United Bankshares (UBSI) 10-Q 6 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 31, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
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		69,573,186

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Assets
Cash and due from banks	$ 143,276	$ 175,713
Interest-bearing deposits with other banks	864,460	576,630
Federal funds sold	722	721
Total cash and cash equivalents	1,008,458	753,064
Securities available for sale at estimated fair value (amortized cost- $1,099,646 at September 30, 2015 and $1,180,016 at December 31, 2014)	1,107,410	1,180,386
Securities held to maturity (estimated fair value-$36,232 at September 30, 2015 and $36,784 at December 31, 2014)	38,795	39,310
Other investment securities	90,387	96,344
Loans held for sale	11,602	8,680
Loans	9,187,949	9,119,492
Less: Unearned income	(14,292)	(14,840)
Loans net of unearned income	9,173,657	9,104,652
Less: Allowance for loan losses	(75,480)	(75,529)
Net loans	9,098,177	9,029,123
Bank premises and equipment	73,915	77,520
Goodwill	710,252	709,794
Accrued interest receivable	35,424	32,334
Other assets	382,509	402,256
TOTAL ASSETS	12,556,929	12,328,811
Deposits:
Noninterest-bearing	2,703,433	2,591,619
Interest-bearing	6,801,463	6,453,866
Total deposits	9,504,896	9,045,485
Borrowings:
Federal funds purchased	32,250	53,840
Securities sold under agreements to repurchase	341,694	434,155
Federal Home Loan Bank borrowings	664,880	830,335
Other long-term borrowings	223,288	222,636
Reserve for lending-related commitments	1,178	1,518
Accrued expenses and other liabilities	78,902	84,682
TOTAL LIABILITIES	$ 10,847,088	$ 10,672,651
Shareholders' Equity
Preferred stock, $1.00 par value; Authorized-50,000,000 shares, none issued
Common stock, $2.50 par value; Authorized-100,000,000 shares; issued-69,583,445 and 69,314,407 at September 30, 2015 and December 31, 2014, respectively, including 21,397 and 18,548 shares in treasury at September 30, 2015 and December 31, 2014, respectively	$ 173,959	$ 173,286
Surplus	751,261	742,960
Retained earnings	814,094	776,311
Accumulated other comprehensive loss	(28,740)	(35,764)
Treasury stock, at cost	(733)	(633)
TOTAL SHAREHOLDERS' EQUITY	1,709,841	1,656,160
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$ 12,556,929	$ 12,328,811

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Securities available for sale, amortized cost	$ 1,099,646	$ 1,180,016
Securities held to maturity	$ 36,232	$ 36,784
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	100,000,000	100,000,000
Common stock, shares issued	69,583,445	69,314,407
Common stock, shares in treasury	21,397	18,548

Consolidated Statements of Inco

Consolidated Statements of Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Interest income
Interest and fees on loans	$ 97,331	$ 97,874	$ 289,184	$ 281,663
Interest on federal funds sold and other short-term investments	461	241	1,142	656
Interest and dividends on securities:
Taxable	7,619	7,873	23,390	21,869
Tax-exempt	898	869	2,674	2,632
Total interest income	106,309	106,857	316,390	306,820
Interest expense
Interest on deposits	7,145	7,077	20,826	20,493
Interest on short-term borrowings	213	234	653	911
Interest on long-term borrowings	2,633	3,628	7,942	10,264
Total interest expense	9,991	10,939	29,421	31,668
Net interest income	96,318	95,918	286,969	275,152
Provision for loan losses	5,182	4,748	16,252	15,628
Net interest income after provision for loan losses	91,136	91,170	270,717	259,524
Other income
Fees from trust and brokerage services	4,737	4,474	14,560	13,708
Fees from deposit services	9,059	11,134	29,266	31,595
Bankcard fees and merchant discounts	1,243	1,101	3,288	2,974
Other service charges, commissions, and fees	527	512	1,644	1,541
Income from bank-owned life insurance	1,234	1,325	3,765	4,021
Income from mortgage banking	665	774	1,873	1,471
Net gain on the sale of bank premises	0	0	0	8,976
Other income	236	251	979	901
Total other-than-temporary impairment losses	0	(561)	(100)	485
Portion of loss recognized in other comprehensive income	0	(4,153)	66	(6,259)
Net other-than-temporary impairment losses	0	(4,714)	(34)	(5,774)
Net gains on sales/calls of investment securities	111	1,309	160	2,134
Net investment securities gains (losses)	111	(3,405)	126	(3,640)
Total other income	17,812	16,166	55,501	61,547
Other expense
Employee compensation	22,700	22,173	63,692	68,726
Employee benefits	6,690	4,753	20,081	15,567
Net occupancy expense	5,654	6,400	18,725	19,349
Other real estate owned (OREO) expense	769	1,818	3,003	4,968
Equipment expense	2,601	2,376	6,745	6,518
Data processing expense	3,582	3,785	11,192	10,611
Bankcard processing expense	390	350	1,092	1,022
FDIC insurance expense	2,098	1,981	6,253	5,559
Other expense	13,200	14,058	42,286	43,503
Total other expense	57,684	57,694	173,069	175,823
Income before income taxes	51,264	49,642	153,149	145,248
Income taxes	16,217	16,382	48,666	48,617
Net income	$ 35,047	$ 33,260	$ 104,483	$ 96,631
Earnings per common share:
Basic	$ 0.50	$ 0.48	$ 1.51	$ 1.45
Diluted	0.50	0.48	1.50	1.44
Dividends per common share	$ 0.32	$ 0.32	$ 0.96	$ 0.96
Average outstanding shares:
Basic	69,391,401	69,044,876	69,302,180	66,836,396
Diluted	69,689,723	69,269,309	69,586,287	67,069,352

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 35,047	$ 33,260	$ 104,483	$ 96,631
Change in net unrealized gain (loss) on available-for-sale (AFS) securities, net of tax	5,482	1,635	4,716	18,445
Accretion of the net unrealized loss on the transfer of AFS securities to held-to-maturity (HTM) securities, net of tax	1	2	4	4
Change in pension plan assets, net of tax	768	309	2,304	928
Comprehensive income, net of tax	$ 41,298	$ 35,206	$ 111,507	$ 116,008

Consolidated Statement of Chang

Consolidated Statement of Changes in Shareholders' Equity (Unaudited) - 9 months ended Sep. 30, 2015 - USD ($) $ in Thousands	Total	Common Stock [Member]	Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Balance at January 1, 2015 at Dec. 31, 2014	$ 1,656,160	$ 173,286	$ 742,960	$ 776,311	$ (35,764)	$ (633)
Beginning Balance, shares at Dec. 31, 2014		69,314,407
Comprehensive income:
Net income	104,483	$ 0	0	104,483	0	0
Other comprehensive income, net of tax:	7,024	0	0	0	7,024	0
Comprehensive income, net of tax	111,507
Stock based compensation expense	2,144	0	2,144	0	0	0
Distribution of treasury stock for deferred compensation plan	1	0	0	0	0	1
Purchase of treasury stock (12 shares)	(1)	0	0	0	0	(1)
Cash dividends ($0.96 per share)	(66,700)	0	0	(66,700)	0	0
Grant of restricted stock (53,071 shares)	0	$ 132	(132)	0	0	0
Grant of restricted stock, shares		53,071
Forfeiture of restricted stock (2,861 shares)	0	$ 0	100	0	0	(100)
Common stock options exercised (215,967 shares)	$ 6,730	$ 541	6,189	0	0	0
Common stock options exercised, shares	215,967	215,967
Balance at September 30, 2015 at Sep. 30, 2015	$ 1,709,841	$ 173,959	$ 751,261	$ 814,094	$ (28,740)	$ (733)
Ending Balance, shares at Sep. 30, 2015		69,583,445,000

Consolidated Statement of Chan7

Consolidated Statement of Changes in Shareholders' Equity (Unaudited) (Parenthetical)	9 Months Ended
	Sep. 30, 2015$ / sharesshares
Cash dividends per share | $ / shares	$ 0.96
Common stock options exercised, shares	215,967
Common Stock [Member]
Grant of restricted stock, shares	53,071
Forfeiture of restricted stock, shares	2,861
Common stock options exercised, shares	215,967
Treasury Stock [Member]
Distribution of treasury stock for deferred compensation plan, shares	24
Purchase of treasury stock, shares	12

Condensed Consolidated Statemen

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Statement of Cash Flows [Abstract]
NET CASH PROVIDED BY OPERATING ACTIVITIES	$ 127,687	$ 99,495
INVESTING ACTIVITIES
Proceeds from maturities and calls of securities held to maturity	400	897
Proceeds from sales of securities available for sale	6,233	92,413
Proceeds from maturities and calls of securities available for sale	123,793	408,079
Purchases of securities available for sale	(50,955)	(403,277)
Purchases of bank premises and equipment	(3,940)	(6,300)
Proceeds from sales of bank premises and equipment	998	11,428
Redemption of bank-owned life insurance policies	0	8,930
Purchases of other investment securities	(11,979)	(59,123)
Proceeds from sales and redemptions of other investment securities	18,005	42,282
Acquisition of Virginia Commerce Bancorp, Inc., net of cash paid	0	97,298
Net change in loans	(78,266)	(308,225)
NET CASH PROVIDED BY (USED IN) INVESTING ACTIVITIES	4,289	(115,598)
FINANCING ACTIVITIES
Cash dividends paid	(66,607)	(60,354)
Excess tax benefits from stock-based compensation arrangements	853	482
Acquisition of treasury stock	(1)	(2)
Proceeds from exercise of stock options	6,590	7,172
Repayment of long-term Federal Home Loan Bank borrowings	(790,455)	(421,390)
Proceeds from issuance of long-term Federal Home Loan Bank borrowings	625,000	775,000
Distribution of treasury stock for deferred compensation plan	1	81
Changes in:
Deposits	460,978	110,112
Federal funds purchased, securities sold under agreements to repurchase and other short-term borrowings	(112,941)	(220,345)
NET CASH PROVIDED BY FINANCING ACTIVITIES	123,418	190,756
Increase in cash and cash equivalents	255,394	174,653
Cash and cash equivalents at beginning of year	753,064	416,617
Cash and cash equivalents at end of period	$ 1,008,458	$ 591,270

General

General	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	1. GENERAL 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 and with the instructions for Form 10-Q and Article 10 of Regulation S-X. Accordingly, the financial statements do not contain all of the information and footnotes required by accounting principles generally accepted in the United States. In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. The financial statements presented as of September 30, 2015 and 2014 and for the three-month and nine-month periods then ended have not been audited. The consolidated balance sheet as of December 31, 2014 has been extracted from the audited financial statements included in United’s 2014 Annual Report to Shareholders. The accounting and reporting policies followed in the presentation of these financial statements are consistent with those applied in the preparation of the 2014 Annual Report of United on Form 10-K. To conform to the 2015 presentation, certain reclassifications have been made to prior period amounts, which had no impact on net income, comprehensive income or stockholders’ equity. In the opinion of management, all adjustments necessary for a fair presentation of financial position and results of operations for the interim periods have been made. Such adjustments are of a normal and recurring nature. 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 September 2015, the FASB issued ASU 2015-16, “Simplifying the Accounting for Measurement-Period Adjustments”, as part of its simplification initiative. ASU 2015-16 requires an acquirer to “recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined.” In addition, the acquirer must record, in the financial statements for the same period, “the effect on earnings of changes in depreciation, amortization, or other income effect, if any, as a result of the change to the provisional amounts, calculated as if the accounting had been completed at the acquisition date.” Entities must also “present separately on the face of the income statement or disclose in the notes the portion of the amount recorded in the current-period earnings by line item that would have been recorded in previous reporting periods if the adjustment to the provisional amount had been recognized as of the acquisition date.” ASU 2015-16 is effective for United on January 1, 2016 and is not expected to have a significant impact on the Company’s financial condition or results of operation. In May 2015, the FASB issued ASU 2015-07, “Disclosures for Investment in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent), a consensus of the FASB Emerging Issues Task Force.” ASU 2015-07 modifies certain provision of FASB Accounting Standards Codification Topic 820, Fair Value Measurement (ASC 820). ASU 2015-07 eliminates the requirement to categorize investments in the fair value hierarchy if an investment’s fair value is measured based on net asset value (NAV) per share (or its equivalent) using the practical expedient. The reporting entities will no longer be required to provide the related fair value disclosures for these securities but instead, will be required to disclose information to help users understand the nature of the investments as well as risks, including whether it is probable that the amount realized on the sale of the investments would differ from net asset value. ASU 2015-07 is effective for United on January 1, 2016 and is not expected to have a significant impact on the Company’s financial condition or results of operation. In April 2015, the FASB issued ASU 2015-04, “Compensation – Retirement Benefits: Practical Expedient for the Measurement Date of an Employer’s Defined Benefit Obligation and Plan Assets.” ASU 2015-04 gives an employer whose fiscal year-end does not coincide with a calendar month-end the ability, as a practical expedient, to measure defined benefit retirement obligations and related plan assets as of the month-end that is closest to its fiscal year-end. ASU 2015-04 also provides guidance on accounting for contributions to the plan and significant events that require a remeasurement that occur during the period between a month-end measurement and the employer’s fiscal year-end. ASU 2015-04 is effective for United on January 1, 2016 and is not expected to have a significant impact on the Company’s financial condition or results of operation. In April 2015, the FASB issued ASU 2015-03, “Simplifying the Presentation of Debt Issuance Costs.” Under ASU 2015-03, debt issuance costs are required to be presented as a direct deduction of debt balances on the statement of financial condition, similar to the presentation of debt discounts. ASU 2015-03 is limited to simplifying the presentation of debt issuance costs and does not change the recognition and measurement guidance for debt issuance costs. ASU 2015-03 is effective for United on January 1, 2016 and is not expected to have a significant impact on the Company’s financial condition or results of operation. In February 2015, the FASB issued ASU 2015-02, “Amendments to the Consolidation Analysis.” ASU 2015-02 improves targeted areas of the consolidation guidance and reduces the number of consolidation models. The new consolidation standard eliminates the deferral of FAS 167 and makes changes to both the variable interest model and the voting model in ASC 810. ASU 2015-02 affects all entities, could change consolidation conclusions and may trigger additional disclosures. ASU 2015-02 is effective for United on January 1, 2016 and is not expected to have a significant impact on the Company’s financial condition or results of operation. In January 2015, the FASB issued ASU 2015-01, “Income Statement, Extraordinary and Unusual Items (Subtopic 225-20).” ASU 2015-01 eliminates the separate presentation of extraordinary items but does not change the requirement to disclose material items that are unusual or infrequent in nature. Eliminating the concept of extraordinary items will allow entities to no longer have to assess whether a particular event or transaction is both unusual in nature and infrequent in occurrence. ASU 2015-01 is effective for United on January 1, 2016 and is not expected to have a significant impact on the Company’s financial condition or results of operation. In June 2014, the FASB issued ASU 2014-12, “Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period.” ASU 2014-12 amends the guidance in FASB ASC 718, “Compensation-Stock Compensation”, to bring consistency to the accounting for share-based payment awards that require a specific performance target to be achieved in order for employees to become eligible to vest in the awards. The amendments affect all entities that grant their employees share-based payments in which the terms of the award provide that a performance target that affects vesting could be achieved after the requisite service period. ASU 2014-12 is effective for United on January 1, 2016, and is not expected to have a significant impact on the Company’s financial condition or results of operation. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 supersedes the revenue recognition requirements in Accounting Standards Codification Topic 605, “Revenue Recognition”, and most industry-specific guidance throughout the Accounting Standards Codification. The amendments require an entity to recognize revenue upon the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. The new revenue recognition standard sets forth a five step principle-based approach for determining revenue recognition. In April 2015, the FASB voted to defer the effective date of ASU 2014-09 by one-year for both public and private companies, and gave both public and private companies the option to “early” adopt using the original effective dates. ASU 2014-09 now will be effective for United on January 1, 2018 with early adoption permitted on January 1, 2017. Management is currently evaluating this guidance to determine the impact on the Company’s financial condition or results of operation.

Mergers and Acquisitions

Mergers and Acquisitions	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
Mergers and Acquisitions	2. MERGERS AND ACQUISITIONS At the close of business on January 31, 2014 (Acquisition Date), United acquired 100% of the outstanding common stock of Virginia Commerce Bancorp, Inc. (Virginia Commerce), a Virginia corporation headquartered in Arlington, Virginia. The acquisition of Virginia Commerce significantly enhances United’s existing footprint in the Washington, D.C. Metropolitan Statistical Area. The results of operations of Virginia Commerce are included in the consolidated results of operations from the date of acquisition. At consummation, Virginia Commerce had assets of $2,769,716, loans of $2,065,490 and deposits of $2,018,962. The transaction was accounted for under the purchase acquisition method of accounting and accordingly, assets acquired, liabilities assumed and consideration exchanged were recorded at estimated fair value on the Acquisition Date. The aggregate purchase price was $585,533 including common stock issued valued at $547,894, stock options exchanged valued at $4,368, cash paid of $33,263 to redeem the warrant held by the U.S. Department of the Treasury (the Treasury) issued by Virginia Commerce in connection with the TARP Capital Purchase Program and $8 paid in cash to holders of Virginia Commerce common stock and restricted stock in lieu of fractional shares of United common stock. The cash portion of the purchase price was funded by cash on hand. The purchase price of the warrant was based on its fair market as agreed upon by United and the Treasury. As a result of the purchase by United, the warrant has been canceled. The number of shares issued in the transaction was 18,330,347, which were valued based on the closing market price of $29.89 for United’s common shares on January 31, 2014. The purchase price has been allocated to the identifiable tangible and intangible assets resulting in additions to goodwill and core deposit intangibles of $336,102 and $17,143, 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 Virginia Commerce acquisition is deductible for tax purposes. As a result of the merger, United recorded a downward fair value adjustment of $88,129 on the loans acquired from Virginia Commerce, a downward fair value adjustment of $1,708 on certain other real estate owned properties, a premium on interest-bearing deposits of $6,007, a premium on term securities sold under agreements to repurchase of $3,700 and a discount of $16,384 on junior subordinated debt securities. The 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 September 30, 2015, the premium on the interest-bearing deposits and the securities sold under agreements to repurchase has an estimated remaining life of three months and 0.83 years, respectively, while the discount on the junior subordinated debt securities has an estimated remaining life of 18.83 years. United assumed $109 of liabilities to provide severance benefits to terminated employees of Virginia Commerce which has no remaining balance as of September 30, 2015. 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 Virginia Commerce’s previously established allowance for loan losses. As a result, standard industry coverage ratios with regard to the allowance for credit losses are less meaningful after the acquisition of Virginia Commerce. The acquired loans were divided into loans with evidence of credit quality deterioration, which are accounted for under ASC topic 310-30 (acquired impaired) and loans that do not meet this criteria, which are accounted for under ASC topic 310-20 (acquired performing). Acquired impaired loans have experienced a deterioration of credit quality from origination to acquisition for which it is probable that United will be unable to collect all contractually required payments receivable, including both principal and interest. Subsequent decreases in the expected cash flows require United to evaluate the need for additions to the Company’s allowance for credit losses. Subsequent improvements in expected cash flows generally result in the recognition of additional interest income over the then remaining lives of the loans. In conjunction with the Virginia Commerce merger, the acquired loan portfolio was accounted for at fair value as follows: January 31, 2014 Contractually required principal and interest at acquisition $ 2,685,339 Contractual cash flows not expected to be collected (396,024 ) Expected cash flows at acquisition 2,289,315 Interest component of expected cash flows (274,539 ) Basis in acquired loans at acquisition – estimated fair value $ 2,014,776 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 $427,858, $189,277, and $179,199, respectively. The following table shows the consideration paid for Virginia Commerce’s common equity and the amounts of acquired identifiable assets and liabilities assumed as of the Acquisition Date. Purchase price: Value of common shares issued (18,330,347 shares) $ 547,894 Fair value of stock options assumed 4,368 Cash to redeem the Treasury warrant 33,263 Cash for fractional shares 8 Total purchase price 585,533 Identifiable assets: Cash and cash equivalents 130,569 Investment securities 476,541 Loans 2,014,776 Premises and equipment 10,786 Core deposit intangibles 17,143 Other assets 104,131 Total identifiable assets $ 2,753,946 Identifiable liabilities: Deposits $ 2,024,969 Short-term borrowings 263,816 Long-term borrowings 204,335 Other liabilities 11,395 Total identifiable liabilities 2,504,515 Net assets acquired including identifiable intangible assets 249,431 Resulting goodwill $ 336,102 The following table provides a reconciliation of goodwill: Goodwill at December 31, 2014 $ 709,794 Addition to goodwill from Virginia Commerce acquisition 458 Goodwill at September 30, 2015 $ 710,252

