Weighted Unvested units outstanding at beginning of period 2,858,357 $ 12.56 2,556,174 $ 13.51 Granted 2,004,895 5.95 1,182,197 10.94 Net adjustment due to performance 47,290 13.00 — — Vested (592,602) 14.50 (655,208) 13.15 Forfeited/expired (169,552) 13.05 (325,253) 12.72 Dividend reinvestment 173,990 6.99 80,738 11.62 Unvested units outstanding at end of period 4,322,378 9.45 2,838,648 12.54 The following table provides certain information related to restricted stock units: TABLE 13.2 (in millions) Nine Months Ended 2020 2019 Stock-based compensation expense $ 13 $ 8 Tax benefit related to stock-based compensation expense 3 2 Fair value of units vested 4 7 As of September 30, 2020, there was $13.8 million of unrecognized compensation cost related to unvested restricted stock units, including $0.9 million that is subject to accelerated vesting under the Plan’s immediate vesting upon retirement. Stock-based compensation expense increased $5.4 million, or 65% for the nine months ended September 30, 2020, compared to the same period of 2019, as we made a change to long-term stock-based compensation retirement vesting that resulted in accelerated grant date expense recognition for certain 2020 awards, with full expense recognition on grant date instead of recognizing the same expense amount over a 36-month vesting period. These awards are not released until the three three The components of the restricted stock units as of September 30, 2020 are as follows: TABLE 13.3 (dollars in millions) Service- Performance- Total Unvested restricted stock units 2,987,784 1,334,594 4,322,378 Unrecognized compensation expense $ 11 $ 3 $ 14 Intrinsic value $ 20 $ 9 $ 29 Weighted average remaining life (in years) 1.86 1.31 1.69 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, 2020, we had 207,030 stock options outstanding and exercisable at a weighted average exercise price per share of $8.42, compared to 397,628 stock options outstanding and exercisable at a weighted average exercise price per share of $8.10 as of September 30, 2019. The intrinsic value of outstanding and exercisable stock options at September 30, 2020 was $0.1 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, 2020
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 14.1 Three Months Ended Nine Months Ended (in millions) 2020 2019 2020 2019 Current income taxes: Federal taxes $ 16 $ (3) $ 62 $ 24 State taxes 1 — 6 3 Total current income taxes 17 (3) 68 27 Deferred income taxes: Federal taxes — 19 (24) 34 State taxes — 1 — 2 Total deferred income taxes — 20 (24) 36 Total income taxes $ 17 $ 17 $ 44 $ 63 Statutory tax rate 21.0 % 21.0 % 21.0 % 21.0 % Effective tax rate 17.0 % 14.5 % 17.0 % 17.8 % The effective tax rate for the nine months ended September 30, 2020 and September 30, 2019 was lower than the statutory tax rate of 21% due to tax benefits resulting from tax-exempt income on investments and loans, tax credits and income from BOLI. The lower effective tax rate for the nine months ended September 30, 2020 compared to the nine months ended September 30, 2019 is primarily due to lower pre-tax income levels in the 2020 COVID-19 environment. However, the higher effective tax rate of 17.0% in the third quarter of 2020 compared to 14.5% in the third quarter of 2019 is due to the recognition of renewable energy investment tax credits in the third quarter of 2019. 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 $52.6 million and $25.1 million at September 30, 2020 and December 31, 2019, respectively.

OTHER COMPREHENSIVE INCOME

OTHER COMPREHENSIVE INCOME	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
OTHER COMPREHENSIVE INCOME	OTHER COMPREHENSIVE INCOME The following table presents changes in AOCI, net of tax, by component: TABLE 15.1 (in millions) Unrealized Unrealized Unrecognized Total Nine Months Ended September 30, 2020 Balance at beginning of period $ 11 $ (18) $ (58) $ (65) Other comprehensive (loss) income before reclassifications 63 (32) 1 32 Amounts reclassified from AOCI — 7 — 7 Net current period other comprehensive (loss) income 63 (25) 1 39 Balance at end of period $ 74 $ (43) $ (57) $ (26) 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 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, 2020
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. Diluted weighted average common shares for 2019 have also been adjusted for the dilutive effect of potential common shares issuable for warrants, which have all been exercised or forfeited during 2019. 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 16.1 Three Months Ended Nine Months Ended ( dollars in millions, except per share data) 2020 2019 2020 2019 Net income $ 83 $ 103 $ 214 $ 292 Less: Preferred stock dividends 2 2 6 6 Net income available to common stockholders $ 81 $ 101 $ 208 $ 286 Basic weighted average common shares outstanding 323,379,720 325,031,140 323,642,925 324,875,436 Net effect of dilutive stock options, warrants and restricted stock 2,283,060 1,068,730 2,051,221 893,725 Diluted weighted average common shares outstanding 325,662,780 326,099,870 325,694,146 325,769,161 Earnings per common share: Basic $ 0.25 $ 0.31 $ 0.64 $ 0.88 Diluted $ 0.25 $ 0.31 $ 0.64 $ 0.88 The following table shows the average shares excluded from the above calculation as their effect would have been anti-dilutive: TABLE 16.2 Three Months Ended Nine Months Ended 2020 2019 2020 2019 Average shares excluded from the diluted earnings per common share calculation 44,755 1 22,263 122

CASH FLOW INFORMATION

CASH FLOW INFORMATION	9 Months Ended
	Sep. 30, 2020
Supplemental Cash Flow Elements [Abstract]
CASH FLOW INFORMATION	CASH FLOW INFORMATION Following is a summary of supplemental cash flow information: TABLE 17.1 Nine Months Ended 2020 2019 (in millions) Interest paid on deposits and other borrowings $ 179 $ 248 Income taxes paid 34 40 Transfers of loans to other real estate owned 2 5 Loans transferred to held for sale from portfolio 508 389 Loans transferred to portfolio from held for sale — 110

BUSINESS SEGMENTS

BUSINESS SEGMENTS	9 Months Ended
	Sep. 30, 2020
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 agency 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 18.1 (in millions) Community Wealth Insurance Parent and Consolidated 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 At or for the Three Months Ended September 30, 2019 Interest income $ 314 $ — $ — $ — $ 314 Interest expense 79 — — 5 84 Net interest income 235 — — (5) 230 Provision for credit losses 12 — — — 12 Non-interest income 65 12 5 (2) 80 Non-interest expense (1) 158 8 4 4 174 Amortization of intangibles 3 — 1 — 4 Income tax expense (benefit) 19 1 — (3) 17 Net income (loss) 108 3 — (8) 103 Total assets 34,207 29 36 57 34,329 Total intangibles 2,294 10 29 — 2,333 (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, 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 At or for the Nine Months Ended September 30, 2019 Interest income $ 940 $ — $ — $ 1 $ 941 Interest expense 236 — — 14 250 Net interest income 704 — — (13) 691 Provision for credit losses 37 — — — 37 Non-interest income 177 35 14 (6) 220 Non-interest expense (1) 462 26 12 8 508 Amortization of intangibles 10 — 1 — 11 Income tax expense (benefit) 66 2 — (5) 63 Net income (loss) 306 7 1 (22) 292 Total assets 34,207 29 36 57 34,329 Total intangibles 2,294 10 29 — 2,333 (1) Excludes amortization of intangibles, which is presented separately.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Refer to Note 24 "Fair Value Measurements" to the Consolidated Financial Statements included in our 2019 Annual Report on Form 10-K filed with the SEC on February 27, 2020 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 19.1 (in millions) Level 1 Level 2 Level 3 Total September 30, 2020 Assets Measured at Fair Value Debt securities available for sale U.S. Treasury $ 300 $ — $ — $ 300 U.S. government agencies — 160 — 160 U.S. government-sponsored entities — 137 — 137 Residential mortgage-backed securities: Agency mortgage-backed securities — 1,096 — 1,096 Agency collateralized mortgage obligations — 976 — 976 Commercial mortgage-backed securities — 416 — 416 States of the U.S. and political subdivisions (municipals) — 14 — 14 Other debt securities — 2 — 2 Total debt securities available for sale 300 2,801 — 3,101 Loans held for sale — 138 — 138 Derivative financial instruments Trading — 397 — 397 Not for trading — 4 22 26 Total derivative financial instruments — 401 22 423 Total assets measured at fair value on a recurring basis $ 300 $ 3,340 $ 22 $ 3,662 Liabilities Measured at Fair Value Derivative financial instruments Trading $ — $ 42 $ — $ 42 Not for trading — 3 — 3 Total derivative financial instruments — 45 — 45 Total liabilities measured at fair value on a recurring basis $ — $ 45 $ — $ 45 (in millions) Level 1 Level 2 Level 3 Total December 31, 2019 Assets Measured at Fair Value Debt securities available for sale U.S. government agencies $ — $ 151 $ — $ 151 U.S. government-sponsored entities — 226 — 226 Residential mortgage-backed securities: Agency mortgage-backed securities — 1,314 — 1,314 Agency collateralized mortgage obligations — 1,240 — 1,240 Commercial mortgage-backed securities — 345 — 345 States of the U.S. and political subdivisions (municipals) — 11 — 11 Other debt securities — 2 — 2 Total debt securities available for sale — 3,289 — 3,289 Loans held for sale — 41 — 41 Derivative financial instruments Trading — 149 — 149 Not for trading — 2 3 5 Total derivative financial instruments — 151 3 154 Total assets measured at fair value on a recurring basis $ — $ 3,481 $ 3 $ 3,484 Liabilities Measured at Fair Value Derivative financial instruments Trading $ — $ 24 $ — $ 24 Not for trading — 1 — 1 Total derivative financial instruments — 25 — 25 Total liabilities measured at fair value on a recurring basis $ — $ 25 $ — $ 25 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 19.2 (in millions) Interest Total Nine Months Ended September 30, 2020 Balance at beginning of period $ 3 $ 3 Purchases, issuances, sales and settlements: Issuances 22 22 Settlements (3) (3) Balance at end of period $ 22 $ 22 Year Ended December 31, 2019 Balance at beginning of period $ 1 $ 1 Purchases, issuances, sales and settlements: Issuances 3 3 Settlements (1) (1) Balance at end of period $ 3 $ 3 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 2020 or 2019. 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 24 "Fair Value Measurements" to the Consolidated Financial Statements included in 2019 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 19.3 (in millions) Level 1 Level 2 Level 3 Total September 30, 2020 Collateral dependent loans $ — $ — $ 45 $ 45 Other real estate owned — — 9 9 Other assets - SBA servicing asset — — 3 3 Other assets - MSRs — — 34 34 December 31, 2019 Impaired loans $ — $ — $ 5 $ 5 Other real estate owned — — 4 4 Other assets - SBA servicing asset — — 3 3 Other assets - MSRs — — 30 30 Substantially all of the fair value amounts in the table above were estimated at a date during the nine months or twelve months ended September 30, 2020 and December 31, 2019, respectively. Consequently, the fair value information presented is not necessarily as of the period’s end. MSRs measured at fair value on a non-recurring basis of $42.7 million had a valuation allowance of $9.1 million, bringing the September 30, 2020 carrying value to $33.7 million. The valuation allowance includes a provision expense of $7.5 million included in earnings for the nine months ended September 30, 2020. Collateral dependent loans measured or re-measured at fair value on a non-recurring basis during the nine months ended September 30, 2020 had a carrying amount of $45.3 million, which includes an allocated ACL of $25.4 million. The ACL includes a provision applicable to the current period fair value measurements of $32.0 million, which was included in provision for credit losses for the nine months ended September 30, 2020. OREO with a carrying amount of $10.4 million was written down to $9.2 million, resulting in a loss of $1.2 million, which was included in earnings for the nine months ended September 30, 2020. Fair Value of Financial Instruments Refer to Note 24 "Fair Value Measurements" to the Consolidated Financial Statements included in our 2019 Annual Report on Form 10-K filed with the SEC on February 27, 2020 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 19.4 Fair Value Measurements (in millions) Carrying Fair Level 1 Level 2 Level 3 September 30, 2020 Financial Assets Cash and cash equivalents $ 900 $ 900 $ 900 $ — $ — Debt securities available for sale 3,101 3,101 300 2,801 — Debt securities held to maturity 2,966 3,072 — 3,072 — Net loans and leases, including loans held for sale 25,996 25,872 — 138 25,734 Loan servicing rights 37 37 — — 37 Derivative assets 423 423 — 401 22 Accrued interest receivable 90 90 90 — — Financial Liabilities Deposits 28,836 28,882 24,811 4,071 — Short-term borrowings 1,899 1,904 1,904 — — Long-term borrowings 1,397 1,379 — — 1,379 Derivative liabilities 45 45 — 45 — Accrued interest payable 14 14 14 — — December 31, 2019 Financial Assets Cash and cash equivalents $ 599 $ 599 $ 599 $ — $ — Debt securities available for sale 3,289 3,289 — 3,289 — Debt securities held to maturity 3,275 3,305 — 3,305 — Net loans and leases, including loans held for sale 23,144 22,930 — 41 22,889 Loan servicing rights 46 48 — — 48 Derivative assets 154 154 — 151 3 Accrued interest receivable 109 109 109 — — Financial Liabilities Deposits 24,786 24,797 20,058 4,739 — Short-term borrowings 3,216 3,219 3,219 — — Long-term borrowings 1,340 1,355 — — 1,355 Derivative liabilities 25 25 — 25 — Accrued interest payable 21 21 21 — —

