WesBanco (WSBC) 10-Q 30 Oct 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 23, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Trading Symbol	WSBC
Entity Registrant Name	WESBANCO INC
Entity Central Index Key	203,596
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		44,033,267

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
ASSETS
Cash and due from banks, including interest bearing amounts of $14,704 and $21,913, respectively	$ 110,871	$ 128,170
Securities:
Trading securities, at fair value	7,929	7,071
Available-for-sale, at fair value	1,305,532	1,241,176
Held-to-maturity (fair values of $1,044,748 and $1,076,790, respectively)	1,025,688	1,067,967
Total securities	2,339,149	2,316,214
Loans held for sale	26,888	17,315
Portfolio loans, net of unearned income	6,373,049	6,249,436
Allowance for loan losses	(45,487)	(43,674)
Net portfolio loans	6,327,562	6,205,762
Premises and equipment, net	133,497	133,297
Accrued interest receivable	30,152	28,299
Goodwill and other intangible assets, net	590,249	593,187
Bank-owned life insurance	191,466	188,145
Other assets	168,443	180,488
Total Assets	9,918,277	9,790,877
Deposits:
Non-interest bearing demand	1,851,167	1,789,522
Interest bearing demand	1,666,117	1,546,890
Money market	990,788	995,477
Savings deposits	1,258,887	1,213,168
Certificates of deposit	1,334,066	1,495,822
Total deposits	7,101,025	7,040,879
Federal Home Loan Bank borrowings	1,015,011	968,946
Other short-term borrowings	165,576	199,376
Subordinated debt and junior subordinated debt	164,278	163,598
Total borrowings	1,344,865	1,331,920
Accrued interest payable	3,924	2,204
Other liabilities	73,905	74,466
Total Liabilities	8,523,719	8,449,469
SHAREHOLDERS' EQUITY
Preferred stock, no par value; 1,000,000 shares authorized; none outstanding
Common stock, $2.0833 par value; 100,000,000 shares authorized in 2017 and 2016, respectively; 44,041,572 and 43,931,715 shares issued, respectively; 44,033,585 and 43,931,715 shares outstanding, respectively	91,753	91,524
Capital surplus	683,348	680,507
Retained earnings	641,329	597,071
Treasury stock (7,987 and 0 shares in 2017 and 2016, respectively, at cost)	(300)
Accumulated other comprehensive loss	(20,837)	(27,126)
Deferred benefits for directors	(735)	(568)
Total Shareholders' Equity	1,394,558	1,341,408
Total Liabilities and Shareholders' Equity	$ 9,918,277	$ 9,790,877

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Interest bearing deposits, banks	$ 14,704	$ 21,913
Held-to-maturity securities, fair values	$ 1,044,748	$ 1,076,790
Preferred stock, no par value
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 2.0833	$ 2.0833
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	44,041,572	43,931,715
Common stock, shares outstanding	44,033,585	43,931,715
Treasury stock, shares	7,987	0

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
INTEREST AND DIVIDEND INCOME
Loans, including fees	$ 70,342	$ 55,822	$ 202,600	$ 160,858
Interest and dividends on securities:
Taxable	9,711	9,137	28,682	29,129
Tax-exempt	4,862	4,559	14,617	13,620
Total interest and dividends on securities	14,573	13,696	43,299	42,749
Other interest income	574	574	1,674	1,671
Total interest and dividend income	85,489	70,092	247,573	205,278
INTEREST EXPENSE
Interest bearing demand deposits	1,814	691	4,413	1,841
Money market deposits	751	444	1,970	1,350
Savings deposits	189	173	555	502
Certificates of deposit	2,610	2,592	7,512	7,835
Total interest expense on deposits	5,364	3,900	14,450	11,528
Federal Home Loan Bank borrowings	3,628	3,005	9,608	9,104
Other short-term borrowings	394	118	954	299
Subordinated debt and junior subordinated debt	1,849	1,043	5,449	2,706
Total interest expense	11,235	8,066	30,461	23,637
NET INTEREST INCOME	74,254	62,026	217,112	181,641
Provision for credit losses	2,516	2,214	7,610	6,350
Net interest income after provision for credit losses	71,738	59,812	209,502	175,291
NON-INTEREST INCOME
Trust fees	5,358	5,413	17,073	16,160
Service charges on deposits	5,320	4,733	15,254	12,861
Electronic banking fees	4,883	3,945	14,395	11,290
Net securities brokerage revenue	1,721	1,473	5,164	5,119
Bank-owned life insurance	1,164	995	3,671	2,910
Net gains on sales of mortgage loans	1,103	814	3,511	2,045
Net securities gains	6	598	511	2,293
Net (loss)/gain on other real estate owned and other assets	(298)	184	9	380
Other income	1,642	2,862	6,318	6,943
Total non-interest income	20,899	21,017	65,906	60,001
NON-INTEREST EXPENSE
Salaries and wages	24,957	21,225	71,575	60,136
Employee benefits	7,728	6,275	23,670	20,684
Net occupancy	4,132	3,647	12,969	10,459
Equipment	3,905	3,557	12,043	10,387
Marketing	1,599	1,295	4,482	3,876
FDIC insurance	945	961	2,677	3,225
Amortization of intangible assets	1,223	837	3,736	2,263
Restructuring and merger-related expense		9,883	491	10,577
Other operating expenses	11,265	9,921	34,380	28,696
Total non-interest expense	55,754	57,601	166,023	150,303
Income before provision for income taxes	36,883	23,228	109,385	84,989
Provision for income taxes	10,527	5,793	30,801	22,572
NET INCOME	$ 26,356	$ 17,435	$ 78,584	$ 62,417
EARNINGS PER COMMON SHARE
Basic	$ 0.60	$ 0.44	$ 1.79	$ 1.61
Diluted	$ 0.60	$ 0.44	$ 1.78	$ 1.61
AVERAGE COMMON SHARES OUTSTANDING
Basic	44,031,813	39,715,516	43,992,017	38,828,618
Diluted	44,086,881	39,743,291	44,059,469	38,855,453
DIVIDENDS DECLARED PER COMMON SHARE	$ 0.26	$ 0.24	$ 0.78	$ 0.72
COMPREHENSIVE INCOME	$ 27,637	$ 15,470	$ 84,873	$ 78,309

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Deferred Benefits for Directors [Member]
Beginning Balance at Dec. 31, 2015	$ 1,122,132	$ 80,304	$ 516,294	$ 549,921	$ (2,640)	$ (20,954)	$ (793)
Beginning Balance, shares at Dec. 31, 2015		38,459,635
Net income	62,417			62,417
Other comprehensive income	15,892					15,892
Comprehensive income	78,309
Common dividends declared ($0.78 and $0.72 per share in September 30, 2017 and 2016 respectively)	(28,946)			(28,946)
Shares issued for acquisition	177,149	$ 11,071	162,934		3,144
Shares issued for acquisition, shares		5,423,348
Treasury shares acquired	(3,674)		56		(3,730)
Treasury shares acquired, shares		(130,041)
Stock options exercised	792	$ 2	(165)		955
Stock options exercised, shares		31,541
Issuance of restricted stock			(2,271)		2,271
Issuance of restricted stock, shares		76,400
Stock compensation expense	1,389		1,389
Deferred benefits for directors- net			(230)				230
Ending Balance at Sep. 30, 2016	1,347,151	$ 91,377	678,007	583,392		(5,062)	(563)
Ending Balance, shares at Sep. 30, 2016		43,860,883
Beginning Balance at Dec. 31, 2016	1,341,408	$ 91,524	680,507	597,071		(27,126)	(568)
Beginning Balance, shares at Dec. 31, 2016		43,931,715
Net income	78,584			78,584
Other comprehensive income	6,289					6,289
Comprehensive income	84,873
Common dividends declared ($0.78 and $0.72 per share in September 30, 2017 and 2016 respectively)	(34,326)			(34,326)
Treasury shares acquired	(488)				(488)
Treasury shares acquired, shares		(12,987)
Stock options exercised	1,121	$ 75	858		188
Stock options exercised, shares		40,834
Issuance of restricted stock		$ 154	(154)
Issuance of restricted stock, shares		74,023
Stock compensation expense	1,970		1,970
Deferred benefits for directors- net			167				(167)
Ending Balance at Sep. 30, 2017	$ 1,394,558	$ 91,753	$ 683,348	$ 641,329	$ (300)	$ (20,837)	$ (735)
Ending Balance, shares at Sep. 30, 2017		44,033,585

Consolidated Statements of Cha6

Consolidated Statements of Changes in Shareholders' Equity (Parenthetical) - $ / shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Common dividends declared, per share	$ 0.78	$ 0.72
Retained Earnings [Member]
Common dividends declared, per share	$ 0.78	$ 0.72

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Statement of Cash Flows [Abstract]
NET CASH PROVIDED BY OPERATING ACTIVITIES	$ 93,506	$ 89,175
INVESTING ACTIVITIES
Net increase in loans held for investment	(122,332)	(160,654)
Securities available-for-sale:
Proceeds from sales	7,760	277,225
Proceeds from maturities, prepayments and calls	156,944	214,786
Purchases of securities	(225,404)	(171,169)
Securities held-to-maturity:
Proceeds from maturities, prepayments and calls	90,457	72,859
Purchases of securities	(53,251)	(34,530)
Proceeds from bank-owned life insurance	349	19
Cash received to acquire a business, net		4,863
Purchases of premises and equipment - net	(6,223)	(3,894)
Net cash (used in) provided by investing activities	(151,700)	199,505
FINANCING ACTIVITIES
Increase (decrease) in deposits	61,389	(123,708)
Proceeds from Federal Home Loan Bank borrowings	560,000
Repayment of Federal Home Loan Bank borrowings	(513,911)	(112,116)
Increase in other short-term borrowings	20,200	6,832
Decrease in federal funds purchased	(54,000)
Dividends paid to common shareholders	(33,416)	(27,277)
Issuance of common stock	991	2
Treasury shares purchased - net	(358)	(2,966)
Net cash provided by (used in) financing activities	40,895	(259,233)
Net (decrease) increase in cash and cash equivalents	(17,299)	29,447
Cash and cash equivalents at beginning of the period	128,170	86,685
Cash and cash equivalents at end of the period	110,871	116,132
SUPPLEMENTAL DISCLOSURES
Interest paid on deposits and other borrowings	29,857	24,141
Income taxes paid	20,825	17,925
Transfers of loans to other real estate owned	$ 506	3,368
Non-cash transactions related to the YCB acquisition		$ 177,149

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 1. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of presentation — 10-Q S-X. 10-K WesBanco’s interim financial statements have been prepared following the significant accounting policies disclosed in Note 1 of the Notes to the Consolidated Financial Statements of its 2016 Annual Report on Form 10-K Recent accounting pronouncements — No. 2017-12 2017-12 In May 2017, the FASB issued ASU No. 2017-09 2017-09 In March 2017, FASB issued ASU 2017-08 In March 2017, the FASB issued ASU 2017-07 non-interest In January 2017, the FASB issued ASU 2017-04 In January 2017, the FASB issued ASU No. 2017-01, 2017-01 2017-01 In October 2016, the FASB issued ASU 2016-16 In August 2016, the FASB issued ASU 2016-15 zero-coupon In June 2016, the FASB issued ASU 2016-13 held-to-maturity available-for-sale In March 2016, the FASB issued ASU 2016-09 In March 2016, the FASB issued ASU 2016-07 In February 2016, the FASB issued ASU 2016-02 In January 2016, the FASB issued ASU 2016-01 In May 2014, the FASB issued ASU 2014-09 one-year 2016-08, 2016-10, 2016-12, In January 2014, the FASB issued ASU No. 2014-01,

Mergers and Acquisitions

Mergers and Acquisitions	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Mergers and Acquisitions	NOTE 2. MERGERS AND ACQUISITIONS On September 9, 2016, WesBanco completed its acquisition of Your Community Bankshares, Inc. (“YCB”), and its wholly-owned On the acquisition date, YCB had $1.5 billion in total assets, excluding goodwill, including $1.0 billion in loans and $173.2 million in securities. The YCB acquisition was valued at $220.5 million, based on WesBanco’s closing stock price on September 9, 2016 of $32.62, and resulted in WesBanco issuing 5,423,348 shares of its common stock and $43.3 million in cash in exchange for all of the outstanding shares of YCB common stock. The assets and liabilities of YCB were recorded on WesBanco’s balance sheet at their fair value as of September 9, 2016, the acquisition date, and YCB’s results of operations have been included in WesBanco’s Consolidated Statements of Income since that date. Based on the final purchase price allocation, WesBanco recorded $93.0 million in goodwill and $12.0 million in core deposit intangibles in its Community Banking segment, representing the principal change in goodwill and intangibles in 2016. None of the goodwill is deductible for income tax purposes, as the acquisition is accounted for as a tax-free For the nine months ended September 30, 2017 and for the twelve months ended December 31, 2016, WesBanco recorded merger-related expenses of $0.5 million and $13.3 million, respectively, associated with the YCB acquisition. The final purchase price of the YCB acquisition and resulting goodwill is summarized as follows: (unaudited, in thousands) September 9, 2016 Purchase Price: Fair value of WesBanco shares issued $ 177,149 Cash consideration for outstanding YCB shares 43,349 Total purchase price $ 220,498 Fair value of: Tangible assets acquired $ 1,398,183 Core deposit and other intangible assets acquired 11,957 Liabilities assumed (1,330,887 ) Net cash received in the acquisition 48,212 Fair value of net assets acquired $ 127,465 Goodwill recognized $ 93,033 The following table presents the allocation of the purchase price of the assets acquired and the liabilities assumed at the date of acquisition. (unaudited, in thousands) September 9, 2016 Assets acquired Cash and due from banks $ 48,212 Securities 173,223 Loans 1,012,410 Goodwill and other intangible assets 104,990 Accrued income and other assets (1) 212,550 Total assets acquired $ 1,551,385 Liabilities assumed Deposits $ 1,193,010 Borrowings 123,001 Accrued expenses and other liabilities 14,876 Total liabilities assumed 1,330,887 Net assets acquired $ 220,498 (1) Includes receivables of $105.8 million from the sale of available-for-sale There were no adjustments to the allocation of the purchase price of the assets acquired and the liabilities assumed during the third quarter of 2017. The following table presents the changes in the allocation of the purchase price of the assets acquired and the liabilities assumed at the date of the acquisition previously reported as of December 31, 2016: (unaudited, in thousands) September 9, 2016 Goodwill recognized as of December 31, 2016 $ 92,889 Change in fair value of net assets acquired: Assets Loans (1,156 ) Accrued income and other assets 743 Liabilities Borrowings — Accrued expenses and other liabilities 269 Fair value of net assets acquired $ (144 ) Increase in goodwill recognized 144 Goodwill recognized as of September 30, 2017 $ 93,033

Earnings Per Common Share

Earnings Per Common Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Common Share	NOTE 3. EARNINGS PER COMMON SHARE Earnings per common share are calculated as follows: (unaudited, in thousands, except shares and per share amounts) For the Three Months Ended For the Nine Months Ended 2017 2016 2017 2016 Numerator for both basic and diluted earnings per common share: Net income $ 26,356 $ 17,435 $ 78,584 $ 62,417 Denominator: Total average basic common shares outstanding 44,031,813 39,715,516 43,992,017 38,828,618 Effect of dilutive stock options and other stock compensation 55,068 27,775 67,452 26,835 Total diluted average common shares outstanding 44,086,881 39,743,291 44,059,469 38,855,453 Earnings per common share – basic $ 0.60 $ 0.44 $ 1.79 $ 1.61 Earnings per common share – diluted $ 0.60 $ 0.44 $ 1.78 $ 1.61 Options to purchase 117,550 shares and 96,600 shares at September 30, 2017 and 2016, respectively, were not included in the computation of net income per diluted share for the three months ended September 30, 2017 and 2016, respectively, because the exercise price was greater than the average market price of the common shares and, therefore, the effect would be antidilutive. All options to purchase shares were included in the nine months ended September 30, 2017 computation of net income per diluted share. Options to purchase 185,250 shares were not included in the computation of net income per diluted share for the nine months ended September 30, 2016 because the exercise price was greater than the average market price of the common shares and, therefore, the effect would be antidilutive. As of September 30, 2017, 28,502 shares of market and performance-based restricted stock were not included in the computation of net income per diluted share for the three and nine months ended September 30, 2017 because the effect would be antidilutive. There were no antidilutive shares of restricted stock excluded from the computation of net income for the three or nine months ended September 30, 2016. On September 9, 2016, WesBanco issued 5,423,348 shares of common stock (109,257 of which shares were treasury stock) to complete its acquisition of YCB. These shares are included in average shares outstanding beginning on that date. For additional information relating to the YCB acquisition, refer to Note 2, “Mergers and Acquisitions.”

Securities

Securities	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Securities	NOTE 4. SECURITIES The following table presents the fair value and amortized cost of available-for-sale held-to-maturity September 30, 2017 December 31, 2016 (unaudited, in thousands) Amortized Gross Gross Estimated Value Amortized Gross Gross Estimated Value Available-for-sale U.S. Government sponsored entities and agencies $ 72,672 $ 88 $ (441 ) $ 72,319 $ 54,803 $ 3 $ (763 ) $ 54,043 Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 974,370 776 (11,672 ) 963,474 953,475 884 (16,070 ) 938,289 Commercial mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 122,908 77 (1,151 ) 121,834 98,922 27 (2,139 ) 96,810 Obligations of states and political subdivisions 104,228 3,187 (568 ) 106,847 110,208 3,114 (1,659 ) 111,663 Corporate debt securities 35,249 325 (71 ) 35,503 35,292 117 (108 ) 35,301 Total debt securities $ 1,309,427 $ 4,453 $ (13,903 ) $ 1,299,977 $ 1,252,700 $ 4,145 $ (20,739 ) $ 1,236,106 Equity securities 4,238 1,320 (3 ) 5,555 4,062 1,032 (24 ) 5,070 Total available-for-sale $ 1,313,665 $ 5,773 $ (13,906 ) $ 1,305,532 $ 1,256,762 $ 5,177 $ (20,763 ) $ 1,241,176 Held-to-maturity U.S. Government sponsored entities and agencies $ 12,128 $ — $ (254 ) $ 11,874 $ 13,394 $ — $ (414 ) $ 12,980 Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 178,429 763 (1,467 ) 177,725 215,141 1,279 (2,563 ) 213,857 Obligations of states and political subdivisions 801,760 20,153 (1,200 ) 820,713 805,019 15,652 (5,529 ) 815,142 Corporate debt securities 33,371 1,065 — 34,436 34,413 418 (20 ) 34,811 Total held-to-maturity $ 1,025,688 $ 21,981 $ (2,921 ) $ 1,044,748 $ 1,067,967 $ 17,349 $ (8,526 ) $ 1,076,790 Total $ 2,339,353 $ 27,754 $ (16,827 ) $ 2,350,280 $ 2,324,729 $ 22,526 $ (29,289 ) $ 2,317,966 Trading securities, which consist of investments in various mutual funds held in grantor trusts formed in connection with the Company’s deferred compensation plan, are recorded at fair value and totaled $7.9 million and $7.1 million, at September 30, 2017 and December 31, 2016, respectively. At September 30, 2017 and December 31, 2016, there were no holdings of any one issuer, other than U.S. government sponsored entities and its agencies, in an amount greater than 10% of WesBanco’s shareholders’ equity. The following table presents the fair value of available-for-sale held-to-maturity September 30, 2017 One Year One to Five to After Mortgage-backed (unaudited, in thousands) or less Five Years Ten Years Ten Years and Equity Total Available-for-sale U.S. Government sponsored entities and agencies $ — $ 11,967 $ 16,855 $ 6,908 $ 36,589 $ 72,319 Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies (1) — — — — 963,474 963,474 Commercial mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies (1) — — — — 121,834 121,834 Obligations of states and political subdivisions 7,723 17,886 36,514 44,724 — 106,847 Corporate debt securities — 30,483 5,020 — — 35,503 Equity securities (2) — — — — 5,555 5,555 Total available-for-sale $ 7,723 $ 60,336 $ 58,389 $ 51,632 $ 1,127,452 $ 1,305,532 Held-to-maturity (3) U.S. Government sponsored entities and agencies $ — $ — $ — $ — $ 11,874 $ 11,874 Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies (1) — — — — 177,725 177,725 Obligations of states and political subdivisions 4,703 88,402 412,322 315,286 — 820,713 Corporate debt securities — 2,804 31,632 — — 34,436 Total held-to-maturity $ 4,703 $ 91,206 $ 443,954 $ 315,286 $ 189,599 $ 1,044,748 Total $ 12,426 $ 151,542 $ 502,343 $ 366,918 $ 1,317,051 $ 2,350,280 (1) Mortgage-backed and collateralized mortgage securities, which have prepayment provisions, are not assigned to maturity categories due to fluctuations in their prepayment speeds. (2) Equity securities, which have no stated maturity, are not assigned a maturity category. (3) The held-to-maturity Securities with aggregate fair values of $1.4 billion and $1.2 billion at September 30, 2017 and December 31, 2016, respectively, were pledged as security for public and trust funds, and securities sold under agreements to repurchase. Proceeds from the sale of available-for-sale available-for-sale The following table presents the gross realized gains and losses on sales and calls of available-for-sale held-to-maturity non-interest For the Three For the Nine September 30, September 30, (unaudited, in thousands) 2017 2016 2017 2016 Gross realized gains $ 29 $ 602 $ 603 $ 2,517 Gross realized losses (23 ) (4 ) (92 ) (224 ) Net realized gains $ 6 $ 598 $ 511 $ 2,293 The following tables provide information on unrealized losses on investment securities that have been in an unrealized loss position for less than twelve months and twelve months or more as of September 30, 2017 and December 31, 2016: September 30, 2017 Less than 12 months 12 months or more Total Fair Unrealized # of Fair Unrealized # of Fair Unrealized # of (unaudited, dollars in thousands) Value Losses Securities Value Losses Securities Value Losses Securities U.S. Government sponsored entities and agencies $ 29,875 $ (208 ) 6 $ 36,284 $ (487 ) 5 $ 66,159 $ (695 ) 11 Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 729,219 (6,426 ) 180 254,554 (6,713 ) 69 983,773 (13,139 ) 249 Commercial mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 93,924 (1,135 ) 13 660 (16 ) 2 94,584 (1,151 ) 15 Obligations of states and political subdivisions 96,323 (526 ) 153 73,210 (1,242 ) 156 169,533 (1,768 ) 309 Corporate debt securities 4,015 (22 ) 1 6,960 (49 ) 2 10,975 (71 ) 3 Equity securities 1,359 (3 ) 1 — — — 1,359 (3 ) 1 Total temporarily impaired securities $ 954,715 $ (8,320 ) 354 $ 371,668 $ (8,507 ) 234 $ 1,326,383 $ (16,827 ) 588 December 31, 2016 Less than 12 months 12 months or more Total Fair Unrealized # of Fair Unrealized # of Fair Unrealized # of (unaudited, dollars in thousands) Value Losses Securities Value Losses Securities Value Losses Securities U.S. Government sponsored entities and agencies $ 58,108 $ (1,177 ) 11 $ — $ — — $ 58,108 $ (1,177 ) 11 Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 969,174 (16,436 ) 232 58,839 (2,197 ) 14 1,028,013 (18,633 ) 246 Commercial mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 88,169 (2,122 ) 14 679 (17 ) 2 88,848 (2,139 ) 16 Obligations of states and political subdivisions 364,583 (7,121 ) 604 2,047 (67 ) 3 366,630 (7,188 ) 607 Corporate debt securities 10,011 (78 ) 3 5,973 (50 ) 2 15,984 (128 ) 5 Equity securities 2,938 (24 ) 2 — — — 2,938 (24 ) 2 Total temporarily impaired securities $ 1,492,983 $ (26,958 ) 866 $ 67,538 $ (2,331 ) 21 $ 1,560,521 $ (29,289 ) 887 Unrealized losses on debt securities in the tables represent temporary fluctuations resulting from changes in market rates in relation to fixed yields. Unrealized losses in the available-for-sale WesBanco does not believe the securities presented above are impaired due to reasons of credit quality, as substantially all debt securities are rated above investment grade and all are paying principal and interest according to their contractual terms. WesBanco does not intend to sell, nor is it more likely than not that it will be required to sell, loss position securities prior to recovery of their cost, and therefore, management believes the unrealized losses detailed above are temporary and no impairment loss relating to these securities has been recognized. Securities that do not have readily determinable fair values and for which WesBanco does not exercise significant influence are carried at cost. Cost method investments consist primarily of FHLB of Pittsburgh, Cincinnati and Indianapolis stock totaling $48.6 million and $46.4 million at September 30, 2017 and December 31, 2016, respectively, and are included in other assets in the Consolidated Balance Sheets. Cost method investments are evaluated for impairment whenever events or circumstances suggest that their carrying value may not be recoverable.

