United Bankshares (UBSI) 10-Q 8 Nov 19 2019 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2019	Oct. 31, 2019
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Fiscal Year Focus	2019
Document Period End Date	Sep. 30, 2019
Document Fiscal Period Focus	Q3
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		101,546,153
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

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Assets
Cash and due from banks	$ 228,005,000	$ 187,886,000
Interest-bearing deposits with other banks	747,332,000	831,707,000
Federal funds sold	817,000	803,000
Total cash and cash equivalents	976,154,000	1,020,396,000
Securities available for sale at estimated fair value (amortized cost-$2,425,849 at September 30, 2019 and $2,360,884 at December 31, 2018)	2,452,097,000	2,337,039,000
Securities held to maturity (estimated fair value-$1,472 at September 30, 2019 and $18,655 at December 31, 2018)	1,471,000	19,999,000
Equity securities at estimated fair value	8,914,000	9,734,000
Other investment securities	210,830,000	176,955,000
Loans held for sale (at fair value-$407,463 at September 30, 2019 and $247,104 at December 31, 2018)	412,194,000	249,846,000
Loans	13,637,238,000	13,429,532,000
Less: Unearned income	(3,811,000)	(7,310,000)
Loans net of unearned income	13,633,427,000	13,422,222,000
Less: Allowance for loan losses	(77,098,000)	(76,703,000)
Net loans	13,556,329,000	13,345,519,000
Bank premises and equipment	94,800,000	95,245,000
Operating lease right-of-use assets	60,318,000	0
Goodwill	1,478,014,000	1,478,014,000
Accrued interest receivable	57,626,000	60,597,000
Other assets	442,714,000	457,154,000
TOTAL ASSETS	19,751,461,000	19,250,498,000
Deposits:
Noninterest-bearing	4,572,122,000	4,416,815,000
Interest-bearing	9,523,289,000	9,577,934,000
Total deposits	14,095,411,000	13,994,749,000
Borrowings:
Federal funds purchased	0	23,400,000
Securities sold under agreements to repurchase	129,966,000	152,927,000
Federal Home Loan Bank (FHLB) borrowings	1,672,448,000	1,439,198,000
Other long-term borrowings	235,849,000	234,905,000
Reserve for lending-related commitments	1,776,000	1,389,000
Operating lease liabilities	63,987,000	0
Accrued expenses and other liabilities	197,682,000	152,306,000
TOTAL LIABILITIES	16,397,119,000	15,998,874,000
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-105,464,161 and 105,239,121 at September 30, 2019 and December 31, 2018, respectively, including 3,908,465 and 2,915,633 shares in treasury at September 30, 2019 and December 31, 2018, respectively	263,660,000	263,098,000
Surplus	2,138,240,000	2,134,462,000
Retained earnings	1,104,837,000	1,013,037,000
Accumulated other comprehensive loss	(15,781,000)	(57,019,000)
Treasury stock, at cost	(136,614,000)	(101,954,000)
TOTAL SHAREHOLDERS' EQUITY	3,354,342,000	3,251,624,000
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 19,751,461,000	$ 19,250,498,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Securities available for sale, amortized cost	$ 2,425,849	$ 2,360,884
Securities held to maturity	1,472	18,655
Loans held for sale at fair value	$ 407,463	$ 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	105,464,161	105,239,121
Common stock, shares in treasury	3,908,465	2,915,633

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest income
Interest and fees on loans	$ 165,149	$ 164,229	$ 505,150	$ 472,451
Interest on federal funds sold and other short-term investments	6,236	5,485	17,478	13,867
Interest and dividends on securities:
Taxable	18,168	13,994	53,279	39,679
Tax-exempt	798	1,322	2,786	4,218
Total interest income	190,351	185,030	578,693	530,215
Interest expense
Interest on deposits	36,368	26,368	104,461	61,101
Interest on short-term borrowings	539	618	1,838	1,503
Interest on long-term borrowings	11,526	9,269	35,755	25,671
Total interest expense	48,433	36,255	142,054	88,275
Net interest income	141,918	148,775	436,639	441,940
Provision for loan losses	5,033	4,808	15,446	16,190
Net interest income after provision for loan losses	136,885	143,967	421,193	425,750
Other income
Income from bank-owned life insurance	1,280	1,251	4,433	3,776
Net investment securities gains (losses)	116	(152)	66	(692)
Other income	325	419	991	1,406
Total other income	42,224	31,686	113,242	98,885
Other expense
Employee compensation	46,313	41,312	129,563	125,268
Employee benefits	8,615	8,645	26,624	27,514
Net occupancy expense	8,698	9,273	26,116	27,776
Other real estate owned (OREO) expense	1,837	921	3,886	2,423
Equipment expense	3,698	3,892	10,688	10,328
Data processing expense	5,776	6,068	16,505	17,735
Bankcard processing expense	474	485	1,402	1,431
FDIC insurance expense	465	3,530	7,065	8,220
FHLB prepayment penalties	0	0	5,105	0
Other expense	20,258	19,189	58,800	56,482
Total other expense	96,134	93,315	285,754	277,177
Income before income taxes	82,975	82,338	248,681	247,458
Income taxes	17,010	17,926	51,867	55,066
Net income	$ 65,965	$ 64,412	$ 196,814	$ 192,392
Earnings per common share:
Basic	$ 0.65	$ 0.62	$ 1.93	$ 1.84
Diluted	$ 0.65	$ 0.62	$ 1.93	$ 1.83
Average outstanding shares:
Basic	101,432,243	103,617,590	101,698,530	104,382,094
Diluted	101,711,740	103,933,959	101,967,135	104,679,876
Fees From Trust Services [Member]
Other income
Revenue from contract	$ 3,574	$ 3,350	$ 10,276	$ 9,545
Fees from Brokerage Services [Member]
Other income
Revenue from contract	2,378	2,787	7,668	6,964
Fees from Deposit Services [Member]
Other income
Revenue from contract	8,702	8,673	25,219	25,323
Bankcard Fees and Merchant Discounts [Member]
Other income
Revenue from contract	1,262	1,549	3,520	4,384
Other Service Charges, Commissions, and Fees [Member]
Other income
Revenue from contract	568	532	1,665	1,640
Mortgage Banking [Member]
Other income
Revenue from contract	$ 24,019	$ 13,277	$ 59,404	$ 46,539

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 65,965	$ 67,207	$ 63,642	$ 64,412	$ 66,274	$ 61,706	$ 196,814	$ 192,392
Change in net unrealized gain (loss) on available-for-sale (AFS) securities, net of tax	3,637			(7,579)			38,420	(30,853)
Accretion of the net unrealized loss on the transfer of AFS securities to held-to-maturity (HTM) securities, net of tax	0			2			0	4
Change in pension plan assets, net of tax	949			918			2,768	2,703
Comprehensive income, net of tax	$ 70,551	$ 86,110	$ 81,341	$ 57,753	$ 60,826	$ 45,667	$ 238,002	$ 164,246

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, 2017	$ 3,240,530	$ 262,675	$ 2,129,077	$ 891,816	$ (42,025)	$ (1,013)
Beginning Balance, shares at Dec. 31, 2017		105,069,821
Cumulative effect of adopting Accounting Standard Update	0	$ 0	0	136	(136)	0
Reclass due to adopting Accounting Standard Update	0	0	0	6,353	(6,353)	0
Net income	61,706	0	0	61,706	0	0
Other comprehensive income, net of tax	(16,039)	0	0	0	(16,039)	0
Comprehensive income, net of tax	45,667
Stock based compensation expense	968	0	968	0	0	0
Purchase of treasury stock	(404)	0	0	0	0	(404)
Cash dividends	(35,748)			(35,748)	0	0
Grant of restricted stock	0	$ 243	(243)	0	0	0
Grant of restricted stock, shares		97,004
Forfeiture of restricted stock	0	$ 0	27	0	0	(27)
Common stock options exercised	$ 300	$ 37	263	0	0	0
Common stock options exercised, shares	15,043	15,043
Ending Balance at Mar. 31, 2018	$ 3,251,313	$ 262,955	2,130,092	924,263	(64,553)	(1,444)
Ending Balance, shares at Mar. 31, 2018		105,181,868
Beginning Balance at Dec. 31, 2017	3,240,530	$ 262,675	2,129,077	891,816	(42,025)	(1,013)
Beginning Balance, shares at Dec. 31, 2017		105,069,821
Net income	192,392
Other comprehensive income, net of tax	(28,146)
Comprehensive income, net of tax	$ 164,246
Common stock options exercised, shares	60,161
Ending Balance at Sep. 30, 2018	$ 3,251,128	$ 263,068	2,133,157	984,062	(76,660)	(52,499)
Ending Balance, shares at Sep. 30, 2018		105,226,986
Beginning Balance at Mar. 31, 2018	3,251,313	$ 262,955	2,130,092	924,263	(64,553)	(1,444)
Beginning Balance, shares at Mar. 31, 2018		105,181,868
Net income	66,274	$ 0	0	66,274	0	0
Other comprehensive income, net of tax	(5,448)	0	0	0	(5,448)	0
Comprehensive income, net of tax	60,826
Stock based compensation expense	1,024	0	1,024	0	0	0
Purchase of treasury stock	(35,580)	0	0	0	0	(35,580)
Cash dividends	(35,584)	0	0	(35,584)	0	0
Forfeiture of restricted stock	0	0	82	0	0	(82)
Common stock options exercised	$ 566	$ 67	499	0	0	0
Common stock options exercised, shares	27,046	27,046
Ending Balance at Jun. 30, 2018	$ 3,242,565	$ 263,022	2,131,697	954,953	(70,001)	(37,106)
Ending Balance, shares at Jun. 30, 2018		105,208,914
Net income	64,412	$ 0	0	64,412	0	0
Other comprehensive income, net of tax	(6,659)	0	0	0	(6,659)	0
Comprehensive income, net of tax	57,753
Stock based compensation expense	1,024	0	1,024	0	0	0
Distribution of treasury stock for deferred compensation plan	1	0	0	0	0	1
Purchase of treasury stock	(15,339)	0	0	0	0	(15,339)
Cash dividends	(35,303)	0	0	(35,303)	0	0
Forfeiture of restricted stock	0	0	55	0	0	(55)
Common stock options exercised	$ 427	$ 46	381	0	0	0
Common stock options exercised, shares	18,072	18,072
Ending Balance at Sep. 30, 2018	$ 3,251,128	$ 263,068	2,133,157	984,062	(76,660)	(52,499)
Ending Balance, shares at Sep. 30, 2018		105,226,986
Beginning Balance at Dec. 31, 2018	3,251,624	$ 263,098	2,134,462	1,013,037	(57,019)	(101,954)
Beginning 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	63,642	0	0	63,642	0	0
Other comprehensive income, net of tax	17,699	0	0	0	17,699	0
Comprehensive income, net of tax	81,341
Stock based compensation expense	1,113	0	1,113	0	0	0
Purchase of treasury stock	(12,072)	0	0	0	0	(12,072)
Cash dividends	(34,759)	0	0	(34,759)	0	0
Grant of restricted stock	0	$ 316	(316)	0	0	0
Grant of restricted stock, shares		126,427
Common stock options exercised	$ 643	$ 84	559	0	0	0
Common stock options exercised, shares	33,816	33,816
Ending Balance at Mar. 31, 2019	$ 3,286,891	$ 263,498	2,135,818	1,040,871	(39,270)	(114,026)
Ending Balance, shares at Mar. 31, 2019		105,399,364
Beginning Balance at Dec. 31, 2018	3,251,624	$ 263,098	2,134,462	1,013,037	(57,019)	(101,954)
Beginning Balance, shares at Dec. 31, 2018		105,239,121
Reclass due to adopting Accounting Standard Update					50
Net income	196,814
Other comprehensive income, net of tax	41,188				41,188
Comprehensive income, net of tax	$ 238,002
Common stock options exercised, shares	98,613
Ending Balance at Sep. 30, 2019	$ 3,354,342	$ 263,660	2,138,240	1,104,837	(15,781)	(136,614)
Ending Balance, shares at Sep. 30, 2019		105,464,161
Beginning Balance at Mar. 31, 2019	3,286,891	$ 263,498	2,135,818	1,040,871	(39,270)	(114,026)
Beginning Balance, shares at Mar. 31, 2019		105,399,364
Net income	67,207	$ 0	0	67,207	0	0
Other comprehensive income, net of tax	18,903	0	0	0	18,903	0
Comprehensive income, net of tax	86,110
Stock based compensation expense	1,198	0	1,198	0	0	0
Purchase of treasury stock	(6,032)	0	0	0	0	(6,032)
Cash dividends	(34,688)	0	0	(34,688)	0	0
Forfeiture of restricted stock	0	0	100	0	0	(100)
Common stock options exercised	$ 379	$ 36	343	0	0	0
Common stock options exercised, shares	14,144	14,144
Ending Balance at Jun. 30, 2019	$ 3,333,858	$ 263,534	2,137,459	1,073,390	(20,367)	(120,158)
Ending Balance, shares at Jun. 30, 2019		105,413,508
Net income	65,965	$ 0	0	65,965	0	0
Other comprehensive income, net of tax	4,586	0	0	0	4,586	0
Comprehensive income, net of tax	70,551
Stock based compensation expense	1,194	0	1,194	0	0	0
Distribution of treasury stock for deferred compensation plan	1	0	0	0	0	1
Purchase of treasury stock	(16,395)	0	0	0	0	(16,395)
Cash dividends	(34,518)	0	0	(34,518)	0	0
Forfeiture of restricted stock	0	0	62	0	0	(62)
Common stock options exercised	$ (349)	$ 126	(475)	0	0	0
Common stock options exercised, shares	50,653	50,653
Ending Balance at Sep. 30, 2019	$ 3,354,342	$ 263,660	$ 2,138,240	$ 1,104,837	$ (15,781)	$ (136,614)
Ending Balance, shares at Sep. 30, 2019		105,464,161

Consolidated Statement of Cha_2

Consolidated Statement of Changes in Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018
Cash dividends per share	$ 0.34	$ 0.34	$ 0.34	$ 0.34	$ 0.34	$ 0.34
Common stock options exercised, shares	50,653	14,144	33,816	18,072	27,046	15,043
Common Stock [Member]
Grant of restricted stock, shares			126,427			97,004
Forfeiture of restricted stock, shares	1,610	2,539		1,400	2,170	683
Common stock options exercised, shares	50,653	14,144	33,816	18,072	27,046	15,043
Treasury Stock [Member]
Purchase of treasury stock, shares	456,404	166,604	365,702	414,404	962,504	10,842
Deferred Compensation Plan [Member] | Treasury Stock [Member]
Stock Issued During Period, Shares, Treasury Stock Reissued	27			26

Condensed Consolidated Statemen

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
OPERATING ACTIVITIES
NET CASH PROVIDED BY OPERATING ACTIVITIES	$ 90,956	$ 218,771
INVESTING ACTIVITIES
Proceeds from maturities and calls of securities held to maturity	6,975	2
Proceeds from sales of securities available for sale	333,414	86,061
Proceeds from maturities and calls of securities available for sale	240,260	201,107
Purchases of securities available for sale	(630,162)	(629,760)
Proceeds from sales of equity securities	1,865	1,825
Purchases of equity securities	(742)	(598)
Proceeds from sales and redemptions of other investment securities	80,281	35,987
Purchases of other investment securities	(114,156)	(45,075)
Redemption of bank-owned life insurance policies	2,829	0
Purchases of bank premises and equipment	(6,800)	(4,439)
Proceeds from sales of bank premises and equipment	251	2,171
Proceeds from the sales of OREO properties	4,620	9,105
Net change in loans	(205,480)	(248,623)
NET CASH USED IN INVESTING ACTIVITIES	(286,845)	(592,237)
FINANCING ACTIVITIES
Cash dividends paid	(104,421)	(107,046)
Acquisition of treasury stock	(34,499)	(51,323)
Proceeds from exercise of stock options	672	1,277
Repayment of long-term Federal Home Loan Bank borrowings	(1,115,000)	(635,000)
Proceeds from issuance of long-term Federal Home Loan Bank borrowings	1,325,000	650,000
Repayment of trust preferred issuance	0	(9,374)
Distribution of treasury stock for deferred compensation plan	1	1
Changes in:
Deposits	101,255	261,529
Federal funds purchased, securities sold under agreements to repurchase and other short-term borrowings	(21,361)	(148,079)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	151,647	(38,015)
Decrease in cash and cash equivalents	(44,242)	(411,481)
Cash and cash equivalents at beginning of year	1,020,396	1,666,167
Cash and cash equivalents at end of period	976,154	1,254,686
Noncash investing activities:
Transfers of loans to OREO	9,386	1,809
Transfer of held to maturity debt securities to available for sale debt securities	$ 11,544	$ 0

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation The accompanying unaudited consolidated interim financial statements of United Bankshares, Inc. and Subsidiaries (“United” or “the Company”) have been prepared in accordance with accounting principles for interim financial information generally accepted in the United States (GAAP) and with the instructions for Form 10-Q S-X. 10-K. The accompanying consolidated interim financial statements include the accounts of United and its wholly owned subsidiaries. United operates in two business segments: community banking and mortgage banking. All significant intercompany accounts and transactions have been eliminated in the consolidated financial statements. Information is presented in these notes to the unaudited consolidated interim financial statements with dollars expressed in thousands, except per share or unless otherwise noted. New Accounting Standards In April 2019, the Financial Accounting Standards Board (FASB) issued ASU No. 2019-04 In August 2018, the FASB issued ASU No. 2018-14 — 715-20): 2018-14 2018-14 In August 2018, the FASB issued ASU No. 2018-13 2018-13 2018-13 In June 2018, the FASB issued Accounting Standards Update (ASU) No. 2018-07 non-employees non-employee 2018-07 2018-07 In August 2017, the FASB issued ASU No. 2017-12, one-time 2017-12 one-time In July 2017, the FASB issued ASU No. 2017-11, 2017-11 2017-11 In March 2017, the FASB issued ASU No. 2017-08, 310-20): 2017-08 In January 2017, the FASB issued ASU No. 2017-04, 2017-04 2017-04 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 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 the standard using the modified retrospective transition method on January 1, 2019. The Company evaluated and elected the package of practical expedients, which allows for existing leases to be accounted for consistent with

