F.N.B. (FNB) 10-K 27 Feb 20 2019 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2019	Jan. 31, 2020	Jun. 30, 2019
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
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 Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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 Public Float			$ 3,729,406,078
Entity Common Stock, Shares Outstanding		325,017,013
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of F.N.B. Corporation’s definitive proxy statement to be filed pursuant to Regulation 14A for the Annual Meeting of Stockholders to be held on May 13, 2020 are incorporated by reference into Part III, Items 10, 11, 12, 13 and 14, of this Annual Report on Form 10-K. F.N.B. Corporation will file its definitive proxy statement with the Securities and Exchange Commission on or before April 15, 2020 .
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Registrant Name	FNB CORP/PA/
Entity Central Index Key	0000037808
Current Fiscal Year End Date	--12-31
NEW YORK STOCK EXCHANGE, INC. | 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, INC. | 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		Dec. 31, 2019	Dec. 31, 2018
Assets
Cash and due from banks		$ 407	$ 451
Interest-bearing deposits with banks		192	37
Cash and Cash Equivalents		599	488
Debt securities available for sale		3,289	3,341
Debt securities held to maturity (fair value of $3,305 and $3,155)		3,275	3,254
Loans held for sale (includes $41 and $14 measured at fair value)	[1]	51	22
Loans and leases, net of unearned income of $1 and $3		23,289	22,153
Allowance for credit losses		(196)	(180)
Net Loans and Leases		23,093	21,973
Premises and equipment, net		333	330
Goodwill		2,262	2,255
Core deposit and other intangible assets, net		67	79
Bank owned life insurance		544	537
Other assets		1,102	823
Total Assets		34,615	33,102
Deposits:
Non-interest-bearing demand		6,384	6,000
Interest-bearing demand		11,049	9,660
Savings		2,625	2,526
Certificates and other time deposits		4,728	5,269
Total Deposits		24,786	23,455
Short-term borrowings		3,216	4,129
Long-term borrowings		1,340	627
Other liabilities		390	283
Total Liabilities		29,732	28,494
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 – 327,242,364 and 326,120,832 shares		3	3
Additional paid-in capital		4,067	4,049
Retained earnings		798	576
Accumulated other comprehensive loss		(65)	(106)
Treasury stock – 2,227,804 and 1,806,303 shares at cost		(27)	(21)
Total Stockholders’ Equity		4,883	4,608
Total Liabilities and Stockholders’ Equity		$ 34,615	$ 33,102
[1]	Amount represents loans for which we have elected the fair value option. See Note 24.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Securities held to maturity, Fair Value		$ 3,305	$ 3,155
Loans held for sale	[1]	41	14
Unearned income on loans		$ 1	$ 3
Preferred stock, par value (USD per Share)		$ 0.01	$ 0.01
Preferred stock, liquidation preference per share (USD per Share)		$ 1,000	$ 1,000
Preferred stock, shares authorized (in shares)		20,000,000	20,000,000
Preferred stock, shares issued (in shares)		110,877	110,877
Common stock, par value (USD per Share)		$ 0.01	$ 0.01
Common stock, shares authorized (in shares)		500,000,000	500,000,000
Common stock, shares issued (in shares)		327,242,364	326,120,832
Treasury stock, shares (in shares)		2,227,804	1,806,303
[1]	Amount represents loans for which we have elected the fair value option. See Note 24.

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest Income
Loans and leases, including fees	$ 1,085	$ 1,022	$ 862
Securities:
Taxable	126	119	97
Tax-exempt	32	28	20
Other	4	1	1
Total Interest Income	1,247	1,170	980
Interest Expense
Deposits	217	142	72
Short-term borrowings	80	75	44
Long-term borrowings	33	21	18
Total Interest Expense	330	238	134
Net Interest Income	917	932	846
Provision for credit losses	44	61	61
Net Interest Income After Provision for Credit Losses	873	871	785
Non-Interest Income
Service charges	124	126	120
Trust services	28	26	23
Insurance commissions and fees	20	18	19
Securities commissions and fees	17	18	15
Capital markets income	33	21	17
Mortgage banking operations	32	22	20
Dividends on non-marketable equity securities	19	16	9
Bank owned life insurance	12	13	12
Net securities gains	0	0	6
Other	9	16	11
Total Non-Interest Income	294	276	252
Non-Interest Expense
Salaries and employee benefits	375	370	327
Net occupancy	59	60	54
Equipment	62	55	49
Amortization of intangibles	14	16	18
Outside services	64	66	56
FDIC insurance	23	33	33
Bank shares and franchise taxes	12	12	10
Merger-related	0	0	57
Other	87	83	77
Total Non-Interest Expense	696	695	681
Income Before Income Taxes	471	452	356
Income taxes	84	79	157
Net Income	387	373	199
Preferred stock dividends	8	8	8
Net Income Available to Common Stockholders	$ 379	$ 365	$ 191
Earnings per Common Share
Basic (in usd per share)	$ 1.17	$ 1.13	$ 0.63
Diluted (in usd per share)	$ 1.16	$ 1.12	$ 0.63

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 387	$ 373	$ 199
Securities available for sale:
Unrealized gains (losses) arising during the period, net of tax expense (benefit) of $16, $5 and $3	57	(17)	(6)
Reclassification adjustment for gains included in net income, net of tax expense of $0, $0 and $0	0	0	0
Derivative instruments:
Unrealized losses arising during the period, net of tax benefit of $5, $1 and $0	(17)
Unrealized losses arising during the period, net of tax benefit of $5, $1 and $0		(2)	(1)
Reclassification adjustment for gains included in net income, net of tax expense of $0, $0 and $0	(2)
Reclassification adjustment for gains included in net income, net of tax expense of $0, $0 and $0		(2)	0
Pension and postretirement benefit obligations:
Unrealized gains (losses) arising during the period, net of tax expense (benefit) of $(1), $1 and $0	3	(2)	0
Other Comprehensive Income (Loss)	41	(23)	(7)
Comprehensive Income	$ 428	$ 350	$ 192

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Unrealized gains arising during the period, net of tax benefit	$ 16	$ 5	$ 3
Reclassification adjustment for gains included in net income, net of tax expense	0	0	0
Unrealized (losses) gains arising during the period, net of tax (benefit) expense	(5)
Unrealized (losses) gains arising during the period, net of tax (benefit) expense		(1)	0
Reclassification adjustment for gains included in net income, net of tax expense	0
Reclassification adjustment for gains included in net income, net of tax expense		0	0
Unrealized (losses) gains arising during the period, net of tax (benefit) expense	$ (1)	$ 1	$ 0

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Balance at beginning of period at Dec. 31, 2016	$ 2,572	$ 107	$ 2	$ 2,235	$ 304	$ (61)	$ (15)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	192				199	(7)
Dividends declared:
Preferred stock: $72.52/share	(8)				(8)
Common stock: $0.48/share	(142)				(142)
Issuance of common stock	3			7			(4)
Issuance of common stock – acquisitions	1,783		1	1,782
Assumption of warrant due to acquisition	1			1
Restricted stock compensation	8			8
Reclassification due to tax reform	0				15	(15)
Balance at end of period at Dec. 31, 2017	4,409	107	3	4,033	368	(83)	(19)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	350				373	(23)
Dividends declared:
Preferred stock: $72.52/share	(8)				(8)
Common stock: $0.48/share	(157)				(157)
Issuance of common stock	4			6			(2)
Restricted stock compensation	10			10
Balance at end of period at Dec. 31, 2018	4,608	107	3	4,049	576	(106)	(21)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Comprehensive income (loss)	428				387	41
Dividends declared:
Preferred stock: $72.52/share	(8)				(8)
Common stock: $0.48/share	(157)				(157)
Issuance of common stock	0			6			(6)
Restricted stock compensation	12			12
Balance at end of period at Dec. 31, 2019	$ 4,883	$ 107	$ 3	$ 4,067	$ 798	$ (65)	$ (27)

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Stockholders' Equity [Abstract]
Preferred stock dividends per share (in usd per share)	$ 72.52	$ 72.52	$ 72.52
Common stock dividends per share (in usd per share)	$ 0.48	$ 0.48	$ 0.48

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Activities
Net income	$ 387	$ 373	$ 199
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion	45	109	89
Provision for credit losses	44	61	61
Deferred tax expense	33	33	129
Net securities gains	0	0	(6)
Loans originated for sale	(1,481)	(1,117)	(1,098)
Loans sold	1,495	1,210	1,047
Net gain on sale of loans	(25)	(22)	(17)
Net change in:
Interest receivable	(8)	(6)	(18)
Interest payable	1	7	2
Bank owned life insurance, excluding purchases	(7)	(10)	(11)
Other, net	(225)	(27)	(98)
Net cash flows provided by operating activities	259	611	279
Investing Activities
Net change in loans and leases, excluding sales	(1,427)	(1,394)	(1,100)
Securities available for sale:
Purchases	(655)
Purchases		(1,200)	(1,142)
Sales	0	0	787
Maturities	770	592	570
Debt securities held to maturity:
Purchases	(494)	(387)	(1,186)
Sales	0	0	57
Maturities	468	370	395
Purchase of bank owned life insurance	0	0	(50)
Increase in premises and equipment	(46)	(35)	(57)
Net cash received in business combinations and divestitures	0	134	197
Loans sold, not originated for sale	262	0	0
Other, net	(9)	0	0
Net cash flows used in investing activities	(1,131)	(1,920)	(1,529)
Financing Activities
Demand (non-interest-bearing and interest-bearing) and savings accounts	1,873	406	406
Time deposits	(539)	653	757
Short-term borrowings	(913)	450	379
Proceeds from issuance of long-term borrowings	954	37	155
Repayment of long-term borrowings	(239)	(77)	(199)
Net proceeds from issuance of common stock	12	14	11
Cash dividends paid:
Preferred stock	(8)	(8)	(8)
Common stock	(157)	(157)	(143)
Net cash flows provided by financing activities	983	1,318	1,358
Net Increase (Decrease) in Cash and Cash Equivalents	111	9	108
Cash and cash equivalents at beginning of year	488	479	371
Cash and Cash Equivalents at End of Year	$ 599	$ 488	$ 479

Nature of Operations

Nature of Operations	12 Months Ended
	Dec. 31, 2019
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 December 31, 2019 , we had 369 banking offices throughout Pennsylvania, Ohio, Maryland, West Virginia, North Carolina and South Carolina.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
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 include subsidiaries in which we have a controlling financial interest. We own and operate FNBPA, FNTC, First National Investment Services Company, LLC, FNBIA, FNIA, 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 more than a 50% voting equity interest, or a controlling financial interest, or are a variable interest entity (VIE) in which we have the power to direct the activities of an entity that most significantly impact the entity’s economic performance and has an obligation to absorb losses or the right to receive benefits from the VIE which could potentially be significant to the VIE are consolidated. 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 does not have an obligation to absorb losses or the right to receive benefits from the VIE 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 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 December 31, 2019 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. 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. Actual results could materially differ from those estimates. Material estimates that are particularly susceptible to significant changes include the allowance for credit losses, accounting for loans acquired in a business combination, fair value of financial instruments, goodwill and other intangible assets, litigation, income taxes and deferred tax assets. Revenue from Contracts with Customers We earn certain revenues from contracts with customers. These revenues are recognized when control of the promised services is transferred to the customers in an amount that reflects the consideration we expect to be entitled to in an exchange for those services. In determining the appropriate revenue recognition for our contracts with customers, we consider whether the contract has commercial substance and is approved by both parties with identifiable contractual rights, payment terms, and the collectability of consideration is probable. Generally, we satisfy our performance obligations upon the completion of services at the amount to which we have the right to invoice or charge under contracts with an original expected duration of one year or less. We apply this guidance on a portfolio basis to contracts with similar characteristics and for which we believe the results would not differ materially from applying this guidance to individual contracts. Our services provided under contracts with customers are transferred at the point in time when the services are rendered. Generally, we do not defer incremental direct costs to obtain contracts with customers that would be amortized in one year or less under the practical expedient. These costs are recognized as expense, primarily salary and benefit expense, in the period incurred. Deposit Services . We recognize revenue on deposit services based on published fees for services provided. Demand and savings deposit customers have the right to cancel their depository arrangements and withdraw their deposited funds at any time without prior notice. When services involve deposited funds that can be retrieved by customers without penalties, we consider the service contract term to be day-to-day, where each day represents the renewal of the contract. The contract does not extend beyond the services performed and revenue is recognized at the end of the contract term (daily) as the performance obligation is satisfied. No deposit services fees exist for long-term deposit products beyond early withdrawal penalties, which are earned on these products at the time of early termination. Revenue from deposit services fees are reduced where we have a history of waived or reduced fees by customer request or due to a customer service issue, by historical experience, or another acceptable method in the same period as the related revenues. Revenues from deposit services are reported in the Consolidated Statements of Income as service charges and in the Community Banking segment as non-interest income. Wealth Management Services. Wealth advisory and trust services are provided on a month-to-month basis and invoiced as services are rendered. Fees are based on a fixed amount or a scale based on the level of services provided or assets under management. The customer has the right to terminate their services agreement at any time. We determine the value of services performed based on the fee schedule in effect at the time the services are performed. Revenues from wealth advisory and trust services are reported in the Consolidated Statements of Income as trust services and securities commissions and fees, and in the Wealth segment as non-interest income. Insurance Services. Insurance services include full-service insurance brokerage services offering numerous lines of commercial and personal insurance through major carriers to businesses and individuals within our geographic markets. We recognize revenue on insurance contracts in effect based on contractually specified commission payments on premiums that are paid by the customer to the insurance carrier. Contracts are cancellable at any time and we have no performance obligation to the customers beyond the time the insurance is placed into effect. Revenues from insurance services are reported in the Consolidated Statements of Income as insurance commissions and fees, and in the Insurance segment as non-interest income. Business Combinations Business combinations are accounted for by applying the acquisition method . Under the acquisition method, identifiable assets acquired and liabilities assumed, and any non-controlling interest in the acquiree at the acquisition date are measured at their fair values as of that date, and are recognized separately from goodwill. Results of operations of the acquired entities are included in the Consolidated Statements of Income from the date of acquisition. Cash and Cash Equivalents Cash and cash equivalents include cash on hand, cash items in transit and amounts due from the Federal Reserve Bank and other depository institutions (including interest-bearing deposits). 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 December 31, 2019 and 2018 , we did not hold any trading debt securities. Debt securities HTM are the securities that management has the positive intent and ability to hold until their maturity. Such securities are carried at cost, adjusted for related amortization of premiums and accretion of discounts through interest income from securities, and subject to evaluation for OTTI. Debt securities that are not classified as trading or HTM are classified as AFS. Such securities are carried at fair value with net unrealized gains and losses deemed to be temporary and OTTI attributable to non-credit factors reported separately as a component of OCI, net of tax. We evaluate our debt securities in a loss position for OTTI on a quarterly basis at the individual security level based on our intent to sell. If we intend to sell the debt security or it is more likely than not we will be required to sell the security before recovery of its amortized cost basis, OTTI must be recognized in earnings equal to the entire difference between the investments’ amortized cost basis and its fair value. If we do not intend to sell the debt security and it is not more likely than not that we will be required to sell the security before recovery of its amortized cost basis, OTTI must be separated into the amount representing credit loss and the amount related to all other market factors. The amount related to credit loss will be recognized in earnings. The amount related to other market factors will be recognized in OCI, net of tax. We perform our OTTI evaluation process in a consistent and systematic manner and include an evaluation of all available evidence. This process considers factors such as length of time and anticipated recovery period of the impairment, recent events specific to the issuer and recent experience regarding principal and interest payments. Securities Sold Under Agreements to Repurchase Securities sold under agreements to repurchase are accounted for as collateralized financing transactions and are recorded at the amounts at which the securities were sold plus accrued interest. Securities, generally U.S. government and federal agency securities, pledged as collateral under these financing arrangements cannot be sold or repledged by the secured party. The fair value of collateral either received from or provided to a third party is continually monitored and additional collateral is obtained or is requested to be returned to us as deemed appropriate. Derivative Instruments and Hedging Activities From time to time, we may enter into derivative transactions principally to protect against the risk of adverse price or interest rate movements on the value of certain assets and liabilities and on future cash flows. Foreign exchange derivatives are entered into to accommodate the needs of customers. All derivative instruments are carried at fair value on the Consolidated Balance Sheets as either an asset or liability. Accounting for the changes in fair value of a derivative is dependent upon whether it has been designated in a formal, qualifying hedging relationship. For derivatives in qualifying hedging relationships, we formally document all relationships between hedging instruments and hedged items, as well as our risk management objective and strategy for undertaking each hedge transaction. Cash flows from hedging activities are classified in the same category as the items hedged. Beginning in the first quarter of 2019, we adopted ASU 2017-12 which provides targeted improvements to the hedge accounting model that more closely aligns the accounting and reporting for hedging relationships with risk management activities. In addition, ASU 2017-12 provides administrative relief by easing documentation requirements, simplifying the application of hedge accounting by expanding the application of the shortcut method, eliminating the separate measurement and reporting of hedge ineffectiveness and generally requiring the entire effect of the hedging instrument and the hedged item to be presented in the same income statement line item. We believe these changes will provide users with more useful information about the effect of our risk management activities on the financial statements. Changes in fair value of a derivative instrument that has been designated and qualifies as a cash flow hedge, including any ineffectiveness, are recorded in accumulated other comprehensive income, net of tax. Amounts are reclassified from AOCI to the consolidated statements of income in the same line item used to present the earnings effect of the hedged item in the period or periods in which the hedged transaction affects earnings. Prior to 2019, the ineffective portion, if any, was reported in earnings immediately. At the hedge’s inception, a formal assessment is performed to determine whether changes in the fair values or cash flows of the derivative instruments have been highly effective in offsetting changes in fair values or cash flows of the hedged items and whether they are expected to be highly effective in the future. At each reporting period thereafter, a statistical regression or qualitative analysis is performed to evaluate hedge effectiveness. If it is determined a derivative instrument has not been or will not continue to be highly effective as a hedge, hedge accounting is discontinued. We also enter into interest rate swap agreements to meet the interest rate risk management needs of qualifying commercial loan customers. These agreements provide the customer the ability to convert from variable to fixed interest rates. We then enter into positions with a derivative counterparty in order to offset our exposure on the fixed components of the customer agreements. The credit risk associated with derivatives executed with customers is essentially the same as that involved in extending loans and is subject to normal credit policies and monitoring. We seek to minimize counterparty credit risk by entering into transactions with only high-quality institutions and using collateral agreements and other contract provisions. These arrangements meet the definition of derivatives, but are not designated as qualifying hedging relationships. The interest rate swap agreement with the loan customer and with the counterparty 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. Loans Held for Sale and Loan Commitments Certain of our residential mortgage loans are originated or purchased for sale in the secondary mortgage loan market. We make an automatic election to account for all originated or purchased residential mortgage loans held for sale under the FVO. The FVO election is intended to better reflect the underlying economics and better facilitate the economic hedging of the loans. The FVO is applied on an instrument by instrument basis and is an irrevocable election. Additionally, with the election of the FVO, fees and costs associated with the origination and acquisition of residential mortgage loans held for sale are expensed as incurred, rather than deferred. Changes in fair value under the FVO are recorded in mortgage banking operations non-interest income on the consolidated statements of income. Fair value is determined on the basis of rates obtained in the respective secondary market for the type of loan held for sale. Gain or loss on the sale of loans is recorded in mortgage banking operations non-interest income. Interest income on loans held for sale is recorded in interest income. We routinely issue interest rate lock commitments for residential mortgage loans that we intend to sell. These interest rate lock commitments are considered derivatives. We also enter into loan sale commitments to sell these loans when funded to mitigate the risk that the market value of residential mortgage loans may decline between the time the rate commitment is issued to the customer and the time we sell the loan. These loan sale commitments are also derivatives. Both types of derivatives are recorded at fair value on the Consolidated Balance Sheets with changes in fair value recorded in mortgage banking operations non-interest income. We also originate loans guaranteed by the SBA for the purchase of businesses, business startups, business expansion, equipment, and working capital. All SBA loans are underwritten and documented as prescribed by the SBA. SBA loans originated with the intention to sell on the secondary market are classified as held for sale and carried at the lower of cost or fair value. At the time of the sale, we allocate the carrying value of the entire loan between the guaranteed portion sold and the unguaranteed portion retained based on their relative fair value which results in a discount recorded on the retained portion of the loan. The guaranteed portion is typically sold at a premium and the gain is recognized in other income for any net premium received in excess of the relative fair value of the portion of the loan transferred. The net carrying value of the retained portion of the loans is included in the appropriate commercial loan classification for disclosure purposes. Loans (Excluding Loans Acquired in a Business Combination) Loans we intend to hold for the foreseeable future or until maturity or payoff are reported at their outstanding principal balances, net of any unearned income, deferred origination fees or costs, or premium 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 and 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 Interest is not accrued on loans where collectability is uncertain. We 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 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. Past due status is based on the contractual terms of the loan. When a loan is placed on non-accrual status, all unpaid interest is reversed against interest income and the amortization of deferred fees and costs is suspended. Payments subsequently received are generally applied to either principal or interest or both, depending on management’s evaluation of collectability. A loan is returned to accrual status when principal and interest are no longer past due and collectability is probable. This generally requires a sustained period of timely principal and interest payments. Loans are generally charged-off when deemed uncollectible or when they reach a predetermined number of days past due depending upon loan product, terms, and other factors. Recoveries of amounts previously charged-off are credited to the allowance for credit losses. We consider a loan impaired when, based on current information and events, it is probable that we will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered in determining impairment include payment status, collateral value and the probability of collecting scheduled principal and interest payments when due. The impairment loss is measured by either the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s obtainable market price, or the fair value of the collateral, less estimated selling costs, if the loan is collateral dependent. Purchased credit impaired loans are not classified as non-performing assets as the loans are considered to be performing. Restructured loans are those in which concessions of terms have been made as a result of deterioration in a borrower’s financial condition. In general, the modification or restructuring of a debt constitutes a TDR if we for economic or legal reasons related to the borrower’s financial difficulties grant a concession to the borrower that we would not otherwise consider under current market conditions. Debt restructurings or loan modifications for a borrower occur in the normal course of business and do not necessarily constitute TDRs. To designate a loan as a TDR, the presence of both borrower financial distress and a concession of terms must exist. 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 the borrower does not otherwise meet the criteria for non-accrual status, we will continue to accrue interest on the loan. A restructured acquired loan that is accounted for as a component of a pool is not considered a TDR. Allowance for Credit Losses The allowance for credit losses is established as losses are estimated to have occurred through a provision charged to earnings. Loan losses are charged-off against the allowance for credit losses when management believes the uncollectability of a loan balance is confirmed. Subsequent recoveries, if any, are credited to the allowance for credit losses. Allowances for impaired commercial loans over $1.0 million are generally determined based on collateral values or the present value of estimated cash flows. All other impaired loans are evaluated in the aggregate based on loan segment loss given default. Changes in the allowance for credit losses related to impaired loans are charged or credited to the provision for credit losses. The allowance for credit losses is maintained at a level that, in management’s judgment, is believed appropriate to absorb probable losses associated with specifically identified loans, as well as estimated probable credit losses inherent in the remainder of the loan portfolio. The appropriateness of the allowance for credit losses is based on management’s evaluation of potential loan losses in the loan portfolio, which includes an assessment of past experience, current economic conditions in specific industries and geographic areas, general economic conditions, known and inherent risks in the loan portfolio, the estimated value of underlying collateral and residuals and changes in the composition of the loan portfolio. Determination of the allowance for credit losses is inherently subjective as it requires significant estimates, including the amounts and timing of expected future cash flows on impaired loans, estimated losses on pools of homogeneous loans based on transition matrices with predefined loss emergence and lookback periods, and consideration of qualitative factors, all of which are susceptible to significant change. Loans Acquired in a Business Combination Loans acquired in a business combination (impaired and non-impaired) are initially recorded at their acquisition-date fair values. Fair values are based on a discounted cash flow methodology that involves assumptions and judgments as to credit risk, default rates, loss severity, collateral values, discount rates, payment speeds, prepayment risk, and liquidity risk. The carryover of allowance for credit losses related to loans acquired in a business combination is prohibited as any credit losses in the loans are included in the determination of the fair value of the loans at the acquisition date. The allowance for credit losses on loans acquired in a business combination reflects only those losses incurred after acquisition and represents the present value of cash flows expected at acquisition that is no longer expected to be collected. At acquisition, we consider the following factors as indicators that an acquired loan has evidence of deterioration in credit quality and is therefore impaired and in the scope of ASC 310-30: • loans that were 90 days or more past due; • loans that had an internal risk rating of substandard or worse. Substandard is consistent with regulatory definitions and is defined as having a well-defined weakness that jeopardizes liquidation of the loan; • loans that were classified as non-accrual by the acquired bank at the time of acquisition; or • loans that had been previously modified in a TDR. Any loans acquired in a business combination that were not individually in the scope of ASC 310-30 because they didn’t meet the criteria above were pooled into groups of similar loans based on various factors including borrower type, loan purpose, and collateral type. For these pools, we used certain loan information, including outstanding principal balance, estimated expected losses, weighted average maturity, weighted average margin, and weighted average interest rate along with estimated prepayment rates, probability of default and loss given default to estimate the expected cash flow for each loan pool. We believe analogizing to ASC 310-30 is the more appropriate option to follow in accounting for discount accretion on non-impaired loans acquired in a business combination other than revolving loans and therefore account for such loans in accordance with ASC 310-30. ASC 310-30 guidance does not apply to revolving loans. Consequently, discount accretion on revolving loans acquired is accounted for using the ASC 310-20 approach. The excess of cash flows expected to be collected at acquisition over recorded fair value is referred to as the accretable yield. The accretable yield is recognized into income over the remaining life of the loan, or pool of loans, using an effective yield method, if the timing and/or amount of cash flows expected to be collected can be reasonably estimated (the accretion model). The difference between the loan’s total scheduled principal and interest payments over all cash flows expected at acquisition is referred to as the non-accretable difference. The non-accretable difference represents contractually required principal and interest payments which we do not expect to collect. Over the life of the acquired loan, we continue to estimate cash flows expected to be collected. Decreases in expected cash flows, other than from prepayments or rate adjustments, are recognized as impairments through a charge to the provision for credit losses resulting in an increase in the allowance for credit losses. Subsequent improvements in cash flows result in first, reversal of existing valuation allowances recognized subsequent to acquisition, if any, and next, an increase in the amount of accretable yield to be subsequently recognized on a prospective basis over the loan’s remaining life. Loans acquired in a business combination that met the criteria for non-accrual of interest prior to acquisition are considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if we can reasonably estimate the timing and amount of expected cash flows on such loans. Accordingly, we do not consider contractually delinquent purchased credit impaired loans to be non-accrual or non-performing and continue to recognize interest income on these loans using the accretion model. Premises and Equipment Premises and equipment are stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the asset’s estimated useful life. Leasehold improvements are expensed over the lesser of the asset’s estimated useful life or the term of the lease including renewal periods when reasonably assured. Useful lives are dependent upon the nature and condition of the asset and range from 3 to 39 years. Maintenance and repairs are charged to expense as incurred, while major improvements are capitalized and amortized to expense over the identified useful life. Premises and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying value may not be recoverable. Cloud Computing Arrangements W e evaluate fees paid for cloud computing arrangements to determine if those arrangements include the purchase of or license to use software that should be accounted for separately as internal-use software. If a contract includes the purchase or license to use software that should be accounted for separately as internal-use software, the contract is amortized over the software’s identified useful life in amortization of intangibles. For contracts that do not include a software license, the contract is accounted for as a service contract with fees paid recorded in other non-interest expense. In the third quarter of 2018, we early adopted, on a prospective basis, ASU 2018-15 which allows for implementation costs for activities performed in cloud computing arrangements that are a service contract to be accounted for under the internal-use software guidance which allows for certain implementation costs to be capitalized depending on the nature of the costs and the project stage. Prior to the adoption of ASU 2018-15 all implementation costs for cloud computing arrangements that were a service contract were expensed as incurred. Other Real Estate Owned OREO is comprised principally of commercial and residential real estate properties obtained in partial or total satisfaction of loan obligations. OREO acquired in settlement of indebtedness is included in other assets initially at the lower of estimated fair value of the asset less estimated selling costs or the carrying amount of the loan. Changes to the value subsequent to transfer are recorded in non-interest expense along with direct operating expenses. Gains or losses not previously recognized resulting from sales of OREO are recognized in non-interest income on the date of sale. Goodwill and Other Intangible Assets Goodwill represents the excess of the cost of an acquisition over the fair value of the net assets acquired. Other intangible assets represent purchased assets that lack physical substance but can be distinguished from goodwill because of contractual or other legal rights. Intangible assets that have finite lives, such as core deposit intangibles, customer relationship intangibles and renewal lists, are amortized over their estimated useful lives and subject to periodic impairment testing. Core deposit intangibles are primarily amortized over ten years using accelerated methods. Customer renewal lists are amortized over their estimated useful lives which range from eight to thirteen years . Goodwill and other intangibles are subject to impairment testing at the reporting unit level, which must be conducted at least annually. We perform impairment testing during the fourth quarter of each year, or more frequently if impairment indicators exist. We also continue to monitor other intangibles for impairment and to evaluate carrying amounts, as necessary. Determining the fair value of a reporting unit under the goodwill impairment test is judgmental and often involves the use of significant estimates and assumptions. Similarly, estimates and assumptions are used in determining the fair value of other intangible assets. Estimates of fair value are primarily determined using discounted cash flows, market comparisons and recent transactions. These approaches use significant estimates and assumptions including projected future cash flows, discount rates reflecting the market rate of return, projected growth rates and determination and evaluation of appropriate market comparables. However, future events could cause us to conclude that goodwill or other intangibles have become impaired, which would result in recording an impairment loss. Any resulting impairment loss could have a material adverse impact on our financial condition and results of operations. Loan Servicing Rights We have two primary classes of servicing rights, residential mortgage loan servicing and SBA-guaranteed loan servicing. We recognize the right to service residential mortgage loans and SBA-guaranteed loans for others as an asset whether we purchase the servicing rights or as a result from a sale of loans that we originated or purchased when the servicing is contractually separated from the underlying loan and retained by us. We initially record servicing rights at fair value in other assets on the Consolidated Balance Sheets. Subsequently, servicing rights are measured at the lower of cost or fair value. Servicing rights are amortized in proportion to, and over the period of, estimated net servicing income in mortgage banking operations n

New Accounting Standards

New Accounting Standards	12 Months Ended
	Dec. 31, 2019
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 or will be adopting in the future. TABLE 2.1 Standard Description Financial Statements Impact Derivative and Hedging Activities ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities This Update improves the financial reporting of hedging to better align with a company’s risk management activities. In addition, this Update makes certain targeted improvements to simplify the application of the current hedge accounting guidance. We adopted this Update in the first quarter of 2019 using a modified retrospective transition method. The presentation and disclosure guidance were applied prospectively. The adoption of this Update did not have a material effect on our Consolidated Financial Statements. This Update was effective as of January 1, 2019. Securities ASU 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities This Update shortens the amortization period for the premium on certain purchased callable securities to the earliest call date. The accounting for purchased callable debt securities held at a discount does not change. We adopted this Update in the first quarter of 2019 using a modified retrospective transition method. The adoption of this Update did not have a material effect on our Consolidated Financial Statements. This Update was effective as of January 1, 2019. Leases ASU 2016-02, Leases (Topic 842) ASU 2018-10, Codification Improvements to Topic 842, Leases ASU 2018-11, Leases (Topic 842), Targeted Improvements ASU 2018-20, Leases (Topic 842), Narrow-Scope Improvements for Lessors ASU 2019-01, Lease (Topic 842), Codification Improvements These Updates require lessees to put most leases on the Consolidated Balance Sheets but recognize expenses in the Consolidated Statements of Income similar to current accounting. In addition, the Update changes the guidance for sales-leaseback transactions, initial direct costs and lease executory costs for most entities. All entities will classify leases to determine how to recognize lease related revenue and expense. We adopted these Updates in the first quarter of 2019 under the modified retrospective transition method. In addition, the new standard provides a number of optional practical expedients in transition. We elected the ‘package of practical expedients,’ which permits us to not reassess our prior conclusions about lease identification, lease classification and initial direct costs. Adoption of the new standard resulted in the recording of $116 million in right-of-use assets and corresponding lease liabilities of $126 million for operating leases on our Consolidated Balance Sheet. The standard did not materially impact our consolidated net earnings and had no impact on cash flows. These Updates were effective as of January 1, 2019. 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 ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments ASU 2019-05, Financial Instruments-Credit Losses, (Topic 326): Targeted Transition Relief ASU 2019-11, 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. These Updates are to be applied using a cumulative-effect adjustment to retained earnings. While these Updates change the measurement of the Allowance for Credit Losses (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 current 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 loans 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 necessary. Based on our portfolio composition and forecasts of relatively stable macroeconomic conditions over the next two years, we currently estimate that our CECL ACL on the originated portfolio will increase approximately 30%, primarily driven by our consumer portfolios. The overall ACL including the "gross-up" for PCI loans of approximately $50 million is approximately $300-$310 million. There is no capital impact related to the PCI loans at adoption. The impact for the adoption of CECL is a reduction to retained earnings of approximately $52 million. The impact of this Update is 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 is immaterial. Model development, as well as the development of policies and procedures and, internal controls are complete. This Update is effective as of January 1, 2020.

Securities

Securities	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Securities	SECURITIES The amortized cost and fair value of debt securities are as follows: TABLE 3.1 (in millions) Amortized Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt Securities Available for Sale: 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 11 — — 11 Other debt securities 2 — — 2 Total debt securities available for sale $ 3,275 $ 24 $ (10 ) $ 3,289 December 31, 2018 U.S. government agencies $ 188 $ — $ (1 ) $ 187 U.S. government-sponsored entities 317 — (4 ) 313 Residential mortgage-backed securities: Agency mortgage-backed securities 1,465 — (36 ) 1,429 Agency collateralized mortgage obligations 1,179 5 (23 ) 1,161 Commercial mortgage-backed securities 229 — (1 ) 228 States of the U.S. and political subdivisions 21 — — 21 Other debt securities 2 — — 2 Total debt securities available for sale 3,401 5 (65 ) 3,341 (in millions) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt Securities Held to Maturity: 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 1,120 26 (2 ) 1,144 Total debt securities held to maturity $ 3,275 $ 42 $ (12 ) $ 3,305 December 31, 2018 U.S. Treasury $ 1 $ — $ — $ 1 U.S. government agencies 2 — — 2 U.S. government-sponsored entities 215 — (4 ) 211 Residential mortgage-backed securities: Agency mortgage-backed securities 1,036 — (26 ) 1,010 Agency collateralized mortgage obligations 794 1 (24 ) 771 Commercial mortgage-backed securities 126 1 (1 ) 126 States of the U.S. and political subdivisions 1,080 3 (49 ) 1,034 Total debt securities held to maturity $ 3,254 $ 5 $ (104 ) $ 3,155 Gross gains and gross losses were realized on securities as follows: TABLE 3.2 Year Ended December 31 2019 2018 2017 (in millions) Gross gains $ — $ — $ 7 Gross losses — — (1 ) Net gains $ — $ — $ 6 As of December 31, 2019 , the amortized cost and fair value of debt securities, by contractual maturities, were as follows: TABLE 3.3 Available for Sale Held to Maturity (in millions) Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 93 $ 93 $ 58 $ 58 Due after one year but within five years 147 148 131 131 Due after five years but within ten years 62 62 117 119 Due after ten years 88 87 991 1,013 390 390 1,297 1,321 Residential mortgage-backed securities: Agency mortgage-backed securities 1,310 1,314 949 955 Agency collateralized mortgage obligations 1,234 1,240 721 720 Commercial mortgage-backed securities 341 345 308 309 Total debt securities $ 3,275 $ 3,289 $ 3,275 $ 3,305 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 3.4 December 31 2019 2018 (dollars in millions) Securities pledged (carrying value): To secure public deposits, trust deposits and for other purposes as required by law $ 4,494 $ 3,874 As collateral for short-term borrowings 285 279 Securities pledged as a percent of total securities 72.8 % 63.0 % Following are summaries of the fair values and unrealized losses of temporarily impaired debt securities, segregated by length of impairment: TABLE 3.5 Less than 12 Months 12 Months or More Total (dollars in millions) # Fair Value Unrealized Losses # Fair Value Unrealized Losses # Fair Value Unrealized Losses Debt Securities Available for Sale: 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 ) States of the U.S. and political subdivisions — — — — — — — — — Other debt securities — — — 1 2 — 1 2 — Total temporarily impaired debt securities AFS 32 $ 685 $ (4 ) 78 $ 712 $ (6 ) 110 $ 1,397 $ (10 ) December 31, 2018 U.S. government agencies 20 $ 145 $ (1 ) — $ — $ — 20 $ 145 $ (1 ) U.S. government-sponsored entities 1 36 — 11 227 (4 ) 12 263 (4 ) Residential mortgage-backed securities: Agency mortgage-backed securities 16 259 (4 ) 71 1,159 (32 ) 87 1,418 (36 ) Agency collateralized mortgage obligations 2 82 (1 ) 47 590 (22 ) 49 672 (23 ) Non-agency collateralized mortgage obligations 1 — — — — — 1 — — Commercial mortgage-backed securities 4 155 (1 ) — — — 4 155 (1 ) States of the U.S. and political subdivisions 2 2 — 6 10 — 8 12 — Other debt securities — — — 1 2 — 1 2 — Total temporarily impaired debt securities AFS 46 $ 679 $ (7 ) 136 $ 1,988 $ (58 ) 182 $ 2,667 $ (65 ) Less than 12 Months 12 Months or More Total (dollars in millions) # Fair Value Unrealized Losses # Fair Value Unrealized Losses # Fair Value Unrealized Losses Debt Securities Held to Maturity: December 31, 2019 U.S. government-sponsored entities — $ — $ — 8 $ 160 $ — 8 $ 160 $ — Residential mortgage-backed securities: Agency mortgage-backed securities 5 134 (1 ) 11 135 (1 ) 16 269 (2 ) Agency collateralized mortgage obligations 2 50 — 33 317 (6 ) 35 367 (6 ) Commercial mortgage-backed securities 5 184 (2 ) 1 7 — 6 191 (2 ) States of the U.S. and political subdivisions 18 63 (1 ) 7 29 (1 ) 25 92 (2 ) Total temporarily impaired debt securities HTM 30 $ 431 $ (4 ) 60 $ 648 $ (8 ) 90 $ 1,079 $ (12 ) December 31, 2018 U.S. government-sponsored entities — $ — $ — 12 $ 211 $ (4 ) 12 $ 211 $ (4 ) Residential mortgage-backed securities: Agency mortgage-backed securities 43 294 (4 ) 47 694 (22 ) 90 988 (26 ) Agency collateralized mortgage obligations 3 42 — 49 611 (24 ) 52 653 (24 ) Commercial mortgage-backed securities 5 26 — 4 43 (1 ) 9 69 (1 ) States of the U.S. and political subdivisions 159 590 (27 ) 51 161 (22 ) 210 751 (49 ) Total temporarily impaired debt securities HTM 210 $ 952 $ (31 ) 163 $ 1,720 $ (73 ) 373 $ 2,672 $ (104 ) We do not intend to sell the debt securities and it is not more likely than not that we will be required to sell the securities before recovery of their amortized cost basis. Other-Than-Temporary Impairment We evaluate our investment securities portfolio for OTTI on a quarterly basis. Impairment is assessed at the individual security level. We consider an investment security impaired if the fair value of the security is less than its cost or amortized cost basis. We did not recognize any OTTI losses on securities for the years ended December 31, 2019 , 2018 and 2017 . States of the U.S. and Political Subdivisions Our municipal bond portfolio with a carrying amount of $1.1 billion as of December 31, 2019 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 66% 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 $3.4 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.