Loans and the Allowance for Cre

Loans and the Allowance for Credit Losses	9 Months Ended
	Sep. 30, 2017
Receivables [Abstract]
Loans and the Allowance for Credit Losses	NOTE 5. LOANS AND THE ALLOWANCE FOR CREDIT LOSSES The recorded investment in loans is presented in the Consolidated Balance Sheets net of deferred loan fees and costs, and discounts on purchased loans. The deferred loan (costs) and fees were $(1.0) million and $0.3 million at September 30, 2017 and December 31, 2016, respectively. The unamortized discount on purchased loans from acquisitions was $23.0 million, including $11.1 million related to YCB, and $24.1 million at September 30, 2017 and December 31, 2016, respectively. (unaudited, in thousands) September 30, December 31, Commercial real estate: Land and construction $ 606,593 $ 496,539 Improved property 2,407,819 2,376,972 Total commercial real estate 3,014,412 2,873,511 Commercial and industrial 1,125,693 1,088,118 Residential real estate 1,356,580 1,383,390 Home equity 527,216 508,359 Consumer 349,148 396,058 Total portfolio loans 6,373,049 6,249,436 Loans held for sale 26,888 17,315 Total loans $ 6,399,937 $ 6,266,751 The following tables summarize changes in the allowance for credit losses applicable to each category of the loan portfolio: Allowance for Credit Losses By Category For the Nine Months Ended September 30, 2017 and 2016 Commercial Commercial Real Estate- Real Estate- Land and Improved Commercial Residential Home Deposit (unaudited, in thousands) Construction Property & Industrial Real Estate Equity Consumer Overdraft Total Balance at December 31, 2016: Allowance for loan losses $ 4,348 $ 18,628 $ 8,412 $ 4,106 $ 3,422 $ 3,998 $ 760 $ 43,674 Allowance for loan commitments 151 17 188 9 162 44 — 571 Total beginning allowance for credit losses 4,499 18,645 8,600 4,115 3,584 4,042 760 44,245 Provision for credit losses: Provision for loan losses 415 1,619 2,842 (203 ) 1,259 922 680 7,534 Provision for loan commitments (18 ) 4 45 — 49 (4 ) — 76 Total provision for credit losses 397 1,623 2,887 (203 ) 1,308 918 680 7,610 Charge-offs — (1,752 ) (2,255 ) (797 ) (372 ) (2,877 ) (947 ) (9,000 ) Recoveries 89 492 649 266 180 1,336 267 3,279 Net charge-offs 89 (1,260 ) (1,606 ) (531 ) (192 ) (1,541 ) (680 ) (5,721 ) Balance at September 30, 2017: Allowance for loan losses 4,852 18,987 9,648 3,372 4,489 3,379 760 45,487 Allowance for loan commitments 133 21 233 9 211 40 — 647 Total ending allowance for credit losses $ 4,985 $ 19,008 $ 9,881 $ 3,381 $ 4,700 $ 3,419 $ 760 $ 46,134 Balance at December 31, 2015: Allowance for loan losses $ 4,390 $ 14,748 $ 10,002 $ 4,582 $ 2,883 $ 4,763 $ 342 $ 41,710 Allowance for loan commitments 157 26 260 7 117 46 — 613 Total beginning allowance for credit losses 4,547 14,774 10,262 4,589 3,000 4,809 342 42,323 Provision for credit losses: Provision for loan losses 498 1,351 2,827 (67 ) 301 918 559 6,387 Provision for loan commitments (5 ) — (40 ) 2 8 (2 ) — (37 ) Total provision for credit losses 493 1,351 2,787 (65 ) 309 916 559 6,350 Charge-offs (73 ) (1,732 ) (2,883 ) (529 ) (345 ) (2,733 ) (585 ) (8,880 ) Recoveries 3 1,406 241 351 171 1,199 167 3,538 Net charge-offs (70 ) (326 ) (2,642 ) (178 ) (174 ) (1,534 ) (418 ) (5,342 ) Balance at September 30, 2016: Allowance for loan losses 4,818 15,773 10,187 4,337 3,010 4,147 483 42,755 Allowance for loan commitments 152 26 220 9 125 44 — 576 Total ending allowance for credit losses $ 4,970 $ 15,799 $ 10,407 $ 4,346 $ 3,135 $ 4,191 $ 483 $ 43,331 The following tables present the allowance for credit losses and recorded investments in loans by category: Allowance for Credit Losses and Recorded Investment in Loans Commercial Commercial Real Estate- Real Estate- Commercial Residential Deposit Land and Improved and Real Home Over- (unaudited, in thousands) Construction Property Industrial Estate Equity Consumer draft Total September 30, 2017 Allowance for credit losses: Allowance for loans individually evaluated for impairment $ — $ 579 $ — $ — $ — $ — $ — $ 579 Allowance for loans collectively evaluated for impairment 4,852 18,408 9,648 3,372 4,489 3,379 760 44,908 Allowance for loan commitments 133 21 233 9 211 40 — 647 Total allowance for credit losses $ 4,985 $ 19,008 $ 9,881 $ 3,381 $ 4,700 $ 3,419 $ 760 $ 46,134 Portfolio loans: Individually evaluated for impairment (1) $ — $ 5,117 $ — $ — $ — $ — $ — $ 5,117 Collectively evaluated for impairment 605,100 2,397,278 1,124,824 1,355,829 527,216 349,141 — 6,359,388 Acquired with deteriorated credit quality 1,493 5,424 869 751 — 7 — 8,544 Total portfolio loans $ 606,593 $ 2,407,819 $ 1,125,693 $ 1,356,580 $ 527,216 $ 349,148 $ — $ 6,373,049 December 31, 2016 Allowance for credit losses: Allowance for loans individually evaluated for impairment $ — $ 470 $ 407 $ — $ — $ — $ — $ 877 Allowance for loans collectively evaluated for impairment 4,348 18,158 8,005 4,106 3,422 3,998 760 42,797 Allowance for loan commitments 151 17 188 9 162 44 — 571 Total allowance for credit losses $ 4,499 $ 18,645 $ 8,600 $ 4,115 $ 3,584 $ 4,042 $ 760 $ 44,245 Portfolio loans: Individually evaluated for impairment (1) $ — $ 3,012 $ 1,270 $ — $ — $ — $ — $ 4,282 Collectively evaluated for impairment 494,928 2,364,067 1,086,445 1,382,447 508,359 396,049 — 6,232,295 Acquired with deteriorated credit quality 1,611 9,893 403 943 — 9 — 12,859 Total portfolio loans $ 496,539 $ 2,376,972 $ 1,088,118 $ 1,383,390 $ 508,359 $ 396,058 $ — $ 6,249,436 (1) Commercial loans greater than $1 million that are reported as non-accrual WesBanco maintains an internal loan grading system to reflect the credit quality of commercial loans. Commercial loan risk grades are determined based on an evaluation of the relevant characteristics of each loan, assigned at the inception of each loan and adjusted thereafter at any time to reflect changes in the risk profile throughout the life of each loan. The primary factors used to determine the risk grade are the reliability and sustainability of the primary source of repayment and overall financial strength of the borrower. This includes an analysis of cash flow available to repay debt, profitability, liquidity, leverage, and overall financial trends. Other factors include management, industry or property type risks, an assessment of secondary sources of repayment such as collateral or guarantees, other terms and conditions of the loan that may increase or reduce its risk, and economic conditions and other external factors that may influence repayment capacity and financial condition. Commercial real estate – land and construction consists of loans to finance investments in vacant land, land development, construction of residential housing, and construction of commercial buildings. Commercial real estate – improved property consists of loans for the purchase or refinance of all types of improved owner-occupied and investment properties. Factors that are considered in assigning the risk grade vary depending on the type of property financed. The risk grade assigned to construction and development loans is based on the overall viability of the project, the experience and financial capacity of the developer or builder to successfully complete the project, project specific and market absorption rates and comparable property values, and the amount of pre-sales pre-leases non-real Pass loans are those that exhibit a history of positive financial results that are at least comparable to the average for their industry or type of real estate. The primary source of repayment is acceptable and these loans are expected to perform satisfactorily during most economic cycles. Pass loans typically have no significant external factors that are expected to adversely affect these borrowers more than others in the same industry or property type. Any minor unfavorable characteristics of these loans are outweighed or mitigated by other positive factors including but not limited to adequate secondary or tertiary sources of repayment. Criticized or compromised loans are currently protected but have weaknesses, which, if not corrected, may be inadequately protected at some future date. These loans represent an unwarranted credit risk and would generally not be extended in the normal course of lending. Specific issues which may warrant this grade include declining financial results, increased reliance on secondary sources of repayment or guarantor support and adverse external influences that may negatively impact the business or property. Substandard and doubtful loans are equivalent to the classifications used by banking regulators. Substandard loans are inadequately protected by the current repayment capacity and equity of the borrower or collateral pledged, if any. Substandard loans have one or more well-defined weaknesses that jeopardize their repayment or collection in full. These loans may or may not be reported as non-accrual. The following tables summarize commercial loans by their assigned risk grade: Commerical Loans by Internally Assigned Risk Grade (unaudited, in thousands) Commercial Real Estate- Land and Construction Commercial Real Estate- Improved Property Commercial & Industrial Total Commercial Loans As of September 30, 2017 Pass $ 600,325 $ 2,350,919 $ 1,109,774 $ 4,061,018 Criticized - compromised 2,971 24,550 7,263 34,784 Classified - substandard 3,297 32,350 8,656 44,303 Classified - doubtful — — — — Total $ 606,593 $ 2,407,819 $ 1,125,693 $ 4,140,105 As of December 31, 2016 Pass $ 489,380 $ 2,324,755 $ 1,072,751 $ 3,886,886 Criticized - compromised 4,405 15,295 5,078 24,778 Classified - substandard 2,754 36,922 10,289 49,965 Classified - doubtful — — — — Total $ 496,539 $ 2,376,972 $ 1,088,118 $ 3,961,629 Residential real estate, home equity and consumer loans are not assigned internal risk grades other than as required by regulatory guidelines that are based primarily on the age of past due loans. WesBanco primarily evaluates the credit quality of residential real estate, home equity and consumer loans based on repayment performance and historical loss rates. The aggregate amount of residential real estate, home equity and consumer loans classified as substandard in accordance with regulatory guidelines was $22.4 million at September 30, 2017 and $20.6 million at December 31, 2016, of which $4.6 million and $3.4 million were accruing, respectively. The aggregate amount of residential real estate, home equity and consumer loans classified as substandard are not included in the tables above. Acquired YCB Loans 310-30, non-accrual. Acquired ESB Loans 310-30, non-accrual. The following table provides changes in accretable yield for loans acquired with deteriorated credit quality: For the Nine Months Ended (unaudited, in thousands) September 30, 2017 September 30, 2016 Balance at beginning of period $ 1,717 $ 1,206 Acquisitions — 669 Reduction due to change in projected cash flows — (324 ) Reclass from non-accretable difference 1,490 1,065 Transfers (216 ) (328 ) Accretion (1,384 ) (398 ) Balance at end of period $ 1,607 $ 1,890 The following tables summarize the age analysis of all categories of loans: Age Analysis of Loans (unaudited, in thousands) Current 30-59 Days Past Due 60-89 Days Past Due 90 Days or More Past Due Total Past Due Total Loans 90 Days or More Past Due and Accruing (1) As of September 30, 2017 Commercial real estate: Land and construction $ 606,122 $ — $ — $ 471 $ 471 $ 606,593 $ — Improved property 2,391,693 2,235 617 13,274 16,126 2,407,819 542 Total commercial real estate 2,997,815 2,235 617 13,745 16,597 3,014,412 542 Commercial and industrial 1,121,307 1,363 497 2,526 4,386 1,125,693 20 Residential real estate 1,341,924 4,831 759 9,066 14,656 1,356,580 2,418 Home equity 519,110 3,354 808 3,944 8,106 527,216 1,289 Consumer 344,241 3,134 901 872 4,907 349,148 587 Total portfolio loans 6,324,397 14,917 3,582 30,153 48,652 6,373,049 4,856 Loans held for sale 26,888 — — — — 26,888 — Total loans $ 6,351,285 $ 14,917 $ 3,582 $ 30,153 $ 48,652 $ 6,399,937 $ 4,856 Impaired loans included above are as follows: Non-accrual $ 9,360 $ 873 $ 226 $ 24,999 $ 26,098 $ 35,458 TDRs accruing interest (1) 6,232 108 — 298 406 6,638 Total impaired $ 15,592 $ 981 $ 226 $ 25,297 $ 26,504 $ 42,096 As of December 31, 2016 Commercial real estate: Land and construction $ 496,245 $ — $ — $ 294 $ 294 $ 496,539 $ — Improved property 2,367,790 1,154 363 7,665 9,182 2,376,972 318 Total commercial real estate 2,864,035 1,154 363 7,959 9,476 2,873,511 318 Commercial and industrial 1,082,390 2,508 1,011 2,209 5,728 1,088,118 229 Residential real estate 1,365,956 6,701 1,043 9,690 17,434 1,383,390 1,922 Home equity 502,087 2,358 862 3,052 6,272 508,359 626 Consumer 390,354 3,674 1,149 881 5,704 396,058 644 Total portfolio loans 6,204,822 16,395 4,428 23,791 44,614 6,249,436 3,739 Loans held for sale 17,315 — — — — 17,315 — Total loans $ 6,222,137 $ 16,395 $ 4,428 $ 23,791 $ 44,614 $ 6,266,751 $ 3,739 Impaired loans included above are as follows: Non-accrual $ 7,570 $ 3,479 $ 923 $ 19,812 $ 24,214 $ 31,784 TDRs accruing interest (1) 7,014 342 50 240 632 7,646 Total impaired $ 14,584 $ 3,821 $ 973 $ 20,052 $ 24,846 $ 39,430 (1) Loans 90 days or more past due and accruing interest exclude TDRs 90 days or more past due and accruing interest. The following tables summarize impaired loans: Impaired Loans September 30, 2017 December 31, 2016 Unpaid Principal Balance (1 Recorded Investment Related Allowance Unpaid Principal Balance (1) Recorded Investment Related Allowance (unaudited, in thousands) With no related specific allowance recorded: Commercial real estate: Land and construction $ 666 $ 474 $ — $ 1,212 $ 766 $ — Improved property 15,981 10,709 — 9,826 8,141 — Commercial and industrial 3,884 3,083 — 4,456 3,181 — Residential real estate 18,925 17,094 — 20,152 18,305 — Home equity 5,528 4,845 — 4,589 4,011 — Consumer 934 774 — 884 744 — Total impaired loans without a specific allowance 45,918 36,979 — 41,119 35,148 — With a specific allowance recorded: Commercial real estate: Land and construction — — — — — — Improved property 5,117 5,117 579 3,012 3,012 470 Commercial and industrial — — — 4,875 1,270 407 Total impaired loans with a specific allowance 5,117 5,117 579 7,887 4,282 877 Total impaired loans $ 51,035 $ 42,096 $ 579 $ 49,006 $ 39,430 $ 877 (1) The difference between the unpaid principal balance and the recorded investment generally reflects amounts that have been previously charged-off Impaired Loans For the Three Months Ended For the Nine Months Ended September 30, 2017 September 30, 2016 September 30, 2017 September 30, 2016 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized (unaudited, in thousands) With no related specific allowance recorded: Commercial real estate: Land and construction $ 444 $ — $ 701 $ — $ 516 $ — $ 1,062 $ — Improved Property 10,923 31 8,403 28 10,271 400 9,408 86 Commercial and industrial 3,588 2 3,172 2 3,700 6 3,246 7 Residential real estate 17,039 57 17,013 81 17,743 192 16,882 256 Home equity 4,727 4 3,613 4 4,456 14 3,381 16 Consumer 731 2 814 — 746 5 953 6 Total impaired loans without a specific allowance 37,452 96 33,716 115 37,432 617 34,932 371 With a specific allowance recorded: Commercial real estate: Land and construction — — — — — — — — Improved Property 5,137 — 3,012 — 5,032 — 3,012 — Commercial and industrial — — 2,678 — 318 — 3,700 — Total impaired loans with a specific allowance 5,137 — 5,690 — 5,350 — 6,712 — Total impaired loans $ 42,589 $ 96 $ 39,406 $ 115 $ 42,782 $ 617 $ 41,644 $ 371 The following tables present the recorded investment in non-accrual Non-accrual (1) (unaudited, in thousands) September 30, 2017 December 31, 2016 Commercial real estate: Land and construction $ 474 $ 766 Improved property 14,263 9,535 Total commercial real estate 14,737 10,301 Commercial and industrial 2,950 4,299 Residential real estate 12,641 12,994 Home equity 4,426 3,538 Consumer 704 652 Total $ 35,458 $ 31,784 (1) At September 30, 2017, there were three borrowers with loans greater than $1.0 million totaling $8.6 million, as compared to two borrowers with loans greater than $1.0 million totaling $4.3 million at December 31, 2016. Total non-accrual non-accrual TDRs September 30, 2017 December 31, 2016 (unaudited, in thousands) Accruing Non-Accrual Total Accruing Non-Accrual Total Commercial real estate: Land and construction $ — $ 4 $ 4 $ — $ 8 $ 8 Improved property 1,563 446 2,009 1,618 688 2,306 Total commercial real estate 1,563 450 2,013 1,618 696 2,314 Commercial and industrial 133 164 297 152 151 303 Residential real estate 4,453 1,810 6,263 5,311 2,212 7,523 Home equity 419 419 838 473 297 770 Consumer 70 139 209 92 190 282 Total $ 6,638 $ 2,982 $ 9,620 $ 7,646 $ 3,546 $ 11,192 As of September 30, 2017 and December 31, 2016, there were no TDRs greater than $1.0 million. The concessions granted in the majority of loans reported as accruing and non-accrual The following tables present details related to loans identified as TDRs during the three and nine months ended September 30, 2017 and 2016, respectively: New TDRs (1) For the Three Months Ended September 30, 2017 September 30, 2016 Pre- Post- Pre- Post- Modification Modification Modification Modification Outstanding Outstanding Outstanding Outstanding Number of Recorded Recorded Number of Recorded Recorded (unaudited, dollars in thousands) Modifications Investment Investment Modifications Investment Investment Commercial real estate: Land and construction — $ — $ — — $ — $ — Improved Property 1 190 185 — — — Total commercial real estate 1 190 185 — — — Commercial and industrial — — — 2 125 122 Residential real estate — — — 2 124 122 Home equity 2 94 88 — — — Consumer 1 7 6 4 26 23 Total 4 $ 291 $ 279 8 $ 275 $ 267 (1) Excludes loans that were either paid off or charged-off pre-modification New TDRs (1) For the Nine Months Ended September 30, 2017 September 30, 2016 (unaudited, dollars in thousands) Number of Pre- Post- Number of Pre- Post- Commercial real estate: Land and construction — $ — $ — — $ — $ — Improved Property 1 190 185 — — — Total commercial real estate 1 190 185 — — — Commercial and industrial 1 64 59 2 125 122 Residential real estate 2 22 17 3 150 143 Home equity 3 141 132 1 44 41 Consumer 4 42 33 10 70 54 Total 11 $ 459 $ 426 16 $ 389 $ 360 (1) Excludes loans that were either paid off or charged-off pre-modification The following table summarizes TDRs which defaulted (defined as past due 90 days) during the nine months ended September 30, 2017 and 2016, respectively, that were restructured within the last twelve months prior to September 30, 2017 and 2016, respectively: Defaulted TDRs (1) For the Nine Months Ended September 30, 2017 September 30, 2016 (unaudited, dollars in thousands) Number of Recorded Number of Recorded Commercial real estate: Land and construction — $ — — $ — Improved property — — — — Total commercial real estate — — — — Commercial and industrial — — 1 40 Residential real estate 1 7 — — Home equity — — — — Consumer 1 7 — — Total 2 $ 14 1 $ 40 (1) Excludes loans that were either charged-off TDRs that default are placed on non-accrual The following table summarizes other real estate owned and repossessed assets included in other assets: (unaudited, in thousands) September 30, December 31, Other real estate owned $ 5,636 $ 8,206 Repossessed assets 146 140 Total other real estate owned and repossessed assets $ 5,782 $ 8,346 At September 30, 2017, other real estate owned includes $1.1 million from the YCB acquisition and $3.1 million at December 31, 2016. Residential real estate included in other real estate owned at September 30, 2017 and December 31, 2016 was $1.7 million and $1.6 million, respectively. At September 30, 2017 and December 31, 2016, formal foreclosure proceedings were in process on residential real estate loans totaling $3.3 million and $4.1 million, respectively.