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	9 Months Ended
	Sep. 30, 2020
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 and F.N.B. Capital Corporation, 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. 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. Certain prior period amounts have been reclassified to conform to the current period presentation. Such reclassifications had no impact on our net income and stockholders’ equity. Events occurring subsequent to September 30, 2020 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 Securities and Exchange Commission. 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 2019 Annual Report on Form 10-K filed with the SEC on February 27, 2020.
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, accounting for loans acquired in a business combination prior to January 1, 2020, fair value of financial instruments, goodwill and other intangible assets, income taxes and deferred tax assets.
New Accounting Standards	Adoption of New Accounting Standards On January 1, 2020, we adopted ASU 2016-13, Financial Instruments-Credit Losses (Topic 326), which replaces the incurred credit loss impairment methodology with a methodology that reflects lifetime current expected credit losses (commonly referred to as CECL) for most financial assets measured at amortized cost, including loans, HTM debt securities, net investment in leases and certain off-balance sheet credit exposure. We adopted CECL using the modified retrospective method for financial assets measured at amortized cost, net investments in leases and off-balance sheet credit exposures. As a result, we recorded a reduction of $50.6 million in retained earnings as of January 1, 2020 for the cumulative effect of the adoption. The transition adjustment was primarily driven by longer duration commercial and consumer real estate loans. Results for reporting periods prior to January 1, 2020 continue to be reported in accordance with previously applicable GAAP. We used the prospective transition method for PCD financial assets that were previously classified as PCI and accounted for under ASC 310-30, including loans accounted for by analogy under ASC 310-30. In accordance with the transition guidance, we did not reassess whether PCI assets met the criteria for PCD assets nor did we reassess whether modifications to individual acquired financial assets previously accounted for in pools were TDRs as of the date of adoption. We discontinued the use of pools beyond transition accounting and account for these loans on an individual loan basis. After transition, loans previously accounted for in pools are grouped with other loans with similar risk characteristics for purposes of estimating expected credit losses. As a result, beginning in 2020 certain credit metrics and ratios which previously excluded PCI loans now include PCD loans. On January 1, 2020, the amortized cost basis of the PCD assets was adjusted to reflect the addition of an ACL for $50.3 million. The net noncredit discount, after the adjustment for the ACL, will be accreted into interest income at the loan’s effective interest rate over the remaining contractual life. We made an accounting policy election to write-off accrued interest receivable balances by reversing interest income in accordance with our non-accrual policies instead of measuring an ACL for accrued interest receivable for all classes of financing receivables and major security types. We do not hold any securities at adoption for which other-than-temporary impairment had been recognized prior to January 1, 2020. The following table illustrates the impact of the adoption of ASC 326: TABLE 1.1 January 1, 2020 (in millions) As Reported Under ASC 326 Pre-ASC 326 Adoption Impact of ASC 326 Adoption Assets: Allowance for credit losses on debt securities held-to-maturity States of the U.S. and political subdivisions (municipals) $ — $ — $ — Loans Commercial real estate $ 138 $ 60 $ 78 Commercial and industrial 65 53 12 Commercial leases 11 11 — Commercial other — 9 (9) Direct installment 24 13 11 Residential mortgages 32 22 10 Indirect installment 21 19 2 Consumer lines of credit 10 9 1 Allowance for credit losses on loans $ 301 $ 196 $ 105 Liabilities: Allowance for credit losses on off-balance sheet credit exposures $ 13 $ 3 $ 10 The following table summarizes accounting pronouncements issued by the FASB that we recently adopted. TABLE 2.1 Standard Description Financial Statements Impact Credit Losses ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments ASU 2018-19, Codification Improvements to Topic 326, Financial Instruments - Credit Losses Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments Financial Instruments-Credit Losses, (Topic 326): Targeted Transition Relief Codification Improvements to Topic 326, Financial Instruments - Credit Losses These Updates replace the current long-standing incurred loss impairment methodology with a methodology that reflects current expected credit losses (commonly referred to as CECL) for most financial assets measured at amortized cost and certain other instruments, including loans, HTM debt securities, net investments in leases and off-balance sheet credit exposures except for unconditionally cancellable commitments. CECL requires loss estimates for the remaining life of the financial asset at the time the asset is originated or acquired, considering historical experience, current conditions and reasonable and supportable forecasts. In addition, the Update will require the use of a modified AFS debt security impairment model and eliminate the current accounting for PCI loans and debt securities. On January 1, 2020, we adopted CECL using the modified retrospective method for financial assets measured at amortized cost, net investments in leases and off-balance sheet credit exposures. While these Updates change the measurement of the ACL, it does not change the credit risk of our lending portfolios or the ultimate losses in those portfolios. However, the CECL ACL methodology will produce higher volatility in the quarterly provision for credit losses than our prior reserve process. We created a cross-functional management steering group to govern implementation and the Audit and Risk Committees and the Board of Directors received regular updates. For financial assets measured at amortized cost we have implemented a new modeling platform and integrated other auxiliary models to support a calculation of expected credit losses under CECL. We have made decisions on segmentation, a reasonable and supportable forecast period, a reversion method and period and a historical loss forecast covering the remaining contractual life, adjusted for prepayments as well as other criteria. Based on our portfolio composition and forecasts of relatively stable macroeconomic conditions over the next two years at the adoption date, we recorded an overall ACL of $301 million. This reflected an increase on the originated portfolio of $55 million, primarily driven by our longer duration commercial and consumer real estate loans and a "gross-up" for PCI loans of $50 million. There is no capital impact related to the PCI loans at adoption. The impact for the adoption of CECL was a reduction to retained earnings of $51 million, which included a $10 million increase to the AULC. The impact upon adoption was dependent on the portfolio composition and credit quality, as well as historical experience, current conditions and forecasts of economic conditions and interest rates at the time of adoption. The impact to our AFS and HTM debt securities was immaterial. Model development, as well as the development of policies and procedures and, internal controls were complete at the time of adoption.
Debt Securities	Debt Securities Debt securities comprise a significant portion of our Consolidated Balance Sheets. Such securities can be classified as trading, HTM or AFS. As of September 30, 2020 and December 31, 2019, we did not hold any trading debt securities. Interest income on debt securities includes amortization of purchase premiums or accretion of discounts. Premiums and discounts on debt securities are generally amortized on the level-yield method without anticipating prepayments, except for mortgage-backed securities where prepayments are anticipated. Premiums on callable debt securities are amortized to their earliest call date. A debt security is placed on non-accrual when principal or interest becomes greater than 90 days delinquent. Interest accrued but not received for a security placed on non-accrual is reversed against interest income. Gains and losses on the sale of securities are recorded on the trade date and are determined using the specific identification method. HTM debt securities are securities that management has the positive intent and ability to hold until their maturity. Such securities are carried at amortized cost. Beginning in 2020, for certain HTM securities we have an expectation of zero expected credit losses. Based on a long history with no credit losses, high credit ratings, guarantees, and/or implied risk-free characteristics, we expect the nonpayment of our UST, Fannie Mae, Freddie Mac, FHLB, Ginnie Mae, and the SBA securities to be zero, and accordingly, have no ACL on those securities. We believe that these qualitative factors are indicators that historical credit loss information should be nominally impacted, if at all, by current conditions and reasonable and supportable forecasts. As such, we believe that without a change in these indicators, we may continue to assume zero credit losses on securities concluded to exhibit those factors. We also have a portfolio of HTM debt securities where we do not expect credit losses to be zero. This portfolio consists of high-grade municipal securities. To calculate the expected credit losses on these securities we group securities by major security type, rating and maturity and apply respective cumulative default rates from a third party data provider. The baseline credit loss estimate is adjusted using a qualitative approach to account for potential variability in probabilities of default data for current conditions and reasonable and supportable forecasts. Where available, expected credit losses take into consideration any enhancement a security has such as insurance or state aid. Debt securities that are not classified as trading or HTM are classified as AFS and are carried at fair value. AFS debt securities in unrealized loss positions are evaluated for impairment related to credit losses at least quarterly. Impairment may result from credit deterioration of the issuer or collateral underlying the security. In performing an assessment of whether any decline in fair value is due to a credit loss, all relevant information is considered at the individual security level. Beginning in 2020, for AFS debt securities in an unrealized loss position, we first determine whether we have the intent to sell, or it is more likely than not that we will be required to sell, the security before recovery of its amortized cost basis. If the criteria for intent or requirement to sell is met, the security’s amortized cost is written down to fair value and the write down is charged against the ACL with any incremental impairment reported in earnings in the Provision for Credit Losses line on the Consolidated Statements of Income. For AFS debt securities that do not meet the criteria for intent or requirement to sell, we evaluate whether the decline in fair value has resulted from credit losses or other factors. We first qualitatively evaluate each security to assess whether a potential credit loss exists. If as a result of this qualitative analysis we expect to get all of our principal back, then we conclude that the present value of expected cash flows equals or exceeds its amortized cost and no credit loss exists. If it was determined a potential credit loss exists, we compare the present value of cash flows expected to be collected with our amortized cost basis to measure its value. The credit loss is recorded through the ACL and limited to the amount the fair value is less than the amortized cost basis. We have made an accounting policy election for each major security type of AFS debt securities to adjust the effective interest rate used to discount expected cash flows to consider the timing of expected cash flows resulting from expected prepayments. Impairment for noncredit-related factors is recorded in OCI, net of income taxes. Changes in the ACL are recorded as a provision for credit loss expense. Losses are charged against the ACL when an AFS debt security is not collectible or when we believe the criteria regarding the intent or requirement to sell is met.
Loans and Leases	Loans and Leases Loans we intend to hold for the foreseeable future or until maturity or payoff are reported at amortized cost, net of the ACL. Amortized cost primarily consists of the principal balances outstanding, deferred origination fees or costs and premiums or discounts on purchased loans. Interest income on loans is computed over the term of the loans using the effective interest method. Loan origination fees or costs, premiums or discounts are deferred and amortized over the term of the loan or loan commitment period as an adjustment to the related loan yield.
Non-performing Loans	Non-performing Loans We place loans on non-accrual status and discontinue interest accruals on loans generally when principal or interest is due and has remained unpaid for a certain number of days, unless the loan is both well secured and in the process of collection. Commercial loans and leases are placed on non-accrual at 90 days, installment loans are placed on non-accrual at 120 days and residential mortgages and consumer lines of credit are generally placed on non-accrual at 180 days, though we may place a loan on non-accrual prior to these past due thresholds as warranted. When a loan is placed on non-accrual status, all unpaid accrued interest is reversed against interest income and the amortization of deferred fees and costs is suspended. Non-accrual loans may not be restored to accrual status until all delinquent principal and interest have been paid and the ultimate ability to collect the remaining principal and interest is reasonably assured. Loans are charged-off against the ACL and recoveries of amounts previously charged-off are credited to the ACL when realized. Prior to 2020, PCI loans were not classified as non-performing assets as the loans were considered to be performing. Beginning in 2020, PCI loans previously accounted for in pools are grouped with other loans with similar risk characteristics for purposes of estimating expected credit losses and non-performing classification. Troubled Debt Restructured Loans Debt restructurings or loan modifications for a borrower occur in the normal course of business and do not necessarily constitute TDRs. In general, the modification or restructuring of a debt constitutes a TDR, including reasonably expected TDR, if, for economic or legal reasons related to the borrower’s financial difficulties, we grant a concession to the borrower that we would not otherwise consider under current market conditions or once we have determined that a loan modification for a financially troubled borrower is the most appropriate strategy. Additionally, a loan designated as a TDR does not necessarily result in the automatic placement of the loan on non-accrual status. When the full collection of principal and interest is reasonably assured on a loan designated as a TDR and where the borrower would not otherwise meet the criteria for non-accrual status, we will continue to accrue interest on the loan. Prior to 2020, we did not consider a restructured acquired loan as a TDR if the loan was accounted for as a component of a pool.
Allowance for Credit Losses on Loans and Leases	Allowance for Credit Losses on Loans and Leases We estimate the ACL on loans and leases using relevant available information, from internal and external sources, relating to past events, current conditions, and reasonable and supportable forecasts under the CECL methodology effective January 1, 2020. The ACL is measured on a collective (pool) basis when similar risk characteristics exist. Our portfolio segmentation is characterized by similarities in initial measurement, risk attributes, and the manner in which we monitor and assess credit risk and is comprised of commercial real estate, commercial and industrial, commercial leases, commercial - other, direct installment, residential mortgages, indirect installment and consumer lines of credit. The ACL on loans and leases represents our current estimate of lifetime credit losses inherent in our loan portfolio at the balance sheet date. In determining the ACL, we estimate expected future losses for the loan's entire contractual term adjusted for expected prepayments when appropriate. The contractual term excludes expected extensions, renewals, and modifications. The ACL is the sum of three components: quantitative (formulaic or pooled) reserves; asset specific / individual loan reserves; and qualitative (judgmental) reserves. Quantitative Component We use a non-discounted cash flow factor-based approach to estimate expected credit losses that include component PD/LGD/EAD models as well as less complex estimation methods for smaller loan portfolios. • PD: This component model is used to estimate the likelihood that a borrower will cease making payments as agreed. The major contributors to this are the borrower credit attributes and macro-economic trends. • LGD: This component model is used to estimate the loss on a loan once a loan is in default. • EAD: Estimates the loan balance at the time the borrower stops making payments. For all term loans, an amortization based formulaic approach is used for account level EAD estimates. We calculate EAD using a portfolio specific method in each of our revolving product portfolios. Asset Specific / Individual Component Loans that do not share risk characteristics are generally evaluated on an individual basis. Loans evaluated individually are not included in the collective evaluation. We have elected to apply the practical expedient to measure expected credit losses of a collateral dependent asset using the fair value of the collateral, less any costs to sell. Individual reserves are determined as follows: • For commercial loans in default which are greater than or equal to $1.0 million, individual reserves are determined based on an analysis of the present value of the loan's expected future cash flows, the loan's observable market value, or the fair value of the collateral less costs to sell. • For commercial and consumer loans in default which are below $1.0 million, an established LGD percentage is multiplied by the loan balance and the results are aggregated for purposes of measuring specific reserve impairment. Qualitative Component The ACL also includes identified qualitative factors related to idiosyncratic risk factors, changes in current economic conditions that may not be reflected in quantitatively derived results, and other relevant factors to ensure the ACL reflects our best estimate of current expected credit losses. While our reserve methodologies strive to reflect all relevant risk factors, there continues to be uncertainty associated with, but not limited to, potential imprecision in the estimation process due to the inherent time lag of obtaining information and normal variations between estimates and actual outcomes. We provide additional reserves that are designed to provide coverage for losses attributable to such risks. The ACL also includes factors that may not be directly measured in the determination of individual or collective reserves. Such qualitative factors may include: • Lending policies and procedures, including changes in policies and underwriting standards and practices for collections, write-offs, and recoveries; • The experience, ability, and depth of lending, investment, collection, and other relevant personnel; • The quality of the institution’s credit review function; • Concentrations of credit or changes in the level of such concentration; • The effect of other external factors such as the regulatory, legal and technological environments; competition; and events such as natural disasters (e.g., pandemics); and • Forecast uncertainty and imprecision. Liability for Credit Losses on Unfunded Lending-Related Commitments The AULC, such as letters of credit, is included in other liabilities on the Consolidated Balance Sheets. Expected credit losses are estimated over the contractual period in which we are exposed to credit risk via a contractual obligation including home equity lines of credit. We do not reserve for other obligations which are unconditionally cancellable by us. The estimate includes consideration of the likelihood that funding will occur and an estimate of expected credit losses on commitments expected to be funded over its estimated useful life. Consistent with our estimation process on our loan and lease portfolio, we use a non-discounted cash flow factor-based approach to estimate expected credit losses that include component PD/LGD/EAD models as well as less complex estimation methods for smaller portfolios.
Purchased Credit Deteriorated Loans and Leases	Purchased Credit Deteriorated Loans and Leases We have purchased loans and leases, some of which have experienced more than insignificant credit deterioration since origination. Beginning in 2020, we have established criteria to assess whether a purchased financial asset, or group of assets, should be accounted for as PCD on the acquisition date. The selection of which criteria to apply, or the addition of new criteria, to a specific acquisition will be based on the facts and circumstances at the time of review, as well as the availability of information supplied by the acquiree. Generally, more-than-insignificant deterioration in credit quality since origination would include risk ratings of special mention or below, inconsistency of loan payments, non-accrual status at the time of acquisition, or loans modified in a TDR, in bankruptcy or for regulatory purposes.

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The following table illustrates the impact of the adoption of ASC 326: TABLE 1.1 January 1, 2020 (in millions) As Reported Under ASC 326 Pre-ASC 326 Adoption Impact of ASC 326 Adoption Assets: Allowance for credit losses on debt securities held-to-maturity States of the U.S. and political subdivisions (municipals) $ — $ — $ — Loans Commercial real estate $ 138 $ 60 $ 78 Commercial and industrial 65 53 12 Commercial leases 11 11 — Commercial other — 9 (9) Direct installment 24 13 11 Residential mortgages 32 22 10 Indirect installment 21 19 2 Consumer lines of credit 10 9 1 Allowance for credit losses on loans $ 301 $ 196 $ 105 Liabilities: Allowance for credit losses on off-balance sheet credit exposures $ 13 $ 3 $ 10 The following table summarizes accounting pronouncements issued by the FASB that we recently adopted. TABLE 2.1 Standard Description Financial Statements Impact Credit Losses ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments ASU 2018-19, Codification Improvements to Topic 326, Financial Instruments - Credit Losses Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments Financial Instruments-Credit Losses, (Topic 326): Targeted Transition Relief Codification Improvements to Topic 326, Financial Instruments - Credit Losses These Updates replace the current long-standing incurred loss impairment methodology with a methodology that reflects current expected credit losses (commonly referred to as CECL) for most financial assets measured at amortized cost and certain other instruments, including loans, HTM debt securities, net investments in leases and off-balance sheet credit exposures except for unconditionally cancellable commitments. CECL requires loss estimates for the remaining life of the financial asset at the time the asset is originated or acquired, considering historical experience, current conditions and reasonable and supportable forecasts. In addition, the Update will require the use of a modified AFS debt security impairment model and eliminate the current accounting for PCI loans and debt securities. On January 1, 2020, we adopted CECL using the modified retrospective method for financial assets measured at amortized cost, net investments in leases and off-balance sheet credit exposures. While these Updates change the measurement of the ACL, it does not change the credit risk of our lending portfolios or the ultimate losses in those portfolios. However, the CECL ACL methodology will produce higher volatility in the quarterly provision for credit losses than our prior reserve process. We created a cross-functional management steering group to govern implementation and the Audit and Risk Committees and the Board of Directors received regular updates. For financial assets measured at amortized cost we have implemented a new modeling platform and integrated other auxiliary models to support a calculation of expected credit losses under CECL. We have made decisions on segmentation, a reasonable and supportable forecast period, a reversion method and period and a historical loss forecast covering the remaining contractual life, adjusted for prepayments as well as other criteria. Based on our portfolio composition and forecasts of relatively stable macroeconomic conditions over the next two years at the adoption date, we recorded an overall ACL of $301 million. This reflected an increase on the originated portfolio of $55 million, primarily driven by our longer duration commercial and consumer real estate loans and a "gross-up" for PCI loans of $50 million. There is no capital impact related to the PCI loans at adoption. The impact for the adoption of CECL was a reduction to retained earnings of $51 million, which included a $10 million increase to the AULC. The impact upon adoption was dependent on the portfolio composition and credit quality, as well as historical experience, current conditions and forecasts of economic conditions and interest rates at the time of adoption. The impact to our AFS and HTM debt securities was immaterial. Model development, as well as the development of policies and procedures and, internal controls were complete at the time of adoption.

NEW ACCOUNTING STANDARDS (Table

NEW ACCOUNTING STANDARDS (Tables)	9 Months Ended
	Sep. 30, 2020
Accounting Changes and Error Corrections [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The following table illustrates the impact of the adoption of ASC 326: TABLE 1.1 January 1, 2020 (in millions) As Reported Under ASC 326 Pre-ASC 326 Adoption Impact of ASC 326 Adoption Assets: Allowance for credit losses on debt securities held-to-maturity States of the U.S. and political subdivisions (municipals) $ — $ — $ — Loans Commercial real estate $ 138 $ 60 $ 78 Commercial and industrial 65 53 12 Commercial leases 11 11 — Commercial other — 9 (9) Direct installment 24 13 11 Residential mortgages 32 22 10 Indirect installment 21 19 2 Consumer lines of credit 10 9 1 Allowance for credit losses on loans $ 301 $ 196 $ 105 Liabilities: Allowance for credit losses on off-balance sheet credit exposures $ 13 $ 3 $ 10 The following table summarizes accounting pronouncements issued by the FASB that we recently adopted. TABLE 2.1 Standard Description Financial Statements Impact Credit Losses ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments ASU 2018-19, Codification Improvements to Topic 326, Financial Instruments - Credit Losses Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments Financial Instruments-Credit Losses, (Topic 326): Targeted Transition Relief Codification Improvements to Topic 326, Financial Instruments - Credit Losses These Updates replace the current long-standing incurred loss impairment methodology with a methodology that reflects current expected credit losses (commonly referred to as CECL) for most financial assets measured at amortized cost and certain other instruments, including loans, HTM debt securities, net investments in leases and off-balance sheet credit exposures except for unconditionally cancellable commitments. CECL requires loss estimates for the remaining life of the financial asset at the time the asset is originated or acquired, considering historical experience, current conditions and reasonable and supportable forecasts. In addition, the Update will require the use of a modified AFS debt security impairment model and eliminate the current accounting for PCI loans and debt securities. On January 1, 2020, we adopted CECL using the modified retrospective method for financial assets measured at amortized cost, net investments in leases and off-balance sheet credit exposures. While these Updates change the measurement of the ACL, it does not change the credit risk of our lending portfolios or the ultimate losses in those portfolios. However, the CECL ACL methodology will produce higher volatility in the quarterly provision for credit losses than our prior reserve process. We created a cross-functional management steering group to govern implementation and the Audit and Risk Committees and the Board of Directors received regular updates. For financial assets measured at amortized cost we have implemented a new modeling platform and integrated other auxiliary models to support a calculation of expected credit losses under CECL. We have made decisions on segmentation, a reasonable and supportable forecast period, a reversion method and period and a historical loss forecast covering the remaining contractual life, adjusted for prepayments as well as other criteria. Based on our portfolio composition and forecasts of relatively stable macroeconomic conditions over the next two years at the adoption date, we recorded an overall ACL of $301 million. This reflected an increase on the originated portfolio of $55 million, primarily driven by our longer duration commercial and consumer real estate loans and a "gross-up" for PCI loans of $50 million. There is no capital impact related to the PCI loans at adoption. The impact for the adoption of CECL was a reduction to retained earnings of $51 million, which included a $10 million increase to the AULC. The impact upon adoption was dependent on the portfolio composition and credit quality, as well as historical experience, current conditions and forecasts of economic conditions and interest rates at the time of adoption. The impact to our AFS and HTM debt securities was immaterial. Model development, as well as the development of policies and procedures and, internal controls were complete at the time of adoption.

SECURITIES (Tables)

SECURITIES (Tables)	9 Months Ended
	Sep. 30, 2020
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 for the current period are as follows. There was no ACL in the AFS portfolio during the nine months ended September 30, 2020. Accrued interest receivable on AFS debt securities totaled $5.8 million at September 30, 2020 and is excluded from the estimate of credit losses and recorded 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, 2020 U.S. Treasury $ 300 $ — $ — $ 300 U.S. government agencies 161 — (1) 160 U.S. government-sponsored entities 135 2 — 137 Residential mortgage-backed securities: Agency mortgage-backed securities 1,057 39 — 1,096 Agency collateralized mortgage obligations 941 35 — 976 Commercial mortgage-backed securities 396 20 — 416 States of the U.S. and political subdivisions (municipals) 14 — — 14 Other debt securities 2 — — 2 Total debt securities AFS $ 3,006 $ 96 $ (1) $ 3,101 The amortized cost and fair value of debt securities AFS for December 31, 2019 are as follows: TABLE 3.2 (in millions) Amortized Gross Gross Fair Debt Securities AFS: December 31, 2019 U.S. government agencies $ 152 $ — $ (1) $ 151 U.S. government-sponsored entities 225 1 — 226 Residential mortgage-backed securities: Agency mortgage-backed securities 1,310 7 (3) 1,314 Agency collateralized mortgage obligations 1,234 10 (4) 1,240 Commercial mortgage-backed securities 341 6 (2) 345 States of the U.S. and political subdivisions (municipals) 11 — — 11 Other debt securities 2 — — 2 Total debt securities AFS $ 3,275 $ 24 $ (10) $ 3,289
Schedule of Amortized Cost and Fair Value of Securities Held to Maturity	The amortized cost and fair value of HTM debt securities for the current period are presented in the table below. The ACL for the HTM municipal bond portfolio was $0.05 million at September 30, 2020. Accrued interest receivable on HTM debt securities totaled $12.2 million at September 30, 2020 and is excluded from the estimate of credit losses and recorded separately in other assets in the Consolidated Balance Sheets. TABLE 3.3 (in millions) Amortized Gross Gross Fair Debt Securities HTM: September 30, 2020 U.S. Treasury $ 1 $ — $ — $ 1 U.S. government agencies 1 — — 1 U.S. government-sponsored entities 160 1 — 161 Residential mortgage-backed securities: Agency mortgage-backed securities 811 32 — 843 Agency collateralized mortgage obligations 571 19 — 590 Commercial mortgage-backed securities 278 12 — 290 States of the U.S. and political subdivisions (municipals) 1,144 42 — 1,186 Total debt securities HTM $ 2,966 $ 106 $ — $ 3,072 The amortized cost and fair value of HTM debt securities for December 31, 2019 are as follows: TABLE 3.4 (in millions) Amortized Gross Gross Fair Debt Securities HTM: December 31, 2019 U.S. Treasury $ 1 $ — $ — $ 1 U.S. government agencies 1 — — 1 U.S. government-sponsored entities 175 — — 175 Residential mortgage-backed securities: Agency mortgage-backed securities 949 8 (2) 955 Agency collateralized mortgage obligations 721 5 (6) 720 Commercial mortgage-backed securities 308 3 (2) 309 States of the U.S. and political subdivisions (municipals) 1,120 26 (2) 1,144 Total debt securities HTM $ 3,275 $ 42 $ (12) $ 3,305
Amortized Cost and Fair Value of Securities, by Contractual Maturities	As of September 30, 2020, the amortized cost and fair value of debt securities, by contractual maturities, were as follows: TABLE 3.5 Available for Sale Held to Maturity (in millions) Amortized Fair Amortized Fair Due in one year or less $ 343 $ 343 $ 142 $ 143 Due after one year but within five years 107 108 41 41 Due after five years but within ten years 69 69 144 148 Due after ten years 93 93 979 1,017 612 613 1,306 1,349 Residential mortgage-backed securities: Agency mortgage-backed securities 1,057 1,096 811 843 Agency collateralized mortgage obligations 941 976 571 590 Commercial mortgage-backed securities 396 416 278 290 Total debt securities $ 3,006 $ 3,101 $ 2,966 $ 3,072
Schedule of Securities Pledged as Collateral	Following is information relating to securities pledged: TABLE 3.6 (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 $ 5,427 $ 4,494 As collateral for short-term borrowings 390 285 Securities pledged as a percent of total securities 95.9 % 72.8 %
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 surety type and length of continuous loss position: TABLE 3.7 Less than 12 Months 12 Months or More Total (dollars in millions) # Fair Unrealized # Fair Unrealized # Fair Unrealized Debt Securities AFS September 30, 2020 U.S. Treasury 1 $ 100 $ — — $ — $ — 1 $ 100 $ — U.S. government agencies 1 13 — 17 74 (1) 18 87 (1) Residential mortgage-backed securities: Agency collateralized mortgage obligations 2 5 — — — — 2 5 — Other debt securities — — — 1 2 — 1 2 — Total 4 $ 118 $ — 18 $ 76 $ (1) 22 $ 194 $ (1) Less than 12 Months 12 Months or More Total (dollars in millions) # Fair Unrealized # Fair Unrealized # Fair Unrealized Debt Securities AFS December 31, 2019 U.S. government agencies 5 $ 48 $ — 15 $ 61 $ (1) 20 $ 109 $ (1) U.S. government-sponsored entities — — — 6 130 — 6 130 — Residential mortgage-backed securities: Agency mortgage-backed securities 13 200 (1) 24 314 (2) 37 514 (3) Agency collateralized mortgage obligations 11 323 (1) 32 205 (3) 43 528 (4) Commercial mortgage-backed securities 3 114 (2) — — — 3 114 (2) Other debt securities — — — 1 2 — 1 2 — Total temporarily impaired debt securities AFS 32 $ 685 $ (4) 78 $ 712 $ (6) 110 $ 1,397 $ (10)