Other Securities

Other Securities	12 Months Ended
	Dec. 31, 2019
Banking and Thrift, Interest [Abstract]
Other Securities	OTHER SECURITIES Following is a summary of non-marketable equity securities: TABLE 4.1 December 31 2019 2018 (in millions) Federal Home Loan Bank stock $ 256 $ 209 Federal Reserve Bank stock 123 122 Other non-marketable equity securities 1 1 Total non-marketable equity securities $ 380 $ 332 We are a member of the FHLB of Pittsburgh and the FRB of Cleveland. Both institutions require members to purchase and hold a specified minimum level of stock based upon their membership, level of borrowings, collateral balances or participation in other programs. The FHLB and FRB stock is restricted in that they can only be sold back to the respective institutions. These non-marketable equity securities are included in other assets on the Consolidated Balance Sheets. The investments are carried at cost and evaluated for impairment periodically based on the ultimate recoverability of the par value. We determined there was no impairment at December 31, 2019 and 2018

Loans and Leases

Loans and Leases	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Loans and Leases	LOANS AND LEASES Following is a summary of loans and leases, net of unearned income: TABLE 5.1 (in millions) Originated Loans and Leases Loans Acquired in a Business Combination Total Loans and Leases December 31, 2019 Commercial real estate $ 7,114 $ 1,846 $ 8,960 Commercial and industrial 5,063 245 5,308 Commercial leases 432 — 432 Other 21 — 21 Total commercial loans and leases 12,630 2,091 14,721 Direct installment 1,758 63 1,821 Residential mortgages 2,995 379 3,374 Indirect installment 1,922 — 1,922 Consumer lines of credit 1,092 359 1,451 Total consumer loans 7,767 801 8,568 Total loans and leases, net of unearned income $ 20,397 $ 2,892 $ 23,289 December 31, 2018 Commercial real estate $ 6,171 $ 2,615 $ 8,786 Commercial and industrial 4,140 416 4,556 Commercial leases 373 — 373 Other 46 — 46 Total commercial loans and leases 10,730 3,031 13,761 Direct installment 1,668 96 1,764 Residential mortgages 2,612 501 3,113 Indirect installment 1,933 — 1,933 Consumer lines of credit 1,119 463 1,582 Total consumer loans 7,332 1,060 8,392 Total loans and leases, net of unearned income $ 18,062 $ 4,091 $ 22,153 The loans and leases portfolio categories are comprised of the following: • Commercial real estate includes both owner-occupied and non-owner-occupied loans secured by commercial properties; • Commercial and industrial includes loans to businesses that are not secured by real estate; • Commercial leases consist of leases for new or used equipment; • Other is comprised primarily of credit cards and mezzanine loans; • 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; • Residential mortgages consist of conventional and jumbo mortgage loans for 1-4 family properties; • Indirect installment is comprised of loans originated by approved third parties and underwritten by us, primarily automobile loans; 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. The loans and leases portfolio consists principally of loans to individuals and small- and medium-sized businesses within our primary market in seven states and the District of Columbia. Our primary market coverage spans several major metropolitan areas including: Pittsburgh, Pennsylvania; Baltimore, Maryland; Cleveland, Ohio; Washington, D.C.; and Charlotte, Raleigh, Durham and the Piedmont Triad (Winston-Salem, Greensboro and High Point) in North Carolina. The following table shows certain information relating to commercial real estate loans: TABLE 5.2 December 31 2019 2018 (dollars in millions) Commercial construction, acquisition and development loans $ 1,275 $ 1,152 Percent of total loans and leases 5.5 % 5.2 % Commercial real estate: Percent owner-occupied 30.6 % 35.1 % Percent non-owner-occupied 69.4 % 64.9 % Additionally, as of December 31, 2019 and 2018 , we had residential construction loans of $297.3 million and $273.4 million , representing 1.3% and 1.2% of total loans and leases, respectively. We have extended credit to certain directors and executive officers and their related interests. These related-party loans were made in the ordinary course of business under normal credit terms and do not involve more than a normal risk of collection. Following is a summary of the activity for these loans to related parties during 2019 : TABLE 5.3 (in millions) Balance at beginning of period $ 16 New loans 1 Repayments (10 ) Balance at end of period $ 7 Loans Acquired in a Business Combination All loans acquired in a business combination were initially recorded at fair value at the acquisition date. Refer to the Loans Acquired in a Business Combination section in Note 1, “Summary of Significant Accounting Policies,” for a discussion of ASC 310-20 and ASC 310-30 loans. The outstanding balance and the carrying amount of loans acquired in a business combination included in the Consolidated Balance Sheets are as follows: TABLE 5.4 December 31 2019 2018 (in millions) Accounted for under ASC 310-30: Outstanding balance $ 2,684 $ 3,768 Carrying amount 2,461 3,570 Accounted for under ASC 310-20: Outstanding balance 436 602 Carrying amount 425 513 Total loans acquired in a business combination: Outstanding balance 3,120 4,370 Carrying amount 2,886 4,083 The outstanding balance is the undiscounted sum of all amounts owed under the loan, including amounts deemed principal, interest, fees, penalties and other, whether or not currently due and whether or not any such amounts have been charged-off. The carrying amount of PCI loans included in the table above totaled $1.5 million at December 31, 2019 and $1.7 million at December 31, 2018 , representing 0.05% and 0.04% , respectively, of the carrying amount of total loans acquired in a business combination as of each date. The following table provides changes in accretable yield for all loans acquired in business combinations that are accounted for under ASC 310-30. Loans accounted for under ASC 310-20 are not included in this table. TABLE 5.5 Year Ended December 31 2019 2018 (in millions) Balance at beginning of period $ 605 $ 708 Reduction due to unexpected early payoffs (102 ) (146 ) Reclass from non-accretable difference to accretable yield 97 267 Disposals/transfers (1 ) (1 ) Other (1 ) (1 ) Accretion (179 ) (222 ) Balance at end of period $ 419 $ 605 Cash flows expected to be collected on loans acquired in business combinations are estimated quarterly by incorporating several key assumptions similar to the initial estimate of fair value. These key assumptions include probability of default and the amount of actual prepayments after the acquisition date. Prepayments affect the estimated life of the loans and could change the amount of interest income. In reforecasting future estimated cash flows, credit loss expectations are adjusted as necessary. Improved cash flow expectations for loans or pools are recorded first as a reversal of previously recorded impairment, if any, and then as an increase in prospective yield when all previously recorded impairment has been recaptured. Decreases in expected cash flows are recognized as impairment through a charge to the provision for credit losses and credit to the allowance for credit losses. During 2019 , there was an overall improvement in cash flow expectations which resulted in a net reclassification of $97.0 million from the non-accretable difference to accretable yield primarily driven by overall improvement in the primary credit quality indicators of the majority of the acquired loan pools. This reclassification was $266.5 million for 2018 . The reclassification from the non-accretable difference to the accretable yield results in prospective yield adjustments on the loan pools. Credit Quality Management monitors the credit quality of our loan portfolio using several performance measures based on payment activity and borrower performance. Non-performing loans include non-accrual loans and non-performing TDRs. 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, or when the full amount of principal and 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 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. 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. The majority of TDRs are loans in which we have granted a concession on the original repayment terms due to the borrower’s financial distress. Following is a summary of non-performing assets: TABLE 5.6 December 31 2019 2018 (dollars in millions) Non-accrual loans $ 81 $ 79 Troubled debt restructurings 22 21 Total non-performing loans 103 100 Other real estate owned 26 35 Total non-performing assets $ 129 $ 135 Asset quality ratios: Non-performing loans / total loans and leases 0.44 % 0.45 % Non-performing loans + OREO / total loans and leases + OREO 0.55 % 0.61 % Non-performing assets / total assets 0.37 % 0.41 % 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 $3.3 million at December 31, 2019 and $6.3 million at December 31, 2018 . The recorded investment of residential-secured consumer OREO for which formal foreclosure proceedings are in process at December 31, 2019 and December 31, 2018 totaled $9.2 million and $8.9 million , respectively. The following tables provide an analysis of the aging of loans by class segregated by loans and leases originated and loans acquired: TABLE 5.7 (in millions) 30-89 Days Past Due ≥ 90 Days Past Due and Still Accruing Non- Accrual Total Past Due Current Total Loans and Leases 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 December 31, 2018 Commercial real estate $ 7 $ — $ 17 $ 24 $ 6,147 $ 6,171 Commercial and industrial 5 — 19 24 4,116 4,140 Commercial leases 1 — 2 3 370 373 Other — — 1 1 45 46 Total commercial loans and leases 13 — 39 52 10,678 10,730 Direct installment 8 — 8 16 1,652 1,668 Residential mortgages 16 3 6 25 2,587 2,612 Indirect installment 11 1 2 14 1,919 1,933 Consumer lines of credit 5 1 3 9 1,110 1,119 Total consumer loans 40 5 19 64 7,268 7,332 Total originated loans and leases $ 53 $ 5 $ 58 $ 116 $ 17,946 $ 18,062 (in millions) 30-89 Days Past Due ≥ 90 Days Past Due and Still Accruing Non- Accrual Total Past Due (1) (2) Current (Discount)/ Premium Total Loans 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 December 31, 2018 Commercial real estate $ 19 $ 38 $ 3 $ 60 $ 2,723 $ (168 ) $ 2,615 Commercial and industrial 3 4 17 24 420 (28 ) 416 Total commercial loans 22 42 20 84 3,143 (196 ) 3,031 Direct installment 3 2 — 5 91 — 96 Residential mortgages 13 6 — 19 498 (16 ) 501 Consumer lines of credit 8 3 1 12 461 (10 ) 463 Total consumer loans 24 11 1 36 1,050 (26 ) 1,060 Total loans acquired in a business combination $ 46 $ 53 $ 21 $ 120 $ 4,193 $ (222 ) $ 4,091 (1) Past due information for loans acquired in a business combination is based on the contractual balance outstanding at December 31, 2019 and 2018 . (2) Loans acquired in a business combination are considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if we can reasonably estimate the timing and amount of expected cash flows on such loans. In these instances, we do not consider acquired contractually delinquent loans to be non-accrual or non-performing and continue to recognize interest income on these loans using the accretion method. 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. We utilize the following categories to monitor credit quality within our commercial loan and lease portfolio: TABLE 5.8 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 estimate a quantitative portion of credit risk. Our internal credit risk grading system is based on past experiences with similarly graded loans and leases and conforms with regulatory categories. In general, loan and lease risk ratings within each category are reviewed on an ongoing basis according to our policy for each class of loans and leases. Each quarter, management analyzes the resulting ratings, as well as other external statistics and factors such as delinquency, to track the migration performance of the commercial loan and lease portfolio. Loans and leases within the Pass credit category or that migrate toward the Pass credit category generally have a lower risk of loss compared to loans and leases that migrate toward the Substandard or Doubtful credit categories. Accordingly, management applies higher risk factors to Substandard and Doubtful credit categories. The following tables present a summary of our commercial loans and leases by credit quality category segregated by loans and leases originated and loans acquired: TABLE 5.9 Commercial Loan and Lease Credit Quality Categories (in millions) Pass Special Mention 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 and leases $ 12,032 $ 323 $ 272 $ 3 $ 12,630 December 31, 2018 Commercial real estate $ 5,883 $ 163 $ 125 $ — $ 6,171 Commercial and industrial 3,879 180 81 — 4,140 Commercial leases 366 1 6 — 373 Other 45 — 1 — 46 Total originated commercial loans and leases $ 10,173 $ 344 $ 213 $ — $ 10,730 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 December 31, 2018 Commercial real estate $ 2,256 $ 168 $ 191 $ — $ 2,615 Commercial and industrial 355 18 43 — 416 Total commercial loans acquired in a business combination $ 2,611 $ 186 $ 234 $ — $ 3,031 Credit quality information for loans acquired in a business combination is based on the contractual balance outstanding at December 31, 2019 and 2018 . We use delinquency transition matrices within the consumer and other loan classes to enable management to estimate a quantitative portion of credit risk. Each month, management analyzes payment and volume activity, FICO scores and other external factors such as unemployment, to determine how consumer loans are performing. Following is a table showing consumer loans by payment status: TABLE 5.10 Consumer Loan Credit Quality by Payment Status (in millions) Performing Non-Performing 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 December 31, 2018 Direct installment $ 1,654 $ 14 $ 1,668 Residential mortgages 2,598 14 2,612 Indirect installment 1,931 2 1,933 Consumer lines of credit 1,114 5 1,119 Total originated consumer loans $ 7,297 $ 35 $ 7,332 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 December 31, 2018 Direct installment $ 96 $ — $ 96 Residential mortgages 501 — 501 Consumer lines of credit 462 1 463 Total consumer loans acquired in a business combination $ 1,059 $ 1 $ 1,060 Loans are designated as impaired when, in the opinion of management, based on current information and events, the collection of principal and interest in accordance with the loan and lease contract is doubtful. Typically, we do not consider loans for impairment unless a sustained period of delinquency (i.e., 90 -plus days) is noted or there are subsequent events that impact repayment probability (i.e., negative financial trends, bankruptcy filings, imminent foreclosure proceedings, etc.). Impairment is evaluated in the aggregate for consumer installment loans, residential mortgages, consumer lines of credit and commercial loan relationships less than $1.0 million based on loan segment loss given default. For commercial loan relationships greater than or equal to $1.0 million , a specific valuation allowance is allocated, if necessary, so that the loan is reported net, at the present value of estimated future cash flows using a market interest rate or at the fair value of collateral if repayment is expected solely from the sale of the collateral. Consistent with our existing method of income recognition for loans, interest income on impaired loans, except those classified as non-accrual, is recognized using the accrual method. Impaired loans, or portions thereof, are charged off when deemed uncollectible. Following is a summary of information pertaining to loans and leases considered to be impaired, by class of loan and lease: TABLE 5.11 (in millions) Unpaid Contractual Principal Balance Recorded Investment With No Specific Reserve Recorded Investment With Specific Reserve Total Recorded Investment Specific Reserve Average Recorded Investment At or for the Year Ended Commercial real estate $ 30 $ 25 $ 2 $ 27 $ 2 $ 26 Commercial and industrial 35 21 — 21 2 22 Commercial leases 1 1 — 1 — 1 Total commercial loans and leases 66 47 2 49 4 49 Direct installment 16 13 — 13 — 13 Residential mortgages 20 18 — 18 — 17 Indirect installment 5 3 — 3 — 3 Consumer lines of credit 7 5 — 5 — 5 Total consumer loans 48 39 — 39 — 38 Total $ 114 $ 86 $ 2 $ 88 $ 4 $ 87 At or for the Year Ended Commercial real estate $ 20 $ 16 $ 1 $ 17 $ — $ 18 Commercial and industrial 46 20 13 33 4 32 Commercial leases 2 2 — 2 — 4 Total commercial loans and leases 68 38 14 52 4 54 Direct installment 17 14 — 14 — 14 Residential mortgages 16 14 — 14 — 15 Indirect installment 5 2 — 2 — 2 Consumer lines of credit 7 5 — 5 — 5 Total consumer loans 45 35 — 35 — 36 Total $ 113 $ 73 $ 14 $ 87 $ 4 $ 90 Interest income continued to accrue on certain impaired loans and totaled approximately $5.9 million , $5.9 million and $6.1 million during 2019 , 2018 and 2017 , respectively. The above tables include one loan acquired in a business combination with a specific reserve at December 31, 2018 . Following is a summary of the allowance for credit losses required for loans acquired in a business combination due to changes in credit quality subsequent to the acquisition date: TABLE 5.12 December 31 2019 2018 (in millions) Commercial real estate $ 4 $ 2 Commercial and industrial — 4 Total commercial loans 4 6 Direct installment 1 1 Residential mortgages 2 — Total consumer loans 3 1 Total allowance on loans acquired in a business combination $ 7 $ 7 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. Following is a summary of the composition of total TDRs: TABLE 5.13 (in millions) Originated Acquired Total December 31, 2019 Accruing: Performing $ 19 $ — $ 19 Non-performing 18 4 22 Non-accrual 14 1 15 Total TDRs $ 51 $ 5 $ 56 December 31, 2018 Accruing: Performing $ 18 $ — $ 18 Non-performing 17 4 21 Non-accrual 9 — 9 Total TDRs $ 44 $ 4 $ 48 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 2019 , we returned to performing status $4.4 million in restructured residential mortgage loans that have consistently met their modified obligations for more than six months. TDRs that are accruing and non-performing are comprised of consumer loans that have not demonstrated a consistent repayment pattern on the modified terms for more than six months, however it is expected that we will collect all future principal and interest payments. 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 allowance for credit losses. Excluding purchased credit impaired loans, commercial loans over $1.0 million whose terms have been modified in a TDR are generally placed on non-accrual, individually analyzed and measured for estimated impairment based on the fair value of the underlying collateral. Our allowance for credit losses included specific reserves for commercial TDRs and pooled reserves for individually impaired loans under $1.0 million based on loan segment loss given default. Our allowance for loan losses includes specific reserves for commercial TDRs of less than $0.5 million at December 31, 2019 and 2018 , respectively, and pooled reserves for individual loans of $0.8 million and $0.5 million for those same respective periods, 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 allowance for credit losses. All other classes of loans whose terms have been modified in a TDR are pooled and measured for estimated impairment based on the expected net present value of the estimated future cash flows of the pool. Our allowance for credit losses included pooled reserves for these classes of loans of $4.1 million and $4.0 million at December 31, 2019 and 2018 , respectively. 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: TABLE 5.14 Year Ended December 31 2019 2018 (dollars in millions) Number of Contracts Pre-Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Commercial real estate 20 $ 5 $ 5 4 $ 1 $ 1 Commercial and industrial 23 5 3 10 — — Total commercial loans 43 10 8 14 1 1 Direct installment 65 3 3 80 4 4 Residential mortgages 18 3 3 15 1 1 Consumer lines of credit 27 2 1 26 1 1 Total consumer loans 110 8 7 121 6 6 Total 153 $ 18 $ 15 135 $ 7 $ 7 The items in the above tables have been adjusted for loans that have been paid off and/or sold. 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. Default occurs when a loan is 90 days or more past due and is within 12 months of restructuring. TABLE 5.15 Year Ended December 31 2019 2018 (dollars in millions) Number of Contracts Recorded Investment Number of Contracts Recorded Investment Commercial real estate 5 $ 1 3 $ 1 Commercial and industrial 1 — 1 — Total commercial loans 6 1 4 1 Direct installment 5 — 7 1 Residential mortgages 2 — 4 — Consumer lines of credit 1 — 3 — Total consumer loans 8 — 14 1 Total 14 $ 1 18 $ 2

Allowance for Credit Losses

Allowance for Credit Losses	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Allowance for Credit Losses	ALLOWANCE FOR CREDIT LOSSES Following is a summary of changes in the allowance for credit losses, by loan and lease class: TABLE 6.1 (in millions) Balance at Beginning of Year Charge- Offs Recoveries Net Charge- Offs Provision for Credit Losses Balance at End of Year Year Ended December 31, 2019 Commercial real estate $ 55 $ (4 ) $ 4 $ — $ 5 $ 60 Commercial and industrial 49 (10 ) 4 (6 ) 10 53 Commercial leases 8 — — — 3 11 Other 2 (3 ) — (3 ) 3 2 Total commercial loans and leases 114 (17 ) 8 (9 ) 21 126 Direct installment 14 (1 ) — (1 ) — 13 Residential mortgages 20 (2 ) — (2 ) 4 22 Indirect installment 15 (11 ) 4 (7 ) 11 19 Consumer lines of credit 10 (2 ) — (2 ) 1 9 Total consumer loans 59 (16 ) 4 (12 ) 16 63 Total allowance on originated loans and leases 173 (33 ) 12 (21 ) 37 189 Purchased credit-impaired loans 1 — — — — 1 Other loans acquired in a business combination 6 (9 ) 2 (7 ) 7 6 Total allowance on loans acquired in a business combination 7 (9 ) 2 (7 ) 7 7 Total allowance for credit losses $ 180 $ (42 ) $ 14 $ (28 ) $ 44 $ 196 (in millions) Balance at Beginning of Year Charge- Offs Recoveries Net Charge- Offs Provision for Credit Losses Balance at End of Year Year Ended December 31, 2018 Commercial real estate $ 50 $ (7 ) $ 3 $ (4 ) $ 9 $ 55 Commercial and industrial 52 (20 ) 2 (18 ) 15 49 Commercial leases 5 (3 ) — (3 ) 6 8 Other 2 (4 ) — (4 ) 4 2 Total commercial loans and leases 109 (34 ) 5 (29 ) 34 114 Direct installment 21 (17 ) 2 (15 ) 8 14 Residential mortgages 16 — — — 4 20 Indirect installment 12 (9 ) 4 (5 ) 8 15 Consumer lines of credit 10 (3 ) — (3 ) 3 10 Total consumer loans 59 (29 ) 6 (23 ) 23 59 Total allowance on originated loans and leases 168 (63 ) 11 (52 ) 57 173 Purchased credit-impaired loans 1 — — — — 1 Other loans acquired in a business combination 6 (7 ) 3 (4 ) 4 6 Total allowance on loans acquired in a business combination 7 (7 ) 3 (4 ) 4 7 Total allowance for credit losses $ 175 $ (70 ) $ 14 $ (56 ) $ 61 $ 180 Year Ended December 31, 2017 Commercial real estate $ 47 $ (2 ) $ 2 $ — $ 3 $ 50 Commercial and industrial 48 (27 ) 2 (25 ) 29 52 Commercial leases 3 (1 ) — (1 ) 3 5 Other 1 (4 ) 1 (3 ) 4 2 Total commercial loans and leases 99 (34 ) 5 (29 ) 39 109 Direct installment 21 (12 ) 2 (10 ) 10 21 Residential mortgages 10 — — — 6 16 Indirect installment 11 (10 ) 4 (6 ) 7 12 Consumer lines of credit 10 (2 ) — (2 ) 2 10 Total consumer loans 52 (24 ) 6 (18 ) 25 59 Total allowance on originated loans and leases 151 (58 ) 11 (47 ) 64 168 Purchased credit-impaired loans 1 (1 ) — (1 ) 1 1 Other loans acquired in a business combination 6 (1 ) 5 4 (4 ) 6 Total allowance on loans acquired in a business combination 7 (2 ) 5 3 (3 ) 7 Total allowance for credit losses $ 158 $ (60 ) $ 16 $ (44 ) $ 61 $ 175 Following is a summary of the individual and collective allowance for credit losses and corresponding loan and lease balances by class: TABLE 6.2 Allowance Loans and Leases Outstanding (in millions) Individually Evaluated for Impairment Collectively Evaluated for Impairment Loans and Leases Individually Evaluated for Impairment Collectively Evaluated for Impairment 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 December 31, 2018 Commercial real estate $ — $ 55 $ 6,171 $ 7 $ 6,164 Commercial and industrial 4 49 4,140 11 4,129 Commercial leases — 9 373 — 373 Other — 2 46 — 46 Total commercial loans and leases 4 115 10,730 18 10,712 Direct installment — 14 1,668 — 1,668 Residential mortgages — 19 2,612 — 2,612 Indirect installment — 15 1,933 — 1,933 Consumer lines of credit — 10 1,119 — 1,119 Total consumer loans — 58 7,332 — 7,332 Total $ 4 $ 173 $ 18,062 $ 18 $ 18,044 The above table excludes loans acquired in a business combination that were pooled into groups of loans for evaluating impairment.

Loan Servicing

Loan Servicing	12 Months Ended
	Dec. 31, 2019
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, as of December 31, 2019 and 2018 , is listed below: TABLE 7.1 December 31 2019 2018 (in millions) Mortgage loans sold with servicing retained $ 4,686 $ 3,968 The following table summarizes activity relating to mortgage loans sold with servicing retained: TABLE 7.2 Year Ended December 31 2019 2018 2017 (in millions) Mortgage loans sold with servicing retained $ 1,381 $ 1,060 $ 1,769 Pretax gains resulting from above loan sales (1) 32 19 22 Mortgage servicing fees (1) 11 9 8 (1) Recorded in mortgage banking operations on the Consolidated Statements of Income. Following is a summary activity relating to MSRs: TABLE 7.3 Year Ended December 31 2019 2018 2017 (in millions) Balance at beginning of period $ 37 $ 29 $ 14 Fair value of MSRs acquired — — 8 Additions 14 13 11 Payoffs and curtailments (5 ) (2 ) (2 ) Impairment charge (1 ) (1 ) — Amortization (2 ) (2 ) (2 ) Balance at end of period $ 43 $ 37 $ 29 Fair value, beginning of period $ 41 $ 32 $ 18 Fair value, end of period 45 41 32 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 7.4 December 31 2019 2018 (dollars in millions) Weighted average life (months) 78.9 82.2 Constant prepayment rate (annualized) 10.6 % 10.1 % Discount rate 9.7 % 9.7 % Effect on fair value due to change in interest rates: +0.25% $ 3 $ 3 +0.50% 5 5 -0.25% (3 ) (3 ) -0.50% (5 ) (6 ) 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 $1.5 million valuation allowance for MSRs as of December 31, 2019 , compared to $0.5 million at December 31, 2018 . SBA-Guaranteed Loan Servicing We retain the servicing rights on SBA-guaranteed loans sold to investors. The standard sale structure under the SBA Secondary Participation Guaranty Agreement provides for us to retain a portion of the cash flow from the interest payment received on the SBA guaranteed portion of the loan, which is commonly known as a servicing spread. The unpaid principal balance of SBA-guaranteed loans serviced for investors, as of December 31, 2019 and December 31, 2018 , was as follows: TABLE 7.5 December 31 2019 2018 (in millions) SBA loans sold to investors with servicing retained $ 225 $ 283 The following table summarizes activity relating to SBA loans sold with servicing retained: TABLE 7.6 Year Ended December 31 2019 2018 2017 (in millions) SBA loans sold with servicing retained $ 23 $ 41 $ 54 Pretax gains resulting from above loan sales (1) 2 4 2 SBA servicing fees (1) 2 3 2 (1) Recorded in non-interest income. Following is a summary of the activity in SBA servicing rights: TABLE 7.7 Year Ended December 31 2019 2018 2017 (in millions) Balance at beginning of period $ 4 $ 5 $ — Fair value of servicing rights acquired — — 5 Additions — 1 1 Payoffs, curtailments and amortization (1 ) (1 ) (1 ) Impairment (charge) / recovery — (1 ) — Balance at end of period $ 3 $ 4 $ 5 Fair value, beginning of period $ 4 $ 5 $ — Fair value, end of period 3 4 5 Following is a summary of key assumptions and the sensitivity of the SBA servicing rights to changes in these assumptions. The declines in fair values were immaterial in the scenarios presented. TABLE 7.8 December 31 2019 2018 (dollars in millions) Weighted average life (months) 42.0 52.2 Constant prepayment rate 16.8 % 12.5 % Discount rate 16.2 % 19.4 % Decline in fair value due to change in interest rates: 1% adverse change $ (0.1 ) $ (0.1 ) 2% adverse change (0.1 ) (0.2 ) Decline in fair value due to change in constant prepayment rates: 10% adverse change (0.1 ) (0.2 ) 20% adverse change (0.3 ) (0.3 ) The fair value of the SBA servicing rights is compared to the amortized basis. If the amortized basis exceeds the fair value, the asset is considered impaired and is written down to fair value through a valuation allowance on the asset and a charge against other non-interest income. We had a $1.2 million valuation allowance for SBA servicing rights as of December 31, 2019 , compared to $0.8 million at December 31, 2018 .

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Premises and Equipment	PREMISES AND EQUIPMENT Following is a summary of premises and equipment: TABLE 8.1 December 31 2019 2018 (in millions) Land $ 62 $ 64 Premises 233 238 Equipment 276 236 571 538 Accumulated depreciation (238 ) (208 ) Total premises and equipment, net $ 333 $ 330 Depreciation expense for premises and equipment is presented in the following table: TABLE 8.2 December 31 2019 2018 2017 (in millions) Depreciation expense for premises and equipment $ 42 $ 39 $ 34

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	GOODWILL AND OTHER INTANGIBLE ASSETS The following table shows a rollforward of goodwill by line of business: TABLE 9.1 (in millions) Community Banking Wealth Manage- ment Insurance Other (1) Total Balance at January 1, 2018 $ 2,228 $ 8 $ 11 $ 2 $ 2,249 Goodwill (deductions) additions 3 — 5 (2 ) 6 Balance at December 31, 2018 2,231 8 16 — 2,255 Goodwill (deductions) additions — — 7 — 7 Balance at December 31, 2019 $ 2,231 $ 8 $ 23 $ — $ 2,262 (1) Other represents Consumer Finance which was a reportable segment prior to December 31, 2018. The deduction of goodwill for the Consumer Finance segment in 2018 was the result of the sale of Regency to Mariner Finance, LLC on August 31, 2018, as part of our strategy to enhance the overall positioning of our consumer banking operations. The addition of goodwill for the Insurance segment in 2018 and 2019 was the result of the FNIA acquisitions of a Maryland-based insurance agency on December 17, 2018 and a North Carolina-based insurance agency on June 17, 2019. We recorded goodwill in the Community Banking segment during 2018 as a result of the purchase accounting adjustments relating to the YDKN acquisition described in Note 27, “Mergers and Acquisitions.” The following table shows a summary of core deposit intangibles and customer renewal lists: TABLE 9.2 (in millions) Core Deposit Intangibles Customer Renewal Lists Total December 31, 2019 Gross carrying amount $ 196 $ 18 $ 214 Accumulated amortization (136 ) (11 ) (147 ) Net carrying amount $ 60 $ 7 $ 67 December 31, 2018 Gross carrying amount $ 196 $ 15 $ 211 Accumulated amortization (122 ) (10 ) (132 ) Net carrying amount $ 74 $ 5 $ 79 Core deposit intangibles are being amortized primarily over 10 years using accelerated methods. Customer renewal lists are being amortized over their estimated useful lives, which range from eight to thirteen years . The following table summarizes amortization expense recognized: TABLE 9.3 December 31 2019 2018 2017 (in millions) Amortization expense $ 14 $ 16 $ 18 Following is a summary of the expected amortization expense on finite-lived intangible assets, assuming no new additions, for each of the five years following December 31, 2019 : TABLE 9.4 (in millions) 2020 $ 13 2021 12 2022 10 2023 10 2024 8 Total $ 53 Goodwill and 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 test in 2019 and 2018 and determined that our intangible assets are not impaired.

Operating Leases

Operating Leases	12 Months Ended
	Dec. 31, 2019
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 December 31, 2019 , we had operating lease right-of-use assets and operating lease liabilities of $121.4 million and $128.2 million , respectively. Our operating lease agreements do not contain any material residual value guarantees or material restrictive covenants. As of December 31, 2019 , 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 $29.0 million in right-of-use assets and other liabilities. These operating leases will commence in 2020 with lease terms of 6 years to 15 years. The components of lease expense were as follows: TABLE 10.1 Twelve Months Ended (dollars in millions) 2019 Operating lease cost $ 27 Short-term lease cost 1 Variable lease cost 4 Sublease income — Total lease cost $ 32 Rental expense totaled $33.2 million and $29.1 million for 2018 and 2017 , respectively. Other information related to leases is as follows: TABLE 10.2 Twelve Months Ended (dollars in millions) 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 26 Right-of-use assets obtained in exchange for lease obligations: Operating leases 25 Weighted average remaining lease term (years): Operating leases 9.61 Weighted average discount rate: Operating leases 3.0 % Maturities of operating lease liabilities were as follows: TABLE 10.3 (in millions) December 31, 2020 $ 24 2021 22 2022 17 2023 13 2024 12 Later years 62 Total lease payments 150 Less: imputed interest (22 ) Present value of lease liabilities $ 128

Deposits

Deposits	12 Months Ended
	Dec. 31, 2019
Deposits [Abstract]
Deposits	DEPOSITS Following is a summary of deposits: TABLE 11.1 December 31 2019 2018 (in millions) Non-interest-bearing demand $ 6,384 $ 6,000 Interest-bearing demand 11,049 9,660 Savings 2,625 2,526 Certificates and other time deposits: Less than $100,000 2,262 2,816 $100,000 through $250,000 1,494 1,478 Greater than $250,000 972 975 Total certificates and other time deposits 4,728 5,269 Total deposits $ 24,786 $ 23,455 Following is a summary of the scheduled maturities of certificates and other time deposits for the years following December 31, 2019 : TABLE 11.2 (in millions) 2020 $ 3,035 2021 1,041 2022 236 2023 214 2024 115 Later years 87 Total $ 4,728

Short-Term Borrowings

Short-Term Borrowings	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Short-Term Borrowings	SHORT-TERM BORROWINGS Following is a summary of short-term borrowings: TABLE 12.1 December 31 2019 2018 (in millions) Securities sold under repurchase agreements $ 278 $ 251 Federal Home Loan Bank advances 2,255 2,230 Federal funds purchased 575 1,535 Subordinated notes 108 113 Total short-term borrowings $ 3,216 $ 4,129 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. Of the total short-term FHLB advances, there were no overnight maturities as of December 31, 2019 . Of the total short-term FHLB advances as of December 31, 2018 , 57.2% had overnight maturities. At December 31, 2019 , $1.5 billion , or 64.5% , of the short-term FHLB advances were swapped to a fixed rate with maturities in 2020. This compares to $1.0 billion , or 42.8% , as of December 31, 2018 . The following represents weighted average interest rates on short-term borrowings: TABLE 12.2 December 31 2019 2018 2017 Year-to-date average 2.24 % 1.89 % 1.16 % Period-end 1.76 % 2.49 % 1.44 %

Long-Term Borrowings

Long-Term Borrowings	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Long-Term Borrowings	LONG-TERM BORROWINGS Following is a summary of long-term borrowings: TABLE 13.1 December 31 2019 2018 (in millions) Federal Home Loan Bank advances $ 935 $ 270 Subordinated notes 90 87 Junior subordinated debt 66 111 Other subordinated debt 249 159 Total long-term borrowings $ 1,340 $ 627 Scheduled annual maturities for the long-term borrowings for the years following December 31, 2019 are as follows: TABLE 13.2 (in millions) 2020 $ 122 2021 563 2022 311 2023 30 2024 1 Later years 313 Total $ 1,340 Federal Home Loan Bank advances Our banking affiliate has available credit with the FHLB of $7.9 billion , of which $3.2 billion was utilized as of December 31, 2019 . 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 1.62% to 2.71% for the year ended December 31, 2019 and 1.39% to 4.19% for the year ended December 31, 2018 . Subordinated notes Subordinated notes are unsecured and subordinated to our other indebtedness. The subordinated notes mature in various amounts periodically through the year 2029. At December 31, 2019 , all of the subordinated notes are redeemable by the holders prior to maturity at a discount equal to three to 12 months of interest, depending on the term of the note. We may require the holder to give 30 days prior written notice. No sinking fund is required and none has been established to retire the notes. The weighted average interest rate on the subordinated notes are presented in the following table: TABLE 13.3 December 31 2019 2018 2017 Subordinated notes weighted average interest rate 3.33 % 3.08 % 2.85 % Junior subordinated debt The junior subordinated debt is comprised of the debt securities issued by FNB in relation to our three unconsolidated subsidiary trusts (collectively, the Trusts), which are unconsolidated variable interest entities and are included on the Consolidated Balance Sheets in long-term borrowings. One hundred percent of the common equity of each Trust is owned by FNB. The Trusts were formed for the purpose of issuing FNB-obligated mandatorily redeemable capital securities, or TPS to third-party investors. The proceeds from the sale of TPS and the issuance of common equity by the Trusts were invested in junior subordinated debt securities issued by FNB, which are the sole assets of each Trust. Since third-party investors are the primary beneficiaries, the Trusts are not consolidated in our Financial Statements. The Trusts pay dividends on the TPS at the same rate as the distributions paid by us on the junior subordinated debt held by the Trusts. F.N.B. Statutory Trust II was formed by us, and the other two statutory trusts were assumed through acquisitions. The acquired statutory trusts were adjusted to fair value in conjunction with the various acquisitions. We record the distributions on the junior subordinated debt issued to the Trusts as interest expense. The TPS are subject to mandatory redemption, in whole or in part, upon repayment of the junior subordinated debt. The TPS are eligible for redemption, at any time, at our discretion. Under capital guidelines, the junior subordinated debt, net of our investments in the Trusts, is included in tier 2 capital. We have entered into agreements which, when taken collectively, fully and unconditionally guarantee the obligations under the TPS subject to the terms of each of the guarantees. The following table provides information relating to the Trusts as of December 31, 2019 : TABLE 13.4 (dollars in millions) Trust Preferred Securities Common Securities Junior Subordinated Debt Stated Maturity Date Interest Rate Rate Reset Factor F.N.B. Statutory Trust II $ 22 $ 1 $ 22 6/15/2036 3.54 % LIBOR + 165 basis points (bps) Yadkin Valley Statutory Trust I 25 1 22 12/15/2037 3.21 % LIBOR + 132 bps FNB Financial Services Capital Trust I 25 1 22 9/30/2035 3.42 % LIBOR + 146 bps Total $ 72 $ 3 $ 66 During the first half of 2019, we redeemed $44.0 million of TPS that we previously assumed through various acquisitions. Other subordinated debt The following table provides information relating to our other subordinated debt as of December 31, 2019 . 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, at which time the floating rate will be LIBOR plus 240 basis points. These subordinated notes are eligible for treatment as tier 2 capital for regulatory capital purposes. TABLE 13.5 (dollars in millions) Aggregate Principal Amount Issued Net Proceeds (2) Carrying Value Stated Maturity Date Interest Rate 4.95% Fixed-To-Floating Rate Subordinated Notes due 2029 $ 120 $ 118 $ 118 2/14/2029 4.95 % 4.875% Subordinated Notes due 2025 100 98 99 10/2/2025 4.88 % 7.625% Subordinated Notes due August 12, 2023 (1) 38 46 32 8/12/2023 7.63 % Total $ 258 $ 262 $ 249 (1) Assumed from YDKN 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 YDKN, this is the fair value of the debt at the time of the acquisition. During the first half of 2019, we repurchased and retired $9.5 million and redeemed $15.5 million

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	12 Months Ended
	Dec. 31, 2019
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 14.1 December 31 2019 2018 Notional Amount Fair Value Notional Amount Fair Value (in millions) Asset Liability Asset Liability Gross Derivatives Subject to master netting arrangements: Interest rate contracts – designated $ 1,655 $ 1 $ — $ 1,155 $ — $ 3 Interest rate swaps – not designated 3,640 — 23 2,740 2 10 Equity contracts – not designated — — — 1 — — Total subject to master netting arrangements 5,295 1 23 3,896 2 13 Not subject to master netting arrangements: Interest rate swaps – not designated 3,640 149 1 2,740 40 26 Interest rate lock commitments – not designated 163 3 — 47 1 — Forward delivery commitments – not designated 195 1 1 55 — — Credit risk contracts – not designated 265 — — 203 — — Equity contracts – not designated — — — 1 — — Total not subject to master netting arrangements 4,263 153 2 3,046 41 26 Total $ 9,558 $ 154 $ 25 $ 6,942 $ 43 $ 39 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. 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 14.2 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 Year Ended Year Ended (in millions) 2019 2018 2017 2019 2018 2017 Derivatives in cash flow hedging relationships: Interest rate contracts $ (22 ) $ (3 ) $ 1 Interest income (expense) $ 2 $ 2 $ — The following table represents gains (losses) recognized in the Consolidated Statements of Income on cash flow hedging relationships: TABLE 14.3 Year Ended December 31, 2019 2018 2017 (in millions) Interest Income - Loans and Leases Interest Expense - Short-Term Borrowings 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) $ 1,085 $ 80 $ 1,022 $ 75 $ 862 $ 44 The effects of cash flow hedging: Gain (loss) on cash flow hedging relationships — — — — — — Interest rate contracts — — — — — — Amount of gain (loss) reclassified from AOCI into net income (1 ) 3 (1 ) 3 1 (1 ) Amount of gain (loss) reclassified from AOCI into income as a result of that a forecasted transaction is no longer probable of occurring — — — — — — As of December 31, 2019 , the maximum length of time over which forecasted interest cash flows are hedged is 4.9 years. In the twelve months that follow December 31, 2019 , we expect to reclassify from the amount currently reported in AOCI net derivative gains of $4.5 million ( $3.5 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 December 31, 2019 . 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 years ended December 31, 2019 and 2018 , 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 Interest Rate Swaps. We enter into interest rate swap agreements to meet the financing, interest rate and equity risk management needs of qualifying commercial loan customers. These agreements provide the customer the ability to convert from variable to fixed interest rates. The credit risk associated with derivatives executed with customers is essentially the same as that involved in extending loans and is subject to normal credit policies and monitoring. Swap derivative transactions with customers are not subject to enforceable master netting arrangements and are generally secured by rights to non-financial collateral, such as real and personal property. We enter into positions with a derivative counterparty in order to offset our exposure on the fixed components of the customer interest rate swap agreements. We seek to minimize counterparty credit risk by entering into transactions only with high-quality financial dealer institutions. The interest rate swap agreement with the loan customer and with the counterparty is 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. Interest Rate Lock Commitments . Interest rate lock commitments represent an agreement to extend credit to a mortgage loan borrower, or an agreement to purchase a loan from a third-party originator, whereby the interest rate on the loan is set prior to funding. We are bound to fund the loan at a specified rate, regardless of whether interest rates have changed between the commitment date and the loan funding date, subject to the loan approval process. The borrower is not obligated to perform under the commitment. As such, outstanding IRLCs subject us to interest rate risk and related price risk during the period from the commitment to the borrower through the loan funding date, or commitment expiration. The IRLCs generally range between 30 to 270 days. The IRLCs 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 mortgage banking operations income. Forward Delivery Commitments . Forward delivery commitments on mortgage-backed securities are used to manage the interest rate and price risk of our IRLCs and mortgage loan held for sale inventory by fixing the forward sale price that will be realized upon sale of the mortgage loans into the secondary market. Historical commitment-to-closing ratios are considered to estimate the quantity of mortgage loans that will fund within the terms of the IRLCs. The forward delivery contracts 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 mortgage banking operations income. Credit Risk Contracts. We purchase and sell credit protection under risk participation agreements to share with other counterparties some of the credit exposure related to interest rate derivative contracts or to take on credit exposure to generate revenue. We will make/receive payments under these agreements if a customer defaults on their obligation to perform under certain derivative swap contracts. Risk participation agreements sold with notional amounts totaling $201.5 million as of December 31, 2019 have remaining terms ranging from two months to nine years . Under these agreements, our maximum exposure assuming a customer defaults on their obligation to perform under certain derivative swap contracts with third parties would be $0.3 million and $0.1 million at December 31, 2019 and 2018 , respectively. The fair values of risk participation agreements purchased and sold were $0.1 million and $0.3 million , respectively, at December 31, 2019 and $0.05 million and $0.11 million , respectively, at December 31, 2018 . The following table presents the effect of certain derivative financial instruments on the Consolidated Statements of Income: TABLE 14.4 Year Ended December 31, (in millions) Consolidated Statements of Income Location 2019 2018 2017 Interest rate swaps Non-interest income - other $ — $ 1 $ (1 ) 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 $0.1 million and $0.7 million as of December 31, 2019 and 2018 , 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 14.5 Amount Not Offset in the (in millions) Net Amount Financial Cash Net 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 $ — $ — December 31, 2018 Derivative Assets Interest rate contracts: Not designated $ 2 $ 2 $ — $ — Total $ 2 $ 2 $ — $ — Derivative Liabilities Interest rate contracts: Designated $ 3 $ 3 $ — $ — Not designated 10 9 — 1 Total $ 13 $ 12 $ — $ 1

Commitments, Credit Risk and Co

Commitments, Credit Risk and Contingencies	12 Months Ended
	Dec. 31, 2019
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 15.1 December 31 2019 2018 (in millions) Commitments to extend credit $ 8,089 $ 7,378 Standby letters of credit 150 126 At December 31, 2019 , funding of 74.2% 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. 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 Notes 12 and 13. 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 our Company 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	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Stock Incentive Plans	STOCK INCENTIVE PLANS Restricted Stock We issue restricted stock awards to key employees under our Incentive Compensation Plan (Plan). We issue time-based awards and performance-based awards under this Plan, both of which are based on a three -year vesting period. The grant date fair value of the time-based awards is equal to the price of our common stock on the grant date. The fair value of the performance-based awards is based on a Monte-Carlo simulation valuation of our common stock as of the grant date. The assumptions used for this valuation include stock price volatility, risk-free interest rate and dividend yield. We issued 353,656 and 283,037 performance-based restricted stock units in 2019 and 2018 , respectively. As of December 31, 2019 , we had available up to 1,620,243 shares of common stock to issue under this Plan. The following table details our issuance of restricted stock units and the aggregate weighted average grant date fair values under these plans for the years indicated: TABLE 16.1 (dollars in millions) 2019 2018 2017 Restricted stock units 1,182,197 962,799 713,998 Weighted average grant date fair values $ 13 $ 13 $ 10 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 16.2 2019 2018 2017 Units Weighted Average Grant Price per Share Units Weighted Average Grant Price per Share Units Weighted Average Grant Price per Share Unvested units outstanding at beginning of year 2,556,174 $ 13.51 1,975,862 $ 13.64 1,836,363 $ 12.97 Granted 1,182,197 10.94 962,799 13.21 713,998 14.67 Net adjustment due to performance — — — — (64,861 ) 13.85 Vested (655,208 ) 13.15 (258,031 ) 13.19 (542,580 ) 12.71 Forfeited/expired (332,814 ) 12.72 (214,743 ) 13.39 (31,018 ) 14.03 Dividend reinvestment 108,008 11.84 90,287 12.61 63,960 13.80 Unvested units outstanding at end of year 2,858,357 12.56 2,556,174 13.51 1,975,862 13.64 The following table provides certain information related to restricted stock units: TABLE 16.3 Year Ended December 31 2019 2018 2017 (in millions) Stock-based compensation expense $ 12 $ 10 $ 8 Tax benefit related to stock-based compensation expense 2 2 3 Fair value of units vested 7 3 8 As of December 31, 2019 , there was $14.3 million of unrecognized compensation cost related to unvested restricted stock units including $0.5 million that is subject to accelerated vesting under the Plan’s immediate vesting upon retirement. The components of the restricted stock units as of December 31, 2019 are as follows: TABLE 16.4 (dollars in millions) Service- Based Units Performance- Based Units Total Unvested restricted stock units 1,922,120 936,237 2,858,357 Unrecognized compensation expense $ 10 $ 4 $ 14 Intrinsic value $ 24 $ 12 $ 36 Weighted average remaining life (in years) 1.83 1.81 1.82 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. The following table summarizes the activity relating to stock options during the periods indicated: TABLE 16.5 2019 Weighted Average Exercise Price per Share 2018 Weighted Average Exercise Price per Share 2017 Weighted Average Exercise Price per Share Options outstanding at beginning of year 458,354 $ 7.99 722,650 $ 7.96 892,532 $ 8.95 Assumed from acquisitions — — — — 207,645 8.92 Exercised (183,566 ) 7.86 (253,899 ) 7.77 (255,503 ) 10.21 Forfeited/expired (28,704 ) 7.65 (10,397 ) 11.98 (122,024 ) 12.12 Options outstanding and exercisable at end of year 246,084 8.14 458,354 7.99 722,650 7.96 The following table summarizes information about stock options outstanding at December 31, 2019 : TABLE 16.6 Range of Exercise Prices Options Outstanding and Exercisable Weighted Average Remaining Contractual Years Weighted Average Exercise Price $3.45 - $5.18 54,148 1.26 $ 4.82 $5.19 - $7.78 40,022 3.11 6.90 $7.79 - $11.37 151,914 4.71 9.64 246,084 The intrinsic value of outstanding and exercisable stock options at December 31, 2019 was $1.1 million . The aggregate intrinsic value represents the amount by which the fair value of underlying stock exceeds the option exercise price. The following table summarizes certain information relating to stock options exercised: TABLE 16.7 Year Ended December 31 2019 2018 2017 (in millions) Proceeds from stock options exercised $ 1 $ 2 $ 2 Intrinsic value of stock options exercised 1 1 1 The tax benefit recognized from stock options exercised was $0.2 million , $0.3 million and $0.4 million for 2019 , 2018 and 2017, respectively. Warrants As of December 31, 2019 , there were no longer any outstanding warrants. The following paragraphs summarize the warrants that were previously issued that have been exercised or expired in 2018 and 2019. In conjunction with our participation in the UST’s CPP, we issued to the UST a warrant to purchase up to 1,302,083 shares of our common stock. Pursuant to Section 13(H) of the Warrant to Purchase Common Stock, the number of shares of common stock issuable upon exercise of the warrant was reduced in half to 651,042 shares on June 16, 2009, the date we completed a public offering. The warrant, which expired in January 2019 without being exercised, was sold at auction by the UST and had an exercise price of $11.52 per share. In conjunction with the ANNB acquisition on April 6, 2013, the warrant issued by ANNB to the UST under the CPP has been converted into a warrant to purchase up to 342,564 shares of our common stock at an exercise price of $3.57 per share. Subsequent adjustments related to actual dividends paid by us have increased the share amount of these warrants to 405,489 , with a resulting lower exercise price of $3.02 per share as of March 31, 2018, prior to being exercised in May 2018. In conjunction with the YDKN acquisition on March 11, 2017, the warrant issued by YDKN to the UST under the CPP has been converted into a warrant to purchase up to 207,320 shares of our common stock at an exercise price of $9.63 per share. Subsequent adjustments related to actual dividends paid by us have increased the share amount of these warrants to 225,439 , with a resulting lower exercise price of $8.86 per share as of June 30, 2019. The warrant, which was recorded at its fair value on March 11, 2017, was sold at auction by the UST and was exercised prior to expiring in July 2019.

