United Bankshares (UBSI) 10-Q 9 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Jul. 31, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Trading Symbol	UBSI
Entity Registrant Name	UNITED BANKSHARES INC/WV
Entity Central Index Key	729,986
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		104,961,997

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Assets
Cash and due from banks	$ 203,109	$ 175,468
Interest-bearing deposits with other banks	1,207,110	1,258,334
Federal funds sold	785	725
Total cash and cash equivalents	1,411,004	1,434,527
Securities available for sale at estimated fair value (amortized cost-$1,614,955 at June 30, 2017 and $1,277,639 at December 31, 2016)	1,606,813	1,259,214
Securities held to maturity (estimated fair value-$20,008 at June 30, 2017 and $31,178 at December 31, 2016)	20,401	33,258
Other investment securities	163,273	111,166
Loans held for sale ($335,521 and $0 at fair value at June 30, 2017 and $0 at December 31, 2016, respectively)	339,403	8,445
Loans	13,410,477	10,356,719
Less: Unearned income	(17,999)	(15,582)
Loans net of unearned income	13,392,478	10,341,137
Less: Allowance for loan losses	(72,983)	(72,771)
Net loans	13,319,495	10,268,366
Bank premises and equipment	96,330	75,909
Goodwill	1,485,113	863,767
Accrued interest receivable	48,546	39,400
Other assets	545,222	414,840
TOTAL ASSETS	19,035,600	14,508,892
Deposits:
Noninterest-bearing	4,013,445	3,171,841
Interest-bearing	9,957,776	7,625,026
Total deposits	13,971,221	10,796,867
Borrowings:
Federal funds purchased	8,260	22,235
Securities sold under agreements to repurchase	313,062	237,316
Federal Home Loan Bank borrowings	1,122,714	897,707
Other long-term borrowings	241,817	224,319
Reserve for lending-related commitments	738	1,044
Accrued expenses and other liabilities	140,367	93,657
TOTAL LIABILITIES	15,798,179	12,273,145
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-104,975,124 and 81,068,252 at June 30, 2017 and December 31, 2016, respectively, including 28,773 and 28,278 shares in treasury at June 30, 2017 and December 31, 2016, respectively	262,438	202,671
Surplus	2,125,364	1,205,778
Retained earnings	887,460	872,990
Accumulated other comprehensive loss	(36,846)	(44,717)
Treasury stock, at cost	(995)	(975)
TOTAL SHAREHOLDERS' EQUITY	3,237,421	2,235,747
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 19,035,600	$ 14,508,892

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Securities available for sale, amortized cost	$ 1,614,955	$ 1,277,639
Securities held to maturity	20,008	31,178
Loans held for sale at fair value	$ 335,521	$ 0
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	104,975,124	81,068,252
Common stock, shares in treasury	28,773	28,278

Consolidated Statements of Inco

Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Interest income
Interest and fees on loans	$ 140,899	$ 103,329	$ 249,841	$ 202,663
Interest on federal funds sold and other short-term investments	3,785	642	6,471	1,264
Interest and dividends on securities:
Taxable	8,809	8,257	16,820	15,964
Tax-exempt	1,454	859	2,573	1,692
Total interest income	154,947	113,087	275,705	221,583
Interest expense
Interest on deposits	12,586	6,670	21,054	13,555
Interest on short-term borrowings	415	365	719	579
Interest on long-term borrowings	5,701	3,327	10,067	6,440
Total interest expense	18,702	10,362	31,840	20,574
Net interest income	136,245	102,725	243,865	201,009
Provision for loan losses	8,251	7,667	14,150	11,702
Net interest income after provision for loan losses	127,994	95,058	229,715	189,307
Other income
Fees from trust and brokerage services	4,745	4,792	9,631	9,661
Fees from deposit services	8,528	8,390	16,234	16,363
Bankcard fees and merchant discounts	1,216	1,365	2,100	2,203
Other service charges, commissions, and fees	521	796	998	1,225
Income from bank-owned life insurance	1,258	1,192	2,475	2,372
Income from mortgage banking activities	22,537	789	23,212	1,517
Other income	954	430	1,315	801
Total other-than-temporary impairment losses	(16)	339	(60)	339
Portion of loss recognized in other comprehensive income	0	(372)	0	(372)
Net other-than-temporary impairment losses	(16)	(33)	(60)	(33)
Net gains on sales/calls of investment securities	763	246	4,747	250
Net investment securities gains	747	213	4,687	217
Total other income	40,506	17,967	60,652	34,359
Other expense
Employee compensation	55,461	22,631	78,932	44,910
Employee benefits	10,329	7,294	17,794	13,897
Net occupancy expense	13,913	7,773	20,697	14,026
Other real estate owned (OREO) expense	524	2,663	1,938	3,312
Equipment expense	2,471	2,058	4,436	4,065
Data processing expense	5,331	3,596	9,374	7,147
Bankcard processing expense	442	435	907	803
FDIC insurance expense	1,771	2,135	3,522	4,255
Other expense	21,895	16,270	37,379	30,496
Total other expense	112,137	64,855	174,979	122,911
Income before income taxes	56,363	48,170	115,388	100,755
Income taxes	19,304	16,378	39,520	34,257
Net income	$ 37,059	$ 31,792	$ 75,868	$ 66,498
Earnings per common share:
Basic	$ 0.37	$ 0.44	$ 0.84	$ 0.94
Diluted	0.37	0.44	0.84	0.94
Dividends per common share	$ 0.33	$ 0.33	$ 0.66	$ 0.66
Average outstanding shares:
Basic	99,197,807	71,483,703	90,100,627	70,490,596
Diluted	99,620,045	71,809,021	90,570,289	70,766,964

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 37,059	$ 31,792	$ 75,868	$ 66,498
Change in net unrealized gain (loss) on available-for-sale (AFS) securities, net of tax	3,101	4,316	6,479	12,809
Accretion of the net unrealized loss on the transfer of AFS securities to held-to-maturity (HTM) securities, net of tax	1	1	2	2
Change in pension plan assets, net of tax	695	729	1,390	1,458
Comprehensive income, net of tax	$ 40,856	$ 36,838	$ 83,739	$ 80,767

Consolidated Statement of Chang

Consolidated Statement of Changes in Shareholders' Equity (Unaudited) - 6 months ended Jun. 30, 2017 - USD ($) $ in Thousands	Total	Cardinal Financial Corporation [Member]	Deferred Compensation Plan [Member]	Common Stock [Member]	Common Stock [Member]Cardinal Financial Corporation [Member]	Common Stock [Member]Deferred Compensation Plan [Member]	Surplus [Member]	Surplus [Member]Cardinal Financial Corporation [Member]	Surplus [Member]Deferred Compensation Plan [Member]	Retained Earnings [Member]	Retained Earnings [Member]Cardinal Financial Corporation [Member]	Retained Earnings [Member]Deferred Compensation Plan [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Other Comprehensive Income (Loss) [Member]Cardinal Financial Corporation [Member]	Accumulated Other Comprehensive Income (Loss) [Member]Deferred Compensation Plan [Member]	Treasury Stock [Member]	Treasury Stock [Member]Cardinal Financial Corporation [Member]	Treasury Stock [Member]Deferred Compensation Plan [Member]
Balance at January 1, 2017 at Dec. 31, 2016	$ 2,235,747			$ 202,671			$ 1,205,778			$ 872,990			$ (44,717)			$ (975)
Beginning Balance, shares at Dec. 31, 2016				81,068,252
Comprehensive income:
Net income	75,868			$ 0			0			75,868			0			0
Other comprehensive income, net of tax:	7,871			0			0			0			7,871			0
Total comprehensive income, net of tax	83,739
Stock based compensation expense	1,680			0			1,680			0			0			0
Acquisition, Values		$ 975,254			$ 59,226			$ 916,028			$ 0			$ 0			$ 0
Acquisition, Shares					23,690,589
Purchase of treasury stock	(1)			0			0			0			0			(1)
Distribution of treasury stock for deferred compensation plan			$ 0			$ 0			$ 0			$ 0			$ 0			$ 0
Cash dividends	(61,398)						0			(61,398)			0			0
Grant of restricted stock	0			$ 224			(224)			0			0			0
Grant of restricted stock, shares				89,475
Forfeiture of restricted stock	0			$ 0			19			0			0			(19)
Common stock options exercised	$ 2,400			$ 317			2,083			0			0			0
Common stock options exercised, shares	126,808			126,808
Balance at June 30, 2017 at Jun. 30, 2017	$ 3,237,421			$ 262,438			$ 2,125,364			$ 887,460			$ (36,846)			$ (995)
Ending Balance, shares at Jun. 30, 2017				104,975,124

Consolidated Statement of Chan7

Consolidated Statement of Changes in Shareholders' Equity (Unaudited) (Parenthetical)	6 Months Ended
	Jun. 30, 2017$ / sharesshares
Cash dividends per share | $ / shares	$ 0.66
Common stock options exercised, shares	126,808
Common Stock [Member]
Purchase of treasury stock, shares	78
Grant of restricted stock, shares	89,475
Forfeiture of restricted stock, shares	420
Common stock options exercised, shares	126,808
Deferred Compensation Plan [Member] | Common Stock [Member]
Distribution of treasury stock for deferred compensation plan, shares	3
Cardinal Financial Corporation [Member] | Common Stock [Member]
Acquisition, Shares	23,690,589

Condensed Consolidated Statemen

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Statement of Cash Flows [Abstract]
NET CASH PROVIDED BY OPERATING ACTIVITIES	$ 35,919	$ 63,280
INVESTING ACTIVITIES
Proceeds from maturities and calls of securities held to maturity	12,888	5,002
Proceeds from sales of securities available for sale	234,816	103,399
Proceeds from maturities and calls of securities available for sale	332,488	90,833
Purchases of securities available for sale	(524,561)	(216,315)
Purchases of bank premises and equipment	(2,798)	(2,463)
Proceeds from sales of bank premises and equipment	13	0
Purchases of other investment securities	(43,337)	(40,245)
Proceeds from the sales of OREO properties	3,835	12,952
Proceeds from sales and redemptions of other investment securities	9,272	18,299
Acquisition of subsidiaries, net of cash paid	44,531	29,330
Net change in loans	112,150	(79,923)
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	179,297	(79,131)
FINANCING ACTIVITIES
Cash dividends paid	(52,092)	(45,969)
Acquisition of treasury stock	(1)	0
Proceeds from exercise of stock options	2,546	2,089
Repayment of long-term Federal Home Loan Bank borrowings	(825,191)	(725,051)
Proceeds from issuance of long-term Federal Home Loan Bank borrowings	845,000	795,000
Changes in:
Deposits	(174,557)	2,641
Federal funds purchased, securities sold under agreements to repurchase and other short-term borrowings	(34,444)	231,275
NET CASH (USED IN) PROVIDED BY FINANCING ACTIVITIES	(238,739)	259,985
(Decrease) increase in cash and cash equivalents	(23,523)	244,134
Cash and cash equivalents at beginning of year	1,434,527	857,335
Cash and cash equivalents at end of period	1,411,004	1,101,469
Noncash investing activities:
Transfers of loans to OREO	$ 1,951	$ 18,336

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2017
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. six-month 10-K. The accompanying consolidated interim financial statements include the accounts of United and its wholly owned subsidiaries. United considers all of its principal business activities to be bank related. All significant intercompany accounts and transactions have been eliminated in the consolidated financial statements. Dollars are in thousands, except per share or unless otherwise noted. New Accounting Standards In May 2017, the FASB issued ASU No. 2017-09, non-substantive No. 2017-09 No. 2017-09 In March 2017, the FASB issued ASU 2017-07, 2017-07 2017-07 In January 2017, the FASB issued ASU 2017-04, 2017-04 2017-04 In January 2017, the FASB issued ASU 2017-01, 2017-01 2017-01 In August 2016, the FASB issued ASU 2016-15, 2016-15 2016-15 2016-15 In June 2016, the FASB issued ASU 2016-13, 2016-13 available-for-sale 2016-13 2016-13 In March 2016, the FASB issued ASU 2016-09, 2016-09 2016-09 2016-09 2016-09 tax-related 2016-09 In February 2016, the FASB issued ASU 2016-02, 2016-02 2016-02 right-of-use 2016-02 In January 2016, the FASB issued ASU 2016-01, 2016-01 2016-01 available-for-sale 2016-01 In May 2014, the FASB issued ASU 2014-09, 2014-09 2014-09 2014-09 2014-09

Mergers and Acquisitions

Mergers and Acquisitions	6 Months Ended
	Jun. 30, 2017
Business Combinations [Abstract]
Mergers and Acquisitions	2. MERGERS AND ACQUISITIONS Cardinal Financial Corporation On April 21, 2017 (Cardinal Acquisition Date), United acquired 100% of the outstanding common stock of Cardinal Financial Corporation (Cardinal), headquartered in Tysons Corner, Virginia. The acquisition of Cardinal expands United’s existing footprint in the Washington, D.C. Metropolitan Statistical Area. At consummation, Cardinal had assets of $4,136,008, loans of $3,313,033 and deposits of $3,344,740. Cardinal also operated George Mason Mortgage, LLC (George Mason), a residential mortgage lending company based in Fairfax, Virginia with offices located in Virginia, Maryland, North Carolina, South Carolina and the District of Columbia. As a result of the merger, George Mason became an indirectly-owned subsidiary of United. The merger was accounted for under the acquisition method of accounting. The results of operations of Cardinal are included in the consolidated results of operations from the Cardinal Acquisition Date. The aggregate purchase price was approximately $975,254, including common stock valued at $972,499, stock options assumed valued at $2,741, and cash paid for fractional shares of $14. The number of shares issued in the transaction was 23,690,589, which were valued based on the closing market price of $41.05 for United’s common shares on April 21, 2017. The preliminary purchase price has been allocated to the identifiable tangible and intangible assets resulting in preliminary additions to goodwill and core deposit intangibles of $620,019 and $33,713, respectively. The core deposit intangibles are expected to be amortized over ten years. Because the consideration paid was greater than the net fair value of the acquired assets and liabilities, the Company recorded goodwill as part of the acquisition. None of the goodwill from the Cardinal acquisition is expected to be deductible for tax purposes. United used an independent third party to help determine the fair values of the assets and liabilities acquired from Cardinal. As a result of the merger, United recorded preliminary fair value discounts of $143,916 on the loans acquired, $2,282 on leases and $8,738 on trust preferred issuances, respectively, and premiums of $4,408 on land acquired, $4,994 on interest-bearing deposits and $10,740 on long-term FHLB advances, respectively. The remaining discount and premium amounts are being accreted or amortized on an accelerated or straight-line basis over each asset’s or liability’s estimated remaining life at the time of acquisition except for loans and land. The discount on loans will be accreted into income based on the discussion below. The premium on land will not be amortized. At June 30, 2017, the discounts on leases and trust preferred issuances had an average estimated remaining life of 6.25 years and 17.22 years, respectively, and the premiums on the interest-bearing deposits and the FHLB advances each had an average estimated remaining life of 5.25 years and 5.06 years, respectively. United assumed approximately $1,825 of liabilities to provide severance benefits to terminated employees of Cardinal, which has a remaining balance of $6 as of June 30, 2017. The estimated fair values of the acquired assets and assumed liabilities, including identifiable intangible assets are preliminary as of June 30, 2017 and are subject to refinement as additional information relative to closing date fair values becomes available. Any subsequent adjustments to the fair values of acquired assets and liabilities assumed, identifiable intangible assets, or other purchase accounting adjustments will result in adjustments to goodwill within the measurement period following the date of acquisition. In many cases, determining the estimated fair value of the acquired assets and assumed liabilities required United to estimate cash flows expected to result from those assets and liabilities and to discount those cash flows at appropriate rates of interest. The most significant of those determinations related to the fair valuation of acquired loans. The fair value of the acquired loans was based on the present value of the expected cash flows. Periodic principal and interest cash flows were adjusted for expected losses and prepayments, then discounted to determine the present value and summed to arrive at the estimated fair value. For such loans, the excess of cash flows expected at acquisition over the estimated fair value is recognized as interest income over the remaining lives of the loans. The difference between contractually required payments at acquisition and the cash flows expected to be collected at acquisition reflects the impact of estimated credit losses and other factors, such as prepayments. In accordance with GAAP, there was no carry-over of Cardinal’s previously established allowance for loan losses. The acquired loans were divided into loans with evidence of credit quality deterioration, which are accounted for under ASC topic 310-30 310-20 In conjunction with the Cardinal merger, the acquired loan portfolio was accounted for at fair value as follows: April 21, 2017 Contractually required principal and interest at acquisition $ 4,211,662 Contractual cash flows not expected to be collected (55,603 ) Expected cash flows at acquisition 4,156,059 Interest component of expected cash flows (986,942 ) Basis in acquired loans at acquisition – estimated fair value $ 3,169,117 Included in the above table is information related to acquired impaired loans. Specifically, contractually required principal and interest, cash flows expected to be collected and estimated fair value of acquired impaired loans were $131,575, $107,596, and $86,293, respectively. The consideration paid for Cardinal’s common equity and the preliminary amounts of acquired identifiable assets and liabilities assumed as of the Cardinal Acquisition Date were as follows: Purchase price: Value of common shares issued (23,690,589 shares) $ 972,499 Fair value of stock options assumed 2,741 Cash for fractional shares 14 Total purchase price 975,254 Identifiable assets: Cash and cash equivalents 44,545 Investment securities 395,829 Loans held for sale 271,301 Loans 3,169,117 Premises and equipment 21,926 Core deposit intangibles 33,713 Other assets 133,321 Total identifiable assets $ 4,069,752 Identifiable liabilities: Deposits $ 3,349,734 Short-term borrowings 96,215 Long-term borrowings 220,119 Other liabilities 48,449 Total identifiable liabilities 3,714,517 Preliminary fair value of net assets acquired including identifiable intangible assets 355,235 Preliminary resulting goodwill $ 620,019 The operating results of United for the six months ended June 30, 2017 include operating results of acquired assets and assumed liabilities subsequent to the Cardinal Acquisition Date. The operations of United’s metropolitan Washington D.C. geographic area, which primarily includes the acquired operations of Cardinal, provided $67,016 in total revenues, which represents net interest income plus other income, and $32,473 in net income from the period from the Cardinal Acquisition Date to June 30, 2017. These amounts are included in United’s consolidated financial statements as of and for the six months ended June 30, 2017. Cardinal’s results of operations prior to the Cardinal Acquisition Date are not included in United’s consolidated financial statements. The following table presents certain unaudited pro forma information for the results of operations for the six months ended June 30, 2017 and 2016, as if the Cardinal merger had occurred on January 1, 2017 and 2016, respectively. These results combine the historical results of Cardinal into United’s consolidated statement of income and, while certain adjustments were made for the estimated impact of certain fair valuation adjustments and other acquisition-related activity, they are not indicative of what would have occurred had the acquisition taken place on the indicated date nor are they intended to represent or be indicative of future results of operations. In particular, no adjustments have been made to eliminate the amount of Cardinal’s provision for credit losses for 2017 and 2016 that may not have been necessary had the acquired loans been recorded at fair value as of the beginning of 2017 and 2016. Additionally, United expects to achieve operating cost savings and other business synergies as a result of the acquisition which are not reflected in the pro forma amounts. Proforma Six Months Ended June 30 2017 2016 Total Revenues (1) $ 380,235 $ 373,109 Net Income 77,011 96,259 (1) Represents net interest income plus other income Bank of Georgetown After the close of business on June 3, 2016 (BOG Acquisition Date), United acquired 100% of the outstanding common stock of Bank of Georgetown, a privately held community bank headquartered in Washington, D.C. With this transaction, United continues to expand its existing footprint in the D.C. Metro Region. The results of operations of Bank of Georgetown are included in the consolidated results of operations from the BOG Acquisition Date. At consummation, Bank of Georgetown had assets of $1,278,837, loans of $999,773, and deposits of $971,369. The transaction was accounted for under the acquisition method of accounting and accordingly, assets acquired, liabilities assumed and consideration exchanged were recorded at estimated fair value on the BOG Acquisition Date. The aggregate purchase price was $264,505, including common stock valued at $253,799, stock options assumed valued at $10,696, and cash paid for fractional shares of $10. The number of shares issued in the transaction was 6,527,746, which were valued based on the closing market price of $38.88 for United’s common shares on June 3, 2016. The purchase price has been allocated to the identifiable tangible and intangible assets resulting in additions to goodwill and core deposit intangibles of $152,845 and $9,058, respectively. The core deposit intangibles are being amortized over ten years. Because the consideration paid was greater than the net fair value of the acquired assets and liabilities, the Company recorded goodwill as part of the acquisition. None of the goodwill from the Bank of Georgetown acquisition is expected to be deductible for tax purposes. United used an independent third party to help determine the fair values of the assets and liabilities acquired from the Bank of Georgetown. As a result of the merger, United recorded fair value discounts of $43,072 on the loans acquired and $1,550 on leasehold improvements, respectively, and premiums on interest-bearing deposits acquired of $316 and a premium on long-term FHLB advances of $2,659. The remaining discount and premium amounts are being amortized or accreted on an accelerated basis over each asset’s or liability’s estimated remaining life at the time of acquisition. At June 30, 2017, the premium on the interest-bearing deposits and the FHLB advances had an estimated remaining life of 0.58 years and 8.17 years, respectively. United assumed approximately $300 of liabilities to provide severance benefits to terminated employees of Bank of Georgetown, which has no remaining balance as of June 30, 2017. The estimated fair values of the acquired assets and assumed liabilities, including identifiable intangible assets are considered final as of June 30, 2017. In many cases, determining the estimated fair value of the acquired assets and assumed liabilities required United to estimate cash flows expected to result from those assets and liabilities and to discount those cash flows at appropriate rates of interest. The most significant of those determinations related to the fair valuation of acquired loans. The fair value of the acquired loans was based on the present value of the expected cash flows. Periodic principal and interest cash flows were adjusted for expected losses and prepayments, then discounted to determine the present value and summed to arrive at the estimated fair value. For such loans, the excess of cash flows expected at acquisition over the estimated fair value is recognized as interest income over the remaining lives of the loans. The difference between contractually required payments at acquisition and the cash flows expected to be collected at acquisition reflects the impact of estimated credit losses and other factors, such as prepayments. In accordance with GAAP, there was no carry-over of Bank of Georgetown’s previously established allowance for loan losses. In conjunction with the Bank of Georgetown merger, the acquired loan portfolio was accounted for at fair value as follows: June 3, 2016 Contractually required principal and interest at acquisition $ 1,275,398 Contractual cash flows not expected to be collected (33,980 ) Expected cash flows at acquisition 1,241,418 Interest component of expected cash flows (274,548 ) Basis in acquired loans at acquisition – estimated fair value $ 966,870 Included in the above table is information related to acquired impaired loans. Specifically, contractually required principal and interest, cash flows expected to be collected and estimated fair value of acquired impaired loans were $138,125, $117,564, and $95,570, respectively. The consideration paid for Bank of Georgetown’s common equity and the fair value of acquired identifiable assets and liabilities assumed as of the BOG Acquisition Date were as follows: Purchase price: Value of common shares issued (6,527,746 shares) $ 253,799 Fair value of stock options assumed 10,696 Cash for fractional shares 10 Total purchase price 264,505 Identifiable assets: Cash and cash equivalents 29,340 Investment securities 219,783 Loans 966,870 Premises and equipment 5,574 Core deposit intangibles 9,058 Other assets 31,605 Total identifiable assets $ 1,262,230 Identifiable liabilities: Deposits $ 971,685 Short-term borrowings 101,021 Long-term borrowings 67,659 Other liabilities 11,532 Total identifiable liabilities 1,151,897 Fair value of net assets acquired including identifiable intangible assets 110,333 Resulting goodwill $ 154,172