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Investment Securities	2. 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. September 30, 2019 Gross Gross Estimated Cumulative Amortized Unrealized Unrealized Fair OTTI in Cost Gains Losses Value AOCI (1) U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 63,444 $ 591 $ 1 $ 64,034 $ 0 State and political subdivisions 234,552 4,588 625 238,515 0 Residential mortgage-backed securities Agency 853,521 14,493 733 867,281 0 Non-agency 3,533 462 0 3,995 86 Commercial mortgage-backed securities Agency 611,038 11,751 1,137 621,652 0 Asset-backed securities 284,593 0 4,886 279,707 0 Trust preferred collateralized debt obligations 6,130 0 1,061 5,069 661 Single issue trust preferred securities 18,188 172 1,816 16,544 0 Other corporate securities 350,850 4,485 35 355,300 0 Total $ 2,425,849 $ 36,542 $ 10,294 $ 2,452,097 $ 747 December 31, 2018 Gross Gross Estimated Cumulative Amortized Unrealized Unrealized Fair OTTI in Cost Gains Losses Value AOCI (1) U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 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) Non-credit before-tax. The following is a summary of securities available for sale which were in an unrealized loss position at September 30, 2019 and December 31, 2018. Less than 12 months 12 months or longer Fair Unrealized Fair Unrealized Value Losses Value Losses September 30, 2019 U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 1,420 $ 1 $ 0 $ 0 State and political subdivisions 62,394 614 2,946 11 Residential mortgage-backed securities Agency 30,433 101 82,977 632 Non-agency 0 0 0 0 Commercial mortgage-backed securities Agency 145,382 962 54,441 175 Asset-backed securities 243,909 4,084 35,798 802 Trust preferred collateralized debt obligations 2,969 661 2,100 400 Single issue trust preferred securities 0 0 13,332 1,816 Other corporate securities 8,978 35 0 0 Total $ 495,485 $ 6,458 $ 191,594 $ 3,836 Less than 12 months 12 months or longer Fair Unrealized Fair Unrealized Value Losses Value Losses 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. Three Months Ended September 30 Nine Months Ended September 30 2019 2018 2019 2018 Proceeds from sales and calls $ 188,911 $ 109,093 $ 573,674 $ 283,953 Gross realized gains 412 93 1,166 1,314 Gross realized losses 346 207 1,318 1,604 At September 30, 2019, gross unrealized losses on available for sale securities were $10,294 on 145 securities of a total portfolio of 738 available for sale securities. Securities with the most significant gross unrealized losses at September 30, 2019 consisted primarily of asset-backed securities, agency commercial mortgage-backed securities, single issue trust preferred securities , (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. commercial commercial and the trust preferred collateralized debt obligations mainly 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 $234,552 at September 30, 2019. As of September 30, 2019, approximately 71% of 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 less than one percent of the portfolio was rated below investment grade as of September 30, 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 September 30, 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 $1,464,559 at September 30, 2019. Of the $1,464,559 amount, $611,038 was related to agency commercial mortgage-backed securities and $853,521 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-tha​​​​​​​n-temporarily impaired at September 30, 2019. Non-agency United’s non-agency non-agency 3,533 non-agency n non-agency ere 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 September 30, 2019 consisted of $4,040 in investment grade bonds, $5,936 in split rated bonds, $2,480 in below investment grade rated bonds, and $5,732 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 third 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 $6,130 as of September 30, 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 September 30, 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 September 30, 2019. The total amount of OTTI recognized in earnings on this security during the third quarter of 2019 was $9. Corporate securities As of September 30, 2019, United’s Corporate securities portfolio had a total amortized cost balance of $350,850. The majority of the portfolio consisted of debt issuances of corporations representing a variety of industries, including financial institutions. Of the $ 350,850​​​​​​​ 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. Three Months Ended September 30 Nine Months Ended September 30 2019 2018 2019 2018 Balance of cumulative credit losses at beginning of period $ 3,192 $ 3,199 $ 3,138 $ 18,060 Additional credit losses on securities for which OTTI was previously recognized 9 0 63 0 Reductions for securities sold or paid off during the period 0 0 0 (14,861 ) Balance of cumulative credit losses at end of period $ 3,201 $ 3,199 $ 3,201 $ 3,199 The amortized cost and estimated fair value of securities available for sale at September 30, 2019 and December 31, 2018 by contractual maturity are shown as follows. Expected maturities may differ from contractual maturities because the issuers may have the right to call or prepay obligations without penalties. September 30, 2019 December 31, 2018 Estimated Estimated Amortized Fair Amortized Fair Cost Value Cost Value Due in one year or less $ 110,865 $ 111,001 $ 77,534 $ 77,266 Due after one year through five years 568,839 576,687 518,975 514,734 Due after five years through ten years 549,442 558,540 483,567 477,135 Due after ten years 1,196,703 1,205,869 1,280,808 1,267,904 Total $ 2,425,849 $ 2,452,097 $ 2,360,884 $ 2,337,039 Securities Held to Maturity The amortized cost and estimated fair values of securities held to maturity are summarized as follows: September 30, 2019 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 25 $ 0 $ 0 $ 25 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 $ 1,471 $ 1 $ 0 $ 1,472 December 31, 2018 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses 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 There were no gross realized gains or losses on calls and sales of held to maturity securities included in earnings for the third quarter and first nine months of 2019 and 2018. The amortized cost and estimated fair value of debt securities held to maturity at September 30, 2019 and December 31, 2018 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.​​​​​​​ September 30, 2019 December 31, 2018 Estimated Estimated Amortized Fair Amortized Fair Cost Value Cost Value Due in one year or less $ 235 $ 235 $ 7,913 $ 8,005 Due after one year through five years 216 217 1,059 1,061 Due after five years through ten years 0 0 8,030 7,134 Due after ten years 1,020 1,020 2,997 2,455 Total $ 1,471 $ 1,472 $ 19,999 $ 18,655 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 $8,914 at September 30, 2019 and $9,734 at December 31, 2018. Three Months Ended September 30 Nine Months Ended September 30 2019 2018 2019 2018 Net gains (losses) recognized during the period $ 59 $ (38 ) $ 302 $ (102 ) Net gains (losses) recognized during the period on equity securities sold (1 ) (2 ) 133 (4 ) Unrealized gains recognized during the period on equity securities still held at period end 60 0 181 50 Unrealized losses recognized during the period on equity securities still held at period end 0 (36 ) (12 ) (148 ) Other investment securities During the third quarter of 2019, United evaluated all of its cost method investments to determine if certain events or changes in circumstances during the third 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 third 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 $1,568,888 and $1,887,176 at September 30, 2019 and December 31, 2018 respectively.

Loans

Loans	9 Months Ended
	Sep. 30, 2019
Receivables [Abstract]
Loans	3. LOANS Major classes of loans are as follows: September 30, December 31, Commercial, financial and agricultural: Owner-occupied commercial real estate $ 1,221,647 $ 1,291,790 Nonowner-occupied commercial real estate 4,241,682 4,303,613 Other commercial loans 2,107,865 1,957,641 Total commercial, financial & agricultural 7,571,194 7,553,044 Residential real estate 3,644,568 3,501,393 Construction & land development 1,300,881 1,410,468 Consumer: Bankcard 9,532 10,203 Other consumer 1,111,063 954,424 Total gross loans $ 13,637,238 $ 13,429,532 The table above does not include loans held for sale of $412,194 and $249,846 at September 30, 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 balances in the table above include previously acquired impaired loans with a recorded investment of $103,017 or less th an Activity for the accretable yield for the first nine months of 2019 follows: Accretable yield at the beginning of the period $ 26,289 Accretion (including cash recoveries) (8,303 ) Additions 0 Net reclassifications to accretable from non-accretable 8,746 Disposals (including maturities, foreclosures, and charge-offs) (4,649 ) Accretable yield at the end of the period $ 22,083 United’s subsidiary bank has made loans to the directors and officers of United and its subsidiaries, and to their affiliates. The aggregate dollar amount of these loans was $45,800 and $93,282 at September 30, 2019 and December 31, 2018, respectively.

Credit Quality

Credit Quality	9 Months Ended
	Sep. 30, 2019
Text Block [Abstract]
Credit Quality	4. 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 September 30, 2019, United had TDRs of $60,559 as compared to $59,425 as of December 31, 2018. Of the $60,559 aggregate balance of TDRs at September 30, 2019, $50,757 was on nonaccrual and $1,115 were 30-89 there was a commitment to lend additional funds of $293 to one debtor owing receivables whose terms have been modified in TDRs. During the third quarter of 2019, $24 was advanced to this debtor under a loan that had been previously modified . 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 three months ended September 30, 2019 and 2018, segregated by class of loans: Troubled Debt Restructurings For the Three Months Ended September 30, 2019 September 30, 2018 Number of Pre- Modification Post- Number of Pre- Modification Post- Commercial real estate: Owner-occupied 1 $ 1,030 $ 1,030 0 $ 0 $ 0 Nonowner-occupied 0 0 0 0 0 0 Other commercial 1 5,137 5,076 5 7,420 7,364 Residential real estate 0 0 0 1 272 272 Construction & land development 0 0 0 0 0 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 0 0 0 0 0 0 Total 2 $ 6,167 $ 6,106 6 $ 7,692 $ 7,636 The following table sets forth United’s troubled debt restructurings that have been restructured during the nine months ended September 30, 2019 and 2018, segregated by class of loans: Troubled Debt Restructurings For the Nine Months Ended September 30, 2019 September 30, 2018 Number of Pre- Modification Post- Number of Pre- Modification Post- Commercial real estate: Owner-occupied 2 $ 1,179 $ 1,179 0 $ 0 $ 0 Nonowner-occupied 0 0 0 0 0 0 Other commercial 3 5,962 5,849 9 16,992 16,890 Residential real estate 3 2,258 2,022 3 7,225 7,225 Construction & land development 3 2,266 2,214 0 0 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 0 0 0 0 0 0 Total 11 $ 11,665 $ 11,264 12 $ 24,217 $ 24,115 During the third quarter of 2019, $6,106 of restructured loans were modified by a change in terms. For the first nine months of 2019, $246 thousand of restructured loans were modified by an interest rate reduction and $11,018 of restructured loans were modified by a change in terms. During the third quarter and first nine months of 2018, $7,636 and $24,115 of restructured loans were modified by a change in loan terms. In some instances, the post-modification balance on the restructured loans is larger than the pre-modification The following table presents troubled debt restructurings, by class of loan, that were restructured during the twelve-month period ended September 30, 2019 and had charge-offs during the three and Three September 30, 2019 Nine Months Ended 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 1 534 2 1,477 Residential real estate 0 0 0 0 Construction & land development 0 0 0 0 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total 1 $ 534 2 $ 1,477 The following table presents troubled debt restructurings, by class of loan, that had charge-offs during the three months and nine months ended September 30, 2018. Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 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 1 622 1 622 Residential real estate 0 0 0 0 Construction & land development 0 0 0 0 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total 1 $ 622 1 $ 622 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 September 30, 2019 30-89 90 Days or Total Past Current & Total Financing Recorded Commercial real estate: Owner-occupied $ 17,635 $ 13,463 $ 31,098 $ 1,190,549 $ 1,221,647 $ 1,105 Nonowner-occupied 14,171 19,342 33,513 4,208,169 4,241,682 471 Other commercial 11,446 53,250 64,696 2,043,169 2,107,865 533 Residential real estate 33,863 27,155 61,018 3,583,550 3,644,568 6,248 Construction & land development 5,299 16,024 21,323 1,279,558 1,300,881 478 Consumer: Bankcard 303 155 458 9,074 9,532 155 Other consumer 8,959 1,092 10,051 1,101,012 1,111,063 850 Total $ 91,676 $ 130,481 $ 222,157 $ 13,415,081 $ 13,637,238 $ 9,840 (1) Other includes loans with a recorded investment of $103,017 acquired and accounted for under ASC Topic 310-30 Age Analysis of Past Due Loans As of December 31, 2018 30-89 Days 90 Days or 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 September 30, 2019 December 31, 2018 Commercial real estate: Owner-occupied $ 12,358 $ 17,113 Nonowner-occupied 18,871 16,921 Other commercial 52,717 43,190 Residential real estate 20,907 21,137 Construction & land development 15,546 18,732 Consumer: Bankcard 0 0 Other consumer 242 350 Total $ 120,641 $ 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 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 mitigants. For some substandard loans, the likelihood of full collection of interest and principal may be in doubt and thus, placed on nonaccrual. For loans with a consumer credit exposure, loans that are 90 days or more past due or that have been placed on nonaccrual 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 Corporate Credit Exposure As of September 30, 2019 Commercial Real Estate Other Construction & Owner- Nonowner- Grade: Pass $ 1,147,536 $ 4,141,992 $ 1,964,260 $ 1,221,350 Special mention 20,588 27,493 62,015 10,105 Substandard 53,164 72,197 81,320 69,426 Doubtful 359 0 270 0 Total $ 1,221,647 $ 4,241,682 $ 2,107,865 $ 1,300,881 As of December 31, 2018 Commercial Real Estate Other Construction & Owner- Nonowner- 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 Consumer Credit Exposure As of September 30, 2019 Residential Bankcard Other Grade: Pass $ 3,596,942 $ 9,073 $ 1,100,971 Special mention 9,776 304 8,962 Substandard 37,850 155 1,130 Doubtful 0 0 0 Total $ 3,644,568 $ 9,532 $ 1,111,063 As of December 31, 2018 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 days or more) is noted or there are subsequent events that impact repayment probability (i.e. negative financial trends, bankruptcy filings, eminent foreclosure proceedings, etc.). Impairment is evaluated in total for smaller-balance loans of a similar nature and on an individual loan basis for other loans. 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. Impaired loans, or portions thereof, are charged off when deemed uncollectible. The following table sets forth United’s impaired loans information, by class of loans: Impaired Loans September 30, 2019 December 31, 2018 Recorded Unpaid Related Recorded Unpaid Related With no related allowance recorded: Commercial real estate: Owner-occupied $ 68,541 $ 70,625 $ 0 $ 63,633 $ 63,798 $ 0 Nonowner-occupied 45,039 45,232 0 98,845 98,904 0 Other commercial 59,855 67,441 0 40,291 50,459 0 Residential real estate 31,992 33,864 0 28,207 29,279 0 Construction & land development 29,900 35,825 0 37,174 40,459 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 31 31 0 27 27 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 1,066 $ 1,066 $ 25 $ 10,004 $ 10,004 $ 2,542 Nonowner-occupied 13,515 13,623 1,900 15,720 15,720 2,715 Other commercial 40,866 43,250 10,491 61,266 62,812 17,581 Residential real estate 6,080 6,081 433 19,623 22,064 3,265 Construction & land development 14,877 16,927 1,937 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 $ 69,607 $ 71,691 $ 25 $ 73,637 $ 73,802 $ 2,542 Nonowner-occupied 58,554 58,855 1,900 114,565 114,624 2,715 Other commercial 100,721 110,691 10,491 101,557 113,271 17,581 Residential real estate 38,072 39,945 433 47,830 51,343 3,265 Construction & land development 44,777 52,752 1,937 51,916 59,905 2,254 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 31 31 0 27 27 0 Impaired Loans For the Three Months Ended September 30, 2019 September 30, 2018 Average Interest Average Interest With no related allowance recorded: Commercial real estate: Owner-occupied $ 70,245 $ 425 $ 65,625 $ 365 Nonowner-occupied 47,633 261 99,005 311 Other commercial 61,488 257 56,489 313 Residential real estate 33,482 146 28,753 144 Construction & land development 33,384 193 41,036 278 Consumer: Bankcard 0 0 0 0 Other consumer 31 0 23 0 Impaired Loans For the Three Months Ended September 30, 2019 September 30, 2018 Average Interest Average Interest With an allowance recorded: Commercial real estate: Owner-occupied $ 3,004 $ 0 $ 7,378 $ 6 Nonowner-occupied 11,943 63 12,465 189 Other commercial 38,016 11 47,563 305 Residential real estate 9,047 9 14,975 57 Construction & land development 14,481 32 9,408 20 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 73,249 $ 425 $ 73,003 $ 371 Nonowner-occupied 59,576 324 111,470 500 Other commercial 99,504 268 104,052 618 Residential real estate 42,529 155 43,728 201 Construction & land development 47,865 225 50,444 298 Consumer: Bankcard 0 0 0 0 Other consumer 31 0 23 0 Impaired Loans For the Nine Months Ended September 30, 2019 September 30, 2018 Average Interest Average Interest With no related allowance recorded: Commercial real estate: Owner-occupied $ 69,547 $ 1,354 $ 69,009 $ 1,101 Nonowner-occupied 60,594 914 105,199 928 Other commercial 55,058 790 55,124 1,020 Residential real estate 32,189 479 27,210 501 Construction & land development 34,403 602 43,464 707 Consumer: Bankcard 0 0 0 0 Other consumer 30 0 29 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 3,830 $ 0 $ 6,876 $ 18 Nonowner-occupied 12,645 192 11,158 251 Other commercial 41,383 139 47,736 380 Residential real estate 11,661 73 13,946 247 Construction & land development 14,567 87 6,944 60 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 73,377 $ 1,354 $ 75,885 $ 1,119 Nonowner-occupied 73,239 1,106 116,357 1,179 Other commercial 96,441 929 102,860 1,400 Residential real estate 43,850 552 41,156 748 Construction & land development 48,970 689 50,408 767 Consumer: Bankcard 0 0 0 0 Other consumer 30 0 29 0 At September 30, 2019 and December 31, 2018, other real estate owned (“OREO”) included in other assets in the Consolidated Balance Sheets was $ 18,367 16,865 value of the assets less estimated selling costs. Any adjustment to the fair value at the date of transfer is charged against the allowance for loan losses. Any subsequent valuation ​​​​​​​adjustments as well as any costs relating to operating, holding or disposing of the property are recorded in other expense in the period incurred. At September 30, 2019 and December 31, 2018, the recorded investment of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process was $1,454 and $520, respectively.

Allowance for Credit Losses

Allowance for Credit Losses	9 Months Ended
	Sep. 30, 2019
Receivables [Abstract]
Allowance for Credit Losses	5. 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 Loans deemed to be uncollectible are charged against the allowance for loan losses, while recoveries of previously charged-off charge-off charge-off charged-off charge-off For consumer loans, closed-end open-end charged-off. one-to-four open-end closed-end high-loan-to-value charges-off charged-off charged-off For loans acquired through the completion of a transfer, including loans acquired in a business combination, that have evidence of deterioration of credit quality since origination and for which it is probable, at acquisition, that United will be unable to collect all contractually required payment receivable are initially recorded at fair value (as determined by the present value of expected future cash flows) with no valuation allowance. The difference between the undiscounted cash flows expected at acquisition and the investment in the loan, or the “accretable yield,” is recognized as interest income on a level-yield method over the life of the loan. Contractually required payments for interest and principal that exceed the undiscounted cash flows expected at acquisition, or the “nonaccretable difference,” are not recognized as a yield adjustment or as a loss accrual or a valuation allowance. Increases in expected cash flows subsequent to the initial investment are recognized prospectively through adjustment of the yield on the loan over its remaining life. Decreases in expected cash flows are recognized as impairment. Valuation allowances on these impaired loans reflect only losses incurred after the acquisition (meaning the present value of all cash flows expected at acquisition that ultimately are not to be received). For the three and nine months ended September 30, 2019, the amount of provision for loan losses related to loans acquired that have evidence of deterioration of credit quality resulted in provision for loan losses expense of $631 and $3,899, respectively, as compared to a provision for loan losses expense of $924 and $3,004, respectively, for the three and nine months ended September 30, 2018. 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 $1,776 and $1,389 at September 30, 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 loan losses, by portfolio segment, for the periods indicated is summarized as follows: Allowance for Loan Losses For the Three Months Ended September 30, 2019 Commercial Real Estate Construction Allowance for Owner- Nonowner- Other Residential & Land Consumer Estimated Total Allowance for Loan Losses: Beginning balance $ 5,597 $ 6,041 $ 44,709 $ 10,172 $ 6,925 $ 2,723 $ 233 $ 76,400 Charge-offs (1,340 ) (509 ) (2,135 ) (942 ) (0 ) (478 ) (0 ) (5,404 ) Recoveries 145 16 703 69 12 124 0 1,069 Provision 786 1,118 3,464 14 (750 ) 529 (128 ) 5,033 Ending balance $ 5,188 $ 6,666 $ 46,741 $ 9,313 $ 6,187 $ 2,898 $ 105 $ 77,098 Allowance for Loan Losses and Carrying Amount of Loans For the Nine Months Ended September 30, 2019 Commercial Real Estate Construction Allowance for Owner- Nonowner- Other Residential & Land Consumer Estimated Total Allowance for Loan Losses: Beginning balance $ 5,063 $ 6,919 $ 41,341 $ 12,448 $ 7,992 $ 2,695 $ 245 $ 76,703 Charge-offs (7,861 ) (578 ) (6,714 ) (1,692 ) (573 ) (1,988 ) (0 ) (19,406 ) Recoveries 1,763 57 1,420 423 164 528 0 4,355 Provision 6,223 268 10,694 (1,866 ) (1,396 ) 1,663 (140 ) 15,446 Ending balance $ 5,188 $ 6,666 $ 46,741 $ 9,313 $ 6,187 $ 2,898 $ 105 $ 77,098 Allowance for Loan Losses and Carrying Amount of Loans For the Nine Months Ended September 30, 2019 Commercial Real Estate Construction Allowance for Owner- Nonowner- Other Residential & Land Consumer Estimated Total Ending Balance: individually evaluated for impairment $ 25 $ 1,900 $ 10,490 $ 433 $ 1,937 $ 0 $ 0 $ 14,785 Ending Balance: collectively evaluated for impairment $ 5,163 $ 4,766 $ 36,251 $ 8,880 $ 4,250 $ 2,898 $ 105 $ 62,313 Ending Balance: loans acquired with deteriorated credit quality $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Financing receivables: Ending balance $ 1,221,647 $ 4,241,682 $ 2,107,865 $ 3,644,568 $ 1,300,881 $ 1,120,595 $ 0 $ 13,637,238 Ending Balance: individually evaluated for impairment $ 21,913 $ 28,000 $ 57,465 $ 12,628 $ 14,877 $ 0 $ 0 $ 134,883 Ending Balance: collectively evaluated for impairment $ 1,174,677 $ 4,197,103 $ 2,014,164 $ 3,621,758 $ 1,271,072 $ 1,120,564 $ 0 $ 13,399,338 Ending Balance: loans acquired with deteriorated credit quality $ 25,057 $ 16,579 $ 36,236 $ 10,182 $ 14,932 $ 31 $ 0 $ 103,017 Allowance for Loan Losses and Carrying Amount of Loans For the Year Ended December 31, 2018 Commercial Real Estate Construction Allowance for Owner- Nonowner- Other Residential & Land Consumer Estimated Total Allowance for Loan Losses: 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: individually evaluated for impairment $ 2,543 $ 2,715 $ 17,581 $ 3,265 $ 2,254 $ 0 $ 0 $ 28,358 Ending Balance: collectively evaluated for impairment $ 2,520 $ 4,204 $ 23,760 $ 9,183 $ 5,738 $ 2,695 $ 245 $ 48,345 Ending Balance: loans acquired with deteriorated credit quality $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Allowance for Loan Losses and Carrying Amount of Loans For the Year Ended December 31, 2018 Commercial Real Estate Construction Allowance for Owner- Nonowner- Other Residential & Land Consumer Estimated Total 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: individually evaluated for impairment $ 27,599 $ 25,231 $ 72,300 $ 21,998 $ 14,807 $ 0 $ 0 $ 161,935 Ending Balance: collectively evaluated for impairment $ 1,234,919 $ 4,215,060 $ 1,860,085 $ 3,468,356 $ 1,374,840 $ 964,600 $ 0 $ 13,117,860 Ending Balance: loans acquired with deteriorated credit quality $ 29,272 $ 63,322 $ 25,256 $ 11,039 $ 20,821 $ 27 $ 0 $ 149,737

