United Bankshares (UBSI) 10-K 2 Mar 20 2019 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2019	Jan. 31, 2020	Jun. 30, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Transition Report	false
Document Fiscal Year Focus	2019
Document Period End Date	Dec. 31, 2019
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Registrant Name	UNITED BANKSHARES INC/WV
Entity Central Index Key	0000729986
Entity Current Reporting Status	Yes
Trading Symbol	UBSI
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		101,568,065
Entity Public Float			$ 3,582,635,223
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock
Entity File Number	002-86947
Security Exchange Name	NASDAQ
Entity Tax Identification Number	55-0641179
Entity Address, Address Line One	300 United Center
Entity Address, Address Line Two	500 Virginia Street, East
Entity Address, City or Town	Charleston
Entity Address, State or Province	WV
Entity Address, Postal Zip Code	25301
City Area Code	304
Local Phone Number	424-8716
Entity Incorporation, State or Country Code	WV
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Assets
Cash and due from banks	$ 185,238	$ 187,886
Interest-bearing deposits with other banks	651,435	831,707
Federal funds sold	820	803
Total cash and cash equivalents	837,493	1,020,396
Securities available for sale at estimated fair value (amortized cost-$2,426,924 at December 31, 2019 and $2,360,884 at December 31, 2018)	2,437,296	2,337,039
Securities held to maturity (estimated fair value-$1,447 at December 31, 2019 and $18,655 at December 31, 2018)	1,446	19,999
Equity securities at estimated fair value	8,894	9,734
Other investment securities	222,161	176,955
Loans held for sale (at fair value-$384,375 at December 31, 2019 and $247,104 at December 31, 2018)	387,514	249,846
Loans	13,713,548	13,429,532
Less: Unearned income	(1,419)	(7,310)
Loans net of unearned income	13,712,129	13,422,222
Less: Allowance for loan losses	(77,057)	(76,703)
Net loans	13,635,072	13,345,519
Bank premises and equipment	96,644	95,245
Operating lease right of-use asset	57,783	0
Goodwill	1,478,014	1,478,014
Accrued interest receivable	58,085	60,597
Other assets	441,922	457,154
TOTAL ASSETS	19,662,324	19,250,498
Deposits:
Noninterest-bearing	4,621,362	4,416,815
Interest-bearing	9,231,059	9,577,934
Total deposits	13,852,421	13,994,749
Borrowings:
Federal funds purchased	0	23,400
Securities sold under agreements to repurchase	124,654	152,927
Federal Home Loan Bank borrowings	1,851,865	1,439,198
Other long-term borrowings	236,164	234,905
Reserve for lending-related commitments	1,733	1,389
Operating lease liability	61,342	0
Accrued expenses and other liabilities	170,312	152,306
TOTAL LIABILITIES	16,298,491	15,998,874
Shareholders' Equity
Preferred stock, $1.00 par value; Authorized-50,000,000 shares, none issued	0	0
Common stock, $2.50 par value; Authorized-200,000,000 shares; issued-105,494,290 and 105,239,121 at December 31, 2019 and December 31, 2018, respectively, including 3,940,619 and 2,915,633 shares in treasury at December 31, 2019 and December 31, 2018, respectively	263,736	263,098
Surplus	2,140,175	2,134,462
Retained earnings	1,132,579	1,013,037
Accumulated other comprehensive loss	(34,869)	(57,019)
Treasury stock, at cost	(137,788)	(101,954)
TOTAL SHAREHOLDERS' EQUITY	3,363,833	3,251,624
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 19,662,324	$ 19,250,498

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Securities available for sale, amortized cost	$ 2,426,924	$ 2,360,884
Securities held to maturity	1,447	18,655
Loans held for sale at fair value	$ 384,375	$ 247,104
Preferred stock, par value	$ 1	$ 1
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$ 2.50	$ 2.50
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	105,494,290	105,239,121
Common stock, shares in treasury	3,940,619	2,915,633

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interest income
Interest and fees on loans	$ 666,950	$ 636,720	$ 565,537
Interest on federal funds sold and other short-term investments	21,338	19,268	16,035
Interest and dividends on securities:
Taxable	70,789	56,273	36,715
Tax-exempt	3,485	5,454	5,519
Total interest income	762,562	717,715	623,806
Interest expense
Interest on deposits	135,649	91,507	49,726
Interest on short-term borrowings	2,347	2,245	1,579
Interest on long-term borrowings	46,644	35,318	23,504
Total interest expense	184,640	129,070	74,809
Net interest income	577,922	588,645	548,997
Provision for loan losses	21,313	22,013	28,406
Net interest income after provision for loan losses	556,609	566,632	520,591
Other income
Income from bank-owned life insurance	7,339	5,045	5,110
Net gain on the sale of bank premises	0	2,763	0
Net investment securities gains (losses)	175	(2,618)	5,584
Other income	1,327	1,767	2,039
Total other income	150,484	128,712	131,645
Other expense
Employee compensation	173,962	164,468	166,393
Employee benefits	35,745	36,172	34,997
Net occupancy expense	34,850	36,462	39,067
Other real estate owned (OREO) expense	5,336	3,444	6,003
Equipment expense	14,210	13,846	10,528
Data processing expense	22,232	23,800	21,019
Bankcard processing expense	1,877	1,971	1,809
FDIC insurance expense	8,070	11,464	7,051
FHLB prepayment penalties	5,105	0	0
Other expense	81,267	76,552	80,542
Total other expense	382,654	368,179	367,409
Income before income taxes	324,439	327,165	284,827
Income taxes	64,340	70,823	134,246
Net income	$ 260,099	$ 256,342	$ 150,581
Earnings per common share:
Basic	$ 2.55	$ 2.46	$ 1.54
Diluted	2.55	2.45	1.54
Dividends per common share	$ 1.37	$ 1.36	$ 1.33
Average outstanding shares:
Basic	101,585,599	104,015,976	97,502,633
Diluted	101,852,577	104,298,825	97,890,078
Fees From Trust Services [Member]
Other income
Revenue from contract	$ 13,873	$ 12,930	$ 11,801
Fees from Brokerage Services [Member]
Other income
Revenue from contract	10,136	9,347	7,730
Fees from Deposit Services [Member]
Other income
Revenue from contract	33,768	33,973	33,622
Bankcard Fees and Merchant Discounts [Member]
Other income
Revenue from contract	4,674	5,168	4,795
Other Service Charges, Commissions, and Fees [Member]
Other income
Revenue from contract	2,241	2,228	2,057
Mortgage Banking [Member]
Other income
Revenue from contract	$ 76,951	$ 58,109	$ 58,907

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	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
Statement of Comprehensive Income [Abstract]
Net income	$ 63,285	$ 65,965	$ 67,207	$ 63,642	$ 63,950	$ 64,412	$ 66,274	$ 61,706	$ 260,099	$ 256,342	$ 150,581
Change in net unrealized gain (loss) on available-for-sale (AFS) securities, net of tax									26,245	(9,015)	4,093
Accretion of the net unrealized loss on the transfer of AFS securities to held-to-maturity (HTM) securities, net of tax									0	6	5
Change in defined benefit pension plan, net of tax									(4,145)	504	(1,406)
Comprehensive income, net of tax									$ 282,199	$ 247,837	$ 153,273

Consolidated Statement of Chang

Consolidated Statement of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Beginning Balance at Dec. 31, 2016	$ 2,235,747	$ 202,671	$ 1,205,778	$ 872,990	$ (44,717)	$ (975)
Beginning Balance, shares at Dec. 31, 2016		81,068,252
Net income	150,581	$ 0	0	150,581	0	0
Other comprehensive income, net of tax	2,692	0	0	0	2,692	0
Comprehensive income, net of tax	153,273
Stock based compensation expense	3,555	0	3,555	0	0	0
Acquisition, Values	975,254	$ 59,226	916,028	0	0	0
Acquisition, Shares		23,690,589
Purchase of treasury stock	(1)	$ 0	0	0	0	(1)
Distribution of treasury stock for deferred compensation plan	1	0	0	0	0	1
Cash dividends	(131,755)	0	0	(131,755)	0	0
Grant of restricted stock	$ 0	$ 225	(225)	0	0	0
Grant of restricted stock, shares	90,075	90,075
Forfeiture of restricted stock	$ 0	$ 0	38	0	0	(38)
Common stock options exercised	4,456	$ 553	3,903	0	0	0
Common stock options exercised, shares		220,905
Ending Balance at Dec. 31, 2017	3,240,530	$ 262,675	2,129,077	891,816	(42,025)	(1,013)
Ending Balance, shares at Dec. 31, 2017		105,069,821
Cumulative effect of adopting Accounting Standard Update	0			136	(136)
Reclass due to adopting Accounting Standard Update	0			6,353	(6,353)
Net income	256,342	$ 0	0	256,342	0	0
Other comprehensive income, net of tax	(8,505)	0	0	0	(8,505)	0
Comprehensive income, net of tax	247,837
Stock based compensation expense	4,073	0	4,073		0	0
Purchase of treasury stock	(100,724)	0	0	0	0	(100,724)
Distribution of treasury stock for deferred compensation plan	1	0	0	0	0	1
Cash dividends	(141,610)	0	0	(141,610)	0	0
Grant of restricted stock	$ 0	$ 243	(243)	0	0	0
Grant of restricted stock, shares	97,004	97,004
Forfeiture of restricted stock	$ 0	$ 0	(218)	0	0	(218)
Common stock options exercised	$ 1,517	$ 180	1,337	0	0	0
Common stock options exercised, shares	72,296	72,296
Ending Balance at Dec. 31, 2018	$ 3,251,624	$ 263,098	2,134,462	1,013,037	(57,019)	(101,954)
Ending Balance, shares at Dec. 31, 2018		105,239,121
Cumulative effect of adopting Accounting Standard Update	(1,049)	$ 0	0	(1,049)	0	0
Reclass due to adopting Accounting Standard Update	50	0	0	0	50	0
Net income	260,099	0	0	260,099	0	0
Other comprehensive income, net of tax	22,100	0	0	0	22,100	0
Comprehensive income, net of tax	282,199
Stock based compensation expense	4,914	0	4,914	0	0	0
Purchase of treasury stock	(35,673)	0	0	0	0	(35,673)
Distribution of treasury stock for deferred compensation plan	1	0	0	0	0	1
Cash dividends	(139,508)	0	0	(139,508)	0	0
Grant of restricted stock	$ 0	$ 316	(316)	0	0	0
Grant of restricted stock, shares	126,427	126,427
Forfeiture of restricted stock	$ 0	$ 0	162	0	0	(162)
Common stock options exercised	$ 1,275	$ 322	953	0	0	0
Common stock options exercised, shares	128,742	128,742
Ending Balance at Dec. 31, 2019	$ 3,363,833	$ 263,736	$ 2,140,175	$ 1,132,579	$ (34,869)	$ (137,788)
Ending Balance, shares at Dec. 31, 2019		105,494,290

Consolidated Statement of Cha_2

Consolidated Statement of Changes in Shareholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash dividends per share	$ 1.37	$ 1.36	$ 1.33
Grant of restricted stock, shares	126,427	97,004	90,075
Common stock options exercised, shares	128,742	72,296
Common Stock [Member]
Cash dividends per share	$ 1.37	$ 1.36	$ 1.33
Grant of restricted stock, shares	126,427	97,004	90,075
Forfeiture of restricted stock, shares	4,149	5,636	840
Common stock options exercised, shares	128,742	72,296	220,905
Acquisition, Shares			23,690,589
Treasury Stock [Member]
Purchase of treasury stock, shares	1,020,864	2,880,855	86
Deferred Compensation Plan [Member] | Treasury Stock [Member]
Distribution of treasury stock for deferred compensation plan, shares	27	31	31
Cardinal Financial Corporation [Member] | Common Stock [Member]
Acquisition, Shares			23,690,589

Condensed Consolidated Statemen

Condensed Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
OPERATING ACTIVITIES
Net income	$ 260,099,000	$ 256,342,000	$ 150,581,000
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	21,313,000	22,013,000	28,406,000
Depreciation, amortization and accretion	(20,531,000)	(21,061,000)	(21,567,000)
Loss (Gain) on sales of bank premises, OREO, leases and equipment	3,912,000	(772,000)	4,813,000
(Gain) Loss on securities	(175,000)	2,618,000	(5,584,000)
Loans originated for sale	(2,574,434,000)	(1,994,707,000)	(2,373,622,000)
Proceeds from sales of loans	2,513,717,000	2,041,508,000	2,455,213,000
Gain on sales of loans	(76,951,000)	(58,109,000)	(58,907,000)
Stock-based compensation	4,914,000	4,073,000	3,555,000
Excess tax benefits from stock-based compensation arrangements	223,000	158,000	2,201,000
Deferred income tax expense	14,205,000	9,353,000	60,827,000
Increase in cash surrender value of bank-owned life insurance policies	(1,458,000)	(5,045,000)	(5,110,000)
Contribution to pension plan	0	(7,000,000)	(10,000,000)
Amortization of net periodic pension costs	3,635,000	2,566,000	3,310,000
Changes in:
Loans held for sale	0	27,417,000	(8,893,000)
Interest receivable	2,512,000	(7,782,000)	(2,024,000)
Other assets	(23,449,000)	11,824,000	32,924,000
Accrued expenses and other liabilities	20,162,000	9,137,000	(2,195,000)
NET CASH PROVIDED BY OPERATING ACTIVITIES	147,694,000	292,533,000	253,928,000
INVESTING ACTIVITIES
Proceeds from maturities and calls of held to maturity securities	7,000,000	328,000	14,214,000
Purchases of held to maturity securities	0	0	(1,403,000)
Proceeds from sales of securities available for sale	374,764,000	171,202,000	247,131,000
Proceeds from maturities and calls of securities available for sale	337,793,000	270,754,000	439,181,000
Purchases of securities available for sale	(771,290,000)	(917,907,000)	(932,474,000)
Proceeds from sales of equity securities	2,011,000	2,005,000	0
Purchases of equity securities	(895,000)	(657,000)	0
Proceeds from sales and redemptions of other investment securities	84,541,000	37,860,000	40,837,000
Purchases of other investment securities	(129,747,000)	(57,154,000)	(74,090,000)
Redemption of bank-owned life insurance policies	2,829,000	0	0
Purchases of bank premises and equipment	(11,083,000)	(5,776,000)	(14,357,000)
Proceeds from sales of bank premises and equipment	251,000	8,397,000	17,000
Acquisition of subsidiaries, net of cash paid	0	0	44,531,000
Proceeds from sales of OREO properties	10,026,000	10,816,000	7,066,000
Net change in loans	(285,248,000)	(391,381,000)	496,025,000
NET CASH (USED IN) PROVIDED BY INVESTING ACTIVITIES	(379,048,000)	(871,513,000)	266,678,000
FINANCING ACTIVITIES
Cash dividends paid	(138,939,000)	(142,350,000)	(121,354,000)
Acquisition of treasury stock	(35,673,000)	(100,724,000)	(1,000)
Proceeds from exercise of stock options	1,272,000	1,500,000	4,619,000
Distribution of treasury stock for deferred compensation plan	1,000	1,000	1,000
Repayment of long-term Federal Home Loan Bank borrowings	(1,135,000,000)	(755,000,000)	(845,208,000)
Proceeds from issuance of long-term Federal Home Loan Bank borrowings	1,475,000,000	950,000,000	815,000,000
Repayment of trust preferred issuance	0	(9,374,000)	0
Changes in:
Time deposits	28,408,000	(293,184,000)	614,821,000
Other deposits	(169,945,000)	458,600,000	(928,665,000)
Federal funds purchased, securities sold under agreements to repurchase and other short-term borrowings	23,327,000	(176,260,000)	171,821,000
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	48,451,000	(66,791,000)	(288,966,000)
(DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	(182,903,000)	(645,771,000)	231,640,000
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	1,020,396,000	1,666,167,000	1,434,527,000
CASH AND CASH EQUIVALENTS AT END OF YEAR	837,493,000	1,020,396,000	1,666,167,000
Supplemental information
Cash paid for interest	182,549,000	124,679,000	72,715,000
Cash paid for income taxes	56,459,000	55,336,000	73,096,000
Noncash investing activities:
Transfers of loans to OREO	13,185,000	1,840,000	17,615,000
Transfers of held to maturity debt securities to available for sale debt securities	$ 11,544,000	$ 0	$ 0

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE A—SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Operations: Operating Segments: Basis of Presentation: United determines whether it has a controlling financial interest in an entity by first evaluating whether the entity is a voting interest entity or a variable interest entity (VIE) under U.S. generally accepted accounting principles. Voting interest entities are entities in which the total equity investment at risk is sufficient to enable the entity to finance itself independently and provides the equity holders with the obligation to absorb losses, the right to receive residual returns and the right to make decisions about the entity’s activities. United consolidates voting interest entities in which it has all, or at least a majority of, the voting interest. As defined in applicable accounting standards, VIEs are entities that lack one or more of the characteristics of a voting interest entity. A controlling financial interest in a VIE is present when an enterprise has both the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and an obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The enterprise with a controlling financial interest, known as the primary beneficiary, consolidates the VIE. United’s wholly owned and indirect wholly owned statutory trust subsidiaries are VIEs for which United is not the primary beneficiary. Accordingly, its accounts are not included in United’s consolidated financial statements. The accounting and reporting policies of United conform with U.S. generally accepted accounting principles. In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. To conform to the 2019 presentation, certain reclassifications have been made to prior period amounts, which had no impact on net income, comprehensive income or shareholders’ equity. In the opinion of management, all adjustments necessary for a fair presentation of financial position and results of operations have been made. Such adjustments are of a normal and recurring nature. The Company has evaluated events and transactions subsequent to December 31, 2019 through the date these financial statements were issued. Based on definitions and requirements of generally accepted accounting principles for “Subsequent Events,” the Company has not identified any events that would require adjustments to, or disclosure in the financial statements. Cash and Cash Equivalents: Securities: Gains or losses on sales of securities are recognized by the specific identification method and are reported in securities gains and losses within noninterest income of the Consolidated Statements of Income. United reviews available-for-sale held-to-maturity Certain security investments such as Federal Reserve Bank stock and Federal Home Loan Bank stock that do not have readily determinable fair values and for which United does not exercise significant influence are carried at cost and are classified as other investment securities on the balance sheet. These cost-method investments are reviewed for impairment at least annually or sooner if events or changes in circumstances indicate the carrying value may not be recoverable. Securities Purchased Under Resale Agreements and Securities Sold Under Agreements to Repurchase: Loans: 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 contract is doubtful. Consistent with United’s existing method of income recognition for loans, interest on impaired loans, except those classified as nonaccrual, is recognized as income using the accrual method. United’s method of income recognition for impaired loans that are classified as nonaccrual is to recognize interest income on the cash basis or apply the cash receipt to principal when the ultimate collectibility of principal is in doubt. A loan is categorized as a trouble debt restructuring (TDR) if a concession is granted to provide for a reduction of either interest or principal due to a deterioration in the financial condition of the borrower. A loan classified as a TDR will generally retain such classification until the loan is paid in full. However, a one-to-four-family Loans Acquired Through Transfer: Loans Held for Sale: one-to-four Loans held for sale within the mortgage banking segment are recorded under the fair value option at a fair value measured using valuations from investors for loans with similar characteristics adjusted for the Company’s actual sales experience versus the investor’s indicated pricing. Loans held for sale within the community banking segment are carried at the lower of cost or fair value. The fair value is based on the price secondary markets are currently offering for similar loans using observable market data which is not materially different than cost due to the short duration between origination and sale. Gains and losses on sale of loans are recorded within income from mortgage banking activities. Allowance for Credit Losses: The allowance for loan losses is management’s estimate of the probable credit losses inherent in the loan portfolio. Management’s evaluation of the adequacy of the allowance for loan losses and the appropriate provision for credit losses is based upon a quarterly evaluation of the portfolio. This evaluation is inherently subjective and requires significant estimates, including the amounts and timing of estimated future cash flows, estimated losses on pools of loans based on historical loss experience, and consideration of qualitative factors such as current economic trends, all of which are susceptible to constant and significant change. The amounts allocated to specific credits and loan pools grouped by similar risk characteristics are reviewed on a quarterly basis and adjusted as necessary based upon subsequent changes in circumstances. In determining the components of the allowance for credit losses, management considers the risk arising in part from, but not limited to, qualitative factors such as charge-off charged-off In determining the adequacy of the allowance for loan losses, management makes allocations to specific commercial loans classified by management as to risk. Management determines the loan’s risk by considering the borrowers’ ability to repay, the collateral securing the credit and other borrower-specific factors that may impact collectibility. For impaired loans, specific allocations are based on the present value of expected future cash flows using the loan’s effective interest rate, or as a practical expedient, at the loan’s observable market price or the fair value of the collateral if the loan is collateral-dependent. Other commercial loans not specifically reviewed on an individual basis are evaluated based on loan pools, which are grouped by similar risk characteristics using management’s internal risk ratings. Allocations for these commercial loan pools are determined based upon historical loss experience adjusted for current environmental conditions and risk factors and the estimate period it takes for losses to result in a charge-off, Bank Premises and Equipment: three five Other Real Estate Owned Revenue Recognition Descriptions of our revenue-generating activities that are within the scope of ASC Topic 606, which are presented in our Consolidated Statements of Income as components of Other Income are discussed below. There are no significant judgements relating to the amount and timing of revenue recognition for those revenue streams under the scope of ASC Topic 606. Fees from Trust Services Revenue from trust services primarily is comprised of fees earned from the management and administration of trusts and other customer assets. Trust services include custody of assets, investment management, escrow services, and similar fiduciary activities. The Company’s performance obligation is generally satisfied over time and the resulting fees are recognized monthly, based upon the month-end Fees from Brokerage Services Revenue from brokerage services are recorded as the income is earned at the time the related service is performed. In return for such services, the Company charges a commission for the sales of various securities products primarily consisting of investment company shares, annuity products, and corporate debt and equity securities, for its selling and administrative efforts. For account supervision, advisory and administrative services, revenue is recognized over a period of time as earned based on customer account balances and activity. Fees from Deposit Services Service charges on deposit accounts consist of account analysis fees (i.e., net fees earned on analyzed business and public checking accounts), monthly service fees, check orders, ATM activity fees, debit card fees, and other deposit account related fees. Revenue is recognized when our performance obligation is completed which is generally monthly for account maintenance services or when a transaction has been completed (ATM or debit card activity). Bankcard Fees and Merchant Discounts Bankcard fees and merchant discounts are primarily comprised of credit card income and merchant services income. Credit card income is primarily comprised of interchange fees earned whenever the Company’s credit cards are processed through card payment networks such as Visa. Merchant services income mainly represents fees charged to merchants to process their credit card transactions. The Company’s performance obligation for bankcard fees and i n Advertising Costs: Income Taxes: For uncertain income tax positions, United records a liability based on a recognition threshold of more-likely-than-not, United files a consolidated income tax return with its subsidiaries. Federal income tax expense or benefit has been allocated to subsidiaries on a separate return basis. Intangible Assets: one seven-year Goodwill and intangible assets with indefinite lives (such as a trade name intangible) are not amortized, but are tested for impairment at least annually or sooner if indicators of impairment exist. Intangible assets with definite useful lives (such as core deposit intangibles) are amortized over their respective estimated useful lives to their estimated residual values, and reviewed for impairment at least annually or as indicators of impairment are identified. Based on the most recent goodwill impairment test, no impairment was noted. As of December 31, 2019, and 2018, total goodwill approximated $1,478,014,000. Derivative Financial Instruments: Derivative instruments designated in a hedge relationship to mitigate exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivative instruments designated in a hedge relationship to mitigate exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. For a fair value hedge, the fair value of the interest rate swap is recognized on the balance sheet as either a freestanding asset or liability with a corresponding adjustment to the hedged financial instrument. Subsequent adjustments due to changes in the fair value of a derivative that qualifies as a fair value hedge are offset in current period earnings. For a cash flow hedge, the fair value of the interest rate swap is recognized on the balance sheet as either a freestanding asset or liability with a corresponding adjustment to other comprehensive income within shareholders’ equity, net of tax. Subsequent adjustments due to changes in the fair value of a derivative that qualifies as a cash flow hedge are offset to other comprehensive income, net of tax. The portion of a hedge that is ineffective is recognized immediately in earnings. At inception of a hedge relationship, United formally documents the hedged item, the particular risk management objective, the nature of the risk being hedged, the derivative being used, how effectiveness of the hedge will be assessed and how the ineffectiveness of the hedge will be measured. United also assesses hedge effectiveness at inception and on an ongoing basis using regression analysis. Hedge ineffectiveness is measured by using the change in fair value method. The change in fair value method compares the change in the fair value of the hedging derivative to the change in the fair value of the hedged exposure, attributable to changes in the benchmark rate. United through George Mason enters into interest rate lock commitments to finance residential mortgage loans with its customers. These commitments, which contain fixed expiration dates, offer the borrower an interest rate guarantee provided the loan meets underwriting guidelines and closes within the timeframe established by United. Interest rate risk arises on these commitments and subsequently closed loans if interest rates change between the time of the interest rate lock and the delivery of the loan to the investor. Market risk on interest rate lock commitments and mortgage loans held for sale is managed using corresponding forward mortgage loan sales contracts. United is a party to these forward mortgage loan sales contracts to sell loans servicing released and short sales of mortgage-backed securities. When the interest rate is locked with the borrower, the rate lock commitment, forward sale agreement, and mortgage-backed security position are undesignated derivatives and marked to fair value through earnings. The fair value of the rate lock derivative includes the servicing premium and the interest spread for the difference between retail and wholesale mortgage rates. Income from mortgage banking activities includes the gain recognized for the period presented and associated elements of fair value. United sells mortgage loans on either a best efforts or mandatory delivery basis. For loans sold on a mandatory delivery basis, United enters into forward mortgage-backed securities (the “residual hedge”) to mitigate the effect of interest rate risk. Both the rate lock commitment for mandatory delivery loans and the residual hedge are recorded at fair value through earnings and are not designated as accounting hedges. At the closing of the loan, the loan commitment derivative expires and United records a loan held for sale at fair value and continues to mark these assets to market under the election of the fair value option. United closes out of the trading mortgage-backed securities assigned within the residual hedge and replaces the securities with a forward sales contract once a price has been accepted by an investor and recorded at fair value. For those loans selected to be sold under a best efforts delivery basis, at the closing of the loan, the rate lock commitment derivative expires and the Company records a loan held for sale at fair value under the election of fair value option and continues to be obligated under the same forward loan sales contract entered into at inception of the rate lock commitment. For derivatives that are not designated in a hedge relationship, changes in the fair value of the derivatives are recognized in earnings in the same period as the change in the fair value. Stock-Based Compensation Earnings Per Common Share: two-class non-vested Under the two-class The reconciliation of the numerator and denominator of basic earnings per share with that of diluted earnings per share is presented as follows: Year Ended December 31 (Dollars in thousands, except per share) 2019 2018 2017 Distributed earnings allocated to common stock $ 139,167 $ 141,336 $ 131,527 Undistributed earnings allocated to common stock 120,337 114,542 18,816 Net earnings allocated to common shareholders $ 259,504 $ 255,878 $ 150,343 Average common shares outstanding 101,585,599 104,015,976 97,502,633 Dilutive effect of stock compensation 266,978 282,849 387,445 Average diluted shares outstanding 101,852,577 104,298,825 97,890,078 Earnings per basic common share $ 2.55 $ 2.46 $ 1.54 Earnings per diluted common share $ 2.55 $ 2.45 $ 1.54 Fair Value Measurements ASC Topic 820 specifies a hierarchy of valuation techniques based on whether the inputs to those valuation techniques are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect United’s market assumptions. The three levels of the fair value hierarchy based on these two types of inputs are as follows: Level 1 - Valuation is based on quoted prices in active markets for identical assets and liabilities. Level 2 - Valuation is based on observable inputs including quoted prices in active markets for similar assets and liabilities, quoted prices for identical or similar assets and liabilities in less active markets, and model-based valuation techniques for which significant assumptions can be derived primarily from or corroborated by observable data in the market. Level 3 - Valuation is based on model-based techniques that use one or more significant inputs or assumptions that are unobservable in the market. When determining the fair value measurements for assets and liabilities, United looks to active and observable markets to price identical assets or liabilities whenever possible and classifies such items in Level 1. When identical assets and liabilities are not traded in active markets, United looks to market observable data for similar assets and liabilities and classifies such items as Level 2. Nevertheless, certain assets and liabilities are not actively traded in observable markets and United must use alternative valuation techniques using unobservable inputs to determine a fair value and classifies such items as Level 3. For assets and liabilities that are not actively traded, the fair value measurement is based primarily upon estimates that require significant judgment. Therefore, the results may not be realized in an actual sale or immediate settlement of the asset or liability. Additionally, there are inherent weaknesses in any calculation technique, and changes in the underlying assumptions used, including discount rates and estimates of future cash flows, could significantly affect the results of current or future values. The level within the fair value hierarchy is based on the lowest level of input that is significant in the fair value measurement. Recent Accounting Pronouncements In April 2019, the Financial Accounting Standards Board (FASB) issued ASU No. 2019-04 issues . ASU No. 2019-04 In August 2018, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2018-14 715-20): 2018-14 2018-14 In August 2018, the FASB issued ASU No. 2018-13 2018-13 2018-13 was adopted by United on January 1, 2020. The adoption did not have a material impact on the Company’s financial condition or results of operations. In June 2018, the FASB issued Accounting Standards Update (ASU) No. 2018-07 non-employees non-employee 2018-07 2018-07 In February 2018, the FASB issued ASU No. 2018-03, 825-10): 2018-03 2018-03 2018-03 In February 2018, the FASB issued ASU No. 2018-02, 2018-02 In August 2017, the FASB issued ASU No. 2017-12, one-time held-to-maturity available-for-sale 2017-12 one-time In July 2017, the FASB issued ASU No. 2017-11, 2017-11 2017-11 In May 2017, the FASB issued ASU No. 2017-09, Scope of Modification Accounting.” This ASU clarifies when changes to the terms of conditions of a share-based payment award must be accounted for as modifications. Companies will apply the modification accounting guidance if the value, vesting conditions or classification of the award changes. The new guidance should reduce diversity in practice and result in fewer changes to the terms of an award being accounted for as modifications, as the guidance will allow companies to make certain non-substantive 2017-09 2017-09 In March 2017, the FASB issued ASU No. 2017-07, 2017-07 No. 2017-07 2017-07 the practical expedient and used amounts previously disclosed in its Employee Benefits Plan footnote (Note O) to retrospectively adjust prior period amounts of employee compensation and employee benefits within United’s Consolidated Statements of Income. In January 2017, the FASB issued ASU No. 2017-04, 2017-04 2017-04 2017-04 In January 2017, the FASB issued ASU No. 2017-01, 2017-01 2017-01 In August 2016, the FASB issued ASU No. 2016-15, 2016-15 2016-15 2016-15 In June 2016, the FASB issued ASU No. 2016-13, available-for-sale 2016-13 2019-05 2016-13 2016-13, 326-20 825-10. held-to-maturity instrument-by-instrument 2019-05 2016-13, 2016-13 model validation, the documentation of the new standard and internal controls as well as changes to financial statement disclosures. In March 2016, the FASB issued ASU No. 2016-09, 2016-09 in the income statement when the awards vest or are settled. The requirement to report those income tax effects in earnings was applied to settlements occurring on or after January 1, 2017 and the impact of applying that guidance reduced reporting income tax expense by $ for the year of 2017. ASU No. 2016-09 also allows an employer to repurchase more of an employee’s shares than it could previously for tax withholding purposes without triggering liability accounting and make a policy election to account for forfeitures as they occur. The Company will continue to estimate the number of awards expected to be forfeited and adjust the estimate when it is no longer probable that the employee will fulfill the service condition, as was previously required. ASU No. 2016-09 also requires that all income tax-related cash flows resulting from share-based payments be reported as operating activities in the statement of cash flows. Previously, income tax benefits at settlement of an award were reported as a reduction to operating cash flows and an increase to financing cash flows to the extent that those benefits exceeded the income tax benefits reported in earnings during the award’s vesting period. The adoption of ASU No. 2016-09 did not have a material impact on the Company’s financial condition or results of operations. In February 2016, the FASB issued ASU No. 2016-02, 2016-02 2016-02 right-of-use 2018-11 non-lease non-lease 2018-10 2018-10 In January 2016, the FASB issued ASU No. 2016-01, 2016-01 2016-01 available-for-sale 2016-01 In May 2014, the FASB issued ASU No. 2014-09, 2014-09 2014-09 that ASU No. 2014-09 2014-09 2014-09

Mergers and Acquisitions

Mergers and Acquisitions	12 Months Ended
	Dec. 31, 2019
Business Combinations [Abstract]
Mergers and Acquisitions	NOTE B—MERGERS AND ACQUISITIONS On November 17, 2019, United entered into an Agreement and Plan of Merger (the Agreement) with Carolina Financial Corporation (Carolina Financial), a Delaware corporation headquartered in Charleston, South Carolina. In accordance with the Agreement, Carolina Financial will cease to exist and United shall survive and continue to exist as a West Virginia corporation. United may at any time prior to the effective time of the Merger change the method of effecting the combination with Carolina Financial subject to certain conditions contained in the Agreement. The merger with Carolina Financial represents a significant step towards continuing to grow United’s presence in North and South Carolina. The combined organization will have the potential of creating a contiguous Mid-Atlantic The Agreement provides that consummation of the Merger, each outstanding share of common stock of Carolina Financial will be converted into the right to receive 1.13 shares of United common stock, par value $2.50 per share. Pursuant to the Agreement, as of the effective time of the Merger, each outstanding Carolina Financial stock option, whether vested or unvested as of the date of the Agreement, shall, at such option holder’s election, (i) vest and convert into an option to acquire United common stock adjusted based on the 1.13 exchange ratio, or (ii) be entitled to receive cash consideration equal to the difference between (a) the option’s exercise price and (b) the volume weighted average trading price of the Carolina Financial common stock on NASDAQ for the twenty full trading days ending on the second trading day immediately preceding the closing date (the CFC Closing Price) multiplied by the number of shares of Carolina Financial common stock subject to such stock option. Also, at the effective time of the Merger, each restricted stock grant, restricted stock unit grant or any other award of a share of Carolina Financial common stock subject to vesting, repurchase or other lapse restriction under a Carolina Financial stock plan (other than a stock option) (each, a “Stock Award”) that is outstanding immediately prior to the effective time of the Merger, shall fully vest in accordance with the terms of the Carolina Financial stock plan and at the election of the holder (i) convert into the right to receive shares of United common stock based on the 1.13 exchange ratio or (ii) convert into cash in an amount equal to the CFC Closing Price multiplied by the shares of Carolina Financial common stock subject to the Stock Award. At the effective time of the Merger, Crescom Bank, a wholly-owned subsidiary of Carolina Financial, will merge with and into United Bank, a wholly-owned subsidiary of United (the Bank Merger). United Bank will survive the Bank Merger and continue to exist as a Virginia banking corporation. The acquisition of Carolina Financial will afford United the opportunity to expand its existing footprint in North Carolina and South Carolina. As of December 31, 2019, Carolina Financial had $4,708,873,000 in total assets, $ in gross loans and $ in deposits. Carolina Financial has banking locations in North Carolina and South Carolina. CresCom Bank owns and operates Crescent Mortgage Company, which is based in Atlanta, Georgia. United recently filed an amended Form S-4 with the Securities and Exchange Commission regarding the proposed merger with Carolina Financial. United expects the merger to close during the second quarter of 2020.

Investment Securities

Investment Securities	12 Months Ended
	Dec. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Investment Securities	NOTE C—INVESTMENT SECURITIES Securities Available for Sale Securities held for indefinite periods of time are classified as available for sale and carried at estimated fair value. The amortized cost and estimated fair values of securities available for sale are summarized as follows. December 31, 2019 (In thousands) Amortized Gross Gross Estimated Cumulative (1) U.S. Treasury securities and obligations of U.S. $ 58,127 $ 555 $ 6 $ 58,676 $ 0 State and political subdivisions 272,014 3,644 3,296 272,362 0 Residential mortgage-backed securities Agency 826,857 10,923 1,246 836,534 0 Non-agency 3,429 404 0 3,833 86 Commercial mortgage-backed securities Agency 609,461 8,319 2,807 614,973 0 Asset-backed securities 284,390 0 8,251 276,139 0 Trust preferred collateralized debt obligations 6,045 0 1,342 4,703 842 Single issue trust preferred securities 18,196 170 1,592 16,774 0 Other corporate securities 348,405 4,897 0 353,302 0 Total $ 2,426,924 $ 28,912 $ 18,540 $ 2,437,296 $ 928 December 31, 2018 (In thousands) Amortized Gross Gross Estimated Cumulative (1) U.S. Treasury securities and obligations of U.S. $ 86,285 $ 35 $ 430 $ 85,890 $ 0 State and political subdivisions 212,670 439 4,121 208,988 0 Residential mortgage-backed securities Agency 1,047,345 3,235 14,930 1,035,650 0 Non-agency 3,927 332 0 4,259 86 Commercial mortgage-backed securities Agency 560,634 996 7,030 554,600 0 Asset-backed securities 272,459 450 939 271,970 0 Trust preferred collateralized debt obligations 6,176 91 350 5,917 2,586 Single issue trust preferred securities 8,754 169 561 8,362 0 Other corporate securities 162,634 118 1,349 161,403 0 Total $ 2,360,884 $ 5,865 $ 29,710 $ 2,337,039 $ 2,672 (1) Other-than-temporary impairment in accumulated other comprehensive income. Amounts are before-tax. The following is a summary of securities available for sale which were in an unrealized loss position at December 31, 2019 and 2018. Less than 12 months 12 months or longer (In thousands) Fair Value Unrealized Fair Value Unrealized December 31, 2019 U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 1,415 $ 6 $ 0 $ 0 State and political subdivisions 144,307 3,291 885 5 Residential mortgage-backed securities Agency 108,072 502 71,736 744 Non-agency 0 0 0 0 Commercial mortgage-backed securities Agency 173,039 2,676 45,251 131 Asset-backed securities 135,174 3,252 140,965 4,999 Trust preferred collateralized debt obligations 2,703 842 2,000 500 Single issue trust preferred securities 0 0 13,562 1,592 Other corporate securities 0 0 0 0 Total $ 564,710 $ 10,569 $ 274,399 $ 7,971 Less than 12 months 12 months or longer (In thousands) Fair Value Unrealized Fair Value Unrealized December 31, 2018 U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 66,072 $ 250 $ 7,374 $ 180 State and political subdivisions 53,421 544 94,337 3,577 Residential mortgage-backed securities Agency 195,009 1,597 508,041 13,333 Non-agency 0 0 0 0 Commercial mortgage-backed securities Agency 107,443 1,124 294,129 5,906 Asset-backed securities 151,427 939 0 0 Trust preferred collateralized debt obligations 0 0 2,150 350 Single issue trust preferred securities 0 0 5,163 561 Other corporate securities 129,709 1,233 6,879 116 Total $ 703,081 $ 5,687 $ 918,073 $ 24,023 The following table shows the proceeds from maturities, sales and calls of available for sale securities and the gross realized gains and losses on sales and calls of those securities that have been included in earnings as a result of any sales and calls. Gains or losses on sales and calls of available for sale securities were recognized by the specific identification method. The realized losses relate to sales of securities within a rabbi trust for the payment of benefits under a deferred compensation plan for certain key officers and its subsidiaries. Year Ended (In thousands) 2019 2018 2017 Proceeds from maturities, sales and calls $ 712,557 $ 441,956 $ 686,312 Gross realized gains 1,542 1,594 3,274 Gross realized losses 1,445 2,364 1,400 At December 31, 2019, gross unrealized losses on available for sale securities were $18,540,000 on 166 securities of a total portfolio of 641 available for sale securities. Securities with the most significant gross unrealized losses at December 31, 2019 consisted primarily of asset-backed securities, agency commercial mortgage-backed securities, and state and political subdivision securities. The asset-backed securities are backed by Federal Family Education Loan Program (FFELP) student loan collateral which includes a minimum of a 97% government repayment guaranty, as well as additional credit support and subordination in excess of the government guaranteed portion. The agency commercial mortgage-backed securities relate to commercial properties and provide a guaranty of full and timely payments of principal and interest by the issuing agency. The state and political subdivisions securities relate to securities issued by various municipalities. In determining whether or not a security is other-than-temporarily impaired (OTTI), management considered the severity and the duration of the loss in conjunction with United’s positive intent and the more likely than not ability to hold these securities to recovery of their cost basis or maturity. State and political subdivisions United’s state and political subdivisions portfolio relates to securities issued by various municipalities located throughout the United States. The total amortized cost of available for sale state and political subdivision securities was $272,014,000 the portfolio was supported by the general obligation of the issuing municipality, which allows for the securities to be repaid by any means available to the municipality. The majority of the portfolio was rated AA or higher, and no securities within the portfolio were rated below investment grade as of December 31, 2019. In addition to monitoring the credit ratings of these securities, management also evaluates the financial performance of the underlying issuers on an ongoing basis. Based upon management’s analysis and judgment, it was determined that none of the state and political subdivision securities were other-than-temporarily impaired at December 31, 2019. Agency mortgage-backed securities United’s agency mortgage-backed securities portfolio relates to securities issued by Fannie Mae, Freddie Mac, and Ginnie Mae. The total amortized cost of available for sale agency mortgage-backed securities was $1,436,318,000 at December 31, 2019. Of the $1,436,318,000 amount, $609,461,000 was related to agency commercial mortgage-backed securities and $826,857,000 was related to agency residential mortgage-backed securities. Each of the agency mortgage-backed securities provides a guarantee of full and timely payments of principal and interest by the issuing agency. Based upon management’s analysis and judgment, it was determined that none of the agency mortgage-backed securities were other-than-temporarily impaired at December 31, 2019. Non-agency United’s non-agency non-agency All of the securities were rated below investment grade at December 31, 2019. The entire portfolio of the non-agency non-agency and year of 2019 was $21,000 and $42,000, respectively . Single issue trust preferred securities The majority of United’s single issue trust preferred portfolio consists of obligations from large cap banks (i.e. banks with market capitalization in excess of $10 billion). All single issue trust preferred securities are currently receiving interest payments. The amortized cost of available for sale single issue trust preferred securities as of December 31, 2019 consisted of $11,484,000 in investment grade bonds, $977,000 in split rated bonds, and $5,735,000 in unrated bonds. Management reviews each issuer’s current and projected earnings trends, asset quality, capitalization levels, and other key factors. Upon completing the review for the fourth quarter of 2019, it was determined that none of the single issue trust preferred securities were other-than-temporarily impaired. Trust preferred collateralized debt obligations (Trup Cdos) The total amortized cost balance of United’s Trup Cdo portfolio was $6,045,000 as of December 31, 2019. For any securities in an unrealized loss position, the Company first assesses its intentions regarding any sale of securities as well as the likelihood that it would be required to sell prior to recovery of the amortized cost. As of December 31, 2019, the Company has determined that it does not intend to sell any Trup Cdo and that it is not more likely than not that the Company will be required to sell such securities before recovery of their amortized cost. To determine a net realizable value and assess whether other-than-temporary impairment existed, management performed detailed cash flow analysis to determine whether, in management’s judgment, it was more likely that United would not recover the entire amortized cost basis of the security. Based on this review, management determined that one of the Trup Cdo securities was other-than-temporarily impaired as of December 31, 2019. The total amount of OTTI recognized in earnings on this security during the fourth quarter and year of 2019 was $93,000 and $156,000, respectively . Corporate securities As of December 31, 2019, United’s Corporate securities portfolio had a total amortized cost balance of $348,405,000. The majority of the portfolio consisted of debt issuances of corporations representing a variety of industries, including financial institutions. Of the $348,405,000, 92% was investment grade rated and 8% was unrated. For corporate securities, management has evaluated the near-term prospects of the investment in relation to the severity and duration of any impairment. Based upon management’s analysis and judgment, it was determined that none of the other corporate securities were other-than-temporarily impaired at December 31, 2019. Below is a progression of the credit losses on securities which United has recorded other-than-temporary charges. These charges were recorded through earnings and other comprehensive income. (In thousands) Year Ended December 31 2019 2018 2017 Balance of cumulative credit losses at beginning of period $ 3,138 $ 18,060 $ 22,162 Additional credit losses on securities for which OTTI was previously recognized 156 0 0 Reductions for securities sold or paid off during the period (0 ) (14,922 ) (4,102 ) Balance of cumulative credit losses at end of period $ 3,294 $ 3,138 $ 18,060 The amortized cost and estimated fair value of securities available for sale at December 31, 2019 by contractual maturity are shown below. Expected maturities may differ from contractual maturities because the issuers may have the right to call or prepay obligations without penalties. Maturities of mortgage-backed securities with an amortized cost of $1,439,747,000 and an estimated fair value of $1,455,340,000 at December 31, 2019 are included below based upon contractual maturity. Estimated (In thousands) Amortized Fair Cost Value Due in one year or less $ 92,422 $ 92,473 Due after one year through five years 583,715 592,850 Due after five years through ten years 564,922 568,241 Due after ten years 1,185,865 1,183,732 Total $ 2,426,924 $ 2,437,296 Securities Held to Maturity The amortized cost and estimated fair values of securities held to maturity are summarized as follows:. December 31, 2019 (In thousands) Amortized Gross Gross Estimated Fair Value U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 0 $ 0 $ 0 $ 0 State and political subdivisions 1,426 1 0 1,427 Residential mortgage-backed securities Agency 0 0 0 0 Single issue trust preferred securities 0 0 0 0 Other corporate securities 20 0 0 20 Total $ 1,446 $ 1 $ 0 $ 1,447 December 31, 2018 (In thousands) Amortized Gross Gross Estimated Fair Value U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 5,074 $ 90 $ 0 $ 5,164 State and political subdivisions 5,473 7 1 5,479 Residential mortgage-backed securities Agency 20 2 0 22 Single issue trust preferred securities 9,412 0 1,442 7,970 Other corporate securities 20 0 0 20 Total $ 19,999 $ 99 $ 1,443 $ 18,655 No gross realized gains and losses on calls and sales of held to maturity securities have been included in earnings for the years ended December 31, 2019, 2018 and 2017. The amortized cost and estimated fair value of debt securities held to maturity at December 31, 2019 by contractual maturity are shown below. Expected maturities may differ from contractual maturities because the issuers may have the right to call or prepay obligations with or without call or prepayment penalties. Estimated (In thousands) Amortized Fair Cost Value Due in one year or less $ 210 $ 210 Due after one year through five years 216 217 Due after five years through ten years 0 0 Due after ten years 1,020 1,020 Total $ 1,446 $ 1,447 Equity securities at fair value Equity securities consist mainly of equity securities of financial institutions and mutual funds within a rabbi trust for the payment of benefits under a deferred compensation plan for certain key officers of United and its subsidiaries. The fair value of United’s equity securities was $8,894,000 at December 31, 2019 and $9,734,000 at December 31, 2018. (In thousands) Year Ended December 31, 2019 Net gains recognized during the period $ 276 Net gains recognized during the period on equity securities sold 133 Unrealized gains recognized during the period on equity securities still held at period end 177 Unrealized losses recognized during the period on equity securities still held at period end (34 ) Other During the fourth quarter of 2019, United evaluated all of its cost method investments to determine if certain events or changes in circumstances during the fourth quarter of 2019 had a significant adverse effect on the fair value of any of its cost method securities. United determined that there was no individual security that experienced an adverse event during the fourth fourth The carrying value of securities pledged to secure public deposits, securities sold under agreements to repurchase, and for other purposes as required or permitted by law, approximated $1,540,717,000 and $1,887,176,000 at December 31, 2019 and December 31, 2018 respectively. The fair value of mortgage-backed at December 31, 2019 and a net unrealized loss of at December 31, 2018 on all mortgage-backed The following table sets forth the maturities of all securities (based on amortized cost) at December 31, 2019, and the weighted-average yields of such securities (calculated on the basis of the cost and the effective yields weighted for the scheduled maturity of each security). After 1 But After 5 But (Dollars in thousands) Within 1 Year Within 5 Years Within 10 Years After 10 Years Amount Yield Amount Yield Amount Yield Amount Yield U.S. Treasury and other U.S. Government agencies and corporations $ 0 0.00 % $ 51,511 2.41 % $ 6,616 2.74 % $ 0 0.00 % States and political subdivisions (1) 5,364 2.78 % 4,964 3.36 % 38,732 2.80 % 224,380 2.92 % Residential mortgage-backed securities Agency 0 0.00 % 0 0.00 % 230,686 2.60 % 596,171 2.71 % Non-agency 69 5.00 % 0 0.00 % 0 0.00 % 3,360 5.84 % Commercial mortgage-backed Agency 28,178 2.32 % 281,903 2.65 % 241,159 2.40 % 58,221 2.73 % Asset-backed securities 0 0.00 % 0 0.00 % 0 0.00 % 284,390 2.56 % Trust preferred collateralized debt obligations 0 0.00 % 0 0.00 % 0 0.00 % 6,045 3.61 % Single issue trust preferred securities 0 0.00 % 0 0.00 % 10,483 4.80 % 7,713 3.68 % Other corporate securities 59,020 2.63 % 245,553 2.98 % 37,246 4.58 % 6,606 1.28 % Marketable equity securities 0 0.00 % 0 0.00 % 0 0.00 % 8,894 1.49 % Other investment securities 0 0.00 % 100 2.55 % 750 2.08 % 221,311 3.32 % (1) Tax-equivalent 21 There are no securities with a single issuer, other than the U.S. government and its agencies and corporations, the book value of which in the aggregate exceeds 10% of United’s total shareholders’ equity.