Investment Securities

Investment Securities	9 Months Ended
	Sep. 30, 2015
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. September 30, 2015 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 $ 78,864 $ 2,914 $ 0 $ 81,778 $ 0 State and political subdivisions 137,660 2,489 194 139,955 0 Residential mortgage-backed securities Agency 487,995 11,738 63 499,670 0 Non-agency 9,638 476 3 10,111 458 Commercial mortgage-backed securities Agency 308,596 5,680 98 314,178 0 Asset-backed securities 4,273 0 8 4,265 0 Trust preferred collateralized debt obligations 49,894 680 14,863 35,711 25,952 Single issue trust preferred securities 13,798 210 1,780 12,228 0 Other corporate securities 4,999 73 0 5,072 0 Marketable equity securities 3,929 535 22 4,442 0 Total $ 1,099,646 $ 24,795 $ 17,031 $ 1,107,410 $ 26,410 December 31, 2014 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 $ 88,559 $ 1,425 $ 3 $ 89,981 $ 0 State and political subdivisions 133,730 3,165 32 136,863 0 Residential mortgage-backed securities Agency 547,825 8,407 547 555,685 0 Non-agency 11,474 544 0 12,018 458 Commercial mortgage-backed securities Agency 316,707 2,393 2,001 317,099 0 Asset-backed securities 8,004 23 0 8,027 0 Trust preferred collateralized debt obligations 51,328 922 12,692 39,558 25,886 Single issue trust preferred securities 13,760 173 2,189 11,744 0 Other corporate securities 4,998 137 0 5,135 0 Marketable equity securities 3,631 648 3 4,276 0 Total $ 1,180,016 $ 17,837 $ 17,467 $ 1,180,386 $ 26,344 (1) Other-than-temporary impairment in accumulated other comprehensive income. Amounts are before-tax. The following is a summary of securities available-for-sale which were in an unrealized loss position at September 30, 2015 and December 31, 2014. Less than 12 months 12 months or longer Fair Unrealized Fair Unrealized Value Losses Value Losses September 30, 2015 U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 0 $ 0 $ 0 $ 0 State and political subdivisions 17,546 194 0 0 Residential mortgage-backed securities Agency 20,780 63 0 0 Non-agency 378 3 0 0 Commercial mortgage-backed securities Agency 7,934 67 9,527 31 Asset-backed securities 4,265 8 0 0 Trust preferred collateralized debt obligations 1,199 94 29,578 14,769 Single issue trust preferred securities 0 0 3,900 1,780 Marketable equity securities 973 22 0 0 Total $ 53,075 $ 451 $ 43,005 $ 16,580 December 31, 2014 U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 7,142 $ 3 $ 0 $ 0 State and political subdivisions 11,637 32 0 0 Residential mortgage-backed securities Agency 96,550 547 0 0 Commercial mortgage-backed securities Agency 21,674 56 146,897 1,945 Asset-backed securities 0 0 0 0 Trust preferred collateralized debt obligations 0 0 32,241 12,692 Single issue trust preferred securities 0 0 8,080 2,189 Marketable equity securities 23 3 0 0 Total $ 137,026 $ 641 $ 187,218 $ 16,826 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 September 30 Nine Months Ended September 30 2015 2014 2015 2014 Proceeds from sales and calls $ 42,559 $ 64,610 $ 130,027 $ 500,493 Gross realized gains 43 1,314 97 2,366 Gross realized losses 2 5 7 232 At September 30, 2015, gross unrealized losses on available for sale securities were $17,031 on 56 securities of a total portfolio of 449 available for sale securities. Securities in an unrealized loss position at September 30, 2015 consisted primarily of pooled trust preferred collateralized debt obligations (Trup Cdos) and single issue trust preferred securities. The Trup Cdos and the single issue trust preferred securities relate mainly to securities of financial institutions. 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. 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 securities was $796,591 at September 30, 2015. Of the $796,591, $308,596 was related to agency commercial mortgage securities and $487,995 was related to agency residential mortgage securities. Each of the agency mortgage 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 September 30, 2015. Non-agency residential mortgage-backed securities United’s non-agency residential mortgage-backed securities portfolio relates to securities of various private label issuers. The Company has no exposure to real estate investment trusts (REITS) in its investment portfolio. The total amortized cost of available for sale non-agency residential mortgage securities was $9,638 at September 30, 2015. Of the $9,638, $2,141 was rated above investment grade and $7,496 was rated below investment grade. Approximately 30% of the portfolio includes collateral that was originated during the year of 2005 or before. The remaining 70% includes collateral that was originated in the years of 2006 and 2007. The entire portfolio of the non-agency residential mortgage securities are either the senior or super-senior tranches of their respective structure. In determining whether or not the non-agency mortgage-backed securities are other-than-temporarily impaired, management performs an in-depth analysis on each non-agency residential mortgage-backed security on a quarterly basis. The analysis includes a review of the following factors: weighted average loan to value, weighted average maturity, average FICO scores, historical collateral performance, geographic concentration, credit subordination, cross-collateralization, coverage ratios, origination year, full documentation percentage, event risk (repricing), and collateral type. Management completes a quarterly stress test to determine the level of loss protection remaining in each individual security and compares the protection remaining to the future expected performance of the underlying collateral. Additionally, management utilizes a third-party cash flow model to perform a cash flow test for each bond below investment grade. The model produces a bond specific set of cash flows based upon assumptions input by management. The input assumptions that are incorporated include the projected constant default rate (CDR) of the underlying mortgages, the loss severity upon default, and the prepayment rate on the underlying mortgage collateral. CDR and loss severities are forecasted by management after full evaluation of the underlying collateral including recent performance statistics. Therefore, based upon management’s analysis and judgment, there was no additional credit-related or noncredit-related other-than-temporary impairment recognized on the non-agency residential mortgage-backed securities at September 30, 2015. 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, TARP participation status, and other key factors. Upon completing the review for the third quarter of 2015, 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 B+ to a high of BBB-. The amortized cost of available for sale single issue trust preferred securities as of September 30, 2015 consisted of $2,997 in investment grade bonds, $5,121 in split-rated bonds and $5,680 in below investment grade bonds. The amortized cost of available for sale single issue trust preferred securities included $5,680 that was in an unrealized loss position for twelve months or longer as of September 30, 2015. 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 September 30, 2015, 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 TARP participation, 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 flow during the third quarter of 2015, as the expected discounted cash flows from these securities were greater than or equal to the discounted cash flow 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 third quarter of 2015 related to these securities. At September 30, 2015, the balance of the noncredit-related other-than-temporary impairment recognized on United’s Trup Cdo portfolio was $25,952 as compared to $25,886 at December 31, 2014. The amortized cost of available for sale Trup Cdos in an unrealized loss position for twelve months or longer as of September 30, 2015 consisted of $4,617 in investment grade bonds and $39,731 in below investment grade bonds. The following is a summary of the available for sale Trup Cdos as of September 30, 2015: Amortized Cost Class Amortized Cost Fair Value Unrealized Loss Investment Split Below Senior – Bank $ 6,758 $ 5,981 $ 777 $ 4,617 $ 0 $ 2,141 Mezzanine – Bank (now in senior position) 11,859 9,097 2,762 0 0 11,859 Mezzanine – Bank 26,090 16,966 9,124 0 0 26,090 Mezzanine – Bank & Insurance (combination) 5,187 3,667 1,520 0 0 5,187 Totals $ 49,894 $ 35,711 $ 14,183 $ 4,617 $ 0 $ 45,277 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 in the product. Deferral features available to the underlying issuers within each pool are unique to these securities. Additionally, it can be difficult for market participants to predict whether deferrals will ultimately cure or ultimately default. Due to the lack of transparency, market participants will require a higher risk premium, thus resulting in higher required discount rates. • 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, complex structures and high market discount rates 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 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 BBB- to a high of Aaa. The below investment grade Trup Cdos range from a low of Ca to a high of Ba1. On the Trup Cdos that have not been deemed to be other-than-temporarily impaired, the collateralization ratios range from a low of 98.0% to a high of 308.4%, with a median of 147.8%, and a weighted average of 206.9%. 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. Management does not believe any individual security with an unrealized loss as of September 30, 2015 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 $3,929 at September 30, 2015. 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 September 30, 2015. These securities had gross unrealized losses of $22 at September 30, 2015. Other investment securities (cost method) During the third quarter of 2015, United also evaluated all of its cost method investments to determine if certain events or changes in circumstances during the third quarter of 2015 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 third 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 September 30 Nine Months Ended September 30 2015 2014 2015 2014 Balance of cumulative credit losses at beginning of period $ 23,773 $ 34,082 $ 23,739 $ 40,663 Addition for credit losses recognized in earnings during the period: Additional credit losses on securities for which OTTI was previously recognized 0 4,714 34 5,738 Reductions for securities sold or paid off during the period 0 0 0 (7,605 ) Balance of cumulative credit losses at end of period $ 23,773 $ 38,796 $ 23,773 $ 38,796 The amortized cost and estimated fair value of securities available for sale at September 30, 2015 and December 31, 2014 by contractual maturity are shown as follows. Expected maturities may differ from contractual maturities because the issuers may have the right to call or prepay obligations without penalties. September 30, 2015 December 31, 2014 Estimated Estimated Amortized Fair Amortized Fair Cost Value Cost Value Due in one year or less $ 22,311 $ 22,451 $ 38,358 $ 38,727 Due after one year through five years 276,823 281,147 180,821 181,930 Due after five years through ten years 199,455 206,182 313,863 317,663 Due after ten years 597,128 593,188 643,343 637,790 Marketable equity securities 3,929 4,442 3,631 4,276 Total $ 1,099,646 $ 1,107,410 $ 1,180,016 $ 1,180,386 The amortized cost and estimated fair values of securities held to maturity are summarized as follows: September 30, 2015 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 10,470 $ 1,066 $ 0 $ 11,536 State and political subdivisions 8,975 24 304 8,695 Residential mortgage-backed securities Agency 36 7 0 43 Single issue trust preferred securities 19,294 0 3,356 15,938 Other corporate securities 20 0 0 20 Total $ 38,795 $ 1,097 $ 3,660 $ 36,232 December 31, 2014 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 10,599 $ 1,329 $ 0 $ 11,928 State and political subdivisions 9,369 32 294 9,107 Residential mortgage-backed securities Agency 41 7 0 48 Single issue trust preferred securities 19,281 0 3,600 15,681 Other corporate securities 20 0 0 20 Total $ 39,310 $ 1,368 $ 3,894 $ 36,784 Even though the market value of the held-to-maturity investment portfolio is less than its cost, the unrealized loss has no impact on the net worth or regulatory capital requirements of United. As of September 30, 2015, the Company’s two largest held-to-maturity single-issue trust preferred exposures were to Wells Fargo ($9,913) and SunTrust Bank ($7,407). The two held-to-maturity single-issue trust preferred exposures with at least one rating below investment grade included SunTrust Bank ($7,407) and Royal Bank of Scotland ($973). Other corporate securities consist mainly of bonds of corporations. The amortized cost and estimated fair value of debt securities held to maturity at September 30, 2015 and December 31, 2014 by contractual maturity are shown below. Expected maturities may differ from contractual maturities because the issuers may have the right to call or prepay obligations without penalties. September 30, 2015 December 31, 2014 Amortized Estimated Amortized Estimated Due in one year or less $ 5,049 $ 5,215 $ 360 $ 361 Due after one year through five years 9,287 10,200 14,499 15,848 Due after five years through ten years 4,294 3,998 4,293 4,007 Due after ten years 20,165 16,819 20,158 16,568 Total $ 38,795 $ 36,232 $ 39,310 $ 36,784 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 $1,034,982 and $1,081,299 at September 30, 2015 and December 31, 2014, respectively.

Loans

Loans	9 Months Ended
	Sep. 30, 2015
Receivables [Abstract]
Loans	4. LOANS Major classes of loans are as follows: September 30, 2015 December 31, Commercial, financial and agricultural: Owner-occupied commercial real estate $ 942,302 $ 1,016,364 Nonowner-occupied commercial real estate 2,842,158 2,760,189 Other commercial loans 1,609,331 1,577,438 Total commercial, financial & agricultural 5,393,791 5,353,991 Residential real estate 2,252,530 2,263,354 Construction & land development 1,125,908 1,133,251 Consumer: Bankcard 10,171 10,437 Other consumer 405,549 358,459 Total gross loans $ 9,187,949 $ 9,119,492 The table above does not include loans held for sale of $11,602 and $8,680 at September 30, 2015 and December 31, 2014, respectively. Loans held for sale consist of single-family residential real estate loans originated for sale in the secondary market. The outstanding balances in the table above include acquired impaired loans with a recorded investment of $154,180 or 1.68% of total gross loans at September 30, 2015 and $176,339 or 1.93% of total gross loans at December 31, 2014. The contractual principal in these acquired impaired loans was $217,684 and $252,759 at September 30, 2015 and December 31, 2014, 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 nine months of 2015 follows: Accretable yield at the beginning of the period $ 11,339 Accretion (including cash recoveries) (8,590 ) Net reclassifications to accretable from non-accretable 10,393 Disposals (including maturities, foreclosures, and charge-offs) (510 ) Accretable yield at the end of the period $ 12,632 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 $196,403 and $188,516 at September 30, 2015 and December 31, 2014, respectively.

Credit Quality

Credit Quality	9 Months Ended
	Sep. 30, 2015
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 September 30, 2015, United had TDRs of $21,509 as compared to $22,234 as of December 31, 2014. Of the $21,509 aggregate balance of TDRs at September 30, 2015, $9,679 was on nonaccrual status and included in the “Loans on Nonaccrual Status” on the following page. Of the $22,234 aggregate balance of TDRs at December 31, 2014, $4,194 was on nonaccrual status and included in the “Loans on Nonaccrual Status” on the following page. As of September 30, 2015, there were no commitments to lend additional funds to debtors owing receivables whose terms have been modified in TDRs. At September 30, 2015, United had restructured loans in the amount of $3,882 that were modified by a reduction in the interest rate, $7,919 that were modified by a combination of a reduction in the interest rate and the principal and $9,708 that was modified by a change in terms. A loan acquired and accounted for under ASC topic 310-30 “Loans and Debt Securities Acquired with Deteriorated Credit Quality” is reported as an accruing loan and a performing asset. No loans were restructured during the three months ended September 30, 2015 and 2014. The following table sets forth United’s troubled debt restructurings that have been restructured during the nine months ended September 30, 2015 and 2014, segregated by class of loans: Troubled Debt Restructurings For the Nine Months Ended September 30, 2015 September 30, 2014 Number of Pre-Modification Post- Number of Pre-Modification Post- Commercial real estate: Owner-occupied 0 $ 0 $ 0 0 $ 0 $ 0 Nonowner-occupied 1 669 647 0 0 0 Other commercial 1 240 240 2 5,630 5,630 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 2 $ 909 $ 887 2 $ 5,630 $ 5,630 During the first nine months of 2015, restructured loans of $887 were modified by a combination of a reduction in the interest rate and an extension of the maturity date. During the first nine months of 2014, restructured loans of $5,630 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 balance due to the advancement of monies for items such as delinquent taxes on real estate property. The loans were evaluated individually for allocation within United’s allowance for loan losses. The modifications had an immaterial impact on the financial condition and results of operations for United. No loans restructured during the twelve-month period ended September 30, 2015 subsequently defaulted, resulting in a principal charge-off during the three months and first nine months ended September 30, 2015. The following table presents troubled debt restructurings, by class of loan, that had charge-offs during the three months and nine months ended September 30, 2014. During the time periods indicated, the loan’s principal was reduced through a charge-off to the value of the underlying collateral. Three Months Ended September 30, 2014 Nine Months Ended September 30, 2014 (In thousands) Number of Recorded Number of Recorded Troubled Debt Restructurings Commercial real estate: Owner-occupied 0 $ 0 0 $ 0 Nonowner-occupied 1 478 1 478 Other commercial 0 0 0 0 Residential real estate 0 0 0 0 Construction & land development 0 0 0 0 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total 1 $ 478 1 $ 478 The following table sets forth United’s age analysis of its past due loans, segregated by class of loans: Age Analysis of Past Due Loans As of September 30, 2015 30-89 90 Days or more Total Past Current & Total Financing Recorded Commercial real estate: Owner-occupied $ 5,729 $ 14,178 $ 19,907 $ 922,395 $ 942,302 $ 1,394 Nonowner-occupied 12,154 20,978 33,132 2,809,026 2,842,158 1,341 Other commercial 8,751 29,998 38,749 1,570,582 1,609,331 6,375 Residential real estate 34,672 30,605 65,277 2,187,253 2,252,530 4,093 Construction & land development 4,327 15,931 20,258 1,105,650 1,125,908 1,643 Consumer: Bankcard 448 216 664 9,507 10,171 216 Other consumer 7,645 1,308 8,953 396,596 405,549 1,086 Total $ 73,726 $ 113,214 $ 186,940 $ 9,001,009 $ 9,187,949 $ 16,148 (1) Other includes loans with a recorded investment of $154,180 acquired and accounted for under ASC topic 310-30 “Loans and Debt Securities Acquired with Deteriorated Credit Quality”. Age Analysis of Past Due Loans As of December 31, 2014 30-89 90 Days Total Past Current & Total Financing Recorded Commercial real estate: Owner-occupied $ 4,158 $ 13,582 $ 17,740 $ 998,624 $ 1,016,364 $ 1,039 Nonowner-occupied 10,627 14,859 25,486 2,734,703 2,760,189 45 Other commercial 17,348 17,975 35,323 1,542,115 1,577,438 3,034 Residential real estate 40,793 25,544 66,337 2,197,017 2,263,354 5,417 Construction & land development 5,329 17,119 22,448 1,110,803 1,133,251 648 Consumer: Bankcard 471 114 585 9,852 10,437 114 Other consumer 8,992 1,727 10,719 347,740 358,459 1,378 Total $ 87,718 $ 90,920 $ 178,638 $ 8,940,854 $ 9,119,492 $ 11,675 (1) Other includes loans with a recorded investment of $176,339 acquired and accounted for under ASC topic 310-30 “Loans and Debt Securities Acquired with Deteriorated Credit Quality”. The following table sets forth United’s nonaccrual loans, segregated by class of loans: Loans on Nonaccrual Status September 30, 2015 December 31, 2014 Commercial real estate: Owner-occupied $ 12,784 $ 12,543 Nonowner-occupied 19,637 14,814 Other commercial 23,623 14,941 Residential real estate 26,512 20,127 Construction & land development 14,288 16,471 Consumer: Bankcard 0 0 Other consumer 222 349 Total $ 97,066 $ 79,245 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 days are considered special mention. 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 prior to such a classification. Loans classified as doubtful are also considered impaired. The following tables set forth United’s credit quality indicators information, by class of loans: Credit Quality Indicators Corporate Credit Exposure As of September 30, 2015 Commercial Real Estate Other Construction Owner- Nonowner- Grade: Pass $ 857,365 $ 2,691,563 $ 1,454,916 $ 971,431 Special mention 26,129 27,057 46,861 61,767 Substandard 58,808 123,538 100,512 92,710 Doubtful 0 0 7,042 0 Total $ 942,302 $ 2,842,158 $ 1,609,331 $ 1,125,908 As of December 31, 2014 Commercial Real Estate Other Construction Owner- Nonowner- Grade: Pass $ 920,981 $ 2,592,783 $ 1,407,853 $ 966,335 Special mention 26,181 48,382 20,776 64,597 Substandard 69,202 119,024 147,494 102,319 Doubtful 0 0 1,315 0 Total $ 1,016,364 $ 2,760,189 $ 1,577,438 $ 1,133,251 Credit Quality Indicators Consumer Credit Exposure As of September 30, 2015 Residential Bankcard Other Grade: Pass $ 2,182,354 $ 9,507 $ 396,446 Special mention 14,027 448 7,751 Substandard 54,958 216 1,352 Doubtful 1,191 0 0 Total $ 2,252,530 $ 10,171 $ 405,549 As of December 31, 2014 Residential Bankcard Other Grade: Pass $ 2,176,655 $ 9,852 $ 347,442 Special mention 18,254 471 9,113 Substandard 66,973 114 1,904 Doubtful 1,472 0 0 Total $ 2,263,354 $ 10,437 $ 358,459 Loans are designated as impaired when, in the opinion of management, based on current information and events, the collection of principal and interest in accordance with the loan contract is doubtful. Typically, United does not consider loans for impairment unless a sustained period of delinquency (i.e. 90 days or more) is noted or there are subsequent events that impact repayment probability (i.e. negative financial trends, bankruptcy filings, eminent foreclosure proceedings, etc.). Impairment is evaluated in total for smaller-balance loans of a similar nature and on an individual loan basis for other loans. Consistent with United’s existing method of income recognition for loans, interest on impaired loans, except those classified as nonaccrual, is recognized as income using the accrual method. Impaired loans, or portions thereof, are charged off when deemed uncollectible. The following table sets forth United’s impaired loans information, by class of loans: Impaired Loans September 30, 2015 December 31, 2014 Recorded Unpaid Related Recorded Unpaid Related With no related allowance recorded: Commercial real estate: Owner-occupied $ 41,438 $ 41,651 $ 0 $ 37,811 $ 37,811 $ 0 Nonowner-occupied 76,314 76,778 0 48,126 48,462 0 Other commercial 30,002 31,868 0 38,521 40,329 0 Residential real estate 25,776 26,541 0 31,262 31,930 0 Construction & land development 30,131 31,838 0 64,945 68,799 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 39 39 0 41 41 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 4,590 $ 4,590 $ 1,194 $ 5,014 $ 5,014 $ 776 Nonowner-occupied 7,056 7,056 1,339 6,994 6,994 797 Other commercial 18,287 21,788 12,394 17,554 20,554 7,168 Residential real estate 10,054 11,374 3,292 6,028 7,349 2,578 Construction & land development 13,635 19,639 4,467 10,779 14,189 3,627 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 0 0 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 46,028 $ 46,241 $ 1,194 $ 42,825 $ 42,825 $ 776 Nonowner-occupied 83,370 83,834 1,339 55,120 55,456 797 Other commercial 48,289 53,656 12,394 56,075 60,883 7,168 Residential real estate 35,830 37,915 3,292 37,290 39,279 2,578 Construction & land development 43,766 51,477 4,467 75,724 82,988 3,627 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 39 39 0 41 41 0 Impaired Loans For the Three Months Ended September 30, 2015 September 30, 2014 Average Interest Average Interest With no related allowance recorded: Commercial real estate: Owner-occupied $ 42,679 $ 75 $ 37,208 $ 129 Nonowner-occupied 73,694 566 63,035 230 Other commercial 32,839 133 20,679 59 Residential real estate 28,572 31 32,864 46 Construction & land development 31,815 6 44,191 97 Consumer: Bankcard 0 0 0 0 Other consumer 35 0 55 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 4,603 $ 28 $ 4,352 $ 114 Nonowner-occupied 6,891 44 7,332 67 Other commercial 18,990 56 12,537 97 Residential real estate 8,801 6 7,716 8 Construction & land development 12,661 114 11,491 31 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 76 0 Total: Commercial real estate: Owner-occupied $ 47,282 $ 103 $ 41,560 $ 243 Nonowner-occupied 80,585 610 70,367 297 Other commercial 51,829 189 33,216 156 Residential real estate 37,373 37 40,580 54 Construction & land development 44,476 120 55,682 128 Consumer: Bankcard 0 0 0 0 Other consumer 35 0 131 0 Impaired Loans For the Nine Months Ended September 30, 2015 September 30, 2014 Average Interest Average Interest With no related allowance recorded: Commercial real estate: Owner-occupied $ 42,908 $ 254 $ 35,959 $ 617 Nonowner-occupied 68,919 1,083 62,205 440 Other commercial 34,472 373 27,454 217 Residential real estate 29,127 177 30,484 195 Construction & land development 34,703 165 46,747 234 Consumer: Bankcard 0 0 0 0 Other consumer 36 0 45 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 4,664 $ 86 $ 4,236 $ 189 Nonowner-occupied 6,747 90 7,606 159 Other commercial 18,740 274 12,751 185 Residential real estate 7,879 35 8,548 101 Construction & land development 11,606 206 10,694 47 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 102 0 Total: Commercial real estate: Owner-occupied $ 47,572 $ 340 $ 40,195 $ 806 Nonowner-occupied 75,666 1,173 69,811 599 Other commercial 53,212 647 40,205 402 Residential real estate 37,006 212 39,032 296 Construction & land development 46,309 371 57,441 281 Consumer: Bankcard 0 0 0 0 Other consumer 36 0 147 0 At September 30, 2015 and December 31, 2014, other real estate owned (OREO) included in other assets in the Consolidated Balance Sheets was $34,119 and $38,778, 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 September 30, 2015 and December 31, 2014, the recorded investment of consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings are in process was $473 and $311, respectively.