LOANS AND LEASES (Tables)

LOANS AND LEASES (Tables)	9 Months Ended
	Sep. 30, 2020
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, 2020 December 31, 2019 Commercial real estate $ 9,521 $ 8,960 Commercial and industrial 7,547 5,308 Commercial leases 487 432 Other 65 21 Total commercial loans and leases 17,620 14,721 Direct installment 1,977 1,821 Residential mortgages 3,531 3,374 Indirect installment 1,219 1,922 Consumer lines of credit 1,342 1,451 Total consumer loans 8,069 8,568 Total loans and leases, net of unearned income $ 25,689 $ 23,289
Certain Information Relating to Commercial Real Estate Loans	The following table shows certain information relating to commercial real estate loans: TABLE 4.2 (dollars in millions) September 30, December 31, Commercial real estate: Percent owner-occupied 28.3 % 30.6 % Percent non-owner-occupied 71.8 69.4
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 table summarizes the designated loan rating category by loan class including term loans on an amortized cost basis by origination year: TABLE 4.4 September 30, 2020 2020 2019 2018 2017 2016 Prior Revolving Loans Amortized Cost Basis Total (in millions) COMMERCIAL Commercial Real Estate: Risk Rating: Pass $ 1,343 $ 1,810 $ 1,194 $ 1,086 $ 936 $ 2,071 $ 144 $ 8,584 Special Mention 10 31 58 74 60 166 3 402 Substandard 1 25 32 87 133 252 5 535 Total commercial real estate 1,354 1,866 1,284 1,247 1,129 2,489 152 9,521 Commercial and Industrial: Risk Rating: Pass 3,355 1,092 655 363 138 422 1,052 7,077 Special Mention 5 26 40 38 12 28 59 208 Substandard 4 31 55 40 7 46 79 262 Total commercial and industrial 3,364 1,149 750 441 157 496 1,190 7,547 Commercial Leases: Risk Rating: Pass 114 179 94 61 7 4 — 459 Special Mention — 1 5 4 1 2 — 13 Substandard 8 3 2 1 1 — — 15 Total commercial leases 122 183 101 66 9 6 — 487 Other Commercial: Risk Rating: Pass 21 — — — — 3 40 64 Substandard — — — — — 1 — 1 Total other commercial 21 — — — — 4 40 65 Total commercial 4,861 3,198 2,135 1,754 1,295 2,995 1,382 17,620 CONSUMER Direct Installment: Current 525 370 226 160 188 489 — 1,958 Past due — 1 1 1 2 14 — 19 Total direct installment 525 371 227 161 190 503 — 1,977 Residential Mortgages: Current 862 803 344 437 367 661 2 3,476 Past due 1 5 5 6 6 32 — 55 Total residential mortgages 863 808 349 443 373 693 2 3,531 Indirect Installment: Current 249 273 364 169 83 69 — 1,207 Past due — 1 2 2 1 6 — 12 Total indirect installment 249 274 366 171 84 75 — 1,219 Consumer Lines of Credit: Current 3 8 9 4 5 133 1,166 1,328 Past due — — — — 1 12 1 14 Total consumer lines of credit 3 8 9 4 6 145 1,167 1,342 Total consumer 1,640 1,461 951 779 653 1,416 1,169 8,069 Total loans and leases $ 6,501 $ 4,659 $ 3,086 $ 2,533 $ 1,948 $ 4,411 $ 2,551 $ 25,689
Summary of Credit Quality	The following tables present the December 31, 2019 summary of our commercial loans and leases by credit quality category segregated by loans and leases originated and loans acquired: TABLE 4.5 Commercial Loan and Lease Credit Quality Categories (in millions) Pass Special Substandard Doubtful Total Originated Loans and Leases December 31, 2019 Commercial real estate $ 6,821 $ 171 $ 121 $ 1 $ 7,114 Commercial and industrial 4,768 149 144 2 5,063 Commercial leases 423 3 6 — 432 Other 20 — 1 — 21 Total originated commercial loans $ 12,032 $ 323 $ 272 $ 3 $ 12,630 Loans Acquired in a Business Combination December 31, 2019 Commercial real estate $ 1,603 $ 116 $ 127 $ — $ 1,846 Commercial and industrial 201 19 25 — 245 Total commercial loans acquired in a business combination $ 1,804 $ 135 $ 152 $ — $ 2,091
Summary of Consumer Loans by Payment Status	Following is a table showing the December 31, 2019 consumer loans by payment status: TABLE 4.6 Consumer Loan Credit Quality (in millions) Performing Non- Total Originated Loans December 31, 2019 Direct installment $ 1,745 $ 13 $ 1,758 Residential mortgages 2,978 17 2,995 Indirect installment 1,919 3 1,922 Consumer lines of credit 1,086 6 1,092 Total originated consumer loans $ 7,728 $ 39 $ 7,767 Loans Acquired in a Business Combination December 31, 2019 Direct installment $ 63 $ — $ 63 Residential mortgages 379 — 379 Consumer lines of credit 358 1 359 Total consumer loans acquired in a business combination $ 800 $ 1 $ 801
Age Analysis of Past Due Loans, by Class	The following tables provide an analysis of the aging of loans by class. TABLE 4.7 (in millions) 30-89 Days > 90 Days Past Due and Still Accruing Non- Total Current Total Non-accrual with No ACL September 30, 2020 Commercial real estate $ 16 $ — $ 90 $ 106 $ 9,415 $ 9,521 $ 29 Commercial and industrial 8 — 55 63 7,484 7,547 14 Commercial leases 1 — 2 3 484 487 — Other — 1 1 2 63 65 — Total commercial loans and leases 25 1 148 174 17,446 17,620 43 Direct installment 8 2 9 19 1,958 1,977 — Residential mortgages 31 13 11 55 3,476 3,531 — Indirect installment 9 — 3 12 1,207 1,219 — Consumer lines of credit 5 2 7 14 1,328 1,342 — Total consumer loans 53 17 30 100 7,969 8,069 — Total loans and leases $ 78 $ 18 $ 178 $ 274 $ 25,415 $ 25,689 $ 43 (in millions) 30-89 Days > 90 Days Past Due and Still Accruing Non- Total Current Total Originated Loans and Leases December 31, 2019 Commercial real estate $ 10 $ — $ 26 $ 36 $ 7,078 $ 7,114 Commercial and industrial 9 — 28 37 5,026 5,063 Commercial leases 5 — 1 6 426 432 Other — — 1 1 20 21 Total commercial loans and leases 24 — 56 80 12,550 12,630 Direct installment 7 1 7 15 1,743 1,758 Residential mortgages 12 2 8 22 2,973 2,995 Indirect installment 15 1 3 19 1,903 1,922 Consumer lines of credit 5 1 3 9 1,083 1,092 Total consumer loans 39 5 21 65 7,702 7,767 Total originated loans and leases $ 63 $ 5 $ 77 $ 145 $ 20,252 $ 20,397 (in millions) 30-89 > 90 Days Past Due and Still Accruing Non- Total Current (Discount) Premium Total Loans Acquired in a Business Combination December 31, 2019 Commercial real estate $ 12 $ 28 $ 3 $ 43 $ 1,942 $ (139) $ 1,846 Commercial and industrial 2 3 — 5 259 (19) 245 Total commercial loans 14 31 3 48 2,201 (158) 2,091 Direct installment 3 — — 3 60 — 63 Residential mortgages 8 4 — 12 382 (15) 379 Consumer lines of credit 7 2 1 10 357 (8) 359 Total consumer loans 18 6 1 25 799 (23) 801 Total loans acquired in a business combination $ 32 $ 37 $ 4 $ 73 $ 3,000 $ (181) $ 2,892 (1) Prior to the adoption of CECL on January 1, 2020, loans acquired in a business combination were considered performing upon acquisition, regardless of whether the customer was contractually delinquent, if we could reasonably estimate the timing and amount of expected cash flows on such loans. In these instances, we did not consider acquired contractually delinquent loans to be non-accrual or non-performing and continued to recognize interest income on these loans using the accretion method. After the adoption of CECL on January 1, 2020, loans acquired in a business combination are considered non-accrual or non-performing when, due to credit deterioration or other factors, we determine we are no longer able to reasonably estimate the timing and amount of expected cash flows on such loans. We do not recognize interest income on loans acquired in a business combination considered non-accrual or non-performing.
Summary of Non-Performing Assets	Following is a summary of non-performing assets: TABLE 4.8 (dollars in millions) September 30, December 31, Non-accrual loans $ 178 $ 81 Troubled debt restructurings — 22 Total non-performing loans 178 103 Other real estate owned 20 26 Total non-performing assets $ 198 $ 129 Asset quality ratios: Non-performing loans / total loans and leases 0.69 % 0.44 % Non-performing assets + 90 days past due + OREO / total loans and leases + OREO 0.84 % 0.73 %
Summary of the composition of total TDRs	Following is a summary of the composition of total TDRs: TABLE 4.9 (in millions) September 30, December 31, Accruing $ 61 $ 41 Non-accrual 33 15 Total TDRs $ 94 $ 56
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 4.10 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 Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 (dollars in millions) Number Pre- Post- Number Pre- Post- Commercial real estate 4 $ — $ — 16 $ 4 $ 4 Commercial and industrial 1 — — 14 5 3 Total commercial loans 5 — — 30 9 7 Direct installment 15 1 1 47 2 2 Residential mortgages 4 1 1 14 1 1 Consumer lines of credit 7 — — 20 1 1 Total consumer loans 26 2 2 81 4 4 Total 31 $ 2 $ 2 111 $ 13 $ 11 The year-to-date items in the above tables have been adjusted for loans that have been paid off and/or sold.
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 4.11 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
Summary of Originated Troubled Debt Restructurings by Class of Loans and Leases, Payment Default	Following is a summary of originated TDRs, by class, for which there was a payment default, excluding loans that have been paid off and/or sold. TABLE 4.12 Three Months Ended Nine Months Ended (dollars in millions) Number of Recorded Number of Recorded Commercial real estate 1 $ — 5 $ 1 Commercial and industrial — — 1 — Total commercial loans 1 — 6 1 Direct installment 1 — 4 — Residential mortgages — — 1 — Consumer lines of credit 1 — 1 — Total consumer loans 2 — 6 — Total 3 $ — 12 $ 1

ALLOWANCE FOR CREDIT LOSSES O_2

ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES (Tables)	9 Months Ended
	Sep. 30, 2020
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, 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 (in millions) Balance at Charge- Recoveries Net Provision for Credit Losses ASC 326 Adoption Impact Initial ACL on PCD Loans Balance at 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 on loans and leases $ 196 $ (46) $ 13 $ (33) $ 105 $ 55 $ 50 $ 373 Following is a summary of changes in the ACL, by loan and lease class: TABLE 5.2 (in millions) Balance at Charge- Recoveries Net Provision Balance at Three Months Ended September 30, 2019 Commercial real estate $ 61 $ (1) $ — $ (1) $ (2) $ 58 Commercial and industrial 52 (3) 1 (2) 7 57 Commercial leases 9 — — — 1 10 Other 1 — — — 1 2 Total commercial loans and leases 123 (4) 1 (3) 7 127 Direct installment 13 — — — (1) 12 Residential mortgages 20 — — — 3 23 Indirect installment 18 (3) 1 (2) 2 18 Consumer lines of credit 9 — — — — 9 Total consumer loans 60 (3) 1 (2) 4 62 Total allowance for credit losses on originated loans and leases 183 (7) 2 (5) 11 189 Purchased credit-impaired loans 1 — — — — 1 Other acquired loans 4 (2) 1 (1) 1 4 Total allowance for credit losses on acquired loans 5 (2) 1 (1) 1 5 Total allowance for credit losses $ 188 $ (9) $ 3 $ (6) $ 12 $ 194 Nine Months Ended September 30, 2019 Commercial real estate $ 55 $ (3) $ 1 $ (2) $ 5 $ 58 Commercial and industrial 49 (7) 3 (4) 12 57 Commercial leases 8 — — — 2 10 Other 2 (2) — (2) 2 2 Total commercial loans and leases 114 (12) 4 (8) 21 127 Direct installment 14 (1) — (1) (1) 12 Residential mortgages 20 (1) — (1) 4 23 Indirect installment 15 (8) 3 (5) 8 18 Consumer lines of credit 10 (1) — (1) — 9 Total consumer loans 59 (11) 3 (8) 11 62 Total allowance on originated loans and leases 173 (23) 7 (16) 32 189 Purchased credit-impaired loans 1 — — — — 1 Other loans acquired in a business combination 6 (9) 2 (7) 5 4 Total allowance on loans acquired in a business combination 7 (9) 2 (7) 5 5 Total allowance for credit losses $ 180 $ (32) $ 9 $ (23) $ 37 $ 194
Summary of Individual and Collective Allowance for Credit Losses and Loan and Lease Balances by Class	Following is a summary of the individual and collective ACL and corresponding loan and lease balances by class: TABLE 5.3 Allowance for Credit Losses Loans and Leases Outstanding (in millions) Individually Collectively Loans and Individually Collectively December 31, 2019 Commercial real estate $ 2 $ 58 $ 7,114 $ 13 $ 7,101 Commercial and industrial 2 51 5,063 17 5,046 Commercial leases — 11 432 — 432 Other — 2 21 — 21 Total commercial loans and leases 4 122 12,630 30 12,600 Direct installment — 13 1,758 — 1,758 Residential mortgages — 22 2,995 — 2,995 Indirect installment — 19 1,922 — 1,922 Consumer lines of credit — 9 1,092 — 1,092 Total consumer loans — 63 7,767 — 7,767 Total $ 4 $ 185 $ 20,397 $ 30 $ 20,367 The above table excludes loans acquired in a business combination that were pooled into groups of loans for evaluating impairment.

LOAN SERVICING (Tables)

LOAN SERVICING (Tables) - Mortgage Servicing Rights [Member]	9 Months Ended
	Sep. 30, 2020
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 $ 4,626 $ 4,686 The following table summarizes activity relating to mortgage loans sold with servicing retained: TABLE 6.2 Three Months Ended Nine Months Ended (in millions) 2020 2019 2020 2019 Mortgage loans sold with servicing retained $ 466 $ 354 $ 1,142 $ 937 Pretax net gains resulting from above loan sales (1) 25 10 47 23 Mortgage servicing fees (1) 3 3 9 8 (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) 2020 2019 2020 2019 Balance at beginning of period $ 34.0 $ 38.0 $ 42.6 $ 36.8 Additions 4.5 3.5 11.0 9.8 Payoffs and curtailments (4.6) (0.5) (10.5) (1.8) (Impairment) / recovery 0.5 (0.3) (7.5) (2.9) Amortization (0.6) (1.9) (1.8) (3.1) Balance at end of period $ 33.8 $ 38.8 $ 33.8 $ 38.8 Fair value, beginning of period $ 34.0 $ 39.8 $ 45.0 $ 41.1 Fair value, end of period 33.8 40.5 33.8 40.5
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) 62.3 78.9 Constant prepayment rate (annualized) 14.5 % 10.6 % Discount rate 9.6 % 9.7 % Effect on fair value due to change in interest rates: +0.25% $ 2 $ 3 +0.50% 5 5 -0.25% (2) (3) -0.50% (3) (5)

OPERATING LEASES (Tables)

OPERATING LEASES (Tables)	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Lease, Cost	The components of lease expense were as follows: TABLE 8.1 Three Months Ended Nine Months Ended (dollars in millions) 2020 2019 2020 2019 Operating lease cost $ 7 $ 6 $ 20 $ 20 Short-term lease cost 1 1 1 1 Variable lease cost 1 1 3 3 Total lease cost $ 9 $ 8 $ 24 $ 24
Leases, Other Information	Other information related to leases is as follows: TABLE 8.2 Nine Months Ended (dollars in millions) 2020 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 19 $ 19 Right-of-use assets obtained in exchange for lease obligations: Operating leases 5 22 Weighted average remaining lease term (years): Operating leases 9.51 9.78 Weighted average discount rate: Operating leases 2.8 % 3.0 %
Lessor, Operating Lease, Payments to be Received, Maturity	Maturities of operating lease liabilities were as follows: TABLE 8.3 (in millions) September 30, 2020 $ 6 2021 24 2022 19 2023 15 2024 13 Later years 67 Total lease payments 144 Less: imputed interest (20) Present value of lease liabilities $ 124

VARIABLE INTEREST ENTITIES (Tab

VARIABLE INTEREST ENTITIES (Tables)	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Variable Interest Entities, Assets and Liabilities	The following tables provide a summary of the assets and liabilities included in our Consolidated Financial Statements, as well as the maximum exposure to losses, associated with its interests related to unconsolidated VIEs for which we hold an interest, but are not the primary beneficiary, at September 30, 2020 and December 31, 2019. TABLE 9.1 (in millions) Total Assets Total Liabilities Maximum Exposure to Loss September 30, 2020 Trust preferred securities (1) $ 1 $ 66 $ — Affordable housing tax credit partnerships 121 51 121 Other investments 32 8 32 Total $ 154 $ 125 $ 153 December 31, 2019 Trust preferred securities (1) $ 1 $ 66 $ — Affordable housing tax credit partnerships 120 60 120 Other investments 33 10 33 Total $ 154 $ 136 $ 153 (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 9.2 (in millions) September 30, December 31, Proportional amortization method investments included in other assets $ 67 $ 55 Equity method investments included in other assets 3 5 Total LIHTC investments included in other assets $ 70 $ 60 Unfunded LIHTC commitments $ 51 $ 60
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 9.3 Three Months Ended Nine Months Ended (in millions) 2020 2019 2020 2019 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 $ 2 $ 2 $ 8 $ 6 Low-income housing tax credits (3) (3) (9) (7) Other tax benefits related to tax credit investments — — (2) (1) Total provision for income taxes $ (1) $ (1) $ (3) $ (2)

BORROWINGS (Tables)

BORROWINGS (Tables)	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Summary of Short-Term Borrowings	Following is a summary of short-term borrowings: TABLE 10.1 (in millions) September 30, December 31, Securities sold under repurchase agreements $ 405 $ 278 Federal Home Loan Bank advances 1,380 2,255 Federal funds purchased — 575 Subordinated notes 114 108 Total short-term borrowings $ 1,899 $ 3,216
Summary of Long-Term Borrowings	Following is a summary of long-term borrowings: TABLE 10.2 (in millions) September 30, December 31, Federal Home Loan Bank advances $ 700 $ 935 Senior notes 298 — Subordinated notes 84 90 Junior subordinated debt 66 66 Other subordinated debt 249 249 Total long-term borrowings $ 1,397 $ 1,340
Schedule of Subordinated Borrowing	The subordinated notes are eligible for treatment as tier 2 capital for regulatory capital purposes. TABLE 10.3 (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 $ 298 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 31 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, 2020: TABLE 10.4 (dollars in millions) Trust Common Junior Stated Interest Rate F.N.B. Statutory Trust II $ 22 $ 1 $ 22 6/15/2036 1.90 % LIBOR + 165 basis points (bps) Yadkin Valley Statutory Trust I 25 1 22 12/15/2037 1.57 % LIBOR + 132 bps FNB Financial Services Capital Trust I 25 1 22 9/30/2035 1.68 % LIBOR + 146 bps Total $ 72 $ 3 $ 66