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Retirement Plans	RETIREMENT PLANS We sponsor the Retirement Income Plan (RIP), a qualified noncontributory defined benefit pension plan that has been frozen. The RIP covered employees who satisfied minimum age and length of service requirements. Although not required, during 2019 , we made a $5.0 million contribution to the RIP. We also sponsor two supplemental non-qualified retirement plans that have been frozen. The ERISA Excess Retirement Plan provides retirement benefits equal to the difference, if any, between the maximum benefit allowable under the Internal Revenue Code and the amount that would be provided under the RIP, if no limits were applied. The Basic Retirement Plan (BRP) is applicable to certain officers whom the Board of Directors designates. Officers participating in the BRP receive a benefit based on a target benefit percentage based on years of service at retirement and a designated tier as determined by the Board of Directors. When a participant retires, the benefit under the BRP is a monthly benefit equal to the participant's aggregate target benefit percentage multiplied by the participant’s highest average monthly cash compensation, including bonuses, during five consecutive calendar years within the last ten calendar years of employment before 2009. This monthly benefit is reduced by the monthly benefit the participant receives from the Social Security Administration, the RIP, the ERISA Excess Retirement Plan and the annuity equivalent of the automatic contributions paid to participants under the qualified 401(k) defined contribution plan and the ERISA Excess Lost Match Plan. The following tables provide information relating to the accumulated benefit obligation, change in benefit obligation, change in plan assets, the plans’ funded status and the amount included in the Consolidated Balance Sheets for the qualified and non-qualified plans described above (collectively, the Plans): TABLE 17.1 December 31 2019 2018 Qualified Non-Qualified Total Qualified Non-Qualified Total (in millions) Accumulated benefit obligation $ 156 $ 19 $ 175 $ 145 $ 18 $ 163 Projected benefit obligation at beginning of year $ 145 $ 18 $ 163 $ 162 $ 20 $ 182 Interest cost 6 1 7 6 — 6 Actuarial loss (gain) 15 2 17 (12 ) (1 ) (13 ) Benefits paid (10 ) (2 ) (12 ) (11 ) (1 ) (12 ) Projected benefit obligation at end of year $ 156 $ 19 $ 175 $ 145 $ 18 $ 163 Fair value of plan assets at beginning of year $ 150 $ — $ 150 $ 164 $ — $ 164 Actual return on plan assets 28 — 28 (7 ) — (7 ) Corporation contribution 5 2 7 4 1 5 Benefits paid (10 ) (2 ) (12 ) (11 ) (1 ) (12 ) Fair value of plan assets at end of year $ 173 $ — $ 173 $ 150 $ — $ 150 Funded status of plans $ 17 $ (19 ) $ (2 ) $ 5 $ (18 ) $ (13 ) The unrecognized actuarial loss, prior service cost and net transition obligation are required to be recognized into earnings over the average remaining participant life due to the freezing of the RIP, which may, on a net basis reduce future earnings. Actuarial assumptions used in the determination of the projected benefit obligation in the Plans are as follows: TABLE 17.2 Assumptions at December 31 2019 2018 Weighted average discount rate 3.17 % 4.18 % Rates of average increase in compensation levels 3.50 3.50 The discount rate assumption at December 31, 2019 and 2018 was determined using a yield-curve based approach. A yield curve was produced for a universe containing the majority of U.S.-issued Aa-graded corporate bonds, all of which were non-callable (or callable with make-whole provisions), and after excluding the 10% of the bonds with the highest and lowest yields. The discount rate was developed as the level equivalent rate that would produce the same present value as that using spot rates aligned with the projected benefit payments. The net periodic pension cost and other comprehensive income for the Plans included the following components: TABLE 17.3 Year Ended December 31 2019 2018 2017 (in millions) Interest cost $ 7 $ 6 $ 7 Expected return on plan assets (11 ) (11 ) (11 ) Actuarial loss amortization 2 2 2 Total pension income (2 ) (3 ) (2 ) Other changes in plan assets and benefit obligations recognized in other comprehensive income: Current year actuarial loss 1 6 3 Amortization of actuarial loss (2 ) (2 ) (2 ) Total amount recognized in other comprehensive income (1 ) 4 1 Total amount recognized in net periodic benefit cost and other comprehensive income $ (3 ) $ 1 $ (1 ) The plans have an actuarial measurement date of December 31. Actuarial assumptions used in the determination of the net periodic pension cost in the Plans are as follows: TABLE 17.4 Assumptions for the Year Ended December 31 2019 2018 2017 Weighted average discount rate 4.16 % 4.19 % 3.96 % Rates of increase in compensation levels 3.50 3.50 3.50 Expected long-term rate of return on assets 7.25 7.25 7.25 The expected long-term rate of return on plan assets has been established by considering historical and anticipated expected returns on the asset classes invested in by the pension trust and the allocation strategy currently in place among those classes. The change in plan assets reflects benefits paid from the qualified pension plans of $10.0 million and $10.1 million for 2019 and 2018 , respectively. As stated above, we made a $5.0 million contribution to the RIP during 2019 . We made a $4.0 million contribution to the RIP during 2018. For the non-qualified pension plans, the change in plan assets reflects benefits paid from and contributions made to the plans in the same amount. This amount represents the actual benefit payments paid from general assets of $1.5 million for 2019 and $1.4 million for 2018 . The following table provides information regarding estimated future cash flows relating to the Plans at December 31, 2019 : TABLE 17.5 (in millions) Expected employer contributions: 2020 $ 2 Expected benefit payments: 2020 10 2021 10 2022 10 2023 10 2024 11 2025 – 2029 53 The qualified pension plan contributions are deposited into a trust and the qualified benefit payments are made from trust assets. For the non-qualified plans, the contributions and the benefit payments are the same and reflect expected benefit amounts, which we pay from general assets. Our subsidiaries participate in a qualified 401(k) defined contribution plan under which employees may contribute a percentage of their salary. Employees are eligible to participate upon their first day of employment. Under this plan, we match 100% of the first 6% that the employee defers. During the second quarter of 2018, we made a one-time discretionary contribution of $0.9 million to the vast majority of our employees following the tax reform that was enacted in December 2017. Additionally, we may provide a performance-based company contribution of up to 3% if we exceed annual financial goals. Our contribution expense is presented in the following table: TABLE 17.6 Year Ended December 31 2019 2018 2017 (in millions) 401(k) contribution expense $ 15 $ 15 $ 12 We also sponsor an ERISA Excess Lost Match Plan for certain officers. This plan provides retirement benefits equal to the difference, if any, between the maximum benefit allowable under the Internal Revenue Code and the amount that would have been provided under the qualified 401(k) defined contribution plan, if no limits were applied. Pension Plan Investment Policy and Strategy Our investment strategy for the RIP is to diversify plan assets between a wide mix of securities within the equity and debt markets to allow the account the opportunity to meet the expected long-term rate of return requirements while minimizing short-term volatility. In this regard, the plan has targeted allocations within the equity securities category for domestic large cap, domestic mid cap, domestic small cap, real estate investment trusts, emerging market and international securities. Within the debt securities category, the plan has targeted allocation levels for U.S. Treasury, U.S. agency, domestic investment-grade bonds, high-yield bonds, inflation-protected securities and international bonds. The following table presents asset allocations for our pension plans as of December 31, 2019 and 2018 , and the target allocation for 2020 , by asset category: TABLE 17.7 Target Allocation Percentage of Plan Assets December 31 2020 2019 2018 Asset Category Equity securities 45 - 65 60 % 55 % Debt securities 30 - 50 37 41 Cash equivalents 0 - 10 3 4 At December 31, 2019 and 2018 , equity securities included 469,000 and 585,000 shares, respectively, of our common stock, representing 3.5% and 4.0% of total plan assets at December 31, 2019 and 2018 , respectively. Dividends received on our common stock held by the Plan were $0.2 million and $0.3 million for 2019 and 2018 , respectively. The fair values of our pension plan assets by asset category are as follows: TABLE 17.8 (in millions) Level 1 Level 2 Level 3 Total December 31, 2019 Asset Class Cash $ 5 $ — $ — $ 5 Equity securities: F.N.B. Corporation 6 — — 6 Other large-cap U.S. financial services companies 4 — — 4 Other large-cap U.S. companies 54 — — 54 Other equity 1 — — 1 Mutual fund equity investments: U.S. equity index funds: U.S. large-cap equity index funds 1 — — 1 U.S. small-cap equity index funds 3 — — 3 U.S. mid-cap equity index funds 5 — — 5 Non-U.S. equities growth fund 9 — — 9 U.S. equity funds: U.S. mid-cap 12 — — 12 U.S. small-cap 4 — — 4 Other 5 — — 5 Fixed income securities: U.S. government agencies — 51 — 51 Corporate bonds — 1 — 1 Fixed income mutual funds: U.S. investment-grade fixed income securities 12 — — 12 Total $ 121 $ 52 $ — $ 173 (in millions) Level 1 Level 2 Level 3 Total December 31, 2018 Asset Class Cash $ 6 $ — $ — $ 6 Equity securities: F.N.B. Corporation 6 — — 6 Other large-cap U.S. financial services companies 3 — — 3 Other large-cap U.S. companies 43 — — 43 International companies 1 — — 1 Mutual fund equity investments: U.S. equity index funds: U.S. small-cap equity index funds 3 — — 3 U.S. mid-cap equity index funds 4 — — 4 Non-U.S. equities growth fund 6 — — 6 U.S. equity funds: U.S. mid-cap 9 — — 9 U.S. small-cap 3 — — 3 Other 4 — — 4 Fixed income securities: U.S. government agencies — 49 — 49 Corporate bonds — 2 — 2 Fixed income mutual funds: U.S. investment-grade fixed income securities 11 — — 11 Total $ 99 $ 51 $ — $ 150 The classifications for Level 1, Level 2 and Level 3 are discussed in Note 24, “Fair Value Measurements.”

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The TCJA included several changes to existing U.S. tax laws that impact us, most notably a reduction of the U.S. corporate income tax rate from 35% to 21% , which became effective January 1, 2018. We recognized the initial income tax effects of the TCJA in our 2017 Consolidated Financial Statements in accordance with SAB No. 118, which provides SEC staff guidance for the application of ASC 740, Income Taxes , in the reporting period in which the TCJA was signed into law. We recorded a provisional amount of $54.0 million at December 31, 2017 related to the remeasurement of deferred tax balances. Upon final analysis of available information and refinement of our calculations during 2018, we decreased our provisional amount by $1.9 million which is included as a component of income tax expense from continuing operations. We consider the TCJA remeasurement of our deferred taxes to be complete. The effects of changes in tax rates on deferred tax balances are applicable even in situations in which the related income tax effects of such items were originally recognized in other comprehensive income. This results in stranded tax effects for items that were recorded in AOCI rather than in income from continuing operations. In the fourth quarter of 2017, we elected to change our accounting policy to reclassify the income tax effects related to the TCJA of approximately $14.7 million from AOCI to retained earnings. This change in accounting policy results in the appropriate tax rate being recognized in AOCI for debt and equity investments, certain derivative transactions, and pension and other post-retirement benefit plans. Income Tax Expense Federal and state income tax expense consist of the following: TABLE 18.1 Year Ended December 31 2019 2018 2017 (in millions) Current income taxes: Federal taxes $ 47 $ 41 $ 26 State taxes 4 6 2 Total current income taxes 51 47 28 Deferred income taxes: Federal taxes 30 32 128 State taxes 3 — 1 Total deferred income taxes 33 32 129 Total income taxes $ 84 $ 79 $ 157 The following table provides a reconciliation between the statutory tax rate and the actual effective tax rate: TABLE 18.2 Year Ended December 31 2019 2018 2017 Statutory federal tax rate 21.0 % 21.0 % 35.0 % State taxes, net of federal benefit 1.1 1.1 0.5 Tax-exempt interest (2.2 ) (2.1 ) (3.3 ) Cash surrender value on BOLI (0.5 ) (0.5 ) (1.1 ) Tax credits (4.2 ) (2.8 ) (2.6 ) Affordable housing cost amortization, net of tax benefits 1.4 0.7 0.2 Tax Cuts and Jobs Act revaluation of net deferred tax assets — (0.4 ) 15.2 Other items 1.1 0.6 0.2 Effective tax rate 17.7 % 17.6 % 44.1 % The effective tax rates of 17.7% and 17.6% in 2019 and 2018 , respectively, were lower than the 21% TCJA statutory federal tax rate primarily due to the tax benefits resulting from renewable energy investment and historic tax credits, tax-exempt income on investments and loans and income from BOLI. For the years ended December 31, 2019 and 2018 , we recognized net investment tax credits of $7.9 million and $6.5 million , respectively. Income tax expense related to net gains on the sale of securities is presented in the following table: TABLE 18.3 Year Ended December 31 2019 2018 2017 (in millions) Income tax expense related to net gains on sale of securities $ — $ — $ 2 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. DTAs and DTLs 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. The following table presents the tax effects of significant temporary differences that give rise to federal and state DTAs and DTLs: TABLE 18.4 December 31 2019 2018 (in millions) Deferred tax assets: Allowance for credit losses $ 43 $ 40 Discounts on loans acquired in a business combination 41 51 Net operating loss/tax credit carryforwards 38 43 Deferred compensation 11 10 Securities impairments 1 1 Pension and other defined benefit plans 3 5 Lease liability 29 — Net unrealized securities losses 2 12 Other 8 9 Total 176 171 Valuation allowance (28 ) (26 ) Total deferred tax assets 148 145 Deferred tax liabilities: Loan costs (15 ) (14 ) Depreciation (19 ) (17 ) Prepaid expenses (1 ) (1 ) Amortizable intangibles (15 ) (16 ) Lease financing (35 ) (18 ) Mortgage servicing rights (9 ) (8 ) Lease ROU asset (27 ) — Other (2 ) (4 ) Total deferred tax liabilities (123 ) (78 ) Net deferred tax assets $ 25 $ 67 We establish a valuation allowance when it is more likely than not that we will not be able to realize the benefit of the DTAs or when future deductibility is uncertain. Periodically, the valuation allowance is reviewed and adjusted based on management’s assessment of realizable DTAs. As of December 31, 2019 , the valuation allowance of $28 million primarily relates to unused federal and state net operating loss carryforwards expiring from 2020 to 2039 . We anticipate that neither the state net operating loss carryforwards nor the other net DTAs at certain of our subsidiaries will be utilized and, as such, have recorded a valuation allowance against the DTAs related to these items. As of December 31, 2019 , we had approximately $27.4 million of federal net operating loss and built-in loss carryforwards, $2.0 million of federal tax credit carryforwards, and $5.7 million of state tax credit carryforwards to which we succeeded as a result of the YDKN acquisition. The utilization of these tax attributes is subject to annual limitations under Section 382 of the Internal Revenue Code, or a similar state-level statute, which will cause the utilization of these attributes to be deferred over a number of years, not to exceed beyond 2036 . We have determined that we will likely have sufficient taxable income in the years during which these tax attributes are available to be utilized and, consequently, have determined that no additional valuation allowance against the recorded DTA is warranted. Uncertain Tax Positions We account for uncertainties in income taxes in accordance with ASC 740, Income Taxes . At December 31, 2019 and 2018 , we have approximately $1.6 million and $0.9 million , respectively, of unrecognized tax benefits related to uncertain tax positions. As of December 31, 2019 , $1.4 million of these tax benefits would affect the effective tax rate if recognized. We recognize potential accrued interest and penalties related to unrecognized tax benefits in income tax expense. To the extent interest is not assessed with respect to uncertain tax positions, amounts accrued will be reduced and reflected as a reduction of the overall income tax provision. We file numerous income tax returns in the U.S. federal jurisdiction and in several state jurisdictions. We are no longer subject to U.S. federal income tax examinations for years prior to 2016 . With limited exception, we are no longer subject to state income tax examinations for years prior to 2016 . We anticipate that a reduction in the unrecognized tax benefit of up to $0.06 million may occur in the next twelve months from the expiration of statutes of limitations which would result in a reduction in income taxes.

Other Comprehensive Income

Other Comprehensive Income	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Other Comprehensive Income	OTHER COMPREHENSIVE INCOME The following table presents changes in AOCI, net of tax, by component: TABLE 19.1 (in millions) Unrealized Net Gains (Losses) on Debt Securities Available for Sale Unrealized Net Gains (Losses) on Derivative Instruments Unrecognized Pension and Postretirement Obligations Total Year Ended December 31, 2019 Balance at beginning of period $ (46 ) $ 1 $ (61 ) $ (106 ) Other comprehensive (loss) income before reclassifications 57 (17 ) 3 43 Amounts reclassified from AOCI — (2 ) — (2 ) Net current period other comprehensive (loss) income 57 (19 ) 3 41 Balance at end of period $ 11 $ (18 ) $ (58 ) $ (65 ) 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 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	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings per Common Share	EARNINGS PER COMMON SHARE The following table sets forth the computation of basic and diluted earnings per common share: TABLE 20.1 Year Ended December 31 2019 2018 2017 (dollars in millions, except per share data) Net income $ 387 $ 373 $ 199 Less: Preferred stock dividends 8 8 8 Net income available to common stockholders $ 379 $ 365 $ 191 Basic weighted average common shares outstanding 324,938,720 324,207,198 302,195,295 Net effect of dilutive stock options, warrants and restricted stock 1,122,418 1,416,405 1,662,681 Diluted weighted average common shares outstanding 326,061,138 325,623,603 303,857,976 Earnings per common share: Basic $ 1.17 $ 1.13 $ 0.63 Diluted $ 1.16 $ 1.12 $ 0.63 The following table shows the average shares excluded from the above calculation as their effect would have been anti-dilutive: TABLE 20.2 Year Ended December 31 2019 2018 2017 Average shares excluded from the diluted earnings per common share calculation — 81 910

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2019
Banking and Thrift [Abstract]
Regulatory Matters	REGULATORY MATTERS FNB and FNBPA are subject to various regulatory capital requirements administered by the federal banking agencies. Quantitative measures established by regulators to ensure capital adequacy require FNB and FNBPA to maintain minimum amounts and ratios of total, tier 1 and common equity tier 1 capital (as defined in the regulations) to risk-weighted assets (as defined) and of leverage ratio (as defined). Failure to meet minimum capital requirements could lead to initiation of certain mandatory, and possibly additional discretionary actions by regulators that, if undertaken, could have a direct material effect on our Consolidated Financial Statements, dividends and future business and corporate strategies. Under capital adequacy guidelines and the regulatory framework for prompt corrective action, FNB and FNBPA must meet specific capital guidelines that involve quantitative measures of assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. FNB’s and FNBPA’s capital amounts and classifications are also subject to qualitative judgments by the regulators about components, risk weightings and other factors. As of December 31, 2019 , the most recent notification from the federal banking agencies categorized FNB and FNBPA as “well-capitalized” under the respective regulatory frameworks. There are no conditions or events since the notification which management believes have changed this categorization. Following are the capital ratios for FNB and FNBPA: TABLE 21.1 Actual Well-Capitalized Requirements (1) Minimum Capital Requirements plus Capital Conservation Buffer (dollars in millions) Amount Ratio Amount Ratio Amount Ratio As of December 31, 2019 F.N.B. Corporation: Total capital $ 3,174 11.81 % $ 2,687 10.00 % $ 2,821 10.50 % Tier 1 capital 2,632 9.79 1,612 6.00 2,284 8.50 Common equity tier 1 2,525 9.40 n/a n/a 1,881 7.00 Leverage 2,632 8.20 n/a n/a 1,283 4.00 Risk-weighted assets 26,866 FNBPA: Total capital 3,039 11.34 2,681 10.00 2,815 10.50 Tier 1 capital 2,841 10.60 2,144 8.00 2,279 8.50 Common equity tier 1 2,761 10.30 1,742 6.50 1,876 7.00 Leverage 2,841 8.87 1,601 5.00 1,281 4.00 Risk-weighted assets 26,806 As of December 31, 2018 F.N.B. Corporation: Total capital $ 2,875 11.54 % $ 2,490 10.00 % $ 2,459 9.88 % Tier 1 capital 2,395 9.62 1,608 6.00 1,961 7.88 Common equity tier 1 2,289 9.19 n/a n/a 1,588 6.38 Leverage 2,395 7.87 n/a n/a 1,218 4.00 Risk-weighted assets 24,900 FNBPA: Total capital 2,735 10.99 2,489 10.00 2,458 9.88 Tier 1 capital 2,553 10.26 1,992 8.00 1,960 7.88 Common equity tier 1 2,473 9.94 1,618 6.50 1,587 6.38 Leverage 2,553 8.39 1,521 5.00 1,217 4.00 Risk-weighted assets 24,894 (1) Reflects the well-capitalized standard under Regulation Y for F.N.B. Corporation and the prompt corrective action framework for FNBPA. In accordance with Basel III standards, the implementation of capital requirements is transitional and was phased-in from January 1, 2015 through January 1, 2019. The minimum capital requirements plus capital conservation buffer, which are presented for each period above based on the phase-in schedule, represent the minimum requirements needed to avoid limitations on distributions of dividends and certain discretionary bonus payments. Due to usable vault cash, the aggregate cash reserves FNBPA was required to maintain with the FRB amounted to less than $1 million at December 31, 2019 . We also maintain deposits for various services such as check clearing. Certain limitations exist under applicable law and regulations by regulatory agencies regarding dividend distributions to a parent by our subsidiaries. As of December 31, 2019 , our subsidiaries had $527.3 million of retained earnings available for distribution to us without prior regulatory approval. Under current FRB regulations, FNBPA is limited in the amount it may lend to non-bank affiliates, including FNB. Such loans must be secured by specified collateral. In addition, any such loans to a non-bank affiliate may not exceed 10% of FNBPA’s capital and surplus and the aggregate of loans to all such affiliates may not exceed 20% of FNBPA’s capital and surplus. The maximum amount that may be borrowed by FNB affiliates under these provisions was $598.3 million at December 31, 2019 .

Cash Flow Information

Cash Flow Information	12 Months Ended
	Dec. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Cash Flow Information	CASH FLOW INFORMATION Following is a summary of supplemental cash flow information: TABLE 22.1 Year Ended December 31 2019 2018 2017 (in millions) Interest paid on deposits and other borrowings $ 329 $ 230 $ 129 Income taxes paid 40 19 53 Transfers of loans to other real estate owned 15 12 35 Loans transferred to held for sale from portfolio 389 — — Loans transferred to portfolio from held for sale 110 — —

Business Segments

Business Segments	12 Months Ended
	Dec. 31, 2019
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. We also previously operated a Consumer Finance segment, which is no longer a reportable segment. This segment primarily made installment loans to individuals and purchased installment sales finance contracts from retail merchants. On August 31, 2018, as part of our strategy to enhance the overall positioning of our consumer banking operations, we sold 100 percent of the issued and outstanding capital stock of Regency to Mariner Finance, LLC. This transaction was completed to accomplish several strategic objectives, including enhancing the credit risk profile of the consumer loan portfolio, offering additional liquidity and selling a non-strategic business segment that no longer fits with our core business. Regency's financial information is included in the Consumer Finance segment in the 2018 and 2017 tables that follow. 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 23.1 (in millions) Community Wealth Insurance Parent Consolidated At or for the Year Ended Interest income $ 1,245 $ — $ — $ 2 $ 1,247 Interest expense 310 — — 20 330 Net interest income 935 — — (18 ) 917 Provision for credit losses 44 — — — 44 Non-interest income 237 46 20 (9 ) 294 Non-interest expense (1) 621 34 17 10 682 Amortization of intangibles 13 — 1 — 14 Income tax expense (benefit) 88 3 — (7 ) 84 Net income (loss) 406 9 2 (30 ) 387 Total assets 34,491 32 35 57 34,615 Total intangibles 2,291 10 28 — 2,329 (in millions) Community Wealth Insurance Consumer Parent Consolidated At or for the Year Ended Interest income $ 1,145 $ — $ — $ 25 $ — $ 1,170 Interest expense 219 — — 2 17 238 Net interest income 926 — — 23 (17 ) 932 Provision for credit losses 54 — — 6 1 61 Non-interest income 213 44 16 2 1 276 Non-interest expense (1) 609 33 17 15 5 679 Amortization of intangibles 15 1 — — — 16 Income tax expense (benefit) 82 2 — 1 (6 ) 79 Net income (loss) 379 8 (1 ) 3 (16 ) 373 Total assets 32,997 26 25 — 54 33,102 Total intangibles 2,304 10 20 — — 2,334 At or for the Year Ended Interest income $ 944 $ — $ — $ 40 $ (4 ) $ 980 Interest expense 118 — — 4 12 134 Net interest income 826 — — 36 (16 ) 846 Provision for credit losses 53 — — 8 — 61 Non-interest income 197 39 16 3 (3 ) 252 Non-interest expense (1) 597 30 15 21 — 663 Amortization of intangibles 17 1 — — — 18 Income tax expense (benefit) 153 3 — 5 (4 ) 157 Net income (loss) 203 5 1 5 (15 ) 199 Total assets 31,156 24 21 181 36 31,418 Total intangibles 2,317 10 12 2 — 2,341 (1) Excludes amortization of intangibles, which is presented separately.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS We use fair value measurements to record fair value adjustments to certain financial assets and liabilities and to determine fair value disclosures. Securities AFS, mortgage loans held for sale accounted for under FVO and derivatives are recorded at fair value on a recurring basis. Additionally, from time to time, we may be required to record at fair value other assets on a non-recurring basis, such as certain impaired loans, OREO and certain other assets. Fair value is defined as an exit price, representing the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value measurements are not adjusted for transaction costs. Fair value is a market-based measure considered from the perspective of a market participant who holds the asset or owes the liability rather than an entity-specific measure. In determining fair value, we use various valuation approaches, including market, income and cost approaches. ASC 820, Fair Value Measurements and Disclosures , establishes a hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that observable inputs be used when available. Observable inputs are inputs that market participants would use in pricing the asset or liability, which are developed based on market data obtained from independent sources. Unobservable inputs reflect our assumptions about the assumptions that market participants would use in pricing an asset or liability, which are developed based on the best information available in the circumstances. The fair value hierarchy gives the highest priority to unadjusted quoted market prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). The fair value hierarchy is broken down into three levels based on the reliability of inputs as follows: TABLE 24.1 Measurement Category Definition Level 1 valuation is based upon unadjusted quoted market prices for identical instruments traded in active markets. Level 2 valuation is based upon quoted market prices for similar instruments traded in active markets, quoted market prices for identical or similar instruments traded in markets that are not active and model-based valuation techniques for which all significant assumptions are observable in the market or can be corroborated by market data. Level 3 valuation is derived from other valuation methodologies including discounted cash flow models and similar techniques that use significant assumptions not observable in the market. These unobservable assumptions reflect estimates of assumptions that market participants would use in determining fair value. A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. Following is a description of the valuation methodologies we use for financial instruments recorded at fair value on either a recurring or non-recurring basis: Securities Available For Sale These securities are recorded at fair value on a recurring basis. At December 31, 2019 , 100.0% of AFS securities used valuation methodologies involving market-based or market-derived information, collectively Level 1 and Level 2 measurements, to measure fair value. We closely monitor market conditions involving assets that have become less actively traded. If the fair value measurement is based upon recent observable market activity of such assets or comparable assets (other than forced or distressed transactions) that occur in sufficient volume, and do not require significant adjustment using unobservable inputs, those assets are classified as Level 1 or Level 2; if not, they are classified as Level 3. Making this assessment requires significant judgment. We use prices from independent pricing services and, to a lesser extent, indicative (non-binding) quotes from independent brokers, to measure the fair value of AFS securities. We validate prices received from pricing services or brokers using a variety of methods, including, but not limited to, comparison to secondary pricing services, corroboration of pricing by reference to other independent market data such as secondary broker quotes and relevant benchmark indices, and review of pricing information by corporate personnel familiar with market liquidity and other market-related conditions. Derivative Financial Instruments We determine fair value for derivatives using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects contractual terms of the derivative, including the period to maturity and uses observable market based inputs, including interest rate curves and implied volatilities. We incorporate credit valuation adjustments to appropriately reflect both our own non-performance risk and the respective counterparty’s non-performance risk in the fair value measurements. In adjusting the fair value of our derivative contracts for the effect of non-performance risk, we consider the impact of netting and any applicable credit enhancements, such as collateral postings, thresholds, mutual puts and guarantees. Although we have determined that the majority of the inputs used to value our derivatives fall within Level 2 of the fair value hierarchy, the credit valuation adjustments associated with our derivatives and IRLCs utilize Level 3 inputs. Credit valuation estimates of current credit spreads are used to evaluate the likelihood of our default and the default of our counterparties. However, as of December 31, 2019 and 2018 , we have assessed the significance of the impact of the credit valuation adjustments on the overall valuation of our non-IRLC derivative positions and have determined that the credit valuation adjustments are not significant to the overall valuation of our derivatives. As a result, we have determined that our derivative valuations in their entirety are classified in Level 2 of the fair value hierarchy. The fair value of IRLCs is based upon the estimated fair value of the underlying mortgage loan, including the expected cash flows related to MSRs and the estimated percentage of IRLCs that will result in a closed mortgage loan, and is classified as Level 3. Loans Held For Sale Residential mortgage loans held for sale are carried at fair value under the FVO. Fair value for residential mortgage loans held for sale, when recorded, is based on independent quoted market prices and is classified as Level 2. SBA loans held for sale are carried under lower of cost or fair value, for which, periodically, it may be necessary to record non-recurring fair value adjustments. Fair value for SBA loans held for sale, when recorded, is based on independent quoted market prices and is classified as Level 2. Impaired Loans We reserve for commercial loan relationships greater than or equal to $1.0 million that we consider impaired as defined in ASC 310 at the time we identify the loan as impaired based upon the present value of expected future cash flows available to pay the loan, or based upon the fair value of the collateral less estimated selling costs where a loan is collateral dependent. Collateral may be real estate and/or business assets including equipment, inventory and accounts receivable. We determine the fair value of real estate based on appraisals by licensed or certified appraisers. The value of business assets is generally based on amounts reported on the business’ financial statements. Management must rely on the financial statements prepared and certified by the borrower or their accountants in determining the value of these business assets on an ongoing basis, which may be subject to significant change over time. Based on the quality of information or statements provided, management may require the use of business asset appraisals and site-inspections to better value these assets. We may discount appraised and reported values based on management’s historical knowledge, changes in market conditions from the time of valuation or management’s knowledge of the borrower and the borrower’s business. Since not all valuation inputs are observable, we classify these non-recurring fair value determinations as Level 2 or Level 3 based on the lowest level of input that is significant to the fair value measurement. We review and evaluate impaired loans no less frequently than quarterly for additional impairment based on the same factors identified above. Other Real Estate Owned OREO is comprised principally of commercial and residential real estate properties obtained in partial or total satisfaction of loan obligations. OREO acquired in settlement of indebtedness is recorded at the lower of carrying amount of the loan or fair value less costs to sell. Subsequently, these assets are carried at the lower of carrying value or fair value less costs to sell. Accordingly, it may be necessary to record non-recurring fair value adjustments. Fair value is generally based upon appraisals by licensed or certified appraisers and other market information and is classified as Level 3. Other Assets - MSRs and SBA Servicing Assets We carry MSRs at the lower of cost or fair value, and therefore, they are subject to fair value measurements on a non-recurring basis. Since sales of MSRs tend to occur in private transactions and the precise terms and conditions of the sales are typically not readily available, there is a limited market to refer to in determining the fair value of MSRs. As such we rely primarily on a discounted cash flow model, incorporating assumptions about loan prepayment rates, discount rates, servicing costs and other economic factors, to estimate the fair value of our MSRs. We utilize a third-party vendor to perform the modeling to estimate the fair value of our MSRs. Since the valuation model uses significant unobservable inputs, we classify MSRs within Level 3. We retain the servicing rights on SBA-guaranteed loans sold to investors. The standard sale structure under the SBA Secondary Participation Guaranty Agreement provides for us to retain a portion of the cash flow from the interest payment received on the SBA guaranteed portion of the loan, which is commonly known as a servicing spread. We utilize a third-party vendor to perform the modeling to estimate the fair value of our SBA servicing asset. Since the valuation model uses significant unobservable inputs, we classify SBA servicing assets within Level 3. The following table presents the balances of assets and liabilities measured at fair value on a recurring basis: TABLE 24.2 (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 — 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 (in millions) Level 1 Level 2 Level 3 Total December 31, 2018 Assets Measured at Fair Value Debt securities available for sale U.S. government agencies $ — $ 187 $ — $ 187 U.S. government-sponsored entities — 313 — 313 Residential mortgage-backed securities Agency mortgage-backed securities — 1,429 — 1,429 Agency collateralized mortgage obligations — 1,161 — 1,161 Commercial mortgage-backed securities — 228 — 228 States of the U.S. and political subdivisions — 21 — 21 Other debt securities — 2 — 2 Total debt securities available for sale — 3,341 — 3,341 Loans held for sale — 14 — 14 Derivative financial instruments Trading — 42 1 43 Total derivative financial instruments — 42 1 43 Total assets measured at fair value on a recurring basis $ — $ 3,397 $ 1 $ 3,398 Liabilities Measured at Fair Value Derivative financial instruments Trading $ — $ 36 $ — $ 36 Not for trading — 3 — 3 Total derivative financial instruments — 39 — 39 Total liabilities measured at fair value on a recurring basis $ — $ 39 $ — $ 39 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 24.3 (in millions) Interest Total 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 Year Ended December 31, 2018 Balance at beginning of period $ 2 $ 2 Purchases, issuances, sales and settlements: Issuances 5 5 Settlements (6 ) (6 ) Balance at end of period $ 1 $ 1 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. See the “Securities Available for Sale” discussion within this footnote for information relating to determining Level 3 fair values. There were no transfers of assets or liabilities between the hierarchy levels during 2019 or 2018 . For the year ended December 31, 2018 , we recorded in earnings $0.6 million of unrealized gains relating to the adoption of ASU 2016-01 and market value adjustments on marketable equity securities. These unrealized gains included in earnings are in the other non-interest income line item in the Consolidated Statement of Income. 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 previously described. 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 24.4 (in millions) Level 1 Level 2 Level 3 Total 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 December 31, 2018 Impaired loans $ — $ — $ 15 $ 15 Other real estate owned — — 5 5 Other assets - SBA servicing asset — — 4 4 Substantially all of the fair value amounts in the table above were estimated at a date during the twelve months ended December 31, 2019 and 2018 . 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 $31.4 million had a valuation allowance of $1.5 million , bringing the December 31, 2019 carrying value to $29.9 million . The valuation allowance includes a provision expense included in 2019 earnings of $1.0 million . Impaired loans measured or re-measured at fair value on a non-recurring basis during 2019 had a carrying amount of $4.8 million which includes an allocated allowance for credit losses of $3.7 million . The allowance for credit losses includes a provision applicable to the current period fair value measurements of $6.2 million , which was included in the provision for credit losses for 2019 . OREO with a carrying amount of $3.6 million was written down to $2.2 million , resulting in a loss of $1.4 million , which was included in earnings for 2019 . Fair Value of Financial Instruments The following methods and assumptions were used to estimate the fair value of each financial instrument: Cash and Cash Equivalents, Accrued Interest Receivable and Accrued Interest Payable. For these short-term instruments, the carrying amount is a reasonable estimate of fair value. Securities. For both securities AFS and securities HTM, fair value equals the quoted market price from an active market, if available, and is classified within Level 1. If a quoted market price is not available, fair value is estimated using quoted market prices for similar securities or pricing models, and is classified as Level 2. Where there is limited market activity or significant valuation inputs are unobservable, securities are classified within Level 3. Under current market conditions, assumptions used to determine the fair value of Level 3 securities have greater subjectivity due to the lack of observable market transactions. Loans and Leases. The fair value of fixed rate loans and leases is estimated by discounting the future cash flows using the current rates at which similar loans and leases would be made to borrowers with similar credit ratings and for the same remaining maturities less an illiquidity discount, as the fair value measurement represents an exit price from a market participants' viewpoint. The fair value of variable and adjustable rate loans and leases approximates the carrying amount. Due to the significant judgment involved in evaluating credit quality, loans and leases are classified within Level 3 of the fair value hierarchy. Loan Servicing Rights . For both MSRs and SBA servicing rights, both classified as Level 3 assets, fair value is determined using a discounted cash flow valuation method. These models use significant unobservable inputs including discount rates, prepayment rates and cost to service which have greater subjectivity due to the lack of observable market transactions. Derivative Assets and Liabilities. See the “Derivative Financial Instruments” discussion included within this footnote . Deposits. The estimated fair value of demand deposits, savings accounts and certain money market deposits is the amount payable on demand at the reporting date because of the customers’ ability to withdraw funds immediately. The fair value of fixed-maturity deposits is estimated by discounting future cash flows using rates currently offered for deposits of similar remaining maturities. Short-Term Borrowings. The carrying amounts for short-term borrowings approximate fair value for amounts that mature in 90 days or less. The fair value of subordinated notes is estimated by discounting future cash flows using rates currently offered. Long-Term Borrowings. The fair value of long-term borrowings is estimated by discounting future cash flows based on the market prices for the same or similar issues or on the current rates offered to us for debt of the same remaining maturities. Loan Commitments and Standby Letters of Credit. Estimates of the fair value of these off-balance sheet items were not made because of the short-term nature of these arrangements and the credit standing of the counterparties. Also, unfunded loan commitments relate principally to variable rate commercial loans, typically are non-binding, and fees are not normally assessed on these balances. Nature of Estimates . Many of the estimates presented herein are based upon the use of highly subjective information and assumptions and, accordingly, the results may not be precise. Management believes that fair value estimates may not be comparable to other financial institutions due to the wide range of permitted valuation techniques and numerous estimates which must be made. Further, because the disclosed fair value amounts were estimated as of the Balance Sheet date, the amounts actually realized or paid upon maturity or settlement of the various financial instruments could be significantly different. The fair values of our financial instruments are as follows: TABLE 24.5 Fair Value Measurements (in millions) Carrying Amount Fair Value Level 1 Level 2 Level 3 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 — — December 31, 2018 Financial Assets Cash and cash equivalents $ 488 $ 488 $ 488 $ — $ — Debt securities available for sale 3,341 3,341 — 3,341 — Debt securities held to maturity 3,254 3,155 — 3,155 — Net loans and leases, including loans held for sale 21,995 21,742 — 14 21,728 Loan servicing rights 41 45 — — 45 Derivative assets 43 43 — 42 1 Accrued interest receivable 101 101 101 — — Financial Liabilities Deposits 23,455 23,411 18,142 5,269 — Short-term borrowings 4,129 4,130 4,130 — — Long-term borrowings 627 618 — — 618 Derivative liabilities 39 39 — 39 — Accrued interest payable 20 20 20 — —

Parent Company Financial Statem

Parent Company Financial Statements	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Disclosure [Abstract]
Parent Company Financial Statements	PARENT COMPANY FINANCIAL STATEMENTS The following is condensed financial information of F.N.B. Corporation (parent company only). In this information, the parent company’s investments in subsidiaries are stated at cost plus equity in undistributed earnings of subsidiaries since acquisition. This information should be read in conjunction with the Consolidated Financial Statements. TABLE 25.1 Balance Sheets (in millions) December 31 2019 2018 Assets Cash and cash equivalents $ 251 $ 254 Other assets 18 19 Investment in bank subsidiary 5,072 4,754 Investments in and advances to non-bank subsidiaries 104 97 Total Assets $ 5,445 $ 5,124 Liabilities Other liabilities $ 34 $ 32 Advances from affiliates 197 197 Long-term borrowings 323 279 Subordinated notes: Short-term 7 7 Long-term 1 1 Total Liabilities 562 516 Stockholders’ Equity 4,883 4,608 Total Liabilities and Stockholders’ Equity $ 5,445 $ 5,124 TABLE 25.2 Statements of Income (in millions) Year Ended December 31 2019 2018 2017 Income Dividend income from subsidiaries: Bank $ 179 $ 162 $ 149 Non-bank 2 8 9 181 170 158 Interest income — 4 5 Other income — 5 — Total Income 181 179 163 Expenses Interest expense 19 20 18 Other expenses 18 15 10 Total Expenses 37 35 28 Income Before Taxes and Equity in Undistributed Income of Subsidiaries 144 144 135 Income tax benefit 7 6 3 151 150 138 Equity in undistributed income (loss) of subsidiaries: Bank 236 225 60 Non-bank — (2 ) 1 Net Income $ 387 $ 373 $ 199 TABLE 25.3 Statements of Cash Flows (in millions) Year Ended December 31 2019 2018 2017 Operating Activities Net income $ 387 $ 373 $ 199 Adjustments to reconcile net income to net cash flows from operating activities: Undistributed earnings from subsidiaries (236 ) (222 ) (61 ) Other, net 2 (13 ) 6 Net cash flows provided by operating activities 153 138 144 Investing Activities Proceeds from sale of securities available for sale — 1 — Net (increase) decrease in advances to subsidiaries — 20 (10 ) Payment for further investment in subsidiaries (47 ) (22 ) (4 ) Net cash received in business combinations — 123 3 Net cash flows (used in) provided by investing activities (47 ) 122 (11 ) Financing Activities Net decrease in advance from affiliate — (19 ) 10 Net decrease in short-term borrowings — (1 ) — Decrease in long-term debt (77 ) (2 ) (2 ) Increase in long-term debt 121 1 1 Net proceeds from issuance of common stock 12 14 11 Cash dividends paid: Preferred stock (8 ) (8 ) (8 ) Common stock (157 ) (157 ) (143 ) Net cash flows (used in) provided by financing activities (109 ) (172 ) (131 ) Net (Decrease) Increase in Cash and Cash Equivalents (3 ) 88 2 Cash and cash equivalents at beginning of year 254 166 164 Cash and Cash Equivalents at End of Year $ 251 $ 254 $ 166 Cash paid during the year for: Interest $ 20 $ 17 $ 16

Quarterly Earnings Summary (Una

Quarterly Earnings Summary (Unaudited)	12 Months Ended
	Dec. 31, 2019
Quarterly Earnings Summary (Unaudited) [Abstract]
Quarterly Earnings Summary (Unaudited)	QUARTERLY EARNINGS SUMMARY (UNAUDITED) TABLE 26.1 (Dollars in millions, except per share data) Quarter Ended 2019 Dec. 31 Sept. 30 June 30 Mar. 31 Total interest income $ 306 $ 314 $ 317 $ 310 Total interest expense 80 84 87 79 Net interest income 226 230 230 231 Provision for credit losses 7 12 11 14 Total non-interest income 74 80 75 65 Total non-interest expense 177 178 175 166 Net income 95 103 95 94 Net income available to common stockholders 93 101 93 92 Per Common Share Basic earnings per share $ 0.29 $ 0.31 $ 0.29 $ 0.28 Diluted earnings per share 0.29 0.31 0.29 0.28 Quarter Ended 2018 Total interest income $ 305 $ 298 $ 294 $ 273 Total interest expense 74 63 54 47 Net interest income 231 235 240 226 Provision for credit losses 15 16 16 14 Other non-interest income 69 75 65 67 Total non-interest expense 170 171 183 171 Net income 100 101 85 87 Net income available to common stockholders 98 99 83 85 Per Common Share Basic earnings per share $ 0.30 $ 0.30 $ 0.26 $ 0.26 Diluted earnings per share 0.30 0.30 0.26 0.26

