S&T Bancorp (STBA) 10-Q 1 Aug 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Jul. 31, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Entity Registrant Name	S&T BANCORP INC
Entity Central Index Key	719,220
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		35,008,546

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
ASSETS
Cash and due from banks, including interest-bearing deposits of $81,210 and $61,965 at June 30, 2018 and December 31, 2017	$ 137,933	$ 117,152
Securities, at fair value	688,341	698,291
Loans held for sale	3,801	4,485
Portfolio loans, net of unearned income	5,786,118	5,761,449
Allowance for loan losses	(60,517)	(56,390)
Portfolio loans, net	5,725,601	5,705,059
Bank owned life insurance	73,122	72,150
Premises and equipment, net	40,889	42,702
Federal Home Loan Bank and other restricted stock, at cost	35,782	29,270
Goodwill	287,446	291,670
Other intangible assets, net	2,909	3,677
Other assets	101,522	95,799
Total Assets	7,097,346	7,060,255
Deposits:
Noninterest-bearing demand	1,410,211	1,387,712
Interest-bearing demand	553,729	603,141
Money market	1,267,623	1,146,156
Savings	845,526	893,119
Certificates of deposit	1,316,444	1,397,763
Total Deposits	5,393,533	5,427,891
Securities sold under repurchase agreements	44,724	50,161
Short-term borrowings	600,000	540,000
Long-term borrowings	46,062	47,301
Junior subordinated debt securities	45,619	45,619
Other liabilities	60,275	65,252
Total Liabilities	6,190,213	6,176,224
SHAREHOLDERS’ EQUITY
Common stock ($2.50 par value) Authorized—50,000,000 shares Issued—36,130,480 shares at June 30, 2018 and December 31, 2017 Outstanding— 35,009,945 shares at June 30, 2018 and 34,971,929 shares at December 31, 2017	90,326	90,326
Additional paid-in capital	216,885	216,106
Retained earnings	662,112	628,107
Accumulated other comprehensive (loss) income	(30,945)	(18,427)
Treasury stock (1,120,535 shares at June 30, 2018 and 1,158,551 shares at December 31, 2017, at cost)	(31,245)	(32,081)
Total Shareholders’ Equity	907,133	884,031
Total Liabilities and Shareholders’ Equity	$ 7,097,346	$ 7,060,255

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Cash and due from banks, interest-bearing amounts	$ 81,210	$ 61,965
Common stock, par value (in dollars per share)	$ 2.50	$ 2.50
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	36,130,480	36,130,480
Common stock, shares outstanding (in shares)	35,009,945	34,971,929
Treasury stock, shares (in shares)	1,120,535	1,158,551

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
INTEREST INCOME
Loans, including fees	$ 66,610	$ 60,558	$ 129,665	$ 117,458
Investment Securities:
Taxable	3,519	2,947	6,948	5,796
Tax-exempt	872	928	1,746	1,848
Dividends	580	481	1,251	963
Total Interest Income	71,581	64,914	139,610	126,065
INTEREST EXPENSE
Deposits	9,166	5,976	17,012	11,355
Borrowings and junior subordinated debt securities	4,012	2,368	7,264	4,261
Total Interest Expense	13,178	8,344	24,276	15,616
NET INTEREST INCOME	58,403	56,570	115,334	110,449
Provision for loan losses	9,345	4,869	11,817	10,052
Net Interest Income After Provision for Loan Losses	49,058	51,701	103,517	100,397
NONINTEREST INCOME
Net gain (loss) on sale of securities	0	3,617	0	3,987
Mortgage banking	831	675	1,432	1,408
Insurance	134	1,458	303	2,913
Gain on sale of a majority interest of insurance business	0	0	1,873	0
Other	2,134	2,048	4,323	4,225
Total Noninterest Income	12,251	16,265	26,044	29,261
NONINTEREST EXPENSE
Salaries and employee benefits	18,611	19,903	37,426	40,444
Net occupancy	2,804	2,751	5,677	5,566
Data processing and information technology	2,379	2,163	4,704	4,386
Furniture, equipment and software	2,134	1,810	4,090	3,857
Other taxes	1,739	1,083	3,587	2,060
Marketing	1,190	948	1,892	1,702
Professional services and legal	888	931	1,939	1,999
FDIC insurance	739	1,185	1,847	2,308
Other	5,379	5,823	10,783	11,084
Total Noninterest Expense	35,863	36,597	71,945	73,406
Income Before Taxes	25,446	31,369	57,616	56,252
Provision for income taxes	4,010	8,604	10,017	15,299
Net Income	$ 21,436	$ 22,765	$ 47,599	$ 40,953
Earnings per share—basic (in dollars per share)	$ 0.62	$ 0.66	$ 1.37	$ 1.18
Earnings per share—diluted (in dollars per share)	0.61	0.65	1.36	1.17
Dividends declared per share (in dollars per share)	$ 0.25	$ 0.20	$ 0.47	$ 0.40
Comprehensive Income	$ 20,444	$ 22,503	$ 35,081	$ 41,879
Debit and credit card
NONINTEREST INCOME
Revenues from contract with customers	3,309	3,042	6,347	5,885
Service charges on deposit accounts
NONINTEREST INCOME
Revenues from contract with customers	3,227	2,997	6,468	6,012
Wealth management
NONINTEREST INCOME
Revenues from contract with customers	$ 2,616	$ 2,428	$ 5,298	$ 4,831

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($)		Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive (Loss)/Income	Reclassifications Related to Funded Status of Pension	Reclassifications Related to Unrealized Gains on Available for Sale Securities	Treasury Stock
Beginning Balance at Dec. 31, 2016		$ 841,956,000	$ 90,326,000	$ 213,098,000	$ 585,891,000	$ (13,784,000)			$ (33,575,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		40,953,000			40,953,000
Other comprehensive income (loss), net of tax		926,000				926,000
Cash dividends declared ($0.47 and $0.40 per share)		(13,927,000)			(13,927,000)
Treasury stock issued for restricted awards (66,615 shares, net of 37,592 forfeitures, and 74,903 shares, net of 7,370 forfeitures)		(689,000)			(2,413,000)				1,724,000
Recognition of restricted stock compensation expense		1,843,000		1,843,000
Ending Balance at Jun. 30, 2017		871,062,000	90,326,000	214,941,000	610,504,000	(12,858,000)			(31,851,000)
Effect of new accounting pronouncement on Consolidated Financial Statements | ASU No. 2018-02		0
Effect of new accounting pronouncement on Consolidated Financial Statements | ASU No. 2016-01	[1]				862,000	(862,000)
Beginning Balance at Dec. 31, 2017		884,031,000	90,326,000	216,106,000	628,107,000	(18,427,000)			(32,081,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		47,599,000			47,599,000
Other comprehensive income (loss), net of tax		(8,229,000)				(8,229,000)
Reclassification of tax effects from the Tax Act | ASU No. 2018-02	[2]				3,427,000	(3,427,000)	$ (3,660,000)	$ 233,000
Cash dividends declared ($0.47 and $0.40 per share)		(16,391,000)			(16,391,000)
Treasury stock issued for restricted awards (66,615 shares, net of 37,592 forfeitures, and 74,903 shares, net of 7,370 forfeitures)		(656,000)			(1,492,000)				836,000
Recognition of restricted stock compensation expense		779,000		779,000
Ending Balance at Jun. 30, 2018		$ 907,133,000	$ 90,326,000	$ 216,885,000	$ 662,112,000	$ (30,945,000)			$ (31,245,000)
[1]	Reclassification due to the adoption of ASU No. 2016-01.