DERIVATIVE INSTRUMENTS AND HE_2

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Tables)	9 Months Ended
	Sep. 30, 2020
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 11.1 September 30, 2020 December 31, 2019 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 $ 3 $ — $ 1,655 $ 1 $ — Interest rate swaps – not designated 4,601 — 42 3,640 — 23 Total subject to master netting arrangements 6,181 3 42 5,295 1 23 Not subject to master netting arrangements: Interest rate swaps – not designated 4,601 397 — 3,640 149 1 Interest rate lock commitments – not designated 532 22 — 163 3 — Forward delivery commitments – not designated 479 1 2 195 1 1 Credit risk contracts – not designated 445 — 1 265 — — Total not subject to master netting arrangements 6,057 420 3 4,263 153 2 Total $ 12,238 $ 423 $ 45 $ 9,558 $ 154 $ 25
Summary of Amounts Reclassified from Accumulated Other Comprehensive Income (AOCI)	The following table shows amounts reclassified from AOCI: TABLE 11.2 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) 2020 2019 2020 2019 Derivatives in cash flow hedging relationships: Interest rate contracts $ (42) $ (31) Interest income (expense) $ (9) $ 2 Other income (expense) (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 11.3 Nine months ended September 30, 2020 2019 (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) $ 750 $ 31 $ 819 $ 66 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 2 (11) (1) 3 Amount of gain (loss) reclassified from AOCI into income as a — — — —
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 11.4 Nine Months Ended (in millions) Consolidated Statements of Income Location 2020 2019 Interest rate swaps Non-interest income - other $ — $ — Interest rate lock commitments Mortgage banking operations — — Forward delivery contracts Mortgage banking operations (1) (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 11.5 Amount Not Offset in the (in millions) Net Amount Financial Cash Net September 30, 2020 Derivative Assets Interest rate contracts: Designated $ 3 $ — $ 3 $ — Total $ 3 $ — $ 3 $ — Derivative Liabilities Interest rate contracts: Not designated $ 42 $ — $ 42 $ — Total $ 42 $ — $ 42 $ — December 31, 2019 Derivative Assets Interest rate contracts: Designated $ 1 $ 1 $ — $ — Total $ 1 $ 1 $ — $ — Derivative Liabilities Interest rate contracts: Not designated $ 23 $ 23 $ — $ — Total $ 23 $ 23 $ — $ —

COMMITMENTS, CREDIT RISK AND _2

COMMITMENTS, CREDIT RISK AND CONTINGENCIES (Tables)	9 Months Ended
	Sep. 30, 2020
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 12.1 (in millions) September 30, December 31, Commitments to extend credit $ 9,121 $ 8,089 Standby letters of credit 156 150

STOCK INCENTIVE PLANS (Tables)

STOCK INCENTIVE PLANS (Tables)	9 Months Ended
	Sep. 30, 2020
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 13.1 Nine Months Ended September 30, 2020 2019 Units Weighted Units Weighted Unvested units outstanding at beginning of period 2,858,357 $ 12.56 2,556,174 $ 13.51 Granted 2,004,895 5.95 1,182,197 10.94 Net adjustment due to performance 47,290 13.00 — — Vested (592,602) 14.50 (655,208) 13.15 Forfeited/expired (169,552) 13.05 (325,253) 12.72 Dividend reinvestment 173,990 6.99 80,738 11.62 Unvested units outstanding at end of period 4,322,378 9.45 2,838,648 12.54
Schedule of Certain Information Related to Restricted Stock Units	The following table provides certain information related to restricted stock units: TABLE 13.2 (in millions) Nine Months Ended 2020 2019 Stock-based compensation expense $ 13 $ 8 Tax benefit related to stock-based compensation expense 3 2 Fair value of units vested 4 7
Components of Restricted Stock Units	The components of the restricted stock units as of September 30, 2020 are as follows: TABLE 13.3 (dollars in millions) Service- Performance- Total Unvested restricted stock units 2,987,784 1,334,594 4,322,378 Unrecognized compensation expense $ 11 $ 3 $ 14 Intrinsic value $ 20 $ 9 $ 29 Weighted average remaining life (in years) 1.86 1.31 1.69

INCOME TAXES (Tables)

INCOME TAXES (Tables)	9 Months Ended
	Sep. 30, 2020
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 14.1 Three Months Ended Nine Months Ended (in millions) 2020 2019 2020 2019 Current income taxes: Federal taxes $ 16 $ (3) $ 62 $ 24 State taxes 1 — 6 3 Total current income taxes 17 (3) 68 27 Deferred income taxes: Federal taxes — 19 (24) 34 State taxes — 1 — 2 Total deferred income taxes — 20 (24) 36 Total income taxes $ 17 $ 17 $ 44 $ 63 Statutory tax rate 21.0 % 21.0 % 21.0 % 21.0 % Effective tax rate 17.0 % 14.5 % 17.0 % 17.8 %

OTHER COMPREHENSIVE INCOME (Tab

OTHER COMPREHENSIVE INCOME (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Changes in AOCI, Net of Tax, by Component	The following table presents changes in AOCI, net of tax, by component: TABLE 15.1 (in millions) Unrealized Unrealized Unrecognized Total Nine Months Ended September 30, 2020 Balance at beginning of period $ 11 $ (18) $ (58) $ (65) Other comprehensive (loss) income before reclassifications 63 (32) 1 32 Amounts reclassified from AOCI — 7 — 7 Net current period other comprehensive (loss) income 63 (25) 1 39 Balance at end of period $ 74 $ (43) $ (57) $ (26)

EARNINGS PER COMMON SHARE (Tabl

EARNINGS PER COMMON SHARE (Tables)	9 Months Ended
	Sep. 30, 2020
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 16.1 Three Months Ended Nine Months Ended ( dollars in millions, except per share data) 2020 2019 2020 2019 Net income $ 83 $ 103 $ 214 $ 292 Less: Preferred stock dividends 2 2 6 6 Net income available to common stockholders $ 81 $ 101 $ 208 $ 286 Basic weighted average common shares outstanding 323,379,720 325,031,140 323,642,925 324,875,436 Net effect of dilutive stock options, warrants and restricted stock 2,283,060 1,068,730 2,051,221 893,725 Diluted weighted average common shares outstanding 325,662,780 326,099,870 325,694,146 325,769,161 Earnings per common share: Basic $ 0.25 $ 0.31 $ 0.64 $ 0.88 Diluted $ 0.25 $ 0.31 $ 0.64 $ 0.88
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 16.2 Three Months Ended Nine Months Ended 2020 2019 2020 2019 Average shares excluded from the diluted earnings per common share calculation 44,755 1 22,263 122

CASH FLOW INFORMATION (Tables)

CASH FLOW INFORMATION (Tables)	9 Months Ended
	Sep. 30, 2020
Supplemental Cash Flow Elements [Abstract]
Summary of Supplemental Cash Flow Information	Following is a summary of supplemental cash flow information: TABLE 17.1 Nine Months Ended 2020 2019 (in millions) Interest paid on deposits and other borrowings $ 179 $ 248 Income taxes paid 34 40 Transfers of loans to other real estate owned 2 5 Loans transferred to held for sale from portfolio 508 389 Loans transferred to portfolio from held for sale — 110

BUSINESS SEGMENTS (Tables)

BUSINESS SEGMENTS (Tables)	9 Months Ended
	Sep. 30, 2020
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 18.1 (in millions) Community Wealth Insurance Parent and Consolidated 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 At or for the Three Months Ended September 30, 2019 Interest income $ 314 $ — $ — $ — $ 314 Interest expense 79 — — 5 84 Net interest income 235 — — (5) 230 Provision for credit losses 12 — — — 12 Non-interest income 65 12 5 (2) 80 Non-interest expense (1) 158 8 4 4 174 Amortization of intangibles 3 — 1 — 4 Income tax expense (benefit) 19 1 — (3) 17 Net income (loss) 108 3 — (8) 103 Total assets 34,207 29 36 57 34,329 Total intangibles 2,294 10 29 — 2,333 (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, 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 At or for the Nine Months Ended September 30, 2019 Interest income $ 940 $ — $ — $ 1 $ 941 Interest expense 236 — — 14 250 Net interest income 704 — — (13) 691 Provision for credit losses 37 — — — 37 Non-interest income 177 35 14 (6) 220 Non-interest expense (1) 462 26 12 8 508 Amortization of intangibles 10 — 1 — 11 Income tax expense (benefit) 66 2 — (5) 63 Net income (loss) 306 7 1 (22) 292 Total assets 34,207 29 36 57 34,329 Total intangibles 2,294 10 29 — 2,333 (1) Excludes amortization of intangibles, which is presented separately.

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	9 Months Ended
	Sep. 30, 2020
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 19.1 (in millions) Level 1 Level 2 Level 3 Total September 30, 2020 Assets Measured at Fair Value Debt securities available for sale U.S. Treasury $ 300 $ — $ — $ 300 U.S. government agencies — 160 — 160 U.S. government-sponsored entities — 137 — 137 Residential mortgage-backed securities: Agency mortgage-backed securities — 1,096 — 1,096 Agency collateralized mortgage obligations — 976 — 976 Commercial mortgage-backed securities — 416 — 416 States of the U.S. and political subdivisions (municipals) — 14 — 14 Other debt securities — 2 — 2 Total debt securities available for sale 300 2,801 — 3,101 Loans held for sale — 138 — 138 Derivative financial instruments Trading — 397 — 397 Not for trading — 4 22 26 Total derivative financial instruments — 401 22 423 Total assets measured at fair value on a recurring basis $ 300 $ 3,340 $ 22 $ 3,662 Liabilities Measured at Fair Value Derivative financial instruments Trading $ — $ 42 $ — $ 42 Not for trading — 3 — 3 Total derivative financial instruments — 45 — 45 Total liabilities measured at fair value on a recurring basis $ — $ 45 $ — $ 45 (in millions) Level 1 Level 2 Level 3 Total December 31, 2019 Assets Measured at Fair Value Debt securities available for sale U.S. government agencies $ — $ 151 $ — $ 151 U.S. government-sponsored entities — 226 — 226 Residential mortgage-backed securities: Agency mortgage-backed securities — 1,314 — 1,314 Agency collateralized mortgage obligations — 1,240 — 1,240 Commercial mortgage-backed securities — 345 — 345 States of the U.S. and political subdivisions (municipals) — 11 — 11 Other debt securities — 2 — 2 Total debt securities available for sale — 3,289 — 3,289 Loans held for sale — 41 — 41 Derivative financial instruments Trading — 149 — 149 Not for trading — 2 3 5 Total derivative financial instruments — 151 3 154 Total assets measured at fair value on a recurring basis $ — $ 3,481 $ 3 $ 3,484 Liabilities Measured at Fair Value Derivative financial instruments Trading $ — $ 24 $ — $ 24 Not for trading — 1 — 1 Total derivative financial instruments — 25 — 25 Total liabilities measured at fair value on a recurring basis $ — $ 25 $ — $ 25
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 19.2 (in millions) Interest Total Nine Months Ended September 30, 2020 Balance at beginning of period $ 3 $ 3 Purchases, issuances, sales and settlements: Issuances 22 22 Settlements (3) (3) Balance at end of period $ 22 $ 22 Year Ended December 31, 2019 Balance at beginning of period $ 1 $ 1 Purchases, issuances, sales and settlements: Issuances 3 3 Settlements (1) (1) Balance at end of period $ 3 $ 3
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 19.3 (in millions) Level 1 Level 2 Level 3 Total September 30, 2020 Collateral dependent loans $ — $ — $ 45 $ 45 Other real estate owned — — 9 9 Other assets - SBA servicing asset — — 3 3 Other assets - MSRs — — 34 34 December 31, 2019 Impaired loans $ — $ — $ 5 $ 5 Other real estate owned — — 4 4 Other assets - SBA servicing asset — — 3 3 Other assets - MSRs — — 30 30
Fair Values of Financial Instruments	The fair values of our financial instruments are as follows: TABLE 19.4 Fair Value Measurements (in millions) Carrying Fair Level 1 Level 2 Level 3 September 30, 2020 Financial Assets Cash and cash equivalents $ 900 $ 900 $ 900 $ — $ — Debt securities available for sale 3,101 3,101 300 2,801 — Debt securities held to maturity 2,966 3,072 — 3,072 — Net loans and leases, including loans held for sale 25,996 25,872 — 138 25,734 Loan servicing rights 37 37 — — 37 Derivative assets 423 423 — 401 22 Accrued interest receivable 90 90 90 — — Financial Liabilities Deposits 28,836 28,882 24,811 4,071 — Short-term borrowings 1,899 1,904 1,904 — — Long-term borrowings 1,397 1,379 — — 1,379 Derivative liabilities 45 45 — 45 — Accrued interest payable 14 14 14 — — December 31, 2019 Financial Assets Cash and cash equivalents $ 599 $ 599 $ 599 $ — $ — Debt securities available for sale 3,289 3,289 — 3,289 — Debt securities held to maturity 3,275 3,305 — 3,305 — Net loans and leases, including loans held for sale 23,144 22,930 — 41 22,889 Loan servicing rights 46 48 — — 48 Derivative assets 154 154 — 151 3 Accrued interest receivable 109 109 109 — — Financial Liabilities Deposits 24,786 24,797 20,058 4,739 — Short-term borrowings 3,216 3,219 3,219 — — Long-term borrowings 1,340 1,355 — — 1,355 Derivative liabilities 25 25 — 25 — Accrued interest payable 21 21 21 — —

NATURE OF OPERATIONS (Detail)

NATURE OF OPERATIONS (Detail)	9 Months Ended
	Sep. 30, 2020StateOffice
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of states, Company operating financial services | State	7
Number of banking offices | Office	355

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Detail) - USD ($) $ in Millions	Jan. 01, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' equity attributable to parent		$ 4,951	$ 4,897	$ 4,883	$ 4,820	$ 4,753	$ 4,608
Initial ACL on PCD Loans	$ 50.3	$ 50.3
Impact of ASC 326 Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' equity attributable to parent				(50)
Commercial Loan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Threshold period past due for non-accrual loans		90 days
Installment Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Threshold period past due for non-accrual loans		120 days
Residential Mortgages and Consumer Lines of Credit [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Threshold period past due for non-accrual loans		180 days
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' equity attributable to parent		$ 838	$ 796	798	$ 744	$ 683	$ 576
Retained Earnings [Member] | Impact of ASC 326 Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' equity attributable to parent				$ (50)
Retained Earnings [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' equity attributable to parent	(51)
Retained Earnings [Member] | Accounting Standards Update 2016-13 [Member] | Impact of ASC 326 Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' equity attributable to parent	$ (50.6)
Minimum [Member] | Commercial Loan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing receivable, individual reserves in default, threshold		1
Maximum [Member] | Commercial and Consumer Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing receivable, individual reserves in default, threshold		$ 1

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Impact of Adoption (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Jan. 01, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt securities held to maturity, allowance for credit losses	$ 50
Allowance for credit loss	373,000	$ 365,000	$ 196,000	$ 196,000	$ 194,000	$ 188,000	$ 180,000
Allowance for credit losses on off-balance sheet credit exposures			3,000
As Reported Under ASC 326 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			301,000
Allowance for credit losses on off-balance sheet credit exposures			13,000
Impact of ASC 326 Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			105,000
Allowance for credit losses on off-balance sheet credit exposures			10,000
States of the U.S. and Political Subdivisions (municipals) [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt securities held to maturity, allowance for credit losses	50		0
States of the U.S. and Political Subdivisions (municipals) [Member] | As Reported Under ASC 326 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt securities held to maturity, allowance for credit losses			0
States of the U.S. and Political Subdivisions (municipals) [Member] | Impact of ASC 326 Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Debt securities held to maturity, allowance for credit losses			0
Commercial Real Estate [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss	184,000	163,000	60,000	60,000
Commercial Real Estate [Member] | As Reported Under ASC 326 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			138,000
Commercial Real Estate [Member] | Impact of ASC 326 Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			78,000
Commercial and Industrial [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss	93,000	98,000	53,000	53,000
Commercial and Industrial [Member] | As Reported Under ASC 326 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			65,000
Commercial and Industrial [Member] | Impact of ASC 326 Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			12,000
Commercial Leases [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss	17,000	17,000	11,000	11,000
Commercial Leases [Member] | As Reported Under ASC 326 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			11,000
Commercial Leases [Member] | Impact of ASC 326 Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			0
Other [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss	1,000	1,000	9,000	9,000
Other [Member] | As Reported Under ASC 326 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			0
Other [Member] | Impact of ASC 326 Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			(9,000)
Direct Installment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss	24,000	25,000	13,000	13,000
Direct Installment [Member] | As Reported Under ASC 326 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			24,000
Direct Installment [Member] | Impact of ASC 326 Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			11,000
Residential Mortgages [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss	31,000	33,000	22,000	22,000
Residential Mortgages [Member] | As Reported Under ASC 326 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			32,000
Residential Mortgages [Member] | Impact of ASC 326 Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			10,000
Indirect Installment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss	12,000	17,000	19,000	19,000
Indirect Installment [Member] | As Reported Under ASC 326 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			21,000
Indirect Installment [Member] | Impact of ASC 326 Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			2,000
Consumer Lines of Credit [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss	$ 11,000	$ 11,000	9,000	$ 9,000
Consumer Lines of Credit [Member] | As Reported Under ASC 326 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			10,000
Consumer Lines of Credit [Member] | Impact of ASC 326 Adoption [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss			$ 1,000

NEW ACCOUNTING STANDARDS (Detai

NEW ACCOUNTING STANDARDS (Details) - USD ($) $ in Millions	Jan. 01, 2020	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss	$ 196	$ 373	$ 365	$ 196	$ 194	$ 188	$ 180
Financing receivable, allowance for credit loss, period increase (decrease)	105.3	177.1
Stockholders' equity attributable to parent		4,951	4,897	4,883	4,820	4,753	4,608
Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss	301
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' equity attributable to parent		$ 838	$ 796	$ 798	744	683	576
Retained Earnings [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' equity attributable to parent	(51)
Originated Loans And Leases [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss					$ 189	$ 183	$ 173
Originated Loans And Leases [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing receivable, allowance for credit loss, period increase (decrease)	55
Longer Duration Loans and Gross Up [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing receivable, allowance for credit loss, period increase (decrease)	50
Unfunded Loan Commitment [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit loss	10
Financing receivable, allowance for credit loss, period increase (decrease)	$ 10

SECURITIES - Additional Informa

SECURITIES - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2020	Jan. 01, 2020
Schedule Of Securities [Line Items]
Debt securities available for sale, allowance for credit losses	$ 0
Debt securities held to maturity, allowance for credit losses	50,000
Municipal bond portfolio, value	$ 1,200,000,000
Percentage of formal credit enhancement insurance of municipalities	63.00%
Securities, held-to-maturity, provision expense	$ 10,000
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 [Member] | Minimum [Member]
Schedule Of Securities [Line Items]
Percentage of portfolio	100.00%
Municipal Bonds [Member] | Credit Concentration Risk [Member] | General Obligation Bonds [Member] | A Rating or Better [Member]
Schedule Of Securities [Line Items]
Percentage of portfolio	99.00%
Municipal Bonds [Member] | Geographic Concentration Risk [Member] | Pennsylvania, Ohio and Maryland [Member]
Schedule Of Securities [Line Items]
Percentage of portfolio	67.00%
Available-for-sale Debt Securities [Member]
Schedule Of Securities [Line Items]
Accrued investment income receivable	$ 5,800,000
Municipal Portfolio [Member]
Schedule Of Securities [Line Items]
Debt securities held to maturity, allowance for credit losses	50,000	$ 0
Held-to-maturity Securities [Member]
Schedule Of Securities [Line Items]
Accrued investment income receivable	$ 12,200,000