Mergers and Acquisitions

Mergers and Acquisitions	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Mergers and Acquisitions	MERGERS AND ACQUISITIONS Yadkin Financial Corporation On March 11, 2017, we completed our acquisition of YDKN, a bank holding company based in Raleigh, North Carolina. YDKN’s banking affiliate, Yadkin Bank, was also merged into FNBPA on March 11, 2017. YDKN’s results of operations have been included in our Consolidated Statements of Income since that date. The acquisition enabled us to enter several southeastern markets, including Raleigh, Charlotte and the Piedmont Triad, which is comprised of Winston-Salem, Greensboro and High Point. We also completed the core systems conversion activities during the first quarter of 2017. On the acquisition date, the fair values of YDKN included $6.8 billion in assets, of which there was $5.1 billion in loans and $5.2 billion in deposits. The acquisition was valued at $1.8 billion based on the acquisition-date FNB common stock closing price of $15.97 and resulted in FNB issuing 111,619,622 shares of our common stock in exchange for 51,677,565 shares of YDKN common stock. Under the terms of the merger agreement, shareholders of YDKN received 2.16 shares of FNB common stock for each share of YDKN common stock and cash in lieu of fractional shares. YDKN’s fully vested and outstanding stock options were converted into options to purchase and receive FNB common stock. In conjunction with the acquisition, we assumed a warrant that was issued by YDKN to the UST under the CPP. Based on the exchange ratio, this warrant was converted into a warrant to purchase up to 207,320 shares of FNB common stock with an exercise price of $9.63 . The warrant was exercised in 2019. The acquisition of YDKN constituted a business combination and has been accounted for using the acquisition method of accounting, and accordingly, assets acquired, liabilities assumed and consideration exchanged were recorded at estimated fair value on the acquisition date. The determination of estimated fair values required management to make certain estimates about discount rates, future expected cash flows, market conditions, and other future events that are highly subjective in nature and may require adjustments, which can be updated for up to a year following the acquisition. Any adjustments to fair values and related adjustments to goodwill were recorded within the 12-month period. Based on the purchase price allocation, we recorded $1.2 billion in goodwill and $70.0 million in core deposit intangibles as a result of the acquisition. None of the goodwill is deductible for income tax purposes as the acquisition is accounted for as a tax-free exchange for tax purposes. In connection with the YDKN acquisition, we incurred expenses related to systems conversions and other costs of integrating and conforming acquired operations with and into FNB. These merger-related expenses, that were expensed as incurred, amounted to $56.2 million for the year ended December 31, 2017. Contract terminations and severance costs comprised 30.9% and 24.3% , respectively, of the merger-related expenses, with the remainder consisting of other non-interest expenses, including professional services, marketing and advertising, technology and communications, occupancy and equipment, and charitable contributions. We also incurred issuance costs of $0.6 million which were charged to additional paid-in capital.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Our accompanying Consolidated Financial Statements and these Notes to Consolidated Financial Statements include subsidiaries in which we have a controlling financial interest. We own and operate FNBPA, FNTC, First National Investment Services Company, LLC, FNBIA, FNIA, 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 more than a 50% voting equity interest, or a controlling financial interest, or are a variable interest entity (VIE) in which we have the power to direct the activities of an entity that most significantly impact the entity’s economic performance and has an obligation to absorb losses or the right to receive benefits from the VIE which could potentially be significant to the VIE are consolidated. 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 does not have an obligation to absorb losses or the right to receive benefits from the VIE 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 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 December 31, 2019 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.
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. Actual results could materially differ from those estimates. Material estimates that are particularly susceptible to significant changes include the allowance for credit losses, accounting for loans acquired in a business combination, fair value of financial instruments, goodwill and other intangible assets, litigation, income taxes and deferred tax assets.
Revenue from Contracts with Customers	Revenue from Contracts with Customers We earn certain revenues from contracts with customers. These revenues are recognized when control of the promised services is transferred to the customers in an amount that reflects the consideration we expect to be entitled to in an exchange for those services. In determining the appropriate revenue recognition for our contracts with customers, we consider whether the contract has commercial substance and is approved by both parties with identifiable contractual rights, payment terms, and the collectability of consideration is probable. Generally, we satisfy our performance obligations upon the completion of services at the amount to which we have the right to invoice or charge under contracts with an original expected duration of one year or less. We apply this guidance on a portfolio basis to contracts with similar characteristics and for which we believe the results would not differ materially from applying this guidance to individual contracts. Our services provided under contracts with customers are transferred at the point in time when the services are rendered. Generally, we do not defer incremental direct costs to obtain contracts with customers that would be amortized in one year or less under the practical expedient. These costs are recognized as expense, primarily salary and benefit expense, in the period incurred. Deposit Services . We recognize revenue on deposit services based on published fees for services provided. Demand and savings deposit customers have the right to cancel their depository arrangements and withdraw their deposited funds at any time without prior notice. When services involve deposited funds that can be retrieved by customers without penalties, we consider the service contract term to be day-to-day, where each day represents the renewal of the contract. The contract does not extend beyond the services performed and revenue is recognized at the end of the contract term (daily) as the performance obligation is satisfied. No deposit services fees exist for long-term deposit products beyond early withdrawal penalties, which are earned on these products at the time of early termination. Revenue from deposit services fees are reduced where we have a history of waived or reduced fees by customer request or due to a customer service issue, by historical experience, or another acceptable method in the same period as the related revenues. Revenues from deposit services are reported in the Consolidated Statements of Income as service charges and in the Community Banking segment as non-interest income. Wealth Management Services. Wealth advisory and trust services are provided on a month-to-month basis and invoiced as services are rendered. Fees are based on a fixed amount or a scale based on the level of services provided or assets under management. The customer has the right to terminate their services agreement at any time. We determine the value of services performed based on the fee schedule in effect at the time the services are performed. Revenues from wealth advisory and trust services are reported in the Consolidated Statements of Income as trust services and securities commissions and fees, and in the Wealth segment as non-interest income. Insurance Services. Insurance services include full-service insurance brokerage services offering numerous lines of commercial and personal insurance through major carriers to businesses and individuals within our geographic markets. We recognize revenue on insurance contracts in effect based on contractually specified commission payments on premiums that are paid by the customer to the insurance carrier. Contracts are cancellable at any time and we have no performance obligation to the customers beyond the time the insurance is placed into effect. Revenues from insurance services are reported in the Consolidated Statements of Income as insurance commissions and fees, and in the Insurance segment as non-interest income.
Business Combinations	Business Combinations Business combinations are accounted for by applying the acquisition method . Under the acquisition method, identifiable assets acquired and liabilities assumed, and any non-controlling interest in the acquiree at the acquisition date are measured at their fair values as of that date, and are recognized separately from goodwill. Results of operations of the acquired entities are included in the Consolidated Statements of Income from the date of acquisition.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include cash on hand, cash items in transit and amounts due from the Federal Reserve Bank and other depository institutions (including interest-bearing deposits).
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 December 31, 2019 and 2018 , we did not hold any trading debt securities. Debt securities HTM are the securities that management has the positive intent and ability to hold until their maturity. Such securities are carried at cost, adjusted for related amortization of premiums and accretion of discounts through interest income from securities, and subject to evaluation for OTTI. Debt securities that are not classified as trading or HTM are classified as AFS. Such securities are carried at fair value with net unrealized gains and losses deemed to be temporary and OTTI attributable to non-credit factors reported separately as a component of OCI, net of tax. We evaluate our debt securities in a loss position for OTTI on a quarterly basis at the individual security level based on our intent to sell. If we intend to sell the debt security or it is more likely than not we will be required to sell the security before recovery of its amortized cost basis, OTTI must be recognized in earnings equal to the entire difference between the investments’ amortized cost basis and its fair value. If we do not intend to sell the debt security and it is not more likely than not that we will be required to sell the security before recovery of its amortized cost basis, OTTI must be separated into the amount representing credit loss and the amount related to all other market factors. The amount related to credit loss will be recognized in earnings. The amount related to other market factors will be recognized in OCI, net of tax. We perform our OTTI evaluation process in a consistent and systematic manner and include an evaluation of all available evidence. This process considers factors such as length of time and anticipated recovery period of the impairment, recent events specific to the issuer and recent experience regarding principal and interest payments.
Securities Sold Under Agreements to Repurchase	Securities Sold Under Agreements to Repurchase Securities sold under agreements to repurchase are accounted for as collateralized financing transactions and are recorded at the amounts at which the securities were sold plus accrued interest. Securities, generally U.S. government and federal agency securities, pledged as collateral under these financing arrangements cannot be sold or repledged by the secured party. The fair value of collateral either received from or provided to a third party is continually monitored and additional collateral is obtained or is requested to be returned to us as deemed appropriate.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities From time to time, we may enter into derivative transactions principally to protect against the risk of adverse price or interest rate movements on the value of certain assets and liabilities and on future cash flows. Foreign exchange derivatives are entered into to accommodate the needs of customers. All derivative instruments are carried at fair value on the Consolidated Balance Sheets as either an asset or liability. Accounting for the changes in fair value of a derivative is dependent upon whether it has been designated in a formal, qualifying hedging relationship. For derivatives in qualifying hedging relationships, we formally document all relationships between hedging instruments and hedged items, as well as our risk management objective and strategy for undertaking each hedge transaction. Cash flows from hedging activities are classified in the same category as the items hedged. Beginning in the first quarter of 2019, we adopted ASU 2017-12 which provides targeted improvements to the hedge accounting model that more closely aligns the accounting and reporting for hedging relationships with risk management activities. In addition, ASU 2017-12 provides administrative relief by easing documentation requirements, simplifying the application of hedge accounting by expanding the application of the shortcut method, eliminating the separate measurement and reporting of hedge ineffectiveness and generally requiring the entire effect of the hedging instrument and the hedged item to be presented in the same income statement line item. We believe these changes will provide users with more useful information about the effect of our risk management activities on the financial statements. Changes in fair value of a derivative instrument that has been designated and qualifies as a cash flow hedge, including any ineffectiveness, are recorded in accumulated other comprehensive income, net of tax. Amounts are reclassified from AOCI to the consolidated statements of income in the same line item used to present the earnings effect of the hedged item in the period or periods in which the hedged transaction affects earnings. Prior to 2019, the ineffective portion, if any, was reported in earnings immediately. At the hedge’s inception, a formal assessment is performed to determine whether changes in the fair values or cash flows of the derivative instruments have been highly effective in offsetting changes in fair values or cash flows of the hedged items and whether they are expected to be highly effective in the future. At each reporting period thereafter, a statistical regression or qualitative analysis is performed to evaluate hedge effectiveness. If it is determined a derivative instrument has not been or will not continue to be highly effective as a hedge, hedge accounting is discontinued. We also enter into interest rate swap agreements to meet the interest rate risk management needs of qualifying commercial loan customers. These agreements provide the customer the ability to convert from variable to fixed interest rates. We then enter into positions with a derivative counterparty in order to offset our exposure on the fixed components of the customer agreements. The credit risk associated with derivatives executed with customers is essentially the same as that involved in extending loans and is subject to normal credit policies and monitoring. We seek to minimize counterparty credit risk by entering into transactions with only high-quality institutions and using collateral agreements and other contract provisions. These arrangements meet the definition of derivatives, but are not designated as qualifying hedging relationships. The interest rate swap agreement with the loan customer and with the counterparty 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.
Loans Held for Sale and Loan Commitments	Loans Held for Sale and Loan Commitments Certain of our residential mortgage loans are originated or purchased for sale in the secondary mortgage loan market. We make an automatic election to account for all originated or purchased residential mortgage loans held for sale under the FVO. The FVO election is intended to better reflect the underlying economics and better facilitate the economic hedging of the loans. The FVO is applied on an instrument by instrument basis and is an irrevocable election. Additionally, with the election of the FVO, fees and costs associated with the origination and acquisition of residential mortgage loans held for sale are expensed as incurred, rather than deferred. Changes in fair value under the FVO are recorded in mortgage banking operations non-interest income on the consolidated statements of income. Fair value is determined on the basis of rates obtained in the respective secondary market for the type of loan held for sale. Gain or loss on the sale of loans is recorded in mortgage banking operations non-interest income. Interest income on loans held for sale is recorded in interest income. We routinely issue interest rate lock commitments for residential mortgage loans that we intend to sell. These interest rate lock commitments are considered derivatives. We also enter into loan sale commitments to sell these loans when funded to mitigate the risk that the market value of residential mortgage loans may decline between the time the rate commitment is issued to the customer and the time we sell the loan. These loan sale commitments are also derivatives. Both types of derivatives are recorded at fair value on the Consolidated Balance Sheets with changes in fair value recorded in mortgage banking operations non-interest income. We also originate loans guaranteed by the SBA for the purchase of businesses, business startups, business expansion, equipment, and working capital. All SBA loans are underwritten and documented as prescribed by the SBA. SBA loans originated with the intention to sell on the secondary market are classified as held for sale and carried at the lower of cost or fair value. At the time of the sale, we allocate the carrying value of the entire loan between the guaranteed portion sold and the unguaranteed portion retained based on their relative fair value which results in a discount recorded on the retained portion of the loan. The guaranteed portion is typically sold at a premium and the gain is recognized in other income for any net premium received in excess of the relative fair value of the portion of the loan transferred. The net carrying value of the retained portion of the loans is included in the appropriate commercial loan classification for disclosure purposes.
Loans (Excluding Loans Acquired in a Business Combination)	Loans (Excluding Loans Acquired in a Business Combination) Loans we intend to hold for the foreseeable future or until maturity or payoff are reported at their outstanding principal balances, net of any unearned income, deferred origination fees or costs, or premium 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 and 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 Interest is not accrued on loans where collectability is uncertain. We 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 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. Past due status is based on the contractual terms of the loan. When a loan is placed on non-accrual status, all unpaid interest is reversed against interest income and the amortization of deferred fees and costs is suspended. Payments subsequently received are generally applied to either principal or interest or both, depending on management’s evaluation of collectability. A loan is returned to accrual status when principal and interest are no longer past due and collectability is probable. This generally requires a sustained period of timely principal and interest payments. Loans are generally charged-off when deemed uncollectible or when they reach a predetermined number of days past due depending upon loan product, terms, and other factors. Recoveries of amounts previously charged-off are credited to the allowance for credit losses. We consider a loan impaired when, based on current information and events, it is probable that we will be unable to collect the scheduled payments of principal or interest when due according to the contractual terms of the loan agreement. Factors considered in determining impairment include payment status, collateral value and the probability of collecting scheduled principal and interest payments when due. The impairment loss is measured by either the present value of expected future cash flows discounted at the loan’s effective interest rate, the loan’s obtainable market price, or the fair value of the collateral, less estimated selling costs, if the loan is collateral dependent. Purchased credit impaired loans are not classified as non-performing assets as the loans are considered to be performing. Restructured loans are those in which concessions of terms have been made as a result of deterioration in a borrower’s financial condition. In general, the modification or restructuring of a debt constitutes a TDR if we for economic or legal reasons related to the borrower’s financial difficulties grant a concession to the borrower that we would not otherwise consider under current market conditions. Debt restructurings or loan modifications for a borrower occur in the normal course of business and do not necessarily constitute TDRs. To designate a loan as a TDR, the presence of both borrower financial distress and a concession of terms must exist. 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 the borrower does not otherwise meet the criteria for non-accrual status, we will continue to accrue interest on the loan. A restructured acquired loan that is accounted for as a component of a pool is not considered a TDR.
Allowance for Credit Losses	Allowance for Credit Losses The allowance for credit losses is established as losses are estimated to have occurred through a provision charged to earnings. Loan losses are charged-off against the allowance for credit losses when management believes the uncollectability of a loan balance is confirmed. Subsequent recoveries, if any, are credited to the allowance for credit losses. Allowances for impaired commercial loans over $1.0 million are generally determined based on collateral values or the present value of estimated cash flows. All other impaired loans are evaluated in the aggregate based on loan segment loss given default. Changes in the allowance for credit losses related to impaired loans are charged or credited to the provision for credit losses. The allowance for credit losses is maintained at a level that, in management’s judgment, is believed appropriate to absorb probable losses associated with specifically identified loans, as well as estimated probable credit losses inherent in the remainder of the loan portfolio. The appropriateness of the allowance for credit losses is based on management’s evaluation of potential loan losses in the loan portfolio, which includes an assessment of past experience, current economic conditions in specific industries and geographic areas, general economic conditions, known and inherent risks in the loan portfolio, the estimated value of underlying collateral and residuals and changes in the composition of the loan portfolio. Determination of the allowance for credit losses is inherently subjective as it requires significant estimates, including the amounts and timing of expected future cash flows on impaired loans, estimated losses on pools of homogeneous loans based on transition matrices with predefined loss emergence and lookback periods, and consideration of qualitative factors, all of which are susceptible to significant change.
Loans Acquired in a Business Combination	Loans Acquired in a Business Combination Loans acquired in a business combination (impaired and non-impaired) are initially recorded at their acquisition-date fair values. Fair values are based on a discounted cash flow methodology that involves assumptions and judgments as to credit risk, default rates, loss severity, collateral values, discount rates, payment speeds, prepayment risk, and liquidity risk. The carryover of allowance for credit losses related to loans acquired in a business combination is prohibited as any credit losses in the loans are included in the determination of the fair value of the loans at the acquisition date. The allowance for credit losses on loans acquired in a business combination reflects only those losses incurred after acquisition and represents the present value of cash flows expected at acquisition that is no longer expected to be collected. At acquisition, we consider the following factors as indicators that an acquired loan has evidence of deterioration in credit quality and is therefore impaired and in the scope of ASC 310-30: • loans that were 90 days or more past due; • loans that had an internal risk rating of substandard or worse. Substandard is consistent with regulatory definitions and is defined as having a well-defined weakness that jeopardizes liquidation of the loan; • loans that were classified as non-accrual by the acquired bank at the time of acquisition; or • loans that had been previously modified in a TDR. Any loans acquired in a business combination that were not individually in the scope of ASC 310-30 because they didn’t meet the criteria above were pooled into groups of similar loans based on various factors including borrower type, loan purpose, and collateral type. For these pools, we used certain loan information, including outstanding principal balance, estimated expected losses, weighted average maturity, weighted average margin, and weighted average interest rate along with estimated prepayment rates, probability of default and loss given default to estimate the expected cash flow for each loan pool. We believe analogizing to ASC 310-30 is the more appropriate option to follow in accounting for discount accretion on non-impaired loans acquired in a business combination other than revolving loans and therefore account for such loans in accordance with ASC 310-30. ASC 310-30 guidance does not apply to revolving loans. Consequently, discount accretion on revolving loans acquired is accounted for using the ASC 310-20 approach. The excess of cash flows expected to be collected at acquisition over recorded fair value is referred to as the accretable yield. The accretable yield is recognized into income over the remaining life of the loan, or pool of loans, using an effective yield method, if the timing and/or amount of cash flows expected to be collected can be reasonably estimated (the accretion model). The difference between the loan’s total scheduled principal and interest payments over all cash flows expected at acquisition is referred to as the non-accretable difference. The non-accretable difference represents contractually required principal and interest payments which we do not expect to collect. Over the life of the acquired loan, we continue to estimate cash flows expected to be collected. Decreases in expected cash flows, other than from prepayments or rate adjustments, are recognized as impairments through a charge to the provision for credit losses resulting in an increase in the allowance for credit losses. Subsequent improvements in cash flows result in first, reversal of existing valuation allowances recognized subsequent to acquisition, if any, and next, an increase in the amount of accretable yield to be subsequently recognized on a prospective basis over the loan’s remaining life. Loans acquired in a business combination that met the criteria for non-accrual of interest prior to acquisition are considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if we can reasonably estimate the timing and amount of expected cash flows on such loans. Accordingly, we do not consider contractually delinquent purchased credit impaired loans to be non-accrual or non-performing and continue to recognize interest income on these loans using the accretion model.
Premises and Equipment	Premises and Equipment Premises and equipment are stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method over the asset’s estimated useful life. Leasehold improvements are expensed over the lesser of the asset’s estimated useful life or the term of the lease including renewal periods when reasonably assured. Useful lives are dependent upon the nature and condition of the asset and range from 3 to 39 years. Maintenance and repairs are charged to expense as incurred, while major improvements are capitalized and amortized to expense over the identified useful life. Premises and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying value may not be recoverable.
Cloud Computing Arrangements	Cloud Computing Arrangements W e evaluate fees paid for cloud computing arrangements to determine if those arrangements include the purchase of or license to use software that should be accounted for separately as internal-use software. If a contract includes the purchase or license to use software that should be accounted for separately as internal-use software, the contract is amortized over the software’s identified useful life in amortization of intangibles. For contracts that do not include a software license, the contract is accounted for as a service contract with fees paid recorded in other non-interest expense. In the third quarter of 2018, we early adopted, on a prospective basis, ASU 2018-15 which allows for implementation costs for activities performed in cloud computing arrangements that are a service contract to be accounted for under the internal-use software guidance which allows for certain implementation costs to be capitalized depending on the nature of the costs and the project stage. Prior to the adoption of ASU 2018-15 all implementation costs for cloud computing arrangements that were a service contract were expensed as incurred.
Other Real Estate Owned	Other Real Estate Owned OREO is comprised principally of commercial and residential real estate properties obtained in partial or total satisfaction of loan obligations. OREO acquired in settlement of indebtedness is included in other assets initially at the lower of estimated fair value of the asset less estimated selling costs or the carrying amount of the loan. Changes to the value subsequent to transfer are recorded in non-interest expense along with direct operating expenses. Gains or losses not previously recognized resulting from sales of OREO are recognized in non-interest income on the date of sale.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill represents the excess of the cost of an acquisition over the fair value of the net assets acquired. Other intangible assets represent purchased assets that lack physical substance but can be distinguished from goodwill because of contractual or other legal rights. Intangible assets that have finite lives, such as core deposit intangibles, customer relationship intangibles and renewal lists, are amortized over their estimated useful lives and subject to periodic impairment testing. Core deposit intangibles are primarily amortized over ten years using accelerated methods. Customer renewal lists are amortized over their estimated useful lives which range from eight to thirteen years . Goodwill and other intangibles are subject to impairment testing at the reporting unit level, which must be conducted at least annually. We perform impairment testing during the fourth quarter of each year, or more frequently if impairment indicators exist. We also continue to monitor other intangibles for impairment and to evaluate carrying amounts, as necessary. Determining the fair value of a reporting unit under the goodwill impairment test is judgmental and often involves the use of significant estimates and assumptions. Similarly, estimates and assumptions are used in determining the fair value of other intangible assets. Estimates of fair value are primarily determined using discounted cash flows, market comparisons and recent transactions. These approaches use significant estimates and assumptions including projected future cash flows, discount rates reflecting the market rate of return, projected growth rates and determination and evaluation of appropriate market comparables. However, future events could cause us to conclude that goodwill or other intangibles have become impaired, which would result in recording an impairment loss. Any resulting impairment loss could have a material adverse impact on our financial condition and results of operations.
Loan Servicing Rights	Loan Servicing Rights We have two primary classes of servicing rights, residential mortgage loan servicing and SBA-guaranteed loan servicing. We recognize the right to service residential mortgage loans and SBA-guaranteed loans for others as an asset whether we purchase the servicing rights or as a result from a sale of loans that we originated or purchased when the servicing is contractually separated from the underlying loan and retained by us. We initially record servicing rights at fair value in other assets on the Consolidated Balance Sheets. Subsequently, servicing rights are measured at the lower of cost or fair value. Servicing rights are amortized in proportion to, and over the period of, estimated net servicing income in mortgage banking operations non-interest income for residential mortgage loans and other non-interest income for SBA-guaranteed loans. The amount and timing of estimated future net cash flows are updated based on actual results and updated projections. MSRs are separated into pools based on common risk characteristics of the underlying loans and evaluated for impairment at least quarterly. SBA-guaranteed servicing rights are evaluated for impairment at least quarterly on an aggregate basis. Impairment, if any, is recognized when carrying value exceeds the fair value as determined by calculating the present value of expected net future cash flows. If impairment exists at the pool level for residential mortgage loans or on an aggregate basis for SBA-guaranteed loans, the servicing right is written down through a valuation allowance and is charged against mortgage banking operations non-interest income or other non-interest income, respectively.
Bank-Owned Life Insurance (BOLI)	Bank Owned Life Insurance We have purchased life insurance policies on certain current and former directors, officers and employees for which the Corporation is the owner and beneficiary. These policies are recorded in the Consolidated Balance Sheets at their cash surrender value, or the amount that could be realized by surrendering the policies. Tax-exempt income from death benefits and changes in the net cash surrender value are recorded in bank owned life insurance non-interest income.
Low Income Housing Tax Credit Partnerships	Low Income Housing Tax Credit Partnerships
Leases, lessee	Leases We determine if an arrangement is, or contains, a lease at inception of the contract. As a lessee, we consider a contract to be, or contain, a lease if the contract conveys the right to control the use of an identified asset in exchange for consideration. We recognize in our Consolidated Balance Sheets the obligation to make lease payments and a right-of-use asset representing our right to use the underlying asset for the lease term. For an operating lease, the right-of-use asset and lease liability are included in other assets and other liabilities, respectively. Finance leases are included in premises and equipment, and other liabilities. We do not record leases with an initial term of 12 months or less on the Consolidated Balance Sheets, instead we recognize lease expense for these leases on a straight-line basis over the lease term. For leases that commenced before January 1, 2019, we have applied the modified retrospective transition method which resulted in comparative information not being restated. The new standard provides a number of optional practical expedients in transition. We elected the ‘package of practical expedients’, which permits us to not reassess our prior conclusions about lease identification, lease classification and initial direct costs. Right-of-use assets and liabilities are initially measured at the present value of lease payments over the lease term, discounted using the interest rate implicit in the lease at the commencement date. Right-of-use assets are adjusted for any lease payments made prior to lease commencement, lease incentives, and accrued rent. If the rate implicit in the lease cannot be readily determined, we discount the lease using our incremental borrowing rate which is derived by reference to FNB's secured borrowing rate. Our leases may include options to extend or terminate the lease. When it is reasonably certain that we will exercise such an option, the lease term includes those periods. Lease expense for operating leases is recognized on a straight-line basis over the lease term. Lease expense for finance leases is recognized using the effective interest method. Certain of our lease agreements include variable rental payments based on a percentage of transactions and others include variable rental payments that periodically adjust to rates and charges stated in the agreements. Variable costs, such as maintenance expenses, property taxes, property insurance, transaction-based lease payments and index-based rate increases, are expensed as incurred. Right-of-use assets are reviewed for impairment when events or circumstances indicate that the carrying amount may not be recoverable. For operating leases, if deemed impaired, the right-of-use asset is written down and the remaining balance is subsequently amortized on a straight-line basis. We have real estate lease agreements with lease and non-lease components, which are generally accounted for as a single lease component.
Leases, lessor	As a lessor, when a lease meets certain criteria indicating that we effectively have transferred control of the underlying asset to the customer, the lease is classified as a sales-type lease. When a lease does not meet the criteria for a sales-type lease but meets the criteria of a direct financing lease, the lease is classified as a direct financing lease. When none of the required criteria for sales-type lease or direct-financing lease are met, the lease is classified as an operating lease. Both sales-type leases and direct financing leases are recognized as a net investment in the lease on the Consolidated Balance Sheets. The net investment comprises the lease receivable including any residual value of the underlying asset that is guaranteed by the customer or any other third party unrelated to us and the unguaranteed residual value of the underlying asset. Operating lease income is recognized over the lease term on a straight-line basis. We do not evaluate whether sales taxes and similar taxes imposed by a governmental authority on lease transactions and collected by us are our primary obligation as owner of the underlying leased asset and exclude from lease income all taxes collected.
Income Taxes	Income Taxes We file a consolidated federal income tax return. The provision for federal and state income taxes is based on income reported on the Consolidated Financial Statements, rather than the amounts reported on the respective income tax returns. DTAs and DTLs are computed using tax rates expected to apply to taxable income in the years in which those assets and liabilities are expected to be realized. The effect on DTAs and DTLs resulting from a change in tax rates is recognized as income or expense in the period that the change in tax rates is enacted. Beginning in the fourth quarter of 2017, we made an accounting policy election to reclassify the stranded tax effects that relate to a change in the federal tax rate from AOCI to retained earnings in accordance with newly adopted accounting guidance. We believe this change in accounting policy reduces the cost and complexity of accounting for stranded tax effects due to a change in federal tax rates. We make certain estimates and judgments in determining income tax expense for financial statement purposes. These estimates and judgments are applied in the calculation of certain tax credits and in the calculation of the deferred income tax expense or benefit associated with certain deferred tax assets and liabilities. Significant changes to these estimates may result in an increase or decrease to our tax provision in a subsequent period. We recognize interest and/or penalties related to income tax matters in income tax expense. We assess the likelihood that we will be able to recover our DTAs. If recovery is not likely, we will increase our valuation allowance against the DTAs that are unlikely to be recovered by recording a provision for income taxes. We believe that we will ultimately recover the DTAs recorded on our Consolidated Balance Sheets. We periodically review the tax positions we take on our tax return and apply a more likely than not recognition threshold for all tax positions that are uncertain. The amount recognized in the Consolidated Financial Statements is the largest amount of tax benefit that is greater than 50% likely of being realized on examination. For tax positions not meeting the more likely than not test, no tax benefit is recorded.
Marketing Costs	Marketing Costs Marketing costs are generally expensed as incurred. Marketing expense totaled $13.1 million , $12.8 million and $11.5 million for 2019 , 2018 and 2017 , respectively.
Per Share Amounts	Per Share Amounts Earnings per common share is computed using net income available to common stockholders, which is net income adjusted for preferred stock dividends. 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, warrants and restricted shares, as calculated using the treasury stock method. Adjustments to net income available to common stockholders and the weighted average number of shares of common stock outstanding are made only when such adjustments dilute earnings per common share. The assumed proceeds from applying the treasury stock method when computing diluted earnings per share excludes the amount of excess tax benefits that would have been recognized in accumulated paid-in capital.
Retirement Plans	Retirement Plans We sponsor retirement plans for our employees. The calculation of the obligations and related expenses under these plans requires use of actuarial valuation methods and assumptions. The plans utilize assumptions and methods including reflecting trust assets at their fair value for the qualified pension plans and recognizing the overfunded and underfunded status of the plans on our Consolidated Balance Sheets. Gains and losses, prior service costs and credits are recognized in AOCI, net of tax, until they are amortized, or immediately upon curtailment.
Stock Based Compensation	Stock-Based Compensation Our stock-based compensation awards require the measurement and recognition of compensation expense, based on estimated fair values, for all stock-based awards, including stock options and restricted stock units, made to employees and stock awards made to directors. Generally, these restricted stock unit awards to employees vest over a three -year service period and the stock awards made to directors vest immediately. We are required to estimate the fair value of stock-based awards on the date of grant. For time-based awards, the value of the award is recognized as expense in our Consolidated Statements of Income over the shorter of requisite service periods or the period through the date that the employee first becomes eligible to retire. Prior to 2018, we granted restricted stock unit awards that had market conditions. Compensation cost for awards with market-based performance targets is recognized based on the award’s grant date fair value. Beginning in 2018, we granted restricted stock unit awards with multiple-conditions, both performance and market conditions. These awards were accounted for by considering the market condition in the grant date fair value and recognizing compensation expense over the service period based on the grant date fair value and the probability that the performance condition will be met. We account for forfeitures as they occur.
New Accounting Standards	The following table summarizes accounting pronouncements issued by the FASB that we recently adopted or will be adopting in the future. TABLE 2.1 Standard Description Financial Statements Impact Derivative and Hedging Activities ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities This Update improves the financial reporting of hedging to better align with a company’s risk management activities. In addition, this Update makes certain targeted improvements to simplify the application of the current hedge accounting guidance. We adopted this Update in the first quarter of 2019 using a modified retrospective transition method. The presentation and disclosure guidance were applied prospectively. The adoption of this Update did not have a material effect on our Consolidated Financial Statements. This Update was effective as of January 1, 2019. Securities ASU 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities This Update shortens the amortization period for the premium on certain purchased callable securities to the earliest call date. The accounting for purchased callable debt securities held at a discount does not change. We adopted this Update in the first quarter of 2019 using a modified retrospective transition method. The adoption of this Update did not have a material effect on our Consolidated Financial Statements. This Update was effective as of January 1, 2019. Leases ASU 2016-02, Leases (Topic 842) ASU 2018-10, Codification Improvements to Topic 842, Leases ASU 2018-11, Leases (Topic 842), Targeted Improvements ASU 2018-20, Leases (Topic 842), Narrow-Scope Improvements for Lessors ASU 2019-01, Lease (Topic 842), Codification Improvements These Updates require lessees to put most leases on the Consolidated Balance Sheets but recognize expenses in the Consolidated Statements of Income similar to current accounting. In addition, the Update changes the guidance for sales-leaseback transactions, initial direct costs and lease executory costs for most entities. All entities will classify leases to determine how to recognize lease related revenue and expense. We adopted these Updates in the first quarter of 2019 under the modified retrospective transition method. In addition, the new standard provides a number of optional practical expedients in transition. We elected the ‘package of practical expedients,’ which permits us to not reassess our prior conclusions about lease identification, lease classification and initial direct costs. Adoption of the new standard resulted in the recording of $116 million in right-of-use assets and corresponding lease liabilities of $126 million for operating leases on our Consolidated Balance Sheet. The standard did not materially impact our consolidated net earnings and had no impact on cash flows. These Updates were effective as of January 1, 2019. 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 ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments ASU 2019-05, Financial Instruments-Credit Losses, (Topic 326): Targeted Transition Relief ASU 2019-11, 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. These Updates are to be applied using a cumulative-effect adjustment to retained earnings. While these Updates change the measurement of the Allowance for Credit Losses (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 current 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 loans 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 necessary. Based on our portfolio composition and forecasts of relatively stable macroeconomic conditions over the next two years, we currently estimate that our CECL ACL on the originated portfolio will increase approximately 30%, primarily driven by our consumer portfolios. The overall ACL including the "gross-up" for PCI loans of approximately $50 million is approximately $300-$310 million. There is no capital impact related to the PCI loans at adoption. The impact for the adoption of CECL is a reduction to retained earnings of approximately $52 million. The impact of this Update is 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 is immaterial. Model development, as well as the development of policies and procedures and, internal controls are complete. This Update is effective as of January 1, 2020.

New Accounting Standards (Table

New Accounting Standards (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Changes and Error Corrections [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The following table summarizes accounting pronouncements issued by the FASB that we recently adopted or will be adopting in the future. TABLE 2.1 Standard Description Financial Statements Impact Derivative and Hedging Activities ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities This Update improves the financial reporting of hedging to better align with a company’s risk management activities. In addition, this Update makes certain targeted improvements to simplify the application of the current hedge accounting guidance. We adopted this Update in the first quarter of 2019 using a modified retrospective transition method. The presentation and disclosure guidance were applied prospectively. The adoption of this Update did not have a material effect on our Consolidated Financial Statements. This Update was effective as of January 1, 2019. Securities ASU 2017-08, Receivables-Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities This Update shortens the amortization period for the premium on certain purchased callable securities to the earliest call date. The accounting for purchased callable debt securities held at a discount does not change. We adopted this Update in the first quarter of 2019 using a modified retrospective transition method. The adoption of this Update did not have a material effect on our Consolidated Financial Statements. This Update was effective as of January 1, 2019. Leases ASU 2016-02, Leases (Topic 842) ASU 2018-10, Codification Improvements to Topic 842, Leases ASU 2018-11, Leases (Topic 842), Targeted Improvements ASU 2018-20, Leases (Topic 842), Narrow-Scope Improvements for Lessors ASU 2019-01, Lease (Topic 842), Codification Improvements These Updates require lessees to put most leases on the Consolidated Balance Sheets but recognize expenses in the Consolidated Statements of Income similar to current accounting. In addition, the Update changes the guidance for sales-leaseback transactions, initial direct costs and lease executory costs for most entities. All entities will classify leases to determine how to recognize lease related revenue and expense. We adopted these Updates in the first quarter of 2019 under the modified retrospective transition method. In addition, the new standard provides a number of optional practical expedients in transition. We elected the ‘package of practical expedients,’ which permits us to not reassess our prior conclusions about lease identification, lease classification and initial direct costs. Adoption of the new standard resulted in the recording of $116 million in right-of-use assets and corresponding lease liabilities of $126 million for operating leases on our Consolidated Balance Sheet. The standard did not materially impact our consolidated net earnings and had no impact on cash flows. These Updates were effective as of January 1, 2019. 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 ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments ASU 2019-05, Financial Instruments-Credit Losses, (Topic 326): Targeted Transition Relief ASU 2019-11, 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. These Updates are to be applied using a cumulative-effect adjustment to retained earnings. While these Updates change the measurement of the Allowance for Credit Losses (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 current 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 loans 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 necessary. Based on our portfolio composition and forecasts of relatively stable macroeconomic conditions over the next two years, we currently estimate that our CECL ACL on the originated portfolio will increase approximately 30%, primarily driven by our consumer portfolios. The overall ACL including the "gross-up" for PCI loans of approximately $50 million is approximately $300-$310 million. There is no capital impact related to the PCI loans at adoption. The impact for the adoption of CECL is a reduction to retained earnings of approximately $52 million. The impact of this Update is 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 is immaterial. Model development, as well as the development of policies and procedures and, internal controls are complete. This Update is effective as of January 1, 2020.

Securities (Tables)

Securities (Tables)	12 Months Ended
	Dec. 31, 2019
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 debt securities are as follows: TABLE 3.1 (in millions) Amortized Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt Securities Available for Sale: 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 11 — — 11 Other debt securities 2 — — 2 Total debt securities available for sale $ 3,275 $ 24 $ (10 ) $ 3,289 December 31, 2018 U.S. government agencies $ 188 $ — $ (1 ) $ 187 U.S. government-sponsored entities 317 — (4 ) 313 Residential mortgage-backed securities: Agency mortgage-backed securities 1,465 — (36 ) 1,429 Agency collateralized mortgage obligations 1,179 5 (23 ) 1,161 Commercial mortgage-backed securities 229 — (1 ) 228 States of the U.S. and political subdivisions 21 — — 21 Other debt securities 2 — — 2 Total debt securities available for sale 3,401 5 (65 ) 3,341
Schedule of Amortized Cost and Fair Value of Securities Held to Maturity	(in millions) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Debt Securities Held to Maturity: 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 1,120 26 (2 ) 1,144 Total debt securities held to maturity $ 3,275 $ 42 $ (12 ) $ 3,305 December 31, 2018 U.S. Treasury $ 1 $ — $ — $ 1 U.S. government agencies 2 — — 2 U.S. government-sponsored entities 215 — (4 ) 211 Residential mortgage-backed securities: Agency mortgage-backed securities 1,036 — (26 ) 1,010 Agency collateralized mortgage obligations 794 1 (24 ) 771 Commercial mortgage-backed securities 126 1 (1 ) 126 States of the U.S. and political subdivisions 1,080 3 (49 ) 1,034 Total debt securities held to maturity $ 3,254 $ 5 $ (104 ) $ 3,155
Gross Gains and Gross Losses Realized on Sales of Securities	Gross gains and gross losses were realized on securities as follows: TABLE 3.2 Year Ended December 31 2019 2018 2017 (in millions) Gross gains $ — $ — $ 7 Gross losses — — (1 ) Net gains $ — $ — $ 6
Amortized Cost and Fair Value of Securities, by Contractual Maturities	As of December 31, 2019 , the amortized cost and fair value of debt securities, by contractual maturities, were as follows: TABLE 3.3 Available for Sale Held to Maturity (in millions) Amortized Cost Fair Value Amortized Cost Fair Value Due in one year or less $ 93 $ 93 $ 58 $ 58 Due after one year but within five years 147 148 131 131 Due after five years but within ten years 62 62 117 119 Due after ten years 88 87 991 1,013 390 390 1,297 1,321 Residential mortgage-backed securities: Agency mortgage-backed securities 1,310 1,314 949 955 Agency collateralized mortgage obligations 1,234 1,240 721 720 Commercial mortgage-backed securities 341 345 308 309 Total debt securities $ 3,275 $ 3,289 $ 3,275 $ 3,305
Schedule of Securities Pledged as Collateral	Following is information relating to securities pledged: TABLE 3.4 December 31 2019 2018 (dollars in millions) Securities pledged (carrying value): To secure public deposits, trust deposits and for other purposes as required by law $ 4,494 $ 3,874 As collateral for short-term borrowings 285 279 Securities pledged as a percent of total securities 72.8 % 63.0 %
Summaries of Fair Values and Unrealized Losses of Securities, Segregated by Length of Impairment	Following are summaries of the fair values and unrealized losses of temporarily impaired debt securities, segregated by length of impairment: TABLE 3.5 Less than 12 Months 12 Months or More Total (dollars in millions) # Fair Value Unrealized Losses # Fair Value Unrealized Losses # Fair Value Unrealized Losses Debt Securities Available for Sale: 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 ) States of the U.S. and political subdivisions — — — — — — — — — Other debt securities — — — 1 2 — 1 2 — Total temporarily impaired debt securities AFS 32 $ 685 $ (4 ) 78 $ 712 $ (6 ) 110 $ 1,397 $ (10 ) December 31, 2018 U.S. government agencies 20 $ 145 $ (1 ) — $ — $ — 20 $ 145 $ (1 ) U.S. government-sponsored entities 1 36 — 11 227 (4 ) 12 263 (4 ) Residential mortgage-backed securities: Agency mortgage-backed securities 16 259 (4 ) 71 1,159 (32 ) 87 1,418 (36 ) Agency collateralized mortgage obligations 2 82 (1 ) 47 590 (22 ) 49 672 (23 ) Non-agency collateralized mortgage obligations 1 — — — — — 1 — — Commercial mortgage-backed securities 4 155 (1 ) — — — 4 155 (1 ) States of the U.S. and political subdivisions 2 2 — 6 10 — 8 12 — Other debt securities — — — 1 2 — 1 2 — Total temporarily impaired debt securities AFS 46 $ 679 $ (7 ) 136 $ 1,988 $ (58 ) 182 $ 2,667 $ (65 ) Less than 12 Months 12 Months or More Total (dollars in millions) # Fair Value Unrealized Losses # Fair Value Unrealized Losses # Fair Value Unrealized Losses Debt Securities Held to Maturity: December 31, 2019 U.S. government-sponsored entities — $ — $ — 8 $ 160 $ — 8 $ 160 $ — Residential mortgage-backed securities: Agency mortgage-backed securities 5 134 (1 ) 11 135 (1 ) 16 269 (2 ) Agency collateralized mortgage obligations 2 50 — 33 317 (6 ) 35 367 (6 ) Commercial mortgage-backed securities 5 184 (2 ) 1 7 — 6 191 (2 ) States of the U.S. and political subdivisions 18 63 (1 ) 7 29 (1 ) 25 92 (2 ) Total temporarily impaired debt securities HTM 30 $ 431 $ (4 ) 60 $ 648 $ (8 ) 90 $ 1,079 $ (12 ) December 31, 2018 U.S. government-sponsored entities — $ — $ — 12 $ 211 $ (4 ) 12 $ 211 $ (4 ) Residential mortgage-backed securities: Agency mortgage-backed securities 43 294 (4 ) 47 694 (22 ) 90 988 (26 ) Agency collateralized mortgage obligations 3 42 — 49 611 (24 ) 52 653 (24 ) Commercial mortgage-backed securities 5 26 — 4 43 (1 ) 9 69 (1 ) States of the U.S. and political subdivisions 159 590 (27 ) 51 161 (22 ) 210 751 (49 ) Total temporarily impaired debt securities HTM 210 $ 952 $ (31 ) 163 $ 1,720 $ (73 ) 373 $ 2,672 $ (104 )

Other Securities (Tables)

Other Securities (Tables)	12 Months Ended
	Dec. 31, 2019
Banking and Thrift, Interest [Abstract]
Schedule of Other Securities	Following is a summary of non-marketable equity securities: TABLE 4.1 December 31 2019 2018 (in millions) Federal Home Loan Bank stock $ 256 $ 209 Federal Reserve Bank stock 123 122 Other non-marketable equity securities 1 1 Total non-marketable equity securities $ 380 $ 332

Loans and Leases (Tables)