Allowance for Credit Losses

Allowance for Credit Losses	9 Months Ended
	Sep. 30, 2015
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. Management’s evaluation of the adequacy of the allowance for loan losses and the appropriate provision for credit losses is based upon a quarterly evaluation of the portfolio. This evaluation is inherently subjective and requires significant estimates, including the amounts and timing of estimated future cash flows, estimated losses on pools of loans based on historical loss experience, and consideration of current economic trends, all of which are susceptible to constant and significant change. Allocations are made for specific commercial loans based upon management’s estimate of the borrowers’ ability to repay and other factors impacting collectibility. Other commercial loans not specifically reviewed on an individual basis are evaluated based on historical loss percentages applied to loan pools that have been segregated by the type of risk. Allocations for loans other than commercial loans are made based upon historical loss experience adjusted for current environmental conditions. The allowance for credit losses includes estimated probable inherent but undetected losses within the portfolio due to uncertainties in economic conditions, delays in obtaining information, including unfavorable information about a borrower’s financial condition, the difficulty in identifying triggering events that correlate perfectly to subsequent loss rates, and risk factors that have not yet fully manifested themselves in loss allocation factors. In addition, a portion of the allowance accounts for the inherent imprecision in the allowance for credit losses analysis. For purposes of determining the general allowance, the loan portfolio is segregated by loan product type to recognize differing risk profiles among loan categories. It is further segregated by credit grade for risk-rated loan pools and delinquency for homogeneous loan pools. The outstanding principal balance within each pool is multiplied by historical loss data and certain qualitative factors to derive the general loss allocation per pool. Specific loss allocations are calculated for loans in excess of $500 thousand in accordance with ASC topic 310. Risk characteristics of owner-occupied commercial real estate loans and other commercial loans are similar in that they are normally dependent upon the borrower’s internal cash flow from operations to service debt. Nonowner-occupied commercial real estate loans differ in that cash flow to service debt is normally dependent on external income from third parties for use of the real estate such as rents, leases and room rates. Residential real estate loans are dependent upon individual borrowers who are affected by changes in general economic conditions, demand for housing and resulting residential real estate valuation. Construction and land development loans are impacted mainly by demand whether for new residential housing or for retail, industrial, office and other types of commercial construction within a given area. Consumer loan pool risk characteristics are influenced by general, regional and local economic conditions. During the first nine months of 2015, there were no material changes to the accounting policy or methodology related to the allowance for loan losses. Loans deemed to be uncollectible are charged against the allowance for loan losses, while recoveries of previously charged-off amounts are credited to the allowance for loan losses. For commercial loans, when a loan or a portion of a loan is identified to contain a loss, a charge-off recommendation is directed to management to charge-off all or a portion of that loan. Generally, any unsecured commercial loan more than six months delinquent in payment of interest must be charged-off in full. If secured, the charge-off is generally made to reduce the loan balance to a level equal to the liquidation value of the collateral when payment of principal and interest is six months delinquent. Any commercial loan, secured or unsecured, on which a principal or interest payment has not been made within 90 days, is reviewed monthly for appropriate action. For consumer loans, closed-end retail loans that are 120 cumulative days delinquent from the contractual due date and open-end loans 180 cumulative days delinquent from the contractual due date are charged-off. Any consumer loan on which a principal or interest payment has not been made within 90 days is reviewed monthly for appropriate action. For a one-to-four family open-end or closed-end residential real estate loan, home equity loan, or high-loan-to-value loan that has reached 180 or more days past due, management evaluates the collateral position and charge-offs any amount that exceeds the value of the collateral. On retail credits for which the borrower is in bankruptcy, all amounts deemed unrecoverable are charged off within 60 days of the receipt of the notification. On retail credits effected by fraud, a loan is charged-off within 90 days of the discovery of the fraud. In the event of the borrower’s death and if repayment within the required timeframe is uncertain, the loan is generally charged-off as soon as the amount of the loss is determined. 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). The amount of provision for loan losses related to loans acquired that have evidence of deterioration of credit quality was $267 and $381 for the third quarter of 2015 and 2014, respectively, and $4,299 and $727 for the nine months ended September 30, 2015 and 2014, respectively. United maintains an allowance for loan losses and a reserve for lending-related commitments such as unfunded loan commitments and letters of credit. The reserve for lending-related commitments of $1,178 and $1,518 at September 30, 2015 and December 31, 2014, respectively, is separately classified on the balance sheet and is included in other liabilities. The combined allowance for loan losses and reserve for lending-related commitments are referred to as the allowance for credit losses. A progression of the allowance for loan losses, by portfolio segment, for the periods indicated is summarized as follows: Allowance for Loan Losses For the Three Months Ended September 30, 2015 Commercial Real Estate Other Residential Construction Consumer Allowance Total Owner- Nonowner- Allowance for Loan Losses: Beginning balance $ 4,247 $ 7,296 $ 28,476 $ 14,920 $ 16,975 $ 3,169 $ 132 $ 75,215 Charge-offs 175 28 3,889 756 54 505 0 5,407 Recoveries 129 15 101 76 64 105 0 490 Provision 158 (255 ) 6,736 (1,041 ) (1,190 ) 817 (43 ) 5,182 Ending balance $ 4,359 $ 7,028 $ 31,424 $ 13,199 $ 15,795 $ 3,586 $ 89 $ 75,480 Allowance for Loan Losses and Carrying Amount of Loans For the Nine Months Ended September 30, 2015 Commercial Real Estate Other Residential Construction Consumer Allowance Total Owner- Nonowner- Allowance for Loan Losses: Beginning balance $ 4,041 $ 8,167 $ 26,931 $ 13,835 $ 19,402 $ 3,083 $ 70 $ 75,529 Charge-offs 4,303 355 7,941 2,888 825 1,830 0 18,142 Recoveries 249 53 297 347 451 444 0 1,841 Provision 4,372 (837 ) 12,137 1,905 (3,233 ) 1,889 19 16,252 Ending balance $ 4,359 $ 7,028 $ 31,424 $ 13,199 $ 15,795 $ 3,586 $ 89 $ 75,480 Ending Balance: individually evaluated for impairment $ 1,194 $ 1,339 $ 12,394 $ 3,291 $ 4,468 $ 0 $ 0 $ 22,686 Ending Balance: collectively evaluated for impairment $ 3,165 $ 5,689 $ 19,030 $ 9,908 $ 11,327 $ 3,586 $ 89 $ 52,794 Ending Balance: loans acquired with deteriorated credit quality $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Financing receivables: Ending balance $ 942,302 $ 2,842,158 $ 1,609,331 $ 2,252,530 $ 1,125,908 $ 415,720 $ 0 $ 9,187,949 Ending Balance: individually evaluated for impairment $ 12,753 $ 28,385 $ 25,136 $ 14,741 $ 17,010 $ 0 $ 0 $ 98,025 Ending Balance: collectively evaluated for impairment $ 902,958 $ 2,760,084 $ 1,564,569 $ 2,220,777 $ 1,071,684 $ 415,672 $ 0 $ 8,935,744 Ending Balance: loans acquired with deteriorated credit quality $ 26,591 $ 53,689 $ 19,626 $ 17,012 $ 37,214 $ 48 $ 0 $ 154,180 Allowance for Loan Losses and Carrying Amount of Loans For the Year Ended December 31, 2014 Commercial Real Estate Other Residential Construction Consumer Allowance Total Owner- Nonowner- Allowance for Loan Losses: Beginning balance $ 5,653 $ 8,992 $ 20,917 $ 16,694 $ 18,953 $ 2,945 $ 44 $ 74,198 Charge-offs 3,073 2,097 4,947 5,027 7,476 2,621 0 25,241 Recoveries 2,372 268 294 573 685 443 0 4,635 Provision (911 ) 1,004 10,667 1,595 7,240 2,316 26 21,937 Ending balance $ 4,041 $ 8,167 $ 26,931 $ 13,835 $ 19,402 $ 3,083 $ 70 $ 75,529 Ending Balance: individually evaluated for impairment $ 776 $ 797 $ 7,168 $ 2,578 $ 3,627 $ 0 $ 0 $ 14,946 Ending Balance: collectively evaluated for impairment $ 3,265 $ 7,370 $ 19,763 $ 11,257 $ 15,775 $ 3,083 $ 70 $ 60,583 Ending Balance: loans acquired with deteriorated credit quality $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Financing receivables: Ending balance $ 1,016,364 $ 2,760,189 $ 1,577,438 $ 2,263,354 $ 1,133,251 $ 368,896 $ 0 $ 9,119,492 Ending Balance: individually evaluated for impairment $ 12,869 $ 13,733 $ 27,491 $ 16,189 $ 17,168 $ 0 $ 0 $ 87,450 Ending Balance: collectively evaluated for impairment $ 971,408 $ 2,692,374 $ 1,523,504 $ 2,227,605 $ 1,071,966 $ 368,846 $ 0 $ 8,855,703 Ending Balance: loans acquired with deteriorated credit quality $ 32,087 $ 54,082 $ 26,443 $ 19,560 $ 44,117 $ 50 $ 0 $ 176,339

Intangible Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2015
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: As of September 30, 2015 Gross Carrying Accumulated Net Carrying Amortized intangible assets: Core deposit intangible assets $ 60,577 ($ 41,882 ) $ 18,695 Goodwill not subject to amortization $ 710,252 As of December 31, 2014 Gross Carrying Accumulated Net Carrying Amortized intangible assets: Core deposit intangible assets $ 60,577 ($ 39,317 ) $ 21,260 Goodwill not subject to amortization $ 709,794 United incurred amortization expense of $855 and $2,565 for the quarter and nine months ended September 30, 2015, respectively, and $1,054 and $2,967 for the quarter and nine months ended September 30, 2014, respectively. The following table sets forth the anticipated amortization expense for intangible assets for the years subsequent to 2014: Year Amount 2015 $ 3,420 2016 2,981 2017 2,767 2018 2,574 2019 and thereafter 9,518

Short-Term Borrowings

Short-Term Borrowings	9 Months Ended
	Sep. 30, 2015
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 $254,000. These lines of credit, which bear interest at prevailing market rates, permit United to borrow funds in the overnight market, and are renewable annually subject to certain conditions. At September 30, 2015, federal funds purchased were $32,250 while securities sold under agreements to repurchase (REPOs) were $290,461. Excluded from the $290,461 of total REPOs were wholesale REPOs of $51,233, including purchase accounting amounts, assumed in the Virginia Commerce merger. These wholesale REPOs are 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 basis and will carry an indexed, floating-rate of interest. The line requires compliance with various financial and nonfinancial covenants. At September 30, 2015, United had no outstanding balance under this line of credit.

Long-Term Borrowings

Long-Term Borrowings	9 Months Ended
	Sep. 30, 2015
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 September 30, 2015, United had an unused borrowing amount of approximately $2,559,566 available subject to delivery of collateral after certain trigger points. Advances may be called by the FHLB or redeemed by United based on predefined factors and penalties. At September 30, 2015, $664,880 of FHLB advances with a weighted-average interest rate of 0.43% are scheduled to mature within the next four years. No overnight funds are included in the $664,880 above at September 30, 2015. The scheduled maturities of these FHLB borrowings are as follows: Year Amount 2015 $ 628,975 2016 618 2017 287 2018 0 2019 and thereafter 35,000 Total $ 664,880 At September 30, 2015, United had a total of thirteen statutory business trusts that were formed for the purpose of issuing or participating in pools of trust preferred capital securities (Capital Securities) with the proceeds invested in junior subordinated debt securities (Debentures) of United. The Debentures, which are subordinate and junior in right of payment to all present and future senior indebtedness and certain other financial obligations of United, are the sole assets of the trusts and United’s payment under the Debentures is the sole source of revenue for the trusts. At September 30, 2015 and December 31, 2014, the outstanding balance of the Debentures was $223,288 and $222,636, 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. During the fourth quarter of 2014, United redeemed the Capital Securities of Sequoia Capital Trust I. As part of the redemption, United retired the $2,000 principal of 10.18% Junior Subordinated Debentures issued by Sequoia Capital Trust I. Also, during the fourth quarter of 2014, United redeemed the Capital Securities of VCBI Capital Trust IV. As part of the redemption, United retired the $25,000 principal amount of 10.20% Junior Subordinated Debentures issued by VCBI Capital Trust IV. The redemptions were funded with excess cash available to United. In July of 2013, United’s primary federal regulator, the Federal Reserve, published final rules (the “Basel III Capital Rules”) establishing a new comprehensive capital framework for U.S. banking organizations which were effective for United on January 1, 2015. The Basel III Capital Rules permit bank holding companies such as United with less than $15 billion in total consolidated assets as of December 31, 2009 to include in additional Tier 1 Capital trust preferred securities and cumulative perpetual preferred stock issued and included in Tier 1 Capital prior to May 19, 2010 on a permanent basis, without any phase-out. However, United’s Trust Preferred Securities are subject to a limit of 25 percent of Tier 1 capital elements excluding any non-qualifying capital instruments and after all regulatory capital deductions and adjustments applied to Tier 1 capital. Trust Preferred Securities no longer included in United’s Tier 1 capital may be included as a component of Tier 2 capital on a permanent basis without phase-out. As of September 30, 2015, all of United’s Trust Preferred Securities qualify as Tier 1 Capital.

Commitments and Contingent Liab

Commitments and Contingent Liabilities	9 Months Ended
	Sep. 30, 2015
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 risk in the normal course of business to meet the financing needs of its customers and to alter its own exposure to fluctuations in interest rates. These financial instruments include loan commitments, standby letters of credit, and interest rate swap agreements. The instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the financial statements. 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 sheet instruments. Collateral may be obtained, if deemed necessary, based on management’s credit evaluation of the counterparty. 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 $2,556,542 and $2,763,129 of loan commitments outstanding as of September 30, 2015 and December 31, 2014, respectively, approximately half of which expire within one year. Commercial and standby letters of credit are agreements used by United’s customers as a means of improving their credit standing in their dealings with others. Under these agreements, United guarantees certain financial commitments of its customers. A commercial letter of credit is issued specifically to facilitate trade or commerce. Typically, under the terms of a commercial letter of credit, a commitment is drawn upon when the underlying transaction is consummated as intended between the customer and a third party. As of September 30, 2015 and December 31, 2014, United had $226 and $216, respectively, of outstanding commercial letters of credit. A standby letter of credit is generally contingent upon the failure of a customer to perform according to the terms of an underlying contract with a third party. United has issued standby letters of credit of $144,698 and $160,230 as of September 30, 2015 and December 31, 2014, 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. United and its subsidiaries are currently involved in various legal proceedings in the normal course of business. Management is vigorously pursuing all its legal and factual defenses and, after consultation with legal counsel, believes that all such litigation will be resolved with no material effect on United’s financial position.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2015
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. As of September 30, 2015, United has only fair value 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. 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 table sets forth certain information regarding the interest rate derivatives portfolio used for interest-rate risk management purposes and designated as accounting hedges under the Derivatives and Hedging topic at September 30, 2015. Derivative Classifications and Hedging Relationships September 30, 2015 Notional Amount Average Pay Rate Fair Value Hedges: Pay Fixed Swaps (Hedging Commercial Loans) $ 36,481 3.44 % Total Derivatives Used in Fair Value Hedges $ 36,481 Total Derivatives Used for Interest Rate Risk Management and Designated as Hedges $ 36,481 The following tables summarize the fair value of United’s derivative financial instruments. Asset Derivatives September 30, 2015 December 31, 2014 Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Interest rate contracts Other assets $ 0 Other assets $ 90 Total derivatives designated as hedging instruments $ 0 $ 90 Derivatives not designated as hedging instruments Interest rate contracts Other assets $ 3,259 Other assets $ 3,704 Total derivatives not designated as hedging instruments $ 3,259 $ 3,704 Total asset derivatives $ 3,259 $ 3,794 Liability Derivatives September 30, 2015 December 31, 2014 Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Interest rate contracts Other liabilities $ 1,196 Other liabilities $ 432 Total derivatives designated as hedging instruments $ 1,196 $ 432 Derivatives not designated as hedging instruments Interest rate contracts Other liabilities $ 3,257 Other liabilities $ 3,704 Total derivatives not designated as hedging instruments $ 3,257 $ 3,704 Total liability derivatives $ 4,453 $ 4,136 Derivative contracts involve the risk of dealing with both bank customers and institutional derivative counterparties and their ability to meet contractual terms. Credit risk arises from the possible inability of counterparties to meet the terms of their contracts. United’s exposure is limited to the replacement value of the contracts rather than the notional amount of the contract. The Company’s agreements generally contain provisions that limit the unsecured exposure up to an agreed upon threshold. Additionally, the Company attempts to minimize credit risk through certain approval processes established by management. The effect of United’s derivative financial instruments on its unaudited Consolidated Statements of Income for the three and nine months ended September 30, 2015 and 2014 are presented as follows: Three Months Ended Income Statement Location September 30, September 30, Derivatives in fair value hedging relationships Interest rate contracts Interest income/ (expense) $ (332 ) $ (271 ) Total derivatives in fair value hedging relationships $ (332 ) $ (271 ) Derivatives not designated as hedging instruments Interest rate contracts (1) Other income $ 3 $ 0 Total derivatives not designated as hedging instruments $ 3 $ 0 Total derivatives $ (329 ) $ (271 ) Nine Months Ended Income Statement Location September 30, September 30, Derivatives in fair value hedging relationships Interest rate contracts Interest income/ (expense) $ (661 ) $ (795 ) Total derivatives in fair value hedging relationships $ (661 ) $ (795 ) Derivatives not designated as hedging instruments Interest rate contracts (1) Other income $ 3 $ 0 Total derivatives not designated as hedging instruments $ 3 $ 0 Total derivatives $ (658 ) $ (795 ) (1) Represents net gains from derivative assets not designated as hedging instruments.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2015
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 model-based techniques that use one or more significant inputs or assumptions that are unobservable in the market. When determining the fair value measurements for assets and liabilities, United looks to active and observable markets to price identical assets or liabilities whenever possible and classifies such items in Level 1. When identical assets and liabilities are not traded in active markets, United looks to market observable data for similar assets and liabilities and classifies such items as Level 2. Nevertheless, certain assets and liabilities are not actively traded in observable markets and United must use alternative valuation techniques using unobservable inputs to determine a fair value and classifies such items as Level 3. For assets and liabilities that are not actively traded, the fair value measurement is based primarily upon estimates that require significant judgment. Therefore, the results may not be realized in an actual sale or immediate settlement of the asset or liability. Additionally, there are inherent weaknesses in any calculation technique, and changes in the underlying assumptions used, including discount rates and estimates of future cash flows, could significantly affect the results of current or future values. The level within the fair value hierarchy is based on the lowest level of input that is significant in the fair value measurement. In accordance with ASC topic 820, the following describes the valuation techniques used by United to measure certain financial assets and liabilities recorded at fair value on a recurring basis in the financial statements: Securities available for sale 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. For derivatives that are not designated in a hedge relationship, changes in the fair value of the derivatives are recognized in earnings in the same period as the change in the fair value. Unrealized gains and losses due to changes in the fair value of other derivative financial instruments not in hedge relationship are included in noninterest income and noninterest expense, respectively. The following tables present the balances of financial assets and liabilities measured at fair value on a recurring basis as of September 30, 2015 and December 31, 2014, segregated by the level of the valuation inputs within the fair value hierarchy. Fair Value at September 30, 2015 Using Description Balance as of September 30, 2015 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 $ 81,778 $ 0 $ 81,778 $ 0 State and political subdivisions 139,955 0 139,955 0 Residential mortgage-backed securities Agency 499,670 0 499,670 0 Non-agency 10,111 0 10,111 0 Asset-backed securities 4,265 0 4,265 0 Commercial mortgage-backed securities Agency 314,178 0 314,178 0 Trust preferred collateralized debt obligations 35,711 0 0 35,711 Single issue trust preferred securities 12,228 0 12,228 0 Other corporate securities 5,072 0 5,072 0 Total available for sale debt securities 1,102,968 0 1,067,257 35,711 Available for sale equity securities: Financial services industry 2,520 798 1,722 0 Equity mutual funds (1) 819 819 0 0 Other equity securities 1,103 1,103 0 0 Total available for sale equity securities 4,442 2,720 1,722 0 Total available for sale securities 1,107,410 2,720 1,068,979 35,711 Derivative financial assets: Interest rate contracts 3,259 0 3,259 0 Liabilities Derivative financial liabilities: Interest rate contracts 4,453 0 4,453 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, 2014 Using Description Balance as of December 31, 2014 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 $ 89,981 $ 0 $ 89,981 $ 0 State and political subdivisions 136,863 0 136,863 0 Residential mortgage-backed securities Agency 555,685 0 555,685 0 Non-agency 12,018 0 12,018 0 Asset-backed securities 8,027 0 8,027 0 Commercial mortgage-backed securities Agency 317,099 0 317,099 0 Trust preferred collateralized debt obligations 39,558 0 0 39,558 Single issue trust preferred securities 11,744 0 11,744 0 Other corporate securities 5,135 0 5,135 0 Total available for sale debt securities 1,176,110 0 1,136,552 39,558 Available for sale equity securities: Financial services industry 2,533 759 1,774 0 Equity mutual funds (1) 560 560 0 0 Other equity securities 1,183 1,183 0 0 Total available for sale equity securities 4,276 2,502 1,774 0 Total available for sale securities 1,180,386 2,502 1,138,326 39,558 Derivative financial assets: Interest rate contracts 3,794 0 3,794 0 Liabilities Derivative financial liabilities: Interest rate contracts 4,136 0 4,136 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. The following table presents additional information about financial assets and liabilities measured at fair value at September 30, 2015 and December 31, 2014 on a recurring basis and for which United has utilized Level 3 inputs to determine fair value: Available-for-sale Securities Trust preferred collateralized debt obligations September 30, 2015 December 31, Balance, beginning of period $ 39,558 $ 43,449 Total gains or losses (realized/unrealized): Included in earnings (or changes in net assets) (34 ) (4,034 ) Included in other comprehensive income (3,813 ) 12,312 Purchases, issuances, and settlements 0 (12,169 ) Transfers in and/or out of Level 3 0 0 Balance, end of period $ 35,711 $ 39,558 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 accounting or write-downs of individual assets. The following describes the valuation techniques used by United to measure certain financial assets recorded at fair value on a non-recurring basis in the financial statements. Loans held for sale Impaired Loans OREO Intangible Assets: The following table summarizes United’s financial assets that were measured at fair value on a nonrecurring basis during the period: Description Balance as of September 30, Carrying value at September 30, 2015 YTD Losses Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Impaired Loans $ 53,622 $ 0 $ 13,315 $ 40,307 $ 6,911 OREO 34,119 0 34,119 0 721 Description Balance as of December 31, 2014 Carrying value at December 31, 2014 YTD Losses Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Impaired Loans $ 46,369 $ 0 $ 8,518 $ 37,851 $ 7,349 OREO 38,778 0 38,778 0 3,307 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: Deposits: Short-term Borrowings: Long-term Borrowings: 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) September 30, 2015 Cash and cash equivalents $ 1,008,458 $ 1,008,458 $ 0 $ 1,008,458 $ 0 Securities available for sale 1,107,410 1,107,410 2,720 1,068,979 35,711 Securities held to maturity 38,795 36,232 0 34,212 2,020 Other securities 90,387 85,867 0 0 85,867 Loans held for sale 11,602 11,602 0 11,602 0 Loans 9,098,177 9,101,220 0 0 9,101,220 Derivative financial assets 3,259 3,259 0 3,259 0 Deposits 9,504,896 9,494,045 0 9,494,045 0 Short-term borrowings 322,711 322,711 0 322,711 0 Long-term borrowings 939,401 912,648 0 912,648 0 Derivative financial liabilities 4,453 4,453 0 4,453 0 December 31, 2014 Cash and cash equivalents $ 753,064 $ 753,064 $ 0 $ 753,064 $ 0 Securities available for sale 1,180,386 1,180,386 2,502 1,138,326 39,558 Securities held to maturity 39,310 36,784 0 34,764 2,020 Other securities 96,344 91,527 0 0 91,527 Loans held for sale 8,680 8,680 0 8,680 0 Loans 9,029,123 9,055,281 0 0 9,055,281 Derivative financial assets 3,794 3,794 0 3,794 0 Deposits 9,045,485 9,044,976 0 9,044,976 0 Short-term borrowings 435,652 435,652 0 435,652 0 Long-term borrowings 1,105,314 1,081,133 0 1,081,133 0 Derivative financial liabilities 4,136 4,136 0 4,136 0

Stock Based Compensation

Stock Based Compensation	9 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Based Compensation	13. STOCK BASED COMPENSATION On May 16, 2011, United’s shareholders approved the 2011 Long-Term Incentive Plan (2011 LTI Plan). The 2011 LTI Plan became effective as of July 1, 2011. An award granted under the 2011 LTI Plan may consist of any non-qualified stock options or incentive stock options, stock appreciation rights, restricted stock, or restricted stock units. These awards all relate to the common stock of United. The maximum number of shares of United common stock which may be issued under the 2011 LTI Plan is 1,500,000. Any and all shares may be issued in respect of any of the types of awards, provided that (1) the aggregate number of shares that may be issued in respect of restricted stock awards, and restricted stock units awards which are settled in shares is 350,000, and (2) the aggregate number of shares that may be issued pursuant to stock options is 1,150,000. The shares to be offered under the 2011 LTI Plan may be authorized and unissued shares or treasury shares. With respect to awards that are intended to satisfy the requirements for performance-based compensation under Code Section 162(m), the maximum number of options and stock appreciation rights, in the aggregate, which may be awarded pursuant to the 2011 LTI Plan to any individual participant during any calendar year is 100,000, and the maximum number of shares of restricted stock and/or shares subject to a restricted stock units award that may be granted pursuant to the 2011 LTI Plan to any individual participant during any calendar year is 50,000 shares. A participant may be any key employee of United or its affiliates or a non-employee member of United’s Board of Directors. Subject to certain change in control provisions, stock options, SARs, restricted stock and restricted stock units generally will vest in 25% increments over the first four anniversaries of the awards unless the Committee specifies otherwise in the award agreement. No award will vest sooner than 1/3 per year over the first three anniversaries of the award. Beginning in 2014, awards granted to executive officers of United have performance based vesting conditions. A Form S-8 was filed on September 2, 2011 with the Securities and Exchange Commission to register all the shares which were available for the 2011 LTI Plan. During the first nine months of 2015, a total of 189,705 non-qualified stock options and 53,071 shares of restricted stock were granted under the 2011 LTI Plan. Compensation expense of $756 and $2,144 related to the nonvested awards under the 2011 LTI Plan and the 2006 Stock Option Plan was incurred for the third quarter and first nine months of 2015, respectively, as compared to the compensation expense of $433 and $1,593 related to the nonvested awards under the 2006 Stock Option Plan incurred for the third quarter and first nine months of 2014, 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 2011 LTI Plan (the Prior Plans); however, no common shares of United stock are available for grants under the Prior Plans as these plans have expired. Awards outstanding under the Prior Plans will remain in effect in accordance with their respective terms. The maximum term for options granted under the plans is ten (10) years. A summary of activity under United’s stock option plans as of September 30, 2015, and the changes during the first nine months of 2015 are presented below: Nine Months Ended September 30, 2015 Weighted Average Shares Aggregate Remaining Exercise Outstanding at January 1, 2015 1,380,548 $ 27.94 Granted 189,705 36.92 Exercised (215,967 ) 30.14 Forfeited or expired (13,361 ) 32.22 Outstanding at September 30, 2015 1,340,925 $ 12,389 5.9 $ 28.75 Exercisable at September 30, 2015 905,842 $ 9,741 4.6 $ 27.24 The following table summarizes the status of United’s nonvested stock option awards during the first nine months of 2015: Shares Weighted-Average Nonvested at January 1, 2015 377,264 $ 6.29 Granted 189,705 7.23 Vested (121,673 ) 6.33 Forfeited or expired (10,213 ) 6.58 Nonvested at September 30, 2015 435,083 $ 6.68 During the nine months ended September 30, 2015 and 2014, 215,967 and 368,856 shares, respectively, were issued in connection with stock option exercises. All shares issued in connection with stock option exercises for the nine months ended September 30, 2015 were issued from authorized and unissued stock. Of the 368,856 shares issued in connection with stock option exercises, 342,382 were issued from available treasury stock while 26,474 shares were issued from authorized and unissued stock for the nine months ended September 30, 2014. The total intrinsic value of options exercised under the Plans during the nine months ended September 30, 2015 and 2014 was $1,908 and $3,977 respectively. Restricted Stock Under the 2011 LTI Plan, United may award restricted common shares to key employees and non-employee directors. Restricted shares granted to participants have a four-year time-based vesting period except those granted to executive officers of United that have performance based vesting conditions. Recipients of restricted shares do not pay any consideration to United for the shares, have the right to vote all shares subject to such grant and receive all dividends with respect to such shares, whether or not the shares have vested. Presently, these nonvested participating securities have an immaterial impact on diluted earnings per share. The following summarizes the changes to United’s restricted common shares for the period ended September 30, 2015: Number of Weighted-Average Outstanding at January 1, 2015 120,308 $ 28.29 Granted 53,071 36.92 Vested (38,041 ) 28.31 Forfeited (2,861 ) 30.69 Outstanding at September 30, 2015 132,477 $ 31.69