SECURITIES - Amortized Cost and

SECURITIES - Amortized Cost and Fair Value of Securities Available for Sale (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 3,006	$ 3,275
Gross Unrealized Gains	96	24
Gross Unrealized Losses	(1)	(10)
Total securities available for sale, fair value	3,101	3,289
U.S. Treasury [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	300
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Total securities available for sale, fair value	300
US Government Agencies [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	161	152
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	(1)
Total securities available for sale, fair value	160	151
U.S. Government-Sponsored Entities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	135	225
Gross Unrealized Gains	2	1
Gross Unrealized Losses	0	0
Total securities available for sale, fair value	137	226
Agency Mortgage-Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,057	1,310
Gross Unrealized Gains	39	7
Gross Unrealized Losses	0	(3)
Total securities available for sale, fair value	1,096	1,314
Agency Collateralized Mortgage Obligations [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	941	1,234
Gross Unrealized Gains	35	10
Gross Unrealized Losses	0	(4)
Total securities available for sale, fair value	976	1,240
Commercial Mortgage-Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	396	341
Gross Unrealized Gains	20	6
Gross Unrealized Losses	0	(2)
Total securities available for sale, fair value	416	345
States of the U.S. and Political Subdivisions (municipals) [Member]
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	14	11
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Total securities available for sale, fair value	14	11
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
Total securities available for sale, fair value	$ 2	$ 2

SECURITIES - Amortized Cost a_2

SECURITIES - Amortized Cost and Fair Value of Securities Held to Maturity (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Investment Securities Held To Maturity [Line Items]
Amortized Cost	$ 2,966	$ 3,275
Gross Unrealized Gains	106	42
Gross Unrealized Losses	0	(12)
Fair  Value	3,072	3,305
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	160	175
Gross Unrealized Gains	1	0
Gross Unrealized Losses	0	0
Fair  Value	161	175
Agency Mortgage-Backed Securities [Member]
Investment Securities Held To Maturity [Line Items]
Amortized Cost	811	949
Gross Unrealized Gains	32	8
Gross Unrealized Losses	0	(2)
Fair  Value	843	955
Agency Collateralized Mortgage Obligations [Member]
Investment Securities Held To Maturity [Line Items]
Amortized Cost	571	721
Gross Unrealized Gains	19	5
Gross Unrealized Losses	0	(6)
Fair  Value	590	720
Commercial Mortgage-Backed Securities [Member]
Investment Securities Held To Maturity [Line Items]
Amortized Cost	278	308
Gross Unrealized Gains	12	3
Gross Unrealized Losses	0	(2)
Fair  Value	290	309
States of the U.S. and Political Subdivisions (municipals) [Member]
Investment Securities Held To Maturity [Line Items]
Amortized Cost	1,144	1,120
Gross Unrealized Gains	42	26
Gross Unrealized Losses	0	(2)
Fair  Value	$ 1,186	$ 1,144

SECURITIES - Amortized Cost a_3

SECURITIES - Amortized Cost and Fair Value of Securities, by Contractual Maturities (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Schedule Of Securities [Line Items]
Available for sale, due in one year or less, amortized cost	$ 343
Available for sale, due after one year but within five years, amortized cost	107
Available for sale, due after five years but within ten years, amortized cost	69
Available for sale, due after ten years, amortized cost	93
Available for sale, with contractual maturities, amortized cost	612
Amortized Cost	3,006	$ 3,275
Available for sale, due in one year or less, fair value	343
Available for sale, due after one year but within five years, fair value	108
Available for sale, due after five years but within ten years, fair value	69
Available for sale, due after ten years, fair value	93
Available for sale, with contractual maturities, fair value	613
Total securities available for sale, fair value	3,101	3,289
Held to maturity, due in one year or less, amortized cost	142
Held to maturity, due after one year but within five years, amortized cost	41
Held to maturity, due after five years but within ten years, amortized cost	144
Held to maturity, due after ten years, amortized cost	979
Held to maturity, with contractual maturities, amortized cost	1,306
Amortized Cost	2,966	3,275
Held to maturity, due in one year or less, fair value	143
Held to maturity, due after one year but within five years, fair value	41
Held to maturity, due after five years but within ten years, fair value	148
Held to maturity, due after ten years, fair value	1,017
Securities held to maturity, with contractual maturities, fair value	1,349
Held-to-maturity, fair value, net	3,072	3,305
Agency Mortgage-Backed Securities [Member]
Schedule Of Securities [Line Items]
Available-for-sale, amortized cost	1,057
Amortized Cost	1,057	1,310
Available for sale, fair value	1,096
Total securities available for sale, fair value	1,096	1,314
Held-to-maturity, amortized cost	811
Amortized Cost	811	949
Held-to-maturity, fair value	843
Held-to-maturity, fair value, net	843	955
Agency Collateralized Mortgage Obligations [Member]
Schedule Of Securities [Line Items]
Available-for-sale, amortized cost	941
Amortized Cost	941	1,234
Available for sale, fair value	976
Total securities available for sale, fair value	976	1,240
Held-to-maturity, amortized cost	571
Amortized Cost	571	721
Held-to-maturity, fair value	590
Held-to-maturity, fair value, net	590	720
Commercial Mortgage-Backed Securities [Member]
Schedule Of Securities [Line Items]
Available-for-sale, amortized cost	396
Amortized Cost	396	341
Available for sale, fair value	416
Total securities available for sale, fair value	416	345
Held-to-maturity, amortized cost	278
Amortized Cost	278	308
Held-to-maturity, fair value	290
Held-to-maturity, fair value, net	$ 290	$ 309

SECURITIES - Schedule of Securi

SECURITIES - Schedule of Securities Pledged as Collateral (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Securities pledged (carrying value), to secure public deposits, trust deposits and for other purposes as required by law	$ 5,427	$ 4,494
Securities pledged (carrying value), as collateral for short-term borrowings	$ 390	$ 285
Securities pledged as a percent of total securities	95.90%	72.80%

SECURITIES - Fair Values and Un

SECURITIES - Fair Values and Unrealized Losses of Impaired Securities, by Length of Impairment (Detail) $ in Millions	Sep. 30, 2020USD ($)Security	Dec. 31, 2019USD ($)Security
Schedule Of Securities [Line Items]
Number of temporarily impaired available for sale securities, Less than 1 year | Security	4	32
Number of temporarily impaired available for sale securities, Greater than 1 year | Security	18	78
Number of temporarily impaired available for sale securities | Security	22	110
Temporarily impaired securities available for sale, less than 12 months, fair value	$ 118	$ 685
Temporarily impaired securities available for sale, 12 months or more, fair value	76	712
Temporarily impaired securities available for sale, fair value, total	194	1,397
Temporarily impaired securities available for sale, less than 12 months, unrealized losses	0	(4)
Temporarily impaired securities available for sale, 12 months or more, unrealized losses	(1)	(6)
Temporarily impaired securities available for sale, unrealized losses, total	$ (1)	$ (10)
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 | Security	1
Temporarily impaired securities available for sale, less than 12 months, fair value	$ 100
Temporarily impaired securities available for sale, 12 months or more, fair value	0
Temporarily impaired securities available for sale, fair value, total	100
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	1	5
Number of temporarily impaired available for sale securities, Greater than 1 year | Security	17	15
Number of temporarily impaired available for sale securities | Security	18	20
Temporarily impaired securities available for sale, less than 12 months, fair value	$ 13	$ 48
Temporarily impaired securities available for sale, 12 months or more, fair value	74	61
Temporarily impaired securities available for sale, fair value, total	87	109
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	(1)	(1)
Temporarily impaired securities available for sale, unrealized losses, total	$ (1)	$ (1)
U.S. Government-Sponsored Entities [Member]
Schedule Of Securities [Line Items]
Number of temporarily impaired available for sale securities, Less than 1 year | Security		0
Number of temporarily impaired available for sale securities, Greater than 1 year | Security		6
Number of temporarily impaired available for sale securities | Security		6
Temporarily impaired securities available for sale, less than 12 months, fair value		$ 0
Temporarily impaired securities available for sale, 12 months or more, fair value		130
Temporarily impaired securities available for sale, fair value, total		130
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
Agency Mortgage-Backed Securities [Member]
Schedule Of Securities [Line Items]
Number of temporarily impaired available for sale securities, Less than 1 year | Security		13
Number of temporarily impaired available for sale securities, Greater than 1 year | Security		24
Number of temporarily impaired available for sale securities | Security		37
Temporarily impaired securities available for sale, less than 12 months, fair value		$ 200
Temporarily impaired securities available for sale, 12 months or more, fair value		314
Temporarily impaired securities available for sale, fair value, total		514
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		(2)
Temporarily impaired securities available for sale, unrealized losses, total		$ (3)
Agency Collateralized Mortgage Obligations [Member]
Schedule Of Securities [Line Items]
Number of temporarily impaired available for sale securities, Less than 1 year | Security	2	11
Number of temporarily impaired available for sale securities, Greater than 1 year | Security	0	32
Number of temporarily impaired available for sale securities | Security	2	43
Temporarily impaired securities available for sale, less than 12 months, fair value	$ 5	$ 323
Temporarily impaired securities available for sale, 12 months or more, fair value	0	205
Temporarily impaired securities available for sale, fair value, total	5	528
Temporarily impaired securities available for sale, less than 12 months, unrealized losses	0	(1)
Temporarily impaired securities available for sale, 12 months or more, unrealized losses	0	(3)
Temporarily impaired securities available for sale, unrealized losses, total	$ 0	$ (4)
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 | Security		3
Temporarily impaired securities available for sale, less than 12 months, fair value		$ 114
Temporarily impaired securities available for sale, 12 months or more, fair value		0
Temporarily impaired securities available for sale, fair value, total		114
Temporarily impaired securities available for sale, less than 12 months, unrealized losses		(2)
Temporarily impaired securities available for sale, 12 months or more, unrealized losses		0
Temporarily impaired securities available for sale, unrealized losses, total		$ (2)
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 | 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 (Detail) $ in Millions	Apr. 24, 2020USD ($)	Jan. 01, 2020USD ($)	Sep. 30, 2020USD ($)State	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)	Jun. 30, 2020USD ($)	Jun. 30, 2019USD ($)	Dec. 31, 2018USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accrued interest receivable			$ 64.5
Purchased with credit deterioration included with allowance for credit losses, amount		$ 50.3	50.3
Purchased with credit deterioration, discount			$ 110
Number of states, Company operating financial services | State			7
Transfer of indirect installment loans to loans held for sale			$ 508	$ 389
Allocation balance	$ 349,000
Additional authorized amount	$ 320,000
Payment deferral period with forgiveness determination	10 months
Loans granted short-term modification due to COVID-19			792
Restructured loans returned to performing status			6.9
Total loan on allowance		$ 196	373	$ 194	$ 196	$ 365	$ 188	$ 180
Pooled reserves for all other classes of loans			$ 4.6		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]
Fixed interest rate	1.00%
Term	2 years
Guaranteed percentage	100.00%
SBA-Guaranteed Loan Servicing [Member] | Minimum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Processing fee paid by the SBA	1.00%
SBA-Guaranteed Loan Servicing [Member] | Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Processing fee paid by the SBA	5.00%
Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value of OREO through foreclosure			$ 2.9		3.3
Mortgage loans on real estate, foreclosure			10.7		9.2
Paycheck Protection Program Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans to customers			2,500
Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, collateral dependent			112
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
Total Commercial Loans and Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loan on allowance			295		133	$ 279
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			1.6
Total Commercial Loans and Leases [Member] | Specific Reserves for Commercial Troubled Debt Restructurings [Member] | Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loan on allowance					0.5
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			$ 3.4		$ 0.8

LOANS AND LEASES - Net of Unear

LOANS AND LEASES - Net of Unearned Income (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	$ 25,689	$ 23,289
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	9,521	8,960
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	7,547	5,308
Commercial Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	487	432
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	65	21
Total Commercial Loans and Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	17,620	14,721
Direct Installment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	1,977	1,821
Residential Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	3,531	3,374
Indirect Installment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	1,219	1,922
Consumer Lines of Credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	1,342	1,451
Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amortized cost loans and leases, carrying amount	$ 8,069	$ 8,568

LOANS AND LEASES - Commercial R

LOANS AND LEASES - Commercial Real Estate Loans (Detail) - Loan Portfolio Diversification Risk [Member] - Commercial Real Estate Loans [Member]	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Owner-Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Percent of total loans and leases	28.30%	30.60%
Non-Owner-Occupied [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Percent of total loans and leases	71.80%	69.40%

LOANS AND LEASES - Origination

LOANS AND LEASES - Origination Year (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 6,501
2019	4,659
2018	3,086
2017	2,533
2016	1,948
Prior	4,411
Revolving Loans Amortized Cost Basis	2,551
Total Loans and Leases	25,689	$ 23,289
Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,354
2019	1,866
2018	1,284
2017	1,247
2016	1,129
Prior	2,489
Revolving Loans Amortized Cost Basis	152
Total Loans and Leases	9,521
Commercial Real Estate [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,343
2019	1,810
2018	1,194
2017	1,086
2016	936
Prior	2,071
Revolving Loans Amortized Cost Basis	144
Total Loans and Leases	8,584
Commercial Real Estate [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	10
2019	31
2018	58
2017	74
2016	60
Prior	166
Revolving Loans Amortized Cost Basis	3
Total Loans and Leases	402
Commercial Real Estate [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1
2019	25
2018	32
2017	87
2016	133
Prior	252
Revolving Loans Amortized Cost Basis	5
Total Loans and Leases	535
Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,364
2019	1,149
2018	750
2017	441
2016	157
Prior	496
Revolving Loans Amortized Cost Basis	1,190
Total Loans and Leases	7,547	5,308
Commercial and Industrial [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3,355
2019	1,092
2018	655
2017	363
2016	138
Prior	422
Revolving Loans Amortized Cost Basis	1,052
Total Loans and Leases	7,077
Commercial and Industrial [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	5
2019	26
2018	40
2017	38
2016	12
Prior	28
Revolving Loans Amortized Cost Basis	59
Total Loans and Leases	208
Commercial and Industrial [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	4
2019	31
2018	55
2017	40
2016	7
Prior	46
Revolving Loans Amortized Cost Basis	79
Total Loans and Leases	262
Commercial Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	122
2019	183
2018	101
2017	66
2016	9
Prior	6
Revolving Loans Amortized Cost Basis	0
Total Loans and Leases	487	432
Commercial Leases [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	114
2019	179
2018	94
2017	61
2016	7
Prior	4
Revolving Loans Amortized Cost Basis	0
Total Loans and Leases	459
Commercial Leases [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	1
2018	5
2017	4
2016	1
Prior	2
Revolving Loans Amortized Cost Basis	0
Total Loans and Leases	13
Commercial Leases [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	8
2019	3
2018	2
2017	1
2016	1
Prior	0
Revolving Loans Amortized Cost Basis	0
Total Loans and Leases	15
Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	21
2019	0
2018	0
2017	0
2016	0
Prior	4
Revolving Loans Amortized Cost Basis	40
Total Loans and Leases	65	21
Other [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	21
2019	0
2018	0
2017	0
2016	0
Prior	3
Revolving Loans Amortized Cost Basis	40
Total Loans and Leases	64
Other [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	1
Revolving Loans Amortized Cost Basis	0
Total Loans and Leases	1
Total Commercial Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	4,861
2019	3,198
2018	2,135
2017	1,754
2016	1,295
Prior	2,995
Revolving Loans Amortized Cost Basis	1,382
Total Loans and Leases	17,620	14,721
Direct Installment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	525
2019	371
2018	227
2017	161
2016	190
Prior	503
Revolving Loans Amortized Cost Basis	0
Total Loans and Leases	1,977	1,821
Direct Installment [Member] | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	525
2019	370
2018	226
2017	160
2016	188
Prior	489
Revolving Loans Amortized Cost Basis	0
Total Loans and Leases	1,958
Direct Installment [Member] | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	1
2018	1
2017	1
2016	2
Prior	14
Revolving Loans Amortized Cost Basis	0
Total Loans and Leases	19
Residential Mortgages [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	863
2019	808
2018	349
2017	443
2016	373
Prior	693
Revolving Loans Amortized Cost Basis	2
Total Loans and Leases	3,531	3,374
Residential Mortgages [Member] | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	862
2019	803
2018	344
2017	437
2016	367
Prior	661
Revolving Loans Amortized Cost Basis	2
Total Loans and Leases	3,476
Residential Mortgages [Member] | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1
2019	5
2018	5
2017	6
2016	6
Prior	32
Revolving Loans Amortized Cost Basis	0
Total Loans and Leases	55
Indirect Installment [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	249
2019	274
2018	366
2017	171
2016	84
Prior	75
Revolving Loans Amortized Cost Basis	0
Total Loans and Leases	1,219	1,922
Indirect Installment [Member] | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	249
2019	273
2018	364
2017	169
2016	83
Prior	69
Revolving Loans Amortized Cost Basis	0
Total Loans and Leases	1,207
Indirect Installment [Member] | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	1
2018	2
2017	2
2016	1
Prior	6
Revolving Loans Amortized Cost Basis	0
Total Loans and Leases	12
Consumer Lines of Credit [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3
2019	8
2018	9
2017	4
2016	6
Prior	145
Revolving Loans Amortized Cost Basis	1,167
Total Loans and Leases	1,342	1,451
Consumer Lines of Credit [Member] | Current [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	3
2019	8
2018	9
2017	4
2016	5
Prior	133
Revolving Loans Amortized Cost Basis	1,166
Total Loans and Leases	1,328
Consumer Lines of Credit [Member] | Past Due [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	1
Prior	12
Revolving Loans Amortized Cost Basis	1
Total Loans and Leases	14
Consumer Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
2020	1,640
2019	1,461
2018	951
2017	779
2016	653
Prior	1,416
Revolving Loans Amortized Cost Basis	1,169
Total Loans and Leases	$ 8,069	$ 8,568

LOANS AND LEASES - Commercial L

LOANS AND LEASES - Commercial Loans and Leases by Credit Quality (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount	$ 25,689	$ 23,289
Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount	9,521	8,960
Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount	7,547	5,308
Commercial Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount	487	432
Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount	65	21
Total Commercial Loans and Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount	17,620	14,721
Originated Loans And Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		20,397
Originated Loans And Leases [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		7,114
Originated Loans And Leases [Member] | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		5,063
Originated Loans And Leases [Member] | Commercial Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		432
Originated Loans And Leases [Member] | Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		21
Originated Loans And Leases [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		12,630
Acquired Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		2,892
Acquired Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		1,846
Acquired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		245
Acquired Loans [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		2,091
Pass [Member] | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount	7,077
Pass [Member] | Commercial Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount	459
Pass [Member] | Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount	64
Pass [Member] | Originated Loans And Leases [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		6,821
Pass [Member] | Originated Loans And Leases [Member] | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		4,768
Pass [Member] | Originated Loans And Leases [Member] | Commercial Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		423
Pass [Member] | Originated Loans And Leases [Member] | Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		20
Pass [Member] | Originated Loans And Leases [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		12,032
Pass [Member] | Acquired Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		1,603
Pass [Member] | Acquired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		201
Pass [Member] | Acquired Loans [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		1,804
Special Mention [Member] | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount	208
Special Mention [Member] | Commercial Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount	13
Special Mention [Member] | Originated Loans And Leases [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		171
Special Mention [Member] | Originated Loans And Leases [Member] | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		149
Special Mention [Member] | Originated Loans And Leases [Member] | Commercial Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		3
Special Mention [Member] | Originated Loans And Leases [Member] | Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		0
Special Mention [Member] | Originated Loans And Leases [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		323
Special Mention [Member] | Acquired Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		116
Special Mention [Member] | Acquired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		19
Special Mention [Member] | Acquired Loans [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		135
Substandard [Member] | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount	262
Substandard [Member] | Commercial Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount	15
Substandard [Member] | Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount	$ 1
Substandard [Member] | Originated Loans And Leases [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		121
Substandard [Member] | Originated Loans And Leases [Member] | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		144
Substandard [Member] | Originated Loans And Leases [Member] | Commercial Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		6
Substandard [Member] | Originated Loans And Leases [Member] | Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		1
Substandard [Member] | Originated Loans And Leases [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		272
Substandard [Member] | Acquired Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		127
Substandard [Member] | Acquired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		25
Substandard [Member] | Acquired Loans [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		152
Doubtful [Member] | Originated Loans And Leases [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		1
Doubtful [Member] | Originated Loans And Leases [Member] | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		2
Doubtful [Member] | Originated Loans And Leases [Member] | Commercial Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		0
Doubtful [Member] | Originated Loans And Leases [Member] | Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		0
Doubtful [Member] | Originated Loans And Leases [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		3
Doubtful [Member] | Acquired Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		0
Doubtful [Member] | Acquired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		0
Doubtful [Member] | Acquired Loans [Member] | Total Commercial Loans and Leases [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Amortized cost loans and leases, carrying amount		$ 0