Loans and Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Summary of Loans and Leases, Net of Unearned Income	Following is a summary of loans and leases, net of unearned income: TABLE 5.1 (in millions) Originated Loans and Leases Loans Acquired in a Business Combination Total Loans and Leases December 31, 2019 Commercial real estate $ 7,114 $ 1,846 $ 8,960 Commercial and industrial 5,063 245 5,308 Commercial leases 432 — 432 Other 21 — 21 Total commercial loans and leases 12,630 2,091 14,721 Direct installment 1,758 63 1,821 Residential mortgages 2,995 379 3,374 Indirect installment 1,922 — 1,922 Consumer lines of credit 1,092 359 1,451 Total consumer loans 7,767 801 8,568 Total loans and leases, net of unearned income $ 20,397 $ 2,892 $ 23,289 December 31, 2018 Commercial real estate $ 6,171 $ 2,615 $ 8,786 Commercial and industrial 4,140 416 4,556 Commercial leases 373 — 373 Other 46 — 46 Total commercial loans and leases 10,730 3,031 13,761 Direct installment 1,668 96 1,764 Residential mortgages 2,612 501 3,113 Indirect installment 1,933 — 1,933 Consumer lines of credit 1,119 463 1,582 Total consumer loans 7,332 1,060 8,392 Total loans and leases, net of unearned income $ 18,062 $ 4,091 $ 22,153
Certain Information Relating to Commercial Real Estate Loans	The following table shows certain information relating to commercial real estate loans: TABLE 5.2 December 31 2019 2018 (dollars in millions) Commercial construction, acquisition and development loans $ 1,275 $ 1,152 Percent of total loans and leases 5.5 % 5.2 % Commercial real estate: Percent owner-occupied 30.6 % 35.1 % Percent non-owner-occupied 69.4 % 64.9 %
Summary of Loans to Related Parties	Following is a summary of the activity for these loans to related parties during 2019 : TABLE 5.3 (in millions) Balance at beginning of period $ 16 New loans 1 Repayments (10 ) Balance at end of period $ 7
Summary of Outstanding Principal Balance and Carrying Amount of Acquired Loans Acquired In A Business Combination	The outstanding balance and the carrying amount of loans acquired in a business combination included in the Consolidated Balance Sheets are as follows: TABLE 5.4 December 31 2019 2018 (in millions) Accounted for under ASC 310-30: Outstanding balance $ 2,684 $ 3,768 Carrying amount 2,461 3,570 Accounted for under ASC 310-20: Outstanding balance 436 602 Carrying amount 425 513 Total loans acquired in a business combination: Outstanding balance 3,120 4,370 Carrying amount 2,886 4,083
Schedule Of Changes In Accretable Yields Of Loans Acquired In A Business Combination	The following table provides changes in accretable yield for all loans acquired in business combinations that are accounted for under ASC 310-30. Loans accounted for under ASC 310-20 are not included in this table. TABLE 5.5 Year Ended December 31 2019 2018 (in millions) Balance at beginning of period $ 605 $ 708 Reduction due to unexpected early payoffs (102 ) (146 ) Reclass from non-accretable difference to accretable yield 97 267 Disposals/transfers (1 ) (1 ) Other (1 ) (1 ) Accretion (179 ) (222 ) Balance at end of period $ 419 $ 605
Summary of Non-Performing Assets	Following is a summary of non-performing assets: TABLE 5.6 December 31 2019 2018 (dollars in millions) Non-accrual loans $ 81 $ 79 Troubled debt restructurings 22 21 Total non-performing loans 103 100 Other real estate owned 26 35 Total non-performing assets $ 129 $ 135 Asset quality ratios: Non-performing loans / total loans and leases 0.44 % 0.45 % Non-performing loans + OREO / total loans and leases + OREO 0.55 % 0.61 % Non-performing assets / total assets 0.37 % 0.41 %
Age Analysis of Past Due Loans, by Class	The following tables provide an analysis of the aging of loans by class segregated by loans and leases originated and loans acquired: TABLE 5.7 (in millions) 30-89 Days Past Due ≥ 90 Days Past Due and Still Accruing Non- Accrual Total Past Due Current Total Loans and Leases 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 December 31, 2018 Commercial real estate $ 7 $ — $ 17 $ 24 $ 6,147 $ 6,171 Commercial and industrial 5 — 19 24 4,116 4,140 Commercial leases 1 — 2 3 370 373 Other — — 1 1 45 46 Total commercial loans and leases 13 — 39 52 10,678 10,730 Direct installment 8 — 8 16 1,652 1,668 Residential mortgages 16 3 6 25 2,587 2,612 Indirect installment 11 1 2 14 1,919 1,933 Consumer lines of credit 5 1 3 9 1,110 1,119 Total consumer loans 40 5 19 64 7,268 7,332 Total originated loans and leases $ 53 $ 5 $ 58 $ 116 $ 17,946 $ 18,062 (in millions) 30-89 Days Past Due ≥ 90 Days Past Due and Still Accruing Non- Accrual Total Past Due (1) (2) Current (Discount)/ Premium Total Loans 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 December 31, 2018 Commercial real estate $ 19 $ 38 $ 3 $ 60 $ 2,723 $ (168 ) $ 2,615 Commercial and industrial 3 4 17 24 420 (28 ) 416 Total commercial loans 22 42 20 84 3,143 (196 ) 3,031 Direct installment 3 2 — 5 91 — 96 Residential mortgages 13 6 — 19 498 (16 ) 501 Consumer lines of credit 8 3 1 12 461 (10 ) 463 Total consumer loans 24 11 1 36 1,050 (26 ) 1,060 Total loans acquired in a business combination $ 46 $ 53 $ 21 $ 120 $ 4,193 $ (222 ) $ 4,091 (1) Past due information for loans acquired in a business combination is based on the contractual balance outstanding at December 31, 2019 and 2018 . (2) Loans acquired in a business combination are considered performing upon acquisition, regardless of whether the customer is contractually delinquent, if we can reasonably estimate the timing and amount of expected cash flows on such loans. In these instances, we do not consider acquired contractually delinquent loans to be non-accrual or non-performing and continue to recognize interest income on these loans using the accretion method. 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.
Loan, Credit Quality Indicators	We utilize the following categories to monitor credit quality within our commercial loan and lease portfolio: TABLE 5.8 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
Summary of Commercial Loans by Credit Quality	The following tables present a summary of our commercial loans and leases by credit quality category segregated by loans and leases originated and loans acquired: TABLE 5.9 Commercial Loan and Lease Credit Quality Categories (in millions) Pass Special Mention 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 and leases $ 12,032 $ 323 $ 272 $ 3 $ 12,630 December 31, 2018 Commercial real estate $ 5,883 $ 163 $ 125 $ — $ 6,171 Commercial and industrial 3,879 180 81 — 4,140 Commercial leases 366 1 6 — 373 Other 45 — 1 — 46 Total originated commercial loans and leases $ 10,173 $ 344 $ 213 $ — $ 10,730 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 December 31, 2018 Commercial real estate $ 2,256 $ 168 $ 191 $ — $ 2,615 Commercial and industrial 355 18 43 — 416 Total commercial loans acquired in a business combination $ 2,611 $ 186 $ 234 $ — $ 3,031
Summary of Consumer Loans by Payment Status	Following is a table showing consumer loans by payment status: TABLE 5.10 Consumer Loan Credit Quality by Payment Status (in millions) Performing Non-Performing 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 December 31, 2018 Direct installment $ 1,654 $ 14 $ 1,668 Residential mortgages 2,598 14 2,612 Indirect installment 1,931 2 1,933 Consumer lines of credit 1,114 5 1,119 Total originated consumer loans $ 7,297 $ 35 $ 7,332 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 December 31, 2018 Direct installment $ 96 $ — $ 96 Residential mortgages 501 — 501 Consumer lines of credit 462 1 463 Total consumer loans acquired in a business combination $ 1,059 $ 1 $ 1,060
Summary of Impaired Loans and Leases, by Class	Following is a summary of information pertaining to loans and leases considered to be impaired, by class of loan and lease: TABLE 5.11 (in millions) Unpaid Contractual Principal Balance Recorded Investment With No Specific Reserve Recorded Investment With Specific Reserve Total Recorded Investment Specific Reserve Average Recorded Investment At or for the Year Ended Commercial real estate $ 30 $ 25 $ 2 $ 27 $ 2 $ 26 Commercial and industrial 35 21 — 21 2 22 Commercial leases 1 1 — 1 — 1 Total commercial loans and leases 66 47 2 49 4 49 Direct installment 16 13 — 13 — 13 Residential mortgages 20 18 — 18 — 17 Indirect installment 5 3 — 3 — 3 Consumer lines of credit 7 5 — 5 — 5 Total consumer loans 48 39 — 39 — 38 Total $ 114 $ 86 $ 2 $ 88 $ 4 $ 87 At or for the Year Ended Commercial real estate $ 20 $ 16 $ 1 $ 17 $ — $ 18 Commercial and industrial 46 20 13 33 4 32 Commercial leases 2 2 — 2 — 4 Total commercial loans and leases 68 38 14 52 4 54 Direct installment 17 14 — 14 — 14 Residential mortgages 16 14 — 14 — 15 Indirect installment 5 2 — 2 — 2 Consumer lines of credit 7 5 — 5 — 5 Total consumer loans 45 35 — 35 — 36 Total $ 113 $ 73 $ 14 $ 87 $ 4 $ 90
Additional Allowance For Credit Losses Related To Loans Acquired In A Business Combination	Following is a summary of the allowance for credit losses required for loans acquired in a business combination due to changes in credit quality subsequent to the acquisition date: TABLE 5.12 December 31 2019 2018 (in millions) Commercial real estate $ 4 $ 2 Commercial and industrial — 4 Total commercial loans 4 6 Direct installment 1 1 Residential mortgages 2 — Total consumer loans 3 1 Total allowance on loans acquired in a business combination $ 7 $ 7
Summary of Composition of Total TDRs	Following is a summary of the composition of total TDRs: TABLE 5.13 (in millions) Originated Acquired Total December 31, 2019 Accruing: Performing $ 19 $ — $ 19 Non-performing 18 4 22 Non-accrual 14 1 15 Total TDRs $ 51 $ 5 $ 56 December 31, 2018 Accruing: Performing $ 18 $ — $ 18 Non-performing 17 4 21 Non-accrual 9 — 9 Total TDRs $ 44 $ 4 $ 48
Summary of Troubled Debt Restructurings by Class of Loans	Following is a summary of TDR loans, by class: TABLE 5.14 Year Ended December 31 2019 2018 (dollars in millions) Number of Contracts Pre-Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Number of Contracts Pre-Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Commercial real estate 20 $ 5 $ 5 4 $ 1 $ 1 Commercial and industrial 23 5 3 10 — — Total commercial loans 43 10 8 14 1 1 Direct installment 65 3 3 80 4 4 Residential mortgages 18 3 3 15 1 1 Consumer lines of credit 27 2 1 26 1 1 Total consumer loans 110 8 7 121 6 6 Total 153 $ 18 $ 15 135 $ 7 $ 7
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. Default occurs when a loan is 90 days or more past due and is within 12 months of restructuring. TABLE 5.15 Year Ended December 31 2019 2018 (dollars in millions) Number of Contracts Recorded Investment Number of Contracts Recorded Investment Commercial real estate 5 $ 1 3 $ 1 Commercial and industrial 1 — 1 — Total commercial loans 6 1 4 1 Direct installment 5 — 7 1 Residential mortgages 2 — 4 — Consumer lines of credit 1 — 3 — Total consumer loans 8 — 14 1 Total 14 $ 1 18 $ 2

Allowance for Credit Losses (Ta

Allowance for Credit Losses (Tables)	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Summary of Changes in Allowance for Credit Losses by Loan and Lease Class	Following is a summary of changes in the allowance for credit losses, by loan and lease class: TABLE 6.1 (in millions) Balance at Beginning of Year Charge- Offs Recoveries Net Charge- Offs Provision for Credit Losses Balance at End of Year Year Ended December 31, 2019 Commercial real estate $ 55 $ (4 ) $ 4 $ — $ 5 $ 60 Commercial and industrial 49 (10 ) 4 (6 ) 10 53 Commercial leases 8 — — — 3 11 Other 2 (3 ) — (3 ) 3 2 Total commercial loans and leases 114 (17 ) 8 (9 ) 21 126 Direct installment 14 (1 ) — (1 ) — 13 Residential mortgages 20 (2 ) — (2 ) 4 22 Indirect installment 15 (11 ) 4 (7 ) 11 19 Consumer lines of credit 10 (2 ) — (2 ) 1 9 Total consumer loans 59 (16 ) 4 (12 ) 16 63 Total allowance on originated loans and leases 173 (33 ) 12 (21 ) 37 189 Purchased credit-impaired loans 1 — — — — 1 Other loans acquired in a business combination 6 (9 ) 2 (7 ) 7 6 Total allowance on loans acquired in a business combination 7 (9 ) 2 (7 ) 7 7 Total allowance for credit losses $ 180 $ (42 ) $ 14 $ (28 ) $ 44 $ 196 (in millions) Balance at Beginning of Year Charge- Offs Recoveries Net Charge- Offs Provision for Credit Losses Balance at End of Year Year Ended December 31, 2018 Commercial real estate $ 50 $ (7 ) $ 3 $ (4 ) $ 9 $ 55 Commercial and industrial 52 (20 ) 2 (18 ) 15 49 Commercial leases 5 (3 ) — (3 ) 6 8 Other 2 (4 ) — (4 ) 4 2 Total commercial loans and leases 109 (34 ) 5 (29 ) 34 114 Direct installment 21 (17 ) 2 (15 ) 8 14 Residential mortgages 16 — — — 4 20 Indirect installment 12 (9 ) 4 (5 ) 8 15 Consumer lines of credit 10 (3 ) — (3 ) 3 10 Total consumer loans 59 (29 ) 6 (23 ) 23 59 Total allowance on originated loans and leases 168 (63 ) 11 (52 ) 57 173 Purchased credit-impaired loans 1 — — — — 1 Other loans acquired in a business combination 6 (7 ) 3 (4 ) 4 6 Total allowance on loans acquired in a business combination 7 (7 ) 3 (4 ) 4 7 Total allowance for credit losses $ 175 $ (70 ) $ 14 $ (56 ) $ 61 $ 180 Year Ended December 31, 2017 Commercial real estate $ 47 $ (2 ) $ 2 $ — $ 3 $ 50 Commercial and industrial 48 (27 ) 2 (25 ) 29 52 Commercial leases 3 (1 ) — (1 ) 3 5 Other 1 (4 ) 1 (3 ) 4 2 Total commercial loans and leases 99 (34 ) 5 (29 ) 39 109 Direct installment 21 (12 ) 2 (10 ) 10 21 Residential mortgages 10 — — — 6 16 Indirect installment 11 (10 ) 4 (6 ) 7 12 Consumer lines of credit 10 (2 ) — (2 ) 2 10 Total consumer loans 52 (24 ) 6 (18 ) 25 59 Total allowance on originated loans and leases 151 (58 ) 11 (47 ) 64 168 Purchased credit-impaired loans 1 (1 ) — (1 ) 1 1 Other loans acquired in a business combination 6 (1 ) 5 4 (4 ) 6 Total allowance on loans acquired in a business combination 7 (2 ) 5 3 (3 ) 7 Total allowance for credit losses $ 158 $ (60 ) $ 16 $ (44 ) $ 61 $ 175
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 allowance for credit losses and corresponding loan and lease balances by class: TABLE 6.2 Allowance Loans and Leases Outstanding (in millions) Individually Evaluated for Impairment Collectively Evaluated for Impairment Loans and Leases Individually Evaluated for Impairment Collectively Evaluated for Impairment 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 December 31, 2018 Commercial real estate $ — $ 55 $ 6,171 $ 7 $ 6,164 Commercial and industrial 4 49 4,140 11 4,129 Commercial leases — 9 373 — 373 Other — 2 46 — 46 Total commercial loans and leases 4 115 10,730 18 10,712 Direct installment — 14 1,668 — 1,668 Residential mortgages — 19 2,612 — 2,612 Indirect installment — 15 1,933 — 1,933 Consumer lines of credit — 10 1,119 — 1,119 Total consumer loans — 58 7,332 — 7,332 Total $ 4 $ 173 $ 18,062 $ 18 $ 18,044 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)	12 Months Ended
	Dec. 31, 2019
Mortgage Servicing Rights
Servicing Assets at Fair Value [Line Items]
Servicing Asset at Amortized Cost	The unpaid principal balance of mortgage loans serviced for others, as of December 31, 2019 and 2018 , is listed below: TABLE 7.1 December 31 2019 2018 (in millions) Mortgage loans sold with servicing retained $ 4,686 $ 3,968 The following table summarizes activity relating to mortgage loans sold with servicing retained: TABLE 7.2 Year Ended December 31 2019 2018 2017 (in millions) Mortgage loans sold with servicing retained $ 1,381 $ 1,060 $ 1,769 Pretax gains resulting from above loan sales (1) 32 19 22 Mortgage servicing fees (1) 11 9 8 (1) Recorded in mortgage banking operations on the Consolidated Statements of Income. Following is a summary activity relating to MSRs: TABLE 7.3 Year Ended December 31 2019 2018 2017 (in millions) Balance at beginning of period $ 37 $ 29 $ 14 Fair value of MSRs acquired — — 8 Additions 14 13 11 Payoffs and curtailments (5 ) (2 ) (2 ) Impairment charge (1 ) (1 ) — Amortization (2 ) (2 ) (2 ) Balance at end of period $ 43 $ 37 $ 29 Fair value, beginning of period $ 41 $ 32 $ 18 Fair value, end of period 45 41 32
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 7.4 December 31 2019 2018 (dollars in millions) Weighted average life (months) 78.9 82.2 Constant prepayment rate (annualized) 10.6 % 10.1 % Discount rate 9.7 % 9.7 % Effect on fair value due to change in interest rates: +0.25% $ 3 $ 3 +0.50% 5 5 -0.25% (3 ) (3 ) -0.50% (5 ) (6 )
SBA-Guaranteed Loan Servicing
Servicing Assets at Fair Value [Line Items]
Servicing Asset at Amortized Cost	The unpaid principal balance of SBA-guaranteed loans serviced for investors, as of December 31, 2019 and December 31, 2018 , was as follows: TABLE 7.5 December 31 2019 2018 (in millions) SBA loans sold to investors with servicing retained $ 225 $ 283 The following table summarizes activity relating to SBA loans sold with servicing retained: TABLE 7.6 Year Ended December 31 2019 2018 2017 (in millions) SBA loans sold with servicing retained $ 23 $ 41 $ 54 Pretax gains resulting from above loan sales (1) 2 4 2 SBA servicing fees (1) 2 3 2 (1) Recorded in non-interest income. Following is a summary of the activity in SBA servicing rights: TABLE 7.7 Year Ended December 31 2019 2018 2017 (in millions) Balance at beginning of period $ 4 $ 5 $ — Fair value of servicing rights acquired — — 5 Additions — 1 1 Payoffs, curtailments and amortization (1 ) (1 ) (1 ) Impairment (charge) / recovery — (1 ) — Balance at end of period $ 3 $ 4 $ 5 Fair value, beginning of period $ 4 $ 5 $ — Fair value, end of period 3 4 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 key assumptions and the sensitivity of the SBA servicing rights to changes in these assumptions. The declines in fair values were immaterial in the scenarios presented. TABLE 7.8 December 31 2019 2018 (dollars in millions) Weighted average life (months) 42.0 52.2 Constant prepayment rate 16.8 % 12.5 % Discount rate 16.2 % 19.4 % Decline in fair value due to change in interest rates: 1% adverse change $ (0.1 ) $ (0.1 ) 2% adverse change (0.1 ) (0.2 ) Decline in fair value due to change in constant prepayment rates: 10% adverse change (0.1 ) (0.2 ) 20% adverse change (0.3 ) (0.3 )

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Summary of Premises and Equipment	Following is a summary of premises and equipment: TABLE 8.1 December 31 2019 2018 (in millions) Land $ 62 $ 64 Premises 233 238 Equipment 276 236 571 538 Accumulated depreciation (238 ) (208 ) Total premises and equipment, net $ 333 $ 330
Depreciation Expense for Premises and Equipment	Depreciation expense for premises and equipment is presented in the following table: TABLE 8.2 December 31 2019 2018 2017 (in millions) Depreciation expense for premises and equipment $ 42 $ 39 $ 34

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Rollforward of Goodwill	The following table shows a rollforward of goodwill by line of business: TABLE 9.1 (in millions) Community Banking Wealth Manage- ment Insurance Other (1) Total Balance at January 1, 2018 $ 2,228 $ 8 $ 11 $ 2 $ 2,249 Goodwill (deductions) additions 3 — 5 (2 ) 6 Balance at December 31, 2018 2,231 8 16 — 2,255 Goodwill (deductions) additions — — 7 — 7 Balance at December 31, 2019 $ 2,231 $ 8 $ 23 $ — $ 2,262 (1) Other represents Consumer Finance which was a reportable segment prior to December 31, 2018. The deduction of goodwill for the Consumer Finance segment in 2018 was the result of the sale of Regency to Mariner Finance, LLC on August 31, 2018, as part of our strategy to enhance the overall positioning of our consumer banking operations.
Summary of Core Deposit Intangibles, Customer Renewal Lists and Mortgage Servicing Rights	The following table shows a summary of core deposit intangibles and customer renewal lists: TABLE 9.2 (in millions) Core Deposit Intangibles Customer Renewal Lists Total December 31, 2019 Gross carrying amount $ 196 $ 18 $ 214 Accumulated amortization (136 ) (11 ) (147 ) Net carrying amount $ 60 $ 7 $ 67 December 31, 2018 Gross carrying amount $ 196 $ 15 $ 211 Accumulated amortization (122 ) (10 ) (132 ) Net carrying amount $ 74 $ 5 $ 79
Schedule of Amortization Expense Recognized	The following table summarizes amortization expense recognized: TABLE 9.3 December 31 2019 2018 2017 (in millions) Amortization expense $ 14 $ 16 $ 18
Schedule of Expected Amortization Expenses on Finite-Lived Intangible Assets	Following is a summary of the expected amortization expense on finite-lived intangible assets, assuming no new additions, for each of the five years following December 31, 2019 : TABLE 9.4 (in millions) 2020 $ 13 2021 12 2022 10 2023 10 2024 8 Total $ 53

Operating Leases (Tables)

Operating Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Lease, Cost	The components of lease expense were as follows: TABLE 10.1 Twelve Months Ended (dollars in millions) 2019 Operating lease cost $ 27 Short-term lease cost 1 Variable lease cost 4 Sublease income — Total lease cost $ 32
Leases, Other Information	Other information related to leases is as follows: TABLE 10.2 Twelve Months Ended (dollars in millions) 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 26 Right-of-use assets obtained in exchange for lease obligations: Operating leases 25 Weighted average remaining lease term (years): Operating leases 9.61 Weighted average discount rate: Operating leases 3.0 %
Lessor, Operating Lease, Payments to be Received, Maturity	Maturities of operating lease liabilities were as follows: TABLE 10.3 (in millions) December 31, 2020 $ 24 2021 22 2022 17 2023 13 2024 12 Later years 62 Total lease payments 150 Less: imputed interest (22 ) Present value of lease liabilities $ 128

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2019
Deposits [Abstract]
Summary of Deposits	Following is a summary of deposits: TABLE 11.1 December 31 2019 2018 (in millions) Non-interest-bearing demand $ 6,384 $ 6,000 Interest-bearing demand 11,049 9,660 Savings 2,625 2,526 Certificates and other time deposits: Less than $100,000 2,262 2,816 $100,000 through $250,000 1,494 1,478 Greater than $250,000 972 975 Total certificates and other time deposits 4,728 5,269 Total deposits $ 24,786 $ 23,455
Summary of Scheduled Maturities of Certificates and Other Time Deposits	Following is a summary of the scheduled maturities of certificates and other time deposits for the years following December 31, 2019 : TABLE 11.2 (in millions) 2020 $ 3,035 2021 1,041 2022 236 2023 214 2024 115 Later years 87 Total $ 4,728

Short-Term Borrowings (Tables)

Short-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Summary of Short-Term Borrowings	Following is a summary of short-term borrowings: TABLE 12.1 December 31 2019 2018 (in millions) Securities sold under repurchase agreements $ 278 $ 251 Federal Home Loan Bank advances 2,255 2,230 Federal funds purchased 575 1,535 Subordinated notes 108 113 Total short-term borrowings $ 3,216 $ 4,129
Schedule of Weighted Average Interest Rates on Short-Term Borrowings	The following represents weighted average interest rates on short-term borrowings: TABLE 12.2 December 31 2019 2018 2017 Year-to-date average 2.24 % 1.89 % 1.16 % Period-end 1.76 % 2.49 % 1.44 %

Long-Term Borrowings (Tables)

Long-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Summary of Long-Term Borrowings	Following is a summary of long-term borrowings: TABLE 13.1 December 31 2019 2018 (in millions) Federal Home Loan Bank advances $ 935 $ 270 Subordinated notes 90 87 Junior subordinated debt 66 111 Other subordinated debt 249 159 Total long-term borrowings $ 1,340 $ 627
Scheduled Annual Maturities for Long-Term Borrowings	Scheduled annual maturities for the long-term borrowings for the years following December 31, 2019 are as follows: TABLE 13.2 (in millions) 2020 $ 122 2021 563 2022 311 2023 30 2024 1 Later years 313 Total $ 1,340
Schedule of Weighted Average Interest Rate on Subordinated Notes	The weighted average interest rate on the subordinated notes are presented in the following table: TABLE 13.3 December 31 2019 2018 2017 Subordinated notes weighted average interest rate 3.33 % 3.08 % 2.85 %
Schedule of Junior Subordinated Debt Trusts	The following table provides information relating to the Trusts as of December 31, 2019 : TABLE 13.4 (dollars in millions) Trust Preferred Securities Common Securities Junior Subordinated Debt Stated Maturity Date Interest Rate Rate Reset Factor F.N.B. Statutory Trust II $ 22 $ 1 $ 22 6/15/2036 3.54 % LIBOR + 165 basis points (bps) Yadkin Valley Statutory Trust I 25 1 22 12/15/2037 3.21 % LIBOR + 132 bps FNB Financial Services Capital Trust I 25 1 22 9/30/2035 3.42 % LIBOR + 146 bps Total $ 72 $ 3 $ 66
Schedule of Other Subordinated Debt	The following table provides information relating to our other subordinated debt as of December 31, 2019 . 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, at which time the floating rate will be LIBOR plus 240 basis points. These subordinated notes are eligible for treatment as tier 2 capital for regulatory capital purposes. TABLE 13.5 (dollars in millions) Aggregate Principal Amount Issued Net Proceeds (2) Carrying Value Stated Maturity Date Interest Rate 4.95% Fixed-To-Floating Rate Subordinated Notes due 2029 $ 120 $ 118 $ 118 2/14/2029 4.95 % 4.875% Subordinated Notes due 2025 100 98 99 10/2/2025 4.88 % 7.625% Subordinated Notes due August 12, 2023 (1) 38 46 32 8/12/2023 7.63 % Total $ 258 $ 262 $ 249 (1) Assumed from YDKN 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 YDKN, this is the fair value of the debt at the time of the acquisition.

Derivative Instruments and He_2

Derivative Instruments and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2019
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 14.1 December 31 2019 2018 Notional Amount Fair Value Notional Amount Fair Value (in millions) Asset Liability Asset Liability Gross Derivatives Subject to master netting arrangements: Interest rate contracts – designated $ 1,655 $ 1 $ — $ 1,155 $ — $ 3 Interest rate swaps – not designated 3,640 — 23 2,740 2 10 Equity contracts – not designated — — — 1 — — Total subject to master netting arrangements 5,295 1 23 3,896 2 13 Not subject to master netting arrangements: Interest rate swaps – not designated 3,640 149 1 2,740 40 26 Interest rate lock commitments – not designated 163 3 — 47 1 — Forward delivery commitments – not designated 195 1 1 55 — — Credit risk contracts – not designated 265 — — 203 — — Equity contracts – not designated — — — 1 — — Total not subject to master netting arrangements 4,263 153 2 3,046 41 26 Total $ 9,558 $ 154 $ 25 $ 6,942 $ 43 $ 39
Summary of Amounts Reclassified from Accumulated Other Comprehensive Income (AOCI)	The following table shows amounts reclassified from AOCI: TABLE 14.2 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 Year Ended Year Ended (in millions) 2019 2018 2017 2019 2018 2017 Derivatives in cash flow hedging relationships: Interest rate contracts $ (22 ) $ (3 ) $ 1 Interest income (expense) $ 2 $ 2 $ —
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 14.3 Year Ended December 31, 2019 2018 2017 (in millions) Interest Income - Loans and Leases Interest Expense - Short-Term Borrowings 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) $ 1,085 $ 80 $ 1,022 $ 75 $ 862 $ 44 The effects of cash flow hedging: Gain (loss) on cash flow hedging relationships — — — — — — Interest rate contracts — — — — — — Amount of gain (loss) reclassified from AOCI into net income (1 ) 3 (1 ) 3 1 (1 ) Amount of gain (loss) reclassified from AOCI into income as a result of that a forecasted transaction is no longer probable of occurring — — — — — —
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 14.4 Year Ended December 31, (in millions) Consolidated Statements of Income Location 2019 2018 2017 Interest rate swaps Non-interest income - other $ — $ 1 $ (1 ) 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 14.5 Amount Not Offset in the (in millions) Net Amount Financial Cash Net 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 $ — $ — December 31, 2018 Derivative Assets Interest rate contracts: Not designated $ 2 $ 2 $ — $ — Total $ 2 $ 2 $ — $ — Derivative Liabilities Interest rate contracts: Designated $ 3 $ 3 $ — $ — Not designated 10 9 — 1 Total $ 13 $ 12 $ — $ 1

Commitments, Credit Risk and _2

Commitments, Credit Risk and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2019
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 15.1 December 31 2019 2018 (in millions) Commitments to extend credit $ 8,089 $ 7,378 Standby letters of credit 150 126

Stock Incentive Plans (Tables)

Stock Incentive Plans (Tables)	12 Months Ended
	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Schedule of Issuance of Restricted Stock Units and Aggregate Weighted Average Grant Date Fair Values	The following table details our issuance of restricted stock units and the aggregate weighted average grant date fair values under these plans for the years indicated: TABLE 16.1 (dollars in millions) 2019 2018 2017 Restricted stock units 1,182,197 962,799 713,998 Weighted average grant date fair values $ 13 $ 13 $ 10
Summary of Activity Relating to Restricted Stock Units	The following table summarizes the activity relating to restricted stock units during the periods indicated: TABLE 16.2 2019 2018 2017 Units Weighted Average Grant Price per Share Units Weighted Average Grant Price per Share Units Weighted Average Grant Price per Share Unvested units outstanding at beginning of year 2,556,174 $ 13.51 1,975,862 $ 13.64 1,836,363 $ 12.97 Granted 1,182,197 10.94 962,799 13.21 713,998 14.67 Net adjustment due to performance — — — — (64,861 ) 13.85 Vested (655,208 ) 13.15 (258,031 ) 13.19 (542,580 ) 12.71 Forfeited/expired (332,814 ) 12.72 (214,743 ) 13.39 (31,018 ) 14.03 Dividend reinvestment 108,008 11.84 90,287 12.61 63,960 13.80 Unvested units outstanding at end of year 2,858,357 12.56 2,556,174 13.51 1,975,862 13.64
Schedule of Certain Information Related to Restricted Stock Units	The following table provides certain information related to restricted stock units: TABLE 16.3 Year Ended December 31 2019 2018 2017 (in millions) Stock-based compensation expense $ 12 $ 10 $ 8 Tax benefit related to stock-based compensation expense 2 2 3 Fair value of units vested 7 3 8
Components of Restricted Stock Units	The components of the restricted stock units as of December 31, 2019 are as follows: TABLE 16.4 (dollars in millions) Service- Based Units Performance- Based Units Total Unvested restricted stock units 1,922,120 936,237 2,858,357 Unrecognized compensation expense $ 10 $ 4 $ 14 Intrinsic value $ 24 $ 12 $ 36 Weighted average remaining life (in years) 1.83 1.81 1.82
Summary of Activity Related to Stock Options Units	The following table summarizes the activity relating to stock options during the periods indicated: TABLE 16.5 2019 Weighted Average Exercise Price per Share 2018 Weighted Average Exercise Price per Share 2017 Weighted Average Exercise Price per Share Options outstanding at beginning of year 458,354 $ 7.99 722,650 $ 7.96 892,532 $ 8.95 Assumed from acquisitions — — — — 207,645 8.92 Exercised (183,566 ) 7.86 (253,899 ) 7.77 (255,503 ) 10.21 Forfeited/expired (28,704 ) 7.65 (10,397 ) 11.98 (122,024 ) 12.12 Options outstanding and exercisable at end of year 246,084 8.14 458,354 7.99 722,650 7.96
Summary of Stock Options Outstanding	The following table summarizes information about stock options outstanding at December 31, 2019 : TABLE 16.6 Range of Exercise Prices Options Outstanding and Exercisable Weighted Average Remaining Contractual Years Weighted Average Exercise Price $3.45 - $5.18 54,148 1.26 $ 4.82 $5.19 - $7.78 40,022 3.11 6.90 $7.79 - $11.37 151,914 4.71 9.64 246,084
Summary of Stock Options Exercised	The following table summarizes certain information relating to stock options exercised: TABLE 16.7 Year Ended December 31 2019 2018 2017 (in millions) Proceeds from stock options exercised $ 1 $ 2 $ 2 Intrinsic value of stock options exercised 1 1 1

Retirement Plans (Tables)

Retirement Plans (Tables)	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Schedule of Accumulated Benefit Obligation, Change in Benefit Obligation, Change in Plan Assets, Plans' Funded Status and Amount Included in Consolidated Balance Sheets	The following tables provide information relating to the accumulated benefit obligation, change in benefit obligation, change in plan assets, the plans’ funded status and the amount included in the Consolidated Balance Sheets for the qualified and non-qualified plans described above (collectively, the Plans): TABLE 17.1 December 31 2019 2018 Qualified Non-Qualified Total Qualified Non-Qualified Total (in millions) Accumulated benefit obligation $ 156 $ 19 $ 175 $ 145 $ 18 $ 163 Projected benefit obligation at beginning of year $ 145 $ 18 $ 163 $ 162 $ 20 $ 182 Interest cost 6 1 7 6 — 6 Actuarial loss (gain) 15 2 17 (12 ) (1 ) (13 ) Benefits paid (10 ) (2 ) (12 ) (11 ) (1 ) (12 ) Projected benefit obligation at end of year $ 156 $ 19 $ 175 $ 145 $ 18 $ 163 Fair value of plan assets at beginning of year $ 150 $ — $ 150 $ 164 $ — $ 164 Actual return on plan assets 28 — 28 (7 ) — (7 ) Corporation contribution 5 2 7 4 1 5 Benefits paid (10 ) (2 ) (12 ) (11 ) (1 ) (12 ) Fair value of plan assets at end of year $ 173 $ — $ 173 $ 150 $ — $ 150 Funded status of plans $ 17 $ (19 ) $ (2 ) $ 5 $ (18 ) $ (13 )
Schedule of Actuarial Assumptions Used in Determination of Projected Benefit Obligation	Actuarial assumptions used in the determination of the projected benefit obligation in the Plans are as follows: TABLE 17.2 Assumptions at December 31 2019 2018 Weighted average discount rate 3.17 % 4.18 % Rates of average increase in compensation levels 3.50 3.50
Schedule of Net Periodic Pension Cost and Other Comprehensive Income	The net periodic pension cost and other comprehensive income for the Plans included the following components: TABLE 17.3 Year Ended December 31 2019 2018 2017 (in millions) Interest cost $ 7 $ 6 $ 7 Expected return on plan assets (11 ) (11 ) (11 ) Actuarial loss amortization 2 2 2 Total pension income (2 ) (3 ) (2 ) Other changes in plan assets and benefit obligations recognized in other comprehensive income: Current year actuarial loss 1 6 3 Amortization of actuarial loss (2 ) (2 ) (2 ) Total amount recognized in other comprehensive income (1 ) 4 1 Total amount recognized in net periodic benefit cost and other comprehensive income $ (3 ) $ 1 $ (1 )
Schedule of Actuarial Assumptions Used in Determination of Net Periodic Pension Cost	The plans have an actuarial measurement date of December 31. Actuarial assumptions used in the determination of the net periodic pension cost in the Plans are as follows: TABLE 17.4 Assumptions for the Year Ended December 31 2019 2018 2017 Weighted average discount rate 4.16 % 4.19 % 3.96 % Rates of increase in compensation levels 3.50 3.50 3.50 Expected long-term rate of return on assets 7.25 7.25 7.25
Schedule of Estimated Future Cash Flows	The following table provides information regarding estimated future cash flows relating to the Plans at December 31, 2019 : TABLE 17.5 (in millions) Expected employer contributions: 2020 $ 2 Expected benefit payments: 2020 10 2021 10 2022 10 2023 10 2024 11 2025 – 2029 53
Schedule of Contribution Expense	Our contribution expense is presented in the following table: TABLE 17.6 Year Ended December 31 2019 2018 2017 (in millions) 401(k) contribution expense $ 15 $ 15 $ 12
Schedule of Asset Allocations for Pension Plans	The following table presents asset allocations for our pension plans as of December 31, 2019 and 2018 , and the target allocation for 2020 , by asset category: TABLE 17.7 Target Allocation Percentage of Plan Assets December 31 2020 2019 2018 Asset Category Equity securities 45 - 65 60 % 55 % Debt securities 30 - 50 37 41 Cash equivalents 0 - 10 3 4
Schedule of Fair Values of Pension Plan Assets by Asset Category	The fair values of our pension plan assets by asset category are as follows: TABLE 17.8 (in millions) Level 1 Level 2 Level 3 Total December 31, 2019 Asset Class Cash $ 5 $ — $ — $ 5 Equity securities: F.N.B. Corporation 6 — — 6 Other large-cap U.S. financial services companies 4 — — 4 Other large-cap U.S. companies 54 — — 54 Other equity 1 — — 1 Mutual fund equity investments: U.S. equity index funds: U.S. large-cap equity index funds 1 — — 1 U.S. small-cap equity index funds 3 — — 3 U.S. mid-cap equity index funds 5 — — 5 Non-U.S. equities growth fund 9 — — 9 U.S. equity funds: U.S. mid-cap 12 — — 12 U.S. small-cap 4 — — 4 Other 5 — — 5 Fixed income securities: U.S. government agencies — 51 — 51 Corporate bonds — 1 — 1 Fixed income mutual funds: U.S. investment-grade fixed income securities 12 — — 12 Total $ 121 $ 52 $ — $ 173 (in millions) Level 1 Level 2 Level 3 Total December 31, 2018 Asset Class Cash $ 6 $ — $ — $ 6 Equity securities: F.N.B. Corporation 6 — — 6 Other large-cap U.S. financial services companies 3 — — 3 Other large-cap U.S. companies 43 — — 43 International companies 1 — — 1 Mutual fund equity investments: U.S. equity index funds: U.S. small-cap equity index funds 3 — — 3 U.S. mid-cap equity index funds 4 — — 4 Non-U.S. equities growth fund 6 — — 6 U.S. equity funds: U.S. mid-cap 9 — — 9 U.S. small-cap 3 — — 3 Other 4 — — 4 Fixed income securities: U.S. government agencies — 49 — 49 Corporate bonds — 2 — 2 Fixed income mutual funds: U.S. investment-grade fixed income securities 11 — — 11 Total $ 99 $ 51 $ — $ 150

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Summary of Income Tax Expense Allocated Based on Separate Tax Return Basis	Federal and state income tax expense consist of the following: TABLE 18.1 Year Ended December 31 2019 2018 2017 (in millions) Current income taxes: Federal taxes $ 47 $ 41 $ 26 State taxes 4 6 2 Total current income taxes 51 47 28 Deferred income taxes: Federal taxes 30 32 128 State taxes 3 — 1 Total deferred income taxes 33 32 129 Total income taxes $ 84 $ 79 $ 157
Summary of Reconciliation Between the Statutory Tax Rate and Actual Effective Tax Rate	The following table provides a reconciliation between the statutory tax rate and the actual effective tax rate: TABLE 18.2 Year Ended December 31 2019 2018 2017 Statutory federal tax rate 21.0 % 21.0 % 35.0 % State taxes, net of federal benefit 1.1 1.1 0.5 Tax-exempt interest (2.2 ) (2.1 ) (3.3 ) Cash surrender value on BOLI (0.5 ) (0.5 ) (1.1 ) Tax credits (4.2 ) (2.8 ) (2.6 ) Affordable housing cost amortization, net of tax benefits 1.4 0.7 0.2 Tax Cuts and Jobs Act revaluation of net deferred tax assets — (0.4 ) 15.2 Other items 1.1 0.6 0.2 Effective tax rate 17.7 % 17.6 % 44.1 %
Summary of Income Tax Expense Related to Net Gains on Sale of Securities	Income tax expense related to net gains on the sale of securities is presented in the following table: TABLE 18.3 Year Ended December 31 2019 2018 2017 (in millions) Income tax expense related to net gains on sale of securities $ — $ — $ 2
Summary of Deferred Tax Assets and Liabilities from Tax Effects of Temporary Differences	The following table presents the tax effects of significant temporary differences that give rise to federal and state DTAs and DTLs: TABLE 18.4 December 31 2019 2018 (in millions) Deferred tax assets: Allowance for credit losses $ 43 $ 40 Discounts on loans acquired in a business combination 41 51 Net operating loss/tax credit carryforwards 38 43 Deferred compensation 11 10 Securities impairments 1 1 Pension and other defined benefit plans 3 5 Lease liability 29 — Net unrealized securities losses 2 12 Other 8 9 Total 176 171 Valuation allowance (28 ) (26 ) Total deferred tax assets 148 145 Deferred tax liabilities: Loan costs (15 ) (14 ) Depreciation (19 ) (17 ) Prepaid expenses (1 ) (1 ) Amortizable intangibles (15 ) (16 ) Lease financing (35 ) (18 ) Mortgage servicing rights (9 ) (8 ) Lease ROU asset (27 ) — Other (2 ) (4 ) Total deferred tax liabilities (123 ) (78 ) Net deferred tax assets $ 25 $ 67

Other Comprehensive Income (Tab

Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Changes in AOCI, net of tax, by component	The following table presents changes in AOCI, net of tax, by component: TABLE 19.1 (in millions) Unrealized Net Gains (Losses) on Debt Securities Available for Sale Unrealized Net Gains (Losses) on Derivative Instruments Unrecognized Pension and Postretirement Obligations Total Year Ended December 31, 2019 Balance at beginning of period $ (46 ) $ 1 $ (61 ) $ (106 ) Other comprehensive (loss) income before reclassifications 57 (17 ) 3 43 Amounts reclassified from AOCI — (2 ) — (2 ) Net current period other comprehensive (loss) income 57 (19 ) 3 41 Balance at end of period $ 11 $ (18 ) $ (58 ) $ (65 )

Earnings per Common Share (Tabl

Earnings per Common Share (Tables)	12 Months Ended
	Dec. 31, 2019
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 20.1 Year Ended December 31 2019 2018 2017 (dollars in millions, except per share data) Net income $ 387 $ 373 $ 199 Less: Preferred stock dividends 8 8 8 Net income available to common stockholders $ 379 $ 365 $ 191 Basic weighted average common shares outstanding 324,938,720 324,207,198 302,195,295 Net effect of dilutive stock options, warrants and restricted stock 1,122,418 1,416,405 1,662,681 Diluted weighted average common shares outstanding 326,061,138 325,623,603 303,857,976 Earnings per common share: Basic $ 1.17 $ 1.13 $ 0.63 Diluted $ 1.16 $ 1.12 $ 0.63
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 20.2 Year Ended December 31 2019 2018 2017 Average shares excluded from the diluted earnings per common share calculation — 81 910

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2019
Banking and Thrift [Abstract]
Schedule of Capital Ratios	Following are the capital ratios for FNB and FNBPA: TABLE 21.1 Actual Well-Capitalized Requirements (1) Minimum Capital Requirements plus Capital Conservation Buffer (dollars in millions) Amount Ratio Amount Ratio Amount Ratio As of December 31, 2019 F.N.B. Corporation: Total capital $ 3,174 11.81 % $ 2,687 10.00 % $ 2,821 10.50 % Tier 1 capital 2,632 9.79 1,612 6.00 2,284 8.50 Common equity tier 1 2,525 9.40 n/a n/a 1,881 7.00 Leverage 2,632 8.20 n/a n/a 1,283 4.00 Risk-weighted assets 26,866 FNBPA: Total capital 3,039 11.34 2,681 10.00 2,815 10.50 Tier 1 capital 2,841 10.60 2,144 8.00 2,279 8.50 Common equity tier 1 2,761 10.30 1,742 6.50 1,876 7.00 Leverage 2,841 8.87 1,601 5.00 1,281 4.00 Risk-weighted assets 26,806 As of December 31, 2018 F.N.B. Corporation: Total capital $ 2,875 11.54 % $ 2,490 10.00 % $ 2,459 9.88 % Tier 1 capital 2,395 9.62 1,608 6.00 1,961 7.88 Common equity tier 1 2,289 9.19 n/a n/a 1,588 6.38 Leverage 2,395 7.87 n/a n/a 1,218 4.00 Risk-weighted assets 24,900 FNBPA: Total capital 2,735 10.99 2,489 10.00 2,458 9.88 Tier 1 capital 2,553 10.26 1,992 8.00 1,960 7.88 Common equity tier 1 2,473 9.94 1,618 6.50 1,587 6.38 Leverage 2,553 8.39 1,521 5.00 1,217 4.00 Risk-weighted assets 24,894 (1) Reflects the well-capitalized standard under Regulation Y for F.N.B. Corporation and the prompt corrective action framework for FNBPA.