[2]	Reclassification due to the adoption of ASU No. 2018-02 - $(3,660) relates to funded status of pension and $233 relates to net unrealized gains on available-for-sale securities.

Consolidated Statements of Cha6

Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Dividends declared per share (in dollars per share)	$ 0.47	$ 0.40
Retained Earnings
Dividends declared per share (in dollars per share)	$ 0.47	$ 0.40
Treasury stock issued for restricted awards, net of forfeitures (in shares)	75,608	89,351
Forfeitures of restricted stock (in shares)	37,592	22,094

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
OPERATING ACTIVITIES
Net income	$ 47,599	$ 40,953
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	11,817	10,052
Recovery for unfunded loan commitments	(114)	(334)
Net depreciation, amortization and accretion	2,174	850
Net amortization of discounts and premiums on securities	1,572	2,030
Stock-based compensation expense	779	1,843
Net (gain) loss on sale of securities	0	(3,987)
Mortgage loans originated for sale	(41,631)	(38,899)
Proceeds from the sale of mortgage loans	42,998	38,041
Gain on the sale of mortgage loans, net	(683)	(719)
Gain on the sale of majority interest of insurance business	(1,873)	0
Net increase in interest receivable	(520)	(666)
Net increase in interest payable	699	246
Net (increase) decrease in other assets	(853)	4,484
Net increase (decrease) in other liabilities	2,529	(1,775)
Net Cash Provided by Operating Activities	64,493	52,119
INVESTING ACTIVITIES
Purchases of securities	(54,481)	(36,604)
Proceeds from maturities, prepayments and calls of securities	45,487	35,256
Proceeds from sales of securities	0	7,751
Net (purchases) sales of Federal Home Loan Bank stock	(6,512)	1,600
Net increase in loans	(37,957)	(176,768)
Proceeds from sale of loans not originated for resale	3,922	3,581
Purchases of premises and equipment	(804)	(3,018)
Proceeds from the sale of premises and equipment	110	273
Proceeds from the sale of majority interest of insurance business	4,540	0
Net Cash Used in Investing Activities	(45,695)	(167,929)
FINANCING ACTIVITIES
Net increase in core deposits	46,962	44,914
Net (decrease) increase in certificates of deposit	(81,255)	92,427
Net decrease in securities sold under repurchase agreements	(5,437)	(4,343)
Net increase (decrease) in short-term borrowings	60,000	(15,000)
Repayments of long-term borrowings	(1,239)	(1,195)
Treasury shares issued-net	(657)	(689)
Cash dividends paid to common shareholders	(16,391)	(13,927)
Net Cash Provided by Financing Activities	1,983	102,187
Net increase (decrease) in cash and cash equivalents	20,781	(13,623)
Cash and cash equivalents at beginning of period	117,152	139,486
Cash and Cash Equivalents at End of Period	137,933	125,863
Supplemental Disclosures
Loans transferred to held for sale	3,922	17,750
Interest paid	23,576	15,369
Income taxes paid, net of refunds	11,103	13,399
Transfer net assets to investment in insurance company partnership	1,917	0
Transfers to other real estate owned and other repossessed assets	$ 2,841	$ 1,407

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION Principles of Consolidation The interim Consolidated Financial Statements include the accounts of S&T Bancorp, Inc., or S&T, and its wholly owned subsidiaries. All significant intercompany transactions have been eliminated in consolidation. Investments of 20 percent to 50 percent of the outstanding common stock of investees are accounted for using the equity method of accounting. Basis of Presentation The accompanying unaudited interim Consolidated Financial Statements of S&T have been prepared in accordance with generally accepted accounting principles, or GAAP, in the United States for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the audited consolidated financial statements included in our annual report on Form 10-K for the year ended December 31, 2017 , filed with the Securities and Exchange Commission, or SEC, on March 1, 2018. In the opinion of management, the accompanying interim financial information reflects all adjustments, consisting of normal recurring adjustments, necessary to present fairly our financial position and the results of operations for each of the interim periods presented. Results of operations for interim periods are not necessarily indicative of the results of operations that may be expected for a full year or any future period. On January 1, 2018, we sold a 70 percent majority interest in the assets of our wholly-owned subsidiary S&T Evergreen Insurance, LLC. We transferred our remaining ownership interest in the net assets of S&T Evergreen Insurance, LLC for a 30 percent ownership interest in a new partnership entity (see Note 13: Sale of a Majority Interest of Insurance Business). We use the equity method of accounting to recognize our partial ownership interest in the new entity. Reclassification A mounts in prior period financial statements and footnotes are reclassified whenever necessary to conform to the current period presentation. Reclassifications had no effect on our results of operations or financial condition. Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates. Recently Adopted Accounting Standards Updates, or ASU or Update Income Statement - Reporting Comprehensive Income - Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income In February 2018, the FASB issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220), Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The amendments in this Update allow a reclassification from accumulated other comprehensive income, or AOCI, to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act, or Tax Act. The amendments eliminate the stranded tax effects resulting from the Tax Act and will improve the usefulness of information reported to financial statement users and will require certain disclosures about the stranded tax effects. This Update is effective for all entities for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. Early adoption is permitted, including adoption in any interim period, for public business entities for reporting periods for which financial statements have not been issued or made available for issuance. We have elected to reclassify all tax effects related to the Tax Act from AOCI to retained earnings as of January 1, 2018. As such, we have early adopted this Update and reclassified $3.4 million for the release of stranded income tax effects relating to unrealized gains and losses on our securities portfolio and our pension plan from AOCI to retained earnings as of March 31, 2018. The adoption of this ASU had no impact on our Consolidated Statements of Comprehensive Income. Our policy for releasing income tax effects from AOCI is to release them as investments are sold or mature and liabilities are extinguished. Compensation - Retirement Benefits - Improving the Presentation of Net Periodic Pension Costs and Net Periodic Post Retirement Benefit Costs In March 2017, the FASB issued ASU No. 2017-07, Compensation Retirement Benefits - Improving the Presentation of Net Periodic Pension Costs and Net Periodic Post Retirement Benefit Costs (Topic 715). The main objective of this ASU is to provide financial statement users with clearer and disaggregated information related to the components of net periodic benefit cost and improve transparency of the presentation of net periodic benefit cost in the financial statements. This Update was effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. Early adoption was permitted as of the beginning of an annual period for which financial statements have not been issued or made available for issuance. Effective March 31, 2016, our qualified and nonqualified defined benefit plans were amended to freeze benefit accruals for all persons entitled to benefits under the plan; as such, the adoption of this ASU had no impact on our Consolidated Balance Sheets or Consolidated Statements of Comprehensive Income. Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets - Clarifying the Scope of Assets Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets In February 2017, the FASB issued ASU No. 2017-05, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20). The main objective of this ASU is to provide greater detail on what types of transactions should be accounted for as partial sales of nonfinancial assets. This ASU, as originally issued in ASU No. 2014-09, is intended to reduce the complexity of current GAAP requirements by clarifying which accounting guidance applies to various types of contracts that transfer assets or ownership interest to another entity. This Update was effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017 and at the same time that ASU No. 2014-09 was effective. Early adoption was permitted, but only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. The adoption of this ASU was applied to the partial sale of our insurance subsidiary in January 2018. As such, the subsidiary is no longer included in our consolidated financial statements and we recognized a $1.9 million gain on the transaction. Business Combinations - Clarifying the Definition of a Business In January 2017, the FASB issued ASU No. 2017-01, Business Combinations - Clarifying the Definition of a Business (Topic 805). The main objective of this ASU is to help financial statement preparers evaluate whether a set of transferred assets and activities (either acquired or disposed of) is a business under Topic 805, Business Combinations by changing the definition of a business. The revised definition results in fewer acquisitions being accounted for as business combinations than under previous guidance. The definition of a business is significant because it affects the accounting for acquisitions, the identification of reporting units, consolidation evaluations and the accounting for dispositions. This Update was effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. Early adoption was permitted for transactions not yet reflected in financial statements that have been issued or made available for issuance. The adoption of this ASU had no impact on our Consolidated Balance Sheets or Consolidated Statements of Comprehensive Income. Income Taxes - Intra-Entity Transfers of Assets Other Than Inventory In October 2016, the FASB issued ASU No. 2016-16, Intra-Entity Transfers of Assets Other Than Inventory. The main objective of this ASU is to require companies to recognize the income tax effects of intercompany sales and transfers of assets other than inventory in the period in which the transfer occurs. This represents a change from previous guidance, which required companies to defer the income tax effects of intercompany transfers of assets until the asset has been sold to an outside party or otherwise recognized. The new guidance requires companies to defer the income tax effects only of intercompany transfers of inventory. This Update was effective for annual periods beginning after December 15, 2017. Early adoption was permitted as of the beginning of an annual period. If an entity chose to early adopt the amendments in the ASU, it had to do so in the first interim period of its annual financial statements. That is, an entity could not have adopted the amendments in the ASU in a later interim period and apply them as if they were in effect as of the beginning of the year. The adoption of this ASU had no impact on our Consolidated Balance Sheets or Consolidated Statements of Comprehensive Income. Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments. The main objective of this ASU is to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. The amendments in this Update provide guidance on the following eight specific cash flow issues: debt prepayment or debt extinguishment costs, settlement of zero-coupon debt instruments, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of bank-owned life insurance (BOLI) policies, distributions received from equity method investments, beneficial interests in securitization transactions, and separately identifiable cash flows and application of the predominance principle. This Update was effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. Early adoption was permitted, provided that all of the amendments are adopted in the same period. The adoption of this ASU had no material impact to the presentation of activities in our Consolidated Statements of Cash Flows. Revenue from Contracts with Customers In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). This revenue pronouncement established a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and superseded most previous revenue recognition guidance in GAAP. We adopted the new standard January 1, 2018. Our primary sources of revenue are derived from interest and dividends earned on loans, investment securities and other financial instruments that are not within the scope of ASU No. 2014-09. We evaluated the nature of our contracts with customers and related revenue streams, including service charges on deposit accounts, debit and credit cards and wealth management and determined that revenue recognition did not change significantly from current practice. We evaluated certain costs related to these revenue streams to determine whether such costs should be presented as expenses or contra-revenue. The adoption of this ASU had no material impact on our Consolidated Balance Sheets or Consolidated Statements of Comprehensive Income. Accounting for Financial Instruments - Overall: Classification and Measurement In January 2016, the FASB issued ASU No. 2016-01, Accounting for Financial Instruments - Overall: Classification and Measurement (Subtopic 825-10). The amendments in this ASU address the following: 1. require equity investments to be measured at fair value with changes in fair value recognized in net income; 2. simplify the impairment assessment of equity investments without readily-determinable fair values by requiring a qualitative assessment to identify impairment; 3. eliminate the requirement to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet; 4. require entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; 5. require separate presentation in other comprehensive income for the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments; 6. require separate presentation of financial assets and financial liabilities by measurement category and form of financial asset (that is, securities or loans and receivables) on the balance sheet or in the accompanying notes to the financial statements; and 7. clarify that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity's other deferred tax assets. This ASU was effective for annual and interim periods in fiscal years beginning after December 15, 2017. We adopted ASU No. 2016-01 as of January 1, 2018 and have concluded that the provisions of this ASU did not materially impact our Balance Sheets or Statements of Comprehensive Income. The new guidance resulted in a change in the fair value measurement of our loan portfolio as of March 31, 2018 using an exit price notion (see Note 3: Fair Value Measurements). The new guidance also resulted in a cumulative-effect adjustment of $0.9 million from AOCI to retained earnings at January 1, 2018 for net unrealized gains on our marketable equities portfolio. As a result of the new guidance, we recognized $0.3 million of net unrealized gains in our Consolidated Statements of Comprehensive Income during the six months ended June 30, 2018 on our marketable equity securities portfolio. Accounting Standards Issued But Not Yet Adopted Leases - Land Easement Practical Expedient for Transition to Topic 842 In January 2018, the FASB issued ASU No. 2018-01, Leases - Land Easement Practical Expedient for Transition to Topic 842. The amendments in this ASU permit an entity to elect an optional transition practical expedient to not evaluate under Topic 842 land easements, that existed or expired before the entity's adoption of Topic 842 and that were not previously accounted for as leases under Topic 840. This ASU is effective for annual and interim periods in fiscal years beginning after December 15, 2018. We are evaluating the amendments in this ASU; however, we do not anticipate that these amendments will materially impact our Consolidated Balance Sheets or Consolidated Statements of Comprehensive Income. Intangibles - Goodwill and Other - Simplifying the Test for Goodwill Impairment In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other - Simplifying the Test for Goodwill Impairment (Topic 350). The main objective of this ASU is intended to simplify the current requirements for testing goodwill for impairment by eliminating step two from the goodwill impairment test. The amendments