Employee Benefit Plans

Employee Benefit Plans	9 Months Ended
	Sep. 30, 2015
Compensation and Retirement Disclosure [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, including those retained in the Virginia Commerce acquisition, will be eligible to participate in United’s Savings and Stock Investment 401(k) plan. This change had no impact on current employees hired prior to October 1, 2007 as they will continue to participate in the Plan, with no change in benefit provisions, and will continue to be eligible to participate in United’s Savings and Stock Investment 401(k) plan. Included in accumulated other comprehensive income at December 31, 2014 were the following amounts that have not yet been recognized in net periodic pension cost: unrecognized prior service costs of $1 ($1 net of tax) and unrecognized actuarial losses of $58,576 ($38,074 net of tax). The amortization of these items expected to be recognized in net periodic pension cost during the fiscal year ended December 31, 2015 is $1 ($1 net of tax), and $4,900 ($3,185 net of tax), respectively. Net periodic pension cost for the three and nine months ended September 30, 2015 and 2014 included the following components: Three Months Ended September 30 Nine Months Ended September 30 2015 2014 2015 2014 Service cost $ 756 $ 579 $ 2,244 $ 1,720 Interest cost 1,462 1,361 4,338 4,039 Expected return on plan assets (2,344 ) (2,293 ) (6,956 ) (6,806 ) Amortization of transition asset 0 0 0 0 Recognized net actuarial loss 1,235 491 3,665 1,458 Amortization of prior service cost 1 1 1 1 Net periodic pension (benefit) cost $ 1,110 $ 139 $ 3,292 $ 412 Weighted-Average Assumptions: Discount rate 4.35 % 5.20 % 4.35 % 5.20 % Expected return on assets 7.50 % 7.50 % 7.50 % 7.50 % Rate of compensation increase (prior to age 45) 3.50 % 3.50 % 3.50 % 3.50 % Rate of compensation increase 3.00 % 3.00 % 3.00 % 3.00 %

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2015
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, and a measurement attribute for all tax positions taken on a tax return, in order for those tax positions to be recognized in the financial statements. As of September 30, 2015, United has provided a liability for $2,431 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, 2012, 2013 and 2014 and State Taxing authorities for the years ended December 31, 2011 through 2014. As of September 30, 2015 and 2014, the total amount of accrued interest related to uncertain tax positions was $548 and $540, 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	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Comprehensive Income	16. COMPREHENSIVE INCOME The components of total comprehensive income for the three and nine months ended September 30, 2015 and 2014 are as follows: Three Months Ended Nine Months Ended 2015 2014 2015 2014 Net Income $ 35,047 $ 33,260 $ 104,483 $ 96,631 Available for sale (“AFS”) securities: AFS securities with OTTI charges during the period 0 (4,714 ) (100 ) (5,774 ) Related income tax effect 0 1,650 36 2,021 Income tax rate change 0 0 316 0 Less : OTTI charges recognized in net income 0 4,714 34 5,774 Related income tax benefit 0 (1,650 ) (12 ) (2,021 ) Reclassification of previous noncredit OTTI to credit OTTI 0 4,153 0 6,259 Related income tax benefit 0 (1,453 ) 0 (2,190 ) Net unrealized (losses) gains on AFS securities with OTTI 0 2,700 274 4,069 AFS securities – all other: Change in net unrealized gain on AFS securities arising during the period 8,635 (339 ) 7,053 24,242 Related income tax effect (3,126 ) 119 (2,553 ) (8,485 ) Net reclassification adjustment for (gains) losses included in net income (42 ) (1,300 ) (91 ) (2,125 ) Related income tax expense (benefit) 15 455 33 744 5,482 (1,065 ) 4,442 14,376 Net effect of AFS securities on other comprehensive income 5,482 1,635 4,716 18,445 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 1 2 6 6 Related income tax expense (0 ) (0 ) (2 ) (2 ) Net effect of HTM securities on other comprehensive income 1 2 4 4 Pension plan: Amortization of prior service cost 1 1 1 1 Related income tax benefit 0 0 0 0 Recognized net actuarial loss 1,235 491 3,665 1,458 Related income tax benefit (468 ) (183 ) (1,362 ) (531 ) Net effect of change in pension plan asset on other comprehensive income 768 309 2,304 928 Total change in other comprehensive income 6,251 1,946 7,024 19,377 Total Comprehensive Income $ 41,298 $ 35,206 $ 111,507 $ 116,008 The components of accumulated other comprehensive income for the nine months ended September 30, 2015 are as follows: Changes in Accumulated Other Comprehensive Income (AOCI) by Component (a) For the Nine Months Ended September 30, 2015 (Dollars in thousands) Unrealized Accretion on Defined Items Total Balance at January 1, 2015 $ 1,553 ($ 62 ) ($ 37,255 ) ($ 35,764 ) Other comprehensive income before reclassification 4,774 4 0 4,778 Amounts reclassified from accumulated other comprehensive income (58 ) 0 2,304 2,246 Net current-period other comprehensive income, net of tax 4,716 4 2,304 7,024 Balance at September 30, 2015 $ 6,269 ($ 58 ) ($ 34,951 ) ($ 28,740 ) (a) All amounts are net-of-tax. Reclassifications out of Accumulated Other Comprehensive Income (AOCI) For the Nine Months Ended September 30, 2015 (Dollars in thousands) 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 (91 ) Net gains on sales/calls of investment securities Reclassifications out of Accumulated Other Comprehensive Income (AOCI) For the Nine Months Ended September 30, 2015 (Dollars in thousands) Details about AOCI Components Amount from AOCI Affected Line Item in the Statement Where Net Income is Presented (91 ) Total before tax Related income tax effect 33 Tax expense (58 ) Net of Tax Pension plan: Amortization of transition asset 1 (a) Recognized net actuarial loss 3,665 (a) 3,666 Total before tax Related income tax effect (1,362 ) Tax expense 2,304 Net of tax Total reclassifications for the period $ 2,246 (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	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Earnings Per Share	17. EARNINGS PER SHARE The reconciliation of the numerator and denominator of basic earnings per share with that of diluted earnings per share is presented as follows: Three Months Ended Nine Months Ended 2015 2014 2015 2014 Distributed earnings allocated to common stock $ 22,216 $ 22,101 $ 66,572 $ 66,261 Undistributed earnings allocated to common stock 12,768 11,102 37,725 30,194 Net earnings allocated to common shareholders $ 34,984 $ 33,203 $ 104,297 $ 96,455 Average common shares outstanding 69,391,401 69,044,876 69,302,180 66,836,396 Equivalents from stock options 298,322 224,433 284,107 232,956 Average diluted shares outstanding 69,689,723 69,269,309 69,586,287 67,069,352 Earnings per basic common share $ 0.50 $ 0.48 $ 1.51 $ 1.45 Earnings per diluted common share $ 0.50 $ 0.48 $ 1.50 $ 1.44

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2015
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 thirteen statutory business trusts that were created for the purpose of raising funds that qualified for Tier I 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. The trusts utilized in these transactions are VIEs as the third-party equity holders lack a controlling financial interest in the trusts through their inability to make decisions that have a significant effect on the operations and success of the entities. United does not consolidate these trusts as it is not the primary beneficiary of these entities because United’s equity interest does not absorb the majority of the trusts’ expected losses or receive a majority of their expected residual returns. During the fourth quarter of 2014, United redeemed the trust preferred securities listed below. The Federal Reserve Board did not object to the redemption of the securities. The redemptions were funded with excess cash that was available to United. Trust Interest Redemption Principal Amount Principal Amount Redemption Date Sequoia Capital Trust I 10.18 % 103.563 % $ 2,000 $ 2,000 December 8, 2014 VCBI Capital Trust IV 10.20 % 100.000 % $ 25,000 $ 25,000 December 30, 2014 Information related to United’s statutory trusts is presented in the table below: Description Issuance Date Amount of 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 LIBOR + 2.85% December 17, 2033 United Statutory Trust IV December 19, 2003 $ 25,000 3-month LIBOR + 2.85% January 23, 2034 United Statutory Trust V July 12, 2007 $ 50,000 3-month LIBOR + 1.55% October 1, 2037 United Statutory Trust VI September 20, 2007 $ 30,000 3-month LIBOR + 1.30% December 15, 2037 Premier Statutory Trust II September 25, 2003 $ 6,000 3-month LIBOR + 3.10% October 8, 2033 Premier Statutory Trust III May 16, 2005 $ 8,000 3-month LIBOR + 1.74% June 15, 2035 Premier Statutory Trust IV June 20, 2006 $ 14,000 3-month LIBOR + 1.55% September 23, 2036 Premier Statutory Trust V December 14, 2006 $ 10,000 3-month LIBOR + 1.61% March 1, 2037 Centra Statutory Trust I September 20, 2004 $ 10,000 3-month LIBOR + 2.29% September 20, 2034 Centra Statutory Trust II June 15, 2006 $ 10,000 3-month LIBOR + 1.65% July 7, 2036 Virginia Commerce Trust II December 19, 2002 $ 15,000 6-month LIBOR + 3.30% December 19, 2032 Virginia Commerce Trust III December 20, 2005 $ 25,000 3-month LIBOR + 1.42% February 23, 2036 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 September 30, 2015 As of December 31, 2014 Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Trust preferred securities $ 240,346 $ 232,393 $ 7,953 $ 241,147 $ 233,222 $ 7,925 (1) Represents investment in VIEs.

General (Policies)

General (Policies)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
New Accounting Standards	New Accounting Standards In September 2015, the FASB issued ASU 2015-16, “Simplifying the Accounting for Measurement-Period Adjustments”, as part of its simplification initiative. ASU 2015-16 requires an acquirer to “recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined.” In addition, the acquirer must record, in the financial statements for the same period, “the effect on earnings of changes in depreciation, amortization, or other income effect, if any, as a result of the change to the provisional amounts, calculated as if the accounting had been completed at the acquisition date.” Entities must also “present separately on the face of the income statement or disclose in the notes the portion of the amount recorded in the current-period earnings by line item that would have been recorded in previous reporting periods if the adjustment to the provisional amount had been recognized as of the acquisition date.” ASU 2015-16 is effective for United on January 1, 2016 and is not expected to have a significant impact on the Company’s financial condition or results of operation. In May 2015, the FASB issued ASU 2015-07, “Disclosures for Investment in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent), a consensus of the FASB Emerging Issues Task Force.” ASU 2015-07 modifies certain provision of FASB Accounting Standards Codification Topic 820, Fair Value Measurement (ASC 820). ASU 2015-07 eliminates the requirement to categorize investments in the fair value hierarchy if an investment’s fair value is measured based on net asset value (NAV) per share (or its equivalent) using the practical expedient. The reporting entities will no longer be required to provide the related fair value disclosures for these securities but instead, will be required to disclose information to help users understand the nature of the investments as well as risks, including whether it is probable that the amount realized on the sale of the investments would differ from net asset value. ASU 2015-07 is effective for United on January 1, 2016 and is not expected to have a significant impact on the Company’s financial condition or results of operation. In April 2015, the FASB issued ASU 2015-04, “Compensation – Retirement Benefits: Practical Expedient for the Measurement Date of an Employer’s Defined Benefit Obligation and Plan Assets.” ASU 2015-04 gives an employer whose fiscal year-end does not coincide with a calendar month-end the ability, as a practical expedient, to measure defined benefit retirement obligations and related plan assets as of the month-end that is closest to its fiscal year-end. ASU 2015-04 also provides guidance on accounting for contributions to the plan and significant events that require a remeasurement that occur during the period between a month-end measurement and the employer’s fiscal year-end. ASU 2015-04 is effective for United on January 1, 2016 and is not expected to have a significant impact on the Company’s financial condition or results of operation. In April 2015, the FASB issued ASU 2015-03, “Simplifying the Presentation of Debt Issuance Costs.” Under ASU 2015-03, debt issuance costs are required to be presented as a direct deduction of debt balances on the statement of financial condition, similar to the presentation of debt discounts. ASU 2015-03 is limited to simplifying the presentation of debt issuance costs and does not change the recognition and measurement guidance for debt issuance costs. ASU 2015-03 is effective for United on January 1, 2016 and is not expected to have a significant impact on the Company’s financial condition or results of operation. In February 2015, the FASB issued ASU 2015-02, “Amendments to the Consolidation Analysis.” ASU 2015-02 improves targeted areas of the consolidation guidance and reduces the number of consolidation models. The new consolidation standard eliminates the deferral of FAS 167 and makes changes to both the variable interest model and the voting model in ASC 810. ASU 2015-02 affects all entities, could change consolidation conclusions and may trigger additional disclosures. ASU 2015-02 is effective for United on January 1, 2016 and is not expected to have a significant impact on the Company’s financial condition or results of operation. In January 2015, the FASB issued ASU 2015-01, “Income Statement, Extraordinary and Unusual Items (Subtopic 225-20).” ASU 2015-01 eliminates the separate presentation of extraordinary items but does not change the requirement to disclose material items that are unusual or infrequent in nature. Eliminating the concept of extraordinary items will allow entities to no longer have to assess whether a particular event or transaction is both unusual in nature and infrequent in occurrence. ASU 2015-01 is effective for United on January 1, 2016 and is not expected to have a significant impact on the Company’s financial condition or results of operation. In June 2014, the FASB issued ASU 2014-12, “Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period.” ASU 2014-12 amends the guidance in FASB ASC 718, “Compensation-Stock Compensation”, to bring consistency to the accounting for share-based payment awards that require a specific performance target to be achieved in order for employees to become eligible to vest in the awards. The amendments affect all entities that grant their employees share-based payments in which the terms of the award provide that a performance target that affects vesting could be achieved after the requisite service period. ASU 2014-12 is effective for United on January 1, 2016, and is not expected to have a significant impact on the Company’s financial condition or results of operation. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606).” ASU 2014-09 supersedes the revenue recognition requirements in Accounting Standards Codification Topic 605, “Revenue Recognition”, and most industry-specific guidance throughout the Accounting Standards Codification. The amendments require an entity to recognize revenue upon the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. The new revenue recognition standard sets forth a five step principle-based approach for determining revenue recognition. In April 2015, the FASB voted to defer the effective date of ASU 2014-09 by one-year for both public and private companies, and gave both public and private companies the option to “early” adopt using the original effective dates. ASU 2014-09 now will be effective for United on January 1, 2018 with early adoption permitted on January 1, 2017. Management is currently evaluating this guidance to determine the impact on the Company’s financial condition or results of operation.
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 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)	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
Schedule of Acquired Loans Accounted for at Fair value	In conjunction with the Virginia Commerce merger, the acquired loan portfolio was accounted for at fair value as follows: January 31, Contractually required principal and interest at acquisition $ 2,685,339 Contractual cash flows not expected to be collected (396,024 ) Expected cash flows at acquisition 2,289,315 Interest component of expected cash flows (274,539 ) Basis in acquired loans at acquisition – estimated fair value $ 2,014,776
Schedule of Acquired Identifiable Assets and Liabilities Assumed	The following table shows the consideration paid for Virginia Commerce’s common equity and the amounts of acquired identifiable assets and liabilities assumed as of the Acquisition Date. Purchase price: Value of common shares issued (18,330,347 shares) $ 547,894 Fair value of stock options assumed 4,368 Cash to redeem the Treasury warrant 33,263 Cash for fractional shares 8 Total purchase price 585,533 Identifiable assets: Cash and cash equivalents 130,569 Investment securities 476,541 Loans 2,014,776 Premises and equipment 10,786 Core deposit intangibles 17,143 Other assets 104,131 Total identifiable assets $ 2,753,946 Identifiable liabilities: Deposits $ 2,024,969 Short-term borrowings 263,816 Long-term borrowings 204,335 Other liabilities 11,395 Total identifiable liabilities 2,504,515 Net assets acquired including identifiable intangible assets 249,431 Resulting goodwill $ 336,102
Schedule of Acquired Reconciliation of Goodwill	The following table provides a reconciliation of goodwill: Goodwill at December 31, 2014 $ 709,794 Addition to goodwill from Virginia Commerce acquisition 458 Goodwill at September 30, 2015 $ 710,252

Investment Securities (Tables)

Investment Securities (Tables)	9 Months Ended
	Sep. 30, 2015
Summary of Amortized Cost and Estimated Fair Values of Available for Sale Securities	The amortized cost and estimated fair values of securities available for sale are summarized as follows. September 30, 2015 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 $ 78,864 $ 2,914 $ 0 $ 81,778 $ 0 State and political subdivisions 137,660 2,489 194 139,955 0 Residential mortgage-backed securities Agency 487,995 11,738 63 499,670 0 Non-agency 9,638 476 3 10,111 458 Commercial mortgage-backed securities Agency 308,596 5,680 98 314,178 0 Asset-backed securities 4,273 0 8 4,265 0 Trust preferred collateralized debt obligations 49,894 680 14,863 35,711 25,952 Single issue trust preferred securities 13,798 210 1,780 12,228 0 Other corporate securities 4,999 73 0 5,072 0 Marketable equity securities 3,929 535 22 4,442 0 Total $ 1,099,646 $ 24,795 $ 17,031 $ 1,107,410 $ 26,410 December 31, 2014 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 $ 88,559 $ 1,425 $ 3 $ 89,981 $ 0 State and political subdivisions 133,730 3,165 32 136,863 0 Residential mortgage-backed securities Agency 547,825 8,407 547 555,685 0 Non-agency 11,474 544 0 12,018 458 Commercial mortgage-backed securities Agency 316,707 2,393 2,001 317,099 0 Asset-backed securities 8,004 23 0 8,027 0 Trust preferred collateralized debt obligations 51,328 922 12,692 39,558 25,886 Single issue trust preferred securities 13,760 173 2,189 11,744 0 Other corporate securities 4,998 137 0 5,135 0 Marketable equity securities 3,631 648 3 4,276 0 Total $ 1,180,016 $ 17,837 $ 17,467 $ 1,180,386 $ 26,344 (1) Other-than-temporary impairment in accumulated other comprehensive income. Amounts are before-tax.
Summary of Securities Available for Sale in an Unrealized Loss Position	The following is a summary of securities available-for-sale which were in an unrealized loss position at September 30, 2015 and December 31, 2014. Less than 12 months 12 months or longer Fair Unrealized Fair Unrealized Value Losses Value Losses September 30, 2015 U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 0 $ 0 $ 0 $ 0 State and political subdivisions 17,546 194 0 0 Residential mortgage-backed securities Agency 20,780 63 0 0 Non-agency 378 3 0 0 Commercial mortgage-backed securities Agency 7,934 67 9,527 31 Asset-backed securities 4,265 8 0 0 Trust preferred collateralized debt obligations 1,199 94 29,578 14,769 Single issue trust preferred securities 0 0 3,900 1,780 Marketable equity securities 973 22 0 0 Total $ 53,075 $ 451 $ 43,005 $ 16,580 December 31, 2014 U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 7,142 $ 3 $ 0 $ 0 State and political subdivisions 11,637 32 0 0 Residential mortgage-backed securities Agency 96,550 547 0 0 Commercial mortgage-backed securities Agency 21,674 56 146,897 1,945 Asset-backed securities 0 0 0 0 Trust preferred collateralized debt obligations 0 0 32,241 12,692 Single issue trust preferred securities 0 0 8,080 2,189 Marketable equity securities 23 3 0 0 Total $ 137,026 $ 641 $ 187,218 $ 16,826
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 September 30 Nine Months Ended September 30 2015 2014 2015 2014 Proceeds from sales and calls $ 42,559 $ 64,610 $ 130,027 $ 500,493 Gross realized gains 43 1,314 97 2,366 Gross realized losses 2 5 7 232
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 September 30, 2015: Amortized Cost Class Amortized Cost Fair Value Unrealized Loss Investment Split Below Senior – Bank $ 6,758 $ 5,981 $ 777 $ 4,617 $ 0 $ 2,141 Mezzanine – Bank (now in senior position) 11,859 9,097 2,762 0 0 11,859 Mezzanine – Bank 26,090 16,966 9,124 0 0 26,090 Mezzanine – Bank & Insurance (combination) 5,187 3,667 1,520 0 0 5,187 Totals $ 49,894 $ 35,711 $ 14,183 $ 4,617 $ 0 $ 45,277
Roll Forward of Credit Losses on Securities	Below is a progression of the credit losses on securities which United has recorded other-than-temporary charges. These charges were recorded through earnings and other comprehensive income. Three Months Ended September 30 Nine Months Ended September 30 2015 2014 2015 2014 Balance of cumulative credit losses at beginning of period $ 23,773 $ 34,082 $ 23,739 $ 40,663 Addition for credit losses recognized in earnings during the period: Additional credit losses on securities for which OTTI was previously recognized 0 4,714 34 5,738 Reductions for securities sold or paid off during the period 0 0 0 (7,605 ) Balance of cumulative credit losses at end of period $ 23,773 $ 38,796 $ 23,773 $ 38,796
Summary of Amortized Cost and Estimated Fair Values of Securities Held to Maturity	The amortized cost and estimated fair values of securities held to maturity are summarized as follows: September 30, 2015 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 10,470 $ 1,066 $ 0 $ 11,536 State and political subdivisions 8,975 24 304 8,695 Residential mortgage-backed securities Agency 36 7 0 43 Single issue trust preferred securities 19,294 0 3,356 15,938 Other corporate securities 20 0 0 20 Total $ 38,795 $ 1,097 $ 3,660 $ 36,232 December 31, 2014 Gross Gross Estimated Amortized Unrealized Unrealized Fair Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. Government corporations and agencies $ 10,599 $ 1,329 $ 0 $ 11,928 State and political subdivisions 9,369 32 294 9,107 Residential mortgage-backed securities Agency 41 7 0 48 Single issue trust preferred securities 19,281 0 3,600 15,681 Other corporate securities 20 0 0 20 Total $ 39,310 $ 1,368 $ 3,894 $ 36,784
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 September 30, 2015 and December 31, 2014 by contractual maturity are shown as follows. Expected maturities may differ from contractual maturities because the issuers may have the right to call or prepay obligations without penalties. September 30, 2015 December 31, 2014 Estimated Estimated Amortized Fair Amortized Fair Cost Value Cost Value Due in one year or less $ 22,311 $ 22,451 $ 38,358 $ 38,727 Due after one year through five years 276,823 281,147 180,821 181,930 Due after five years through ten years 199,455 206,182 313,863 317,663 Due after ten years 597,128 593,188 643,343 637,790 Marketable equity securities 3,929 4,442 3,631 4,276 Total $ 1,099,646 $ 1,107,410 $ 1,180,016 $ 1,180,386
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 September 30, 2015 and December 31, 2014 by contractual maturity are shown below. Expected maturities may differ from contractual maturities because the issuers may have the right to call or prepay obligations without penalties. September 30, 2015 December 31, 2014 Amortized Estimated Amortized Estimated Due in one year or less $ 5,049 $ 5,215 $ 360 $ 361 Due after one year through five years 9,287 10,200 14,499 15,848 Due after five years through ten years 4,294 3,998 4,293 4,007 Due after ten years 20,165 16,819 20,158 16,568 Total $ 38,795 $ 36,232 $ 39,310 $ 36,784