Pension Plan

Pension Plan	9 Months Ended
	Sep. 30, 2017
Retirement Benefits [Abstract]
Pension Plan	NOTE 6. PENSION PLAN The following table presents the net periodic pension cost for WesBanco’s Defined Benefit Pension Plan (the “Plan”) and the related components: For the Three Months Ended For the Nine Months Ended (unaudited, in thousands) 2017 2016 2017 2016 Service cost – benefits earned during year $ 650 $ 703 $ 1,929 $ 2,095 Interest cost on projected benefit obligation 1,107 1,280 3,287 3,813 Expected return on plan assets (1,928 ) (1,940 ) (5,721 ) (5,778 ) Amortization of prior service cost 7 8 19 20 Amortization of net loss 812 759 2,409 2,261 Net periodic pension cost $ 648 $ 810 $ 1,923 $ 2,411 The Plan covers all employees of WesBanco and its subsidiaries who were hired on or before August 1, 2007 who satisfy minimum age and length of service requirements, and is not available to employees hired after such date. A minimum required contribution of $2.7 million is due for 2017, which could be all or partially offset by the Plan’s $46.9 million available credit balance. A voluntary contribution of $2.5 million was made in June 2017. On September 9, 2016, WesBanco assumed YCB’s obligation for a predecessor bank’s participation in the Pentegra Defined Benefit Plan for Financial Institutions (“Pentegra Plan”). The participating employer plan had been frozen to new participants since 2002. WesBanco spun out the assets from the Pentegra Plan in the second quarter of 2017, and contributed approximately $2.8 million to satisfy the final costs to do so. The spin off had no impact on earnings as the liability was included in YCB’s balance sheet as of the acquisition date. The $8.4 million in distributed assets from the Pentegra Plan were transferred to a new plan providing the same benefits to the participants.

Fair Value Measurement

Fair Value Measurement	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurement	NOTE 7. FAIR VALUE MEASUREMENT Fair value estimates are based on quoted market prices, if available, quoted market prices of similar assets or liabilities, or the present value of expected future cash flows and other valuation techniques. These valuations are significantly affected by discount rates, cash flow assumptions, and risk assumptions used. Therefore, fair value estimates may not be substantiated by comparison to independent markets and are not intended to reflect the proceeds that may be realizable in an immediate settlement of the instruments. Fair value is determined at one point in time and is not representative of future value. These amounts do not reflect the total value of a going concern organization. Management does not have the intention to dispose of a significant portion of its assets and liabilities and therefore, the unrealized gains or losses should not be interpreted as a forecast of future earnings and cash flows. The following is a discussion of assets and liabilities measured at fair value on a recurring basis and valuation techniques applied: Investment securities: over-the-counter Derivatives: WesBanco determines the fair value for derivatives using widely accepted valuation techniques including discounted cash flow analysis on the expected cash flows of each derivative. This analysis reflects contractual terms of the derivative, including the period to maturity, and uses observable market based inputs, including interest rate curves and implied volatilities. WesBanco incorporates credit valuation adjustments to appropriately reflect both its own non-performance non-performance We may be required from time to time to measure certain assets and liabilities at fair value on a nonrecurring basis in accordance with GAAP. These adjustments to fair value usually result from the application of lower of cost or market accounting or write-downs of individual assets and liabilities. Impaired loans: Other real estate owned and repossessed assets: Loans held for sale: Certain investments that are measured at fair value using the net asset value per share (or its equivalent) practical expedient have not been categorized in the fair value hierarchy. The fair value amounts presented in the table below are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position. The following tables set forth WesBanco’s financial assets and liabilities that were accounted for at fair value on a recurring and nonrecurring basis by level within the fair value hierarchy as of September 30, 2017 and December 31, 2016: September 30, 2017 Fair Value Measurements Using: September 30, 2017 Quoted Prices in Significant Significant Investments (unaudited, in thousands) (level 1) (level 2) (level 3) Value Recurring fair value measurements Trading securities $ 7,929 $ 6,457 $ — $ — $ 1,472 Securities - available-for-sale U.S. Government sponsored entities and agencies 72,319 — 72,319 — — Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 963,474 — 963,474 — — Commercial mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 121,834 — 121,834 — — Obligations of state and political subdivisions 106,847 — 106,847 — — Corporate debt securities 35,503 — 35,503 — — Equity securities 5,555 5,555 — — — Total securities - available-for-sale $ 1,305,532 $ 5,555 $ 1,299,977 $ — $ — Other assets - interest rate derivatives agreements $ 5,506 $ — $ 5,506 $ — $ — Total assets recurring fair value measurements $ 1,318,967 $ 12,012 $ 1,305,483 $ — $ 1,472 Other liabilities - interest rate derivatives agreements $ 5,443 $ — $ 5,443 $ — $ — Total liabilities recurring fair value measurements $ 5,443 $ — $ 5,443 $ — $ — Nonrecurring fair value measurements Impaired loans $ 4,538 $ — $ — $ 4,538 $ — Other real estate owned and repossessed assets 5,782 — — 5,782 — Loans held for sale 26,888 — 26,888 — — Total nonrecurring fair value measurements $ 37,208 $ — $ 26,888 $ 10,320 $ — December 31, 2016 Fair Value Measurements Using: December 31, Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Investments Measured at Net Asset (unaudited, in thousands) 2016 (level 1) (level 2) (level 3) Value Recurring fair value measurements Trading securities $ 7,071 $ 5,633 $ — $ — $ 1,438 Securities - available-for-sale U.S. Government sponsored entities and agencies 54,043 — 54,043 — — Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 938,289 — 938,289 — — Commercial mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 96,810 — 96,810 — — Obligations of state and political subdivisions 111,663 — 111,663 — — Corporate debt securities 35,301 — 35,301 — — Equity securities 5,070 2,938 2,132 — — Total securities - available-for-sale $ 1,241,176 $ 2,938 $ 1,238,238 $ — $ — Other assets - interest rate derivatives agreements $ 5,596 $ — $ 5,596 $ — $ — Total assets recurring fair value measurements $ 1,253,843 $ 8,571 $ 1,243,834 $ — $ 1,438 Other liabilities - interest rate derivatives agreements $ 5,199 $ — $ 5,199 $ — $ — Total liabilities recurring fair value measurements $ 5,199 $ — $ 5,199 $ — $ — Nonrecurring fair value measurements Impaired loans $ 3,405 $ — $ — $ 3,405 $ — Other real estate owned and repossessed assets 8,346 — — 8,346 — Loans held for sale 17,315 — 17,315 — — Total nonrecurring fair value measurements $ 29,066 $ — $ 17,315 $ 11,751 $ — WesBanco’s policy is to recognize transfers between levels as of the actual date of the event or change in circumstances that caused the transfer. There were no transfers between level 1, 2 or 3 for the three and nine months ended September 30, 2017 or for the year ended December 31, 2016. The following table presents additional quantitative information about assets measured at fair value on a nonrecurring basis and for which WesBanco has utilized level 3 inputs to determine fair value: Quantitative Information about Level 3 Fair Value Measurements Fair Value Valuation Unobservable Range (Weighted (unaudited, in thousands) Estimate Techniques Input Average) September 30, 2017 Impaired loans $ 4,538 Appraisal of collateral (1) Appraisal adjustments (2) 0% to (4.8%) /(1.9%) Liquidation expenses (2) (7.6%) to (8.0%) / (7.9%) Other real estate owned and repossessed assets 5,782 Appraisal of collateral (1), (3) December 31, 2016: Impaired loans $ 3,405 Appraisal of collateral (1) Appraisal adjustments (2) 0% to (70.0%) / (36.6%) Liquidation expenses (2) (1.5%) to (8.0%) / (4.6%) Other real estate owned and repossessed assets 8,346 Appraisal of collateral (1), (3) (1) Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various level 3 inputs, which are not identifiable. (2) Appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses. The range and weighted average of appraisal adjustments and liquidation expenses are presented as a percent of the appraisal. (3) Includes estimated liquidation expenses and numerous dissimilar qualitative adjustments by management which are not identifiable. The estimated fair values of WesBanco’s financial instruments are summarized below: Fair Value Measurements at September 30, 2017 (unaudited, in thousands) Carrying Fair Value Quoted Prices in (level 1) Significant Other (level 2) Significant (level 3) Investments Financial Assets Cash and due from banks $ 110,871 $ 110,871 $ 110,871 $ — $ — $ — Trading securities 7,929 7,929 6,457 — — 1,472 Securities available-for-sale 1,305,532 1,305,532 5,555 1,299,977 — — Securities held-to-maturity 1,025,688 1,044,748 — 1,044,135 613 — Net loans 6,327,562 6,241,388 — — 6,241,388 — Loans held for sale 26,888 26,888 — 26,888 — — Other assets - interest rate derivatives 5,506 5,506 — 5,506 — — Accrued interest receivable 30,152 30,152 30,152 — — — Financial Liabilities Deposits 7,101,025 7,112,593 5,766,959 1,345,634 — — Federal Home Loan Bank borrowings 1,015,011 1,014,117 — 1,014,117 — — Other borrowings 165,576 165,579 163,532 2,047 — — Subordinated debt and junior subordinated debt 164,278 138,421 — 138,421 — — Other liabilities - interest rate derivatives 5,443 5,443 — 5,443 — — Accrued interest payable 3,924 3,924 3,924 — — — Fair Value Measurements at December 31, 2016 (unaudited, in thousands) Carrying Fair Value Quoted Prices in (level 1) Significant Other (level 2) Significant (level 3) Investments Financial Assets Cash and due from banks $ 128,170 $ 128,170 $ 128,170 $ — $ — $ — Trading securities 7,071 7,071 5,633 — — 1,438 Securities available-for-sale 1,241,176 1,241,176 2,938 1,238,238 — — Securities held-to-maturity 1,067,967 1,076,790 — 1,076,189 601 — Net loans 6,205,762 6,073,558 — — 6,073,558 — Loans held for sale 17,315 17,315 — 17,315 — — Other assets - interest rate derivatives 5,596 5,596 — 5,596 — — Accrued interest receivable 28,299 28,299 28,299 — — — Financial Liabilities Deposits 7,040,879 7,052,501 5,545,057 1,507,444 — — Federal Home Loan Bank borrowings 968,946 974,430 — 974,430 — — Other borrowings 199,376 199,385 197,164 2,221 — — Subordinated debt and junior subordinated debt 163,598 134,859 — 134,859 — — Other liabilities - interest rate derivatives 5,199 5,199 — 5,199 — — Accrued interest payable 2,204 2,204 2,204 — — — The following methods and assumptions were used to measure the fair value of financial instruments recorded at cost on WesBanco’s consolidated balance sheets: Cash and due from banks: Securities held-to-maturity: held-to-maturity Net loans: Accrued interest receivable: . Deposits: Federal Home Loan Bank borrowings: Other borrowings: Subordinated debt and junior subordinated debt: Accrued interest payable: Off-balance Off-balance

Comprehensive Income

Comprehensive Income	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Comprehensive Income	NOTE 8. COMPREHENSIVE INCOME The activity in accumulated other comprehensive income for the nine months ended September 30, 2017 and 2016 is as follows: Accumulated Other Comprehensive Income/(Loss) (1) (unaudited, in thousands) Defined Unrealized on Securities Available-for-Sale Unrealized Gains Available-for-Sale to Held-to-Maturity Total Balance at December 31, 2016 $ (17,758 ) $ (9,890 ) $ 522 $ (27,126 ) Other comprehensive income before reclassifications — 4,740 — 4,740 Amounts reclassified from accumulated other comprehensive income 1,679 35 (165 ) 1,549 Period change 1,679 4,775 (165 ) 6,289 Balance at September 30, 2017 $ (16,079 ) $ (5,115 ) $ 357 $ (20,837 ) Balance at December 31, 2015 $ (17,539 ) $ (4,162 ) $ 747 $ (20,954 ) Other comprehensive income before reclassifications — 16,065 — 16,065 Amounts reclassified from accumulated other comprehensive income 1,407 (1,428 ) (152 ) (173 ) Period change 1,407 14,637 (152 ) 15,892 Balance at September 30, 2016 $ (16,132 ) $ 10,475 $ 595 $ (5,062 ) (1) All amounts are net of tax. Related income tax expense or benefit is calculated using a combined Federal and State income tax rate approximating 37%. The following table provides details about amounts reclassified from accumulated other comprehensive income for the three and nine months ended September 30, 2017 and 2016: Details about Accumulated Other Comprehensive For the Three Months Ended For the Nine Months Ended September 30, Affected Line Item in the Statement of Net Income (unaudited, in thousands) 2017 2016 2017 2016 Securities available-for-sale (1) Net securities gains reclassified into earnings $ — $ (579 ) $ 55 $ (2,251 ) Net securities gains (Non-interest Related income tax expense (benefit) — 211 (20 ) 823 Provision for income taxes Net effect on accumulated other comprehensive income for the period — (368 ) 35 (1,428 ) Securities held-to-maturity (1) Amortization of unrealized gain transferred from available-for-sale (66 ) (77 ) (256 ) (242 ) Interest and dividends on securities (Interest and dividend income) Related income tax expense 24 28 91 90 Provision for income taxes Net effect on accumulated other comprehensive income for the period (42 ) (49 ) (165 ) (152 ) Defined benefit pension plan (2) Amortization of net loss and prior service costs 816 766 2,429 2,280 Employee benefits (Non-interest Related income tax benefit (303 ) (280 ) (750 ) (873 ) Provision for income taxes Net effect on accumulated other comprehensive income for the period 513 486 1,679 1,407 Total reclassifications for the period $ 471 $ 69 $ 1,549 $ (173 ) (1) For additional detail related to unrealized gains on securities and related amounts reclassified from accumulated other comprehensive income, see Note 4, “Securities.” (2) Included in the computation of net periodic pension cost. See Note 6, “Pension Plan” for additional detail.

Commitments and Contingent Liab

Commitments and Contingent Liabilities	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingent Liabilities	NOTE 9. COMMITMENTS AND CONTINGENT LIABILITIES Commitments — off-balance non-performance Letters of credit are conditional commitments issued by banks to guarantee the performance of a customer to a third party. Those guarantees are primarily issued to support public and private borrowing arrangements, including normal business activities, bond financing and similar transactions. Letters of credit are considered guarantees. The liability associated with letters of credit was $0.2 million, as of both September 30, 2017 and December 31, 2016. Contingent obligations to purchase loans funded by other entities include affordable housing plan guarantees, credit card guarantees and mortgages sold into the secondary market with recourse. Affordable housing plan guarantees are performance guarantees for various building project loans. The guarantee amortizes as the loan balances decrease. Credit card guarantees are credit card balances not owned by WesBanco, whereby the Bank guarantees the performance of the cardholder. The following table presents total commitments to extend credit, guarantees and various letters of credit outstanding: September 30, December 31, (unaudited, in thousands) 2017 2016 Lines of credit $ 1,468,470 $ 1,418,329 Loans approved but not closed 243,723 185,253 Overdraft limits 126,936 126,517 Letters of credit 32,328 32,907 Contingent obligations to purchase loans funded by other entities 6,974 13,036 Contingent Liabilities —

Business Segments

Business Segments	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Business Segments	NOTE 10. BUSINESS SEGMENTS WesBanco operates two reportable segments: community banking and trust and investment services. WesBanco’s community banking segment offers services traditionally offered by full-service commercial banks, including commercial demand, individual demand and time deposit accounts, as well as commercial, mortgage and individual installment loans, and certain non-traditional Condensed financial information by business segment is presented below: Trust and Community Investment (unaudited, in thousands) Banking Services Consolidated For the Three Months ended September 30, 2017: Interest income $ 85,489 $ — $ 85,489 Interest expense 11,235 — 11,235 Net interest income 74,254 — 74,254 Provision for credit losses 2,516 — 2,516 Net interest income after provision for credit losses 71,738 — 71,738 Non-interest 15,541 5,358 20,899 Non-interest 52,355 3,399 55,754 Income before provision for income taxes 34,924 1,959 36,883 Provision for income taxes 9,744 783 10,527 Net income $ 25,180 $ 1,176 $ 26,356 For the Three Months ended September 30, 2016: Interest income $ 70,092 $ — $ 70,092 Interest expense 8,066 — 8,066 Net interest income 62,026 — 62,026 Provision for credit losses 2,214 — 2,214 Net interest income after provision for credit losses 59,812 — 59,812 Non-interest 15,604 5,413 21,017 Non-interest 54,569 3,032 57,601 Income before provision for income taxes 20,847 2,381 23,228 Provision for income taxes 4,841 952 5,793 Net income $ 16,006 $ 1,429 $ 17,435 For the Nine Months ended September 30, 2017: Interest income $ 247,573 $ — $ 247,573 Interest expense 30,461 — 30,461 Net interest income 217,112 — 217,112 Provision for credit losses 7,610 — 7,610 Net interest income after provision for credit losses 209,502 — 209,502 Non-interest 48,833 17,073 65,906 Non-interest 156,102 9,921 166,023 Income before provision for income taxes 102,233 7,152 109,385 Provision for income taxes 27,940 2,861 30,801 Net income $ 74,293 $ 4,291 $ 78,584 For the Nine Months ended September 30, 2016: Interest income $ 205,278 $ — $ 205,278 Interest expense 23,637 — 23,637 Net interest income 181,641 — 181,641 Provision for credit losses 6,350 — 6,350 Net interest income after provision for credit losses 175,291 — 175,291 Non-interest 43,841 16,160 60,001 Non-interest 141,029 9,274 150,303 Income before provision for income taxes 78,103 6,886 84,989 Provision for income taxes 19,818 2,754 22,572 Net income $ 58,285 $ 4,132 $ 62,417 Total non-fiduciary