Cash Flow Information (Tables)

Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Summary of Cash Flow Information	Following is a summary of supplemental cash flow information: TABLE 22.1 Year Ended December 31 2019 2018 2017 (in millions) Interest paid on deposits and other borrowings $ 329 $ 230 $ 129 Income taxes paid 40 19 53 Transfers of loans to other real estate owned 15 12 35 Loans transferred to held for sale from portfolio 389 — — Loans transferred to portfolio from held for sale 110 — —

Business Segments (Tables)

Business Segments (Tables)	12 Months Ended
	Dec. 31, 2019
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 23.1 (in millions) Community Wealth Insurance Parent Consolidated At or for the Year Ended Interest income $ 1,245 $ — $ — $ 2 $ 1,247 Interest expense 310 — — 20 330 Net interest income 935 — — (18 ) 917 Provision for credit losses 44 — — — 44 Non-interest income 237 46 20 (9 ) 294 Non-interest expense (1) 621 34 17 10 682 Amortization of intangibles 13 — 1 — 14 Income tax expense (benefit) 88 3 — (7 ) 84 Net income (loss) 406 9 2 (30 ) 387 Total assets 34,491 32 35 57 34,615 Total intangibles 2,291 10 28 — 2,329 (in millions) Community Wealth Insurance Consumer Parent Consolidated At or for the Year Ended Interest income $ 1,145 $ — $ — $ 25 $ — $ 1,170 Interest expense 219 — — 2 17 238 Net interest income 926 — — 23 (17 ) 932 Provision for credit losses 54 — — 6 1 61 Non-interest income 213 44 16 2 1 276 Non-interest expense (1) 609 33 17 15 5 679 Amortization of intangibles 15 1 — — — 16 Income tax expense (benefit) 82 2 — 1 (6 ) 79 Net income (loss) 379 8 (1 ) 3 (16 ) 373 Total assets 32,997 26 25 — 54 33,102 Total intangibles 2,304 10 20 — — 2,334 At or for the Year Ended Interest income $ 944 $ — $ — $ 40 $ (4 ) $ 980 Interest expense 118 — — 4 12 134 Net interest income 826 — — 36 (16 ) 846 Provision for credit losses 53 — — 8 — 61 Non-interest income 197 39 16 3 (3 ) 252 Non-interest expense (1) 597 30 15 21 — 663 Amortization of intangibles 17 1 — — — 18 Income tax expense (benefit) 153 3 — 5 (4 ) 157 Net income (loss) 203 5 1 5 (15 ) 199 Total assets 31,156 24 21 181 36 31,418 Total intangibles 2,317 10 12 2 — 2,341 (1) Excludes amortization of intangibles, which is presented separately.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurement Inputs and Valuation Techniques	The fair value hierarchy is broken down into three levels based on the reliability of inputs as follows: TABLE 24.1 Measurement Category Definition Level 1 valuation is based upon unadjusted quoted market prices for identical instruments traded in active markets. Level 2 valuation is based upon quoted market prices for similar instruments traded in active markets, quoted market prices for identical or similar instruments traded in markets that are not active and model-based valuation techniques for which all significant assumptions are observable in the market or can be corroborated by market data. Level 3 valuation is derived from other valuation methodologies including discounted cash flow models and similar techniques that use significant assumptions not observable in the market. These unobservable assumptions reflect estimates of assumptions that market participants would use in determining fair value.
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 24.2 (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 — 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 (in millions) Level 1 Level 2 Level 3 Total December 31, 2018 Assets Measured at Fair Value Debt securities available for sale U.S. government agencies $ — $ 187 $ — $ 187 U.S. government-sponsored entities — 313 — 313 Residential mortgage-backed securities Agency mortgage-backed securities — 1,429 — 1,429 Agency collateralized mortgage obligations — 1,161 — 1,161 Commercial mortgage-backed securities — 228 — 228 States of the U.S. and political subdivisions — 21 — 21 Other debt securities — 2 — 2 Total debt securities available for sale — 3,341 — 3,341 Loans held for sale — 14 — 14 Derivative financial instruments Trading — 42 1 43 Total derivative financial instruments — 42 1 43 Total assets measured at fair value on a recurring basis $ — $ 3,397 $ 1 $ 3,398 Liabilities Measured at Fair Value Derivative financial instruments Trading $ — $ 36 $ — $ 36 Not for trading — 3 — 3 Total derivative financial instruments — 39 — 39 Total liabilities measured at fair value on a recurring basis $ — $ 39 $ — $ 39
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 24.3 (in millions) Interest Total 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 Year Ended December 31, 2018 Balance at beginning of period $ 2 $ 2 Purchases, issuances, sales and settlements: Issuances 5 5 Settlements (6 ) (6 ) Balance at end of period $ 1 $ 1
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 24.4 (in millions) Level 1 Level 2 Level 3 Total 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 December 31, 2018 Impaired loans $ — $ — $ 15 $ 15 Other real estate owned — — 5 5 Other assets - SBA servicing asset — — 4 4
Fair Values of Financial Instruments	The fair values of our financial instruments are as follows: TABLE 24.5 Fair Value Measurements (in millions) Carrying Amount Fair Value Level 1 Level 2 Level 3 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 — — December 31, 2018 Financial Assets Cash and cash equivalents $ 488 $ 488 $ 488 $ — $ — Debt securities available for sale 3,341 3,341 — 3,341 — Debt securities held to maturity 3,254 3,155 — 3,155 — Net loans and leases, including loans held for sale 21,995 21,742 — 14 21,728 Loan servicing rights 41 45 — — 45 Derivative assets 43 43 — 42 1 Accrued interest receivable 101 101 101 — — Financial Liabilities Deposits 23,455 23,411 18,142 5,269 — Short-term borrowings 4,129 4,130 4,130 — — Long-term borrowings 627 618 — — 618 Derivative liabilities 39 39 — 39 — Accrued interest payable 20 20 20 — —

Parent Company Financial Stat_2

Parent Company Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Disclosure [Abstract]
Consolidated Balance Sheet of Parent Company Only	Balance Sheets (in millions) December 31 2019 2018 Assets Cash and cash equivalents $ 251 $ 254 Other assets 18 19 Investment in bank subsidiary 5,072 4,754 Investments in and advances to non-bank subsidiaries 104 97 Total Assets $ 5,445 $ 5,124 Liabilities Other liabilities $ 34 $ 32 Advances from affiliates 197 197 Long-term borrowings 323 279 Subordinated notes: Short-term 7 7 Long-term 1 1 Total Liabilities 562 516 Stockholders’ Equity 4,883 4,608 Total Liabilities and Stockholders’ Equity $ 5,445 $ 5,124
Statements of Income of Parent Company Only	Statements of Income (in millions) Year Ended December 31 2019 2018 2017 Income Dividend income from subsidiaries: Bank $ 179 $ 162 $ 149 Non-bank 2 8 9 181 170 158 Interest income — 4 5 Other income — 5 — Total Income 181 179 163 Expenses Interest expense 19 20 18 Other expenses 18 15 10 Total Expenses 37 35 28 Income Before Taxes and Equity in Undistributed Income of Subsidiaries 144 144 135 Income tax benefit 7 6 3 151 150 138 Equity in undistributed income (loss) of subsidiaries: Bank 236 225 60 Non-bank — (2 ) 1 Net Income $ 387 $ 373 $ 199
Statements of Cash Flows of Parent Company Only	Statements of Cash Flows (in millions) Year Ended December 31 2019 2018 2017 Operating Activities Net income $ 387 $ 373 $ 199 Adjustments to reconcile net income to net cash flows from operating activities: Undistributed earnings from subsidiaries (236 ) (222 ) (61 ) Other, net 2 (13 ) 6 Net cash flows provided by operating activities 153 138 144 Investing Activities Proceeds from sale of securities available for sale — 1 — Net (increase) decrease in advances to subsidiaries — 20 (10 ) Payment for further investment in subsidiaries (47 ) (22 ) (4 ) Net cash received in business combinations — 123 3 Net cash flows (used in) provided by investing activities (47 ) 122 (11 ) Financing Activities Net decrease in advance from affiliate — (19 ) 10 Net decrease in short-term borrowings — (1 ) — Decrease in long-term debt (77 ) (2 ) (2 ) Increase in long-term debt 121 1 1 Net proceeds from issuance of common stock 12 14 11 Cash dividends paid: Preferred stock (8 ) (8 ) (8 ) Common stock (157 ) (157 ) (143 ) Net cash flows (used in) provided by financing activities (109 ) (172 ) (131 ) Net (Decrease) Increase in Cash and Cash Equivalents (3 ) 88 2 Cash and cash equivalents at beginning of year 254 166 164 Cash and Cash Equivalents at End of Year $ 251 $ 254 $ 166 Cash paid during the year for: Interest $ 20 $ 17 $ 16

Quarterly Earnings Summary (U_2

Quarterly Earnings Summary (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Earnings Summary (Unaudited) [Abstract]
Quarterly Financial Information	TABLE 26.1 (Dollars in millions, except per share data) Quarter Ended 2019 Dec. 31 Sept. 30 June 30 Mar. 31 Total interest income $ 306 $ 314 $ 317 $ 310 Total interest expense 80 84 87 79 Net interest income 226 230 230 231 Provision for credit losses 7 12 11 14 Total non-interest income 74 80 75 65 Total non-interest expense 177 178 175 166 Net income 95 103 95 94 Net income available to common stockholders 93 101 93 92 Per Common Share Basic earnings per share $ 0.29 $ 0.31 $ 0.29 $ 0.28 Diluted earnings per share 0.29 0.31 0.29 0.28 Quarter Ended 2018 Total interest income $ 305 $ 298 $ 294 $ 273 Total interest expense 74 63 54 47 Net interest income 231 235 240 226 Provision for credit losses 15 16 16 14 Other non-interest income 69 75 65 67 Total non-interest expense 170 171 183 171 Net income 100 101 85 87 Net income available to common stockholders 98 99 83 85 Per Common Share Basic earnings per share $ 0.30 $ 0.30 $ 0.26 $ 0.26 Diluted earnings per share 0.30 0.30 0.26 0.26

Nature of Operations - Addition

Nature of Operations - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019OfficeState
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of states, company operating financial services | State	7
Number of banking offices | Office	369

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Summary Of Significant Accounting Policies [Line Items]
Minimum corporation reserves for commercial loan	$ 1
Core deposit intangibles amortization period, years	10 years
Qualified affordable housing project investments	$ 59.6	$ 43.7
Qualified affordable housing project investments, unfunded commitments	$ 60.1	57
Largest amount recognized in the financial statement of tax benefit threshold, minimum	Greater than 50%
Marketing expense	$ 13.1	$ 12.8	$ 11.5
Restricted Stock Units (RSUs)
Summary Of Significant Accounting Policies [Line Items]
Vesting period of awards issued, years	3 years
Total commercial loans
Summary Of Significant Accounting Policies [Line Items]
Number of days placed on non-accrual	90 days
Installment Loans
Summary Of Significant Accounting Policies [Line Items]
Number of days placed on non-accrual	120 days
Residential Mortgages
Summary Of Significant Accounting Policies [Line Items]
Number of days placed on non-accrual	180 days
Minimum
Summary Of Significant Accounting Policies [Line Items]
Useful life of the asset, years	3 years
Estimated useful life of intangibles, years	8 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Useful life of the asset, years	39 years
Estimated useful life of intangibles, years	13 years

New Accounting Standards (Detai

New Accounting Standards (Details) - USD ($) $ in Millions	Jan. 01, 2020	Dec. 31, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use asset		$ 121.4
Present value of lease liabilities		$ 128.2
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use asset			$ 116
Present value of lease liabilities			$ 126
Subsequent Event | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing receivable, allowance for credit loss, percentage increase (decrease)	30.00%
Subsequent Event | Minimum | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing receivable, allowance for credit loss, period increase (decrease)	$ 300
Subsequent Event | Maximum | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing receivable, allowance for credit loss, period increase (decrease)	310
Retained Earnings | Subsequent Event | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle in period of adoption	52
Purchased credit-impaired loans | Subsequent Event | Accounting Standards Update 2016-13
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of new accounting principle in period of adoption	$ 50

Securities - Schedule of Amorti

Securities - Schedule of Amortized Cost and Fair Value of Securities Available for Sale (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Schedule of Investments [Line Items]
Amortized Cost	$ 3,275	$ 3,401
Gross Unrealized Gains	24	5
Gross Unrealized Losses	(10)	(65)
Fair Value	3,289	3,341
U.S. government agencies
Schedule of Investments [Line Items]
Amortized Cost	152	188
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	(1)
Fair Value	151	187
U.S. government-sponsored entities
Schedule of Investments [Line Items]
Amortized Cost	225	317
Gross Unrealized Gains	1	0
Gross Unrealized Losses	0	(4)
Fair Value	226	313
Agency mortgage-backed securities
Schedule of Investments [Line Items]
Amortized Cost	1,310	1,465
Gross Unrealized Gains	7	0
Gross Unrealized Losses	(3)	(36)
Fair Value	1,314	1,429
Agency collateralized mortgage obligations
Schedule of Investments [Line Items]
Amortized Cost	1,234	1,179
Gross Unrealized Gains	10	5
Gross Unrealized Losses	(4)	(23)
Fair Value	1,240	1,161
Commercial mortgage-backed securities
Schedule of Investments [Line Items]
Amortized Cost	341	229
Gross Unrealized Gains	6	0
Gross Unrealized Losses	(2)	(1)
Fair Value	345	228
States of the U.S. and political subdivisions
Schedule of Investments [Line Items]
Amortized Cost	11	21
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	11	21
Other debt securities
Schedule of Investments [Line Items]
Amortized Cost	2	2
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	$ 2	$ 2

Securities - Schedule of Amor_2

Securities - Schedule of Amortized Cost and Fair Value of Securities Held to Maturity (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 3,275	$ 3,254
Gross Unrealized Gains	42	5
Gross Unrealized Losses	(12)	(104)
Securities held to maturity, Fair Value	3,305	3,155
U.S. Treasury
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	1	1
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Securities held to maturity, Fair Value	1	1
U.S. government agencies
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	1	2
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Securities held to maturity, Fair Value	1	2
U.S. government-sponsored entities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	175	215
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(4)
Securities held to maturity, Fair Value	175	211
Agency mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	949	1,036
Gross Unrealized Gains	8	0
Gross Unrealized Losses	(2)	(26)
Securities held to maturity, Fair Value	955	1,010
Agency collateralized mortgage obligations
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	721	794
Gross Unrealized Gains	5	1
Gross Unrealized Losses	(6)	(24)
Securities held to maturity, Fair Value	720	771
Commercial mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	308	126
Gross Unrealized Gains	3	1
Gross Unrealized Losses	(2)	(1)
Securities held to maturity, Fair Value	309	126
States of the U.S. and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	1,120	1,080
Gross Unrealized Gains	26	3
Gross Unrealized Losses	(2)	(49)
Securities held to maturity, Fair Value	$ 1,144	$ 1,034

Securities - Gross Gains and Gr

Securities - Gross Gains and Gross Losses Realized on Sales of Securities (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Gross gains	$ 0	$ 0	$ 7
Gross losses	0	0	(1)
Net gains	$ 0	$ 0	$ 6

Securities - Amortized Cost and

Securities - Amortized Cost and Fair Value of Securities, by Contractual Maturities (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Securities [Line Items]
Available for sale, due in one year or less, amortized cost	$ 93
Available for sale, due after one year but within five years, amortized cost	147
Available for sale, due after five year but within ten years, amortized cost	62
Available for sale, due after ten years, amortized cost	88
Available for sale, with contractual maturities, amortized cost	390
Amortized Cost	3,275	$ 3,401
Available for sale, due in one year or less, fair value	93
Available for sale, due after one year but within five years, fair value	148
Available for sale, due after five year but within ten years, fair value	62
Available for sale, due after ten years, fair value	87
Available for sale, with contractual maturities, amortized cost	390
Total securities available for sale, fair value	3,289	3,341
Held to maturity, due in one year or less, amortized cost	58
Held to maturity, due after one year but within five years, amortized cost	131
Held to maturity, due after five year but within ten years, amortized cost	117
Held to maturity, due after ten years, amortized cost	991
Held to maturity, with contractual maturities, amortized cost	1,297
Amortized Cost	3,275	3,254
Held to maturity, due in one year or less, fair value	58
Held to maturity, due after one year but within five years, fair value	131
Held to maturity, due after five year but within ten years, fair value	119
Held to maturity, due after ten years, fair value	1,013
Held to maturity, with contractual maturities, amortized cost	1,321
Held-to-maturity, fair value, net	3,305	3,155
Agency mortgage-backed securities
Schedule Of Securities [Line Items]
Available-for-sale, amortized cost	1,310
Amortized Cost	1,310	1,465
Available for sale, fair value	1,314
Total securities available for sale, fair value	1,314	1,429
Held-to-maturity, amortized cost	949
Amortized Cost	949	1,036
Held-to-maturity, fair value	955
Held-to-maturity, fair value, net	955	1,010
Agency collateralized mortgage obligations
Schedule Of Securities [Line Items]
Available-for-sale, amortized cost	1,234
Amortized Cost	1,234	1,179
Available for sale, fair value	1,240
Total securities available for sale, fair value	1,240	1,161
Held-to-maturity, amortized cost	721
Amortized Cost	721	794
Held-to-maturity, fair value	720
Held-to-maturity, fair value, net	720	771
Commercial mortgage-backed securities
Schedule Of Securities [Line Items]
Available-for-sale, amortized cost	341
Amortized Cost	341	229
Available for sale, fair value	345
Total securities available for sale, fair value	345	228
Held-to-maturity, amortized cost	308
Amortized Cost	308	126
Held-to-maturity, fair value	309
Held-to-maturity, fair value, net	$ 309	$ 126

Securities - Schedule of Securi

Securities - Schedule of Securities Pledged as Collateral (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
To secure public deposits, trust deposits and for other purposes as required by law	$ 4,494	$ 3,874
As collateral for short-term borrowings	$ 285	$ 279
Securities pledged as a percent of total securities	72.80%	63.00%

Securities - Summaries of Fair

Securities - Summaries of Fair Values and Unrealized Losses of Securities, Segregated by Length of Impairment (Detail) $ in Millions	Dec. 31, 2019USD ($)Security	Dec. 31, 2018USD ($)Security
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions | Security	32	46
Debt securities, available-for-sale, 12 months or longer, number of positions | Security	78	136
Debt securities, available-for-sale, number of positions | Security	110	182
Debt securities, available-for-sale, less than 12 months	$ 685	$ 679
Debt securities, available-for-sale, 12 months or longer	712	1,988
Debt securities, available-for-sale, unrealized loss position	1,397	2,667
Debt securities, available-for-sale, less than 12 months, accumulated loss	(4)	(7)
Debt securities, available-for-sale, 12 months or longer, accumulated loss	(6)	(58)
Debt securities, available-for-sale, accumulated loss	$ (10)	$ (65)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	90	373
Securities held to maturity, less than 12 months, fair value	$ 431	$ 952
Securities held to maturity, less than 12 months, unrealized losses	(4)	(31)
Securities held to maturity, greater than 12 months, fair value	648	1,720
Securities held to maturity, greater than 12 months, unrealized losses	(8)	(73)
Securities held to maturity, fair value, total	1,079	2,672
Securities held to maturity, unrealized losses, total	$ (12)	$ (104)
Less than 12 Months
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	30	210
12 Months or More
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	60	163
U.S. government agencies
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions | Security	5	20
Debt securities, available-for-sale, 12 months or longer, number of positions | Security	15	0
Debt securities, available-for-sale, number of positions | Security	20	20
Debt securities, available-for-sale, less than 12 months	$ 48	$ 145
Debt securities, available-for-sale, 12 months or longer	61	0
Debt securities, available-for-sale, unrealized loss position	109	145
Debt securities, available-for-sale, less than 12 months, accumulated loss	0	(1)
Debt securities, available-for-sale, 12 months or longer, accumulated loss	(1)	0
Debt securities, available-for-sale, accumulated loss	$ (1)	$ (1)
U.S. government-sponsored entities
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions | Security	0	1
Debt securities, available-for-sale, 12 months or longer, number of positions | Security	6	11
Debt securities, available-for-sale, number of positions | Security	6	12
Debt securities, available-for-sale, less than 12 months	$ 0	$ 36
Debt securities, available-for-sale, 12 months or longer	130	227
Debt securities, available-for-sale, unrealized loss position	130	263
Debt securities, available-for-sale, less than 12 months, accumulated loss	0	0
Debt securities, available-for-sale, 12 months or longer, accumulated loss	0	(4)
Debt securities, available-for-sale, accumulated loss	$ 0	$ (4)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	8	12
Securities held to maturity, less than 12 months, fair value	$ 0	$ 0
Securities held to maturity, less than 12 months, unrealized losses	0	0
Securities held to maturity, greater than 12 months, fair value	160	211
Securities held to maturity, greater than 12 months, unrealized losses	0	(4)
Securities held to maturity, fair value, total	160	211
Securities held to maturity, unrealized losses, total	$ 0	$ (4)
U.S. government-sponsored entities | Less than 12 Months
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	0	0
U.S. government-sponsored entities | 12 Months or More
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	8	12
Agency mortgage-backed securities
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions | Security	13	16
Debt securities, available-for-sale, 12 months or longer, number of positions | Security	24	71
Debt securities, available-for-sale, number of positions | Security	37	87
Debt securities, available-for-sale, less than 12 months	$ 200	$ 259
Debt securities, available-for-sale, 12 months or longer	314	1,159
Debt securities, available-for-sale, unrealized loss position	514	1,418
Debt securities, available-for-sale, less than 12 months, accumulated loss	(1)	(4)
Debt securities, available-for-sale, 12 months or longer, accumulated loss	(2)	(32)
Debt securities, available-for-sale, accumulated loss	$ (3)	$ (36)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	16	90
Securities held to maturity, less than 12 months, fair value	$ 134	$ 294
Securities held to maturity, less than 12 months, unrealized losses	(1)	(4)
Securities held to maturity, greater than 12 months, fair value	135	694
Securities held to maturity, greater than 12 months, unrealized losses	(1)	(22)
Securities held to maturity, fair value, total	269	988
Securities held to maturity, unrealized losses, total	$ (2)	$ (26)
Agency mortgage-backed securities | Less than 12 Months
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	5	43
Agency mortgage-backed securities | 12 Months or More
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	11	47
Agency collateralized mortgage obligations
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions | Security	11	2
Debt securities, available-for-sale, 12 months or longer, number of positions | Security	32	47
Debt securities, available-for-sale, number of positions | Security	43	49
Debt securities, available-for-sale, less than 12 months	$ 323	$ 82
Debt securities, available-for-sale, 12 months or longer	205	590
Debt securities, available-for-sale, unrealized loss position	528	672
Debt securities, available-for-sale, less than 12 months, accumulated loss	(1)	(1)
Debt securities, available-for-sale, 12 months or longer, accumulated loss	(3)	(22)
Debt securities, available-for-sale, accumulated loss	$ (4)	$ (23)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	35	52
Securities held to maturity, less than 12 months, fair value	$ 50	$ 42
Securities held to maturity, less than 12 months, unrealized losses	0	0
Securities held to maturity, greater than 12 months, fair value	317	611
Securities held to maturity, greater than 12 months, unrealized losses	(6)	(24)
Securities held to maturity, fair value, total	367	653
Securities held to maturity, unrealized losses, total	$ (6)	$ (24)
Agency collateralized mortgage obligations | Less than 12 Months
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	2	3
Agency collateralized mortgage obligations | 12 Months or More
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	33	49
Non-agency collateralized mortgage obligations
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions | Security		1
Debt securities, available-for-sale, 12 months or longer, number of positions | Security		0
Debt securities, available-for-sale, number of positions | Security		1
Debt securities, available-for-sale, less than 12 months		$ 0
Debt securities, available-for-sale, 12 months or longer		0
Debt securities, available-for-sale, unrealized loss position		0
Debt securities, available-for-sale, less than 12 months, accumulated loss		0
Debt securities, available-for-sale, 12 months or longer, accumulated loss		0
Debt securities, available-for-sale, accumulated loss		$ 0
Commercial mortgage-backed securities
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions | Security	3	4
Debt securities, available-for-sale, 12 months or longer, number of positions | Security	0	0
Debt securities, available-for-sale, number of positions | Security	3	4
Debt securities, available-for-sale, less than 12 months	$ 114	$ 155
Debt securities, available-for-sale, 12 months or longer	0	0
Debt securities, available-for-sale, unrealized loss position	114	155
Debt securities, available-for-sale, less than 12 months, accumulated loss	(2)	(1)
Debt securities, available-for-sale, 12 months or longer, accumulated loss	0	0
Debt securities, available-for-sale, accumulated loss	$ (2)	$ (1)
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	6	9
Securities held to maturity, less than 12 months, fair value	$ 184	$ 26
Securities held to maturity, less than 12 months, unrealized losses	(2)	0
Securities held to maturity, greater than 12 months, fair value	7	43
Securities held to maturity, greater than 12 months, unrealized losses	0	(1)
Securities held to maturity, fair value, total	191	69
Securities held to maturity, unrealized losses, total	$ (2)	$ (1)
Commercial mortgage-backed securities | Less than 12 Months
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	5	5
Commercial mortgage-backed securities | 12 Months or More
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	1	4
States of the U.S. and political subdivisions
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions | Security	0	2
Debt securities, available-for-sale, 12 months or longer, number of positions | Security	0	6
Debt securities, available-for-sale, number of positions | Security	0	8
Debt securities, available-for-sale, less than 12 months	$ 0	$ 2
Debt securities, available-for-sale, 12 months or longer	0	10
Debt securities, available-for-sale, unrealized loss position	0	12
Debt securities, available-for-sale, less than 12 months, accumulated loss	0	0
Debt securities, available-for-sale, 12 months or longer, accumulated loss	0	0
Debt securities, available-for-sale, accumulated loss	$ 0	$ 0
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	25	210
Securities held to maturity, less than 12 months, fair value	$ 63	$ 590
Securities held to maturity, less than 12 months, unrealized losses	(1)	(27)
Securities held to maturity, greater than 12 months, fair value	29	161
Securities held to maturity, greater than 12 months, unrealized losses	(1)	(22)
Securities held to maturity, fair value, total	92	751
Securities held to maturity, unrealized losses, total	$ (2)	$ (49)
States of the U.S. and political subdivisions | Less than 12 Months
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	18	159
States of the U.S. and political subdivisions | 12 Months or More
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Number of positions | Security	7	51
Other debt securities
Schedule Of Securities [Line Items]
Debt securities, available-for-sale, less than 12 months, number of positions | Security	0	0
Debt securities, available-for-sale, 12 months or longer, number of positions | Security	1	1
Debt securities, available-for-sale, number of positions | Security	1	1
Debt securities, available-for-sale, less than 12 months	$ 0	$ 0
Debt securities, available-for-sale, 12 months or longer	2	2
Debt securities, available-for-sale, unrealized loss position	2	2
Debt securities, available-for-sale, less than 12 months, accumulated loss	0	0
Debt securities, available-for-sale, 12 months or longer, accumulated loss	0	0
Debt securities, available-for-sale, accumulated loss	$ 0	$ 0

Securities - Additional Informa

Securities - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Securities [Line Items]
OTTI losses on debt securities	$ 0	$ 0	$ 0
Municipal bond portfolio, value	$ 1,100,000,000
Percentage of formal credit enhancement insurance of municipalities	63.00%
Municipal Bonds | Weighted Average
Schedule Of Securities [Line Items]
Average holding size of securities in bond portfolio	$ 3,400,000
Municipal Bonds | Credit Concentration Risk | General Obligation Bonds | A Rating | Minimum
Schedule Of Securities [Line Items]
Percentage of portfolio	100.00%
Municipal Bonds | Credit Concentration Risk | General Obligation Bonds | A Rating or Better
Schedule Of Securities [Line Items]
Percentage of portfolio	99.00%
Municipal Bonds | Geographic Concentration Risk | Pennsylvania, Ohio and Maryland
Schedule Of Securities [Line Items]
Percentage of portfolio	66.00%

Other Securities - Additional I

Other Securities - Additional Information (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Banking and Thrift [Abstract]
Federal Home Loan Bank stock	$ 256,000,000	$ 209,000,000
Federal Reserve Bank stock	123,000,000	122,000,000
Other non-marketable equity securities	1,000,000	1,000,000
Total non-marketable equity securities	380,000,000	332,000,000
Other non-marketable equity securities, impairment	$ 0	$ 0

Loans and Leases - Summary of L

Loans and Leases - Summary of Loans and Leases, Net of Unearned Income (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	$ 23,289	$ 22,153
Total commercial loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	14,721	13,761
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	8,960	8,786
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	5,308	4,556
Commercial leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	432	373
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	21	46
Total consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	8,568	8,392
Direct installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,821	1,764
Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	3,374	3,113
Indirect installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,922	1,933
Consumer lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,451	1,582
Originated Loans and Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	20,397	18,062
Originated Loans and Leases | Total commercial loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	12,630	10,730
Originated Loans and Leases | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	7,114	6,171
Originated Loans and Leases | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	5,063	4,140
Originated Loans and Leases | Commercial leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	432	373
Originated Loans and Leases | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	21	46
Originated Loans and Leases | Total consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	7,767	7,332
Originated Loans and Leases | Direct installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,758	1,668
Originated Loans and Leases | Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	2,995	2,612
Originated Loans and Leases | Indirect installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,922	1,933
Originated Loans and Leases | Consumer lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,092	1,119
Loans Acquired in a Business Combination
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	2,892	4,091
Loans Acquired in a Business Combination | Total commercial loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	2,091	3,031
Loans Acquired in a Business Combination | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	1,846	2,615
Loans Acquired in a Business Combination | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	245	416
Loans Acquired in a Business Combination | Commercial leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0	0
Loans Acquired in a Business Combination | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0	0
Loans Acquired in a Business Combination | Total consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	801	1,060
Loans Acquired in a Business Combination | Direct installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	63	96
Loans Acquired in a Business Combination | Residential mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	379	501
Loans Acquired in a Business Combination | Indirect installment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	0	0
Loans Acquired in a Business Combination | Consumer lines of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans and Leases	$ 359	$ 463

Loans and Leases - Additional I

Loans and Leases - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)State	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of states within primary market | State	7
Carrying amount	$ 23,289	$ 22,153
Reclassification from non-accretable difference	$ 97	266.5
Sustained period of delinquency for impairment evaluation	90 days
Valuation for impairment of loans with pooled reserves	$ 1
Minimum amount to allocate specific valuation allowance	1
Interest income on impaired loans still accruing	5.9	5.9	$ 6.1
Restructured loans returned to performing status	4.4
Minimum corporation reserves for commercial loan	1
Reserves in allowance for loan losses	196	180	$ 175	$ 158
Pooled reserves for all other classes of loans	4.1	4
Purchased credit-impaired loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	$ 1.5	$ 1.7
Loan portfolio diversification risk | Residential construction loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of portfolio	1.30%	1.20%
Credit concentration risk | Acquired loans receivable | Purchased credit-impaired loans | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of portfolio	0.05%
Credit concentration risk | Acquired loans receivable | Purchased credit-impaired loans | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of portfolio		0.04%
Total commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Threshold period past due for default non-accrual status of trade accounts receivable	90 days
Installment Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Threshold period past due for default non-accrual status of trade accounts receivable	120 days
Residential Mortgages
Accounts, Notes, Loans and Financing Receivable [Line Items]
Threshold period past due for default non-accrual status of trade accounts receivable	180 days
Carrying value of OREO through foreclosure	$ 3.3	$ 6.3
Mortgage loans on real estate, foreclosure	9.2	8.9
Total commercial loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	14,721	13,761
Specific reserves for commercial troubled debt restructurings | Total commercial loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reserves in allowance for loan losses	0.5	0.5
Pooled reserves for individual commercial loans | Total commercial loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reserves in allowance for loan losses	0.8	0.5
Residential construction loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	$ 297.3	$ 273.4

Loans and Leases - Certain Info

Loans and Leases - Certain Information Relating to Commercial Real Estate Loans (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Loans and Leases Receivable Disclosure [Line Items]
Commercial construction, acquisition and development loans	$ 1,275	$ 1,152
Credit concentration risk | Commercial construction loans
Loans and Leases Receivable Disclosure [Line Items]
Percent of total loans and leases	5.50%	5.20%
Loan portfolio diversification risk | Commercial real estate loans | Percent owner-occupied
Loans and Leases Receivable Disclosure [Line Items]
Percent of total loans and leases	30.60%	35.10%
Loan portfolio diversification risk | Commercial real estate loans | Percent non-owner-occupied
Loans and Leases Receivable Disclosure [Line Items]
Percent of total loans and leases	69.40%	64.90%

Loans and Leases - Summary of_2

Loans and Leases - Summary of Loans to Related Parties (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Loans and Leases Receivable, Related Parties [Roll Forward]
Balance at beginning of period	$ 16
New loans	1
Repayments	(10)
Balance at end of period	$ 7

Loans and Leases - Summary of O

Loans and Leases - Summary of Outstanding Principal Balance and Carrying Amount of Acquired Loans (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount	$ 23,289	$ 22,153
Accounted for under ASC 310-30:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	2,684	3,768
Carrying amount	2,461	3,570
Accounted for under ASC 310-20:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	436	602
Carrying amount	425	513
Total loans acquired in a business combination:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding balance	3,120	4,370
Carrying amount	$ 2,886	$ 4,083

Loans and Leases - Summary of C

Loans and Leases - Summary of Change in Accretable Yield of Acquired Loans (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 605	$ 708
Reduction due to unexpected early payoffs	(102)	(146)
Reclass from non-accretable difference to accretable yield	97	266.5
Disposals/transfers	(1)	(1)
Other	(1)	(1)
Accretion	(179)	(222)
Balance at end of period	$ 419	$ 605

Loans and Leases - Summary of N

Loans and Leases - Summary of Non-Performing Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Troubled debt restructurings	$ 56	$ 48
Non-Performing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	81	79
Troubled debt restructurings	22	21
Total non-performing loans	103	100
Other real estate owned	26	35
Total non-performing assets	$ 129	$ 135
Non-performing loans / total loans and leases	0.44%	0.45%
Non-performing loans OREO / total loans and leases OREO	0.55%	0.61%
Non-performing assets / total assets	0.37%	0.41%

Loans and Leases - Age Analysis

Loans and Leases - Age Analysis of Past Due Loans, by Class (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	$ 23,289	$ 22,153
Total commercial loans and leases
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	14,721	13,761
Commercial real estate
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	8,960	8,786
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	5,308	4,556
Commercial leases
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	432	373
Other
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	21	46
Total consumer loans
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	8,568	8,392
Direct installment
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,821	1,764
Residential mortgages
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	3,374	3,113
Indirect installment
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,922	1,933
Consumer lines of credit
Financing Receivable, Past Due [Line Items]
Total Loans and Leases	1,451	1,582
Originated Loans and Leases
Financing Receivable, Past Due [Line Items]
Total Past Due	145	116
Non- Accrual	77	58
Current	20,252	17,946
Total Loans and Leases	20,397	18,062
Originated Loans and Leases | Total commercial loans and leases
Financing Receivable, Past Due [Line Items]
Total Past Due	80	52
Non- Accrual	56	39
Current	12,550	10,678
Total Loans and Leases	12,630	10,730
Originated Loans and Leases | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	36	24
Non- Accrual	26	17
Current	7,078	6,147
Total Loans and Leases	7,114	6,171
Originated Loans and Leases | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	37	24
Non- Accrual	28	19
Current	5,026	4,116
Total Loans and Leases	5,063	4,140
Originated Loans and Leases | Commercial leases
Financing Receivable, Past Due [Line Items]
Total Past Due	6	3
Non- Accrual	1	2
Current	426	370
Total Loans and Leases	432	373
Originated Loans and Leases | Other
Financing Receivable, Past Due [Line Items]
Total Past Due	1	1
Non- Accrual	1	1
Current	20	45
Total Loans and Leases	21	46
Originated Loans and Leases | Total consumer loans
Financing Receivable, Past Due [Line Items]
Total Past Due	65	64
Non- Accrual	21	19
Current	7,702	7,268
Total Loans and Leases	7,767	7,332
Originated Loans and Leases | Direct installment
Financing Receivable, Past Due [Line Items]
Total Past Due	15	16
Non- Accrual	7	8
Current	1,743	1,652
Total Loans and Leases	1,758	1,668
Originated Loans and Leases | Residential mortgages
Financing Receivable, Past Due [Line Items]
Total Past Due	22	25
Non- Accrual	8	6
Current	2,973	2,587
Total Loans and Leases	2,995	2,612
Originated Loans and Leases | Indirect installment
Financing Receivable, Past Due [Line Items]
Total Past Due	19	14
Non- Accrual	3	2
Current	1,903	1,919
Total Loans and Leases	1,922	1,933
Originated Loans and Leases | Consumer lines of credit
Financing Receivable, Past Due [Line Items]
Total Past Due	9	9
Non- Accrual	3	3
Current	1,083	1,110
Total Loans and Leases	1,092	1,119
Loans Acquired in a Business Combination
Financing Receivable, Past Due [Line Items]
Total Past Due	73	120
Non- Accrual	4	21
Current	3,000	4,193
(Discount)/ Premium	(181)	(222)
Total Loans and Leases	2,892	4,091
Loans Acquired in a Business Combination | Total commercial loans and leases
Financing Receivable, Past Due [Line Items]
Total Past Due	48	84
Non- Accrual	3	20
Current	2,201	3,143
(Discount)/ Premium	(158)	(196)
Total Loans and Leases	2,091	3,031
Loans Acquired in a Business Combination | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	43	60
Non- Accrual	3	3
Current	1,942	2,723
(Discount)/ Premium	(139)	(168)
Total Loans and Leases	1,846	2,615
Loans Acquired in a Business Combination | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	5	24
Non- Accrual	0	17
Current	259	420
(Discount)/ Premium	(19)	(28)
Total Loans and Leases	245	416
Loans Acquired in a Business Combination | Total consumer loans
Financing Receivable, Past Due [Line Items]
Total Past Due	25	36
Non- Accrual	1	1
Current	799	1,050
(Discount)/ Premium	(23)	(26)
Total Loans and Leases	801	1,060
Loans Acquired in a Business Combination | Direct installment
Financing Receivable, Past Due [Line Items]
Total Past Due	3	5
Non- Accrual	0	0
Current	60	91
(Discount)/ Premium	0	0
Total Loans and Leases	63	96
Loans Acquired in a Business Combination | Residential mortgages
Financing Receivable, Past Due [Line Items]
Total Past Due	12	19
Non- Accrual	0	0
Current	382	498
(Discount)/ Premium	(15)	(16)
Total Loans and Leases	379	501
Loans Acquired in a Business Combination | Consumer lines of credit
Financing Receivable, Past Due [Line Items]
Total Past Due	10	12
Non- Accrual	1	1
Current	357	461
(Discount)/ Premium	(8)	(10)
Total Loans and Leases	359	463
30-89 Days Past Due | Originated Loans and Leases
Financing Receivable, Past Due [Line Items]
Total Past Due	63	53
30-89 Days Past Due | Originated Loans and Leases | Total commercial loans and leases
Financing Receivable, Past Due [Line Items]
Total Past Due	24	13
30-89 Days Past Due | Originated Loans and Leases | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	10	7
30-89 Days Past Due | Originated Loans and Leases | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	9	5
30-89 Days Past Due | Originated Loans and Leases | Commercial leases
Financing Receivable, Past Due [Line Items]
Total Past Due	5	1
30-89 Days Past Due | Originated Loans and Leases | Other
Financing Receivable, Past Due [Line Items]
Total Past Due	0	0
30-89 Days Past Due | Originated Loans and Leases | Total consumer loans
Financing Receivable, Past Due [Line Items]
Total Past Due	39	40
30-89 Days Past Due | Originated Loans and Leases | Direct installment
Financing Receivable, Past Due [Line Items]
Total Past Due	7	8
30-89 Days Past Due | Originated Loans and Leases | Residential mortgages
Financing Receivable, Past Due [Line Items]
Total Past Due	12	16
30-89 Days Past Due | Originated Loans and Leases | Indirect installment
Financing Receivable, Past Due [Line Items]
Total Past Due	15	11
30-89 Days Past Due | Originated Loans and Leases | Consumer lines of credit
Financing Receivable, Past Due [Line Items]
Total Past Due	5	5
30-89 Days Past Due | Loans Acquired in a Business Combination
Financing Receivable, Past Due [Line Items]
Total Past Due	32	46
30-89 Days Past Due | Loans Acquired in a Business Combination | Total commercial loans and leases
Financing Receivable, Past Due [Line Items]
Total Past Due	14	22
30-89 Days Past Due | Loans Acquired in a Business Combination | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	12	19
30-89 Days Past Due | Loans Acquired in a Business Combination | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	2	3
30-89 Days Past Due | Loans Acquired in a Business Combination | Total consumer loans
Financing Receivable, Past Due [Line Items]
Total Past Due	18	24
30-89 Days Past Due | Loans Acquired in a Business Combination | Direct installment
Financing Receivable, Past Due [Line Items]
Total Past Due	3	3
30-89 Days Past Due | Loans Acquired in a Business Combination | Residential mortgages
Financing Receivable, Past Due [Line Items]
Total Past Due	8	13
30-89 Days Past Due | Loans Acquired in a Business Combination | Consumer lines of credit
Financing Receivable, Past Due [Line Items]
Total Past Due	7	8
≥ 90 Days Past Due and Still Accruing | Originated Loans and Leases
Financing Receivable, Past Due [Line Items]
Total Past Due	5	5
≥ 90 Days Past Due and Still Accruing | Originated Loans and Leases | Total commercial loans and leases
Financing Receivable, Past Due [Line Items]
Total Past Due	0	0
≥ 90 Days Past Due and Still Accruing | Originated Loans and Leases | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	0	0
≥ 90 Days Past Due and Still Accruing | Originated Loans and Leases | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	0	0
≥ 90 Days Past Due and Still Accruing | Originated Loans and Leases | Commercial leases
Financing Receivable, Past Due [Line Items]
Total Past Due	0	0
≥ 90 Days Past Due and Still Accruing | Originated Loans and Leases | Other
Financing Receivable, Past Due [Line Items]
Total Past Due	0	0
≥ 90 Days Past Due and Still Accruing | Originated Loans and Leases | Total consumer loans
Financing Receivable, Past Due [Line Items]
Total Past Due	5	5
≥ 90 Days Past Due and Still Accruing | Originated Loans and Leases | Direct installment
Financing Receivable, Past Due [Line Items]
Total Past Due	1	0
≥ 90 Days Past Due and Still Accruing | Originated Loans and Leases | Residential mortgages
Financing Receivable, Past Due [Line Items]
Total Past Due	2	3
≥ 90 Days Past Due and Still Accruing | Originated Loans and Leases | Indirect installment
Financing Receivable, Past Due [Line Items]
Total Past Due	1	1
≥ 90 Days Past Due and Still Accruing | Originated Loans and Leases | Consumer lines of credit
Financing Receivable, Past Due [Line Items]
Total Past Due	1	1
≥ 90 Days Past Due and Still Accruing | Loans Acquired in a Business Combination
Financing Receivable, Past Due [Line Items]
Total Past Due	37	53
≥ 90 Days Past Due and Still Accruing | Loans Acquired in a Business Combination | Total commercial loans and leases
Financing Receivable, Past Due [Line Items]
Total Past Due	31	42
≥ 90 Days Past Due and Still Accruing | Loans Acquired in a Business Combination | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total Past Due	28	38
≥ 90 Days Past Due and Still Accruing | Loans Acquired in a Business Combination | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total Past Due	3	4
≥ 90 Days Past Due and Still Accruing | Loans Acquired in a Business Combination | Total consumer loans
Financing Receivable, Past Due [Line Items]
Total Past Due	6	11
≥ 90 Days Past Due and Still Accruing | Loans Acquired in a Business Combination | Direct installment
Financing Receivable, Past Due [Line Items]
Total Past Due	0	2
≥ 90 Days Past Due and Still Accruing | Loans Acquired in a Business Combination | Residential mortgages
Financing Receivable, Past Due [Line Items]
Total Past Due	4	6
≥ 90 Days Past Due and Still Accruing | Loans Acquired in a Business Combination | Consumer lines of credit
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 2	$ 3

Loans and Leases - Summary of_3

Loans and Leases - Summary of Commercial Loans and Leases by Credit Quality (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	$ 23,289	$ 22,153
Total commercial loans and leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	14,721	13,761
Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	8,960	8,786
Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	5,308	4,556
Commercial leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	432	373
Other
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	21	46
Originated Loans and Leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	20,397	18,062
Originated Loans and Leases | Total commercial loans and leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	12,630	10,730
Originated Loans and Leases | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	7,114	6,171
Originated Loans and Leases | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	5,063	4,140
Originated Loans and Leases | Commercial leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	432	373
Originated Loans and Leases | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	21	46
Loans Acquired in a Business Combination
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	2,892	4,091
Loans Acquired in a Business Combination | Total commercial loans and leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	2,091	3,031
Loans Acquired in a Business Combination | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	1,846	2,615
Loans Acquired in a Business Combination | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	245	416
Pass | Originated Loans and Leases | Total commercial loans and leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	12,032	10,173
Pass | Originated Loans and Leases | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	6,821	5,883
Pass | Originated Loans and Leases | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	4,768	3,879
Pass | Originated Loans and Leases | Commercial leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	423	366
Pass | Originated Loans and Leases | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	20	45
Pass | Loans Acquired in a Business Combination | Total commercial loans and leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	1,804	2,611
Pass | Loans Acquired in a Business Combination | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	1,603	2,256
Pass | Loans Acquired in a Business Combination | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	201	355
Special Mention | Originated Loans and Leases | Total commercial loans and leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	323	344
Special Mention | Originated Loans and Leases | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	171	163
Special Mention | Originated Loans and Leases | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	149	180
Special Mention | Originated Loans and Leases | Commercial leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	3	1
Special Mention | Originated Loans and Leases | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	0	0
Special Mention | Loans Acquired in a Business Combination | Total commercial loans and leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	135	186
Special Mention | Loans Acquired in a Business Combination | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	116	168
Special Mention | Loans Acquired in a Business Combination | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	19	18
Substandard | Originated Loans and Leases | Total commercial loans and leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	272	213
Substandard | Originated Loans and Leases | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	121	125
Substandard | Originated Loans and Leases | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	144	81
Substandard | Originated Loans and Leases | Commercial leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	6	6
Substandard | Originated Loans and Leases | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	1	1
Substandard | Loans Acquired in a Business Combination | Total commercial loans and leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	152	234
Substandard | Loans Acquired in a Business Combination | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	127	191
Substandard | Loans Acquired in a Business Combination | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	25	43
Doubtful | Originated Loans and Leases | Total commercial loans and leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	3	0
Doubtful | Originated Loans and Leases | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	1	0
Doubtful | Originated Loans and Leases | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	2	0
Doubtful | Originated Loans and Leases | Commercial leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	0	0
Doubtful | Originated Loans and Leases | Other
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	0	0
Doubtful | Loans Acquired in a Business Combination | Total commercial loans and leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	0	0
Doubtful | Loans Acquired in a Business Combination | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	0	0
Doubtful | Loans Acquired in a Business Combination | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Total Loans and Leases	$ 0	$ 0