Intangible Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangibles	6. INTANGIBLE ASSETS The following is a summary of intangible assets subject to amortization and those not subject to amortization: September 30, 2019 Community Banking Mortgage Banking Total Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Amortized intangible assets: Core deposit intangible assets $ 98,359 $ (67,754 ) $ 0 $ 0 $ 98,359 $ (67,754 ) Non-amortized George Mason trade name $ 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 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization 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 provides a reconciliation of goodwill: Community Mortgage Total Goodwill at December 31, 2018 $ 1,472,699 $ 5,315 $ 1,478,014 Additions to goodwill 0 0 0 Goodwill at September 30, 2019 $ 1,472,699 $ 5,315 $ 1,478,014 United incurred amortization expense on intangible assets of $1,754 and $5,262 for the quarter and nine months ended September 30, 2019, respectively, and $2,009 and $6,029 for the quarter and nine months ended September 30, 2018, respectively. The following table sets forth the anticipated amortization expense for intangible assets for the years subsequent to 2018: Year Amount 2019 $ 7,016 2020 6,309 2021 5,369 2022 4,581 2023 and thereafter 12,592

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases	7. 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 not United’s operating leases are subject to renewal options under various terms. United’s operating leases have remaining terms of 1 to 14 years, some of which include options to extend leases generally for periods of 5 years. United rents or subleases certain real estate to third parties. Our sublease portfolio consists of operating leases to other organizations for former branch offices. 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 The components of lease expense were as follows: Three Months Ended Nine Months Ended Classification September 30, 2019 September 30, 2019 Operating lease cost Net occupancy expense $ 4,864 $ 14,571 Sublease income Net occupancy expense (197 ) (671 ) Net lease cost $ 4,667 $ 13,900 Supplemental balance sheet information related to leases was as follows: Classification September 30, 2019 Operating lease right-of-use Operating lease right-of-use $ 60,318 Operating lease liabilities Operating lease liabilities $ 63,987 Other information related to leases was as follows: September 30, 2019 Weighted-average remaining lease term: Operating leases 5.01 Weighted-average discount rate: Operating leases 3.23 % Supplemental cash flow information related to leases was as follows: Three Months Ended Nine Months Ended September 30, 2019 September 30, 2019 Cash paid for amounts in the measurement of lease liabilities: Operating cash flows from operating leases $ 4,903 $ 14,552 ROU assets obtained in the exchange for lease liabilties 1,537 5,953 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, 2018, consists of the following as of September 30, 2019 and December 31, 2018: Amount Year As of September 30, 2019 As of December 31, 2018 2019 $ 4,817 $ 18,590 2020 17,415 16,359 2021 14,868 13,850 2022 11,206 10,269 2023 8,431 7,600 Thereafter 12,798 10,640 Total lease payments 69,535 77,308 Less: imputed interest (5,548 ) (0 ) Total $ 63,987 $ 77,308

Short-Term Borrowings

Short-Term Borrowings	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Short-Term Borrowings	8. SHORT-TERM BORROWINGS Federal funds purchased and securities sold under agreements to repurchase are 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. 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. At September 30, 2019, United did not have any federal funds purchased while total securities sold under agreements to repurchase (REPOs) were $129,966. The securities sold under agreements to repurchase were accounted for as collateralized financial transactions. They were recorded at the amounts at which the securities were acquired or sold plus accrued interest. United has a $20,000 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 will be renewable on a 360-day

Long-Term Borrowings

Long-Term Borrowings	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Long-Term Borrowings	9. 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 September 30, 2019, United had an unused borrowing amount of approximately $3,894,693 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 September 30, 2019, $1,672,448 of FHLB advances with a weighted-average interest rate of 2.11% are scheduled to mature within the next six years. Overnight funds of $200,000 with an interest rate of 2.15% are included in the FHLB advances of $1,672,448 at September 30, 2019. The scheduled maturities of these FHLB borrowings are as follows: Year Amount 2019 $ 220,918 2020 591,837 2021 827,636 2022 20,918 2023 and thereafter 11,139 Total $ 1,672,448 At September 30, 2019, United had a total of fourteen statutory business trusts that were formed for the purpose of issuing or participating in pools of trust preferred capital securities (“Capital Securities”) with the proceeds invested in junior subordinated debt securities (“Debentures”) of United. The Debentures, which are subordinate and junior in right of payment to all present and future senior indebtedness and certain other financial obligations of United, are the sole assets of the trusts and United’s payment under the Debentures is the sole source of revenue for the trusts. At September 30, 2019 and December 31, 2018, the outstanding balance of the Debentures was $235,849 and $234,905, respectively, and was included in the category of long-term debt on the Consolidated Balance Sheets entitled “Other long-term borrowings.” The Capital Securities are not included as a component of shareholders’ equity in the Consolidated Balance Sheets. United fully and unconditionally guarantees each individual trust’s obligations under the Capital Securities. 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. In accordance with the fully-phased in “Basel III Capital Rules” as published by United’s primary federal regulator, the Federal Reserve, United is unable to consider the Capital Securities as Tier 1 capital, but rather the Capital Securities are included as a component of United’s Tier 2 capital. United can include the Capital Securities in its Tier 2 capital on a permanent basis.

Commitments and Contingent Liab

Commitments and Contingent Liabilities	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	10. COMMITMENTS AND CONTINGENT LIABILITIES 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 $3,831,866 and $3,826,370 of loan commitments outstanding as of September 30, 2019 and December 31, 2018, respectively, approximately half of which contractually expire within one year. Included in the September 30, 2019 amount are commitments to extend credit of $311,366 related to George Mason’s mortgage loan funding commitments and are of a short-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 September 30, 2019, United had $5,092 of commercial letters of credit outstanding. 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 $136,962 and $141,032 as of September 30, 2019 and December 31, 2018, respectively. In accordance with the Contingencies Topic of the FASB Accounting Standards Codification, 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. 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 $1,173 as of September 30, 2019. 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. 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.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	11. 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 recorded in income in the same period and in the same income statement line as changes in the fair values of the hedged items that relate to the hedged risk(s). 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 recorded as a component of other comprehensive income, net of deferred taxes, and reclassified to earnings when the hedged transaction affects earnings. 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 September 30, 2019 and December 31, 2018. Asset Derivatives September 30, 2019 December 31, 2018 Balance Sheet Location Notional Amount Fair Value Balance Sheet Location Notional Amount Fair Value Derivatives designated as hedging instruments 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 30,969 44 Other assets 21,604 542 Interest rate lock commitments Other assets 262,313 7,030 Other assets 93,955 4,103 Total derivatives not designated as hedging instruments $ 293,282 $ 7,074 $ 115,559 $ 4,645 Total asset derivatives $ 293,282 $ 7,074 $ 201,182 $ 6,504 Liability Derivatives September 30, 2019 December 31, 2018 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 $ 83,328 $ 3,921 Other liabilities $ 0 $ 0 Total derivatives designated as hedging instruments $ 83,328 $ 3,921 $ 0 $ 0 Derivatives not designated as hedging instruments Interest rate swap contracts Other liabilities $ 0 $ 0 Other liabilities $ 0 $ 0 TBA mortgage-backed securities Other liabilities 427,500 835 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 $ 427,500 $ 835 $ 200,281 $ 3,002 Total liability derivatives $ 510,828 $ 4,756 $ 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 included in the carrying amount of the hedged assets/(liabilities) that are designated as a fair value accounting relationship as of September 30, 2019. September 30, 2019 Derivatives in Fair Value Hedging Relationships Location in the Statement Carrying Amount of the Hedged Cumulative Amount Hedging Adjustment the Hedged Cumulative Amount of for any Hedged Assets/ Interest rate swaps Loans, net of unearned income $ 82,470 $ (3,921 ) $ 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 unaudited Consolidated Statements of Income for the three and nine months ended September 30, 2019 and 2018 are presented as follows: Three Months Ended Income Statement Location September 30, September 30, Derivatives in hedging relationships Fair Value Hedges: Interest rate swap contracts Interest income/(expense) $ (187 ) $ (24 ) Total derivatives in hedging relationships $ (187 ) $ (24 ) Derivatives not designated as hedging instruments Forward loan sales commitments Income from Mortgage Banking Activities 44 (197 ) TBA mortgage-backed securities Income from Mortgage Banking Activities 2,641 2,583 Interest rate lock commitments Income from Mortgage Banking Activities 602 (3,262 ) Total derivatives not designated as hedging instruments $ 3,287 $ (876 ) Total derivatives $ 3,100 $ (900 ) Nine Months Ended Income Statement Location September 30, September 30, Derivatives in fair value hedging relationships Fair Value Hedges: Interest rate swap contracts Interest income/(expense) $ (285 ) $ (42 ) Cash Flow Hedges: Forward loan sales commitments Other income 0 0 Total derivatives in hedging relationships $ (285 ) $ (42 ) Derivatives not designated as hedging instruments Forward loan sales commitments Income from Mortgage Banking Activities 916 (12 ) TBA mortgage-backed securities Income from Mortgage Banking Activities 2,167 1,473 Interest rate lock commitments Income from Mortgage Banking Activities 6,472 (1,643 ) Total derivatives not designated as hedging instruments $ 9,555 $ (182 ) Total derivatives $ 9,270 $ (224 )

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	12. FAIR VALUE MEASUREMENTS United determines the fair values of its financial instruments based on the fair value hierarchy established by ASC Topic 820, which also clarifies that fair value of certain assets and liabilities is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. The Fair Value Measurements and Disclosures Topic 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 prices, inputs and 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. 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 bid-ask 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 Trup Cdos as Level 3. Based upon management’s review of the market conditions for Trup Cdos, 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” worthiness prior to the extension of the commitment. Market risk arises if interest rates move adversely between the time of the interest rate lock by the borrower and the sale date of the loan to the investor. To mitigate the effect of the interest rate risk inherent in providing rate lock commitments to borrowers, George Mason enters into either a forward sales contract to sell loans to investors when using best efforts or a TBA mortgage-backed security under mandatory delivery. As TBA mortgage-backed securities are actively traded in an open market, TBA mortgage-backed securities fall into a Level 2 category. The forward sales contracts lock in an interest rate and price for the sale of loans similar to the specific rate lock commitments. Under the Company’s best efforts model, the rate lock commitments to borrowers and the forward sales contracts to investors through to the date the loan closes are undesignated derivatives and accordingly, are marked to fair value through earnings. These valuations fall into a Level 2 category. For residential mortgage loans sold in the mortgage banking segment, the interest rate lock commitments are recorded at fair value which is measured using valuations from investors for loans with similar characteristics adjusted for the Company’s actual sales experience versus the investor’s indicated pricing. These valuations fall into the Level 3 category. The unobservable input is the Company’s historical sales prices. The range of historical sales prices increased the investor’s indicated pricing by a range of 0.25% to 0.59% with a weighted average increase of 0.40%. 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 tables present the balances of financial assets and liabilities measured at fair value on a recurring basis as of September 30, 2019 and December 31, 2018, segregated by the level of the valuation inputs within the fair value hierarchy. Fair Value at September 30, 2019 Using Description Balance as of September 30, 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 $ 64,034 $ 0 $ 64,034 $ 0 State and political subdivisions 238,515 0 238,515 0 Residential mortgage-backed securities Agency 867,281 0 867,281 0 Non-agency 3,995 0 3,995 0 Commercial mortgage-backed securities Agency 621,652 0 621,652 0 Asset-backed securities 279,707 0 279,707 0 Trust preferred collateralized debt obligations 5,069 0 0 5,069 Single issue trust preferred securities 16,544 0 16,544 0 Other corporate securities 355,300 6,673 348,627 0 Total available for sale securities 2,452,097 6,673 2,440,355 5,069 Equity securities: Financial services industry 159 159 0 0 Equity mutual funds (1) 3,965 3,965 0 0 Other equity securities 4,790 4,790 0 0 Total equity securities 8,914 8,914 0 0 407,463 0 0 407,463 Derivative financial assets: Fair Value at September 30, 2019 Using Description Balance as of September 30, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Interest rate swap contracts 0 0 0 0 Forward sales commitments 44 0 44 0 Interest rate lock commitments 7,030 0 0 7,030 Total derivative financial assets 7,074 0 44 7,030 Liabilities Derivative financial liabilities: Interest rate swap contracts 3,921 0 3.921 0 TBA mortgage-backed securities 835 0 835 0 Total derivative financial liabilities 4,756 0 4,756 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 Value at December 31, 2018 Using 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 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 transfers between Level 1 and Level 2 for financial assets and liabilities measured at fair value on a recurring basis during the nine months ended September 30, 2019 and the year ended December 31, 2018. The following table presents additional information about financial assets and liabilities measured at fair value at September 30, 2019 and December 31, 2018 on a recurring basis and for which United has utilized Level 3 inputs to determine fair value: Available for sale Securities Trust preferred collateralized debt obligations September 30, 2019 December 31, Balance, beginning of period $ 5,917 $ 34,269 Total gains or losses (realized/unrealized): Included in earnings (or changes in net assets) (62 ) 28 Included in other comprehensive income (786 ) 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 $ 5,069 $ 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 September 30, 2019 December 31, Balance, beginning of period $ 247,104 $ 263,308 Originations 2,164,410 2,619,454 Sales (2,067,954 ) (2,676,797 ) Total gains or losses during the period recognized in earnings 63,903 68,555 Transfers in and/or out of Level 3 0 (27,416 ) Balance, end of period $ 407,463 $ 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 Derivative Financial Assets Interest Rate Lock Commitments September 30, 2019 December 31, Balance, beginning of period $ 4,103 $ 4,559 Transfers other 2,927 (456 ) Balance, end of period $ 7,030 $ 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 unre​​​​​​​alized 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: Description Three Months Ended September 30, 2019 Three Months Ended September 30, 2018 Assets Loans held for sale Income from mortgage banking activities $ (1,304 ) $ (5,929 ) Description Nine Months Ended September 30, 2019 Nine Months Ended September 30, 2018 Assets Loans held for sale Income from mortgage banking activities $ 5,238 $ (2,838 ) 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: September 30, 2019 December 31, 2018 Description Unpaid Fair Value Fair Value Unpaid Fair Value Fair Value Assets Loans held for sale $ 399,341 $ 407,463 $ 8,122 $ 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 : Loans held for sale within the community banking segment that are delivered on a best efforts basis 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 (Level 2). As such, United records any fair value adjustments for these loans held for sale on a nonrecurring basis. No nonrecurring fair value adjustments were recorded on loans held for sale during the nine months ended September 30, 2019. Gains and losses on sale of loans are recorded within income from mortgage banking activities on the Consolidated Statements of Income. Impaired Loans : Loans are designated as impaired when, in the judgment of management based on current information and events, it is probable that all amounts due according to the contractual terms of the loan agreement will not be collected. Impairment is measured based upon the present value of expected future cash flows from the loan discounted at the loan’s effective rate and the loan’s observable market price or the fair value of collateral, if the loan is collateral dependent. Fair value is measured using a market approach based on the value of the collateral securing the loans. Collateral may be in the form of real estate or business assets including equipment, inventory, and accounts receivable. The vast majority of the collateral is real estate. The value of real estate collateral is determined utilizing an appraisal conducted by an independent, licensed appraiser outside of the Company using comparable property sales (Level 2). However, if the collateral is a house or building in the process of construction or if an appraisal of the real estate property is over two years old, then the fair value is considered Level 3. The value of business equipment is based upon an outside appraisal if deemed significant, or the net book value on the applicable business’ financial statements if not considered significant using observable market data. Likewise, values for inventory and accounts receivables collateral are based on financial statement balances or aging reports (Level 3). For impaired loans, a specific reserve is established through the Allowance for Loan Losses, if necessary, by estimating the fair value of the underlying collateral on a nonrecurring basis. Any fair value adjustments are recorded in the period incurred as provision for credit losses expense on the Consolidated Statements of Income. OREO bi-annual Intangible Assets: No The following table summarizes United’s financial assets that were measured at fair value on a nonrecurring basis during the period: Description Carrying value at September 30, 2019 Balance as of September 30, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) YTD Gains (Losses) Assets Loans held for sale $ 4,731 $ 0 $ 4,731 $ 0 $ (4 ) Impaired Loans 76,404 0 69,560 6,844 2,795 OREO 18,367 0 18,291 76 (1,453 ) Description Carrying value at December 31, 2018 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) YTD Gains (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 Deposits Short-term Borrowings: Long-term Borrowings: Summary of Fair Values for All Financial Instruments The estimated fair values of United’s financial instruments, including those measured at amortized cost on the balance sheet, are summarized below: Fair Value Measurements Carrying Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) September 30, 2019 Cash and cash equivalents $ 976,154 $ 976,154 $ 0 $ 976,154 $ 0 Securities available for sale 2,452,097 2,452,097 6,673 2,440,355 5,069 Securities held to maturity 1,471 1,472 0 452 1,020 Equity securities 8,914 8,914 8,914 0 0 Other securities 210,830 200,288 0 0 200,288 Loans held for sale 412,194 412,194 0 4,731 407,463 Net l 13,556,427 13,051,670 0 0 13,051,670 Derivative financial assets 7,074 7,074 0 44 7,030 Deposits 14,095,411 14,071,344 0 14,071,344 0 Short-term borrowings 329,966 329,966 0 329,966 0 Long-term borrowings 1,708,297 1,688,577 0 1,688,577 0 Derivative financial liabilities 4,756 4,756 0 4,756 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 l 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

Stock Based Compensation

Stock Based Compensation	9 Months Ended
	Sep. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Based Compensation	13. 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 Compensation expense of $1,194 and $3,505 related to the nonvested awards under United’s Long-Term Incentive Plans was incurred for the third quarter and first nine months of 2019, respectively, as compared to the compensation expense of $1,024 and $3,016 related to the nonvested awards under United’s Long-Term Incentive Plans incurred for the third quarter and first nine months of 2018, respectively. Compensation expense was included in employee compensation in the unaudited Consolidated Statements of Income. 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) years. A summary of activity under United’s stock option plans as of September 30, 2019, and the changes during the first nine months of 2019 are presented below: Nine Months Ended September 30, 2019 Weighted Average Aggregate Remaining Intrinsic Contractual Exercise Shares Value Term (Yrs.) Price Outstanding at January 1, 2019 1,730,389 $ 32.43 Granted 240,205 38.49 Exercised (98,613 ) 22.86 Forfeited or expired (116,561 ) 25.20 Outstanding at September 30, 2019 1,755,420 $ 8,251,397 5.8 $ 34.27 Exercisable at September 30, 2019 1,165,233 $ 8,074,702 4.4 $ 31.71 The following table summarizes the status of United’s nonvested stock option awards during the first nine months of 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 (210,876 ) 7.74 Forfeited or expired (14,814 ) 7.55 Nonvested at September 30, 2019 590,187 $ 7.62 During the nine months ended September 30, 2019 and 2018, 98,613 and 60,161 shares, respectively, were issued in connection with stock option exercises. All shares issued in connection with stock option exercises for the nine months ended September 30, 2019 and 2018 were issued from authorized and unissued stock. The total intrinsic value of options exercised under the Plans during the nine months ended September 30, 2019 and 2018 was $1,463 and $851 respectively. Restricted Stock Under the 2011 LTI Plan, United may award restricted common shares to key employees and non-employee four The following summarizes the changes to United’s restricted common shares for the period ended September 30, 2019: Number of Shares Weighted-Average Grant Date Fair Value Per Share Outstanding at January 1, 2019 199,303 $ 39.67 Granted 126,427 38.49 Vested (73,535 ) 39.28 Forfeited (4,149 ) 39.08 Outstanding at September 30, 2019 248,046 $ 39.19

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2019
Retirement Benefits [Abstract]
Employee Benefit Plans	14. 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 are intended to provide not only for benefits attributed to service to date, but also for those expected to be earned in the future. During the first nine months of 2018, United made discretionary contributions of $7,000. No discretionary contributions were made during the first nine months of 2019. 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 had taken similar steps. The amendment provides that employees hired on or after October 1, 2007, will not be eligible to participate in the Plan. However, new employees will 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. Included in accumulated other comprehensive income at December 31, 2018 are unrecognized actuarial losses of $55,535 ($42,595 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, 2019 is $4,744 ($3,639 net of tax). Net periodic pension cost for the three and nine months ended September 30, 2019 and 2018 included the following components: Three Months Ended September 30 Nine Months Ended September 30 2019 2018 2019 2018 Service cost $ 567 $ 673 $ 1,683 $ 1,997 Interest cost 1,474 1,324 4,375 3,927 Expected return on plan assets (2,382 ) (2,578 ) (7,068 ) (7,651 ) Recognized net actuarial loss 1,198 1,174 3,553 3,485 Net periodic pension (benefit) cost $ 857 $ 593 $ 2,543 $ 1,758 Weighted-Average Assumptions: Discount rate 4.52 % 3.83 % 4.52 % 3.83 % Expected return on assets 7.00 % 7.00 % 7.00 % 7.00 % Rate of compensation increase (prior to age 45) 3.50 % 3.50 % 3.50 % 3.50 % Rate of compensation increase 3.00 % 3.00 % 3.00 % 3.00 %

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	15. INCOME TAXES United records a liability for uncertain income tax positions based on a recognition threshold of more-likely-than-not, As of September 30, 2019 and 2018, the total amount of accrued interest related to uncertain tax positions was $641 and $649, respectively. United accounts for interest and penalties related to uncertain tax positions as part of its provision for federal and state income taxes. 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. United’s effective tax rate was 20.50% and 20.86% for the third quarter and first nine months of 2019 and 21.77% and 22.25% for the third quarter and first nine months of 2018.