are expected to reduce the complexity and costs associated with performing the goodwill impairment test, which could result in recording impairment charges sooner than under the current guidance. This Update is effective for any interim and annual impairment tests in reporting periods in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We are evaluating the provisions of this ASU; however, we do not anticipate that this ASU will materially impact our Consolidated Balance Sheets or Consolidated Statements of Comprehensive Income. Financial Instruments - Credit Losses In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments. The main objective of this ASU is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The amendments of this Update replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to form credit loss estimates. The collective changes to the recognition and measurement accounting standards for financial instruments and their anticipated impact on the allowance for credit losses modeling have been universally referred to as CECL, or current expected credit loss, model. This Update is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2019. Early adoption is permitted for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. We have created a CECL Committee to govern the implementation of these amendments consisting of key stakeholders from Credit Administration, Finance, Risk Management and Internal Audit. We have engaged a third-party to assist us in developing our CECL methodology. We continue to evaluate the provisions of this ASU to determine the potential impact on our Consolidated Balance Sheets and Consolidated Statements of Comprehensive Income. Leases - Section A-Amendments to the FASB Accounting Standards Codification, Section B-Conforming Amendments Related to Leases and Section C-Background Information and Basis for Conclusions In February 2016, the FASB issued ASU No. 2016-02, Leases, which requires lessees to recognize a right-to-use asset and a lease obligation for all leases on the balance sheet. Lessor accounting remains substantially similar to current GAAP. ASU No. 2016-02 supersedes Topic 840, Leases. This ASU is effective for annual and interim periods in fiscal years beginning after December 15, 2018. ASU No. 2016-02 mandates a modified retrospective transition method for all entities. Early adoption of this ASU is permitted. We anticipate that this ASU will impact our financial statements as it relates to the recognition of right-to-use assets and lease obligations on our Consolidated Balance Sheets. We have approximately 50 lease agreements for our branch and loan production offices, which are currently accounted for as operating leases. We expect the new guidance will require these lease agreements to be included on our Consolidated Balance Sheets as right-to-use assets with a corresponding lease liability. We expect that these changes to our Consolidated Balance Sheets will impact our regulatory capital ratios. We have compiled a preliminary inventory of our leases and continue to evaluate the standard. We anticipate that this ASU will impact total assets and total liabilities presented on our Balance Sheets; however, we do not believe that it will materially impact our Consolidated Statements of Comprehensive Income.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
EARNINGS PER SHARE	The following table reconciles the numerators and denominators of basic and diluted earnings per share for the periods presented: Three Months Ended June 30, Six Months Ended June 30, (in thousands, except share and per share data) 2018 2017 2018 2017 Numerator for Earnings per Share—Basic: Net income $ 21,436 $ 22,765 $ 47,599 $ 40,953 Less: Income allocated to participating shares 62 81 141 141 Net Income Allocated to Shareholders $ 21,374 $ 22,684 $ 47,458 $ 40,812 Numerator for Earnings per Share—Diluted: Net income $ 21,436 $ 22,765 $ 47,599 $ 40,953 Net Income Available to Shareholders $ 21,436 $ 22,765 $ 47,599 $ 40,953 Denominators for Earnings per Share: Weighted Average Shares Outstanding—Basic 34,793,160 34,724,925 34,775,043 34,707,683 Add: Potentially dilutive shares 264,416 181,571 267,998 199,693 Denominator for Treasury Stock Method—Diluted 35,057,576 34,906,496 35,043,041 34,907,376 Weighted Average Shares Outstanding—Basic 34,793,160 34,724,925 34,775,043 34,707,683 Add: Average participating shares outstanding 100,212 123,729 103,449 119,585 Denominator for Two-Class Method—Diluted 34,893,372 34,848,654 34,878,492 34,827,268 Earnings per share—basic $ 0.62 $ 0.66 $ 1.37 $ 1.18 Earnings per share—diluted $ 0.61 $ 0.65 $ 1.36 $ 1.17 Warrants considered anti-dilutive excluded from potentially dilutive shares - exercise price $31.53 per share, expires January 2019 374,314 466,554 386,747 456,749 Restricted stock considered anti-dilutive excluded from potentially dilutive shares 89,974 126,332 76,325 105,187

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	We use fair value measurements when recording and disclosing certain financial assets and liabilities. Debt securities, equity securities, trading assets and derivative financial instruments are recorded at fair value on a recurring basis. Additionally, from time to time, we may be required to record other assets at fair value on a nonrecurring basis, such as loans held for sale, impaired loans, other real estate owned, or OREO, and other repossessed assets, mortgage servicing rights, or MSRs, and certain other assets. Fair value is the price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market in an orderly transaction between market participants at the measurement date. An orderly transaction is a transaction that assumes exposure to the market for a period prior to the measurement date to allow for marketing activities that are usual and customary for transactions involving such assets or liabilities; it is not a forced transaction. In determining fair value, we use various valuation approaches, including market, income and cost approaches. The fair value standard establishes a hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that observable inputs be used when available. Observable inputs are inputs that market participants would use in pricing an asset or liability, which are developed based on market data that we have obtained from independent sources. Unobservable inputs reflect our estimates of assumptions that market participants would use in pricing an asset or liability, which are developed based on the best information available in the circumstances. The fair value hierarchy gives the highest priority to unadjusted quoted market prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). The fair value hierarchy is broken down into three levels based on the reliability of inputs as follows: Level 1: valuation is based upon unadjusted quoted market prices for identical instruments traded in active markets. Level 2: valuation is based upon quoted market prices for similar instruments traded in active markets, quoted market prices for identical or similar instruments traded in markets that are not active and model-based valuation techniques for which all significant assumptions are observable in the market or can be corroborated by market data. Level 3: valuation is derived from other valuation methodologies, including discounted cash flow models and similar techniques that use significant assumptions not observable in the market. These unobservable assumptions reflect estimates of assumptions that market participants would use in determining fair value. A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. Our policy is to recognize transfers between any of the fair value hierarchy levels at the end of the reporting period in which the transfer occurred. The following are descriptions of the valuation methodologies that we use for financial instruments recorded at fair value on either a recurring or nonrecurring basis. Recurring Basis Debt Securities Available-for-Sale We obtain fair values for debt securities from a third-party pricing service which utilizes several sources for valuing fixed-income securities. We validate prices received from our pricing service through comparison to a secondary pricing service and broker quotes. We review the methodologies of the pricing service which provide us with a sufficient