Loans and Leases - Summary of_4

Loans and Leases - Summary of Consumer Loans by Payment Status (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Credit Quality [Line Items]
Total Loans and Leases	$ 23,289	$ 22,153
Direct installment
Credit Quality [Line Items]
Total Loans and Leases	1,821	1,764
Residential mortgages
Credit Quality [Line Items]
Total Loans and Leases	3,374	3,113
Indirect installment
Credit Quality [Line Items]
Total Loans and Leases	1,922	1,933
Originated Loans and Leases
Credit Quality [Line Items]
Total Loans and Leases	20,397	18,062
Originated Loans and Leases | Direct installment
Credit Quality [Line Items]
Total Loans and Leases	1,758	1,668
Originated Loans and Leases | Residential mortgages
Credit Quality [Line Items]
Total Loans and Leases	2,995	2,612
Originated Loans and Leases | Indirect installment
Credit Quality [Line Items]
Total Loans and Leases	1,922	1,933
Loans Acquired in a Business Combination
Credit Quality [Line Items]
Total Loans and Leases	2,892	4,091
Loans Acquired in a Business Combination | Direct installment
Credit Quality [Line Items]
Total Loans and Leases	63	96
Loans Acquired in a Business Combination | Residential mortgages
Credit Quality [Line Items]
Total Loans and Leases	379	501
Total consumer loans | Originated Loans and Leases
Credit Quality [Line Items]
Total Loans and Leases	7,767	7,332
Total consumer loans | Originated Loans and Leases | Performing
Credit Quality [Line Items]
Total Loans and Leases	7,728	7,297
Total consumer loans | Originated Loans and Leases | Non-Performing
Credit Quality [Line Items]
Total Loans and Leases	39	35
Total consumer loans | Originated Loans and Leases | Direct installment
Credit Quality [Line Items]
Total Loans and Leases	1,758	1,668
Total consumer loans | Originated Loans and Leases | Direct installment | Performing
Credit Quality [Line Items]
Total Loans and Leases	1,745	1,654
Total consumer loans | Originated Loans and Leases | Direct installment | Non-Performing
Credit Quality [Line Items]
Total Loans and Leases	13	14
Total consumer loans | Originated Loans and Leases | Residential mortgages
Credit Quality [Line Items]
Total Loans and Leases	2,995	2,612
Total consumer loans | Originated Loans and Leases | Residential mortgages | Performing
Credit Quality [Line Items]
Total Loans and Leases	2,978	2,598
Total consumer loans | Originated Loans and Leases | Residential mortgages | Non-Performing
Credit Quality [Line Items]
Total Loans and Leases	17	14
Total consumer loans | Originated Loans and Leases | Indirect installment
Credit Quality [Line Items]
Total Loans and Leases	1,922	1,933
Total consumer loans | Originated Loans and Leases | Indirect installment | Performing
Credit Quality [Line Items]
Total Loans and Leases	1,919	1,931
Total consumer loans | Originated Loans and Leases | Indirect installment | Non-Performing
Credit Quality [Line Items]
Total Loans and Leases	3	2
Total consumer loans | Originated Loans and Leases | Consumer lines of credit
Credit Quality [Line Items]
Total Loans and Leases	1,092	1,119
Total consumer loans | Originated Loans and Leases | Consumer lines of credit | Performing
Credit Quality [Line Items]
Total Loans and Leases	1,086	1,114
Total consumer loans | Originated Loans and Leases | Consumer lines of credit | Non-Performing
Credit Quality [Line Items]
Total Loans and Leases	6	5
Total consumer loans | Loans Acquired in a Business Combination
Credit Quality [Line Items]
Total Loans and Leases	801	1,060
Total consumer loans | Loans Acquired in a Business Combination | Performing
Credit Quality [Line Items]
Total Loans and Leases	800	1,059
Total consumer loans | Loans Acquired in a Business Combination | Non-Performing
Credit Quality [Line Items]
Total Loans and Leases	1	1
Total consumer loans | Loans Acquired in a Business Combination | Direct installment
Credit Quality [Line Items]
Total Loans and Leases	63	96
Total consumer loans | Loans Acquired in a Business Combination | Direct installment | Performing
Credit Quality [Line Items]
Total Loans and Leases	63	96
Total consumer loans | Loans Acquired in a Business Combination | Direct installment | Non-Performing
Credit Quality [Line Items]
Total Loans and Leases	0	0
Total consumer loans | Loans Acquired in a Business Combination | Residential mortgages
Credit Quality [Line Items]
Total Loans and Leases	379	501
Total consumer loans | Loans Acquired in a Business Combination | Residential mortgages | Performing
Credit Quality [Line Items]
Total Loans and Leases	379	501
Total consumer loans | Loans Acquired in a Business Combination | Residential mortgages | Non-Performing
Credit Quality [Line Items]
Total Loans and Leases	0	0
Total consumer loans | Loans Acquired in a Business Combination | Consumer lines of credit
Credit Quality [Line Items]
Total Loans and Leases	359	463
Total consumer loans | Loans Acquired in a Business Combination | Consumer lines of credit | Performing
Credit Quality [Line Items]
Total Loans and Leases	358	462
Total consumer loans | Loans Acquired in a Business Combination | Consumer lines of credit | Non-Performing
Credit Quality [Line Items]
Total Loans and Leases	$ 1	$ 1

Loans and Leases - Summary of I

Loans and Leases - Summary of Impaired Loans and Lease, by Class (Detail) - Originated Loans and Leases - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	$ 114	$ 113
Recorded Investment With No Specific Reserve	86	73
Recorded Investment With Specific Reserve	2	14
Total Recorded Investment	88	87
Specific Reserve	4	4
Average Recorded Investment	87	90
Total commercial loans and leases
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	66	68
Recorded Investment With No Specific Reserve	47	38
Recorded Investment With Specific Reserve	2	14
Total Recorded Investment	49	52
Specific Reserve	4	4
Average Recorded Investment	49	54
Commercial real estate
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	30	20
Recorded Investment With No Specific Reserve	25	16
Recorded Investment With Specific Reserve	2	1
Total Recorded Investment	27	17
Specific Reserve	2	0
Average Recorded Investment	26	18
Commercial and industrial
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	35	46
Recorded Investment With No Specific Reserve	21	20
Recorded Investment With Specific Reserve	0	13
Total Recorded Investment	21	33
Specific Reserve	2	4
Average Recorded Investment	22	32
Commercial leases
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	1	2
Recorded Investment With No Specific Reserve	1	2
Recorded Investment With Specific Reserve	0	0
Total Recorded Investment	1	2
Specific Reserve	0	0
Average Recorded Investment	1	4
Total consumer loans
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	48	45
Recorded Investment With No Specific Reserve	39	35
Recorded Investment With Specific Reserve	0	0
Total Recorded Investment	39	35
Specific Reserve	0	0
Average Recorded Investment	38	36
Direct installment
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	16	17
Recorded Investment With No Specific Reserve	13	14
Recorded Investment With Specific Reserve	0	0
Total Recorded Investment	13	14
Specific Reserve	0	0
Average Recorded Investment	13	14
Residential mortgages
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	20	16
Recorded Investment With No Specific Reserve	18	14
Recorded Investment With Specific Reserve	0	0
Total Recorded Investment	18	14
Specific Reserve	0	0
Average Recorded Investment	17	15
Indirect installment
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	5	5
Recorded Investment With No Specific Reserve	3	2
Recorded Investment With Specific Reserve	0	0
Total Recorded Investment	3	2
Specific Reserve	0	0
Average Recorded Investment	3	2
Consumer lines of credit
Financial Receivables Impaired Or Restructured [Line Items]
Unpaid Contractual Principal Balance	7	7
Recorded Investment With No Specific Reserve	5	5
Recorded Investment With Specific Reserve	0	0
Total Recorded Investment	5	5
Specific Reserve	0	0
Average Recorded Investment	$ 5	$ 5

Loans and Leases - Additional A

Loans and Leases - Additional Allowance for Credit Losses Relating to Loans Acquired In Business Combination (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and leases receivable, allowance	$ 196	$ 180	$ 175	$ 158
Loans Acquired in a Business Combination
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and leases receivable, allowance	7	7	$ 7	$ 7
Loans Acquired in a Business Combination | Total commercial loans and leases
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and leases receivable, allowance	4	6
Loans Acquired in a Business Combination | Commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and leases receivable, allowance	4	2
Loans Acquired in a Business Combination | Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and leases receivable, allowance	0	4
Loans Acquired in a Business Combination | Total consumer loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and leases receivable, allowance	3	1
Loans Acquired in a Business Combination | Direct installment
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans and leases receivable, allowance	$ 1	$ 1

Loans and Leases - Summary of P

Loans and Leases - Summary of Payment Status of Originated TDRs (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	$ 56	$ 48
Performing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	19	18
Non-Performing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	22	21
Non-accrual
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	15	9
Originated Loans and Leases
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	51	44
Originated Loans and Leases | Performing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	19	18
Originated Loans and Leases | Non-Performing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	18	17
Originated Loans and Leases | Non-accrual
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	14	9
Loans Acquired in a Business Combination
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	5	4
Loans Acquired in a Business Combination | Performing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	0	0
Loans Acquired in a Business Combination | Non-Performing
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	4	4
Loans Acquired in a Business Combination | Non-accrual
Financing Receivable, Troubled Debt Restructuring [Line Items]
Troubled debt restructurings ("TDRs")	$ 1	$ 0

Loans and Leases - Summary of T

Loans and Leases - Summary of Troubled Debt Restructurings by Class of Loans (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)Contract	Dec. 31, 2018USD ($)Contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	153	135
Pre-Modification Outstanding Recorded Investment	$ 18	$ 7
Post- Modification Outstanding Recorded Investment	$ 15	$ 7
Total commercial loans and leases
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	43	14
Pre-Modification Outstanding Recorded Investment	$ 10	$ 1
Post- Modification Outstanding Recorded Investment	$ 8	$ 1
Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	20	4
Pre-Modification Outstanding Recorded Investment	$ 5	$ 1
Post- Modification Outstanding Recorded Investment	$ 5	$ 1
Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	23	10
Pre-Modification Outstanding Recorded Investment	$ 5	$ 0
Post- Modification Outstanding Recorded Investment	$ 3	$ 0
Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	110	121
Pre-Modification Outstanding Recorded Investment	$ 8	$ 6
Post- Modification Outstanding Recorded Investment	$ 7	$ 6
Direct installment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	65	80
Pre-Modification Outstanding Recorded Investment	$ 3	$ 4
Post- Modification Outstanding Recorded Investment	$ 3	$ 4
Residential mortgages
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	18	15
Pre-Modification Outstanding Recorded Investment	$ 3	$ 1
Post- Modification Outstanding Recorded Investment	$ 3	$ 1
Consumer lines of credit
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	27	26
Pre-Modification Outstanding Recorded Investment	$ 2	$ 1
Post- Modification Outstanding Recorded Investment	$ 1	$ 1

Loans and Leases - Summary of_5

Loans and Leases - Summary of Originated Troubled Debt Restructurings by Class of Loans and Leases, Payment Default (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)Contract	Dec. 31, 2018USD ($)Contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	14	18
Recorded Investment | $	$ 1	$ 2
Total commercial loans and leases
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	6	4
Recorded Investment | $	$ 1	$ 1
Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	5	3
Recorded Investment | $	$ 1	$ 1
Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	1	1
Recorded Investment | $	$ 0	$ 0
Total consumer loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	8	14
Recorded Investment | $	$ 0	$ 1
Direct installment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	5	7
Recorded Investment | $	$ 0	$ 1
Residential mortgages
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	2	4
Recorded Investment | $	$ 0	$ 0
Consumer lines of credit
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	1	3
Recorded Investment | $	$ 0	$ 0

Allowance for Credit Losses - S

Allowance for Credit Losses - Summary of Changes in Allowance for Credit Losses by Loan and Lease Class (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				$ 180				$ 175	$ 180	$ 175	$ 158
Charge- Offs									(42)	(70)	(60)
Recoveries									14	14	16
Net Charge- Offs									(28)	(56)	(44)
Provision for credit losses	$ 7	$ 12	$ 11	14	$ 15	$ 16	$ 16	14	44	61	61
Balance at End of Year	196				180				196	180	175
Originated Loans and Leases
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				173				168	173	168	151
Charge- Offs									(33)	(63)	(58)
Recoveries									12	11	11
Net Charge- Offs									(21)	(52)	(47)
Provision for credit losses									37	57	64
Balance at End of Year	189				173				189	173	168
Loans Acquired in a Business Combination
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				7				7	7	7	7
Charge- Offs									(9)	(7)	(2)
Recoveries									2	3	5
Net Charge- Offs									(7)	(4)	3
Provision for credit losses									7	4	(3)
Balance at End of Year	7				7				7	7	7
Total commercial loans and leases | Originated Loans and Leases
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				114				109	114	109	99
Charge- Offs									(17)	(34)	(34)
Recoveries									8	5	5
Net Charge- Offs									(9)	(29)	(29)
Provision for credit losses									21	34	39
Balance at End of Year	126				114				126	114	109
Total commercial loans and leases | Loans Acquired in a Business Combination
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				6					6
Balance at End of Year	4				6				4	6
Commercial real estate | Originated Loans and Leases
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				55				50	55	50	47
Charge- Offs									(4)	(7)	(2)
Recoveries									4	3	2
Net Charge- Offs									0	(4)	0
Provision for credit losses									5	9	3
Balance at End of Year	60				55				60	55	50
Commercial real estate | Loans Acquired in a Business Combination
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				2					2
Balance at End of Year	4				2				4	2
Commercial and industrial | Originated Loans and Leases
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				49				52	49	52	48
Charge- Offs									(10)	(20)	(27)
Recoveries									4	2	2
Net Charge- Offs									(6)	(18)	(25)
Provision for credit losses									10	15	29
Balance at End of Year	53				49				53	49	52
Commercial and industrial | Loans Acquired in a Business Combination
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				4					4
Balance at End of Year	0				4				0	4
Commercial leases | Originated Loans and Leases
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				8				5	8	5	3
Charge- Offs									0	(3)	(1)
Recoveries									0	0	0
Net Charge- Offs									0	(3)	(1)
Provision for credit losses									3	6	3
Balance at End of Year	11				8				11	8	5
Other | Originated Loans and Leases
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				2				2	2	2	1
Charge- Offs									(3)	(4)	(4)
Recoveries									0	0	1
Net Charge- Offs									(3)	(4)	(3)
Provision for credit losses									3	4	4
Balance at End of Year	2				2				2	2	2
Total consumer loans | Originated Loans and Leases
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				59				59	59	59	52
Charge- Offs									(16)	(29)	(24)
Recoveries									4	6	6
Net Charge- Offs									(12)	(23)	(18)
Provision for credit losses									16	23	25
Balance at End of Year	63				59				63	59	59
Total consumer loans | Loans Acquired in a Business Combination
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				1					1
Balance at End of Year	3				1				3	1
Direct installment | Originated Loans and Leases
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				14				21	14	21	21
Charge- Offs									(1)	(17)	(12)
Recoveries									0	2	2
Net Charge- Offs									(1)	(15)	(10)
Provision for credit losses									0	8	10
Balance at End of Year	13				14				13	14	21
Direct installment | Loans Acquired in a Business Combination
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				1					1
Balance at End of Year	1				1				1	1
Residential mortgages | Originated Loans and Leases
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				20				16	20	16	10
Charge- Offs									(2)	0	0
Recoveries									0	0	0
Net Charge- Offs									(2)	0	0
Provision for credit losses									4	4	6
Balance at End of Year	22				20				22	20	16
Residential mortgages | Loans Acquired in a Business Combination
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				0					0
Balance at End of Year	2				0				2	0
Indirect installment | Originated Loans and Leases
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				15				12	15	12	11
Charge- Offs									(11)	(9)	(10)
Recoveries									4	4	4
Net Charge- Offs									(7)	(5)	(6)
Provision for credit losses									11	8	7
Balance at End of Year	19				15				19	15	12
Consumer lines of credit | Originated Loans and Leases
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				10				10	10	10	10
Charge- Offs									(2)	(3)	(2)
Recoveries									0	0	0
Net Charge- Offs									(2)	(3)	(2)
Provision for credit losses									1	3	2
Balance at End of Year	9				10				9	10	10
Purchased credit-impaired loans | Loans Acquired in a Business Combination
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				1				1	1	1	1
Charge- Offs									0	0	(1)
Recoveries									0	0	0
Net Charge- Offs									0	0	(1)
Provision for credit losses									0	0	1
Balance at End of Year	1				1				1	1	1
Other loans acquired in a business combination | Loans Acquired in a Business Combination
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Balance at Beginning of Year				$ 6				$ 6	6	6	6
Charge- Offs									(9)	(7)	(1)
Recoveries									2	3	5
Net Charge- Offs									(7)	(4)	4
Provision for credit losses									7	4	(4)
Balance at End of Year	$ 6				$ 6				$ 6	$ 6	$ 6

Allowance for Credit Losses -_2

Allowance for Credit Losses - Summary of Individual and Collective Allowance for Credit Losses and Loan and Lease Balances by Class (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Valuation Allowance [Line Items]
Total Loans and Leases	$ 23,289	$ 22,153
Total commercial loans and leases
Valuation Allowance [Line Items]
Total Loans and Leases	14,721	13,761
Commercial real estate
Valuation Allowance [Line Items]
Total Loans and Leases	8,960	8,786
Commercial and industrial
Valuation Allowance [Line Items]
Total Loans and Leases	5,308	4,556
Commercial leases
Valuation Allowance [Line Items]
Total Loans and Leases	432	373
Other
Valuation Allowance [Line Items]
Total Loans and Leases	21	46
Total consumer loans
Valuation Allowance [Line Items]
Total Loans and Leases	8,568	8,392
Direct installment
Valuation Allowance [Line Items]
Total Loans and Leases	1,821	1,764
Residential mortgages
Valuation Allowance [Line Items]
Total Loans and Leases	3,374	3,113
Indirect installment
Valuation Allowance [Line Items]
Total Loans and Leases	1,922	1,933
Consumer lines of credit
Valuation Allowance [Line Items]
Total Loans and Leases	1,451	1,582
Originated Loans and Leases
Valuation Allowance [Line Items]
Allowance, individually evaluated for impairment	4	4
Allowance, collectively evaluated for impairment	185	173
Total Loans and Leases	20,397	18,062
Loans and leases outstanding, individually evaluated for impairment	30	18
Loans and leases outstanding, collectively evaluated for impairment	20,367	18,044
Originated Loans and Leases | Total commercial loans and leases
Valuation Allowance [Line Items]
Allowance, individually evaluated for impairment	4	4
Allowance, collectively evaluated for impairment	122	115
Total Loans and Leases	12,630	10,730
Loans and leases outstanding, individually evaluated for impairment	30	18
Loans and leases outstanding, collectively evaluated for impairment	12,600	10,712
Originated Loans and Leases | Commercial real estate
Valuation Allowance [Line Items]
Allowance, individually evaluated for impairment	2	0
Allowance, collectively evaluated for impairment	58	55
Total Loans and Leases	7,114	6,171
Loans and leases outstanding, individually evaluated for impairment	13	7
Loans and leases outstanding, collectively evaluated for impairment	7,101	6,164
Originated Loans and Leases | Commercial and industrial
Valuation Allowance [Line Items]
Allowance, individually evaluated for impairment	2	4
Allowance, collectively evaluated for impairment	51	49
Total Loans and Leases	5,063	4,140
Loans and leases outstanding, individually evaluated for impairment	17	11
Loans and leases outstanding, collectively evaluated for impairment	5,046	4,129
Originated Loans and Leases | Commercial leases
Valuation Allowance [Line Items]
Allowance, individually evaluated for impairment	0	0
Allowance, collectively evaluated for impairment	11	9
Total Loans and Leases	432	373
Loans and leases outstanding, individually evaluated for impairment	0	0
Loans and leases outstanding, collectively evaluated for impairment	432	373
Originated Loans and Leases | Other
Valuation Allowance [Line Items]
Allowance, individually evaluated for impairment	0	0
Allowance, collectively evaluated for impairment	2	2
Total Loans and Leases	21	46
Loans and leases outstanding, individually evaluated for impairment	0	0
Loans and leases outstanding, collectively evaluated for impairment	21	46
Originated Loans and Leases | Total consumer loans
Valuation Allowance [Line Items]
Allowance, individually evaluated for impairment	0	0
Allowance, collectively evaluated for impairment	63	58
Total Loans and Leases	7,767	7,332
Loans and leases outstanding, individually evaluated for impairment	0	0
Loans and leases outstanding, collectively evaluated for impairment	7,767	7,332
Originated Loans and Leases | Direct installment
Valuation Allowance [Line Items]
Allowance, individually evaluated for impairment	0	0
Allowance, collectively evaluated for impairment	13	14
Total Loans and Leases	1,758	1,668
Loans and leases outstanding, individually evaluated for impairment	0	0
Loans and leases outstanding, collectively evaluated for impairment	1,758	1,668
Originated Loans and Leases | Residential mortgages
Valuation Allowance [Line Items]
Allowance, individually evaluated for impairment	0	0
Allowance, collectively evaluated for impairment	22	19
Total Loans and Leases	2,995	2,612
Loans and leases outstanding, individually evaluated for impairment	0	0
Loans and leases outstanding, collectively evaluated for impairment	2,995	2,612
Originated Loans and Leases | Indirect installment
Valuation Allowance [Line Items]
Allowance, individually evaluated for impairment	0	0
Allowance, collectively evaluated for impairment	19	15
Total Loans and Leases	1,922	1,933
Loans and leases outstanding, individually evaluated for impairment	0	0
Loans and leases outstanding, collectively evaluated for impairment	1,922	1,933
Originated Loans and Leases | Consumer lines of credit
Valuation Allowance [Line Items]
Allowance, individually evaluated for impairment	0	0
Allowance, collectively evaluated for impairment	9	10
Total Loans and Leases	1,092	1,119
Loans and leases outstanding, individually evaluated for impairment	0	0
Loans and leases outstanding, collectively evaluated for impairment	$ 1,092	$ 1,119

Loan Servicing - Mortgage Servi

Loan Servicing - Mortgage Servicing Rights Activity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Servicing Assets at Fair Value [Line Items]
Mortgage banking operations	$ 32	$ 22	$ 20
Mortgage Servicing Rights
Servicing Assets at Fair Value [Line Items]
SBA loans sold to investors with servicing retained	4,686	3,968
Mortgage loans sold with servicing retained	1,381	1,060	1,769
Pretax gains resulting from above loan sales	32	19	22
Mortgage banking operations	11	9	8
Valuation allowance for impairment of recognized servicing assets, balance	1.5	0.5
Servicing Asset at Amortized Cost, Balance [Roll Forward]
Balance at beginning of period	37	29	14
Fair value of MSRs acquired	0	0	8
Additions	14	13	11
Payoffs and curtailments	(5)	(2)	(2)
Impairment charge	(1)	(1)	0
Amortization	(2)	(2)	(2)
Balance at end of period	43	37	29
Fair value, beginning of period	41	32	18
Fair value, end of period	$ 45	$ 41	$ 32

Loan Servicing - Sensitivity of

Loan Servicing - Sensitivity of Fair Value to Changes in key Assumptions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Mortgage Servicing Rights
Servicing Assets at Fair Value [Line Items]
Weighted average life (months)	78 months 27 days	82 months 6 days
Constant prepayment rate (annualized)	10.60%	10.10%
Discount rate	9.70%	9.70%
Sensitivity analysis of fair value of interests continued to be held by transferor servicing assets or liabilities impact of zero point two five percent favorable change in prepayment speed	$ 3	$ 3
Sensitivity analysis of fair value of interests continued to be held by transferor servicing assets or liabilities impact of zero point five zero percent favorable change in prepayment speed	5	5
Sensitivity analysis of fair value of interests continued to be held by transferor servicing assets or liabilities impact of zero point two five percent adverse change in prepayment speed	(3)	(3)
Sensitivity analysis of fair value of interests continued to be held by transferor servicing assets or liabilities impact of zero point five zero percent adverse change in prepayment speed	$ (5)	$ (6)
SBA-Guaranteed Loan Servicing
Servicing Assets at Fair Value [Line Items]
Weighted average life (months)	42 months	52 months 6 days
Constant prepayment rate (annualized)	16.80%	12.50%
Discount rate	16.20%	19.40%
Sensitivity analysis of fair value, transferor's interests in transferred financial assets, impact of 10 percent adverse change in prepayment speed	$ (0.1)	$ (0.2)
Sensitivity analysis of fair value, transferor's interests in transferred financial assets, impact of 20 percent adverse change in prepayment speed	(0.3)	(0.3)
Sensitivity analysis of fair value, transferor's interests in transferred financial assets, impact of 1 percent adverse change in discount rate	(0.1)	(0.1)
Sensitivity analysis of fair value, transferor's interests in transferred financial assets, impact of 2 percent adverse change in discount rate	$ (0.1)	$ (0.2)

Loan Servicing - Activity in SB

Loan Servicing - Activity in SBA-Guaranteed Loan Servicing Asset (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Servicing Assets at Fair Value [Line Items]
Service charges	$ 124	$ 126	$ 120
SBA-Guaranteed Loan Servicing
Servicing Assets at Fair Value [Line Items]
SBA loans sold to investors with servicing retained	225	283
Mortgage loans sold with servicing retained	23	41	54
Pretax gains resulting from above loan sales	2	4	2
Service charges	2	3	2
Valuation allowance for impairment of recognized servicing assets, balance	1.2	0.8
Servicing Asset at Fair Value, Amount [Roll Forward]
Balance at beginning of period	4	5	0
Fair value of servicing rights acquired	0	0	5
Additions	0	1	1
Payoffs, curtailments and amortization	(1)	(1)	(1)
Impairment (charge) / recovery	0	(1)	0
Balance at end of period	3	4	5
Fair value, beginning of period	4	5	0
Fair value, end of period	$ 3	$ 4	$ 5

Premises and Equipment - Summar

Premises and Equipment - Summary of Premises and Equipment (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Land	$ 62	$ 64
Premises	233	238
Equipment	276	236
Property Plant and Equipment Gross	571	538
Accumulated depreciation	(238)	(208)
Total premises and equipment, net	$ 333	$ 330

Premises and Equipment - Deprec

Premises and Equipment - Depreciation Expense for Premises and Equipment (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Depreciation expense for premises and equipment	$ 42	$ 39	$ 34

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Rollforward of Goodwill (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 2,255	$ 2,249
Goodwill (deductions) additions	7	6
Goodwill, Ending Balance	2,262	2,255
Community Banking
Goodwill [Roll Forward]
Goodwill, Beginning Balance	2,231	2,228
Goodwill (deductions) additions	0	3
Goodwill, Ending Balance	2,231	2,231
Wealth Management
Goodwill [Roll Forward]
Goodwill, Beginning Balance	8	8
Goodwill (deductions) additions	0	0
Goodwill, Ending Balance	8	8
Insurance
Goodwill [Roll Forward]
Goodwill, Beginning Balance	16	11
Goodwill (deductions) additions	7	5
Goodwill, Ending Balance	23	16
Other
Goodwill [Roll Forward]
Goodwill, Beginning Balance	0	2
Goodwill (deductions) additions	0	(2)
Goodwill, Ending Balance	$ 0	$ 0

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Summary of Core Deposit Intangibles, Customer Renewal Lists and Mortgage Servicing Rights (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 214	$ 211
Accumulated amortization	(147)	(132)
Net carrying amount	67	79
Core Deposit Intangibles
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	196	196
Accumulated amortization	(136)	(122)
Net carrying amount	60	74
Customer Renewal Lists
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	18	15
Accumulated amortization	(11)	(10)
Net carrying amount	$ 7	$ 5

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019
Minimum
Finite-Lived Intangible Assets [Line Items]
Amortization period of intangible assets, years	8 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Amortization period of intangible assets, years	13 years
Core Deposit Intangibles
Finite-Lived Intangible Assets [Line Items]
Amortization period of intangible assets, years	10 years
Customer Renewal Lists | Minimum
Finite-Lived Intangible Assets [Line Items]
Amortization period of intangible assets, years	8 years
Customer Renewal Lists | Maximum
Finite-Lived Intangible Assets [Line Items]
Amortization period of intangible assets, years	13 years

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets - Schedule of Amortization Expense Recognized (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 14	$ 16	$ 18

Goodwill and Other Intangible_7

Goodwill and Other Intangible Assets - Schedule of Expected Amortization Expense on Finite-Lived Intangible Assets (Detail) $ in Millions	Dec. 31, 2019USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2020	$ 13
2021	12
2022	10
2023	10
2024	8
Total	$ 53

Operating Leases - Other Inform

Operating Leases - Other Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Right-of-use asset			$ 121.4
Present value of lease liabilities			128.2
Operating lease, lease not yet commenced, expense			$ 29
Rental expense	$ 33.2	$ 29.1
Minimum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, lease not yet commenced, term of contract			6 years
Maximum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, lease not yet commenced, term of contract			15 years

Operating Leases - Lease Expens

Operating Leases - Lease Expense (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Leases [Abstract]
Operating lease cost	$ 27
Short-term lease cost	1
Variable lease cost	4
Sublease income	0
Total lease cost	32
Operating cash flows from operating leases	26
Right-of-use assets obtained in exchange for lease obligations	$ 25
Weighted average remaining lease term, Operating leases	9 years 7 months 9 days
Weighted average discount rate, Operating leases	3.00%

Operating Leases - Maturities (

Operating Leases - Maturities (Details) $ in Millions	Dec. 31, 2019USD ($)
Leases [Abstract]
2019	$ 24
2020	22
2021	17
2022	13
2023	12
Later years	62
Total lease payments	150
Less: imputed interest	(22)
Present value of lease liabilities	$ 128.2

Deposits - Summary of Deposits

Deposits - Summary of Deposits (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deposits [Abstract]
Non-interest-bearing demand	$ 6,384	$ 6,000
Interest-bearing demand	11,049	9,660
Savings	2,625	2,526
Less than $100,000	2,262	2,816
$100,000 through $250,000	1,494	1,478
Greater than $250,000	972	975
Total certificates and other time deposits	4,728	5,269
Total Deposits	$ 24,786	$ 23,455

Deposits - Summary of Scheduled

Deposits - Summary of Scheduled Maturities of Certificates and Other Time Deposits (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Deposits [Abstract]
2020	$ 3,035
2021	1,041
2022	236
2023	214
2024	115
Later years	87
Total certificates and other time deposits	$ 4,728	$ 5,269

Short-Term Borrowings - Summary

Short-Term Borrowings - Summary of Short-Term Borrowings (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Securities sold under repurchase agreements	$ 278	$ 251
Federal Home Loan Bank advances	2,255	2,230
Federal funds purchased	575	1,535
Subordinated notes	108	113
Total short-term borrowings	$ 3,216	$ 4,129
Short-term advances, overnight maturities	0.00%	57.20%
Short-term advances	$ 1,500	$ 1,000
Short-term advances, percentage bearing fixed interest rate	64.50%	42.80%

Short-Term Borrowings - Schedul

Short-Term Borrowings - Schedule of Weighted Average Interest Rates on Short-Term Borrowings (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Year-to-date average	2.24%	1.89%	1.16%
Period-end	1.76%	2.49%	1.44%

Long-Term Borrowings - Summary

Long-Term Borrowings - Summary of Long-Term Borrowings (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Federal Home Loan Bank advances	$ 935	$ 270
Subordinated notes	90	87
Junior subordinated debt	66	111
Other subordinated debt	249	159
Total long-term borrowings	$ 1,340	$ 627

Long-Term Borrowings - Schedule

Long-Term Borrowings - Scheduled Annual Maturities for Long-Term Borrowings (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
2019	$ 122
2021	563
2022	311
2023	30
2024	1
Later years	313
Total long-term borrowings	$ 1,340	$ 627

Long-Term Borrowings - Addition

Long-Term Borrowings - Additional Information (Detail) $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Dec. 31, 2019USD ($)Trust	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Number of unconsolidated subsidiary trusts | Trust			3
Percent of the common equity of each Trust owned by the Corporation			100.00%
Repayments of long-term debt			$ 239	$ 77	$ 199
Repayments of subordinated debt	$ 9.5
Repayments of other long-term debt		$ 15.5
FHLB
Debt Instrument [Line Items]
Credit available with FHLB			7,900
Credit with FHLB used			$ 3,200
Subordinated Notes
Debt Instrument [Line Items]
Written notice for holder			30 days
Minimum | FHLB
Debt Instrument [Line Items]
Effective interest rates			1.62%	1.39%
Minimum | Subordinated Notes
Debt Instrument [Line Items]
Months prior to maturity, interest discount			3 months
Maximum | FHLB
Debt Instrument [Line Items]
Effective interest rates			2.71%	4.19%
Maximum | Subordinated Notes
Debt Instrument [Line Items]
Months prior to maturity, interest discount			12 months
Trust Preferred Securities
Debt Instrument [Line Items]
Repayments of long-term debt		$ 44

Long-Term Borrowings - Summar_2

Long-Term Borrowings - Summary of Weighted Average Interest Rate on Subordinated Notes (Detail)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Subordinated notes weighted average interest rate	3.33%	3.08%	2.85%

Long-Term Borrowings - Junior S

Long-Term Borrowings - Junior Subordinated Debt Trusts (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 66	$ 111
Trust Preferred Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	72
Common Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	3
F.N.B. Statutory Trust II
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 22
Stated Maturity Date	Jun. 15, 2036
Interest Rate	3.54%
Description of variable rate	LIBOR + 165 basis points (bps)
Basis points	1.65%
F.N.B. Statutory Trust II | Trust Preferred Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 22
F.N.B. Statutory Trust II | Common Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	1
Yadkin Valley Statutory Trust I
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 22
Stated Maturity Date	Dec. 15, 2037
Interest Rate	3.21%
Description of variable rate	LIBOR + 132 bps
Basis points	1.32%
Yadkin Valley Statutory Trust I | Trust Preferred Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 25
Yadkin Valley Statutory Trust I | Common Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	1
FNB Financial Services Capital Trust I
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 22
Stated Maturity Date	Sep. 30, 2035
Interest Rate	3.42%
Description of variable rate	LIBOR + 146 bps
Basis points	1.46%
FNB Financial Services Capital Trust I | Trust Preferred Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 25
FNB Financial Services Capital Trust I | Common Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 1

Long-Term Borrowings Long-Term

Long-Term Borrowings Long-Term Borrowings - Schedule of Subordinated Debt (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Aggregate principal amount issued	$ 258
Net proceeds	262
Carrying value	249
4.95% Fixed-To-Floating Rate Subordinated Notes due 2029
Debt Instrument [Line Items]
Aggregate principal amount issued	120
Net proceeds	118
Carrying value	$ 118
Interest Rate	4.95%
4.875% Subordinated Notes due 2025
Debt Instrument [Line Items]
Aggregate principal amount issued	$ 100
Net proceeds	98
Carrying value	$ 99
Interest Rate	4.875%
Yadkin Financial Corporation (YDKN) | 7.625% Subordinated Notes due August 12, 2013
Debt Instrument [Line Items]
Aggregate principal amount issued	$ 38
Net proceeds	46
Carrying value	$ 32
Interest Rate	7.625%

Derivative Instruments and He_3

Derivative Instruments and Hedging Activities - Schedule of Notional Amounts and Gross Fair Values of Derivative Assets and Derivative Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Notional amount	$ 9,558	$ 6,942
Derivative asset, fair value, amount not offset against collateral	1	2
Derivative liability, fair value, amount not offset against collateral	23	13
Derivative asset, not subject to master netting arrangement	153	41
Derivative liability, not subject to master netting arrangement	2	26
Derivative asset	154	43
Derivative liabilities	25	39
Interest rate contracts
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, amount not offset against collateral	1	0
Derivative liability, fair value, amount not offset against collateral	0	3
Interest Rate Swap
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, amount not offset against collateral	0	2
Derivative liability, fair value, amount not offset against collateral	23	10
Derivative asset, not subject to master netting arrangement	149	40
Derivative liability, not subject to master netting arrangement	1	26
Equity Contracts
Derivatives, Fair Value [Line Items]
Derivative asset, fair value, amount not offset against collateral	0	0
Derivative liability, fair value, amount not offset against collateral	0	0
Derivative asset, not subject to master netting arrangement	0	0
Derivative liability, not subject to master netting arrangement	0	0
Interest Rate Lock Commitments
Derivatives, Fair Value [Line Items]
Derivative asset, not subject to master netting arrangement	3	1
Derivative liability, not subject to master netting arrangement	0	0
Forward Delivery Commitments
Derivatives, Fair Value [Line Items]
Derivative asset, not subject to master netting arrangement	1	0
Derivative liability, not subject to master netting arrangement	1	0
Credit Risk Contracts
Derivatives, Fair Value [Line Items]
Notional amount	201.5
Derivative asset, not subject to master netting arrangement	0	0
Derivative liability, not subject to master netting arrangement	0	0
Subject to Master Netting Arrangement
Derivatives, Fair Value [Line Items]
Notional amount	5,295	3,896
Subject to Master Netting Arrangement | Interest rate contracts
Derivatives, Fair Value [Line Items]
Notional amount	1,655	1,155
Subject to Master Netting Arrangement | Interest Rate Swap
Derivatives, Fair Value [Line Items]
Notional amount	3,640	2,740
Subject to Master Netting Arrangement | Equity Contracts
Derivatives, Fair Value [Line Items]
Notional amount	0	1
Not Subject to Master Netting Arrangement
Derivatives, Fair Value [Line Items]
Notional amount	4,263	3,046
Not Subject to Master Netting Arrangement | Interest Rate Swap
Derivatives, Fair Value [Line Items]
Notional amount	3,640	2,740
Not Subject to Master Netting Arrangement | Equity Contracts
Derivatives, Fair Value [Line Items]
Notional amount	0	1
Not Subject to Master Netting Arrangement | Interest Rate Lock Commitments
Derivatives, Fair Value [Line Items]
Notional amount	163	47
Not Subject to Master Netting Arrangement | Forward Delivery Commitments
Derivatives, Fair Value [Line Items]
Notional amount	195	55
Not Subject to Master Netting Arrangement | Credit Risk Contracts
Derivatives, Fair Value [Line Items]
Notional amount	$ 265	$ 203

Derivative Instruments and He_4

Derivative Instruments and Hedging Activities - Amounts Reclassified from AOCI (Details) - Interest rate contracts - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Amount of Gain (Loss) Recognized in OCI on Derivatives	$ (22)
Amount of Gain (Loss) Recognized in OCI on Derivatives		$ (3)	$ 1
Amount of Gain (Loss) Reclassified from AOCI into Income	0
Amount of Gain (Loss) Reclassified from AOCI into Income		0
Interest income (expense)
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Amount of Gain (Loss) Reclassified from AOCI into Income	$ 2
Amount of Gain (Loss) Reclassified from AOCI into Income		$ 2	$ 0

Derivative Instruments and He_5

Derivative Instruments and Hedging Activities - Effect of Cash Flow Hedging on Income Statement (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Loans and leases, including fees	$ 1,085	$ 1,022	$ 862
Interest Expense - Short-term borrowings	80	75	44
Interest rate contracts
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into net income	0
Amount of Gain (Loss) Reclassified from AOCI into Income		0
Interest income – loans and leases | Interest rate contracts
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into net income	(1)
Amount of Gain (Loss) Reclassified from AOCI into Income		(1)	1
Amount of gain (loss) reclassified from AOCI into income as a result of that a forecasted transaction is no longer probable of occurring	0	0	0
Interest expense – short-term borrowings | Interest rate contracts
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into net income	3
Amount of Gain (Loss) Reclassified from AOCI into Income		3	(1)
Amount of gain (loss) reclassified from AOCI into income as a result of that a forecasted transaction is no longer probable of occurring	$ 0	$ 0	$ 0

Derivative Instruments and He_6

Derivative Instruments and Hedging Activities - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Notional amount	$ 9,558,000,000	$ 6,942,000,000
Additional amount in excess of posted collateral required in case of breached agreements	$ 100,000	700,000
Interest rate contracts
Derivative [Line Items]
Maximum length of time hedged in interest rate cash flow hedge	4 years 10 months 24 days
Period to reclassification of cash flow hedge gain loss	12 months
Derivative gains to be reclassified within twelve months	$ 4,500,000
Derivative gains to be reclassified within twelve months, net of tax	3,500,000
Hedge ineffectiveness	0
Amount of gain (loss) reclassified from AOCI into net income	$ 0
Gains or losses from cash flow hedge derivatives reclassified to earnings		0
Interest Rate Lock Commitments | Minimum
Derivative [Line Items]
Lock in period for interest rates	30 days
Interest Rate Lock Commitments | Maximum
Derivative [Line Items]
Lock in period for interest rates	270 days
Credit Risk Contracts
Derivative [Line Items]
Notional amount	$ 201,500,000
Maximum exposure under credit risk agreement assuming customer default	300,000	100,000
Credit risk derivatives, purchased at fair value	100,000	50,000
Credit risk derivatives, sold at fair value	$ 300,000	$ 110,000
Credit Risk Contracts | Minimum
Derivative [Line Items]
Risk participation agreements, term	2 months
Credit Risk Contracts | Maximum
Derivative [Line Items]
Risk participation agreements, term	9 years

Derivative Instruments and He_7

Derivative Instruments and Hedging Activities - Effect of Derivative Financial Instruments on Income Statement (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest Rate Swap | Non-interest income - other
Derivative [Line Items]
Derivative financial instrument, net	$ 0	$ 1	$ (1)
Interest Rate Lock Commitments | Mortgage banking operations
Derivative [Line Items]
Derivative financial instrument, net	0	0	0
Forward Delivery Commitments | Mortgage banking operations
Derivative [Line Items]
Derivative financial instrument, net	(1)	1	0
Credit Risk Contracts | Non-interest income - other
Derivative [Line Items]
Derivative financial instrument, net	$ 0	$ 0	$ 0

Derivative Instruments and He_8

Derivative Instruments and Hedging Activities - Derivative Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Net Amount Presented in the Balance Sheet	$ 1	$ 2
Gross amounts not offset in the consolidated balance sheets financial instruments, derivative assets	1	2
Gross amounts not offset in the consolidated balance sheets cash collateral received, derivative assets	0	0
Net Amount	0	0
Interest rate contracts
Derivative [Line Items]
Net Amount Presented in the Balance Sheet	1	0
Gross amounts not offset in the consolidated balance sheets financial instruments, derivative assets	1
Gross amounts not offset in the consolidated balance sheets cash collateral received, derivative assets	0
Net Amount	0
Interest rate contracts
Derivative [Line Items]
Net Amount Presented in the Balance Sheet	$ 0	2
Gross amounts not offset in the consolidated balance sheets financial instruments, derivative assets		2
Gross amounts not offset in the consolidated balance sheets cash collateral received, derivative assets		0
Net Amount		$ 0

Derivative Instruments and He_9

Derivative Instruments and Hedging Activities - Derivative Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Net Amount Presented in the Balance Sheet	$ 23	$ 13
Gross amount not offset in the balance sheet financial instruments, derivative liabilities	23	12
Gross amount not offset in the balance sheet cash collateral pledged, derivative liabilities	0	0
Net Amount	0	1
Interest rate contracts
Derivative [Line Items]
Net Amount Presented in the Balance Sheet	23	10
Gross amount not offset in the balance sheet financial instruments, derivative liabilities	23	9
Gross amount not offset in the balance sheet cash collateral pledged, derivative liabilities	0	0
Net Amount	0	1
Interest rate contracts
Derivative [Line Items]
Net Amount Presented in the Balance Sheet	$ 0	3
Gross amount not offset in the balance sheet financial instruments, derivative liabilities		3
Gross amount not offset in the balance sheet cash collateral pledged, derivative liabilities		0
Net Amount		$ 0

Commitments, Credit Risk and _3

Commitments, Credit Risk and Contingencies - Summary of Off-Balance Sheet Credit Risk Information (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Standby letters of credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Extended credit and standby letters of credit	$ 150	$ 126
Commitments to extend credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Extended credit and standby letters of credit	$ 8,089	$ 7,378

Commitments, Credit Risk and _4

Commitments, Credit Risk and Contingencies - Additional Information (Detail)	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Percentage of commitments to extend credit dependent upon the financial condition of the customers	74.20%

Stock Incentive Plans - Additio

Stock Incentive Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jun. 30, 2019	Mar. 31, 2018	Mar. 11, 2017	Apr. 06, 2013	Jun. 15, 2009
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards issued (in shares)	1,182,197	962,799	713,998
Common stock shares available under incentive compensation plans (in shares)	1,620,243
Unrecognized compensation expense	$ 14,000,000
Intrinsic value of outstanding and exercisable stock options	1,100,000
Common shares available for purchase under warrants (in shares)								651,042
Tax benefit recognized from stock options exercised	200,000	$ 300,000	$ 400,000
Warrants outstanding	$ 0
Annapolis Bancorp, Inc. (ANNB)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrant issued, exercise price (in usd per share)					$ 3.02
Warrant issued, shares (in shares)							342,564
Warrants converted to purchase common stock (in shares)					405,489
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards issued, years	3 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards issued (in shares)	1,182,197	962,799	713,998
Unrecognized compensation expense	$ 14,300,000
Amount subject to accelerated vesting under Incentive Compensation Plan	$ 500,000
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common shares available for purchase under warrants (in shares)								1,302,083
Service- Based Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of awards issued, years	3 years
Unrecognized compensation expense	$ 10,000,000
Performance- Based Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 4,000,000
Performance- Based Units | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock awards issued (in shares)	353,656	283,037
Warrant Expires in 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrant issued, exercise price (in usd per share)	$ 11.52
Warrant Expires in 2019 | Annapolis Bancorp, Inc. (ANNB)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrant issued, exercise price (in usd per share)							$ 3.57
Warrant Expires in 2019 | Yadkin Financial Corporation (YDKN)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrant issued, exercise price (in usd per share)						$ 9.63
Warrant issued, shares (in shares)						207,320
Capital Purchase Program | Yadkin Financial Corporation (YDKN)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Warrant issued, exercise price (in usd per share)				$ 8.86		$ 9.63
Warrant issued, shares (in shares)				225,439		207,320