Loans (Tables)

Loans (Tables)	9 Months Ended
	Sep. 30, 2015
Receivables [Abstract]
Major Classes of Loans	Major classes of loans are as follows: September 30, 2015 December 31, Commercial, financial and agricultural: Owner-occupied commercial real estate $ 942,302 $ 1,016,364 Nonowner-occupied commercial real estate 2,842,158 2,760,189 Other commercial loans 1,609,331 1,577,438 Total commercial, financial & agricultural 5,393,791 5,353,991 Residential real estate 2,252,530 2,263,354 Construction & land development 1,125,908 1,133,251 Consumer: Bankcard 10,171 10,437 Other consumer 405,549 358,459 Total gross loans $ 9,187,949 $ 9,119,492
Activity for Accretable Yield	Activity for the accretable yield for the first nine months of 2015 follows: Accretable yield at the beginning of the period $ 11,339 Accretion (including cash recoveries) (8,590 ) Net reclassifications to accretable from non-accretable 10,393 Disposals (including maturities, foreclosures, and charge-offs) (510 ) Accretable yield at the end of the period $ 12,632

Credit Quality (Tables)

Credit Quality (Tables)	9 Months Ended
	Sep. 30, 2015
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 nine months ended September 30, 2015 and 2014, segregated by class of loans: Troubled Debt Restructurings For the Nine Months Ended September 30, 2015 September 30, 2014 Number of Pre- Modification Post- Number of Pre- Modification Post- Commercial real estate: Owner-occupied 0 $ 0 $ 0 0 $ 0 $ 0 Nonowner-occupied 1 669 647 0 0 0 Other commercial 1 240 240 2 5,630 5,630 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 2 $ 909 $ 887 2 $ 5,630 $ 5,630
Schedule of Charged-off Troubled Debt Restructurings on Financing Receivables	The following table presents troubled debt restructurings, by class of loan, that had charge-offs during the three months and nine months ended September 30, 2014. During the time periods indicated, the loan’s principal was reduced through a charge-off to the value of the underlying collateral. Three Months Ended September 30, 2014 Nine Months Ended September 30, 2014 (In thousands) Number of Recorded Number of Recorded Troubled Debt Restructurings Commercial real estate: Owner-occupied 0 $ 0 0 $ 0 Nonowner-occupied 1 478 1 478 Other commercial 0 0 0 0 Residential real estate 0 0 0 0 Construction & land development 0 0 0 0 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 0 0 Total 1 $ 478 1 $ 478
Schedule of Age Analysis of Past Due Loans, Segregated by Class of Loans	The following table sets forth United’s age analysis of its past due loans, segregated by class of loans: Age Analysis of Past Due Loans As of September 30, 2015 30-89 90 Days or more Total Past Current & Total Financing Recorded Commercial real estate: Owner-occupied $ 5,729 $ 14,178 $ 19,907 $ 922,395 $ 942,302 $ 1,394 Nonowner-occupied 12,154 20,978 33,132 2,809,026 2,842,158 1,341 Other commercial 8,751 29,998 38,749 1,570,582 1,609,331 6,375 Residential real estate 34,672 30,605 65,277 2,187,253 2,252,530 4,093 Construction & land development 4,327 15,931 20,258 1,105,650 1,125,908 1,643 Consumer: Bankcard 448 216 664 9,507 10,171 216 Other consumer 7,645 1,308 8,953 396,596 405,549 1,086 Total $ 73,726 $ 113,214 $ 186,940 $ 9,001,009 $ 9,187,949 $ 16,148 (1) Other includes loans with a recorded investment of $154,180 acquired and accounted for under ASC topic 310-30 “Loans and Debt Securities Acquired with Deteriorated Credit Quality”. Age Analysis of Past Due Loans As of December 31, 2014 30-89 90 Days Total Past Current & Total Financing Recorded Commercial real estate: Owner-occupied $ 4,158 $ 13,582 $ 17,740 $ 998,624 $ 1,016,364 $ 1,039 Nonowner-occupied 10,627 14,859 25,486 2,734,703 2,760,189 45 Other commercial 17,348 17,975 35,323 1,542,115 1,577,438 3,034 Residential real estate 40,793 25,544 66,337 2,197,017 2,263,354 5,417 Construction & land development 5,329 17,119 22,448 1,110,803 1,133,251 648 Consumer: Bankcard 471 114 585 9,852 10,437 114 Other consumer 8,992 1,727 10,719 347,740 358,459 1,378 Total $ 87,718 $ 90,920 $ 178,638 $ 8,940,854 $ 9,119,492 $ 11,675 (1) Other includes loans with a recorded investment of $176,339 acquired and accounted for under ASC topic 310-30 “Loans and Debt Securities Acquired with Deteriorated Credit Quality”.
Schedule of Nonaccrual Loans, Segregated by Class of Loans	The following table sets forth United’s nonaccrual loans, segregated by class of loans: Loans on Nonaccrual Status September 30, 2015 December 31, 2014 Commercial real estate: Owner-occupied $ 12,784 $ 12,543 Nonowner-occupied 19,637 14,814 Other commercial 23,623 14,941 Residential real estate 26,512 20,127 Construction & land development 14,288 16,471 Consumer: Bankcard 0 0 Other consumer 222 349 Total $ 97,066 $ 79,245
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 September 30, 2015 Commercial Real Estate Other Construction Owner- Nonowner- Grade: Pass $ 857,365 $ 2,691,563 $ 1,454,916 $ 971,431 Special mention 26,129 27,057 46,861 61,767 Substandard 58,808 123,538 100,512 92,710 Doubtful 0 0 7,042 0 Total $ 942,302 $ 2,842,158 $ 1,609,331 $ 1,125,908 As of December 31, 2014 Commercial Real Estate Other Construction Owner- Nonowner- Grade: Pass $ 920,981 $ 2,592,783 $ 1,407,853 $ 966,335 Special mention 26,181 48,382 20,776 64,597 Substandard 69,202 119,024 147,494 102,319 Doubtful 0 0 1,315 0 Total $ 1,016,364 $ 2,760,189 $ 1,577,438 $ 1,133,251 Credit Quality Indicators Consumer Credit Exposure As of September 30, 2015 Residential Bankcard Other Grade: Pass $ 2,182,354 $ 9,507 $ 396,446 Special mention 14,027 448 7,751 Substandard 54,958 216 1,352 Doubtful 1,191 0 0 Total $ 2,252,530 $ 10,171 $ 405,549 As of December 31, 2014 Residential Bankcard Other Grade: Pass $ 2,176,655 $ 9,852 $ 347,442 Special mention 18,254 471 9,113 Substandard 66,973 114 1,904 Doubtful 1,472 0 0 Total $ 2,263,354 $ 10,437 $ 358,459
Schedule of Impaired Loans Information by Class of Loans	The following table sets forth United’s impaired loans information, by class of loans: Impaired Loans September 30, 2015 December 31, 2014 Recorded Unpaid Related Recorded Unpaid Related With no related allowance recorded: Commercial real estate: Owner-occupied $ 41,438 $ 41,651 $ 0 $ 37,811 $ 37,811 $ 0 Nonowner-occupied 76,314 76,778 0 48,126 48,462 0 Other commercial 30,002 31,868 0 38,521 40,329 0 Residential real estate 25,776 26,541 0 31,262 31,930 0 Construction & land development 30,131 31,838 0 64,945 68,799 0 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 39 39 0 41 41 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 4,590 $ 4,590 $ 1,194 $ 5,014 $ 5,014 $ 776 Nonowner-occupied 7,056 7,056 1,339 6,994 6,994 797 Other commercial 18,287 21,788 12,394 17,554 20,554 7,168 Residential real estate 10,054 11,374 3,292 6,028 7,349 2,578 Construction & land development 13,635 19,639 4,467 10,779 14,189 3,627 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 0 0 0 0 0 0 Total: Commercial real estate: Owner-occupied $ 46,028 $ 46,241 $ 1,194 $ 42,825 $ 42,825 $ 776 Nonowner-occupied 83,370 83,834 1,339 55,120 55,456 797 Other commercial 48,289 53,656 12,394 56,075 60,883 7,168 Residential real estate 35,830 37,915 3,292 37,290 39,279 2,578 Construction & land development 43,766 51,477 4,467 75,724 82,988 3,627 Consumer: Bankcard 0 0 0 0 0 0 Other consumer 39 39 0 41 41 0 Impaired Loans For the Three Months Ended September 30, 2015 September 30, 2014 Average Interest Average Interest With no related allowance recorded: Commercial real estate: Owner-occupied $ 42,679 $ 75 $ 37,208 $ 129 Nonowner-occupied 73,694 566 63,035 230 Other commercial 32,839 133 20,679 59 Residential real estate 28,572 31 32,864 46 Construction & land development 31,815 6 44,191 97 Consumer: Bankcard 0 0 0 0 Other consumer 35 0 55 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 4,603 $ 28 $ 4,352 $ 114 Nonowner-occupied 6,891 44 7,332 67 Other commercial 18,990 56 12,537 97 Residential real estate 8,801 6 7,716 8 Construction & land development 12,661 114 11,491 31 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 76 0 Total: Commercial real estate: Owner-occupied $ 47,282 $ 103 $ 41,560 $ 243 Nonowner-occupied 80,585 610 70,367 297 Other commercial 51,829 189 33,216 156 Residential real estate 37,373 37 40,580 54 Construction & land development 44,476 120 55,682 128 Consumer: Bankcard 0 0 0 0 Other consumer 35 0 131 0 Impaired Loans For the Nine Months Ended September 30, 2015 September 30, 2014 Average Interest Average Interest With no related allowance recorded: Commercial real estate: Owner-occupied $ 42,908 $ 254 $ 35,959 $ 617 Nonowner-occupied 68,919 1,083 62,205 440 Other commercial 34,472 373 27,454 217 Residential real estate 29,127 177 30,484 195 Construction & land development 34,703 165 46,747 234 Consumer: Bankcard 0 0 0 0 Other consumer 36 0 45 0 With an allowance recorded: Commercial real estate: Owner-occupied $ 4,664 $ 86 $ 4,236 $ 189 Nonowner-occupied 6,747 90 7,606 159 Other commercial 18,740 274 12,751 185 Residential real estate 7,879 35 8,548 101 Construction & land development 11,606 206 10,694 47 Consumer: Bankcard 0 0 0 0 Other consumer 0 0 102 0 Total: Commercial real estate: Owner-occupied $ 47,572 $ 340 $ 40,195 $ 806 Nonowner-occupied 75,666 1,173 69,811 599 Other commercial 53,212 647 40,205 402 Residential real estate 37,006 212 39,032 296 Construction & land development 46,309 371 57,441 281 Consumer: Bankcard 0 0 0 0 Other consumer 36 0 147 0

Allowance for Credit Losses (Ta

Allowance for Credit Losses (Tables)	9 Months Ended
	Sep. 30, 2015
Receivables [Abstract]
Schedule of Allowance for Loan Losses and Carrying Amount of Loans	A progression of the allowance for loan losses, by portfolio segment, for the periods indicated is summarized as follows: Allowance for Loan Losses For the Three Months Ended September 30, 2015 Commercial Real Estate Other Residential Construction Consumer Allowance Total Owner- Nonowner- Allowance for Loan Losses: Beginning balance $ 4,247 $ 7,296 $ 28,476 $ 14,920 $ 16,975 $ 3,169 $ 132 $ 75,215 Charge-offs 175 28 3,889 756 54 505 0 5,407 Recoveries 129 15 101 76 64 105 0 490 Provision 158 (255 ) 6,736 (1,041 ) (1,190 ) 817 (43 ) 5,182 Ending balance $ 4,359 $ 7,028 $ 31,424 $ 13,199 $ 15,795 $ 3,586 $ 89 $ 75,480 Allowance for Loan Losses and Carrying Amount of Loans For the Nine Months Ended September 30, 2015 Commercial Real Estate Other Residential Construction Consumer Allowance Total Owner- Nonowner- Allowance for Loan Losses: Beginning balance $ 4,041 $ 8,167 $ 26,931 $ 13,835 $ 19,402 $ 3,083 $ 70 $ 75,529 Charge-offs 4,303 355 7,941 2,888 825 1,830 0 18,142 Recoveries 249 53 297 347 451 444 0 1,841 Provision 4,372 (837 ) 12,137 1,905 (3,233 ) 1,889 19 16,252 Ending balance $ 4,359 $ 7,028 $ 31,424 $ 13,199 $ 15,795 $ 3,586 $ 89 $ 75,480 Ending Balance: individually evaluated for impairment $ 1,194 $ 1,339 $ 12,394 $ 3,291 $ 4,468 $ 0 $ 0 $ 22,686 Ending Balance: collectively evaluated for impairment $ 3,165 $ 5,689 $ 19,030 $ 9,908 $ 11,327 $ 3,586 $ 89 $ 52,794 Ending Balance: loans acquired with deteriorated credit quality $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Financing receivables: Ending balance $ 942,302 $ 2,842,158 $ 1,609,331 $ 2,252,530 $ 1,125,908 $ 415,720 $ 0 $ 9,187,949 Ending Balance: individually evaluated for impairment $ 12,753 $ 28,385 $ 25,136 $ 14,741 $ 17,010 $ 0 $ 0 $ 98,025 Ending Balance: collectively evaluated for impairment $ 902,958 $ 2,760,084 $ 1,564,569 $ 2,220,777 $ 1,071,684 $ 415,672 $ 0 $ 8,935,744 Ending Balance: loans acquired with deteriorated credit quality $ 26,591 $ 53,689 $ 19,626 $ 17,012 $ 37,214 $ 48 $ 0 $ 154,180 Allowance for Loan Losses and Carrying Amount of Loans For the Year Ended December 31, 2014 Commercial Real Estate Other Residential Construction Consumer Allowance Total Owner- Nonowner- Allowance for Loan Losses: Beginning balance $ 5,653 $ 8,992 $ 20,917 $ 16,694 $ 18,953 $ 2,945 $ 44 $ 74,198 Charge-offs 3,073 2,097 4,947 5,027 7,476 2,621 0 25,241 Recoveries 2,372 268 294 573 685 443 0 4,635 Provision (911 ) 1,004 10,667 1,595 7,240 2,316 26 21,937 Ending balance $ 4,041 $ 8,167 $ 26,931 $ 13,835 $ 19,402 $ 3,083 $ 70 $ 75,529 Ending Balance: individually evaluated for impairment $ 776 $ 797 $ 7,168 $ 2,578 $ 3,627 $ 0 $ 0 $ 14,946 Ending Balance: collectively evaluated for impairment $ 3,265 $ 7,370 $ 19,763 $ 11,257 $ 15,775 $ 3,083 $ 70 $ 60,583 Ending Balance: loans acquired with deteriorated credit quality $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 $ 0 Financing receivables: Ending balance $ 1,016,364 $ 2,760,189 $ 1,577,438 $ 2,263,354 $ 1,133,251 $ 368,896 $ 0 $ 9,119,492 Ending Balance: individually evaluated for impairment $ 12,869 $ 13,733 $ 27,491 $ 16,189 $ 17,168 $ 0 $ 0 $ 87,450 Ending Balance: collectively evaluated for impairment $ 971,408 $ 2,692,374 $ 1,523,504 $ 2,227,605 $ 1,071,966 $ 368,846 $ 0 $ 8,855,703 Ending Balance: loans acquired with deteriorated credit quality $ 32,087 $ 54,082 $ 26,443 $ 19,560 $ 44,117 $ 50 $ 0 $ 176,339

Intangible Assets (Tables)

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2015
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: As of September 30, 2015 Gross Carrying Accumulated Net Carrying Amortized intangible assets: Core deposit intangible assets $ 60,577 ($ 41,882 ) $ 18,695 Goodwill not subject to amortization $ 710,252 As of December 31, 2014 Gross Carrying Accumulated Net Carrying Amortized intangible assets: Core deposit intangible assets $ 60,577 ($ 39,317 ) $ 21,260 Goodwill not subject to amortization $ 709,794
Schedule of Anticipated Amortization Expense	The following table sets forth the anticipated amortization expense for intangible assets for the years subsequent to 2014: Year Amount 2015 $ 3,420 2016 2,981 2017 2,767 2018 2,574 2019 and thereafter 9,518

Long-Term Borrowings (Tables)

Long-Term Borrowings (Tables)	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Schedule of Maturities of FHLB Borrowings	The scheduled maturities of these FHLB borrowings are as follows: Year Amount 2015 $ 628,975 2016 618 2017 287 2018 0 2019 and thereafter 35,000 Total $ 664,880

Derivative Financial Instrume35

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	The following table sets forth certain information regarding the interest rate derivatives portfolio used for interest-rate risk management purposes and designated as accounting hedges under the Derivatives and Hedging topic at September 30, 2015. Derivative Classifications and Hedging Relationships September 30, 2015 Notional Amount Average Pay Rate Fair Value Hedges: Pay Fixed Swaps (Hedging Commercial Loans) $ 36,481 3.44 % Total Derivatives Used in Fair Value Hedges $ 36,481 Total Derivatives Used for Interest Rate Risk Management and Designated as Hedges $ 36,481
Schedule of Fair Value Derivative Financial Instruments	The following tables summarize the fair value of United’s derivative financial instruments. Asset Derivatives September 30, 2015 December 31, 2014 Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Interest rate contracts Other assets $ 0 Other assets $ 90 Total derivatives designated as hedging instruments $ 0 $ 90 Derivatives not designated as hedging instruments Interest rate contracts Other assets $ 3,259 Other assets $ 3,704 Total derivatives not designated as hedging instruments $ 3,259 $ 3,704 Total asset derivatives $ 3,259 $ 3,794 Liability Derivatives September 30, 2015 December 31, 2014 Balance Sheet Location Fair Value Balance Sheet Location Fair Value Derivatives designated as hedging instruments Interest rate contracts Other liabilities $ 1,196 Other liabilities $ 432 Total derivatives designated as hedging instruments $ 1,196 $ 432 Derivatives not designated as hedging instruments Interest rate contracts Other liabilities $ 3,257 Other liabilities $ 3,704 Total derivatives not designated as hedging instruments $ 3,257 $ 3,704 Total liability derivatives $ 4,453 $ 4,136
Schedule of Derivative Financial Instruments on Statement of Income	The effect of United’s derivative financial instruments on its unaudited Consolidated Statements of Income for the three and nine months ended September 30, 2015 and 2014 are presented as follows: Three Months Ended Income Statement Location September 30, September 30, Derivatives in fair value hedging relationships Interest rate contracts Interest income/ (expense) $ (332 ) $ (271 ) Total derivatives in fair value hedging relationships $ (332 ) $ (271 ) Derivatives not designated as hedging instruments Interest rate contracts (1) Other income $ 3 $ 0 Total derivatives not designated as hedging instruments $ 3 $ 0 Total derivatives $ (329 ) $ (271 ) Nine Months Ended Income Statement Location September 30, September 30, Derivatives in fair value hedging relationships Interest rate contracts Interest income/ (expense) $ (661 ) $ (795 ) Total derivatives in fair value hedging relationships $ (661 ) $ (795 ) Derivatives not designated as hedging instruments Interest rate contracts (1) Other income $ 3 $ 0 Total derivatives not designated as hedging instruments $ 3 $ 0 Total derivatives $ (658 ) $ (795 ) (1) Represents net gains from derivative assets not designated as hedging instruments.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured at Fair Value	The following tables present the balances of financial assets and liabilities measured at fair value on a recurring basis as of September 30, 2015 and December 31, 2014, segregated by the level of the valuation inputs within the fair value hierarchy. Fair Value at September 30, 2015 Using Description Balance as of September 30, 2015 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 $ 81,778 $ 0 $ 81,778 $ 0 State and political subdivisions 139,955 0 139,955 0 Residential mortgage-backed securities Agency 499,670 0 499,670 0 Non-agency 10,111 0 10,111 0 Asset-backed securities 4,265 0 4,265 0 Commercial mortgage-backed securities Agency 314,178 0 314,178 0 Trust preferred collateralized debt obligations 35,711 0 0 35,711 Single issue trust preferred securities 12,228 0 12,228 0 Other corporate securities 5,072 0 5,072 0 Total available for sale debt securities 1,102,968 0 1,067,257 35,711 Available for sale equity securities: Financial services industry 2,520 798 1,722 0 Equity mutual funds (1) 819 819 0 0 Other equity securities 1,103 1,103 0 0 Total available for sale equity securities 4,442 2,720 1,722 0 Total available for sale securities 1,107,410 2,720 1,068,979 35,711 Derivative financial assets: Interest rate contracts 3,259 0 3,259 0 Liabilities Derivative financial liabilities: Interest rate contracts 4,453 0 4,453 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, 2014 Using Description Balance as of December 31, 2014 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 $ 89,981 $ 0 $ 89,981 $ 0 State and political subdivisions 136,863 0 136,863 0 Residential mortgage-backed securities Agency 555,685 0 555,685 0 Non-agency 12,018 0 12,018 0 Asset-backed securities 8,027 0 8,027 0 Commercial mortgage-backed securities Agency 317,099 0 317,099 0 Trust preferred collateralized debt obligations 39,558 0 0 39,558 Single issue trust preferred securities 11,744 0 11,744 0 Other corporate securities 5,135 0 5,135 0 Total available for sale debt securities 1,176,110 0 1,136,552 39,558 Available for sale equity securities: Financial services industry 2,533 759 1,774 0 Equity mutual funds (1) 560 560 0 0 Other equity securities 1,183 1,183 0 0 Total available for sale equity securities 4,276 2,502 1,774 0 Total available for sale securities 1,180,386 2,502 1,138,326 39,558 Derivative financial assets: Interest rate contracts 3,794 0 3,794 0 Liabilities Derivative financial liabilities: Interest rate contracts 4,136 0 4,136 0 (1) The equity mutual funds are within a rabbi trust for the payment of benefits under a deferred compensation plan for certain key officers of United and its subsidiaries.
Schedule of Additional Information about Financial Assets and Liabilities Measured at Fair Value Utilized Level 3	The following table presents additional information about financial assets and liabilities measured at fair value at September 30, 2015 and December 31, 2014 on a recurring basis and for which United has utilized Level 3 inputs to determine fair value: Available-for-sale Securities Trust preferred collateralized debt obligations September 30, 2015 December 31, Balance, beginning of period $ 39,558 $ 43,449 Total gains or losses (realized/unrealized): Included in earnings (or changes in net assets) (34 ) (4,034 ) Included in other comprehensive income (3,813 ) 12,312 Purchases, issuances, and settlements 0 (12,169 ) Transfers in and/or out of Level 3 0 0 Balance, end of period $ 35,711 $ 39,558 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
Summary of Financial Assets Measured at Fair Value on Nonrecurring Basis	The following table summarizes United’s financial assets that were measured at fair value on a nonrecurring basis during the period: Description Balance as of September 30, Carrying value at September 30, 2015 YTD Losses Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Impaired Loans $ 53,622 $ 0 $ 13,315 $ 40,307 $ 6,911 OREO 34,119 0 34,119 0 721 Description Balance as of December 31, 2014 Carrying value at December 31, 2014 YTD Losses Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Assets Impaired Loans $ 46,369 $ 0 $ 8,518 $ 37,851 $ 7,349 OREO 38,778 0 38,778 0 3,307
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) September 30, 2015 Cash and cash equivalents $ 1,008,458 $ 1,008,458 $ 0 $ 1,008,458 $ 0 Securities available for sale 1,107,410 1,107,410 2,720 1,068,979 35,711 Securities held to maturity 38,795 36,232 0 34,212 2,020 Other securities 90,387 85,867 0 0 85,867 Loans held for sale 11,602 11,602 0 11,602 0 Loans 9,098,177 9,101,220 0 0 9,101,220 Derivative financial assets 3,259 3,259 0 3,259 0 Deposits 9,504,896 9,494,045 0 9,494,045 0 Short-term borrowings 322,711 322,711 0 322,711 0 Long-term borrowings 939,401 912,648 0 912,648 0 Derivative financial liabilities 4,453 4,453 0 4,453 0 December 31, 2014 Cash and cash equivalents $ 753,064 $ 753,064 $ 0 $ 753,064 $ 0 Securities available for sale 1,180,386 1,180,386 2,502 1,138,326 39,558 Securities held to maturity 39,310 36,784 0 34,764 2,020 Other securities 96,344 91,527 0 0 91,527 Loans held for sale 8,680 8,680 0 8,680 0 Loans 9,029,123 9,055,281 0 0 9,055,281 Derivative financial assets 3,794 3,794 0 3,794 0 Deposits 9,045,485 9,044,976 0 9,044,976 0 Short-term borrowings 435,652 435,652 0 435,652 0 Long-term borrowings 1,105,314 1,081,133 0 1,081,133 0 Derivative financial liabilities 4,136 4,136 0 4,136 0