understanding of the valuation models, assumptions, inputs and pricing to reasonably measure the fair value of our debt securities. The market evaluation sources for debt securities include observable inputs rather than significant unobservable inputs and are classified as Level 2. The service provider utilizes pricing models that vary by asset class and include available trade, bid and other market information. Generally, the methodologies include broker quotes, proprietary models, vast descriptive terms and conditions databases, and extensive quality control programs. Equity Securities Marketable equity securities that have an active, quotable market are classified as Level 1. Marketable equity securities that are quotable, but are thinly traded or inactive, are classified as Level 2. Marketable equity securities that are not readily traded and do not have a quotable market are classified as Level 3. Trading Assets We use quoted market prices to determine the fair value of our trading assets. Our trading assets are held in a Rabbi Trust under a deferred compensation plan and are invested in readily quoted mutual funds. Accordingly, these assets are classified as Level 1. Rabbi Trust assets are reported in other assets in the Consolidated Balance Sheets. Derivative Financial Instruments We use derivative instruments, including interest rate swaps for commercial loans with our customers, interest rate lock commitments and the sale of mortgage loans in the secondary market. We calculate the fair value for derivatives using widely accepted valuation techniques, including discounted cash flow analysis on the expected cash flows of each derivative. Each valuation considers the contractual terms of the derivative, including the period to maturity, and uses observable market-based inputs, such as interest rate curves and implied volatilities. Accordingly, derivatives are classified as Level 2. We incorporate credit valuation adjustments into the valuation models to appropriately reflect both our own nonperformance risk and the respective counterparties' nonperformance risk in calculating fair value measurements. In adjusting the fair value of our derivative contracts for the effect of nonperformance risk, we have considered the impact of netting and any applicable credit enhancements and collateral postings. Nonrecurring Basis Loans Held for Sale Loans held for sale consist of 1-4 family residential loans originated for sale in the secondary market and, from time to time, certain loans transferred from the loan portfolio to loans held for sale, all of which are carried at the lower of cost or fair value. The fair value of 1-4 family residential loans is based on the principal or most advantageous market currently offered for similar loans using observable market data. The fair value of the loans transferred from the loan portfolio is based on the amounts offered for these loans in currently pending sales transactions. Loans held for sale carried at fair value are classified as Level 3. Impaired Loans Impaired loans are carried at the lower of carrying value or fair value. Fair value is determined as the recorded investment balance less any specific reserve. We establish specific reserves based on the following three impairment methods: 1) the present value of expected future cash flows discounted at the loan’s original effective interest rate; 2) the loan’s observable market price; or 3) the fair value of the collateral less estimated selling costs when the loan is collateral dependent and we expect to liquidate the collateral. However, if repayment is expected to come from the operation of the collateral, rather than liquidation, then we do not consider estimated selling costs in determining the fair value of the collateral. Collateral values are generally based upon appraisals by approved, independent state certified appraisers. Appraisals may be discounted based on our historical knowledge, changes in market conditions from the time of appraisal or our knowledge of the borrower and the borrower’s business. Impaired loans carried at fair value are classified as Level 3. OREO and Other Repossessed Assets OREO and other repossessed assets obtained in partial or total satisfaction of a loan are recorded at the lower of recorded investment in the loan or fair value less cost to sell. Subsequent to foreclosure, these assets are carried at the lower of the amount recorded at acquisition date or fair value less cost to sell. Accordingly, it may be necessary to record nonrecurring fair value adjustments. Fair value, when recorded, is generally based upon appraisals by approved, independent state certified appraisers. Like impaired loans, appraisals on OREO may be discounted based on our historical knowledge, changes in market conditions from the time of appraisal or other information available to us. OREO and other repossessed assets carried at fair value are classified as Level 3. Mortgage Servicing Rights The fair value of MSRs is determined by calculating the present value of estimated future net servicing cash flows, considering expected mortgage loan prepayment rates, discount rates, servicing costs and other economic factors, which are determined based on current market conditions. The expected rate of mortgage loan prepayments is the most significant factor driving the value of MSRs. MSRs are considered impaired if the carrying value exceeds fair value. The valuation model includes significant unobservable inputs; therefore, MSRs are classified as Level 3. MSRs are reported in other assets in the Consolidated Balance Sheets and are amortized into noninterest income in the Consolidated Statements of Comprehensive Income. Other Assets We measure certain other assets at fair value on a nonrecurring basis. Fair value is based on the application of lower of cost or fair value accounting, or write-downs of individual assets. Valuation methodologies used to measure fair value are consistent with overall principles of fair value accounting and consistent with those described above. Financial Instruments In addition to financial instruments recorded at fair value in our financial statements, fair value accounting guidance requires disclosure of the fair value of all of an entity’s assets and liabilities that are considered financial instruments. The majority of our assets and liabilities are considered financial instruments. Many of these instruments lack an available trading market as characterized by a willing buyer and a willing seller engaged in an exchange transaction. Also, it is our general practice and intent to hold our financial instruments to maturity and to not engage in trading or sales activities with respect to such financial instruments. For fair value disclosure purposes, we substantially utilize the fair value measurement criteria as required and explained above. In cases where quoted fair values are not available, we use present value methods to determine the fair value of our financial instruments. Cash and Cash Equivalents The carrying amounts reported in the Consolidated Balance Sheets for cash and due from banks, including interest-bearing deposits, approximate fair value. Loans With the adoption of ASU No. 2016-01, Accounting for Financial Instruments - Overall: Classification and Measurement, on January 1, 2018, we refined our methodology to estimate the fair value of our loan portfolio to use the exit price notion as required by the standard. The guidance was applied on a prospective basis resulting in prior-periods no longer being comparable. The fair value of variable rate loans that may reprice frequently at short-term market rates is based on carrying values adjusted for liquidity and credit risk. The fair value of variable rate loans that reprice at intervals of one year or longer, such as adjustable rate mortgage products, is estimated using discounted cash flow analyses that utilize interest rates currently being offered for similar loans and adjusted for liquidity and credit risk. The fair value of fixed rate loans is estimated using a discounted cash flow analysis that utilizes interest rates currently being offered for similar loans adjusted for liquidity and credit risk. Bank Owned Life Insurance Fair value approximates net cash surrender value of bank owned life insurance, or BOLI. Federal Home Loan Bank, or FHLB, and