Investment Securities

Investment Securities	6 Months Ended
	Jun. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Investment Securities	3. INVESTMENT SECURITIES Securities held for indefinite periods of time and all marketable equity securities 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. June 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Cumulative OTTI in AOCI (1) U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 116,784 $ 910 $ 296 $ 117,398 $ 0 State and political subdivisions 308,153 2,410 2,768 307,795 0 Residential mortgage-backed securities Agency 730,688 3,954 4,576 730,066 0 Non-agency 5,748 600 0 6,348 86 Commercial mortgage-backed securities Agency 367,698 2,354 985 369,067 0 Asset-backed securities 0 0 0 0 0 Trust preferred collateralized debt obligations 47,759 1,531 11,206 38,084 25,952 Single issue trust preferred securities 13,390 292 1,338 12,344 0 Other corporate securities 14,997 187 0 15,184 0 Marketable equity securities 9,738 798 9 10,527 0 Total $ 1,614,955 $ 13,036 $ 21,178 $ 1,606,813 $ 26,038 December 31, 2016 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 $ 95,247 $ 698 $ 159 $ 95,786 $ 0 State and political subdivisions 196,350 1,364 4,902 192,812 0 Residential mortgage-backed securities Agency 585,208 3,999 5,111 584,096 0 Non-agency 6,629 426 12 7,043 86 Commercial mortgage-backed securities Agency 304,635 1,948 1,242 305,341 0 Asset-backed securities 217 0 0 217 0 Trust preferred collateralized debt obligations 48,558 729 15,735 33,552 25,952 Single issue trust preferred securities 13,363 284 2,170 11,477 0 Other corporate securities 14,996 66 0 15,062 0 Marketable equity securities 12,436 1,398 6 13,828 0 Total $ 1,277,639 $ 10,912 $ 29,337 $ 1,259,214 $ 26,038 (1) Non-credit before-tax. The following is a summary of securities available-for-sale Less than 12 months 12 months or longer Fair Unrealized Fair Unrealized Value Losses Value Losses June 30, 2017 U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 61,739 $ 296 $ 0 $ 0 State and political subdivisions 148,796 2,506 6,894 262 Residential mortgage-backed securities Agency 414,498 4,002 25,485 574 Non-agency 0 0 0 0 Commercial mortgage-backed securities Agency 183,803 985 0 0 Asset-backed securities 0 0 0 0 Trust preferred collateralized debt obligations 0 0 31,510 11,206 Single issue trust preferred securities 0 0 4,365 1,338 Marketable equity securities 0 0 354 9 Total $ 808,836 $ 7,789 $ 68,608 $ 13,389 Less than 12 months 12 months or longer Fair Unrealized Fair Unrealized Value Losses Value Losses December 31, 2016 U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 24,101 $ 159 $ 0 $ 0 State and political subdivisions 116,300 4,902 0 0 Residential mortgage-backed securities Agency 309,376 5,111 0 0 Non-agency 0 0 218 12 Commercial mortgage-backed securities Agency 162,479 1,242 0 0 Asset-backed securities 0 0 0 0 Trust preferred collateralized debt obligations 0 0 28,579 15,735 Single issue trust preferred securities 0 0 8,185 2,170 Marketable equity securities 357 6 0 0 Total $ 612,613 $ 11,420 $ 36,982 $ 17,917 Marketable 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 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 those 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 of United and its subsidiaries. Three Months Ended June 30 Six Months Ended June 30 2017 2016 2017 2016 Proceeds from sales and calls $ 468,506 $ 159,232 $ 567,304 $ 194,231 Gross realized gains 845 250 1,059 256 Gross realized losses 82 4 82 6 At June 30, 2017, gross unrealized losses on available for sale securities were $21,178 on 410 securities of a total portfolio of 821 available for sale securities. Securities in an unrealized loss position at June 30, 2017 consisted primarily of pooled trust preferred collateralized debt obligations (“Trup Cdos”), state and political subdivision securities, single issue trust preferred securities and agency residential mortgage-backed securities. The Trup Cdos and the single issue trust preferred securities relate mainly to securities of financial institutions. The state and political subdivisions securities relate to securities issued by various municipalities The agency residential mortgage-backed securities relate to residential properties and provide a guaranty of full and timely payments of principal and interest by the issuing agency. 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 $308,153 at June 30, 2017. As of June 30, 2017, approximately 76% 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 June 30, 2017. 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 June 30, 2017. 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 $1,098,386 at June 30, 2017. Of the $1,098,386 amount, $367,698 was related to agency commercial mortgage-backed securities and $730,688 was related to agency residential mortgage-backed securities. Each of the agency mortgage-backed securities provides a guarantee of full and timely payments of principal and interest by the issuing agency. Based upon management’s analysis and judgment, it was determined that none of the agency mortgage-backed securities were other-than-temporarily impaired at June 30, 2017. Non-agency United’s non-agency non-agency non-agency non-agency non-agency non-credit 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). Management reviews each issuer’s current and projected earnings trends, asset quality, capitalization levels, and other key factors. Upon completing the review for the second quarter of 2017, it was determined that none of the single issue securities were other-than-temporarily impaired. All single-issue trust preferred securities are currently receiving interest payments. The available for sale single issue trust preferred securities’ ratings ranged from a low of Ba1 to a high of BBB-. Trust preferred collateralized debt obligations (Trup Cdos) In order to determine how and when the Company recognizes OTTI, 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 June 30, 2017, the Company has determined that it does not intend to sell any pooled trust preferred security 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. The Company discounts the security-specific cash flow projection at the security-specific interest rate and compares the present value to the amortized cost. Management’s cash flow analysis was performed for each security and considered the current deferrals and defaults within the underlying collateral, the likelihood that current deferrals would cure or ultimately default, potential future deferrals and defaults, potential prepayments, cash reserves, excess interest spread, credit analysis of the underlying collateral and the priority of payments in the cash flow structure. The underlying collateral analysis for each issuer took into consideration multiple factors including capital adequacy, earnings trends and asset quality. After completing its analysis of estimated cash flows, management determined that none of the Trup Cdos experienced an adverse change in cash flows during the second quarter of 2017, as the expected discounted cash flows from these particular securities were greater than or equal to the discounted cash flows originally expected at purchase or from the previous date of other-than-temporary impairment (cash flows are discounted at the contractual coupon rate for purposes of assessing OTTI). There was no credit-related other-than-temporary impairment recognized in earnings for the second quarter of 2017 related to these securities. The balance of noncredit-related other-than-temporary impairment recognized on United’s Trup Cdo portfolio was $25,952 at June 30, 2017. The following is a summary of the available for sale Trup Cdos as of June 30, 2017: Amortized Cost Class Amortized Cost Fair Value Unrealized Loss Investment Split Below Senior – Bank $ 5,356 $ 5,318 $ 38 $ 3,558 $ 0 $ 1,798 Mezzanine – Bank (now in senior position) 11,268 9,377 1,891 0 2,741 8,527 Mezzanine – Bank 26,095 18,878 7,217 0 0 26,095 Mezzanine – Bank & Insurance (combination) 5,040 4,511 529 0 0 5,040 Totals $ 47,759 $ 38,084 $ 9,675 $ 3,558 $ 2,741 $ 41,460 While a large difference remains between the fair value and amortized cost, the Company believes the remaining unrealized losses are related to the illiquid market for Trup Cdos rather than an adverse change in expected cash flows. The expected future cash flow substantiates the return of the remaining amortized cost of the security. The Company believes the following evidence supports the position that the remaining unrealized loss is related to the illiquid market for Trup Cdos: • The market for new issuance of Trup Cdos was robust from 2000 to 2007 with an estimated $60 billion in new issuance. The new market issuances came to an abrupt halt in 2007. • The secondary market for Trup Cdos ultimately became illiquid and although the market has improved, trading activity remains limited on these securities. In making this determination, the Company holds discussions with institutional traders to identify trends in the number and type of transactions related to the Trup Cdos. • The presence of a below-investment grade rating severely limits the pool of available buyers and contributes to the illiquidity of the market. • Trup Cdos have a more complex structure than most debt instruments, making projections of tranche returns difficult for non-specialists • The variability of cash flows at the time the securities were originated was expected to be very limited. Due to the financial crisis, Trup Cdos have experienced more substantive variability of cash flows compared to expectations, resulting in a higher risk premium when evaluating discount rates. • The limited, yet relevant, observable inputs indicate that market yield requirements for Trup Cdos, on a credit-adjusted basis, remained very high relative to discount rates at purchase and compared to other similarly rated debt securities. Overall, the Company believes the lack of new issuances, illiquid secondary market, limited pool of buyers, below investment grade ratings, and complex structures are the key drivers of the remaining unrealized losses in the Company’s Trup Cdos and the robust expected cash flow analysis substantiates the return of the remaining amortized cost under ASC topic 320. Management also considered the ratings of the Company’s bonds in its portfolio and the extent of downgrades in United’s impairment analysis. However, management considered it imperative to independently perform its own credit analysis based on cash flows as described. The ratings of the investment grade Trup Cdos in the table above range from a low of AA to a high of Aaa. The split-rated Trup Cdos range from a low of Ba1 to a high of BBB. The below investment grade Trup Cdos range from a low of D to a high of Ba2. On the Trup Cdos that have not been deemed to be other-than-temporarily impaired, the collateralization ratios range from a low of 105.0% to a high of 397.3%, with a median of 160.7%, and a weighted average of 240.5%. The collateralization ratio is defined as the current performing collateral in a security, divided by the current balance of the specific tranche the Company owns, plus any debt which is senior or pari passu with the Company’s security’s priority level. Performing collateral excludes the balance of any issuer that has either defaulted or has deferred its interest payment. It is not uncommon for the collateralization of a security that is not other-than-temporarily impaired to be less than 100% due to the excess spread built into the securitization structure. Except for the debt securities that have already been deemed to be other-than-temporarily impaired, management does not believe any other individual security with an unrealized loss as of June 30, 2017 is other-than-temporarily impaired. For these securities, United believes the decline in value resulted from changes in market interest rates, credit spreads and liquidity, not a change in the expected contractual cash flows. Based on a review of each of the securities in the investment portfolio, management concluded that it expected to recover the amortized cost basis of the investment in such securities. Equity securities The amortized cost of United’s equity securities was $9,738 at June 30, 2017. For equity securities, management has evaluated the near-term prospects of the investment in relation to the severity and duration of any impairment and based on that evaluation, management determined that no equity securities were other-than-temporarily impaired at June 30, 2017. Other investment securities (cost method) During the second quarter of 2017, United also evaluated all of its cost method investments to determine if certain events or changes in circumstances during the second quarter of 2017 had a significant adverse effect on the fair value of any of its cost method securities. United determined that there were no events or changes in circumstances during the second quarter which would have an adverse effect on the fair value of any of its cost method securities. Therefore, no impairment was recorded. 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 June 30 Six Months Ended June 30 2017 2016 2017 2016 Balance of cumulative credit losses at beginning of period $ 22,162 $ 23,773 $ 22,162 $ 23,773 Additional credit losses on securities for which OTTI was previously recognized 0 33 0 33 Reductions during the period for securities for which the amount previously recognized in other comprehensive income was recognized in earnings 0 (1,644 ) 0 (1,644 ) Balance of cumulative credit losses at end of period $ 22,162 $ 22,162 $ 22,162 $ 22,162 The amortized cost and estimated fair value of securities available for sale at June 30, 2017 and December 31, 2016 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. June 30, 2017 December 31, 2016 Estimated Estimated Amortized Fair Amortized Fair Cost Value Cost Value Due in one year or less $ 47,004 $ 46,981 $ 53,286 $ 53,330 Due after one year through five years 345,448 346,601 296,181 297,385 Due after five years through ten years 355,077 356,740 213,094 213,791 Due after ten years 857,688 845,964 702,642 680,880 Marketable equity securities 9,738 10,527 12,436 13,828 Total $ 1,614,955 $ 1,606,813 $ 1,277,639 $ 1,259,214 The amortized cost and estimated fair values of securities held to maturity are summarized as follows: June 30, 2017 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 5,242 $ 459 $ 0 $ 5,701 State and political subdivisions 5,714 12 0 5,726 Residential mortgage-backed securities Agency 27 4 0 31 Single issue trust preferred securities 9,398 0 868 8,530 Other corporate securities 20 0 0 20 Total $ 20,401 $ 475 $ 868 $ 20,008 December 31, 2016 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 5,295 $ 570 $ 0 $ 5,865 State and political subdivisions 8,598 17 0 8,615 Residential mortgage-backed securities Agency 30 5 0 35 Single issue trust preferred securities 19,315 0 2,672 16,643 Other corporate securities 20 0 0 20 Total $ 33,258 $ 592 $ 2,672 $ 31,178 Even though the market value of the held-to-maturity held-to-maturity held-to-maturity There were no gross realized gains or losses on calls and sales of held to maturity securities included in earnings for the second quarter and first six months of 2017 and 2016. The amortized cost and estimated fair value of debt securities held to maturity at June 30, 2017 and December 31, 2016 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. June 30, 2017 December 31, 2016 Estimated Estimated Amortized Fair Amortized Fair Cost Value Cost Value Due in one year or less $ 40 $ 40 $ 1,040 $ 1,041 Due after one year through five years 9,216 9,685 8,268 8,850 Due after five years through ten years 5,700 5,364 3,585 3,589 Due after ten years 5,445 4,919 20,365 17,698 Total $ 20,401 $ 20,008 $ 33,258 $ 31,178 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 $1,319,179 and $1,137,408 at June 30, 2017 and December 31, 2016, respectively.

Loans

Loans	6 Months Ended
	Jun. 30, 2017
Receivables [Abstract]
Loans	4. LOANS Major classes of loans are as follows: June 30, 2017 December 31, Commercial, financial and agricultural: Owner-occupied commercial real estate $ 1,394,507 $ 1,049,885 Nonowner-occupied commercial real estate 4,702,008 3,425,453 Other commercial loans 1,866,487 1,613,437 Total commercial, financial & agricultural 7,963,002 6,088,775 Residential real estate 3,079,160 2,403,437 Construction & land development 1,698,232 1,255,738 Consumer: Bankcard 14,098 14,187 Other consumer 655,985 594,582 Total gross loans $ 13,410,477 $ 10,356,719 The table above does not include loans held for sale of $339,403 and $8,445 at June 30, 2017 and December 31, 2016, respectively. The increase was due to the acquisition of Cardinal and it mortgage banking subsidiary, George Mason. 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 $236,466 or 1.76% of total gross loans at June 30, 2017 and $171,596 or 1.66% of total gross loans at December 31, 2016. The contractual principal in these acquired impaired loans was $320,938 and $231,096 at June 30, 2017 and December 31, 2016, respectively. The balances above do not include future accretable net interest (i.e. the difference between the undiscounted expected cash flows and the recorded investment in the loan) on the acquired impaired loans. Activity for the accretable yield for the first six months of 2017 follows: Accretable yield at the beginning of the period $ 29,165 Accretion (including cash recoveries) (6,341 ) Additions 11,356 Net reclassifications to accretable from non-accretable 12,857 Disposals (including maturities, foreclosures, and charge-offs) (1,845 ) Accretable yield at the end of the period $ 45,192 United’s subsidiary banks have made loans to the directors and officers of United and its subsidiaries, and to their affiliates. The aggregate dollar amount of these loans was $459,591 and $255,476 at June 30, 2017 and December 31, 2016, respectively.

Credit Quality

Credit Quality	6 Months Ended
	Jun. 30, 2017
Text Block [Abstract]
Credit Quality	5. 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 June 30, 2017, United had TDRs of $49,037 as compared to $21,152 as of December 31, 2016. Of the $49,037 aggregate balance of TDRs at June 30, 2017, $31,606 was on nonaccrual status and included in the “Loans on Nonaccrual Status” on the following pages. Of the $21,152 aggregate balance of TDRs at December 31, 2016, $11,106 was on nonaccrual status and included in the “Loans on Nonaccrual Status” on the following page. As of June 30, 2017, there were no commitments to lend additional funds to debtors owing receivables whose terms have been modified in TDRs. At June 30, 2017, United had restructured loans in the amount of $2,612 that were modified by a reduction in the interest rate, $4,510 that were modified by a combination of a reduction in the interest rate and the principal and $41,915 that was modified by a change in terms. A loan acquired and accounted for under ASC topic 310-30 The following table sets forth United’s troubled debt restructurings that have been restructured during the three months ended June 30, 2017 and 2016, segregated by class of loans: Troubled Debt Restructurings For the Three Months Ended June 30, 2017 June 30, 2016 Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Commercial real estate: Owner-occupied 1 $ 5,333 $ 5,333 1 $ 1,190 $ 1,188 Nonowner-occupied 0 0 0 0 0 0 Other commercial 4 21,355 21,355 1 700 700 Residential real estate 0 0 0 0 0 0 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 5 $ 26,688 $ 26,688 2 $ 1,890 $ 1,888 The following table sets forth United’s troubled debt restructurings that have been restructured during the six months ended June 30, 2017 and 2016, segregated by class of loans: Troubled Debt Restructurings For the Six Months Ended June 30, 2017 June 30, 2016 Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Commercial real estate: Owner-occupied 1 $ 5,333 $ 5,333 1 $ 1,190 $ 1,188 Nonowner-occupied 0 0 0 0 0 0 Other commercial 8 24,107 24,032 4 2,141 2,134 Residential real estate 0 0 0 1 1,400 1,400 Construction & land development 1 1,456 1,437 0 0 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 0 0 0 0 0 0 Total 10 $ 30,896 $ 30,802 6 $ 4,731 $ 4,722 During the second quarter and first six months of 2017, $26,688 and $30,802, respectively, of restructured loans were modified by a change in terms. During the second quarter and first six months of 2016, $1,888 and $3,322, respectively, of restructured loans were modified by a change in loan terms. In addition, during the first six months of 2016, $1,400 of restructured loans were modified by a combination of a reduction in the interest rate and an extension of the maturity date. In some instances, the post-modification balance on the restructured loans is larger than the pre-modification No loans restructured during the twelve-month periods ended June 30, 2017 and 2016 subsequently defaulted, resulting in a principal charge-off 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 June 30, 2017 30-89 Days Past Due 90 Days or more Past Due Total Past Due Current & Other (1) Total Financing Receivables Recorded Investment >90 Days & Accruing Commercial real estate: Owner-occupied $ 18,242 $ 5,794 $ 24,036 $ 1,370,471 $ 1,394,507 $ 261 Nonowner-occupied 19,843 23,659 43,502 4.658,506 4,702,008 0 Other commercial 19,257 76,715 95,972 1,770,515 1,866,487 1,913 Residential real estate 31,497 25,477 56,974 3,022,186 3,079,160 4,939 Construction & land development 5,985 4,250 10,235 1,687,997 1,698,232 685 Consumer: Bankcard 235 187 422 13,676 14,098 187 Other consumer 7,326 692 8,018 647,967 655,985 504 Total $ 102,385 $ 136,774 $ 239,159 $ 13,171,318 $ 13,410,477 $ 8,489 (1) Other includes loans with a recorded investment of $236,466 acquired and accounted for under ASC topic 310-30 Age Analysis of Past Due Loans As of December 31, 2016 (In thousands) 30-89 Days Past Due 90 Days or more Past Due Total Past Due Current & Other (1) Total Financing Receivables Recorded Investment >90 Days & Accruing Commercial real estate: Owner-occupied $ 5,850 $ 3,981 $ 9,831 $ 1,040,054 $ 1,049,885 $ 94 Nonowner-occupied 9,288 20,847 30,135 3,395,318 3,425,453 172 Other commercial 15,273 42,766 58,039 1,555,398 1,613,437 2,518 Residential real estate 29,976 25,991 55,967 2,347,470 2,403,437 4,216 Construction & land development 3,809 7,779 11,588 1,244,150 1,255,738 33 Consumer: Bankcard 422 141 563 13,624 14,187 141 Other consumer 10,015 1,712 11,727 582,855 594,582 1,412 Total $ 74,633 $ 103,217 $ 177,850 $ 10,178,869 $ 10,356,719 $ 8,586 (1) Other includes loans with a recorded investment of $171,596 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 June 30, 2017 December 31, 2016 Commercial real estate: Owner-occupied $ 5,533 $ 3,887 Nonowner-occupied 23,659 20,675 Other commercial 74,802 40,248 Residential real estate 20,538 21,775 Construction & land development 3,565 7,746 Consumer: Bankcard 0 0 Other consumer 188 300 Total $ 128,285 $ 94,631 United assigns credit quality indicators of pass, special mention, substandard and doubtful to its loans. For United’s loans with a corporate credit exposure, United internally assigns a grade based on the creditworthiness of the borrower. For loans with a consumer credit exposure, United internally assigns a grade based upon an individual loan’s delinquency status. United reviews and updates, as necessary, these grades on a quarterly basis. Special mention loans, with a corporate credit exposure, have potential weaknesses that deserve management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects for the loans or in the Company’s credit position at some future date. Borrowers may be experiencing adverse operating trends (declining revenues or margins) or an ill proportioned balance sheet (e.g., increasing inventory without an increase in sales, high leverage, tight liquidity). Adverse economic or market conditions, such as interest rate increases or the entry of a new competitor, may also support a special mention rating. Nonfinancial reasons for rating a credit exposure special mention include management problems, pending litigation, an ineffective loan agreement or other material structural weakness, and any other significant deviation from prudent lending practices. For loans with a consumer credit exposure, loans that are past due 30-89 A substandard loan with a corporate credit exposure is inadequately protected by the current sound worth and paying capacity of the obligor or of the collateral pledged, if any. Loans so classified have a well-defined weakness, or weaknesses, that jeopardize the liquidation of the debt by the borrower. They are characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. They require more intensive supervision by management. Substandard loans are generally characterized by current or expected unprofitable operations, inadequate debt service coverage, inadequate liquidity, or marginal capitalization. Repayment may depend on collateral or other credit risk 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 June 30, 2017 Commercial Real Estate Other Construction & Land Owner- Nonowner- Grade: Pass $ 1,308,141 $ 4,562,334 $ 1,728,795 $ 1,580,263 Special mention 21,710 48,782 21,275 19,866 Substandard 64,656 90,892 115,152 98,103 Doubtful 0 0 1,265 0 Total $ 1,394,507 $ 4,702,008 $ 1,866,487 $ 1,698,232 As of December 31, 2016 Commercial Real Estate Other Construction & Land Owner- Nonowner- Grade: Pass $ 963,503 $ 3,284,497 $ 1,463,797 $ 1,126,742 Special mention 20,490 36,462 26,537 52,327 Substandard 65,892 104,494 122,893 76,669 Doubtful 0 0 210 0 Total $ 1,049,885 $ 3,425,453 $ 1,613,437 $ 1,255,738 Credit Quality Indicators Consumer Credit Exposure As of June 30, 2017 Residential Bankcard Other Grade: Pass $ 3,024,753 $ 13,676 $ 647,858 Special mention 18,056 235 7,429 Substandard 36,351 187 698 Doubtful 0 0 0 Total $ 3,079,160 $ 14,098 $ 655,985 As of December 31, 2016 Residential Bankcard Other Grade: Pass $ 2,348,017 $ 13,624 $ 582,704 Special mention 18,240 422 10,132 Substandard 36,995 141 1,746 Doubtful 185 0 0 Total $ 2,403,437 $ 14,187 $ 594,582 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 June 30, 2017 December 31, 2016 Recorded Unpaid Related Recorded Unpaid Related With no related allowance recorded: Commercial real estate: Owner-occupied $ 66,975 $ 72,524 $ 0 $ 46,575 $ 47,108 $ 0 Nonowner-occupied 145,120 168,694 0 92,654 93,104 0 Other commercial 60,438 64,763 0 46,064 48,308 0 Residential real estate 19,318 23,406 0 22,747 24,404 0 Construction & land development 16,733 19,039 0 19,863 21,746 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 35 35 0 36 36 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 15,029 $ 15,029 $ 1,815 $ 1,787 $ 2,082 $ 815 Nonowner-occupied 14,633 14,633 2,397 17,938 17,938 2,524 Other commercial 75,327 82,784 20,595 43,774 46,188 13,441 Residential real estate 16,707 18,883 2,753 12,066 12,801 3,431 Construction & land development 1,870 6,368 490 4,940 7,899 3,206 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 0 0 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 82,004 $ 87,553 $ 1,815 $ 48,362 $ 49,190 $ 815 Nonowner-occupied 159,753 183,327 2,397 110,592 111,042 2,524 Other commercial 135,765 147,547 20,595 89,838 94,496 13,441 Residential real estate 36,025 42,289 2,753 34,813 37,205 3,431 Construction & land development 18,603 25,407 490 24,803 29,645 3,206 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 35 35 0 36 36 0 Impaired Loans For the Three Months Ended June 30, 2017 June 30, 2016 Average Interest Average Interest With no related allowance recorded: Commercial real estate: Owner-occupied $ 64,440 $ 267 $ 27,267 $ 125 Nonowner-occupied 123,259 285 62,049 186 Other commercial 59,912 271 25,816 124 Residential real estate 19,607 73 28,074 97 Construction & land development 17,155 6 22,838 40 Consumer: Bankcard 0 0 0 0 Other consumer 36 0 33 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 14,284 $ 156 $ 4,552 $ 30 Nonowner-occupied 14,443 139 8,615 195 Other commercial 72,612 569 37,584 98 Residential real estate 15,434 65 8,174 19 Construction & land development 2,626 21 11,919 48 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 78,724 $ 423 $ 31,819 $ 155 Nonowner-occupied 137,702 424 70,664 381 Other commercial 132,524 840 63,400 222 Residential real estate 35,041 138 36,248 116 Construction & land development 19,781 27 34,757 88 Consumer: Bankcard 0 0 0 0 Other consumer 36 0 33 0 Impaired Loans For the Six Months Ended June 30, 2017 June 30, 2016 Average Interest Average Interest With no related allowance recorded: Commercial real estate: Owner-occupied $ 58,148 $ 635 $ 33,221 $ 184 Nonowner-occupied 106,125 499 66,395 393 Other commercial 55,861 589 27,861 224 Residential real estate 21,950 132 26,872 237 Construction & land development 21,906 11 25,916 67 Consumer: Bankcard 0 0 0 0 Other consumer 34 0 34 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 10,274 $ 293 $ 4,564 $ 57 Nonowner-occupied 15,765 274 8,507 238 Other commercial 62,688 1,194 34,134 228 Residential real estate 13,636 73 9,339 25 Construction & land development 3,629 43 12,994 90 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 68,422 $ 928 $ 37,785 $ 241 Nonowner-occupied 121,890 773 74,902 631 Other commercial 118,549 1,783 61,995 452 Residential real estate 35,586 205 36,211 262 Construction & land development 25,535 54 38,910 157 Consumer: Bankcard 0 0 0 0 Other consumer 34 0 34 0 At June 30, 2017 and December 31, 2016, other real estate owned (“OREO”) included in other assets in the Consolidated Balance Sheets was $28,157 and $31,510, respectively. OREO consists of real estate acquired in foreclosure or other settlement of loans. Such assets are carried at the lower of the investment in the assets or the fair 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 June 30, 2017 and December 31, 2016, the recorded investment of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process was $529 and $660, respectively.