Stock Based Compensation (Table

Stock Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Plans	A summary of activity under United’s stock option plans as of September 30, 2015, and the changes during the first nine months of 2015 are presented below: Nine Months Ended September 30, 2015 Weighted Average Shares Aggregate Remaining Exercise Outstanding at January 1, 2015 1,380,548 $ 27.94 Granted 189,705 36.92 Exercised (215,967 ) 30.14 Forfeited or expired (13,361 ) 32.22 Outstanding at September 30, 2015 1,340,925 $ 12,389 5.9 $ 28.75 Exercisable at September 30, 2015 905,842 $ 9,741 4.6 $ 27.24
Status of United's Nonvested Stock Option Awards	The following table summarizes the status of United’s nonvested stock option awards during the first nine months of 2015: Shares Weighted-Average Nonvested at January 1, 2015 377,264 $ 6.29 Granted 189,705 7.23 Vested (121,673 ) 6.33 Forfeited or expired (10,213 ) 6.58 Nonvested at September 30, 2015 435,083 $ 6.68
Changes to United's Restricted Common Shares	The following summarizes the changes to United’s restricted common shares for the period ended September 30, 2015: Number of Weighted-Average Outstanding at January 1, 2015 120,308 $ 28.29 Granted 53,071 36.92 Vested (38,041 ) 28.31 Forfeited (2,861 ) 30.69 Outstanding at September 30, 2015 132,477 $ 31.69

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2015
Compensation and Retirement Disclosure [Abstract]
Net Periodic Pension Cost	Net periodic pension cost for the three and nine months ended September 30, 2015 and 2014 included the following components: Three Months Ended September 30 Nine Months Ended September 30 2015 2014 2015 2014 Service cost $ 756 $ 579 $ 2,244 $ 1,720 Interest cost 1,462 1,361 4,338 4,039 Expected return on plan assets (2,344 ) (2,293 ) (6,956 ) (6,806 ) Amortization of transition asset 0 0 0 0 Recognized net actuarial loss 1,235 491 3,665 1,458 Amortization of prior service cost 1 1 1 1 Net periodic pension (benefit) cost $ 1,110 $ 139 $ 3,292 $ 412 Weighted-Average Assumptions: Discount rate 4.35 % 5.20 % 4.35 % 5.20 % Expected return on assets 7.50 % 7.50 % 7.50 % 7.50 % Rate of compensation increase (prior to age 45) 3.50 % 3.50 % 3.50 % 3.50 % Rate of compensation increase 3.00 % 3.00 % 3.00 % 3.00 %

Comprehensive Income (Tables)

Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Components of Total Comprehensive Income	The components of total comprehensive income for the three and nine months ended September 30, 2015 and 2014 are as follows: Three Months Ended Nine Months Ended 2015 2014 2015 2014 Net Income $ 35,047 $ 33,260 $ 104,483 $ 96,631 Available for sale (“AFS”) securities: AFS securities with OTTI charges during the period 0 (4,714 ) (100 ) (5,774 ) Related income tax effect 0 1,650 36 2,021 Income tax rate change 0 0 316 0 Less : OTTI charges recognized in net income 0 4,714 34 5,774 Related income tax benefit 0 (1,650 ) (12 ) (2,021 ) Reclassification of previous noncredit OTTI to credit OTTI 0 4,153 0 6,259 Related income tax benefit 0 (1,453 ) 0 (2,190 ) Net unrealized (losses) gains on AFS securities with OTTI 0 2,700 274 4,069 AFS securities – all other: Change in net unrealized gain on AFS securities arising during the period 8,635 (339 ) 7,053 24,242 Related income tax effect (3,126 ) 119 (2,553 ) (8,485 ) Net reclassification adjustment for (gains) losses included in net income (42 ) (1,300 ) (91 ) (2,125 ) Related income tax expense (benefit) 15 455 33 744 5,482 (1,065 ) 4,442 14,376 Net effect of AFS securities on other comprehensive income 5,482 1,635 4,716 18,445 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 1 2 6 6 Related income tax expense (0 ) (0 ) (2 ) (2 ) Net effect of HTM securities on other comprehensive income 1 2 4 4 Pension plan: Amortization of prior service cost 1 1 1 1 Related income tax benefit 0 0 0 0 Recognized net actuarial loss 1,235 491 3,665 1,458 Related income tax benefit (468 ) (183 ) (1,362 ) (531 ) Net effect of change in pension plan asset on other comprehensive income 768 309 2,304 928 Total change in other comprehensive income 6,251 1,946 7,024 19,377 Total Comprehensive Income $ 41,298 $ 35,206 $ 111,507 $ 116,008
Components of Accumulated Other Comprehensive Income	The components of accumulated other comprehensive income for the nine months ended September 30, 2015 are as follows: Changes in Accumulated Other Comprehensive Income (AOCI) by Component (a) For the Nine Months Ended September 30, 2015 (Dollars in thousands) Unrealized Accretion on Defined Items Total Balance at January 1, 2015 $ 1,553 ($ 62 ) ($ 37,255 ) ($ 35,764 ) Other comprehensive income before reclassification 4,774 4 0 4,778 Amounts reclassified from accumulated other comprehensive income (58 ) 0 2,304 2,246 Net current-period other comprehensive income, net of tax 4,716 4 2,304 7,024 Balance at September 30, 2015 $ 6,269 ($ 58 ) ($ 34,951 ) ($ 28,740 ) (a) All amounts are net-of-tax.
Reclassifications Out of Accumulated Other Comprehensive Income	Reclassifications out of Accumulated Other Comprehensive Income (AOCI) For the Nine Months Ended September 30, 2015 (Dollars in thousands) 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 (91 ) Net gains on sales/calls of investment securities Reclassifications out of Accumulated Other Comprehensive Income (AOCI) For the Nine Months Ended September 30, 2015 (Dollars in thousands) Details about AOCI Components Amount from AOCI Affected Line Item in the Statement Where Net Income is Presented (91 ) Total before tax Related income tax effect 33 Tax expense (58 ) Net of Tax Pension plan: Amortization of transition asset 1 (a) Recognized net actuarial loss 3,665 (a) 3,666 Total before tax Related income tax effect (1,362 ) Tax expense 2,304 Net of tax Total reclassifications for the period $ 2,246 (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)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Reconciliation of Numerator and Denominator of Basic Earnings Per Share with that of Diluted Earnings Per Share	The reconciliation of the numerator and denominator of basic earnings per share with that of diluted earnings per share is presented as follows: Three Months Ended Nine Months Ended 2015 2014 2015 2014 Distributed earnings allocated to common stock $ 22,216 $ 22,101 $ 66,572 $ 66,261 Undistributed earnings allocated to common stock 12,768 11,102 37,725 30,194 Net earnings allocated to common shareholders $ 34,984 $ 33,203 $ 104,297 $ 96,455 Average common shares outstanding 69,391,401 69,044,876 69,302,180 66,836,396 Equivalents from stock options 298,322 224,433 284,107 232,956 Average diluted shares outstanding 69,689,723 69,269,309 69,586,287 67,069,352 Earnings per basic common share $ 0.50 $ 0.48 $ 1.51 $ 1.45 Earnings per diluted common share $ 0.50 $ 0.48 $ 1.50 $ 1.44

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Trust Preferred Securities Redemption	During the fourth quarter of 2014, United redeemed the trust preferred securities listed below. Trust Interest Redemption Principal Amount Principal Amount Redemption Date Sequoia Capital Trust I 10.18 % 103.563 % $ 2,000 $ 2,000 December 8, 2014 VCBI Capital Trust IV 10.20 % 100.000 % $ 25,000 $ 25,000 December 30, 2014
Information Related to Statutory Trusts	Information related to United’s statutory trusts is presented in the table below: Description Issuance Date Amount of Interest Rate Maturity Date Century Trust March 23, 2000 $ 8,800 10.875% Fixed March 8, 2030 United Statutory Trust III December 17, 2003 $ 20,000 3-month LIBOR + 2.85% December 17, 2033 United Statutory Trust IV December 19, 2003 $ 25,000 3-month LIBOR + 2.85% January 23, 2034 United Statutory Trust V July 12, 2007 $ 50,000 3-month LIBOR + 1.55% October 1, 2037 United Statutory Trust VI September 20, 2007 $ 30,000 3-month LIBOR + 1.30% December 15, 2037 Premier Statutory Trust II September 25, 2003 $ 6,000 3-month LIBOR + 3.10% October 8, 2033 Premier Statutory Trust III May 16, 2005 $ 8,000 3-month LIBOR + 1.74% June 15, 2035 Premier Statutory Trust IV June 20, 2006 $ 14,000 3-month LIBOR + 1.55% September 23, 2036 Premier Statutory Trust V December 14, 2006 $ 10,000 3-month LIBOR + 1.61% March 1, 2037 Centra Statutory Trust I September 20, 2004 $ 10,000 3-month LIBOR + 2.29% September 20, 2034 Centra Statutory Trust II June 15, 2006 $ 10,000 3-month LIBOR + 1.65% July 7, 2036 Virginia Commerce Trust II December 19, 2002 $ 15,000 6-month LIBOR + 3.30% December 19, 2032 Virginia Commerce Trust III December 20, 2005 $ 25,000 3-month LIBOR + 1.42% February 23, 2036
Summary of Quantitative Information Related to Significant Involvement in Unconsolidated Variable Interest Entities	The following table summarizes quantitative information about United’s significant involvement in unconsolidated VIEs: As of September 30, 2015 As of December 31, 2014 Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Aggregate Assets Aggregate Liabilities Risk Of Loss (1) Trust preferred securities $ 240,346 $ 232,393 $ 7,953 $ 241,147 $ 233,222 $ 7,925 (1) Represents investment in VIEs.

Mergers and Acquisitions - Addi

Mergers and Acquisitions - Additional Information (Detail) - USD ($)	Jan. 31, 2014	Sep. 30, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Total assets at consummation		$ 12,556,929,000	$ 12,328,811,000
Loans at consummation		9,187,949,000	9,119,492,000
Deposits at consummation		9,504,896,000	9,045,485,000
Resulting goodwill		$ 710,252,000	$ 709,794,000
Contractually required principal and interest at acquisition	$ 427,858,000
Expected cash flows at acquisition	189,277,000
Estimated fair value of acquired impaired loans at acquisition	$ 179,199,000
Virginia Commerce Bancorp, Inc. [Member]
Business Acquisition [Line Items]
Outstanding common stock acquired	100.00%
Business acquisition date		Jan. 31, 2014
Total assets at consummation	$ 2,769,716,000
Loans at consummation	2,065,490,000
Deposits at consummation	2,018,962,000
Common stock paid in cash	585,533,000
Common stock value	547,894,000
Stock options exchanged value	4,368,000
Cash to redeem the Treasury warrant	$ 33,263,000
Number of shares issued in the transaction	18,330,347
Resulting goodwill	$ 336,102,000
Goodwill from acquisition expected to be tax deductible	0
Downward fair value adjustment on loans acquired	88,129,000
Downward fair value adjustment on other real estate owned properties	1,708,000
Premium on interest-bearing deposits acquired	6,007,000
Premium on term securities to purchase	3,700,000
Discount on junior subordinated debt securities acquired	16,384,000
Estimated remaining life of premium on interest-bearing deposits acquired		3 months
Estimated remaining life on premium of term securities to purchase		9 months 29 days
Estimated remaining life of discount on junior subordinated debt securities acquired		18 years 9 months 29 days
Assumed liabilities to provide severance benefits		$ 109,000
Liabilities to provide severance benefits		$ 0
Contractually required principal and interest at acquisition	2,685,339,000
Expected cash flows at acquisition	2,289,315,000
Estimated fair value of acquired impaired loans at acquisition	2,014,776,000
Virginia Commerce Bancorp, Inc. [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Common stock paid in cash	8,000
Common stock value	$ 547,894,000
Number of shares issued in the transaction	18,330,347
Closing market price per common share	$ 29.89
Virginia Commerce Bancorp, Inc. [Member] | Core Deposit Intangible Assets [Member]
Business Acquisition [Line Items]
Purchase price allocation of Identifiable Intangible assets	$ 17,143,000
Estimated period of amortization of core deposit intangibles	10 years

Mergers and Acquisitions - Sche

Mergers and Acquisitions - Schedule of Acquired Loans Accounted for at Fair value (Detail) $ in Thousands	Jan. 31, 2014USD ($)
Business Acquisition [Line Items]
Contractually required principal and interest at acquisition	$ 427,858
Expected cash flows at acquisition	189,277
Basis in acquired loans at acquisition - estimated fair value	179,199
Virginia Commerce Bancorp, Inc. [Member]
Business Acquisition [Line Items]
Contractually required principal and interest at acquisition	2,685,339
Contractual cash flows not expected to be collected	(396,024)
Expected cash flows at acquisition	2,289,315
Interest component of expected cash flows	(274,539)
Basis in acquired loans at acquisition - estimated fair value	$ 2,014,776

Mergers and Acquisitions - Sc44

Mergers and Acquisitions - Schedule of Acquired Identifiable Assets and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Jan. 31, 2014	Sep. 30, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Resulting goodwill		$ 710,252	$ 709,794
Virginia Commerce Bancorp, Inc. [Member]
Business Acquisition [Line Items]
Value of common shares issued (18,330,347 shares)	$ 547,894
Fair value of stock options assumed	4,368
Cash to redeem the Treasury warrant	33,263
Cash for fractional shares	8
Total purchase price	585,533
Cash and cash equivalents	130,569
Investment securities	476,541
Loans	2,014,776
Premises and equipment	10,786
Other assets	104,131
Total identifiable assets	2,753,946
Deposits	2,024,969
Short-term borrowings	263,816
Long-term borrowings	204,335
Other liabilities	11,395
Total identifiable liabilities	2,504,515
Net assets acquired including identifiable intangible assets	249,431
Resulting goodwill	336,102
Virginia Commerce Bancorp, Inc. [Member] | Core Deposit Intangible Assets [Member]
Business Acquisition [Line Items]
Core deposit intangibles	$ 17,143

Mergers and Acquisitions - Sc45

Mergers and Acquisitions - Schedule of Acquired Identifiable Assets and Liabilities Assumed (Parenthetical) (Detail)	Jan. 31, 2014shares
Virginia Commerce Bancorp, Inc. [Member]
Business Acquisition [Line Items]
Common stock, shares issued	18,330,347

Mergers and Acquisitions - Sc46

Mergers and Acquisitions - Schedule of Acquired Reconciliation of Goodwill (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Goodwill [Line Items]
Beginning balance	$ 709,794
Ending balance	710,252
Virginia Commerce Bancorp, Inc. [Member]
Goodwill [Line Items]
Addition to goodwill from Virginia Commerce acquisition	$ 458

Investment Securities - Summary

Investment Securities - Summary of Amortized Cost and Estimated Fair Values of Available for Sale Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Investments [Line Items]
Amortized Cost	$ 1,099,646	$ 1,180,016
Gross Unrealized Gains	24,795	17,837
Gross Unrealized Losses	17,031	17,467
Estimated Fair Value	1,107,410	1,180,386
Cumulative OTTI in AOCI	26,410	26,344
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Schedule of Investments [Line Items]
Amortized Cost	78,864	88,559
Gross Unrealized Gains	2,914	1,425
Gross Unrealized Losses	0	3
Estimated Fair Value	81,778	89,981
Cumulative OTTI in AOCI	0	0
State and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Amortized Cost	137,660	133,730
Gross Unrealized Gains	2,489	3,165
Gross Unrealized Losses	194	32
Estimated Fair Value	139,955	136,863
Cumulative OTTI in AOCI	0	0
Residential Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Amortized Cost	487,995	547,825
Gross Unrealized Gains	11,738	8,407
Gross Unrealized Losses	63	547
Estimated Fair Value	499,670	555,685
Cumulative OTTI in AOCI	0	0
Residential Mortgage-Backed Securities, Non-agency [Member]
Schedule of Investments [Line Items]
Amortized Cost	9,638	11,474
Gross Unrealized Gains	476	544
Gross Unrealized Losses	3	0
Estimated Fair Value	10,111	12,018
Cumulative OTTI in AOCI	458	458
Commercial Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Amortized Cost	308,596	316,707
Gross Unrealized Gains	5,680	2,393
Gross Unrealized Losses	98	2,001
Estimated Fair Value	314,178	317,099
Cumulative OTTI in AOCI	0	0
Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	4,273	8,004
Gross Unrealized Gains	0	23
Gross Unrealized Losses	8	0
Estimated Fair Value	4,265	8,027
Cumulative OTTI in AOCI	0	0
Trust Preferred Collateralized Debt Obligations [Member]
Schedule of Investments [Line Items]
Amortized Cost	49,894	51,328
Gross Unrealized Gains	680	922
Gross Unrealized Losses	14,863	12,692
Estimated Fair Value	35,711	39,558
Cumulative OTTI in AOCI	25,952	25,886
Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	13,798	13,760
Gross Unrealized Gains	210	173
Gross Unrealized Losses	1,780	2,189
Estimated Fair Value	12,228	11,744
Cumulative OTTI in AOCI	0	0
Other Corporate Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	4,999	4,998
Gross Unrealized Gains	73	137
Gross Unrealized Losses	0	0
Estimated Fair Value	5,072	5,135
Cumulative OTTI in AOCI	0	0
Marketable Equity Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	3,929	3,631
Gross Unrealized Gains	535	648
Gross Unrealized Losses	22	3
Estimated Fair Value	4,442	4,276
Cumulative OTTI in AOCI	$ 0	$ 0

Investment Securities - Summa48

Investment Securities - Summary of Securities Available for Sale in an Unrealized Loss Position (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	$ 53,075	$ 137,026
Less than 12 months, Unrealized Losses	451	641
12 months or longer, Fair Value	43,005	187,218
12 months or longer, Unrealized Losses	16,580	16,826
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	0	7,142
Less than 12 months, Unrealized Losses	0	3
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	17,546	11,637
Less than 12 months, Unrealized Losses	194	32
12 months or longer, Fair Value	0	0
12 months or longer, Unrealized Losses	0	0
Residential Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	20,780	96,550
Less than 12 months, Unrealized Losses	63	547
12 months or longer, Fair Value	0	0
12 months or longer, Unrealized Losses	0	0
Residential Mortgage-Backed Securities, Non-agency [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	378
Less than 12 months, Unrealized Losses	3
12 months or longer, Fair Value	0
12 months or longer, Unrealized Losses	0
Commercial Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	7,934	21,674
Less than 12 months, Unrealized Losses	67	56
12 months or longer, Fair Value	9,527	146,897
12 months or longer, Unrealized Losses	31	1,945
Asset-Backed Securities [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	4,265	0
Less than 12 months, Unrealized Losses	8	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	1,199	0
Less than 12 months, Unrealized Losses	94	0
12 months or longer, Fair Value	29,578	32,241
12 months or longer, Unrealized Losses	14,769	12,692
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	3,900	8,080
12 months or longer, Unrealized Losses	1,780	2,189
Marketable Equity Securities [Member]
Schedule of Investments [Line Items]
Less than 12 months, Fair Value	973	23
Less than 12 months, Unrealized Losses	22	3
12 months or longer, Fair Value	0	0
12 months or longer, Unrealized Losses	$ 0	$ 0

Investment Securities - Summa49

Investment Securities - Summary of Gains or Losses on Proceeds from Maturities, Sales and Calls of Available for Sale Securities by Specific Identification Method (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales and calls	$ 42,559	$ 64,610	$ 130,027	$ 500,493
Gross realized gains	43	1,314	97	2,366
Gross realized losses	$ 2	$ 5	$ 7	$ 232

Investment Securities - Additio

Investment Securities - Additional Information (Detail)	3 Months Ended	9 Months Ended	96 Months Ended
	Sep. 30, 2015USD ($)Securities	Sep. 30, 2015USD ($)Securities	Dec. 31, 2007USD ($)	Dec. 31, 2014USD ($)
Schedule of Investments [Line Items]
Equity securities gross unrealized losses	$ 17,031,000	$ 17,031,000		$ 17,467,000
Available for sale securities in unrealized loss position | Securities	56	56
Available for sale securities in portfolio, number | Securities	449	449
Amortized cost of available for sale securities	$ 1,099,646,000	$ 1,099,646,000		1,180,016,000
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	26,410,000	$ 26,410,000		26,344,000
New issuance of Preferred Stock estimated			$ 60,000,000,000
Security other-than-temporarily impaired		100.00%
Amortized cost equity securities	3,929,000	$ 3,929,000
Carrying value of securities pledged	1,034,982,000	1,034,982,000		1,081,299,000
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	25,952,000	25,952,000		25,886,000
Wells Fargo [Member]
Schedule of Investments [Line Items]
Amortized cost of trust preferred securities	9,913,000	9,913,000
SunTrust Bank [Member]
Schedule of Investments [Line Items]
Amortized cost of trust preferred securities	7,407,000	7,407,000
Royal Bank of Scotland [Member]
Schedule of Investments [Line Items]
Amortized cost of trust preferred securities	973,000	$ 973,000
Minimum [Member]
Schedule of Investments [Line Items]
Other-than-temporarily impaired, the collateralization ratios		98.00%
Maximum [Member]
Schedule of Investments [Line Items]
Other-than-temporarily impaired, the collateralization ratios		308.40%
Median [Member]
Schedule of Investments [Line Items]
Other-than-temporarily impaired, the collateralization ratios		147.80%
Weighted Average [Member]
Schedule of Investments [Line Items]
Other-than-temporarily impaired, the collateralization ratios		206.90%
Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale single issue trust preferred securities	2,997,000	$ 2,997,000
Investment Grade [Member] | TRUP CDOs [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale securities	4,617,000	4,617,000
Below Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale single issue trust preferred securities	5,680,000	5,680,000
Amortized cost of available for sale TRUP CDOs and single issue trust preferred securities in an unrealized loss position 12 months or longer	5,680,000	5,680,000
Below Investment Grade [Member] | TRUP CDOs [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale securities	39,731,000	39,731,000
Split Rated [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale single issue trust preferred securities	5,121,000	5,121,000
Residential Mortgage-Backed Securities, Non-agency [Member]
Schedule of Investments [Line Items]
Equity securities gross unrealized losses	3,000	3,000		0
Amortized cost of available for sale securities	9,638,000	9,638,000		11,474,000
Credit-related other-than-temporary impairment recognized in earnings		0
Noncredit-related other-than-temporary impairment recognized in accumulated other comprehensive income (loss)		0
Noncredit-related other-than-temporary impairment recognized	458,000	$ 458,000		458,000
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		30.00%
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		70.00%
Residential Mortgage-Backed Securities, Non-agency [Member] | Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale securities	2,141,000	$ 2,141,000
Residential Mortgage-Backed Securities, Non-agency [Member] | Below Investment Grade [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale securities	7,496,000	7,496,000
Agency Mortgage Backed Securities [Member]
Schedule of Investments [Line Items]
Amortized cost of available for sale securities	796,591,000	796,591,000
Commercial Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Equity securities gross unrealized losses	98,000	98,000		2,001,000
Amortized cost of available for sale securities	308,596,000	308,596,000		316,707,000
Noncredit-related other-than-temporary impairment recognized	0	0		0
Residential Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Equity securities gross unrealized losses	63,000	63,000		547,000
Amortized cost of available for sale securities	487,995,000	487,995,000		547,825,000
Noncredit-related other-than-temporary impairment recognized	0	0		0
Marketable Equity Securities [Member]
Schedule of Investments [Line Items]
Equity securities gross unrealized losses	22,000	22,000		3,000
Amortized cost of available for sale securities	3,929,000	3,929,000		3,631,000
Noncredit-related other-than-temporary impairment recognized	$ 0	$ 0		$ 0
Number of equity securities other-than-temporarily impaired | Securities	0	0