Summary of Significant Accoun18

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of presentation	Basis of presentation — 10-Q S-X. 10-K WesBanco’s interim financial statements have been prepared following the significant accounting policies disclosed in Note 1 of the Notes to the Consolidated Financial Statements of its 2016 Annual Report on Form 10-K
Recent accounting pronouncements	Recent accounting pronouncements — No. 2017-12 2017-12 In May 2017, the FASB issued ASU No. 2017-09 2017-09 In March 2017, FASB issued ASU 2017-08 In March 2017, the FASB issued ASU 2017-07 non-interest In January 2017, the FASB issued ASU 2017-04 In January 2017, the FASB issued ASU No. 2017-01, 2017-01 2017-01 In October 2016, the FASB issued ASU 2016-16 In August 2016, the FASB issued ASU 2016-15 zero-coupon In June 2016, the FASB issued ASU 2016-13 held-to-maturity available-for-sale In March 2016, the FASB issued ASU 2016-09 In March 2016, the FASB issued ASU 2016-07 In February 2016, the FASB issued ASU 2016-02 In January 2016, the FASB issued ASU 2016-01 In May 2014, the FASB issued ASU 2014-09 one-year 2016-08, 2016-10, 2016-12, In January 2014, the FASB issued ASU No. 2014-01,

Mergers and Acquisitions (Table

Mergers and Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2017
Allocation of Purchase Price of Assets Acquired and Liabilities Assumed	The following table presents the allocation of the purchase price of the assets acquired and the liabilities assumed at the date of acquisition. (unaudited, in thousands) September 9, 2016 Assets acquired Cash and due from banks $ 48,212 Securities 173,223 Loans 1,012,410 Goodwill and other intangible assets 104,990 Accrued income and other assets (1) 212,550 Total assets acquired $ 1,551,385 Liabilities assumed Deposits $ 1,193,010 Borrowings 123,001 Accrued expenses and other liabilities 14,876 Total liabilities assumed 1,330,887 Net assets acquired $ 220,498 (1) Includes receivables of $105.8 million from the sale of available-for-sale
Your Community Bankshares, Inc [Member]
Summary of Purchase Price of Acquisition and Resulting Goodwill	The final purchase price of the YCB acquisition and resulting goodwill is summarized as follows: (unaudited, in thousands) September 9, 2016 Purchase Price: Fair value of WesBanco shares issued $ 177,149 Cash consideration for outstanding YCB shares 43,349 Total purchase price $ 220,498 Fair value of: Tangible assets acquired $ 1,398,183 Core deposit and other intangible assets acquired 11,957 Liabilities assumed (1,330,887 ) Net cash received in the acquisition 48,212 Fair value of net assets acquired $ 127,465 Goodwill recognized $ 93,033
Purchase Price Allocation Adjustment [Member]
Allocation of Purchase Price of Assets Acquired and Liabilities Assumed	The following table presents the changes in the allocation of the purchase price of the assets acquired and the liabilities assumed at the date of the acquisition previously reported as of December 31, 2016: (unaudited, in thousands) September 9, 2016 Goodwill recognized as of December 31, 2016 $ 92,889 Change in fair value of net assets acquired: Assets Loans (1,156 ) Accrued income and other assets 743 Liabilities Borrowings — Accrued expenses and other liabilities 269 Fair value of net assets acquired $ (144 ) Increase in goodwill recognized 144 Goodwill recognized as of September 30, 2017 $ 93,033

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Summary of Earnings Per Common Share	Earnings per common share are calculated as follows: (unaudited, in thousands, except shares and per share amounts) For the Three Months Ended For the Nine Months Ended 2017 2016 2017 2016 Numerator for both basic and diluted earnings per common share: Net income $ 26,356 $ 17,435 $ 78,584 $ 62,417 Denominator: Total average basic common shares outstanding 44,031,813 39,715,516 43,992,017 38,828,618 Effect of dilutive stock options and other stock compensation 55,068 27,775 67,452 26,835 Total diluted average common shares outstanding 44,086,881 39,743,291 44,059,469 38,855,453 Earnings per common share – basic $ 0.60 $ 0.44 $ 1.79 $ 1.61 Earnings per common share – diluted $ 0.60 $ 0.44 $ 1.78 $ 1.61

Securities (Tables)

Securities (Tables)	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule of Fair Value and Amortized Cost of Available-for-sale and Held-to-maturity Securities	The following table presents the fair value and amortized cost of available-for-sale held-to-maturity September 30, 2017 December 31, 2016 (unaudited, in thousands) Amortized Gross Gross Estimated Value Amortized Gross Gross Estimated Value Available-for-sale U.S. Government sponsored entities and agencies $ 72,672 $ 88 $ (441 ) $ 72,319 $ 54,803 $ 3 $ (763 ) $ 54,043 Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 974,370 776 (11,672 ) 963,474 953,475 884 (16,070 ) 938,289 Commercial mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 122,908 77 (1,151 ) 121,834 98,922 27 (2,139 ) 96,810 Obligations of states and political subdivisions 104,228 3,187 (568 ) 106,847 110,208 3,114 (1,659 ) 111,663 Corporate debt securities 35,249 325 (71 ) 35,503 35,292 117 (108 ) 35,301 Total debt securities $ 1,309,427 $ 4,453 $ (13,903 ) $ 1,299,977 $ 1,252,700 $ 4,145 $ (20,739 ) $ 1,236,106 Equity securities 4,238 1,320 (3 ) 5,555 4,062 1,032 (24 ) 5,070 Total available-for-sale $ 1,313,665 $ 5,773 $ (13,906 ) $ 1,305,532 $ 1,256,762 $ 5,177 $ (20,763 ) $ 1,241,176 Held-to-maturity U.S. Government sponsored entities and agencies $ 12,128 $ — $ (254 ) $ 11,874 $ 13,394 $ — $ (414 ) $ 12,980 Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 178,429 763 (1,467 ) 177,725 215,141 1,279 (2,563 ) 213,857 Obligations of states and political subdivisions 801,760 20,153 (1,200 ) 820,713 805,019 15,652 (5,529 ) 815,142 Corporate debt securities 33,371 1,065 — 34,436 34,413 418 (20 ) 34,811 Total held-to-maturity $ 1,025,688 $ 21,981 $ (2,921 ) $ 1,044,748 $ 1,067,967 $ 17,349 $ (8,526 ) $ 1,076,790 Total $ 2,339,353 $ 27,754 $ (16,827 ) $ 2,350,280 $ 2,324,729 $ 22,526 $ (29,289 ) $ 2,317,966
Schedule of Fair Value of Available-for-sale and Held-to-maturity Securities by Contractual Maturity	The following table presents the fair value of available-for-sale held-to-maturity September 30, 2017 One Year One to Five to After Mortgage-backed (unaudited, in thousands) or less Five Years Ten Years Ten Years and Equity Total Available-for-sale U.S. Government sponsored entities and agencies $ — $ 11,967 $ 16,855 $ 6,908 $ 36,589 $ 72,319 Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies (1) — — — — 963,474 963,474 Commercial mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies (1) — — — — 121,834 121,834 Obligations of states and political subdivisions 7,723 17,886 36,514 44,724 — 106,847 Corporate debt securities — 30,483 5,020 — — 35,503 Equity securities (2) — — — — 5,555 5,555 Total available-for-sale $ 7,723 $ 60,336 $ 58,389 $ 51,632 $ 1,127,452 $ 1,305,532 Held-to-maturity (3) U.S. Government sponsored entities and agencies $ — $ — $ — $ — $ 11,874 $ 11,874 Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies (1) — — — — 177,725 177,725 Obligations of states and political subdivisions 4,703 88,402 412,322 315,286 — 820,713 Corporate debt securities — 2,804 31,632 — — 34,436 Total held-to-maturity $ 4,703 $ 91,206 $ 443,954 $ 315,286 $ 189,599 $ 1,044,748 Total $ 12,426 $ 151,542 $ 502,343 $ 366,918 $ 1,317,051 $ 2,350,280 (1) Mortgage-backed and collateralized mortgage securities, which have prepayment provisions, are not assigned to maturity categories due to fluctuations in their prepayment speeds. (2) Equity securities, which have no stated maturity, are not assigned a maturity category. (3) The held-to-maturity
Schedule of Gross Realized Gains and Losses on Sales and Calls of Available-for-Sale and Held-to-Maturity Securities	The following table presents the gross realized gains and losses on sales and calls of available-for-sale held-to-maturity non-interest For the Three For the Nine September 30, September 30, (unaudited, in thousands) 2017 2016 2017 2016 Gross realized gains $ 29 $ 602 $ 603 $ 2,517 Gross realized losses (23 ) (4 ) (92 ) (224 ) Net realized gains $ 6 $ 598 $ 511 $ 2,293
Schedule of Unrealized Losses on Investment Securities	The following tables provide information on unrealized losses on investment securities that have been in an unrealized loss position for less than twelve months and twelve months or more as of September 30, 2017 and December 31, 2016: September 30, 2017 Less than 12 months 12 months or more Total Fair Unrealized # of Fair Unrealized # of Fair Unrealized # of (unaudited, dollars in thousands) Value Losses Securities Value Losses Securities Value Losses Securities U.S. Government sponsored entities and agencies $ 29,875 $ (208 ) 6 $ 36,284 $ (487 ) 5 $ 66,159 $ (695 ) 11 Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 729,219 (6,426 ) 180 254,554 (6,713 ) 69 983,773 (13,139 ) 249 Commercial mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 93,924 (1,135 ) 13 660 (16 ) 2 94,584 (1,151 ) 15 Obligations of states and political subdivisions 96,323 (526 ) 153 73,210 (1,242 ) 156 169,533 (1,768 ) 309 Corporate debt securities 4,015 (22 ) 1 6,960 (49 ) 2 10,975 (71 ) 3 Equity securities 1,359 (3 ) 1 — — — 1,359 (3 ) 1 Total temporarily impaired securities $ 954,715 $ (8,320 ) 354 $ 371,668 $ (8,507 ) 234 $ 1,326,383 $ (16,827 ) 588 December 31, 2016 Less than 12 months 12 months or more Total Fair Unrealized # of Fair Unrealized # of Fair Unrealized # of (unaudited, dollars in thousands) Value Losses Securities Value Losses Securities Value Losses Securities U.S. Government sponsored entities and agencies $ 58,108 $ (1,177 ) 11 $ — $ — — $ 58,108 $ (1,177 ) 11 Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 969,174 (16,436 ) 232 58,839 (2,197 ) 14 1,028,013 (18,633 ) 246 Commercial mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 88,169 (2,122 ) 14 679 (17 ) 2 88,848 (2,139 ) 16 Obligations of states and political subdivisions 364,583 (7,121 ) 604 2,047 (67 ) 3 366,630 (7,188 ) 607 Corporate debt securities 10,011 (78 ) 3 5,973 (50 ) 2 15,984 (128 ) 5 Equity securities 2,938 (24 ) 2 — — — 2,938 (24 ) 2 Total temporarily impaired securities $ 1,492,983 $ (26,958 ) 866 $ 67,538 $ (2,331 ) 21 $ 1,560,521 $ (29,289 ) 887

Loans and the Allowance for C22

Loans and the Allowance for Credit Losses (Tables)	9 Months Ended
	Sep. 30, 2017
Receivables [Abstract]
Schedule of Recorded Investment in Loans by Category	The recorded investment in loans is presented in the Consolidated Balance Sheets net of deferred loan fees and costs, and discounts on purchased loans. The deferred loan (costs) and fees were $(1.0) million and $0.3 million at September 30, 2017 and December 31, 2016, respectively. The unamortized discount on purchased loans from acquisitions was $23.0 million, including $11.1 million related to YCB, and $24.1 million at September 30, 2017 and December 31, 2016, respectively. (unaudited, in thousands) September 30, December 31, Commercial real estate: Land and construction $ 606,593 $ 496,539 Improved property 2,407,819 2,376,972 Total commercial real estate 3,014,412 2,873,511 Commercial and industrial 1,125,693 1,088,118 Residential real estate 1,356,580 1,383,390 Home equity 527,216 508,359 Consumer 349,148 396,058 Total portfolio loans 6,373,049 6,249,436 Loans held for sale 26,888 17,315 Total loans $ 6,399,937 $ 6,266,751
Summary of Changes in Allowance for Credit Losses	The following tables summarize changes in the allowance for credit losses applicable to each category of the loan portfolio: Allowance for Credit Losses By Category For the Nine Months Ended September 30, 2017 and 2016 Commercial Commercial Real Estate- Real Estate- Land and Improved Commercial Residential Home Deposit (unaudited, in thousands) Construction Property & Industrial Real Estate Equity Consumer Overdraft Total Balance at December 31, 2016: Allowance for loan losses $ 4,348 $ 18,628 $ 8,412 $ 4,106 $ 3,422 $ 3,998 $ 760 $ 43,674 Allowance for loan commitments 151 17 188 9 162 44 — 571 Total beginning allowance for credit losses 4,499 18,645 8,600 4,115 3,584 4,042 760 44,245 Provision for credit losses: Provision for loan losses 415 1,619 2,842 (203 ) 1,259 922 680 7,534 Provision for loan commitments (18 ) 4 45 — 49 (4 ) — 76 Total provision for credit losses 397 1,623 2,887 (203 ) 1,308 918 680 7,610 Charge-offs — (1,752 ) (2,255 ) (797 ) (372 ) (2,877 ) (947 ) (9,000 ) Recoveries 89 492 649 266 180 1,336 267 3,279 Net charge-offs 89 (1,260 ) (1,606 ) (531 ) (192 ) (1,541 ) (680 ) (5,721 ) Balance at September 30, 2017: Allowance for loan losses 4,852 18,987 9,648 3,372 4,489 3,379 760 45,487 Allowance for loan commitments 133 21 233 9 211 40 — 647 Total ending allowance for credit losses $ 4,985 $ 19,008 $ 9,881 $ 3,381 $ 4,700 $ 3,419 $ 760 $ 46,134 Balance at December 31, 2015: Allowance for loan losses $ 4,390 $ 14,748 $ 10,002 $ 4,582 $ 2,883 $ 4,763 $ 342 $ 41,710 Allowance for loan commitments 157 26 260 7 117 46 — 613 Total beginning allowance for credit losses 4,547 14,774 10,262 4,589 3,000 4,809 342 42,323 Provision for credit losses: Provision for loan losses 498 1,351 2,827 (67 ) 301 918 559 6,387 Provision for loan commitments (5 ) — (40 ) 2 8 (2 ) — (37 ) Total provision for credit losses 493 1,351 2,787 (65 ) 309 916 559 6,350 Charge-offs (73 ) (1,732 ) (2,883 ) (529 ) (345 ) (2,733 ) (585 ) (8,880 ) Recoveries 3 1,406 241 351 171 1,199 167 3,538 Net charge-offs (70 ) (326 ) (2,642 ) (178 ) (174 ) (1,534 ) (418 ) (5,342 ) Balance at September 30, 2016: Allowance for loan losses 4,818 15,773 10,187 4,337 3,010 4,147 483 42,755 Allowance for loan commitments 152 26 220 9 125 44 — 576 Total ending allowance for credit losses $ 4,970 $ 15,799 $ 10,407 $ 4,346 $ 3,135 $ 4,191 $ 483 $ 43,331
Allowance for Credit Losses and Recorded Investments in Loans	The following tables present the allowance for credit losses and recorded investments in loans by category: Allowance for Credit Losses and Recorded Investment in Loans Commercial Commercial Real Estate- Real Estate- Commercial Residential Deposit Land and Improved and Real Home Over- (unaudited, in thousands) Construction Property Industrial Estate Equity Consumer draft Total September 30, 2017 Allowance for credit losses: Allowance for loans individually evaluated for impairment $ — $ 579 $ — $ — $ — $ — $ — $ 579 Allowance for loans collectively evaluated for impairment 4,852 18,408 9,648 3,372 4,489 3,379 760 44,908 Allowance for loan commitments 133 21 233 9 211 40 — 647 Total allowance for credit losses $ 4,985 $ 19,008 $ 9,881 $ 3,381 $ 4,700 $ 3,419 $ 760 $ 46,134 Portfolio loans: Individually evaluated for impairment (1) $ — $ 5,117 $ — $ — $ — $ — $ — $ 5,117 Collectively evaluated for impairment 605,100 2,397,278 1,124,824 1,355,829 527,216 349,141 — 6,359,388 Acquired with deteriorated credit quality 1,493 5,424 869 751 — 7 — 8,544 Total portfolio loans $ 606,593 $ 2,407,819 $ 1,125,693 $ 1,356,580 $ 527,216 $ 349,148 $ — $ 6,373,049 December 31, 2016 Allowance for credit losses: Allowance for loans individually evaluated for impairment $ — $ 470 $ 407 $ — $ — $ — $ — $ 877 Allowance for loans collectively evaluated for impairment 4,348 18,158 8,005 4,106 3,422 3,998 760 42,797 Allowance for loan commitments 151 17 188 9 162 44 — 571 Total allowance for credit losses $ 4,499 $ 18,645 $ 8,600 $ 4,115 $ 3,584 $ 4,042 $ 760 $ 44,245 Portfolio loans: Individually evaluated for impairment (1) $ — $ 3,012 $ 1,270 $ — $ — $ — $ — $ 4,282 Collectively evaluated for impairment 494,928 2,364,067 1,086,445 1,382,447 508,359 396,049 — 6,232,295 Acquired with deteriorated credit quality 1,611 9,893 403 943 — 9 — 12,859 Total portfolio loans $ 496,539 $ 2,376,972 $ 1,088,118 $ 1,383,390 $ 508,359 $ 396,058 $ — $ 6,249,436 (1) Commercial loans greater than $1 million that are reported as non-accrual
Summary of Commercial Loans by Risk Grade	The following tables summarize commercial loans by their assigned risk grade: Commerical Loans by Internally Assigned Risk Grade (unaudited, in thousands) Commercial Real Estate- Land and Construction Commercial Real Estate- Improved Property Commercial & Industrial Total Commercial Loans As of September 30, 2017 Pass $ 600,325 $ 2,350,919 $ 1,109,774 $ 4,061,018 Criticized - compromised 2,971 24,550 7,263 34,784 Classified - substandard 3,297 32,350 8,656 44,303 Classified - doubtful — — — — Total $ 606,593 $ 2,407,819 $ 1,125,693 $ 4,140,105 As of December 31, 2016 Pass $ 489,380 $ 2,324,755 $ 1,072,751 $ 3,886,886 Criticized - compromised 4,405 15,295 5,078 24,778 Classified - substandard 2,754 36,922 10,289 49,965 Classified - doubtful — — — — Total $ 496,539 $ 2,376,972 $ 1,088,118 $ 3,961,629
Summary of Changes in Accretable Yield for Loans Acquired with Deteriorated Credit Quality	The following table provides changes in accretable yield for loans acquired with deteriorated credit quality: For the Nine Months Ended (unaudited, in thousands) September 30, 2017 September 30, 2016 Balance at beginning of period $ 1,717 $ 1,206 Acquisitions — 669 Reduction due to change in projected cash flows — (324 ) Reclass from non-accretable difference 1,490 1,065 Transfers (216 ) (328 ) Accretion (1,384 ) (398 ) Balance at end of period $ 1,607 $ 1,890
Summary of Age Analysis of Loan Categories	The following tables summarize the age analysis of all categories of loans: Age Analysis of Loans (unaudited, in thousands) Current 30-59 Days Past Due 60-89 Days Past Due 90 Days or More Past Due Total Past Due Total Loans 90 Days or More Past Due and Accruing (1) As of September 30, 2017 Commercial real estate: Land and construction $ 606,122 $ — $ — $ 471 $ 471 $ 606,593 $ — Improved property 2,391,693 2,235 617 13,274 16,126 2,407,819 542 Total commercial real estate 2,997,815 2,235 617 13,745 16,597 3,014,412 542 Commercial and industrial 1,121,307 1,363 497 2,526 4,386 1,125,693 20 Residential real estate 1,341,924 4,831 759 9,066 14,656 1,356,580 2,418 Home equity 519,110 3,354 808 3,944 8,106 527,216 1,289 Consumer 344,241 3,134 901 872 4,907 349,148 587 Total portfolio loans 6,324,397 14,917 3,582 30,153 48,652 6,373,049 4,856 Loans held for sale 26,888 — — — — 26,888 — Total loans $ 6,351,285 $ 14,917 $ 3,582 $ 30,153 $ 48,652 $ 6,399,937 $ 4,856 Impaired loans included above are as follows: Non-accrual $ 9,360 $ 873 $ 226 $ 24,999 $ 26,098 $ 35,458 TDRs accruing interest (1) 6,232 108 — 298 406 6,638 Total impaired $ 15,592 $ 981 $ 226 $ 25,297 $ 26,504 $ 42,096 As of December 31, 2016 Commercial real estate: Land and construction $ 496,245 $ — $ — $ 294 $ 294 $ 496,539 $ — Improved property 2,367,790 1,154 363 7,665 9,182 2,376,972 318 Total commercial real estate 2,864,035 1,154 363 7,959 9,476 2,873,511 318 Commercial and industrial 1,082,390 2,508 1,011 2,209 5,728 1,088,118 229 Residential real estate 1,365,956 6,701 1,043 9,690 17,434 1,383,390 1,922 Home equity 502,087 2,358 862 3,052 6,272 508,359 626 Consumer 390,354 3,674 1,149 881 5,704 396,058 644 Total portfolio loans 6,204,822 16,395 4,428 23,791 44,614 6,249,436 3,739 Loans held for sale 17,315 — — — — 17,315 — Total loans $ 6,222,137 $ 16,395 $ 4,428 $ 23,791 $ 44,614 $ 6,266,751 $ 3,739 Impaired loans included above are as follows: Non-accrual $ 7,570 $ 3,479 $ 923 $ 19,812 $ 24,214 $ 31,784 TDRs accruing interest (1) 7,014 342 50 240 632 7,646 Total impaired $ 14,584 $ 3,821 $ 973 $ 20,052 $ 24,846 $ 39,430 (1) Loans 90 days or more past due and accruing interest exclude TDRs 90 days or more past due and accruing interest.
Summary of Impaired Loans	The following tables summarize impaired loans: Impaired Loans September 30, 2017 December 31, 2016 Unpaid Principal Balance (1 Recorded Investment Related Allowance Unpaid Principal Balance (1) Recorded Investment Related Allowance (unaudited, in thousands) With no related specific allowance recorded: Commercial real estate: Land and construction $ 666 $ 474 $ — $ 1,212 $ 766 $ — Improved property 15,981 10,709 — 9,826 8,141 — Commercial and industrial 3,884 3,083 — 4,456 3,181 — Residential real estate 18,925 17,094 — 20,152 18,305 — Home equity 5,528 4,845 — 4,589 4,011 — Consumer 934 774 — 884 744 — Total impaired loans without a specific allowance 45,918 36,979 — 41,119 35,148 — With a specific allowance recorded: Commercial real estate: Land and construction — — — — — — Improved property 5,117 5,117 579 3,012 3,012 470 Commercial and industrial — — — 4,875 1,270 407 Total impaired loans with a specific allowance 5,117 5,117 579 7,887 4,282 877 Total impaired loans $ 51,035 $ 42,096 $ 579 $ 49,006 $ 39,430 $ 877 (1) The difference between the unpaid principal balance and the recorded investment generally reflects amounts that have been previously charged-off Impaired Loans For the Three Months Ended For the Nine Months Ended September 30, 2017 September 30, 2016 September 30, 2017 September 30, 2016 Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized (unaudited, in thousands) With no related specific allowance recorded: Commercial real estate: Land and construction $ 444 $ — $ 701 $ — $ 516 $ — $ 1,062 $ — Improved Property 10,923 31 8,403 28 10,271 400 9,408 86 Commercial and industrial 3,588 2 3,172 2 3,700 6 3,246 7 Residential real estate 17,039 57 17,013 81 17,743 192 16,882 256 Home equity 4,727 4 3,613 4 4,456 14 3,381 16 Consumer 731 2 814 — 746 5 953 6 Total impaired loans without a specific allowance 37,452 96 33,716 115 37,432 617 34,932 371 With a specific allowance recorded: Commercial real estate: Land and construction — — — — — — — — Improved Property 5,137 — 3,012 — 5,032 — 3,012 — Commercial and industrial — — 2,678 — 318 — 3,700 — Total impaired loans with a specific allowance 5,137 — 5,690 — 5,350 — 6,712 — Total impaired loans $ 42,589 $ 96 $ 39,406 $ 115 $ 42,782 $ 617 $ 41,644 $ 371
Recorded Investment in Non-Accrual Loans and TDRs	The following tables present the recorded investment in non-accrual Non-accrual (1) (unaudited, in thousands) September 30, 2017 December 31, 2016 Commercial real estate: Land and construction $ 474 $ 766 Improved property 14,263 9,535 Total commercial real estate 14,737 10,301 Commercial and industrial 2,950 4,299 Residential real estate 12,641 12,994 Home equity 4,426 3,538 Consumer 704 652 Total $ 35,458 $ 31,784 (1) At September 30, 2017, there were three borrowers with loans greater than $1.0 million totaling $8.6 million, as compared to two borrowers with loans greater than $1.0 million totaling $4.3 million at December 31, 2016. Total non-accrual non-accrual TDRs September 30, 2017 December 31, 2016 (unaudited, in thousands) Accruing Non-Accrual Total Accruing Non-Accrual Total Commercial real estate: Land and construction $ — $ 4 $ 4 $ — $ 8 $ 8 Improved property 1,563 446 2,009 1,618 688 2,306 Total commercial real estate 1,563 450 2,013 1,618 696 2,314 Commercial and industrial 133 164 297 152 151 303 Residential real estate 4,453 1,810 6,263 5,311 2,212 7,523 Home equity 419 419 838 473 297 770 Consumer 70 139 209 92 190 282 Total $ 6,638 $ 2,982 $ 9,620 $ 7,646 $ 3,546 $ 11,192
Loans Identified as TDRs	The following tables present details related to loans identified as TDRs during the three and nine months ended September 30, 2017 and 2016, respectively: New TDRs (1) For the Three Months Ended September 30, 2017 September 30, 2016 Pre- Post- Pre- Post- Modification Modification Modification Modification Outstanding Outstanding Outstanding Outstanding Number of Recorded Recorded Number of Recorded Recorded (unaudited, dollars in thousands) Modifications Investment Investment Modifications Investment Investment Commercial real estate: Land and construction — $ — $ — — $ — $ — Improved Property 1 190 185 — — — Total commercial real estate 1 190 185 — — — Commercial and industrial — — — 2 125 122 Residential real estate — — — 2 124 122 Home equity 2 94 88 — — — Consumer 1 7 6 4 26 23 Total 4 $ 291 $ 279 8 $ 275 $ 267 (1) Excludes loans that were either paid off or charged-off pre-modification New TDRs (1) For the Nine Months Ended September 30, 2017 September 30, 2016 (unaudited, dollars in thousands) Number of Pre- Post- Number of Pre- Post- Commercial real estate: Land and construction — $ — $ — — $ — $ — Improved Property 1 190 185 — — — Total commercial real estate 1 190 185 — — — Commercial and industrial 1 64 59 2 125 122 Residential real estate 2 22 17 3 150 143 Home equity 3 141 132 1 44 41 Consumer 4 42 33 10 70 54 Total 11 $ 459 $ 426 16 $ 389 $ 360 (1) Excludes loans that were either paid off or charged-off pre-modification
TDRs Defaulted Later Restructured	The following table summarizes TDRs which defaulted (defined as past due 90 days) during the nine months ended September 30, 2017 and 2016, respectively, that were restructured within the last twelve months prior to September 30, 2017 and 2016, respectively: Defaulted TDRs (1) For the Nine Months Ended September 30, 2017 September 30, 2016 (unaudited, dollars in thousands) Number of Recorded Number of Recorded Commercial real estate: Land and construction — $ — — $ — Improved property — — — — Total commercial real estate — — — — Commercial and industrial — — 1 40 Residential real estate 1 7 — — Home equity — — — — Consumer 1 7 — — Total 2 $ 14 1 $ 40 (1) Excludes loans that were either charged-off
Summary of Other Real Estate Owned and Repossessed Assets	The following table summarizes other real estate owned and repossessed assets included in other assets: (unaudited, in thousands) September 30, December 31, Other real estate owned $ 5,636 $ 8,206 Repossessed assets 146 140 Total other real estate owned and repossessed assets $ 5,782 $ 8,346