Allowance for Credit Losses

Allowance for Credit Losses	6 Months Ended
	Jun. 30, 2017
Receivables [Abstract]
Allowance for Credit Losses	6. 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 six months ended June 30, 2017, the re-estimation 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 $738 and $1,044 at June 30, 2017 and December 31, 2016, 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 June 30, 2017 Commercial Real Estate Construction Allowance Owner- Nonowner- Other Residential Real & Land Consumer Estimated Total Allowance for Loan Losses: Beginning balance $ 4,212 $ 6,615 $ 36,173 $ 14,123 $ 8,615 $ 2,822 $ 315 $ 72,875 Charge-offs 287 190 6,631 1,287 780 747 0 9,922 Recoveries 1,110 14 161 159 201 134 0 1,779 Provision 94 660 7,584 (516 ) (522 ) 506 445 8,251 Ending balance $ 5,129 $ 7,099 $ 37,287 $ 12,479 $ 7,514 $ 2,715 $ 760 $ 72,983 Allowance for Loan Losses and Carrying Amount of Loans For the Six Months Ended June 30, 2017 Commercial Real Estate Construction Allowance Owner- Nonowner- Other Residential & Land Consumer Estimated Total Allowance for Loan Losses: Beginning balance $ 5,273 $ 6,883 $ 33,087 $ 13,770 $ 10,606 $ 2,805 $ 347 $ 72,771 Charge-offs 915 295 10,029 2,032 2,522 1,414 0 17,207 Recoveries 1,193 30 665 292 616 473 0 3,269 Provision (422 ) 481 13,564 449 (1,186 ) 851 413 14,150 Ending balance $ 5,129 $ 7,099 $ 37,287 $ 12,479 $ 7,514 $ 2,715 $ 760 $ 72,983 Ending Balance: individually evaluated for impairment $ 1,943 $ 2,372 $ 20,494 $ 2,761 $ 481 $ 0 $ 0 $ 28,051 Ending Balance: collectively evaluated for impairment $ 3,186 $ 4,727 $ 16,793 $ 9,718 $ 7,033 $ 2,715 $ 760 $ 44,932 Ending Balance: loans acquired with deteriorated credit quality $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Financing receivables: Ending balance $ 1,394,507 $ 4,702,008 $ 1,866,487 $ 3,079,160 $ 1,698,232 $ 670,083 $ 0 $ 13,410,477 Ending Balance: individually evaluated for impairment $ 38,976 $ 26,758 $ 98,644 $ 17,718 $ 2,988 $ 0 $ 0 $ 185,084 Ending Balance: collectively evaluated for impairment $ 1,319,277 $ 4,548,388 $ 1,734,526 $ 3,047,291 $ 1,669,397 $ 670,048 $ 0 $ 12,988,927 Ending Balance: loans acquired with deteriorated credit quality $ 36,254 $ 126,862 $ 33,317 $ 14,151 $ 25,847 $ 35 $ 0 $ 236,466 Allowance for Loan Losses and Carrying Amount of Loans For the Year Ended December 31, 2016 Commercial Real Estate Other Residential Construction Consumer Allowance for Total Owner- Nonowner- & Land Estimated Allowance for Loan Losses: Beginning balance $ 3,637 $ 5,309 $ 31,328 $ 15,148 $ 18,205 $ 1,995 $ 104 $ 75,726 Charge-offs 5,281 419 20,430 4,597 2,659 2,794 0 36,180 Recoveries 3,071 675 3,452 639 433 446 0 8,716 Provision 3,846 1,318 18,737 2,580 (5,373 ) 3,158 243 24,509 Ending balance $ 5,273 $ 6,883 $ 33,087 $ 13,770 $ 10,606 $ 2,805 $ 347 $ 72,771 Ending Balance: individually evaluated for impairment $ 815 $ 2,524 $ 13,441 $ 3,431 $ 3,206 $ 0 $ 0 $ 23,417 Ending Balance: collectively evaluated for impairment $ 4,458 $ 4,359 $ 19,646 $ 10,339 $ 7,400 $ 2,805 $ 347 $ 49,354 Ending Balance: loans acquired with deteriorated credit quality $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Financing receivables: Ending balance $ 1,049,885 $ 3,425,453 $ 1,613,437 $ 2,403,437 $ 1,255,738 $ 608,769 $ 0 $ 10,356,719 Ending Balance: individually evaluated for impairment $ 18,976 $ 26,835 $ 56,091 $ 14,766 $ 8,152 $ 0 $ 0 $ 124,820 Ending Balance: collectively evaluated for impairment $ 1,005,999 $ 3,323,117 $ 1,527,479 $ 2,373,969 $ 1,221,006 $ 608,733 $ 0 $ 10,060,303 Ending Balance: loans acquired with deteriorated credit quality $ 24,910 $ 75,501 $ 29,867 $ 14,702 $ 26,580 $ 36 $ 0 $ 171,596

Intangible Assets

Intangible Assets	6 Months Ended
	Jun. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	7. INTANGIBLE ASSETS The following is a summary of intangible assets subject to amortization and those not subject to amortization: June 30, 2017 Community Banking Mortgage Banking Total Gross Carrying Amount Accumulated Gross Accumulated Gross Accumulated Amortized intangible assets: Core deposit intangible assets $ 103,348 ($ 49,821 ) $ 0 ($ 0 ) $ 103,348 ($ 49,821 ) Goodwill not subject to amortization $ 1,462,152 $ 22,961 $ 1,485,113 December 31, 2016 Community Banking Total Gross Carrying Accumulated Gross Accumulated Amortized intangible assets: Core deposit intangible assets $ 69,635 ($ 46,681 ) $ 69,635 ($ 46,681 ) Goodwill not subject to amortization $ 863,767 $ 863,767 The following table provides a reconciliation of goodwill: Community Mortgage Total Goodwill at December 31, 2016 $ 863,767 $ 0 $ 863,767 Addition to goodwill from Bank of Georgetown acquisition 1,327 0 1,327 Preliminary addition to goodwill from Cardinal acquisition 597,058 22,961 620,019 Goodwill at June 30, 2017 $ 1,462,152 $ 22,961 $ 1,485,113 United incurred amortization expense on intangible assets of $2,093 and $3,141 for the quarter and six months ended June 30, 2017, respectively, and $919 and $1,664 for the quarter and six months ended June 30, 2016, respectively. The following table sets forth the anticipated amortization expense for intangible assets for the years subsequent to 2016: Year Amount 2017 $ 8,373 2018 8,774 2019 7,629 2020 6,841 2021 and thereafter 25,050

Short-Term Borrowings

Short-Term Borrowings	6 Months Ended
	Jun. 30, 2017
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 $264,000. 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 June 30, 2017, federal funds purchased were $8,260 while total securities sold under agreements to repurchase (“REPOs”) were $313,062. Included in the $313,062 of total REPOs is a wholesale REPOs of $50,000, assumed in the Virginia Commerce merger. This wholesale REPO is scheduled to mature in May of 2018. 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	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Long-Term Borrowings	9. LONG-TERM BORROWINGS United’s subsidiary banks are members 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 June 30, 2017, United had an unused borrowing amount of approximately $5,569,655 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 June 30, 2017, $1,122,714 of FHLB advances with a weighted-average interest rate of 1.43% are scheduled to mature within the next eight years. Overnight funds of $50,000 with an interest rate of 1.27% are included in the $1,122,714 above at June 30, 2017. The scheduled maturities of these FHLB borrowings are as follows: Year Amount 2017 $ 665,873 2018 131,610 2019 187,955 2020 42,364 2021 and thereafter 94,912 Total $ 1,122,714 At June 30, 2017, United had a total of fifteen 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 June 30, 2017 and December 31, 2016, the outstanding balance of the Debentures was $241,817 and $224,319, 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. If interest payments on the subordinated debt are deferred, the dividends on the Capital Securities are also deferred. Interest on the subordinated debt is cumulative. In prior quarters, the Trust Preferred Securities qualified as Tier 1 regulatory capital under the “Basel III Capital Rules” as published by United’s primary federal regulator, the Federal Reserve, in July of 2013. The “Basel III Capital Rules” established a new comprehensive capital framework for U.S. banking organizations. Because United was less than $15 billion in total consolidated assets, the Basel III Capital Rules grandfathered United’s Trust Preferred Securities as Tier 1 capital under the limitations for restricted capital elements in the general risk-based capital rules. As a result, beginning in 2015 (the adoption date), United’s Trust Preferred Securities was subject to a limit of 25 percent of Tier 1 capital elements excluding any non-qualifying phase-out. However, with the acquisition of Cardinal on April 21, 2017, United’s total consolidated assets now exceeds $15 billion. As a result, United’s Trust Preferred Securities are no longer included in United’s Tier 1 capital but are included as a component of Tier 2 capital on a permanent basis without phase-out.

Commitments and Contingent Liab

Commitments and Contingent Liabilities	6 Months Ended
	Jun. 30, 2017
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 $4,367,220 and $2,823,396 of loan commitments outstanding as of June 30, 2017 and December 31, 2016, respectively, approximately half of which expire within one year. Included in the June 30, 2017 amount are commitments to extend credit of $374,124 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 June 30, 2017, United had no outstanding commercial letters of credit and $9 as of December 31, 2016. 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 $150,978 and $121,584 as of June 30, 2017 and December 31, 2016, 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 $500 as of June 30, 2017. 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	6 Months Ended
	Jun. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	11. DERIVATIVE FINANCIAL INSTRUMENTS United uses derivative instruments to help manage adverse prices 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 the Derivatives and Hedging topic of the FASB Accounting Standards Codification. The Derivatives and Hedging topic require all derivative instruments to be carried at fair value on the balance sheet. United has designated certain derivative instruments used to manage interest rate risk as hedge relationships with certain assets, liabilities or cash flows being hedged. Certain derivatives used for interest rate risk management are not designated in a hedge relationship. Derivative instruments designated in a hedge relationship to mitigate exposure to changes in the fair value of an asset, liability, or firm commitment attributable to a particular risk, such as interest rate risk, are considered fair value hedges. Derivative instruments designated in a hedge relationship to mitigate exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. For a fair value hedge, the fair value of the interest rate swap is recognized on the balance sheet as either a freestanding asset or liability with a corresponding adjustment to the hedged financial instrument. Subsequent adjustments due to changes in the fair value of a derivative that qualifies as a fair value hedge are offset in current period earnings. For a cash flow hedge, the fair value of the interest rate swap is recognized on the balance sheet as either a freestanding asset or liability with a corresponding adjustment to other comprehensive income within shareholders’ equity, net of tax. Subsequent adjustments due to changes in the fair value of a derivative that qualifies as a cash flow hedge are offset to other comprehensive income, net of tax. The portion of a hedge that is ineffective is recognized immediately in earnings. At inception of a hedge relationship, United formally documents the hedged item, the particular risk management objective, the nature of the risk being hedged, the derivative being used, how effectiveness of the hedge will be assessed and how the ineffectiveness of the hedge will be measured. United also assesses hedge effectiveness at inception and on an ongoing basis using regression analysis. Hedge ineffectiveness is measured by using the change in fair value method. The change in fair value method compares the change in the fair value of the hedging derivative to the change in the fair value of the hedged exposure, attributable to changes in the benchmark rate. The portion of a hedge that is ineffective is recognized immediately in earnings. United through George Mason enters into interest rate lock commitments to finance residential mortgage loans with its customers. These commitments, which contain fixed expiration dates, offer the borrower an interest rate guarantee provided the loan meets underwriting guidelines and closes within the timeframe established by United. Interest rate risk arises on these commitments and subsequently closed loans if interest rates change between the time of the interest rate lock and the delivery of the loan to the investor. Market risk on interest rate lock commitments and mortgage loans held for sale is managed using corresponding forward mortgage loan sales contracts. United is a party to these forward mortgage loan sales contracts to sell loans servicing released and short sales of mortgage-backed securities. When the interest rate is locked with the borrower, the rate lock commitment, forward sale agreement, and mortgage-backed security position are undesignated derivatives and marked to fair value through earnings. The fair value of the rate lock derivative includes the servicing premium and the interest spread for the difference between retail and wholesale mortgage rates. Income from mortgage banking activities includes the gain recognized for the period presented and associated elements of fair value. United sells mortgage loans on either a best efforts or mandatory delivery basis. For both types of loans sold, 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. 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 June 30, 2017 and December 31, 2016. Asset Derivatives June 30, 2017 December 31, 2016 Balance Sheet Location Notional Amount Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Fair Value Hedges: Interest rate swap contracts (hedging commercial loans) Other assets $ 14,853 $ 27 Other assets $ 24 Total derivatives designated as hedging instruments $ 14,853 $ 27 $ 24 Derivatives not designated as hedging instruments Interest rate swap contracts Other assets $ 14,149 $ 2,032 Other assets $ 2,267 TBA mortgage-backed securities Other assets 435,000 926 Other assets 0 Interest rate lock commitments Other assets 263,962 10,175 Other assets 0 Total derivatives not designated as hedging instruments $ 713,111 $ 13,133 $ 2,267 Total asset derivatives $ 727,964 $ 13,160 $ 2,291 Liability Derivatives June 30, 2017 December 31, 2016 Balance Sheet Location Notional Amount Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Fair Value Hedges: Interest rate swap contracts (hedging commercial loans) Other liabilities $ 77,767 $ 472 Other liabilities $ 338 Total derivatives designated as hedging instruments $ 77,767 $ 472 $ 338 Derivatives not designated as hedging instruments Interest rate swap contracts Other liabilities $ 14,149 $ 2,032 Other liabilities $ 2,267 Forward loan sales commitments Other liabilities 61,317 170 Other liabilities 0 Interest rate lock commitments Other liabilities 105,691 531 Other liabilities 0 Total derivatives not designated as hedging instruments $ 181,157 $ 2,733 $ 2,267 Total liability derivatives $ 258,924 $ 3,205 $ 2,605 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 six months ended June 30, 2017 and 2016 are presented as follows: Three Months Ended Income Statement Location June 30, June 30, Derivatives in hedging relationships Fair Value Hedges: Interest rate swap contracts Interest income/ (expense) $ (282 ) $ (249 ) Total derivatives in hedging relationships $ (282 ) $ (249 ) Derivatives not designated as hedging instruments Forward loan sales commitments Income from Mortgage (170 ) 0 TBA mortgage-backed securities Income from Mortgage 2,784 0 Interest rate lock commitments Income from Mortgage 1,019 0 Total derivatives not designated as hedging instruments $ 3,633 $ 0 Total derivatives $ 3,351 $ (249 ) Six Months Ended Income Statement Location June 30, June 30, Derivatives in fair value hedging relationships Fair Value Hedges: Interest rate swap contracts Interest income/ (expense) $ (440 ) $ 32 Cash Flow Hedges: Forward loan sales commitments Other income 0 0 Total derivatives in hedging relationships $ (440 ) $ 32 Derivatives not designated as hedging instruments Forward loan sales commitments Income from Mortgage (170 ) 0 TBA mortgage-backed securities Income from Mortgage 2,784 0 Interest rate lock commitments Income from Mortgage 1,019 0 Total derivatives not designated as hedging instruments $ 3,633 $ 0 Total derivatives $ 3,193 $ 32

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2017
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. Assets and Liabilities Measured at Fair Value on a Recurring Basis 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 bid-ask available-for-sale 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” 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 0.27% to 0.40% with a weighted average increase of 0.36%. 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 June 30, 2017 and December 31, 2016, segregated by the level of the valuation inputs within the fair value hierarchy. Fair Value at June 30, 2017 Using Description Balance as of June 30, 2017 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 $ 117,398 $ 0 $ 117,398 $ 0 State and political subdivisions 307,795 0 307,795 0 Residential mortgage-backed securities Agency 730,066 0 730,066 0 Non-agency 6,348 0 6,348 0 Commercial mortgage-backed securities Agency 369,067 0 369,067 0 Trust preferred collateralized debt obligations 38,084 0 0 38,084 Single issue trust preferred securities 12,344 0 12,344 0 Other corporate securities 15,184 0 15,184 0 Total available for sale debt securities 1,596,286 0 1,558,202 38,084 Available for sale equity securities: Financial services industry 3,252 387 2,865 0 Equity mutual funds (1) 6,111 6,111 0 0 Other equity securities 1,164 1,164 0 0 Total available for sale equity securities 10,527 7,662 2,865 0 Total available for sale securities 1,606,813 7,662 1,561,067 38,084 Loans held for sale 335,521 0 0 335,521 Derivative financial assets: Interest rate swap contracts 2,059 0 2.059 0 Interest rate lock commitments 10,175 0 0 10,175 TBA mortgage-backed securities 926 926 0 0 Total derivative financial assets 13,160 926 2,059 10,175 Liabilities Derivative financial liabilities: Interest rate swap contracts 2,504 0 2,504 0 Forward sales commitments 170 0 170 0 Interest rate lock commitments 531 0 531 0 Total derivative financial liabilties 3,205 0 3,205 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, 2016 Using Description Balance as of December 31, 2016 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 $ 95,786 $ 0 $ 95,786 $ 0 State and political subdivisions 192,812 0 192,812 0 Residential mortgage-backed securities Agency 584,096 0 584,096 0 Non-agency 7,043 0 7,043 0 Asset-backed securities 217 0 217 0 Commercial mortgage-backed securities Agency 305,341 0 305,341 0 Trust preferred collateralized debt obligations 33,552 0 0 33,552 Single issue trust preferred securities 11,477 0 11,477 0 Other corporate securities 15,062 0 15,062 0 Total available for sale debt securities 1,245,386 0 1,211,834 33,552 Available for sale equity securities: Financial services industry 10,735 1,372 9,363 0 Equity mutual funds (1) 1,820 1,820 0 0 Other equity securities 1,273 1,273 0 0 Total available for sale equity securities 13,828 4,465 9,363 0 Total available for sale securities 1,259,214 4,465 1,221,197 33,552 Derivative financial assets: Interest rate swap contracts 2,291 0 2,291 0 Liabilities Derivative financial liabilities: Interest rate swap contracts 2,605 0 2,605 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 six months ended June 30, 2017 and the year ended December 31, 2016. The following table presents additional information about financial assets and liabilities measured at fair value at June 30, 2017 and December 31, 2016 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 June 30, 2017 December 31, Balance, beginning of period $ 33,552 $ 34,686 Total gains or losses (realized/unrealized): Included in earnings (or changes in net assets) 0 0 Included in other comprehensive income 4,532 (1,134 ) Purchases, issuances, and settlements 0 0 Transfers in and/or out of Level 3 0 0 Balance, end of period $ 38,084 $ 33,552 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 June 30, 2017 December 31, Balance, beginning of period $ 0 $ 0 Acquired in Cardinal merger 271,301 0 Originations 786,318 0 Sales (732,091 ) 0 Total gains or losses during the period recognized in earnings 21,993 0 Transfers in and/or out of Level 3 (12,000 ) 0 Balance, end of period $ 335,521 $ 0 The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at reporting date $ 0 $ 0 Certain financial assets are measured at fair value on a nonrecurring basis in accordance with GAAP. Adjustments to the fair value of these assets usually result from the application of lower-of-cost-or-market 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 June 30, 2017 Six Months Ended June 30, 2017 Assets Loans held for sale Income from mortgage banking activities $ (2,439 ) $ (2,439 ) 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: June 30, 2017 December 31, 2016 Description Unpaid Fair Value Fair Value Over/(Under) Unpaid Principal Balance Unpaid Principal Balance Fair Value Fair Value Over/(Under) Unpaid Principal Balance Assets Loans held for sale $ 326,741 $ 335,521 $ 8,780 $ 0 $ 0 $ 0 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 Impaired Loans OREO bi-annual Intangible Assets: The following table summarizes United’s financial assets that were measured at fair value on a nonrecurring basis during the period: Carrying value at June 30, 2017 Description Balance as of June 30, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) YTD Losses Assets Impaired Loans 123,566 0 59,465 64,101 6,837 OREO 28,157 0 28,157 0 992 Carrying value at December 31, 2016 Description Balance as of December 31, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) YTD Losses Assets Impaired Loans $ 80,505 $ 0 $ 27,609 $ 52,896 $ 5,119 OREO 31,510 0 31,510 0 2,086 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 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) June 30, 2017 Cash and cash equivalents $ 1,411,004 $ 1,411,004 $ 0 $ 1,411,004 $ 0 Securities available for sale 1,606,813 1,606,813 7,662 1,561,067 38,084 Securities held to maturity 20,401 20,008 0 16,988 3,020 Other securities 163,273 155,109 0 0 155,109 Loans held for sale 339,403 339,403 0 3,882 335,521 Loans 13,319,495 12,791,323 0 0 12,791,323 Derivative financial assets 13,160 13,160 926 2,059 10,175 Deposits 13,971,221 13,956,271 0 13,956,271 0 Short-term borrowings 321,322 321,322 0 321,322 0 Long-term borrowings 1,364,531 1,331,638 0 1,331,638 0 Derivative financial liabilities 3,205 3,205 0 3,205 0 December 31, 2016 Cash and cash equivalents $ 1,434,527 $ 1,434,527 $ 0 $ 1,434,527 $ 0 Securities available for sale 1,259,214 1,259,214 4,465 1,221,197 33,552 Securities held to maturity 33,258 31,178 0 28,158 3,020 Other securities 111,166 105,608 0 0 105,608 Loans held for sale 8,445 8,445 0 8,445 0 Loans 10,268,366 10,122,486 0 0 10,122,486 Derivative financial assets 2,291 2,291 0 2,291 0 Deposits 10,796,867 10,785,294 0 10,785,294 0 Short-term borrowings 209,551 209,551 0 209,551 0 Long-term borrowings 1,172,026 1,142,782 0 1,142,782 0 Derivative financial liabilities 2,605 2,605 0 2,605 0

Stock Based Compensation

Stock Based Compensation	6 Months Ended
	Jun. 30, 2017
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 and replaced the 2011 Long-Term Incentive Plan (2011 LTI Plan) which expired during the second quarter of 2016. An award granted under the 2016 LTI Plan may consist of any non-qualified non-employee non-employee S-8 non-qualified Compensation expense of $998 and $1,680 related to the nonvested awards under United’s Long-Term Incentive Plans was incurred for the second quarter and first six months of 2017, respectively, as compared to the compensation expense of $672 and $1,330 related to the nonvested awards under United’s Long-Term Incentive Plans incurred for the second quarter and first six months of 2016, 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 June 30, 2017, and the changes during the first six months of 2017 are presented below: Six Months Ended June 30, 2017 Weighted Average Aggregate Remaining Intrinsic Contractual Exercise Shares Value Term (Yrs.) Price Outstanding at January 1, 2017 1,411,735 $ 28.05 Assumed in Cardinal merger 153,602 21.47 Granted 253,417 45.27 Exercised (126,808 ) 21.20 Forfeited or expired (2,430 ) 41.47 Outstanding at June 30, 2017 1,689,516 $ 16,186 6.0 $ 30.52 Exercisable at June 30, 2017 1,172,594 $ 14,992 4.8 $ 26.41 The following table summarizes the status of United’s nonvested stock option awards during the first six months of 2017: Shares Weighted-Average Nonvested at January 1, 2017 430,278 $ 6.84 Granted 253,417 8.85 Vested (165,273 ) 6.63 Forfeited or expired (1,500 ) 8.85 Nonvested at June 30, 2017 516,922 $ 7.88 During the six months ended June 30, 2017 and 2016, 126,808 and 105,010 shares, respectively, were issued in connection with stock option exercises. All shares issued in connection with stock option exercises for the six months ended June 30, 2017 and 2016 were issued from authorized and unissued stock. The total intrinsic value of options exercised under the Plans during the six months ended June 30, 2017 and 2016 was $2,501 and $1,774 respectively. Restricted Stock Under the 2011 LTI Plan, United may award restricted common shares to key employees and non-employee The following summarizes the changes to United’s restricted common shares for the period ended June 30, 2017: Number Weighted-Average Outstanding at January 1, 2017 137,268 $ 33.61 Granted 89,475 45.27 Vested (53,424 ) 32.17 Forfeited (420 ) 45.30 Outstanding at June 30, 2017 172,899 $ 40.06

Employee Benefit Plans

Employee Benefit Plans	6 Months Ended
	Jun. 30, 2017
Retirement Benefits [Abstract]
Employee Benefit Plans	14. EMPLOYEE BENEFIT PLANS United has a defined benefit retirement plan covering a majority of all 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. 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. As of December 31, 2016, United changed the method used to estimate the interest cost component of net periodic benefit cost for the Plan. Under the previous method, appropriate spot rates were used to discount the projected benefit obligation (PBO) cash flows based on date of measurement. Then, a single aggregated discount rate was calculated such that the present value of the PBO remained the same. This rate is technically a weighted-average of the spot rates. This single discount rate was applied to the interest and service costs as well. Under the full yield curve approach, separate discount rates are used to calculate the present value for each projected cash flow. This does not have any impact on the present value of the PBO as the PBO was originally discounted with spot rates. The adoption of this method concerns the manner in which it affects interest and service costs. This new method constitutes a change in an accounting estimate under the provisions of ASC topic 250, “Accounting Changes and Error Corrections,” that is inseparable from a change in accounting principle and was accounted for prospectively, with the resulting change impacting the recognition of net periodic pension cost beginning January 1, 2017. The impact of this accounting change on United’s net periodic pension cost for the second quarter and first six months of 2017 was a decline of $249 and $496, respectively, in expense from the amount that would have been recorded under the previous method. Included in accumulated other comprehensive income at December 31, 2016 are unrecognized actuarial losses of $53,991 ($34,014 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, 2017 is $4,411 ($2,779 net of tax). Net periodic pension cost for the three and six months ended June 30, 2017 and 2016 included the following components: Three Months Ended June 30 Six Months Ended June 30 2017 2016 2017 2016 Service cost $ 569 $ 608 $ 1,131 $ 1,215 Interest cost 1,279 1,456 2,544 2,912 Expected return on plan assets (2,049 ) (2,012 ) (4,076 ) (4,024 ) Recognized net actuarial loss 1,100 1,149 2,187 2,297 Net periodic pension (benefit) cost $ 899 $ 1,201 $ 1,786 $ 2,400 Weighted-Average Assumptions: Discount rate 4.49 % 4.75 % 4.49 % 4.75 % Expected return on assets 7.00 % 7.25 % 7.00 % 7.25 % 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	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017, United has provided a liability for $2,966 of unrecognized tax benefits related to various federal and state income tax matters. The entire amount of unrecognized tax benefits, if recognized, would impact United’s effective tax rate. Over the next 12 months, the statute of limitations will close on certain income tax periods. However, at this time, United cannot reasonably estimate the amount of tax benefits it may recognize over the next 12 months. United is currently open to audit under the statute of limitations by the Internal Revenue Service for the years ended December 31, 2013, 2014 and 2015 and certain State Taxing authorities for the years ended December 31, 2013 through 2015. As of June 30, 2017 and 2016, the total amount of accrued interest related to uncertain tax positions was $609 and $772, respectively. United accounts for interest and penalties related to uncertain tax positions as part of its provision for federal and state income taxes.