Investment Securities - Summa51

Investment Securities - Summary of Unrealized Loss Positions of Available for Sale TRUP CDOs and Single Issue Trust Preferred Securities (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Investments [Line Items]
Amortized Cost	$ 1,099,646	$ 1,180,016
Fair Value	1,107,410	$ 1,180,386
Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	49,894
Fair Value	35,711
Unrealized Loss	14,183
Senior - Bank [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	6,758
Fair Value	5,981
Unrealized Loss	777
Mezzanine - Bank (now in senior position) [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	11,859
Fair Value	9,097
Unrealized Loss	2,762
Mezzanine - Bank [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	26,090
Fair Value	16,966
Unrealized Loss	9,124
Mezzanine - Bank & Insurance (combination) [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	5,187
Fair Value	3,667
Unrealized Loss	1,520
Investment Grade [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	4,617
Investment Grade [Member] | Senior - Bank [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	4,617
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	0
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	0
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	45,277
Below Investment Grade [Member] | Senior - Bank [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	2,141
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	11,859
Below Investment Grade [Member] | Mezzanine - Bank [Member] | Trup CDOs and Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	26,090
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	$ 5,187

Investment Securities - Roll Fo

Investment Securities - Roll Forward of Credit Losses on Securities (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Investments, Debt and Equity Securities [Abstract]
Cumulative credit losses, Beginning Balance	$ 23,773	$ 34,082	$ 23,739	$ 40,663
Additional credit losses on securities for which OTTI was previously recognized	0	4,714	34	5,738
Reductions for securities sold or paid off during the period	0	0	0	(7,605)
Cumulative credit losses, Ending Balance	$ 23,773	$ 38,796	$ 23,773	$ 38,796

Investment Securities - Summa53

Investment Securities - Summary of Maturities of Securities Available for Sale by Amortized Cost and Estimated Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Due in one year or less, Amortized Cost	$ 22,311	$ 38,358
Due after one year through five years, Amortized Cost	276,823	180,821
Due after five years through ten years, Amortized Cost	199,455	313,863
Due after ten years, Amortized Cost	597,128	643,343
Marketable equity securities, Amortized Cost	3,929	3,631
Amortized Cost	1,099,646	1,180,016
Due in one year or less, Estimated Fair Value	22,451	38,727
Due after one year through five years, Estimated Fair Value	281,147	181,930
Due after five years through ten years, Estimated Fair Value	206,182	317,663
Due after ten years, Estimated Fair Value	593,188	637,790
Marketable equity securities, Estimated Fair Value	4,442	4,276
Total available for sale securities	$ 1,107,410	$ 1,180,386

Investment Securities - Summa54

Investment Securities - Summary of Amortized Cost and Estimated Fair Values of Securities Held to Maturity (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Investments [Line Items]
Amortized Cost	$ 38,795	$ 39,310
Gross Unrealized Gains	1,097	1,368
Gross Unrealized Losses	3,660	3,894
Estimated Fair Value	36,232	36,784
U.S. Treasury Securities and Obligations of U.S. Government Corporations and Agencies [Member]
Schedule of Investments [Line Items]
Amortized Cost	10,470	10,599
Gross Unrealized Gains	1,066	1,329
Gross Unrealized Losses	0	0
Estimated Fair Value	11,536	11,928
State and Political Subdivisions [Member]
Schedule of Investments [Line Items]
Amortized Cost	8,975	9,369
Gross Unrealized Gains	24	32
Gross Unrealized Losses	304	294
Estimated Fair Value	8,695	9,107
Residential Mortgage-Backed Securities, Agency [Member]
Schedule of Investments [Line Items]
Amortized Cost	36	41
Gross Unrealized Gains	7	7
Gross Unrealized Losses	0	0
Estimated Fair Value	43	48
Single Issue Trust Preferred Securities [Member]
Schedule of Investments [Line Items]
Amortized Cost	19,294	19,281
Gross Unrealized Gains	0	0
Gross Unrealized Losses	3,356	3,600
Estimated Fair Value	15,938	15,681
Other Corporate Securities [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 - Summa55

Investment Securities - Summary of Maturities of Debt Securities Held to Maturity by Amortized Cost and Estimated Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Due in one year or less, Amortized Cost	$ 5,049	$ 360
Due after one year through five years, Amortized Cost	9,287	14,499
Due after five years through ten years, Amortized Cost	4,294	4,293
Due after ten years, Amortized Cost	20,165	20,158
Amortized Cost	38,795	39,310
Due in one year or less, Estimated Fair Value	5,215	361
Due after one year through five years, Estimated Fair Value	10,200	15,848
Due after five years through ten years, Estimated Fair Value	3,998	4,007
Due after ten years, Estimated Fair Value	16,819	16,568
Estimated Fair Value, Total	$ 36,232	$ 36,784

Loans - Major Classes of Loans

Loans - Major Classes of Loans (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Commercial, financial and agricultural:
Total commercial, financial & agricultural	$ 5,393,791	$ 5,353,991
Residential real estate	2,252,530	2,263,354
Construction & land development	1,125,908	1,133,251
Consumer:
Bankcard	10,171	10,437
Other consumer	405,549	358,459
Total Financing Receivables	9,187,949	9,119,492
Owner-Occupied [Member]
Commercial, financial and agricultural:
Total commercial, financial & agricultural	942,302	1,016,364
Nonowner-Occupied [Member]
Commercial, financial and agricultural:
Total commercial, financial & agricultural	2,842,158	2,760,189
Other Commercial Loans [Member]
Commercial, financial and agricultural:
Total commercial, financial & agricultural	$ 1,609,331	$ 1,577,438

Loans - Additional Information

Loans - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Loans held for sale	$ 11,602	$ 8,680
Acquired impaired loans from merger	$ 9,187,949	$ 9,119,492
Percentage of acquired impaired loans from merger on total gross loans	1.68%	1.93%
Recorded investment in acquired impaired loans	$ 217,684	$ 252,759
Directors and Officers [Member]
Related party loans	196,403	188,516
Loans Acquired with Deteriorated Credit Quality [Member]
Acquired impaired loans from merger	$ 154,180	$ 176,339

Loans - Activity for Accretable

Loans - Activity for Accretable Yield (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Loans [Abstract]
Accretable yield at the beginning of the period	$ 11,339
Accretion (including cash recoveries)	(8,590)
Net reclassifications to accretable from non-accretable	10,393
Disposals (including maturities, foreclosures, and charge-offs)	(510)
Accretable yield at the end of the period	$ 12,632

Credit Quality - Additional Inf

Credit Quality - Additional Information (Detail) $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2015USD ($)SecurityLoan	Sep. 30, 2015USD ($)SecurityLoan	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)
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		$ 21,509		$ 22,234
Restructured loans on nonaccrual status	$ 9,679	9,679		4,194
Restructured loans modified by reduction in interest	3,882	3,882
Restructured loan and interest	7,919	7,919
Restructured loans modified by change in terms	$ 9,708	$ 9,708
Number of loans restructured | SecurityLoan	0	0
Restructured loans modified by reduction in interest and extension of maturity		$ 887	$ 5,630
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	$ 34,119	$ 34,119		38,778
Loans in process of foreclosure	$ 473	$ 473		$ 311

Credit Quality - Schedule of Tr

Credit Quality - Schedule of Troubled Debt Restructurings, Segregated by Class of Loans (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)Contract	Sep. 30, 2014USD ($)Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	2	2
Pre-Modification Outstanding Recorded Investment	$ 909	$ 5,630
Post-Modification Outstanding Recorded Investment	$ 887	$ 5,630
Construction & Land Development [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	0
Pre-Modification Outstanding Recorded Investment	$ 669	$ 0
Post-Modification Outstanding Recorded Investment	$ 647	$ 0
Other Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	2
Pre-Modification Outstanding Recorded Investment	$ 240	$ 5,630
Post-Modification Outstanding Recorded Investment	$ 240	$ 5,630
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0
Consumer [Member] | Bankcard [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0
Consumer [Member] | Other Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0

Credit Quality - Schedule of Ch

Credit Quality - Schedule of Charged-off Troubled Debt Restructurings on Financing Receivables (Detail) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2014USD ($)Contract	Sep. 30, 2014USD ($)Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	1
Recorded Investment	$ 478	$ 478
Construction & Land Development [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Recorded Investment	$ 0	$ 0
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Recorded Investment	$ 0	$ 0
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	1	1
Recorded Investment	$ 478	$ 478
Other Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Recorded Investment	$ 0	$ 0
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Recorded Investment	$ 0	$ 0
Consumer [Member] | Bankcard [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Recorded Investment	$ 0	$ 0
Consumer [Member] | Other Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract	0	0
Recorded Investment	$ 0	$ 0

Credit Quality - Schedule of Ag

Credit Quality - Schedule of Age Analysis of its Past Due Loans, Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	$ 73,726	$ 87,718
Loans, Total Past Due	186,940	178,638
Loans, Current & Other	9,001,009	8,940,854
Total Financing Receivables	9,187,949	9,119,492
Loans, Recorded Investment >90 Days & Accruing	16,148	11,675
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total Past Due	113,214	90,920
Construction & Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	4,327	5,329
Loans, Total Past Due	20,258	22,448
Loans, Current & Other	1,105,650	1,110,803
Total Financing Receivables	1,125,908	1,133,251
Loans, Recorded Investment >90 Days & Accruing	1,643	648
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	15,931	17,119
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	5,729	4,158
Loans, Total Past Due	19,907	17,740
Loans, Current & Other	922,395	998,624
Total Financing Receivables	942,302	1,016,364
Loans, Recorded Investment >90 Days & Accruing	1,394	1,039
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	14,178	13,582
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	12,154	10,627
Loans, Total Past Due	33,132	25,486
Loans, Current & Other	2,809,026	2,734,703
Total Financing Receivables	2,842,158	2,760,189
Loans, Recorded Investment >90 Days & Accruing	1,341	45
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	20,978	14,859
Other Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	8,751	17,348
Loans, Total Past Due	38,749	35,323
Loans, Current & Other	1,570,582	1,542,115
Total Financing Receivables	1,609,331	1,577,438
Loans, Recorded Investment >90 Days & Accruing	6,375	3,034
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	29,998	17,975
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	34,672	40,793
Loans, Total Past Due	65,277	66,337
Loans, Current & Other	2,187,253	2,197,017
Total Financing Receivables	2,252,530	2,263,354
Loans, Recorded Investment >90 Days & Accruing	4,093	5,417
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	30,605	25,544
Consumer [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	448	471
Loans, Total Past Due	664	585
Loans, Current & Other	9,507	9,852
Total Financing Receivables	10,171	10,437
Loans, Recorded Investment >90 Days & Accruing	216	114
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	216	114
Consumer [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, 30-89 Days Past Due	7,645	8,992
Loans, Total Past Due	8,953	10,719
Loans, Current & Other	396,596	347,740
Total Financing Receivables	405,549	358,459
Loans, Recorded Investment >90 Days & Accruing	1,086	1,378
Consumer [Member] | Other Consumer [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans, Total Past Due	$ 1,308	$ 1,727

Credit Quality - Schedule of 63

Credit Quality - Schedule of Age Analysis of its Past Due Loans, Segregated by Class of Loans (Parenthetical) (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Acquired impaired loans from merger	$ 9,187,949	$ 9,119,492
Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Acquired impaired loans from merger	154,180	176,339
Loans Acquired with Deteriorated Credit Quality [Member] | Loans and Debt Securities Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Acquired impaired loans from merger	$ 154,180	$ 176,339

Credit Quality - Schedule of No

Credit Quality - Schedule of Nonaccrual Loans, Segregated by Class of Loans (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	$ 97,066	$ 79,245
Construction & Land Development [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	14,288	16,471
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	12,784	12,543
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	19,637	14,814
Other Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	23,623	14,941
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans on Nonaccrual Status	26,512	20,127
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	$ 222	$ 349

Credit Quality - Schedule of Cr

Credit Quality - Schedule of Credit Quality Indicators Information, by Class of Loans (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	$ 9,187,949	$ 9,119,492
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	2,252,530	2,263,354
Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,609,331	1,577,438
Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	10,171	10,437
Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	405,549	358,459
Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	942,302	1,016,364
Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	2,842,158	2,760,189
Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,125,908	1,133,251
Pass [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	2,182,354	2,176,655
Pass [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,454,916	1,407,853
Pass [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	9,507	9,852
Pass [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	396,446	347,442
Pass [Member] | Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	857,365	920,981
Pass [Member] | Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	2,691,563	2,592,783
Pass [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	971,431	966,335
Special Mention [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	14,027	18,254
Special Mention [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	46,861	20,776
Special Mention [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	448	471
Special Mention [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	7,751	9,113
Special Mention [Member] | Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	26,129	26,181
Special Mention [Member] | Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	27,057	48,382
Special Mention [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	61,767	64,597
Substandard [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	54,958	66,973
Substandard [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	100,512	147,494
Substandard [Member] | Bankcard [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	216	114
Substandard [Member] | Other Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,352	1,904
Substandard [Member] | Owner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	58,808	69,202
Substandard [Member] | Nonowner-Occupied [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	123,538	119,024
Substandard [Member] | Construction & Land Development [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	92,710	102,319
Doubtful [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	1,191	1,472
Doubtful [Member] | Other Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing receivable, credit quality indicators information	7,042	1,315
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		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Construction & Land Development [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	$ 30,131		$ 30,131		$ 64,945
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	31,838		31,838		68,799
Impaired Loans, Recorded Investment, With an allowance recorded	13,635		13,635		10,779
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	19,639		19,639		14,189
Impaired Loans, Related Allowance	4,467		4,467		3,627
Impaired Loans, Recorded Investment	43,766		43,766		75,724
Impaired Loans, Unpaid Principal Balance	51,477		51,477		82,988
Impaired Loans, Related Allowance	4,467		4,467		3,627
Impaired Loans, Average Recorded Investment, With no related allowance recorded	31,815	$ 44,191	34,703	$ 46,747
Impaired Loans, Interest Income Recognized, With no related allowance recorded	6	97	165	234
Impaired Loans, Average Recorded Investment, With an allowance recorded	12,661	11,491	11,606	10,694
Impaired Loans, Interest Income Recognized, With an allowance recorded	114	31	206	47
Impaired Loans, Average Recorded Investment	44,476	55,682	46,309	57,441
Impaired Loans, Interest Income Recognized	120	128	371	281
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	41,438		41,438		37,811
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	41,651		41,651		37,811
Impaired Loans, Recorded Investment, With an allowance recorded	4,590		4,590		5,014
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	4,590		4,590		5,014
Impaired Loans, Related Allowance	1,194		1,194		776
Impaired Loans, Recorded Investment	46,028		46,028		42,825
Impaired Loans, Unpaid Principal Balance	46,241		46,241		42,825
Impaired Loans, Related Allowance	1,194		1,194		776
Impaired Loans, Average Recorded Investment, With no related allowance recorded	42,679	37,208	42,908	35,959
Impaired Loans, Interest Income Recognized, With no related allowance recorded	75	129	254	617
Impaired Loans, Average Recorded Investment, With an allowance recorded	4,603	4,352	4,664	4,236
Impaired Loans, Interest Income Recognized, With an allowance recorded	28	114	86	189
Impaired Loans, Average Recorded Investment	47,282	41,560	47,572	40,195
Impaired Loans, Interest Income Recognized	103	243	340	806
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	76,314		76,314		48,126
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	76,778		76,778		48,462
Impaired Loans, Recorded Investment, With an allowance recorded	7,056		7,056		6,994
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	7,056		7,056		6,994
Impaired Loans, Related Allowance	1,339		1,339		797
Impaired Loans, Recorded Investment	83,370		83,370		55,120
Impaired Loans, Unpaid Principal Balance	83,834		83,834		55,456
Impaired Loans, Related Allowance	1,339		1,339		797
Impaired Loans, Average Recorded Investment, With no related allowance recorded	73,694	63,035	68,919	62,205
Impaired Loans, Interest Income Recognized, With no related allowance recorded	566	230	1,083	440
Impaired Loans, Average Recorded Investment, With an allowance recorded	6,891	7,332	6,747	7,606
Impaired Loans, Interest Income Recognized, With an allowance recorded	44	67	90	159
Impaired Loans, Average Recorded Investment	80,585	70,367	75,666	69,811
Impaired Loans, Interest Income Recognized	610	297	1,173	599
Other Commercial [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	30,002		30,002		38,521
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	31,868		31,868		40,329
Impaired Loans, Recorded Investment, With an allowance recorded	18,287		18,287		17,554
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	21,788		21,788		20,554
Impaired Loans, Related Allowance	12,394		12,394		7,168
Impaired Loans, Recorded Investment	48,289		48,289		56,075
Impaired Loans, Unpaid Principal Balance	53,656		53,656		60,883
Impaired Loans, Related Allowance	12,394		12,394		7,168
Impaired Loans, Average Recorded Investment, With no related allowance recorded	32,839	20,679	34,472	27,454
Impaired Loans, Interest Income Recognized, With no related allowance recorded	133	59	373	217
Impaired Loans, Average Recorded Investment, With an allowance recorded	18,990	12,537	18,740	12,751
Impaired Loans, Interest Income Recognized, With an allowance recorded	56	97	274	185
Impaired Loans, Average Recorded Investment	51,829	33,216	53,212	40,205
Impaired Loans, Interest Income Recognized	189	156	647	402
Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	25,776		25,776		31,262
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	26,541		26,541		31,930
Impaired Loans, Recorded Investment, With an allowance recorded	10,054		10,054		6,028
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	11,374		11,374		7,349
Impaired Loans, Related Allowance	3,292		3,292		2,578
Impaired Loans, Recorded Investment	35,830		35,830		37,290
Impaired Loans, Unpaid Principal Balance	37,915		37,915		39,279
Impaired Loans, Related Allowance	3,292		3,292		2,578
Impaired Loans, Average Recorded Investment, With no related allowance recorded	28,572	32,864	29,127	30,484
Impaired Loans, Interest Income Recognized, With no related allowance recorded	31	46	177	195
Impaired Loans, Average Recorded Investment, With an allowance recorded	8,801	7,716	7,879	8,548
Impaired Loans, Interest Income Recognized, With an allowance recorded	6	8	35	101
Impaired Loans, Average Recorded Investment	37,373	40,580	37,006	39,032
Impaired Loans, Interest Income Recognized	37	54	212	296
Consumer [Member] | Bankcard [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	0		0		0
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	0		0		0
Impaired Loans, Recorded Investment, With an allowance recorded	0		0		0
Impaired Loans, Unpaid Principal Balance, With an allowance recorded	0		0		0
Impaired Loans, Related Allowance	0		0		0
Impaired Loans, Recorded Investment	0		0		0
Impaired Loans, Unpaid Principal Balance	0		0		0
Impaired Loans, Related Allowance	0		0		0
Impaired Loans, Average Recorded Investment, With no related allowance recorded	0	0	0	0
Impaired Loans, Interest Income Recognized, With no related allowance recorded	0	0	0	0
Impaired Loans, Average Recorded Investment, With an allowance recorded	0	0	0	0
Impaired Loans, Interest Income Recognized, With an allowance recorded	0	0	0	0
Impaired Loans, Average Recorded Investment	0	0	0	0
Impaired Loans, Interest Income Recognized	0	0	0	0
Consumer [Member] | Other Consumer [Member]
Financing Receivable, Impaired [Line Items]
Impaired Loans, Recorded Investment, With no related allowance recorded	39		39		41
Impaired Loans, Unpaid Principal Balance, With no related allowance recorded	39		39		41
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	39		39		41
Impaired Loans, Unpaid Principal Balance	39		39		41
Impaired Loans, Related Allowance	0		0		$ 0
Impaired Loans, Average Recorded Investment, With no related allowance recorded	35	55	36	45
Impaired Loans, Interest Income Recognized, With no related allowance recorded	0	0	0	0
Impaired Loans, Average Recorded Investment, With an allowance recorded	0	76	0	102
Impaired Loans, Interest Income Recognized, With an allowance recorded	0	0	0	0
Impaired Loans, Average Recorded Investment	35	131	36	147
Impaired Loans, Interest Income Recognized	$ 0	$ 0	$ 0	$ 0

Allowance for Credit Losses - A

Allowance for Credit Losses - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Specific loss allocations are calculated for loans in excess			$ 500
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	$ 267	$ 381	$ 4,299	$ 727
Reserve for lending-related commitments	$ 1,178		$ 1,178		$ 1,518
Closed-End Retail Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of days delinquent from contractual due date			120 days
Open-End Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of days delinquent from contractual due date			180 days

Allowance for Credit Losses - S

Allowance for Credit Losses - Schedule of Allowance for Loan Losses and Carrying Amount of Loans (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	$ 75,215		$ 75,529	$ 74,198	$ 74,198
Charge-offs	5,407		18,142		25,241
Recoveries	490		1,841		4,635
Provision	5,182	$ 4,748	16,252	15,628	21,937
Allowance for Loan Losses Ending balance	75,480		75,480		75,529
Allowance for Loan Losses, individually evaluated for impairment	22,686		22,686		14,946
Allowance for Loan Losses, collectively evaluated for impairment	52,794		52,794		60,583
Financing receivables	9,187,949		9,187,949		9,119,492
Financing receivables, individually evaluated for impairment	98,025		98,025		87,450
Financing receivables, collectively evaluated for impairment	8,935,744		8,935,744		8,855,703
Loans Acquired with Deteriorated Credit Quality [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses	0		0		0
Financing receivables	154,180		154,180		176,339
Construction & Land Development [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	16,975		19,402	18,953	18,953
Charge-offs	54		825		7,476
Recoveries	64		451		685
Provision	(1,190)		(3,233)		7,240
Allowance for Loan Losses Ending balance	15,795		15,795		19,402
Allowance for Loan Losses, individually evaluated for impairment	4,468		4,468		3,627
Allowance for Loan Losses, collectively evaluated for impairment	11,327		11,327		15,775
Financing receivables	1,125,908		1,125,908		1,133,251
Financing receivables, individually evaluated for impairment	17,010		17,010		17,168
Financing receivables, collectively evaluated for impairment	1,071,684		1,071,684		1,071,966
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	37,214		37,214		44,117
Allowance for Estimated Imprecision [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	132		70	44	44
Charge-offs	0		0		0
Recoveries	0		0		0
Provision	(43)		19		26
Allowance for Loan Losses Ending balance	89		89		70
Allowance for Loan Losses, individually evaluated for impairment	0		0		0
Allowance for Loan Losses, collectively evaluated for impairment	89		89		70
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	4,247		4,041	5,653	5,653
Charge-offs	175		4,303		3,073
Recoveries	129		249		2,372
Provision	158		4,372		(911)
Allowance for Loan Losses Ending balance	4,359		4,359		4,041
Allowance for Loan Losses, individually evaluated for impairment	1,194		1,194		776
Allowance for Loan Losses, collectively evaluated for impairment	3,165		3,165		3,265
Financing receivables	942,302		942,302		1,016,364
Financing receivables, individually evaluated for impairment	12,753		12,753		12,869
Financing receivables, collectively evaluated for impairment	902,958		902,958		971,408
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	26,591		26,591		32,087
Commercial Real Estate [Member] | Nonowner-Occupied [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	7,296		8,167	8,992	8,992
Charge-offs	28		355		2,097
Recoveries	15		53		268
Provision	(255)		(837)		1,004
Allowance for Loan Losses Ending balance	7,028		7,028		8,167
Allowance for Loan Losses, individually evaluated for impairment	1,339		1,339		797
Allowance for Loan Losses, collectively evaluated for impairment	5,689		5,689		7,370
Financing receivables	2,842,158		2,842,158		2,760,189
Financing receivables, individually evaluated for impairment	28,385		28,385		13,733
Financing receivables, collectively evaluated for impairment	2,760,084		2,760,084		2,692,374
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	53,689		53,689		54,082
Other Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	28,476		26,931	20,917	20,917
Charge-offs	3,889		7,941		4,947
Recoveries	101		297		294
Provision	6,736		12,137		10,667
Allowance for Loan Losses Ending balance	31,424		31,424		26,931
Allowance for Loan Losses, individually evaluated for impairment	12,394		12,394		7,168
Allowance for Loan Losses, collectively evaluated for impairment	19,030		19,030		19,763
Financing receivables	1,609,331		1,609,331		1,577,438
Financing receivables, individually evaluated for impairment	25,136		25,136		27,491
Financing receivables, collectively evaluated for impairment	1,564,569		1,564,569		1,523,504
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	19,626		19,626		26,443
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	14,920		13,835	16,694	16,694
Charge-offs	756		2,888		5,027
Recoveries	76		347		573
Provision	(1,041)		1,905		1,595
Allowance for Loan Losses Ending balance	13,199		13,199		13,835
Allowance for Loan Losses, individually evaluated for impairment	3,291		3,291		2,578
Allowance for Loan Losses, collectively evaluated for impairment	9,908		9,908		11,257
Financing receivables	2,252,530		2,252,530		2,263,354
Financing receivables, individually evaluated for impairment	14,741		14,741		16,189
Financing receivables, collectively evaluated for impairment	2,220,777		2,220,777		2,227,605
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	17,012		17,012		19,560
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses Beginning balance	3,169		3,083	$ 2,945	2,945
Charge-offs	505		1,830		2,621
Recoveries	105		444		443
Provision	817		1,889		2,316
Allowance for Loan Losses Ending balance	3,586		3,586		3,083
Allowance for Loan Losses, individually evaluated for impairment	0		0		0
Allowance for Loan Losses, collectively evaluated for impairment	3,586		3,586		3,083
Financing receivables	415,720		415,720		368,896
Financing receivables, individually evaluated for impairment	0		0		0
Financing receivables, collectively evaluated for impairment	415,672		415,672		368,846
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	$ 48		$ 48		$ 50