Pension Plan (Tables)

Pension Plan (Tables)	9 Months Ended
	Sep. 30, 2017
Retirement Benefits [Abstract]
Components of Net Periodic Pension Cost	The following table presents the net periodic pension cost for WesBanco’s Defined Benefit Pension Plan (the “Plan”) and the related components: For the Three Months Ended For the Nine Months Ended (unaudited, in thousands) 2017 2016 2017 2016 Service cost – benefits earned during year $ 650 $ 703 $ 1,929 $ 2,095 Interest cost on projected benefit obligation 1,107 1,280 3,287 3,813 Expected return on plan assets (1,928 ) (1,940 ) (5,721 ) (5,778 ) Amortization of prior service cost 7 8 19 20 Amortization of net loss 812 759 2,409 2,261 Net periodic pension cost $ 648 $ 810 $ 1,923 $ 2,411

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Assets and Liabilities Measured on Recurring and Nonrecurring Basis	The following tables set forth WesBanco’s financial assets and liabilities that were accounted for at fair value on a recurring and nonrecurring basis by level within the fair value hierarchy as of September 30, 2017 and December 31, 2016: September 30, 2017 Fair Value Measurements Using: September 30, 2017 Quoted Prices in Significant Significant Investments (unaudited, in thousands) (level 1) (level 2) (level 3) Value Recurring fair value measurements Trading securities $ 7,929 $ 6,457 $ — $ — $ 1,472 Securities - available-for-sale U.S. Government sponsored entities and agencies 72,319 — 72,319 — — Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 963,474 — 963,474 — — Commercial mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 121,834 — 121,834 — — Obligations of state and political subdivisions 106,847 — 106,847 — — Corporate debt securities 35,503 — 35,503 — — Equity securities 5,555 5,555 — — — Total securities - available-for-sale $ 1,305,532 $ 5,555 $ 1,299,977 $ — $ — Other assets - interest rate derivatives agreements $ 5,506 $ — $ 5,506 $ — $ — Total assets recurring fair value measurements $ 1,318,967 $ 12,012 $ 1,305,483 $ — $ 1,472 Other liabilities - interest rate derivatives agreements $ 5,443 $ — $ 5,443 $ — $ — Total liabilities recurring fair value measurements $ 5,443 $ — $ 5,443 $ — $ — Nonrecurring fair value measurements Impaired loans $ 4,538 $ — $ — $ 4,538 $ — Other real estate owned and repossessed assets 5,782 — — 5,782 — Loans held for sale 26,888 — 26,888 — — Total nonrecurring fair value measurements $ 37,208 $ — $ 26,888 $ 10,320 $ — December 31, 2016 Fair Value Measurements Using: December 31, Quoted Prices in Active Markets for Identical Assets Significant Other Observable Inputs Significant Unobservable Inputs Investments Measured at Net Asset (unaudited, in thousands) 2016 (level 1) (level 2) (level 3) Value Recurring fair value measurements Trading securities $ 7,071 $ 5,633 $ — $ — $ 1,438 Securities - available-for-sale U.S. Government sponsored entities and agencies 54,043 — 54,043 — — Residential mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 938,289 — 938,289 — — Commercial mortgage-backed securities and collateralized mortgage obligations of government sponsored entities and agencies 96,810 — 96,810 — — Obligations of state and political subdivisions 111,663 — 111,663 — — Corporate debt securities 35,301 — 35,301 — — Equity securities 5,070 2,938 2,132 — — Total securities - available-for-sale $ 1,241,176 $ 2,938 $ 1,238,238 $ — $ — Other assets - interest rate derivatives agreements $ 5,596 $ — $ 5,596 $ — $ — Total assets recurring fair value measurements $ 1,253,843 $ 8,571 $ 1,243,834 $ — $ 1,438 Other liabilities - interest rate derivatives agreements $ 5,199 $ — $ 5,199 $ — $ — Total liabilities recurring fair value measurements $ 5,199 $ — $ 5,199 $ — $ — Nonrecurring fair value measurements Impaired loans $ 3,405 $ — $ — $ 3,405 $ — Other real estate owned and repossessed assets 8,346 — — 8,346 — Loans held for sale 17,315 — 17,315 — — Total nonrecurring fair value measurements $ 29,066 $ — $ 17,315 $ 11,751 $ —
Schedule of Assets Measured at Fair Value on Nonrecurring Basis	The following table presents additional quantitative information about assets measured at fair value on a nonrecurring basis and for which WesBanco has utilized level 3 inputs to determine fair value: Quantitative Information about Level 3 Fair Value Measurements Fair Value Valuation Unobservable Range (Weighted (unaudited, in thousands) Estimate Techniques Input Average) September 30, 2017 Impaired loans $ 4,538 Appraisal of collateral (1) Appraisal adjustments (2) 0% to (4.8%) /(1.9%) Liquidation expenses (2) (7.6%) to (8.0%) / (7.9%) Other real estate owned and repossessed assets 5,782 Appraisal of collateral (1), (3) December 31, 2016: Impaired loans $ 3,405 Appraisal of collateral (1) Appraisal adjustments (2) 0% to (70.0%) / (36.6%) Liquidation expenses (2) (1.5%) to (8.0%) / (4.6%) Other real estate owned and repossessed assets 8,346 Appraisal of collateral (1), (3) (1) Fair value is generally determined through independent appraisals of the underlying collateral, which generally include various level 3 inputs, which are not identifiable. (2) Appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses. The range and weighted average of appraisal adjustments and liquidation expenses are presented as a percent of the appraisal. (3) Includes estimated liquidation expenses and numerous dissimilar qualitative adjustments by management which are not identifiable.
Estimates Fair Values of Financial Instruments	The estimated fair values of WesBanco’s financial instruments are summarized below: Fair Value Measurements at September 30, 2017 (unaudited, in thousands) Carrying Fair Value Quoted Prices in (level 1) Significant Other (level 2) Significant (level 3) Investments Financial Assets Cash and due from banks $ 110,871 $ 110,871 $ 110,871 $ — $ — $ — Trading securities 7,929 7,929 6,457 — — 1,472 Securities available-for-sale 1,305,532 1,305,532 5,555 1,299,977 — — Securities held-to-maturity 1,025,688 1,044,748 — 1,044,135 613 — Net loans 6,327,562 6,241,388 — — 6,241,388 — Loans held for sale 26,888 26,888 — 26,888 — — Other assets - interest rate derivatives 5,506 5,506 — 5,506 — — Accrued interest receivable 30,152 30,152 30,152 — — — Financial Liabilities Deposits 7,101,025 7,112,593 5,766,959 1,345,634 — — Federal Home Loan Bank borrowings 1,015,011 1,014,117 — 1,014,117 — — Other borrowings 165,576 165,579 163,532 2,047 — — Subordinated debt and junior subordinated debt 164,278 138,421 — 138,421 — — Other liabilities - interest rate derivatives 5,443 5,443 — 5,443 — — Accrued interest payable 3,924 3,924 3,924 — — — Fair Value Measurements at December 31, 2016 (unaudited, in thousands) Carrying Fair Value Quoted Prices in (level 1) Significant Other (level 2) Significant (level 3) Investments Financial Assets Cash and due from banks $ 128,170 $ 128,170 $ 128,170 $ — $ — $ — Trading securities 7,071 7,071 5,633 — — 1,438 Securities available-for-sale 1,241,176 1,241,176 2,938 1,238,238 — — Securities held-to-maturity 1,067,967 1,076,790 — 1,076,189 601 — Net loans 6,205,762 6,073,558 — — 6,073,558 — Loans held for sale 17,315 17,315 — 17,315 — — Other assets - interest rate derivatives 5,596 5,596 — 5,596 — — Accrued interest receivable 28,299 28,299 28,299 — — — Financial Liabilities Deposits 7,040,879 7,052,501 5,545,057 1,507,444 — — Federal Home Loan Bank borrowings 968,946 974,430 — 974,430 — — Other borrowings 199,376 199,385 197,164 2,221 — — Subordinated debt and junior subordinated debt 163,598 134,859 — 134,859 — — Other liabilities - interest rate derivatives 5,199 5,199 — 5,199 — — Accrued interest payable 2,204 2,204 2,204 — — —

Comprehensive Income (Tables)

Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Components of Accumulated Other Comprehensive Income	The activity in accumulated other comprehensive income for the nine months ended September 30, 2017 and 2016 is as follows: Accumulated Other Comprehensive Income/(Loss) (1) (unaudited, in thousands) Defined Unrealized on Securities Available-for-Sale Unrealized Gains Available-for-Sale to Held-to-Maturity Total Balance at December 31, 2016 $ (17,758 ) $ (9,890 ) $ 522 $ (27,126 ) Other comprehensive income before reclassifications — 4,740 — 4,740 Amounts reclassified from accumulated other comprehensive income 1,679 35 (165 ) 1,549 Period change 1,679 4,775 (165 ) 6,289 Balance at September 30, 2017 $ (16,079 ) $ (5,115 ) $ 357 $ (20,837 ) Balance at December 31, 2015 $ (17,539 ) $ (4,162 ) $ 747 $ (20,954 ) Other comprehensive income before reclassifications — 16,065 — 16,065 Amounts reclassified from accumulated other comprehensive income 1,407 (1,428 ) (152 ) (173 ) Period change 1,407 14,637 (152 ) 15,892 Balance at September 30, 2016 $ (16,132 ) $ 10,475 $ 595 $ (5,062 ) (1) All amounts are net of tax. Related income tax expense or benefit is calculated using a combined Federal and State income tax rate approximating 37%.
Schedule of Amounts Reclassified from Accumulated Other Comprehensive Income	The following table provides details about amounts reclassified from accumulated other comprehensive income for the three and nine months ended September 30, 2017 and 2016: Details about Accumulated Other Comprehensive For the Three Months Ended For the Nine Months Ended September 30, Affected Line Item in the Statement of Net Income (unaudited, in thousands) 2017 2016 2017 2016 Securities available-for-sale (1) Net securities gains reclassified into earnings $ — $ (579 ) $ 55 $ (2,251 ) Net securities gains (Non-interest Related income tax expense (benefit) — 211 (20 ) 823 Provision for income taxes Net effect on accumulated other comprehensive income for the period — (368 ) 35 (1,428 ) Securities held-to-maturity (1) Amortization of unrealized gain transferred from available-for-sale (66 ) (77 ) (256 ) (242 ) Interest and dividends on securities (Interest and dividend income) Related income tax expense 24 28 91 90 Provision for income taxes Net effect on accumulated other comprehensive income for the period (42 ) (49 ) (165 ) (152 ) Defined benefit pension plan (2) Amortization of net loss and prior service costs 816 766 2,429 2,280 Employee benefits (Non-interest Related income tax benefit (303 ) (280 ) (750 ) (873 ) Provision for income taxes Net effect on accumulated other comprehensive income for the period 513 486 1,679 1,407 Total reclassifications for the period $ 471 $ 69 $ 1,549 $ (173 ) (1) For additional detail related to unrealized gains on securities and related amounts reclassified from accumulated other comprehensive income, see Note 4, “Securities.” (2) Included in the computation of net periodic pension cost. See Note 6, “Pension Plan” for additional detail.