Loans

Loans	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Loans	NOTE D—LOANS Major classes of loans are as follows: December 31 (In thousands) 2019 2018 Commercial, financial, and agricultural Owner-occupied $ 1,201,652 $ 1,291,790 Nonowner-occupied 3,965,960 4,303,613 Other commercial 2,285,037 1,957,641 Total commercial, financial & agricultural 7,452,649 7,553,044 Residential real estate 3,686,401 3,501,393 Construction & land development 1,408,205 1,410,468 Consumer: Bankcard 10,074 10,203 Other Consumer 1,156,219 954,424 Less: Unearned income (1,419 ) (7,310 ) Total Loans, net of unearned income $ 13,712,129 $ 13,422,222 The table above does not include loans held for sale of $387,514,000 and $249,846,000 at December 31, 2019 and December 31, 2018, respectively. Loans held for sale consist of single-family residential real estate loans originated for sale in the secondary market. The outstanding loan balances in the table above include previously acquired impaired loans with a recorded investment of $96,004,000 or less than accretable discounts of $71,542,000 and $93,372,000 at December 31, 2019 and December 31, 2018, respectively. Activity for the accretable yield for the year of 2019 follows : (In thousands) Accretable yield at the beginning of the period $ 26,289 Accretion (including cash recoveries) (10,688 ) Additions 0 Net reclassifications to accretable from non-accretable 10,627 Disposals (including maturities, foreclosures, and charge-offs) (5,140 ) Accretable yield at the ending of the period $ 21,088 At December 31, 2019 and 2018, loans-in-process United’s subsidiary bank has made loans, in the normal course of business, to the directors and officers of United and its subsidiaries, and to their associates. The aggregate dollar amount of these loans was $38,558,000 and $93,282,000 at December 31, 2019 and 2018, respectively. During 2019, $9,358,000 of new loans were made and repayments totaled $64,082,000.

Credit Quality

Credit Quality	12 Months Ended
	Dec. 31, 2019
Text Block [Abstract]
Credit Quality	NOTE E—CREDIT QUALITY Management monitors the credit quality of its loans on an ongoing basis. Measurement of delinquency and past due status are based on the contractual terms of each loan. For all loan classes, past due loans are reviewed on a monthly basis to identify loans for nonaccrual status. Generally, when collection in full of the principal and interest is jeopardized, the loan is placed on nonaccrual status. The accrual of interest income on commercial and most consumer loans generally is discontinued when a loan becomes 90 to 120 days past due as to principal or interest. However, regardless of delinquency status, if a loan is fully secured and in the process of collection and resolution of collection is expected in the near term (generally less than 90 days), then the loan will not be placed on nonaccrual status. When interest accruals are discontinued, unpaid interest recognized in income in the current year is reversed, and unpaid interest accrued in prior years is charged to the allowance for loan losses. United’s method of income recognition for loans that are classified as nonaccrual is to recognize interest income on a cash basis or apply the cash receipt to principal when the ultimate collectibility of principal is in doubt. Nonaccrual loans will not normally be returned to accrual status unless all past due principal and interest has been paid and the borrower has evidenced their ability to meet the contractual provisions of the note. A loan is categorized as a troubled debt restructuring (TDR) if a concession is granted and there is deterioration in the financial condition of the borrower. TDRs can take the form of a reduction of the stated interest rate, splitting a loan into separate loans with market terms on one loan and concessionary terms on the other loan, receipts of assets from a debtor in partial or full satisfaction of a loan, the extension of the maturity date or dates at a stated interest rate lower than the current market rate for new debt with similar risk, the reduction of the face amount or maturity amount of the debt as stated in the instrument or other agreement, the reduction of accrued interest or any other concessionary type of renegotiated debt. As of December 31, 2019, United had TDRs of $58,369,000. Of the $ 58,369,000 48,387,000 902,000 as - 89 59,425,000 48,899,000 690,000 additional funds of $1,159,000 to two debtors owing receivables whose terms have been modified in TDRs. During the year of 2019, $39,000 was advanced to one of these debtors under a loan that had been previously modified. At December 31, 2019, United had restructured loans in the amount of $1,685,000 that were modified by a reduction in the interest rate, $1,733,000 that were modified by a combination of a reduction in the interest rate and the principal and $54,951,000 that were modified by a change in terms. A loan acquired and accounted for under ASC Topic 310-30 The following table sets forth United’s troubled debt restructurings that have been restructured during the year ended December 31, 2019 and 2018, segregated by class of loans: Troubled Debt Restructurings For the Year Ended December 31, 2019 December 31, 2018 (Dollars in thousands) Number of Pre- Modification Post- Number of Pre- Modification Post- Modification Commercial real estate: Owner-occupied 2 $ 1,179 $ 1,144 0 $ 0 $ 0 Nonowner-occupied 0 0 0 1 61 61 Other commercial 3 5,962 5,722 9 16,991 16,560 Residential real estate 3 2,258 1,970 3 7,225 6,077 Construction & land development 3 2,287 2,104 0 0 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 0 0 0 0 0 0 Total 11 $ 11,686 $ 10,940 13 $ 24,277 $ 22,698 During 2019, $241,000 of restructured loans were modified by an interest rate reduction and $10,699,000 of restructured loans were modified by a change in terms. During 2018, $22,698,000 of restructured loans were modified by a change in loan terms. In some instances, the post-modification balance on a restructured loan is larger than the pre-modification balance due to the advancement of monies for items such as delinquent taxes on real estate property. The loans were evaluated individually for allocation within United’s allowance for loan losses. The modifications had an immaterial impact on the financial condition and results of operations for United The following table presents troubled debt restructurings, by class of loan, that had charge-offs during the year ended December 31, 2019 and 2018. These loans were restructured during the twelve months ended December 31, 2019 and 2018 and subsequently defaulted, resulting in principal charge-offs during the year of 2019 and 2018. Year Ended December 31, 2019 Year Ended December 31, 2018 (In thousands) Number of Recorded Number of Recorded Troubled Debt Restructurings Commercial real estate: Owner-occupied 0 $ 0 0 $ 0 Nonowner-occupied 0 0 0 0 Other commercial 2 1,477 1 0 Residential real estate 0 0 1 2,173 Construction & land development 0 0 0 0 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total 2 $ 1,477 2 $ 2,173 The following table sets forth United’s age analysis of its past due loans, segregated by class of loans: Age Analysis of Past Due Loans As of December 31, 2019 (In thousands) 30-89 90 Days or Past Due Total Past Current & Total Financing Recorded Commercial real estate: Owner-occupied $ 8,878 $ 11,209 $ 20,087 $ 1,181,565 $ 1,201,652 $ 544 Nonowner-occupied 6,318 16,129 22,447 3,943,513 3,965,960 471 Other commercial 5,238 51,541 56,779 2,228,258 2,285,037 668 Residential real estate 31,727 24,343 56,070 3,630,331 3,686,401 6,256 Construction & land development 2,219 16,043 18,262 1,389,943 1,408,205 0 Consumer: Bankcard 445 218 663 9,411 10,074 218 Other consumer 10,991 1,607 12,598 1,143,621 1,156,219 1,337 Total $ 65,816 $ 121,090 $ 186,906 $ 13,526,642 $ 13,713,548 $ 9,494 (1) Other includes loans with a recorded investment of $96,004 acquired and accounted for under ASC Topic 310-30 Age Analysis of Past Due Loans As of December 31, 2018 (In thousands) 30-89 90 Days or Past Due Total Past Current & Total Financing Recorded Commercial real estate: Owner-occupied $ 9,224 $ 17,742 $ 26,966 $ 1,264,824 $ 1,291,790 $ 629 Nonowner-occupied 16,108 18,092 34,200 4,269,413 4,303,613 1,171 Other commercial 13,556 46,040 59,596 1,898,045 1,957,641 2,850 Residential real estate 37,111 30,278 67,389 3,434,004 3,501,393 9,141 Construction & land development 8,462 19,412 27,874 1,382,594 1,410,468 680 Consumer: Bankcard 657 177 834 9,369 10,203 177 Other consumer 8,909 1,243 10,152 944,272 954,424 893 Total $ 94,027 $ 132,984 $ 227,011 $ 13,202,521 $ 13,429,532 $ 15,541 (1) Other includes loans with a recorded investment of $149,737 acquired and accounted for under ASC Topic 310-30 The following table sets forth United’s nonaccrual loans, segregated by class of loans: Loans on Nonaccrual Status (In thousands) December 31, 2019 December 31, 2018 Commercial real estate: Owner-occupied $ 10,665 $ 17,113 Nonowner-occupied 15,658 16,921 Other commercial 50,873 43,190 Residential real estate 18,087 21,137 Construction & land development 16,043 18,732 Consumer: Bankcard 0 0 Other consumer 270 350 Total $ 111,596 $ 117,443 United assigns credit quality indicators of pass, special mention, substandard and doubtful to its loans. For United’s loans with a corporate credit exposure, United internally assigns a grade based on the creditworthiness of the borrower. For loans with a consumer credit exposure, United internally assigns a grade based upon an individual loan’s delinquency status. United reviews and updates, as necessary, these grades on a quarterly basis. Special mention loans, with a corporate credit exposure, have potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the loans or in the Company’s credit position at some future date. Borrowers may be experiencing adverse operating trends (declining revenues or margins) or an ill proportioned balance sheet (e.g., increasing inventory without an increase in sales, high leverage, tight liquidity). Adverse economic or market conditions, such as interest rate increases or the entry of a new competitor, may also support a special mention rating. Nonfinancial reasons for rating a credit exposure special mention include management problems, pending litigation, an ineffective loan agreement or other material structural weakness, and any other significant deviation from prudent lending practices. For loans with a consumer credit exposure, loans that are past due 30 89 A substandard loan with a corporate credit exposure is inadequately protected by the current sound worth and paying capacity of the obligor or of the collateral pledged, if any. Loans so classified have a well-defined weakness, or weaknesses, that jeopardize the liquidation of the debt by the borrower. They are characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. They require more intensive supervision by management. Substandard loans are generally characterized by current or expected unprofitable operations, inadequate debt service coverage, inadequate liquidity, or marginal capitalization. Repayment may depend on collateral or other credit risk . For some substandard loans, the likelihood of full collection of interest and principal may be in doubt and thus, placed on . For loans with a consumer credit exposure, loans that are or more past due or that have been placed on are considered substandard. A loan with corporate credit exposure is classified as doubtful if it has all the weaknesses inherent in one classified as substandard with the added characteristic that the weaknesses make collection in full, on the basis of currently existing facts, conditions, and values, highly questionable and improbable. A doubtful loan has a high probability of total or substantial loss, but because of specific pending events that may strengthen the loan, its classification as loss is deferred. Doubtful borrowers are usually in default, lack adequate liquidity or capital, and lack the resources necessary to remain an operating entity. Pending events can include mergers, acquisitions, liquidations, capital injections, the perfection of liens on additional collateral, the valuation of collateral, and refinancing. Generally, there are not any loans with a consumer credit exposure that are classified as doubtful. Usually, they are charged-off The following tables set forth United’s credit quality indicators information, by class of loans: Credit Quality Indicators As of December 31, 2019 Commercial Real Estate (In thousands) Owner- Nonowner- Other Construction & Grade: Pass $ 1,136,589 $ 3,850,886 $ 2,136,266 $ 1,334,950 Special mention 14,449 44,134 75,511 4,614 Substandard 50,346 70,940 72,451 68,641 Doubtful 268 0 809 0 Total $ 1,201,652 $ 3,965,960 $ 2,285,037 $ 1,408,205 Credit Quality Indicators As of December 31, 2018 Commercial Real Estate (In thousands) Owner- Nonowner- Other Construction & Grade: Pass $ 1,201,387 $ 4,161,149 $ 1,858,821 $ 1,330,899 Special mention 34,487 46,442 14,424 28,629 Substandard 55,916 96,022 81,946 50,940 Doubtful 0 0 2,450 0 Total $ 1,291,790 $ 4,303,613 $ 1,957,641 $ 1,410,468 Credit Quality Indicators As of December 31, 2019 (In thousands) Residential Bankcard Other Grade: Pass $ 3,645,654 $ 9,411 $ 1,143,608 Special mention 12,038 445 10,993 Substandard 28,572 218 1,618 Doubtful 137 0 0 Total $ 3,686,401 $ 10,074 $ 1,156,219 As of December 31, 2018 (In thousands) Residential Bankcard Other Grade: Pass $ 3,436,584 $ 9,369 $ 944,241 Special mention 19,051 657 8,914 Substandard 45,758 177 1.269 Doubtful 0 0 0 Total $ 3,501,393 $ 10,203 $ 954,424 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 contract is doubtful. Typically, United does not consider loans for impairment unless a sustained period of delinquency (i.e. 90-plus The following table set forth United’s impaired loans information, by class of loans: Impaired Loans December 31, 2019 December 31, 2018 (In thousands) Recorded Unpaid Related Recorded Unpaid Related With no related allowance recorded: Commercial real estate: Owner-occupied $ 58,709 $ 58,709 $ 0 $ 63,633 $ 63,798 $ 0 Nonowner-occupied 38,011 38,070 0 98,845 98,904 0 Other commercial 56,717 62,796 0 40,291 50,459 0 Residential real estate 28,096 29,022 0 28,207 29,279 0 Construction & land development 39,599 47,594 0 37,174 40,459 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 11 11 0 27 27 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 3,904 $ 5,223 $ 974 $ 10,004 $ 10,004 $ 2,542 Nonowner-occupied 15,947 15,947 2,979 15,720 15,720 2,715 Other commercial 40,300 42,684 11,931 61,266 62,812 17,581 Residential real estate 6,793 6,793 354 19,623 22,064 3,265 Construction & land development 1,269 1,269 262 14,742 19,446 2,254 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 0 0 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 62,613 $ 63,932 $ 974 $ 73,637 $ 73,802 $ 2,542 Nonowner-occupied 53,958 54,017 2,979 114,565 114,624 2,715 Other commercial 97,017 105,480 11,931 101,557 113,271 17,581 Residential real estate 34,889 35,815 354 47,830 51,343 3,265 Construction & land development 40,868 48,863 262 51,916 59,905 2,254 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 11 11 0 27 27 0 Impaired Loans For the Year Ended December 31, 2019 December 31, 2018 (In thousands) Average Interest Average Interest With no related allowance recorded: Commercial real estate: Owner-occupied $ 66,838 $ 1,568 $ 67,665 $ 1,548 Nonowner-occupied 54,948 1,064 103,611 1,516 Other commercial 55,473 1,008 51,416 718 Residential real estate 31,166 630 27,459 657 Construction & land development 35,702 799 41,892 914 Consumer: Bankcard 0 0 0 0 Other consumer 25 0 28 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 3,848 $ 0 $ 7,658 $ 25 Nonowner-occupied 13,471 404 12,298 387 Other commercial 41,112 182 51,118 1,072 Residential real estate 10,444 267 15,365 460 Construction & land development 11,243 79 8,893 79 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 70,686 $ 1,568 $ 75,323 $ 1,573 Nonowner-occupied 68,419 1,468 115,909 1,903 Other commercial 96,585 1,190 102,534 1,790 Residential real estate 41,610 897 42,824 1,117 Construction & land development 46,945 878 50,785 993 Consumer: Bankcard 0 0 0 0 Other consumer 25 0 28 0

Allowance for Credit Losses

Allowance for Credit Losses	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Allowance for Credit Losses	NOTE F—ALLOWANCE FOR CREDIT LOSSES The allowance for loan losses is management’s estimate of the probable credit losses inherent in the loan portfolio. For purposes of determining the general allowance, the loan portfolio is segregated by product type to recognize differing risk profiles among categories. It is further segregated by credit grade for non-homogenous of $500,000 in accordance with ASC Topic 310. Risk characteristics of owner-occupied commercial real estate loans and other commercial loans are similar in that they are normally dependent upon the borrower’s internal cash flow from operations to service debt. Nonowner-occupied commercial real estate loans differ in that cash flow to service debt is normally dependent on external income from third parties for use of the real estate such as rents, leases and room rates. Residential real estate loans are dependent upon individual borrowers who are affected by changes in general economic conditions, demand for housing and resulting residential real estate valuation. Construction and land development loans are impacted mainly by demand whether for new residential housing or for retail, industrial, office and other types of commercial construction within a given area. Consumer loan pool risk characteristics are influenced by general, regional and local economic conditions. Loans deemed to be uncollectible are charged against the allowance for loan losses, while recoveries of previously charged-off charge-off charge-off 95 A progression of the allowance for loan losses, by portfolio segment, for the year ended December 31, 2019 and 2018 is summarized as follows: Allowance for Loan Losses and Carrying Amount of Loans For the Year Ended December 31, 2019 (In thousands) Commercial Real Estate Other Residential Construction & Land Consumer Allowance Total Owner- Nonowner- Allowance for Loan Beginning balance $ 5,063 $ 6,919 $ 41,341 $ 12,448 $ 7,992 $ 2,695 $ 245 $ 76,703 Charge-offs (7,905 ) (1,093 ) (12,975 ) (2,967 ) (1,303 ) (2,867 ) 0 (29,110 ) Recoveries 3,733 80 2,599 858 175 706 0 8,151 Provision 4,663 2,618 16,360 (1,342 ) (3,511 ) 2,473 52 21,313 Ending balance $ 5,554 $ 8,524 $ 47,325 $ 8,997 $ 3,353 $ 3,007 $ 297 $ 77,057 Ending Balance: $ 973 $ 2,979 $ 11,931 $ 354 $ 262 $ 0 $ 0 $ 16,499 Ending Balance: $ 4,581 $ 5,545 $ 35,394 $ 8,643 $ 3,091 $ 3,007 $ 297 $ 60,558 Ending Balance: loans $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Allowance for Loan Losses and Carrying Amount of Loans For the Year Ended December 31, 2019 (In thousands) Commercial Real Other Residential Construction & Land Consumer Allowance Total Owner- Nonowner- Financing receivables: Ending balance $ 1,201,652 $ 3,965,960 $ 2,285,037 $ 3,686,401 $ 1,408,205 $ 1,166,293 $ 0 $ 13,713,548 Ending Balance: individually evaluated for impairment $ 16,703 $ 27,121 $ 54,108 $ 11,526 $ 14,047 $ 0 $ 0 $ 123,505 Ending Balance: collectively evaluated for impairment $ 1,160,556 $ 3,925,249 $ 2,194,432 $ 3,665,140 $ 1,382,369 $ 1,166,293 $ 0 $ 13,494,039 Ending Balance: loans acquired with deteriorated credit quality $ 24,393 $ 13,590 $ 36,497 $ 9,735 $ 11,789 $ 0 $ 0 $ 96,004 Allowance for Loan Losses and Carrying Amount of Loans For the Year Ended December 31, 2018 (In thousands) Commercial Real Other Residential Real Construction & Land Development Consumer Allowance for Estimated Total Owner- Nonowner- Allowance for Loan Beginning balance $ 5,401 $ 6,369 $ 45,189 $ 9,927 $ 7,187 $ 2,481 $ 73 $ 76,627 Charge-offs (3,225) (314) (16,424) (3,162) (2,731) (2,750) 0 (28,606) Recoveries 1,189 563 2,944 1,114 197 662 0 6,669 Provision 1,698 301 9,632 4,569 3,339 2,302 172 22,013 Ending balance $ 5,063 $ 6,919 $ 41,341 $ 12,448 $ 7,992 $ 2,695 $ 245 $ 76,703 Ending Balance: $ 2,543 $ 2,715 $ 17,581 $ 3,265 $ 2,254 $ 0 $ 0 $ 28,358 Ending Balance: $ 2,520 $ 4,204 $ 23,760 $ 9,183 $ 5,738 $ 2,695 $ 245 $ 48,345 Ending Balance: loans $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Financing receivables: Ending balance $ 1,291,790 $ 4,303,613 $ 1,957,641 $ 3,501,393 $ 1,410,468 $ 964,627 $ 0 $ 13,429,532 Ending Balance: $ 27,599 $ 25,231 $ 72,300 $ 21,998 $ 14,807 $ 0 $ 0 $ 161,935 Ending Balance: $ 1,234,919 $ 4,215,060 $ 1,860,085 $ 3,468,356 $ 1,374,840 $ 964,600 $ 0 $ 13,117,860 Ending Balance: loans $ 29,272 $ 63,322 $ 25,256 $ 11,039 $ 20,821 $ 27 $ 0 $ 149,737 United maintains an allowance for loan losses and a reserve for lending-related commitments such as unfunded loan commitments and letters of credit. The reserve for lending-related commitments of $1,733,000 and $1,389,000 at December 31, 2019 and December 31, 2018, respectively, is separately classified on the balance sheet and is included in other liabilities. The combined allowance for loan losses and reserve for lending-related commitments are referred to as the allowance for credit losses A progression of the allowance for credit losses, which includes the allowance for loan losses and the reserve for lending-related commitments, for the periods presented is summarized as follows: Year Ended December 31 (In thousands) 2019 2018 2017 Balance of allowance for loan losses at beginning of period $ 76,703 $ 76,627 $ 72,771 Provision for loan losses 21,313 22,013 28,406 98,016 98,640 101,177 Loans charged off (29,110) (28,606) (32,863) R 8,151 6,669 8,313 Net charge-offs (20,959) (21,937) (24,550) Balance of allowance for loan losses at end of period $ 77,057 $ 76,703 $ 76,627 Reserve for lending-related commitments 1,733 1,389 679 Balance of allowance for credit losses at end of period $ 78,790 $ 78,092 $ 77,306

Bank Premises and Equipment and

Bank Premises and Equipment and Leases	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Bank Premises and Equipment and Leases	NOTE G—BANK PREMISES AND EQUIPMENT Bank premises and equipment are summarized as follows: December 31 (In thousands) 2019 2018 Land $ 32,085 $ 31,679 Buildings and improvements 105,759 103,014 Leasehold improvements 40,789 41,001 Furniture, fixtures and equipment 71,377 72,045 250,010 247,739 Less allowance for depreciation and amortization (153,366 ) (152,494 ) Net bank premises and equipment $ 96,644 $ 95,245

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	NOTE H—LEASES United determines if an arrangement is a lease at inception. United and certain subsidiaries have entered into various noncancelable-operating leases for branch and loan production offices as well as operating facilities. Operating leases are included in operating lease right-of-use United’s operating leases are subject to renewal options under various terms. United’s operating leases have remaining terms of 1 ROU assets represent United’s right to use an underlying asset for the lease term and lease liabilities represent United’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. As most of United’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives. Lease terms may include options to extend the lease when it is reasonably certain that United will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. The components of lease expense were as follows: Year Ended (In thousands) Classification December 31, Operating lease cost Net occupancy expense $ 19,508 Sublease income Net occupancy expense (825) Net lease cost $ 18,683 Supplemental balance sheet information related to leases was as follows: (In thousands) Classification December 31, 2019 Operating lease right-of-use Operating lease right-of-use $ 57,783 Operating lease liabilities Operating lease liabilities $ 61,342 Other information related to leases was as follows: December 31, 2019 Weighted-average remaining lease term: Operating leases 4.91 years Weighted-average discount rate: Operating leases 3.20 % Supplemental cash flow information related to leases was as follows: Year Ended (In thousands) December 31, 2019 Cash paid for amounts in the measurement of lease liabilities: Operating cash flows from operating leases $ 19,601 ROU assets obtained in the exchange for lease liabilities 7,630 Maturities of lease liabilities by year and in the aggregate, under operating leases with initial or remaining terms of one year or more, for years subsequent to December 31, 2019, consists of the following: Year Amount (In thousands) 2020 $ 17,725 2021 15,180 2022 11,522 2023 8,751 2024 5,127 Thereafter 8,190 Total lease payments 66,495 Less: imputed interest (5,153 ) Total $ 61,342

Goodwill and Other Intangibles

Goodwill and Other Intangibles	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangibles	NOTE I The following is a summary of intangible assets subject to amortization and those not subject to amortization: December 31, 2019 Community Banking Mortgage Banking Total (In thousands) Gross Carrying Accumulated Gross Carrying Accumulated Gross Carrying Accumulated Amortized intangible assets: Core deposit $ 98,359 $ (69,508 ) $ 0 $ 0 $ 98,359 $ (69,508 ) Non-amortized George Mason $ 0 $ 1,080 $ 1,080 Goodwill not subject to amortization $ 1,472,699 $ 5,315 $ 1,478,014 December 31, 2018 Community Banking Mortgage Banking Total (In thousands) Gross Carrying Accumulated Gross Carrying Accumulated Gross Carrying Accumulated Amortized intangible assets: Core deposit intangible assets $ 98,359 $ (62,492 ) $ 0 $ 0 $ 98,359 $ (62,492 ) Non-amortized George Mason trade name $ 0 $ 1,080 $ 1,080 Goodwill not subject to amortization $ 1,472,699 $ 5,315 $ 1,478,014 The following table sets forth the anticipated amortization expense for intangible assets for the years subsequent to 2019: Year Amount (In thousands) 2020 $ 6,309 2021 5,369 2022 4,582 2023 4,322 2024 and thereafter 8,269

Deposits

Deposits	12 Months Ended
	Dec. 31, 2019
Banking and Thrift [Abstract]
Deposits	NOTE J The book value of deposits consisted of the following: (In thousands) December 31 2019 2018 Demand deposits $ 3,381,866 $ 3,212,878 Interest-bearing checking 372,175 374,495 Regular savings 882,889 954,961 Money market accounts 6,891,696 7,157,028 Time deposits under $100,000 723,941 712,313 Time deposits over $100,000 1,599,854 1,583,074 Total deposits $ 13,852,421 $ 13,994,749 Included in time deposits over $ 100 250 United’s subsidiary banks have received deposits, in the normal course of business, from the directors and officers of United and its subsidiaries, and their associates. Such related party deposits were accepted on substantially the same terms, including interest rates and maturities, as those prevailing at the time for comparable transactions with unrelated persons. The aggregate dollar amount of these deposits was $15,350,000 and $24,102,000 at December 31, 2019 and 2018, respectively.

Short-Term Borrowings

Short-Term Borrowings	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Short-Term Borrowings	NOTE At December 31, 2019 and 2018, short-term borrowings and the related weighted-average interest rates were as follows: 2019 2018 Weighted- Weighted- (Dollars in thousands) Average Average Amount Rate Amount Rate Federal funds purchased $ 0 0.00 % $ 23,400 2.40 % Securities sold under agreements to repurchase 124,654 1.09 % 152,927 (1) 0.96 % (1) Total $ 124,654 $ 176,627 (1) Excludes a wholesale security sold under an agreement to repurchase of $50,000 assumed in the Virginia Commerce merger that matured in May of 2018. Federal funds purchased and securities sold under agreements to repurchase have been a significant source of funds for the company. United has various unused lines of credit available from certain of its correspondent banks in the aggregate amount of $230,000,000. These lines of credit, which bear interest at prevailing market rates, permit United to borrow funds in the overnight market, and are renewable annually subject to certain conditions. The following table shows the distribution of United’s federal funds purchased and securities sold under agreements to repurchase and the weighted-average interest rates thereon at the end of each of the last three years. Also provided are the maximum amount of borrowings and the average amounts of borrowings as well as weighted-average interest rates for the last three years. The table does not include the long-term wholesale security sold under an agreement to repurchase mentioned above assumed in the Virginia Commerce merger. (Dollars in thousands) Federal Funds Purchased Securities Sold Under Agreements To Repurchase At December 31: 2019 $ 0 $ 124,654 2018 23,400 152,927 2017 16,235 261,352 101 (Dollars in thousands) Federal Funds Purchased Securities Sold Under To Repurchase Weighted-average interest rate at year-end: 2019 0.00 % 1.09 % 2018 2.40 % 0.96 % 2017 1.40 % 0.36 % Maximum amount outstanding at any month’s end: 2019 $ 0 $ 161,175 2018 25,790 328,484 2017 25,800 377,687 Average amount outstanding during the year: 2019 $ 1,899 $ 131,187 2018 16,773 194,956 2017 18,433 287,663 Weighted-average interest rate during the year: 2019 2.52 % 1.33 % 2018 1.86 % 0.61 % 2017 0.88 % 0.33 % At December 31, 2019, all the repurchase agreements were in overnight accounts. The rates offered on these funds vary according to movements in the federal funds and short-term United has a $20,000,000 line of credit with an unrelated financial institution to provide for general liquidity needs. The line is an unsecured, revolving line of credit. The line is renewable on a 360 day basis and carries an indexed, floating-rate of interest. The line requires compliance with various financial and nonfinancial covenants. At December 31, 2019, United had no Interest paid on short-term borrowings approximated $2,359,000, $2,238,000, and $

Long-Term Borrowings

Long-Term Borrowings	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Long-Term Borrowings	NOTE L—LONG-TERM BORROWINGS United’s subsidiary bank is a member of the Federal Home Loan Bank (FHLB). Membership in the FHLB makes available short-term and long-term borrowings from collateralized advances. All FHLB borrowings are collateralized by a mix of single-family residential mortgage loans, commercial loans and investment securities. At December 31, 2019, the total carrying value of loans pledged as collateral for FHLB advances approximated $4,317,748,000. United had an unused borrowing amount as of December 31, 2019 of approximately $3,666,479,000 available subject to delivery of collateral after certain trigger points. Advances may be called by the FHLB or redeemed by United based on predefined factors and penalties. At December 31, 2019 and 2018, FHLB advances and the related weighted-average interest rates were as follows: 2019 2018 Weighted- Weighted- Weighted- Weighted- (Dollars in thousands) Average Average Average Average Contractual Effective Contractual Effective Amount Rate Rate Amount Rate Rate FHLB advances $ 1,851,865 2.03 % 2.03 % $ 1,439,198 2.42 % 2.42 % Overnight funds of $250,000,000 were included in the $1,851,865,000 above at December 31, 2019. Overnight funds of $175,000,000 were included in the $1,439,198,000 above at December 31, 2018. The weighted-average effective rate considers the effect of any interest rate swaps designated as fair value hedges outstanding at year-end R At December 31, 2019, United had a total of fourteen Under the provisions of the subordinated debt, United has the right to defer payment of interest on the subordinated debt at any time, or from time to time, for periods not exceeding five years For reporting periods prior to June 30, 2017, the Trust Preferred Securities qualified as Tier 1 regulatory capital under the “Basel III Capital Rules” as published by United’s primary federal regulator, the Federal Reserve, in July of 2013. The “Basel III Capital Rules” established a new comprehensive capital framework for U.S. banking organizations. Because United was less than $15 billion in total consolidated assets, the Basel III Capital Rules grandfathered United’s Trust Preferred Securities as Tier 1 capital under the limitations for restricted capital elements in the general risk-based capital rules. As a result, beginning in 2015 (the adoption date), United’s Trust Preferred Securities was subject to a limit of 25 percent of Tier 1 capital elements excluding any non-qualifying phase-out. Information related to United’s statutory trusts is presented in the table below: (Dollars in thousands) Description Issuance Date Amount of Interest Rate Maturity Date United Statutory Trust III December 17, 2003 $20,000 3-month LIBOR + 2.85% December 17, 2033 United Statutory Trust IV December 19, 2003 $25,000 3-month LIBOR + 2.85% January 23, 2034 United Statutory Trust V July 12, 2007 $50,000 3-month LIBOR + 1.55% October 1, 2037 United Statutory Trust VI September 20, 2007 $30,000 3-month LIBOR + 1.30% December 15, 2037 Premier Statutory Trust II September 25, 2003 $ 6,000 3-month LIBOR + 3.10% October 8, 2033 Premier Statutory Trust III May 16, 2005 $ 8,000 3-month LIBOR + 1.74% June 15, 2035 Premier Statutory Trust IV June 20, 2006 $14,000 3-month LIBOR + 1.55% September 23, 2036 Premier Statutory Trust V December 14, 2006 $10,000 3-month LIBOR + 1.61% March 1, 2037 Centra Statutory Trust I September 20, 2004 $10,000 3-month LIBOR + 2.29% September 20, 2034 Centra Statutory Trust II June 15, 2006 $10,000 3-month LIBOR + 1.65% July 7, 2036 Virginia Commerce Trust II December 19, 2002 $15,000 6-month LIBOR + 3.30% December 19, 2032 Virginia Commerce Trust III December 20, 2005 $25,000 3-month LIBOR + 1.42% February 23, 2036 Cardinal Statutory Trust I July 27, 2004 $20,000 3-month LIBOR + 2.40% September 15, 2034 UFBC Capital Trust I December 30, 2004 $ 5,000 3-month LIBOR + 2.10% March 15, 2035 At December 31, 2019 and 2018, the Debentures and their related weighted-average interest rates were as follows: 2019 2018 (Dollars in thousands) Amount Weighted- Amount Weighted- United Statutory Trust III $ 20,619 4.75 % $ 20,619 5.64 % United Statutory Trust IV 25,774 4.79 % 25,774 5.37 % United Statutory Trust V 51,547 3.65 % 51,547 3.95 % United Statutory Trust VI 30,928 3.19 % 30,928 4.09 % Premier Statutory Trust II 6,186 5.09 % 6,186 5.54 % Premier Statutory Trust III 8,248 3.63 % 8,248 4.53 % Premier Statutory Trust IV 14,433 3.48 % 14,433 4.37 % Premier Statutory Trust V 10,310 3.52 % 10,310 4.35 % Centra Statutory Trust I 10,000 4.20 % 10,000 5.08 % Centra Statutory Trust II 10,000 3.64 % 10,000 4.09 % Virginia Commerce Trust II 12,475 5.22 % 12,245 5.80 % Virginia Commerce Trust III 17,268 3.33 % 16,742 4.07 % Cardinal Statutory Trust I 14,825 4.29 % 14,428 5.19 % UFBC Capital Trust I 3,551 3.99 % 3,445 4.89 % Total $ 236,164 $ 234,905 At December 31, 2019, the scheduled maturities of long-term borrowings were as follows: Year Amount (In thousands) 2020 $ 740,734 2021 826,527 2022 19,737 2023 0 2024 0 2025 and thereafter 251,031 Total $ 1,838,029 Interest paid on long-term borrowings approximated $43,830,000, $35,222,000, and $22,254,000 in 2019, 2018 and 2017, respectively.