Intangible Assets - Summary of

Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Goodwill not subject to amortization	$ 710,252	$ 709,794
Core Deposit Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	60,577	60,577
Accumulated Amortization	(41,882)	(39,317)
Net Carrying Amount	$ 18,695	$ 21,260

Intangible Assets - Additional

Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Intangible Liability Disclosure [Abstract]
Amortization expense	$ 855	$ 1,054	$ 2,565	$ 2,967

Intangible Assets - Schedule of

Intangible Assets - Schedule of Anticipated Amortization Expense (Detail) $ in Thousands	Sep. 30, 2015USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2,015	$ 3,420
2,016	2,981
2,017	2,767
2,018	2,574
2019 and thereafter	$ 9,518

Short-Term Borrowings - Additio

Short-Term Borrowings - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Short-term Debt [Line Items]
Unused lines of credit	$ 254,000,000
Federal funds purchased	32,250,000	$ 53,840,000
Repurchase agreements	290,461,000
Wholesale REPO	$ 51,233,000
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)	3 Months Ended	9 Months Ended
	Dec. 31, 2014USD ($)	Sep. 30, 2015USD ($)Trust	Dec. 31, 2009USD ($)
Debt Instrument [Line Items]
Unused borrowing amount		$ 2,559,566,000
FHLB advances	$ 830,335,000	$ 664,880,000
FHLB advances, weighted-average interest rate		0.43%
FHLB advances, maximum maturity period		4 years
Overnight funds		$ 0
Number of statutory business trusts | Trust		13
Outstanding balances of debentures	222,636,000	$ 223,288,000
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]
Tier 1 risk based assets			$ 15,000,000,000
Sequoia Trust I [Member]
Debt Instrument [Line Items]
Junior subordinate debenture, issued	$ 2,000,000
Percentage of junior subordinate debenture, issued	10.18%
VCBI Capital Trust IV [Member]
Debt Instrument [Line Items]
Junior subordinate debenture, issued	$ 25,000,000
Percentage of junior subordinate debenture, issued	10.20%
Capital Securities [Member]
Debt Instrument [Line Items]
Number of statutory business trusts | Trust		13

Long-Term Borrowings - Schedule

Long-Term Borrowings - Schedule of Maturities of FHLB Borrowings (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Federal Home Loan Bank, Advances, Fiscal Year Maturity [Abstract]
2,015	$ 628,975
2,016	618
2,017	287
2,018	0
2019 and thereafter	35,000
Total	$ 664,880	$ 830,335

Commitments and Contingent Li75

Commitments and Contingent Liabilities - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Loss Contingencies [Line Items]
Loan commitments outstanding	$ 2,556,542	$ 2,763,129
Loan commitments expiry period	1 year
Commercial Letters of Credit [Member]
Loss Contingencies [Line Items]
Letters of credit issued	$ 226	216
Standby Letters of Credit [Member]
Loss Contingencies [Line Items]
Letters of credit issued	$ 144,698	$ 160,230

Derivative Financial Instrume76

Derivative Financial Instruments - Schedule of Derivative Instruments (Detail)	9 Months Ended
	Sep. 30, 2015USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Total Derivatives Used for Interest Rate Risk Management and Designated as Hedges	$ 36,481,000
Average Pay Rate	3.44%
Fair Value Hedging [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount, Pay Fixed Swap (Hedging Commercial Loans)	$ 36,481,000
Cash Flow Hedging [Member] | Interest Rate Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional Amount, Pay Fixed Swap (Hedging Commercial Loans)	$ 36,481,000

Derivative Financial Instrume77

Derivative Financial Instruments - Schedule of Fair Value Derivative Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Derivative [Line Items]
Asset derivatives designated as hedging instruments	$ 0	$ 90
Asset derivatives not designated as hedging instruments	3,259	3,704
Total asset derivatives	3,259	3,794
Liability derivatives designated as hedging instruments	1,196	432
Liability derivatives not designated as hedging instruments	3,257	3,704
Total liability derivatives	4,453	4,136
Interest Rate Contracts [Member] | Other Assets [Member]
Derivative [Line Items]
Asset derivatives designated as hedging instruments	0	90
Asset derivatives not designated as hedging instruments	3,259	3,704
Interest Rate Contracts [Member] | Other Liabilities [Member]
Derivative [Line Items]
Liability derivatives designated as hedging instruments	1,196	432
Liability derivatives not designated as hedging instruments	$ 3,257	$ 3,704

Derivative Financial Instrume78

Derivative Financial Instruments - Schedule of Derivative Financial Instruments on Statement of Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Interest Rate Contracts [Member]
Derivative [Line Items]
Derivatives in fair value hedging relationships	$ (329)	$ (271)	$ (658)	$ (795)
Interest Income/ (Expense) [Member]
Derivative [Line Items]
Derivatives in fair value hedging relationships	(332)	(271)	(661)	(795)
Interest Income/ (Expense) [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Derivatives in fair value hedging relationships	(332)	(271)	(661)	(795)
Other Income [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, loss	3	0	3	0
Derivative instruments not designated as hedging instruments, net	$ 3	$ 0	$ 3	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Discount rates utilized, minimum	3.75%	3.75%
Discount rates utilized, maximum	10.75%	10.75%
Amount of decrease in fair value of securities		$ 6,284,000
Nonrecurring fair value adjustments on loans held for sale	$ 0
Fair value measurement of intangible assets	$ 0	$ 0	$ 0
Trust Preferred Collateralized Debt Obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Decrease in fair value of securities		18.00%
Increase in discount rates, basis point	2.00%	2.00%

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Financial Assets and Liabilities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	$ 4,442	$ 4,276
Total available for sale securities	1,107,410	1,180,386
Derivative financial assets	3,259	3,794
Derivative financial liabilities	4,453	4,136
Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	1,102,968	1,176,110
Available for sale equity securities	4,442	4,276
Total available for sale securities	1,107,410	1,180,386
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	81,778	89,981
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	81,778	89,981
State and Political Subdivisions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	139,955	136,863
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	139,955	136,863
Residential Mortgage-Backed Securities, Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	499,670	555,685
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	499,670	555,685
Residential Mortgage-Backed Securities, Non-agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	10,111	12,018
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	10,111	12,018
Asset-Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	4,265	8,027
Asset-Backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	4,265	8,027
Commercial Mortgage-Backed Securities, Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	314,178	317,099
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	314,178	317,099
Trust Preferred Collateralized Debt Obligations [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	35,711	39,558
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	35,711	39,558
Single Issue Trust Preferred Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	12,228	11,744
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	12,228	11,744
Other Corporate Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	5,072	5,135
Other Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	5,072	5,135
Financial Services Industry [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	2,520	2,533
Other Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	1,103	1,183
Interest Rate Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets	3,259	3,794
Derivative financial liabilities	4,453	4,136
Equity Mutual Funds [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	819	560
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	2,720	2,502
Derivative financial assets	0	0
Derivative financial liabilities	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	0	0
Available for sale equity securities	2,720	2,502
Total available for sale securities	2,720	2,502
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	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] | Other Corporate 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] | Financial Services Industry [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale equity securities	798	759
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	1,103	1,183
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Interest Rate Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets	0	0
Derivative financial liabilities	0	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	819	560
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total available for sale securities	1,068,979	1,138,326
Derivative financial assets	3,259	3,794
Derivative financial liabilities	4,453	4,136
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	1,067,257	1,136,552
Available for sale equity securities	1,722	1,774
Total available for sale securities	1,068,979	1,138,326
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	81,778	89,981
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	139,955	136,863
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	499,670	555,685
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	10,111	12,018
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	4,265	8,027
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	314,178	317,099
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	12,228	11,744
Significant Other Observable Inputs (Level 2) [Member] | Other Corporate Securities [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available for sale debt securities	5,072	5,135
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	1,722	1,774
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 Contracts [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative financial assets	3,259	3,794
Derivative financial liabilities	4,453	4,136
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	35,711	39,558
Derivative financial assets	0	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	35,711	39,558
Available for sale equity securities	0	0
Total available for sale securities	35,711	39,558
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	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	35,711	39,558
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] | Other Corporate 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] | 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 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] | 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 - Sch81

Fair Value Measurements - Schedule of Additional Information about Financial Assets and Liabilities Measured at Fair Value Utilized Level 3 (Detail) - Trust Preferred Collateralized Debt Obligations [Member] - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Balance, beginning of period	$ 39,558	$ 43,449
Included in earnings (or changes in net assets)	(34)	(4,034)
Included in other comprehensive income	(3,813)	12,312
Purchases, issuances, and settlements	0	(12,169)
Transfers in and/or out of Level 3	0	0
Balance, end of period	35,711	39,558
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 - Summa

Fair Value Measurements - Summary of Financial Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
YTD Losses, Impaired Loans	$ 6,911	$ 7,349
YTD Losses, OREO	721	3,307
Impaired Loans	53,622	46,369
OREO	34,119	38,778
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	13,315	8,518
OREO	34,119	38,778
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impaired Loans	40,307	37,851
OREO	$ 0	$ 0

Fair Value Measurements - Sum83

Fair Value Measurements - Summary of Estimated Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 1,008,458	$ 753,064
Securities available for sale	1,107,410	1,180,386
Securities held to maturity	38,795	39,310
Other securities	90,387	96,344
Loans held for sale	11,602	8,680
Loans	9,173,657	9,104,652
Derivative financial assets	3,259	3,794
Deposits	9,504,896	9,045,485
Derivative financial liabilities	4,453	4,136
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1,008,458	753,064
Securities available for sale	1,107,410	1,180,386
Securities held to maturity	38,795	39,310
Other securities	90,387	96,344
Loans held for sale	11,602	8,680
Loans	9,098,177	9,029,123
Derivative financial assets	3,259	3,794
Deposits	9,504,896	9,045,485
Short-term borrowings	322,711	435,652
Long-term borrowings	939,401	1,105,314
Derivative financial liabilities	4,453	4,136
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1,008,458	753,064
Securities available for sale	1,107,410	1,180,386
Securities held to maturity	36,232	36,784
Other securities	85,867	91,527
Loans held for sale	11,602	8,680
Loans	9,101,220	9,055,281
Derivative financial assets	3,259	3,794
Deposits	9,494,045	9,044,976
Short-term borrowings	322,711	435,652
Long-term borrowings	912,648	1,081,133
Derivative financial liabilities	4,453	4,136
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	2,720	2,502
Securities held to maturity	0	0
Other securities	0	0
Loans held for sale	0	0
Loans	0	0
Derivative financial assets	0	0
Deposits	0	0
Short-term borrowings	0	0
Long-term borrowings	0	0
Derivative financial liabilities	0	0
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	1,008,458	753,064
Securities available for sale	1,068,979	1,138,326
Securities held to maturity	34,212	34,764
Other securities	0	0
Loans held for sale	11,602	8,680
Loans	0	0
Derivative financial assets	3,259	3,794
Deposits	9,494,045	9,044,976
Short-term borrowings	322,711	435,652
Long-term borrowings	912,648	1,081,133
Derivative financial liabilities	4,453	4,136
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	35,711	39,558
Securities held to maturity	2,020	2,020
Other securities	85,867	91,527
Loans held for sale	0	0
Loans	9,101,220	9,055,281
Derivative financial assets	0	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. 16, 2011	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized shares of stock, option plan, maximum	1,500,000
Aggregate number of shares issued in respect of restricted stock awards	350,000
Options available for award each plan year	1,150,000
Maximum number of shares of restricted stock or shares subject to a restricted stock units award granted				50,000
Maximum number of options and stock appreciation rights				100,000
Percentage of restricted stock and restricted stock units vest				25.00%
Vesting period of awards				1/3 per year
Recognition of compensation expense		$ 756	$ 433	$ 2,144	$ 1,593
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				215,967	368,856
Total intrinsic value of options exercised				$ 1,908	$ 3,977
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Granted				53,071
Vesting period				4 years
Non-qualified Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares, Granted				189,705
Treasury Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued related stock option exercises					342,382
Authorized and Unissued Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued related stock option exercises					26,474

Stock Based Compensation - Summ

Stock Based Compensation - Summary of Stock Option Plans (Detail) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares, Outstanding, Beginning balance	1,380,548
Shares, Granted	189,705
Shares, Exercised	(215,967)	(368,856)
Shares, Forfeited or expired	(13,361)
Shares, Outstanding, Ending balance	1,340,925
Shares, Exercisable at September 30, 2015	905,842
Aggregate Intrinsic Value, Outstanding at September 30, 2015	$ 12,389
Aggregate Intrinsic Value, Exercisable at September 30, 2015	$ 9,741
Weighted Average Remaining Contractual Term, Outstanding at September 30, 2015	5 years 10 months 24 days
Weighted Average Remaining Contractual Term, Exercisable at September 30, 2015	4 years 7 months 6 days
Weighted Average Exercise Price, Outstanding, Beginning balance	$ 27.94
Weighted Average Exercise Price, Granted	36.92
Weighted Average Exercise Price, Exercised	30.14
Weighted Average Exercise Price, Forfeited or expired	32.22
Weighted Average Exercise Price, Outstanding, Ending balance	28.75
Weighted Average Exercise Price, Exercisable	$ 27.24

Stock Based Compensation - Stat

Stock Based Compensation - Status of United's Nonvested Stock Option Awards (Detail)	9 Months Ended
	Sep. 30, 2015$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares, Nonvested, Beginning balance	377,264
Shares, Granted	189,705
Shares, Vested	(121,673)
Shares, Forfeited or expired	(10,213)
Shares, Nonvested, Ending balance	435,083
Weighted-Average Grant Date Fair Value Per Share, Nonvested Beginning balance | $ / shares	$ 6.29
Weighted-Average Grant Date Fair Value Per Share, Granted | $ / shares	7.23
Weighted-Average Grant Date Fair Value Per Share, Vested | $ / shares	6.33
Weighted-Average Grant Date Fair Value Per Share, Forfeited or expired | $ / shares	6.58
Weighted-Average Grant Date Fair Value Per Share, Nonvested Ending balance | $ / shares	$ 6.68

Stock Based Compensation - Chan

Stock Based Compensation - Changes to United's Restricted Common Shares (Detail) - Restricted Stock [Member]	9 Months Ended
	Sep. 30, 2015$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Outstanding, Beginning balance	120,308
Shares, Granted	53,071
Shares, Vested	(38,041)
Shares, Forfeited	(2,861)
Number of Shares, Outstanding, Ending balance	132,477
Weighted-Average Grant Date Fair Value Per Share, Outstanding, Beginning balance | $ / shares	$ 28.29
Weighted-Average Grant Date Fair Value Per Share, Granted | $ / shares	36.92
Weighted-Average Grant Date Fair Value Per Share, Vested | $ / shares	28.31
Weighted-Average Grant Date Fair Value Per Share, Forfeited | $ / shares	30.69
Weighted-Average Grant Date Fair Value Per Share, Outstanding, Ending balance | $ / shares	$ 31.69

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Compensation and Retirement Disclosure [Abstract]
Unrecognized prior service costs, before tax	$ 1
Unrecognized prior service costs, net of tax	1
Unrecognized actuarial gains (losses), before tax	58,576
Unrecognized actuarial gains (losses), net of tax	38,074
Future Amortization of Prior Service Cost, before tax	1
Future Amortization of Prior Service Cost, net of tax	1
Unrecognized actuarial gains (losses), before tax	4,900
Unrecognized actuarial gains (losses), net of tax	$ 3,185

Employee Benefit Plans - Net Pe

Employee Benefit Plans - Net Periodic Pension Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 756	$ 579	$ 2,244	$ 1,720
Interest cost	1,462	1,361	4,338	4,039
Expected return on plan assets	(2,344)	(2,293)	(6,956)	(6,806)
Amortization of transition asset	0	0	0	0
Recognized net actuarial loss	1,235	491	3,665	1,458
Amortization of prior service cost	1	1	1	1
Net periodic pension (benefit) cost	$ 1,110	$ 139	$ 3,292	$ 412
Weighted-Average Assumptions:
Discount rate	4.35%	5.20%	4.35%	5.20%
Expected return on assets	7.50%	7.50%	7.50%	7.50%
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	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Liability of unrecognized tax benefits	$ 2,431
Estimate of unrecognized tax benefits, reasonable possible	United cannot reasonably estimate the amount of tax benefits it may recognize over the next 12 months.
Accrued interest related to uncertain tax positions	$ 548	$ 540

Comprehensive Income - Componen

Comprehensive Income - Components of Total Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net income	$ 35,047	$ 33,260	$ 104,483	$ 96,631
Available for sale ("AFS") securities:
AFS securities with OTTI charges during the period	0	(4,714)	(100)	(5,774)
Related income tax effect	0	1,650	36	2,021
Income tax rate change	0	0	316	0
Less: OTTI charges recognized in net income	0	4,714	34	5,774
Related income tax benefit	0	(1,650)	(12)	(2,021)
Reclassification of previous noncredit OTTI to credit OTTI	0	4,153	0	6,259
Related income tax benefit	0	(1,453)	0	(2,190)
Net unrealized (losses) gains on AFS securities with OTTI	0	2,700	274	4,069
AFS securities - all other:
Change in net unrealized gain on AFS securities arising during the period	8,635	(339)	7,053	24,242
Related income tax effect	(3,126)	119	(2,553)	(8,485)
Net reclassification adjustment for (gains) losses included in net income	(42)	(1,300)	(91)	(2,125)
Related income tax expense (benefit)	15	455	33	744
Total AFS securities - all other	5,482	(1,065)	4,442	14,376
Net effect of AFS securities on other comprehensive income	5,482	1,635	4,716	18,445
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	1	2	6	6
Related income tax expense	0	0	(2)	(2)
Net effect of HTM securities on other comprehensive income	1	2	4	4
Pension plan:
Amortization of prior service cost	1	1	1	1
Related income tax benefit	0	0	0	0
Recognized net actuarial loss	1,235	491	3,665	1,458
Related income tax benefit	(468)	(183)	(1,362)	(531)
Net effect of change in pension plan asset on other comprehensive income	768	309	2,304	928
Net current-period other comprehensive income, net of tax	6,251	1,946	7,024	19,377
Total Comprehensive Income	$ 41,298	$ 35,206	$ 111,507	$ 116,008

Comprehensive Income - Compon92

Comprehensive Income - Components of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at January 1, 2015			$ 1,656,160
Net current-period other comprehensive income, net of tax	$ 6,251	$ 1,946	7,024	$ 19,377
Balance at September 30, 2015	1,709,841		1,709,841
Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at January 1, 2015			(37,255)
Other comprehensive income before reclassification			0
Amounts reclassified from accumulated other comprehensive income			2,304
Net current-period other comprehensive income, net of tax			2,304
Balance at September 30, 2015	(34,951)		(34,951)
Unrealized Gains/Losses on AFS Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at January 1, 2015			1,553
Other comprehensive income before reclassification			4,774
Amounts reclassified from accumulated other comprehensive income			(58)
Net current-period other comprehensive income, net of tax			4,716
Balance at September 30, 2015	6,269		6,269
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, 2015			(62)
Other comprehensive income before reclassification			4
Amounts reclassified from accumulated other comprehensive income			0
Net current-period other comprehensive income, net of tax			4
Balance at September 30, 2015	(58)		(58)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at January 1, 2015			(35,764)
Other comprehensive income before reclassification			4,778
Amounts reclassified from accumulated other comprehensive income			2,246
Net current-period other comprehensive income, net of tax			7,024
Balance at September 30, 2015	$ (28,740)		$ (28,740)

Comprehensive Income - Reclassi

Comprehensive Income - Reclassifications Out of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Available for sale ("AFS") securities:
Reclassification of previous noncredit OTTI to credit OTTI	$ 0	$ (561)	$ (100)	$ 485
Net reclassification adjustment for losses (gains) included in net income	111	1,309	160	2,134
Income before income taxes	51,264	49,642	153,149	145,248
Related income tax effect	(16,217)	(16,382)	(48,666)	(48,617)
Net earnings allocated to common shareholders	35,047	33,260	104,483	96,631
Pension plan:
Amortization of transition asset	1	1	1	1
Recognized net actuarial loss	1,235	491	3,665	1,458
Income before income taxes	51,264	49,642	153,149	145,248
Related income tax effect	(16,217)	(16,382)	(48,666)	(48,617)
Net earnings allocated to common shareholders	$ 35,047	$ 33,260	104,483	$ 96,631
Reclassification out of Accumulated Other Comprehensive Income [Member]
Available for sale ("AFS") securities:
Net earnings allocated to common shareholders			2,246
Pension plan:
Net earnings allocated to common shareholders			2,246
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			(91)
Income before income taxes			(91)
Related income tax effect			33
Net earnings allocated to common shareholders			(58)
Pension plan:
Income before income taxes			(91)
Related income tax effect			33
Net earnings allocated to common shareholders			(58)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Available for sale ("AFS") securities:
Income before income taxes			3,666
Related income tax effect			(1,362)
Net earnings allocated to common shareholders			2,304
Pension plan:
Amortization of transition asset			1
Recognized net actuarial loss			3,665
Income before income taxes			3,666
Related income tax effect			(1,362)
Net earnings allocated to common shareholders			$ 2,304

Earnings Per Share - Reconcilia

Earnings Per Share - Reconciliation of Numerator and Denominator of Basic Earnings Per Share with that of Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Distributed earnings allocated to common stock	$ 22,216	$ 22,101	$ 66,572	$ 66,261
Undistributed earnings allocated to common stock	12,768	11,102	37,725	30,194
Net earnings allocated to common shareholders	$ 34,984	$ 33,203	$ 104,297	$ 96,455
Average common shares outstanding	69,391,401	69,044,876	69,302,180	66,836,396
Equivalents from stock options	298,322	224,433	284,107	232,956
Average diluted shares outstanding	69,689,723	69,269,309	69,586,287	67,069,352
Earnings per basic common share	$ 0.50	$ 0.48	$ 1.51	$ 1.45
Earnings per diluted common share	$ 0.50	$ 0.48	$ 1.50	$ 1.44

Variable Interest Entities - Ad

Variable Interest Entities - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2015Trust
Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract]
Number of statutory business trusts	13
Percentage of equity shares of each trust owned by the company	100.00%

Variable Interest Entities - Sc

Variable Interest Entities - Schedule of Trust Preferred Securities Redemption (Detail) $ in Thousands	3 Months Ended
	Dec. 31, 2014USD ($)
Sequoia Capital Trust I [Member]
Debt Instrument, Redemption [Line Items]
Interest Rate	10.18%
Redemption Price	103.563%
Principal Amount Outstanding	$ 2,000
Principal Amount to be Redeemed	$ 2,000
Redemption Date	Dec. 8, 2014
VCBI Capital Trust IV [Member]
Debt Instrument, Redemption [Line Items]
Interest Rate	10.20%
Redemption Price	100.00%
Principal Amount Outstanding	$ 25,000
Principal Amount to be Redeemed	$ 25,000
Redemption Date	Dec. 30, 2014

Variable Interest Entities - In

Variable Interest Entities - Information Related to Statutory Trusts (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
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

Variable Interest Entities - Su

Variable Interest Entities - Summary of Quantitative Information Related to Significant Involvement in Unconsolidated Variable Interest Entities (Detail) - Trust Preferred Securities [Member] - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Aggregate Assets	$ 240,346	$ 241,147
Aggregate Liabilities	232,393	233,222
Risk Of Loss	$ 7,953	$ 7,925