Comprehensive Income

Comprehensive Income	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Comprehensive Income	16. COMPREHENSIVE INCOME The components of total comprehensive income for the three and nine months ended September 30, 2019 and 2018 are as follows: Three Months Ended Nine Months Ended September 30 September 30 2019 2018 2019 2018 Net Income $ 65,965 $ 64,412 $ 196,814 $ 192,392 Available for sale (“AFS”) securities: AFS securities with OTTI charges during the period (272 ) 0 (347 ) 0 Related income tax effect 64 0 81 0 Less: OTTI charges recognized in net income 9 0 84 0 Related income tax benefit (3 ) 0 (20 ) 0 Reclassification of previous noncredit OTTI to credit OTTI 0 0 2,188 0 Related income tax benefit (0 ) 0 (510 ) 0 Net unrealized (losses) gains on AFS securities with OTTI (202 ) 0 1,476 0 AFS securities – all other: Change in net unrealized gain on AFS securities arising during the period 5,070 (9,995 ) 48,014 (42,696 ) Related income tax effect (1,181 ) 2,329 (11,187 ) 11,621 Net reclassification adjustment for (gains) losses included in net income (66 ) 114 152 290 Related income tax expense (benefit) 16 (27 ) (35 ) (68 ) 3,839 (7,579 ) 36,944 (30,853 ) Net effect of AFS securities on other comprehensive income 3,637 (7,579 ) 38,420 (30,853 ) Held to maturity (“HTM”) securities: Accretion on the unrealized loss for securities transferred from AFS to the HTM 0 2 0 6 Related income tax expense (0 ) (0 ) (0 ) (2 ) Net effect of HTM securities on other comprehensive income 0 2 0 4 Pension plan: Recognized net actuarial loss 1,198 1,174 3,553 3,485 Related income tax benefit (249 ) (256 ) (785 ) (782 ) Net effect of change in pension plan asset on other comprehensive income 949 918 2,768 2,703 Total change in other comprehensive income 4,586 (6,659 ) 41,188 (28,146 ) Total Comprehensive Income $ 70,551 $ 57,753 $ 238,002 $ 164,246 The components of accumulated other comprehensive income for the nine months ended September 30, 2019 are as follows: Changes in Accumulated Other Comprehensive Income (AOCI) by Component (a) For the Nine Months Ended September 30, 2019 Unrealized Gains/Losses on AFS Securities Accretion on the unrealized loss for securities transferred from AFS to the HTM Defined Benefit Pension 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 36,625 0 0 36,625 Amounts reclassified from accumulated other comprehensive income 1,795 0 2,768 4,563 Net current-period other comprehensive income, net of tax 38,420 0 2,768 41,188 Balance at September 30, 2019 $ 20,131 $ 0 $ (35,912 ) $ (15,781 ) (a) All amounts are net-of-tax. Reclassifications out of Accumulated Other Comprehensive Income (AOCI) For the Nine Months Ended September 30, 2019 Details about AOCI Components Amount 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 Net investment securities (losses) gains Net reclassification adjustment for losses (gains) included in net income 152 Net investment securities (losses) gains 2,340 Total before tax Related income tax effect (545 ) Tax expense 1,795 Net of tax Pension plan: Recognized net actuarial loss 3,553 (a) 3,553 Total before tax Related income tax effect (785 ) Tax expense 2,768 Net of tax Total reclassifications for the period $ 4,563 (a) This AOCI component is included in the net periodic pension cost (see Note 14, Employee Benefit Plans)

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Earnings Per Share	17. 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: Three Months Ended Nine Months Ended September 30 September 30 2019 2018 2019 2018 Distributed earnings allocated to common stock $ 34,434 $ 35,234 $ 103,711 $ 106,429 Undistributed earnings allocated to common stock 31,378 29,060 92,654 85,617 Net earnings allocated to common shareholders $ 65,812 $ 64,294 $ 196,365 $ 192,046 Average common shares outstanding 101,432,243 103,617,590 101,698,530 104,382,094 Equivalents from stock options 279,497 316,369 268,605 297,782 Average diluted shares outstanding 101,711,740 103,933,959 101,967,135 104,679,876 Earnings per basic common share $ 0.65 $ 0.62 $ 1.93 $ 1.84 Earnings per diluted common share $ 0.65 $ 0.62 $ 1.93 $ 1.83

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	18. VARIABLE INTEREST ENTITIES 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 for the purpose of raising funds that originally qualified for Tier I regulatory capital. As previously discussed, these trusts now are considered Tier II regulatory capital. These trusts, of which several were acquired through bank acquisitions, issued or participated in pools of trust preferred capital securities to third-party investors with the proceeds invested in junior subordinated debt securities of United. The Company, through a small capital contribution, owns 100% of the voting equity shares of each trust. The assets, liabilities, operations, and cash flows of each trust are solely related to the issuance, administration, and repayment of the preferred equity securities held by third-party investors. United fully and unconditionally guarantees the obligations of each trust and is obligated to redeem the junior subordinated debentures upon maturity. United does not consolidate these trusts as it is not the primary beneficiary of these entities because United’s wholly owned and indirect wholly owned statutory trust subsidiaries do not have a controlling financial interest in the VIEs. A controlling financial interest 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. Information related to United’s statutory trusts is presented in the table below: Description Issuance Date Amount of Interest Rate Maturity Date United Statutory Trust III December 17, 2003 $ 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 United, through its banking subsidiary, 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 September 30, 2019 As of December 31, 2018 Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Trust preferred securities $ 258,123 $ 248,918 $ 9,205 $ 257,754 $ 248,741 $ 9,013 (1) Represents investment in VIEs.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Segment Information	19. 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 the 30-day 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 three and nine months ended September 30, 2019 and 2018 is as follows: At and For the Three Months Ended September 30, 2019 Community Mortgage Other Intersegment Eliminations Consolidated Net interest income $ 143,615 $ 203 $ (3,052 ) $ 1,152 $ 141,918 Provision for loans losses 5,033 0 0 0 5,033 Other income 18,696 24,331 87 (890 ) 42,224 Other expense 77,312 20,256 (1,696 ) 262 96,134 Income taxes 16,393 877 (260 ) 0 17,010 Net income (loss) $ 63,573 $ 3,401 $ (1,009 ) $ 0 $ 65,965 Total assets (liabilities) $ 19,593,009 $ 491,832 $ 17,120 $ (350,500 ) $ 19,751,461 Average assets (liabilities) 19,579,180 398,880 16,925 (328,377 ) 19,666,608 At and For the Three Months Ended September 30, 2018 Community Mortgage Other Intersegment Eliminations Consolidated Net interest income $ 149,770 $ 388 $ (3,168 ) $ 1,785 $ 148,775 Provision for loans losses 4,808 0 0 0 4,808 Other income 18,717 16,478 58 (3,567 ) 31,686 Other expense 75,255 17,957 1,885 (1,782 ) 93,315 Income taxes 19,296 (246 ) (1,124 ) 0 17,926 Net income (loss) $ 69,128 $ (845 ) $ (3,871 ) $ 0 $ 64,412 Total assets (liabilities) $ 19,080,734 $ 288,638 $ 12,545 $ (194,274 ) $ 19,187,643 Average assets (liabilities) 18,982,530 303,556 5,468 (243,867 ) 19,047,689 At and For the Nine Months Ended September 30, 2019 Community Mortgage Other Intersegment Eliminations Consolidated Net interest income $ 442,022 $ 369 $ (9,584 ) $ 3,832 $ 436,639 Provision for loans losses 15,446 0 0 0 15,446 Other income 54,746 63,938 342 (5,784 ) 113,242 Other expense 235,610 53,869 (1,773 ) (1,952 ) 285,754 Income taxes 51,266 2,163 (1,562 ) 0 51,867 Net income (loss) $ 194,446 $ 8,275 $ (5,907 ) $ 0 $ 196,814 Total assets (liabilities) $ 19,593,009 $ 491,832 $ 17,120 $ (350,500 ) $ 19,751,461 Average assets (liabilities) 19,410,636 330,668 6,926 (269,306 ) 19,478,924 At and For the Nine Months Ended September 30, 2018 Community Mortgage Other Intersegment Eliminations Consolidated Net interest income $ 444,840 $ 1,028 $ (8,794 ) $ 4,866 $ 441,940 Provision for loans losses 16,190 0 0 0 16,190 Other income 53,952 54,829 (696 ) (9,200 ) 98,885 Other expense 224,240 57,566 (295 ) (4,334 ) 277,177 Income taxes 57,519 (385 ) (2,068 ) 0 55,066 Net income (loss) $ 200,843 $ (1,324 ) $ ) $ 0 $ 192,392 Total assets (liabilities) $ 19,080,734 $ 288,638 $ 12,545 $ (194,274 ) $ 19,187,643 Average assets (liabilities) 18,718,295 284,100 8,043 (240,505 ) 18,769,934

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited consolidated interim financial statements of United Bankshares, Inc. and Subsidiaries (“United” or “the Company”) have been prepared in accordance with accounting principles for interim financial information generally accepted in the United States (GAAP) and with the instructions for Form 10-Q S-X. 10-K. The accompanying consolidated interim financial statements include the accounts of United and its wholly owned subsidiaries. United operates in two business segments: community banking and mortgage banking. All significant intercompany accounts and transactions have been eliminated in the consolidated financial statements. Information is presented in these notes to the unaudited consolidated interim financial statements with dollars expressed in thousands, except per share or unless otherwise noted.
Recent Accounting Pronouncements	New Accounting Standards In April 2019, the Financial Accounting Standards Board (FASB) issued ASU No. 2019-04 In August 2018, the FASB issued ASU No. 2018-14 — 715-20): 2018-14 2018-14 In August 2018, the FASB issued ASU No. 2018-13 2018-13 2018-13 In June 2018, the FASB issued Accounting Standards Update (ASU) No. 2018-07 non-employees non-employee 2018-07 2018-07 In August 2017, the FASB issued ASU No. 2017-12, one-time 2017-12 one-time In July 2017, the FASB issued ASU No. 2017-11, 2017-11 2017-11 In March 2017, the FASB issued ASU No. 2017-08, 310-20): 2017-08 In January 2017, the FASB issued ASU No. 2017-04, 2017-04 2017-04 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 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 the standard using the modified retrospective transition method on January 1, 2019. The Company evaluated and elected the package of practical expedients, which allows for existing leases to be accounted for consistent with

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2019
Summary of Amortized Cost and Estimated Fair Values of Available for Sale Securities	The amortized cost and estimated fair values of securities available for sale are summarized as follows. September 30, 2019 Gross Gross Estimated Cumulative Amortized Unrealized Unrealized Fair OTTI in Cost Gains Losses Value AOCI (1) U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 63,444 $ 591 $ 1 $ 64,034 $ 0 State and political subdivisions 234,552 4,588 625 238,515 0 Residential mortgage-backed securities Agency 853,521 14,493 733 867,281 0 Non-agency 3,533 462 0 3,995 86 Commercial mortgage-backed securities Agency 611,038 11,751 1,137 621,652 0 Asset-backed securities 284,593 0 4,886 279,707 0 Trust preferred collateralized debt obligations 6,130 0 1,061 5,069 661 Single issue trust preferred securities 18,188 172 1,816 16,544 0 Other corporate securities 350,850 4,485 35 355,300 0 Total $ 2,425,849 $ 36,542 $ 10,294 $ 2,452,097 $ 747 December 31, 2018 Gross Gross Estimated Cumulative Amortized Unrealized Unrealized Fair OTTI in Cost Gains Losses Value AOCI (1) U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 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) Non-credit 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 September 30, 2019 and December 31, 2018. Less than 12 months 12 months or longer Fair Unrealized Fair Unrealized Value Losses Value Losses September 30, 2019 U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 1,420 $ 1 $ 0 $ 0 State and political subdivisions 62,394 614 2,946 11 Residential mortgage-backed securities Agency 30,433 101 82,977 632 Non-agency 0 0 0 0 Commercial mortgage-backed securities Agency 145,382 962 54,441 175 Asset-backed securities 243,909 4,084 35,798 802 Trust preferred collateralized debt obligations 2,969 661 2,100 400 Single issue trust preferred securities 0 0 13,332 1,816 Other corporate securities 8,978 35 0 0 Total $ 495,485 $ 6,458 $ 191,594 $ 3,836 Less than 12 months 12 months or longer Fair Unrealized Fair Unrealized Value Losses Value Losses 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. Three Months Ended September 30 Nine Months Ended September 30 2019 2018 2019 2018 Proceeds from sales and calls $ 188,911 $ 109,093 $ 573,674 $ 283,953 Gross realized gains 412 93 1,166 1,314 Gross realized losses 346 207 1,318 1,604
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. Three Months Ended September 30 Nine Months Ended September 30 2019 2018 2019 2018 Balance of cumulative credit losses at beginning of period $ 3,192 $ 3,199 $ 3,138 $ 18,060 Additional credit losses on securities for which OTTI was previously recognized 9 0 63 0 Reductions for securities sold or paid off during the period 0 0 0 (14,861 ) Balance of cumulative credit losses at end of period $ 3,201 $ 3,199 $ 3,201 $ 3,199
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: September 30, 2019 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 25 $ 0 $ 0 $ 25 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 $ 1,471 $ 1 $ 0 $ 1,472 December 31, 2018 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses 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	The fair value of United’s equity securities was $8,914 at September 30, 2019 and $9,734 at December 31, 2018. Three Months Ended September 30 Nine Months Ended September 30 2019 2018 2019 2018 Net gains (losses) recognized during the period $ 59 $ (38 ) $ 302 $ (102 ) Net gains (losses) recognized during the period on equity securities sold (1 ) (2 ) 133 (4 ) Unrealized gains recognized during the period on equity securities still held at period end 60 0 181 50 Unrealized losses recognized during the period on equity securities still held at period end 0 (36 ) (12 ) (148 )
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. September 30, 2019 December 31, 2018 Estimated Estimated Amortized Fair Amortized Fair Cost Value Cost Value Due in one year or less $ 110,865 $ 111,001 $ 77,534 $ 77,266 Due after one year through five years 568,839 576,687 518,975 514,734 Due after five years through ten years 549,442 558,540 483,567 477,135 Due after ten years 1,196,703 1,205,869 1,280,808 1,267,904 Total $ 2,425,849 $ 2,452,097 $ 2,360,884 $ 2,337,039
Held-to-maturity 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. September 30, 2019 December 31, 2018 Estimated Estimated Amortized Fair Amortized Fair Cost Value Cost Value Due in one year or less $ 235 $ 235 $ 7,913 $ 8,005 Due after one year through five years 216 217 1,059 1,061 Due after five years through ten years 0 0 8,030 7,134 Due after ten years 1,020 1,020 2,997 2,455 Total $ 1,471 $ 1,472 $ 19,999 $ 18,655

Loans (Tables)

Loans (Tables)	9 Months Ended
	Sep. 30, 2019
Receivables [Abstract]
Major Classes of Loans	Major classes of loans are as follows: September 30, December 31, Commercial, financial and agricultural: Owner-occupied commercial real estate $ 1,221,647 $ 1,291,790 Nonowner-occupied commercial real estate 4,241,682 4,303,613 Other commercial loans 2,107,865 1,957,641 Total commercial, financial & agricultural 7,571,194 7,553,044 Residential real estate 3,644,568 3,501,393 Construction & land development 1,300,881 1,410,468 Consumer: Bankcard 9,532 10,203 Other consumer 1,111,063 954,424 Total gross loans $ 13,637,238 $ 13,429,532
Activity for Accretable Yield	Activity for the accretable yield for the first nine months of 2019 follows: Accretable yield at the beginning of the period $ 26,289 Accretion (including cash recoveries) (8,303 ) Additions 0 Net reclassifications to accretable from non-accretable 8,746 Disposals (including maturities, foreclosures, and charge-offs) (4,649 ) Accretable yield at the end of the period $ 22,083

Credit Quality (Tables)

Credit Quality (Tables)	9 Months Ended
	Sep. 30, 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 three months ended September 30, 2019 and 2018, segregated by class of loans: Troubled Debt Restructurings For the Three Months Ended September 30, 2019 September 30, 2018 Number of Pre- Modification Post- Number of Pre- Modification Post- Commercial real estate: Owner-occupied 1 $ 1,030 $ 1,030 0 $ 0 $ 0 Nonowner-occupied 0 0 0 0 0 0 Other commercial 1 5,137 5,076 5 7,420 7,364 Residential real estate 0 0 0 1 272 272 Construction & land development 0 0 0 0 0 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 0 0 0 0 0 0 Total 2 $ 6,167 $ 6,106 6 $ 7,692 $ 7,636 The following table sets forth United’s troubled debt restructurings that have been restructured during the nine months ended September 30, 2019 and 2018, segregated by class of loans: Troubled Debt Restructurings For the Nine Months Ended September 30, 2019 September 30, 2018 Number of Pre- Modification Post- Number of Pre- Modification Post- Commercial real estate: Owner-occupied 2 $ 1,179 $ 1,179 0 $ 0 $ 0 Nonowner-occupied 0 0 0 0 0 0 Other commercial 3 5,962 5,849 9 16,992 16,890 Residential real estate 3 2,258 2,022 3 7,225 7,225 Construction & land development 3 2,266 2,214 0 0 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 0 0 0 0 0 0 Total 11 $ 11,665 $ 11,264 12 $ 24,217 $ 24,115
Schedule of Charged-off Troubled Debt Restructurings on Financing Receivables	The following table presents troubled debt restructurings, by class of loan, that were restructured during the twelve-month period ended September 30, 2019 and had charge-offs during the three and Three September 30, 2019 Nine Months Ended 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 1 534 2 1,477 Residential real estate 0 0 0 0 Construction & land development 0 0 0 0 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total 1 $ 534 2 $ 1,477 The following table presents troubled debt restructurings, by class of loan, that had charge-offs during the three months and nine months ended September 30, 2018. Three Months Ended September 30, 2018 Nine Months Ended September 30, 2018 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 1 622 1 622 Residential real estate 0 0 0 0 Construction & land development 0 0 0 0 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total 1 $ 622 1 $ 622
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 September 30, 2019 30-89 90 Days or Total Past Current & Total Financing Recorded Commercial real estate: Owner-occupied $ 17,635 $ 13,463 $ 31,098 $ 1,190,549 $ 1,221,647 $ 1,105 Nonowner-occupied 14,171 19,342 33,513 4,208,169 4,241,682 471 Other commercial 11,446 53,250 64,696 2,043,169 2,107,865 533 Residential real estate 33,863 27,155 61,018 3,583,550 3,644,568 6,248 Construction & land development 5,299 16,024 21,323 1,279,558 1,300,881 478 Consumer: Bankcard 303 155 458 9,074 9,532 155 Other consumer 8,959 1,092 10,051 1,101,012 1,111,063 850 Total $ 91,676 $ 130,481 $ 222,157 $ 13,415,081 $ 13,637,238 $ 9,840 (1) Other includes loans with a recorded investment of $103,017 acquired and accounted for under ASC Topic 310-30 Age Analysis of Past Due Loans As of December 31, 2018 30-89 Days 90 Days or 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 September 30, 2019 December 31, 2018 Commercial real estate: Owner-occupied $ 12,358 $ 17,113 Nonowner-occupied 18,871 16,921 Other commercial 52,717 43,190 Residential real estate 20,907 21,137 Construction & land development 15,546 18,732 Consumer: Bankcard 0 0 Other consumer 242 350 Total $ 120,641 $ 117,443
Schedule of Credit Quality Indicators Information, by Class of Loans	Credit Quality Indicators Corporate Credit Exposure As of September 30, 2019 Commercial Real Estate Other Construction & Owner- Nonowner- Grade: Pass $ 1,147,536 $ 4,141,992 $ 1,964,260 $ 1,221,350 Special mention 20,588 27,493 62,015 10,105 Substandard 53,164 72,197 81,320 69,426 Doubtful 359 0 270 0 Total $ 1,221,647 $ 4,241,682 $ 2,107,865 $ 1,300,881 As of December 31, 2018 Commercial Real Estate Other Construction & Owner- Nonowner- 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 Consumer Credit Exposure As of September 30, 2019 Residential Bankcard Other Grade: Pass $ 3,596,942 $ 9,073 $ 1,100,971 Special mention 9,776 304 8,962 Substandard 37,850 155 1,130 Doubtful 0 0 0 Total $ 3,644,568 $ 9,532 $ 1,111,063 As of December 31, 2018 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 sets forth United’s impaired loans information, by class of loans: Impaired Loans September 30, 2019 December 31, 2018 Recorded Unpaid Related Recorded Unpaid Related With no related allowance recorded: Commercial real estate: Owner-occupied $ 68,541 $ 70,625 $ 0 $ 63,633 $ 63,798 $ 0 Nonowner-occupied 45,039 45,232 0 98,845 98,904 0 Other commercial 59,855 67,441 0 40,291 50,459 0 Residential real estate 31,992 33,864 0 28,207 29,279 0 Construction & land development 29,900 35,825 0 37,174 40,459 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 31 31 0 27 27 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 1,066 $ 1,066 $ 25 $ 10,004 $ 10,004 $ 2,542 Nonowner-occupied 13,515 13,623 1,900 15,720 15,720 2,715 Other commercial 40,866 43,250 10,491 61,266 62,812 17,581 Residential real estate 6,080 6,081 433 19,623 22,064 3,265 Construction & land development 14,877 16,927 1,937 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 $ 69,607 $ 71,691 $ 25 $ 73,637 $ 73,802 $ 2,542 Nonowner-occupied 58,554 58,855 1,900 114,565 114,624 2,715 Other commercial 100,721 110,691 10,491 101,557 113,271 17,581 Residential real estate 38,072 39,945 433 47,830 51,343 3,265 Construction & land development 44,777 52,752 1,937 51,916 59,905 2,254 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 31 31 0 27 27 0 Impaired Loans For the Three Months Ended September 30, 2019 September 30, 2018 Average Interest Average Interest With no related allowance recorded: Commercial real estate: Owner-occupied $ 70,245 $ 425 $ 65,625 $ 365 Nonowner-occupied 47,633 261 99,005 311 Other commercial 61,488 257 56,489 313 Residential real estate 33,482 146 28,753 144 Construction & land development 33,384 193 41,036 278 Consumer: Bankcard 0 0 0 0 Other consumer 31 0 23 0 Impaired Loans For the Three Months Ended September 30, 2019 September 30, 2018 Average Interest Average Interest With an allowance recorded: Commercial real estate: Owner-occupied $ 3,004 $ 0 $ 7,378 $ 6 Nonowner-occupied 11,943 63 12,465 189 Other commercial 38,016 11 47,563 305 Residential real estate 9,047 9 14,975 57 Construction & land development 14,481 32 9,408 20 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 73,249 $ 425 $ 73,003 $ 371 Nonowner-occupied 59,576 324 111,470 500 Other commercial 99,504 268 104,052 618 Residential real estate 42,529 155 43,728 201 Construction & land development 47,865 225 50,444 298 Consumer: Bankcard 0 0 0 0 Other consumer 31 0 23 0 Impaired Loans For the Nine Months Ended September 30, 2019 September 30, 2018 Average Interest Average Interest With no related allowance recorded: Commercial real estate: Owner-occupied $ 69,547 $ 1,354 $ 69,009 $ 1,101 Nonowner-occupied 60,594 914 105,199 928 Other commercial 55,058 790 55,124 1,020 Residential real estate 32,189 479 27,210 501 Construction & land development 34,403 602 43,464 707 Consumer: Bankcard 0 0 0 0 Other consumer 30 0 29 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 3,830 $ 0 $ 6,876 $ 18 Nonowner-occupied 12,645 192 11,158 251 Other commercial 41,383 139 47,736 380 Residential real estate 11,661 73 13,946 247 Construction & land development 14,567 87 6,944 60 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 73,377 $ 1,354 $ 75,885 $ 1,119 Nonowner-occupied 73,239 1,106 116,357 1,179 Other commercial 96,441 929 102,860 1,400 Residential real estate 43,850 552 41,156 748 Construction & land development 48,970 689 50,408 767 Consumer: Bankcard 0 0 0 0 Other consumer 30 0 29 0