LOANS AND LEASES - Consumer Loa

LOANS AND LEASES - Consumer Loans by Payment Status (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount	$ 25,689	$ 23,289
Direct Installment [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount	1,977	1,821
Residential Mortgages [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount	3,531	3,374
Indirect Installment [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount	$ 1,219	1,922
Originated Loans And Leases [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		20,397
Originated Loans And Leases [Member] | Direct Installment [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		1,758
Originated Loans And Leases [Member] | Residential Mortgages [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		2,995
Originated Loans And Leases [Member] | Indirect Installment [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		1,922
Acquired Loans [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		2,892
Acquired Loans [Member] | Direct Installment [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		63
Acquired Loans [Member] | Residential Mortgages [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		379
Consumer Loan [Member] | Originated Loans And Leases [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		7,767
Consumer Loan [Member] | Originated Loans And Leases [Member] | Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		7,728
Consumer Loan [Member] | Originated Loans And Leases [Member] | Non-Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		39
Consumer Loan [Member] | Originated Loans And Leases [Member] | Direct Installment [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		1,758
Consumer Loan [Member] | Originated Loans And Leases [Member] | Direct Installment [Member] | Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		1,745
Consumer Loan [Member] | Originated Loans And Leases [Member] | Direct Installment [Member] | Non-Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		13
Consumer Loan [Member] | Originated Loans And Leases [Member] | Residential Mortgages [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		2,995
Consumer Loan [Member] | Originated Loans And Leases [Member] | Residential Mortgages [Member] | Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		2,978
Consumer Loan [Member] | Originated Loans And Leases [Member] | Residential Mortgages [Member] | Non-Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		17
Consumer Loan [Member] | Originated Loans And Leases [Member] | Indirect Installment [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		1,922
Consumer Loan [Member] | Originated Loans And Leases [Member] | Indirect Installment [Member] | Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		1,919
Consumer Loan [Member] | Originated Loans And Leases [Member] | Indirect Installment [Member] | Non-Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		3
Consumer Loan [Member] | Originated Loans And Leases [Member] | Consumer Lines of Credit [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		1,092
Consumer Loan [Member] | Originated Loans And Leases [Member] | Consumer Lines of Credit [Member] | Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		1,086
Consumer Loan [Member] | Originated Loans And Leases [Member] | Consumer Lines of Credit [Member] | Non-Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		6
Consumer Loan [Member] | Acquired Loans [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		801
Consumer Loan [Member] | Acquired Loans [Member] | Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		800
Consumer Loan [Member] | Acquired Loans [Member] | Non-Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		1
Consumer Loan [Member] | Acquired Loans [Member] | Direct Installment [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		63
Consumer Loan [Member] | Acquired Loans [Member] | Direct Installment [Member] | Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		63
Consumer Loan [Member] | Acquired Loans [Member] | Direct Installment [Member] | Non-Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		0
Consumer Loan [Member] | Acquired Loans [Member] | Residential Mortgages [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		379
Consumer Loan [Member] | Acquired Loans [Member] | Residential Mortgages [Member] | Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		379
Consumer Loan [Member] | Acquired Loans [Member] | Residential Mortgages [Member] | Non-Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		0
Consumer Loan [Member] | Acquired Loans [Member] | Consumer Lines of Credit [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		359
Consumer Loan [Member] | Acquired Loans [Member] | Consumer Lines of Credit [Member] | Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		358
Consumer Loan [Member] | Acquired Loans [Member] | Consumer Lines of Credit [Member] | Non-Performing [Member]
Credit Quality [Line Items]
Amortized cost loans and leases, carrying amount		$ 1

LOANS AND LEASES - Age Analysis

LOANS AND LEASES - Age Analysis of Past Due Loans (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	$ 25,689	$ 23,289
Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	9,521	8,960
Commercial and Industrial [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	7,547	5,308
Commercial Leases [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	487	432
Other [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	65	21
Total Commercial Loans [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	17,620	14,721
Direct Installment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,977	1,821
Residential Mortgages [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	3,531	3,374
Indirect Installment [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,219	1,922
Consumer Lines of Credit [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,342	1,451
Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	8,069	8,568
Loans and Leases [Member]
Financing Receivable, Past Due [Line Items]
Past Due	274
Non-accrual loans	178
Current	25,415
Total Loans and Leases	25,689
Non-accrual with No ACL	43
Loans and Leases [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due	78
Loans and Leases [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due	18
Loans and Leases [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Past Due	106
Non-accrual loans	90
Current	9,415
Total Loans and Leases	9,521
Non-accrual with No ACL	29
Loans and Leases [Member] | Commercial Real Estate [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due	16
Loans and Leases [Member] | Commercial Real Estate [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due	0
Loans and Leases [Member] | Commercial and Industrial [Member]
Financing Receivable, Past Due [Line Items]
Past Due	63
Non-accrual loans	55
Current	7,484
Total Loans and Leases	7,547
Non-accrual with No ACL	14
Loans and Leases [Member] | Commercial and Industrial [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due	8
Loans and Leases [Member] | Commercial and Industrial [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due	0
Loans and Leases [Member] | Commercial Leases [Member]
Financing Receivable, Past Due [Line Items]
Past Due	3
Non-accrual loans	2
Current	484
Total Loans and Leases	487
Non-accrual with No ACL	0
Loans and Leases [Member] | Commercial Leases [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due	1
Loans and Leases [Member] | Commercial Leases [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due	0
Loans and Leases [Member] | Other [Member]
Financing Receivable, Past Due [Line Items]
Past Due	2
Non-accrual loans	1
Current	63
Total Loans and Leases	65
Non-accrual with No ACL	0
Loans and Leases [Member] | Other [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due	0
Loans and Leases [Member] | Other [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due	1
Loans and Leases [Member] | Total Commercial Loans [Member]
Financing Receivable, Past Due [Line Items]
Past Due	174
Non-accrual loans	148
Current	17,446
Total Loans and Leases	17,620
Non-accrual with No ACL	43
Loans and Leases [Member] | Total Commercial Loans [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due	25
Loans and Leases [Member] | Total Commercial Loans [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due	1
Loans and Leases [Member] | Direct Installment [Member]
Financing Receivable, Past Due [Line Items]
Past Due	19
Non-accrual loans	9
Current	1,958
Total Loans and Leases	1,977
Non-accrual with No ACL	0
Loans and Leases [Member] | Direct Installment [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due	8
Loans and Leases [Member] | Direct Installment [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due	2
Loans and Leases [Member] | Residential Mortgages [Member]
Financing Receivable, Past Due [Line Items]
Past Due	55
Non-accrual loans	11
Current	3,476
Total Loans and Leases	3,531
Non-accrual with No ACL	0
Loans and Leases [Member] | Residential Mortgages [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due	31
Loans and Leases [Member] | Residential Mortgages [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due	13
Loans and Leases [Member] | Indirect Installment [Member]
Financing Receivable, Past Due [Line Items]
Past Due	12
Non-accrual loans	3
Current	1,207
Total Loans and Leases	1,219
Non-accrual with No ACL	0
Loans and Leases [Member] | Indirect Installment [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due	9
Loans and Leases [Member] | Indirect Installment [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due	0
Loans and Leases [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Past Due [Line Items]
Past Due	14
Non-accrual loans	7
Current	1,328
Total Loans and Leases	1,342
Non-accrual with No ACL	0
Loans and Leases [Member] | Consumer Lines of Credit [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due	5
Loans and Leases [Member] | Consumer Lines of Credit [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due	2
Loans and Leases [Member] | Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Past Due	100
Non-accrual loans	30
Current	7,969
Total Loans and Leases	8,069
Non-accrual with No ACL	0
Loans and Leases [Member] | Consumer Loan [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due	53
Loans and Leases [Member] | Consumer Loan [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due	$ 17
Originated Loans And Leases [Member]
Financing Receivable, Past Due [Line Items]
Past Due		145
Non-accrual loans		77
Current		20,252
Total Loans and Leases		20,397
Originated Loans And Leases [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		63
Originated Loans And Leases [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		5
Originated Loans And Leases [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Past Due		36
Non-accrual loans		26
Current		7,078
Total Loans and Leases		7,114
Originated Loans And Leases [Member] | Commercial Real Estate [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		10
Originated Loans And Leases [Member] | Commercial Real Estate [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		0
Originated Loans And Leases [Member] | Commercial and Industrial [Member]
Financing Receivable, Past Due [Line Items]
Past Due		37
Non-accrual loans		28
Current		5,026
Total Loans and Leases		5,063
Originated Loans And Leases [Member] | Commercial and Industrial [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		9
Originated Loans And Leases [Member] | Commercial and Industrial [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		0
Originated Loans And Leases [Member] | Commercial Leases [Member]
Financing Receivable, Past Due [Line Items]
Past Due		6
Non-accrual loans		1
Current		426
Total Loans and Leases		432
Originated Loans And Leases [Member] | Commercial Leases [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		5
Originated Loans And Leases [Member] | Commercial Leases [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		0
Originated Loans And Leases [Member] | Other [Member]
Financing Receivable, Past Due [Line Items]
Past Due		1
Non-accrual loans		1
Current		20
Total Loans and Leases		21
Originated Loans And Leases [Member] | Other [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		0
Originated Loans And Leases [Member] | Other [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		0
Originated Loans And Leases [Member] | Total Commercial Loans [Member]
Financing Receivable, Past Due [Line Items]
Past Due		80
Non-accrual loans		56
Current		12,550
Total Loans and Leases		12,630
Originated Loans And Leases [Member] | Total Commercial Loans [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		24
Originated Loans And Leases [Member] | Total Commercial Loans [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		0
Originated Loans And Leases [Member] | Direct Installment [Member]
Financing Receivable, Past Due [Line Items]
Past Due		15
Non-accrual loans		7
Current		1,743
Total Loans and Leases		1,758
Originated Loans And Leases [Member] | Direct Installment [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		7
Originated Loans And Leases [Member] | Direct Installment [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		1
Originated Loans And Leases [Member] | Residential Mortgages [Member]
Financing Receivable, Past Due [Line Items]
Past Due		22
Non-accrual loans		8
Current		2,973
Total Loans and Leases		2,995
Originated Loans And Leases [Member] | Residential Mortgages [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		12
Originated Loans And Leases [Member] | Residential Mortgages [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		2
Originated Loans And Leases [Member] | Indirect Installment [Member]
Financing Receivable, Past Due [Line Items]
Past Due		19
Non-accrual loans		3
Current		1,903
Total Loans and Leases		1,922
Originated Loans And Leases [Member] | Indirect Installment [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		15
Originated Loans And Leases [Member] | Indirect Installment [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		1
Originated Loans And Leases [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Past Due [Line Items]
Past Due		9
Non-accrual loans		3
Current		1,083
Total Loans and Leases		1,092
Originated Loans And Leases [Member] | Consumer Lines of Credit [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		5
Originated Loans And Leases [Member] | Consumer Lines of Credit [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		1
Originated Loans And Leases [Member] | Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Past Due		65
Non-accrual loans		21
Current		7,702
Total Loans and Leases		7,767
Originated Loans And Leases [Member] | Consumer Loan [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		39
Originated Loans And Leases [Member] | Consumer Loan [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		5
Acquired Loans [Member]
Financing Receivable, Past Due [Line Items]
Past Due		73
Non-accrual loans		4
Current		3,000
(Discount) Premium		(181)
Total Loans and Leases		2,892
Acquired Loans [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		32
Acquired Loans [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		37
Acquired Loans [Member] | Commercial Real Estate [Member]
Financing Receivable, Past Due [Line Items]
Past Due		43
Non-accrual loans		3
Current		1,942
(Discount) Premium		(139)
Total Loans and Leases		1,846
Acquired Loans [Member] | Commercial Real Estate [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		12
Acquired Loans [Member] | Commercial Real Estate [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		28
Acquired Loans [Member] | Commercial and Industrial [Member]
Financing Receivable, Past Due [Line Items]
Past Due		5
Non-accrual loans		0
Current		259
(Discount) Premium		(19)
Total Loans and Leases		245
Acquired Loans [Member] | Commercial and Industrial [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		2
Acquired Loans [Member] | Commercial and Industrial [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		3
Acquired Loans [Member] | Total Commercial Loans [Member]
Financing Receivable, Past Due [Line Items]
Past Due		48
Non-accrual loans		3
Current		2,201
(Discount) Premium		(158)
Total Loans and Leases		2,091
Acquired Loans [Member] | Total Commercial Loans [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		14
Acquired Loans [Member] | Total Commercial Loans [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		31
Acquired Loans [Member] | Direct Installment [Member]
Financing Receivable, Past Due [Line Items]
Past Due		3
Non-accrual loans		0
Current		60
(Discount) Premium		0
Total Loans and Leases		63
Acquired Loans [Member] | Direct Installment [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		3
Acquired Loans [Member] | Direct Installment [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		0
Acquired Loans [Member] | Residential Mortgages [Member]
Financing Receivable, Past Due [Line Items]
Past Due		12
Non-accrual loans		0
Current		382
(Discount) Premium		(15)
Total Loans and Leases		379
Acquired Loans [Member] | Residential Mortgages [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		8
Acquired Loans [Member] | Residential Mortgages [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		4
Acquired Loans [Member] | Consumer Lines of Credit [Member]
Financing Receivable, Past Due [Line Items]
Past Due		10
Non-accrual loans		1
Current		357
(Discount) Premium		(8)
Total Loans and Leases		359
Acquired Loans [Member] | Consumer Lines of Credit [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		7
Acquired Loans [Member] | Consumer Lines of Credit [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		2
Acquired Loans [Member] | Consumer Loan [Member]
Financing Receivable, Past Due [Line Items]
Past Due		25
Non-accrual loans		1
Current		799
(Discount) Premium		(23)
Total Loans and Leases		801
Acquired Loans [Member] | Consumer Loan [Member] | 30-89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Past Due		18
Acquired Loans [Member] | Consumer Loan [Member] | Equal to Greater than 90 Days Past Due and Still Accruing [Member]
Financing Receivable, Past Due [Line Items]
Past Due		$ 6

LOANS AND LEASES - Non-Performi

LOANS AND LEASES - Non-Performing Assets (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructurings	$ 94	$ 56
Non-Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	178	81
Troubled debt restructurings	0	22
Total non-performing loans	178	103
Other real estate owned	20	26
Non Performing Assets	$ 198	$ 129
Non-performing loans / total loans and leases	0.69%	0.44%
Non-performing assets + 90 days past due + OREO / total loans and leases + OREO	0.84%	0.73%
Past due	90 days	90 days

LOANS AND LEASES - Summary of P

LOANS AND LEASES - Summary of Payment Status of TDRs (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	$ 94	$ 56
Performing [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	61	41
Non-Accrual [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	$ 33	$ 15

LOANS AND LEASES - Troubled Deb

LOANS AND LEASES - Troubled Debt Restructurings (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)Contract	Sep. 30, 2019USD ($)Contract	Sep. 30, 2020USD ($)Contract	Sep. 30, 2019USD ($)Contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	36	31	147	111
Pre- Modification Outstanding Recorded Investment	$ 4	$ 2	$ 18	$ 13
Post- Modification Outstanding Recorded Investment	$ 4	$ 2	$ 14	$ 11
Total Commercial Loans and Leases [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	11	5	43	30
Pre- Modification Outstanding Recorded Investment	$ 2	$ 0	$ 11	$ 9
Post- Modification Outstanding Recorded Investment	$ 2	$ 0	$ 8	$ 7
Commercial Real Estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	7	4	23	16
Pre- Modification Outstanding Recorded Investment	$ 2	$ 0	$ 8	$ 4
Post- Modification Outstanding Recorded Investment	$ 2	$ 0	$ 6	$ 4
Commercial and Industrial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	4	1	19	14
Pre- Modification Outstanding Recorded Investment	$ 0	$ 0	$ 3	$ 5
Post- Modification Outstanding Recorded Investment	$ 0	$ 0	$ 2	$ 3
Other [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	0		1
Pre- Modification Outstanding Recorded Investment	$ 0		$ 0
Post- Modification Outstanding Recorded Investment	$ 0		$ 0
Consumer Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	25	26	104	81
Pre- Modification Outstanding Recorded Investment	$ 2	$ 2	$ 7	$ 4
Post- Modification Outstanding Recorded Investment	$ 2	$ 2	$ 6	$ 4
Direct Installment [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	14	15	50	47
Pre- Modification Outstanding Recorded Investment	$ 1	$ 1	$ 3	$ 2
Post- Modification Outstanding Recorded Investment	$ 1	$ 1	$ 3	$ 2
Residential Mortgages [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	2	4	18	14
Pre- Modification Outstanding Recorded Investment	$ 1	$ 1	$ 3	$ 1
Post- Modification Outstanding Recorded Investment	$ 1	$ 1	$ 2	$ 1
Consumer Lines of Credit [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	9	7	36	20
Pre- Modification Outstanding Recorded Investment	$ 0	$ 0	$ 1	$ 1
Post- Modification Outstanding Recorded Investment	$ 0	$ 0	$ 1	$ 1

LOANS AND LEASES - Originated T

LOANS AND LEASES - Originated Troubled Debt Restructurings, Payment Default (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)Contract	Sep. 30, 2019USD ($)Contract	Sep. 30, 2020USD ($)Contract	Sep. 30, 2019USD ($)Contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	6	3	28	12
Recorded Investment | $	$ 0	$ 0	$ 4	$ 1
Total Commercial Loans and Leases [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	1	1	11	6
Recorded Investment | $	$ 0	$ 0	$ 3	$ 1
Commercial Real Estate [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	0	1	8	5
Recorded Investment | $	$ 0	$ 0	$ 3	$ 1
Commercial and Industrial [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	1	0	3	1
Recorded Investment | $	$ 0	$ 0	$ 0	$ 0
Consumer Loan [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	5	2	17	6
Recorded Investment | $	$ 0	$ 0	$ 1	$ 0
Direct Installment [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	4	1	12	4
Recorded Investment | $	$ 0	$ 0	$ 1	$ 0
Residential Mortgages [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	0	0	2	1
Recorded Investment | $	$ 0	$ 0	$ 0	$ 0
Consumer Lines of Credit [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	1	1	3	1
Recorded Investment | $	$ 0	$ 0	$ 0	$ 0