Commitments and Contingent Li26

Commitments and Contingent Liabilities (Tables)	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments to Extend Credit, Guarantees and Various Letters of Credit Outstanding	The following table presents total commitments to extend credit, guarantees and various letters of credit outstanding: September 30, December 31, (unaudited, in thousands) 2017 2016 Lines of credit $ 1,468,470 $ 1,418,329 Loans approved but not closed 243,723 185,253 Overdraft limits 126,936 126,517 Letters of credit 32,328 32,907 Contingent obligations to purchase loans funded by other entities 6,974 13,036

Business Segments (Tables)

Business Segments (Tables)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Financial Information by Business Segment	Condensed financial information by business segment is presented below: Trust and Community Investment (unaudited, in thousands) Banking Services Consolidated For the Three Months ended September 30, 2017: Interest income $ 85,489 $ — $ 85,489 Interest expense 11,235 — 11,235 Net interest income 74,254 — 74,254 Provision for credit losses 2,516 — 2,516 Net interest income after provision for credit losses 71,738 — 71,738 Non-interest 15,541 5,358 20,899 Non-interest 52,355 3,399 55,754 Income before provision for income taxes 34,924 1,959 36,883 Provision for income taxes 9,744 783 10,527 Net income $ 25,180 $ 1,176 $ 26,356 For the Three Months ended September 30, 2016: Interest income $ 70,092 $ — $ 70,092 Interest expense 8,066 — 8,066 Net interest income 62,026 — 62,026 Provision for credit losses 2,214 — 2,214 Net interest income after provision for credit losses 59,812 — 59,812 Non-interest 15,604 5,413 21,017 Non-interest 54,569 3,032 57,601 Income before provision for income taxes 20,847 2,381 23,228 Provision for income taxes 4,841 952 5,793 Net income $ 16,006 $ 1,429 $ 17,435 For the Nine Months ended September 30, 2017: Interest income $ 247,573 $ — $ 247,573 Interest expense 30,461 — 30,461 Net interest income 217,112 — 217,112 Provision for credit losses 7,610 — 7,610 Net interest income after provision for credit losses 209,502 — 209,502 Non-interest 48,833 17,073 65,906 Non-interest 156,102 9,921 166,023 Income before provision for income taxes 102,233 7,152 109,385 Provision for income taxes 27,940 2,861 30,801 Net income $ 74,293 $ 4,291 $ 78,584 For the Nine Months ended September 30, 2016: Interest income $ 205,278 $ — $ 205,278 Interest expense 23,637 — 23,637 Net interest income 181,641 — 181,641 Provision for credit losses 6,350 — 6,350 Net interest income after provision for credit losses 175,291 — 175,291 Non-interest 43,841 16,160 60,001 Non-interest 141,029 9,274 150,303 Income before provision for income taxes 78,103 6,886 84,989 Provision for income taxes 19,818 2,754 22,572 Net income $ 58,285 $ 4,132 $ 62,417

Summary of Significant Accoun28

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accounting Policies [Abstract]
Service cost component of net periodic benefit cost	$ 650	$ 703	$ 1,929	$ 2,095
Partnerships losses and impairment	$ 400		$ 1,200

Mergers and Acquisitions - Addi

Mergers and Acquisitions - Additional Information (Detail) - USD ($)	Sep. 09, 2016	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Your Community Bankshares, Inc [Member]
Business Acquisition [Line Items]
Total assets acquired, excluding goodwill	$ 1,500,000,000
Loans	1,012,410,000
Securities	173,223,000
Value of acquisition	$ 220,498,000
Common shares issued	5,423,348
Cash consideration for outstanding YCB shares	$ 43,349,000
Goodwill acquired	93,033,000
Purchase price allocation in core deposit intangible	$ 11,957,000
Closing stock price	$ 32.62
Merger related expense			$ 500,000		$ 13,300,000
Purchase Price Allocation Adjustment [Member]
Business Acquisition [Line Items]
Loans	$ (1,156,000)
Assets acquired, adjustments		$ 0
Liabilities assumed, adjustments		$ 0
Common Stock [Member]
Business Acquisition [Line Items]
Common shares issued				5,423,348
Common Stock [Member] | Your Community Bankshares, Inc [Member]
Business Acquisition [Line Items]
Common shares issued	5,423,348
Cash consideration for outstanding YCB shares	$ 43,300,000

Mergers and Acquisitions - Summ

Mergers and Acquisitions - Summary of Purchase Price of Acquisition and Resulting Goodwill (Detail) - Your Community Bankshares, Inc [Member] $ in Thousands	Sep. 09, 2016USD ($)
Purchase Price:
Fair value of WesBanco shares issued	$ 177,149
Cash consideration for outstanding YCB shares	43,349
Total purchase price	220,498
Fair value of:
Tangible assets acquired	1,398,183
Core deposit and other intangible assets acquired	11,957
Liabilities assumed	(1,330,887)
Net cash received in the acquisition	48,212
Fair value of net assets acquired	127,465
Goodwill recognized	$ 93,033

Mergers and Acquisitions - Allo

Mergers and Acquisitions - Allocation of Purchase Price of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Sep. 09, 2016	Sep. 30, 2017	Dec. 31, 2016
Purchase Price Allocation Adjustment [Member]
Business Acquisition [Line Items]
Loans	$ (1,156)
Accrued income and other assets	743
Liabilities
Accrued expenses and other liabilities	269
Fair value of net assets acquired	(144)
Increase in goodwill recognized	144
Goodwill recognized		$ 93,033	$ 92,889
Your Community Bankshares, Inc [Member]
Business Acquisition [Line Items]
Cash and due from banks	48,212
Securities	173,223
Loans	1,012,410
Goodwill and other intangible assets	104,990
Accrued income and other assets	212,550
Total assets acquired	1,551,385
Liabilities
Deposits	1,193,010
Borrowings	123,001
Accrued expenses and other liabilities	14,876
Total liabilities assumed	1,330,887
Net assets acquired	220,498
Fair value of net assets acquired	$ 127,465

Mergers and Acquisitions - Al32

Mergers and Acquisitions - Allocation of Purchase Price of Assets Acquired and Liabilities Assumed (Parenthetical) (Detail) $ in Millions	Sep. 09, 2016USD ($)
Your Community Bankshares, Inc [Member]
Business Acquisition [Line Items]
Receivables from sale of available-for-sale securities	$ 105.8

Earnings Per Common Share - Sum

Earnings Per Common Share - Summary of Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Numerator for both basic and diluted earnings per common share:
Net income	$ 26,356	$ 17,435	$ 78,584	$ 62,417
Denominator:
Total average basic common shares outstanding	44,031,813	39,715,516	43,992,017	38,828,618
Effect of dilutive stock options and other stock compensation	55,068	27,775	67,452	26,835
Total diluted average common shares outstanding	44,086,881	39,743,291	44,059,469	38,855,453
Earnings per common share - basic	$ 0.60	$ 0.44	$ 1.79	$ 1.61
Earnings per common share - diluted	$ 0.60	$ 0.44	$ 1.78	$ 1.61

Earnings Per Common Share - Add

Earnings Per Common Share - Additional Information (Detail) - shares	Sep. 09, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded from computation of net income per diluted shares		117,550	96,600		185,250
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded from computation of net income per diluted shares		28,502	0	28,502	0
Your Community Bankshares, Inc [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares issued for acquisition, shares	5,423,348
Your Community Bankshares, Inc [Member] | Treasury Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Shares issued for acquisition, shares	109,257

Securities - Schedule of Fair V

Securities - Schedule of Fair Value and Amortized Cost of Available-for-sale and Held-to-maturity Securities (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Schedule of Trading Securities and Other Trading Assets [Line Items]
Available-for-sale, Amortized Cost	$ 1,313,665	$ 1,256,762
Available-for-sale, Gross Unrealized Gains	5,773	5,177
Available-for-sale, Gross Unrealized Losses	(13,906)	(20,763)
Available-for-sale, Estimated Fair Value	1,305,532	1,241,176
Held-to-maturity, Amortized Cost	1,025,688	1,067,967
Held-to-maturity, Gross Unrealized Gains	21,981	17,349
Held-to-maturity, Gross Unrealized Losses	(2,921)	(8,526)
Held-to-maturity securities, Fair value	1,044,748	1,076,790
Total, Amortized Cost	2,339,353	2,324,729
Total, Gross Unrealized Gains	27,754	22,526
Total, Gross Unrealized Losses	(16,827)	(29,289)
Total, Estimated Fair Value	2,350,280	2,317,966
U.S. Government Sponsored Entities and Agencies [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Available-for-sale, Amortized Cost	72,672	54,803
Available-for-sale, Gross Unrealized Gains	88	3
Available-for-sale, Gross Unrealized Losses	(441)	(763)
Available-for-sale, Estimated Fair Value	72,319	54,043
Held-to-maturity, Amortized Cost	12,128	13,394
Held-to-maturity, Gross Unrealized Losses	(254)	(414)
Held-to-maturity securities, Fair value	11,874	12,980
Residential Mortgage-Backed Securities and Collateralized Mortgage Obligations of Government Sponsored Entities and Agencies [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Available-for-sale, Amortized Cost	974,370	953,475
Available-for-sale, Gross Unrealized Gains	776	884
Available-for-sale, Gross Unrealized Losses	(11,672)	(16,070)
Available-for-sale, Estimated Fair Value	963,474	938,289
Held-to-maturity, Amortized Cost	178,429	215,141
Held-to-maturity, Gross Unrealized Gains	763	1,279
Held-to-maturity, Gross Unrealized Losses	(1,467)	(2,563)
Held-to-maturity securities, Fair value	177,725	213,857
Commercial Mortgage-Backed Securities and Collateralized Mortgage Obligations of Government Sponsored Entities and Agencies [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Available-for-sale, Amortized Cost	122,908	98,922
Available-for-sale, Gross Unrealized Gains	77	27
Available-for-sale, Gross Unrealized Losses	(1,151)	(2,139)
Available-for-sale, Estimated Fair Value	121,834	96,810
Obligations of State and Political Subdivisions [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Available-for-sale, Amortized Cost	104,228	110,208
Available-for-sale, Gross Unrealized Gains	3,187	3,114
Available-for-sale, Gross Unrealized Losses	(568)	(1,659)
Available-for-sale, Estimated Fair Value	106,847	111,663
Held-to-maturity, Amortized Cost	801,760	805,019
Held-to-maturity, Gross Unrealized Gains	20,153	15,652
Held-to-maturity, Gross Unrealized Losses	(1,200)	(5,529)
Held-to-maturity securities, Fair value	820,713	815,142
Corporate Debt Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Available-for-sale, Amortized Cost	35,249	35,292
Available-for-sale, Gross Unrealized Gains	325	117
Available-for-sale, Gross Unrealized Losses	(71)	(108)
Available-for-sale, Estimated Fair Value	35,503	35,301
Held-to-maturity, Amortized Cost	33,371	34,413
Held-to-maturity, Gross Unrealized Gains	1,065	418
Held-to-maturity, Gross Unrealized Losses		(20)
Held-to-maturity securities, Fair value	34,436	34,811
Debt Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Available-for-sale, Amortized Cost	1,309,427	1,252,700
Available-for-sale, Gross Unrealized Gains	4,453	4,145
Available-for-sale, Gross Unrealized Losses	(13,903)	(20,739)
Available-for-sale, Estimated Fair Value	1,299,977	1,236,106
Equity Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Available-for-sale, Amortized Cost	4,238	4,062
Available-for-sale, Gross Unrealized Gains	1,320	1,032
Available-for-sale, Gross Unrealized Losses	(3)	(24)
Available-for-sale, Estimated Fair Value	$ 5,555	$ 5,070

Securities - Additional Informa

Securities - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2017USD ($)Holdings	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)Holdings
Investments, Debt and Equity Securities [Abstract]
Trading securities, at fair value	$ 7,929,000		$ 7,071,000
Maximum percentage of equity of one issuer	10.00%
Number of holdings greater than specified percentage of equity | Holdings	0		0
Securities with aggregate fair values	$ 1,400,000,000		$ 1,200,000,000
Proceeds from sale of available-for-sale securities	7,760,000	$ 277,225,000
Net unrealized losses on available-for-sale securities included in AOCI	5,100,000		9,900,000
Impairment loss relating to securities	0
Federal home loan bank stock, Total	$ 48,600,000		$ 46,400,000

Securities - Schedule of Fair37

Securities - Schedule of Fair Value of Available-for-Sale and Held-to-Maturity Securities by Contractual Maturity (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Total available-for-sale securities, One Year or less	$ 7,723
Total available-for-sale securities, One to Five Years	60,336
Total available-for-sale securities, Five to Ten Years	58,389
Total available-for-sale securities, After Ten Years	51,632
Total available-for-sale securities, Mortgage-backed and Equity	1,127,452
Available-for-sale, Estimated Fair Value	1,305,532	$ 1,241,176
Total held-to-maturity securities, One Year or less	4,703
Total held-to-maturity securities, One to Five Years	91,206
Total held-to-maturity securities, Five to Ten Years	443,954
Total held-to-maturity securities, After Ten Years	315,286
Total held-to-maturity securities, Mortgage-backed and Equity	189,599
Held-to-maturity securities, Fair value	1,044,748	1,076,790
Total, One Year or less	12,426
Total, One to Five Years	151,542
Total, Five to Ten Years	502,343
Total, After Ten Years, Fair value	366,918
Total, Mortgage- backed and Equity	1,317,051
Total, Fair value	2,350,280	2,317,966
U.S. Government Sponsored Entities and Agencies [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Total available-for-sale securities, One to Five Years	11,967
Total available-for-sale securities, Five to Ten Years	16,855
Total available-for-sale securities, After Ten Years	6,908
Total available-for-sale securities, Mortgage-backed and Equity	36,589
Available-for-sale, Estimated Fair Value	72,319	54,043
Total held-to-maturity securities, Mortgage-backed and Equity	11,874
Held-to-maturity securities, Fair value	11,874	12,980
Residential Mortgage-Backed Securities and Collateralized Mortgage Obligations of Government Sponsored Entities and Agencies [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Total available-for-sale securities, Mortgage-backed and Equity	963,474
Available-for-sale, Estimated Fair Value	963,474	938,289
Total held-to-maturity securities, Mortgage-backed and Equity	177,725
Held-to-maturity securities, Fair value	177,725	213,857
Commercial Mortgage-Backed Securities and Collateralized Mortgage Obligations of Government Sponsored Entities and Agencies [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Total available-for-sale securities, Mortgage-backed and Equity	121,834
Available-for-sale, Estimated Fair Value	121,834	96,810
Obligations of State and Political Subdivisions [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Total available-for-sale securities, One Year or less	7,723
Total available-for-sale securities, One to Five Years	17,886
Total available-for-sale securities, Five to Ten Years	36,514
Total available-for-sale securities, After Ten Years	44,724
Available-for-sale, Estimated Fair Value	106,847	111,663
Total held-to-maturity securities, One Year or less	4,703
Total held-to-maturity securities, One to Five Years	88,402
Total held-to-maturity securities, Five to Ten Years	412,322
Total held-to-maturity securities, After Ten Years	315,286
Held-to-maturity securities, Fair value	820,713	815,142
Corporate Debt Securities [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Total available-for-sale securities, One to Five Years	30,483
Total available-for-sale securities, Five to Ten Years	5,020
Available-for-sale, Estimated Fair Value	35,503	35,301
Total held-to-maturity securities, One to Five Years	2,804
Total held-to-maturity securities, Five to Ten Years	31,632
Held-to-maturity securities, Fair value	34,436	34,811
Equity Securities [Member]
Schedule Of Available For Sale Securities And Held To Maturity [Line Items]
Total available-for-sale securities, Mortgage-backed and Equity	5,555
Available-for-sale, Estimated Fair Value	$ 5,555	$ 5,070

Securities - Schedule of Fair38

Securities - Schedule of Fair Value of Available-for-Sale and Held-to-Maturity Securities by Contractual Maturity (Parenthetical) (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Held-to-maturity, Amortized Cost	$ 1,025,688	$ 1,067,967

Securities - Schedule of Gross

Securities - Schedule of Gross Realized Gains and Losses on Sales and Calls of Available-for-Sale and Held-to-Maturity Securities (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Securities Gross Realized Gain Loss [Abstract]
Gross realized gains	$ 29	$ 602	$ 603	$ 2,517
Gross realized losses	(23)	(4)	(92)	(224)
Net realized gains	$ 6	$ 598	$ 511	$ 2,293

Securities - Schedule of Unreal

Securities - Schedule of Unrealized Losses on Investment Securities (Detail) $ in Thousands	Sep. 30, 2017USD ($)Security	Dec. 31, 2016USD ($)Security
U.S. Government Sponsored Entities and Agencies [Member]
Net Unrealized Gains And Losses On Investments [Line Items]
Less than 12 months, Fair Value	$ 29,875	$ 58,108
Less than 12 months, Unrealized Losses	$ (208)	$ (1,177)
Less than 12 months, Number of Securities | Security	6	11
12 months or more, Fair Value	$ 36,284
12 months or more, Unrealized Losses	$ (487)
12 months or more, Number of Securities | Security	5
Fair Value, Total	$ 66,159	$ 58,108
Unrealized Losses, Total	$ (695)	$ (1,177)
Number of Securities Total | Security	11	11
Residential Mortgage-Backed Securities and Collateralized Mortgage Obligations of Government Sponsored Entities and Agencies [Member]
Net Unrealized Gains And Losses On Investments [Line Items]
Less than 12 months, Fair Value	$ 729,219	$ 969,174
Less than 12 months, Unrealized Losses	$ (6,426)	$ (16,436)
Less than 12 months, Number of Securities | Security	180	232
12 months or more, Fair Value	$ 254,554	$ 58,839
12 months or more, Unrealized Losses	$ (6,713)	$ (2,197)
12 months or more, Number of Securities | Security	69	14
Fair Value, Total	$ 983,773	$ 1,028,013
Unrealized Losses, Total	$ (13,139)	$ (18,633)
Number of Securities Total | Security	249	246
Commercial Mortgage-Backed Securities and Collateralized Mortgage Obligations of Government Sponsored Entities and Agencies [Member]
Net Unrealized Gains And Losses On Investments [Line Items]
Less than 12 months, Fair Value	$ 93,924	$ 88,169
Less than 12 months, Unrealized Losses	$ (1,135)	$ (2,122)
Less than 12 months, Number of Securities | Security	13	14
12 months or more, Fair Value	$ 660	$ 679
12 months or more, Unrealized Losses	$ (16)	$ (17)
12 months or more, Number of Securities | Security	2	2
Fair Value, Total	$ 94,584	$ 88,848
Unrealized Losses, Total	$ (1,151)	$ (2,139)
Number of Securities Total | Security	15	16
Obligations of State and Political Subdivisions [Member]
Net Unrealized Gains And Losses On Investments [Line Items]
Less than 12 months, Fair Value	$ 96,323	$ 364,583
Less than 12 months, Unrealized Losses	$ (526)	$ (7,121)
Less than 12 months, Number of Securities | Security	153	604
12 months or more, Fair Value	$ 73,210	$ 2,047
12 months or more, Unrealized Losses	$ (1,242)	$ (67)
12 months or more, Number of Securities | Security	156	3
Fair Value, Total	$ 169,533	$ 366,630
Unrealized Losses, Total	$ (1,768)	$ (7,188)
Number of Securities Total | Security	309	607
Corporate Debt Securities [Member]
Net Unrealized Gains And Losses On Investments [Line Items]
Less than 12 months, Fair Value	$ 4,015	$ 10,011
Less than 12 months, Unrealized Losses	$ (22)	$ (78)
Less than 12 months, Number of Securities | Security	1	3
12 months or more, Fair Value	$ 6,960	$ 5,973
12 months or more, Unrealized Losses	$ (49)	$ (50)
12 months or more, Number of Securities | Security	2	2
Fair Value, Total	$ 10,975	$ 15,984
Unrealized Losses, Total	$ (71)	$ (128)
Number of Securities Total | Security	3	5
Equity Securities [Member]
Net Unrealized Gains And Losses On Investments [Line Items]
Less than 12 months, Fair Value	$ 1,359	$ 2,938
Less than 12 months, Unrealized Losses	$ (3)	$ (24)
Less than 12 months, Number of Securities | Security	1	2
Fair Value, Total	$ 1,359	$ 2,938
Unrealized Losses, Total	$ (3)	$ (24)
Number of Securities Total | Security	1	2
Total Temporarily Impaired Securities [Member]
Net Unrealized Gains And Losses On Investments [Line Items]
Less than 12 months, Fair Value	$ 954,715	$ 1,492,983
Less than 12 months, Unrealized Losses	$ (8,320)	$ (26,958)
Less than 12 months, Number of Securities | Security	354	866
12 months or more, Fair Value	$ 371,668	$ 67,538
12 months or more, Unrealized Losses	$ (8,507)	$ (2,331)
12 months or more, Number of Securities | Security	234	21
Fair Value, Total	$ 1,326,383	$ 1,560,521
Unrealized Losses, Total	$ (16,827)	$ (29,289)
Number of Securities Total | Security	588	887

Loans and the Allowance for C41

Loans and the Allowance for Credit Losses - Additional Information (Detail)	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)Contract	Dec. 31, 2016USD ($)Contract	Sep. 30, 2016USD ($)	Sep. 09, 2016USD ($)	Dec. 31, 2015USD ($)
Financing Receivable, Recorded Investment [Line Items]
Deferred loan (costs) and fees	$ (1,000,000)	$ 300,000
Unamortized discount on purchased loans from acquisitions	23,000,000	24,100,000
Aggregate amount of residential real estate, home equity and consumer loans classified as substandard	22,400,000	20,600,000
Internally assigned loan grades to residential real estate, home equity and consumer loans	4,600,000	3,400,000
Loans acquired with deteriorated credit quality	8,544,000	12,859,000
Allowance for loan losses	$ 45,487,000	$ 43,674,000	$ 42,755,000		$ 41,710,000
Number of restructured contracts greater than $1 million | Contract	0	0
Accruing and non accrual TDR permitted interest-only payment period	3 months
Unfunded commitments to debtors for impaired loans	$ 100,000	$ 0
Other real estate owned	5,636,000	8,206,000
Your Community Bankshares, Inc [Member]
Financing Receivable, Recorded Investment [Line Items]
Unamortized discount on purchased loans from acquisitions	11,100,000
Loans acquired with deteriorated credit quality	4,500,000	5,700,000
Fair value of acquired loans				$ 1,012,410,000
Allowance for loan losses	0	0
Loans acquired accretable	500,000
Your Community Bankshares, Inc [Member] | Cost Recovery Method [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value of acquired loans	800,000	1,400,000
ESB Financial Corporation [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans acquired with deteriorated credit quality	4,000,000	7,200,000
Allowance for loan losses	2,000,000	1,800,000
Loans acquired accretable	1,100,000
ESB Financial Corporation [Member] | Cost Recovery Method [Member]
Financing Receivable, Recorded Investment [Line Items]
Fair value of acquired loans	3,500,000	0
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans acquired with deteriorated credit quality	751,000	943,000
Allowance for loan losses	3,372,000	4,106,000	$ 4,337,000		$ 4,582,000
Other real estate owned	1,700,000	1,600,000
Foreclosure proceedings in process on residential real estate loans	3,300,000	4,100,000
Residential Real Estate [Member] | Your Community Bankshares, Inc [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Real estate owned from acquisition	$ 1,100,000	$ 3,100,000