Other Expense

Other Expense	12 Months Ended
	Dec. 31, 2019
Other Income and Expenses [Abstract]
Other Expense	NOTE M The following details certain items of other expense for the periods indicated: Year Ended December 31 (In thousands) 2019 2018 2017 Legal, consulting & other professional services $ 12,360 $ 13,248 $ 11,844 Franchise & other taxes not on income 11,330 11,428 12,586 Automated Teller Machine (ATM) expenses 7,336 6,892 6,686

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	NOTE N—INCOME TAXES The income tax provisions included in the consolidated statements of income are summarized as follows: Year Ended December 31 (In thousands) 2019 2018 2017 Current expense: Federal $ 43,337 $ 52,041 $ 65,459 State 6,798 9,429 7,960 Deferred expense: Federal 12,522 8,298 20,920 Tax Act remeasurement 0 (120 ) 37,732 State 1,683 1,175 2,175 Total income taxes $ 64,340 $ 70,823 $ 134,246 On December 22, 2017, the Tax Cuts and Jobs Act (the “Tax Act”) was signed into law. The Tax Act lowered the Federal corporate tax rate from 35% to 21% effective January 1, 2018 and made numerous other tax law changes. U.S. generally accepted accounting principles (GAAP) requires companies to recognize the effect of tax law changes in the period of enactment. As a result of the Tax Act, United was required to remeasure deferred tax assets and liabilities at the new tax rate and as a result, recorded provisional deferred income tax expense of $37,732,000 in the fourth quarter of 2017. Upon final analysis of available information and refinement of its calculations during 2018, United decreased the provisional amount by $120,000 which is included as a component of deferred income tax expense in the table above. The following is a reconciliation of income tax expense to the amount computed by applying the statutory federal income tax rate to income before income taxes: Year Ended December 31 (Dollars in thousands) 2019 2018 2017 Amount % Amount % Amount % Tax on income before taxes at statutory federal rate $ 68,132 21.0 $ 68,704 21.0 $ 99,689 35.0 Plus: State income taxes net of federal tax benefits 6,690 2.1 8,362 2.6 6,207 2.2 74,822 23.1 77,066 23.6 105,896 37.2 Increase (decrease) resulting from: Tax-exempt (2,813 ) (0.9 ) (3,298 ) (1.0 ) (5,362 ) (1.9 ) Tax credits (5,636 ) (1.7 ) (2,054 ) (0.6 ) (1,171 ) (0.4 ) Deferred taxes due to the Tax Act (0 ) 0.0 (120 ) 0.0 37,732 13.2 Other items-net (2,033 ) (0.7 ) (771 ) (0.3 ) (2,849 ) (1.0 ) Income taxes $ 64,340 19.8 $ 70,823 21.7 $ 134,246 47.1 For years ended 2019, 2018 and 2017, United incurred federal income tax expense of $54,000, a federal tax benefit of $ and federal income tax expense of $ , respectively , applicable to the sales and calls of securities . Income taxes paid approximated $56,459,000 , $ 55,336,000 , and $ 73,096,000 in 2019, 2018 and 2017, respectively. Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. At December 31, 2019, United had no federal or state net operating loss . Taxes not on income, which consists mainly of business franchise taxes, were $11,330,000, $11,428,000, and $12,586,000, for the years ended December 31, 2019, 2018 and 2017, respectively. These amounts are recorded in other expense in the Consolidated Statements of Income. Significant components of United’s deferred tax assets and liabilities (included in other assets in the Consolidated Balance Sheets) at December 31, 2019 and 2018 are as follows: (In thousands) 2019 2018 Deferred tax assets: Allowance for credit losses $ 18,358 $ 18,109 Accrued benefits payable 13.459 13,914 Other accrued liabilities 992 846 Pension plan accruals 3,313 1,217 Unrealized loss on securities available for sale 0 5,572 Other real estate owned 2,482 2,482 Lease liabilities under operating leases 14,293 0 Deferred mortgage points 0 983 Purchase accounting intangibles 5,917 18,091 Total deferred tax assets 58,814 61,214 Deferred tax liabilities: Premises and equipment 2,963 1,414 Unrealized gain on securities available for sale 2,755 0 Right-of-use assets under operating leases 13,464 0 Deferred mortgage points 389 0 Other 2,300 2,899 Total deferred tax liabilities 21,871 4,313 Net deferred tax assets $ 36,943 $ 56,901 At December 31, 2019 and 2018, United believes that all of the deferred tax amounts shown above are more likely than not to be realized based on an assessment of all available positive and negative evidence and therefore no In accordance with ASC Topic 740, “Income Taxes,” United records a liability for uncertain income tax positions based on a recognition threshold of more-likely-than-not, Below is a reconciliation of the total amounts of unrecognized tax benefits: December 31 (In thousands) 2019 2018 Unrecognized tax benefits at beginning of year $ 2,005 $ 2,894 Increase in unrecognized tax benefits as a result of tax positions taken during the current period 152 156 Decreases in the unrecognized tax benefits as a result of a (589 ) (1,045 ) Unrecognized tax benefits at end of year $ 1,568 2,005 The entire amount of unrecognized tax benefits, if recognized, would impact United’s effective tax rate. Over the next 12 months, the statute of limitations will close on certain income tax returns. However, at this time, United cannot reasonably estimate the amount of tax benefits, if any, it may recognize over the next 12 months. United is currently open to audit under the statute of limitations by the Internal Revenue Service for the years ended December 31, 2016, 2017 and 2018 and certain State Taxing authorities for the years ended December 31, 2016 through 2018. As of December 31, 2019, and 2018, the total amount of accrued interest related to uncertain tax positions was $667,000 and $675,000, respectively. United accounts for interest and penalties related to uncertain tax positions as part of its provision for federal and state income taxes. No

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Employee Benefit Plans	NOTE O—EMPLOYEE BENEFIT PLANS United has a defined benefit retirement plan covering qualified employees. Pension benefits are based on years of service and the average of the employee’s highest five consecutive plan years of basic compensation paid during the ten plan years preceding the date of determination. Contributions by United are intended to provide not only for benefits attributed to service to date, but also for those expected to be earned in the future. In September of 2007, after a recommendation by United’s Pension Committee and approval by United’s Board of Directors, the United Bankshares, Inc. Pension Plan (the Plan) was amended to change the participation rules. The decision to change the participation rules for the Plan followed current industry trends, as many large and medium size companies have taken similar steps. The amendment provided that employees hired on or after October 1, 2007, will not be eligible to participate in the Plan. However, new employees will continue to be eligible to participate in United’s Savings and Stock Investment 401(k) plan. This change had no impact on current employees hired prior to October 1, 2007 as they will continue to participate in the Plan, with no change in benefit provisions, and will continue to be eligible to participate in United’s Savings and Stock Investment 401(k) Plan. As of December 31, 2016, United changed the method used to estimate the interest cost component of net periodic benefit cost for the Plan. Under the previous method, appropriate spot rates were used to discount the projected benefit obligation (PBO) cash flows based on date of measurement. Then, a single aggregated discount rate was calculated such that the present value of the PBO remained the same. This rate is technically a weighted-average of the spot rates. This single discount rate was applied to the interest and service costs as well. Under the full yield curve approach, separate discount rates are used to calculate the present value for each projected cash flow. That is, individual spot rates are applied to the cash flows in each time period. This does not have any impact on the present value of the PBO as the PBO was originally discounted with spot rates. The adoption of this method concerns the manner in which it affects interest and service costs. Interest costs typically decrease when using this method because of the different weightings applied to the cash flows; that is, interest costs closer to the current period will be discounted with a smaller rate than those further in the future based on a typical yield curve, and greater future Interest Costs values are discounted with greater longer-term spot rates. Similarly, service costs typically have longer durations and will thus be subject to longer-term spot rates, decreasing the present value of these costs. As a result, the full yield curve method is preferable as it provides a more granular, and thus a more accurate, determination of costs. This new method constitutes a change in an accounting estimate under the provisions of ASC Topic 250, “Accounting Changes and Error Corrections,” that is inseparable from a change in accounting principle and was accounted for prospectively, with the resulting change impacting the recognition of net periodic pension cost beginning January 1, 2017. The impact of this accounting change on United’s net periodic pension cost for the year of 2017 was a decline of $1,000,000 in expense from the amount that would have been recorded under the previous method Net consolidated periodic pension cost included the following components: (Dollars in thousands) Year Ended December 31, 2019 2018 2017 Service cost $ 2,173 $ 2,566 $ 2,146 Interest cost 5,931 5,341 5,149 Expected return on plan assets (9,434) (10,260) (8,538) Recognized net actuarial loss 4,965 4,919 4,553 Net periodic pension cost $ 3,635 $ 2,566 $ 3,310 Weighted-Average Assumptions: Discount rate 4.52% 3.83% 4.49% Expected return on assets 7.00% 7.00% 7.00% Rate of Compensation Increase (prior to age 45) 3.50% 3.50% 3.50% Rate of Compensation Increase (otherwise) 3.00% 3.00% 3.00% Amounts related to the Plan recognized as a component of other comprehensive income were as follows: (In thousands) Year Ended December 31, 2019 2018 2017 Net actuarial loss $ 10,324 $ 4,232 $ 6,784 Amortization of: Prior service cost 0 0 0 Actuarial loss (4,965) (4,919) (4,553) Total recognized in other comprehensive income $ 5,359 $ (687) $ 2,231 Included in accumulated other comprehensive income at December 31, 2019 are unrecognized actuarial losses of $60,894,000 ($46,706,000 net of tax) that have not yet been recognized in net periodic pension cost. The amortization of this item expected to be recognized in net periodic pension cost during the fiscal year ended December 31, 2020 is $5,802,000 ($4,450,000 net of tax). The reconciliation of the beginning and ending balances of the projected benefit obligation and the fair value of plan assets for the years ended December 31, 2019 and 2018 and the accumulated benefit obligation at December 31, 2019 and 2018 are as follows: (Dollars in thousands) December 31, Change in Projected Benefit Obligation Projected Benefit Obligation at the Beginning of the Year $ 142,632 $ 152,740 Service Cost 2,173 2,566 Interest Cost 5,931 5,341 Actuarial Loss (Gain) 28,364 (13,301 ) Benefits Paid (5,323 ) (4,714 ) Projected Benefit at the End of the Year $ 173,777 $ 142,632 Accumulated Benefit Obligation at the End of the Year $ 157,154 $ 130,567 Change in Plan Assets Fair Value of Plan Assets at the Beginning of the Year $ 137,408 $ 142,395 Actual Return on Plan Assets 27,475 (7,273 ) Benefits Paid (5,323 ) (4,714 ) Employer Contributions 0 7,000 Fair value of plan assets at end of year $ 159,560 $ 137,408 Net Amount Recognized Funded Status $ (14,217 ) $ (5,224 ) Unrecognized Transition Asset 0 0 Unrecognized Prior Service Cost 0 0 Unrecognized Net Loss 60,894 55,535 Net Amount Recognized $ 46,677 $ 50,311 Weighted-Average Assumptions at the End of the Year Discount Rate 3.42 % 4.52 % Rate of Compensation Increase (prior to age 40) 5.00 % n/a Rate of Compensation Increase (ages 40-54) 4.00 % n/a Rate of Compensation Increase (prior to age 45) n/a 3.50 % Rate of Compensation Increase (otherwise) 3.50 % 3.00 % Asset allocation for the defined benefit pension plan as of the measurement date, by asset category, is as follows: Plan Assets Target Allocation 2020 Allowable Allocation Range Percentage of Plan Assets at December 31, December 31, Equity Securities 62 % 50-70 % 63 % 67% Debt Securities 35 % 20-50 % 35 % 26% Other 3 % 3-15 % 2 % 7% Total 100 % 100% Equity securities include United common stock in the amounts of $4,091,000 (3%) at December 31, 2019 and $3,292,000 (4%) at December 31, 2018 . The policy, as established by the Pension Committee, primarily consisting of United’s Executive Management, is to invest assets based upon the target allocations stated above. The assets are reallocated periodically to meet the above target allocations. The investment policy is reviewed at least annually, subject to the approval of the Pension Committee, to determine if the policy should be changed. Prohibited investments include, but are not limited to, futures contracts, private placements, uncovered options, real estate, the use of margin, short sales, derivatives for speculative purposes, and other investments that are speculative in nature. In order to achieve a prudent level of portfolio diversification, the securities of any one company are not to exceed 10% of the total plan assets, and no more than the 15% of total plan assets is to be invested in any one industry (other than securities of U.S. Government or Agencies). Additionally, no more than 15% of the plan assets is to be invested in foreign securities, both equity and fixed. The expected long-term rate of return for the plan’s total assets is based on the expected return of each of the above categories, weighted based on the median of the target allocation for each class. United uses the corridor approach based on 10% of the greater of the projected benefit obligation and the market-related value of plan assets to amortize actuarial gains and losses. At December 31, 2019, the benefits expected to be paid in each of the next five fiscal years, and in the aggregate for the five years thereafter are as follows: Year Amount (In thousands) 2020 $ 5,906 2021 6,267 2022 6,637 2023 7,055 2024 7,390 2025 through 2029 42,310 United did not contribute to the plan in 2019 as no contributions were required by funding regulations or law. During the first quarter of 2018 and the third quarter of 2017, United made discretionary contributions of $7,000,000 and $10,000,000, respectively. For 2020, no contributions to the plan are required by funding regulations or law. However, United may make a discretionary contribution in 2020, the amount of which cannot be reasonably estimated at this time. In accordance with ASC Topic 715 and using the guidance contained in ASC Topic 820, the following is a description of the valuation methodologies used to measure the plan assets at fair value. Cash and Cash Equivalents: Debt Securities Common and Preferred Stock: Mutual Funds: The following tables present the balances of the plan assets, by fair value hierarchy level, as of December 31, 2019 and 2018: Fair Value Measurements at December 31, 2019 Using (In thousands) Description Balance as of December 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and Cash equivalents $ 2,504 $ 2,504 $ 0 $ 0 Fixed Income Mutual Funds: Taxable 55,588 55,588 0 0 Equity Securities: Common stock 23,932 23,932 0 0 Equity Mutual Funds: Fair Value Measurements at December 31, 2019 Using (In thousands) Description Balance as of December 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Global equity 5,247 5,247 0 0 Domestic equity large cap 28,743 28,743 0 0 Domestic equity small cap 22,216 22,216 0 0 International emerging equity 8,228 8,228 0 0 International equity develope d 13,102 13,102 0 0 Total $ 159,560 $ 159,560 $ 0 $ 0 Fair Value Measurements at December 31, 2018 Using (In thousands) Description Balance as of December 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and Cash equivalents $ 10,086 $ 10,086 $ 0 $ 0 Fixed Income Mutual Funds: Taxable 35,086 35,086 0 0 Equity Securities: Common stock 22,846 22,846 0 0 Equity Mutual Funds: Domestic equity large cap 28,090 28,090 0 0 Domestic equity small cap 15,212 15,212 0 0 International emerging equity 8,791 8,791 0 0 International equity developed 17,297 17,297 0 0 Total $ 137,408 $ 137,408 $ 0 $ 0 Common stock investments are diversified amongst various industries with no industry representing more than 5% of the total plan assets. The United Bankshares, Inc. Savings and Stock Investment Plan (the Plan) is a defined contribution plan under Section 401(k) of the Internal Revenue Code. Each employee of United, who completes ninety (90) days of qualified service, is eligible to participate in the Plan. Each participant may contribute from 1% to 100% of compensation to his/her account, subject to Internal Revenue Service maximum deferral limits. United matches 100% of the first 4% of salary deferred with United stock. Vesting is 100% for employee deferrals and the company match at the time the employee makes his/her deferral. United’s expense relating to the Plan approximated $4,565,000, $4,486,000, and $3,201,000 in 2019, 2018 and 2017, respectively. The assets of United’s defined benefit plan and 401(k) Plan each include investments in United common stock. At December 31, 2019 and 2018, the combined plan assets included 1,176,283 and 1,099,386 shares, respectively, of United common stock with an approximate fair value of $45,475,000 and $34,202,000, respectively. Dividends paid on United common stock held by the plans approximated $1,566,000, $1,401,000, and $1,218,000 for the years ended December 31, 2019, 2018, and 2017, respectively. United has certain other supplemental deferred compensation plans covering various key employees. Periodic charges are made to operations so that the liability due each employee is fully recorded as of the date of their retirement. Amounts charged to expense have not been significant in any year.

Stock Based Compensation

Stock Based Compensation	12 Months Ended
	Dec. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Based Compensation	NOTE P—STOCK BASED COMPENSATION On May 18, 2016, United’s shareholders approved the 2016 Long-Term Incentive Plan (2016 LTI Plan). The 2016 LTI Plan became effective as of May 18, 2016. An award granted under the 2016 LTI Plan may consist of any non-qualified non-employee non-employee S-8 During the year of 2019, a total of 240,205 non-qualified Stock Options United currently has options outstanding from various option plans other than the 2016 LTI Plan (the Prior Plans); however, no common shares of United stock are available for grants under the Prior Plans as these plans have expired. Awards outstanding under the Prior Plans will remain in effect in accordance with their respective terms. The maximum term for options granted under the plans is ten ( 10 The fair value of the options for 2019 was estimated at the date of grant using a binomial lattice option pricing model with the following weighted-average assumptions: risk-free interest rates of 2.54%; dividend yield of 3.00%; volatility factors of the expected market price of United’s common stock of 0.243; and a weighted-average expected option life of 6.72 years, respectively. The estimated fair value of the options at the date of grant was $7.16 for the options granted during 2019. ASC Topic 718, “Compensation – Stock Compensation” defines a lattice model as a model that produces an estimated fair value based on the assumed changes in prices of a financial instrument over successive periods of time. A binomial lattice model assumes at least two price movements are possible in each period of time. A summary of activity under the United’s stock option plans as of December 31, 2019, and the changes during the year of 2019 are presented below: Year ended December 31, 2019 Weighted Average (Dollars in thousands, except per share data) Aggregate Remaining Exercise Shares Value Term (Yrs.) Price Outstanding at January 1, 2019 1,730,389 $ 32.43 Granted 240,205 38.49 Exercised (128,742 ) 23.12 Forfeited or expired (126,536 ) 25.44 Year ended December 31, 2019 Weighted Average (Dollars in thousands, except per share data) Aggregate Remaining Exercise Shares Value Term (Yrs.) Price Outstanding at December 31, 2019 1,715,316 $ 8,707 5.6 $ 34.49 Exercisable at December 31, 2019 1,125,579 $ 8,342 4.2 $ 31.97 The following table summarizes the status of United’s nonvested awards for the year ended December 31, 2019: Shares Weighted-Average Grant Date Fair Value Per Share Nonvested at January 1, 2019 575,672 $ 7.86 Granted 240,205 7.16 Vested (211,326 ) 7.74 Forfeited or expired (14,814 ) 7.55 Nonvested at December 31, 2019 589,737 $ 7.62 As of December 31, 2019, the total unrecognized compensation cost related to nonvested option awards was $2,871,000 with a weighted-average expense recognition period of 1.2 years. The total fair value of awards vested during the year ended December 31, 2019, was $1,636,000. Cash received from options exercised under the Plans for the years ended December 31, 2019, 2018 and 2017 was $1,272,000, $ 1,500,000 4,619,000 ASC Topic 230, “Statement of Cash Flows,” requires the benefits of tax deductions in excess of recognized compensation cost to be reported as an operating cash flow. This requirement reduces net operating cash flows. While the company cannot estimate what those amounts will be in the future (because they depend on, among other things, the date employees exercise stock options), United recognized cash flows used in operating activities of $ 223,000, 158,000 2,201,000 Restricted Stock Under the 2016 non-employee four The following summarizes the changes to United’s restricted common shares for the year ended December 31, 2019: Number of Weighted-Average Grant Date Fair Value Per Share Outstanding at January 1, 2019 199,303 $ 39.67 Granted 126,427 38.49 Vested (73,685) 39.28 Forfeited (4,149) 39.08 Outstanding at December 31, 2019 247,896 $ 39.20

Commitments and Contingent Liab

Commitments and Contingent Liabilities	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	NOTE Q—COMMITMENTS AND CONTINGENT LIABILITIES Lending-related Commitments United is a party to financial instruments with off-balance-sheet United’s maximum exposure to credit loss in the event of nonperformance by the counterparty to the financial instrument for the loan commitments and standby letters of credit is the contractual or notional amount of those instruments. United uses the same policies in making commitments and conditional obligations as it does for on-balance Commitments to extend credit are agreements to lend to a customer as long as there is no violation of any condition established in the commitment contract. Commitments generally have fixed expiration dates or other termination clauses and may require the payment of a fee. Since many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily, and historically do not, represent future cash requirements. The amount of collateral obtained, if deemed necessary upon the extension of credit, is based on management’s credit evaluation of the counterparty. United had approximately $3,610,777,000 and $3,826,370,000 of loan commitments outstanding as of December 31, 2019 and 2018, respectively, approximately half of which contractually expire within one year. Included in the December 31, 2019 amount are commitments to extend credit of $235,883,000 related to George Mason’s mortgage loan funding commitments and are of a shot-term nature. Commercial and standby letters of credit are agreements used by United’s customers as a means of improving their credit standing in their dealings with others. Under these agreements, United guarantees certain financial commitments of its customers. A commercial letter of credit is issued specifically to facilitate trade or commerce. Typically, under the terms of a commercial letter of credit, a commitment is drawn upon when the underlying transaction is consummated as intended between the customer and a third party. As of December 31, 2019 , United had approximately $5,092,000 of outstanding commercial letters of credit. As of December 31, 2018, United had no outstanding commercial letters of credit. A standby letter of credit is generally contingent upon the failure of a customer to perform according to the terms of an underlying contract with a third party. United has issued standby letters of credit of $145,105,000 and $141,032,000 as of December 31, 2019 and 2018, respectively. In accordance with ASC Topic 450, “Contingencies,” United has determined that substantially all of its letters of credit are renewed on an annual basis and the fees associated with these letters of credit are immaterial. Mortgage Repurchase Reserve George Mason provides for its estimated exposure to repurchase loans previously sold to investors for which borrowers failed to provide full and accurate information on their loan application or for which appraisals have not been acceptable or where the loan was not underwritten in accordance with the loan program specified by the loan investor, and for other exposure to its investors related to loan sales activities. United evaluates the merits of each claim and estimates its reserve based on actual and expected claims received and considers the historical amounts paid to settle such claims. George Mason has a reserve of $ as of December , . United has derivative counter-party risk that may arise from the possible inability of George Mason’s third party investors to meet the terms of their forward sales contracts. George Mason works with third-party investors that are generally well-capitalized, are investment grade and exhibit strong financial performance to mitigate this risk. United does not expect any third-party investor to fail to meet its obligation. Legal Proceedings United and its subsidiaries are currently involved in various legal proceedings in the normal course of business. Management is vigorously pursuing all its legal and factual defenses and, after consultation with legal counsel, believes that all such litigation will be resolved with no material effect on United’s financial position. Regulatory Matters A variety of consumer products, including mortgage and deposit products, and certain fees and charges related to such products, have come under increased regulatory scrutiny. It is possible that regulatory authorities could bring enforcement actions, including civil money penalties, or take other actions against United in regard to these consumer products. United could also determine of its own accord, or be required by regulators, to refund or otherwise make remediation payments to customers in connection with these products. It is not possible at this time for management to assess the probability of a material adverse outcome or reasonably estimate the amount of any potential loss related to such matters.

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	NOTE R—DERIVATIVE FINANCIAL INSTRUMENTS United uses derivative instruments to help aid against adverse price changes or interest rate movements on the value of certain assets or liabilities and on future cash flows. These derivatives may consist of interest rate swaps, caps, floors, collars, futures, forward contracts, written and purchased options. United also executes derivative instruments with its commercial banking customers to facilitate its risk management strategies. United accounts for its derivative financial instruments in accordance with ASC Topic 815 which requires all derivative instruments to be carried at fair value on the balance sheet. United has designated certain derivative instruments used to manage interest rate risk as hedge relationships with certain assets, liabilities or cash flows being hedged. Certain derivatives used for interest rate risk management are not designated in a hedge relationship. Derivative instruments designated in a hedge relationship to mitigate exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivative instruments designated in a hedge relationship to mitigate exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. For a fair value hedge, the fair value of the interest rate swap is recognized on the balance sheet as either a freestanding asset or liability with a corresponding adjustment to the hedged financial instrument. Subsequent adjustments due to changes in the fair value of a derivative that qualifies as a fair value hedge are offset in current period earnings. For a cash flow hedge, the fair value of the interest rate swap is recognized on the balance sheet as either a freestanding asset or liability with a corresponding adjustment to other comprehensive income within shareholders’ equity, net of tax. Subsequent adjustments due to changes in the fair value of a derivative that qualifies as a cash flow hedge are offset to other comprehensive income, net of tax. The portion of a hedge that is ineffective is recognized immediately in earnings. At inception of a hedge relationship, United formally documents the hedged item, the particular risk management objective, the nature of the risk being hedged, the derivative being used, how effectiveness of the hedge will be assessed and how the ineffectiveness of the hedge will be measured. United also assesses hedge effectiveness at inception and on an ongoing basis using regression analysis. Hedge ineffectiveness is measured by using the change in fair value method. The change in fair value method compares the change in the fair value of the hedging derivative to the change in the fair value of the hedged exposure, attributable to changes in the benchmark rate. The portion of a hedge that is ineffective is recognized immediately in earnings. United through George Mason enters into interest rate lock commitments to finance residential mortgage loans with its customers. These commitments, which contain fixed expiration dates, offer the borrower an interest rate guarantee provided the loan meets underwriting guidelines and closes within the timeframe established by United. Interest rate risk arises on these commitments and subsequently closed loans if interest rates change between the time of the interest rate lock and the delivery of the loan to the investor. Market risk on interest rate lock commitments and mortgage loans held for sale is managed using corresponding forward mortgage loan sales contracts. United is a party to these forward mortgage loan sales contracts to sell loans servicing released and short sales of mortgage-backed securities. When the interest rate is locked with the borrower, the rate lock commitment, forward sale agreement, and mortgage-backed security position are undesignated derivatives and marked to fair value through earnings. The fair value of the rate lock derivative includes the servicing premium and the interest spread for the difference between retail and wholesale mortgage rates. Income from mortgage banking activities includes the gain recognized for the period presented and associated elements of fair value. United sells mortgage loans on either a best efforts or mandatory delivery basis. For loans sold on a mandatory delivery basis, United enters into forward mortgage-backed securities (the “residual hedge”) to mitigate the effect of interest rate risk. Both the rate lock commitment under mandatory delivery and the residual hedge are recorded at fair value through earnings and are not designated as accounting hedges. At the closing of the loan, the loan commitment derivative expires and United records a loan held for sale at fair value and continues to mark these assets to market under the election of fair value option. United closes out of the trading mortgage-backed securities assigned within the residual hedge and replaces the securities with a forward sales contract once a price has been accepted by an investor and recorded at fair value. For those loans selected to be sold under best efforts delivery, at the closing of the loan, the rate lock commitment derivative expires and the Company records a loan held for sale at fair value under the election of fair value option and continues to be obligated under the same forward loan sales contract entered into at inception of the rate lock commitment. The derivative portfolio also includes derivative financial instruments not included in hedge relationships. These derivatives consist of interest rate swaps used for interest rate management purposes and derivatives executed with commercial banking customers to facilitate their interest rate management strategies. For derivatives that are not designated in a hedge relationship, changes in the fair value of the derivatives are recognized in earnings in the same period as the change in fair value. Gains and losses on other derivative financial instruments are included in noninterest income and noninterest expense, respectively. The following tables disclose the derivative instruments’ location on the Company’s Consolidated Balance Sheets and the notional amount and fair value of those instruments at December 31, 2019 and 2018. Asset Derivatives December 31, 2019 December 31, 2018 (In thousands) Balance Sheet Location Notional Amount Fair Value Balance Sheet Location Notional Amount Fair Value Derivatives designated as hedging instruments Fair Value Hedges: Interest rate swap contracts (hedging commercial loans) Other assets $ 0 $ 0 Other assets $ 85,623 $ 1,859 Total derivatives designated as hedging instruments $ 0 $ 0 $ 85,623 $ 1,859 Derivatives not designated as hedging instruments Interest rate swap contracts Other assets $ 0 $ 0 Other assets $ 0 $ 0 Forward loan sales commitments Other assets 27,260 9 Other assets 21,604 542 Interest rate lock commitments Other assets 117,252 4,518 Other assets 93,955 4,103 Total derivatives not designated as hedging instruments $ 144,512 $ 4,527 $ 115,559 $ 4,645 Total asset derivatives $ 144,512 $ 4,527 $ 201,182 $ 6,504 Liability Derivatives December 31, 2019 December 31, 2018 (In thousands) Balance Sheet Location Notional Amount Fair Value Balance Sheet Location Notional Amount Fair Value Derivatives designated as hedging instruments Fair Value Hedges: Interest rate swap contracts (hedging commercial loans) Other liabilities $ 82,243 $ 2,394 Other liabilities $ 0 $ 0 Total derivatives designated as hedging instruments $ 82,243 $ 2,394 $ 0 $ 0 Liability Derivatives December 31, 2019 December 31, 2018 (In thousands) Balance Sheet Location Notional Amount Fair Value Balance Sheet Location Notional Amount Fair Value Derivatives not designated as hedging instruments Interest rate swap contracts Other liabilities $ 0 $ 0 Other liabilities $ 0 $ 0 TBA mortgage-backed securities Other liabilities 274,000 671 Other liabilities 200,281 3,002 Interest rate lock commitments Other liabilities 0 0 Other liabilities 0 0 Total derivatives not designated as hedging instruments $ 274,000 $ 671 $ 200,281 $ 3,002 Total liability derivatives $ 356,243 $ 3,065 $ 200,281 $ 3,002 The following table represents the carrying amount of the hedged assets/(liabilities) and the cumulative amount of fair value hedging adjustment December 31, 2019 (In thousands) Derivatives in Fair Value Hedging Relationships Location in the Statement Carrying Amount of Assets/(Liabilities) Cumulative Amount Cumulative Amount of Interest rate swaps Loans, net of unearned income $ 81,397 $ (2,394 ) $ 0 Derivative contracts involve the risk of dealing with both bank customers and institutional derivative counterparties and their ability to meet contractual terms. Credit risk arises from the possible inability of counterparties to meet the terms of their contracts. United’s exposure is limited to the replacement value of the contracts rather than the notional amount of the contract. The Company’s agreements generally contain provisions that limit the unsecured exposure up to an agreed upon threshold. Additionally, the Company attempts to minimize credit risk through certain approval processes established by management. The effect of United’s derivative financial instruments on its Consolidated Statements of Income for the years ended December 31, 2019, 2018 and 2017 is presented as follows: Year Ended (In thousands) Income Statement Location December 31, December 31, December 31, Derivatives in hedging relationships Fair Value Hedges: Interest rate swap contracts Interest income/ (expense) $ (95 ) $ (170 ) $ (781 ) Total derivatives in hedging relationships $ (95 ) $ (170 ) $ (781 ) Derivatives not designated as hedging instruments Forward loan sales commitments Income from Mortgage Banking Activities 925 530 (426 ) TBA mortgage-backed securities Income from Mortgage Banking Activities 2,331 (2,690 ) 1,547 Interest rate lock commitments Income from Mortgage Banking Activities 3,607 (2,413 ) (7,730 ) Total derivatives not designated as hedging instruments $ 6,863 $ (4,573 ) $ (6,609 ) Total derivatives $ 6,768 $ (4,743 ) $ (7,390 ) For the years ended December 31, 2019, 2018 and 2017, changes in the fair value of any interest rate swaps attributed to hedge ineffectiveness were recorded, but not significant to United’s Consolidated Statements of Income.

Comprehensive Income

Comprehensive Income	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Comprehensive Income	NOTE S—COMPREHENSIVE INCOME The changes in accumulated other comprehensive income are as follows: For the Years Ended December 31 (In thousands) 2019 2018 2017 Net Income $ 260,099 $ 256,342 $ 150,581 Available for sale (“AFS”) securities: AFS securities with OTTI charges during the period (641 ) (1,456 ) (60 ) Related income tax effect 149 339 22 Less : OTTI charges recognized in net income 198 1,456 60 Related income tax benefit (46 ) (339 ) (22 ) Reclassification of previous noncredit OTTI to credit OTTI 2,188 0 0 Related income tax benefit (510 ) 0 0 Net unrealized gains on AFS securities with OTTI 1,338 0 0 AFS securities – all other: Change in net unrealized gains (losses) on AFS securities arising during the period 32,376 (14,715 ) 8,371 Related income tax effect (7,543 ) 5,109 (3,097 ) Net reclassification adjustment for gains included in net income 97 770 (1,874 ) Related income tax (benefit) expense (23 ) (179 ) 693 24,907 (9,015 ) 4,093 Net effect of AFS securities on other comprehensive income 26,245 (9,015 ) 4,093 Held to maturity (“HTM”) securities: Accretion on the unrealized loss for securities transferred from AFS to the HTM investment portfolio prior to call or maturity 0 8 8 Related income tax benefit (0 ) (2 ) (3 ) Net effect of HTM securities on other comprehensive income 0 6 5 Defined benefit pension plan: Net actuarial loss during the period (10,324) (4,232) (6,784) Related income tax expense 2,384 1,063 2,510 Amortization of prior service cost recognized in net income 0 0 0 Related income tax benefit 0 0 0 Amortization of net actuarial loss recognized in net income 4,965 4,919 4,553 Related income tax benefit (1,170) (1,246) (1,685) Net effect of change in defined benefit pension plan on other comprehensive income (4,145) 504 (1,406) Total change in other comprehensive income, net of tax 22,100 (8,505 ) 2,692 Total Comprehensive Income $ 282,199 $ 247,837 $ 153,273 The components of accumulated other comprehensive income for the year ended December 31, 2019 are as follows: Changes in Accumulated Other Comprehensive Income (AOCI) by Component (a) For the Year Ended December 31, 2019 (Dollars in thousands) Unrealized Accretion on the Defined Items Total Balance at January 1, 2019 $ (18,289 ) $ (50 ) $ (38,680 ) $ (57,019 ) Reclass due to adopting Accounting Standard Update 2017-12 0 50 0 50 Other comprehensive income before reclassification 24,493 0 0 24,493 Amounts reclassified from accumulated other comprehensive income 1,752 0 (4,145 ) (2,393 ) Net current-period other comprehensive income, net of tax 26,245 0 (4,145 ) 22,100 Balance at December 31, 2019 $ 7,956 $ 0 $ (42,825 ) $ (34,869 ) (a) All amounts are net-of-tax. Reclassifications out of Accumulated Other Comprehensive Income (AOCI) For the Year Ended December 31, 2019 (Dollars in thousands) Details about AOCI Components Amount Reclassified from AOCI Affected Line Item in the Statement Where Net Income is Presented Available for sale (“AFS”) securities: Reclassification of previous noncredit OTTI to credit OTTI $ 2,188 Total other-than-temporary impairment losses Net reclassification adjustment for losses (gains) included in net income 97 Net gains on sales/calls of investment securities 2,285 Total before tax Related income tax effect (533 ) Tax expense 1,752 Net of tax Pension plan: Net actuarial loss (10,324 )(a) Amortization of net actuarial loss 4,965 (b) (5,359 ) Total before tax Related income tax effect 1,214 Tax expense (4,145 ) Net of tax Total reclassifications for the period $ (2,393 ) (a) This AOCI component is included in the computation of changes in plan assets (see Note O (b) This AOCI component is included in the computation of net periodic pension cost (see Note O

United Bankshares, Inc. (Parent

United Bankshares, Inc. (Parent Company Only) Financial Information	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Disclosure [Abstract]
United Bankshares, Inc. (Parent CompanyOnly) Financial Information	NOTE T—UNITED BANKSHARES, INC. (PARENT COMPANY ONLY) FINANCIAL INFORMATION Condensed Balance Sheets December 31 (In thousands) 2019 2018 Assets Cash and due from banks $ 126,697 $ 68,186 Securities available for sale 7,451 6,822 Securities held to maturity 20 997 Equity securities 4,126 5,094 Other investment securities 10,053 163 Investment in subsidiaries: Bank subsidiaries 3,519,661 3,478,956 Nonbank subsidiaries 22,439 14,706 Goodwill (16,008 ) (16,008 ) Condensed Balance Sheets December 31 (In thousands) 2019 2018 Other assets 12,286 10,615 Total Assets $ 3,686,725 $ 3,569,531 Liabilities and Shareholders’ Equity Junior subordinated debentures of subsidiary trusts $ 236,164 $ 234,905 Accrued expenses and other liabilities 86,728 83,002 Shareholders’ equity (including other accumulated comprehensive loss of $34,869 and $57,019 at December 31, 2019 and 2018, respectively) 3,363,833 3,251,624 Total Liabilities and Shareholders’ Equity $ 3,686,725 $ 3,569,531 Condensed Statements of Income Year Ended December 31 (In thousands) 2019 2018 2017 Income Dividends from banking subsidiaries: Bank subsidiaries $ 249,000 $ 215,000 $ 115,000 Nonbank subsidiaries 0 0 58 Net interest income 126 227 437 Management fees: Bank subsidiaries 27,325 25,026 45,693 Nonbank subsidiaries 27 27 27 Other income 147 (596 ) 1,766 Total Income 276,625 239,684 162,981 Expenses Operating expenses 38,569 37,214 71,653 Income Before Income Taxes and Equity in Undistributed Net Income of Subsidiaries 238,056 202,470 91,328 Applicable income tax benefit (2,123 ) (2,470 ) (6,126 ) Income Before Equity in Undistributed Net Income of Subsidiaries 240,179 204,940 97,454 Equity in undistributed net income of subsidiaries: Bank subsidiaries 19,557 51,392 50,560 Nonbank subsidiaries 363 10 2,567 Net Income $ 260,099 $ 256,342 $ 150,581 Condensed Statements of Cash Flows Year Ended December 31 (In thousands) 2019 2018 2017 Operating Activities Net income $ 260,099 $ 256,342 $ 150,581 Adjustments to reconcile net income to net cash provided by operating activities: Equity in undistributed net income of subsidiaries (19,920 ) (51,402) (53,127) Amortization of net periodic pension costs 302 293 228 Stock-based compensation 4,914 4,073 3,555 Excess tax benefits from stock-based compensation arrangements 223 158 2,201 Net gain on securities transactions 0 607 (1,185) Net change in other assets and liabilities 1,770 (1,904) 8,764 Net Cash Provided by Operating Activities 247,388 208,167 111,017 Investing Activities Net proceeds from sales (purchases) of securities 236 9,446 (19,268) Net proceeds from sales of equity securities 1,116 1,348 0 Condensed Statements of Cash Flows Year Ended December 31 (In thousands) 2019 2018 2017 Net cash paid in acquisition of subsidiary 0 0 22,146 Increase in investment in subsidiaries (7,000) (2,400) (34,203) Change in other investment securities (9,890) 0 (63) Net Cash (Used in) Provided by Investing Activities (15,538) 8,394 (31,388) Financing Activities Proceeds from issuance of common stock 0 0 0 Cash dividends paid (138,939 ) (142,350) (121,354) Acquisition of treasury stock (35,573 ) (100,724) (1) Proceeds from sale of treasury stock from deferred compensation plan 1 1 1 Proceeds from exercise of stock options 1,272 1,500 4,619 Net Cash Used in Financing Activities (173,339 ) (241,573) (116,735) Increase (De crease) 58,511 (25,012) (37,106) Cash and Cash Equivalents at Beginning of Year 68,186 93,198 130,304 Cash and Cash Equivalents at End of Year $ 126,697 $ 68,186 $ 93,198

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2019
Banking and Thrift [Abstract]
Regulatory Matters	NOTE U—REGULATORY MATTERS The subsidiary banks are required to maintain average reserve balances with their respective Federal Reserve Bank. The average amount of those consolidated reserve balances maintained and required for the year ended December 31, 2019, were approximately $653,653,000 and $255,894,000, respectively. The average amount of those consolidated reserve balances maintained and required for the year ended December 31, 2018, was approximately $791,237,000 and $334,280,000, respectively. The primary source of funds for the dividends paid by United to its shareholders is dividends received from its subsidiary bank. Dividends paid by United’s subsidiary banks are subject to certain regulatory limitations. Generally, the most restrictive provision requires regulatory approval if dividends declared in any year exceed that year’s net income, as defined, plus the retained net profits of the two preceding years. During 2020, the retained net profits available for distribution to United by United Bank as dividends without regulatory approval, are approximately $70,949,000, plus net income for the interim period through the date of declaration. Under Federal Reserve regulation, United Bank is also limited as to the amount they may loan to affiliates, including the parent company. Loans from United Bank to the parent company are limited to 10% of the banking subsidiaries’ capital and surplus, as defined, or $282,863,000 at December 31, 2019, and must be secured by qualifying collateral. United’s subsidiary banks are subject to various regulatory capital requirements administered by federal banking agencies. Pursuant to capital adequacy guidelines, United’s subsidiary banks must meet specific capital guidelines that involve various quantitative measures of the banks’ assets, liabilities, and certain off-balance-sheet As previously mentioned, the new Basel III Capital Rules became effective for United and United Bank on January 1, 2015 (subject to a phase-in 9 At December 31, 2019, the most recent notification from its regulators, United and United Bank were categorized as well-capitalized. To be categorized as well-capitalized, United must maintain minimum total risk-based, Tier I risk-based, Common Tier I risk-based, and Tier I leverage ratios as set forth in the following table. There are no conditions or events since that notification that management believes would impact United’s well-capitalized status. United’s and United Bank, capital amounts (in thousands of dollars) and ratios are presented in the following table. (Dollars in thousands) Actual For Capital Adequacy Purposes To Be Well- Capitalized Amount Ratio Amount Ratio Amount Ratio As of December 31, 2019: Total Capital (to Risk-Weighted Assets): United Bankshares $ 2,217,547 14.7 % $ 1,206,812 ≥ $ 1,508,515 ≥ United Bank 2,106,457 14.0 % 1,204,264 ≥ 1,505,330 ≥ Tier I Capital (to Risk-Weighted Assets): United Bankshares $ 1,890,757 12.5 % $ 905,109 ≥ $ 1,206,812 ≥ United Bank 2,027,667 13.5 % 903,198 ≥ 1,204,264 ≥ Common Tier I Capital (to Risk Weighted Assets): United Bankshares $ 1,890,757 12.5 % $ 678,832 ≥ $ 980,535 ≥ United Bank 2,027,667 13.5 % 677,399 ≥ 978,465 ≥ Tier I Capital (to Average Assets): United Bankshares $ 1,890,757 10.5 % $ 721,691 ≥ $ 902,114 ≥ United Bank 2,027,667 11.3 % 720,232 ≥ 900,290 ≥ As of December 31, 2018: Total Capital (to Risk-Weighted Assets): United Bankshares $ 2,119,774 14.4 % $ 1,179,708 ≥ $ 1,474,635 ≥ United Bank 2,080,234 14.1 % 1,177,953 ≥ 1,472,441 ≥ Tier I Capital (to Risk-Weighted Assets): United Bankshares $ 1,793,682 12.2 % $ 884,781 ≥ $ 1,179,708 ≥ United Bank 2,002,142 13.6 % 883,465 ≥ 1,177,953 ≥ Common Tier I Capital (to Risk Weighted Assets): United Bankshares $ 1,793,682 12.2 % $ 663,586 ≥ $ 958,513 ≥ United Bank 2,002,142 13.6 % 662,599 ≥ 957,087 ≥ Tier I Capital (to Average Assets): United Bankshares $ 1,793,682 10.1 % $ 707,916 ≥ $ 884,895 ≥ United Bank 2,002,142 11.3 % 706,977 ≥ 883,721 ≥ United’s mortgage banking entity, George Mason, is subject to net worth requirements issued by the U.S. Department of Housing and Urban Development (HUD). Failure to meet minimum capital requirements of HUD can result in certain mandatory and possibly additional discretionary actions that, if undertaken, could have a direct material effect on George Mason’s operations. The minimum net worth requirement of HUD at December 31, 2019 was $2,500,000. George Mason’s net worth was $35,556,000 at December 31, 2019, which exceeded the HUD requirements.