Comprehensive Income

Comprehensive Income	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Comprehensive Income	16. COMPREHENSIVE INCOME The components of total comprehensive income for the three and six months ended June 30, 2017 and 2016 are as follows: Three Months Ended Six Months Ended June 30 June 30 2017 2016 2017 2016 Net Income $ 37,059 $ 31,792 $ 75,868 $ 66,498 Available for sale (“AFS”) securities: AFS securities with OTTI charges during the period (16 ) (77 ) (60 ) (77 ) Related income tax effect 6 28 22 28 Less: OTTI charges recognized in net income 16 33 60 33 Related income tax benefit (6 ) (12 ) (22 ) (12 ) Reclassification of previous noncredit OTTI to credit OTTI 0 415 0 415 Related income tax benefit (0 ) (150 ) (0 ) (150 ) Net unrealized (losses) gains on AFS securities with OTTI 0 237 0 237 AFS securities – all other: Change in net unrealized gain on AFS securities arising during the period 5,686 6,638 11,262 19,955 Related income tax effect (2,104 ) (2,403 ) (4,167 ) (7,224 ) Net reclassification adjustment for (gains) losses included in net income (763 ) (246 ) (977 ) (250 ) Related income tax expense (benefit) 282 90 361 91 3,101 4,079 6,479 12,572 Net effect of AFS securities on other comprehensive income 3,101 4,316 6,479 12,809 Held to maturity (“HTM”) securities: Accretion on the unrealized loss for securities transferred from AFS to the HTM investment portfolio prior to call or maturity 2 3 4 4 Related income tax expense (1 ) (2 ) (2 ) (2 ) Net effect of HTM securities on other comprehensive income 1 1 2 2 Pension plan: Recognized net actuarial loss 1,100 1,149 2,187 2,297 Related income tax benefit (405 ) (420 ) (797 ) (839 ) Net effect of change in pension plan asset on other comprehensive income 695 729 1,390 1,458 Total change in other comprehensive income 3,797 5,046 7,871 14,269 Total Comprehensive Income $ 40,856 $ 36,838 $ 83,739 $ 80,767 The components of accumulated other comprehensive income for the six months ended June 30, 2017 are as follows: Changes in Accumulated Other Comprehensive Income (AOCI) by Component (a) For the Six Months Ended June 30, 2017 Unrealized Accretion on Defined Items Total Balance at January 1, 2017 ($ 10,297 ) ($ 51 ) ($ 34,369 ) ($ 44,717 ) Other comprehensive income before reclassification 7,095 2 0 7,097 Amounts reclassified from accumulated other comprehensive income (616 ) 0 1,390 774 Net current-period other comprehensive income, net of tax 6,479 2 1,390 7,871 Balance at June 30, 2017 ($ 3,818 ) ($ 49 ) ($ 32,979 ) ($ 36,846 ) Reclassifications out of Accumulated Other Comprehensive Income (AOCI) For the Six Months Ended June 30, 2017 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 $ 0 Total other-than-temporary impairment losses Net reclassification adjustment for losses (gains) included in net income (977 ) Net gains on sales/calls of investment securities (977 ) Total before tax Related income tax effect 361 Tax expense (616 ) Net of tax Pension plan: Recognized net actuarial loss 2,187 (a) 2,187 Total before tax Related income tax effect (797 ) Tax expense 1,390 Net of tax Total reclassifications for the period $ 774 (a) This AOCI component is included in the computation of net periodic pension cost (see Note 14, Employee Benefit Plans)

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2017
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 Six Months Ended June 30 June 30 2017 2016 2017 2016 Distributed earnings allocated to common stock $ 34,562 $ 25,114 $ 61,284 $ 48,068 Undistributed earnings allocated to common stock 2,440 6,623 14,454 18,311 Net earnings allocated to common shareholders $ 37,002 $ 31,737 $ 75,738 $ 66,379 Average common shares outstanding 99,197,807 71,483,703 90,100,627 70,490,596 Equivalents from stock options 422,238 325,318 469,662 276,368 Average diluted shares outstanding 99,620,045 71,809,021 90,570,289 70,766,964 Earnings per basic common share $ 0.37 $ 0.44 $ 0.84 $ 0.94 Earnings per diluted common share $ 0.37 $ 0.44 $ 0.84 $ 0.94

Variable Interest Entities

Variable Interest Entities	6 Months Ended
	Jun. 30, 2017
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 fifteen statutory business trusts that were created for the purpose of raising funds that originally qualified for Tier I regulatory capital. As previously discussed, with the acquisition of Cardinal, 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 Capital Securities Issued Interest Rate Maturity Date Century Trust March 23, 2000 $ 8,800 10.875% Fixed March 8, 2030 United Statutory Trust III December 17, 2003 $ 20,000 3-month December 17, 2033 United Statutory Trust IV December 19, 2003 $ 25,000 3-month January 23, 2034 United Statutory Trust V July 12, 2007 $ 50,000 3-month October 1, 2037 United Statutory Trust VI September 20, 2007 $ 30,000 3-month December 15, 2037 Premier Statutory Trust II September 25, 2003 $ 6,000 3-month October 8, 2033 Premier Statutory Trust III May 16, 2005 $ 8,000 3-month June 15, 2035 Premier Statutory Trust IV June 20, 2006 $ 14,000 3-month September 23, 2036 Premier Statutory Trust V December 14, 2006 $ 10,000 3-month March 1, 2037 Centra Statutory Trust I September 20, 2004 $ 10,000 3-month September 20, 2034 Centra Statutory Trust II June 15, 2006 $ 10,000 3-month July 7, 2036 Virginia Commerce Trust II December 19, 2002 $ 15,000 6-month December 19, 2032 Virginia Commerce Trust III December 20, 2005 $ 25,000 3-month February 23, 2036 Cardinal Statutory Trust I July 27, 2004 $ 20,000 3-month September 15, 2034 UFBC Capital Trust I December 30, 2004 $ 5,000 3-month March 15, 2035 United, through its banking subsidiaries, also makes limited partner equity investments in various low income housing and community development partnerships sponsored by independent third-parties. United invests in these partnerships to either realize tax credits on its consolidated federal income tax return or for purposes of earning a return on its investment. These partnerships are considered VIEs as the limited partners lack a controlling financial interest in the entities through their inability to make decisions that have a significant effect on the operations and success of the partnerships. United’s limited partner interests in these entities is immaterial, however; these partnerships are not consolidated as United is not deemed to be the primary beneficiary. The following table summarizes quantitative information about United’s significant involvement in unconsolidated VIEs: As of June 30, 2017 As of December 31, 2016 Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Trust preferred securities $ 266,551 $ 257,636 $ 8,915 $ 240,668 $ 232,583 $ 8,085 (1) Represents investment in VIEs.

Segment Information

Segment Information	6 Months Ended
	Jun. 30, 2017
Segment Reporting [Abstract]
Segment Information	19. SEGMENT INFORMATION As a result of the Cardinal acquisition, United now operates in two business segments: community banking and mortgage banking. Prior to the Cardinal acquisition, United’s business activities were confined to just one reportable segment of community 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 prime rate. These transactions are eliminated in the consolidation process. 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 six months ended June 30, 2017 and 2016 is as follows: At and For the Three Months Ended June 30, 2017 Community Mortgage Other Consolidated Net interest income $ 138,498 $ 90 $ (2,343 ) $ 136,245 Provision for loans losses 8,251 0 0 8,251 Other income 18,223 22,393 (110 ) 40,506 Other expense 78,631 18,708 14,798 112,137 Income taxes 23,920 1,293 (5,909 ) 19,304 Net income (loss) $ 45,919 $ 2,482 $ (11,342 ) $ 37,059 Total assets $ 18,658,321 $ 382,086 $ (4,807 ) $ 19,035,600 Average assets 17,967,121 236,074 (20,180 ) 18,183,015 At and For the Three Months Ended June 30, 2016 Community Banking Other Consolidated Net interest income $ 104,676 $ (1,951 ) $ 102,725 Provision for loans losses 7,667 0 7,667 Other income 18,616 (649 ) 17,967 Other expense 64,092 763 64,855 Income taxes 17,521 (1,143 ) 16,378 Net income (loss) $ 34,012 $ (2,220 ) $ 31,792 Total assets $ 14,358,021 $ (20,009 ) $ 14,338,012 Average assets 12,820,946 (24,404 ) 12,796,542 At and For the Six Months Ended June 30, 2017 Community Banking Mortgage Banking Other Consolidated Net interest income $ 248,158 $ 90 $ (4,383 ) $ 243,865 Provision for loans losses 14,150 0 0 14,150 Other income 35,036 22,393 3,223 60,652 Other expense 141,383 18,708 14,888 174,979 Income taxes 43,724 1,293 (5,497 ) 39,520 Net income (loss) $ 83,937 $ 2,482 $ (10,551 ) $ 75,868 Total assets $ 18,658,321 $ 382,086 $ (4,807 ) $ 19,035,600 Average assets 16,210,026 118,689 (24,551 ) 16,304,164 At and For the Six Months Ended June 30, 2016 Community Banking Other Consolidated Net interest income $ 204,802 $ (3,793 ) $ 201,009 Provision for loans losses 11,702 0 11,702 Other income 35,657 (1,298 ) 34,359 Other expense 123,314 (403 ) 122,911 Income taxes 35,851 (1,594 ) 34,257 Net income (loss) $ 69,592 $ (3,094 ) $ 66,498 Total assets $ 14,358,021 $ (20,009 ) $ 14,338,012 Average assets 12,592,765 (20,790 ) 12,571,975

Summary of Significant Accoun28

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2017
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. six-month 10-K. The accompanying consolidated interim financial statements include the accounts of United and its wholly owned subsidiaries. United considers all of its principal business activities to be bank related. All significant intercompany accounts and transactions have been eliminated in the consolidated financial statements. Dollars are in thousands, except per share or unless otherwise noted.
New Accounting Standards	New Accounting Standards In May 2017, the FASB issued ASU No. 2017-09, non-substantive No. 2017-09 No. 2017-09 In March 2017, the FASB issued ASU 2017-07, 2017-07 2017-07 In January 2017, the FASB issued ASU 2017-04, 2017-04 2017-04 In January 2017, the FASB issued ASU 2017-01, 2017-01 2017-01 In August 2016, the FASB issued ASU 2016-15, 2016-15 2016-15 2016-15 In June 2016, the FASB issued ASU 2016-13, 2016-13 available-for-sale 2016-13 2016-13 In March 2016, the FASB issued ASU 2016-09, 2016-09 2016-09 2016-09 2016-09 tax-related 2016-09 In February 2016, the FASB issued ASU 2016-02, 2016-02 2016-02 right-of-use 2016-02 In January 2016, the FASB issued ASU 2016-01, 2016-01 2016-01 available-for-sale 2016-01 In May 2014, the FASB issued ASU 2014-09, 2014-09 2014-09 2014-09 2014-09
Fair Value Measurement	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.

Mergers and Acquisitions (Table

Mergers and Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2017
Schedule of Acquired Loans Accounted for at Fair Value	In conjunction with the Bank of Georgetown merger, the acquired loan portfolio was accounted for at fair value as follows: June 3, 2016 Contractually required principal and interest at acquisition $ 1,275,398 Contractual cash flows not expected to be collected (33,980 ) Expected cash flows at acquisition 1,241,418 Interest component of expected cash flows (274,548 ) Basis in acquired loans at acquisition – estimated fair value $ 966,870
Schedule of Fair Value of Acquired Identifiable Assets and Liabilities Assumed	The consideration paid for Bank of Georgetown’s common equity and the fair value of acquired identifiable assets and liabilities assumed as of the BOG Acquisition Date were as follows: Purchase price: Value of common shares issued (6,527,746 shares) $ 253,799 Fair value of stock options assumed 10,696 Cash for fractional shares 10 Total purchase price 264,505 Identifiable assets: Cash and cash equivalents 29,340 Investment securities 219,783 Loans 966,870 Premises and equipment 5,574 Core deposit intangibles 9,058 Other assets 31,605 Total identifiable assets $ 1,262,230 Identifiable liabilities: Deposits $ 971,685 Short-term borrowings 101,021 Long-term borrowings 67,659 Other liabilities 11,532 Total identifiable liabilities 1,151,897 Fair value of net assets acquired including identifiable intangible assets 110,333 Resulting goodwill $ 154,172
Cardinal Financial Corporation [Member]
Schedule of Acquired Loans Accounted for at Fair Value	In conjunction with the Cardinal merger, the acquired loan portfolio was accounted for at fair value as follows: April 21, 2017 Contractually required principal and interest at acquisition $ 4,211,662 Contractual cash flows not expected to be collected (55,603 ) Expected cash flows at acquisition 4,156,059 Interest component of expected cash flows (986,942 ) Basis in acquired loans at acquisition – estimated fair value $ 3,169,117
Schedule of Fair Value of Acquired Identifiable Assets and Liabilities Assumed	The consideration paid for Cardinal’s common equity and the preliminary amounts of acquired identifiable assets and liabilities assumed as of the Cardinal Acquisition Date were as follows: Purchase price: Value of common shares issued (23,690,589 shares) $ 972,499 Fair value of stock options assumed 2,741 Cash for fractional shares 14 Total purchase price 975,254 Identifiable assets: Cash and cash equivalents 44,545 Investment securities 395,829 Loans held for sale 271,301 Loans 3,169,117 Premises and equipment 21,926 Core deposit intangibles 33,713 Other assets 133,321 Total identifiable assets $ 4,069,752 Identifiable liabilities: Deposits $ 3,349,734 Short-term borrowings 96,215 Long-term borrowings 220,119 Other liabilities 48,449 Total identifiable liabilities 3,714,517 Preliminary fair value of net assets acquired including identifiable intangible assets 355,235 Preliminary resulting goodwill $ 620,019
Schedule of Business Acquisition Pro Forma Information	The following table presents certain unaudited pro forma information for the results of operations for the six months ended June 30, 2017 and 2016, as if the Cardinal merger had occurred on January 1, 2017 and 2016, respectively. Proforma Six Months Ended June 30 2017 2016 Total Revenues (1) $ 380,235 $ 373,109 Net Income 77,011 96,259 (1) Represents net interest income plus other income

Investment Securities (Tables)

Investment Securities (Tables)	6 Months Ended
	Jun. 30, 2017
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. June 30, 2017 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Cumulative OTTI in AOCI (1) U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 116,784 $ 910 $ 296 $ 117,398 $ 0 State and political subdivisions 308,153 2,410 2,768 307,795 0 Residential mortgage-backed securities Agency 730,688 3,954 4,576 730,066 0 Non-agency 5,748 600 0 6,348 86 Commercial mortgage-backed securities Agency 367,698 2,354 985 369,067 0 Asset-backed securities 0 0 0 0 0 Trust preferred collateralized debt obligations 47,759 1,531 11,206 38,084 25,952 Single issue trust preferred securities 13,390 292 1,338 12,344 0 Other corporate securities 14,997 187 0 15,184 0 Marketable equity securities 9,738 798 9 10,527 0 Total $ 1,614,955 $ 13,036 $ 21,178 $ 1,606,813 $ 26,038 December 31, 2016 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 $ 95,247 $ 698 $ 159 $ 95,786 $ 0 State and political subdivisions 196,350 1,364 4,902 192,812 0 Residential mortgage-backed securities Agency 585,208 3,999 5,111 584,096 0 Non-agency 6,629 426 12 7,043 86 Commercial mortgage-backed securities Agency 304,635 1,948 1,242 305,341 0 Asset-backed securities 217 0 0 217 0 Trust preferred collateralized debt obligations 48,558 729 15,735 33,552 25,952 Single issue trust preferred securities 13,363 284 2,170 11,477 0 Other corporate securities 14,996 66 0 15,062 0 Marketable equity securities 12,436 1,398 6 13,828 0 Total $ 1,277,639 $ 10,912 $ 29,337 $ 1,259,214 $ 26,038 (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 Less than 12 months 12 months or longer Fair Unrealized Fair Unrealized Value Losses Value Losses June 30, 2017 U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 61,739 $ 296 $ 0 $ 0 State and political subdivisions 148,796 2,506 6,894 262 Residential mortgage-backed securities Agency 414,498 4,002 25,485 574 Non-agency 0 0 0 0 Commercial mortgage-backed securities Agency 183,803 985 0 0 Asset-backed securities 0 0 0 0 Trust preferred collateralized debt obligations 0 0 31,510 11,206 Single issue trust preferred securities 0 0 4,365 1,338 Marketable equity securities 0 0 354 9 Total $ 808,836 $ 7,789 $ 68,608 $ 13,389 Less than 12 months 12 months or longer Fair Unrealized Fair Unrealized Value Losses Value Losses December 31, 2016 U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 24,101 $ 159 $ 0 $ 0 State and political subdivisions 116,300 4,902 0 0 Residential mortgage-backed securities Agency 309,376 5,111 0 0 Non-agency 0 0 218 12 Commercial mortgage-backed securities Agency 162,479 1,242 0 0 Asset-backed securities 0 0 0 0 Trust preferred collateralized debt obligations 0 0 28,579 15,735 Single issue trust preferred securities 0 0 8,185 2,170 Marketable equity securities 357 6 0 0 Total $ 612,613 $ 11,420 $ 36,982 $ 17,917
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 of United and its subsidiaries. Three Months Ended June 30 Six Months Ended June 30 2017 2016 2017 2016 Proceeds from sales and calls $ 468,506 $ 159,232 $ 567,304 $ 194,231 Gross realized gains 845 250 1,059 256 Gross realized losses 82 4 82 6
Summary of Unrealized Loss Positions of Available for Sale TRUP CDOs and Single Issue Trust Preferred Securities	The following is a summary of the available for sale Trup Cdos as of June 30, 2017: Amortized Cost Class Amortized Cost Fair Value Unrealized Loss Investment Split Below Senior – Bank $ 5,356 $ 5,318 $ 38 $ 3,558 $ 0 $ 1,798 Mezzanine – Bank (now in senior position) 11,268 9,377 1,891 0 2,741 8,527 Mezzanine – Bank 26,095 18,878 7,217 0 0 26,095 Mezzanine – Bank & Insurance (combination) 5,040 4,511 529 0 0 5,040 Totals $ 47,759 $ 38,084 $ 9,675 $ 3,558 $ 2,741 $ 41,460
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 June 30 Six Months Ended June 30 2017 2016 2017 2016 Balance of cumulative credit losses at beginning of period $ 22,162 $ 23,773 $ 22,162 $ 23,773 Additional credit losses on securities for which OTTI was previously recognized 0 33 0 33 Reductions during the period for securities for which the amount previously recognized in other comprehensive income was recognized in earnings 0 (1,644 ) 0 (1,644 ) Balance of cumulative credit losses at end of period $ 22,162 $ 22,162 $ 22,162 $ 22,162
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: June 30, 2017 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 5,242 $ 459 $ 0 $ 5,701 State and political subdivisions 5,714 12 0 5,726 Residential mortgage-backed securities Agency 27 4 0 31 Single issue trust preferred securities 9,398 0 868 8,530 Other corporate securities 20 0 0 20 Total $ 20,401 $ 475 $ 868 $ 20,008 December 31, 2016 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 5,295 $ 570 $ 0 $ 5,865 State and political subdivisions 8,598 17 0 8,615 Residential mortgage-backed securities Agency 30 5 0 35 Single issue trust preferred securities 19,315 0 2,672 16,643 Other corporate securities 20 0 0 20 Total $ 33,258 $ 592 $ 2,672 $ 31,178
Available-for-sale Securities [Member]
Summary of Maturities of Debt Securities Held to Maturity by Amortized Cost and Estimated Fair Value	The amortized cost and estimated fair value of securities available for sale at June 30, 2017 and December 31, 2016 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. June 30, 2017 December 31, 2016 Estimated Estimated Amortized Fair Amortized Fair Cost Value Cost Value Due in one year or less $ 47,004 $ 46,981 $ 53,286 $ 53,330 Due after one year through five years 345,448 346,601 296,181 297,385 Due after five years through ten years 355,077 356,740 213,094 213,791 Due after ten years 857,688 845,964 702,642 680,880 Marketable equity securities 9,738 10,527 12,436 13,828 Total $ 1,614,955 $ 1,606,813 $ 1,277,639 $ 1,259,214
Held-to-maturity Securities [Member]
Summary of Maturities of Debt Securities Held to Maturity by Amortized Cost and Estimated Fair Value	The amortized cost and estimated fair value of debt securities held to maturity at June 30, 2017 and December 31, 2016 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. June 30, 2017 December 31, 2016 Estimated Estimated Amortized Fair Amortized Fair Cost Value Cost Value Due in one year or less $ 40 $ 40 $ 1,040 $ 1,041 Due after one year through five years 9,216 9,685 8,268 8,850 Due after five years through ten years 5,700 5,364 3,585 3,589 Due after ten years 5,445 4,919 20,365 17,698 Total $ 20,401 $ 20,008 $ 33,258 $ 31,178

Loans (Tables)

Loans (Tables)	6 Months Ended
	Jun. 30, 2017
Receivables [Abstract]
Major Classes of Loans	Major classes of loans are as follows: June 30, 2017 December 31, Commercial, financial and agricultural: Owner-occupied commercial real estate $ 1,394,507 $ 1,049,885 Nonowner-occupied commercial real estate 4,702,008 3,425,453 Other commercial loans 1,866,487 1,613,437 Total commercial, financial & agricultural 7,963,002 6,088,775 Residential real estate 3,079,160 2,403,437 Construction & land development 1,698,232 1,255,738 Consumer: Bankcard 14,098 14,187 Other consumer 655,985 594,582 Total gross loans $ 13,410,477 $ 10,356,719
Activity for Accretable Yield	Activity for the accretable yield for the first six months of 2017 follows: Accretable yield at the beginning of the period $ 29,165 Accretion (including cash recoveries) (6,341 ) Additions 11,356 Net reclassifications to accretable from non-accretable 12,857 Disposals (including maturities, foreclosures, and charge-offs) (1,845 ) Accretable yield at the end of the period $ 45,192

Credit Quality (Tables)