Allowance for Credit Losses (Ta

Allowance for Credit Losses (Tables)	9 Months Ended
	Sep. 30, 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 periods indicated is summarized as follows: Allowance for Loan Losses For the Three Months Ended September 30, 2019 Commercial Real Estate Construction Allowance for Owner- Nonowner- Other Residential & Land Consumer Estimated Total Allowance for Loan Losses: Beginning balance $ 5,597 $ 6,041 $ 44,709 $ 10,172 $ 6,925 $ 2,723 $ 233 $ 76,400 Charge-offs (1,340 ) (509 ) (2,135 ) (942 ) (0 ) (478 ) (0 ) (5,404 ) Recoveries 145 16 703 69 12 124 0 1,069 Provision 786 1,118 3,464 14 (750 ) 529 (128 ) 5,033 Ending balance $ 5,188 $ 6,666 $ 46,741 $ 9,313 $ 6,187 $ 2,898 $ 105 $ 77,098 Allowance for Loan Losses and Carrying Amount of Loans For the Nine Months Ended September 30, 2019 Commercial Real Estate Construction Allowance for Owner- Nonowner- Other Residential & Land Consumer Estimated Total Allowance for Loan Losses: Beginning balance $ 5,063 $ 6,919 $ 41,341 $ 12,448 $ 7,992 $ 2,695 $ 245 $ 76,703 Charge-offs (7,861 ) (578 ) (6,714 ) (1,692 ) (573 ) (1,988 ) (0 ) (19,406 ) Recoveries 1,763 57 1,420 423 164 528 0 4,355 Provision 6,223 268 10,694 (1,866 ) (1,396 ) 1,663 (140 ) 15,446 Ending balance $ 5,188 $ 6,666 $ 46,741 $ 9,313 $ 6,187 $ 2,898 $ 105 $ 77,098 Allowance for Loan Losses and Carrying Amount of Loans For the Nine Months Ended September 30, 2019 Commercial Real Estate Construction Allowance for Owner- Nonowner- Other Residential & Land Consumer Estimated Total Ending Balance: individually evaluated for impairment $ 25 $ 1,900 $ 10,490 $ 433 $ 1,937 $ 0 $ 0 $ 14,785 Ending Balance: collectively evaluated for impairment $ 5,163 $ 4,766 $ 36,251 $ 8,880 $ 4,250 $ 2,898 $ 105 $ 62,313 Ending Balance: loans acquired with deteriorated credit quality $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Financing receivables: Ending balance $ 1,221,647 $ 4,241,682 $ 2,107,865 $ 3,644,568 $ 1,300,881 $ 1,120,595 $ 0 $ 13,637,238 Ending Balance: individually evaluated for impairment $ 21,913 $ 28,000 $ 57,465 $ 12,628 $ 14,877 $ 0 $ 0 $ 134,883 Ending Balance: collectively evaluated for impairment $ 1,174,677 $ 4,197,103 $ 2,014,164 $ 3,621,758 $ 1,271,072 $ 1,120,564 $ 0 $ 13,399,338 Ending Balance: loans acquired with deteriorated credit quality $ 25,057 $ 16,579 $ 36,236 $ 10,182 $ 14,932 $ 31 $ 0 $ 103,017 Allowance for Loan Losses and Carrying Amount of Loans For the Year Ended December 31, 2018 Commercial Real Estate Construction Allowance for Owner- Nonowner- Other Residential & Land Consumer Estimated Total Allowance for Loan Losses: 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: individually evaluated for impairment $ 2,543 $ 2,715 $ 17,581 $ 3,265 $ 2,254 $ 0 $ 0 $ 28,358 Ending Balance: collectively evaluated for impairment $ 2,520 $ 4,204 $ 23,760 $ 9,183 $ 5,738 $ 2,695 $ 245 $ 48,345 Ending Balance: loans acquired with deteriorated credit quality $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Allowance for Loan Losses and Carrying Amount of Loans For the Year Ended December 31, 2018 Commercial Real Estate Construction Allowance for Owner- Nonowner- Other Residential & Land Consumer Estimated Total 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: individually evaluated for impairment $ 27,599 $ 25,231 $ 72,300 $ 21,998 $ 14,807 $ 0 $ 0 $ 161,935 Ending Balance: collectively evaluated for impairment $ 1,234,919 $ 4,215,060 $ 1,860,085 $ 3,468,356 $ 1,374,840 $ 964,600 $ 0 $ 13,117,860 Ending Balance: loans acquired with deteriorated credit quality $ 29,272 $ 63,322 $ 25,256 $ 11,039 $ 20,821 $ 27 $ 0 $ 149,737

Intangible Assets (Tables)

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 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: September 30, 2019 Community Banking Mortgage Banking Total Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Amortized intangible assets: Core deposit intangible assets $ 98,359 $ (67,754 ) $ 0 $ 0 $ 98,359 $ (67,754 ) Non-amortized George Mason trade name $ 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 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization 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
Reconciliation of Goodwill	The following table provides a reconciliation of goodwill: Community Mortgage Total Goodwill at December 31, 2018 $ 1,472,699 $ 5,315 $ 1,478,014 Additions to goodwill 0 0 0 Goodwill at September 30, 2019 $ 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 2018: Year Amount 2019 $ 7,016 2020 6,309 2021 5,369 2022 4,581 2023 and thereafter 12,592

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Components of Lease Expense	The components of lease expense were as follows: Three Months Ended Nine Months Ended Classification September 30, 2019 September 30, 2019 Operating lease cost Net occupancy expense $ 4,864 $ 14,571 Sublease income Net occupancy expense (197 ) (671 ) Net lease cost $ 4,667 $ 13,900
Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases was as follows: Classification September 30, 2019 Operating lease right-of-use Operating lease right-of-use $ 60,318 Operating lease liabilities Operating lease liabilities $ 63,987
Other Information Related to Leases	Other information related to leases was as follows: September 30, 2019 Weighted-average remaining lease term: Operating leases 5.01 Weighted-average discount rate: Operating leases 3.23 %
Supplemental Cash Flow Information Related to Leases	Supplemental cash flow information related to leases was as follows: Three Months Ended Nine Months Ended September 30, 2019 September 30, 2019 Cash paid for amounts in the measurement of lease liabilities: Operating cash flows from operating leases $ 4,903 $ 14,552 ROU assets obtained in the exchange for lease liabilties 1,537 5,953
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, 2018, consists of the following as of September 30, 2019 and December 31, 2018: Amount Year As of September 30, 2019 As of December 31, 2018 2019 $ 4,817 $ 18,590 2020 17,415 16,359 2021 14,868 13,850 2022 11,206 10,269 2023 8,431 7,600 Thereafter 12,798 10,640 Total lease payments 69,535 77,308 Less: imputed interest (5,548 ) (0 ) Total $ 63,987 $ 77,308

Long-Term Borrowings (Tables)

Long-Term Borrowings (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule of Maturities of Long-term Borrowings	The scheduled maturities of these FHLB borrowings are as follows: Year Amount 2019 $ 220,918 2020 591,837 2021 827,636 2022 20,918 2023 and thereafter 11,139 Total $ 1,672,448

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2019 and December 31, 2018. Asset Derivatives September 30, 2019 December 31, 2018 Balance Sheet Location Notional Amount Fair Value Balance Sheet Location Notional Amount Fair Value Derivatives designated as hedging instruments 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 30,969 44 Other assets 21,604 542 Interest rate lock commitments Other assets 262,313 7,030 Other assets 93,955 4,103 Total derivatives not designated as hedging instruments $ 293,282 $ 7,074 $ 115,559 $ 4,645 Total asset derivatives $ 293,282 $ 7,074 $ 201,182 $ 6,504 Liability Derivatives September 30, 2019 December 31, 2018 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 $ 83,328 $ 3,921 Other liabilities $ 0 $ 0 Total derivatives designated as hedging instruments $ 83,328 $ 3,921 $ 0 $ 0 Derivatives not designated as hedging instruments Interest rate swap contracts Other liabilities $ 0 $ 0 Other liabilities $ 0 $ 0 TBA mortgage-backed securities Other liabilities 427,500 835 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 $ 427,500 $ 835 $ 200,281 $ 3,002 Total liability derivatives $ 510,828 $ 4,756 $ 200,281 $ 3,002
Summary of Carrying Amount Hedged Assets/(Liabilities)	The following table represents the carrying amount of the hedged assets/(liabilities) and the cumulative amount of fair value hedging adjustment included in the carrying amount of the hedged assets/(liabilities) that are designated as a fair value accounting relationship as of September 30, 2019. September 30, 2019 Derivatives in Fair Value Hedging Relationships Location in the Statement Carrying Amount of the Hedged Cumulative Amount Hedging Adjustment the Hedged Cumulative Amount of for any Hedged Assets/ Interest rate swaps Loans, net of unearned income $ 82,470 $ (3,921 ) $ 0
Schedule of Derivative Financial Instruments on Statement of Income	The effect of United’s derivative financial instruments on its unaudited Consolidated Statements of Income for the three and nine months ended September 30, 2019 and 2018 are presented as follows: Three Months Ended Income Statement Location September 30, September 30, Derivatives in hedging relationships Fair Value Hedges: Interest rate swap contracts Interest income/(expense) $ (187 ) $ (24 ) Total derivatives in hedging relationships $ (187 ) $ (24 ) Derivatives not designated as hedging instruments Forward loan sales commitments Income from Mortgage Banking Activities 44 (197 ) TBA mortgage-backed securities Income from Mortgage Banking Activities 2,641 2,583 Interest rate lock commitments Income from Mortgage Banking Activities 602 (3,262 ) Total derivatives not designated as hedging instruments $ 3,287 $ (876 ) Total derivatives $ 3,100 $ (900 ) Nine Months Ended Income Statement Location September 30, September 30, Derivatives in fair value hedging relationships Fair Value Hedges: Interest rate swap contracts Interest income/(expense) $ (285 ) $ (42 ) Cash Flow Hedges: Forward loan sales commitments Other income 0 0 Total derivatives in hedging relationships $ (285 ) $ (42 ) Derivatives not designated as hedging instruments Forward loan sales commitments Income from Mortgage Banking Activities 916 (12 ) TBA mortgage-backed securities Income from Mortgage Banking Activities 2,167 1,473 Interest rate lock commitments Income from Mortgage Banking Activities 6,472 (1,643 ) Total derivatives not designated as hedging instruments $ 9,555 $ (182 ) Total derivatives $ 9,270 $ (224 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured at Fair Value	The following tables present the balances of financial assets and liabilities measured at fair value on a recurring basis as of September 30, 2019 and December 31, 2018, segregated by the level of the valuation inputs within the fair value hierarchy. Fair Value at September 30, 2019 Using Description Balance as of September 30, 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 $ 64,034 $ 0 $ 64,034 $ 0 State and political subdivisions 238,515 0 238,515 0 Residential mortgage-backed securities Agency 867,281 0 867,281 0 Non-agency 3,995 0 3,995 0 Commercial mortgage-backed securities Agency 621,652 0 621,652 0 Asset-backed securities 279,707 0 279,707 0 Trust preferred collateralized debt obligations 5,069 0 0 5,069 Single issue trust preferred securities 16,544 0 16,544 0 Other corporate securities 355,300 6,673 348,627 0 Total available for sale securities 2,452,097 6,673 2,440,355 5,069 Equity securities: Financial services industry 159 159 0 0 Equity mutual funds (1) 3,965 3,965 0 0 Other equity securities 4,790 4,790 0 0 Total equity securities 8,914 8,914 0 0 407,463 0 0 407,463 Derivative financial assets: Fair Value at September 30, 2019 Using Description Balance as of September 30, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Interest rate swap contracts 0 0 0 0 Forward sales commitments 44 0 44 0 Interest rate lock commitments 7,030 0 0 7,030 Total derivative financial assets 7,074 0 44 7,030 Liabilities Derivative financial liabilities: Interest rate swap contracts 3,921 0 3.921 0 TBA mortgage-backed securities 835 0 835 0 Total derivative financial liabilities 4,756 0 4,756 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 Value at December 31, 2018 Using 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 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 September 30, 2019 and December 31, 2018 on a recurring basis and for which United has utilized Level 3 inputs to determine fair value: Available for sale Securities Trust preferred collateralized debt obligations September 30, 2019 December 31, Balance, beginning of period $ 5,917 $ 34,269 Total gains or losses (realized/unrealized): Included in earnings (or changes in net assets) (62 ) 28 Included in other comprehensive income (786 ) 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 $ 5,069 $ 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 September 30, 2019 December 31, Balance, beginning of period $ 247,104 $ 263,308 Originations 2,164,410 2,619,454 Sales (2,067,954 ) (2,676,797 ) Total gains or losses during the period recognized in earnings 63,903 68,555 Transfers in and/or out of Level 3 0 (27,416 ) Balance, end of period $ 407,463 $ 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 Derivative Financial Assets Interest Rate Lock Commitments September 30, 2019 December 31, Balance, beginning of period $ 4,103 $ 4,559 Transfers other 2,927 (456 ) Balance, end of period $ 7,030 $ 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 unre​​​​​​​alized 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: Description Three Months Ended September 30, 2019 Three Months Ended September 30, 2018 Assets Loans held for sale Income from mortgage banking activities $ (1,304 ) $ (5,929 ) Description Nine Months Ended September 30, 2019 Nine Months Ended September 30, 2018 Assets Loans held for sale Income from mortgage banking activities $ 5,238 $ (2,838 )
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: September 30, 2019 December 31, 2018 Description Unpaid Fair Value Fair Value Unpaid Fair Value Fair Value Assets Loans held for sale $ 399,341 $ 407,463 $ 8,122 $ 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: Description Carrying value at September 30, 2019 Balance as of September 30, Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) YTD Gains (Losses) Assets Loans held for sale $ 4,731 $ 0 $ 4,731 $ 0 $ (4 ) Impaired Loans 76,404 0 69,560 6,844 2,795 OREO 18,367 0 18,291 76 (1,453 ) Description Carrying value at December 31, 2018 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) YTD Gains (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, including those measured at amortized cost on the balance sheet, are summarized below: Fair Value Measurements Carrying Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) September 30, 2019 Cash and cash equivalents $ 976,154 $ 976,154 $ 0 $ 976,154 $ 0 Securities available for sale 2,452,097 2,452,097 6,673 2,440,355 5,069 Securities held to maturity 1,471 1,472 0 452 1,020 Equity securities 8,914 8,914 8,914 0 0 Other securities 210,830 200,288 0 0 200,288 Loans held for sale 412,194 412,194 0 4,731 407,463 Net l 13,556,427 13,051,670 0 0 13,051,670 Derivative financial assets 7,074 7,074 0 44 7,030 Deposits 14,095,411 14,071,344 0 14,071,344 0 Short-term borrowings 329,966 329,966 0 329,966 0 Long-term borrowings 1,708,297 1,688,577 0 1,688,577 0 Derivative financial liabilities 4,756 4,756 0 4,756 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 l 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

Stock Based Compensation (Table

Stock Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Plans	A summary of activity under United’s stock option plans as of September 30, 2019, and the changes during the first nine months of 2019 are presented below: Nine Months Ended September 30, 2019 Weighted Average Aggregate Remaining Intrinsic Contractual Exercise Shares Value Term (Yrs.) Price Outstanding at January 1, 2019 1,730,389 $ 32.43 Granted 240,205 38.49 Exercised (98,613 ) 22.86 Forfeited or expired (116,561 ) 25.20 Outstanding at September 30, 2019 1,755,420 $ 8,251,397 5.8 $ 34.27 Exercisable at September 30, 2019 1,165,233 $ 8,074,702 4.4 $ 31.71
Changes to United's Restricted Common Shares	The following table summarizes the status of United’s nonvested stock option awards during the first nine months of 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 (210,876 ) 7.74 Forfeited or expired (14,814 ) 7.55 Nonvested at September 30, 2019 590,187 $ 7.62
Status of United's Nonvested Stock Option Awards	Number of Shares Weighted-Average Grant Date Fair Value Per Share Outstanding at January 1, 2019 199,303 $ 39.67 Granted 126,427 38.49 Vested (73,535 ) 39.28 Forfeited (4,149 ) 39.08 Outstanding at September 30, 2019 248,046 $ 39.19

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2019
Retirement Benefits [Abstract]
Net Periodic Pension Cost	Net periodic pension cost for the three and nine months ended September 30, 2019 and 2018 included the following components: Three Months Ended September 30 Nine Months Ended September 30 2019 2018 2019 2018 Service cost $ 567 $ 673 $ 1,683 $ 1,997 Interest cost 1,474 1,324 4,375 3,927 Expected return on plan assets (2,382 ) (2,578 ) (7,068 ) (7,651 ) Recognized net actuarial loss 1,198 1,174 3,553 3,485 Net periodic pension (benefit) cost $ 857 $ 593 $ 2,543 $ 1,758 Weighted-Average Assumptions: Discount rate 4.52 % 3.83 % 4.52 % 3.83 % Expected return on assets 7.00 % 7.00 % 7.00 % 7.00 % Rate of compensation increase (prior to age 45) 3.50 % 3.50 % 3.50 % 3.50 % Rate of compensation increase 3.00 % 3.00 % 3.00 % 3.00 %

Comprehensive Income (Tables)

Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Components of Total Comprehensive Income	The components of total comprehensive income for the three and nine months ended September 30, 2019 and 2018 are as follows: Three Months Ended Nine Months Ended September 30 September 30 2019 2018 2019 2018 Net Income $ 65,965 $ 64,412 $ 196,814 $ 192,392 Available for sale (“AFS”) securities: AFS securities with OTTI charges during the period (272 ) 0 (347 ) 0 Related income tax effect 64 0 81 0 Less: OTTI charges recognized in net income 9 0 84 0 Related income tax benefit (3 ) 0 (20 ) 0 Reclassification of previous noncredit OTTI to credit OTTI 0 0 2,188 0 Related income tax benefit (0 ) 0 (510 ) 0 Net unrealized (losses) gains on AFS securities with OTTI (202 ) 0 1,476 0 AFS securities – all other: Change in net unrealized gain on AFS securities arising during the period 5,070 (9,995 ) 48,014 (42,696 ) Related income tax effect (1,181 ) 2,329 (11,187 ) 11,621 Net reclassification adjustment for (gains) losses included in net income (66 ) 114 152 290 Related income tax expense (benefit) 16 (27 ) (35 ) (68 ) 3,839 (7,579 ) 36,944 (30,853 ) Net effect of AFS securities on other comprehensive income 3,637 (7,579 ) 38,420 (30,853 ) Held to maturity (“HTM”) securities: Accretion on the unrealized loss for securities transferred from AFS to the HTM 0 2 0 6 Related income tax expense (0 ) (0 ) (0 ) (2 ) Net effect of HTM securities on other comprehensive income 0 2 0 4 Pension plan: Recognized net actuarial loss 1,198 1,174 3,553 3,485 Related income tax benefit (249 ) (256 ) (785 ) (782 ) Net effect of change in pension plan asset on other comprehensive income 949 918 2,768 2,703 Total change in other comprehensive income 4,586 (6,659 ) 41,188 (28,146 ) Total Comprehensive Income $ 70,551 $ 57,753 $ 238,002 $ 164,246
Components of Accumulated Other Comprehensive Income	The components of accumulated other comprehensive income for the nine months ended September 30, 2019 are as follows: Changes in Accumulated Other Comprehensive Income (AOCI) by Component (a) For the Nine Months Ended September 30, 2019 Unrealized Gains/Losses on AFS Securities Accretion on the unrealized loss for securities transferred from AFS to the HTM Defined Benefit Pension 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 36,625 0 0 36,625 Amounts reclassified from accumulated other comprehensive income 1,795 0 2,768 4,563 Net current-period other comprehensive income, net of tax 38,420 0 2,768 41,188 Balance at September 30, 2019 $ 20,131 $ 0 $ (35,912 ) $ (15,781 ) (a) All amounts are net-of-tax.
Reclassifications Out of Accumulated Other Comprehensive Income	Reclassifications out of Accumulated Other Comprehensive Income (AOCI) For the Nine Months Ended September 30, 2019 Details about AOCI Components Amount 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 Net investment securities (losses) gains Net reclassification adjustment for losses (gains) included in net income 152 Net investment securities (losses) gains 2,340 Total before tax Related income tax effect (545 ) Tax expense 1,795 Net of tax Pension plan: Recognized net actuarial loss 3,553 (a) 3,553 Total before tax Related income tax effect (785 ) Tax expense 2,768 Net of tax Total reclassifications for the period $ 4,563 (a) This AOCI component is included in the net periodic pension cost (see Note 14, Employee Benefit Plans)

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [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: Three Months Ended Nine Months Ended September 30 September 30 2019 2018 2019 2018 Distributed earnings allocated to common stock $ 34,434 $ 35,234 $ 103,711 $ 106,429 Undistributed earnings allocated to common stock 31,378 29,060 92,654 85,617 Net earnings allocated to common shareholders $ 65,812 $ 64,294 $ 196,365 $ 192,046 Average common shares outstanding 101,432,243 103,617,590 101,698,530 104,382,094 Equivalents from stock options 279,497 316,369 268,605 297,782 Average diluted shares outstanding 101,711,740 103,933,959 101,967,135 104,679,876 Earnings per basic common share $ 0.65 $ 0.62 $ 1.93 $ 1.84 Earnings per diluted common share $ 0.65 $ 0.62 $ 1.93 $ 1.83

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Information Related to Statutory Trusts	Information related to United’s statutory trusts is presented in the table below: Description Issuance Date Amount of Interest Rate Maturity Date United Statutory Trust III December 17, 2003 $ 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
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 September 30, 2019 As of December 31, 2018 Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Trust preferred securities $ 258,123 $ 248,918 $ 9,205 $ 257,754 $ 248,741 $ 9,013 (1) Represents investment in VIEs.

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 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 three and nine months ended September 30, 2019 and 2018 is as follows: At and For the Three Months Ended September 30, 2019 Community Mortgage Other Intersegment Eliminations Consolidated Net interest income $ 143,615 $ 203 $ (3,052 ) $ 1,152 $ 141,918 Provision for loans losses 5,033 0 0 0 5,033 Other income 18,696 24,331 87 (890 ) 42,224 Other expense 77,312 20,256 (1,696 ) 262 96,134 Income taxes 16,393 877 (260 ) 0 17,010 Net income (loss) $ 63,573 $ 3,401 $ (1,009 ) $ 0 $ 65,965 Total assets (liabilities) $ 19,593,009 $ 491,832 $ 17,120 $ (350,500 ) $ 19,751,461 Average assets (liabilities) 19,579,180 398,880 16,925 (328,377 ) 19,666,608 At and For the Three Months Ended September 30, 2018 Community Mortgage Other Intersegment Eliminations Consolidated Net interest income $ 149,770 $ 388 $ (3,168 ) $ 1,785 $ 148,775 Provision for loans losses 4,808 0 0 0 4,808 Other income 18,717 16,478 58 (3,567 ) 31,686 Other expense 75,255 17,957 1,885 (1,782 ) 93,315 Income taxes 19,296 (246 ) (1,124 ) 0 17,926 Net income (loss) $ 69,128 $ (845 ) $ (3,871 ) $ 0 $ 64,412 Total assets (liabilities) $ 19,080,734 $ 288,638 $ 12,545 $ (194,274 ) $ 19,187,643 Average assets (liabilities) 18,982,530 303,556 5,468 (243,867 ) 19,047,689 At and For the Nine Months Ended September 30, 2019 Community Mortgage Other Intersegment Eliminations Consolidated Net interest income $ 442,022 $ 369 $ (9,584 ) $ 3,832 $ 436,639 Provision for loans losses 15,446 0 0 0 15,446 Other income 54,746 63,938 342 (5,784 ) 113,242 Other expense 235,610 53,869 (1,773 ) (1,952 ) 285,754 Income taxes 51,266 2,163 (1,562 ) 0 51,867 Net income (loss) $ 194,446 $ 8,275 $ (5,907 ) $ 0 $ 196,814 Total assets (liabilities) $ 19,593,009 $ 491,832 $ 17,120 $ (350,500 ) $ 19,751,461 Average assets (liabilities) 19,410,636 330,668 6,926 (269,306 ) 19,478,924 At and For the Nine Months Ended September 30, 2018 Community Mortgage Other Intersegment Eliminations Consolidated Net interest income $ 444,840 $ 1,028 $ (8,794 ) $ 4,866 $ 441,940 Provision for loans losses 16,190 0 0 0 16,190 Other income 53,952 54,829 (696 ) (9,200 ) 98,885 Other expense 224,240 57,566 (295 ) (4,334 ) 277,177 Income taxes 57,519 (385 ) (2,068 ) 0 55,066 Net income (loss) $ 200,843 $ (1,324 ) $ ) $ 0 $ 192,392 Total assets (liabilities) $ 19,080,734 $ 288,638 $ 12,545 $ (194,274 ) $ 19,187,643 Average assets (liabilities) 18,718,295 284,100 8,043 (240,505 ) 18,769,934

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	Jan. 01, 2019	Aug. 31, 2017	Sep. 30, 2019	Sep. 30, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Held-to-maturity securities, transferred security, at carrying value			$ 11,544	$ 0
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
Decrease in AOCI due to transfer of held to maturity securities		$ 1,098
Accounting Standards Update 2018-10 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net lease assets	$ 67,040
Net lease liabilities	70,692
Effect on retained earnings	$ 1,049

Investment Securities - Summary

Investment Securities - Summary of Amortized Cost and Estimated Fair Values of Available for Sale Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule of Investments [Line Items]
Amortized Cost	$ 2,425,849	$ 2,360,884
Gross Unrealized Gains	36,542	5,865
Gross Unrealized Losses	10,294	29,710
Estimated Fair Value	2,452,097	2,337,039
Cumulative OTTI in AOCI	747	2,672
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Schedule of Investments [Line Items]
Amortized Cost	63,444	86,285
Gross Unrealized Gains	591	35
Gross Unrealized Losses	1	430
Estimated Fair Value	64,034	85,890
Cumulative OTTI in AOCI	0	0
State and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Amortized Cost	234,552	212,670
Gross Unrealized Gains	4,588	439
Gross Unrealized Losses	625	4,121
Estimated Fair Value	238,515	208,988
Cumulative OTTI in AOCI	0	0
Residential Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	853,521	1,047,345
Gross Unrealized Gains	14,493	3,235
Gross Unrealized Losses	733	14,930
Estimated Fair Value	867,281	1,035,650
Cumulative OTTI in AOCI	0	0
Residential Mortgage-Backed Securities, Non-agency [Member]
Schedule of Investments [Line Items]
Amortized Cost	3,533	3,927
Gross Unrealized Gains	462	332
Gross Unrealized Losses	0	0
Estimated Fair Value	3,995	4,259
Cumulative OTTI in AOCI	86	86
Commercial Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	611,038	560,634
Gross Unrealized Gains	11,751	996
Gross Unrealized Losses	1,137	7,030
Estimated Fair Value	621,652	554,600
Cumulative OTTI in AOCI	0	0
Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	284,593	272,459
Gross Unrealized Gains	0	450
Gross Unrealized Losses	4,886	939
Estimated Fair Value	279,707	271,970
Cumulative OTTI in AOCI	0	0
Trust Preferred Collateralized Debt Obligations [Member]
Schedule of Investments [Line Items]
Amortized Cost	6,130	6,176
Gross Unrealized Gains	0	91
Gross Unrealized Losses	1,061	350
Estimated Fair Value	5,069	5,917
Cumulative OTTI in AOCI	661	2,586
Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	18,188	8,754
Gross Unrealized Gains	172	169
Gross Unrealized Losses	1,816	561
Estimated Fair Value	16,544	8,362
Cumulative OTTI in AOCI	0	0
Corporate Bonds [Member]
Schedule of Investments [Line Items]
Amortized Cost	350,850	162,634
Gross Unrealized Gains	4,485	118
Gross Unrealized Losses	35	1,349
Estimated Fair Value	355,300	161,403
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	Sep. 30, 2019	Dec. 31, 2018
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	$ 495,485	$ 703,081
Less than 12 months, Unrealized Losses	6,458	5,687
12 months or longer, Fair Value	191,594	918,073
12 months or longer, Unrealized Losses	3,836	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	1,420	66,072
Less than 12 months, Unrealized Losses	1	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	62,394	53,421
Less than 12 months, Unrealized Losses	614	544
12 months or longer, Fair Value	2,946	94,337
12 months or longer, Unrealized Losses	11	3,577
Residential Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	30,433	195,009
Less than 12 months, Unrealized Losses	101	1,597
12 months or longer, Fair Value	82,977	508,041
12 months or longer, Unrealized Losses	632	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	145,382	107,443
Less than 12 months, Unrealized Losses	962	1,124
12 months or longer, Fair Value	54,441	294,129
12 months or longer, Unrealized Losses	175	5,906
Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	243,909	151,427
Less than 12 months, Unrealized Losses	4,084	939
12 months or longer, Fair Value	35,798	0
12 months or longer, Unrealized Losses	802	0
Trust Preferred Collateralized Debt Obligations [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	2,969	0
Less than 12 months, Unrealized Losses	661	0
12 months or longer, Fair Value	2,100	2,150
12 months or longer, Unrealized Losses	400	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	13,332	5,163
12 months or longer, Unrealized Losses	1,816	561
Corporate Bonds [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	8,978	129,709
Less than 12 months, Unrealized Losses	35	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	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales and calls	$ 188,911	$ 109,093	$ 573,674	$ 283,953
Gross realized gains	412	93	1,166	1,314
Gross realized losses	$ 346	$ 207	$ 1,318	$ 1,604

Investment Securities - Additio

Investment Securities - Additional Information (Detail) $ in Thousands	3 Months Ended
	Sep. 30, 2019USD ($)Securities	Dec. 31, 2018USD ($)
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	$ 10,294	$ 29,710
Available for sale securities in unrealized loss position | Securities	145
Available for sale securities in portfolio, number | Securities	738
Amortized cost of available for sale securities	$ 2,425,849	2,360,884
Capitalization of banks, equal to or greater than, in the single-issue trust preferred portfolio	10,000,000
Equity securities at estimated fair value	8,914	9,734
Carrying value of securities pledged	$ 1,568,888	1,887,176
Percentage Of Guarantee Repayment By Government	97.00%
Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale single issue trust preferred securities	$ 4,040
Below Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale single issue trust preferred securities	2,480
Split Rated Bonds Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale single issue trust preferred securities	5,936
Unrated Bonds Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale single issue trust preferred securities	5,732
State and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	625	4,121
Amortized cost of available for sale securities	$ 234,552	212,670
Percent of portfolio with credit support	71.00%
Agency Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale securities	$ 1,464,559
Commercial Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	1,137	7,030
Amortized cost of available for sale securities	611,038	560,634
Residential Mortgage-Backed Securities [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	733	14,930
Amortized cost of available for sale securities	853,521	1,047,345
Residential Mortgage-Backed Securities, Non-agency [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	0	0
Amortized cost of available for sale securities	3,533	3,927
Residential Mortgage-Backed Securities, Non-agency [Member] | Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale securities	2
Residential Mortgage-Backed Securities, Non-agency [Member] | Below Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale securities	3,531
Trust Preferred Collateralized Debt Obligations [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	1,061	350
Amortized cost of available for sale securities	6,130	6,176
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	9
Corporate Bonds [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	35	1,349
Amortized cost of available for sale securities	$ 350,850	$ 162,634
Corporate Bonds [Member] | Investment Grade [Member]
Schedule of Investments [Line Items]
Percent of corporate securities portfolio	92.00%
Corporate Bonds [Member] | Unrated Bonds Investment Grade [Member]
Schedule of Investments [Line Items]
Percent of corporate securities portfolio	8.00%

Investment Securities - Roll Fo

Investment Securities - Roll Forward of Credit Losses on Securities (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Cumulative credit losses, Beginning Balance	$ 3,192	$ 3,199	$ 3,138	$ 18,060
Additional credit losses on securities for which OTTI was previously recognized	9	0	63	0
Reductions for securities sold or paid off during the period	0	0	0	(14,861)
Cumulative credit losses, Ending Balance	$ 3,201	$ 3,199	$ 3,201	$ 3,199

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	Sep. 30, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Due in one year or less, Amortized Cost	$ 110,865	$ 77,534
Due after one year through five years, Amortized Cost	568,839	518,975
Due after five years through ten years, Amortized Cost	549,442	483,567
Due after ten years, Amortized Cost	1,196,703	1,280,808
Amortized Cost	2,425,849	2,360,884
Due in one year or less, Estimated Fair Value	111,001	77,266
Due after one year through five years, Estimated Fair Value	576,687	514,734
Due after five years through ten years, Estimated Fair Value	558,540	477,135
Due after ten years, Estimated Fair Value	1,205,869	1,267,904
Total available for sale securities	$ 2,452,097	$ 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	Sep. 30, 2019	Dec. 31, 2018
Schedule of Investments [Line Items]
Amortized Cost	$ 1,471	$ 19,999
Gross Unrealized Gains	1	99
Gross Unrealized Losses	0	1,443
Estimated Fair Value	1,472	18,655
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Schedule of Investments [Line Items]
Amortized Cost	25	5,074
Gross Unrealized Gains	0	90
Gross Unrealized Losses	0	0
Estimated Fair Value	25	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	Sep. 30, 2019	Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Due in one year or less, Amortized Cost	$ 235	$ 7,913
Due after one year through five years, Amortized Cost	216	1,059
Due after five years through ten years, Amortized Cost	0	8,030
Due after ten years, Amortized Cost	1,020	2,997
Amortized Cost	1,471	19,999
Due in one year or less, Estimated Fair Value	235	8,005
Due after one year through five years, Estimated Fair Value	217	1,061
Due after five years through ten year, Estimated Fair Value	0	7,134
Due after ten years, Estimated Fair Value	1,020	2,455
Estimated Fair Value, Total	$ 1,472	$ 18,655

Investment Securities - Summa_7

Investment Securities - Summary of Equity Securities (Detail) - Marketable Equity Securities [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Debt Securities, Available-for-sale [Line Items]
Net gains (losses) recognized during the period	$ 59	$ (38)	$ 302	$ (102)
Net gains (losses) recognized during the period on equity securities sold	(1)	(2)	133	(4)
Unrealized gains recognized during the period on equity securities still held at period end	60	0	181	50
Unrealized losses recognized during the period on equity securities still held at period end	$ 0	$ (36)	$ (12)	$ (148)

Loans - Major Classes of Loans

Loans - Major Classes of Loans (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Commercial, financial, and agricultural
Total commercial, financial & agricultural	$ 7,571,194	$ 7,553,044
Residential real estate	3,644,568	3,501,393
Construction & land development	1,300,881	1,410,468
Consumer:
Bankcard	9,532	10,203
Other consumer	1,111,063	954,424
Total Financing Receivables	13,637,238	13,429,532
Owner-Occupied Commercial Real Estate [Member]
Commercial, financial, and agricultural
Total commercial, financial & agricultural	1,221,647	1,291,790
Nonowner-Occupied Commercial Real Estate [Member]
Commercial, financial, and agricultural
Total commercial, financial & agricultural	4,241,682	4,303,613
Other Commercial Loans [Member]
Commercial, financial, and agricultural
Total commercial, financial & agricultural	$ 2,107,865	$ 1,957,641

Loans - Additional Information

Loans - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Loans held for sale	$ 412,194	$ 249,846
Acquired impaired loans from merger	$ 13,637,238	$ 13,429,532
Percentage of acquired impaired loans from merger on total gross loans	1.00%	1.12%
Recorded investment in acquired impaired loans	$ 134,125	$ 195,706
Directors and Officers [Member]
Related party loans	45,800	93,282
Loans Acquired with Deteriorated Credit Quality [Member]
Acquired impaired loans from merger	$ 103,017	$ 149,737

Loans - Activity for Accretable

Loans - Activity for Accretable Yield (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 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)	(8,303)
Additions	0
Net reclassifications to accretable from non-accretable	8,746
Disposals (including maturities, foreclosures, and charge-offs)	(4,649)
Accretable yield at the end of the period	$ 22,083

Credit Quality - Additional Inf

Credit Quality - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
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			$ 60,559		$ 59,425
Restructured loans on nonaccrual status	$ 50,757		50,757		48,899
Restructured loans modified by reduction in interest	1,728		1,728
Restructured loan and interest	1,784		1,784
Restructured loans modified by change in terms	57,047		$ 57,047
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
OREO	18,367		$ 18,367		16,865
Recorded investment of consumer mortgage loans	1,454		1,454		520
Restructured Loans Modified By Reduction InInterest Rate Amount During Period	6,106	$ 7,636	246	$ 24,115
Restructured Loans Modified By Change In Terms Amount During Period			11,018
Troubled debt restructurings post modification additional funds recorded investment	293
Post-Modification Outstanding Recorded Investment	6,106	$ 7,636	11,264	$ 24,115
Debtor One [Member]
Post-Modification Outstanding Recorded Investment	24
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Restructured loans on nonaccrual status	$ 1,115		$ 1,115		$ 690

Credit Quality - Schedule of Tr

Credit Quality - Schedule of Troubled Debt Restructurings, Segregated by Class of Loans (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)Contract	Sep. 30, 2018USD ($)Contract	Sep. 30, 2019USD ($)Contract	Sep. 30, 2018USD ($)Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	2	6	11	12
Pre-Modification Outstanding Recorded Investment	$ 6,167	$ 7,692	$ 11,665	$ 24,217
Post-Modification Outstanding Recorded Investment	$ 6,106	$ 7,636	$ 11,264	$ 24,115
Construction & Land Development [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0	3	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 2,266	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 2,214	$ 0
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	0	2	0
Pre-Modification Outstanding Recorded Investment	$ 1,030	$ 0	$ 1,179	$ 0
Post-Modification Outstanding Recorded Investment	$ 1,030	$ 0	$ 1,179	$ 0
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Other Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	5	3	9
Pre-Modification Outstanding Recorded Investment	$ 5,137	$ 7,420	$ 5,962	$ 16,992
Post-Modification Outstanding Recorded Investment	$ 5,076	$ 7,364	$ 5,849	$ 16,890
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	1	3	3
Pre-Modification Outstanding Recorded Investment	$ 0	$ 272	$ 2,258	$ 7,225
Post-Modification Outstanding Recorded Investment	$ 0	$ 272	$ 2,022	$ 7,225
Consumer [Member] | Bankcard [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Consumer [Member] | Other Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 0