Fair Values of Financial Instru

Fair Values of Financial Instruments	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Values of Financial Instruments	NOTE V—FAIR VALUES OF FINANCIAL INSTRUMENTS In accordance with ASC Topic 820, the following describes the valuation techniques used by United to measure certain financial assets and liabilities recorded at fair value on a recurring basis in the financial statements. Securities available for sale and equity securities market approach valuation methodology, third party vendors compile prices based on observable market inputs, which include benchmark yields, reported trades, issuer spreads, benchmark securities, and “To Be Announced” prices (Level 2). Management internally reviews the fair values provided by third party vendors on a monthly basis. Management also performs a quarterly price testing analysis at the individual security level which compares the pricing provided by the third party vendors to an independent pricing source’s valuation of the same securities. Variances that are deemed to be material are reviewed by management. Additionally, to further assess the reliability of the information received from third party vendors, management obtains documentation from third party vendors related to the sources, methodologies, and inputs utilized in valuing securities classified as Level 2. Management analyzes this information to ensure the underlying assumptions appear reasonable. Management also obtains an independent service auditor’s report from third party vendors to provide reasonable assurance that appropriate controls are in place over the valuation process. Upon completing its review of the pricing from third party vendors at December 31, 2019, management determined that the prices provided by its third party pricing source were reasonable and in line with management’s expectations for the market values of these securities. Therefore, prices obtained from third party vendors that did not reflect forced liquidation or distressed sales were not adjusted by management at December 31, 2019. Management utilizes a number of factors to determine if a market is inactive, all of which may require a significant level of judgment. Factors that management considers include: a significant widening of the bid-ask spread, a considerable decline in the volume and level of trading activity in the instrument, a significant variance in prices among market participants, and a significant reduction in the level of observable inputs. Any securities available for sale not valued based upon quoted market prices or third party pricing models that consider observable market data are considered Level 3. Currently, United considers its valuation of available-for-sale as Level 3. Based upon management’s review of the market conditions for , it was determined that an income approach valuation technique (present value technique) that maximizes the use of relevant observable inputs and minimizes the use of unobservable inputs is the most representative measurement technique for these securities. The present value technique discounts expected future cash flows of a security to arrive at a present value. Management considers the following items when calculating the appropriate discount rate: the implied rate of return when the market was last active, changes in the implied rate of return as markets moved from very active to inactive, recent changes in credit ratings, and recent activity showing that the market has built in increased liquidity and credit premiums. Management’s internal credit review of each security was also factored in to determine the appropriate discount rate. The credit review considered each security’s collateral, subordination, excess spread, priority of claims, principal and interest. Loans held for sale Derivatives For a fair value hedge, the fair value of the interest rate swap is recognized on the balance sheet as either a freestanding asset or liability with a corresponding adjustment to the hedged financial instrument. Subsequent adjustments due to changes in the fair value of a derivative that qualifies as a fair value hedge are offset in current period earnings either in interest income or interest expense depending on the nature of the hedged financial instrument. For a cash flow hedge, the fair value of the interest rate swap is recognized on the balance sheet as either a freestanding asset or liability with a corresponding adjustment to other comprehensive income within shareholders’ equity, net of tax. Subsequent adjustments due to changes in the fair value of a derivative that qualifies as a cash flow hedge are offset to other comprehensive income, net of tax. The portion of a hedge that is ineffective is recognized immediately in earnings. The Company records its interest rate lock commitments and forward loan sales commitments at fair value determined as the amount that would be required to settle each of these derivative financial instruments at the balance sheet date. In the normal course of business, George Mason enters into contractual interest rate lock commitments to extend credit to borrowers with fixed expiration dates. The commitments become effective when the borrowers “lock-in” For interest rate swap derivatives that are not designated in a hedge relationship, changes in the fair value of the derivatives are recognized in earnings in the same period as the change in the fair value. Unrealized gains and losses due to changes in the fair value of other derivative financial instruments not in hedge relationship are included in noninterest income and noninterest expense, respectively. The following table presents the balances of financial assets and liabilities measured at fair value on a recurring basis as of December 31, 2019 and 2018, segregated by the level of the valuation inputs within the fair value hierarchy: Fair Value at December 31, 2019 Using (In thousands) Description Balance as of December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Available for sale debt securities: U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 58,676 $ 0 $ 58,676 $ 0 State and political subdivisions 272,362 0 272,362 0 Residential mortgage-backed securities Agency 836,534 0 836,534 0 Non-agency 3,832 0 3,832 0 Commercial mortgage-backed securities Agency 614,973 0 614,973 0 Asset-backed securities 276,139 0 276,139 0 Trust preferred collateralized debt obligations 4,704 0 0 4,704 Fair Value at December 31, 2019 Using (In thousands) Description Balance as of December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Single issue trust preferred securities 16,774 0 16,774 0 Other corporate securities 353,302 6,586 346,716 0 Total available for sale securities 2,437,296 6,586 2,426,006 4,704 Equity securities: Financial services industry 154 154 0 0 Equity mutual funds (1) 3,971 3,971 0 0 Other equity securities 4,769 4,769 0 0 Total equity securities 8,894 8,894 0 0 Loans held for sale 384,375 0 0 384,375 Derivative financial assets: Forward sales commitments 9 0 9 0 Interest rate lock commitments 4,518 0 0 4,518 Total derivative financial assets 4,527 0 9 4,518 Liabilities Derivative financial liabilities: Interest rate swap contracts 2,394 0 2,394 0 TBA mortgage-backed securities 671 0 671 0 Total derivative financial liabilities 3,065 0 3,065 0 Fair Value at December 31, 2018 Using (In thousands) Description Balance as of December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Available for sale debt securities: U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 85,890 $ 0 $ 85,890 $ 0 State and political subdivisions 208,988 0 208,988 0 Residential mortgage-backed securities Agency 1,035,650 0 1,035,650 0 Non-agency 4,259 0 4,259 0 Commercial mortgage-backed securities Agency 554,600 0 554,600 0 Asset-backed securities 271,970 0 271,970 0 Trust preferred collateralized debt obligations 5,917 0 0 5,917 Single issue trust preferred securities 8,362 0 8,362 0 Other corporate securities 161,403 6,822 154,581 0 Total available for sale securities 2,337,039 6,822 2,324,300 5,917 Equity securities: Financial services industry 140 140 0 0 Equity mutual funds (1) 4,954 4,954 0 0 Other equity securities 4,640 4,640 0 0 Total equity securities 9,734 9,734 0 0 Loans held for sale 247,104 0 0 247,104 Derivative financial assets: Interest rate swap contracts 1,859 0 1,859 0 Fair Value at December 31, 2018 Using (In thousands) Description Balance as of December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Forward sales commitments 542 0 542 0 Interest rate lock commitments 4,103 0 0 4,103 Total derivative financial assets 6,504 0 2,401 4,103 Liabilities Derivative financial liabilities: TBA mortgage-backed securities 3,002 0 3,002 0 Total derivative financial liabilities 3,002 0 3,002 0 (1) The equity mutual funds are within a rabbi trust for the payment of benefits under a deferred compensation plan for certain key officers of United and its subsidiaries. There were no The following table presents additional information about financial assets and liabilities measured at fair value at December 31, 2019 and 2018 on a recurring basis and for which United has utilized Level 3 inputs to determine fair value: Available-for-sale (In thousands) Trust preferred collateralized debt obligations 2019 2018 Balance, beginning of year $ 5,917 $ 34,269 Total gains or losses (realized/unrealized): Included in earnings (or changes in net assets) (155 ) 28 Included in other comprehensive income (1,059 ) 920 Purchases, issuances, and settlements 0 0 Sales 0 (29,300 ) Transfers in and/or out of Level 3 0 0 Balance, ending of year $ 4,703 $ 5,917 The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at reporting date 0 0 Loans held for sale (In thousands) 2019 2018 Balance, beginning of period 247,104 263,308 Originations 2,941,722 2,619,454 Sales (2,888,257 ) (2,676,797 ) Total gains or losses during the period recognized in earnings 83,806 68,555 Transfers in and/or out of Level 3 (0 ) (27,416 ) Balance, end of period 384,375 247,104 The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at reporting date 0 0 (In thousands) Derivative Financial Assets Interest Rate Lock Commitments 2019 2018 Balance, beginning of period $ 4,103 $ 4,559 Transfers other 415 (456 ) Balance, end of perio d $ 4,518 $ 4,103 The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at reporting date $ 0 $ 0 Certain financial assets are measured at fair value on a nonrecurring basis in accordance with GAAP. Adjustments to the fair value of these assets usually result from the application of lower-of-cost-or Fair Value Option United elected the fair value option for the loans held for sale in its mortgage banking segment to mitigate a divergence between accounting losses and economic exposure. The following table reflects the change in fair value included in earnings of financial instruments for which the fair value option has been elected: (In thousands) Description Year Ended December 31, 2019 Year Ended December 31, 2018 Assets Loans held for sale Income from mortgage banking activities $ 3,705 $ (281) The following table reflects the difference between the aggregate fair value and the remaining contractual principal outstanding for financial instruments for which the fair value option has been elected: December 31, 2019 December 31, 2018 (In thousands) Description Unpaid Fair Value Fair Value Unpaid Fair Value Fair Value Assets Loans held for sale 375,274 384,375 9,101 241,293 247,104 5,811 Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis The following describes the valuation techniques used by United to measure certain financial assets recorded at fair value on a nonrecurring basis in the financial statements. Loans held for sale one-to-four Impaired Loans form of real estate or business assets including equipment, inventory, and accounts receivable. The vast majority of the collateral is real estate. OREO bi-annual Intangible Assets: more-likely-than-not No 2018 The following table summarizes United’s financial assets that were measured at fair value on a nonrecurring basis during the period: Carrying value at December 31, 2019 (In thousands) Description Balance as of December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant (Level 2) Significant (Level 3) YTD Gains ( Losses ) Assets Loans held for sale $ 3,139 $ 0 $ 3,139 $ 0 $ (4 ) Impaired Loans 68,213 0 55,792 12,421 1,831 OREO 15,515 0 15,495 20 (785 ) Carrying value at December 31, 2018 (In thousands) Description Balance as of December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant (Level 2) Significant (Level 3) YTD Losses Assets Loans held for sale $ 2,742 $ 0 $ 2,742 $ 0 $ 3 Impaired Loans 121,355 0 108,899 12,456 12,301 OREO 16,865 0 16,865 0 910 Fair Value of Other Financial Instruments The following methods and assumptions were used by United in estimating its fair value disclosures for other financial instruments: Cash and Cash Equivalents: Securities held to maturity and other securities Loans: one-to-four cash flow analyses, using market interest rates currently being offered for loans with similar terms to borrowers of similar creditworthiness, which include adjustments for liquidity concerns. For acquired impaired loans, fair value is assumed to equal United’s carrying value, which represents the present value of expected future principal and interest cash flows, as adjusted for any Allowance for Loan Losses recorded for these loans. Deposits: Short-term Borrowings: Long-term Borrowings: arrangements Summary of Fair Values for All Financial Instruments The estimated fair values of United’s financial instruments are summarized below: Fair Value Measurements (In thousands) Carrying Fair Value in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) December 31, 2019 Cash and cash equivalents $ 837,493 $ 837,493 $ 0 $ 837,493 $ 0 Securities available for sale 2,437,296 2,437,296 6,586 2,426,006 4,704 Securities held to maturity 1,446 1,447 0 427 1,020 Equity securities 8,894 8,894 8,894 0 0 Other securities 222,161 211,053 0 0 211,053 Loans held for sale 387,514 387,514 0 3,139 384,375 Net loans 13,635,072 13,185,955 0 0 13,185,955 Derivative financial assets 4,527 4,527 0 9 4,518 Deposits 13,852,421 13,843,077 0 13,843,077 0 Short-term borrowings 374,654 374,654 0 374,654 0 Long-term borrowings 1,838,029 1,820,297 0 1,820,297 0 Derivative financial liabilities 3,065 3,065 0 3,065 0 December 31, 2018 Cash and cash equivalents $ 1,020,396 $ 1,020,396 $ 0 $ 1,020,396 $ 0 Securities available for sale 2,337,039 2,337,039 6,822 2,324,300 5,917 Securities held to maturity 19,999 18,655 0 15,635 3,020 Equity securities 9,734 9,734 9,734 0 0 Other securities 176,955 168,107 0 0 168,107 Loans held for sale 249,846 249,846 0 2,742 247,104 Net loans 13,345,519 12,657,073 0 0 12,657,073 Derivative financial assets 6,504 6,504 0 2,401 4,103 Deposits 13,994,749 13,954,574 0 13,954,574 0 Short-term borrowings 351,327 351,327 0 351,327 0 Long-term borrowings 1,499,103 1,475,237 0 1,475,237 0 Derivative financial liabilities 3,002 3,002 0 3,002 0

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	N Variable interest entities (VIEs) are entities that either have a total equity investment that is insufficient to permit the entity to finance its activities without additional subordinated financial support or whose equity investors lack the characteristics of a controlling financial interest (i.e., ability to make significant decisions, through voting rights, right to receive the expected residual returns of the entity, and obligation to absorb the expected losses of the entity). VIEs can be structured as corporations, trusts, partnerships, or other legal entities. United’s business practices include relationships with certain VIEs. For United, the business purpose of these relationships primarily consists of funding activities in the form of issuing trust preferred securities. United currently sponsors fourteen statutory business trusts that were created The trusts utilized in these transactions are variable interest entities (VIEs) as the third-party equity holders lack a controlling financial interest in the trusts through their inability to make decisions that have a significant effect on the operations and success of the entities. United does not consolidate these trusts as it is not the primary beneficiary of these entities because United does not hold a controlling financial interest as evidenced by the power to direct the activities of the VIEs that most significantly impact their economic performance and the obligation to absorb losses of, or the right to receive benefits from, the VIEs that could potentially be significant to the VIEs. Information related to United’s statutory trusts is presented in Note L United, through its banking subsidiaries, also makes limited partner equity investments in various low income housing and community development partnerships sponsored by independent third-parties. United invests in these partnerships to either realize tax credits on its consolidated federal income tax return or for purposes of earning a return on its investment. These partnerships are considered VIEs as the limited partners lack a controlling financial interest in the entities through their inability to make decisions that have a significant effect on the operations and success of the partnerships. United’s limited partner interests in these entities is immaterial, however; these partnerships are not consolidated as United is not deemed to be the primary beneficiary. The following table summarizes quantitative information about United’s significant involvement in unconsolidated VIEs: As of December 31, 2019 As of December 31, 2018 (In thousands) Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Trust preferred securities $ 257,941 $ 248,680 $ 9,261 $ 257,754 $ 248,741 $ 9,013 (1)

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Segment Information	NOTE X—SEGMENT INFORMATION United operates in two business segments: community banking and mortgage banking. Through its community banking segment, United offers a full range of products and services through various delivery channels. In particular, the community banking segment includes both commercial and consumer lending and provides customers with such products as commercial loans, real estate loans, business financing and consumer loans. In addition, this segment provides customers with several choices of deposit products including demand deposit accounts, savings accounts and certificates of deposit as well as investment and financial advisory services to businesses and individuals, including financial planning, retirement/estate planning, and investment management. The mortgage banking segment engages primarily in the origination and acquisition of residential mortgages for sale into the secondary market though George Mason. The community banking segment provides the mortgage banking segment (George Mason) with short-term funds to originate mortgage loans through a warehouse line of credit and charges the mortgage banking segment interest based on a LIBOR The Company does not have any operating segments other than those reported. The “Other” category consists of financial information not directly attributable to a specific segment, including interest income from investments and net securities gains or losses of parent companies and their non-banking non-segment Information about the reportable segments and reconciliation of this information to the consolidated financial statements at and for the years ended December 31, 2019, 2018 and 2017 is as follows: At and For the Year Ended December 31, 2019 (In thousands) Community Mortgage Other Intersegment Eliminations Consolidated Net interest income $ 583,547 $ 916 $ (12,472 ) $ 5,931 $ 577,922 Provision for loans losses 21,313 0 0 0 21,313 Other income 74,956 83,884 392 (8,748 ) 150,484 Other expense 314,710 72,288 (1,527 ) (2,817 ) 382,654 Income taxes 64,080 2,355 (2,095 ) 0 64,340 Net income (loss) $ 258,400 $ 10,157 $ (8,458 ) $ 0 $ 260,099 Total assets (liabilities) $ 19,564,036 $ 507,124 $ 17,777 $ (426,613 ) $ 19,662,324 Average assets (liabilities) 19,401,397 358,087 8,411 (292,427 ) 19,475,468 At and For the Year Ended December 31, 2018 (In thousands) Community Mortgage Other Intersegment Eliminations Consolidated Net interest income $ 593,108 $ 1,315 $ (11,886 ) $ 6,108 $ 588,645 Provision for loans losses 22,013 0 0 0 22,013 Other income 72,539 68,555 (667 ) (11,715 ) 128,712 Other expense 301,123 72,632 31 (5,607 ) 368,179 Income taxes 73,861 (505 ) (2,533 ) 0 70,823 Net income (loss) $ 268,650 $ (2,257 ) $ (10,051 ) $ 0 $ 256,342 Total assets (liabilities) $ 19,191,215 $ 320,299 $ 3,222 $ (264,238 ) $ 19,250,498 Average assets (liabilities) 18,798,880 279,618 6,104 (236,575 ) 18,848,027 At and For the Year Ended December 31, 2017 (In thousands) Community Mortgage Other Intersegment Eliminations Consolidated Net interest income $ 558,622 $ (69 ) $ (9,556 ) $ 0 $ 548,997 Provision for loans losses 28,406 0 0 0 28,406 Other income 69,615 58,532 3,498 0 131,645 Other expense 291,584 62,072 13,753 0 367,409 Income taxes 139,980 (901 ) (4,833 ) 0 134,246 Net income (loss) $ 168,267 $ (2,708 ) $ (14,978 ) $ 0 $ 150,581 Total assets (liabilities) $ 19,016,619 $ 280,293 $ 17,158 $ (255,111 ) $ 19,058,959 Average assets (liabilities) 17,565,464 212,212 19,769 (180,016 ) 17,617,429

Quarterly Financial Data

Quarterly Financial Data	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data	NOTE Y—QUARTERLY FINANCIAL DATA (UNAUDITED) Quarterly financial data for 2019 2018 (Dollars in thousands) 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter 2019 Interest income $ 189,097 $ 199,245 $ 190,351 $ 183,869 Interest expense 44,929 48,692 48,433 42,586 Net interest income 144,168 150,553 141,918 141,283 Provision for credit losses 4,996 5,417 5,033 5,867 Mortgage banking income 13,681 21,704 24,019 17,547 Securities gains (losses), net (159 ) 109 116 109 Other noninterest income 17,701 17,982 18,089 19,586 Noninterest expense 89,425 100,195 96,134 96,900 Income taxes 17,328 17,529 17,010 12,473 Net income (1) 63,642 67,207 65,965 63,285 (Dollars in thousands) 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Per share data: Average shares outstanding (000s): Basic 101,895 101,774 101,432 101,250 Diluted 102,163 102,048 101,712 101,538 Net income per share: Basic $ 0.62 $ 0.66 $ 0.65 $ 0.62 Diluted $ 0.62 $ 0.66 $ 0.65 $ 0.62 Dividends per share $ 0.34 $ 0.34 $ 0.34 $ 0.35 2018 Interest income $ 167,185 $ 178,000 $ 185,030 $ 187,500 Interest expense 23,142 28,878 36,255 40,795 Net interest income 144,043 149,122 148,775 146,705 Provision for credit losses 5,178 6,204 4,808 5,823 Mortgage banking income 14,570 18,692 13,277 11,570 Securities losses, net (485 ) (55 ) (152 ) (1,926 ) Other noninterest income 17,107 17,370 18,561 20,183 Noninterest expense 90,452 93,410 93,315 91,002 Income taxes 17,899 19,241 17,926 15,757 Net income (1) 61,706 66,274 64,412 63,950 Per share data: Average shares outstanding (000s): Basic 104,859 104,683 103,618 102,930 Diluted 105,163 104,953 103,934 103,164 Net income per share: Basic $ 0.59 $ 0.63 $ 0.62 $ 0.62 Diluted $ 0.59 $ 0.63 $ 0.62 $ 0.62 Dividends per share $ 0.34 $ 0.34 $ 0.34 $ 0.34 (1) For further information, see the related discussion “Quarterly Results” included in Management’s Discussion and Analysis.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations:
Operating Segments	Operating Segments:
Basis of Presentation	Basis of Presentation: United determines whether it has a controlling financial interest in an entity by first evaluating whether the entity is a voting interest entity or a variable interest entity (VIE) under U.S. generally accepted accounting principles. Voting interest entities are entities in which the total equity investment at risk is sufficient to enable the entity to finance itself independently and provides the equity holders with the obligation to absorb losses, the right to receive residual returns and the right to make decisions about the entity’s activities. United consolidates voting interest entities in which it has all, or at least a majority of, the voting interest. As defined in applicable accounting standards, VIEs are entities that lack one or more of the characteristics of a voting interest entity. A controlling financial interest in a VIE is present when an enterprise has both the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and an obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The enterprise with a controlling financial interest, known as the primary beneficiary, consolidates the VIE. United’s wholly owned and indirect wholly owned statutory trust subsidiaries are VIEs for which United is not the primary beneficiary. Accordingly, its accounts are not included in United’s consolidated financial statements. The accounting and reporting policies of United conform with U.S. generally accepted accounting principles. In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. To conform to the 2019 presentation, certain reclassifications have been made to prior period amounts, which had no impact on net income, comprehensive income or shareholders’ equity. In the opinion of management, all adjustments necessary for a fair presentation of financial position and results of operations have been made. Such adjustments are of a normal and recurring nature. The Company has evaluated events and transactions subsequent to December 31, 2019 through the date these financial statements were issued. Based on definitions and requirements of generally accepted accounting principles for “Subsequent Events,” the Company has not identified any events that would require adjustments to, or disclosure in the financial statements.
Cash and Cash Equivalents	Cash and Cash Equivalents:
Securities	Securities: Gains or losses on sales of securities are recognized by the specific identification method and are reported in securities gains and losses within noninterest income of the Consolidated Statements of Income. United reviews available-for-sale held-to-maturity Certain security investments such as Federal Reserve Bank stock and Federal Home Loan Bank stock that do not have readily determinable fair values and for which United does not exercise significant influence are carried at cost and are classified as other investment securities on the balance sheet. These cost-method investments are reviewed for impairment at least annually or sooner if events or changes in circumstances indicate the carrying value may not be recoverable.
Securities Purchased Under Resale Agreements and Securities Sold Under Agreements to Repurchase	Securities Purchased Under Resale Agreements and Securities Sold Under Agreements to Repurchase:
Loans	Loans: 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 contract is doubtful. Consistent with United’s existing method of income recognition for loans, interest on impaired loans, except those classified as nonaccrual, is recognized as income using the accrual method. United’s method of income recognition for impaired loans that are classified as nonaccrual is to recognize interest income on the cash basis or apply the cash receipt to principal when the ultimate collectibility of principal is in doubt. A loan is categorized as a trouble debt restructuring (TDR) if a concession is granted to provide for a reduction of either interest or principal due to a deterioration in the financial condition of the borrower. A loan classified as a TDR will generally retain such classification until the loan is paid in full. However, a one-to-four-family
Loans Acquired Through Transfer	Loans Acquired Through Transfer:
Loans Held for Sale	Loans Held for Sale: one-to-four Loans held for sale within the mortgage banking segment are recorded under the fair value option at a fair value measured using valuations from investors for loans with similar characteristics adjusted for the Company’s actual sales experience versus the investor’s indicated pricing. Loans held for sale within the community banking segment are carried at the lower of cost or fair value. The fair value is based on the price secondary markets are currently offering for similar loans using observable market data which is not materially different than cost due to the short duration between origination and sale. Gains and losses on sale of loans are recorded within income from mortgage banking activities.
Allowance for Credit Losses	Allowance for Credit Losses: The allowance for loan losses is management’s estimate of the probable credit losses inherent in the loan portfolio. Management’s evaluation of the adequacy of the allowance for loan losses and the appropriate provision for credit losses is based upon a quarterly evaluation of the portfolio. This evaluation is inherently subjective and requires significant estimates, including the amounts and timing of estimated future cash flows, estimated losses on pools of loans based on historical loss experience, and consideration of qualitative factors such as current economic trends, all of which are susceptible to constant and significant change. The amounts allocated to specific credits and loan pools grouped by similar risk characteristics are reviewed on a quarterly basis and adjusted as necessary based upon subsequent changes in circumstances. In determining the components of the allowance for credit losses, management considers the risk arising in part from, but not limited to, qualitative factors such as charge-off charged-off In determining the adequacy of the allowance for loan losses, management makes allocations to specific commercial loans classified by management as to risk. Management determines the loan’s risk by considering the borrowers’ ability to repay, the collateral securing the credit and other borrower-specific factors that may impact collectibility. For impaired loans, specific allocations are based on the present value of expected future cash flows using the loan’s effective interest rate, or as a practical expedient, at the loan’s observable market price or the fair value of the collateral if the loan is collateral-dependent. Other commercial loans not specifically reviewed on an individual basis are evaluated based on loan pools, which are grouped by similar risk characteristics using management’s internal risk ratings. Allocations for these commercial loan pools are determined based upon historical loss experience adjusted for current environmental conditions and risk factors and the estimate period it takes for losses to result in a charge-off,
Bank Premises and Equipment	Bank Premises and Equipment: three five
Other Real Estate Owned	Other Real Estate Owned
Revenue Recognition	Revenue Recognition Descriptions of our revenue-generating activities that are within the scope of ASC Topic 606, which are presented in our Consolidated Statements of Income as components of Other Income are discussed below. There are no significant judgements relating to the amount and timing of revenue recognition for those revenue streams under the scope of ASC Topic 606. Fees from Trust Services Revenue from trust services primarily is comprised of fees earned from the management and administration of trusts and other customer assets. Trust services include custody of assets, investment management, escrow services, and similar fiduciary activities. The Company’s performance obligation is generally satisfied over time and the resulting fees are recognized monthly, based upon the month-end Fees from Brokerage Services Revenue from brokerage services are recorded as the income is earned at the time the related service is performed. In return for such services, the Company charges a commission for the sales of various securities products primarily consisting of investment company shares, annuity products, and corporate debt and equity securities, for its selling and administrative efforts. For account supervision, advisory and administrative services, revenue is recognized over a period of time as earned based on customer account balances and activity. Fees from Deposit Services Service charges on deposit accounts consist of account analysis fees (i.e., net fees earned on analyzed business and public checking accounts), monthly service fees, check orders, ATM activity fees, debit card fees, and other deposit account related fees. Revenue is recognized when our performance obligation is completed which is generally monthly for account maintenance services or when a transaction has been completed (ATM or debit card activity). Bankcard Fees and Merchant Discounts Bankcard fees and merchant discounts are primarily comprised of credit card income and merchant services income. Credit card income is primarily comprised of interchange fees earned whenever the Company’s credit cards are processed through card payment networks such as Visa. Merchant services income mainly represents fees charged to merchants to process their credit card transactions. The Company’s performance obligation for bankcard fees and i n
Advertising Costs	Advertising Costs:
Income Taxes	Income Taxes: For uncertain income tax positions, United records a liability based on a recognition threshold of more-likely-than-not, United files a consolidated income tax return with its subsidiaries. Federal income tax expense or benefit has been allocated to subsidiaries on a separate return basis.
Intangible Assets	Intangible Assets: one seven-year Goodwill and intangible assets with indefinite lives (such as a trade name intangible) are not amortized, but are tested for impairment at least annually or sooner if indicators of impairment exist. Intangible assets with definite useful lives (such as core deposit intangibles) are amortized over their respective estimated useful lives to their estimated residual values, and reviewed for impairment at least annually or as indicators of impairment are identified. Based on the most recent goodwill impairment test, no impairment was noted. As of December 31, 2019, and 2018, total goodwill approximated $1,478,014,000.
Derivative Financial Instruments	Derivative Financial Instruments: Derivative instruments designated in a hedge relationship to mitigate exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivative instruments designated in a hedge relationship to mitigate exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. For a fair value hedge, the fair value of the interest rate swap is recognized on the balance sheet as either a freestanding asset or liability with a corresponding adjustment to the hedged financial instrument. Subsequent adjustments due to changes in the fair value of a derivative that qualifies as a fair value hedge are offset in current period earnings. For a cash flow hedge, the fair value of the interest rate swap is recognized on the balance sheet as either a freestanding asset or liability with a corresponding adjustment to other comprehensive income within shareholders’ equity, net of tax. Subsequent adjustments due to changes in the fair value of a derivative that qualifies as a cash flow hedge are offset to other comprehensive income, net of tax. The portion of a hedge that is ineffective is recognized immediately in earnings. At inception of a hedge relationship, United formally documents the hedged item, the particular risk management objective, the nature of the risk being hedged, the derivative being used, how effectiveness of the hedge will be assessed and how the ineffectiveness of the hedge will be measured. United also assesses hedge effectiveness at inception and on an ongoing basis using regression analysis. Hedge ineffectiveness is measured by using the change in fair value method. The change in fair value method compares the change in the fair value of the hedging derivative to the change in the fair value of the hedged exposure, attributable to changes in the benchmark rate. United through George Mason enters into interest rate lock commitments to finance residential mortgage loans with its customers. These commitments, which contain fixed expiration dates, offer the borrower an interest rate guarantee provided the loan meets underwriting guidelines and closes within the timeframe established by United. Interest rate risk arises on these commitments and subsequently closed loans if interest rates change between the time of the interest rate lock and the delivery of the loan to the investor. Market risk on interest rate lock commitments and mortgage loans held for sale is managed using corresponding forward mortgage loan sales contracts. United is a party to these forward mortgage loan sales contracts to sell loans servicing released and short sales of mortgage-backed securities. When the interest rate is locked with the borrower, the rate lock commitment, forward sale agreement, and mortgage-backed security position are undesignated derivatives and marked to fair value through earnings. The fair value of the rate lock derivative includes the servicing premium and the interest spread for the difference between retail and wholesale mortgage rates. Income from mortgage banking activities includes the gain recognized for the period presented and associated elements of fair value. United sells mortgage loans on either a best efforts or mandatory delivery basis. For loans sold on a mandatory delivery basis, United enters into forward mortgage-backed securities (the “residual hedge”) to mitigate the effect of interest rate risk. Both the rate lock commitment for mandatory delivery loans and the residual hedge are recorded at fair value through earnings and are not designated as accounting hedges. At the closing of the loan, the loan commitment derivative expires and United records a loan held for sale at fair value and continues to mark these assets to market under the election of the fair value option. United closes out of the trading mortgage-backed securities assigned within the residual hedge and replaces the securities with a forward sales contract once a price has been accepted by an investor and recorded at fair value. For those loans selected to be sold under a best efforts delivery basis, at the closing of the loan, the rate lock commitment derivative expires and the Company records a loan held for sale at fair value under the election of fair value option and continues to be obligated under the same forward loan sales contract entered into at inception of the rate lock commitment. For derivatives that are not designated in a hedge relationship, changes in the fair value of the derivatives are recognized in earnings in the same period as the change in the fair value.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense was $ 4,914 4,073 3,555
Treasury Stock	Treasury Stock
Trust Assets and Income	Trust Assets and Income:
Earnings Per Common Share	Earnings Per Common Share: two-class non-vested Under the two-class The reconciliation of the numerator and denominator of basic earnings per share with that of diluted earnings per share is presented as follows: Year Ended December 31 (Dollars in thousands, except per share) 2019 2018 2017 Distributed earnings allocated to common stock $ 139,167 $ 141,336 $ 131,527 Undistributed earnings allocated to common stock 120,337 114,542 18,816 Net earnings allocated to common shareholders $ 259,504 $ 255,878 $ 150,343 Average common shares outstanding 101,585,599 104,015,976 97,502,633 Dilutive effect of stock compensation 266,978 282,849 387,445 Average diluted shares outstanding 101,852,577 104,298,825 97,890,078 Earnings per basic common share $ 2.55 $ 2.46 $ 1.54 Earnings per diluted common share $ 2.55 $ 2.45 $ 1.54
Fair Value Measurements	Fair Value Measurements ASC Topic 820 specifies a hierarchy of valuation techniques based on whether the inputs to those valuation techniques are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect United’s market assumptions. The three levels of the fair value hierarchy based on these two types of inputs are as follows: Level 1 - Valuation is based on quoted prices in active markets for identical assets and liabilities. Level 2 - Valuation is based on observable inputs including quoted prices in active markets for similar assets and liabilities, quoted prices for identical or similar assets and liabilities in less active markets, and model-based valuation techniques for which significant assumptions can be derived primarily from or corroborated by observable data in the market. Level 3 - Valuation is based on model-based techniques that use one or more significant inputs or assumptions that are unobservable in the market. When determining the fair value measurements for assets and liabilities, United looks to active and observable markets to price identical assets or liabilities whenever possible and classifies such items in Level 1. When identical assets and liabilities are not traded in active markets, United looks to market observable data for similar assets and liabilities and classifies such items as Level 2. Nevertheless, certain assets and liabilities are not actively traded in observable markets and United must use alternative valuation techniques using unobservable inputs to determine a fair value and classifies such items as Level 3. For assets and liabilities that are not actively traded, the fair value measurement is based primarily upon estimates that require significant judgment. Therefore, the results may not be realized in an actual sale or immediate settlement of the asset or liability. Additionally, there are inherent weaknesses in any calculation technique, and changes in the underlying assumptions used, including discount rates and estimates of future cash flows, could significantly affect the results of current or future values. The level within the fair value hierarchy is based on the lowest level of input that is significant in the fair value measurement.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In April 2019, the Financial Accounting Standards Board (FASB) issued ASU No. 2019-04 issues . ASU No. 2019-04 In August 2018, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2018-14 715-20): 2018-14 2018-14 In August 2018, the FASB issued ASU No. 2018-13 2018-13 2018-13 was adopted by United on January 1, 2020. The adoption did not have a material impact on the Company’s financial condition or results of operations. In June 2018, the FASB issued Accounting Standards Update (ASU) No. 2018-07 non-employees non-employee 2018-07 2018-07 In February 2018, the FASB issued ASU No. 2018-03, 825-10): 2018-03 2018-03 2018-03 In February 2018, the FASB issued ASU No. 2018-02, 2018-02 In August 2017, the FASB issued ASU No. 2017-12, one-time held-to-maturity available-for-sale 2017-12 one-time In July 2017, the FASB issued ASU No. 2017-11, 2017-11 2017-11 In May 2017, the FASB issued ASU No. 2017-09, Scope of Modification Accounting.” This ASU clarifies when changes to the terms of conditions of a share-based payment award must be accounted for as modifications. Companies will apply the modification accounting guidance if the value, vesting conditions or classification of the award changes. The new guidance should reduce diversity in practice and result in fewer changes to the terms of an award being accounted for as modifications, as the guidance will allow companies to make certain non-substantive 2017-09 2017-09 In March 2017, the FASB issued ASU No. 2017-07, 2017-07 No. 2017-07 2017-07 the practical expedient and used amounts previously disclosed in its Employee Benefits Plan footnote (Note O) to retrospectively adjust prior period amounts of employee compensation and employee benefits within United’s Consolidated Statements of Income. In January 2017, the FASB issued ASU No. 2017-04, 2017-04 2017-04 2017-04 In January 2017, the FASB issued ASU No. 2017-01, 2017-01 2017-01 In August 2016, the FASB issued ASU No. 2016-15, 2016-15 2016-15 2016-15 In June 2016, the FASB issued ASU No. 2016-13, available-for-sale 2016-13 2019-05 2016-13 2016-13, 326-20 825-10. held-to-maturity instrument-by-instrument 2019-05 2016-13, 2016-13 model validation, the documentation of the new standard and internal controls as well as changes to financial statement disclosures. In March 2016, the FASB issued ASU No. 2016-09, 2016-09 in the income statement when the awards vest or are settled. The requirement to report those income tax effects in earnings was applied to settlements occurring on or after January 1, 2017 and the impact of applying that guidance reduced reporting income tax expense by $ for the year of 2017. ASU No. 2016-09 also allows an employer to repurchase more of an employee’s shares than it could previously for tax withholding purposes without triggering liability accounting and make a policy election to account for forfeitures as they occur. The Company will continue to estimate the number of awards expected to be forfeited and adjust the estimate when it is no longer probable that the employee will fulfill the service condition, as was previously required. ASU No. 2016-09 also requires that all income tax-related cash flows resulting from share-based payments be reported as operating activities in the statement of cash flows. Previously, income tax benefits at settlement of an award were reported as a reduction to operating cash flows and an increase to financing cash flows to the extent that those benefits exceeded the income tax benefits reported in earnings during the award’s vesting period. The adoption of ASU No. 2016-09 did not have a material impact on the Company’s financial condition or results of operations. In February 2016, the FASB issued ASU No. 2016-02, 2016-02 2016-02 right-of-use 2018-11 non-lease non-lease 2018-10 2018-10 In January 2016, the FASB issued ASU No. 2016-01, 2016-01 2016-01 available-for-sale 2016-01 In May 2014, the FASB issued ASU No. 2014-09, 2014-09 2014-09 that ASU No. 2014-09 2014-09 2014-09

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Reconciliation of Numerator and Denominator of Basic Earnings Per Share with that of Diluted Earnings Per Share	The reconciliation of the numerator and denominator of basic earnings per share with that of diluted earnings per share is presented as follows: Year Ended December 31 (Dollars in thousands, except per share) 2019 2018 2017 Distributed earnings allocated to common stock $ 139,167 $ 141,336 $ 131,527 Undistributed earnings allocated to common stock 120,337 114,542 18,816 Net earnings allocated to common shareholders $ 259,504 $ 255,878 $ 150,343 Average common shares outstanding 101,585,599 104,015,976 97,502,633 Dilutive effect of stock compensation 266,978 282,849 387,445 Average diluted shares outstanding 101,852,577 104,298,825 97,890,078 Earnings per basic common share $ 2.55 $ 2.46 $ 1.54 Earnings per diluted common share $ 2.55 $ 2.45 $ 1.54

Investment Securities (Tables)

Investment Securities (Tables)	12 Months Ended
	Dec. 31, 2019
Summary of Amortized Cost and Estimated Fair Values of Available for Sale Securities	Securities held for indefinite periods of time are classified as available for sale and carried at estimated fair value. The amortized cost and estimated fair values of securities available for sale are summarized as follows. December 31, 2019 (In thousands) Amortized Gross Gross Estimated Cumulative (1) U.S. Treasury securities and obligations of U.S. $ 58,127 $ 555 $ 6 $ 58,676 $ 0 State and political subdivisions 272,014 3,644 3,296 272,362 0 Residential mortgage-backed securities Agency 826,857 10,923 1,246 836,534 0 Non-agency 3,429 404 0 3,833 86 Commercial mortgage-backed securities Agency 609,461 8,319 2,807 614,973 0 Asset-backed securities 284,390 0 8,251 276,139 0 Trust preferred collateralized debt obligations 6,045 0 1,342 4,703 842 Single issue trust preferred securities 18,196 170 1,592 16,774 0 Other corporate securities 348,405 4,897 0 353,302 0 Total $ 2,426,924 $ 28,912 $ 18,540 $ 2,437,296 $ 928 December 31, 2018 (In thousands) Amortized Gross Gross Estimated Cumulative (1) U.S. Treasury securities and obligations of U.S. $ 86,285 $ 35 $ 430 $ 85,890 $ 0 State and political subdivisions 212,670 439 4,121 208,988 0 Residential mortgage-backed securities Agency 1,047,345 3,235 14,930 1,035,650 0 Non-agency 3,927 332 0 4,259 86 Commercial mortgage-backed securities Agency 560,634 996 7,030 554,600 0 Asset-backed securities 272,459 450 939 271,970 0 Trust preferred collateralized debt obligations 6,176 91 350 5,917 2,586 Single issue trust preferred securities 8,754 169 561 8,362 0 Other corporate securities 162,634 118 1,349 161,403 0 Total $ 2,360,884 $ 5,865 $ 29,710 $ 2,337,039 $ 2,672 (1) Other-than-temporary impairment in accumulated other comprehensive income. Amounts are before-tax.
Summary of Securities Available for Sale in an Unrealized Loss Position	The following is a summary of securities available for sale which were in an unrealized loss position at December 31, 2019 and 2018. Less than 12 months 12 months or longer (In thousands) Fair Value Unrealized Fair Value Unrealized December 31, 2019 U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 1,415 $ 6 $ 0 $ 0 State and political subdivisions 144,307 3,291 885 5 Residential mortgage-backed securities Agency 108,072 502 71,736 744 Non-agency 0 0 0 0 Commercial mortgage-backed securities Agency 173,039 2,676 45,251 131 Asset-backed securities 135,174 3,252 140,965 4,999 Trust preferred collateralized debt obligations 2,703 842 2,000 500 Single issue trust preferred securities 0 0 13,562 1,592 Other corporate securities 0 0 0 0 Total $ 564,710 $ 10,569 $ 274,399 $ 7,971 Less than 12 months 12 months or longer (In thousands) Fair Value Unrealized Fair Value Unrealized December 31, 2018 U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 66,072 $ 250 $ 7,374 $ 180 State and political subdivisions 53,421 544 94,337 3,577 Residential mortgage-backed securities Agency 195,009 1,597 508,041 13,333 Non-agency 0 0 0 0 Commercial mortgage-backed securities Agency 107,443 1,124 294,129 5,906 Asset-backed securities 151,427 939 0 0 Trust preferred collateralized debt obligations 0 0 2,150 350 Single issue trust preferred securities 0 0 5,163 561 Other corporate securities 129,709 1,233 6,879 116 Total $ 703,081 $ 5,687 $ 918,073 $ 24,023
Summary of Gains or Losses on Proceeds from Maturities, Sales and Calls of Available for Sale Securities by Specific Identification Method	The realized losses relate to sales of securities within a rabbi trust for the payment of benefits under a deferred compensation plan for certain key officers and its subsidiaries. Year Ended (In thousands) 2019 2018 2017 Proceeds from maturities, sales and calls $ 712,557 $ 441,956 $ 686,312 Gross realized gains 1,542 1,594 3,274 Gross realized losses 1,445 2,364 1,400
Roll Forward of Credit Losses on Securities	Below is a progression of the credit losses on securities which United has recorded other-than-temporary charges. These charges were recorded through earnings and other comprehensive income. (In thousands) Year Ended December 31 2019 2018 2017 Balance of cumulative credit losses at beginning of period $ 3,138 $ 18,060 $ 22,162 Additional credit losses on securities for which OTTI was previously recognized 156 0 0 Reductions for securities sold or paid off during the period (0 ) (14,922 ) (4,102 ) Balance of cumulative credit losses at end of period $ 3,294 $ 3,138 $ 18,060
Summary of Amortized Cost and Estimated Fair Values of Securities Held to Maturity	The amortized cost and estimated fair values of securities held to maturity are summarized as follows:. December 31, 2019 (In thousands) Amortized Gross Gross Estimated Fair Value U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 0 $ 0 $ 0 $ 0 State and political subdivisions 1,426 1 0 1,427 Residential mortgage-backed securities Agency 0 0 0 0 Single issue trust preferred securities 0 0 0 0 Other corporate securities 20 0 0 20 Total $ 1,446 $ 1 $ 0 $ 1,447 December 31, 2018 (In thousands) Amortized Gross Gross Estimated Fair Value U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 5,074 $ 90 $ 0 $ 5,164 State and political subdivisions 5,473 7 1 5,479 Residential mortgage-backed securities Agency 20 2 0 22 Single issue trust preferred securities 9,412 0 1,442 7,970 Other corporate securities 20 0 0 20 Total $ 19,999 $ 99 $ 1,443 $ 18,655
Summary of Equity Securities	(In thousands) Year Ended December 31, 2019 Net gains recognized during the period $ 276 Net gains recognized during the period on equity securities sold 133 Unrealized gains recognized during the period on equity securities still held at period end 177 Unrealized losses recognized during the period on equity securities still held at period end (34 )
Maturities and Weighted Average Yields Of Securities	The following table sets forth the maturities of all securities (based on amortized cost) at December 31, 2019, and the weighted-average yields of such securities (calculated on the basis of the cost and the effective yields weighted for the scheduled maturity of each security). After 1 But After 5 But (Dollars in thousands) Within 1 Year Within 5 Years Within 10 Years After 10 Years Amount Yield Amount Yield Amount Yield Amount Yield U.S. Treasury and other U.S. Government agencies and corporations $ 0 0.00 % $ 51,511 2.41 % $ 6,616 2.74 % $ 0 0.00 % States and political subdivisions (1) 5,364 2.78 % 4,964 3.36 % 38,732 2.80 % 224,380 2.92 % Residential mortgage-backed securities Agency 0 0.00 % 0 0.00 % 230,686 2.60 % 596,171 2.71 % Non-agency 69 5.00 % 0 0.00 % 0 0.00 % 3,360 5.84 % Commercial mortgage-backed Agency 28,178 2.32 % 281,903 2.65 % 241,159 2.40 % 58,221 2.73 % Asset-backed securities 0 0.00 % 0 0.00 % 0 0.00 % 284,390 2.56 % Trust preferred collateralized debt obligations 0 0.00 % 0 0.00 % 0 0.00 % 6,045 3.61 % Single issue trust preferred securities 0 0.00 % 0 0.00 % 10,483 4.80 % 7,713 3.68 % Other corporate securities 59,020 2.63 % 245,553 2.98 % 37,246 4.58 % 6,606 1.28 % Marketable equity securities 0 0.00 % 0 0.00 % 0 0.00 % 8,894 1.49 % Other investment securities 0 0.00 % 100 2.55 % 750 2.08 % 221,311 3.32 %
Available-for-sale Securities [Member]
Summary of Maturities of Debt Securities Held to Maturity by Amortized Cost and Estimated Fair Value	Expected maturities may differ from contractual maturities because the issuers may have the right to call or prepay obligations without penalties. Maturities of mortgage-backed securities with an amortized cost of $1,439,747,000 and an estimated fair value of $1,455,340,000 at December 31, 2019 are included below based upon contractual maturity. Estimated (In thousands) Amortized Fair Cost Value Due in one year or less $ 92,422 $ 92,473 Due after one year through five years 583,715 592,850 Due after five years through ten years 564,922 568,241 Due after ten years 1,185,865 1,183,732 Total $ 2,426,924 $ 2,437,296
Held-to-maturity Securities [Member]
Summary of Amortized Cost and Estimated Fair Values of Securities Held to Maturity	Estimated (In thousands) Amortized Fair Cost Value Due in one year or less $ 210 $ 210 Due after one year through five years 216 217 Due after five years through ten years 0 0 Due after ten years 1,020 1,020 Total $ 1,446 $ 1,447

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Major Classes of Loans	Major classes of loans are as follows: December 31 (In thousands) 2019 2018 Commercial, financial, and agricultural Owner-occupied $ 1,201,652 $ 1,291,790 Nonowner-occupied 3,965,960 4,303,613 Other commercial 2,285,037 1,957,641 Total commercial, financial & agricultural 7,452,649 7,553,044 Residential real estate 3,686,401 3,501,393 Construction & land development 1,408,205 1,410,468 Consumer: Bankcard 10,074 10,203 Other Consumer 1,156,219 954,424 Less: Unearned income (1,419 ) (7,310 ) Total Loans, net of unearned income $ 13,712,129 $ 13,422,222
Activity for Accretable Yield	Activity for the accretable yield for the year of 2019 follows : (In thousands) Accretable yield at the beginning of the period $ 26,289 Accretion (including cash recoveries) (10,688 ) Additions 0 Net reclassifications to accretable from non-accretable 10,627 Disposals (including maturities, foreclosures, and charge-offs) (5,140 ) Accretable yield at the ending of the period $ 21,088

Credit Quality (Tables)