Credit Quality (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 and 2016, segregated by class of loans: Troubled Debt Restructurings For the Three Months Ended June 30, 2017 June 30, 2016 Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Commercial real estate: Owner-occupied 1 $ 5,333 $ 5,333 1 $ 1,190 $ 1,188 Nonowner-occupied 0 0 0 0 0 0 Other commercial 4 21,355 21,355 1 700 700 Residential real estate 0 0 0 0 0 0 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 5 $ 26,688 $ 26,688 2 $ 1,890 $ 1,888 The following table sets forth United’s troubled debt restructurings that have been restructured during the six months ended June 30, 2017 and 2016, segregated by class of loans: Troubled Debt Restructurings For the Six Months Ended June 30, 2017 June 30, 2016 Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Number of Contracts Pre- Modification Outstanding Recorded Investment Post- Modification Outstanding Recorded Investment Commercial real estate: Owner-occupied 1 $ 5,333 $ 5,333 1 $ 1,190 $ 1,188 Nonowner-occupied 0 0 0 0 0 0 Other commercial 8 24,107 24,032 4 2,141 2,134 Residential real estate 0 0 0 1 1,400 1,400 Construction & land development 1 1,456 1,437 0 0 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 0 0 0 0 0 0 Total 10 $ 30,896 $ 30,802 6 $ 4,731 $ 4,722
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 June 30, 2017 30-89 Days Past Due 90 Days or more Past Due Total Past Due Current & Other (1) Total Financing Receivables Recorded Investment >90 Days & Accruing Commercial real estate: Owner-occupied $ 18,242 $ 5,794 $ 24,036 $ 1,370,471 $ 1,394,507 $ 261 Nonowner-occupied 19,843 23,659 43,502 4.658,506 4,702,008 0 Other commercial 19,257 76,715 95,972 1,770,515 1,866,487 1,913 Residential real estate 31,497 25,477 56,974 3,022,186 3,079,160 4,939 Construction & land development 5,985 4,250 10,235 1,687,997 1,698,232 685 Consumer: Bankcard 235 187 422 13,676 14,098 187 Other consumer 7,326 692 8,018 647,967 655,985 504 Total $ 102,385 $ 136,774 $ 239,159 $ 13,171,318 $ 13,410,477 $ 8,489 (1) Other includes loans with a recorded investment of $236,466 acquired and accounted for under ASC topic 310-30 Age Analysis of Past Due Loans As of December 31, 2016 (In thousands) 30-89 Days Past Due 90 Days or more Past Due Total Past Due Current & Other (1) Total Financing Receivables Recorded Investment >90 Days & Accruing Commercial real estate: Owner-occupied $ 5,850 $ 3,981 $ 9,831 $ 1,040,054 $ 1,049,885 $ 94 Nonowner-occupied 9,288 20,847 30,135 3,395,318 3,425,453 172 Other commercial 15,273 42,766 58,039 1,555,398 1,613,437 2,518 Residential real estate 29,976 25,991 55,967 2,347,470 2,403,437 4,216 Construction & land development 3,809 7,779 11,588 1,244,150 1,255,738 33 Consumer: Bankcard 422 141 563 13,624 14,187 141 Other consumer 10,015 1,712 11,727 582,855 594,582 1,412 Total $ 74,633 $ 103,217 $ 177,850 $ 10,178,869 $ 10,356,719 $ 8,586 (1) Other includes loans with a recorded investment of $171,596 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 June 30, 2017 December 31, 2016 Commercial real estate: Owner-occupied $ 5,533 $ 3,887 Nonowner-occupied 23,659 20,675 Other commercial 74,802 40,248 Residential real estate 20,538 21,775 Construction & land development 3,565 7,746 Consumer: Bankcard 0 0 Other consumer 188 300 Total $ 128,285 $ 94,631
Schedule of Credit Quality Indicators Information, by Class of Loans	The following tables set forth United’s credit quality indicators information, by class of loans: Credit Quality Indicators Corporate Credit Exposure As of June 30, 2017 Commercial Real Estate Other Construction & Land Owner- Nonowner- Grade: Pass $ 1,308,141 $ 4,562,334 $ 1,728,795 $ 1,580,263 Special mention 21,710 48,782 21,275 19,866 Substandard 64,656 90,892 115,152 98,103 Doubtful 0 0 1,265 0 Total $ 1,394,507 $ 4,702,008 $ 1,866,487 $ 1,698,232 As of December 31, 2016 Commercial Real Estate Other Construction & Land Owner- Nonowner- Grade: Pass $ 963,503 $ 3,284,497 $ 1,463,797 $ 1,126,742 Special mention 20,490 36,462 26,537 52,327 Substandard 65,892 104,494 122,893 76,669 Doubtful 0 0 210 0 Total $ 1,049,885 $ 3,425,453 $ 1,613,437 $ 1,255,738 Credit Quality Indicators Consumer Credit Exposure As of June 30, 2017 Residential Bankcard Other Grade: Pass $ 3,024,753 $ 13,676 $ 647,858 Special mention 18,056 235 7,429 Substandard 36,351 187 698 Doubtful 0 0 0 Total $ 3,079,160 $ 14,098 $ 655,985 As of December 31, 2016 Residential Bankcard Other Grade: Pass $ 2,348,017 $ 13,624 $ 582,704 Special mention 18,240 422 10,132 Substandard 36,995 141 1,746 Doubtful 185 0 0 Total $ 2,403,437 $ 14,187 $ 594,582
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 June 30, 2017 December 31, 2016 Recorded Unpaid Related Recorded Unpaid Related With no related allowance recorded: Commercial real estate: Owner-occupied $ 66,975 $ 72,524 $ 0 $ 46,575 $ 47,108 $ 0 Nonowner-occupied 145,120 168,694 0 92,654 93,104 0 Other commercial 60,438 64,763 0 46,064 48,308 0 Residential real estate 19,318 23,406 0 22,747 24,404 0 Construction & land development 16,733 19,039 0 19,863 21,746 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 35 35 0 36 36 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 15,029 $ 15,029 $ 1,815 $ 1,787 $ 2,082 $ 815 Nonowner-occupied 14,633 14,633 2,397 17,938 17,938 2,524 Other commercial 75,327 82,784 20,595 43,774 46,188 13,441 Residential real estate 16,707 18,883 2,753 12,066 12,801 3,431 Construction & land development 1,870 6,368 490 4,940 7,899 3,206 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 0 0 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 82,004 $ 87,553 $ 1,815 $ 48,362 $ 49,190 $ 815 Nonowner-occupied 159,753 183,327 2,397 110,592 111,042 2,524 Other commercial 135,765 147,547 20,595 89,838 94,496 13,441 Residential real estate 36,025 42,289 2,753 34,813 37,205 3,431 Construction & land development 18,603 25,407 490 24,803 29,645 3,206 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 35 35 0 36 36 0 Impaired Loans For the Three Months Ended June 30, 2017 June 30, 2016 Average Interest Average Interest With no related allowance recorded: Commercial real estate: Owner-occupied $ 64,440 $ 267 $ 27,267 $ 125 Nonowner-occupied 123,259 285 62,049 186 Other commercial 59,912 271 25,816 124 Residential real estate 19,607 73 28,074 97 Construction & land development 17,155 6 22,838 40 Consumer: Bankcard 0 0 0 0 Other consumer 36 0 33 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 14,284 $ 156 $ 4,552 $ 30 Nonowner-occupied 14,443 139 8,615 195 Other commercial 72,612 569 37,584 98 Residential real estate 15,434 65 8,174 19 Construction & land development 2,626 21 11,919 48 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 78,724 $ 423 $ 31,819 $ 155 Nonowner-occupied 137,702 424 70,664 381 Other commercial 132,524 840 63,400 222 Residential real estate 35,041 138 36,248 116 Construction & land development 19,781 27 34,757 88 Consumer: Bankcard 0 0 0 0 Other consumer 36 0 33 0 Impaired Loans For the Six Months Ended June 30, 2017 June 30, 2016 Average Interest Average Interest With no related allowance recorded: Commercial real estate: Owner-occupied $ 58,148 $ 635 $ 33,221 $ 184 Nonowner-occupied 106,125 499 66,395 393 Other commercial 55,861 589 27,861 224 Residential real estate 21,950 132 26,872 237 Construction & land development 21,906 11 25,916 67 Consumer: Bankcard 0 0 0 0 Other consumer 34 0 34 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 10,274 $ 293 $ 4,564 $ 57 Nonowner-occupied 15,765 274 8,507 238 Other commercial 62,688 1,194 34,134 228 Residential real estate 13,636 73 9,339 25 Construction & land development 3,629 43 12,994 90 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 68,422 $ 928 $ 37,785 $ 241 Nonowner-occupied 121,890 773 74,902 631 Other commercial 118,549 1,783 61,995 452 Residential real estate 35,586 205 36,211 262 Construction & land development 25,535 54 38,910 157 Consumer: Bankcard 0 0 0 0 Other consumer 34 0 34 0

Allowance for Credit Losses (Ta

Allowance for Credit Losses (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 Commercial Real Estate Construction Allowance Owner- Nonowner- Other Residential Real & Land Consumer Estimated Total Allowance for Loan Losses: Beginning balance $ 4,212 $ 6,615 $ 36,173 $ 14,123 $ 8,615 $ 2,822 $ 315 $ 72,875 Charge-offs 287 190 6,631 1,287 780 747 0 9,922 Recoveries 1,110 14 161 159 201 134 0 1,779 Provision 94 660 7,584 (516 ) (522 ) 506 445 8,251 Ending balance $ 5,129 $ 7,099 $ 37,287 $ 12,479 $ 7,514 $ 2,715 $ 760 $ 72,983 Allowance for Loan Losses and Carrying Amount of Loans For the Six Months Ended June 30, 2017 Commercial Real Estate Construction Allowance Owner- Nonowner- Other Residential & Land Consumer Estimated Total Allowance for Loan Losses: Beginning balance $ 5,273 $ 6,883 $ 33,087 $ 13,770 $ 10,606 $ 2,805 $ 347 $ 72,771 Charge-offs 915 295 10,029 2,032 2,522 1,414 0 17,207 Recoveries 1,193 30 665 292 616 473 0 3,269 Provision (422 ) 481 13,564 449 (1,186 ) 851 413 14,150 Ending balance $ 5,129 $ 7,099 $ 37,287 $ 12,479 $ 7,514 $ 2,715 $ 760 $ 72,983 Ending Balance: individually evaluated for impairment $ 1,943 $ 2,372 $ 20,494 $ 2,761 $ 481 $ 0 $ 0 $ 28,051 Ending Balance: collectively evaluated for impairment $ 3,186 $ 4,727 $ 16,793 $ 9,718 $ 7,033 $ 2,715 $ 760 $ 44,932 Ending Balance: loans acquired with deteriorated credit quality $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Financing receivables: Ending balance $ 1,394,507 $ 4,702,008 $ 1,866,487 $ 3,079,160 $ 1,698,232 $ 670,083 $ 0 $ 13,410,477 Ending Balance: individually evaluated for impairment $ 38,976 $ 26,758 $ 98,644 $ 17,718 $ 2,988 $ 0 $ 0 $ 185,084 Ending Balance: collectively evaluated for impairment $ 1,319,277 $ 4,548,388 $ 1,734,526 $ 3,047,291 $ 1,669,397 $ 670,048 $ 0 $ 12,988,927 Ending Balance: loans acquired with deteriorated credit quality $ 36,254 $ 126,862 $ 33,317 $ 14,151 $ 25,847 $ 35 $ 0 $ 236,466 Allowance for Loan Losses and Carrying Amount of Loans For the Year Ended December 31, 2016 Commercial Real Estate Other Residential Construction Consumer Allowance for Total Owner- Nonowner- & Land Estimated Allowance for Loan Losses: Beginning balance $ 3,637 $ 5,309 $ 31,328 $ 15,148 $ 18,205 $ 1,995 $ 104 $ 75,726 Charge-offs 5,281 419 20,430 4,597 2,659 2,794 0 36,180 Recoveries 3,071 675 3,452 639 433 446 0 8,716 Provision 3,846 1,318 18,737 2,580 (5,373 ) 3,158 243 24,509 Ending balance $ 5,273 $ 6,883 $ 33,087 $ 13,770 $ 10,606 $ 2,805 $ 347 $ 72,771 Ending Balance: individually evaluated for impairment $ 815 $ 2,524 $ 13,441 $ 3,431 $ 3,206 $ 0 $ 0 $ 23,417 Ending Balance: collectively evaluated for impairment $ 4,458 $ 4,359 $ 19,646 $ 10,339 $ 7,400 $ 2,805 $ 347 $ 49,354 Ending Balance: loans acquired with deteriorated credit quality $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Financing receivables: Ending balance $ 1,049,885 $ 3,425,453 $ 1,613,437 $ 2,403,437 $ 1,255,738 $ 608,769 $ 0 $ 10,356,719 Ending Balance: individually evaluated for impairment $ 18,976 $ 26,835 $ 56,091 $ 14,766 $ 8,152 $ 0 $ 0 $ 124,820 Ending Balance: collectively evaluated for impairment $ 1,005,999 $ 3,323,117 $ 1,527,479 $ 2,373,969 $ 1,221,006 $ 608,733 $ 0 $ 10,060,303 Ending Balance: loans acquired with deteriorated credit quality $ 24,910 $ 75,501 $ 29,867 $ 14,702 $ 26,580 $ 36 $ 0 $ 171,596

Intangible Assets (Tables)

Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2017
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: June 30, 2017 Community Banking Mortgage Banking Total Gross Carrying Amount Accumulated Gross Accumulated Gross Accumulated Amortized intangible assets: Core deposit intangible assets $ 103,348 ($ 49,821 ) $ 0 ($ 0 ) $ 103,348 ($ 49,821 ) Goodwill not subject to amortization $ 1,462,152 $ 22,961 $ 1,485,113 December 31, 2016 Community Banking Total Gross Carrying Accumulated Gross Accumulated Amortized intangible assets: Core deposit intangible assets $ 69,635 ($ 46,681 ) $ 69,635 ($ 46,681 ) Goodwill not subject to amortization $ 863,767 $ 863,767
Reconciliation of Goodwill	The following table provides a reconciliation of goodwill: Community Mortgage Total Goodwill at December 31, 2016 $ 863,767 $ 0 $ 863,767 Addition to goodwill from Bank of Georgetown acquisition 1,327 0 1,327 Preliminary addition to goodwill from Cardinal acquisition 597,058 22,961 620,019 Goodwill at June 30, 2017 $ 1,462,152 $ 22,961 $ 1,485,113
Schedule of Anticipated Amortization Expense	The following table sets forth the anticipated amortization expense for intangible assets for the years subsequent to 2016: Year Amount 2017 $ 8,373 2018 8,774 2019 7,629 2020 6,841 2021 and thereafter 25,050

Long-Term Borrowings (Tables)

Long-Term Borrowings (Tables)	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Schedule of Maturities of FHLB Borrowings	The scheduled maturities of these FHLB borrowings are as follows: Year Amount 2017 $ 665,873 2018 131,610 2019 187,955 2020 42,364 2021 and thereafter 94,912 Total $ 1,122,714

Derivative Financial Instrume36

Derivative Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 and December 31, 2016. Asset Derivatives June 30, 2017 December 31, 2016 Balance Sheet Location Notional Amount Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Fair Value Hedges: Interest rate swap contracts (hedging commercial loans) Other assets $ 14,853 $ 27 Other assets $ 24 Total derivatives designated as hedging instruments $ 14,853 $ 27 $ 24 Derivatives not designated as hedging instruments Interest rate swap contracts Other assets $ 14,149 $ 2,032 Other assets $ 2,267 TBA mortgage-backed securities Other assets 435,000 926 Other assets 0 Interest rate lock commitments Other assets 263,962 10,175 Other assets 0 Total derivatives not designated as hedging instruments $ 713,111 $ 13,133 $ 2,267 Total asset derivatives $ 727,964 $ 13,160 $ 2,291 Liability Derivatives June 30, 2017 December 31, 2016 Balance Sheet Location Notional Amount Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Fair Value Hedges: Interest rate swap contracts (hedging commercial loans) Other liabilities $ 77,767 $ 472 Other liabilities $ 338 Total derivatives designated as hedging instruments $ 77,767 $ 472 $ 338 Derivatives not designated as hedging instruments Interest rate swap contracts Other liabilities $ 14,149 $ 2,032 Other liabilities $ 2,267 Forward loan sales commitments Other liabilities 61,317 170 Other liabilities 0 Interest rate lock commitments Other liabilities 105,691 531 Other liabilities 0 Total derivatives not designated as hedging instruments $ 181,157 $ 2,733 $ 2,267 Total liability derivatives $ 258,924 $ 3,205 $ 2,605
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 six months ended June 30, 2017 and 2016 are presented as follows: Three Months Ended Income Statement Location June 30, June 30, Derivatives in hedging relationships Fair Value Hedges: Interest rate swap contracts Interest income/ (expense) $ (282 ) $ (249 ) Total derivatives in hedging relationships $ (282 ) $ (249 ) Derivatives not designated as hedging instruments Forward loan sales commitments Income from Mortgage (170 ) 0 TBA mortgage-backed securities Income from Mortgage 2,784 0 Interest rate lock commitments Income from Mortgage 1,019 0 Total derivatives not designated as hedging instruments $ 3,633 $ 0 Total derivatives $ 3,351 $ (249 ) Six Months Ended Income Statement Location June 30, June 30, Derivatives in fair value hedging relationships Fair Value Hedges: Interest rate swap contracts Interest income/ (expense) $ (440 ) $ 32 Cash Flow Hedges: Forward loan sales commitments Other income 0 0 Total derivatives in hedging relationships $ (440 ) $ 32 Derivatives not designated as hedging instruments Forward loan sales commitments Income from Mortgage (170 ) 0 TBA mortgage-backed securities Income from Mortgage 2,784 0 Interest rate lock commitments Income from Mortgage 1,019 0 Total derivatives not designated as hedging instruments $ 3,633 $ 0 Total derivatives $ 3,193 $ 32

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017 and December 31, 2016, segregated by the level of the valuation inputs within the fair value hierarchy. Fair Value at June 30, 2017 Using Description Balance as of June 30, 2017 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 $ 117,398 $ 0 $ 117,398 $ 0 State and political subdivisions 307,795 0 307,795 0 Residential mortgage-backed securities Agency 730,066 0 730,066 0 Non-agency 6,348 0 6,348 0 Commercial mortgage-backed securities Agency 369,067 0 369,067 0 Trust preferred collateralized debt obligations 38,084 0 0 38,084 Single issue trust preferred securities 12,344 0 12,344 0 Other corporate securities 15,184 0 15,184 0 Total available for sale debt securities 1,596,286 0 1,558,202 38,084 Available for sale equity securities: Financial services industry 3,252 387 2,865 0 Equity mutual funds (1) 6,111 6,111 0 0 Other equity securities 1,164 1,164 0 0 Total available for sale equity securities 10,527 7,662 2,865 0 Total available for sale securities 1,606,813 7,662 1,561,067 38,084 Loans held for sale 335,521 0 0 335,521 Derivative financial assets: Interest rate swap contracts 2,059 0 2.059 0 Interest rate lock commitments 10,175 0 0 10,175 TBA mortgage-backed securities 926 926 0 0 Total derivative financial assets 13,160 926 2,059 10,175 Liabilities Derivative financial liabilities: Interest rate swap contracts 2,504 0 2,504 0 Forward sales commitments 170 0 170 0 Interest rate lock commitments 531 0 531 0 Total derivative financial liabilties 3,205 0 3,205 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, 2016 Using Description Balance as of December 31, 2016 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 $ 95,786 $ 0 $ 95,786 $ 0 State and political subdivisions 192,812 0 192,812 0 Residential mortgage-backed securities Agency 584,096 0 584,096 0 Non-agency 7,043 0 7,043 0 Asset-backed securities 217 0 217 0 Commercial mortgage-backed securities Agency 305,341 0 305,341 0 Trust preferred collateralized debt obligations 33,552 0 0 33,552 Single issue trust preferred securities 11,477 0 11,477 0 Other corporate securities 15,062 0 15,062 0 Total available for sale debt securities 1,245,386 0 1,211,834 33,552 Available for sale equity securities: Financial services industry 10,735 1,372 9,363 0 Equity mutual funds (1) 1,820 1,820 0 0 Other equity securities 1,273 1,273 0 0 Total available for sale equity securities 13,828 4,465 9,363 0 Total available for sale securities 1,259,214 4,465 1,221,197 33,552 Derivative financial assets: Interest rate swap contracts 2,291 0 2,291 0 Liabilities Derivative financial liabilities: Interest rate swap contracts 2,605 0 2,605 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 June 30, 2017 and December 31, 2016 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 June 30, 2017 December 31, Balance, beginning of period $ 33,552 $ 34,686 Total gains or losses (realized/unrealized): Included in earnings (or changes in net assets) 0 0 Included in other comprehensive income 4,532 (1,134 ) Purchases, issuances, and settlements 0 0 Transfers in and/or out of Level 3 0 0 Balance, end of period $ 38,084 $ 33,552 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 June 30, 2017 December 31, Balance, beginning of period $ 0 $ 0 Acquired in Cardinal merger 271,301 0 Originations 786,318 0 Sales (732,091 ) 0 Total gains or losses during the period recognized in earnings 21,993 0 Transfers in and/or out of Level 3 (12,000 ) 0 Balance, end of period $ 335,521 $ 0 The amount of total gains or losses for the period included in earnings (or changes in net assets) attributable to the change in unrealized gains or losses relating to assets still held at reporting date $ 0 $ 0
Schedule of Changes in Fair Value Included in Earnings of Financial Instruments for which Fair Value Option has been Elected	The following table reflects the change in fair value included in earnings of financial instruments for which the fair value option has been elected: Description Three Months Ended June 30, 2017 Six Months Ended June 30, 2017 Assets Loans held for sale Income from mortgage banking activities $ (2,439 ) $ (2,439 )
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: June 30, 2017 December 31, 2016 Description Unpaid Fair Value Fair Value Over/(Under) Unpaid Principal Balance Unpaid Principal Balance Fair Value Fair Value Over/(Under) Unpaid Principal Balance Assets Loans held for sale $ 326,741 $ 335,521 $ 8,780 $ 0 $ 0 $ 0
Summary of Financial Assets Measured at Fair Value on Nonrecurring Basis	The following table summarizes United’s financial assets that were measured at fair value on a nonrecurring basis during the period: Carrying value at June 30, 2017 Description Balance as of June 30, 2017 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) YTD Losses Assets Impaired Loans 123,566 0 59,465 64,101 6,837 OREO 28,157 0 28,157 0 992 Carrying value at December 31, 2016 Description Balance as of December 31, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) YTD Losses Assets Impaired Loans $ 80,505 $ 0 $ 27,609 $ 52,896 $ 5,119 OREO 31,510 0 31,510 0 2,086
Summary of Estimated Fair Values of Financial Instruments	The estimated fair values of United’s financial instruments 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) June 30, 2017 Cash and cash equivalents $ 1,411,004 $ 1,411,004 $ 0 $ 1,411,004 $ 0 Securities available for sale 1,606,813 1,606,813 7,662 1,561,067 38,084 Securities held to maturity 20,401 20,008 0 16,988 3,020 Other securities 163,273 155,109 0 0 155,109 Loans held for sale 339,403 339,403 0 3,882 335,521 Loans 13,319,495 12,791,323 0 0 12,791,323 Derivative financial assets 13,160 13,160 926 2,059 10,175 Deposits 13,971,221 13,956,271 0 13,956,271 0 Short-term borrowings 321,322 321,322 0 321,322 0 Long-term borrowings 1,364,531 1,331,638 0 1,331,638 0 Derivative financial liabilities 3,205 3,205 0 3,205 0 December 31, 2016 Cash and cash equivalents $ 1,434,527 $ 1,434,527 $ 0 $ 1,434,527 $ 0 Securities available for sale 1,259,214 1,259,214 4,465 1,221,197 33,552 Securities held to maturity 33,258 31,178 0 28,158 3,020 Other securities 111,166 105,608 0 0 105,608 Loans held for sale 8,445 8,445 0 8,445 0 Loans 10,268,366 10,122,486 0 0 10,122,486 Derivative financial assets 2,291 2,291 0 2,291 0 Deposits 10,796,867 10,785,294 0 10,785,294 0 Short-term borrowings 209,551 209,551 0 209,551 0 Long-term borrowings 1,172,026 1,142,782 0 1,142,782 0 Derivative financial liabilities 2,605 2,605 0 2,605 0

Stock Based Compensation (Table

Stock Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2017
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 June 30, 2017, and the changes during the first six months of 2017 are presented below: Six Months Ended June 30, 2017 Weighted Average Aggregate Remaining Intrinsic Contractual Exercise Shares Value Term (Yrs.) Price Outstanding at January 1, 2017 1,411,735 $ 28.05 Assumed in Cardinal merger 153,602 21.47 Granted 253,417 45.27 Exercised (126,808 ) 21.20 Forfeited or expired (2,430 ) 41.47 Outstanding at June 30, 2017 1,689,516 $ 16,186 6.0 $ 30.52 Exercisable at June 30, 2017 1,172,594 $ 14,992 4.8 $ 26.41
Status of United's Nonvested Stock Option Awards	The following table summarizes the status of United’s nonvested stock option awards during the first six months of 2017: Shares Weighted-Average Nonvested at January 1, 2017 430,278 $ 6.84 Granted 253,417 8.85 Vested (165,273 ) 6.63 Forfeited or expired (1,500 ) 8.85 Nonvested at June 30, 2017 516,922 $ 7.88
Changes to United's Restricted Common Shares	The following summarizes the changes to United’s restricted common shares for the period ended June 30, 2017: Number Weighted-Average Outstanding at January 1, 2017 137,268 $ 33.61 Granted 89,475 45.27 Vested (53,424 ) 32.17 Forfeited (420 ) 45.30 Outstanding at June 30, 2017 172,899 $ 40.06

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	6 Months Ended
	Jun. 30, 2017
Retirement Benefits [Abstract]
Net Periodic Pension Cost	Net periodic pension cost for the three and six months ended June 30, 2017 and 2016 included the following components: Three Months Ended June 30 Six Months Ended June 30 2017 2016 2017 2016 Service cost $ 569 $ 608 $ 1,131 $ 1,215 Interest cost 1,279 1,456 2,544 2,912 Expected return on plan assets (2,049 ) (2,012 ) (4,076 ) (4,024 ) Recognized net actuarial loss 1,100 1,149 2,187 2,297 Net periodic pension (benefit) cost $ 899 $ 1,201 $ 1,786 $ 2,400 Weighted-Average Assumptions: Discount rate 4.49 % 4.75 % 4.49 % 4.75 % Expected return on assets 7.00 % 7.25 % 7.00 % 7.25 % 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)	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Components of Total Comprehensive Income	The components of total comprehensive income for the three and six months ended June 30, 2017 and 2016 are as follows: Three Months Ended Six Months Ended June 30 June 30 2017 2016 2017 2016 Net Income $ 37,059 $ 31,792 $ 75,868 $ 66,498 Available for sale (“AFS”) securities: AFS securities with OTTI charges during the period (16 ) (77 ) (60 ) (77 ) Related income tax effect 6 28 22 28 Less: OTTI charges recognized in net income 16 33 60 33 Related income tax benefit (6 ) (12 ) (22 ) (12 ) Reclassification of previous noncredit OTTI to credit OTTI 0 415 0 415 Related income tax benefit (0 ) (150 ) (0 ) (150 ) Net unrealized (losses) gains on AFS securities with OTTI 0 237 0 237 AFS securities – all other: Change in net unrealized gain on AFS securities arising during the period 5,686 6,638 11,262 19,955 Related income tax effect (2,104 ) (2,403 ) (4,167 ) (7,224 ) Net reclassification adjustment for (gains) losses included in net income (763 ) (246 ) (977 ) (250 ) Related income tax expense (benefit) 282 90 361 91 3,101 4,079 6,479 12,572 Net effect of AFS securities on other comprehensive income 3,101 4,316 6,479 12,809 Held to maturity (“HTM”) securities: Accretion on the unrealized loss for securities transferred from AFS to the HTM investment portfolio prior to call or maturity 2 3 4 4 Related income tax expense (1 ) (2 ) (2 ) (2 ) Net effect of HTM securities on other comprehensive income 1 1 2 2 Pension plan: Recognized net actuarial loss 1,100 1,149 2,187 2,297 Related income tax benefit (405 ) (420 ) (797 ) (839 ) Net effect of change in pension plan asset on other comprehensive income 695 729 1,390 1,458 Total change in other comprehensive income 3,797 5,046 7,871 14,269 Total Comprehensive Income $ 40,856 $ 36,838 $ 83,739 $ 80,767
Components of Accumulated Other Comprehensive Income	The components of accumulated other comprehensive income for the six months ended June 30, 2017 are as follows: Changes in Accumulated Other Comprehensive Income (AOCI) by Component (a) For the Six Months Ended June 30, 2017 Unrealized Accretion on Defined Items Total Balance at January 1, 2017 ($ 10,297 ) ($ 51 ) ($ 34,369 ) ($ 44,717 ) Other comprehensive income before reclassification 7,095 2 0 7,097 Amounts reclassified from accumulated other comprehensive income (616 ) 0 1,390 774 Net current-period other comprehensive income, net of tax 6,479 2 1,390 7,871 Balance at June 30, 2017 ($ 3,818 ) ($ 49 ) ($ 32,979 ) ($ 36,846 )
Reclassifications Out of Accumulated Other Comprehensive Income	Reclassifications out of Accumulated Other Comprehensive Income (AOCI) For the Six Months Ended June 30, 2017 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 $ 0 Total other-than-temporary impairment losses Net reclassification adjustment for losses (gains) included in net income (977 ) Net gains on sales/calls of investment securities (977 ) Total before tax Related income tax effect 361 Tax expense (616 ) Net of tax Pension plan: Recognized net actuarial loss 2,187 (a) 2,187 Total before tax Related income tax effect (797 ) Tax expense 1,390 Net of tax Total reclassifications for the period $ 774 (a) This AOCI component is included in the computation of net periodic pension cost (see Note 14, Employee Benefit Plans)

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2017
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 Six Months Ended June 30 June 30 2017 2016 2017 2016 Distributed earnings allocated to common stock $ 34,562 $ 25,114 $ 61,284 $ 48,068 Undistributed earnings allocated to common stock 2,440 6,623 14,454 18,311 Net earnings allocated to common shareholders $ 37,002 $ 31,737 $ 75,738 $ 66,379 Average common shares outstanding 99,197,807 71,483,703 90,100,627 70,490,596 Equivalents from stock options 422,238 325,318 469,662 276,368 Average diluted shares outstanding 99,620,045 71,809,021 90,570,289 70,766,964 Earnings per basic common share $ 0.37 $ 0.44 $ 0.84 $ 0.94 Earnings per diluted common share $ 0.37 $ 0.44 $ 0.84 $ 0.94

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	6 Months Ended
	Jun. 30, 2017
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 Capital Securities Issued Interest Rate Maturity Date Century Trust March 23, 2000 $ 8,800 10.875% Fixed March 8, 2030 United Statutory Trust III December 17, 2003 $ 20,000 3-month December 17, 2033 United Statutory Trust IV December 19, 2003 $ 25,000 3-month January 23, 2034 United Statutory Trust V July 12, 2007 $ 50,000 3-month October 1, 2037 United Statutory Trust VI September 20, 2007 $ 30,000 3-month December 15, 2037 Premier Statutory Trust II September 25, 2003 $ 6,000 3-month October 8, 2033 Premier Statutory Trust III May 16, 2005 $ 8,000 3-month June 15, 2035 Premier Statutory Trust IV June 20, 2006 $ 14,000 3-month September 23, 2036 Premier Statutory Trust V December 14, 2006 $ 10,000 3-month March 1, 2037 Centra Statutory Trust I September 20, 2004 $ 10,000 3-month September 20, 2034 Centra Statutory Trust II June 15, 2006 $ 10,000 3-month July 7, 2036 Virginia Commerce Trust II December 19, 2002 $ 15,000 6-month December 19, 2032 Virginia Commerce Trust III December 20, 2005 $ 25,000 3-month February 23, 2036 Cardinal Statutory Trust I July 27, 2004 $ 20,000 3-month September 15, 2034 UFBC Capital Trust I December 30, 2004 $ 5,000 3-month 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 June 30, 2017 As of December 31, 2016 Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Trust preferred securities $ 266,551 $ 257,636 $ 8,915 $ 240,668 $ 232,583 $ 8,085 (1) Represents investment in VIEs.