ALLOWANCE FOR CREDIT LOSSES O_3

ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES - Changes in Allowance for Credit Losses (Detail) - USD ($) $ in Millions	Jan. 01, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	$ 196	$ 365	$ 188	$ 196	$ 180
Charge- Offs		(23)	(9)	(46)	(32)
Recoveries		4	3	13	9
Net Charge- Offs		(19)	(6)	(33)	(23)
Provision for Credit Losses		27	12	105	37
ASC 326 Adoption Impact	55
Initial ACL on PCD Loans				50
Balance at End of Period	196	373	194	373	194
Originated Loans And Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			183		173
Charge- Offs			(7)		(23)
Recoveries			2		7
Net Charge- Offs			(5)		(16)
Provision for Credit Losses			11		32
Balance at End of Period			189		189
Acquired Loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			5		7
Charge- Offs			(2)		(9)
Recoveries			1		2
Net Charge- Offs			(1)		(7)
Provision for Credit Losses			1		5
Balance at End of Period			5		5
Commercial Real Estate [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	60	163		60
Charge- Offs		(3)		(8)
Recoveries		1		6
Net Charge- Offs		(2)		(2)
Provision for Credit Losses		23		48
ASC 326 Adoption Impact	38
Initial ACL on PCD Loans				40
Balance at End of Period	60	184		184
Commercial Real Estate [Member] | Originated Loans And Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			61		55
Charge- Offs			(1)		(3)
Recoveries			0		1
Net Charge- Offs			(1)		(2)
Provision for Credit Losses			(2)		5
Balance at End of Period			58		58
Commercial and Industrial [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	53	98		53
Charge- Offs		(17)		(25)
Recoveries		1		3
Net Charge- Offs		(16)		(22)
Provision for Credit Losses		11		50
ASC 326 Adoption Impact	8
Initial ACL on PCD Loans				4
Balance at End of Period	53	93		93
Commercial and Industrial [Member] | Originated Loans And Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			52		49
Charge- Offs			(3)		(7)
Recoveries			1		3
Net Charge- Offs			(2)		(4)
Provision for Credit Losses			7		12
Balance at End of Period			57		57
Commercial Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	11	17		11
Charge- Offs		0		0
Recoveries		0		0
Net Charge- Offs		0		0
Provision for Credit Losses		0		6
ASC 326 Adoption Impact	0
Initial ACL on PCD Loans				0
Balance at End of Period	11	17		17
Commercial Leases [Member] | Originated Loans And Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			9		8
Charge- Offs			0		0
Recoveries			0		0
Net Charge- Offs			0		0
Provision for Credit Losses			1		2
Balance at End of Period			10		10
Other [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	9	1		9
Charge- Offs		(1)		(3)
Recoveries		0		0
Net Charge- Offs		(1)		(3)
Provision for Credit Losses		1		4
ASC 326 Adoption Impact	(9)
Initial ACL on PCD Loans				0
Balance at End of Period	9	1		1
Other [Member] | Originated Loans And Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			1		2
Charge- Offs			0		(2)
Recoveries			0		0
Net Charge- Offs			0		(2)
Provision for Credit Losses			1		2
Balance at End of Period			2		2
Total Commercial Loans and Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	133	279		133
Charge- Offs		(21)		(36)
Recoveries		2		9
Net Charge- Offs		(19)		(27)
Provision for Credit Losses		35		108
ASC 326 Adoption Impact	37
Initial ACL on PCD Loans				44
Balance at End of Period		295		295
Total Commercial Loans and Leases [Member] | Originated Loans And Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			123		114
Charge- Offs			(4)		(12)
Recoveries			1		4
Net Charge- Offs			(3)		(8)
Provision for Credit Losses			7		21
Balance at End of Period			127		127
Direct Installment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	13	25		13
Charge- Offs		0		(1)
Recoveries		0		0
Net Charge- Offs		0		(1)
Provision for Credit Losses		(1)		1
ASC 326 Adoption Impact	10
Initial ACL on PCD Loans				1
Balance at End of Period	13	24		24
Direct Installment [Member] | Originated Loans And Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			13		14
Charge- Offs			0		(1)
Recoveries			0		0
Net Charge- Offs			0		(1)
Provision for Credit Losses			(1)		(1)
Balance at End of Period			12		12
Residential Mortgages [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	22	33		22
Charge- Offs		(1)		(1)
Recoveries		1		1
Net Charge- Offs		0		0
Provision for Credit Losses		(2)		(1)
ASC 326 Adoption Impact	6
Initial ACL on PCD Loans				4
Balance at End of Period	22	31		31
Residential Mortgages [Member] | Originated Loans And Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			20		20
Charge- Offs			0		(1)
Recoveries			0		0
Net Charge- Offs			0		(1)
Provision for Credit Losses			3		4
Balance at End of Period			23		23
Indirect Installment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	19	17		19
Charge- Offs		(1)		(6)
Recoveries		1		3
Net Charge- Offs		0		(3)
Provision for Credit Losses		(5)		(6)
ASC 326 Adoption Impact	2
Initial ACL on PCD Loans				0
Balance at End of Period	19	12		12
Indirect Installment [Member] | Originated Loans And Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			18		15
Charge- Offs			(3)		(8)
Recoveries			1		3
Net Charge- Offs			(2)		(5)
Provision for Credit Losses			2		8
Balance at End of Period			18		18
Consumer Lines of Credit [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	9	11		9
Charge- Offs		0		(2)
Recoveries		0		0
Net Charge- Offs		0		(2)
Provision for Credit Losses		0		3
ASC 326 Adoption Impact	0
Initial ACL on PCD Loans				1
Balance at End of Period	9	11		11
Consumer Lines of Credit [Member] | Originated Loans And Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			9		10
Charge- Offs			0		(1)
Recoveries			0		0
Net Charge- Offs			0		(1)
Provision for Credit Losses			0		0
Balance at End of Period			9		9
Consumer Loan [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period	63	86		63
Charge- Offs		(2)		(10)
Recoveries		2		4
Net Charge- Offs		0		(6)
Provision for Credit Losses		(8)		(3)
ASC 326 Adoption Impact	$ 18
Initial ACL on PCD Loans				6
Balance at End of Period		$ 78		$ 78
Consumer Loan [Member] | Originated Loans And Leases [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			60		59
Charge- Offs			(3)		(11)
Recoveries			1		3
Net Charge- Offs			(2)		(8)
Provision for Credit Losses			4		11
Balance at End of Period			62		62
Purchased Credit Impaired Loans [Member] | Acquired Loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			1		1
Charge- Offs			0		0
Recoveries			0		0
Net Charge- Offs			0		0
Provision for Credit Losses			0		0
Balance at End of Period			1		1
Other Acquired Loans [Member] | Acquired Loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Balance at Beginning of Period			4		6
Charge- Offs			(2)		(9)
Recoveries			1		2
Net Charge- Offs			(1)		(7)
Provision for Credit Losses			1		5
Balance at End of Period			$ 4		$ 4

ALLOWANCE FOR CREDIT LOSSES O_4

ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES - Narrative (Details) - USD ($) $ in Millions	Jan. 01, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Jun. 11, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Loss [Line Items]
Stockholders' equity attributable to parent		$ 4,951	$ 4,820	$ 4,951	$ 4,820	$ 4,897		$ 4,883	$ 4,753	$ 4,608
Financing receivable, allowance for credit loss, period increase (decrease)	$ 105.3			177.1
Allowance for credit loss	196	373	194	373	194	365		196	188	180
Percentage of contraction, gross domestic product							7.00%
Percentage of increase, unemployment							10.00%
Allowance for credit loss, net		$ 373		$ 373
Financing receivable, allowance for credit loss, period increase (decrease), percentage				90.40%
Financing receivable, allowance for credit loss, ratio		1.45%		1.45%
Provision for credit losses		$ 27.2		$ 105.2
Financing receivable, allowance for credit loss, write-off		19.3	6.4	33.4	23
Impact of ASC 326 Adoption [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Stockholders' equity attributable to parent								(50)
Allowance for credit loss	105
Retained Earnings [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Stockholders' equity attributable to parent		$ 838	$ 744	$ 838	$ 744	$ 796		798	$ 683	$ 576
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]
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit loss	301
Accounting Standards Update 2016-13 [Member] | Retained Earnings [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Stockholders' equity attributable to parent	(51)
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]
Financing receivable, allowance for credit loss, period increase (decrease)	10
Allowance for credit loss	$ 10

ALLOWANCE FOR CREDIT LOSSES O_5

ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES - Individual and Collective Allowance for Credit Losses (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Valuation Allowance [Line Items]
Amortized cost loans and leases, carrying amount	$ 25,689	$ 23,289
Commercial Real Estate [Member]
Valuation Allowance [Line Items]
Amortized cost loans and leases, carrying amount	9,521	8,960
Commercial and Industrial [Member]
Valuation Allowance [Line Items]
Amortized cost loans and leases, carrying amount	7,547	5,308
Commercial Leases [Member]
Valuation Allowance [Line Items]
Amortized cost loans and leases, carrying amount	487	432
Other [Member]
Valuation Allowance [Line Items]
Amortized cost loans and leases, carrying amount	65	21
Total Commercial Loans and Leases [Member]
Valuation Allowance [Line Items]
Amortized cost loans and leases, carrying amount	17,620	14,721
Direct Installment [Member]
Valuation Allowance [Line Items]
Amortized cost loans and leases, carrying amount	1,977	1,821
Residential Mortgages [Member]
Valuation Allowance [Line Items]
Amortized cost loans and leases, carrying amount	3,531	3,374
Indirect Installment [Member]
Valuation Allowance [Line Items]
Amortized cost loans and leases, carrying amount	1,219	1,922
Consumer Lines of Credit [Member]
Valuation Allowance [Line Items]
Amortized cost loans and leases, carrying amount	1,342	1,451
Consumer Loan [Member]
Valuation Allowance [Line Items]
Amortized cost loans and leases, carrying amount	$ 8,069	8,568
Originated Loans And Leases [Member]
Valuation Allowance [Line Items]
Originated allowance, individually evaluated for impairment		4
Originated allowance, collectively evaluated for impairment		185
Amortized cost loans and leases, carrying amount		20,397
Originated loans and leases outstanding, individually evaluated for impairment		30
Originated loans and leases outstanding, collectively evaluated for impairment		20,367
Originated Loans And Leases [Member] | Commercial Real Estate [Member]
Valuation Allowance [Line Items]
Originated allowance, individually evaluated for impairment		2
Originated allowance, collectively evaluated for impairment		58
Amortized cost loans and leases, carrying amount		7,114
Originated loans and leases outstanding, individually evaluated for impairment		13
Originated loans and leases outstanding, collectively evaluated for impairment		7,101
Originated Loans And Leases [Member] | Commercial and Industrial [Member]
Valuation Allowance [Line Items]
Originated allowance, individually evaluated for impairment		2
Originated allowance, collectively evaluated for impairment		51
Amortized cost loans and leases, carrying amount		5,063
Originated loans and leases outstanding, individually evaluated for impairment		17
Originated loans and leases outstanding, collectively evaluated for impairment		5,046
Originated Loans And Leases [Member] | Commercial Leases [Member]
Valuation Allowance [Line Items]
Originated allowance, individually evaluated for impairment		0
Originated allowance, collectively evaluated for impairment		11
Amortized cost loans and leases, carrying amount		432
Originated loans and leases outstanding, individually evaluated for impairment		0
Originated loans and leases outstanding, collectively evaluated for impairment		432
Originated Loans And Leases [Member] | Other [Member]
Valuation Allowance [Line Items]
Originated allowance, individually evaluated for impairment		0
Originated allowance, collectively evaluated for impairment		2
Amortized cost loans and leases, carrying amount		21
Originated loans and leases outstanding, individually evaluated for impairment		0
Originated loans and leases outstanding, collectively evaluated for impairment		21
Originated Loans And Leases [Member] | Total Commercial Loans and Leases [Member]
Valuation Allowance [Line Items]
Originated allowance, individually evaluated for impairment		4
Originated allowance, collectively evaluated for impairment		122
Amortized cost loans and leases, carrying amount		12,630
Originated loans and leases outstanding, individually evaluated for impairment		30
Originated loans and leases outstanding, collectively evaluated for impairment		12,600
Originated Loans And Leases [Member] | Direct Installment [Member]
Valuation Allowance [Line Items]
Originated allowance, individually evaluated for impairment		0
Originated allowance, collectively evaluated for impairment		13
Amortized cost loans and leases, carrying amount		1,758
Originated loans and leases outstanding, individually evaluated for impairment		0
Originated loans and leases outstanding, collectively evaluated for impairment		1,758
Originated Loans And Leases [Member] | Residential Mortgages [Member]
Valuation Allowance [Line Items]
Originated allowance, individually evaluated for impairment		0
Originated allowance, collectively evaluated for impairment		22
Amortized cost loans and leases, carrying amount		2,995
Originated loans and leases outstanding, individually evaluated for impairment		0
Originated loans and leases outstanding, collectively evaluated for impairment		2,995
Originated Loans And Leases [Member] | Indirect Installment [Member]
Valuation Allowance [Line Items]
Originated allowance, individually evaluated for impairment		0
Originated allowance, collectively evaluated for impairment		19
Amortized cost loans and leases, carrying amount		1,922
Originated loans and leases outstanding, individually evaluated for impairment		0
Originated loans and leases outstanding, collectively evaluated for impairment		1,922
Originated Loans And Leases [Member] | Consumer Lines of Credit [Member]
Valuation Allowance [Line Items]
Originated allowance, individually evaluated for impairment		0
Originated allowance, collectively evaluated for impairment		9
Amortized cost loans and leases, carrying amount		1,092
Originated loans and leases outstanding, individually evaluated for impairment		0
Originated loans and leases outstanding, collectively evaluated for impairment		1,092
Originated Loans And Leases [Member] | Consumer Loan [Member]
Valuation Allowance [Line Items]
Originated allowance, individually evaluated for impairment		0
Originated allowance, collectively evaluated for impairment		63
Amortized cost loans and leases, carrying amount		7,767
Originated loans and leases outstanding, individually evaluated for impairment		0
Originated loans and leases outstanding, collectively evaluated for impairment		$ 7,767

LOAN SERVICING - Activity in MS

LOAN SERVICING - Activity in MSR (Detail) - Mortgage Servicing Rights [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Servicing Assets at Fair Value [Line Items]
Mortgage loans sold with servicing retained	$ 4,626		$ 4,626		$ 4,686
Mortgage loans sold with servicing retained	466	$ 354	1,142	$ 937
Pretax net gains resulting from above loan sales	25	10	47	23
Mortgage banking operations	3	3	9	8
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Balance at beginning of period	34	38	42.6	36.8
Additions	4.5	3.5	11	9.8
Payoffs and curtailments	(4.6)	(0.5)	(10.5)	(1.8)
(Impairment) / recovery	0.5	(0.3)	(7.5)	(2.9)
Amortization	(0.6)	(1.9)	(1.8)	(3.1)
Balance at end of period	33.8	38.8	33.8	38.8
Loan servicing rights, fair value, start	34	39.8	45	41.1
Loan servicing rights, fair value, end	33.8	$ 40.5	33.8	$ 40.5
Valuation allowance for servicing rights	$ 9.1		$ 9.1		$ 1.5

LOAN SERVICING - Sensitivity of

LOAN SERVICING - Sensitivity of Fair Value to Changes in key Assumptions (Detail) - Mortgage Servicing Rights [Member] - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
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)	62 months 10 days	78 months 27 days
Constant prepayment rate (annualized)	14.50%	10.60%
Discount rate	9.60%	9.70%
Sensitivity analysis of fair value, change in interest rates, plus .25%	$ 2	$ 3
Sensitivity analysis of fair value, change in interest rates, plus .50%	5	5
Sensitivity analysis of fair value, change in interest rates, minus .25%	(2)	(3)
Sensitivity analysis of fair value, change in interest rates, minus .50%	$ (3)	$ (5)

GOODWILL AND OTHER INTANGIBLE_2

GOODWILL AND OTHER INTANGIBLE ASSETS (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Goodwill [Line Items]
Goodwill	$ 2,262	$ 2,262
Community Banking [Member]
Goodwill [Line Items]
Goodwill	$ 2,200
Percentage of fair value in excess of carrying amount (less than)	5.00%

OPERATING LEASES (Details)

OPERATING LEASES (Details) $ in Millions	Sep. 30, 2020USD ($)
Lessee, Lease, Description [Line Items]
Operating lease, right-of-use asset	$ 116.6
Operating lease, liability	124.2
Operating lease, lease not yet commenced, expense	$ 28
Minimum [Member]
Lessee, Lease, Description [Line Items]
Lessee, operating lease, lease not yet commenced, term of contract	11 years
Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, operating lease, lease not yet commenced, term of contract	16 years

OPERATING LEASES - Lease Expens

OPERATING LEASES - Lease Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating lease cost	$ 7	$ 6	$ 20	$ 20
Short-term lease cost	1	1	1	1
Variable lease cost	1	1	3	3
Total lease cost	$ 9	$ 8	$ 24	$ 24

OPERATING LEASES - Other Inform

OPERATING LEASES - Other Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Operating lease, Cash paid for amounts included in the measurement of lease liabilities, operating	$ 19	$ 19
Operating lease, right-of-use assets obtained in exchange for lease obligations	$ 5	$ 22
Operating lease, weighted average remaining lease term (in years)	9 years 6 months 3 days	9 years 9 months 10 days
Operating lease, weighted average discount rate, percent	2.80%	3.00%

OPERATING LEASES - Maturities (

OPERATING LEASES - Maturities (Details) $ in Millions	Sep. 30, 2020USD ($)
Leases [Abstract]
2020	$ 6
2021	24
2022	19
2023	15
2024	13
Later years	67
Total lease payments	144
Less: imputed interest	(20)
Present value of lease liabilities	$ 124.2
Operating lease, liability, statement of financial position [extensible list]	us-gaap:OtherLiabilities

VARIABLE INTEREST ENTITIES - As

VARIABLE INTEREST ENTITIES - Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Variable Interest Entity [Line Items]
Assets	$ 37,441	$ 34,615	$ 34,329
Liabilities	32,490	29,732
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Assets	154	154
Liabilities	125	136
Maximum Exposure to Loss	153	153
Trust Preferred Securities [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Assets	1	1
Liabilities	66	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	121	120
Liabilities	51	60
Maximum Exposure to Loss	121	120
Other Investments [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Assets	32	33
Liabilities	8	10
Maximum Exposure to Loss	$ 32	$ 33

VARIABLE INTEREST ENTITIES - Af

VARIABLE INTEREST ENTITIES - Affordable Housing Tax Credit Investments And Related Unfunded Commitments (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Proportional amortization method investments included in other assets	$ 67	$ 55
Equity method investments included in other assets	3	5
Total LIHTC investments included in other assets	70	60
Unfunded LIHTC commitments	$ 51	$ 60

VARIABLE INTEREST ENTITIES - In

VARIABLE INTEREST ENTITIES - Income Statement Effect (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
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	2	2	8	6
Low-income housing tax credits	(3)	(3)	(9)	(7)
Other tax benefits related to tax credit investments	0	0	(2)	(1)
Amortization Method Qualified Affordable Housing Project Investments, Provision For Income Tax	$ (1)	$ (1)	$ (3)	$ (2)

BORROWINGS - Summary of Short-T

BORROWINGS - Summary of Short-Term Borrowings (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Securities sold under repurchase agreements	$ 405	$ 278
Federal Home Loan Bank advances	1,380	2,255
Federal funds purchased	0	575
Subordinated notes	114	108
Total short-term borrowings	$ 1,899	$ 3,216

BORROWINGS - Additional Informa

BORROWINGS - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Short-term advances	$ 1,400,000,000		$ 1,400,000,000	$ 1,500,000,000
Short-term advances, percentage bearing fixed interest rate	100.00%		100.00%	64.50%
Loss on extinguishment of debt and related hedge termination costs	$ 13,300,000
Long-term borrowings, face amount	558,000,000		$ 558,000,000
Proceeds from debt, net of issuance costs			560,000,000
FHLB [Member]
Debt Instrument [Line Items]
Credit available with FHLB	8,400,000,000		8,400,000,000
Credit with FHLB utilized	2,100,000,000		$ 2,100,000,000
Reduction of higher rate outstanding	$ 415,000,000
Minimum [Member] | FHLB [Member]
Debt Instrument [Line Items]
Effective interest rates	0.30%		0.30%	1.62%
Maximum [Member] | FHLB [Member]
Debt Instrument [Line Items]
Effective interest rates	2.45%		2.45%	2.71%
2.20% Senior Notes due February 24, 2023 [Member]
Debt Instrument [Line Items]
Long-term borrowings, face amount	$ 300,000,000	$ 300,000,000	$ 300,000,000
Proceeds from debt, net of issuance costs		$ 297,900,000	$ 298,000,000

BORROWINGS - Summary of Long-Te

BORROWINGS - Summary of Long-Term Borrowings (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Federal Home Loan Bank advances	$ 700	$ 935
Senior notes	298	0
Subordinated notes	84	90
Junior subordinated debt	66	66
Other subordinated debt	249	249
Total long-term borrowings	$ 1,397	$ 1,340

BORROWINGS - Schedule of Subord

BORROWINGS - Schedule of Subordinated Debt (Details) - USD ($)	3 Months Ended	9 Months Ended
	Mar. 31, 2020	Sep. 30, 2020
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	$ 300,000,000
Net Proceeds	$ 297,900,000	298,000,000
Carrying Value		$ 298,000,000
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		$ 31,000,000

BORROWINGS - Junior Subordinate

BORROWINGS - Junior Subordinated Debt Trusts (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 66	$ 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	1.90%
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	1.57%
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	$ 22
Interest Rate	1.68%
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 (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Notional amount	$ 12,238	$ 9,558
Derivative asset, not offset against collateral	3	1
Derivative liability, not offset against collateral	42	23
Derivative asset, not subject to master netting arrangement	420	153
Derivative liability, not subject to master netting arrangement	3	2
Fair value, asset	423	154
Fair value, liability	45	25
Interest rate contracts - designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	225
Derivative asset, not offset against collateral	3	1
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	0	0
Derivative liability, not offset against collateral	42	23
Derivative asset, not subject to master netting arrangement	397	149
Derivative liability, not subject to master netting arrangement	0	1
Interest rate lock commitments – not designated [Member]
Derivatives, Fair Value [Line Items]
Derivative asset, not subject to master netting arrangement	22	3
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	1	1
Derivative liability, not subject to master netting arrangement	2	1
Credit risk contracts - not designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	302.5
Derivative asset, not subject to master netting arrangement	0	0
Derivative liability, not subject to master netting arrangement	1	0
Subject to Master Netting Arrangements [Member]
Derivatives, Fair Value [Line Items]
Notional amount	6,181	5,295
Subject to Master Netting Arrangements [Member] | Interest rate contracts - designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	1,580	1,655
Subject to Master Netting Arrangements [Member] | Interest rate swaps - not designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	4,601	3,640
Not Subject to Master Netting Arrangements [Member]
Derivatives, Fair Value [Line Items]
Notional amount	6,057	4,263
Not Subject to Master Netting Arrangements [Member] | Interest rate swaps - not designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	4,601	3,640
Not Subject to Master Netting Arrangements [Member] | Interest rate lock commitments – not designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	532	163
Not Subject to Master Netting Arrangements [Member] | Forward delivery commitments – not designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	479	195
Not Subject to Master Netting Arrangements [Member] | Credit risk contracts - not designated [Member]
Derivatives, Fair Value [Line Items]
Notional amount	$ 445	$ 265