Other Restricted Stock It is not practical to determine the fair value of our FHLB and other restricted stock due to the restrictions placed on the transferability of these stocks; it is presented at carrying value. Deposits The fair values disclosed for deposits without defined maturities (e.g., noninterest and interest-bearing demand, money market and savings accounts) are by definition equal to the amounts payable on demand. The carrying amounts for variable rate, fixed-term time deposits approximate their fair values. Estimated fair values for fixed rate and other time deposits are based on discounted cash flow analysis using interest rates currently offered for time deposits with similar terms. The carrying amount of accrued interest approximates fair value. Short-Term Borrowings The carrying amounts of securities sold under repurchase agreements, or REPOs, and other short-term borrowings approximate their fair values. Long-Term Borrowings The fair values disclosed for fixed rate long-term borrowings are determined by discounting their contractual cash flows using current interest rates for long-term borrowings of similar remaining maturities. The carrying amounts of variable rate long-term borrowings approximate their fair values. Junior Subordinated Debt Securities The interest rate on the variable rate junior subordinated debt securities is reset quarterly; therefore, the carrying values approximate their fair values. Loan Commitments and Standby Letters of Credit Off-balance sheet financial instruments consist of commitments to extend credit and letters of credit. Except for interest rate lock commitments, estimates of the fair value of these off-balance sheet items are not made because of the short-term nature of these arrangements and the credit standing of the counterparties. Other Estimates of fair value are not made for items that are not defined as financial instruments, including such items as our core deposit intangibles and the value of our trust operations. Assets and Liabilities Recorded at Fair Value on a Recurring Basis The following tables present our assets and liabilities that are measured at fair value on a recurring basis by fair value hierarchy level at June 30, 2018 and December 31, 2017 . There were no transfers between Level 1 and Level 2 for items measured at fair value on a recurring basis during the periods presented. June 30, 2018 (dollars in thousands) Level 1 Level 2 Level 3 Total ASSETS Debt securities available-for-sale: U.S. Treasury securities $ — $ 9,619 $ — $ 9,619 Obligations of U.S. government corporations and agencies — 155,069 — 155,069 Collateralized mortgage obligations of U.S. government corporations and agencies — 118,742 — 118,742 Residential mortgage-backed securities of U.S. government corporations and agencies — 28,442 — 28,442 Commercial mortgage-backed securities of U.S. government corporations and agencies — 247,128 — 247,128 Obligations of states and political subdivisions — 123,916 — 123,916 Total Debt Securities Available-for-Sale — 682,916 — 682,916 Marketable equity securities (1) — 5,425 — 5,425 Total Securities — 688,341 — 688,341 Trading securities held in a Rabbi Trust 4,988 — — 4,988 Derivative financial assets: Interest rate swaps — 6,157 — 6,157 Interest rate lock commitments — 398 — 398 Total Assets $ 4,988 $ 694,896 $ — $ 699,884 LIABILITIES Derivative financial liabilities: Interest rate swaps $ — $ 6,223 $ — $ 6,223 Forward sale contracts — 39 — 39 Total Liabilities $ — $ 6,262 $ — $ 6,262 (1) ASU No. 2016-01 was adopted January 1, 2018, resulting in separate classification of our marketable equity securities previously included in available-for-sale securities. December 31, 2017 (dollars in thousands) Level 1 Level 2 Level 3 Total ASSETS Debt securities available-for-sale: U.S. Treasury securities $ — $ 19,789 $ — $ 19,789 Obligations of U.S. government corporations and agencies — 162,193 — 162,193 Collateralized mortgage obligations of U.S. government corporations and agencies — 108,688 — 108,688 Residential mortgage-backed securities of U.S. government corporations and agencies — 32,854 — 32,854 Commercial mortgage-backed securities of U.S. government corporations and agencies — 242,221 — 242,221 Obligations of states and political subdivisions — 127,402 — 127,402 Total Debt Securities Available-for-Sale — 693,147 — 693,147 Marketable equity securities — 5,144 — 5,144 Total Securities — 698,291 — 698,291 Trading securities held in a Rabbi Trust 5,080 — — 5,080 Derivative financial assets: Interest rate swaps — 3,074 — 3,074 Interest rate lock commitments — 226 — 226 Total Assets $ 5,080 $ 701,591 $ — $ 706,671 LIABILITIES Derivative financial liabilities: Interest rate swaps $ — $ 3,055 $ — $ 3,055 Forward sale contracts — 5 — 5 Total Liabilities $ — $ 3,060 $ — $ 3,060 (1) ASU No. 2016-01 was adopted January 1, 2018, resulting in separate classification of our marketable equity securities previously included in available-for-sale securities. We classify financial instruments as Level 3 when valuation models are used because significant inputs are not observable in the market. We may be required to measure certain assets and liabilities at fair value on a nonrecurring basis. Nonrecurring assets are recorded at the lower of cost or fair value in our financial statements. There were no liabilities measured at fair value on a nonrecurring basis at either June 30, 2018 or December 31, 2017 . The following table presents our assets that are measured at fair value on a nonrecurring basis by the fair value hierarchy level as of the dates presented: June 30, 2018 December 31, 2017 (dollars in thousands) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total ASSETS (1) Impaired loans $ — $ — $ 5,487 $ 5,487 $ — $ — $ 6,759 $ 6,759 Other real estate owned — — 2,719 2,719 — — 444 444 Mortgage servicing rights — — 89 89 — — 178 178 Total Assets $ — $ — $ 8,295 $ 8,295 $ — $ — $ 7,381 $ 7,381 (1) This table presents only the nonrecurring items that are recorded at fair value in our financial statements. The carrying values and fair values of our financial instruments at June 30, 2018 and December 31, 2017 are presented in the following tables: Carrying Value (1) Fair Value Measurements at June 30, 2018 (dollars in thousands) Total Level 1 Level 2 Level 3 ASSETS Cash and due from banks, including interest-bearing deposits $ 137,933 $ 137,933 $ 137,933 $ — $ — Securities 688,341 688,341 — 688,341 — Loans held for sale 3,801 3,927 — — 3,927 Portfolio loans, net 5,725,601 5,558,333 — — 5,558,333 Bank owned life insurance 73,122 73,122 — 73,122 — FHLB and other restricted stock 35,782 35,782 — — 35,782 Trading securities held in a Rabbi Trust 4,988 4,988 4,988 — — Mortgage servicing rights 4,296 5,198 — — 5,198 Interest rate swaps 6,157 6,157 — 6,157 — Interest rate lock commitments 398 398 — 398 — LIABILITIES Deposits $ 5,393,533 $ 5,378,467 $ — $ — $ 5,378,467 Securities sold under repurchase agreements 44,724 44,724 — — 44,724 Short-term borrowings 600,000 600,000 — — 600,000 Long-term borrowings 46,062 46,226 — — 46,226 Junior subordinated debt securities 45,619 45,619 — — 45,619 Interest rate swaps 6,223 6,223 — 6,223 — Forward sales contracts 39 39 — 39 — (1) As reported in the Consolidated Balance Sheets Carrying Value (1) Fair Value Measurements at December 31, 2017 (dollars in thousands) Total Level 1 Level 2 Level 3 ASSETS Cash and due from banks, including interest-bearing deposits $ 117,152 $ 117,152 $ 117,152 $ — $ — Securities 698,291 698,291 — 698,291 — Loans held for sale 4,485 4,583 — — 4,583 Portfolio loans, net 5,705,059 5,690,292 — — 5,690,292 Bank owned life insurance 72,150 72,150 — 72,150 — FHLB and other restricted stock 29,270 29,270 — — 29,270 Trading securities held in a Rabbi Trust 5,080 5,080 5,080 — — Mortgage servicing rights 4,133 4,571 — — 4,571 Interest rate swaps 3,074 3,074 — 3,074 — Interest rate lock commitments 226 226 — 226 — LIABILITIES Deposits $ 5,427,891 $ 5,426,928 $ — $ — $ 5,426,928 Securities sold under repurchase agreements 50,161 50,161 — — 50,161 Short-term borrowings 540,000 540,000 — — 540,000 Long-term borrowings 47,301 47,618 — — 47,618 Junior subordinated debt securities 45,619 45,619 — — 45,619 Interest rate swaps 3,055 3,055 — 3,055 — Forward sales contracts 5 5 — 5 — (1) As reported in the Consolidated Balance Sheets.