Credit Quality (Tables)	12 Months Ended
	Dec. 31, 2019
Text Block [Abstract]
Schedule of Troubled Debt Restructurings, Segregated by Class of Loans	The following table sets forth United’s troubled debt restructurings that have been restructured during the year ended December 31, 2019 and 2018, segregated by class of loans: Troubled Debt Restructurings For the Year Ended December 31, 2019 December 31, 2018 (Dollars in thousands) Number of Pre- Modification Post- Number of Pre- Modification Post- Modification Commercial real estate: Owner-occupied 2 $ 1,179 $ 1,144 0 $ 0 $ 0 Nonowner-occupied 0 0 0 1 61 61 Other commercial 3 5,962 5,722 9 16,991 16,560 Residential real estate 3 2,258 1,970 3 7,225 6,077 Construction & land development 3 2,287 2,104 0 0 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 0 0 0 0 0 0 Total 11 $ 11,686 $ 10,940 13 $ 24,277 $ 22,698
Schedule of Charged-off Troubled Debt Restructurings on Financing Receivables	The following table presents troubled debt restructurings, by class of loan, that had charge-offs during the year ended December 31, 2019 and 2018. These loans were restructured during the twelve months ended December 31, 2019 and 2018 and subsequently defaulted, resulting in principal charge-offs during the year of 2019 and 2018. Year Ended December 31, 2019 Year Ended December 31, 2018 (In thousands) Number of Recorded Number of Recorded Troubled Debt Restructurings Commercial real estate: Owner-occupied 0 $ 0 0 $ 0 Nonowner-occupied 0 0 0 0 Other commercial 2 1,477 1 0 Residential real estate 0 0 1 2,173 Construction & land development 0 0 0 0 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total 2 $ 1,477 2 $ 2,173
Schedule of Age Analysis of Past Due Loans, Segregated by Class of Loans	The following table sets forth United’s age analysis of its past due loans, segregated by class of loans: Age Analysis of Past Due Loans As of December 31, 2019 (In thousands) 30-89 90 Days or Past Due Total Past Current & Total Financing Recorded Commercial real estate: Owner-occupied $ 8,878 $ 11,209 $ 20,087 $ 1,181,565 $ 1,201,652 $ 544 Nonowner-occupied 6,318 16,129 22,447 3,943,513 3,965,960 471 Other commercial 5,238 51,541 56,779 2,228,258 2,285,037 668 Residential real estate 31,727 24,343 56,070 3,630,331 3,686,401 6,256 Construction & land development 2,219 16,043 18,262 1,389,943 1,408,205 0 Consumer: Bankcard 445 218 663 9,411 10,074 218 Other consumer 10,991 1,607 12,598 1,143,621 1,156,219 1,337 Total $ 65,816 $ 121,090 $ 186,906 $ 13,526,642 $ 13,713,548 $ 9,494 (1) Other includes loans with a recorded investment of $96,004 acquired and accounted for under ASC Topic 310-30 Age Analysis of Past Due Loans As of December 31, 2018 (In thousands) 30-89 90 Days or Past Due Total Past Current & Total Financing Recorded Commercial real estate: Owner-occupied $ 9,224 $ 17,742 $ 26,966 $ 1,264,824 $ 1,291,790 $ 629 Nonowner-occupied 16,108 18,092 34,200 4,269,413 4,303,613 1,171 Other commercial 13,556 46,040 59,596 1,898,045 1,957,641 2,850 Residential real estate 37,111 30,278 67,389 3,434,004 3,501,393 9,141 Construction & land development 8,462 19,412 27,874 1,382,594 1,410,468 680 Consumer: Bankcard 657 177 834 9,369 10,203 177 Other consumer 8,909 1,243 10,152 944,272 954,424 893 Total $ 94,027 $ 132,984 $ 227,011 $ 13,202,521 $ 13,429,532 $ 15,541 (1) Other includes loans with a recorded investment of $149,737 acquired and accounted for under ASC Topic 310-30
Schedule of Nonaccrual Loans, Segregated by Class of Loans	The following table sets forth United’s nonaccrual loans, segregated by class of loans: Loans on Nonaccrual Status (In thousands) December 31, 2019 December 31, 2018 Commercial real estate: Owner-occupied $ 10,665 $ 17,113 Nonowner-occupied 15,658 16,921 Other commercial 50,873 43,190 Residential real estate 18,087 21,137 Construction & land development 16,043 18,732 Consumer: Bankcard 0 0 Other consumer 270 350 Total $ 111,596 $ 117,443
Schedule of Credit Quality Indicators Information, by Class of Loans	The following tables set forth United’s credit quality indicators information, by class of loans: Credit Quality Indicators As of December 31, 2019 Commercial Real Estate (In thousands) Owner- Nonowner- Other Construction & Grade: Pass $ 1,136,589 $ 3,850,886 $ 2,136,266 $ 1,334,950 Special mention 14,449 44,134 75,511 4,614 Substandard 50,346 70,940 72,451 68,641 Doubtful 268 0 809 0 Total $ 1,201,652 $ 3,965,960 $ 2,285,037 $ 1,408,205 Credit Quality Indicators As of December 31, 2018 Commercial Real Estate (In thousands) Owner- Nonowner- Other Construction & Grade: Pass $ 1,201,387 $ 4,161,149 $ 1,858,821 $ 1,330,899 Special mention 34,487 46,442 14,424 28,629 Substandard 55,916 96,022 81,946 50,940 Doubtful 0 0 2,450 0 Total $ 1,291,790 $ 4,303,613 $ 1,957,641 $ 1,410,468 Credit Quality Indicators As of December 31, 2019 (In thousands) Residential Bankcard Other Grade: Pass $ 3,645,654 $ 9,411 $ 1,143,608 Special mention 12,038 445 10,993 Substandard 28,572 218 1,618 Doubtful 137 0 0 Total $ 3,686,401 $ 10,074 $ 1,156,219 As of December 31, 2018 (In thousands) Residential Bankcard Other Grade: Pass $ 3,436,584 $ 9,369 $ 944,241 Special mention 19,051 657 8,914 Substandard 45,758 177 1.269 Doubtful 0 0 0 Total $ 3,501,393 $ 10,203 $ 954,424
Schedule of Impaired Loans Information by Class of Loans	The following table set forth United’s impaired loans information, by class of loans: Impaired Loans December 31, 2019 December 31, 2018 (In thousands) Recorded Unpaid Related Recorded Unpaid Related With no related allowance recorded: Commercial real estate: Owner-occupied $ 58,709 $ 58,709 $ 0 $ 63,633 $ 63,798 $ 0 Nonowner-occupied 38,011 38,070 0 98,845 98,904 0 Other commercial 56,717 62,796 0 40,291 50,459 0 Residential real estate 28,096 29,022 0 28,207 29,279 0 Construction & land development 39,599 47,594 0 37,174 40,459 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 11 11 0 27 27 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 3,904 $ 5,223 $ 974 $ 10,004 $ 10,004 $ 2,542 Nonowner-occupied 15,947 15,947 2,979 15,720 15,720 2,715 Other commercial 40,300 42,684 11,931 61,266 62,812 17,581 Residential real estate 6,793 6,793 354 19,623 22,064 3,265 Construction & land development 1,269 1,269 262 14,742 19,446 2,254 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 0 0 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 62,613 $ 63,932 $ 974 $ 73,637 $ 73,802 $ 2,542 Nonowner-occupied 53,958 54,017 2,979 114,565 114,624 2,715 Other commercial 97,017 105,480 11,931 101,557 113,271 17,581 Residential real estate 34,889 35,815 354 47,830 51,343 3,265 Construction & land development 40,868 48,863 262 51,916 59,905 2,254 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 11 11 0 27 27 0 Impaired Loans For the Year Ended December 31, 2019 December 31, 2018 (In thousands) Average Interest Average Interest With no related allowance recorded: Commercial real estate: Owner-occupied $ 66,838 $ 1,568 $ 67,665 $ 1,548 Nonowner-occupied 54,948 1,064 103,611 1,516 Other commercial 55,473 1,008 51,416 718 Residential real estate 31,166 630 27,459 657 Construction & land development 35,702 799 41,892 914 Consumer: Bankcard 0 0 0 0 Other consumer 25 0 28 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 3,848 $ 0 $ 7,658 $ 25 Nonowner-occupied 13,471 404 12,298 387 Other commercial 41,112 182 51,118 1,072 Residential real estate 10,444 267 15,365 460 Construction & land development 11,243 79 8,893 79 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 70,686 $ 1,568 $ 75,323 $ 1,573 Nonowner-occupied 68,419 1,468 115,909 1,903 Other commercial 96,585 1,190 102,534 1,790 Residential real estate 41,610 897 42,824 1,117 Construction & land development 46,945 878 50,785 993 Consumer: Bankcard 0 0 0 0 Other consumer 25 0 28 0

Allowance for Credit Losses (Ta

Allowance for Credit Losses (Tables)	12 Months Ended
	Dec. 31, 2019
Receivables [Abstract]
Schedule of Allowance for Loan Losses and Carrying Amount of Loans	A progression of the allowance for loan losses, by portfolio segment, for the year ended December 31, 2019 and 2018 is summarized as follows: Allowance for Loan Losses and Carrying Amount of Loans For the Year Ended December 31, 2019 (In thousands) Commercial Real Estate Other Residential Construction & Land Consumer Allowance Total Owner- Nonowner- Allowance for Loan Beginning balance $ 5,063 $ 6,919 $ 41,341 $ 12,448 $ 7,992 $ 2,695 $ 245 $ 76,703 Charge-offs (7,905 ) (1,093 ) (12,975 ) (2,967 ) (1,303 ) (2,867 ) 0 (29,110 ) Recoveries 3,733 80 2,599 858 175 706 0 8,151 Provision 4,663 2,618 16,360 (1,342 ) (3,511 ) 2,473 52 21,313 Ending balance $ 5,554 $ 8,524 $ 47,325 $ 8,997 $ 3,353 $ 3,007 $ 297 $ 77,057 Ending Balance: $ 973 $ 2,979 $ 11,931 $ 354 $ 262 $ 0 $ 0 $ 16,499 Ending Balance: $ 4,581 $ 5,545 $ 35,394 $ 8,643 $ 3,091 $ 3,007 $ 297 $ 60,558 Ending Balance: loans $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Allowance for Loan Losses and Carrying Amount of Loans For the Year Ended December 31, 2019 (In thousands) Commercial Real Other Residential Construction & Land Consumer Allowance Total Owner- Nonowner- Financing receivables: Ending balance $ 1,201,652 $ 3,965,960 $ 2,285,037 $ 3,686,401 $ 1,408,205 $ 1,166,293 $ 0 $ 13,713,548 Ending Balance: individually evaluated for impairment $ 16,703 $ 27,121 $ 54,108 $ 11,526 $ 14,047 $ 0 $ 0 $ 123,505 Ending Balance: collectively evaluated for impairment $ 1,160,556 $ 3,925,249 $ 2,194,432 $ 3,665,140 $ 1,382,369 $ 1,166,293 $ 0 $ 13,494,039 Ending Balance: loans acquired with deteriorated credit quality $ 24,393 $ 13,590 $ 36,497 $ 9,735 $ 11,789 $ 0 $ 0 $ 96,004 Allowance for Loan Losses and Carrying Amount of Loans For the Year Ended December 31, 2018 (In thousands) Commercial Real Other Residential Real Construction & Land Development Consumer Allowance for Estimated Total Owner- Nonowner- Allowance for Loan Beginning balance $ 5,401 $ 6,369 $ 45,189 $ 9,927 $ 7,187 $ 2,481 $ 73 $ 76,627 Charge-offs (3,225) (314) (16,424) (3,162) (2,731) (2,750) 0 (28,606) Recoveries 1,189 563 2,944 1,114 197 662 0 6,669 Provision 1,698 301 9,632 4,569 3,339 2,302 172 22,013 Ending balance $ 5,063 $ 6,919 $ 41,341 $ 12,448 $ 7,992 $ 2,695 $ 245 $ 76,703 Ending Balance: $ 2,543 $ 2,715 $ 17,581 $ 3,265 $ 2,254 $ 0 $ 0 $ 28,358 Ending Balance: $ 2,520 $ 4,204 $ 23,760 $ 9,183 $ 5,738 $ 2,695 $ 245 $ 48,345 Ending Balance: loans $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Financing receivables: Ending balance $ 1,291,790 $ 4,303,613 $ 1,957,641 $ 3,501,393 $ 1,410,468 $ 964,627 $ 0 $ 13,429,532 Ending Balance: $ 27,599 $ 25,231 $ 72,300 $ 21,998 $ 14,807 $ 0 $ 0 $ 161,935 Ending Balance: $ 1,234,919 $ 4,215,060 $ 1,860,085 $ 3,468,356 $ 1,374,840 $ 964,600 $ 0 $ 13,117,860 Ending Balance: loans $ 29,272 $ 63,322 $ 25,256 $ 11,039 $ 20,821 $ 27 $ 0 $ 149,737
Progression of Allowance for Credit Losses Including Allowance for Loan Losses and Reserve for Lending-Related Commitment	A progression of the allowance for credit losses, which includes the allowance for loan losses and the reserve for lending-related commitments, for the periods presented is summarized as follows: Year Ended December 31 (In thousands) 2019 2018 2017 Balance of allowance for loan losses at beginning of period $ 76,703 $ 76,627 $ 72,771 Provision for loan losses 21,313 22,013 28,406 98,016 98,640 101,177 Loans charged off (29,110) (28,606) (32,863) R 8,151 6,669 8,313 Net charge-offs (20,959) (21,937) (24,550) Balance of allowance for loan losses at end of period $ 77,057 $ 76,703 $ 76,627 Reserve for lending-related commitments 1,733 1,389 679 Balance of allowance for credit losses at end of period $ 78,790 $ 78,092 $ 77,306

Bank Premises and Equipment a_2

Bank Premises and Equipment and Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Property, Plant and Equipment [Abstract]
Bank Premises and Equipment	Bank premises and equipment are summarized as follows: December 31 (In thousands) 2019 2018 Land $ 32,085 $ 31,679 Buildings and improvements 105,759 103,014 Leasehold improvements 40,789 41,001 Furniture, fixtures and equipment 71,377 72,045 250,010 247,739 Less allowance for depreciation and amortization (153,366 ) (152,494 ) Net bank premises and equipment $ 96,644 $ 95,245

Goodwill and Other Intangibles

Goodwill and Other Intangibles (Tables)	12 Months Ended
	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Intangible Assets	The following is a summary of intangible assets subject to amortization and those not subject to amortization: December 31, 2019 Community Banking Mortgage Banking Total (In thousands) Gross Carrying Accumulated Gross Carrying Accumulated Gross Carrying Accumulated Amortized intangible assets: Core deposit $ 98,359 $ (69,508 ) $ 0 $ 0 $ 98,359 $ (69,508 ) Non-amortized George Mason $ 0 $ 1,080 $ 1,080 Goodwill not subject to amortization $ 1,472,699 $ 5,315 $ 1,478,014 December 31, 2018 Community Banking Mortgage Banking Total (In thousands) Gross Carrying Accumulated Gross Carrying Accumulated Gross Carrying Accumulated Amortized intangible assets: Core deposit intangible assets $ 98,359 $ (62,492 ) $ 0 $ 0 $ 98,359 $ (62,492 ) Non-amortized George Mason trade name $ 0 $ 1,080 $ 1,080 Goodwill not subject to amortization $ 1,472,699 $ 5,315 $ 1,478,014
Schedule of Anticipated Amortization Expense	The following table sets forth the anticipated amortization expense for intangible assets for the years subsequent to 2019: Year Amount (In thousands) 2020 $ 6,309 2021 5,369 2022 4,582 2023 4,322 2024 and thereafter 8,269

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Components of Lease Expense	The components of lease expense were as follows: Year Ended (In thousands) Classification December 31, Operating lease cost Net occupancy expense $ 19,508 Sublease income Net occupancy expense (825) Net lease cost $ 18,683
Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases was as follows: (In thousands) Classification December 31, 2019 Operating lease right-of-use Operating lease right-of-use $ 57,783 Operating lease liabilities Operating lease liabilities $ 61,342
Other Information Related to Leases	Other information related to leases was as follows: December 31, 2019 Weighted-average remaining lease term: Operating leases 4.91 years Weighted-average discount rate: Operating leases 3.20 %
Supplemental Cash Flow Information Related to Leases	Supplemental cash flow information related to leases was as follows: Year Ended (In thousands) December 31, 2019 Cash paid for amounts in the measurement of lease liabilities: Operating cash flows from operating leases $ 19,601 ROU assets obtained in the exchange for lease liabilities 7,630
Maturities of Lease Liabilities by Year	Maturities of lease liabilities by year and in the aggregate, under operating leases with initial or remaining terms of one year or more, for years subsequent to December 31, 2019, consists of the following: Year Amount (In thousands) 2020 $ 17,725 2021 15,180 2022 11,522 2023 8,751 2024 5,127 Thereafter 8,190 Total lease payments 66,495 Less: imputed interest (5,153 ) Total $ 61,342

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2019
Banking and Thrift [Abstract]
Book Value of Deposits	The book value of deposits consisted of the following: (In thousands) December 31 2019 2018 Demand deposits $ 3,381,866 $ 3,212,878 Interest-bearing checking 372,175 374,495 Regular savings 882,889 954,961 Money market accounts 6,891,696 7,157,028 Time deposits under $100,000 723,941 712,313 Time deposits over $100,000 1,599,854 1,583,074 Total deposits $ 13,852,421 $ 13,994,749

Short-Term Borrowings (Tables)

Short-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2019
Funds Purchased and Securities Sold Under Agreements to Repurchase and Weighted-Average Interest Rates	At December 31, 2019 and 2018, short-term borrowings and the related weighted-average interest rates were as follows: 2019 2018 Weighted- Weighted- (Dollars in thousands) Average Average Amount Rate Amount Rate Federal funds purchased $ 0 0.00 % $ 23,400 2.40 % Securities sold under agreements to repurchase 124,654 1.09 % 152,927 (1) 0.96 % (1) Total $ 124,654 $ 176,627 (1) Excludes a wholesale security sold under an agreement to repurchase of $50,000 assumed in the Virginia Commerce merger that matured in May of 2018.
Federal Funds Purchased and Securities Sold under Agreements to Repurchase [Member]
Funds Purchased and Securities Sold Under Agreements to Repurchase and Weighted-Average Interest Rates	The following table shows the distribution of United’s federal funds purchased and securities sold under agreements to repurchase and the weighted-average interest rates thereon at the end of each of the last three years. Also provided are the maximum amount of borrowings and the average amounts of borrowings as well as weighted-average interest rates for the last three years. The table does not include the long-term wholesale security sold under an agreement to repurchase mentioned above assumed in the Virginia Commerce merger. (Dollars in thousands) Federal Funds Purchased Securities Sold Under Agreements To Repurchase At December 31: 2019 $ 0 $ 124,654 2018 23,400 152,927 2017 16,235 261,352 (Dollars in thousands) Federal Funds Purchased Securities Sold Under To Repurchase Weighted-average interest rate at year-end: 2019 0.00 % 1.09 % 2018 2.40 % 0.96 % 2017 1.40 % 0.36 % Maximum amount outstanding at any month’s end: 2019 $ 0 $ 161,175 2018 25,790 328,484 2017 25,800 377,687 Average amount outstanding during the year: 2019 $ 1,899 $ 131,187 2018 16,773 194,956 2017 18,433 287,663 Weighted-average interest rate during the year: 2019 2.52 % 1.33 % 2018 1.86 % 0.61 % 2017 0.88 % 0.33 %

Long-Term Borrowings (Tables)

Long-Term Borrowings (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
FHLB Advances and Related Weighted Average Interest Rates	At December 31, 2019 and 2018, FHLB advances and the related weighted-average interest rates were as follows: 2019 2018 Weighted- Weighted- Weighted- Weighted- (Dollars in thousands) Average Average Average Average Contractual Effective Contractual Effective Amount Rate Rate Amount Rate Rate FHLB advances $ 1,851,865 2.03 % 2.03 % $ 1,439,198 2.42 % 2.42 %
Information Related to Statutory Trusts	Information related to United’s statutory trusts is presented in the table below: (Dollars in thousands) Description Issuance Date Amount of Interest Rate Maturity Date United Statutory Trust III December 17, 2003 $20,000 3-month LIBOR + 2.85% December 17, 2033 United Statutory Trust IV December 19, 2003 $25,000 3-month LIBOR + 2.85% January 23, 2034 United Statutory Trust V July 12, 2007 $50,000 3-month LIBOR + 1.55% October 1, 2037 United Statutory Trust VI September 20, 2007 $30,000 3-month LIBOR + 1.30% December 15, 2037 Premier Statutory Trust II September 25, 2003 $ 6,000 3-month LIBOR + 3.10% October 8, 2033 Premier Statutory Trust III May 16, 2005 $ 8,000 3-month LIBOR + 1.74% June 15, 2035 Premier Statutory Trust IV June 20, 2006 $14,000 3-month LIBOR + 1.55% September 23, 2036 Premier Statutory Trust V December 14, 2006 $10,000 3-month LIBOR + 1.61% March 1, 2037 Centra Statutory Trust I September 20, 2004 $10,000 3-month LIBOR + 2.29% September 20, 2034 Centra Statutory Trust II June 15, 2006 $10,000 3-month LIBOR + 1.65% July 7, 2036 Virginia Commerce Trust II December 19, 2002 $15,000 6-month LIBOR + 3.30% December 19, 2032 Virginia Commerce Trust III December 20, 2005 $25,000 3-month LIBOR + 1.42% February 23, 2036 Cardinal Statutory Trust I July 27, 2004 $20,000 3-month LIBOR + 2.40% September 15, 2034 UFBC Capital Trust I December 30, 2004 $ 5,000 3-month LIBOR + 2.10% March 15, 2035
Debentures and Related Weighted Average Interest Rates	At December 31, 2019 and 2018, the Debentures and their related weighted-average interest rates were as follows: 2019 2018 (Dollars in thousands) Amount Weighted- Amount Weighted- United Statutory Trust III $ 20,619 4.75 % $ 20,619 5.64 % United Statutory Trust IV 25,774 4.79 % 25,774 5.37 % United Statutory Trust V 51,547 3.65 % 51,547 3.95 % United Statutory Trust VI 30,928 3.19 % 30,928 4.09 % Premier Statutory Trust II 6,186 5.09 % 6,186 5.54 % Premier Statutory Trust III 8,248 3.63 % 8,248 4.53 % Premier Statutory Trust IV 14,433 3.48 % 14,433 4.37 % Premier Statutory Trust V 10,310 3.52 % 10,310 4.35 % Centra Statutory Trust I 10,000 4.20 % 10,000 5.08 % Centra Statutory Trust II 10,000 3.64 % 10,000 4.09 % Virginia Commerce Trust II 12,475 5.22 % 12,245 5.80 % Virginia Commerce Trust III 17,268 3.33 % 16,742 4.07 % Cardinal Statutory Trust I 14,825 4.29 % 14,428 5.19 % UFBC Capital Trust I 3,551 3.99 % 3,445 4.89 % Total $ 236,164 $ 234,905
Schedule of Maturities of Long-term Borrowings	At December 31, 2019, the scheduled maturities of long-term borrowings were as follows: Year Amount (In thousands) 2020 $ 740,734 2021 826,527 2022 19,737 2023 0 2024 0 2025 and thereafter 251,031 Total $ 1,838,029

Other Expense (Tables)

Other Expense (Tables)	12 Months Ended
	Dec. 31, 2019
Other Income and Expenses [Abstract]
Other Expense	The following details certain items of other expense for the periods indicated: Year Ended December 31 (In thousands) 2019 2018 2017 Legal, consulting & other professional services $ 12,360 $ 13,248 $ 11,844 Franchise & other taxes not on income 11,330 11,428 12,586 Automated Teller Machine (ATM) expenses 7,336 6,892 6,686

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Tax Provisions Included in the Consolidated Statements of Income	The income tax provisions included in the consolidated statements of income are summarized as follows: Year Ended December 31 (In thousands) 2019 2018 2017 Current expense: Federal $ 43,337 $ 52,041 $ 65,459 State 6,798 9,429 7,960 Deferred expense: Federal 12,522 8,298 20,920 Tax Act remeasurement 0 (120 ) 37,732 State 1,683 1,175 2,175 Total income taxes $ 64,340 $ 70,823 $ 134,246
Reconciliation of Income Tax Expense to the Amount Computed by Applying the Statutory Federal Income Tax Rate	The following is a reconciliation of income tax expense to the amount computed by applying the statutory federal income tax rate to income before income taxes: Year Ended December 31 (Dollars in thousands) 2019 2018 2017 Amount % Amount % Amount % Tax on income before taxes at statutory federal rate $ 68,132 21.0 $ 68,704 21.0 $ 99,689 35.0 Plus: State income taxes net of federal tax benefits 6,690 2.1 8,362 2.6 6,207 2.2 74,822 23.1 77,066 23.6 105,896 37.2 Increase (decrease) resulting from: Tax-exempt (2,813 ) (0.9 ) (3,298 ) (1.0 ) (5,362 ) (1.9 ) Tax credits (5,636 ) (1.7 ) (2,054 ) (0.6 ) (1,171 ) (0.4 ) Deferred taxes due to the Tax Act (0 ) 0.0 (120 ) 0.0 37,732 13.2 Other items-net (2,033 ) (0.7 ) (771 ) (0.3 ) (2,849 ) (1.0 ) Income taxes $ 64,340 19.8 $ 70,823 21.7 $ 134,246 47.1
Components of United's Deferred Tax Assets and Liabilities	Significant components of United’s deferred tax assets and liabilities (included in other assets in the Consolidated Balance Sheets) at December 31, 2019 and 2018 are as follows: (In thousands) 2019 2018 Deferred tax assets: Allowance for credit losses $ 18,358 $ 18,109 Accrued benefits payable 13.459 13,914 Other accrued liabilities 992 846 Pension plan accruals 3,313 1,217 Unrealized loss on securities available for sale 0 5,572 Other real estate owned 2,482 2,482 Lease liabilities under operating leases 14,293 0 Deferred mortgage points 0 983 Purchase accounting intangibles 5,917 18,091 Total deferred tax assets 58,814 61,214 Deferred tax liabilities: Premises and equipment 2,963 1,414 Unrealized gain on securities available for sale 2,755 0 Right-of-use assets under operating leases 13,464 0 Deferred mortgage points 389 0 Other 2,300 2,899 Total deferred tax liabilities 21,871 4,313 Net deferred tax assets $ 36,943 $ 56,901
Reconciliation of the Total Amounts of Unrecognized Tax Benefits	Below is a reconciliation of the total amounts of unrecognized tax benefits: December 31 (In thousands) 2019 2018 Unrecognized tax benefits at beginning of year $ 2,005 $ 2,894 Increase in unrecognized tax benefits as a result of tax positions taken during the current period 152 156 Decreases in the unrecognized tax benefits as a result of a (589 ) (1,045 ) Unrecognized tax benefits at end of year $ 1,568 2,005

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2019
Retirement Benefits [Abstract]
Net Periodic Pension Cost	Net consolidated periodic pension cost included the following components: (Dollars in thousands) Year Ended December 31, 2019 2018 2017 Service cost $ 2,173 $ 2,566 $ 2,146 Interest cost 5,931 5,341 5,149 Expected return on plan assets (9,434) (10,260) (8,538) Recognized net actuarial loss 4,965 4,919 4,553 Net periodic pension cost $ 3,635 $ 2,566 $ 3,310 Weighted-Average Assumptions: Discount rate 4.52% 3.83% 4.49% Expected return on assets 7.00% 7.00% 7.00% Rate of Compensation Increase (prior to age 45) 3.50% 3.50% 3.50% Rate of Compensation Increase (otherwise) 3.00% 3.00% 3.00%
Schedule of Amounts Related to Plan recognized as Component of Other Comprehensive Income	Amounts related to the Plan recognized as a component of other comprehensive income were as follows: (In thousands) Year Ended December 31, 2019 2018 2017 Net actuarial loss $ 10,324 $ 4,232 $ 6,784 Amortization of: Prior service cost 0 0 0 Actuarial loss (4,965) (4,919) (4,553) Total recognized in other comprehensive income $ 5,359 $ (687) $ 2,231
Reconciliation of the Beginning and Ending Balances of the Projected Benefit Obligation and the Fair Value of Plan Assets and the Accumulated Benefit Obligation	The reconciliation of the beginning and ending balances of the projected benefit obligation and the fair value of plan assets for the years ended December 31, 2019 and 2018 and the accumulated benefit obligation at December 31, 2019 and 2018 are as follows: (Dollars in thousands) December 31, Change in Projected Benefit Obligation Projected Benefit Obligation at the Beginning of the Year $ 142,632 $ 152,740 Service Cost 2,173 2,566 Interest Cost 5,931 5,341 Actuarial Loss (Gain) 28,364 (13,301 ) Benefits Paid (5,323 ) (4,714 ) Projected Benefit at the End of the Year $ 173,777 $ 142,632 Accumulated Benefit Obligation at the End of the Year $ 157,154 $ 130,567 Change in Plan Assets Fair Value of Plan Assets at the Beginning of the Year $ 137,408 $ 142,395 Actual Return on Plan Assets 27,475 (7,273 ) Benefits Paid (5,323 ) (4,714 ) Employer Contributions 0 7,000 Fair value of plan assets at end of year $ 159,560 $ 137,408 Net Amount Recognized Funded Status $ (14,217 ) $ (5,224 ) Unrecognized Transition Asset 0 0 Unrecognized Prior Service Cost 0 0 Unrecognized Net Loss 60,894 55,535 Net Amount Recognized $ 46,677 $ 50,311 Weighted-Average Assumptions at the End of the Year Discount Rate 3.42 % 4.52 % Rate of Compensation Increase (prior to age 40) 5.00 % n/a Rate of Compensation Increase (ages 40-54) 4.00 % n/a Rate of Compensation Increase (prior to age 45) n/a 3.50 % Rate of Compensation Increase (otherwise) 3.50 % 3.00 %
Asset Allocation for the Defined Benefit Pension Plan as of the Measurement Date, by Asset Category	Asset allocation for the defined benefit pension plan as of the measurement date, by asset category, is as follows: Plan Assets Target Allocation 2020 Allowable Allocation Range Percentage of Plan Assets at December 31, December 31, Equity Securities 62 % 50-70 % 63 % 67% Debt Securities 35 % 20-50 % 35 % 26% Other 3 % 3-15 % 2 % 7% Total 100 % 100%
Expected Benefit Payments	At December 31, 2019, the benefits expected to be paid in each of the next five fiscal years, and in the aggregate for the five years thereafter are as follows: Year Amount (In thousands) 2020 $ 5,906 2021 6,267 2022 6,637 2023 7,055 2024 7,390 2025 through 2029 42,310
Balances of the Plan Assets, by Fair Value Hierarchy Level	The following tables present the balances of the plan assets, by fair value hierarchy level, as of December 31, 2019 and 2018: Fair Value Measurements at December 31, 2019 Using (In thousands) Description Balance as of December 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and Cash equivalents $ 2,504 $ 2,504 $ 0 $ 0 Fixed Income Mutual Funds: Taxable 55,588 55,588 0 0 Equity Securities: Common stock 23,932 23,932 0 0 Equity Mutual Funds: Fair Value Measurements at December 31, 2019 Using (In thousands) Description Balance as of December 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Global equity 5,247 5,247 0 0 Domestic equity large cap 28,743 28,743 0 0 Domestic equity small cap 22,216 22,216 0 0 International emerging equity 8,228 8,228 0 0 International equity develope d 13,102 13,102 0 0 Total $ 159,560 $ 159,560 $ 0 $ 0 Fair Value Measurements at December 31, 2018 Using (In thousands) Description Balance as of December 31, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash and Cash equivalents $ 10,086 $ 10,086 $ 0 $ 0 Fixed Income Mutual Funds: Taxable 35,086 35,086 0 0 Equity Securities: Common stock 22,846 22,846 0 0 Equity Mutual Funds: Domestic equity large cap 28,090 28,090 0 0 Domestic equity small cap 15,212 15,212 0 0 International emerging equity 8,791 8,791 0 0 International equity developed 17,297 17,297 0 0 Total $ 137,408 $ 137,408 $ 0 $ 0

Stock Based Compensation (Table

Stock Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Plans	A summary of activity under the United’s stock option plans as of December 31, 2019, and the changes during the year of 2019 are presented below: Year ended December 31, 2019 Weighted Average (Dollars in thousands, except per share data) Aggregate Remaining Exercise Shares Value Term (Yrs.) Price Outstanding at January 1, 2019 1,730,389 $ 32.43 Granted 240,205 38.49 Exercised (128,742 ) 23.12 Forfeited or expired (126,536 ) 25.44 Year ended December 31, 2019 Weighted Average (Dollars in thousands, except per share data) Aggregate Remaining Exercise Shares Value Term (Yrs.) Price Outstanding at December 31, 2019 1,715,316 $ 8,707 5.6 $ 34.49 Exercisable at December 31, 2019 1,125,579 $ 8,342 4.2 $ 31.97
Changes to United's Restricted Common Shares	The following summarizes the changes to United’s restricted common shares for the year ended December 31, 2019: Number of Weighted-Average Grant Date Fair Value Per Share Outstanding at January 1, 2019 199,303 $ 39.67 Granted 126,427 38.49 Vested (73,685) 39.28 Forfeited (4,149) 39.08 Outstanding at December 31, 2019 247,896 $ 39.20
Status of United's Nonvested Stock Option Awards	The following table summarizes the status of United’s nonvested awards for the year ended December 31, 2019: Shares Weighted-Average Grant Date Fair Value Per Share Nonvested at January 1, 2019 575,672 $ 7.86 Granted 240,205 7.16 Vested (211,326 ) 7.74 Forfeited or expired (14,814 ) 7.55 Nonvested at December 31, 2019 589,737 $ 7.62

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amount and Fair Value of Derivative Financial Instruments	The following tables disclose the derivative instruments’ location on the Company’s Consolidated Balance Sheets and the notional amount and fair value of those instruments at December 31, 2019 and 2018. Asset Derivatives December 31, 2019 December 31, 2018 (In thousands) Balance Sheet Location Notional Amount Fair Value Balance Sheet Location Notional Amount Fair Value Derivatives designated as hedging instruments Fair Value Hedges: Interest rate swap contracts (hedging commercial loans) Other assets $ 0 $ 0 Other assets $ 85,623 $ 1,859 Total derivatives designated as hedging instruments $ 0 $ 0 $ 85,623 $ 1,859 Derivatives not designated as hedging instruments Interest rate swap contracts Other assets $ 0 $ 0 Other assets $ 0 $ 0 Forward loan sales commitments Other assets 27,260 9 Other assets 21,604 542 Interest rate lock commitments Other assets 117,252 4,518 Other assets 93,955 4,103 Total derivatives not designated as hedging instruments $ 144,512 $ 4,527 $ 115,559 $ 4,645 Total asset derivatives $ 144,512 $ 4,527 $ 201,182 $ 6,504 Liability Derivatives December 31, 2019 December 31, 2018 (In thousands) Balance Sheet Location Notional Amount Fair Value Balance Sheet Location Notional Amount Fair Value Derivatives designated as hedging instruments Fair Value Hedges: Interest rate swap contracts (hedging commercial loans) Other liabilities $ 82,243 $ 2,394 Other liabilities $ 0 $ 0 Total derivatives designated as hedging instruments $ 82,243 $ 2,394 $ 0 $ 0
Summary of Carrying Amount Hedged Assets/(Liabilities)	Liability Derivatives December 31, 2019 December 31, 2018 (In thousands) Balance Sheet Location Notional Amount Fair Value Balance Sheet Location Notional Amount Fair Value Derivatives not designated as hedging instruments Interest rate swap contracts Other liabilities $ 0 $ 0 Other liabilities $ 0 $ 0 TBA mortgage-backed securities Other liabilities 274,000 671 Other liabilities 200,281 3,002 Interest rate lock commitments Other liabilities 0 0 Other liabilities 0 0 Total derivatives not designated as hedging instruments $ 274,000 $ 671 $ 200,281 $ 3,002 Total liability derivatives $ 356,243 $ 3,065 $ 200,281 $ 3,002 The following table represents the carrying amount of the hedged assets/(liabilities) and the cumulative amount of fair value hedging adjustment December 31, 2019 (In thousands) Derivatives in Fair Value Hedging Relationships Location in the Statement Carrying Amount of Assets/(Liabilities) Cumulative Amount Cumulative Amount of Interest rate swaps Loans, net of unearned income $ 81,397 $ (2,394 ) $ 0
Schedule of Derivative Financial Instruments on Statement of Income	The effect of United’s derivative financial instruments on its Consolidated Statements of Income for the years ended December 31, 2019, 2018 and 2017 is presented as follows: Year Ended (In thousands) Income Statement Location December 31, December 31, December 31, Derivatives in hedging relationships Fair Value Hedges: Interest rate swap contracts Interest income/ (expense) $ (95 ) $ (170 ) $ (781 ) Total derivatives in hedging relationships $ (95 ) $ (170 ) $ (781 ) Derivatives not designated as hedging instruments Forward loan sales commitments Income from Mortgage Banking Activities 925 530 (426 ) TBA mortgage-backed securities Income from Mortgage Banking Activities 2,331 (2,690 ) 1,547 Interest rate lock commitments Income from Mortgage Banking Activities 3,607 (2,413 ) (7,730 ) Total derivatives not designated as hedging instruments $ 6,863 $ (4,573 ) $ (6,609 ) Total derivatives $ 6,768 $ (4,743 ) $ (7,390 )

Comprehensive Income (Tables)

Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Components of Total Comprehensive Income	The changes in accumulated other comprehensive income are as follows: For the Years Ended December 31 (In thousands) 2019 2018 2017 Net Income $ 260,099 $ 256,342 $ 150,581 Available for sale (“AFS”) securities: AFS securities with OTTI charges during the period (641 ) (1,456 ) (60 ) Related income tax effect 149 339 22 Less : OTTI charges recognized in net income 198 1,456 60 Related income tax benefit (46 ) (339 ) (22 ) Reclassification of previous noncredit OTTI to credit OTTI 2,188 0 0 Related income tax benefit (510 ) 0 0 Net unrealized gains on AFS securities with OTTI 1,338 0 0 AFS securities – all other: Change in net unrealized gains (losses) on AFS securities arising during the period 32,376 (14,715 ) 8,371 Related income tax effect (7,543 ) 5,109 (3,097 ) Net reclassification adjustment for gains included in net income 97 770 (1,874 ) Related income tax (benefit) expense (23 ) (179 ) 693 24,907 (9,015 ) 4,093 Net effect of AFS securities on other comprehensive income 26,245 (9,015 ) 4,093 Held to maturity (“HTM”) securities: Accretion on the unrealized loss for securities transferred from AFS to the HTM investment portfolio prior to call or maturity 0 8 8 Related income tax benefit (0 ) (2 ) (3 ) Net effect of HTM securities on other comprehensive income 0 6 5 Defined benefit pension plan: Net actuarial loss during the period (10,324) (4,232) (6,784) Related income tax expense 2,384 1,063 2,510 Amortization of prior service cost recognized in net income 0 0 0 Related income tax benefit 0 0 0 Amortization of net actuarial loss recognized in net income 4,965 4,919 4,553 Related income tax benefit (1,170) (1,246) (1,685) Net effect of change in defined benefit pension plan on other comprehensive income (4,145) 504 (1,406) Total change in other comprehensive income, net of tax 22,100 (8,505 ) 2,692 Total Comprehensive Income $ 282,199 $ 247,837 $ 153,273
Components of Accumulated Other Comprehensive Income	The components of accumulated other comprehensive income for the year ended December 31, 2019 are as follows: Changes in Accumulated Other Comprehensive Income (AOCI) by Component (a) For the Year Ended December 31, 2019 (Dollars in thousands) Unrealized Accretion on the Defined Items Total Balance at January 1, 2019 $ (18,289 ) $ (50 ) $ (38,680 ) $ (57,019 ) Reclass due to adopting Accounting Standard Update 2017-12 0 50 0 50 Other comprehensive income before reclassification 24,493 0 0 24,493 Amounts reclassified from accumulated other comprehensive income 1,752 0 (4,145 ) (2,393 ) Net current-period other comprehensive income, net of tax 26,245 0 (4,145 ) 22,100 Balance at December 31, 2019 $ 7,956 $ 0 $ (42,825 ) $ (34,869 ) (a) All amounts are net-of-tax.
Reclassifications Out of Accumulated Other Comprehensive Income	Reclassifications out of Accumulated Other Comprehensive Income (AOCI) For the Year Ended December 31, 2019 (Dollars in thousands) Details about AOCI Components Amount Reclassified from AOCI Affected Line Item in the Statement Where Net Income is Presented Available for sale (“AFS”) securities: Reclassification of previous noncredit OTTI to credit OTTI $ 2,188 Total other-than-temporary impairment losses Net reclassification adjustment for losses (gains) included in net income 97 Net gains on sales/calls of investment securities 2,285 Total before tax Related income tax effect (533 ) Tax expense 1,752 Net of tax Pension plan: Net actuarial loss (10,324 )(a) Amortization of net actuarial loss 4,965 (b) (5,359 ) Total before tax Related income tax effect 1,214 Tax expense (4,145 ) Net of tax Total reclassifications for the period $ (2,393 ) (a) This AOCI component is included in the computation of changes in plan assets (see Note O (b) This AOCI component is included in the computation of net periodic pension cost (see Note O

United Bankshares, Inc. (Pare_2

United Bankshares, Inc. (Parent Company Only) Financial Information (Tables)	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information Disclosure [Abstract]
Condensed Balance Sheets	Condensed Balance Sheets December 31 (In thousands) 2019 2018 Assets Cash and due from banks $ 126,697 $ 68,186 Securities available for sale 7,451 6,822 Securities held to maturity 20 997 Equity securities 4,126 5,094 Other investment securities 10,053 163 Investment in subsidiaries: Bank subsidiaries 3,519,661 3,478,956 Nonbank subsidiaries 22,439 14,706 Goodwill (16,008 ) (16,008 ) Condensed Balance Sheets December 31 (In thousands) 2019 2018 Other assets 12,286 10,615 Total Assets $ 3,686,725 $ 3,569,531 Liabilities and Shareholders’ Equity Junior subordinated debentures of subsidiary trusts $ 236,164 $ 234,905 Accrued expenses and other liabilities 86,728 83,002 Shareholders’ equity (including other accumulated comprehensive loss of $34,869 and $57,019 at December 31, 2019 and 2018, respectively) 3,363,833 3,251,624 Total Liabilities and Shareholders’ Equity $ 3,686,725 $ 3,569,531
Condensed Statements of Income	Condensed Statements of Income Year Ended December 31 (In thousands) 2019 2018 2017 Income Dividends from banking subsidiaries: Bank subsidiaries $ 249,000 $ 215,000 $ 115,000 Nonbank subsidiaries 0 0 58 Net interest income 126 227 437 Management fees: Bank subsidiaries 27,325 25,026 45,693 Nonbank subsidiaries 27 27 27 Other income 147 (596 ) 1,766 Total Income 276,625 239,684 162,981 Expenses Operating expenses 38,569 37,214 71,653 Income Before Income Taxes and Equity in Undistributed Net Income of Subsidiaries 238,056 202,470 91,328 Applicable income tax benefit (2,123 ) (2,470 ) (6,126 ) Income Before Equity in Undistributed Net Income of Subsidiaries 240,179 204,940 97,454 Equity in undistributed net income of subsidiaries: Bank subsidiaries 19,557 51,392 50,560 Nonbank subsidiaries 363 10 2,567 Net Income $ 260,099 $ 256,342 $ 150,581
Condensed Statements of Cash Flows	Condensed Statements of Cash Flows Year Ended December 31 (In thousands) 2019 2018 2017 Operating Activities Net income $ 260,099 $ 256,342 $ 150,581 Adjustments to reconcile net income to net cash provided by operating activities: Equity in undistributed net income of subsidiaries (19,920 ) (51,402) (53,127) Amortization of net periodic pension costs 302 293 228 Stock-based compensation 4,914 4,073 3,555 Excess tax benefits from stock-based compensation arrangements 223 158 2,201 Net gain on securities transactions 0 607 (1,185) Net change in other assets and liabilities 1,770 (1,904) 8,764 Net Cash Provided by Operating Activities 247,388 208,167 111,017 Investing Activities Net proceeds from sales (purchases) of securities 236 9,446 (19,268) Net proceeds from sales of equity securities 1,116 1,348 0 Condensed Statements of Cash Flows Year Ended December 31 (In thousands) 2019 2018 2017 Net cash paid in acquisition of subsidiary 0 0 22,146 Increase in investment in subsidiaries (7,000) (2,400) (34,203) Change in other investment securities (9,890) 0 (63) Net Cash (Used in) Provided by Investing Activities (15,538) 8,394 (31,388) Financing Activities Proceeds from issuance of common stock 0 0 0 Cash dividends paid (138,939 ) (142,350) (121,354) Acquisition of treasury stock (35,573 ) (100,724) (1) Proceeds from sale of treasury stock from deferred compensation plan 1 1 1 Proceeds from exercise of stock options 1,272 1,500 4,619 Net Cash Used in Financing Activities (173,339 ) (241,573) (116,735) Increase (De crease) 58,511 (25,012) (37,106) Cash and Cash Equivalents at Beginning of Year 68,186 93,198 130,304 Cash and Cash Equivalents at End of Year $ 126,697 $ 68,186 $ 93,198