Credit Quality - Schedule of Ch

Credit Quality - Schedule of Charged-off Troubled Debt Restructurings on Financing Receivables (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)Contract	Sep. 30, 2018USD ($)Contract	Sep. 30, 2019USD ($)Contract	Sep. 30, 2018USD ($)Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	1	2	1
Recorded Investment | $	$ 534	$ 622	$ 1,477	$ 622
Construction & Land Development [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0	0	0
Recorded Investment | $	$ 0	$ 0	$ 0	$ 0
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0	0	0
Recorded Investment | $	$ 0	$ 0	$ 0	$ 0
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0	0	0
Recorded Investment | $	$ 0	$ 0	$ 0	$ 0
Other Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	1	2	1
Recorded Investment | $	$ 534	$ 622	$ 1,477	$ 622
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0	0	0
Recorded Investment | $	$ 0	$ 0	$ 0	$ 0
Consumer [Member] | Bankcard [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0	0	0
Recorded Investment | $	$ 0	$ 0	$ 0	$ 0
Consumer [Member] | Other Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0	0	0
Recorded Investment | $	$ 0	$ 0	$ 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	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	$ 91,676	$ 94,027
Loans, Total Past Due	222,157	227,011
Loans, Current & Other	13,415,081	13,202,521
Total Financing Receivables	13,637,238	13,429,532
Loans, Recorded Investment >90 Days & Accruing	9,840	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	130,481	132,984
Construction & Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	5,299	8,462
Loans, Total Past Due	21,323	27,874
Loans, Current & Other	1,279,558	1,382,594
Total Financing Receivables	1,300,881	1,410,468
Loans, Recorded Investment >90 Days & Accruing	478	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	16,024	19,412
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	17,635	9,224
Loans, Total Past Due	31,098	26,966
Loans, Current & Other	1,190,549	1,264,824
Total Financing Receivables	1,221,647	1,291,790
Loans, Recorded Investment >90 Days & Accruing	1,105	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	13,463	17,742
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	14,171	16,108
Loans, Total Past Due	33,513	34,200
Loans, Current & Other	4,208,169	4,269,413
Total Financing Receivables	4,241,682	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	19,342	18,092
Other Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	11,446	13,556
Loans, Total Past Due	64,696	59,596
Loans, Current & Other	2,043,169	1,898,045
Total Financing Receivables	2,107,865	1,957,641
Loans, Recorded Investment >90 Days & Accruing	533	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	53,250	46,040
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	33,863	37,111
Loans, Total Past Due	61,018	67,389
Loans, Current & Other	3,583,550	3,434,004
Total Financing Receivables	3,644,568	3,501,393
Loans, Recorded Investment >90 Days & Accruing	6,248	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	27,155	30,278
Consumer [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	303	657
Loans, Total Past Due	458	834
Loans, Current & Other	9,074	9,369
Total Financing Receivables	9,532	10,203
Loans, Recorded Investment >90 Days & Accruing	155	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	155	177
Consumer [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	8,959	8,909
Loans, Total Past Due	10,051	10,152
Loans, Current & Other	1,101,012	944,272
Total Financing Receivables	1,111,063	954,424
Loans, Recorded Investment >90 Days & Accruing	850	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	$ 1,092	$ 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	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Acquired impaired loans from merger	$ 13,637,238	$ 13,429,532
Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Acquired impaired loans from merger	103,017	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	$ 103,017	$ 149,737

Credit Quality - Schedule of No

Credit Quality - Schedule of Nonaccrual Loans, Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	$ 120,641	$ 117,443
Construction & Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	15,546	18,732
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	12,358	17,113
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	18,871	16,921
Other Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	52,717	43,190
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	20,907	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	$ 242	$ 350

Credit Quality - Schedule of Cr

Credit Quality - Schedule of Credit Quality Indicators Information, by Class of Loans (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	$ 13,637,238	$ 13,429,532
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	3,644,568	3,501,393
Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	2,107,865	1,957,641
Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	9,532	10,203
Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,111,063	954,424
Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,221,647	1,291,790
Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	4,241,682	4,303,613
Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,300,881	1,410,468
Pass [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	3,596,942	3,436,584
Pass [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,964,260	1,858,821
Pass [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	9,073	9,369
Pass [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,100,971	944,241
Pass [Member] | Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,147,536	1,201,387
Pass [Member] | Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	4,141,992	4,161,149
Pass [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,221,350	1,330,899
Special Mention [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	9,776	19,051
Special Mention [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	62,015	14,424
Special Mention [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	304	657
Special Mention [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	8,962	8,914
Special Mention [Member] | Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	20,588	34,487
Special Mention [Member] | Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	27,493	46,442
Special Mention [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	10,105	28,629
Substandard [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	37,850	45,758
Substandard [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	81,320	81,946
Substandard [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	155	177
Substandard [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,130	1,269
Substandard [Member] | Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	53,164	55,916
Substandard [Member] | Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	72,197	96,022
Substandard [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	69,426	50,940
Doubtful [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	0	0
Doubtful [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	270	2,450
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	359	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	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Construction & Land Development [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	$ 29,900		$ 29,900		$ 37,174
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	35,825		35,825		40,459
Impaired Loans, Recorded Investment, With an allowance recorded	14,877		14,877		14,742
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	16,927		16,927		19,446
Impaired Loans, Related Allowance	1,937		1,937		2,254
Impaired Loans, Recorded Investment	44,777		44,777		51,916
Impaired Loans, Unpaid Principal Balance	52,752		52,752		59,905
Impaired Loans, Related Allowance	1,937		1,937		2,254
Impaired Loans, Average Recorded Investment, With no related allowance recorded	33,384	$ 41,036	34,403	$ 43,464
Impaired Loans, Interest Income Recognized, With no related allowance recorded	193	278	602	707
Impaired Loans, Average Recorded Investment, With an allowance recorded	14,481	9,408	14,567	6,944
Impaired Loans, Interest Income Recognized, With an allowance recorded	32	20	87	60
Impaired Loans, Average Recorded Investment	47,865	50,444	48,970	50,408
Impaired Loans, Interest Income Recognized	225	298	689	767
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	68,541		68,541		63,633
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	70,625		70,625		63,798
Impaired Loans, Recorded Investment, With an allowance recorded	1,066		1,066		10,004
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	1,066		1,066		10,004
Impaired Loans, Related Allowance	25		25		2,542
Impaired Loans, Recorded Investment	69,607		69,607		73,637
Impaired Loans, Unpaid Principal Balance	71,691		71,691		73,802
Impaired Loans, Related Allowance	25		25		2,542
Impaired Loans, Average Recorded Investment, With no related allowance recorded	70,245	65,625	69,547	69,009
Impaired Loans, Interest Income Recognized, With no related allowance recorded	425	365	1,354	1,101
Impaired Loans, Average Recorded Investment, With an allowance recorded	3,004	7,378	3,830	6,876
Impaired Loans, Interest Income Recognized, With an allowance recorded	0	6	0	18
Impaired Loans, Average Recorded Investment	73,249	73,003	73,377	75,885
Impaired Loans, Interest Income Recognized	425	371	1,354	1,119
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	45,039		45,039		98,845
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	45,232		45,232		98,904
Impaired Loans, Recorded Investment, With an allowance recorded	13,515		13,515		15,720
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	13,623		13,623		15,720
Impaired Loans, Related Allowance	1,900		1,900		2,715
Impaired Loans, Recorded Investment	58,554		58,554		114,565
Impaired Loans, Unpaid Principal Balance	58,855		58,855		114,624
Impaired Loans, Related Allowance	1,900		1,900		2,715
Impaired Loans, Average Recorded Investment, With no related allowance recorded	47,633	99,005	60,594	105,199
Impaired Loans, Interest Income Recognized, With no related allowance recorded	261	311	914	928
Impaired Loans, Average Recorded Investment, With an allowance recorded	11,943	12,465	12,645	11,158
Impaired Loans, Interest Income Recognized, With an allowance recorded	63	189	192	251
Impaired Loans, Average Recorded Investment	59,576	111,470	73,239	116,357
Impaired Loans, Interest Income Recognized	324	500	1,106	1,179
Other Commercial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	59,855		59,855		40,291
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	67,441		67,441		50,459
Impaired Loans, Recorded Investment, With an allowance recorded	40,866		40,866		61,266
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	43,250		43,250		62,812
Impaired Loans, Related Allowance	10,491		10,491		17,581
Impaired Loans, Recorded Investment	100,721		100,721		101,557
Impaired Loans, Unpaid Principal Balance	110,691		110,691		113,271
Impaired Loans, Related Allowance	10,491		10,491		17,581
Impaired Loans, Average Recorded Investment, With no related allowance recorded	61,488	56,489	55,058	55,124
Impaired Loans, Interest Income Recognized, With no related allowance recorded	257	313	790	1,020
Impaired Loans, Average Recorded Investment, With an allowance recorded	38,016	47,563	41,383	47,736
Impaired Loans, Interest Income Recognized, With an allowance recorded	11	305	139	380
Impaired Loans, Average Recorded Investment	99,504	104,052	96,441	102,860
Impaired Loans, Interest Income Recognized	268	618	929	1,400
Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	31,992		31,992		28,207
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	33,864		33,864		29,279
Impaired Loans, Recorded Investment, With an allowance recorded	6,080		6,080		19,623
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	6,081		6,081		22,064
Impaired Loans, Related Allowance	433		433		3,265
Impaired Loans, Recorded Investment	38,072		38,072		47,830
Impaired Loans, Unpaid Principal Balance	39,945		39,945		51,343
Impaired Loans, Related Allowance	433		433		3,265
Impaired Loans, Average Recorded Investment, With no related allowance recorded	33,482	28,753	32,189	27,210
Impaired Loans, Interest Income Recognized, With no related allowance recorded	146	144	479	501
Impaired Loans, Average Recorded Investment, With an allowance recorded	9,047	14,975	11,661	13,946
Impaired Loans, Interest Income Recognized, With an allowance recorded	9	57	73	247
Impaired Loans, Average Recorded Investment	42,529	43,728	43,850	41,156
Impaired Loans, Interest Income Recognized	155	201	552	748
Consumer [Member] | Bankcard [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	0		0		0
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	0		0		0
Impaired Loans, Recorded Investment, With an allowance recorded	0		0		0
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	0		0		0
Impaired Loans, Related Allowance	0		0		0
Impaired Loans, Recorded Investment	0		0		0
Impaired Loans, Unpaid Principal Balance	0		0		0
Impaired Loans, Related Allowance	0		0		0
Impaired Loans, Average Recorded Investment, With no related allowance recorded	0	0	0	0
Impaired Loans, Interest Income Recognized, With no related allowance recorded	0	0	0	0
Impaired Loans, Average Recorded Investment, With an allowance recorded	0	0	0	0
Impaired Loans, Interest Income Recognized, With an allowance recorded	0	0	0	0
Impaired Loans, Average Recorded Investment	0	0	0	0
Impaired Loans, Interest Income Recognized	0	0	0	0
Consumer [Member] | Other Consumer [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	31		31		27
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	31		31		27
Impaired Loans, Recorded Investment, With an allowance recorded	0		0		0
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	0		0		0
Impaired Loans, Related Allowance	0		0		0
Impaired Loans, Recorded Investment	31		31		27
Impaired Loans, Unpaid Principal Balance	31		31		27
Impaired Loans, Related Allowance	0		0		$ 0
Impaired Loans, Average Recorded Investment, With no related allowance recorded	31	23	30	29
Impaired Loans, Interest Income Recognized, With no related allowance recorded	0	0	0	0
Impaired Loans, Average Recorded Investment, With an allowance recorded	0	0	0	0
Impaired Loans, Interest Income Recognized, With an allowance recorded	0	0	0	0
Impaired Loans, Average Recorded Investment	31	23	30	29
Impaired Loans, Interest Income Recognized	$ 0	$ 0	$ 0	$ 0

Allowance for Credit Losses - A

Allowance for Credit Losses - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
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	$ 631,000	$ 924,000	$ 3,899,000	$ 3,004,000
Reserve for lending-related commitments	$ 1,776,000		$ 1,776,000		$ 1,389,000
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	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	$ 76,400	$ 76,703	$ 76,627
Charge-offs	(5,404)	(19,406)	(28,606)
Recoveries	1,069	4,355	6,669
Provision	5,033	15,446	22,013
Allowance for Loan Losses Ending balance	77,098	77,098	76,703
Allowance for Loan Losses, individually evaluated for impairment	14,785	14,785	28,358
Allowance for Loan Losses, collectively evaluated for impairment	62,313	62,313	48,345
Financing receivables	13,637,238	13,637,238	13,429,532
Financing receivables, individually evaluated for impairment	134,883	134,883	161,935
Financing receivables, collectively evaluated for impairment	13,399,338	13,399,338	13,117,860
Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses	0	0	0
Financing receivables	103,017	103,017	149,737
Construction & Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	6,925	7,992	7,187
Charge-offs	0	(573)	(2,731)
Recoveries	12	164	197
Provision	(750)	(1,396)	3,339
Allowance for Loan Losses Ending balance	6,187	6,187	7,992
Allowance for Loan Losses, individually evaluated for impairment	1,937	1,937	2,254
Allowance for Loan Losses, collectively evaluated for impairment	4,250	4,250	5,738
Financing receivables	1,300,881	1,300,881	1,410,468
Financing receivables, individually evaluated for impairment	14,877	14,877	14,807
Financing receivables, collectively evaluated for impairment	1,271,072	1,271,072	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	0
Financing receivables	14,932	14,932	20,821
Allowance for Estimated Imprecision [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	233	245	73
Charge-offs	0	0	0
Recoveries	0	0	0
Provision	(128)	(140)	172
Allowance for Loan Losses Ending balance	105	105	245
Allowance for Loan Losses, individually evaluated for impairment	0	0	0
Allowance for Loan Losses, collectively evaluated for impairment	105	105	245
Financing receivables	0	0	0
Financing receivables, individually evaluated for impairment	0	0	0
Financing receivables, collectively evaluated for impairment	0	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	0
Financing receivables	0	0	0
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	5,597	5,063	5,401
Charge-offs	(1,340)	(7,861)	(3,225)
Recoveries	145	1,763	1,189
Provision	786	6,223	1,698
Allowance for Loan Losses Ending balance	5,188	5,188	5,063
Allowance for Loan Losses, individually evaluated for impairment	25	25	2,543
Allowance for Loan Losses, collectively evaluated for impairment	5,163	5,163	2,520
Financing receivables	1,221,647	1,221,647	1,291,790
Financing receivables, individually evaluated for impairment	21,913	21,913	27,599
Financing receivables, collectively evaluated for impairment	1,174,677	1,174,677	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	0
Financing receivables	25,057	25,057	29,272
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	6,041	6,919	6,369
Charge-offs	(509)	(578)	(314)
Recoveries	16	57	563
Provision	1,118	268	301
Allowance for Loan Losses Ending balance	6,666	6,666	6,919
Allowance for Loan Losses, individually evaluated for impairment	1,900	1,900	2,715
Allowance for Loan Losses, collectively evaluated for impairment	4,766	4,766	4,204
Financing receivables	4,241,682	4,241,682	4,303,613
Financing receivables, individually evaluated for impairment	28,000	28,000	25,231
Financing receivables, collectively evaluated for impairment	4,197,103	4,197,103	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	0
Financing receivables	16,579	16,579	63,322
Other Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	44,709	41,341	45,189
Charge-offs	(2,135)	(6,714)	(16,424)
Recoveries	703	1,420	2,944
Provision	3,464	10,694	9,632
Allowance for Loan Losses Ending balance	46,741	46,741	41,341
Allowance for Loan Losses, individually evaluated for impairment	10,490	10,490	17,581
Allowance for Loan Losses, collectively evaluated for impairment	36,251	36,251	23,760
Financing receivables	2,107,865	2,107,865	1,957,641
Financing receivables, individually evaluated for impairment	57,465	57,465	72,300
Financing receivables, collectively evaluated for impairment	2,014,164	2,014,164	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	0
Financing receivables	36,236	36,236	25,256
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	10,172	12,448	9,927
Charge-offs	(942)	(1,692)	(3,162)
Recoveries	69	423	1,114
Provision	14	(1,866)	4,569
Allowance for Loan Losses Ending balance	9,313	9,313	12,448
Allowance for Loan Losses, individually evaluated for impairment	433	433	3,265
Allowance for Loan Losses, collectively evaluated for impairment	8,880	8,880	9,183
Financing receivables	3,644,568	3,644,568	3,501,393
Financing receivables, individually evaluated for impairment	12,628	12,628	21,998
Financing receivables, collectively evaluated for impairment	3,621,758	3,621,758	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	0
Financing receivables	10,182	10,182	11,039
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	2,723	2,695	2,481
Charge-offs	(478)	(1,988)	(2,750)
Recoveries	124	528	662
Provision	529	1,663	2,302
Allowance for Loan Losses Ending balance	2,898	2,898	2,695
Allowance for Loan Losses, individually evaluated for impairment	0	0	0
Allowance for Loan Losses, collectively evaluated for impairment	2,898	2,898	2,695
Financing receivables	1,120,595	1,120,595	964,627
Financing receivables, individually evaluated for impairment	0	0	0
Financing receivables, collectively evaluated for impairment	1,120,564	1,120,564	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	0
Financing receivables	$ 31	$ 31	$ 27

Intangible Assets - Summary of

Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 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	(67,754)	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	(67,754)	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

Intangible Assets - Reconciliat

Intangible Assets - Reconciliation of Goodwill (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Goodwill [Line Items]
Goodwill at December 31, 2018	$ 1,478,014
Addition to goodwill	0
Goodwill at September 30, 2019	1,478,014
Community Banking [Member]
Goodwill [Line Items]
Goodwill at December 31, 2018	1,472,699
Addition to goodwill	0
Goodwill at September 30, 2019	1,472,699
Mortgage Banking [Member]
Goodwill [Line Items]
Goodwill at December 31, 2018	5,315
Addition to goodwill	0
Goodwill at September 30, 2019	$ 5,315

Intangible Assets - Additional

Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Amortization Expense On Intangible Assets	$ 1,754	$ 2,009	$ 5,262	$ 6,029

Intangible Assets - Schedule of

Intangible Assets - Schedule of Anticipated Amortization Expense (Detail) $ in Thousands	Sep. 30, 2019USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2019	$ 7,016
2020	6,309
2021	5,369
2022	4,581
2023 and thereafter	$ 12,592

Leases - Additional Information

Leases - Additional Information (Detail)	Sep. 30, 2019
Operating lease remaining lease term	5 years 3 days
Operating leases, option to extend term	0 days
Maximum [Member]
Operating lease remaining lease term	0 days

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Operating lease cost	$ 4,864	$ 14,571
Sublease income	(197)	(671)
Net lease cost	$ 4,667	$ 13,900

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information Related to Leases (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Operating lease right-of-use assets	$ 60,318	$ 0
Operating lease liabilities	$ 63,987	$ 0

Leases - Other Information Rela

Leases - Other Information Related to Leases (Detail)	Sep. 30, 2019
Weightedaverage remaining lease term [Abstract]
Operating leases	5 years 3 days
Weightedaverage discount rate [Abstract]
Operating leases	3.23%

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information Related to Leases (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Cash paid for amounts in the measurement of lease liabilities [Abstract]
Operating cash flows from operating leases	$ 4,903	$ 14,552
ROU assets obtained in the exchange for lease liabilities	$ 1,537	$ 5,953

Leases - Maturities of Lease Li

Leases - Maturities of Lease Liabilities by Year (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
2019	$ 4,817	$ 18,590
2020	17,415	16,359
2021	14,868	13,850
2022	11,206	10,269
2023	8,431	7,600
Thereafter	12,798	10,640
Total lease payments	69,535	77,308
Less: imputed interest	(5,548)	0
Total	$ 63,987	$ 77,308

Short-Term Borrowings - Additio

Short-Term Borrowings - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Short-term Debt [Line Items]
Unused lines of credit	$ 230,000
Federal funds purchased	0	$ 23,400,000
Repurchase agreements	129,966
Unrelated Financial Institution [Member]
Short-term Debt [Line Items]
Unused lines of credit	$ 20,000
Renewal period of line of credit	360-day
Amount of outstanding balance under line of credit	$ 0

Long-Term Borrowings - Addition

Long-Term Borrowings - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Unused borrowing amount	$ 3,894,693
Outstanding balances of debentures	$ 235,849	$ 234,905
Maximum time to defer payment of interest on subordinate debt	5 years
Advances from Federal Home Loan Banks	$ 1,672,448,000	$ 1,439,198,000
Federal Home Loan Bank, Advances, Activity for Year, Average Interest Rate for Year	2.11%
Advances From Federal Home Loan Banks Maximum Maturity Period	6 years
Overnight funds	$ 200,000,000
Overnight funds interest rate	2.15%

Long -Term Borrowings - Schedul

Long -Term Borrowings - Schedule of Maturities of Long-term Borrowings (Detail) $ in Thousands	Sep. 30, 2019USD ($)
Debt Disclosure [Abstract]
2019	$ 220,918
2020	591,837
2021	827,636
2022	20,918
2023 and thereafter	11,139
Total	$ 1,672,448

Commitments and Contingent Li_2

Commitments and Contingent Liabilities - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Loan commitments outstanding	$ 3,831,866	$ 3,826,370
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	$ 1,173
Commitments to Extend Credit [Member] | George Mason [Member] | Short-term Contract with Customer [Member]
Loss Contingencies [Line Items]
Additional commitments to extend credit	311,366
Commercial Letters of Credit [Member]
Loss Contingencies [Line Items]
Letters of credit issued	5,092	0
Standby Letters of Credit [Member]
Loss Contingencies [Line Items]
Letters of credit issued	$ 136,962	$ 141,032