Loans and the Allowance for C42

Loans and the Allowance for Credit Losses - Schedule of Recorded Investment in Loans by Category (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Total portfolio loans	$ 6,373,049	$ 6,249,436
Loans held for sale	26,888	17,315
Total loans	6,399,937	6,266,751
Commercial Real Estate - Land and Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Total portfolio loans	606,593	496,539
Commercial Real Estate - Improved Property [Member]
Financing Receivable, Recorded Investment [Line Items]
Total portfolio loans	2,407,819	2,376,972
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total portfolio loans	1,125,693	1,088,118
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total portfolio loans	3,014,412	2,873,511
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total portfolio loans	1,356,580	1,383,390
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total portfolio loans	349,148	396,058
Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Total portfolio loans	$ 527,216	$ 508,359

Loans and the Allowance for C43

Loans and the Allowance for Credit Losses - Summary of Changes in Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, beginning balance			$ 43,674	$ 41,710
Allowance for loan commitments, beginning balance			571	613
Total beginning allowance for credit losses			44,245	42,323
Provision for loan losses			7,534	6,387
Provision for loan commitments			76	(37)
Total provision for credit losses	$ 2,516	$ 2,214	7,610	6,350
Charge-offs			(9,000)	(8,880)
Recoveries			3,279	3,538
Net charge-offs			(5,721)	(5,342)
Allowance for loan losses, ending balance	45,487	42,755	45,487	42,755
Allowance for loan commitments, ending balance	647	576	647	576
Total ending allowance for credit losses	46,134	43,331	46,134	43,331
Commercial Real Estate - Land and Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, beginning balance			4,348	4,390
Allowance for loan commitments, beginning balance			151	157
Total beginning allowance for credit losses			4,499	4,547
Provision for loan losses			415	498
Provision for loan commitments			(18)	(5)
Total provision for credit losses			397	493
Charge-offs				(73)
Recoveries			89	3
Net charge-offs			89	(70)
Allowance for loan losses, ending balance	4,852	4,818	4,852	4,818
Allowance for loan commitments, ending balance	133	152	133	152
Total ending allowance for credit losses	4,985	4,970	4,985	4,970
Commercial Real Estate - Improved Property [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, beginning balance			18,628	14,748
Allowance for loan commitments, beginning balance			17	26
Total beginning allowance for credit losses			18,645	14,774
Provision for loan losses			1,619	1,351
Provision for loan commitments			4
Total provision for credit losses			1,623	1,351
Charge-offs			(1,752)	(1,732)
Recoveries			492	1,406
Net charge-offs			(1,260)	(326)
Allowance for loan losses, ending balance	18,987	15,773	18,987	15,773
Allowance for loan commitments, ending balance	21	26	21	26
Total ending allowance for credit losses	19,008	15,799	19,008	15,799
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, beginning balance			8,412	10,002
Allowance for loan commitments, beginning balance			188	260
Total beginning allowance for credit losses			8,600	10,262
Provision for loan losses			2,842	2,827
Provision for loan commitments			45	(40)
Total provision for credit losses			2,887	2,787
Charge-offs			(2,255)	(2,883)
Recoveries			649	241
Net charge-offs			(1,606)	(2,642)
Allowance for loan losses, ending balance	9,648	10,187	9,648	10,187
Allowance for loan commitments, ending balance	233	220	233	220
Total ending allowance for credit losses	9,881	10,407	9,881	10,407
Deposit Overdraft [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, beginning balance			760	342
Total beginning allowance for credit losses			760	342
Provision for loan losses			680	559
Total provision for credit losses			680	559
Charge-offs			(947)	(585)
Recoveries			267	167
Net charge-offs			(680)	(418)
Allowance for loan losses, ending balance	760	483	760	483
Total ending allowance for credit losses	760	483	760	483
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, beginning balance			4,106	4,582
Allowance for loan commitments, beginning balance			9	7
Total beginning allowance for credit losses			4,115	4,589
Provision for loan losses			(203)	(67)
Provision for loan commitments				2
Total provision for credit losses			(203)	(65)
Charge-offs			(797)	(529)
Recoveries			266	351
Net charge-offs			(531)	(178)
Allowance for loan losses, ending balance	3,372	4,337	3,372	4,337
Allowance for loan commitments, ending balance	9	9	9	9
Total ending allowance for credit losses	3,381	4,346	3,381	4,346
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, beginning balance			3,998	4,763
Allowance for loan commitments, beginning balance			44	46
Total beginning allowance for credit losses			4,042	4,809
Provision for loan losses			922	918
Provision for loan commitments			(4)	(2)
Total provision for credit losses			918	916
Charge-offs			(2,877)	(2,733)
Recoveries			1,336	1,199
Net charge-offs			(1,541)	(1,534)
Allowance for loan losses, ending balance	3,379	4,147	3,379	4,147
Allowance for loan commitments, ending balance	40	44	40	44
Total ending allowance for credit losses	3,419	4,191	3,419	4,191
Home Equity [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses, beginning balance			3,422	2,883
Allowance for loan commitments, beginning balance			162	117
Total beginning allowance for credit losses			3,584	3,000
Provision for loan losses			1,259	301
Provision for loan commitments			49	8
Total provision for credit losses			1,308	309
Charge-offs			(372)	(345)
Recoveries			180	171
Net charge-offs			(192)	(174)
Allowance for loan losses, ending balance	4,489	3,010	4,489	3,010
Allowance for loan commitments, ending balance	211	125	211	125
Total ending allowance for credit losses	$ 4,700	$ 3,135	$ 4,700	$ 3,135

Loans and the Allowance for C44

Loans and the Allowance for Credit Losses - Allowance for Credit Losses and Recorded Investments in Loans (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loans individually evaluated for impairment	$ 579	$ 877
Allowance for loans collectively evaluated for impairment	44,908	42,797
Allowance for loan commitments	647	571	$ 576	$ 613
Total allowance for credit losses	46,134	44,245	43,331	42,323
Individually evaluated for impairment	5,117	4,282
Collectively evaluated for impairment	6,359,388	6,232,295
Acquired with deteriorated credit quality	8,544	12,859
Total Loans	6,373,049	6,249,436
Commercial Real Estate - Land and Construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loans collectively evaluated for impairment	4,852	4,348
Allowance for loan commitments	133	151	152	157
Total allowance for credit losses	4,985	4,499	4,970	4,547
Collectively evaluated for impairment	605,100	494,928
Acquired with deteriorated credit quality	1,493	1,611
Total Loans	606,593	496,539
Commercial Real Estate - Improved Property [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loans individually evaluated for impairment	579	470
Allowance for loans collectively evaluated for impairment	18,408	18,158
Allowance for loan commitments	21	17	26	26
Total allowance for credit losses	19,008	18,645	15,799	14,774
Individually evaluated for impairment	5,117	3,012
Collectively evaluated for impairment	2,397,278	2,364,067
Acquired with deteriorated credit quality	5,424	9,893
Total Loans	2,407,819	2,376,972
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loans individually evaluated for impairment		407
Allowance for loans collectively evaluated for impairment	9,648	8,005
Allowance for loan commitments	233	188	220	260
Total allowance for credit losses	9,881	8,600	10,407	10,262
Individually evaluated for impairment		1,270
Collectively evaluated for impairment	1,124,824	1,086,445
Acquired with deteriorated credit quality	869	403
Total Loans	1,125,693	1,088,118
Deposit Overdraft [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loans collectively evaluated for impairment	760	760
Total allowance for credit losses	760	760	483	342
Residential Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loans collectively evaluated for impairment	3,372	4,106
Allowance for loan commitments	9	9	9	7
Total allowance for credit losses	3,381	4,115	4,346	4,589
Collectively evaluated for impairment	1,355,829	1,382,447
Acquired with deteriorated credit quality	751	943
Total Loans	1,356,580	1,383,390
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loans collectively evaluated for impairment	3,379	3,998
Allowance for loan commitments	40	44	44	46
Total allowance for credit losses	3,419	4,042	4,191	4,809
Collectively evaluated for impairment	349,141	396,049
Acquired with deteriorated credit quality	7	9
Total Loans	349,148	396,058
Home Equity [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loans collectively evaluated for impairment	4,489	3,422
Allowance for loan commitments	211	162	125	117
Total allowance for credit losses	4,700	3,584	$ 3,135	$ 3,000
Collectively evaluated for impairment	527,216	508,359
Total Loans	$ 527,216	$ 508,359

Loans and the Allowance for C45

Loans and the Allowance for Credit Losses - Allowance for Credit Losses and Recorded Investments in Loans (Parenthetical) (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)
Receivables [Abstract]
Troubled debt restructuring threshold	$ 1

Loans and the Allowance for C46

Loans and the Allowance for Credit Losses - Summary of Commercial Loans by Risk Grade (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Summary of commercial loans by risk grade
Commercial loans	$ 6,327,562	$ 6,205,762
Commercial Portfolio Segment [Member]
Summary of commercial loans by risk grade
Commercial loans	4,140,105	3,961,629
Commercial Portfolio Segment [Member] | Pass [Member]
Summary of commercial loans by risk grade
Commercial loans	4,061,018	3,886,886
Commercial Portfolio Segment [Member] | Criticized [Member]
Summary of commercial loans by risk grade
Commercial loans	34,784	24,778
Commercial Portfolio Segment [Member] | Classified - Substandard [Member]
Summary of commercial loans by risk grade
Commercial loans	44,303	49,965
Commercial Portfolio Segment [Member] | Commercial Real Estate - Land and Construction [Member]
Summary of commercial loans by risk grade
Commercial loans	606,593	496,539
Commercial Portfolio Segment [Member] | Commercial Real Estate - Land and Construction [Member] | Pass [Member]
Summary of commercial loans by risk grade
Commercial loans	600,325	489,380
Commercial Portfolio Segment [Member] | Commercial Real Estate - Land and Construction [Member] | Criticized [Member]
Summary of commercial loans by risk grade
Commercial loans	2,971	4,405
Commercial Portfolio Segment [Member] | Commercial Real Estate - Land and Construction [Member] | Classified - Substandard [Member]
Summary of commercial loans by risk grade
Commercial loans	3,297	2,754
Commercial Portfolio Segment [Member] | Commercial Real Estate - Improved Property [Member]
Summary of commercial loans by risk grade
Commercial loans	2,407,819	2,376,972
Commercial Portfolio Segment [Member] | Commercial Real Estate - Improved Property [Member] | Pass [Member]
Summary of commercial loans by risk grade
Commercial loans	2,350,919	2,324,755
Commercial Portfolio Segment [Member] | Commercial Real Estate - Improved Property [Member] | Criticized [Member]
Summary of commercial loans by risk grade
Commercial loans	24,550	15,295
Commercial Portfolio Segment [Member] | Commercial Real Estate - Improved Property [Member] | Classified - Substandard [Member]
Summary of commercial loans by risk grade
Commercial loans	32,350	36,922
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Summary of commercial loans by risk grade
Commercial loans	1,125,693	1,088,118
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Pass [Member]
Summary of commercial loans by risk grade
Commercial loans	1,109,774	1,072,751
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Criticized [Member]
Summary of commercial loans by risk grade
Commercial loans	7,263	5,078
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Classified - Substandard [Member]
Summary of commercial loans by risk grade
Commercial loans	$ 8,656	$ 10,289

Loans and the Allowance for C47

Loans and the Allowance for Credit Losses - Summary of Changes in Accretable Yield for Loans Acquired with Deteriorated Credit Quality (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period [Abstract]
Balance at beginning of period	$ 1,717	$ 1,206
Acquisitions		669
Reduction due to change in projected cash flows		(324)
Reclass from non-accretable difference	1,490	1,065
Transfers	(216)	(328)
Accretion	(1,384)	(398)
Balance at end of period	$ 1,607	$ 1,890

Loans and the Allowance for C48

Loans and the Allowance for Credit Losses - Summary of Age Analysis of Loan Categories (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Current	$ 6,324,397	$ 6,204,822
Total Past Due	48,652	44,614
Total Loans	6,373,049	6,249,436
90 Days or More Past Due and Accruing	4,856	3,739
Loans held for sale, current	26,888	17,315
Loans held for sale	26,888	17,315
Total loans, current	6,351,285	6,222,137
Total loans	6,399,937	6,266,751
Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Current	519,110	502,087
Total Past Due	8,106	6,272
Total Loans	527,216	508,359
90 Days or More Past Due and Accruing	1,289	626
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Current	2,997,815	2,864,035
Total Past Due	16,597	9,476
Total Loans	3,014,412	2,873,511
90 Days or More Past Due and Accruing	542	318
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Current	1,341,924	1,365,956
Total Past Due	14,656	17,434
Total Loans	1,356,580	1,383,390
90 Days or More Past Due and Accruing	2,418	1,922
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Current	344,241	390,354
Total Past Due	4,907	5,704
Total Loans	349,148	396,058
90 Days or More Past Due and Accruing	587	644
Commercial Real Estate - Land and Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Current	606,122	496,245
Total Past Due	471	294
Total Loans	606,593	496,539
Commercial Real Estate - Improved Property [Member]
Financing Receivable, Recorded Investment [Line Items]
Current	2,391,693	2,367,790
Total Past Due	16,126	9,182
Total Loans	2,407,819	2,376,972
90 Days or More Past Due and Accruing	542	318
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Current	1,121,307	1,082,390
Total Past Due	4,386	5,728
Total Loans	1,125,693	1,088,118
90 Days or More Past Due and Accruing	20	229
Non-Accrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Current	9,360	7,570
Total Past Due	26,098	24,214
Total Loans	35,458	31,784
TDRs Accruing Interest [Member]
Financing Receivable, Recorded Investment [Line Items]
Current	6,232	7,014
Total Past Due	406	632
Total Loans	6,638	7,646
Total Impaired [Member]
Financing Receivable, Recorded Investment [Line Items]
Current	15,592	14,584
Total Past Due	26,504	24,846
Total Loans	42,096	39,430
30-59 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	14,917	16,395
30-59 Days Past Due [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	3,354	2,358
30-59 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	2,235	1,154
30-59 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	4,831	6,701
30-59 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	3,134	3,674
30-59 Days Past Due [Member] | Commercial Real Estate - Improved Property [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	2,235	1,154
30-59 Days Past Due [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	1,363	2,508
30-59 Days Past Due [Member] | Non-Accrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	873	3,479
30-59 Days Past Due [Member] | TDRs Accruing Interest [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	108	342
30-59 Days Past Due [Member] | Total Impaired [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	981	3,821
60-89 Days Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	3,582	4,428
60-89 Days Past Due [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	808	862
60-89 Days Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	617	363
60-89 Days Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	759	1,043
60-89 Days Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	901	1,149
60-89 Days Past Due [Member] | Commercial Real Estate - Improved Property [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	617	363
60-89 Days Past Due [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	497	1,011
60-89 Days Past Due [Member] | Non-Accrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	226	923
60-89 Days Past Due [Member] | TDRs Accruing Interest [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due		50
60-89 Days Past Due [Member] | Total Impaired [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	226	973
90 Days or More Past Due [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	30,153	23,791
90 Days or More Past Due [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	3,944	3,052
90 Days or More Past Due [Member] | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	13,745	7,959
90 Days or More Past Due [Member] | Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	9,066	9,690
90 Days or More Past Due [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	872	881
90 Days or More Past Due [Member] | Commercial Real Estate - Land and Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	471	294
90 Days or More Past Due [Member] | Commercial Real Estate - Improved Property [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	13,274	7,665
90 Days or More Past Due [Member] | Commercial and Industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	2,526	2,209
90 Days or More Past Due [Member] | Non-Accrual Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	24,999	19,812
90 Days or More Past Due [Member] | TDRs Accruing Interest [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	298	240
90 Days or More Past Due [Member] | Total Impaired [Member]
Financing Receivable, Recorded Investment [Line Items]
Total Past Due	$ 25,297	$ 20,052

Loans and the Allowance for C49

Loans and the Allowance for Credit Losses - Summary of Age Analysis of Loan Categories (Parenthetical) (Detail)	9 Months Ended
	Sep. 30, 2017
Receivables [Abstract]
Past due loans excluded TDRs past due and accruing	90 days

Loans and the Allowance for C50

Loans and the Allowance for Credit Losses - Summary of Impaired Loans (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no specific allowance recorded	$ 45,918		$ 45,918		$ 41,119
Unpaid Principal Balance, With a specific allowance recorded	5,117		5,117		7,887
Total impaired loans, Unpaid principal balance	51,035		51,035		49,006
Recorded Investment, With no specific allowance recorded	36,979		36,979		35,148
Recorded Investment, With a specific allowance recorded	5,117		5,117		4,282
Total impaired loans, Recorded investment	42,096		42,096		39,430
Related Allowance, With a specific allowance recorded	579		579		877
Average recorded investment, with no related specific allowance	37,452	$ 33,716	37,432	$ 34,932
Average recorded investment, With a specific allowance recorded	5,137	5,690	5,350	6,712
Total impaired loans, Average recorded investment	42,589	39,406	42,782	41,644
Interest income recognized, With no related specific allowance	96	115	617	371
Interest income recognized, With a specific allowance recorded	0	0	0	0
Total impaired loans, Interest income recognized	96	115	617	371
Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no specific allowance recorded	18,925		18,925		20,152
Recorded Investment, With no specific allowance recorded	17,094		17,094		18,305
Average recorded investment, with no related specific allowance	17,039	17,013	17,743	16,882
Interest income recognized, With no related specific allowance	57	81	192	256
Consumer [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no specific allowance recorded	934		934		884
Recorded Investment, With no specific allowance recorded	774		774		744
Average recorded investment, with no related specific allowance	731	814	746	953
Interest income recognized, With no related specific allowance	2		5	6
Home Equity [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no specific allowance recorded	5,528		5,528		4,589
Recorded Investment, With no specific allowance recorded	4,845		4,845		4,011
Average recorded investment, with no related specific allowance	4,727	3,613	4,456	3,381
Interest income recognized, With no related specific allowance	4	4	14	16
Commercial Real Estate - Land and Construction [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no specific allowance recorded	666		666		1,212
Recorded Investment, With no specific allowance recorded	474		474		766
Average recorded investment, with no related specific allowance	444	701	516	1,062
Interest income recognized, With a specific allowance recorded	0	0	0	0
Commercial Real Estate - Improved Property [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no specific allowance recorded	15,981		15,981		9,826
Unpaid Principal Balance, With a specific allowance recorded	5,117		5,117		3,012
Recorded Investment, With no specific allowance recorded	10,709		10,709		8,141
Recorded Investment, With a specific allowance recorded	5,117		5,117		3,012
Related Allowance, With a specific allowance recorded	579		579		470
Average recorded investment, with no related specific allowance	10,923	8,403	10,271	9,408
Average recorded investment, With a specific allowance recorded	5,137	3,012	5,032	3,012
Interest income recognized, With no related specific allowance	31	28	400	86
Interest income recognized, With a specific allowance recorded	0	0	0	0
Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Unpaid Principal Balance, With no specific allowance recorded	3,884		3,884		4,456
Unpaid Principal Balance, With a specific allowance recorded					4,875
Recorded Investment, With no specific allowance recorded	3,083		3,083		3,181
Recorded Investment, With a specific allowance recorded					1,270
Related Allowance, With a specific allowance recorded					$ 407
Average recorded investment, with no related specific allowance	3,588	3,172	3,700	3,246
Average recorded investment, With a specific allowance recorded		2,678	318	3,700
Interest income recognized, With no related specific allowance	2	2	6	7
Interest income recognized, With a specific allowance recorded	$ 0	$ 0	$ 0	$ 0