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2019
Banking and Thrift [Abstract]
Capital Amounts and Ratios	United’s and United Bank, capital amounts (in thousands of dollars) and ratios are presented in the following table. (Dollars in thousands) Actual For Capital Adequacy Purposes To Be Well- Capitalized Amount Ratio Amount Ratio Amount Ratio As of December 31, 2019: Total Capital (to Risk-Weighted Assets): United Bankshares $ 2,217,547 14.7 % $ 1,206,812 ≥ $ 1,508,515 ≥ United Bank 2,106,457 14.0 % 1,204,264 ≥ 1,505,330 ≥ Tier I Capital (to Risk-Weighted Assets): United Bankshares $ 1,890,757 12.5 % $ 905,109 ≥ $ 1,206,812 ≥ United Bank 2,027,667 13.5 % 903,198 ≥ 1,204,264 ≥ Common Tier I Capital (to Risk Weighted Assets): United Bankshares $ 1,890,757 12.5 % $ 678,832 ≥ $ 980,535 ≥ United Bank 2,027,667 13.5 % 677,399 ≥ 978,465 ≥ Tier I Capital (to Average Assets): United Bankshares $ 1,890,757 10.5 % $ 721,691 ≥ $ 902,114 ≥ United Bank 2,027,667 11.3 % 720,232 ≥ 900,290 ≥ As of December 31, 2018: Total Capital (to Risk-Weighted Assets): United Bankshares $ 2,119,774 14.4 % $ 1,179,708 ≥ $ 1,474,635 ≥ United Bank 2,080,234 14.1 % 1,177,953 ≥ 1,472,441 ≥ Tier I Capital (to Risk-Weighted Assets): United Bankshares $ 1,793,682 12.2 % $ 884,781 ≥ $ 1,179,708 ≥ United Bank 2,002,142 13.6 % 883,465 ≥ 1,177,953 ≥ Common Tier I Capital (to Risk Weighted Assets): United Bankshares $ 1,793,682 12.2 % $ 663,586 ≥ $ 958,513 ≥ United Bank 2,002,142 13.6 % 662,599 ≥ 957,087 ≥ Tier I Capital (to Average Assets): United Bankshares $ 1,793,682 10.1 % $ 707,916 ≥ $ 884,895 ≥ United Bank 2,002,142 11.3 % 706,977 ≥ 883,721 ≥

Fair Values of Financial Inst_2

Fair Values of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured at Fair Value	The following table presents the balances of financial assets and liabilities measured at fair value on a recurring basis as of December 31, 2019 and 2018, segregated by the level of the valuation inputs within the fair value hierarchy: Fair Value at December 31, 2019 Using (In thousands) Description Balance as of December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Available for sale debt securities: U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 58,676 $ 0 $ 58,676 $ 0 State and political subdivisions 272,362 0 272,362 0 Residential mortgage-backed securities Agency 836,534 0 836,534 0 Non-agency 3,832 0 3,832 0 Commercial mortgage-backed securities Agency 614,973 0 614,973 0 Asset-backed securities 276,139 0 276,139 0 Trust preferred collateralized debt obligations 4,704 0 0 4,704 Fair Value at December 31, 2019 Using (In thousands) Description Balance as of December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Single issue trust preferred securities 16,774 0 16,774 0 Other corporate securities 353,302 6,586 346,716 0 Total available for sale securities 2,437,296 6,586 2,426,006 4,704 Equity securities: Financial services industry 154 154 0 0 Equity mutual funds (1) 3,971 3,971 0 0 Other equity securities 4,769 4,769 0 0 Total equity securities 8,894 8,894 0 0 Loans held for sale 384,375 0 0 384,375 Derivative financial assets: Forward sales commitments 9 0 9 0 Interest rate lock commitments 4,518 0 0 4,518 Total derivative financial assets 4,527 0 9 4,518 Liabilities Derivative financial liabilities: Interest rate swap contracts 2,394 0 2,394 0 TBA mortgage-backed securities 671 0 671 0 Total derivative financial liabilities 3,065 0 3,065 0 Fair Value at December 31, 2018 Using (In thousands) Description Balance as of December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Available for sale debt securities: U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 85,890 $ 0 $ 85,890 $ 0 State and political subdivisions 208,988 0 208,988 0 Residential mortgage-backed securities Agency 1,035,650 0 1,035,650 0 Non-agency 4,259 0 4,259 0 Commercial mortgage-backed securities Agency 554,600 0 554,600 0 Asset-backed securities 271,970 0 271,970 0 Trust preferred collateralized debt obligations 5,917 0 0 5,917 Single issue trust preferred securities 8,362 0 8,362 0 Other corporate securities 161,403 6,822 154,581 0 Total available for sale securities 2,337,039 6,822 2,324,300 5,917 Equity securities: Financial services industry 140 140 0 0 Equity mutual funds (1) 4,954 4,954 0 0 Other equity securities 4,640 4,640 0 0 Total equity securities 9,734 9,734 0 0 Loans held for sale 247,104 0 0 247,104 Derivative financial assets: Interest rate swap contracts 1,859 0 1,859 0 Fair Value at December 31, 2018 Using (In thousands) Description Balance as of December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Forward sales commitments 542 0 542 0 Interest rate lock commitments 4,103 0 0 4,103 Total derivative financial assets 6,504 0 2,401 4,103 Liabilities Derivative financial liabilities: TBA mortgage-backed securities 3,002 0 3,002 0 Total derivative financial liabilities 3,002 0 3,002 0 (1) The equity mutual funds are within a rabbi trust for the payment of benefits under a deferred compensation plan for certain key officers of United and its subsidiaries.
Schedule of Additional Information about Financial Assets and Liabilities Measured at Fair Value Utilized Level 3	The following table presents additional information about financial assets and liabilities measured at fair value at December 31, 2019 and 2018 on a recurring basis and for which United has utilized Level 3 inputs to determine fair value: Available-for-sale (In thousands) Trust preferred collateralized debt obligations 2019 2018 Balance, beginning of year $ 5,917 $ 34,269 Total gains or losses (realized/unrealized): Included in earnings (or changes in net assets) (155 ) 28 Included in other comprehensive income (1,059 ) 920 Purchases, issuances, and settlements 0 0 Sales 0 (29,300 ) Transfers in and/or out of Level 3 0 0 Balance, ending of year $ 4,703 $ 5,917 The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at reporting date 0 0 Loans held for sale (In thousands) 2019 2018 Balance, beginning of period 247,104 263,308 Originations 2,941,722 2,619,454 Sales (2,888,257 ) (2,676,797 ) Total gains or losses during the period recognized in earnings 83,806 68,555 Transfers in and/or out of Level 3 (0 ) (27,416 ) Balance, end of period 384,375 247,104 The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at reporting date 0 0 (In thousands) Derivative Financial Assets Interest Rate Lock Commitments 2019 2018 Balance, beginning of period $ 4,103 $ 4,559 Transfers other 415 (456 ) Balance, end of perio d $ 4,518 $ 4,103 The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at reporting date $ 0 $ 0
Schedule of Changes in Fair Value Included in Earnings of Financial Instruments for which Fair Value Option has been Elected	The following table reflects the change in fair value included in earnings of financial instruments for which the fair value option has been elected: (In thousands) Description Year Ended December 31, 2019 Year Ended December 31, 2018 Assets Loans held for sale Income from mortgage banking activities $ 3,705 $ (281)
Summary of Difference Between Aggregate Fair Value and Remaining Contractual Principal Outstanding for Financial Instruments for which Fair Value Option has been Elected	The following table reflects the difference between the aggregate fair value and the remaining contractual principal outstanding for financial instruments for which the fair value option has been elected: December 31, 2019 December 31, 2018 (In thousands) Description Unpaid Fair Value Fair Value Unpaid Fair Value Fair Value Assets Loans held for sale 375,274 384,375 9,101 241,293 247,104 5,811
Summary of Financial Assets Measured at Fair Value on Nonrecurring Basis	The following table summarizes United’s financial assets that were measured at fair value on a nonrecurring basis during the period: Carrying value at December 31, 2019 (In thousands) Description Balance as of December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant (Level 2) Significant (Level 3) YTD Gains ( Losses ) Assets Loans held for sale $ 3,139 $ 0 $ 3,139 $ 0 $ (4 ) Impaired Loans 68,213 0 55,792 12,421 1,831 OREO 15,515 0 15,495 20 (785 ) Carrying value at December 31, 2018 (In thousands) Description Balance as of December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant (Level 2) Significant (Level 3) YTD Losses Assets Loans held for sale $ 2,742 $ 0 $ 2,742 $ 0 $ 3 Impaired Loans 121,355 0 108,899 12,456 12,301 OREO 16,865 0 16,865 0 910
Summary of Estimated Fair Values of Financial Instruments	The estimated fair values of United’s financial instruments are summarized below: Fair Value Measurements (In thousands) Carrying Fair Value in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) December 31, 2019 Cash and cash equivalents $ 837,493 $ 837,493 $ 0 $ 837,493 $ 0 Securities available for sale 2,437,296 2,437,296 6,586 2,426,006 4,704 Securities held to maturity 1,446 1,447 0 427 1,020 Equity securities 8,894 8,894 8,894 0 0 Other securities 222,161 211,053 0 0 211,053 Loans held for sale 387,514 387,514 0 3,139 384,375 Net loans 13,635,072 13,185,955 0 0 13,185,955 Derivative financial assets 4,527 4,527 0 9 4,518 Deposits 13,852,421 13,843,077 0 13,843,077 0 Short-term borrowings 374,654 374,654 0 374,654 0 Long-term borrowings 1,838,029 1,820,297 0 1,820,297 0 Derivative financial liabilities 3,065 3,065 0 3,065 0 December 31, 2018 Cash and cash equivalents $ 1,020,396 $ 1,020,396 $ 0 $ 1,020,396 $ 0 Securities available for sale 2,337,039 2,337,039 6,822 2,324,300 5,917 Securities held to maturity 19,999 18,655 0 15,635 3,020 Equity securities 9,734 9,734 9,734 0 0 Other securities 176,955 168,107 0 0 168,107 Loans held for sale 249,846 249,846 0 2,742 247,104 Net loans 13,345,519 12,657,073 0 0 12,657,073 Derivative financial assets 6,504 6,504 0 2,401 4,103 Deposits 13,994,749 13,954,574 0 13,954,574 0 Short-term borrowings 351,327 351,327 0 351,327 0 Long-term borrowings 1,499,103 1,475,237 0 1,475,237 0 Derivative financial liabilities 3,002 3,002 0 3,002 0

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Quantitative Information Related to Significant Involvement in Unconsolidated Variable Interest Entities	The following table summarizes quantitative information about United’s significant involvement in unconsolidated VIEs: As of December 31, 2019 As of December 31, 2018 (In thousands) Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Trust preferred securities $ 257,941 $ 248,680 $ 9,261 $ 257,754 $ 248,741 $ 9,013 (1)

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2019
Segment Reporting [Abstract]
Summary of Segment Reporting Information	Information about the reportable segments and reconciliation of this information to the consolidated financial statements at and for the years ended December 31, 2019, 2018 and 2017 is as follows: At and For the Year Ended December 31, 2019 (In thousands) Community Mortgage Other Intersegment Eliminations Consolidated Net interest income $ 583,547 $ 916 $ (12,472 ) $ 5,931 $ 577,922 Provision for loans losses 21,313 0 0 0 21,313 Other income 74,956 83,884 392 (8,748 ) 150,484 Other expense 314,710 72,288 (1,527 ) (2,817 ) 382,654 Income taxes 64,080 2,355 (2,095 ) 0 64,340 Net income (loss) $ 258,400 $ 10,157 $ (8,458 ) $ 0 $ 260,099 Total assets (liabilities) $ 19,564,036 $ 507,124 $ 17,777 $ (426,613 ) $ 19,662,324 Average assets (liabilities) 19,401,397 358,087 8,411 (292,427 ) 19,475,468 At and For the Year Ended December 31, 2018 (In thousands) Community Mortgage Other Intersegment Eliminations Consolidated Net interest income $ 593,108 $ 1,315 $ (11,886 ) $ 6,108 $ 588,645 Provision for loans losses 22,013 0 0 0 22,013 Other income 72,539 68,555 (667 ) (11,715 ) 128,712 Other expense 301,123 72,632 31 (5,607 ) 368,179 Income taxes 73,861 (505 ) (2,533 ) 0 70,823 Net income (loss) $ 268,650 $ (2,257 ) $ (10,051 ) $ 0 $ 256,342 Total assets (liabilities) $ 19,191,215 $ 320,299 $ 3,222 $ (264,238 ) $ 19,250,498 Average assets (liabilities) 18,798,880 279,618 6,104 (236,575 ) 18,848,027 At and For the Year Ended December 31, 2017 (In thousands) Community Mortgage Other Intersegment Eliminations Consolidated Net interest income $ 558,622 $ (69 ) $ (9,556 ) $ 0 $ 548,997 Provision for loans losses 28,406 0 0 0 28,406 Other income 69,615 58,532 3,498 0 131,645 Other expense 291,584 62,072 13,753 0 367,409 Income taxes 139,980 (901 ) (4,833 ) 0 134,246 Net income (loss) $ 168,267 $ (2,708 ) $ (14,978 ) $ 0 $ 150,581 Total assets (liabilities) $ 19,016,619 $ 280,293 $ 17,158 $ (255,111 ) $ 19,058,959 Average assets (liabilities) 17,565,464 212,212 19,769 (180,016 ) 17,617,429

Quarterly Financial Data (Table

Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data	Quarterly financial data for 2019 2018 (Dollars in thousands) 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter 2019 Interest income $ 189,097 $ 199,245 $ 190,351 $ 183,869 Interest expense 44,929 48,692 48,433 42,586 Net interest income 144,168 150,553 141,918 141,283 Provision for credit losses 4,996 5,417 5,033 5,867 Mortgage banking income 13,681 21,704 24,019 17,547 Securities gains (losses), net (159 ) 109 116 109 Other noninterest income 17,701 17,982 18,089 19,586 Noninterest expense 89,425 100,195 96,134 96,900 Income taxes 17,328 17,529 17,010 12,473 Net income (1) 63,642 67,207 65,965 63,285 (Dollars in thousands) 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter Per share data: Average shares outstanding (000s): Basic 101,895 101,774 101,432 101,250 Diluted 102,163 102,048 101,712 101,538 Net income per share: Basic $ 0.62 $ 0.66 $ 0.65 $ 0.62 Diluted $ 0.62 $ 0.66 $ 0.65 $ 0.62 Dividends per share $ 0.34 $ 0.34 $ 0.34 $ 0.35 2018 Interest income $ 167,185 $ 178,000 $ 185,030 $ 187,500 Interest expense 23,142 28,878 36,255 40,795 Net interest income 144,043 149,122 148,775 146,705 Provision for credit losses 5,178 6,204 4,808 5,823 Mortgage banking income 14,570 18,692 13,277 11,570 Securities losses, net (485 ) (55 ) (152 ) (1,926 ) Other noninterest income 17,107 17,370 18,561 20,183 Noninterest expense 90,452 93,410 93,315 91,002 Income taxes 17,899 19,241 17,926 15,757 Net income (1) 61,706 66,274 64,412 63,950 Per share data: Average shares outstanding (000s): Basic 104,859 104,683 103,618 102,930 Diluted 105,163 104,953 103,934 103,164 Net income per share: Basic $ 0.59 $ 0.63 $ 0.62 $ 0.62 Diluted $ 0.59 $ 0.63 $ 0.62 $ 0.62 Dividends per share $ 0.34 $ 0.34 $ 0.34 $ 0.34 (1) For further information, see the related discussion “Quarterly Results” included in Management’s Discussion and Analysis.

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Reconciliation of Numerator and Denominator of Basic Earnings Per Share with that of Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	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]
Distributed earnings allocated to common stock									$ 139,167	$ 141,336	$ 131,527
Undistributed earnings allocated to common stock									120,337	114,542	18,816
Net earnings allocated to common shareholders									$ 259,504	$ 255,878	$ 150,343
Average common shares outstanding	101,250,000	101,432,000	101,774,000	101,895,000	102,930,000	103,618,000	104,683,000	104,859,000	101,585,599	104,015,976	97,502,633
Dilutive effect of stock compensation									266,978	282,849	387,445
Average diluted shares outstanding	101,538,000	101,712,000	102,048,000	102,163,000	103,164,000	103,934,000	104,953,000	105,163,000	101,852,577	104,298,825	97,890,078
Earnings per basic common share	$ 0.62	$ 0.65	$ 0.66	$ 0.62	$ 0.62	$ 0.62	$ 0.63	$ 0.59	$ 2.55	$ 2.46	$ 1.54
Earnings per diluted common share	$ 0.62	$ 0.65	$ 0.66	$ 0.62	$ 0.62	$ 0.62	$ 0.63	$ 0.59	$ 2.55	$ 2.45	$ 1.54

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Additional Information (Detail)	Jan. 01, 2019USD ($)	Aug. 31, 2017USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2019USD ($)Region	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number Of Metropolitan Statistical Areas | Region				5
Loan fees net of costs amortized and included in interest income				$ 39,026,000	$ 44,547,000	$ 44,475,000
Minimum days, related to accrual of interest on discontinued commercial and consumer loans				90 days
Maximum days, related to accrual of interest on discontinued commercial and consumer loans				120 days
Sustained period of repayment performance in restructured loans				6 months
Real estate acquired in foreclosure or other settlement of loans				$ 15,515,000	16,865,000
Recorded investment of consumer mortgage loans				890,000	520,000
Advertising Expense				5,082,000	4,643,000	4,519,000
Amortization expense on intangible assets				7,016,000	8,039,000	7,772,000
Total goodwill				1,478,014,000	1,478,014,000
Stock based compensation expense				4,914,000	4,073,000	3,555,000
Reclass due to adopting Accounting Standard Update				50,000	0
Held-to-maturity securities, transferred security, at carrying value				$ 11,544,000	$ 0	0
ASU 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease in income tax expense						$ 1,048,000
Accounting Standards Update 2018-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclass due to adopting Accounting Standard Update			$ 6,353,000
Accounting Standards Update 2017-12 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Held-to-maturity securities, transferred security, at carrying value		$ 11,544,000
Decrease in AOCI due to transfer of held to maturity securities		$ (1,098,000)
Accounting Standards Update 2018-10 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net lease assets	$ 67,040,000
Net lease liabilities	70,692,000
Effect on retained earnings	$ 1,049,000
Minimum [Member] | Core Deposit Intangible Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Intangible assets amortization period				1 year
Maximum [Member] | Core Deposit Intangible Assets [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Intangible assets amortization period				7 years
Furniture, Fixtures and Equipment [Member] | Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Bank premises and equipment, useful life				3 years
Furniture, Fixtures and Equipment [Member] | Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Bank premises and equipment, useful life				15 years
Buildings and Improvements [Member] | Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Bank premises and equipment, useful life				5 years
Buildings and Improvements [Member] | Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Bank premises and equipment, useful life				40 years

Mergers and Acquisitions - Addi

Mergers and Acquisitions - Additional Information (Detail) $ / shares in Units, $ in Thousands	Nov. 17, 2019$ / shares	Dec. 31, 2019USD ($)Location$ / shares	Dec. 31, 2018USD ($)$ / shares
Business Acquisition [Line Items]
Par value of Share | $ / shares		$ 2.50	$ 2.50
Total assets at consummation		$ 19,662,324	$ 19,250,498
Loans at consummation		13,713,548	$ 13,429,532
Carolina Financial [Member]
Business Acquisition [Line Items]
Par value of Share | $ / shares	$ 2.50
Conversion of Option to acquire common stock exchange ratio	1.13
Total assets at consummation		$ 4,708,873
Conversion of stock award to acquire common stock exchange ratio	1.13
Number of bank locations | Location		200
Loans at consummation		$ 3,227,937
Deposits at consummation		$ 3,408,361
Carolina Financial [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Stock issued during period merger conversion ratio	1.13

Investment Securities - Summary

Investment Securities - Summary of Amortized Cost and Estimated Fair Values of Available for Sale Securities (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Schedule of Investments [Line Items]
Amortized Cost	$ 2,426,924,000	$ 2,360,884,000
Gross Unrealized Gains	28,912,000	5,865,000
Gross Unrealized Losses	18,540,000	29,710,000
Estimated Fair Value	2,437,296,000	2,337,039,000
Cumulative OTTI in AOCI	928,000	2,672,000
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Schedule of Investments [Line Items]
Amortized Cost	58,127,000	86,285,000
Gross Unrealized Gains	555,000	35,000
Gross Unrealized Losses	6,000	430,000
Estimated Fair Value	58,676,000	85,890,000
Cumulative OTTI in AOCI	0	0
State and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Amortized Cost	272,014,000	212,670,000
Gross Unrealized Gains	3,644,000	439,000
Gross Unrealized Losses	3,296,000	4,121,000
Estimated Fair Value	272,362,000	208,988,000
Cumulative OTTI in AOCI	0	0
Residential Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	826,857,000	1,047,345,000
Gross Unrealized Gains	10,923,000	3,235,000
Gross Unrealized Losses	1,246,000	14,930,000
Estimated Fair Value	836,534,000	1,035,650,000
Cumulative OTTI in AOCI	0	0
Residential Mortgage-Backed Securities, Non-agency [Member]
Schedule of Investments [Line Items]
Amortized Cost	3,429,000	3,927,000
Gross Unrealized Gains	404,000	332,000
Gross Unrealized Losses	0	0
Estimated Fair Value	3,833,000	4,259,000
Cumulative OTTI in AOCI	86,000	86,000
Commercial Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	609,461,000	560,634,000
Gross Unrealized Gains	8,319,000	996,000
Gross Unrealized Losses	2,807,000	7,030,000
Estimated Fair Value	614,973,000	554,600,000
Cumulative OTTI in AOCI	0	0
Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	284,390,000	272,459,000
Gross Unrealized Gains	0	450,000
Gross Unrealized Losses	8,251,000	939,000
Estimated Fair Value	276,139,000	271,970,000
Cumulative OTTI in AOCI	0	0
Trust Preferred Collateralized Debt Obligations [Member]
Schedule of Investments [Line Items]
Amortized Cost	6,045,000	6,176,000
Gross Unrealized Gains	0	91,000
Gross Unrealized Losses	1,342,000	350,000
Estimated Fair Value	4,703,000	5,917,000
Cumulative OTTI in AOCI	842,000	2,586,000
Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	18,196,000	8,754,000
Gross Unrealized Gains	170,000	169,000
Gross Unrealized Losses	1,592,000	561,000
Estimated Fair Value	16,774,000	8,362,000
Cumulative OTTI in AOCI	0	0
Corporate Bonds [Member]
Schedule of Investments [Line Items]
Amortized Cost	348,405,000	162,634,000
Gross Unrealized Gains	4,897,000	118,000
Gross Unrealized Losses	0	1,349,000
Estimated Fair Value	353,302,000	161,403,000
Cumulative OTTI in AOCI	$ 0	$ 0

Investment Securities - Summa_2

Investment Securities - Summary of Securities Available for Sale in an Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	$ 564,710	$ 703,081
Less than 12 months, Unrealized Losses	10,569	5,687
12 months or longer, Fair Value	274,399	918,073
12 months or longer, Unrealized Losses	7,971	24,023
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	1,415	66,072
Less than 12 months, Unrealized Losses	6	250
12 months or longer, Fair Value	0	7,374
12 months or longer, Unrealized Losses	0	180
State and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	144,307	53,421
Less than 12 months, Unrealized Losses	3,291	544
12 months or longer, Fair Value	885	94,337
12 months or longer, Unrealized Losses	5	3,577
Residential Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	108,072	195,009
Less than 12 months, Unrealized Losses	502	1,597
12 months or longer, Fair Value	71,736	508,041
12 months or longer, Unrealized Losses	744	13,333
Residential Mortgage-Backed Securities, Non-agency [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	0	0
Less than 12 months, Unrealized Losses	0	0
12 months or longer, Fair Value	0	0
12 months or longer, Unrealized Losses	0	0
Commercial Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	173,039	107,443
Less than 12 months, Unrealized Losses	2,676	1,124
12 months or longer, Fair Value	45,251	294,129
12 months or longer, Unrealized Losses	131	5,906
Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	135,174	151,427
Less than 12 months, Unrealized Losses	3,252	939
12 months or longer, Fair Value	140,965	0
12 months or longer, Unrealized Losses	4,999	0
Trust Preferred Collateralized Debt Obligations [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	2,703	0
Less than 12 months, Unrealized Losses	842	0
12 months or longer, Fair Value	2,000	2,150
12 months or longer, Unrealized Losses	500	350
Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	0	0
Less than 12 months, Unrealized Losses	0	0
12 months or longer, Fair Value	13,562	5,163
12 months or longer, Unrealized Losses	1,592	561
Corporate Bonds [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	0	129,709
Less than 12 months, Unrealized Losses	0	1,233
12 months or longer, Fair Value	0	6,879
12 months or longer, Unrealized Losses	$ 0	$ 116

Investment Securities - Summa_3

Investment Securities - Summary of Gains or Losses on Proceeds from Maturities, Sales and Calls of Available for Sale Securities by Specific Identification Method (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Proceeds from maturities, sales and calls	$ 712,557	$ 441,956	$ 686,312
Gross realized gains	1,542	1,594	3,274
Gross realized losses	$ 1,445	$ 2,364	$ 1,400

Investment Securities - Additio

Investment Securities - Additional Information (Detail)	3 Months Ended	12 Months Ended
	Dec. 31, 2019USD ($)Securities	Dec. 31, 2019USD ($)Securities	Dec. 31, 2018USD ($)
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	$ 18,540,000	$ 18,540,000	$ 29,710,000
Available for sale securities in unrealized loss position | Securities	166	166
Available for sale securities in portfolio, number | Securities	641	641
Amortized cost of available for sale securities	$ 2,426,924,000	$ 2,426,924,000	2,360,884,000
Capitalization of banks, equal to or greater than, in the single-issue trust preferred portfolio	10,000,000,000	10,000,000,000
Equity securities at estimated fair value	8,894,000	8,894,000	9,734,000
Carrying value of securities pledged	$ 1,540,717,000	$ 1,540,717,000	1,887,176,000
Percentage Of Guarantee Repayment By Government	97.00%	97.00%
Held-to-maturity securities amortized cost	$ 1,446,000	$ 1,446,000	19,999,000
Held-to-maturity securities estimated fair value	1,447,000	1,447,000	18,655,000
Non Agency Residential Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Other-than-temporary Impairment Loss, Debt Securities, Available-for-sale, Recognized in Earnings	21,000	42,000
Aggregate amount of other than temporary impairment recognised earnings on securities	21,000	42,000
Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale single issue trust preferred securities	11,484,000	11,484,000
Split Rated Bonds Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale single issue trust preferred securities	977,000	977,000
Unrated Bonds Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale single issue trust preferred securities	5,735,000	5,735,000
State and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	3,296,000	3,296,000	4,121,000
Amortized cost of available for sale securities	$ 272,014,000	$ 272,014,000	212,670,000
Percent of portfolio with credit support	66.00%	66.00%
Held-to-maturity securities amortized cost	$ 1,426,000	$ 1,426,000	5,473,000
Held-to-maturity securities estimated fair value	1,427,000	1,427,000	5,479,000
Agency Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale securities	1,436,318,000	1,436,318,000
Commercial Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	2,807,000	2,807,000	7,030,000
Amortized cost of available for sale securities	609,461,000	609,461,000	560,634,000
Residential Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	1,246,000	1,246,000	14,930,000
Amortized cost of available for sale securities	826,857,000	826,857,000	1,047,345,000
Held-to-maturity securities amortized cost	0	0	20,000
Held-to-maturity securities estimated fair value	0	0	22,000
Residential Mortgage-Backed Securities, Non-agency [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	0	0	0
Amortized cost of available for sale securities	3,429,000	3,429,000	3,927,000
Trust Preferred Collateralized Debt Obligations [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	1,342,000	1,342,000	350,000
Amortized cost of available for sale securities	6,045,000	6,045,000	6,176,000
Trust Preferred Collateralized Debt Obligations [Member] | TrupCdos [Member]
Schedule of Investments [Line Items]
Other-than-temporary Impairment Loss, Debt Securities, Available-for-sale, Recognized in Earnings	93,000	156,000
Aggregate amount of other than temporary impairment recognised earnings on securities	93,000	156,000
Corporate Bonds [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	0	0	1,349,000
Amortized cost of available for sale securities	348,405,000	348,405,000	162,634,000
Held-to-maturity securities amortized cost	20,000	20,000	20,000
Held-to-maturity securities estimated fair value	$ 20,000	$ 20,000	20,000
Corporate Bonds [Member] | Investment Grade [Member]
Schedule of Investments [Line Items]
Percent of corporate securities portfolio	92.00%	92.00%
Corporate Bonds [Member] | Unrated Bonds Investment Grade [Member]
Schedule of Investments [Line Items]
Percent of corporate securities portfolio	8.00%	8.00%
Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Net unrealized gains		$ 15,593,000	17,395,000
Held-to-maturity securities amortized cost	$ 1,439,747,000	1,439,747,000
Held-to-maturity securities estimated fair value	1,455,340,000	1,455,340,000
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	6,000	6,000	430,000
Amortized cost of available for sale securities	58,127,000	58,127,000	86,285,000
Held-to-maturity securities amortized cost	0	0	5,074,000
Held-to-maturity securities estimated fair value	$ 0	$ 0	$ 5,164,000
Aggregate book value percentage of securities to shareholders' equity		10.00%

Investment Securities - Roll Fo

Investment Securities - Roll Forward of Credit Losses on Securities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Cumulative credit losses, Beginning Balance	$ 3,138	$ 18,060	$ 22,162
Additional credit losses on securities for which OTTI was previously recognized	156	0	0
Reductions for securities sold or paid off during the period	0	(14,922)	(4,102)
Cumulative credit losses, Ending Balance	$ 3,294	$ 3,138	$ 18,060

Investment Securities - Summa_4

Investment Securities - Summary of Maturities of Securities Available for Sale by Amortized Cost and Estimated Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Due in one year or less, Amortized Cost	$ 92,422
Due after one year through five years, Amortized Cost	583,715
Due after five years through ten years, Amortized Cost	564,922
Due after ten years, Amortized Cost	1,185,865
Amortized Cost	2,426,924	$ 2,360,884
Due in one year or less, Estimated Fair Value	92,473
Due after one year through five years, Estimated Fair Value	592,850
Due after five years through ten years, Estimated Fair Value	568,241
Due after ten years, Estimated Fair Value	1,183,732
Total available for sale securities	$ 2,437,296	$ 2,337,039

Investment Securities - Summa_5

Investment Securities - Summary of Amortized Cost and Estimated Fair Values of Securities Held to Maturity (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule of Investments [Line Items]
Amortized Cost	$ 1,446	$ 19,999
Gross Unrealized Gains	1	99
Gross Unrealized Losses	0	1,443
Estimated Fair Value	1,447	18,655
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Schedule of Investments [Line Items]
Amortized Cost	0	5,074
Gross Unrealized Gains	0	90
Gross Unrealized Losses	0	0
Estimated Fair Value	0	5,164
State and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Amortized Cost	1,426	5,473
Gross Unrealized Gains	1	7
Gross Unrealized Losses	0	1
Estimated Fair Value	1,427	5,479
Residential Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	0	20
Gross Unrealized Gains	0	2
Gross Unrealized Losses	0	0
Estimated Fair Value	0	22
Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	0	9,412
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	1,442
Estimated Fair Value	0	7,970
Corporate Bonds [Member]
Schedule of Investments [Line Items]
Amortized Cost	20	20
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	$ 20	$ 20

Investment Securities - Summa_6

Investment Securities - Summary of Maturities of Debt Securities Held to Maturity by Amortized Cost and Estimated Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Due in one year or less, Amortized Cost	$ 210
Due after one year through five years, Amortized Cost	216
Due after five years through ten years, Amortized Cost	0
Due after ten years, Amortized Cost	1,020
Amortized Cost	1,446	$ 19,999
Due in one year or less, Estimated Fair Value	210
Due after one year through five years, Estimated Fair Value	217
Due after five years through ten year, Estimated Fair Value	0
Due after ten years, Estimated Fair Value	1,020
Estimated Fair Value, Total	$ 1,447	$ 18,655

Investment Securities - Summa_7

Investment Securities - Summary of Equity Securities (Detail) - Marketable Equity Securities [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Debt Securities, Available-for-sale [Line Items]
Net gains recognized during the period	$ 276
Net gains recognized during the period on equity securities sold	133
Unrealized gains recognized during the period on equity securities still held at period end	177
Unrealized losses recognized during the period on equity securities still held at period end	$ (34)

Investment Securities - Maturit

Investment Securities - Maturities and Weighted-Average Yields of Securities (Detail) $ in Thousands	Dec. 31, 2019USD ($)
Schedule of Held-to-maturity Securities [Line Items]
Securities matured Within 1 Year, Amount	$ 210
Securities matured After 1 But Within 5 Years, Amount	216
Securities matured After 5 But Within 10 Years, Amount	0
Securities matured After 10 Years, Amount	1,020
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities matured Within 1 Year, Amount	$ 0
Weighted-average Within 1 Year, Yield	0.00%
Securities matured After 1 But Within 5 Years, Amount	$ 51,511
Weighted-average After 1 But Within 5 Years, Yield	2.41%
Securities matured After 5 But Within 10 Years, Amount	$ 6,616
Weighted-average After 5 But Within 10 Years, Yield	2.74%
Securities matured After 10 Years, Amount	$ 0
Weighted-average After 10 Years, Yield	0.00%
State and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities matured Within 1 Year, Amount	$ 5,364
Weighted-average Within 1 Year, Yield	2.78%
Securities matured After 1 But Within 5 Years, Amount	$ 4,964
Weighted-average After 1 But Within 5 Years, Yield	3.36%
Securities matured After 5 But Within 10 Years, Amount	$ 38,732
Weighted-average After 5 But Within 10 Years, Yield	2.80%
Securities matured After 10 Years, Amount	$ 224,380
Weighted-average After 10 Years, Yield	2.92%
Residential Mortgage-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities matured Within 1 Year, Amount	$ 0
Weighted-average Within 1 Year, Yield	0.00%
Securities matured After 1 But Within 5 Years, Amount	$ 0
Weighted-average After 1 But Within 5 Years, Yield	0.00%
Securities matured After 5 But Within 10 Years, Amount	$ 230,686
Weighted-average After 5 But Within 10 Years, Yield	2.60%
Securities matured After 10 Years, Amount	$ 596,171
Weighted-average After 10 Years, Yield	2.71%
Residential Mortgage-Backed Securities, Non-agency [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities matured Within 1 Year, Amount	$ 69
Weighted-average Within 1 Year, Yield	5.00%
Securities matured After 1 But Within 5 Years, Amount	$ 0
Weighted-average After 1 But Within 5 Years, Yield	0.00%
Securities matured After 5 But Within 10 Years, Amount	$ 0
Weighted-average After 5 But Within 10 Years, Yield	0.00%
Securities matured After 10 Years, Amount	$ 3,360
Weighted-average After 10 Years, Yield	5.84%
Commercial Mortgage-backed Agency [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities matured Within 1 Year, Amount	$ 28,178
Weighted-average Within 1 Year, Yield	2.32%
Securities matured After 1 But Within 5 Years, Amount	$ 281,903
Weighted-average After 1 But Within 5 Years, Yield	2.65%
Securities matured After 5 But Within 10 Years, Amount	$ 241,159
Weighted-average After 5 But Within 10 Years, Yield	2.40%
Securities matured After 10 Years, Amount	$ 58,221
Weighted-average After 10 Years, Yield	2.73%
Asset-Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities matured Within 1 Year, Amount	$ 0
Weighted-average Within 1 Year, Yield	0.00%
Securities matured After 1 But Within 5 Years, Amount	$ 0
Weighted-average After 1 But Within 5 Years, Yield	0.00%
Securities matured After 5 But Within 10 Years, Amount	$ 0
Weighted-average After 5 But Within 10 Years, Yield	0.00%
Securities matured After 10 Years, Amount	$ 284,390
Weighted-average After 10 Years, Yield	2.56%
Trust Preferred Collateralized Debt Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities matured Within 1 Year, Amount	$ 0
Weighted-average Within 1 Year, Yield	0.00%
Securities matured After 1 But Within 5 Years, Amount	$ 0
Weighted-average After 1 But Within 5 Years, Yield	0.00%
Securities matured After 5 But Within 10 Years, Amount	$ 0
Weighted-average After 5 But Within 10 Years, Yield	0.00%
Securities matured After 10 Years, Amount	$ 6,045
Weighted-average After 10 Years, Yield	3.61%
Single Issue Trust Preferred Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities matured Within 1 Year, Amount	$ 0
Weighted-average Within 1 Year, Yield	0.00%
Securities matured After 1 But Within 5 Years, Amount	$ 0
Weighted-average After 1 But Within 5 Years, Yield	0.00%
Securities matured After 5 But Within 10 Years, Amount	$ 10,483
Weighted-average After 5 But Within 10 Years, Yield	4.80%
Securities matured After 10 Years, Amount	$ 7,713
Weighted-average After 10 Years, Yield	3.68%
Corporate Bonds [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities matured Within 1 Year, Amount	$ 59,020
Weighted-average Within 1 Year, Yield	2.63%
Securities matured After 1 But Within 5 Years, Amount	$ 245,553
Weighted-average After 1 But Within 5 Years, Yield	2.98%
Securities matured After 5 But Within 10 Years, Amount	$ 37,246
Weighted-average After 5 But Within 10 Years, Yield	4.58%
Securities matured After 10 Years, Amount	$ 6,606
Weighted-average After 10 Years, Yield	1.28%
Marketable Equity Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities matured Within 1 Year, Amount	$ 0
Weighted-average Within 1 Year, Yield	0.00%
Securities matured After 1 But Within 5 Years, Amount	$ 0
Weighted-average After 1 But Within 5 Years, Yield	0.00%
Securities matured After 5 But Within 10 Years, Amount	$ 0
Weighted-average After 5 But Within 10 Years, Yield	0.00%
Securities matured After 10 Years, Amount	$ 8,894
Weighted-average After 10 Years, Yield	1.49%
Other Investment Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Securities matured Within 1 Year, Amount	$ 0
Weighted-average Within 1 Year, Yield	0.00%
Securities matured After 1 But Within 5 Years, Amount	$ 100
Weighted-average After 1 But Within 5 Years, Yield	2.55%
Securities matured After 5 But Within 10 Years, Amount	$ 750
Weighted-average After 5 But Within 10 Years, Yield	2.08%
Securities matured After 10 Years, Amount	$ 221,311
Weighted-average After 10 Years, Yield	3.32%

Investment Securities - Matur_2

Investment Securities - Maturities and Weighted-Average Yields of Securities (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amortized Cost And Fair Value Debt Securities [Abstract]
Tax on income before taxes at statutory federal rate, rate	21.00%	21.00%	35.00%

Loans - Major Classes of Loans

Loans - Major Classes of Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Commercial, financial, and agricultural
Total commercial, financial & agricultural	$ 7,452,649	$ 7,553,044
Residential real estate	3,686,401	3,501,393
Construction & land development	1,408,205	1,410,468
Consumer:
Bankcard	10,074	10,203
Other consumer	1,156,219	954,424
Less: Unearned income	(1,419)	(7,310)
Loans net of unearned income	13,712,129	13,422,222
Owner-Occupied Commercial Real Estate [Member]
Commercial, financial, and agricultural
Total commercial, financial & agricultural	1,201,652	1,291,790
Nonowner-Occupied Commercial Real Estate [Member]
Commercial, financial, and agricultural
Total commercial, financial & agricultural	3,965,960	4,303,613
Other Commercial Loans [Member]
Commercial, financial, and agricultural
Total commercial, financial & agricultural	$ 2,285,037	$ 1,957,641

Loans - Additional Information

Loans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Loans held for sale	$ 387,514,000	$ 249,846,000
Acquired impaired loans from merger	$ 13,713,548,000	$ 13,429,532,000
Percentage of acquired impaired loans from merger on total gross loans	1.00%	1.12%
Recorded investment in acquired impaired loans	$ 124,779,000	$ 195,706,000
Unamortized deferred loan fees	71,542,000	93,372,000
Loans-in-process	49,456,000	53,997,000
Overdrafts from deposit accounts	22,219,000	13,833,000
Directors and Officers [Member]
Related party loans	38,558,000	93,282,000
Additional amount of loan	9,358,000
Repayment of Loan	64,082,000
Loans Acquired with Deteriorated Credit Quality [Member]
Acquired impaired loans from merger	$ 96,004,000	$ 149,737,000

Loans - Activity for Accretable

Loans - Activity for Accretable Yield (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Accretable yield at the beginning of the period	$ 26,289
Accretion (including cash recoveries)	(10,688)
Additions	0
Net reclassifications to accretable from non-accretable	10,627
Disposals (including maturities, foreclosures, and charge-offs)	(5,140)
Accretable yield at the ending of the period	$ 21,088

Credit Quality - Additional Inf

Credit Quality - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Minimum days for discontinue of accrual interest on commercial and consumer loan	90 days
Maximum days for discontinue of accrual interest on commercial and consumer loan	120 days
Troubled debt restructuring	$ 58,369,000	$ 59,425,000
Restructured loans on nonaccrual status	48,387,000	902,000
Restructured loans modified by reduction in interest	1,685,000
Restructured loan and interest	1,733,000
Restructured loans modified by change in terms	$ 54,951,000
Minimum number of days required for special mention	30 days
Maximum number of days required for special mention	89 days
Number of days required for substandard	90 days
Restructured Loans Modified By Reduction InInterest Rate Amount During Period	$ 10,699,000
Restructured loans modified by reduction in interest rate and change in terms	241,000		$ 22,698,000
Funding commitments	1,159,000
Payments under funding commitments	39,000
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Restructured loans on nonaccrual status	$ 48,899,000	$ 690,000
Financial Asset, 30 to 59 Days Past Due [Member]
Financing receivable threshold period past due	30 days
Financial Asset, 60 to 89 Days Past Due [Member]
Financing receivable threshold period past due	89 days

Credit Quality - Schedule of Tr

Credit Quality - Schedule of Troubled Debt Restructurings, Segregated by Class of Loans (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)Contract	Dec. 31, 2018USD ($)Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	11	13
Pre-Modification Outstanding Recorded Investment	$ 11,686	$ 24,277
Post-Modification Outstanding Recorded Investment	$ 10,940	$ 22,698
Construction & Land Development [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	3	0
Pre-Modification Outstanding Recorded Investment	$ 2,287	$ 0
Post-Modification Outstanding Recorded Investment	$ 2,104	$ 0
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	2	0
Pre-Modification Outstanding Recorded Investment	$ 1,179	$ 0
Post-Modification Outstanding Recorded Investment	$ 1,144	$ 0
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	1
Pre-Modification Outstanding Recorded Investment	$ 0	$ 61
Post-Modification Outstanding Recorded Investment	$ 0	$ 61
Other Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	3	9
Pre-Modification Outstanding Recorded Investment	$ 5,962	$ 16,991
Post-Modification Outstanding Recorded Investment	$ 5,722	$ 16,560
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	3	3
Pre-Modification Outstanding Recorded Investment	$ 2,258	$ 7,225
Post-Modification Outstanding Recorded Investment	$ 1,970	$ 6,077
Consumer [Member] | Bankcard [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0
Consumer [Member] | Other Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0

Credit Quality - Schedule of Ch

Credit Quality - Schedule of Charged-off Troubled Debt Restructurings on Financing Receivables (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)Contract	Dec. 31, 2018USD ($)Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	2	2
Recorded Investment | $	$ 1,477	$ 2,173
Construction & Land Development [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Recorded Investment | $	$ 0	$ 0
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Recorded Investment | $	$ 0	$ 0
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Recorded Investment | $	$ 0	$ 0
Other Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	2	1
Recorded Investment | $	$ 1,477	$ 0
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	1
Recorded Investment | $	$ 0	$ 2,173
Consumer [Member] | Bankcard [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Recorded Investment | $	$ 0	$ 0
Consumer [Member] | Other Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Recorded Investment | $	$ 0	$ 0

Credit Quality - Schedule of Ag

Credit Quality - Schedule of Age Analysis of its Past Due Loans, Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	$ 65,816	$ 94,027
Loans, Total Past Due	186,906	227,011
Loans, Current & Other	13,526,642	13,202,521
Total Financing Receivables	13,713,548	13,429,532
Loans, Recorded Investment >90 Days & Accruing	9,494	15,541
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total Past Due	121,090	132,984
Construction & Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	2,219	8,462
Loans, Total Past Due	18,262	27,874
Loans, Current & Other	1,389,943	1,382,594
Total Financing Receivables	1,408,205	1,410,468
Loans, Recorded Investment >90 Days & Accruing	0	680
Construction & Land Development [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total Past Due	16,043	19,412
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	8,878	9,224
Loans, Total Past Due	20,087	26,966
Loans, Current & Other	1,181,565	1,264,824
Total Financing Receivables	1,201,652	1,291,790
Loans, Recorded Investment >90 Days & Accruing	544	629
Commercial Real Estate [Member] | Owner-Occupied [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total Past Due	11,209	17,742
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	6,318	16,108
Loans, Total Past Due	22,447	34,200
Loans, Current & Other	3,943,513	4,269,413
Total Financing Receivables	3,965,960	4,303,613
Loans, Recorded Investment >90 Days & Accruing	471	1,171
Commercial Real Estate [Member] | Nonowner-Occupied [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total Past Due	16,129	18,092
Other Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	5,238	13,556
Loans, Total Past Due	56,779	59,596
Loans, Current & Other	2,228,258	1,898,045
Total Financing Receivables	2,285,037	1,957,641
Loans, Recorded Investment >90 Days & Accruing	668	2,850
Other Commercial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total Past Due	51,541	46,040
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	31,727	37,111
Loans, Total Past Due	56,070	67,389
Loans, Current & Other	3,630,331	3,434,004
Total Financing Receivables	3,686,401	3,501,393
Loans, Recorded Investment >90 Days & Accruing	6,256	9,141
Residential Real Estate [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total Past Due	24,343	30,278
Consumer [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	445	657
Loans, Total Past Due	663	834
Loans, Current & Other	9,411	9,369
Total Financing Receivables	10,074	10,203
Loans, Recorded Investment >90 Days & Accruing	218	177
Consumer [Member] | Bankcard [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total Past Due	218	177
Consumer [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	10,991	8,909
Loans, Total Past Due	12,598	10,152
Loans, Current & Other	1,143,621	944,272
Total Financing Receivables	1,156,219	954,424
Loans, Recorded Investment >90 Days & Accruing	1,337	893
Consumer [Member] | Other Consumer [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total Past Due	$ 1,607	$ 1,243