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2017
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 six months ended June 30, 2017 and 2016 is as follows: At and For the Three Months Ended June 30, 2017 Community Mortgage Other Consolidated Net interest income $ 138,498 $ 90 $ (2,343 ) $ 136,245 Provision for loans losses 8,251 0 0 8,251 Other income 18,223 22,393 (110 ) 40,506 Other expense 78,631 18,708 14,798 112,137 Income taxes 23,920 1,293 (5,909 ) 19,304 Net income (loss) $ 45,919 $ 2,482 $ (11,342 ) $ 37,059 Total assets $ 18,658,321 $ 382,086 $ (4,807 ) $ 19,035,600 Average assets 17,967,121 236,074 (20,180 ) 18,183,015 At and For the Three Months Ended June 30, 2016 Community Banking Other Consolidated Net interest income $ 104,676 $ (1,951 ) $ 102,725 Provision for loans losses 7,667 0 7,667 Other income 18,616 (649 ) 17,967 Other expense 64,092 763 64,855 Income taxes 17,521 (1,143 ) 16,378 Net income (loss) $ 34,012 $ (2,220 ) $ 31,792 Total assets $ 14,358,021 $ (20,009 ) $ 14,338,012 Average assets 12,820,946 (24,404 ) 12,796,542 At and For the Six Months Ended June 30, 2017 Community Banking Mortgage Banking Other Consolidated Net interest income $ 248,158 $ 90 $ (4,383 ) $ 243,865 Provision for loans losses 14,150 0 0 14,150 Other income 35,036 22,393 3,223 60,652 Other expense 141,383 18,708 14,888 174,979 Income taxes 43,724 1,293 (5,497 ) 39,520 Net income (loss) $ 83,937 $ 2,482 $ (10,551 ) $ 75,868 Total assets $ 18,658,321 $ 382,086 $ (4,807 ) $ 19,035,600 Average assets 16,210,026 118,689 (24,551 ) 16,304,164 At and For the Six Months Ended June 30, 2016 Community Banking Other Consolidated Net interest income $ 204,802 $ (3,793 ) $ 201,009 Provision for loans losses 11,702 0 11,702 Other income 35,657 (1,298 ) 34,359 Other expense 123,314 (403 ) 122,911 Income taxes 35,851 (1,594 ) 34,257 Net income (loss) $ 69,592 $ (3,094 ) $ 66,498 Total assets $ 14,358,021 $ (20,009 ) $ 14,338,012 Average assets 12,592,765 (20,790 ) 12,571,975

Summary of Significant Accoun44

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Increase to net cash from operating activity		$ 35,919	$ 63,280
Decrease to net cash from financing activities		(238,739)	$ 259,985
ASU 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease in income tax expense	$ 717	814
Increase to net cash from operating activity		1,304
Decrease to net cash from financing activities		$ (1,304)

Mergers and Acquisitions - Addi

Mergers and Acquisitions - Additional Information (Detail) - USD ($)	Jun. 30, 2017	Apr. 21, 2017	Jun. 03, 2016	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Business Acquisition [Line Items]
Total assets at consummation	$ 19,035,600,000			$ 19,035,600,000	$ 14,508,892,000	$ 14,338,012,000
Loans at consummation	13,410,477,000			13,410,477,000	10,356,719,000
Deposits at consummation	13,971,221,000			13,971,221,000	10,796,867,000
Resulting goodwill	1,485,113,000			1,485,113,000	$ 863,767,000
Liabilities to provide severance benefits	$ 6,000			$ 6,000
Contractually required principal and interest at acquisition		$ 131,575	$ 138,125
Expected cash flows at acquisition		107,596	117,564
Estimated fair value of acquired impaired loans at acquisition		$ 86,293	95,570
Cardinal Financial Corporation [Member]
Business Acquisition [Line Items]
Acquisition completion date				Apr. 21, 2017
Outstanding common stock acquired		100.00%
Total assets at consummation		$ 4,136,008
Loans at consummation		3,313,033
Deposits at consummation		3,344,740
Common stock paid in cash		975,254,000
Common stock value		972,499,000
Stock options exchanged value		$ 2,741,000
Common stock, shares issued		23,690,589
Resulting goodwill		$ 620,019,000
Fractional shares cash paid per share		14,000
Goodwill from acquisition expected to be tax deductible		0
Fair value discounts on loans acquired		143,916,000
Fair value discounts on leases		2,282,000
Fair value adjustment on trust preferred issuances		8,738,000
Premiums on land acquired		4,408,000
Premiums on interest-bearing deposits acquired		4,994,000
Premium on long-term FHLB advances acquired		10,740,000
Estimated remaining life of discount on leases acquired	6 years 2 months 30 days
Estimated remaining life of discount on trust preferred issuances acquired	17 years 2 months 19 days
Estimated remaining life of premium on interest-bearing deposits acquired	5 years 2 months 30 days
Estimated remaining life of the FHLB advances acquired	5 years 22 days
Assumed liabilities to provide severance benefits		1,825,000
Contractually required principal and interest at acquisition		4,211,662,000
Expected cash flows at acquisition		4,156,059,000
Estimated fair value of acquired impaired loans at acquisition		3,169,117,000
Revenue since acquisition included in consolidated results				$ 67,016
Revenue since acquisition included in consolidated results				$ 32,473
Cardinal Financial Corporation [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Common stock value		$ 972,499,000
Common stock, shares issued		23,690,589
Closing market price per common share		$ 41.05
Cardinal Financial Corporation [Member] | Core Deposit Intangible Assets [Member]
Business Acquisition [Line Items]
Purchase price allocation of Identifiable Intangible assets		$ 33,713,000
Estimated period of amortization of core deposit intangibles		10 years
Fractional shares cash paid per share		$ 14,000
Bank of Georgetown [Member]
Business Acquisition [Line Items]
Outstanding common stock acquired	100.00%			100.00%
Total assets at consummation	$ 1,278,837			$ 1,278,837
Loans at consummation	999,773			999,773
Deposits at consummation	971,369			971,369
Common stock paid in cash			264,505,000
Common stock value			253,799,000
Stock options exchanged value			$ 10,696,000
Common stock, shares issued			6,527,746
Resulting goodwill			$ 154,172,000
Fractional shares cash paid per share			10,000
Goodwill from acquisition expected to be tax deductible			0
Fair value discounts on loans acquired			43,072
Fair value discounts on leases				1,550
Premiums on interest-bearing deposits acquired			316,000
Premium on long-term FHLB advances acquired	$ 2,659			2,659
Estimated remaining life of premium on interest-bearing deposits acquired	6 months 29 days
Estimated remaining life of the FHLB advances acquired	8 years 2 months 1 day
Assumed liabilities to provide severance benefits	$ 300,000			$ 300,000
Contractually required principal and interest at acquisition			1,275,398,000
Expected cash flows at acquisition			1,241,418,000
Estimated fair value of acquired impaired loans at acquisition			966,870,000
Bank of Georgetown [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Common stock value			$ 253,799,000
Common stock, shares issued			6,527,746
Closing market price per common share			$ 38.88
Bank of Georgetown [Member] | Core Deposit Intangible Assets [Member]
Business Acquisition [Line Items]
Purchase price allocation of Identifiable Intangible assets			$ 9,058,000
Estimated period of amortization of core deposit intangibles			10 years
Fractional shares cash paid per share			$ 10,000

Mergers and Acquisitions - Sche

Mergers and Acquisitions - Schedule of Acquired Loans Accounted for at Fair Value (Detail) - USD ($)	Apr. 21, 2017	Jun. 03, 2016
Business Acquisition [Line Items]
Contractually required principal and interest at acquisition	$ 131,575	$ 138,125
Expected cash flows at acquisition	107,596	117,564
Basis in acquired loans at acquisition - estimated fair value	86,293	95,570
Cardinal Financial Corporation [Member]
Business Acquisition [Line Items]
Contractually required principal and interest at acquisition	4,211,662,000
Contractual cash flows not expected to be collected	(55,603,000)
Expected cash flows at acquisition	4,156,059,000
Interest component of expected cash flows	(986,942,000)
Basis in acquired loans at acquisition - estimated fair value	$ 3,169,117,000
Bank of Georgetown [Member]
Business Acquisition [Line Items]
Contractually required principal and interest at acquisition		1,275,398,000
Contractual cash flows not expected to be collected		(33,980,000)
Expected cash flows at acquisition		1,241,418,000
Interest component of expected cash flows		(274,548,000)
Basis in acquired loans at acquisition - estimated fair value		$ 966,870,000

Mergers and Acquisitions - Sc47

Mergers and Acquisitions - Schedule of Fair Value of Acquired Identifiable Assets and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Apr. 21, 2017	Jun. 03, 2016	Jun. 30, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Resulting goodwill			$ 1,485,113	$ 863,767
Cardinal Financial Corporation [Member]
Business Acquisition [Line Items]
Value of common shares issued	$ 972,499
Fair value of stock options assumed	2,741
Cash for fractional shares	14
Total purchase price	975,254
Cash and cash equivalents	44,545
Investment securities	395,829
Loans held for sale	271,301
Loans	3,169,117
Premises and equipment	21,926
Other assets	133,321
Total identifiable assets	4,069,752
Deposits	3,349,734
Short-term borrowings	96,215
Long-term borrowings	220,119
Other liabilities	48,449
Total identifiable liabilities	3,714,517
Fair value of net assets acquired including identifiable intangible assets	355,235
Resulting goodwill	620,019
Cardinal Financial Corporation [Member] | Core Deposit Intangible Assets [Member]
Business Acquisition [Line Items]
Cash for fractional shares	14
Core deposit intangibles	$ 33,713
Bank of Georgetown [Member]
Business Acquisition [Line Items]
Value of common shares issued		$ 253,799
Fair value of stock options assumed		10,696
Cash for fractional shares		10
Total purchase price		264,505
Cash and cash equivalents		29,340
Investment securities		219,783
Loans		966,870
Premises and equipment		5,574
Other assets		31,605
Total identifiable assets		1,262,230
Deposits		971,685
Short-term borrowings		101,021
Long-term borrowings		67,659
Other liabilities		11,532
Total identifiable liabilities		1,151,897
Fair value of net assets acquired including identifiable intangible assets		110,333
Resulting goodwill		154,172
Bank of Georgetown [Member] | Core Deposit Intangible Assets [Member]
Business Acquisition [Line Items]
Cash for fractional shares		10
Core deposit intangibles		$ 9,058

Mergers and Acquisitions - Sc48

Mergers and Acquisitions - Schedule of Fair Value of Acquired Identifiable Assets and Liabilities Assumed (Parenthetical) (Detail) - shares	Apr. 21, 2017	Jun. 03, 2016
Cardinal Financial Corporation [Member]
Business Acquisition [Line Items]
Common stock, shares issued	23,690,589
Bank of Georgetown [Member]
Business Acquisition [Line Items]
Common stock, shares issued		6,527,746

Mergers and Acquisitions - Sc49

Mergers and Acquisitions - Schedule of Business Acquisition Pro Forma Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Business Combinations [Abstract]
Total Revenues	$ 380,235	$ 373,109
Net Income	$ 77,011	$ 96,259

Investment Securities - Summary

Investment Securities - Summary of Amortized Cost and Estimated Fair Values of Available for Sale Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Amortized Cost	$ 1,614,955	$ 1,277,639
Gross Unrealized Gains	13,036	10,912
Gross Unrealized Losses	21,178	29,337
Estimated Fair Value	1,606,813	1,259,214
Cumulative OTTI in AOCI	26,038	26,038
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Schedule of Investments [Line Items]
Amortized Cost	116,784	95,247
Gross Unrealized Gains	910	698
Gross Unrealized Losses	296	159
Estimated Fair Value	117,398	95,786
Cumulative OTTI in AOCI	0	0
State and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Amortized Cost	308,153	196,350
Gross Unrealized Gains	2,410	1,364
Gross Unrealized Losses	2,768	4,902
Estimated Fair Value	307,795	192,812
Cumulative OTTI in AOCI	0	0
Residential Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Amortized Cost	730,688	585,208
Gross Unrealized Gains	3,954	3,999
Gross Unrealized Losses	4,576	5,111
Estimated Fair Value	730,066	584,096
Cumulative OTTI in AOCI	0	0
Residential Mortgage-Backed Securities, Non-agency [Member]
Schedule of Investments [Line Items]
Amortized Cost	5,748	6,629
Gross Unrealized Gains	600	426
Gross Unrealized Losses	0	12
Estimated Fair Value	6,348	7,043
Cumulative OTTI in AOCI	86	86
Commercial Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Amortized Cost	367,698	304,635
Gross Unrealized Gains	2,354	1,948
Gross Unrealized Losses	985	1,242
Estimated Fair Value	369,067	305,341
Cumulative OTTI in AOCI	0	0
Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	0	217
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	0	217
Cumulative OTTI in AOCI	0	0
Trust Preferred Collateralized Debt Obligations [Member]
Schedule of Investments [Line Items]
Amortized Cost	47,759	48,558
Gross Unrealized Gains	1,531	729
Gross Unrealized Losses	11,206	15,735
Estimated Fair Value	38,084	33,552
Cumulative OTTI in AOCI	25,952	25,952
Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	13,390	13,363
Gross Unrealized Gains	292	284
Gross Unrealized Losses	1,338	2,170
Estimated Fair Value	12,344	11,477
Cumulative OTTI in AOCI	0	0
Corporate Bonds [Member]
Schedule of Investments [Line Items]
Amortized Cost	14,997	14,996
Gross Unrealized Gains	187	66
Gross Unrealized Losses	0	0
Estimated Fair Value	15,184	15,062
Cumulative OTTI in AOCI	0	0
Marketable Equity Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	9,738	12,436
Gross Unrealized Gains	798	1,398
Gross Unrealized Losses	9	6
Estimated Fair Value	10,527	13,828
Cumulative OTTI in AOCI	$ 0	$ 0

Investment Securities - Summa51

Investment Securities - Summary of Securities Available for Sale in an Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	$ 808,836	$ 612,613
Less than 12 months, Unrealized Losses	7,789	11,420
12 months or longer, Fair Value	68,608	36,982
12 months or longer, Unrealized Losses	13,389	17,917
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	61,739	24,101
Less than 12 months, Unrealized Losses	296	159
12 months or longer, Fair Value	0	0
12 months or longer, Unrealized Losses	0	0
State and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	148,796	116,300
Less than 12 months, Unrealized Losses	2,506	4,902
12 months or longer, Fair Value	6,894	0
12 months or longer, Unrealized Losses	262	0
Residential Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	414,498	309,376
Less than 12 months, Unrealized Losses	4,002	5,111
12 months or longer, Fair Value	25,485	0
12 months or longer, Unrealized Losses	574	0
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	218
12 months or longer, Unrealized Losses	0	12
Commercial Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	183,803	162,479
Less than 12 months, Unrealized Losses	985	1,242
12 months or longer, Fair Value	0	0
12 months or longer, Unrealized Losses	0	0
Asset-Backed 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	0	0
12 months or longer, Unrealized Losses	0	0
Trust Preferred Collateralized Debt Obligations [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	31,510	28,579
12 months or longer, Unrealized Losses	11,206	15,735
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	4,365	8,185
12 months or longer, Unrealized Losses	1,338	2,170
Marketable Equity Securities [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	0	357
Less than 12 months, Unrealized Losses	0	6
12 months or longer, Fair Value	354	0
12 months or longer, Unrealized Losses	$ 9	$ 0

Investment Securities - Summa52

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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales and calls	$ 468,506	$ 159,232	$ 567,304	$ 194,231
Gross realized gains	845	250	1,059	256
Gross realized losses	$ 82	$ 4	$ 82	$ 6

Investment Securities - Additio

Investment Securities - Additional Information (Detail)	3 Months Ended		6 Months Ended		96 Months Ended
	Jun. 30, 2017USD ($)Securities	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)Securities	Jun. 30, 2016USD ($)	Dec. 31, 2007USD ($)	Dec. 31, 2016USD ($)
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	$ 21,178,000		$ 21,178,000			$ 29,337,000
Available for sale securities in unrealized loss position | Securities	410		410
Available for sale securities in portfolio, number | Securities	821		821
Amortized cost of available for sale securities	$ 1,614,955,000		$ 1,614,955,000			1,277,639,000
Capitalization of banks, equal to or greater than, in the single-issue trust preferred portfolio	10,000,000,000		10,000,000,000
Noncredit-related other-than-temporary impairment recognized	26,038,000		$ 26,038,000			26,038,000
New issuance of Preferred Stock estimated					$ 60,000,000,000
Security other-than-temporarily impaired			100.00%
Amortized cost of equity securities	9,738		$ 9,738
Gross realized gains	0	$ 0	0	$ 0
Gross realized losses	0	$ 0	0	$ 0
Carrying value of securities pledged	1,319,179		1,319,179			1,137,408
TRUP CDOs [Member]
Schedule of Investments [Line Items]
Credit-related other-than-temporary impairment recognized in earnings	0
Noncredit-related other-than-temporary impairment recognized	25,952		25,952
SunTrust Bank [Member]
Schedule of Investments [Line Items]
Amortized cost of trust preferred securities	7,422,000		7,422,000
Royal Bank of Scotland [Member]
Schedule of Investments [Line Items]
Amortized cost of trust preferred securities	976,000		$ 976,000
Minimum [Member]
Schedule of Investments [Line Items]
Other-than-temporarily impaired, the collateralization ratios			105.00%
Maximum [Member]
Schedule of Investments [Line Items]
Other-than-temporarily impaired, the collateralization ratios			397.30%
Weighted Average [Member]
Schedule of Investments [Line Items]
Other-than-temporarily impaired, the collateralization ratios			240.50%
Median [Member]
Schedule of Investments [Line Items]
Other-than-temporarily impaired, the collateralization ratios			160.70%
Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale single issue trust preferred securities	3,014		$ 3,014
Below Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale single issue trust preferred securities	5,703		5,703
Split Rated [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale single issue trust preferred securities	4,673		4,673
State and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	2,768,000		2,768,000			4,902,000
Amortized cost of available for sale securities	$ 308,153,000		$ 308,153,000			196,350,000
Percent of portfolio with credit support	76.00%		76.00%
Investment grade credit rate percentage			1.00%
Number of equity securities other-than-temporarily impaired | Securities	0		0
Noncredit-related other-than-temporary impairment recognized	$ 0		$ 0			0
Agency Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale securities	1,098,386,000		1,098,386,000
Commercial Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	985,000		985,000			1,242,000
Amortized cost of available for sale securities	367,698,000		367,698,000			304,635,000
Noncredit-related other-than-temporary impairment recognized	0		0			0
Residential Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	4,576,000		4,576,000			5,111,000
Amortized cost of available for sale securities	730,688,000		730,688,000			585,208,000
Noncredit-related other-than-temporary impairment recognized	0		0			0
Residential Mortgage-Backed Securities, Non-agency [Member]
Schedule of Investments [Line Items]
Gross unrealized losses on available for sale securities	0		0			12,000
Amortized cost of available for sale securities	5,748,000		$ 5,748,000			6,629,000
Securities other-than-temporarily impaired | Securities			1
Credit-related other-than-temporary impairment recognized in earnings			$ 16,000
Noncredit-related other-than-temporary impairment recognized	86,000		$ 86,000			$ 86,000
Residential Mortgage-Backed Securities, Non-agency [Member] | Originated Prior to 2005 [Member]
Schedule of Investments [Line Items]
Percentage of portfolio of non-agency mortgage backed securities with collateral			21.00%
Residential Mortgage-Backed Securities, Non-agency [Member] | Originated in 2006 and 2007 [Member]
Schedule of Investments [Line Items]
Percentage of portfolio of non-agency mortgage backed securities with collateral			79.00%
Residential Mortgage-Backed Securities, Non-agency [Member] | Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale securities	823,000		$ 823,000
Residential Mortgage-Backed Securities, Non-agency [Member] | Below Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale securities	$ 4,925,000		$ 4,925,000

Investment Securities - Summa54

Investment Securities - Summary of Unrealized Loss Positions of Available for Sale TRUP CDOs and Single Issue Trust Preferred Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Amortized Cost	$ 1,614,955	$ 1,277,639
Fair Value	1,606,813	$ 1,259,214
Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	47,759
Fair Value	38,084
Net Unrealized Loss	9,675
Senior - Bank [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	5,356
Fair Value	5,318
Net Unrealized Loss	38
Mezzanine - Bank (now in senior position) [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	11,268
Fair Value	9,377
Net Unrealized Loss	1,891
Mezzanine - Bank [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	26,095
Fair Value	18,878
Net Unrealized Loss	7,217
Mezzanine - Bank & Insurance (combination) [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	5,040
Fair Value	4,511
Net Unrealized Loss	529
Investment Grade [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	3,558
Investment Grade [Member] | Senior - Bank [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	3,558
Investment Grade [Member] | Mezzanine - Bank (now in senior position) [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	0
Investment Grade [Member] | Mezzanine - Bank [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	0
Investment Grade [Member] | Mezzanine - Bank & Insurance (combination) [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	0
Split Rated [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	2,741
Split Rated [Member] | Senior - Bank [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	0
Split Rated [Member] | Mezzanine - Bank (now in senior position) [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	2,741
Split Rated [Member] | Mezzanine - Bank [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	0
Split Rated [Member] | Mezzanine - Bank & Insurance (combination) [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	0
Below Investment Grade [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	41,460
Below Investment Grade [Member] | Senior - Bank [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	1,798
Below Investment Grade [Member] | Mezzanine - Bank (now in senior position) [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	8,527
Below Investment Grade [Member] | Mezzanine - Bank [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	26,095
Below Investment Grade [Member] | Mezzanine - Bank & Insurance (combination) [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	$ 5,040

Investment Securities - Roll Fo

Investment Securities - Roll Forward of Credit Losses on Securities (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Cumulative credit losses, Beginning Balance	$ 22,162	$ 23,773	$ 22,162	$ 23,773
Additional credit losses on securities for which OTTI was previously recognized	0	33	0	33
Reductions during the period for securities for which the amount previously recognized in other comprehensive income was recognized in earnings	0	(1,644)	0	(1,644)
Cumulative credit losses, Ending Balance	$ 22,162	$ 22,162	$ 22,162	$ 22,162

Investment Securities - Summa56

Investment Securities - Summary of Maturities of Securities Available for Sale by Amortized Cost and Estimated Fair Value (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Due in one year or less, Amortized Cost	$ 47,004	$ 53,286
Due after one year through five years, Amortized Cost	345,448	296,181
Due after five years through ten years, Amortized Cost	355,077	213,094
Due after ten years, Amortized Cost	857,688	702,642
Marketable equity securities, Amortized Cost	9,738	12,436
Amortized Cost	1,614,955	1,277,639
Due in one year or less, Estimated Fair Value	46,981	53,330
Due after one year through five years, Estimated Fair Value	346,601	297,385
Due after five years through ten years, Estimated Fair Value	356,740	213,791
Due after ten years, Estimated Fair Value	845,964	680,880
Marketable equity securities, Estimated Fair Value	10,527	13,828
Total available for sale securities	$ 1,606,813	$ 1,259,214