Loans and the Allowance for C51

Loans and the Allowance for Credit Losses - Recorded Investment in Non-Accrual Loans and TDRs (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Impaired [Line Items]
Non-accrual loans	$ 35,458	$ 31,784
TDRs	9,620	11,192
Accruing TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	6,638	7,646
Non-Accrual TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	2,982	3,546
Commercial Real Estate - Land and Construction [Member]
Financing Receivable, Impaired [Line Items]
Non-accrual loans	474	766
TDRs	4	8
Commercial Real Estate - Land and Construction [Member] | Non-Accrual TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	4	8
Commercial Real Estate - Improved Property [Member]
Financing Receivable, Impaired [Line Items]
Non-accrual loans	14,263	9,535
TDRs	2,009	2,306
Commercial Real Estate - Improved Property [Member] | Accruing TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	1,563	1,618
Commercial Real Estate - Improved Property [Member] | Non-Accrual TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	446	688
Commercial and Industrial [Member]
Financing Receivable, Impaired [Line Items]
Non-accrual loans	2,950	4,299
TDRs	297	303
Commercial and Industrial [Member] | Accruing TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	133	152
Commercial and Industrial [Member] | Non-Accrual TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	164	151
Home Equity [Member]
Financing Receivable, Impaired [Line Items]
Non-accrual loans	4,426	3,538
TDRs	838	770
Home Equity [Member] | Accruing TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	419	473
Home Equity [Member] | Non-Accrual TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	419	297
Commercial Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Non-accrual loans	14,737	10,301
TDRs	2,013	2,314
Commercial Real Estate [Member] | Accruing TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	1,563	1,618
Commercial Real Estate [Member] | Non-Accrual TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	450	696
Residential Real Estate [Member]
Financing Receivable, Impaired [Line Items]
Non-accrual loans	12,641	12,994
TDRs	6,263	7,523
Residential Real Estate [Member] | Accruing TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	4,453	5,311
Residential Real Estate [Member] | Non-Accrual TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	1,810	2,212
Consumer [Member]
Financing Receivable, Impaired [Line Items]
Non-accrual loans	704	652
TDRs	209	282
Consumer [Member] | Accruing TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	70	92
Consumer [Member] | Non-Accrual TDRs [Member]
Financing Receivable, Impaired [Line Items]
TDRs	$ 139	$ 190

Loans and the Allowance for C52

Loans and the Allowance for Credit Losses - Recorded Investment in Non-Accrual Loans and TDRs (Parenthetical) (Detail)	Sep. 30, 2017USD ($)Borrowers	Dec. 31, 2016USD ($)Borrowers
Receivables [Abstract]
Number of borrowers with loans greater than one million | Borrowers	3	2
Borrowers with large amount of loans outstanding, minimum amount of loans per borrower	$ 1,000,000	$ 1,000,000
Borrowers with large amount of loans outstanding, net	$ 8,600,000	$ 4,300,000

Loans and the Allowance for C53

Loans and the Allowance for Credit Losses - Loans Identified as TDRs (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)Contract	Sep. 30, 2016USD ($)Contract	Sep. 30, 2017USD ($)Contract	Sep. 30, 2016USD ($)Contract
Financing Receivable, Modifications [Line Items]
Number of Modifications | Contract	4	8	11	16
Pre-Modification Outstanding Recorded Investment	$ 291	$ 275	$ 459	$ 389
Post-Modification Outstanding Recorded Investment	$ 279	$ 267	$ 426	$ 360
Commercial Real Estate - Improved Property [Member]
Financing Receivable, Modifications [Line Items]
Number of Modifications | Contract	1		1
Pre-Modification Outstanding Recorded Investment	$ 190		$ 190
Post-Modification Outstanding Recorded Investment	$ 185		$ 185
Commercial and Industrial [Member]
Financing Receivable, Modifications [Line Items]
Number of Modifications | Contract		2	1	2
Pre-Modification Outstanding Recorded Investment		$ 125	$ 64	$ 125
Post-Modification Outstanding Recorded Investment		$ 122	$ 59	$ 122
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Modifications | Contract	1		1
Pre-Modification Outstanding Recorded Investment	$ 190		$ 190
Post-Modification Outstanding Recorded Investment	$ 185		$ 185
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Modifications | Contract		2	2	3
Pre-Modification Outstanding Recorded Investment		$ 124	$ 22	$ 150
Post-Modification Outstanding Recorded Investment		$ 122	$ 17	$ 143
Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Modifications | Contract	1	4	4	10
Pre-Modification Outstanding Recorded Investment	$ 7	$ 26	$ 42	$ 70
Post-Modification Outstanding Recorded Investment	$ 6	$ 23	$ 33	$ 54
Home Equity [Member]
Financing Receivable, Modifications [Line Items]
Number of Modifications | Contract	2		3	1
Pre-Modification Outstanding Recorded Investment	$ 94		$ 141	$ 44
Post-Modification Outstanding Recorded Investment	$ 88		$ 132	$ 41

Loans and the Allowance for C54

Loans and the Allowance for Credit Losses - TDRs Defaulted Later Restructured (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)Defaults	Sep. 30, 2016USD ($)Defaults
Financing Receivable, Modifications [Line Items]
Number of Defaults | Defaults	2	1
Recorded Investment | $	$ 14	$ 40
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Defaults | Defaults	1
Recorded Investment | $	$ 7
Consumer [Member]
Financing Receivable, Modifications [Line Items]
Number of Defaults | Defaults	1
Recorded Investment | $	$ 7
Commercial and Industrial [Member]
Financing Receivable, Modifications [Line Items]
Number of Defaults | Defaults		1
Recorded Investment | $		$ 40

Loans and the Allowance for C55

Loans and the Allowance for Credit Losses - Summary of Other Real Estate Owned and Repossessed Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Receivables [Abstract]
Other real estate owned	$ 5,636	$ 8,206
Repossessed assets	146	140
Total other real estate owned and repossessed assets	$ 5,782	$ 8,346

Pension Plan - Components of Ne

Pension Plan - Components of Net Periodic Pension Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost - benefits earned during year	$ 650	$ 703	$ 1,929	$ 2,095
Interest cost on projected benefit obligation	1,107	1,280	3,287	3,813
Expected return on plan assets	(1,928)	(1,940)	(5,721)	(5,778)
Amortization of prior service cost	7	8	19	20
Amortization of net loss	812	759	2,409	2,261
Net periodic pension cost	$ 648	$ 810	$ 1,923	$ 2,411

Pension Plan - Additional Infor

Pension Plan - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Sep. 30, 2017
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Minimum required pension plan contribution			$ 2.7
Available credit balance utilized for minimum required contribution			$ 46.9
Contribution of pension fund		$ 2.5
Pentegra Defined Benefit Plan [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Asset spin off, final costs	$ 2.8
Distributed assets transferred	$ 8.4	$ 8.4

Fair Value Measurement - Schedu

Fair Value Measurement - Schedule of Fair Value of Assets and Liabilities Measured on Recurring and Nonrecurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	$ 7,929	$ 7,071
Total securities - available-for-sale	1,305,532	1,241,176
Other assets - interest rate derivatives agreements	5,506	5,596
Total assets recurring fair value measurements	1,318,967	1,253,843
Other liabilities - interest rate derivatives agreements	5,443	5,199
Total liabilities recurring fair value measurements	5,443	5,199
Other real estate owned and repossessed assets	5,782	8,346
Loans held for sale	26,888	17,315
Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	7,929	7,071
Total securities - available-for-sale	1,305,532	1,241,176
Nonrecurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	4,538	3,405
Other real estate owned and repossessed assets	5,782	8,346
Loans held for sale	26,888	17,315
Total nonrecurring fair value measurements	37,208	29,066
U.S. Government Sponsored Entities and Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	72,319	54,043
U.S. Government Sponsored Entities and Agencies [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	72,319	54,043
Residential Mortgage-Backed Securities and Collateralized Mortgage Obligations of Government Sponsored Entities and Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	963,474	938,289
Residential Mortgage-Backed Securities and Collateralized Mortgage Obligations of Government Sponsored Entities and Agencies [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	963,474	938,289
Commercial Mortgage-Backed Securities and Collateralized Mortgage Obligations of Government Sponsored Entities and Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	121,834	96,810
Commercial Mortgage-Backed Securities and Collateralized Mortgage Obligations of Government Sponsored Entities and Agencies [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	121,834	96,810
Obligations of State and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	106,847	111,663
Obligations of State and Political Subdivisions [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	106,847	111,663
Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	35,503	35,301
Corporate Debt Securities [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	35,503	35,301
Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	5,555	5,070
Equity Securities [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	5,555	5,070
Investments Measured at Net Asset Value [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	1,472	1,438
Total assets recurring fair value measurements	1,472	1,438
Investments Measured at Net Asset Value [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	1,472	1,438
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	6,457	5,633
Total securities - available-for-sale	5,555	2,938
Total assets recurring fair value measurements	12,012	8,571
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	6,457	5,633
Total securities - available-for-sale	5,555	2,938
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	5,555	2,938
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	1,299,977	1,238,238
Other assets - interest rate derivatives agreements	5,506	5,596
Total assets recurring fair value measurements	1,305,483	1,243,834
Other liabilities - interest rate derivatives agreements	5,443	5,199
Total liabilities recurring fair value measurements	5,443	5,199
Loans held for sale	26,888	17,315
Significant Other Observable Inputs (Level 2) [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	1,299,977	1,238,238
Significant Other Observable Inputs (Level 2) [Member] | Nonrecurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	26,888	17,315
Total nonrecurring fair value measurements	26,888	17,315
Significant Other Observable Inputs (Level 2) [Member] | U.S. Government Sponsored Entities and Agencies [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	72,319	54,043
Significant Other Observable Inputs (Level 2) [Member] | Residential Mortgage-Backed Securities and Collateralized Mortgage Obligations of Government Sponsored Entities and Agencies [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	963,474	938,289
Significant Other Observable Inputs (Level 2) [Member] | Commercial Mortgage-Backed Securities and Collateralized Mortgage Obligations of Government Sponsored Entities and Agencies [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	121,834	96,810
Significant Other Observable Inputs (Level 2) [Member] | Obligations of State and Political Subdivisions [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	106,847	111,663
Significant Other Observable Inputs (Level 2) [Member] | Corporate Debt Securities [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale	35,503	35,301
Significant Other Observable Inputs (Level 2) [Member] | Equity Securities [Member] | Recurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total securities - available-for-sale		2,132
Significant Unobservable Inputs (Level 3) [Member] | Nonrecurring Fair Value Measurements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	4,538	3,405
Other real estate owned and repossessed assets	5,782	8,346
Total nonrecurring fair value measurements	$ 10,320	$ 11,751

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Fair value transfer amount	$ 0	$ 0	$ 0

Fair Value Measurement - Sche60

Fair Value Measurement - Schedule of Assets Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Other real estate owned and repossessed assets	$ 5,782	$ 8,346
Nonrecurring Fair Value Measurements [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	4,538	3,405
Other real estate owned and repossessed assets	5,782	8,346
Significant Unobservable Inputs (Level 3) [Member] | Nonrecurring Fair Value Measurements [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans	4,538	3,405
Other real estate owned and repossessed assets	$ 5,782	$ 8,346
Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans, Appraisal adjustments	0.00%	0.00%
Impaired loans, Liquidation expenses	(7.60%)	(1.50%)
Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans, Appraisal adjustments	(4.80%)	(70.00%)
Impaired loans, Liquidation expenses	(8.00%)	(8.00%)
Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans, Appraisal adjustments	(1.90%)	(36.60%)
Impaired loans, Liquidation expenses	(7.90%)	(4.60%)

Fair Value Measurement - Estima

Fair Value Measurement - Estimates Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Financial Assets
Cash and due from banks	$ 110,871	$ 128,170	$ 116,132	$ 86,685
Trading securities	7,929	7,071
Securities available-for-sale	1,305,532	1,241,176
Securities held-to-maturity	1,025,688	1,067,967
Net loans	6,327,562	6,205,762
Loans held for sale	26,888	17,315
Other assets - interest rate derivatives	5,506	5,596
Accrued interest receivable	30,152	28,299
Financial Liabilities
Deposits	7,101,025	7,040,879
Federal Home Loan Bank borrowings	1,015,011	968,946
Other borrowings	165,576	199,376
Subordinated debt and junior subordinated debt	164,278	163,598
Other liabilities - interest rate derivatives	5,443	5,199
Accrued interest payable	3,924	2,204
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial Assets
Cash and due from banks	110,871	128,170
Trading securities	6,457	5,633
Securities available-for-sale	5,555	2,938
Accrued interest receivable	30,152	28,299
Financial Liabilities
Deposits	5,766,959	5,545,057
Other borrowings	163,532	197,164
Accrued interest payable	3,924	2,204
Significant Other Observable Inputs (Level 2) [Member]
Financial Assets
Securities available-for-sale	1,299,977	1,238,238
Securities held-to-maturity	1,044,135	1,076,189
Loans held for sale	26,888	17,315
Other assets - interest rate derivatives	5,506	5,596
Financial Liabilities
Deposits	1,345,634	1,507,444
Federal Home Loan Bank borrowings	1,014,117	974,430
Other borrowings	2,047	2,221
Subordinated debt and junior subordinated debt	138,421	134,859
Other liabilities - interest rate derivatives	5,443	5,199
Significant Unobservable Inputs (Level 3) [Member]
Financial Assets
Securities held-to-maturity	613	601
Net loans	6,241,388	6,073,558
Carrying Amount [Member]
Financial Assets
Cash and due from banks	110,871	128,170
Trading securities	7,929	7,071
Securities available-for-sale	1,305,532	1,241,176
Securities held-to-maturity	1,025,688	1,067,967
Net loans	6,327,562	6,205,762
Loans held for sale	26,888	17,315
Other assets - interest rate derivatives	5,506	5,596
Accrued interest receivable	30,152	28,299
Financial Liabilities
Deposits	7,101,025	7,040,879
Federal Home Loan Bank borrowings	1,015,011	968,946
Other borrowings	165,576	199,376
Subordinated debt and junior subordinated debt	164,278	163,598
Other liabilities - interest rate derivatives	5,443	5,199
Accrued interest payable	3,924	2,204
Fair Value Estimate [Member]
Financial Assets
Cash and due from banks	110,871	128,170
Trading securities	7,929	7,071
Securities available-for-sale	1,305,532	1,241,176
Securities held-to-maturity	1,044,748	1,076,790
Net loans	6,241,388	6,073,558
Loans held for sale	26,888	17,315
Other assets - interest rate derivatives	5,506	5,596
Accrued interest receivable	30,152	28,299
Financial Liabilities
Deposits	7,112,593	7,052,501
Federal Home Loan Bank borrowings	1,014,117	974,430
Other borrowings	165,579	199,385
Subordinated debt and junior subordinated debt	138,421	134,859
Other liabilities - interest rate derivatives	5,443	5,199
Accrued interest payable	3,924	2,204
Investments Measured at Net Asset Value [Member]
Financial Assets
Trading securities	$ 1,472	$ 1,438

Comprehensive Income - Componen

Comprehensive Income - Components of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ 1,341,408	$ 1,122,132
Amounts reclassified from accumulated other comprehensive income	$ 471	$ 69	1,549	(173)
Total other comprehensive income			6,289	15,892
Ending Balance	1,394,558	1,347,151	1,394,558	1,347,151
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(17,758)	(17,539)
Amounts reclassified from accumulated other comprehensive income	513	486	1,679	1,407
Total other comprehensive income			1,679	1,407
Ending Balance	(16,079)	(16,132)	(16,079)	(16,132)
Accumulated Unrealized Gains (Losses) on Securities Available for Sale [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(9,890)	(4,162)
Other comprehensive income before reclassifications			4,740	16,065
Amounts reclassified from accumulated other comprehensive income		(368)	35	(1,428)
Total other comprehensive income			4,775	14,637
Ending Balance	(5,115)	10,475	(5,115)	10,475
Accumulated Unrealized Gains on Securities Transferred from Available For Sale to Held to Maturity [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			522	747
Amounts reclassified from accumulated other comprehensive income	(42)	(49)	(165)	(152)
Total other comprehensive income			(165)	(152)
Ending Balance	357	595	357	595
Accumulated Other Comprehensive (Loss) Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(27,126)	(20,954)
Other comprehensive income before reclassifications			4,740	16,065
Amounts reclassified from accumulated other comprehensive income			1,549	(173)
Total other comprehensive income			6,289	15,892
Ending Balance	$ (20,837)	$ (5,062)	$ (20,837)	$ (5,062)

Comprehensive Income - Compon63

Comprehensive Income - Components of Accumulated Other Comprehensive Income (Parenthetical) (Detail)	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Percentage of Federal and State income tax rate	37.00%	37.00%

Comprehensive Income - Schedule

Comprehensive Income - Schedule of Amounts Reclassified from Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net securities gains (Non-interest income)	$ (6)	$ (598)	$ (511)	$ (2,293)
Interest and dividends on securities (Interest and dividend income)	(14,573)	(13,696)	(43,299)	(42,749)
Employee benefits (Non-interest expense)	7,728	6,275	23,670	20,684
Provision for income taxes	10,527	5,793	30,801	22,572
Net effect on accumulated other comprehensive income for the period	471	69	1,549	(173)
Accumulated Unrealized Gains (Losses) on Securities Available for Sale [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net effect on accumulated other comprehensive income for the period		(368)	35	(1,428)
Accumulated Unrealized Gains on Securities Transferred from Available For Sale to Held to Maturity [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net effect on accumulated other comprehensive income for the period	(42)	(49)	(165)	(152)
Accumulated Defined Benefit Plans Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net effect on accumulated other comprehensive income for the period	513	486	1,679	1,407
Amounts Reclassified From Accumulated Other Comprehensive Income/(Loss) [Member] | Accumulated Unrealized Gains (Losses) on Securities Available for Sale [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net securities gains (Non-interest income)		(579)	55	(2,251)
Provision for income taxes		211	(20)	823
Amounts Reclassified From Accumulated Other Comprehensive Income/(Loss) [Member] | Accumulated Unrealized Gains on Securities Transferred from Available For Sale to Held to Maturity [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest and dividends on securities (Interest and dividend income)	(66)	(77)	(256)	(242)
Provision for income taxes	24	28	91	90
Amounts Reclassified From Accumulated Other Comprehensive Income/(Loss) [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Employee benefits (Non-interest expense)	816	766	2,429	2,280
Provision for income taxes	$ (303)	$ (280)	$ (750)	$ (873)

Commitments and Contingent Li65

Commitments and Contingent Liabilities - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Allowance for credit losses associated with loan commitments	$ 647	$ 571	$ 576	$ 613
Liability associated with letters of credit	$ 200	$ 200

Commitments and Contingent Li66

Commitments and Contingent Liabilities - Commitments to Extend Credit, Guarantees and Various Letters of Credit Outstanding (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Lines of credit	$ 1,468,470	$ 1,418,329
Loans approved but not closed	243,723	185,253
Overdraft limits	126,936	126,517
Letters of credit	32,328	32,907
Contingent obligations to purchase loans funded by other entities	$ 6,974	$ 13,036

Business Segments - Additional

Business Segments - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)Segment	Sep. 30, 2016USD ($)
Segment Reporting Information [Line Items]
Operating segments | Segment	2
Trust and Investment Services [Member]
Segment Reporting Information [Line Items]
Market value of assets managed or held in custody by trust and investment services segment	$ 3,900	$ 3,700
Total non-fiduciary assets of the trust and investment services segment	$ 1.7	$ 3.1

Business Segments - Financial I

Business Segments - Financial Information by Business Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Interest income	$ 85,489	$ 70,092	$ 247,573	$ 205,278
Interest expense	11,235	8,066	30,461	23,637
Net interest income	74,254	62,026	217,112	181,641
Provision for credit losses	2,516	2,214	7,610	6,350
Net interest income after provision for credit losses	71,738	59,812	209,502	175,291
Non-interest income	20,899	21,017	65,906	60,001
Non-interest expense	55,754	57,601	166,023	150,303
Income before provision for income taxes	36,883	23,228	109,385	84,989
Provision for income taxes	10,527	5,793	30,801	22,572
Net income	26,356	17,435	78,584	62,417
Community Banking [Member]
Segment Reporting Information [Line Items]
Interest income	85,489	70,092	247,573	205,278
Interest expense	11,235	8,066	30,461	23,637
Net interest income	74,254	62,026	217,112	181,641
Provision for credit losses	2,516	2,214	7,610	6,350
Net interest income after provision for credit losses	71,738	59,812	209,502	175,291
Non-interest income	15,541	15,604	48,833	43,841
Non-interest expense	52,355	54,569	156,102	141,029
Income before provision for income taxes	34,924	20,847	102,233	78,103
Provision for income taxes	9,744	4,841	27,940	19,818
Net income	25,180	16,006	74,293	58,285
Trust and Investment Services [Member]
Segment Reporting Information [Line Items]
Non-interest income	5,358	5,413	17,073	16,160
Non-interest expense	3,399	3,032	9,921	9,274
Income before provision for income taxes	1,959	2,381	7,152	6,886
Provision for income taxes	783	952	2,861	2,754
Net income	$ 1,176	$ 1,429	$ 4,291	$ 4,132