Credit Quality - Schedule of _2

Credit Quality - Schedule of Age Analysis of its Past Due Loans, Segregated by Class of Loans (Parenthetical) (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Acquired impaired loans from merger	$ 13,713,548	$ 13,429,532
Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Acquired impaired loans from merger	$ 96,004	149,737
Loans Acquired with Deteriorated Credit Quality [Member] | Loans and Debt Securities Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Acquired impaired loans from merger		$ 149,737

Credit Quality - Schedule of No

Credit Quality - Schedule of Nonaccrual Loans, Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	$ 111,596	$ 117,443
Construction & Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	16,043	18,732
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	10,665	17,113
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	15,658	16,921
Other Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	50,873	43,190
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	18,087	21,137
Consumer [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	0	0
Consumer [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	$ 270	$ 350

Credit Quality - Schedule of Cr

Credit Quality - Schedule of Credit Quality Indicators Information, by Class of Loans (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	$ 13,713,548,000	$ 13,429,532,000
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	3,686,401,000	3,501,393,000
Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	2,285,037,000	1,957,641,000
Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	10,074,000	10,203,000
Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,156,219,000	954,424,000
Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,201,652,000	1,291,790,000
Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	3,965,960,000	4,303,613,000
Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,408,205,000	1,410,468,000
Pass [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	3,645,654,000	3,436,584,000
Pass [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	2,136,266,000	1,858,821,000
Pass [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	9,411,000	9,369,000
Pass [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,143,608,000	944,241,000
Pass [Member] | Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,136,589,000	1,201,387,000
Pass [Member] | Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	3,850,886,000	4,161,149,000
Pass [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,334,950,000	1,330,899,000
Special Mention [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	12,038,000	19,051,000
Special Mention [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	75,511,000	14,424,000
Special Mention [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	445,000	657,000
Special Mention [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	10,993,000	8,914,000
Special Mention [Member] | Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	14,449,000	34,487,000
Special Mention [Member] | Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	44,134,000	46,442,000
Special Mention [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	4,614,000	28,629,000
Substandard [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	28,572,000	45,758,000
Substandard [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	72,451,000	81,946,000
Substandard [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	218,000	177,000
Substandard [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,618,000	1,269
Substandard [Member] | Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	50,346,000	55,916,000
Substandard [Member] | Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	70,940,000	96,022,000
Substandard [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	68,641,000	50,940,000
Doubtful [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	137,000	0
Doubtful [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	809,000	2,450,000
Doubtful [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	0	0
Doubtful [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	0	0
Doubtful [Member] | Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	268,000	0
Doubtful [Member] | Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	0	0
Doubtful [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	$ 0	$ 0

Credit Quality - Schedule of Im

Credit Quality - Schedule of Impaired Loans Information by Class of Loans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Construction & Land Development [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	$ 39,599	$ 37,174
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	47,594	40,459
Impaired Loans, Recorded Investment, With an allowance recorded	1,269	14,742
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	1,269	19,446
Impaired Loans, Related Allowance	262	2,254
Impaired Loans, Recorded Investment	40,868	51,916
Impaired Loans, Unpaid Principal Balance	48,863	59,905
Impaired Loans, Average Recorded Investment, With no related allowance recorded	35,702	41,892
Impaired Loans, Interest Income Recognized, With no related allowance recorded	799	914
Impaired Loans, Average Recorded Investment, With an allowance recorded	11,243	8,893
Impaired Loans, Interest Income Recognized, With an allowance recorded	79	79
Impaired Loans, Average Recorded Investment	46,945	50,785
Impaired Loans, Interest Income Recognized	878	993
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	58,709	63,633
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	58,709	63,798
Impaired Loans, Recorded Investment, With an allowance recorded	3,904	10,004
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	5,223	10,004
Impaired Loans, Related Allowance	974	2,542
Impaired Loans, Recorded Investment	62,613	73,637
Impaired Loans, Unpaid Principal Balance	63,932	73,802
Impaired Loans, Average Recorded Investment, With no related allowance recorded	66,838	67,665
Impaired Loans, Interest Income Recognized, With no related allowance recorded	1,568	1,548
Impaired Loans, Average Recorded Investment, With an allowance recorded	3,848	7,658
Impaired Loans, Interest Income Recognized, With an allowance recorded	0	25
Impaired Loans, Average Recorded Investment	70,686	75,323
Impaired Loans, Interest Income Recognized	1,568	1,573
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	38,011	98,845
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	38,070	98,904
Impaired Loans, Recorded Investment, With an allowance recorded	15,947	15,720
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	15,947	15,720
Impaired Loans, Related Allowance	2,979	2,715
Impaired Loans, Recorded Investment	53,958	114,565
Impaired Loans, Unpaid Principal Balance	54,017	114,624
Impaired Loans, Average Recorded Investment, With no related allowance recorded	54,948	103,611
Impaired Loans, Interest Income Recognized, With no related allowance recorded	1,064	1,516
Impaired Loans, Average Recorded Investment, With an allowance recorded	13,471	12,298
Impaired Loans, Interest Income Recognized, With an allowance recorded	404	387
Impaired Loans, Average Recorded Investment	68,419	115,909
Impaired Loans, Interest Income Recognized	1,468	1,903
Other Commercial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	56,717	40,291
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	62,796	50,459
Impaired Loans, Recorded Investment, With an allowance recorded	40,300	61,266
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	42,684	62,812
Impaired Loans, Related Allowance	11,931	17,581
Impaired Loans, Recorded Investment	97,017	101,557
Impaired Loans, Unpaid Principal Balance	105,480	113,271
Impaired Loans, Average Recorded Investment, With no related allowance recorded	55,473	51,416
Impaired Loans, Interest Income Recognized, With no related allowance recorded	1,008	718
Impaired Loans, Average Recorded Investment, With an allowance recorded	41,112	51,118
Impaired Loans, Interest Income Recognized, With an allowance recorded	182	1,072
Impaired Loans, Average Recorded Investment	96,585	102,534
Impaired Loans, Interest Income Recognized	1,190	1,790
Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	28,096	28,207
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	29,022	29,279
Impaired Loans, Recorded Investment, With an allowance recorded	6,793	19,623
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	6,793	22,064
Impaired Loans, Related Allowance	354	3,265
Impaired Loans, Recorded Investment	34,889	47,830
Impaired Loans, Unpaid Principal Balance	35,815	51,343
Impaired Loans, Average Recorded Investment, With no related allowance recorded	31,166	27,459
Impaired Loans, Interest Income Recognized, With no related allowance recorded	630	657
Impaired Loans, Average Recorded Investment, With an allowance recorded	10,444	15,365
Impaired Loans, Interest Income Recognized, With an allowance recorded	267	460
Impaired Loans, Average Recorded Investment	41,610	42,824
Impaired Loans, Interest Income Recognized	897	1,117
Consumer [Member] | Bankcard [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	0	0
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	0	0
Impaired Loans, Recorded Investment, With an allowance recorded	0	0
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	0	0
Impaired Loans, Related Allowance	0	0
Impaired Loans, Recorded Investment	0	0
Impaired Loans, Unpaid Principal Balance	0	0
Impaired Loans, Average Recorded Investment, With no related allowance recorded	0	0
Impaired Loans, Interest Income Recognized, With no related allowance recorded	0	0
Impaired Loans, Average Recorded Investment, With an allowance recorded	0	0
Impaired Loans, Interest Income Recognized, With an allowance recorded	0	0
Impaired Loans, Average Recorded Investment	0	0
Impaired Loans, Interest Income Recognized	0	0
Consumer [Member] | Other Consumer [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	11	27
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	11	27
Impaired Loans, Recorded Investment, With an allowance recorded	0	0
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	0	0
Impaired Loans, Related Allowance	0	0
Impaired Loans, Recorded Investment	11	27
Impaired Loans, Unpaid Principal Balance	11	27
Impaired Loans, Average Recorded Investment, With no related allowance recorded	25	28
Impaired Loans, Interest Income Recognized, With no related allowance recorded	0	0
Impaired Loans, Average Recorded Investment, With an allowance recorded	0	0
Impaired Loans, Interest Income Recognized, With an allowance recorded	0	0
Impaired Loans, Average Recorded Investment	25	28
Impaired Loans, Interest Income Recognized	$ 0	$ 0

Allowance for Credit Losses - A

Allowance for Credit Losses - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Specific loss allocations are calculated for commercial loans in excess	$ 500,000
Number of days for collecting principal or interest on consumer loans	90 days
Minimum collection period for home equity loan or high loan to value loan	180 days
Retail credits amount deemed unrecoverable charged-off period	60 days
Retail credits charged off period after discovery of the fraud	90 days
provision for loan losses related to loans acquired	$ 1,984,000	$ 4,218,000
Reserve for lending-related commitments	$ 1,733,000	$ 1,389,000	$ 679,000
Reversal of provision for loan losses related to loans acquired			$ 1,106,000
Closed-End Retail Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of days delinquent from contractual due date	120 days
Open-End Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of days delinquent from contractual due date	180 days

Allowance for Credit Losses - S

Allowance for Credit Losses - Schedule of Allowance for Loan Losses and Carrying Amount of Loans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	$ 76,703	$ 76,627
Charge-offs	(29,110)	(28,606)
Recoveries	8,151	6,669
Provision	21,313	22,013
Allowance for Loan Losses Ending balance	77,057	76,703
Allowance for Loan Losses, individually evaluated for impairment	16,499	28,358
Allowance for Loan Losses, collectively evaluated for impairment	60,558	48,345
Allowance for Loan Losses	77,057	76,703	$ 76,627	$ 72,771
Financing receivables	13,713,548	13,429,532
Financing receivables, individually evaluated for impairment	123,505	161,935
Financing receivables, collectively evaluated for impairment	13,494,039	13,117,860
Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses	0	0
Financing receivables	96,004	149,737
Construction & Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	7,992	7,187
Charge-offs	(1,303)	(2,731)
Recoveries	175	197
Provision	(3,511)	3,339
Allowance for Loan Losses Ending balance	3,353	7,992
Allowance for Loan Losses, individually evaluated for impairment	262	2,254
Allowance for Loan Losses, collectively evaluated for impairment	3,091	5,738
Financing receivables	1,408,205	1,410,468
Financing receivables, individually evaluated for impairment	14,047	14,807
Financing receivables, collectively evaluated for impairment	1,382,369	1,374,840
Construction & Land Development [Member] | Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses	0	0
Financing receivables	11,789	20,821
Allowance for Estimated Imprecision [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	245	73
Charge-offs	0	0
Recoveries	0	0
Provision	52	172
Allowance for Loan Losses Ending balance	297	245
Allowance for Loan Losses, individually evaluated for impairment	0	0
Allowance for Loan Losses, collectively evaluated for impairment	297	245
Financing receivables	0	0
Financing receivables, individually evaluated for impairment	0	0
Financing receivables, collectively evaluated for impairment	0	0
Allowance for Estimated Imprecision [Member] | Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses	0	0
Financing receivables	0	0
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	5,063	5,401
Charge-offs	(7,905)	(3,225)
Recoveries	3,733	1,189
Provision	4,663	1,698
Allowance for Loan Losses Ending balance	5,554	5,063
Allowance for Loan Losses, individually evaluated for impairment	973	2,543
Allowance for Loan Losses, collectively evaluated for impairment	4,581	2,520
Financing receivables	1,201,652	1,291,790
Financing receivables, individually evaluated for impairment	16,703	27,599
Financing receivables, collectively evaluated for impairment	1,160,556	1,234,919
Commercial Real Estate [Member] | Owner-Occupied [Member] | Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses	0	0
Financing receivables	24,393	29,272
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	6,919	6,369
Charge-offs	(1,093)	(314)
Recoveries	80	563
Provision	2,618	301
Allowance for Loan Losses Ending balance	8,524	6,919
Allowance for Loan Losses, individually evaluated for impairment	2,979	2,715
Allowance for Loan Losses, collectively evaluated for impairment	5,545	4,204
Financing receivables	3,965,960	4,303,613
Financing receivables, individually evaluated for impairment	27,121	25,231
Financing receivables, collectively evaluated for impairment	3,925,249	4,215,060
Commercial Real Estate [Member] | Nonowner-Occupied [Member] | Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses	0	0
Financing receivables	13,590	63,322
Other Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	41,341	45,189
Charge-offs	(12,975)	(16,424)
Recoveries	2,599	2,944
Provision	16,360	9,632
Allowance for Loan Losses Ending balance	47,325	41,341
Allowance for Loan Losses, individually evaluated for impairment	11,931	17,581
Allowance for Loan Losses, collectively evaluated for impairment	35,394	23,760
Financing receivables	2,285,037	1,957,641
Financing receivables, individually evaluated for impairment	54,108	72,300
Financing receivables, collectively evaluated for impairment	2,194,432	1,860,085
Other Commercial [Member] | Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses	0	0
Financing receivables	36,497	25,256
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	12,448	9,927
Charge-offs	(2,967)	(3,162)
Recoveries	858	1,114
Provision	(1,342)	4,569
Allowance for Loan Losses Ending balance	8,997	12,448
Allowance for Loan Losses, individually evaluated for impairment	354	3,265
Allowance for Loan Losses, collectively evaluated for impairment	8,643	9,183
Financing receivables	3,686,401	3,501,393
Financing receivables, individually evaluated for impairment	11,526	21,998
Financing receivables, collectively evaluated for impairment	3,665,140	3,468,356
Residential Real Estate [Member] | Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses	0	0
Financing receivables	9,735	11,039
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	2,695	2,481
Charge-offs	(2,867)	(2,750)
Recoveries	706	662
Provision	2,473	2,302
Allowance for Loan Losses Ending balance	3,007	2,695
Allowance for Loan Losses, individually evaluated for impairment	0	0
Allowance for Loan Losses, collectively evaluated for impairment	3,007	2,695
Financing receivables	1,166,293	964,627
Financing receivables, individually evaluated for impairment	0	0
Financing receivables, collectively evaluated for impairment	1,166,293	964,600
Consumer [Member] | Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses	0	0
Financing receivables	$ 0	$ 27

Allowance for Credit Losses - P

Allowance for Credit Losses - Progression of Allowance for Credit Losses Including Allowance for Loan Losses and Reserve for Lending-Related Commitments (Detail) - USD ($) $ in Thousands	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
Receivables [Abstract]
Balance of allowance for loan losses at beginning of period				$ 76,703				$ 76,627	$ 76,703	$ 76,627	$ 72,771
Provision for loan losses	$ 5,867	$ 5,033	$ 5,417	$ 4,996	$ 5,823	$ 4,808	$ 6,204	$ 5,178	21,313	22,013	28,406
Financing receivable allowance and provisions for credit losses									98,016	98,640	101,177
Loans charged off									(29,110)	(28,606)	(32,863)
Recoveries									8,151	6,669	8,313
Net charge-offs									(20,959)	(21,937)	(24,550)
Balance of allowance for loan losses at end of period	77,057				76,703				77,057	76,703	76,627
Reserve for lending-related commitments	1,733				1,389				1,733	1,389	679
Balance of allowance for credit losses at end of period	$ 78,790				$ 78,092				$ 78,790	$ 78,092	$ 77,306

Bank Premises and Equipment a_3

Bank Premises and Equipment and Leases - Bank Premises and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Bank premises and equipment, Gross	$ 250,010	$ 247,739
Less allowance for depreciation and amortization	(153,366)	(152,494)
Bank premises and equipment, Net	96,644	95,245
Land [Member]
Property, Plant and Equipment [Line Items]
Bank premises and equipment, Gross	32,085	31,679
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Bank premises and equipment, Gross	105,759	103,014
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Bank premises and equipment, Gross	40,789	41,001
Furniture, Fixtures and Equipment [Member]
Property, Plant and Equipment [Line Items]
Bank premises and equipment, Gross	$ 71,377	$ 72,045

Bank Premises and Equipment a_4

Bank Premises and Equipment and Leases - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 9,329,000	$ 10,254,000	$ 8,914,000
Amortization expense	$ 141,000	$ 102,000	$ 122,000

Leases - Additional Information

Leases - Additional Information (Detail)	Dec. 31, 2019
Operating lease remaining lease term	4 years 10 months 28 days
Operating leases, option to extend term	5 years
Maximum [Member]
Operating lease remaining lease term	13 years
Minimum [Member]
Operating lease remaining lease term	1 year

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Operating lease cost	$ 19,508
Sublease income	(825)
Net lease cost	$ 18,683

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information Related to Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Operating lease right-of-use assets	$ 57,783	$ 0
Operating lease liabilities	$ 61,342	$ 0

Leases - Other Information Rela

Leases - Other Information Related to Leases (Detail)	Dec. 31, 2019
Weightedaverage remaining lease term [Abstract]
Operating leases	4 years 10 months 28 days
Weightedaverage discount rate [Abstract]
Operating leases	3.20%

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information Related to Leases (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Cash paid for amounts in the measurement of lease liabilities [Abstract]
Operating cash flows from operating leases	$ 19,601
ROU assets obtained in the exchange for lease liabilities	$ 7,630

Leases - Maturities of Lease Li

Leases - Maturities of Lease Liabilities by Year (Detail) $ in Thousands	Dec. 31, 2019USD ($)
2020	$ 17,725
2021	15,180
2022	11,522
2023	8,751
2024	5,127
Thereafter	8,190
Total lease payments	66,495
Less: imputed interest	(5,153)
Total	$ 61,342

Goodwill and Other Intangible_2

Goodwill and Other Intangibles - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Goodwill not subject to amortization	$ 1,478,014	$ 1,478,014
Core Deposit Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	98,359	98,359
Accumulated Amortization	69,508	62,492
George Mason Trade Name Intangible [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,080	1,080
Community Banking [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill not subject to amortization	1,472,699	1,472,699
Community Banking [Member] | Core Deposit Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	98,359	98,359
Accumulated Amortization	69,508	62,492
Community Banking [Member] | George Mason Trade Name Intangible [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	0	0
Mortgage Banking [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill not subject to amortization	5,315	5,315
Mortgage Banking [Member] | Core Deposit Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	0	0
Accumulated Amortization	0	0
Mortgage Banking [Member] | George Mason Trade Name Intangible [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,080	$ 1,080

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets - Schedule of Anticipated Amortization Expense (Detail) $ in Thousands	Dec. 31, 2019USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2020	$ 6,309
2021	5,369
2022	4,582
2023	4,322
2024 and thereafter	$ 8,269

Deposits - Book Value of Deposi

Deposits - Book Value of Deposits (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deposits [Abstract]
Demand deposits	$ 3,381,866	$ 3,212,878
Interest-bearing checking	372,175	374,495
Regular savings	882,889	954,961
Money market accounts	6,891,696	7,157,028
Time deposits under $100,000	723,941	712,313
Time deposits over $100,000	1,599,854	1,583,074
Total deposits	$ 13,852,421	$ 13,994,749

Deposits - Additional Informati

Deposits - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deposits [Line Items]
Time deposits over $250,000	$ 803,414	$ 979,707
Deposits	13,852,421	13,994,749
Subsidiaries [Member]
Deposits [Line Items]
Deposits	15,350	24,102
Deposits [Member]
Deposits [Line Items]
Interest paid	$ 136,360	$ 87,219	$ 48,887

Short-Term Borrowings - Short-T

Short-Term Borrowings - Short-Term Borrowings and the Related Weighted-Average Interest Rates (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Short-term Debt [Line Items]
Short-term borrowings	$ 124,654	$ 176,627
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Short-term borrowings	$ 0	$ 23,400	$ 16,235
Weighted-Average Rate	0.00%	2.40%	1.40%
Securities Sold Under Agreements to Repurchase [Member]
Short-term Debt [Line Items]
Short-term borrowings	$ 124,654	$ 152,927	$ 261,352
Weighted-Average Rate	1.09%	0.96%	0.36%

Short-Term Borrowings -Short-Te

Short-Term Borrowings -Short-Term Borrowings and the Related Weighted-Average Interest Rates (Parenthetical) (Detail) $ in Thousands	Dec. 31, 2019USD ($)
Long-term borrowings	$ 0
Virginia Commerce Bank
Long-term borrowings	$ 50,000

Short-Term Borrowings - Additio

Short-Term Borrowings - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Short-term Debt [Line Items]
Unused lines of credit	$ 230,000,000
Short-Term Borrowings [Member]
Short-term Debt [Line Items]
Interest paid	2,359,000	$ 2,238,000	$ 1,574,000
Unrelated Financial Institution [Member]
Short-term Debt [Line Items]
Unused lines of credit	$ 20,000,000
Renewal period of line of credit	360 day
Amount of outstanding balance under line of credit	$ 0

Short-Term Borrowings - Funds P

Short-Term Borrowings - Funds Purchased and Securities Sold Under Agreements to Repurchase and Weighted-Average Interest Rates (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Short-term Debt [Line Items]
Short-term borrowings	$ 124,654	$ 176,627
Federal Funds Purchased [Member]
Short-term Debt [Line Items]
Short-term borrowings	$ 0	$ 23,400	$ 16,235
Weighted-average interest rate at year-end	0.00%	2.40%	1.40%
Maximum amount outstanding at any month's end	$ 0	$ 25,790	$ 25,800
Average amount outstanding during the year	$ 1,899	$ 16,773	$ 18,433
Weighted-average interest rate during the year	2.52%	1.86%	0.88%
Securities Sold Under Agreements to Repurchase [Member]
Short-term Debt [Line Items]
Short-term borrowings	$ 124,654	$ 152,927	$ 261,352
Weighted-average interest rate at year-end	1.09%	0.96%	0.36%
Maximum amount outstanding at any month's end	$ 161,175	$ 328,484	$ 377,687
Average amount outstanding during the year	$ 131,187	$ 194,956	$ 287,663
Weighted-average interest rate during the year	1.33%	0.61%	0.33%

Long-Term Borrowings - Addition

Long-Term Borrowings - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019USD ($)Trust	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Unused borrowing amount	$ 3,666,479,000
FHLB advances	1,851,865,000	$ 1,439,198,000
Overnight funds	$ 250,000,000	175,000,000
Number of statutory business trusts | Trust	14
Outstanding balances of debentures	$ 236,164,000	234,905,000
Maximum time to defer payment of interest on subordinate debt	5 years
Long-Term Borrowings [Member]
Debt Instrument [Line Items]
Interest paid	$ 43,830,000	$ 35,222,000	$ 22,254,000
Capital Securities [Member]
Debt Instrument [Line Items]
Number of statutory business trusts | Trust	14
Maximum [Member]
Debt Instrument [Line Items]
Risk based assets			$ 15,000,000,000
Federal Home Loan Bank Borrowings [Member]
Debt Instrument [Line Items]
Carrying value of loans pledged as collateral for FHLB advances	$ 4,317,748,000

Long-Term Borrowings - FHLB Adv

Long-Term Borrowings - FHLB Advances and Related Weighted Average Interest Rates (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
FHLB advances, Amount	$ 1,851,865	$ 1,439,198
FHLB advances, Weighted-Average Contractual Rate	2.03%	2.42%
FHLB advances, Weighted-Average Effective Rate	2.03%	2.42%

Long -Term Borrowings - Informa

Long -Term Borrowings - Information Related to Statutory Trusts (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
United Statutory Trust III [Member]
Variable Interest Entity [Line Items]
Issuance Date	Dec. 17, 2003
Amount of Capital Securities Issued	$ 20,000
Interest Rate	3-month LIBOR + 2.85%
Maturity Date	Dec. 17, 2033
United Statutory Trust IV [Member]
Variable Interest Entity [Line Items]
Issuance Date	Dec. 19, 2003
Amount of Capital Securities Issued	$ 25,000
Interest Rate	3-month LIBOR + 2.85%
Maturity Date	Jan. 23, 2034
United Statutory Trust V [Member]
Variable Interest Entity [Line Items]
Issuance Date	Jul. 12, 2007
Amount of Capital Securities Issued	$ 50,000
Interest Rate	3-month LIBOR + 1.55%
Maturity Date	Oct. 1, 2037
United Statutory Trust VI [Member]
Variable Interest Entity [Line Items]
Issuance Date	Sep. 20, 2007
Amount of Capital Securities Issued	$ 30,000
Interest Rate	3-month LIBOR + 1.30%
Maturity Date	Dec. 15, 2037
Premier Statutory Trust II [Member]
Variable Interest Entity [Line Items]
Issuance Date	Sep. 25, 2003
Amount of Capital Securities Issued	$ 6,000
Interest Rate	3-month LIBOR + 3.10%
Maturity Date	Oct. 8, 2033
Premier Statutory Trust III [Member]
Variable Interest Entity [Line Items]
Issuance Date	May 16, 2005
Amount of Capital Securities Issued	$ 8,000
Interest Rate	3-month LIBOR + 1.74%
Maturity Date	Jun. 15, 2035
Premier Statutory Trust IV [Member]
Variable Interest Entity [Line Items]
Issuance Date	Jun. 20, 2006
Amount of Capital Securities Issued	$ 14,000
Interest Rate	3-month LIBOR + 1.55%
Maturity Date	Sep. 23, 2036
Premier Statutory Trust V [Member]
Variable Interest Entity [Line Items]
Issuance Date	Dec. 14, 2006
Amount of Capital Securities Issued	$ 10,000
Interest Rate	3-month LIBOR + 1.61%
Maturity Date	Mar. 1, 2037
Centra Statutory Trust I [Member]
Variable Interest Entity [Line Items]
Issuance Date	Sep. 20, 2004
Amount of Capital Securities Issued	$ 10,000
Interest Rate	3-month LIBOR + 2.29%
Maturity Date	Sep. 20, 2034
Centra Statutory Trust II [Member]
Variable Interest Entity [Line Items]
Issuance Date	Jun. 15, 2006
Amount of Capital Securities Issued	$ 10,000
Interest Rate	3-month LIBOR + 1.65%
Maturity Date	Jul. 7, 2036
Virginia Commerce Trust II [Member]
Variable Interest Entity [Line Items]
Issuance Date	Dec. 19, 2002
Amount of Capital Securities Issued	$ 15,000
Interest Rate	6-month LIBOR + 3.30%
Maturity Date	Dec. 19, 2032
Virginia Commerce Trust III [Member]
Variable Interest Entity [Line Items]
Issuance Date	Dec. 20, 2005
Amount of Capital Securities Issued	$ 25,000
Interest Rate	3-month LIBOR + 1.42%
Maturity Date	Feb. 23, 2036
Cardinal Statutory Trust I [Member]
Variable Interest Entity [Line Items]
Issuance Date	Jul. 27, 2004
Amount of Capital Securities Issued	$ 20,000
Interest Rate	3-month LIBOR + 2.40%
Maturity Date	Sep. 15, 2034
UFBC Capital Trust I [Member]
Variable Interest Entity [Line Items]
Issuance Date	Dec. 30, 2004
Amount of Capital Securities Issued	$ 5,000
Interest Rate	3-month LIBOR + 2.10%
Maturity Date	Mar. 15, 2035

Long -Term Borrowings - Debentu

Long -Term Borrowings - Debentures and Related Weighted Average Interest Rates (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Amount	$ 236,164	$ 234,905
United Statutory Trust III [Member]
Debt Instrument [Line Items]
Amount	$ 20,619	$ 20,619
Weighted-Average Rate	4.75%	5.64%
United Statutory Trust IV [Member]
Debt Instrument [Line Items]
Amount	$ 25,774	$ 25,774
Weighted-Average Rate	4.79%	5.37%
United Statutory Trust V [Member]
Debt Instrument [Line Items]
Amount	$ 51,547	$ 51,547
Weighted-Average Rate	3.65%	3.95%
United Statutory Trust VI [Member]
Debt Instrument [Line Items]
Amount	$ 30,928	$ 30,928
Weighted-Average Rate	3.19%	4.09%
Premier Statutory Trust II [Member]
Debt Instrument [Line Items]
Amount	$ 6,186	$ 6,186
Weighted-Average Rate	5.09%	5.54%
Premier Statutory Trust III [Member]
Debt Instrument [Line Items]
Amount	$ 8,248	$ 8,248
Weighted-Average Rate	3.63%	4.53%
Premier Statutory Trust IV [Member]
Debt Instrument [Line Items]
Amount	$ 14,433	$ 14,433
Weighted-Average Rate	3.48%	4.37%
Premier Statutory Trust V [Member]
Debt Instrument [Line Items]
Amount	$ 10,310	$ 10,310
Weighted-Average Rate	3.52%	4.35%
Centra Statutory Trust I [Member]
Debt Instrument [Line Items]
Amount	$ 10,000	$ 10,000
Weighted-Average Rate	4.20%	5.08%
Centra Statutory Trust II [Member]
Debt Instrument [Line Items]
Amount	$ 10,000	$ 10,000
Weighted-Average Rate	3.64%	4.09%
Virginia Commerce Trust II [Member]
Debt Instrument [Line Items]
Amount	$ 12,475	$ 12,245
Weighted-Average Rate	5.22%	5.80%
Virginia Commerce Trust III [Member]
Debt Instrument [Line Items]
Amount	$ 17,268	$ 16,742
Weighted-Average Rate	3.33%	4.07%
Cardinal Statutory Trust I [Member]
Debt Instrument [Line Items]
Amount	$ 14,825	$ 14,428
Weighted-Average Rate	4.29%	5.19%
UFBC Capital Trust I [Member]
Debt Instrument [Line Items]
Amount	$ 3,551	$ 3,445
Weighted-Average Rate	3.99%	4.89%

Long -Term Borrowings - Schedul

Long -Term Borrowings - Schedule of Maturities of Long-term Borrowings (Detail) $ in Thousands	Dec. 31, 2019USD ($)
Debt Disclosure [Abstract]
2020	$ 740,734
2021	826,527
2022	19,737
2023	0
2024	0
2025 and thereafter	251,031
Total	$ 1,838,029

Other Expense - Other Expense (

Other Expense - Other Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Income and Expenses [Abstract]
Legal, consulting & other professional services	$ 12,360	$ 13,248	$ 11,844
Franchise & other taxes not on income	11,330	11,428	12,586
Automated Teller Machine (ATM) expenses	$ 7,336	$ 6,892	$ 6,686

Income Taxes - Income Tax Provi

Income Taxes - Income Tax Provisions Included in the Consolidated Statements of Income (Detail) - USD ($) $ in Thousands	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
Current expense:
Federal									$ 43,337	$ 52,041	$ 65,459
State									6,798	9,429	7,960
Deferred expense:
Federal									12,522	8,298	20,920
Tax Act remeasurement									0	(120)	37,732
State									1,683	1,175	2,175
Total income taxes	$ 12,473	$ 17,010	$ 17,529	$ 17,328	$ 15,757	$ 17,926	$ 19,241	$ 17,899	$ 64,340	$ 70,823	$ 134,246

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Line Items]
Federal corporate tax rate		21.00%	21.00%	35.00%
Deferred tax expense due to the Tax Act	$ 37,732,000		$ (120,000)
Federal income tax (benefit) expense applicable to sales and calls of securities		$ 54,000	180,000	$ 2,088,000
Income taxes paid		56,459,000	55,336,000	73,096,000
Franchise & other taxes not on income		11,330,000	11,428,000	12,586,000
Valuation allowance recorded		$ 0	0
Estimate of unrecognized tax benefits, reasonable possible		United cannot reasonably estimate the amount of tax benefits, if any, it may recognize over the next 12 months.
Accrued interest related to uncertain tax positions		$ 667,000	675,000
Interest or penalties were recognized		0	$ 0	$ 0
Federal [Member]
Income Taxes [Line Items]
State net operating loss carryforwards		0
State [Member]
Income Taxes [Line Items]
State net operating loss carryforwards		$ 0

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Income Tax Expense to the Amount Computed by Applying the Statutory Federal Income Tax Rate (Detail) - USD ($) $ in Thousands	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
Income Tax Disclosure [Abstract]
Tax on income before taxes at statutory federal rate									$ 68,132	$ 68,704	$ 99,689
Plus: State income taxes net of federal tax benefits									6,690	8,362	6,207
Income tax before adjustments									74,822	77,066	105,896
Tax-exempt interest income									(2,813)	(3,298)	(5,362)
Tax credits									(5,636)	(2,054)	(1,171)
Deferred taxes due to the Tax Act									0	(120)	37,732
Other items-net									(2,033)	(771)	(2,849)
Total income taxes	$ 12,473	$ 17,010	$ 17,529	$ 17,328	$ 15,757	$ 17,926	$ 19,241	$ 17,899	$ 64,340	$ 70,823	$ 134,246
Tax on income before taxes at statutory federal rate, rate									21.00%	21.00%	35.00%
Plus: State income taxes net of federal tax benefits, rate									2.10%	2.60%	2.20%
Income tax before adjustments, rate									23.10%	23.60%	37.20%
Increase (decrease) resulting from:
Tax-exempt interest income, rate									(0.90%)	(1.00%)	(1.90%)
Tax credits, percentage									(1.70%)	(0.60%)	(0.40%)
Deferred taxes due to the Tax Act, rate									0.00%	0.00%	13.20%
Other items-net, rate									(0.70%)	(0.30%)	(1.00%)
Income taxes, rate									19.80%	21.70%	47.10%

Income Taxes - Components of Un

Income Taxes - Components of United's Deferred Tax Assets and Liabilities (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Allowance for credit losses	$ 18,358,000	$ 18,109,000
Accrued benefits payable	13,459	13,914,000
Other accrued liabilities	992,000	846,000
Pension plan accruals	3,313,000	1,217,000
Unrealized loss on securities available for sale	0	5,572,000
Other real estate owned	2,482,000	2,482,000
Lease liabilities under operating leases	14,293,000	0
Deferred mortgage points	0	983,000
Purchase accounting intangibles	5,917,000	18,091,000
Total deferred tax assets	58,814,000	61,214,000
Deferred tax liabilities:
Premises and equipment	2,963,000	1,414,000
Unrealized gain on securities available for sale	2,755,000	0
Right-of-use assets under operating leases	13,464,000	0
Deferred mortgage points	389,000	0
Other	2,300,000	2,899,000
Total deferred tax liabilities	21,871,000	4,313,000
Net deferred tax assets	$ 36,943,000	$ 56,901,000

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of the Total Amounts of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Unrecognized tax benefits at beginning of year	$ 2,005	$ 2,894
Increase in unrecognized tax benefits as a result of tax positions taken during the current period	152	156
Decreases in the unrecognized tax benefits as a result of a lapse of the applicable statute of limitations	(589)	(1,045)
Unrecognized tax benefits at end of year	$ 1,568	$ 2,005

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Sep. 30, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Net periodic pension cost decline in expense					$ 1,000,000
Unrecognized actuarial gains (losses), before tax			$ 60,894,000
Unrecognized actuarial gains (losses), net of tax			46,706,000
Amortization expected to be recognized			5,802,000
Amortization expected to be recognized, net of tax			4,450,000
Amount of United common stock held in the pension plan			$ 159,560,000	$ 137,408,000	142,395,000
Percentage of equity securities include united common stock			100.00%	100.00%
Percentage of projected benefit obligation			10.00%
Minimum number of days required to be eligible for the participation in the plan			90 days
Employer discretionary contribution amount	$ 7,000,000	$ 10,000,000
Percentage of salary deferred under condition one of contribution by company			100.00%
First percentage of salary deferred under condition one of contribution by company			4.00%
Vesting percentage of employee deferrals			100.00%
Cost related to savings and stock investment plan			$ 4,565,000	$ 4,486,000	3,201,000
Employer contribution in shares of common stock			1,176,283	1,099,386
Dividends paid on United common stock			$ 1,566,000	$ 1,401,000	$ 1,218,000
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Maximum percentage allowed as of contribution to respective accounts by participants			1.00%
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Maximum percentage allowed as of contribution to respective accounts by participants			100.00%
Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Amount of United common stock held in the pension plan			$ 23,932,000	$ 22,846,000
Percentage of equity securities include united common stock			3.00%	4.00%
Common Stock [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Maximum percentage limit of common stock to invest in portfolio for any industry			5.00%
Marketable Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Amount of United common stock held in the pension plan			$ 4,091,000	$ 3,292,000
Percentage of equity securities include united common stock			63.00%	67.00%
Maximum percentage limit of common stock to invest in portfolio for any industry			62.00%
Approximate fair value of plan assets			$ 45,475,000	$ 34,202,000
Marketable Equity Securities [Member] | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Maximum percentage limit of common stock to invest in portfolio for any industry			50.00%
Marketable Equity Securities [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Maximum percentage limit of common stock to invest in portfolio for any industry			70.00%
Individual Company [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Maximum percentage limit of common stock to invest in portfolio for any industry			10.00%
Industry [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Maximum percentage limit of common stock to invest in portfolio for any industry			15.00%
Securities of U.S. Government or Agencies [Member] | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Maximum percentage limit of common stock to invest in portfolio for any industry			15.00%

Employee Benefit Plans - Net Pe

Employee Benefit Plans - Net Periodic Pension Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2,173	$ 2,566	$ 2,146
Interest cost	5,931	5,341	5,149
Expected return on plan assets	(9,434)	(10,260)	(8,538)
Recognized net actuarial loss	4,965	4,919	4,553
Net periodic pension cost	$ 3,635	$ 2,566	$ 3,310
Weighted-Average Assumptions:
Discount rate	4.52%	3.83%	4.49%
Expected return on assets	7.00%	7.00%	7.00%
Rate of Compensation Increase	3.00%	3.00%	3.00%
Prior to Age 45 [Member]
Weighted-Average Assumptions:
Rate of Compensation Increase	3.50%	3.50%	3.50%

Employee Benefit Plans - Schedu

Employee Benefit Plans - Schedule of Amounts Related to Plan recognized as Component of Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan [Abstract]
Net actuarial loss	$ 10,324	$ 4,232	$ 6,784
Prior service cost	0	0	0
Actuarial loss	(4,965)	(4,919)	(4,553)
Total recognized in other comprehensive income	$ 5,359	$ (687)	$ 2,231

Employee Benefit Plans - Reconc

Employee Benefit Plans - Reconciliation of the Beginning and Ending Balances of the Projected Benefit Obligation and the Fair Value of Plan Assets and the Accumulated Benefit Obligation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Change in Projected Benefit Obligation
Projected Benefit Obligation at the Beginning of the Year	$ 142,632	$ 152,740
Service cost	2,173	2,566	$ 2,146
Interest cost	5,931	5,341	5,149
Actuarial Loss (Gain)	28,364	(13,301)
Benefits Paid	(5,323)	(4,714)
Projected Benefit at the End of the Year	173,777	142,632	152,740
Accumulated Benefit Obligation at the End of the Year	157,154	130,567
Change in Plan Assets
Fair Value of Plan Assets at the Beginning of the Year	137,408	142,395
Actual Return on Plan Assets	27,475	(7,273)
Benefits Paid	(5,323)	(4,714)
Employer Contributions	0	7,000
Fair value of plan assets at end of year	159,560	137,408	$ 142,395
Net Amount Recognized
Funded Status	(14,217)	(5,224)
Unrecognized Transition Asset	0	0
Unrecognized Prior Service Cost	0	0
Unrecognized Net Loss	60,894	55,535
Net Amount Recognized	$ 46,677	$ 50,311
Weighted-Average Assumptions at the End of the Year
Discount Rate	3.42%	4.52%
Rate of Compensation Increase	3.50%	3.00%
Prior to Age 40 [Member]
Weighted-Average Assumptions at the End of the Year
Rate of Compensation Increase	5.00%
Ages 40-54 [Member]
Weighted-Average Assumptions at the End of the Year
Rate of Compensation Increase	4.00%
Prior to Age 45 [Member]
Weighted-Average Assumptions at the End of the Year
Rate of Compensation Increase		3.50%

Employee Benefit Plans - Asset

Employee Benefit Plans - Asset Allocation for the Defined Benefit Pension Plan as of the Measurement Date, by Asset Category (Detail)	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	100.00%	100.00%
Marketable Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	62.00%
Percentage of Plan Assets	63.00%	67.00%
Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	35.00%
Percentage of Plan Assets	35.00%	26.00%
Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	3.00%
Percentage of Plan Assets	2.00%	7.00%
Minimum [Member] | Marketable Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	50.00%
Minimum [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	20.00%
Minimum [Member] | Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	3.00%
Maximum [Member] | Marketable Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	70.00%
Maximum [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	50.00%
Maximum [Member] | Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation	15.00%

Employee Benefit Plans - Expect

Employee Benefit Plans - Expected Benefit Payments (Detail) $ in Thousands	Dec. 31, 2019USD ($)
Retirement Benefits [Abstract]
2020	$ 5,906
2021	6,267
2022	6,637
2023	7,055
2024	7,390
2025 through 2029	$ 42,310

Employee Benefit Plans - Balanc

Employee Benefit Plans - Balances of the Plan Assets, by Fair Value Hierarchy Level (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	$ 159,560	$ 137,408	$ 142,395
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	2,504	10,086
Taxable Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	55,588	35,086
Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	23,932	22,846
Equity Mutual Funds Global Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	5,247
Equity Mutual Funds Domestic Equity Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	28,743	28,090
Equity Mutual Funds Domestic Equity Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	22,216	15,212
Equity Mutual Funds International Emerging Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	8,228	8,791
Equity Mutual Funds International Equity Developed [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	13,102	17,297
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	159,560	137,408
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	2,504	10,086
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Taxable Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	55,588	35,086
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	23,932	22,846
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Mutual Funds Global Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	5,247
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Mutual Funds Domestic Equity Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	28,743	28,090
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Mutual Funds Domestic Equity Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	22,216	15,212
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Mutual Funds International Emerging Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	8,228	8,791
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Mutual Funds International Equity Developed [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	13,102	17,297
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Other Observable Inputs (Level 2) [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Other Observable Inputs (Level 2) [Member] | Taxable Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Other Observable Inputs (Level 2) [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Other Observable Inputs (Level 2) [Member] | Equity Mutual Funds Global Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0
Significant Other Observable Inputs (Level 2) [Member] | Equity Mutual Funds Domestic Equity Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Other Observable Inputs (Level 2) [Member] | Equity Mutual Funds Domestic Equity Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Other Observable Inputs (Level 2) [Member] | Equity Mutual Funds International Emerging Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Other Observable Inputs (Level 2) [Member] | Equity Mutual Funds International Equity Developed [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Taxable Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Mutual Funds Global Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Mutual Funds Domestic Equity Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Mutual Funds Domestic Equity Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Mutual Funds International Emerging Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	0	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Mutual Funds International Equity Developed [Member]
Defined Benefit Plan Disclosure [Line Items]
Asset at fair value	$ 0	$ 0