Investment Securities - Summa57

Investment Securities - Summary of Amortized Cost and Estimated Fair Values of Securities Held to Maturity (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Amortized Cost	$ 20,401	$ 33,258
Gross Unrealized Gains	475	592
Gross Unrealized Losses	868	2,672
Estimated Fair Value	20,008	31,178
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Schedule of Investments [Line Items]
Amortized Cost	5,242	5,295
Gross Unrealized Gains	459	570
Gross Unrealized Losses	0	0
Estimated Fair Value	5,701	5,865
State and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Amortized Cost	5,714	8,598
Gross Unrealized Gains	12	17
Gross Unrealized Losses	0	0
Estimated Fair Value	5,726	8,615
Residential Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Amortized Cost	27	30
Gross Unrealized Gains	4	5
Gross Unrealized Losses	0	0
Estimated Fair Value	31	35
Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	9,398	19,315
Gross Unrealized Gains	0	0
Gross Unrealized Losses	868	2,672
Estimated Fair Value	8,530	16,643
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 - Summa58

Investment Securities - Summary of Maturities of Debt Securities Held to Maturity by Amortized Cost and Estimated Fair Value (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Due in one year or less, Amortized Cost	$ 40	$ 1,040
Due after one year through five years, Amortized Cost	9,216	8,268
Due after five years through ten years, Amortized Cost	5,700	3,585
Due after ten years, Amortized Cost	5,445	20,365
Amortized Cost	20,401	33,258
Due in one year or less, Estimated Fair Value	40	1,041
Due after one year through five years, Estimated Fair Value	9,685	8,850
Due after five years through ten year, Estimated Fair Value	5,364	3,589
Due after ten years, Estimated Fair Value	4,919	17,698
Estimated Fair Value, Total	$ 20,008	$ 31,178

Loans - Major Classes of Loans

Loans - Major Classes of Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Commercial, financial, and agricultural
Total commercial, financial & agricultural	$ 7,963,002	$ 6,088,775
Residential real estate	3,079,160	2,403,437
Construction & land development	1,698,232	1,255,738
Consumer:
Bankcard	14,098	14,187
Other consumer	655,985	594,582
Total Financing Receivables	13,410,477	10,356,719
Owner-Occupied [Member]
Commercial, financial, and agricultural
Total commercial, financial & agricultural	1,394,507	1,049,885
Nonowner-Occupied [Member]
Commercial, financial, and agricultural
Total commercial, financial & agricultural	4,702,008	3,425,453
Other Commercial Loans [Member]
Commercial, financial, and agricultural
Total commercial, financial & agricultural	$ 1,866,487	$ 1,613,437

Loans - Additional Information

Loans - Additional Information (Detail) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Loans held for sale	$ 339,403,000	$ 8,445,000
Acquired impaired loans from merger	$ 13,410,477,000	10,356,719,000
Percentage of acquired impaired loans from merger on total gross loans	1.76%
Recorded investment in acquired impaired loans	$ 320,938,000	231,096,000
Directors and Officers [Member]
Related party loans	459,591	$ 255,476
Maximum [Member]
Percentage of acquired impaired loans from merger on total gross loans		1.66%
Loans Acquired with Deteriorated Credit Quality [Member]
Acquired impaired loans from merger	$ 236,466,000	$ 171,596,000

Loans - Activity for Accretable

Loans - Activity for Accretable Yield (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)
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	$ 29,165
Accretion (including cash recoveries)	(6,341)
Additions	11,356
Net reclassifications to accretable from non-accretable	12,857
Disposals (including maturities, foreclosures, and charge-offs)	(1,845)
Accretable yield at the end of the period	$ 45,192

Credit Quality - Additional Inf

Credit Quality - Additional Information (Detail)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)SecurityLoan	Jun. 30, 2016USD ($)SecurityLoan	Dec. 31, 2016USD ($)
Receivables [Abstract]
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			$ 49,037		$ 21,152
Restructured loans on nonaccrual status	$ 31,606		31,606		11,106
Restructured loans modified by reduction in interest	2,612		2,612
Restructured loan and interest	4,510		4,510
Restructured loans modified by change in terms	41,915		41,915
Restructured loans modified by reduction in interest rate and change in terms				$ 1,400,000
Restructured loans modified by change in loan terms amount	26,688,000	$ 1,888,000	$ 30,802,000	$ 3,322,000
Number of loans restructured | SecurityLoan			0	0
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
Real estate acquired in foreclosure or other settlement of loans	28,157,000		$ 28,157,000		31,510,000
Recorded investment of consumer mortgage loans	$ 529,000		$ 529,000		$ 660,000

Credit Quality - Schedule of Tr

Credit Quality - Schedule of Troubled Debt Restructurings, Segregated by Class of Loans (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017USD ($)Contract	Jun. 30, 2016USD ($)Contract	Jun. 30, 2017USD ($)Contract	Jun. 30, 2016USD ($)Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	5	2	10	6
Pre-Modification Outstanding Recorded Investment	$ 26,688	$ 1,890	$ 30,896	$ 4,731
Post-Modification Outstanding Recorded Investment	$ 26,688	$ 1,888	$ 30,802	$ 4,722
Construction & Land Development [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0	1	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 1,456	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 1,437	$ 0
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	1	1	1
Pre-Modification Outstanding Recorded Investment	$ 5,333	$ 1,190	$ 5,333	$ 1,190
Post-Modification Outstanding Recorded Investment	$ 5,333	$ 1,188	$ 5,333	$ 1,188
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	4	1	8	4
Pre-Modification Outstanding Recorded Investment	$ 21,355	$ 700	$ 24,107	$ 2,141
Post-Modification Outstanding Recorded Investment	$ 21,355	$ 700	$ 24,032	$ 2,134
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0	0	1
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 1,400
Post-Modification Outstanding Recorded Investment	$ 0	$ 0	$ 0	$ 1,400
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 Ag

Credit Quality - Schedule of Age Analysis of its Past Due Loans, Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	$ 102,385	$ 74,633
Loans, Total Past Due	239,159	177,850
Loans, Current & Other	13,171,318	10,178,869
Total Financing Receivables	13,410,477	10,356,719
Loans, Recorded Investment >90 Days & Accruing	8,489	8,586
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total Past Due	136,774	103,217
Construction & Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	5,985	3,809
Loans, Total Past Due	10,235	11,588
Loans, Current & Other	1,687,997	1,244,150
Total Financing Receivables	1,698,232	1,255,738
Loans, Recorded Investment >90 Days & Accruing	685	33
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	4,250	7,779
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	18,242	5,850
Loans, Total Past Due	24,036	9,831
Loans, Current & Other	1,370,471	1,040,054
Total Financing Receivables	1,394,507	1,049,885
Loans, Recorded Investment >90 Days & Accruing	261	94
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	5,794	3,981
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	19,843	9,288
Loans, Total Past Due	43,502	30,135
Loans, Current & Other	4,658,506	3,395,318
Total Financing Receivables	4,702,008	3,425,453
Loans, Recorded Investment >90 Days & Accruing	0	172
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	23,659	20,847
Other Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	19,257	15,273
Loans, Total Past Due	95,972	58,039
Loans, Current & Other	1,770,515	1,555,398
Total Financing Receivables	1,866,487	1,613,437
Loans, Recorded Investment >90 Days & Accruing	1,913	2,518
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	76,715	42,766
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	31,497	29,976
Loans, Total Past Due	56,974	55,967
Loans, Current & Other	3,022,186	2,347,470
Total Financing Receivables	3,079,160	2,403,437
Loans, Recorded Investment >90 Days & Accruing	4,939	4,216
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	25,477	25,991
Consumer [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	235	422
Loans, Total Past Due	422	563
Loans, Current & Other	13,676	13,624
Total Financing Receivables	14,098	14,187
Loans, Recorded Investment >90 Days & Accruing	187	141
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	187	141
Consumer [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	7,326	10,015
Loans, Total Past Due	8,018	11,727
Loans, Current & Other	647,967	582,855
Total Financing Receivables	655,985	594,582
Loans, Recorded Investment >90 Days & Accruing	504	1,412
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	$ 692	$ 1,712

Credit Quality - Schedule of 65

Credit Quality - Schedule of Age Analysis of its Past Due Loans, Segregated by Class of Loans (Parenthetical) (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Acquired impaired loans from merger	$ 13,410,477	$ 10,356,719
Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Acquired impaired loans from merger	236,466	171,596
Loans and Debt Securities Acquired with Deteriorated Credit Quality [Member] | Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Acquired impaired loans from merger	$ 236,466	$ 171,596

Credit Quality - Schedule of No

Credit Quality - Schedule of Nonaccrual Loans, Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	$ 128,285	$ 94,631
Construction & Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	3,565	7,746
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	5,533	3,887
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	23,659	20,675
Other Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	74,802	40,248
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	20,538	21,775
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	$ 188	$ 300

Credit Quality - Schedule of Cr

Credit Quality - Schedule of Credit Quality Indicators Information, by Class of Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	$ 13,410,477	$ 10,356,719
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	3,079,160	2,403,437
Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,866,487	1,613,437
Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	14,098	14,187
Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	655,985	594,582
Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,394,507	1,049,885
Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	4,702,008	3,425,453
Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,698,232	1,255,738
Pass [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	3,024,753	2,348,017
Pass [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,728,795	1,463,797
Pass [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	13,676	13,624
Pass [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	647,858	582,704
Pass [Member] | Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,308,141	963,503
Pass [Member] | Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	4,562,334	3,284,497
Pass [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,580,263	1,126,742
Special Mention [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	18,056	18,240
Special Mention [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	21,275	26,537
Special Mention [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	235	422
Special Mention [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	7,429	10,132
Special Mention [Member] | Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	21,710	20,490
Special Mention [Member] | Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	48,782	36,462
Special Mention [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	19,866	52,327
Substandard [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	36,351	36,995
Substandard [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	115,152	122,893
Substandard [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	187	141
Substandard [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	698	1,746
Substandard [Member] | Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	64,656	65,892
Substandard [Member] | Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	90,892	104,494
Substandard [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	98,103	76,669
Doubtful [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	0	185
Doubtful [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,265	210
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	0	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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Construction & Land Development [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	$ 16,733		$ 16,733		$ 19,863
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	19,039		19,039		21,746
Impaired Loans, Recorded Investment, With an allowance recorded	1,870		1,870		4,940
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	6,368		6,368		7,899
Impaired Loans, Related Allowance	490		490		3,206
Impaired Loans, Recorded Investment	18,603		18,603		24,803
Impaired Loans, Unpaid Principal Balance	25,407		25,407		29,645
Impaired Loans, Related Allowance	490		490		3,206
Impaired Loans, Average Recorded Investment, With no related allowance recorded	17,155	$ 22,838	21,906	$ 25,916
Impaired Loans, Interest Income Recognized, With no related allowance recorded	6	40	11	67
Impaired Loans, Average Recorded Investment, With an allowance recorded	2,626	11,919	3,629	12,994
Impaired Loans, Interest Income Recognized, With an allowance recorded	21	48	43	90
Impaired Loans, Average Recorded Investment	19,781	34,757	25,535	38,910
Impaired Loans, Interest Income Recognized	27	88	54	157
Bankcard [Member]
Financing Receivable, Impaired [Line Items]
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
Other Consumer [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Average Recorded Investment, With no related allowance recorded	36	33	34	34
Impaired Loans, Interest Income Recognized, With no related allowance recorded	0	0	0	0
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	66,975		66,975		46,575
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	72,524		72,524		47,108
Impaired Loans, Recorded Investment, With an allowance recorded	15,029		15,029		1,787
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	15,029		15,029		2,082
Impaired Loans, Related Allowance	1,815		1,815		815
Impaired Loans, Recorded Investment	82,004		82,004		48,362
Impaired Loans, Unpaid Principal Balance	87,553		87,553		49,190
Impaired Loans, Related Allowance	1,815		1,815		815
Impaired Loans, Average Recorded Investment, With no related allowance recorded	64,440	27,267	58,148	33,221
Impaired Loans, Interest Income Recognized, With no related allowance recorded	267	125	635	184
Impaired Loans, Average Recorded Investment, With an allowance recorded	14,284	4,552	10,274	4,564
Impaired Loans, Interest Income Recognized, With an allowance recorded	156	30	293	57
Impaired Loans, Average Recorded Investment	78,724	31,819	68,422	37,785
Impaired Loans, Interest Income Recognized	423	155	928	241
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	145,120		145,120		92,654
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	168,694		168,694		93,104
Impaired Loans, Recorded Investment, With an allowance recorded	14,633		14,633		17,938
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	14,633		14,633		17,938
Impaired Loans, Related Allowance	2,397		2,397		2,524
Impaired Loans, Recorded Investment	159,753		159,753		110,592
Impaired Loans, Unpaid Principal Balance	183,327		183,327		111,042
Impaired Loans, Related Allowance	2,397		2,397		2,524
Impaired Loans, Average Recorded Investment, With no related allowance recorded	123,259	62,049	106,125	66,395
Impaired Loans, Interest Income Recognized, With no related allowance recorded	285	186	499	393
Impaired Loans, Average Recorded Investment, With an allowance recorded	14,443	8,615	15,765	8,507
Impaired Loans, Interest Income Recognized, With an allowance recorded	139	195	274	238
Impaired Loans, Average Recorded Investment	137,702	70,664	121,890	74,902
Impaired Loans, Interest Income Recognized	424	381	773	631
Other Commercial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	60,438		60,438		46,064
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	64,763		64,763		48,308
Impaired Loans, Recorded Investment, With an allowance recorded	75,327		75,327		43,774
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	82,784		82,784		46,188
Impaired Loans, Related Allowance	20,595		20,595		13,441
Impaired Loans, Recorded Investment	135,765		135,765		89,838
Impaired Loans, Unpaid Principal Balance	147,547		147,547		94,496
Impaired Loans, Related Allowance	20,595		20,595		13,441
Impaired Loans, Average Recorded Investment, With no related allowance recorded	59,912	25,816	55,861	27,861
Impaired Loans, Interest Income Recognized, With no related allowance recorded	271	124	589	224
Impaired Loans, Average Recorded Investment, With an allowance recorded	72,612	37,584	62,688	34,134
Impaired Loans, Interest Income Recognized, With an allowance recorded	569	98	1,194	228
Impaired Loans, Average Recorded Investment	132,524	63,400	118,549	61,995
Impaired Loans, Interest Income Recognized	840	222	1,783	452
Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	19,318		19,318		22,747
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	23,406		23,406		24,404
Impaired Loans, Recorded Investment, With an allowance recorded	16,707		16,707		12,066
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	18,883		18,883		12,801
Impaired Loans, Related Allowance	2,753		2,753		3,431
Impaired Loans, Recorded Investment	36,025		36,025		34,813
Impaired Loans, Unpaid Principal Balance	42,289		42,289		37,205
Impaired Loans, Related Allowance	2,753		2,753		3,431
Impaired Loans, Average Recorded Investment, With no related allowance recorded	19,607	28,074	21,950	26,872
Impaired Loans, Interest Income Recognized, With no related allowance recorded	73	97	132	237
Impaired Loans, Average Recorded Investment, With an allowance recorded	15,434	8,174	13,636	9,339
Impaired Loans, Interest Income Recognized, With an allowance recorded	65	19	73	25
Impaired Loans, Average Recorded Investment	35,041	36,248	35,586	36,211
Impaired Loans, Interest Income Recognized	138	116	205	262
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 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	35		35		36
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	35		35		36
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	35		35		36
Impaired Loans, Unpaid Principal Balance	35		35		36
Impaired Loans, Related Allowance	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	36	33	34	34
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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Specific loss allocations are calculated for commercial loans in excess			$ 500,000
Number of days for collecting principal or interest on consumer loans			90 days
Minimum collection period for home equity loan or high loan to value loan			180 days
Retail credits amount deemed unrecoverable charged-off period			60 days
Retail credits charged off period after discovery of the fraud			90 days
Provision for loan losses related to loans acquired		$ 1,728,000		$ 1,290,000
Reversal of provision for loan losses related to loans acquired	$ 738,000		$ 371,000
Reserve for lending-related commitments	$ 738,000		$ 738,000		$ 1,044,000
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		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	$ 72,875		$ 72,771	$ 75,726	$ 75,726
Charge-offs	9,922		17,207		36,180
Recoveries	1,779		3,269		8,716
Provision	8,251	$ 7,667	14,150	11,702	24,509
Allowance for Loan Losses Ending balance	72,983		72,983		72,771
Allowance for Loan Losses, individually evaluated for impairment	28,051		28,051		23,417
Allowance for Loan Losses, collectively evaluated for impairment	44,932		44,932		49,354
Financing receivables	13,410,477		13,410,477		10,356,719
Financing receivables, individually evaluated for impairment	185,084		185,084		124,820
Financing receivables, collectively evaluated for impairment	12,988,927		12,988,927		10,060,303
Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses	0		0		0
Financing receivables	236,466		236,466		171,596
Construction & Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	8,615		10,606	18,205	18,205
Charge-offs	780		2,522		2,659
Recoveries	201		616		433
Provision	(522)		(1,186)		(5,373)
Allowance for Loan Losses Ending balance	7,514		7,514		10,606
Allowance for Loan Losses, individually evaluated for impairment	481		481		3,206
Allowance for Loan Losses, collectively evaluated for impairment	7,033		7,033		7,400
Financing receivables	1,698,232		1,698,232		1,255,738
Financing receivables, individually evaluated for impairment	2,988		2,988		8,152
Financing receivables, collectively evaluated for impairment	1,669,397		1,669,397		1,221,006
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	25,847		25,847		26,580
Allowance for Estimated Imprecision [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	315		347	104	104
Charge-offs	0		0		0
Recoveries	0		0		0
Provision	445		413		243
Allowance for Loan Losses Ending balance	760		760		347
Allowance for Loan Losses, individually evaluated for impairment	0		0		0
Allowance for Loan Losses, collectively evaluated for impairment	760		760		347
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	4,212		5,273	3,637	3,637
Charge-offs	287		915		5,281
Recoveries	1,110		1,193		3,071
Provision	94		(422)		3,846
Allowance for Loan Losses Ending balance	5,129		5,129		5,273
Allowance for Loan Losses, individually evaluated for impairment	1,943		1,943		815
Allowance for Loan Losses, collectively evaluated for impairment	3,186		3,186		4,458
Financing receivables	1,394,507		1,394,507		1,049,885
Financing receivables, individually evaluated for impairment	38,976		38,976		18,976
Financing receivables, collectively evaluated for impairment	1,319,277		1,319,277		1,005,999
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	36,254		36,254		24,910
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	6,615		6,883	5,309	5,309
Charge-offs	190		295		419
Recoveries	14		30		675
Provision	660		481		1,318
Allowance for Loan Losses Ending balance	7,099		7,099		6,883
Allowance for Loan Losses, individually evaluated for impairment	2,372		2,372		2,524
Allowance for Loan Losses, collectively evaluated for impairment	4,727		4,727		4,359
Financing receivables	4,702,008		4,702,008		3,425,453
Financing receivables, individually evaluated for impairment	26,758		26,758		26,835
Financing receivables, collectively evaluated for impairment	4,548,388		4,548,388		3,323,117
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	126,862		126,862		75,501
Other Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	36,173		33,087	31,328	31,328
Charge-offs	6,631		10,029		20,430
Recoveries	161		665		3,452
Provision	7,584		13,564		18,737
Allowance for Loan Losses Ending balance	37,287		37,287		33,087
Allowance for Loan Losses, individually evaluated for impairment	20,494		20,494		13,441
Allowance for Loan Losses, collectively evaluated for impairment	16,793		16,793		19,646
Financing receivables	1,866,487		1,866,487		1,613,437
Financing receivables, individually evaluated for impairment	98,644		98,644		56,091
Financing receivables, collectively evaluated for impairment	1,734,526		1,734,526		1,527,479
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	33,317		33,317		29,867
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	14,123		13,770	15,148	15,148
Charge-offs	1,287		2,032		4,597
Recoveries	159		292		639
Provision	(516)		449		2,580
Allowance for Loan Losses Ending balance	12,479		12,479		13,770
Allowance for Loan Losses, individually evaluated for impairment	2,761		2,761		3,431
Allowance for Loan Losses, collectively evaluated for impairment	9,718		9,718		10,339
Financing receivables	3,079,160		3,079,160		2,403,437
Financing receivables, individually evaluated for impairment	17,718		17,718		14,766
Financing receivables, collectively evaluated for impairment	3,047,291		3,047,291		2,373,969
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	14,151		14,151		14,702
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	2,822		2,805	$ 1,995	1,995
Charge-offs	747		1,414		2,794
Recoveries	134		473		446
Provision	506		851		3,158
Allowance for Loan Losses Ending balance	2,715		2,715		2,805
Allowance for Loan Losses, individually evaluated for impairment	0		0		0
Allowance for Loan Losses, collectively evaluated for impairment	2,715		2,715		2,805
Financing receivables	670,083		670,083		608,769
Financing receivables, individually evaluated for impairment	0		0		0
Financing receivables, collectively evaluated for impairment	670,048		670,048		608,733
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	$ 35		$ 35		$ 36

Intangible Assets - Summary of

Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Goodwill not subject to amortization	$ 1,485,113	$ 863,767
Community Banking [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill not subject to amortization	1,462,152	863,767
Mortgage Banking [Member]
Finite-Lived Intangible Assets [Line Items]
Goodwill not subject to amortization	22,961	0
Core Deposit Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	103,348	69,635
Accumulated Amortization	(49,821)	(46,681)
Core Deposit Intangible Assets [Member] | Community Banking [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	103,348	69,635
Accumulated Amortization	(49,821)	$ (46,681)
Core Deposit Intangible Assets [Member] | Mortgage Banking [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	0
Accumulated Amortization	$ 0

Intangible Assets - Reconciliat

Intangible Assets - Reconciliation of Goodwill (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 863,767
Goodwill, Ending Balance	1,485,113
Bank of Georgetown [Member]
Goodwill [Line Items]
Addition to goodwill	1,327
Cardinal Financial Corporation [Member]
Goodwill [Line Items]
Addition to goodwill	620,019
Community Banking [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	863,767
Goodwill, Ending Balance	1,462,152
Community Banking [Member] | Bank of Georgetown [Member]
Goodwill [Line Items]
Addition to goodwill	1,327
Community Banking [Member] | Cardinal Financial Corporation [Member]
Goodwill [Line Items]
Addition to goodwill	597,058
Mortgage Banking [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	0
Goodwill, Ending Balance	22,961
Mortgage Banking [Member] | Bank of Georgetown [Member]
Goodwill [Line Items]
Addition to goodwill	0
Mortgage Banking [Member] | Cardinal Financial Corporation [Member]
Goodwill [Line Items]
Addition to goodwill	$ 22,961

Intangible Assets - Additional

Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Intangible Liability Disclosure [Abstract]
Amortization expense on intangible assets	$ 2,093	$ 919	$ 3,141	$ 1,664

Intangible Assets - Schedule of

Intangible Assets - Schedule of Anticipated Amortization Expense (Detail) $ in Thousands	Jun. 30, 2017USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2,017	$ 8,373
2,018	8,774
2,019	7,629
2,020	6,841
2021 and thereafter	$ 25,050

Short-Term Borrowings - Additio

Short-Term Borrowings - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Unused lines of credit	$ 264,000,000
Federal funds purchased	8,260,000	$ 22,235,000
Repurchase agreements	313,062,000
Wholesale REPO	$ 50,000,000
Maturity date of wholesale REPO	2018-05
Unrelated Financial Institution [Member]
Short-term Debt [Line Items]
Unused lines of credit	$ 20,000,000
Renewal period of line of credit	360 days
Amount of outstanding balance under line of credit	$ 0

Long-Term Borrowings - Addition

Long-Term Borrowings - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2017USD ($)Trust	Apr. 21, 2017USD ($)	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Unused borrowing amount	$ 5,569,655,000
FHLB advances	$ 1,122,714,000		$ 897,707,000
FHLB advances, weighted-average interest rate	1.43%
FHLB advances, maximum maturity period	8 years
Overnight funds	$ 50,000,000
Acquisition accounting adjustment to fair value, interest rate	1.27%
Number of statutory business trusts | Trust	15
Outstanding balances of debentures	$ 241,817,000		$ 224,319,000
Maximum time to defer payment of interest on subordinate debt	5 years
Trust Preferred Securities limit percentage	25.00%
Maximum [Member]
Debt Instrument [Line Items]
Risk based assets	$ 15,000,000,000
Cardinal Financial Corporation [Member] | Minimum [Member]
Debt Instrument [Line Items]
Risk based assets		$ 15,000,000,000
Capital Securities [Member]
Debt Instrument [Line Items]
Number of statutory business trusts | Trust	15

Long -Term Borrowings - Schedul

Long -Term Borrowings - Schedule of Maturities of FHLB Borrowings (Detail) $ in Thousands	Jun. 30, 2017USD ($)
Debt Disclosure [Abstract]
2,017	$ 665,873
2,018	131,610
2,019	187,955
2,020	42,364
2021 and thereafter	94,912
Total	$ 1,122,714

Commitments and Contingent Li78

Commitments and Contingent Liabilities - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Loss Contingencies [Line Items]
Loan commitments outstanding	$ 4,367,220,000	$ 2,823,396,000
Loan commitments expiry period	1 year
George Mason [Member]
Loss Contingencies [Line Items]
Aggregate available reserve amount under specified circumstances	$ 500,000
Commitments to Extend Credit [Member] | George Mason [Member] | Short-term Contract with Customer [Member]
Loss Contingencies [Line Items]
Additional commitments to extend credit	374,124,000
Commercial Letters of Credit [Member]
Loss Contingencies [Line Items]
Letters of credit issued	0	9,000
Standby Letters of Credit [Member]
Loss Contingencies [Line Items]
Letters of credit issued	$ 150,978,000	$ 121,584,000