Derivative Financial Instrume_3

Derivative Financial Instruments - Schedule of Notional Amount and Fair Value Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Asset derivatives, notional amount	$ 293,282	$ 201,182
Asset derivatives designated as hedging instruments	0	1,859
Liability derivatives, notional amount	510,828	200,281
Asset derivatives not designated as hedging instruments	7,074	4,645
Total asset derivatives	7,074	6,504
Liability derivatives designated as hedging instruments	3,921	0
Liability derivatives not designated as hedging instruments	835	3,002
Total liability derivatives	4,756	3,002
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives, notional amount	0	85,623
Liability derivatives, notional amount	83,328	0
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives, notional amount	293,282	115,559
Liability derivatives, notional amount	427,500	200,281
Other Assets [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Asset derivatives not designated as hedging instruments	7,030	4,103
Other Assets [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Asset derivatives, notional amount	262,313	93,955
Other Liabilities [Member] | TBA Mortgage Backed Securities [Member]
Derivative [Line Items]
Liability derivatives not designated as hedging instruments	835	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	427,500	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 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 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 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 Contracts [Member] | Other Liabilities [Member] | Fair Value Hedging [Member] | Hedged Commercial Loans [Member]
Derivative [Line Items]
Liability derivatives designated as hedging instruments	3,921	0
Interest Rate 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	83,328	0
Forward Loan Sale Commitments [Member] | Other Assets [Member]
Derivative [Line Items]
Asset derivatives not designated as hedging instruments	44	542
Forward Loan Sale Commitments [Member] | Other Assets [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives, notional amount	$ 30,969	$ 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	Sep. 30, 2019USD ($)
Carrying Amount of the Hedged Assets/(Liabilities)	$ 82,470
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities)	(3,921)
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	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative [Line Items]
Derivatives in hedging relationships	$ 3,100	$ (900)	$ 9,270	$ (224)
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivatives in hedging relationships	(187)	(24)	(285)	(42)
Designated as Hedging Instrument [Member] | Interest Income Expense [Member] | Interest Rate Contracts [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Derivatives in hedging relationships	(187)	(24)	(285)	(42)
Designated as Hedging Instrument [Member] | Other Income [Member] | Forward Loan Sale Commitments [Member] | Cash Flow Hedging [Member]
Derivative [Line Items]
Derivatives in hedging relationships			0	0
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivatives not designated as hedging instruments	3,287	(876)	9,555	(182)
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	2,641	2,583	2,167	1,473
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	602	(3,262)	6,472	(1,643)
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	$ 44	$ (197)	$ 916	$ (12)

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 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	0.25%
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	0.59%
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	0.40%
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	0.25%
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	0.59%
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	0.40%

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value (Detail) - USD ($)		Sep. 30, 2019	Dec. 31, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held for sale		$ 412,194,000	$ 249,846,000
Derivative financial assets		7,074,000	6,504,000
Derivative financial liabilities		4,756,000	3,002,000
Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		2,452,097,000	2,337,039,000
Available for sale equity securities		8,914,000	9,734,000
Loans held for sale		407,463,000	247,104,000
Derivative financial assets		7,074,000	6,504,000
Derivative financial liabilities		4,756,000	3,002,000
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		64,034,000	85,890,000
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		238,515,000	208,988,000
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		867,281,000	1,035,650,000
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		3,995,000	4,259,000
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		621,652,000	554,600,000
Asset-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		279,707,000	271,970,000
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		5,069,000	5,917,000
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		16,544,000	8,362,000
Corporate Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		355,300,000	161,403,000
Financial Services Industry [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities		159,000	140,000
Other Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities		4,790,000	4,640,000
Forward Sales Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		44,000	542,000
Interest Rate Lock Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		7,030,000	4,103,000
TBA Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial liabilities		835,000	3,002,000
Interest Rate Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		0	1,859,000
Derivative financial liabilities		3,921,000
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]	3,965,000	4,954,000
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
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 debt securities		6,673,000	6,822,000
Available for sale equity securities		8,914,000	9,734,000
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		6,673,000	6,822,000
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		159,000	140,000
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		4,790,000	4,640,000
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 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] | 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 Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		0	0
Derivative financial liabilities		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]	3,965,000	4,954,000
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held for sale		4,731,000	2,742,000
Derivative financial assets		44,000	2,401,000
Derivative financial liabilities		4,756,000	3,002,000
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 debt securities		2,440,355,000	2,324,300,000
Available for sale equity securities		0	0
Loans held for sale		0	0
Derivative financial assets		44,000	2,401,000
Derivative financial liabilities		4,756,000	3,002,000
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		64,034,000	85,890,000
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		238,515,000	208,988,000
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		867,281,000	1,035,650,000
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		3,995,000	4,259,000
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		621,652,000	554,600,000
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		279,707,000	271,970,000
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		16,544,000	8,362,000
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		348,627,000	154,581,000
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] | Forward Sales Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		44,000	542,000
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] | TBA Mortgage Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial liabilities		835,000	3,002,000
Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		0	1,859,000
Derivative financial liabilities		3,921
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]
Loans held for sale		407,463,000	247,104,000
Derivative financial assets		7,030,000	4,103,000
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 debt securities		5,069,000	5,917,000
Available for sale equity securities		0	0
Loans held for sale		407,463,000	247,104,000
Derivative financial assets		7,030,000	4,103,000
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		5,069,000	5,917,000
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] | 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 Lock Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		7,030,000	4,103,000
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 Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets		0	0
Derivative financial liabilities		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 Value Measurements - Sch_2

Fair Value Measurements - 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	9 Months Ended	12 Months Ended
	Sep. 30, 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)	(62)	28
Included in other comprehensive income	(786)	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	5,069	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)	63,903	68,555
Originations	2,164,410	2,619,454
Sales	(2,067,954)	(2,676,797)
Transfers in and/or out of Level 3	0	(27,416)
Balance, end of period	407,463	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	2,927	(456)
Balance, end of period	7,030	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 Value Measurements - Sch_3

Fair Value Measurements - Schedule of Changes in Fair Value Included in Earnings of Financial Instruments for which Fair Value Option has been Elected (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Mortgage Banking [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Income from mortgage banking activities	$ (1,304)	$ (5,929)	$ 5,238	$ (2,838)

Fair Value Measurements - Summa

Fair Value Measurements - 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	Sep. 30, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Loans held for sale, unpaid principal balance	$ 399,341	$ 241,293
Loans held for sale, fair value	407,463	247,104
Loans held for sale, fair value over/(under) unpaid principal balance	$ 8,122	$ 5,811

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 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	2,795	(12,301)
YTD Losses, OREO	(1,453)	(910)
Loans held for sale	407,463	247,104
OREO	18,367	16,865
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans held for sale	4,731	2,742
Impaired Loans	76,404	121,355
OREO	18,367	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	4,731	2,742
Impaired Loans	69,560	108,899
OREO	18,291	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	6,844	12,456
OREO	$ 76	$ 0

Fair Value Measurements - Sum_3

Fair Value Measurements - Summary of Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 976,154	$ 1,020,396	$ 1,254,686	$ 1,666,167
Securities available for sale	2,452,097	2,337,039
Securities held to maturity	1,471	19,999
Other securities	210,830	176,955
Loans held for sale	412,194	249,846
Net loans	13,633,427	13,422,222
Derivative financial assets	7,074	6,504
Deposits	14,095,411	13,994,749
Derivative financial liabilities	4,756	3,002
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	976,154	1,020,396
Securities available for sale	2,452,097	2,337,039
Securities held to maturity	1,471	19,999
Other securities	210,830	176,955
Loans held for sale	412,194	249,846
Net loans	13,556,427	13,345,519
Derivative financial assets	7,074	6,504
Deposits	14,095,411	13,994,749
Short-term borrowings	329,966	351,327
Long-term borrowings	1,708,297	1,499,103
Derivative financial liabilities	4,756	3,002
Carrying Amount [Member] | Marketable Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities	8,914	9,734
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	976,154	1,020,396
Securities available for sale	2,452,097	2,337,039
Securities held to maturity	1,472	18,655
Other securities	200,288	168,107
Loans held for sale	412,194	249,846
Net loans	13,051,670	12,657,073
Derivative financial assets	7,074	6,504
Deposits	14,071,344	13,954,574
Short-term borrowings	329,966	351,327
Long-term borrowings	1,688,577	1,475,237
Derivative financial liabilities	4,756	3,002
Fair Value [Member] | Marketable Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity securities	8,914	9,734
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	6,673	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	8,914	9,734
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	976,154	1,020,396
Securities available for sale	2,440,355	2,324,300
Securities held to maturity	452	15,635
Other securities	0	0
Loans held for sale	4,731	2,742
Net loans	0	0
Derivative financial assets	44	2,401
Deposits	14,071,344	13,954,574
Short-term borrowings	329,966	351,327
Long-term borrowings	1,688,577	1,475,237
Derivative financial liabilities	4,756	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	5,069	5,917
Securities held to maturity	1,020	3,020
Other securities	200,288	168,107
Loans held for sale	407,463	247,104
Net loans	13,051,670	12,657,073
Derivative financial assets	7,030	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

Stock Based Compensation - Addi

Stock Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands	May 18, 2016	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
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
Recognition of compensation expense		$ 1,194			$ 1,024			$ 3,505	$ 3,016
Maximum term for awards granted (years)								10 years
Shares issued related stock option exercises		50,653	14,144	33,816	18,072	27,046	15,043	98,613	60,161
Total intrinsic value of options exercised								$ 1,463	$ 851
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period								4 years

Stock Based Compensation - Summ

Stock Based Compensation - Summary of Stock Option Plans (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Disclosure Stock Based Compensation Stock Option Plan [Abstract]
Shares, Outstanding, Beginning balance			1,730,389				1,730,389
Shares, Granted							240,205
Shares, Exercised	(50,653)	(14,144)	(33,816)	(18,072)	(27,046)	(15,043)	(98,613)	(60,161)
Shares, Forfeited or expired							(116,561)
Shares, Outstanding, Ending balance	1,755,420						1,755,420
Shares, Exercisable at June 30, 2019	1,165,233						1,165,233
Aggregate Intrinsic Value, Outstanding at June 30, 2019	$ 8,251,397						$ 8,251,397
Aggregate Intrinsic Value, Exercisable at June 30, 2019	$ 8,074,702						$ 8,074,702
Weighted Average Remaining Contractual Term, Outstanding at June 30, 2019							5 years 9 months 18 days
Weighted Average Remaining Contractual Term, Exercisable at June 30, 2019							4 years 4 months 24 days
Weighted Average Exercise Price, Outstanding, Beginning balance			$ 32.43				$ 32.43
Weighted Average Exercise Price, Granted							38.49
Weighted Average Exercise Price, Exercised							22.86
Weighted Average Exercise Price, Forfeited or expired							25.20
Weighted Average Exercise Price, Outstanding, Ending balance	$ 34.27						34.27
Weighted Average Exercise Price, Exercisable	$ 31.71						$ 31.71

Stock Based Compensation - Stat

Stock Based Compensation - Status of United's Nonvested Stock Option Awards (Detail)	9 Months Ended
	Sep. 30, 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	(210,876)
Shares, Forfeited or expired | shares	(14,814)
Shares, Nonvested, Ending balance | shares	590,187
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) - Restricted Stock [Member]	9 Months Ended
	Sep. 30, 2019$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding, Beginning balance | shares	199,303
Shares, Granted | shares	126,427
Shares, Vested | shares	(73,535)
Shares, Forfeited | shares	(4,149)
Number of Shares, Outstanding, Ending balance | shares	248,046
Weighted-Average Grant Date Fair Value Per Share, Outstanding, Beginning balance | $ / shares	$ 39.67
Weighted-Average Grant Date Fair Value Per Share, Granted | $ / shares	38.49
Weighted-Average Grant Date Fair Value Per Share, Vested | $ / shares	39.28
Weighted-Average Grant Date Fair Value Per Share, Forfeited | $ / shares	39.08
Weighted-Average Grant Date Fair Value Per Share, Outstanding, Ending balance | $ / shares	$ 39.19

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Unrecognized actuarial gains (losses), before tax			$ 55,535
Unrecognized actuarial gains (losses), net of tax			$ 42,595
Amortization expected to be recognized	$ 4,744
Amortization expected to be recognized, net of tax	3,639
Employer discretionary contribution amount	$ 0	$ 7,000

Employee Benefit Plans - Net Pe

Employee Benefit Plans - Net Periodic Pension Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 567	$ 673	$ 1,683	$ 1,997
Interest cost	1,474	1,324	4,375	3,927
Expected return on plan assets	(2,382)	(2,578)	(7,068)	(7,651)
Recognized net actuarial loss	1,198	1,174	3,553	3,485
Net periodic pension (benefit) cost	$ 857	$ 593	$ 2,543	$ 1,758
Weighted-Average Assumptions:
Discount rate	4.52%	3.83%	4.52%	3.83%
Expected return on assets	7.00%	7.00%	7.00%	7.00%
Rate of Compensation Increase	3.00%	3.00%	3.00%	3.00%
Prior to Age 45 [Member]
Weighted-Average Assumptions:
Rate of Compensation Increase	3.50%	3.50%	3.50%	3.50%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Taxes [Line Items]
Accrued interest related to uncertain tax positions	$ 641	$ 649	$ 641	$ 649
Effective tax rate	20.50%	21.77%	20.86%	22.25%

Comprehensive Income - Componen

Comprehensive Income - Components of Total Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net Income	$ 65,965	$ 67,207	$ 63,642	$ 64,412	$ 66,274	$ 61,706	$ 196,814	$ 192,392
AFS securities with OTTI charges during the period	(272)			0			(347)	0
Related income tax effect	64			0			81	0
Less: OTTI charges recognized in net income	9			0			84	0
Related income tax benefit	(3)			0			(20)	0
Reclassification of previous noncredit OTTI to credit OTTI	0			0			2,188	0
Related income tax benefit	0			0			(510)	0
Net unrealized (losses) gains on AFS securities with OTTI	(202)			0			1,476	0
Change in net unrealized gain on AFS securities arising during the period	5,070			(9,995)			48,014	(42,696)
Related income tax effect	(1,181)			2,329			(11,187)	11,621
Net reclassification adjustment for (gains) losses included in net income	(66)			114			152	290
Related income tax expense (benefit)	16			(27)			(35)	(68)
Total AFS securities - all other	3,839			(7,579)			36,944	(30,853)
Net effect of AFS securities on other comprehensive income	3,637			(7,579)			38,420	(30,853)
Accretion on the unrealized loss for securities transferred from AFS to the HTM investment portfolio prior to call or maturity	0			2			0	6
Related income tax expense	0			0			0	(2)
Net effect of HTM securities on other comprehensive income	0			2			0	4
Pension plan:
Recognized net actuarial loss	1,198			1,174			3,553	3,485
Related income tax benefit	(249)			(256)			(785)	(782)
Net effect of change in pension plan asset on other comprehensive income	949			918			2,768	2,703
Net current-period other comprehensive income, net of tax	4,586	18,903	17,699	(6,659)	(5,448)	(16,039)	41,188	(28,146)
Total Comprehensive Income	$ 70,551	$ 86,110	$ 81,341	$ 57,753	$ 60,826	$ 45,667	$ 238,002	$ 164,246

Comprehensive Income - Compon_2

Comprehensive Income - Components of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 3,333,858	$ 3,286,891	$ 3,251,624	$ 3,242,565	$ 3,251,313	$ 3,240,530	$ 3,251,624	$ 3,240,530
Reclass due to adopting Accounting Standard Update 2017-12			50			0
Net current-period other comprehensive income, net of tax	4,586	18,903	17,699	(6,659)	(5,448)	(16,039)	41,188	(28,146)
Ending Balance	3,354,342	3,333,858	3,286,891	3,251,128	3,242,565	3,251,313	3,354,342	3,251,128
Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(38,680)				(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							2,768
Net current-period other comprehensive income, net of tax							2,768
Ending Balance	(35,912)						(35,912)
Unrealized Gains/Losses on AFS Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(18,289)				(18,289)
Reclass due to adopting Accounting Standard Update 2017-12							0
Other comprehensive income before reclassification							36,625
Amounts reclassified from accumulated other comprehensive income							1,795
Net current-period other comprehensive income, net of tax							38,420
Ending Balance	20,131						20,131
Accumulated Unrealized Loss On Securities Available For Sale Transferred To Held To Maturity [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(50)				(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						0
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(20,367)	(39,270)	(57,019)	(70,001)	(64,553)	(42,025)	(57,019)	(42,025)
Reclass due to adopting Accounting Standard Update 2017-12			50			(6,353)	50
Other comprehensive income before reclassification							36,625
Amounts reclassified from accumulated other comprehensive income							4,563
Net current-period other comprehensive income, net of tax	4,586	18,903	17,699	(6,659)	(5,448)	(16,039)	41,188
Ending Balance	$ (15,781)	$ (20,367)	$ (39,270)	$ (76,660)	$ (70,001)	$ (64,553)	$ (15,781)	$ (76,660)

Comprehensive Income - Reclassi

Comprehensive Income - Reclassifications Out of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands		3 Months Ended						9 Months Ended
		Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Available for sale ("AFS") securities:
Income before income taxes		$ 82,975			$ 82,338			$ 248,681	$ 247,458
Related income tax effect		(17,010)			(17,926)			(51,867)	(55,066)
Net income		65,965	$ 67,207	$ 63,642	64,412	$ 66,274	$ 61,706	196,814	192,392
Pension plan:
Income before income taxes		82,975			82,338			248,681	247,458
Related income tax effect		(17,010)			(17,926)			(51,867)	(55,066)
Net income		$ 65,965	$ 67,207	$ 63,642	$ 64,412	$ 66,274	$ 61,706	196,814	$ 192,392
Reclassification out of Accumulated Other Comprehensive Income [Member]
Available for sale ("AFS") securities:
Net income								4,563
Pension plan:
Net income								4,563
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								152
Income before income taxes								2,340
Related income tax effect								(545)
Net income								1,795
Pension plan:
Income before income taxes								2,340
Related income tax effect								(545)
Net income								1,795
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Available for sale ("AFS") securities:
Income before income taxes								3,553
Related income tax effect								(785)
Net income								2,768
Pension plan:
Recognized net actuarial loss	[1]							3,553
Income before income taxes								3,553
Related income tax effect								(785)
Net income								$ 2,768
[1]	This AOCI component is included in the net periodic pension cost (see Note 14, Employee Benefit Plans)

Earnings Per Share - Reconcilia

Earnings Per Share - 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		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Distributed earnings allocated to common stock	$ 34,434	$ 35,234	$ 103,711	$ 106,429
Undistributed earnings allocated to common stock	31,378	29,060	92,654	85,617
Net earnings allocated to common shareholders	$ 65,812	$ 64,294	$ 196,365	$ 192,046
Average common shares outstanding	101,432,243	103,617,590	101,698,530	104,382,094
Common stock equivalents	279,497	316,369	268,605	297,782
Average diluted shares outstanding	101,711,740	103,933,959	101,967,135	104,679,876
Earnings per basic common share	$ 0.65	$ 0.62	$ 1.93	$ 1.84
Earnings per diluted common share	$ 0.65	$ 0.62	$ 1.93	$ 1.83

Variable Interest Entities - Ad

Variable Interest Entities - Additional Information (Detail)	9 Months Ended
	Sep. 30, 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 - In

Variable Interest Entities - Information Related to Statutory Trusts (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 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

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	Sep. 30, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Aggregate Assets	$ 258,123	$ 257,754
Aggregate Liabilities	248,918	248,741
Risk Of Loss	$ 9,205	$ 9,013

Segment Information - Additiona

Segment Information - Additional Information (Detail)	9 Months Ended
	Sep. 30, 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						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Net interest income	$ 141,918			$ 148,775			$ 436,639	$ 441,940
Provision for loans losses	5,033			4,808			15,446	16,190
Other income	42,224			31,686			113,242	98,885
Other expense	96,134			93,315			285,754	277,177
Income taxes	17,010			17,926			51,867	55,066
Net income	65,965	$ 67,207	$ 63,642	64,412	$ 66,274	$ 61,706	196,814	192,392
Total assets (liabilities)	19,751,461			19,187,643			19,751,461	19,187,643
Average assets (liabilities)	19,666,608			19,047,689			19,478,924	18,769,934
Operating Segments [Member] | Community Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	143,615			149,770			442,022	444,840
Provision for loans losses	5,033			4,808			15,446	16,190
Other income	18,696			18,717			54,746	53,952
Other expense	77,312			75,255			235,610	224,240
Income taxes	16,393			19,296			51,266	57,519
Net income	63,573			69,128			194,446	200,843
Total assets (liabilities)	19,593,009			19,080,734			19,593,009	19,080,734
Average assets (liabilities)	19,579,180			18,982,530			19,410,636	18,718,295
Operating Segments [Member] | Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	203			388			369	1,028
Provision for loans losses	0			0			0	0
Other income	24,331			16,478			63,938	54,829
Other expense	20,256			17,957			53,869	57,566
Income taxes	877			(246)			2,163	(385)
Net income	3,401			(845)			8,275	(1,324)
Total assets (liabilities)	491,832			288,638			491,832	288,638
Average assets (liabilities)	398,880			303,556			330,668	284,100
Other [Member]
Segment Reporting Information [Line Items]
Net interest income	(3,052)			(3,168)			(9,584)	(8,794)
Provision for loans losses	0			0			0	0
Other income	87			58			342	(696)
Other expense	(1,696)			1,885			(1,773)	(295)
Income taxes	(260)			(1,124)			(1,562)	(2,068)
Net income	(1,009)			(3,871)			(5,907)	(7,127)
Total assets (liabilities)	17,120			12,545			17,120	12,545
Average assets (liabilities)	16,925			5,468			6,926	8,043
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net interest income	1,152			1,785			3,832	4,866
Provision for loans losses	0			0			0	0
Other income	(890)			(3,567)			(5,784)	(9,200)
Other expense	262			(1,782)			(1,952)	(4,334)
Income taxes	0			0			0	0
Net income	0			0			0	0
Total assets (liabilities)	(350,500)			(194,274)			(350,500)	(194,274)
Average assets (liabilities)	$ (328,377)			$ (243,867)			$ (269,306)	$ (240,505)