Securities

Securities	6 Months Ended
	Jun. 30, 2018
Investments, Debt and Equity Securities [Abstract]
SECURITIES	The following table presents the fair values of our securities portfolio at the dates presented: (dollars in thousands) June 30, 2018 December 31, 2017 Debt securities available for sale $ 682,916 $ 693,147 Marketable equity securities 5,425 5,144 Total Securities $ 688,341 $ 698,291 Debt Securities Available for Sale The following tables present the amortized cost and fair value of debt securities available for sale as of June 30, 2018 and debt and equity securities available for sale as of December 31, 2017: June 30, 2018 December 31, 2017 (dollars in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury securities $ 9,953 $ — $ (334 ) $ 9,619 $ 19,943 $ — $ (154 ) $ 19,789 Obligations of U.S. government corporations and agencies 156,812 16 (1,759 ) 155,069 162,045 341 (193 ) 162,193 Collateralized mortgage obligations of U.S. government corporations and agencies 121,631 61 (2,950 ) 118,742 109,916 93 (1,321 ) 108,688 Residential mortgage-backed securities of U.S. government corporations and agencies 28,662 309 (529 ) 28,442 32,388 679 (213 ) 32,854 Commercial mortgage-backed securities of U.S. government corporations and agencies (1) 254,458 — (7,330 ) 247,128 244,018 247 (2,044 ) 242,221 Obligations of states and political subdivisions 121,492 2,472 (48 ) 123,916 123,159 4,285 (42 ) 127,402 Total Debt Securities Available-for-Sale 693,008 2,858 (12,950 ) 682,916 691,469 5,645 (3,967 ) 693,147 Total equity securities (2) — — — — 3,815 1,330 (1 ) 5,144 Total Securities $ 693,008 $ 2,858 $ (12,950 ) $ 682,916 $ 695,284 $ 6,975 $ (3,968 ) $ 698,291 (1) Includes a $5.9 million security purchase that was pending settlement as of December 31, 2017. (2) ASU No. 2016-01 was adopted January 1, 2018, resulting in separate classification of our marketable equity securities previously included in available-for-sale securities. The following tables present the fair value and the age of gross unrealized losses on debt securities available for sale by investment category as of the dates presented: June 30, 2018 Less Than 12 Months 12 Months or More Total (dollars in thousands) Number of Securities Fair Value Unrealized Number of Securities Fair Value Unrealized Number of Securities Fair Value Unrealized U.S. Treasury securities 1 $ 9,618 $ (334 ) — $ — $ — 1 $ 9,618 $ (334 ) Obligations of U.S. government corporations and agencies 16 129,180 (1,728 ) 2 10,993 (31 ) 18 140,173 (1,759 ) Collateralized mortgage obligations of U.S. government corporations and agencies 10 66,019 (1,067 ) 7 41,018 (1,883 ) 17 107,037 (2,950 ) Residential mortgage-backed securities of U.S. government corporations and agencies 3 4,803 (131 ) 2 7,721 (398 ) 5 12,524 (529 ) Commercial mortgage-backed securities of U.S. government corporations and agencies 22 199,634 (5,190 ) 5 47,494 (2,140 ) 27 247,128 (7,330 ) Obligations of states and political subdivisions 5 23,109 (48 ) — — — 5 23,109 (48 ) Total Temporarily Impaired Debt Securities 57 $ 432,363 $ (8,498 ) 16 $ 107,226 $ (4,452 ) 73 $ 539,589 $ (12,950 ) December 31, 2017 Less Than 12 Months 12 Months or More Total (dollars in thousands) Number of Securities Fair Value Unrealized Number of Securities Fair Value Unrealized Number of Securities Fair Value Unrealized U.S. Treasury securities 3 $ 19,789 $ (154 ) — $ — $ — 3 $ 19,789 $ (154 ) Obligations of U.S. government corporations and agencies 9 63,635 (144 ) 1 10,017 (49 ) 10 73,652 (193 ) Collateralized mortgage obligations of U.S. government corporations and agencies 7 47,465 (248 ) 7 45,809 (1,073 ) 14 93,274 (1,321 ) Residential mortgage-backed securities of U.S. government corporations and agencies 1 2,333 (10 ) 2 8,638 (203 ) 3 10,971 (213 ) Commercial mortgage-backed securities of U.S. government corporations and agencies 14 128,300 (775 ) 5 48,746 (1,269 ) 19 177,046 (2,044 ) Obligations of states and political subdivisions 2 10,330 (42 ) — — — 2 10,330 (42 ) Total Temporarily Impaired Debt Securities 36 $ 271,852 $ (1,373 ) 15 $ 113,210 $ (2,594 ) 51 $ 385,062 $ (3,967 ) We do not believe any individual unrealized loss as of June 30, 2018 represents an other than temporary impairment, or OTTI. At June 30, 2018 there were 73 debt securities and at December 31, 2017 there were 51 debt securities in an unrealized loss position. The unrealized losses on debt securities were primarily attributable to changes in interest rates and not related to the credit quality of these securities. All debt securities were determined to be investment grade and paying principal and interest according to the contractual terms of the security. We do not intend to sell and it is more likely than not that we will not be required to sell any of the securities in an unrealized loss position before recovery of their amortized cost. The following table presents net unrealized gains and losses, net of tax, on debt securities available-for-sale included in accumulated other comprehensive income/(loss), for the periods presented: June 30, 2018 December 31, 2017 (dollars in thousands) Gross Unrealized Gains Gross Unrealized Losses Net Unrealized Gains/ (Losses) Gross Unrealized Gains Gross Unrealized Losses Net Unrealized Gains/ (Losses) Total unrealized gains (losses) on debt securities available-for-sale $ 2,858 $ (12,950 ) $ (10,092 ) $ 5,645 $ (3,967 ) $ 1,678 Income tax (expense) benefit (607 ) 2,750 2,143 (1,982 ) 1,393 (589 ) Net Unrealized Gains/(Losses), Net of Tax Included in Accumulated Other Comprehensive Income/(Loss) $ 2,251 $ (10,200 ) $ (7,949 ) $ 3,663 $ (2,574 ) $ 1,089 The amortized cost and fair value of debt securities available-for-sale at June 30, 2018 by contractual maturity are included in the table below. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. June 30, 2018 (dollars in thousands) Amortized Cost Fair Value Obligations of the U.S. Treasury, U.S. government corporations and agencies, and obligations of states and political subdivisions Due in one year or less $ 33,878 $ 33,888 Due after one year through five years 152,588 152,374 Due after five years through ten years 73,099 72,961 Due after ten years 28,692 29,381 288,257 288,604 Collateralized mortgage obligations of U.S. government corporations and agencies 121,631 118,742 Residential mortgage-backed securities of U.S. government corporations and agencies 28,662 28,442 Commercial mortgage-backed securities of U.S. government corporations and agencies 254,458 247,128 Total Debt Securities Available-for-Sale $ 693,008 $ 682,916 At June 30, 2018 and December 31, 2017 , debt securities with carrying values of $ 231 million and $249 million were pledged for various regulatory and legal requirements. Marketable Equity Securities The following table presents realized and unrealized net gains and losses for our marketable equity securities for the periods presented: Three Months Ended Six Months Ended (dollars in thousands) 2018 2017 2018 2017 Marketable Equity Securities Net market gains/(losses) recognized $ 230 $ 4,121 $ 282 $ 5,224 Less: Net gains/(losses) recognized for equity securities sold — 3,617 — 3,987 Unrealized Gains/(Losses) on Equity Securities Still Held $ 230 $ 504 $ 282 $ 1,237 Prior to January 1, 2018, net unrealized gains and losses, net of tax, on marketable equity securities were included in AOCI for the periods presented. Net unrealized gains and losses, net of tax on marketable equity securities of $0.9 million were reclassified from AOCI to retained earnings at January 1, 2018.