Stock Based Compensation - Addi

Stock Based Compensation - Additional Information (Detail) - USD ($)	May 18, 2016	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized shares of stock, option plan, maximum	1,700,000
Aggregate number of shares issued in respect of restricted stock awards	500,000
Options available for award each plan year	1,200,000
Maximum number of shares of restricted stock or shares subject to a restricted stock units award granted		50,000
Maximum number of options and SARs		100,000
Maximum number of stock options and SARs awarded		10,000
Maximum number of Shares of restricted stock or shares subject to a restricted stock units award granted to individual non-employee director		5,000
Vesting period of awards		1/3 per year
Number of Options granted		240,205
Recognition of compensation expense		$ 4,914,000	$ 4,073,000	$ 3,555,000
Number of share available for grant for prior plans		0
Maximum term for awards granted (years)		10 years
Weighted average risk free interest rate		2.54%
Weighted average dividend yield		3.00%
Weighted average volatility factors of the expected market price of United's common stock		0.243%
Weighted-average expected option life		6 years 8 months 19 days
Estimated fair value of the options at the date of grant		$ 7.16
Total unrecognized compensation cost related to nonvested option awards		$ 2,871,000
Weighted-average expense recognition period		1 year 2 months 12 days
Total fair value of awards vested		$ 1,636,000
Cash received from options exercised under the plans		$ 1,272,000	$ 1,500,000	$ 4,619,000
Shares issued related stock option exercises		128,742	72,296
Weighted-average grant-date fair value of options granted		$ 7.16	$ 7.56	$ 8.85
Total intrinsic value of options exercised		$ 1,932,000	$ 1,057,000	$ 3,721,000
Excess tax benefits from stock-based compensation arrangements		$ 223,000	$ 158,000	$ 2,201,000
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted		126,427
Total unrecognized compensation cost related to nonvested option awards		$ 6,041,000
Weighted-average expense recognition period		1 year 3 months 18 days
Weighted-average grant-date fair value of options granted		$ 38.49
Vesting period		0 days

Stock Based Compensation - Summ

Stock Based Compensation - Summary of Stock Option Plans (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure Stock Based Compensation Stock Option Plan [Abstract]
Shares, Outstanding, Beginning balance	1,730,389
Shares, Granted	240,205
Shares, Exercised	(128,742)	(72,296)
Shares, Forfeited or expired	(126,536)
Shares, Outstanding, Ending balance	1,715,316	1,730,389
Shares, Exercisable at December 31, 2019	1,125,579
Aggregate Intrinsic Value, Outstanding at December 31, 2019	$ 8,707
Aggregate Intrinsic Value, Exercisable at December 31, 2019	$ 8,342
Weighted Average Remaining Contractual Term, Outstanding at December 31, 2019	5 years 7 months 6 days
Weighted Average Remaining Contractual Term, Exercisable at December 31, 2019	4 years 2 months 12 days
Weighted Average Exercise Price, Outstanding, Beginning balance	$ 32.43
Weighted Average Exercise Price, Granted	38.49
Weighted Average Exercise Price, Exercised	23.12
Weighted Average Exercise Price, Forfeited or expired	25.44
Weighted Average Exercise Price, Outstanding, Ending balance	34.49	$ 32.43
Weighted Average Exercise Price, Exercisable	$ 31.97

Stock Based Compensation - Stat

Stock Based Compensation - Status of United's Nonvested Stock Option Awards (Detail)	12 Months Ended
	Dec. 31, 2019$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares, Nonvested, Beginning balance | shares	575,672
Shares, Granted | shares	240,205
Shares, Vested | shares	(211,326)
Shares, Forfeited or expired | shares	(14,814)
Shares, Nonvested, Ending balance | shares	589,737
Weighted-Average Grant Date Fair Value Per Share, Nonvested Beginning balance | $ / shares	$ 7.86
Weighted-Average Grant Date Fair Value Per Share, Granted | $ / shares	7.16
Weighted-Average Grant Date Fair Value Per Share, Vested | $ / shares	7.74
Weighted-Average Grant Date Fair Value Per Share, Forfeited or expired | $ / shares	7.55
Weighted-Average Grant Date Fair Value Per Share, Nonvested Ending balance | $ / shares	$ 7.62

Stock Based Compensation - Chan

Stock Based Compensation - Changes to United's Restricted Common Shares (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant Date Fair Value Per Share, Granted	$ 7.16	$ 7.56	$ 8.85
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding, Beginning balance	199,303
Shares, Granted	126,427
Shares, Vested	(73,685)
Shares, Forfeited	(4,149)
Number of Shares, Outstanding, Ending balance	247,896	199,303
Weighted-Average Grant Date Fair Value Per Share, Outstanding, Beginning balance	$ 39.67
Weighted-Average Grant Date Fair Value Per Share, Granted	38.49
Weighted-Average Grant Date Fair Value Per Share, Vested	39.28
Weighted-Average Grant Date Fair Value Per Share, Forfeited	39.08
Weighted-Average Grant Date Fair Value Per Share, Outstanding, Ending balance	$ 39.20	$ 39.67

Commitments and Contingent Li_2

Commitments and Contingent Liabilities - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Loan commitments outstanding	$ 3,610,777,000	$ 3,826,370,000
Loan commitments expiry period	1 year
George Mason [Member]
Loss Contingencies [Line Items]
Reserve for possible losses due to the repurchase of loans previously sold to investors	$ 1,377,000
Commitments to Extend Credit [Member] | George Mason [Member] | Short-term Contract with Customer [Member]
Loss Contingencies [Line Items]
Additional commitments to extend credit	235,883,000
Commercial Letters of Credit [Member]
Loss Contingencies [Line Items]
Letters of credit issued	5,092,000	0
Standby Letters of Credit [Member]
Loss Contingencies [Line Items]
Letters of credit issued	$ 145,105,000	$ 141,032,000

Derivative Financial Instrume_3

Derivative Financial Instruments - Schedule of Notional Amount and Fair Value Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Asset derivatives, notional amount	$ 144,512	$ 201,182
Asset derivatives designated as hedging instruments	0	1,859
Liability derivatives, notional amount	356,243	200,281
Asset derivatives not designated as hedging instruments	4,527	4,645
Total asset derivatives	4,527	6,504
Liability derivatives designated as hedging instruments	2,394	0
Liability derivatives not designated as hedging instruments	671	3,002
Total liability derivatives	3,065	3,002
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives, notional amount	0	85,623
Liability derivatives, notional amount	82,243	0
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives, notional amount	144,512	115,559
Liability derivatives, notional amount	274,000	200,281
Other Assets [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Asset derivatives not designated as hedging instruments	4,518	4,103
Other Assets [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Asset derivatives, notional amount	117,252	93,955
Other Liabilities [Member] | TBA Mortgage Backed Securities [Member]
Derivative [Line Items]
Liability derivatives not designated as hedging instruments	671	3,002
Other Liabilities [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Liability derivatives not designated as hedging instruments	0	0
Other Liabilities [Member] | Not Designated as Hedging Instrument [Member] | TBA Mortgage Backed Securities [Member]
Derivative [Line Items]
Liability derivatives, notional amount	274,000	200,281
Other Liabilities [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Liability derivatives, notional amount	0	0
Interest Rate Swap Contracts [Member] | Other Assets [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives, notional amount	0	0
Asset derivatives not designated as hedging instruments	0	0
Interest Rate Swap Contracts [Member] | Other Assets [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Hedged Commercial Loans [Member]
Derivative [Line Items]
Asset derivatives, notional amount	0	85,623
Asset derivatives designated as hedging instruments	0	1,859
Interest Rate Swap Contracts [Member] | Other Liabilities [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Liability derivatives, notional amount	0	0
Liability derivatives not designated as hedging instruments	0	0
Interest Rate Swap Contracts [Member] | Other Liabilities [Member] | Fair Value Hedging [Member] | Hedged Commercial Loans [Member]
Derivative [Line Items]
Liability derivatives designated as hedging instruments	2,394	0
Interest Rate Swap Contracts [Member] | Other Liabilities [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Hedged Commercial Loans [Member]
Derivative [Line Items]
Liability derivatives, notional amount	82,243	0
Forward Loan Sale Commitments [Member] | Other Assets [Member]
Derivative [Line Items]
Asset derivatives not designated as hedging instruments	9	542
Forward Loan Sale Commitments [Member] | Other Assets [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives, notional amount	$ 27,260	$ 21,604

Derivative Financial Instrume_4

Derivative Financial Instruments - Summary of Carrying Amount Hedged Assets/(Liabilities) (Detail) - Designated as Hedging Instrument [Member] - Interest Rate Swap [Member] - Loans Net Of Unearned Income [Member] $ in Thousands	Dec. 31, 2019USD ($)
Carrying Amount of the Hedged Assets/(Liabilities)	$ 81,397
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities)	(2,394)
Cumulative Amount of Fair Value Hedging Adjustment Remaining for any Hedged Assets/(Liabilities) for which Hedge Accounting has been Discontinued	$ 0

Derivative Financial Instrume_5

Derivative Financial Instruments - Schedule of Derivative Financial Instruments on Statements of Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivatives in hedging relationships	$ 6,768	$ (4,743)	$ (7,390)
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivatives in hedging relationships	(95)	(170)	(781)
Designated as Hedging Instrument [Member] | Interest Income/ (Expense) [Member] | Interest Rate Swap Contracts [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Derivatives in hedging relationships	(95)	(170)	(781)
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivatives not designated as hedging instruments	6,863	(4,573)	(6,609)
Not Designated as Hedging Instrument [Member] | Income from Mortgage Banking Activities [Member] | TBA Mortgage Backed Securities [Member]
Derivative [Line Items]
Derivatives not designated as hedging instruments	2,331	(2,690)	1,547
Not Designated as Hedging Instrument [Member] | Income from Mortgage Banking Activities [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Derivatives not designated as hedging instruments	3,607	(2,413)	(7,730)
Not Designated as Hedging Instrument [Member] | Income from Mortgage Banking Activities [Member] | Forward Loan Sale Commitments [Member]
Derivative [Line Items]
Derivatives not designated as hedging instruments	$ 925	$ 530	$ (426)

Comprehensive Income - Componen

Comprehensive Income - Components of Total Comprehensive Income (Detail) - USD ($) $ in Thousands	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
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net Income	$ 63,285	$ 65,965	$ 67,207	$ 63,642	$ 63,950	$ 64,412	$ 66,274	$ 61,706	$ 260,099	$ 256,342	$ 150,581
AFS securities with OTTI charges during the period									(641)	(1,456)	(60)
Related income tax effect									149	339	22
Less: OTTI charges recognized in net income									198	1,456	60
Related income tax benefit									(46)	(339)	(22)
Reclassification of previous noncredit OTTI to credit OTTI									2,188	0	0
Related income tax benefit									(510)	0	0
Net unrealized (losses) gains on AFS securities with OTTI									1,338	0	0
Change in net unrealized gains (losses) on AFS securities arising during the period									32,376	(14,715)	8,371
Related income tax effect									(7,543)	5,109	(3,097)
Net reclassification adjustment for gains included in net income									97	770	(1,874)
Related income tax (benefit) expense									(23)	(179)	693
Total AFS securities - all other									24,907	(9,015)	4,093
Net effect of AFS securities on other comprehensive income									26,245	(9,015)	4,093
Accretion on the unrealized loss for securities transferred from AFS to the HTM investment portfolio prior to call or maturity									0	8	8
Related income tax benefit									0	(2)	(3)
Net effect of HTM securities on other comprehensive income									0	6	5
Pension plan:
Net actuarial loss during the period									(10,324)	(4,232)	(6,784)
Related income tax expense									2,384	1,063	2,510
Amortization of prior service cost recognized in net income									0	0	0
Related income tax benefit									0	0	0
Amortization of net actuarial loss recognized in net income									4,965	4,919	4,553
Related income tax benefit									(1,170)	(1,246)	(1,685)
Net effect of change in defined benefit pension plan on other comprehensive income									(4,145)	504	(1,406)
Net current-period other comprehensive income, net of tax									22,100	(8,505)	2,692
Total Comprehensive Income									$ 282,199	$ 247,837	$ 153,273

Comprehensive Income - Compon_2

Comprehensive Income - Components of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 3,251,624	$ 3,240,530	$ 2,235,747
Reclass due to adopting Accounting Standard Update 2017-12	50	0
Net current-period other comprehensive income, net of tax	22,100	(8,505)	2,692
Ending Balance	3,363,833	3,251,624	3,240,530
Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(38,680)
Reclass due to adopting Accounting Standard Update 2017-12	0
Other comprehensive income before reclassification	0
Amounts reclassified from accumulated other comprehensive income	(4,145)
Net current-period other comprehensive income, net of tax	(4,145)
Ending Balance	(42,825)	(38,680)
Unrealized Gains/Losses on AFS Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(18,289)
Reclass due to adopting Accounting Standard Update 2017-12	0
Other comprehensive income before reclassification	24,493
Amounts reclassified from accumulated other comprehensive income	1,752
Net current-period other comprehensive income, net of tax	26,245
Ending Balance	7,956	(18,289)
Accumulated Unrealized Loss On Securities Available For Sale Transferred To Held To Maturity [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(50)
Reclass due to adopting Accounting Standard Update 2017-12	50
Other comprehensive income before reclassification	0
Amounts reclassified from accumulated other comprehensive income	0
Net current-period other comprehensive income, net of tax	0
Ending Balance	0	(50)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(57,019)	(42,025)	(44,717)
Reclass due to adopting Accounting Standard Update 2017-12	50	(6,353)
Other comprehensive income before reclassification	24,493
Amounts reclassified from accumulated other comprehensive income	(2,393)
Net current-period other comprehensive income, net of tax	22,100	(8,505)	2,692
Ending Balance	$ (34,869)	$ (57,019)	$ (42,025)

Comprehensive Income - Reclassi

Comprehensive Income - Reclassifications Out of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	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
Available for sale ("AFS") securities:
Income before income taxes									$ 324,439	$ 327,165	$ 284,827
Related income tax effect	$ (12,473)	$ (17,010)	$ (17,529)	$ (17,328)	$ (15,757)	$ (17,926)	$ (19,241)	$ (17,899)	(64,340)	(70,823)	(134,246)
Net income	63,285	65,965	67,207	63,642	63,950	64,412	66,274	61,706	260,099	256,342	150,581
Pension plan:
Net actuarial loss									(10,324)	(4,232)	(6,784)
Amortization of net actuarial loss									4,965	4,919	4,553
Income before income taxes									324,439	327,165	284,827
Related income tax effect	(12,473)	(17,010)	(17,529)	(17,328)	(15,757)	(17,926)	(19,241)	(17,899)	(64,340)	(70,823)	(134,246)
Net income	$ 63,285	$ 65,965	$ 67,207	$ 63,642	$ 63,950	$ 64,412	$ 66,274	$ 61,706	260,099	$ 256,342	$ 150,581
Reclassification out of Accumulated Other Comprehensive Income [Member]
Available for sale ("AFS") securities:
Net income									(2,393)
Pension plan:
Net income									(2,393)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains/Losses on AFS Securities [Member]
Available for sale ("AFS") securities:
Reclassification of previous noncredit OTTI to credit OTTI									2,188
Net reclassification adjustment for losses (gains) included in net income									97
Income before income taxes									2,285
Related income tax effect									(533)
Net income									1,752
Pension plan:
Income before income taxes									2,285
Related income tax effect									(533)
Net income									1,752
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Available for sale ("AFS") securities:
Income before income taxes									(5,359)
Related income tax effect									1,214
Net income									(4,145)
Pension plan:
Net actuarial loss									(10,324)
Amortization of net actuarial loss									4,965
Income before income taxes									(5,359)
Related income tax effect									1,214
Net income									$ (4,145)

United Bankshares, Inc. (Pare_3

United Bankshares, Inc. (Parent Company Only) Financial Information - Condensed Balance Sheets (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and due from banks	$ 185,238	$ 187,886
Securities available for sale	2,437,296	2,337,039
Securities held to maturity	1,447	18,655
Equity securities	8,894	9,734
Other investment securities	222,161	176,955
Goodwill	1,478,014	1,478,014
Other assets	441,922	457,154
TOTAL ASSETS	19,662,324	19,250,498
Accrued expenses and other liabilities	170,312	152,306
Shareholders' equity (including other accumulated comprehensive loss of $34,869 and $57,019 at December 31, 2019 and 2018, respectively)	3,363,833	3,251,624	$ 3,240,530	$ 2,235,747
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	19,662,324	19,250,498
United Bankshares [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and due from banks	126,697	68,186
Securities available for sale	7,451	6,822
Securities held to maturity	20	997
Equity securities	4,126	5,094
Other investment securities	10,053	163
Bank subsidiaries	3,519,661	3,478,956
Nonbank subsidiaries	22,439	14,706
Goodwill	(16,008)	(16,008)
Other assets	12,286	10,615
TOTAL ASSETS	3,686,725	3,569,531
Junior subordinated debentures of subsidiary trusts	236,164	234,905
Accrued expenses and other liabilities	86,728	83,002
Shareholders' equity (including other accumulated comprehensive loss of $34,869 and $57,019 at December 31, 2019 and 2018, respectively)	3,363,833	3,251,624
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 3,686,725	$ 3,569,531

United Bankshares, Inc. (Pare_4

United Bankshares, Inc. (Parent Company Only) Financial Information - Condensed Balance Sheets (Parenthetical) (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Condensed Balance Sheet Statements, Captions [Line Items]
Accumulated other comprehensive loss	$ 34,869	$ 57,019
United Bankshares [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Accumulated other comprehensive loss	$ 34,869	$ 57,019

United Bankshares, Inc. (Pare_5

United Bankshares, Inc. (Parent Company Only) Financial Information - Condensed Statements of Income (Detail) - USD ($) $ in Thousands	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]
Net interest income	$ 141,283	$ 141,918	$ 150,553	$ 144,168	$ 146,705	$ 148,775	$ 149,122	$ 144,043	$ 577,922	$ 588,645	$ 548,997
Income before income taxes and Equity in Undistributed Net Income of Subsidiaries									324,439	327,165	284,827
Applicable income tax benefit	12,473	17,010	17,529	17,328	15,757	17,926	19,241	17,899	64,340	70,823	134,246
Net income	$ 63,285	$ 65,965	$ 67,207	$ 63,642	$ 63,950	$ 64,412	$ 66,274	$ 61,706	260,099	256,342	150,581
United Bankshares [Member]
Condensed Income Statements, Captions [Line Items]
Bank subsidiaries									249,000	215,000	115,000
Nonbank subsidiaries									0	0	58
Net interest income									126	227	437
Bank subsidiaries									27,325	25,026	45,693
Nonbank subsidiaries									27	27	27
Other income									147	(596)	1,766
Total Income									276,625	239,684	162,981
Operating expenses									38,569	37,214	71,653
Income before income taxes and Equity in Undistributed Net Income of Subsidiaries									238,056	202,470	91,328
Applicable income tax benefit									(2,123)	(2,470)	(6,126)
Income Before Equity in Undistributed Net Income of Subsidiaries									240,179	204,940	97,454
Bank subsidiaries									19,557	51,392	50,560
Nonbank subsidiaries									363	10	2,567
Net income									$ 260,099	$ 256,342	$ 150,581

United Bankshares, Inc. (Pare_6

United Bankshares, Inc. (Parent Company Only) Financial Information - Condensed Statements of Cash Flows (Detail) - USD ($) $ in Thousands	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
Supplemental Cash Flow Information [Line Items]
Net income	$ 63,285	$ 65,965	$ 67,207	$ 63,642	$ 63,950	$ 64,412	$ 66,274	$ 61,706	$ 260,099	$ 256,342	$ 150,581
Amortization of net periodic pension costs									3,635	2,566	3,310
Stock-based compensation									4,914	4,073	3,555
Excess tax benefits from stock-based compensation arrangements									(223)	(158)	(2,201)
Net gain on securities transactions	109	$ 116	$ 109	(159)	(1,926)	$ (152)	$ (55)	(485)	175	(2,618)	5,584
Net Proceeds from Sales of Equity Securities									2,011	2,005	0
Net cash paid in acquisition of subsidiary									0	0	44,531
Cash dividends paid									138,939	142,350	121,354
Acquisition of treasury stock									35,673	100,724	1
Proceeds from sale of treasury stock from deferred compensation plan									1	1	1
Proceeds from exercise of stock options									1,272	1,500	4,619
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR				1,020,396				1,666,167	1,020,396	1,666,167	1,434,527
CASH AND CASH EQUIVALENTS AT END OF YEAR	837,493				1,020,396				837,493	1,020,396	1,666,167
United Bankshares [Member]
Supplemental Cash Flow Information [Line Items]
Net income									260,099	256,342	150,581
Equity in undistributed net income of subsidiaries									(19,920)	(51,402)	(53,127)
Amortization of net periodic pension costs									302	293	228
Stock-based compensation									4,914	4,073	3,555
Excess tax benefits from stock-based compensation arrangements									223	158	2,201
Net gain on securities transactions									0	607	(1,185)
Net change in other assets and liabilities									1,770	(1,904)	8,764
Net Cash Provided by Operating Activities									247,388	208,167	111,017
Net proceeds from (purchases of) sales of securities									236	9,446	(19,268)
Net Proceeds from Sales of Equity Securities									1,116	1,348	0
Increase in investment in subsidiaries									(7,000)	(2,400)	(34,203)
Net cash paid in acquisition of subsidiary									0	0	22,146
Change in other investment securities									(9,890)	0	(63)
Net Cash (Used in) Provided by Investing Activities									(15,538)	8,394	(31,388)
Proceeds from issuance of common stock									0	0	0
Cash dividends paid									(138,939)	(142,350)	(121,354)
Acquisition of treasury stock									(35,573)	(100,724)	(1)
Proceeds from sale of treasury stock from deferred compensation plan									1	1	1
Proceeds from exercise of stock options									1,272	1,500	4,619
Net Cash Used in Financing Activities									(173,339)	(241,573)	(116,735)
INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS									58,511	(25,012)	(37,106)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR				$ 68,186				$ 93,198	68,186	93,198	130,304
CASH AND CASH EQUIVALENTS AT END OF YEAR	$ 126,697				$ 68,186				$ 126,697	$ 68,186	$ 93,198

Regulatory Matters - Additional

Regulatory Matters - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Regulatory Matters [Line Items]
Average reserve balances to be maintained by subsidiary banks	$ 653,653,000	$ 791,237,000
Average reserve balances required by subsidiary banks	255,894,000	$ 334,280,000
Retained net profits available for distribution to United Bankshares, Inc. by its banking subsidiaries as dividends	$ 70,949,000
Maximum loan to parent company by subsidiaries as percentage it's of capital and surplus	10.00%
Maximum amount of loan to parent company by subsidiaries	$ 282,863,000
Minimum net worth requirement	2,500,000
George Mason [Member]
Regulatory Matters [Line Items]
Net worth	$ 35,556,000

Regulatory Matters - Capital Am

Regulatory Matters - Capital Amounts and Ratios (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
United Bankshares [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital to Risk-Weighted Assets, Actual Amount	$ 2,217,547	$ 2,119,774
Tier 1 Capital to Risk-Weighted Assets, Actual Amount	1,890,757	1,793,682
Common Tier I Capital to Risk Weighted Assets, Actual Amount	1,890,757	1,793,682
Tier 1 Capital to Average Assets, Actual Amount	$ 1,890,757	$ 1,793,682
Total Capital to Risk-Weighted Assets, Actual Ratio	14.70%	14.40%
Tier 1 Capital to Risk-Weighted Assets, Actual Ratio	12.50%	12.20%
Common Tier I Capital to Risk Weighted Assets, Actual Ratio	12.50%	12.20%
Tier 1 Capital to Average Assets, Actual Ratio	10.50%	10.10%
Total Capital to Risk-Weighted Assets, For Capital Adequacy Purposes, Amount	$ 1,206,812	$ 1,179,708
Tier 1 Capital to Risk-Weighted Assets, For Capital Adequacy Purposes, Amount	905,109	884,781
Common Tier I Capital to Risk Weighted Assets, For Capital Adequacy Purposes, Amount	678,832	663,586
Tier 1 Capital to Average Assets, For Capital Adequacy Purposes, Amount	$ 721,691	$ 707,916
Total Capital to Risk-Weighted Assets, For Capital Adequacy, Ratio	8.00%	8.00%
Tier 1 Capital to Risk-Weighted Assets, For Capital Adequacy Purposes, Ratio	6.00%	6.00%
Common Tier I Capital to Risk Weighted Assets, For Capital Adequacy Purposes, Ratio	4.50%	4.50%
Tier 1 Capital to Average Assets, For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Total Capital to Risk-Weighted Assets, To Be Well Capitalized, Amount	$ 1,508,515	$ 1,474,635
Tier 1 Capital to Risk-Weighted Assets, To Be Well Capitalized, Amount	1,206,812	1,179,708
Common Tier I Capital to Risk Weighted Assets, To Be Well Capitalized, Amount	980,535	958,513
Tier 1 Capital to Average Assets, To Be Well Capitalized, Amount	$ 902,114	$ 884,895
Total Capital to Risk-Weighted Assets, To Be Well Capitalized, Ratio	10.00%	10.00%
Tier 1 Capital to Risk-Weighted Assets, To Be Well Capitalized, Ratio	8.00%	8.00%
Common Tier I Capital to Risk Weighted Assets, To Be Well Capitalized, Ratio	6.50%	6.50%
Tier 1 Capital to Average Assets To Be Well Capitalized, Ratio	5.00%	5.00%
United Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital to Risk-Weighted Assets, Actual Amount	$ 2,106,457	$ 2,080,234
Tier 1 Capital to Risk-Weighted Assets, Actual Amount	2,027,667	2,002,142
Common Tier I Capital to Risk Weighted Assets, Actual Amount	2,027,667	2,002,142
Tier 1 Capital to Average Assets, Actual Amount	$ 2,027,667	$ 2,002,142
Total Capital to Risk-Weighted Assets, Actual Ratio	14.00%	14.10%
Tier 1 Capital to Risk-Weighted Assets, Actual Ratio	13.50%	13.60%
Common Tier I Capital to Risk Weighted Assets, Actual Ratio	13.50%	13.60%
Tier 1 Capital to Average Assets, Actual Ratio	11.30%	11.30%
Total Capital to Risk-Weighted Assets, For Capital Adequacy Purposes, Amount	$ 1,204,264	$ 1,177,953
Tier 1 Capital to Risk-Weighted Assets, For Capital Adequacy Purposes, Amount	903,198	883,465
Common Tier I Capital to Risk Weighted Assets, For Capital Adequacy Purposes, Amount	677,399	662,599
Tier 1 Capital to Average Assets, For Capital Adequacy Purposes, Amount	$ 720,232	$ 706,977
Total Capital to Risk-Weighted Assets, For Capital Adequacy, Ratio	8.00%	8.00%
Tier 1 Capital to Risk-Weighted Assets, For Capital Adequacy Purposes, Ratio	6.00%	6.00%
Common Tier I Capital to Risk Weighted Assets, For Capital Adequacy Purposes, Ratio	4.50%	4.50%
Tier 1 Capital to Average Assets, For Capital Adequacy Purposes, Ratio	4.00%	4.00%
Total Capital to Risk-Weighted Assets, To Be Well Capitalized, Amount	$ 1,505,330	$ 1,472,441
Tier 1 Capital to Risk-Weighted Assets, To Be Well Capitalized, Amount	1,204,264	1,177,953
Common Tier I Capital to Risk Weighted Assets, To Be Well Capitalized, Amount	978,465	957,087
Tier 1 Capital to Average Assets, To Be Well Capitalized, Amount	$ 900,290	$ 883,721
Total Capital to Risk-Weighted Assets, To Be Well Capitalized, Ratio	10.00%	10.00%
Tier 1 Capital to Risk-Weighted Assets, To Be Well Capitalized, Ratio	8.00%	8.00%
Common Tier I Capital to Risk Weighted Assets, To Be Well Capitalized, Ratio	6.50%	6.50%
Tier 1 Capital to Average Assets To Be Well Capitalized, Ratio	5.00%	5.00%

Fair Values of Financial Inst_3

Fair Values of Financial Instruments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Transfers from Level 1 to Level 3 for financial assets	$ 0	$ 0
Transfers from Level 3 to Level 1 for financial assets	0	0
Transfers from Level 2 to Level 3 for financial assets	0	0
Transfers from Level 3 to Level 2 for financial assets	0	0
Transfers from Level 1 to Level 3 for financial liabilities	0	0
Transfers from Level 3 to Level 1 for financial liabilities	0	0
Transfers from Level 2 to Level 3 for financial liabilities	0	0
Transfers from Level 3 to Level 2 for financial liabilities	0	0
Nonrecurring fair value adjustments on loans held for sale	0
Fair value measurement of intangible assets	$ 0	$ 0
Loans Held For Sale [Member] | Minimum [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Sales price of loans held for sale increase percentage	0.06%
Loans Held For Sale [Member] | Maximum [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Sales price of loans held for sale increase percentage	0.53%
Loans Held For Sale [Member] | Weighted Average [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Sales price of loans held for sale increase percentage	0.30%
Derivatives [Member] | Minimum [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Sales price of loans held for sale increase percentage	0.06%
Derivatives [Member] | Maximum [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Sales price of loans held for sale increase percentage	0.53%
Derivatives [Member] | Weighted Average [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Sales price of loans held for sale increase percentage	0.30%

Fair Values of Financial Inst_4

Fair Values of Financial Instruments - Schedule of Financial Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities		$ 2,437,296	$ 2,337,039
Loans held for sale		387,514	249,846
Derivative financial assets		4,527	6,504
Derivative financial liabilities		3,065	3,002
Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities		8,894	9,734
Total available for sale securities		2,437,296	2,337,039
Loans held for sale		384,375	247,104
Derivative financial assets		4,527	6,504
Derivative financial liabilities		3,065	3,002
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities		58,676	85,890
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		58,676	85,890
State and Political Subdivisions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities		272,362	208,988
State and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		272,362	208,988
Residential Mortgage-Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities		836,534	1,035,650
Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		836,534	1,035,650
Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Non-Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		3,832	4,259
Commercial Mortgage-Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities		614,973	554,600
Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		614,973	554,600
Asset-Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities		276,139	271,970
Asset-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		276,139	271,970
Trust Preferred Collateralized Debt Obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities		4,703	5,917
Trust Preferred Collateralized Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		4,704	5,917
Single Issue Trust Preferred Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		16,774	8,362
Corporate Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities		353,302	161,403
Corporate Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		353,302	161,403
Financial Services Industry [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities		154	140
Other Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities		4,769	4,640
Interest Rate Lock Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		4,518	4,103
Forward Sales Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		9	542
Interest Rate Swap Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial liabilities		2,394
TBA Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial liabilities		671	3,002
Interest Rate Swap Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets			1,859
Equity Mutual Funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	[1]	3,971	4,954
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities		6,586	6,822
Loans held for sale		0	0
Derivative financial assets		0	0
Derivative financial liabilities		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities		8,894	9,734
Total available for sale securities		6,586	6,822
Loans held for sale		0	0
Derivative financial assets		0	0
Derivative financial liabilities		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | State and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Non-Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Asset-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Trust Preferred Collateralized Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Single Issue Trust Preferred Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Corporate Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		6,586	6,822
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Financial Services Industry [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities		154	140
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Other Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities		4,769	4,640
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Interest Rate Lock Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Forward Sales Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Interest Rate Swap Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial liabilities		0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | TBA Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial liabilities		0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Interest Rate Swap Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets			0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Mutual Funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	[1]	3,971	4,954
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities		2,426,006	2,324,300
Loans held for sale		3,139	2,742
Derivative financial assets		9	2,401
Derivative financial liabilities		3,065	3,002
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities		0	0
Total available for sale securities		2,426,006	2,324,300
Loans held for sale		0	0
Derivative financial assets		9	2,401
Derivative financial liabilities		3,065	3,002
Significant Other Observable Inputs (Level 2) [Member] | U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		58,676	85,890
Significant Other Observable Inputs (Level 2) [Member] | State and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		272,362	208,988
Significant Other Observable Inputs (Level 2) [Member] | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		836,534	1,035,650
Significant Other Observable Inputs (Level 2) [Member] | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Non-Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		3,832	4,259
Significant Other Observable Inputs (Level 2) [Member] | Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		614,973	554,600
Significant Other Observable Inputs (Level 2) [Member] | Asset-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		276,139	271,970
Significant Other Observable Inputs (Level 2) [Member] | Trust Preferred Collateralized Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Significant Other Observable Inputs (Level 2) [Member] | Single Issue Trust Preferred Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		16,774	8,362
Significant Other Observable Inputs (Level 2) [Member] | Corporate Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		346,716	154,581
Significant Other Observable Inputs (Level 2) [Member] | Financial Services Industry [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities		0	0
Significant Other Observable Inputs (Level 2) [Member] | Other Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities		0	0
Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Lock Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		0	0
Significant Other Observable Inputs (Level 2) [Member] | Forward Sales Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		9	542
Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Swap Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial liabilities		2,394
Significant Other Observable Inputs (Level 2) [Member] | TBA Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial liabilities		671	3,002
Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Swap Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets			1,859
Significant Other Observable Inputs (Level 2) [Member] | Equity Mutual Funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	[1]	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities		4,704	5,917
Loans held for sale		384,375	247,104
Derivative financial assets		4,518	4,103
Derivative financial liabilities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities		0	0
Total available for sale securities		4,704	5,917
Loans held for sale		384,375	247,104
Derivative financial assets		4,518	4,103
Derivative financial liabilities		0	0
Significant Unobservable Inputs (Level 3) [Member] | U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | State and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Residential Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Non-Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Commercial Mortgage-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member] | Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Asset-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Trust Preferred Collateralized Debt Obligations [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		4,704	5,917
Significant Unobservable Inputs (Level 3) [Member] | Single Issue Trust Preferred Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Corporate Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Financial Services Industry [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Other Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Lock Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		4,518	4,103
Significant Unobservable Inputs (Level 3) [Member] | Forward Sales Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		0	0
Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Swap Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial liabilities		0
Significant Unobservable Inputs (Level 3) [Member] | TBA Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial liabilities		0	0
Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Swap Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets			0
Significant Unobservable Inputs (Level 3) [Member] | Equity Mutual Funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	[1]	$ 0	$ 0
[1]	The equity mutual funds are within a rabbi trust for the payment of benefits under a deferred compensation plan for certain key officers of United and its subsidiaries.

Fair Values of Financial Inst_5

Fair Values of Financial Instruments - Schedule of Additional Information about Financial Assets and Liabilities Measured at Fair Value Utilized Level 3 (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Trust Preferred Collateralized Debt Obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Balance, beginning of period	$ 5,917	$ 34,269
Included in earnings (or changes in net assets)	(155)	28
Included in other comprehensive income	(1,059)	920
Purchases, issuances, and settlements	0	0
Sales	0	(29,300)
Transfers in and/or out of Level 3	0	0
Balance, end of period	4,703	5,917
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at reporting date	0	0
Loans Held For Sale [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Balance, beginning of period	247,104	263,308
Included in earnings (or changes in net assets)	83,806	68,555
Originations	2,941,722	2,619,454
Sales	(2,888,257)	(2,676,797)
Transfers in and/or out of Level 3	0	(27,416)
Balance, end of period	384,375	247,104
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at reporting date	0	0
Interest Rate Lock Commitments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Balance, beginning of period	4,103	4,559
Transfers in and/or out of Level 3	415	(456)
Balance, end of period	4,518	4,103
The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at reporting date	$ 0	$ 0

Fair Values of Financial Inst_6

Fair Values of Financial Instruments - Schedule of Changes in Fair Value Included in Earnings of Financial Instruments for which Fair Value Option has been Elected (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Mortgage Banking [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Income from mortgage banking activities	$ 3,705	$ (281)

Fair Values of Financial Inst_7

Fair Values of Financial Instruments - Summary of Difference Between Aggregate Fair Value and Remaining Contractual Principal Outstanding for Financial Instruments for which Fair Value Option has been Elected (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Loans held for sale, unpaid principal balance	$ 375,274	$ 241,293
Loans held for sale, fair value	384,375	247,104
Loans held for sale, fair value over/(under) unpaid principal balance	$ 9,101	$ 5,811

Fair Values of Financial Inst_8

Fair Values of Financial Instruments - Summary of Financial Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
YTD Losses, Loans held for sale	$ (4)	$ 3
YTD Losses, Impaired Loans	1,831	12,301
YTD Losses, OREO	(785)	910
Loans held for sale	384,375	247,104
OREO	15,515	16,865
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held for sale	3,139	2,742
Impaired Loans	68,213	121,355
OREO	15,515	16,865
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held for sale	0	0
Impaired Loans	0	0
OREO	0	0
Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held for sale	3,139	2,742
Impaired Loans	55,792	108,899
OREO	15,495	16,865
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held for sale	0	0
Impaired Loans	12,421	12,456
OREO	$ 20	$ 0

Fair Values of Financial Inst_9

Fair Values of Financial Instruments - Summary of Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 837,493	$ 1,020,396	$ 1,666,167	$ 1,434,527
Securities available for sale	2,437,296	2,337,039
Securities held to maturity	1,446	19,999
Other securities	222,161	176,955
Loans held for sale	387,514	249,846
Net loans	13,712,129	13,422,222
Derivative financial assets	4,527	6,504
Deposits	13,852,421	13,994,749
Derivative financial liabilities	3,065	3,002
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	837,493	1,020,396
Securities available for sale	2,437,296	2,337,039
Securities held to maturity	1,446	19,999
Equity securities	8,894	9,734
Other securities	222,161	176,955
Loans held for sale	387,514	249,846
Net loans	13,635,072	13,345,519
Derivative financial assets	4,527	6,504
Deposits	13,852,421	13,994,749
Short-term borrowings	374,654	351,327
Long-term borrowings	1,838,029	1,499,103
Derivative financial liabilities	3,065	3,002
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	837,493	1,020,396
Securities available for sale	2,437,296	2,337,039
Securities held to maturity	1,447	18,655
Equity securities	8,894	9,734
Other securities	211,053	168,107
Loans held for sale	387,514	249,846
Net loans	13,185,955	12,657,073
Derivative financial assets	4,527	6,504
Deposits	13,843,077	13,954,574
Short-term borrowings	374,654	351,327
Long-term borrowings	1,820,297	1,475,237
Derivative financial liabilities	3,065	3,002
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Securities available for sale	6,586	6,822
Securities held to maturity	0	0
Other securities	0	0
Loans held for sale	0	0
Net loans	0	0
Derivative financial assets	0	0
Deposits	0	0
Short-term borrowings	0	0
Long-term borrowings	0	0
Derivative financial liabilities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Marketable Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities	8,894	9,734
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	837,493	1,020,396
Securities available for sale	2,426,006	2,324,300
Securities held to maturity	427	15,635
Other securities	0	0
Loans held for sale	3,139	2,742
Net loans	0	0
Derivative financial assets	9	2,401
Deposits	13,843,077	13,954,574
Short-term borrowings	374,654	351,327
Long-term borrowings	1,820,297	1,475,237
Derivative financial liabilities	3,065	3,002
Significant Other Observable Inputs (Level 2) [Member] | Marketable Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
Securities available for sale	4,704	5,917
Securities held to maturity	1,020	3,020
Other securities	211,053	168,107
Loans held for sale	384,375	247,104
Net loans	13,185,955	12,657,073
Derivative financial assets	4,518	4,103
Deposits	0	0
Short-term borrowings	0	0
Long-term borrowings	0	0
Derivative financial liabilities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Marketable Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities	$ 0	$ 0

Variable Interest Entities - Ad

Variable Interest Entities - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019Trust
Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract]
Number of statutory business trusts	14
Percentage of equity shares of each trust owned by the company	100.00%

Variable Interest Entities - Su

Variable Interest Entities - Summary of Quantitative Information Related to Significant Involvement in Unconsolidated Variable Interest Entities (Detail) - Trust Preferred Securities [Member] - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Aggregate Assets	$ 257,941	$ 257,754
Aggregate Liabilities	248,680	248,741
Risk Of Loss	$ 9,261	$ 9,013

Segment Information - Additiona

Segment Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019Segment
Segment Reporting [Abstract]
Number of business segment	2

Segment Information - Summary o

Segment Information - Summary of Segment Reporting Information (Detail) - USD ($) $ in Thousands	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]
Net interest income	$ 141,283	$ 141,918	$ 150,553	$ 144,168	$ 146,705	$ 148,775	$ 149,122	$ 144,043	$ 577,922	$ 588,645	$ 548,997
Provision for loans losses	5,867	5,033	5,417	4,996	5,823	4,808	6,204	5,178	21,313	22,013	28,406
Other income									150,484	128,712	131,645
Other expense	96,900	96,134	100,195	89,425	91,002	93,315	93,410	90,452	382,654	368,179	367,409
Income taxes	12,473	17,010	17,529	17,328	15,757	17,926	19,241	17,899	64,340	70,823	134,246
Net income	63,285	$ 65,965	$ 67,207	$ 63,642	63,950	$ 64,412	$ 66,274	$ 61,706	260,099	256,342	150,581
Total assets (liabilities)	19,662,324				19,250,498				19,662,324	19,250,498	19,058,959
Average assets (liabilities)									19,475,468	18,848,027	17,617,429
Operating Segments [Member] | Community Banking [Member]
Segment Reporting Information [Line Items]
Net interest income									583,547	593,108	558,622
Provision for loans losses									21,313	22,013	28,406
Other income									74,956	72,539	69,615
Other expense									314,710	301,123	291,584
Income taxes									64,080	73,861	139,980
Net income									258,400	268,650	168,267
Total assets (liabilities)	19,564,036				19,191,215				19,564,036	19,191,215	19,016,619
Average assets (liabilities)									19,401,397	18,798,880	17,565,464
Operating Segments [Member] | Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Net interest income									916	1,315	(69)
Provision for loans losses									0	0	0
Other income									83,884	68,555	58,532
Other expense									72,288	72,632	62,072
Income taxes									2,355	(505)	(901)
Net income									10,157	(2,257)	(2,708)
Total assets (liabilities)	507,124				320,299				507,124	320,299	280,293
Average assets (liabilities)									358,087	279,618	212,212
Other [Member]
Segment Reporting Information [Line Items]
Net interest income									(12,472)	(11,886)	(9,556)
Provision for loans losses									0	0	0
Other income									392	(667)	3,498
Other expense									(1,527)	31	13,753
Income taxes									(2,095)	(2,533)	(4,833)
Net income									(8,458)	(10,051)	(14,978)
Total assets (liabilities)	17,777				3,222				17,777	3,222	17,158
Average assets (liabilities)									8,411	6,104	19,769
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net interest income									5,931	6,108	0
Provision for loans losses									0	0	0
Other income									(8,748)	(11,715)	0
Other expense									(2,817)	(5,607)	0
Income taxes									0	0	0
Net income									0	0	0
Total assets (liabilities)	$ (426,613)				$ (264,238)				(426,613)	(264,238)	(255,111)
Average assets (liabilities)									$ (292,427)	$ (236,575)	$ (180,016)

Quarterly Financial Data - Quar

Quarterly Financial Data - Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	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 Financial Information Disclosure [Abstract]
Interest income	$ 183,869	$ 190,351	$ 199,245	$ 189,097	$ 187,500	$ 185,030	$ 178,000	$ 167,185	$ 762,562	$ 717,715	$ 623,806
Interest expense	42,586	48,433	48,692	44,929	40,795	36,255	28,878	23,142	184,640	129,070	74,809
Net interest income	141,283	141,918	150,553	144,168	146,705	148,775	149,122	144,043	577,922	588,645	548,997
Provision for credit losses	5,867	5,033	5,417	4,996	5,823	4,808	6,204	5,178	21,313	22,013	28,406
Mortgage banking income	17,547	24,019	21,704	13,681	11,570	13,277	18,692	14,570
Securities gains (losses), net	109	116	109	(159)	(1,926)	(152)	(55)	(485)	175	(2,618)	5,584
Other noninterest income	19,586	18,089	17,982	17,701	20,183	18,561	17,370	17,107
Noninterest expense	96,900	96,134	100,195	89,425	91,002	93,315	93,410	90,452	382,654	368,179	367,409
Income taxes	12,473	17,010	17,529	17,328	15,757	17,926	19,241	17,899	64,340	70,823	134,246
Net income	$ 63,285	$ 65,965	$ 67,207	$ 63,642	$ 63,950	$ 64,412	$ 66,274	$ 61,706	$ 260,099	$ 256,342	$ 150,581
Average shares outstanding (000s):
Basic	101,250,000	101,432,000	101,774,000	101,895,000	102,930,000	103,618,000	104,683,000	104,859,000	101,585,599	104,015,976	97,502,633
Diluted	101,538,000	101,712,000	102,048,000	102,163,000	103,164,000	103,934,000	104,953,000	105,163,000	101,852,577	104,298,825	97,890,078
Net income per share:
Basic	$ 0.62	$ 0.65	$ 0.66	$ 0.62	$ 0.62	$ 0.62	$ 0.63	$ 0.59	$ 2.55	$ 2.46	$ 1.54
Diluted	0.62	0.65	0.66	0.62	0.62	0.62	0.63	0.59	2.55	2.45	1.54
Dividends per share	$ 0.35	$ 0.34	$ 0.34	$ 0.34	$ 0.34	$ 0.34	$ 0.34	$ 0.34	$ 1.37	$ 1.36	$ 1.33