DERIVATIVE INSTRUMENTS AND HE_4

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Amounts Reclassified from AOCI (Detail) - Interest rate contracts [Member] - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	$ (42,000,000)	$ (31,000,000)
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	(9,000,000)	2,000,000
Other Income (Expense) [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Amount of Gain (Loss) Reclassified from AOCI into Income	$ (9,000,000)	$ 0

DERIVATIVE INSTRUMENTS AND HE_5

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Effect of Cash Flow Hedging on Income Statement (Detail) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative [Line Items]
Interest Income - Loans and Leases	$ 239,000,000	$ 274,000,000	$ 750,000,000	$ 819,000,000
Interest Expense - Short-Term Borrowings	$ 9,000,000	$ 18,000,000	31,000,000	66,000,000
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			2,000,000	(1,000,000)
Interest Expense - Short-Term Borrowings [Member] | Interest rate contracts [Member]
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into net income			$ (11,000,000)	$ 3,000,000

DERIVATIVE INSTRUMENTS AND HE_6

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Derivative [Line Items]
Notional amount	$ 12,238,000,000		$ 9,558,000,000
Additional amount in excess of posted collateral required in case of breached agreements	$ 300,000		100,000
Interest rate contracts [Member]
Derivative [Line Items]
Maximum length of time hedged in interest rate cash flow hedge	4 years 1 month 6 days
Period to reclassification of cash flow hedge gain loss	12 months
Derivative gains to be reclassified within twelve months	$ 18,700,000
Derivative gains to be reclassified within twelve months, net of tax	14,500,000
Derivative gain or loses excluded from assessment of hedge effectiveness	0
Amount of gain (loss) reclassified from AOCI into net income	0	$ 0
Notional amount	225,000,000
Credit risk contracts - not designated [Member]
Derivative [Line Items]
Notional amount	302,500,000
Maximum exposure under credit risk agreement assuming customer default	700,000		300,000
Credit risk derivatives, purchased at fair value	300,000		100,000
Credit risk derivatives, sold at fair value	$ 700,000		$ 300,000
Credit risk contracts - not designated [Member] | Minimum [Member]
Derivative [Line Items]
Risk participation agreements, term	1 month
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 (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
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	(1)	(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 (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Net Amount Presented in the Balance Sheet	$ 3	$ 1
Financial Instruments	0	1
Cash Collateral	3	0
Net Amount	0	0
Interest rate contracts - designated [Member]
Derivative [Line Items]
Net Amount Presented in the Balance Sheet	3	1
Financial Instruments	0	1
Cash Collateral	3	0
Net Amount	0	0
Interest rate swaps - not designated [Member]
Derivative [Line Items]
Net Amount Presented in the Balance Sheet	$ 0	$ 0

DERIVATIVE INSTRUMENTS AND HE_9

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Derivative Liabilities (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivative [Line Items]
Net Amount Presented in the Consolidated Balance Sheets	$ 42	$ 23
Financial Instruments	0	23
Cash Collateral	42	0
Net Amount	0	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	42	23
Financial Instruments	0	23
Cash Collateral	42	0
Net Amount	$ 0	$ 0

COMMITMENTS, CREDIT RISK AND _3

COMMITMENTS, CREDIT RISK AND CONTINGENCIES - Off-Balance Sheet Credit Risk (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Standby Letters of Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Extended credit and standby letters of credit	$ 156	$ 150
Commitments to Extend Credit [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Extended credit and standby letters of credit	$ 9,121	$ 8,089

COMMITMENTS, CREDIT RISK AND _4

COMMITMENTS, CREDIT RISK AND CONTINGENCIES - Additional Information (Detail) $ in Millions	Sep. 30, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
Percentage of commitments to extend credit dependent upon the financial condition of the customers	75.50%
Allowance for credit losses on loan commitments that are not unconditionally cancellable	$ 14.8

STOCK INCENTIVE PLANS - Additio

STOCK INCENTIVE PLANS - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of units issued, years	3 years
Common stock shares available up to (in shares)	5,525,700
Common stock additional shares registered (in shares)	4,640,000
Unrecognized compensation expense	$ 14
Increase in stock compensation expense	$ 5.4
Increase in stock compensation expense, percentage	65.00%
Performance period of units, years	3 years
Shares, options outstanding and exercisable (in shares)	207,030	397,628
Weighted average exercise price, options outstanding (in USD per share)	$ 8.42	$ 8.10
Intrinsic value of outstanding and exercisable stock options	$ 0.1
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)	2,004,895	1,182,197
Unrecognized compensation expense	$ 13.8
Amount subject to accelerated vesting under Incentive Compensation Plan	$ 0.9
2020 Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of units issued, years	36 months
Performance-based Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 3
Performance-based Units [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards issued (in shares)	571,932	353,656

STOCK INCENTIVE PLANS - Restric

STOCK INCENTIVE PLANS - Restricted Stock Units Activity (Detail) - $ / shares	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
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)	4,322,378
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)	2,858,357	2,556,174
Shares, granted (in shares)	2,004,895	1,182,197
Net adjustment due to performance (in shares)	47,290	0
Shares, vested (in shares)	(592,602)	(655,208)
Shares, forfeited/expired (in shares)	(169,552)	(325,253)
Shares, dividend reinvestment (in shares)	173,990	80,738
Shares, unvested units outstanding at end of period (in shares)	4,322,378	2,838,648
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 USD per share)	$ 12.56	$ 13.51
Weighted average grant price, granted (in USD per share)	5.95	10.94
Weighted average grant price, net adjusted due to performance (in USD per share)	13	0
Weighted average grant price, vested (in USD per share)	14.50	13.15
Weighted average grant price, forfeited/expired (in USD per share)	13.05	12.72
Weighted average grant price, dividend reinvestment (in USD per share)	6.99	11.62
Weighted average grant price, invested units outstanding at end of period (in USD per share)	$ 9.45	$ 12.54

STOCK INCENTIVE PLANS - Schedul

STOCK INCENTIVE PLANS - Schedule of Certain Information Related to Restricted Stock Units (Detail) - Restricted Stock [Member] - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 13	$ 8
Tax benefit related to stock-based compensation expense	3	2
Fair value of units vested	$ 4	$ 7

STOCK INCENTIVE PLANS - Compone

STOCK INCENTIVE PLANS - Components of Restricted Stock Units (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2020USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock units (in shares) | shares	4,322,378
Unrecognized compensation expense	$ 14
Intrinsic value	$ 29
Weighted average remaining life (in years)	1 year 8 months 8 days
Service-Based Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock units (in shares) | shares	2,987,784
Unrecognized compensation expense	$ 11
Intrinsic value	$ 20
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	1,334,594
Unrecognized compensation expense	$ 3
Intrinsic value	$ 9
Weighted average remaining life (in years)	1 year 3 months 21 days

INCOME TAXES - Income Tax Expen

INCOME TAXES - Income Tax Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Current income taxes: Federal taxes	$ 16	$ (3)	$ 62	$ 24
Current income taxes: State taxes	1	0	6	3
Total current income taxes	17	(3)	68	27
Deferred income taxes: Federal taxes	0	19	(24)	34
Deferred income taxes: State taxes	0	1	0	2
Total deferred income taxes	0	20	(24)	36
Income taxes	$ 17	$ 17	$ 44	$ 63
Statutory tax rate	21.00%	21.00%	21.00%	21.00%
Effective tax rate	17.00%	14.50%	17.00%	17.80%

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Effective tax rate	17.00%	14.50%	17.00%	17.80%
Deferred tax assets	$ 52.6		$ 52.6		$ 25.1

OTHER COMPREHENSIVE INCOME (Det

OTHER COMPREHENSIVE INCOME (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2020USD ($)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 4,883
Other comprehensive (loss) income before reclassifications	32
Amounts reclassified from AOCI	7
Net current period other comprehensive (loss) income	39
Balance at end of period	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	11
Other comprehensive (loss) income before reclassifications	63
Amounts reclassified from AOCI	0
Net current period other comprehensive (loss) income	63
Balance at end of period	74
Unrealized Net Gains (Losses) on Derivative Instruments [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(18)
Other comprehensive (loss) income before reclassifications	(32)
Amounts reclassified from AOCI	7
Net current period other comprehensive (loss) income	(25)
Balance at end of period	(43)
Unrecognized Pension and Postretirement Obligations [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(58)
Other comprehensive (loss) income before reclassifications	1
Amounts reclassified from AOCI	0
Net current period other comprehensive (loss) income	1
Balance at end of period	(57)
Accumulated Other Comprehensive Income (Loss) [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(65)
Balance at end of period	$ (26)

EARNINGS PER COMMON SHARE - Com

EARNINGS PER COMMON SHARE - Computation of Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net income	$ 83	$ 103	$ 214	$ 292
Less: Preferred stock dividends	2	2	6	6
Net Income Available to Common Stockholders	$ 81	$ 101	$ 208	$ 286
Basic weighted average common shares outstanding (in shares)	323,379,720	325,031,140	323,642,925	324,875,436
Net effect of dilutive stock options, warrants and restricted stock (in shares)	2,283,060	1,068,730	2,051,221	893,725
Diluted weighted average common shares outstanding (in shares)	325,662,780	326,099,870	325,694,146	325,769,161
Earnings per common share:
Basic (in USD per share)	$ 0.25	$ 0.31	$ 0.64	$ 0.88
Diluted (in USD per share)	$ 0.25	$ 0.31	$ 0.64	$ 0.88

EARNINGS PER COMMON SHARE - Ave

EARNINGS PER COMMON SHARE - Average Shares Excluded from Earnings Per Common Share (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Average shares excluded from the diluted earnings per common share calculation (in shares)	44,755	1	22,263	122

CASH FLOW INFORMATION (Detail)

CASH FLOW INFORMATION (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Supplemental Cash Flow Elements [Abstract]
Interest paid on deposits and other borrowings	$ 179	$ 248
Income taxes paid	34	40
Transfers of loans to other real estate owned	2	5
Loans transferred to held for sale from portfolio	508	389
Loans transferred to portfolio from held for sale	$ 0	$ 110

BUSINESS SEGMENTS - Additional

BUSINESS SEGMENTS - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2020Segment
Segment Reporting [Abstract]
Number of reportable segments	3

BUSINESS SEGMENTS - Financial I

BUSINESS SEGMENTS - Financial Information for Segments (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Interest income	$ 273	$ 314	$ 860	$ 941
Interest expense	46	84	172	250
Net Interest Income	227	230	688	691
Provision for credit losses	27	12	105	37
Non-interest income	80	80	226	220
Non-interest expense	177	174	541	508
Amortization of intangibles	3	4	10	11
Income tax expense (benefit)	17	17	44	63
Net income (loss)	83	103	214	292
Total assets	37,441	34,329	37,441	34,329	$ 34,615
Total intangibles	2,319	2,333	2,319	2,333
Operating Segments [Member] | Community Banking [Member]
Segment Reporting Information [Line Items]
Interest income	273	314	859	940
Interest expense	41	79	155	236
Net Interest Income	232	235	704	704
Provision for credit losses	27	12	105	37
Non-interest income	63	65	180	177
Non-interest expense	162	158	495	462
Amortization of intangibles	3	3	9	10
Income tax expense (benefit)	18	19	47	66
Net income (loss)	85	108	228	306
Total assets	37,315	34,207	37,315	34,207
Total intangibles	2,282	2,294	2,282	2,294
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	12	12	36	35
Non-interest expense	8	8	26	26
Amortization of intangibles	0	0	0	0
Income tax expense (benefit)	1	1	2	2
Net income (loss)	3	3	8	7
Total assets	36	29	36	29
Total intangibles	9	10	9	10
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	7	5	18	14
Non-interest expense	5	4	14	12
Amortization of intangibles	0	1	1	1
Income tax expense (benefit)	1	0	1	0
Net income (loss)	1	0	2	1
Total assets	36	36	36	36
Total intangibles	28	29	28	29
Parent and Other [Member]
Segment Reporting Information [Line Items]
Interest income	0	0	1	1
Interest expense	5	5	17	14
Net Interest Income	(5)	(5)	(16)	(13)
Provision for credit losses	0	0	0	0
Non-interest income	(2)	(2)	(8)	(6)
Non-interest expense	2	4	6	8
Amortization of intangibles	0	0	0	0
Income tax expense (benefit)	(3)	(3)	(6)	(5)
Net income (loss)	(6)	(8)	(24)	(22)
Total assets	54	57	54	57
Total intangibles	$ 0	$ 0	$ 0	$ 0

FAIR VALUE MEASUREMENTS - Asset

FAIR VALUE MEASUREMENTS - Assets and Liabilities on Recurring Basis (Detail) - USD ($) $ in Millions		Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		$ 3,101	$ 3,289
Loans held for sale	[1]	138	41
Derivative assets		423	154
Derivative liabilities		45	25
U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		300
US Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		160	151
U.S. Government-Sponsored Entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		137	226
Agency Collateralized Mortgage Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		976	1,240
Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		416	345
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		14	11
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		300	0
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		2,801	3,289
Derivative assets		401	151
Derivative liabilities		45	25
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		22	3
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		3,101	3,289
Loans held for sale		138	41
Derivative assets		423	154
Assets measured at fair value on a recurring basis, Total		3,662	3,484
Derivative liabilities		45	25
Liabilities measured at fair value on a recurring basis, Total		45	25
Fair Value, Recurring [Member] | Trading Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		42	24
Fair Value, Recurring [Member] | Not for Trading Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities		3	1
Fair Value, Recurring [Member] | Trading Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		397	149
Fair Value, Recurring [Member] | Non Trading Account Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		26	5
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		300
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		160	151
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		137	226
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		1,096	1,314
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		976	1,240
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		416	345
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		14	11
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] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		300	0
Loans held for sale		0	0
Derivative assets		0	0
Assets measured at fair value on a recurring basis, Total		300	0
Derivative liabilities		0	0
Liabilities measured at fair value on a recurring basis, Total		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 1 [Member] | U.S. Treasury [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		300
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 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		2,801	3,289
Loans held for sale		138	41
Derivative assets		401	151
Assets measured at fair value on a recurring basis, Total		3,340	3,481
Derivative liabilities		45	25
Liabilities measured at fair value on a recurring basis, Total		45	25
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		42	24
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		3	1
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		397	149
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	2
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
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		160	151
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		137	226
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		1,096	1,314
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		976	1,240
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		416	345
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		14	11
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 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		22	3
Assets measured at fair value on a recurring basis, Total		22	3
Derivative liabilities		0	0
Liabilities measured at fair value on a recurring basis, Total		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		22	3
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
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
[1]	Amount represents loans for which we have elected the fair value option. See Note 19.

FAIR VALUE MEASUREMENTS - Rollf

FAIR VALUE MEASUREMENTS - Rollforward on Recurring Basis (Detail) - Fair Value, Recurring [Member] - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 3	$ 1
Purchases, issuances, sales and settlements:
Issuances	22	3
Settlements	(3)	(1)
Balance at end of period	22	3
Interest Rate Lock Commitments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	3	1
Purchases, issuances, sales and settlements:
Issuances	22	3
Settlements	(3)	(1)
Balance at end of period	$ 22	$ 3

FAIR VALUE MEASUREMENTS - Addit

FAIR VALUE MEASUREMENTS - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Fair Value Measurements Disclosure [Line Items]
Transfer of assets and liabilities between the hierarchy levels	$ 0	$ 0
Allocated allowance for loan losses	25,400,000
Provision for fair value measurements included in allowance for loan losses	32,000,000
Carrying amount of OREO	10,400,000
Written down of OREO	9,200,000
Loss from OREO included in earnings	1,200,000
Fair Value, Nonrecurring [Member]
Fair Value Measurements Disclosure [Line Items]
Impaired loans, carrying amount	45,300,000
Allocated allowance for loan losses			$ 5,000,000
Mortgage Servicing Rights [Member] | Fair Value, Nonrecurring [Member]
Fair Value Measurements Disclosure [Line Items]
Servicing asset, gross	42,700,000
Valuation allowance for impairment of recognized servicing assets, additions for expenses	9,100,000
Servicing asset	33,700,000
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, additions for expenses	$ 7,500,000

FAIR VALUE MEASUREMENTS - Add_2

FAIR VALUE MEASUREMENTS - Additional Information on Non-Recurring Basis (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ 25.4
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan servicing rights, fair value	0		$ 0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan servicing rights, fair value	0		0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan servicing rights, fair value	37		48
Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans	45
Impaired loans			5
Other real estate owned	9		4
Fair Value, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Collateral dependent loans	0
Impaired loans			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
Impaired loans			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	45
Impaired loans			5
Other real estate owned	9		4
SBA-Guaranteed Loan Servicing [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan servicing rights, fair value	3		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]
Loan servicing rights, fair value	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]
Loan servicing rights, fair value	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]
Loan servicing rights, fair value	3		3
Mortgage Servicing Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan servicing rights, fair value	33.8	$ 34	45	$ 40.5	$ 39.8	$ 41.1
Mortgage Servicing Rights [Member] | Fair Value, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan servicing rights, fair value	34		30
Mortgage Servicing Rights [Member] | Fair Value, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loan servicing rights, fair value	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]
Loan servicing rights, fair value	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]
Loan servicing rights, fair value	$ 34		$ 30

FAIR VALUE MEASUREMENTS - Finan

FAIR VALUE MEASUREMENTS - Financial Instruments (Detail) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 900	$ 599
Debt securities available for sale	3,101	3,289
Securities held to maturity	2,966	3,275
Securities held to maturity, fair value	3,072	3,305
Net loans and leases	25,316	23,093
Derivative assets	423	154
Deposits	28,836	24,786
Short-term borrowings	1,899	3,216
Long-term borrowings	1,397	1,340
Long-term borrowings, fair value	547
Derivative liabilities	45	25
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	900	599
Debt securities available for sale	3,101	3,289
Securities held to maturity	2,966	3,275
Net loans and leases	25,996	23,144
Loan servicing rights	37	46
Derivative assets	423	154
Accrued interest receivable	90	109
Deposits	28,836	24,786
Short-term borrowings	1,899	3,216
Long-term borrowings	1,397	1,340
Derivative liabilities	45	25
Accrued interest payable	14	21
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	900	599
Debt securities available for sale	3,101	3,289
Securities held to maturity, fair value	3,072	3,305
Net loans and leases, fair value	25,872	22,930
Loan servicing rights, fair value	37	48
Derivative assets	423	154
Accrued interest receivable	90	109
Deposits, fair value	28,882	24,797
Short-term borrowings, fair value	1,904	3,219
Long-term borrowings, fair value	1,379	1,355
Derivative liabilities	45	25
Accrued interest payable	14	21
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	900	599
Debt securities available for sale	300	0
Securities held to maturity, fair value	0	0
Net loans and leases, fair value	0	0
Loan servicing rights, fair value	0	0
Derivative assets	0	0
Accrued interest receivable	90	109
Deposits, fair value	24,811	20,058
Short-term borrowings, fair value	1,904	3,219
Long-term borrowings, fair value	0	0
Derivative liabilities	0	0
Accrued interest payable	14	21
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	0	0
Debt securities available for sale	2,801	3,289
Securities held to maturity, fair value	3,072	3,305
Net loans and leases, fair value	138	41
Loan servicing rights, fair value	0	0
Derivative assets	401	151
Accrued interest receivable	0	0
Deposits, fair value	4,071	4,739
Short-term borrowings, fair value	0	0
Long-term borrowings, fair value	0	0
Derivative liabilities	45	25
Accrued interest payable	0	0
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents, fair value	0	0
Debt securities available for sale	0	0
Securities held to maturity, fair value	0	0
Net loans and leases, fair value	25,734	22,889
Loan servicing rights, fair value	37	48
Derivative assets	22	3
Accrued interest receivable	0	0
Deposits, fair value	0	0
Short-term borrowings, fair value	0	0
Long-term borrowings, fair value	1,379	1,355
Derivative liabilities	0	0
Accrued interest payable	$ 0	$ 0