Stock Incentive Plans - Schedul

Stock Incentive Plans - Schedule of Issuance of Restricted Stock Units and Aggregate Weighted Average Grant Date Fair Values (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Payment Arrangement [Abstract]
Restricted stock awards (in shares)	1,182,197	962,799	713,998
Weighted average grant date fair values	$ 13	$ 13	$ 10

Stock Incentive Plans - Summary

Stock Incentive Plans - Summary of Information Concerning Restricted Stock Units (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Units
Shares, granted (in shares)	1,182,197	962,799	713,998
Shares, unvested shares outstanding at end of year (in shares)	2,858,357
Restricted Stock
Units
Shares, unvested shares outstanding at beginning of year (in shares)	2,556,174	1,975,862	1,836,363
Shares, granted (in shares)	1,182,197	962,799	713,998
Shares, net adjustment due to performance (in shares)	0	0	(64,861)
Shares, vested (in shares)	(655,208)	(258,031)	(542,580)
Shares, forfeited/expired (in shares)	(332,814)	(214,743)	(31,018)
Shares, dividend reinvestment (in shares)	108,008	90,287	63,960
Shares, unvested shares outstanding at end of year (in shares)	2,858,357	2,556,174	1,975,862
Weighted Average Grant Price per Share
Weighted average grant price per share, unvested shares outstanding at beginning of year (USD per share)	$ 13.51	$ 13.64	$ 12.97
Weighted average grant price per share, granted (USD per share)	10.94	13.21	14.67
Weighted average grant price per share, net adjustment due to performance (USD per share)	0	0	13.85
Weighted average grant price per share, vested (USD per share)	13.15	13.19	12.71
Weighted average grant price per share, forfeited/expired (USD per share)	12.72	13.39	14.03
Weighted average grant price per share, dividend reinvestment (USD per share)	11.84	12.61	13.80
Weighted average grant price per share, unvested shares outstanding at end of year (USD per share)	$ 12.56	$ 13.51	$ 13.64

Stock Incentive Plans - Sched_2

Stock Incentive Plans - Schedule of Certain Information Related to Restricted Stock Units (Detail) - Restricted Stock - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 12	$ 10	$ 8
Tax benefit related to stock-based compensation expense	2	2	3
Fair value of units vested	$ 7	$ 3	$ 8

Stock Incentive Plans - Compone

Stock Incentive Plans - Components of Restricted Stock Units (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock awards (in shares) | shares	2,858,357
Unrecognized compensation expense	$ 14
Intrinsic value	$ 36
Weighted average remaining life (in years)	1 year 9 months 25 days
Service- Based Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock awards (in shares) | shares	1,922,120
Unrecognized compensation expense	$ 10
Intrinsic value	$ 24
Weighted average remaining life (in years)	1 year 9 months 29 days
Performance- Based Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested restricted stock awards (in shares) | shares	936,237
Unrecognized compensation expense	$ 4
Intrinsic value	$ 12
Weighted average remaining life (in years)	1 year 9 months 21 days

Stock Incentive Plans - Summa_2

Stock Incentive Plans - Summary of Activity Related to Stock Options Units (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Options Outstanding and Exercisable
Shares, options outstanding at beginning of year (in shares)	458,354	722,650	892,532
Shares, assumed from acquisitions (in shares)	0	0	207,645
Shares, exercised (in shares)	(183,566)	(253,899)	(255,503)
Shares, forfeited/expired (in shares)	(28,704)	(10,397)	(122,024)
Shares, options outstanding and exercisable at end of year (in shares)	246,084	458,354	722,650
Weighted Average Exercise Price per Share
Weighted average price per share, options outstanding at beginning of year (USD per share)	$ 7.99	$ 7.96	$ 8.95
Weighted average price per share, assumed from acquisition (USD per share)	0	0	8.92
Weighted average price per share, exercised (USD per share)	7.86	7.77	10.21
Weighted average price per share, forfeited/expired (USD per share)	7.65	11.98	12.12
Weighted average price per share, options outstanding and exercisable at end of year (USD per share)	$ 8.14	$ 7.99	$ 7.96

Stock Incentive Plans - Summa_3

Stock Incentive Plans - Summary of Stock Options Outstanding (Detail)	12 Months Ended
	Dec. 31, 2019$ / sharesshares
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Options Outstanding and Exercisable (in shares) | shares	246,084
$3.45 - $5.18
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum (USD per share)	$ 3.45
Range of Exercise Prices, Maximum (USD per share)	$ 5.18
Options Outstanding and Exercisable (in shares) | shares	54,148
Weighted Average Remaining Contractual Years	1 year 3 months 3 days
Weighted Average Exercise Price (USD per share)	$ 4.82
$5.19 - $7.78
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum (USD per share)	5.19
Range of Exercise Prices, Maximum (USD per share)	$ 7.78
Options Outstanding and Exercisable (in shares) | shares	40,022
Weighted Average Remaining Contractual Years	3 years 1 month 9 days
Weighted Average Exercise Price (USD per share)	$ 6.90
$7.79 - $11.37
Share-based Payment Arrangement, Option, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum (USD per share)	7.79
Range of Exercise Prices, Maximum (USD per share)	$ 11.37
Options Outstanding and Exercisable (in shares) | shares	151,914
Weighted Average Remaining Contractual Years	4 years 8 months 15 days
Weighted Average Exercise Price (USD per share)	$ 9.64

Stock Incentive Plans - Summa_4

Stock Incentive Plans - Summary of Stock Options Exercised (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Payment Arrangement [Abstract]
Proceeds from stock options exercised	$ 1	$ 2	$ 2
Intrinsic value of stock options exercised	$ 1	$ 1	$ 1

Retirement Plans - Additional I

Retirement Plans - Additional Information (Detail) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2018USD ($)	Dec. 31, 2019USD ($)Retirement_Planshares	Dec. 31, 2018USD ($)shares	Dec. 31, 2008
Retirement Plans [Line Items]
Corporation contribution	$ 0.9	$ 7	$ 5
Number of supplemental non-qualified retirement plans sponsored by the Corporation | Retirement_Plan		2
Consecutive calendar years used to calculate BRP benefits				5 years
Term of employment for consideration of BRP				10 years
Percentage of non callable corporate bonds		A yield curve was produced for a universe containing the majority of U.S.-issued Aa-graded corporate bonds, all of which were non-callable (or callable with make-whole provisions), and after excluding the 10% of the bonds with the highest and lowest yields.
Benefits paid		$ 12	12
Percent of employer match		100.00%
Employee contribution percentage		6.00%
Additional discretionary contribution, annual financial goals, percentage		3.00%
Dividends received on common stock		$ 0.2	$ 0.3
Common Stock
Retirement Plans [Line Items]
Common stock, shares | shares		469,000	585,000
Percentage of common stock on total plan assets		3.50%	4.00%
Non Qualified Pension Plans
Retirement Plans [Line Items]
Benefits paid		$ 1.5	$ 1.4
Qualified Pension Plans
Retirement Plans [Line Items]
Benefits paid		10	10.1
Retirement Income Plan (RIP)
Retirement Plans [Line Items]
Corporation contribution		$ 5	$ 4

Retirement Plans - Schedule of

Retirement Plans - Schedule of Accumulated Benefit Obligation, Change in Benefit Obligation, Change in Plan Assets, Plans' Funded Status and Amount Included in Consolidated Balance Sheets (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Benefit Obligation
Accumulated benefit obligation		$ 175	$ 163
Projected benefit obligation at beginning of year		163	182
Interest cost		7	6	$ 7
Actuarial loss (gain)		17	(13)
Benefits paid		(12)	(12)
Projected benefit obligation at end of year		175	163	182
Fair Value of Plan Assets
Fair value of plan assets at beginning of year		150	164
Actual return on plan assets		28	(7)
Corporation contribution	$ 0.9	7	5
Benefits paid		(12)	(12)
Fair value of plan assets at end of year		173	150	164
Funded status of plans		(2)	(13)
Qualified Pension Plans
Benefit Obligation
Accumulated benefit obligation		156	145
Projected benefit obligation at beginning of year		145	162
Interest cost		6	6
Actuarial loss (gain)		15	(12)
Benefits paid		(10)	(11)
Projected benefit obligation at end of year		156	145	162
Fair Value of Plan Assets
Fair value of plan assets at beginning of year		150	164
Actual return on plan assets		28	(7)
Corporation contribution		5	4
Benefits paid		(10)	(11)
Fair value of plan assets at end of year		173	150	164
Funded status of plans		17	5
Non Qualified Pension Plans
Benefit Obligation
Accumulated benefit obligation		19	18
Projected benefit obligation at beginning of year		18	20
Interest cost		1	0
Actuarial loss (gain)		2	(1)
Benefits paid		(2)	(1)
Projected benefit obligation at end of year		19	18	20
Fair Value of Plan Assets
Fair value of plan assets at beginning of year		0	0
Actual return on plan assets		0	0
Corporation contribution		2	1
Benefits paid		(2)	(1)
Fair value of plan assets at end of year		0	0	$ 0
Funded status of plans		$ (19)	$ (18)

Retirement Plans - Schedule o_2

Retirement Plans - Schedule of Actuarial Assumptions Used in Determination of Projected Benefit Obligation (Detail)	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Weighted average discount rate	3.17%	4.18%
Rates of average increase in compensation levels	3.50%	3.50%

Retirement Plans - Schedule o_3

Retirement Plans - Schedule of Net Periodic Pension Cost and Other Comprehensive Income (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Interest cost	$ 7	$ 6	$ 7
Expected return on plan assets	(11)	(11)	(11)
Actuarial loss amortization	2	2	2
Total pension income	(2)	(3)	(2)
Current year actuarial loss	1	6	3
Amortization of actuarial loss	(2)	(2)	(2)
Total amount recognized in other comprehensive income	(1)	4	1
Total amount recognized in net periodic benefit cost and other comprehensive income	$ (3)	$ 1	$ (1)

Retirement Plans - Schedule o_4

Retirement Plans - Schedule of Actuarial Assumptions Used in Determination of Net Periodic Pension Cost (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Weighted average discount rate	4.16%	4.19%	3.96%
Rates of increase in compensation levels	3.50%	3.50%	3.50%
Expected long-term rate of return on assets	7.25%	7.25%	7.25%

Retirement Plans - Schedule o_5

Retirement Plans - Schedule of Estimated Future Cash Flows (Detail) $ in Millions	Dec. 31, 2019USD ($)
Retirement Benefits [Abstract]
Expected employer contributions: 2020	$ 2
Expected benefit payments: 2020	10
Expected benefit payments: 2021	10
Expected benefit payments: 2022	10
Expected benefit payments: 2023	10
Expected benefit payments: 2024	11
Expected benefit payments: 2025 - 2029	$ 53

Retirement Plans - Schedule o_6

Retirement Plans - Schedule of Contribution Expense (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
401(k) contribution expense	$ 15	$ 15	$ 12

Retirement Plans - Schedule o_7

Retirement Plans - Schedule of Asset Allocations for Pension Plans (Detail)	Dec. 31, 2019	Dec. 31, 2018
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	60.00%	55.00%
Total debt securities
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	37.00%	41.00%
Cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	3.00%	4.00%
Minimum | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	45.00%
Minimum | Total debt securities
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	30.00%
Minimum | Cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	0.00%
Maximum | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	65.00%
Maximum | Total debt securities
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	50.00%
Maximum | Cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	10.00%

Retirement Plans - Schedule o_8

Retirement Plans - Schedule of Fair Value of Pension Plan Assets by Asset Category (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 173	$ 150	$ 164
Cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	6
Common Stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	6
Other large-cap U.S. financial services companies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	3
Other large-cap U.S. companies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	54	43
International companies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1
Other equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1
U.S. large-cap equity index funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1
U.S. small-cap equity index funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	3
U.S. mid-cap equity index funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	4
Non-U.S. equities growth fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9	6
U.S. mid-cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	9
U.S. small-cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	3
Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	4
U.S. government agencies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	51	49
Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	2
U.S. investment-grade fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	11
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	121	99
Level 1 | Cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	6
Level 1 | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	6
Level 1 | Other large-cap U.S. financial services companies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	3
Level 1 | Other large-cap U.S. companies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	54	43
Level 1 | International companies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		1
Level 1 | Other equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1
Level 1 | U.S. large-cap equity index funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1
Level 1 | U.S. small-cap equity index funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3	3
Level 1 | U.S. mid-cap equity index funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	4
Level 1 | Non-U.S. equities growth fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9	6
Level 1 | U.S. mid-cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	9
Level 1 | U.S. small-cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4	3
Level 1 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5	4
Level 1 | U.S. government agencies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 1 | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 1 | U.S. investment-grade fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12	11
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	52	51
Level 2 | Cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 2 | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 2 | Other large-cap U.S. financial services companies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 2 | Other large-cap U.S. companies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 2 | International companies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Level 2 | Other equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Level 2 | U.S. large-cap equity index funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Level 2 | U.S. small-cap equity index funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 2 | U.S. mid-cap equity index funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 2 | Non-U.S. equities growth fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 2 | U.S. mid-cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 2 | U.S. small-cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 2 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 2 | U.S. government agencies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	51	49
Level 2 | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1	2
Level 2 | U.S. investment-grade fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | Cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | Common Stock
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | Other large-cap U.S. financial services companies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | Other large-cap U.S. companies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | International companies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0
Level 3 | Other equity
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Level 3 | U.S. large-cap equity index funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Level 3 | U.S. small-cap equity index funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | U.S. mid-cap equity index funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | Non-U.S. equities growth fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | U.S. mid-cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | U.S. small-cap
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | U.S. government agencies
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Level 3 | U.S. investment-grade fixed income securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Contingency [Line Items]
Income tax expense				$ 54,000
Tax cuts and jobs act of 2017, change in tax rate, provisional adjustment			$ 1,900
Reclassification due to tax reform	$ 14,700			$ 0
Effective income tax rate		17.70%	17.60%	44.10%
Investment tax credit		$ 7,900	$ 6,500
Operating loss carryforwards, valuation allowance		(28,000)
Unrecognized tax benefits		1,600	$ 900
Unrecognized tax benefits which affect the effective tax rate if recognized		1,400
Reduction in the unrecognized tax benefit due to statutes of limitations for next twelve months		60
Yadkin Financial Corporation (YDKN) | Federal
Income Tax Contingency [Line Items]
Operating loss carryforwards		27,400
Tax credit carryforward		2,000
Yadkin Financial Corporation (YDKN) | State
Income Tax Contingency [Line Items]
Operating loss carryforwards		$ 5,700

Income Taxes - Summary of Incom

Income Taxes - Summary of Income Tax Expense Allocated Based on Separate Tax Return Basis (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Current income taxes: Federal taxes	$ 47	$ 41	$ 26
Current income taxes: State taxes	4	6	2
Total current income taxes	51	47	28
Deferred income taxes: Federal taxes	30	32	128
Deferred income taxes: State taxes	3	0	1
Total deferred income taxes	33	32	129
Total income taxes	$ 84	$ 79	$ 157

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation Between the Statutory Tax Rate and Actual Effective Tax Rate (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Statutory tax rate	21.00%	21.00%	35.00%
State taxes, net of federal benefit	1.10%	1.10%	0.50%
Tax-exempt interest	(2.20%)	(2.10%)	(3.30%)
Cash surrender value of life insurance	(0.50%)	(0.50%)	(1.10%)
Tax credits	(4.20%)	(2.80%)	(2.60%)
TCJA deferred tax corporate rate change	1.40%	0.70%	0.20%
Tax Cuts and Jobs Act revaluation of net deferred tax assets	0	(0.004)	0.152
Other items	1.10%	0.60%	0.20%
Actual effective tax rate	17.70%	17.60%	44.10%
Income tax expense			$ 54

Income Taxes - Income Tax Expen

Income Taxes - Income Tax Expense Related to Net Gains on Sale of Securities (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax expense related to net gains on sale of securities	$ 0	$ 0	$ 2

Income Taxes - Summary of Defer

Income Taxes - Summary of Deferred Tax Assets and Liabilities from Tax Effects of Temporary Differences (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Allowance for credit losses	$ 43	$ 40
Discounts on loans acquired in a business combination	41	51
Net operating loss/tax credit carryforwards	38	43
Deferred compensation	11	10
Securities impairments	1	1
Pension and other defined benefit plans	3	5
Lease liability	29	0
Net unrealized securities losses	2	12
Other	8	9
Total	176	171
Valuation allowance	(28)	(26)
Total deferred tax assets	148	145
Loan costs	(15)	(14)
Depreciation	(19)	(17)
Prepaid expenses	(1)	(1)
Amortizable intangibles	(15)	(16)
Lease financing	(35)	(18)
Mortgage servicing rights	(9)	(8)
Lease ROU asset	(27)	0
Other	(2)	(4)
Total deferred tax liabilities	(123)	(78)
Net deferred tax assets	$ 25	$ 67

Other Comprehensive Income - Ch

Other Comprehensive Income - Changes in AOCI, Net of Tax, by Component (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 4,608
Other comprehensive (loss) income before reclassifications	43
Amounts reclassified from AOCI	(2)
Net current period other comprehensive (loss) income	41
Balance at end of period	4,883
Unrealized Net Gains (Losses) on Debt Securities Available for Sale
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(46)
Other comprehensive (loss) income before reclassifications	57
Amounts reclassified from AOCI	0
Net current period other comprehensive (loss) income	57
Balance at end of period	11
Unrealized Net Gains (Losses) on Derivative Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	1
Other comprehensive (loss) income before reclassifications	(17)
Amounts reclassified from AOCI	(2)
Net current period other comprehensive (loss) income	(19)
Balance at end of period	(18)
Unrecognized Pension and Postretirement Obligations
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(61)
Other comprehensive (loss) income before reclassifications	3
Amounts reclassified from AOCI	0
Net current period other comprehensive (loss) income	3
Balance at end of period	(58)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(106)
Balance at end of period	$ (65)

Earnings Per Common Share - Com

Earnings Per Common Share - Computation of Basic and Diluted Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net income	$ 95	$ 103	$ 95	$ 94	$ 100	$ 101	$ 85	$ 87	$ 387	$ 373	$ 199
Less: Preferred stock dividends									8	8	8
Net Income Available to Common Stockholders	$ 93	$ 101	$ 93	$ 92	$ 98	$ 99	$ 83	$ 85	$ 379	$ 365	$ 191
Basic weighted average common shares outstanding (in shares)									324,938,720	324,207,198	302,195,295
Net effect of dilutive stock options, warrants and restricted stock (in shares)									1,122,418	1,416,405	1,662,681
Diluted weighted average common shares outstanding (in shares)									326,061,138	325,623,603	303,857,976
Earnings per common share:
Basic (in usd per share)	$ 0.29	$ 0.31	$ 0.29	$ 0.28	$ 0.30	$ 0.30	$ 0.26	$ 0.26	$ 1.17	$ 1.13	$ 0.63
Diluted (in usd per share)	$ 0.29	$ 0.31	$ 0.29	$ 0.28	$ 0.30	$ 0.30	$ 0.26	$ 0.26	$ 1.16	$ 1.12	$ 0.63

Earnings Per Common Share - Sch

Earnings Per Common Share - Schedule of Average Shares Excluded from Diluted Earnings Per Common Share Calculation (Detail) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Average shares excluded from the diluted earnings per common share calculation (in shares)	0	81	910

Regulatory Matters - Schedule o

Regulatory Matters - Schedule of Capital Ratios (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital, actual amount	$ 3,174	$ 2,875
Tier 1 capital, actual amount	2,632	2,395
Common equity tier 1, actual amount	2,525	2,289
Leverage, actual amount	2,632	2,395
Risk weighted assets, actual amount	$ 26,866	$ 24,900
Total capital, actual ratio	11.81%	11.54%
Total capital, actual ratio tier 1 capital, actual ratio	9.79%	9.62%
Common equity tier 1, actual ratio	9.40%	9.19%
Leverage, actual ratio	8.20%	7.87%
Total capital, well-capitalized requirements amount	$ 2,687	$ 2,490
Tier 1 capital, well-capitalized requirements amount	$ 1,612	$ 1,608
Total capital, well-capitalized requirements ratio	10.00%	10.00%
Tier 1 capital, well-capitalized requirements ratio	6.00%	6.00%
Total capital, minimum capital requirements amount	$ 2,821	$ 2,459
Tier 1 capital, minimum capital requirements amount	2,284	1,961
Common equity tier 1, minimum capital requirements amount	1,881	1,588
Leverage, minimum capital requirements amount	$ 1,283	$ 1,218
Total capital, minimum capital requirements ratio	10.50%	9.88%
Tier 1 capital, minimum capital requirements ratio	8.50%	7.88%
Common equity tier 1, minimum capital requirements ratio	7.00%	6.38%
Leverage, minimum capital requirements ratio	4.00%	4.00%
FNBPA
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital, actual amount	$ 3,039	$ 2,735
Tier 1 capital, actual amount	2,841	2,553
Common equity tier 1, actual amount	2,761	2,473
Leverage, actual amount	2,841	2,553
Risk weighted assets, actual amount	$ 26,806	$ 24,894
Total capital, actual ratio	11.34%	10.99%
Total capital, actual ratio tier 1 capital, actual ratio	10.60%	10.26%
Common equity tier 1, actual ratio	10.30%	9.94%
Leverage, actual ratio	8.87%	8.39%
Total capital, well-capitalized requirements amount	$ 2,681	$ 2,489
Tier 1 capital, well-capitalized requirements amount	2,144	1,992
Common equity tier 1, well-capitalized requirements amount	1,742	1,618
Leverage, well-capitalized requirements amount	$ 1,601	$ 1,521
Total capital, well-capitalized requirements ratio	10.00%	10.00%
Tier 1 capital, well-capitalized requirements ratio	8.00%	8.00%
Common equity tier 1, well-capitalized requirements ratio	6.50%	6.50%
Leverage, well-capitalized requirements ratio	5.00%	5.00%
Total capital, minimum capital requirements amount	$ 2,815	$ 2,458
Tier 1 capital, minimum capital requirements amount	2,279	1,960
Common equity tier 1, minimum capital requirements amount	1,876	1,587
Leverage, minimum capital requirements amount	$ 1,281	$ 1,217
Total capital, minimum capital requirements ratio	10.50%	9.88%
Tier 1 capital, minimum capital requirements ratio	8.50%	7.88%
Common equity tier 1, minimum capital requirements ratio	7.00%	6.38%
Leverage, minimum capital requirements ratio	4.00%	4.00%

Regulatory Matters - Additional

Regulatory Matters - Additional Information (Detail) $ in Millions	Dec. 31, 2019USD ($)
Banking and Thrift [Abstract]
Aggregate cash reserves with FRB (less than)	$ 1
Retained earnings available for distribution	527.3
Maximum amount loans that corporation can borrower under current provisions	$ 598.3

Cash Flow Information - Summary

Cash Flow Information - Summary of Cash Flow Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Cash Flows [Abstract]
Interest paid on deposits and other borrowings	$ 329	$ 230	$ 129
Income taxes paid	40	19	53
Transfers of loans to other real estate owned	15	12	35
Loans transferred to held for sale from portfolio	389	0	0
Loans transferred to portfolio from held for sale	$ 110	$ 0	$ 0

Business Segments - Additional

Business Segments - Additional Information (Detail) - Segment	1 Months Ended	12 Months Ended
	Aug. 31, 2018	Dec. 31, 2019
Segment Reporting Information [Line Items]
Number of reportable segments		3
Mariner Finance, LLC
Segment Reporting Information [Line Items]
Stock purchase agreement, stock sold, percentage	100.00%

Business Segments - Financial I

Business Segments - Financial Information for Segments of FNB (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Interest income	$ 306	$ 314	$ 317	$ 310	$ 305	$ 298	$ 294	$ 273	$ 1,247	$ 1,170	$ 980
Interest expense	80	84	87	79	74	63	54	47	330	238	134
Net Interest Income	226	230	230	231	231	235	240	226	917	932	846
Provision for credit losses	7	12	11	14	15	16	16	14	44	61	61
Non-interest income	74	80	75	65	69	75	65	67	294	276	252
Non-interest expense									682	679	663
Amortization of intangibles									14	16	18
Income tax expense (benefit)									84	79	157
Net income (loss)	95	$ 103	$ 95	$ 94	100	$ 101	$ 85	$ 87	387	373	199
Total assets	34,615				33,102				34,615	33,102	31,418
Total intangibles	2,329				2,334				2,329	2,334	2,341
Operating Segments | Community Banking
Segment Reporting Information [Line Items]
Interest income									1,245	1,145	944
Interest expense									310	219	118
Net Interest Income									935	926	826
Provision for credit losses									44	54	53
Non-interest income									237	213	197
Non-interest expense									621	609	597
Amortization of intangibles									13	15	17
Income tax expense (benefit)									88	82	153
Net income (loss)									406	379	203
Total assets	34,491				32,997				34,491	32,997	31,156
Total intangibles	2,291				2,304				2,291	2,304	2,317
Operating Segments | Wealth Management
Segment Reporting Information [Line Items]
Interest income									0	0	0
Interest expense									0	0	0
Net Interest Income									0	0	0
Provision for credit losses									0	0	0
Non-interest income									46	44	39
Non-interest expense									34	33	30
Amortization of intangibles									0	1	1
Income tax expense (benefit)									3	2	3
Net income (loss)									9	8	5
Total assets	32				26				32	26	24
Total intangibles	10				10				10	10	10
Operating Segments | Insurance
Segment Reporting Information [Line Items]
Interest income									0	0	0
Interest expense									0	0	0
Net Interest Income									0	0	0
Provision for credit losses									0	0	0
Non-interest income									20	16	16
Non-interest expense									17	17	15
Amortization of intangibles									1	0	0
Income tax expense (benefit)									0	0	0
Net income (loss)									2	(1)	1
Total assets	35				25				35	25	21
Total intangibles	28				20				28	20	12
Operating Segments | Consumer Finance
Segment Reporting Information [Line Items]
Interest income										25	40
Interest expense										2	4
Net Interest Income										23	36
Provision for credit losses										6	8
Non-interest income										2	3
Non-interest expense										15	21
Amortization of intangibles										0	0
Income tax expense (benefit)										1	5
Net income (loss)										3	5
Total assets					0					0	181
Total intangibles					0					0	2
Parent and Other
Segment Reporting Information [Line Items]
Interest income									2	0	(4)
Interest expense									20	17	12
Net Interest Income									(18)	(17)	(16)
Provision for credit losses									0	1	0
Non-interest income									(9)	1	(3)
Non-interest expense									10	5	0
Amortization of intangibles									0	0	0
Income tax expense (benefit)									(7)	(6)	(4)
Net income (loss)									(30)	(16)	(15)
Total assets	57				54				57	54	36
Total intangibles	$ 0				$ 0				$ 0	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value Measurements Disclosure [Line Items]
Percentage of securities using market-based information	100.00%
Minimum reserves for commercial loan	$ 1,000,000
Transfer of equity security to non-marketable equity securities, included in other assets	0	$ 0
Retained earnings	798,000,000	576,000,000
Allocated allowance for loan losses	3,700,000
Provision for fair value measurements included in allowance for loan losses	6,200,000
Carrying amount of OREO	3,600,000
Written down of OREO	2,200,000
Loss from OREO included in earnings	$ 1,400,000
Short-term borrowings approximate fair value for amounts that mature, days, less than	90 days
Fair value, measurements, nonrecurring
Fair Value Measurements Disclosure [Line Items]
Impaired loans, carrying amount	$ 4,800,000
Allocated allowance for loan losses	5,000,000	15,000,000
Mortgage Servicing Rights
Fair Value Measurements Disclosure [Line Items]
Valuation allowance for impairment of recognized servicing assets, balance	1,500,000	500,000
Mortgage Servicing Rights | Fair value, measurements, nonrecurring
Fair Value Measurements Disclosure [Line Items]
Servicing asset	31,400,000
Valuation allowance for impairment of recognized servicing assets, balance	1,500,000
Servicing asset, carrying value	29,900,000
Valuation allowance for impairment of recognized servicing assets, provision expense	$ 1,000,000
Accounting Standards Update 2016-01
Fair Value Measurements Disclosure [Line Items]
Retained earnings		$ 600,000

Fair Value Measurements - Balan

Fair Value Measurements - Balances of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		$ 3,289	$ 3,341
Loans held for sale	[1]	41	14
Derivative financial instruments		154	43
Derivative financial instruments		25	39
U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		151	187
U.S. government-sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		226	313
Agency collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		1,240	1,161
Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		345	228
States of the U.S. and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		11	21
Other debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		2	2
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Derivative financial instruments		0	0
Derivative financial instruments		0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		3,289	3,341
Derivative financial instruments		151	42
Derivative financial instruments		25	39
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Derivative financial instruments		3	1
Derivative financial instruments		0	0
Fair value, measurements, recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		3,289	3,341
Loans held for sale		41	14
Derivative financial instruments		154	43
Assets, Fair Value Disclosure		3,484	3,398
Derivative financial instruments		25	39
Financial Liabilities Fair Value Disclosure		25	39
Fair value, measurements, recurring | U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		151	187
Fair value, measurements, recurring | U.S. government-sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		226	313
Fair value, measurements, recurring | Agency mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		1,314	1,429
Fair value, measurements, recurring | Agency collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		1,240	1,161
Fair value, measurements, recurring | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		345	228
Fair value, measurements, recurring | States of the U.S. and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		11	21
Fair value, measurements, recurring | Other debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		2	2
Fair value, measurements, recurring | Trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		149	43
Fair value, measurements, recurring | Not for trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		5
Fair value, measurements, recurring | Trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		24	36
Fair value, measurements, recurring | Not for trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		1	3
Fair value, measurements, recurring | Level 1
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 financial instruments		0	0
Assets, Fair Value Disclosure		0	0
Derivative financial instruments		0	0
Financial Liabilities Fair Value Disclosure		0	0
Fair value, measurements, recurring | Level 1 | U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Fair value, measurements, recurring | Level 1 | U.S. government-sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Fair value, measurements, recurring | Level 1 | Agency mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Fair value, measurements, recurring | Level 1 | Agency collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Fair value, measurements, recurring | Level 1 | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Fair value, measurements, recurring | Level 1 | States of the U.S. and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Fair value, measurements, recurring | Level 1 | Other debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Fair value, measurements, recurring | Level 1 | Trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		0	0
Fair value, measurements, recurring | Level 1 | Not for trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		0
Fair value, measurements, recurring | Level 1 | Trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		0	0
Fair value, measurements, recurring | Level 1 | Not for trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		0	0
Fair value, measurements, recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		3,289	3,341
Loans held for sale		41	14
Derivative financial instruments		151	42
Assets, Fair Value Disclosure		3,481	3,397
Derivative financial instruments		25	39
Financial Liabilities Fair Value Disclosure		25	39
Fair value, measurements, recurring | Level 2 | U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		151	187
Fair value, measurements, recurring | Level 2 | U.S. government-sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		226	313
Fair value, measurements, recurring | Level 2 | Agency mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		1,314	1,429
Fair value, measurements, recurring | Level 2 | Agency collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		1,240	1,161
Fair value, measurements, recurring | Level 2 | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		345	228
Fair value, measurements, recurring | Level 2 | States of the U.S. and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		11	21
Fair value, measurements, recurring | Level 2 | Other debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		2	2
Fair value, measurements, recurring | Level 2 | Trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		149	42
Fair value, measurements, recurring | Level 2 | Not for trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		2
Fair value, measurements, recurring | Level 2 | Trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		24	36
Fair value, measurements, recurring | Level 2 | Not for trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		1	3
Fair value, measurements, recurring | Level 3
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 financial instruments		3	1
Assets, Fair Value Disclosure		3	1
Derivative financial instruments		0	0
Financial Liabilities Fair Value Disclosure		0	0
Fair value, measurements, recurring | Level 3 | U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Fair value, measurements, recurring | Level 3 | U.S. government-sponsored entities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Fair value, measurements, recurring | Level 3 | Agency mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Fair value, measurements, recurring | Level 3 | Agency collateralized mortgage obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Fair value, measurements, recurring | Level 3 | Commercial mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Fair value, measurements, recurring | Level 3 | States of the U.S. and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Fair value, measurements, recurring | Level 3 | Other debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt securities available for sale		0	0
Fair value, measurements, recurring | Level 3 | Trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		0	1
Fair value, measurements, recurring | Level 3 | Not for trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		3
Fair value, measurements, recurring | Level 3 | Trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		0	0
Fair value, measurements, recurring | Level 3 | Not for trading
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative financial instruments		$ 0	$ 0
[1]	Amount represents loans for which we have elected the fair value option. See Note 24.

Fair Value Measurements - Add_2

Fair Value Measurements - Additional Information about Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Document Period End Date	Dec. 31, 2019
Fair value, measurements, recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 1	$ 2
Issuances	3	5
Settlements	(1)	(6)
Balance at end of period	3	1
Interest Rate Lock Commitments | Fair value, measurements, recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	1	2
Issuances	3	5
Settlements	(1)	(6)
Balance at end of period	$ 3	$ 1

Fair Value Measurements - Add_3

Fair Value Measurements - Additional Information about Assets Measured at Fair Value on Non-Recurring Basis (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ 3.7
Fair value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	5	$ 15
Other real estate owned	4	5
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0	0
Level 1 | Fair value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Other real estate owned	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0	0
Level 2 | Fair value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	0	0
Other real estate owned	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	48	45
Level 3 | Fair value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	5	15
Other real estate owned	4	5
SBA-Guaranteed Loan Servicing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	3	4	$ 5	$ 0
SBA-Guaranteed Loan Servicing | Fair value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	3	4
SBA-Guaranteed Loan Servicing | Level 1 | Fair value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0	0
SBA-Guaranteed Loan Servicing | Level 2 | Fair value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0	0
SBA-Guaranteed Loan Servicing | Level 3 | Fair value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	3	4
Mortgage Servicing Rights
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	45	$ 41	$ 32	$ 18
Mortgage Servicing Rights | Fair value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	30
Mortgage Servicing Rights | Level 1 | Fair value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0
Mortgage Servicing Rights | Level 2 | Fair value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	0
Mortgage Servicing Rights | Level 3 | Fair value, measurements, nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other assets	$ 30

Fair Value Measurements - Fair

Fair Value Measurements - Fair Values of Corporation's Financial Instruments (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Financial Assets
Cash and cash equivalents	$ 599	$ 488
Debt securities available for sale	3,289	3,341
Securities held to maturity	3,275	3,254
Securities held to maturity	3,305	3,155
Derivative financial instruments	154	43
Financial Liabilities
Deposits	24,786	23,455
Short-term borrowings	3,216	4,129
Long-term borrowings	1,340	627
Long-term borrowings	249
Derivative liabilities	25	39
Carrying Amount
Financial Assets
Cash and cash equivalents	599	488
Debt securities available for sale	3,289	3,341
Securities held to maturity	3,275	3,254
Net loans and leases, including loans held for sale	23,144	21,995
Loan servicing rights	46	41
Derivative financial instruments	154	43
Accrued interest receivable	109	101
Financial Liabilities
Deposits	24,786	23,455
Short-term borrowings	3,216	4,129
Long-term borrowings	1,340	627
Derivative liabilities	25	39
Accrued interest payable	21	20
Fair Value
Financial Assets
Cash and cash equivalents	599	488
Debt securities available for sale	3,289	3,341
Securities held to maturity	3,305	3,155
Net loans and leases, including loans held for sale	22,930	21,742
Loan servicing rights	48	45
Derivative financial instruments	154	43
Accrued interest receivable	109	101
Financial Liabilities
Deposits	24,797	23,411
Short-term borrowings	3,219	4,130
Long-term borrowings	1,355	618
Derivative liabilities	25	39
Accrued interest payable	21	20
Level 1
Financial Assets
Cash and cash equivalents	599	488
Debt securities available for sale	0	0
Securities held to maturity	0	0
Net loans and leases, including loans held for sale	0	0
Loan servicing rights	0	0
Derivative financial instruments	0	0
Accrued interest receivable	109	101
Financial Liabilities
Deposits	20,058	18,142
Short-term borrowings	3,219	4,130
Long-term borrowings	0	0
Derivative liabilities	0	0
Accrued interest payable	21	20
Level 2
Financial Assets
Cash and cash equivalents	0	0
Debt securities available for sale	3,289	3,341
Securities held to maturity	3,305	3,155
Net loans and leases, including loans held for sale	41	14
Loan servicing rights	0	0
Derivative financial instruments	151	42
Accrued interest receivable	0	0
Financial Liabilities
Deposits	4,739	5,269
Short-term borrowings	0	0
Long-term borrowings	0	0
Derivative liabilities	25	39
Accrued interest payable	0	0
Level 3
Financial Assets
Cash and cash equivalents	0	0
Debt securities available for sale	0	0
Securities held to maturity	0	0
Net loans and leases, including loans held for sale	22,889	21,728
Loan servicing rights	48	45
Derivative financial instruments	3	1
Accrued interest receivable	0	0
Financial Liabilities
Deposits	0	0
Short-term borrowings	0	0
Long-term borrowings	1,355	618
Derivative liabilities	0	0
Accrued interest payable	$ 0	$ 0

Parent Company Financial Stat_3

Parent Company Financial Statements - Consolidated Balance Sheet of Parent Company Only (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 599	$ 488
Other assets	1,102	823
Total Assets	34,615	33,102	$ 31,418
Other liabilities	390	283
Long-term borrowings	1,340	627
Long-term	90	87
Total Liabilities	29,732	28,494
Stockholders' Equity	4,883	4,608	$ 4,409	$ 2,572
Total Liabilities and Stockholders’ Equity	34,615	33,102
Parent Company
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	251	254
Other assets	18	19
Total Assets	5,445	5,124
Other liabilities	34	32
Advances from affiliates	197	197
Long-term borrowings	323	279
Short-term	7	7
Long-term	1	1
Total Liabilities	562	516
Stockholders' Equity	4,883	4,608
Total Liabilities and Stockholders’ Equity	5,445	5,124
Parent Company | Bank Subsidiary
Condensed Balance Sheet Statements, Captions [Line Items]
Investment in and advances to subsidiaries	5,072	4,754
Parent Company | Non-bank Subsidiaries
Condensed Balance Sheet Statements, Captions [Line Items]
Investment in and advances to subsidiaries	$ 104	$ 97

Parent Company Financial Stat_4

Parent Company Financial Statements - Statements of Income of Parent Company Only (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Income Statements, Captions [Line Items]
Interest income	$ 306	$ 314	$ 317	$ 310	$ 305	$ 298	$ 294	$ 273	$ 1,247	$ 1,170	$ 980
Other income									4	1	1
Interest expense	80	84	87	79	74	63	54	47	330	238	134
Income tax benefit									(84)	(79)	(157)
Net income	95	$ 103	$ 95	$ 94	100	$ 101	$ 85	$ 87	387	373	199
Parent Company
Condensed Income Statements, Captions [Line Items]
Dividend income from subsidiaries:									181	170	158
Interest income									0	4	5
Other income									0	5	0
Total Income									181	179	163
Interest expense									19	20	18
Other expenses									18	15	10
Total Expenses									37	35	28
Income Before Taxes and Equity in Undistributed Income of Subsidiaries									144	144	135
Income tax benefit									7	6	3
Income after income taxes									151	150	138
Equity in undistributed income (loss) of subsidiaries:	236				222				236	222	61
Net income									387	373	199
Parent Company | Bank
Condensed Income Statements, Captions [Line Items]
Dividend income from subsidiaries:									179	162	149
Equity in undistributed income (loss) of subsidiaries:	236				225				236	225	60
Parent Company | Non-Bank
Condensed Income Statements, Captions [Line Items]
Dividend income from subsidiaries:									2	8	9
Equity in undistributed income (loss) of subsidiaries:	$ 0				$ (2)				$ 0	$ (2)	$ 1

Parent Company Financial Stat_5

Parent Company Financial Statements - Statements of Cash Flows of Parent Company Only (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Activities
Net income	$ 95	$ 103	$ 95	$ 94	$ 100	$ 101	$ 85	$ 87	$ 387	$ 373	$ 199
Other, net									(225)	(27)	(98)
Net cash flows provided by operating activities									259	611	279
Investing Activities
Proceeds from sale of securities available for sale									0	0	787
Net cash flows used in investing activities									(1,131)	(1,920)	(1,529)
Financing Activities
Decrease in long-term debt									(239)	(77)	(199)
Increase in long-term debt									954	37	155
Net proceeds from issuance of common stock									12	14	11
Preferred stock									(8)	(8)	(8)
Common stock									(157)	(157)	(143)
Net cash flows provided by financing activities									983	1,318	1,358
Net (Decrease) Increase in Cash and Cash Equivalents									111	9	108
Cash and cash equivalents at beginning of year				488				479	488	479	371
Cash and Cash Equivalents at End of Year	599				488				599	488	479
Interest									329	230	129
Parent Company
Operating Activities
Net income									387	373	199
Undistributed earnings from subsidiaries	(236)				(222)				(236)	(222)	(61)
Other, net									2	(13)	6
Net cash flows provided by operating activities									153	138	144
Investing Activities
Proceeds from sale of securities available for sale									0	1	0
Net (increase) decrease in advances to subsidiaries									0	20	(10)
Payment for further investment in subsidiaries									(47)	(22)	(4)
Net cash received in business combinations									0	123	3
Net cash flows used in investing activities									(47)	122	(11)
Financing Activities
Net decrease in advance from affiliate									0	(19)	10
Net decrease in short-term borrowings									0	(1)	0
Decrease in long-term debt									(77)	(2)	(2)
Increase in long-term debt									121	1	1
Net proceeds from issuance of common stock									12	14	11
Preferred stock									(8)	(8)	(8)
Common stock									(157)	(157)	(143)
Net cash flows provided by financing activities									(109)	(172)	(131)
Net (Decrease) Increase in Cash and Cash Equivalents									(3)	88	2
Cash and cash equivalents at beginning of year				$ 254				$ 166	254	166	164
Cash and Cash Equivalents at End of Year	$ 251				$ 254				251	254	166
Interest									$ 20	$ 17	$ 16

Quarterly Earnings Summary (U_3

Quarterly Earnings Summary (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Quarterly Earnings Summary (Unaudited) [Abstract]
Interest income	$ 306	$ 314	$ 317	$ 310	$ 305	$ 298	$ 294	$ 273	$ 1,247	$ 1,170	$ 980
Interest expense	80	84	87	79	74	63	54	47	330	238	134
Net Interest Income	226	230	230	231	231	235	240	226	917	932	846
Provision for credit losses	7	12	11	14	15	16	16	14	44	61	61
Total non-interest income	74	80	75	65	69	75	65	67	294	276	252
Total non-interest expense	177	178	175	166	170	171	183	171	696	695	681
Net income	95	103	95	94	100	101	85	87	387	373	199
Net income available to common stockholders	$ 93	$ 101	$ 93	$ 92	$ 98	$ 99	$ 83	$ 85	$ 379	$ 365	$ 191
Earnings per Common Share
Basic (in usd per share)	$ 0.29	$ 0.31	$ 0.29	$ 0.28	$ 0.30	$ 0.30	$ 0.26	$ 0.26	$ 1.17	$ 1.13	$ 0.63
Diluted (in usd per share)	$ 0.29	$ 0.31	$ 0.29	$ 0.28	$ 0.30	$ 0.30	$ 0.26	$ 0.26	$ 1.16	$ 1.12	$ 0.63

Mergers and Acquisitions - Addi

Mergers and Acquisitions - Additional Information (Detail) $ / shares in Units, $ in Millions	Mar. 11, 2017USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / shares	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Business Acquisition [Line Items]
Goodwill recorded as a result of merger		$ 2,262	$ 2,255	$ 2,249
Merger-related expenses		$ 0	$ 0	57
Warrant Expires in 2019
Business Acquisition [Line Items]
Warrant issued, exercise price (in usd per share) | $ / shares		$ 11.52
Yadkin Financial Corporation (YDKN)
Business Acquisition [Line Items]
Assets acquired as a result of merger	$ 6,800
Loans acquired as a result of merger	5,100
Deposits acquired as a result of merger	5,200
Value of acquisition	$ 1,800
Common stock closing price (in usd per share) | $ / shares	$ 15.97
Common shares issued (in shares) | shares	111,619,622
Common shares to be acquired, shares (in shares) | shares	51,677,565
Number of shares entitled to receive as per merger agreement, Ratio	2.16
Goodwill recorded as a result of merger	$ 1,200
Core deposit intangibles recorded as result of the acquisition	$ 70
Merger-related expenses				$ 56.2
Percentage of contract termination cost				30.90%
Issuance costs incurred in connection with acquisition				$ 0.6
Yadkin Financial Corporation (YDKN) | Merger - Related Expenses
Business Acquisition [Line Items]
Severance costs				24.30%
Yadkin Financial Corporation (YDKN) | Warrant Expires in 2019
Business Acquisition [Line Items]
Warrant issued, shares (in shares) | shares	207,320
Warrant issued, exercise price (in usd per share) | $ / shares	$ 9.63