Derivative Financial Instrume79

Derivative Financial Instruments - Schedule of Notional Amount and Fair Value of Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Derivative [Line Items]
Asset derivatives, notional amount	$ 727,964
Asset derivatives designated as hedging instruments	27	$ 24
Liability derivatives, notional amount	258,924
Asset derivatives not designated as hedging instruments	13,133	2,267
Total asset derivatives	13,160	2,291
Liability derivatives designated as hedging instruments	472	338
Liability derivatives not designated as hedging instruments	2,733	2,267
Total liability derivatives	3,205	2,605
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives, notional amount	14,853
Liability derivatives, notional amount	77,767
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives, notional amount	713,111
Liability derivatives, notional amount	181,157
Other Assets [Member] | TBA Mortgage Backed Securities [Member]
Derivative [Line Items]
Asset derivatives not designated as hedging instruments	926	0
Other Assets [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Asset derivatives not designated as hedging instruments	10,175	0
Other Assets [Member] | Not Designated as Hedging Instrument [Member] | TBA Mortgage Backed Securities [Member]
Derivative [Line Items]
Asset derivatives, notional amount	435,000
Other Assets [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Asset derivatives, notional amount	263,962
Other Liabilities [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Liability derivatives not designated as hedging instruments	531	0
Other Liabilities [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Lock Commitments [Member]
Derivative [Line Items]
Liability derivatives, notional amount	105,691
Interest Rate Swap Contracts [Member] | Other Assets [Member]
Derivative [Line Items]
Asset derivatives not designated as hedging instruments	2,032	2,267
Interest Rate Swap Contracts [Member] | Other Assets [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Asset derivatives, notional amount	14,149
Interest Rate Swap Contracts [Member] | Other Assets [Member] | Fair Value Hedging [Member] | Hedged Commercial Loans [Member]
Derivative [Line Items]
Asset derivatives designated as hedging instruments	27	24
Interest Rate Swap Contracts [Member] | Other Assets [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Hedged Commercial Loans [Member]
Derivative [Line Items]
Asset derivatives, notional amount	14,853
Interest Rate Swap Contracts [Member] | Other Liabilities [Member]
Derivative [Line Items]
Liability derivatives not designated as hedging instruments	2,032	2,267
Interest Rate Swap Contracts [Member] | Other Liabilities [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Liability derivatives, notional amount	14,149
Interest Rate Swap Contracts [Member] | Other Liabilities [Member] | Fair Value Hedging [Member] | Hedged Commercial Loans [Member]
Derivative [Line Items]
Liability derivatives designated as hedging instruments	472	338
Interest Rate Swap Contracts [Member] | Other Liabilities [Member] | Fair Value Hedging [Member] | Designated as Hedging Instrument [Member] | Hedged Commercial Loans [Member]
Derivative [Line Items]
Liability derivatives, notional amount	77,767
Forward Loan Sale Commitments [Member] | Other Liabilities [Member]
Derivative [Line Items]
Liability derivatives not designated as hedging instruments	170	$ 0
Forward Loan Sale Commitments [Member] | Other Liabilities [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Liability derivatives, notional amount	$ 61,317

Derivative Financial Instrume80

Derivative Financial Instruments - Schedule of Derivative Financial Instruments on Statement of Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Derivative [Line Items]
Derivatives in hedging relationships	$ 3,351	$ (249)	$ 3,193	$ 32
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivatives in hedging relationships	(282)	(249)	(440)	32
Designated as Hedging Instrument [Member] | Interest Income/ (Expense) [Member] | Interest Rate Swap Contracts [Member] | Fair Value Hedging [Member]
Derivative [Line Items]
Derivatives in hedging relationships	(282)	(249)	(440)	32
Designated as Hedging Instrument [Member] | Other Income [Member] | Forward Loan Sale Commitments [Member] | Cash Flow Hedges [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	3,633	0	3,633	0
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	2,784	0	2,784	0
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	1,019	0	1,019	0
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	$ 170	$ 0	$ 170	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Discount rates utilized, minimum	3.75%
Discount rates utilized, maximum	9.50%
Amount of decrease in fair value of securities	$ 6,496,000
Transfers from Level 1 to Level 2 for financial assets	0	$ 0
Transfers from Level 2 to Level 1 for financial assets	0	0
Transfers from Level 1 to Level 2 for financial liabilities	0	0
Transfers from Level 2 to Level 1 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	0.27%
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	0.40%
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	0.36%
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	0.27%
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	0.40%
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	0.36%
Trust Preferred Collateralized Debt Obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Decrease in fair value of securities	17.00%
Increase in discount rates, basis point	2.00%

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	$ 10,527	$ 13,828
Total available for sale securities	1,606,813	1,259,214
Loans held for sale	339,403	8,445
Derivative financial assets	13,160	2,291
Derivative financial liabilities	3,205	2,605
Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	1,596,286	1,245,386
Available for sale equity securities	10,527	13,828
Total available for sale securities	1,606,813	1,259,214
Loans held for sale	335,521
Derivative financial assets	13,160
Derivative financial liabilities	3,205
Fair Value, Measurements, Recurring [Member] | Interest Rate Lock Commitments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets	10,175
Derivative financial liabilities	531
Fair Value, Measurements, Recurring [Member] | TBA Mortgage Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets	926
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	117,398	95,786
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	117,398	95,786
State and Political Subdivisions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	307,795	192,812
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	307,795	192,812
Residential Mortgage-Backed Securities, Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	730,066	584,096
Residential Mortgage-Backed Securities, Agency [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	730,066	584,096
Residential Mortgage-Backed Securities, Non-agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	6,348	7,043
Residential Mortgage-Backed Securities, Non-agency [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	6,348	7,043
Asset-Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	0	217
Asset-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities		217
Commercial Mortgage-Backed Securities, Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	369,067	305,341
Commercial Mortgage-Backed Securities, Agency [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	369,067	305,341
Trust Preferred Collateralized Debt Obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	38,084	33,552
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	38,084	33,552
Single Issue Trust Preferred Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	12,344	11,477
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	12,344	11,477
Corporate Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	15,184	15,062
Corporate Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	15,184	15,062
Financial Services Industry [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	3,252	10,735
Other Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	1,164	1,273
Interest Rate Swap Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets	2,059	2,291
Derivative financial liabilities	2,504	2,605
Forward Loan Sale Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial liabilities	170
Equity Mutual Funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	6,111	1,820
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	7,662	4,465
Loans held for sale	0	0
Derivative financial assets	926	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	0	0
Available for sale equity securities	7,662	4,465
Total available for sale securities	7,662	4,465
Loans held for sale	0
Derivative financial assets	926
Derivative financial liabilities	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate Lock Commitments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets	0
Derivative financial liabilities	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member] | TBA Mortgage Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets	926
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, Agency [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, Non-agency [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] | 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
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commercial Mortgage-Backed Securities, Agency [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	0	0
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	387	1,372
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	1,164	1,273
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Interest Rate Swap Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets	0	0
Derivative financial liabilities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Forward Loan Sale Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial liabilities	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Mutual Funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	6,111	1,820
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	1,561,067	1,221,197
Loans held for sale	3,882	8,445
Derivative financial assets	2,059	2,291
Derivative financial liabilities	3,205	2,605
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	1,558,202	1,211,834
Available for sale equity securities	2,865	9,363
Total available for sale securities	1,561,067	1,221,197
Loans held for sale	0
Derivative financial assets	2,059
Derivative financial liabilities	3,205
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate Lock Commitments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets	0
Derivative financial liabilities	531
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | TBA Mortgage Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets	0
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	117,398	95,786
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	307,795	192,812
Significant Other Observable Inputs (Level 2) [Member] | Residential Mortgage-Backed Securities, Agency [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	730,066	584,096
Significant Other Observable Inputs (Level 2) [Member] | Residential Mortgage-Backed Securities, Non-agency [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	6,348	7,043
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		217
Significant Other Observable Inputs (Level 2) [Member] | Commercial Mortgage-Backed Securities, Agency [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	369,067	305,341
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	12,344	11,477
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	15,184	15,062
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	2,865	9,363
Significant Other Observable Inputs (Level 2) [Member] | Other Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	0	0
Significant Other Observable Inputs (Level 2) [Member] | Interest Rate Swap Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets	2,059	2,291
Derivative financial liabilities	2,504	2,605
Significant Other Observable Inputs (Level 2) [Member] | Forward Loan Sale Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial liabilities	170
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	0	0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	38,084	33,552
Loans held for sale	335,521	0
Derivative financial assets	10,175	0
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	38,084	33,552
Available for sale equity securities	0	0
Total available for sale securities	38,084	33,552
Loans held for sale	335,521
Derivative financial assets	10,175
Derivative financial liabilities	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate Lock Commitments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets	10,175
Derivative financial liabilities	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member] | TBA Mortgage Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets	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, Agency [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, Non-agency [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] | 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
Significant Unobservable Inputs (Level 3) [Member] | Commercial Mortgage-Backed Securities, Agency [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	38,084	33,552
Significant Unobservable Inputs (Level 3) [Member] | Single Issue Trust Preferred Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Corporate Bonds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Financial Services Industry [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Other Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	0	0
Significant Unobservable Inputs (Level 3) [Member] | Interest Rate Swap 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	0
Significant Unobservable Inputs (Level 3) [Member] | Forward Loan Sale Commitments [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial liabilities	0
Significant Unobservable Inputs (Level 3) [Member] | Equity Mutual Funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	$ 0	$ 0

Fair Value Measurements - Sch83

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	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Trust Preferred Collateralized Debt Obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Balance, beginning of period	$ 33,552	$ 34,686
Included in earnings (or changes in net assets)	0	0
Included in other comprehensive income	4,532	(1,134)
Purchases, issuances, and settlements	0	0
Transfers in and/or out of Level 3	0	0
Balance, end of period	38,084	33,552
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	0	0
Acquired in Cardinal merger	271,301	0
Originations	786,318	0
Sales	(732,091)	0
Included in earnings (or changes in net assets)	21,993	0
Transfers in and/or out of Level 3	(12,000)	0
Balance, end of period	335,521	0
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 - Sch84

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	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017
Mortgage Banking [Member]
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items]
Income from mortgage banking activities	$ (2,439)	$ (2,439)

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	Jun. 30, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Loans held for sale, unpaid principal balance	$ 326,741	$ 0
Loans held for sale, fair value	335,521	0
Loans held for sale, fair value over/(under) unpaid principal balance	$ 8,780	$ 0

Fair Value Measurements - Sum86

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
YTD Losses, Impaired Loans	$ 6,837	$ 5,119
YTD Losses, OREO	992	2,086
Impaired Loans	123,566	80,505
OREO	28,157	31,510
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired Loans	0	0
OREO	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired Loans	59,465	27,609
OREO	28,157	31,510
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired Loans	64,101	52,896
OREO	$ 0	$ 0

Fair Value Measurements - Sum87

Fair Value Measurements - Summary of Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 1,411,004	$ 1,434,527	$ 1,101,469	$ 857,335
Securities available for sale	1,606,813	1,259,214
Securities held to maturity	20,401	33,258
Other securities	163,273	111,166
Loans held for sale	339,403	8,445
Loans	13,392,478	10,341,137
Derivative financial assets	13,160	2,291
Deposits	13,971,221	10,796,867
Derivative financial liabilities	3,205	2,605
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1,411,004	1,434,527
Securities available for sale	1,606,813	1,259,214
Securities held to maturity	20,401	33,258
Other securities	163,273	111,166
Loans held for sale	339,403	8,445
Loans	13,319,495	10,268,366
Derivative financial assets	13,160	2,291
Deposits	13,971,221	10,796,867
Short-term borrowings	321,322	209,551
Long-term borrowings	1,364,531	1,172,026
Derivative financial liabilities	3,205	2,605
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1,411,004	1,434,527
Securities available for sale	1,606,813	1,259,214
Securities held to maturity	20,008	31,178
Other securities	155,109	105,608
Loans held for sale	339,403	8,445
Loans	12,791,323	10,122,486
Derivative financial assets	13,160	2,291
Deposits	13,956,271	10,785,294
Short-term borrowings	321,322	209,551
Long-term borrowings	1,331,638	1,142,782
Derivative financial liabilities	3,205	2,605
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	7,662	4,465
Securities held to maturity	0	0
Other securities	0	0
Loans held for sale	0	0
Loans	0	0
Derivative financial assets	926	0
Deposits	0	0
Short-term borrowings	0	0
Long-term borrowings	0	0
Derivative financial liabilities	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1,411,004	1,434,527
Securities available for sale	1,561,067	1,221,197
Securities held to maturity	16,988	28,158
Other securities	0	0
Loans held for sale	3,882	8,445
Loans	0	0
Derivative financial assets	2,059	2,291
Deposits	13,956,271	10,785,294
Short-term borrowings	321,322	209,551
Long-term borrowings	1,331,638	1,142,782
Derivative financial liabilities	3,205	2,605
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	38,084	33,552
Securities held to maturity	3,020	3,020
Other securities	155,109	105,608
Loans held for sale	335,521	0
Loans	12,791,323	10,122,486
Derivative financial assets	10,175	0
Deposits	0	0
Short-term borrowings	0	0
Long-term borrowings	0	0
Derivative financial liabilities	$ 0	$ 0

Stock Based Compensation - Addi

Stock Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands	May 18, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized shares of stock, option plan, maximum	1,700,000
Aggregate number of shares issued in respect of restricted stock awards	500,000
Options available for award each plan year	1,200,000
Maximum number of shares of restricted stock or shares subject to a restricted stock units award granted				50,000
Maximum number of options and SARs				100,000
Maximum number of stock options and SARs awarded				10,000
Maximum number of Shares of restricted stock or shares subject to a restricted stock units award granted to individual non-employee director				5,000
Vesting period of awards				1/3 per year
Number of Options granted				253,417
Recognition of compensation expense		$ 998	$ 672	$ 1,680	$ 1,330
Number of share available for grant for prior plans		0		0
Maximum term for awards granted (years)				10 years
Shares issued related stock option exercises				126,808	105,010
Total intrinsic value of options exercised				$ 2,501	$ 1,774
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted				89,475
Vesting period				4 years

Stock Based Compensation - Summ

Stock Based Compensation - Summary of Stock Option Plans (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Schedule Of Stock Options [Line Items]
Shares, Outstanding, Beginning balance	1,411,735
Shares, Granted	253,417
Shares, Exercised	(126,808)	(105,010)
Shares, Forfeited or expired	(2,430)
Shares, Outstanding, Ending balance	1,689,516
Shares, Exercisable at June 30, 2017	1,172,594
Aggregate Intrinsic Value, Outstanding at June 30, 2017	$ 16,186
Aggregate Intrinsic Value, Exercisable at June 30, 2017	$ 14,992
Weighted Average Remaining Contractual Term, Outstanding at June 30, 2017	6 years
Weighted Average Remaining Contractual Term, Exercisable at June 30, 2017	4 years 9 months 18 days
Weighted Average Exercise Price, Outstanding, Beginning balance	$ 28.05
Weighted Average Exercise Price, Granted	45.27
Weighted Average Exercise Price, Exercised	21.20
Weighted Average Exercise Price, Forfeited or expired	41.47
Weighted Average Exercise Price, Outstanding, Ending balance	30.52
Weighted Average Exercise Price, Exercisable	$ 26.41
Cardinal Financial Corporation [Member]
Schedule Of Stock Options [Line Items]
Shares, Assumed in Cardinal merger	153,602
Weighted Average Exercise Price, Exercisable	$ 21.47

Stock Based Compensation - Stat

Stock Based Compensation - Status of United's Nonvested Stock Option Awards (Detail)	6 Months Ended
	Jun. 30, 2017$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares, Nonvested, Beginning balance | shares	430,278
Shares, Granted | shares	253,417
Shares, Vested | shares	(165,273)
Shares, Forfeited or expired | shares	(1,500)
Shares, Nonvested, Ending balance | shares	516,922
Weighted-Average Grant Date Fair Value Per Share, Nonvested Beginning balance | $ / shares	$ 6.84
Weighted-Average Grant Date Fair Value Per Share, Granted | $ / shares	8.85
Weighted-Average Grant Date Fair Value Per Share, Vested | $ / shares	6.63
Weighted-Average Grant Date Fair Value Per Share, Forfeited or expired | $ / shares	8.85
Weighted-Average Grant Date Fair Value Per Share, Nonvested Ending balance | $ / shares	$ 7.88

Stock Based Compensation - Chan

Stock Based Compensation - Changes to United's Restricted Common Shares (Detail) - Restricted Stock [Member]	6 Months Ended
	Jun. 30, 2017$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding, Beginning balance | shares	137,268
Shares, Granted | shares	89,475
Shares, Vested | shares	(53,424)
Shares, Forfeited | shares	(420)
Number of Shares, Outstanding, Ending balance | shares	172,899
Weighted-Average Grant Date Fair Value Per Share, Outstanding, Beginning balance | $ / shares	$ 33.61
Weighted-Average Grant Date Fair Value Per Share, Granted | $ / shares	45.27
Weighted-Average Grant Date Fair Value Per Share, Vested | $ / shares	32.17
Weighted-Average Grant Date Fair Value Per Share, Forfeited | $ / shares	45.30
Weighted-Average Grant Date Fair Value Per Share, Outstanding, Ending balance | $ / shares	$ 40.06

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2017USD ($)	Jun. 30, 2017USD ($)
Retirement Benefits [Abstract]
Net periodic pension cost decline in expense	$ 249	$ 496
Unrecognized actuarial gains (losses), before tax	53,991	53,991
Unrecognized actuarial gains (losses), net of tax	34,014	34,014
Amortization expected to be recognized	$ 4,411	4,411
Amortization expected to be recognized, net of tax		$ 2,779

Employee Benefit Plans - Net Pe

Employee Benefit Plans - Net Periodic Pension Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 569	$ 608	$ 1,131	$ 1,215
Interest cost	1,279	1,456	2,544	2,912
Expected return on plan assets	(2,049)	(2,012)	(4,076)	(4,024)
Recognized net actuarial loss	1,100	1,149	2,187	2,297
Net periodic pension (benefit) cost	$ 899	$ 1,201	$ 1,786	$ 2,400
Weighted-Average Assumptions:
Discount rate	4.49%	4.75%	4.49%	4.75%
Expected return on assets	7.00%	7.25%	7.00%	7.25%
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	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Income Tax Disclosure [Abstract]
Estimate of unrecognized tax benefits, reasonable possible	United cannot reasonably estimate the amount of tax benefits it may recognize over the next 12 months.
Liability of unrecognized tax benefits	$ 2,966
Accrued interest related to uncertain tax positions	$ 609	$ 772

Comprehensive Income - Componen

Comprehensive Income - Components of Total Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net income	$ 37,059	$ 31,792	$ 75,868	$ 66,498
AFS securities with OTTI charges during the period	(16)	(77)	(60)	(77)
Related income tax effect	6	28	22	28
Less: OTTI charges recognized in net income	16	33	60	33
Related income tax benefit	(6)	(12)	(22)	(12)
Reclassification of previous noncredit OTTI to credit OTTI	0	415	0	415
Related income tax benefit	0	(150)	0	(150)
Net unrealized (losses) gains on AFS securities with OTTI	0	237	0	237
Change in net unrealized gain on AFS securities arising during the period	5,686	6,638	11,262	19,955
Related income tax effect	(2,104)	(2,403)	(4,167)	(7,224)
Net reclassification adjustment for (gains) losses included in net income	(763)	(246)	(977)	(250)
Related income tax expense (benefit)	282	90	361	91
Total AFS securities - all other	3,101	4,079	6,479	12,572
Net effect of AFS securities on other comprehensive income	3,101	4,316	6,479	12,809
Accretion on the unrealized loss for securities transferred from AFS to the HTM investment portfolio prior to call or maturity	2	3	4	4
Related income tax expense	(1)	(2)	(2)	(2)
Net effect of HTM securities on other comprehensive income	1	1	2	2
Pension plan:
Recognized net actuarial loss	1,100	1,149	2,187	2,297
Related income tax benefit	(405)	(420)	(797)	(839)
Net effect of change in pension plan asset on other comprehensive income	695	729	1,390	1,458
Net current-period other comprehensive income, net of tax	3,797	5,046	7,871	14,269
Comprehensive income, net of tax	$ 40,856	$ 36,838	$ 83,739	$ 80,767

Comprehensive Income - Compon96

Comprehensive Income - Components of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at January 1, 2017			$ 2,235,747
Net current-period other comprehensive income, net of tax	$ 3,797	$ 5,046	7,871	$ 14,269
Balance at June 30, 2017	3,237,421		3,237,421
Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at January 1, 2017			(34,369)
Other comprehensive income before reclassification			0
Amounts reclassified from accumulated other comprehensive income			1,390
Net current-period other comprehensive income, net of tax			1,390
Balance at June 30, 2017	(32,979)		(32,979)
Unrealized Gains/Losses on AFS Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at January 1, 2017			(10,297)
Other comprehensive income before reclassification			7,095
Amounts reclassified from accumulated other comprehensive income			(616)
Net current-period other comprehensive income, net of tax			6,479
Balance at June 30, 2017	(3,818)		(3,818)
Accumulated Unrealized Loss On Securities Available For Sale Transferred To Held To Maturity [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at January 1, 2017			(51)
Other comprehensive income before reclassification			2
Amounts reclassified from accumulated other comprehensive income			0
Net current-period other comprehensive income, net of tax			2
Balance at June 30, 2017	(49)		(49)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at January 1, 2017			(44,717)
Other comprehensive income before reclassification			7,097
Amounts reclassified from accumulated other comprehensive income			774
Net current-period other comprehensive income, net of tax			7,871
Balance at June 30, 2017	$ (36,846)		$ (36,846)

Comprehensive Income - Reclassi

Comprehensive Income - Reclassifications Out of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Available for sale ("AFS") securities:
Net reclassification adjustment for losses (gains) included in net income	$ 763	$ 246	$ 4,747	$ 250
Income before income taxes	56,363	48,170	115,388	100,755
Related income tax effect	(19,304)	(16,378)	(39,520)	(34,257)
Net income	37,059	31,792	75,868	66,498
Pension plan:
Recognized net actuarial loss	1,100	1,149	2,187	2,297
Income before income taxes	56,363	48,170	115,388	100,755
Related income tax effect	(19,304)	(16,378)	(39,520)	(34,257)
Net income	$ 37,059	$ 31,792	75,868	$ 66,498
Reclassification out of Accumulated Other Comprehensive Income [Member]
Available for sale ("AFS") securities:
Net income			774
Pension plan:
Net income			774
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			0
Net reclassification adjustment for losses (gains) included in net income			(977)
Income before income taxes			(977)
Related income tax effect			361
Net income			(616)
Pension plan:
Income before income taxes			(977)
Related income tax effect			361
Net income			(616)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Available for sale ("AFS") securities:
Income before income taxes			2,187
Related income tax effect			(797)
Net income			1,390
Pension plan:
Recognized net actuarial loss			2,187
Income before income taxes			2,187
Related income tax effect			(797)
Net income			$ 1,390

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		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share [Abstract]
Distributed earnings allocated to common stock	$ 34,562	$ 25,114	$ 61,284	$ 48,068
Undistributed earnings allocated to common stock	2,440	6,623	14,454	18,311
Net earnings allocated to common shareholders	$ 37,002	$ 31,737	$ 75,738	$ 66,379
Average common shares outstanding	99,197,807	71,483,703	90,100,627	70,490,596
Equivalents from stock options	422,238	325,318	469,662	276,368
Average diluted shares outstanding	99,620,045	71,809,021	90,570,289	70,766,964
Earnings per basic common share	$ 0.37	$ 0.44	$ 0.84	$ 0.94
Earnings per diluted common share	$ 0.37	$ 0.44	$ 0.84	$ 0.94

Variable Interest Entities - Ad

Variable Interest Entities - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2017Trust
Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract]
Number of statutory business trusts	15
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	6 Months Ended
	Jun. 30, 2017USD ($)
Century Trust [Member]
Variable Interest Entity [Line Items]
Issuance Date	Mar. 23, 2000
Amount of Capital Securities Issued	$ 8,800
Interest Rate	10.875% Fixed
Maturity Date	Mar. 8, 2030
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	Jun. 30, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Aggregate Assets	$ 266,551	$ 240,668
Aggregate Liabilities	257,636	232,583
Risk Of Loss	$ 8,915	$ 8,085

Segment Information - Additiona

Segment Information - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2017Segment
Segment Reporting [Abstract]
Number of reportable segments	1
Number of business segment	2

Segment Information - Summary o

Segment Information - Summary of Segment Reporting Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net interest income	$ 136,245	$ 102,725	$ 243,865	$ 201,009
Provision for loans losses	8,251	7,667	14,150	11,702	$ 24,509
Other income	40,506	17,967	60,652	34,359
Other expense	112,137	64,855	174,979	122,911
Income taxes	19,304	16,378	39,520	34,257
Net income	37,059	31,792	75,868	66,498
Total assets	19,035,600	14,338,012	19,035,600	14,338,012	$ 14,508,892
Average assets	18,183,015	12,796,542	16,304,164	12,571,975
Operating Segments [Member] | Community Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	138,498	104,676	248,158	204,802
Provision for loans losses	8,251	7,667	14,150	11,702
Other income	18,223	18,616	35,036	35,657
Other expense	78,631	64,092	141,383	123,314
Income taxes	23,920	17,521	43,724	35,851
Net income	45,919	34,012	83,937	69,592
Total assets	18,658,321	14,358,021	18,658,321	14,358,021
Average assets	17,967,121	12,820,946	16,210,026	12,592,765
Operating Segments [Member] | Mortgage Banking [Member]
Segment Reporting Information [Line Items]
Net interest income	90		90
Provision for loans losses	0		0
Other income	22,393		22,393
Other expense	18,708		18,708
Income taxes	1,293		1,293
Net income	2,482		2,482
Total assets	382,086		382,086
Average assets	236,074		118,689
Other [Member]
Segment Reporting Information [Line Items]
Net interest income	(2,343)	(1,951)	(4,383)	(3,793)
Provision for loans losses	0	0	0	0
Other income	(110)	(649)	3,223	(1,298)
Other expense	14,798	763	14,888	(403)
Income taxes	(5,909)	(1,143)	(5,497)	(1,594)
Net income	(11,342)	(2,220)	(10,551)	(3,094)
Total assets	(4,807)	(20,009)	(4,807)	(20,009)
Average assets	$ (20,180)	$ (24,404)	$ (24,551)	$ (20,790)