Loans and Loans Held for Sale

Loans and Loans Held for Sale	6 Months Ended
	Jun. 30, 2018
Receivables [Abstract]
LOANS AND LOANS HELD FOR SALE	Loans are presented net of unearned income of $5.4 million and $5.2 million at June 30, 2018 and December 31, 2017 . The following table indicates the composition of loans as of the dates presented: (dollars in thousands) June 30, 2018 December 31, 2017 Commercial Commercial real estate $ 2,788,641 $ 2,685,994 Commercial and industrial 1,455,578 1,433,266 Commercial construction 299,787 384,334 Total Commercial Loans 4,544,006 4,503,594 Consumer Residential mortgage 698,440 698,774 Home equity 471,622 487,326 Installment and other consumer 66,638 67,204 Consumer construction 5,412 4,551 Total Consumer Loans 1,242,112 1,257,855 Total Portfolio Loans 5,786,118 5,761,449 Loans held for sale 3,801 4,485 Total Loans $ 5,789,919 $ 5,765,934 We attempt to limit our exposure to credit risk by diversifying our loan portfolio by segment, geography, collateral and industry and actively managing concentrations. When concentrations exist in certain segments, we mitigate this risk by reviewing the relevant economic indicators and internal risk rating trends and through stress testing of the loans in these segments. Total commercial loans represented 79 percent of total portfolio loans at June 30, 2018 and 78 percent at December 31, 2017 . Within our commercial portfolio, the Commercial Real Estate, or CRE, and Commercial Construction portfolios combined comprised $3.1 billion or 68 percent of total commercial loans and 53 percent of total portfolio loans at both June 30, 2018 and at December 31, 2017 . Further segmentation of the CRE and Commercial Construction portfolios by collateral type reveals no concentration in excess of 13 percent of both total CRE and Commercial Construction loans at June 30, 2018 and 14 percent at December 31, 2017 . Our market area includes Pennsylvania and the contiguous states of Ohio, West Virginia, New York and Maryland. The majority of our commercial and consumer loans are made to businesses and individuals in this market area, resulting in a geographic concentration. We believe our knowledge and familiarity with customers and conditions locally outweighs this geographic concentration risk. The conditions of the local and regional economies are monitored closely through publicly available data and information supplied by our customers. Our CRE and Commercial Construction portfolios have out-of-market exposure of 5.3 percent of their combined portfolios and 2.8 percent of total portfolio loans at June 30, 2018 . This compares to 5.2 percent of their combined portfolios and 2.8 percent of total portfolio loans at December 31, 2017 . We individually evaluate all substandard commercial loans that have experienced a forbearance or change in terms agreement, and all substandard consumer and residential mortgage loans that entered into an agreement to modify their existing loan, to determine if they should be designated as troubled debt restructurings, or TDRs. All TDRs are considered to be impaired loans and will be reported as impaired loans for the remaining life of the loan, unless the restructuring agreement specifies an interest rate equal to or greater than the rate that would be accepted at the time of the restructuring for a new loan with comparable risk and it is fully expected that the remaining principal and interest will be collected according to the restructured agreement. Further, all impaired loans are reported as nonaccrual loans unless the loan is a TDR that has met the requirements to be returned to accruing status. TDRs can be returned to accruing status if the ultimate collectability of all contractual amounts due, according to the restructured agreement, is not in doubt and there is a period of a minimum of six months of satisfactory payment performance by the borrower either immediately before or after the restructuring. The following table summarizes restructured loans as of the dates presented: June 30, 2018 December 31, 2017 (dollars in thousands) Performing TDRs Nonperforming TDRs Total TDRs Performing TDRs Nonperforming TDRs Total TDRs Commercial real estate $ 2,136 $ 925 $ 3,061 $ 2,579 $ 967 $ 3,546 Commercial and industrial 14,149 2,599 16,748 3,946 3,197 7,143 Commercial construction 2,400 410 2,810 2,420 2,413 4,833 Residential mortgage 2,157 1,924 4,081 2,039 3,585 5,624 Home equity 3,569 1,536 5,105 3,885 979 4,864 Installment and other consumer 43 1 44 32 9 41 Total $ 24,454 $ 7,395 $ 31,849 $ 14,901 $ 11,150 $ 26,051 There were no TDRs that returned to accruing status during the three and six months ended June 30, 2018. There was one TDR that returned to accruing status totaling $2.0 million during the three and six months ended June 30, 2017 . The following tables present the restructured loans by loan segment and by type of concession for the three and six months ended June 30, 2018 and 2017: Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 (dollars in thousands) Number of Pre-Modification (1) Post-Modification (1) Total Difference Number of Pre-Modification ( 1) Post-Modification (1) Total Difference Totals by Loan Segment Commercial real estate Principal deferral — $ — $ — $ — 1 $ 100 $ 100 $ — Total Commercial Real Estate — — — — 1 100 100 — Commercial and industrial Maturity date extension and interest rate reduction — — — — 2 1,800 1,800 — Principal deferral 3 4,815 5,034 219 1 429 429 — Total Commercial and Industrial 3 4,815 5,034 219 3 2,229 2,229 — Commercial Construction . Total Commercial Construction — — — — — — — — Residential mortgage Chapter 7 bankruptcy (2) 1 41 41 — 1 33 33 — Total Residential Mortgage 1 41 41 — 1 33 33 — Home equity Chapter 7 bankruptcy (2) 2 26 26 — 3 40 38 (2 ) Maturity date extension — — — — 1 231 231 — Maturity date extension and interest rate reduction 2 47 47 — — — — — Total Home Equity 4 73 73 — 4 271 269 (2 ) Installment and other consumer Chapter 7 bankruptcy (2) 2 8 7 (1 ) 2 37 34 (3 ) Total Installment and Other Consumer 2 8 7 (1 ) 2 37 34 (3 ) Totals by Concession Type Chapter 7 bankruptcy (2) 5 75 74 (1 ) 6 110 105 $ (5 ) Maturity date extension and interest rate reduction 2 47 47 — 2 1,800 1,800 — Maturity date extension — — — — 1 231 231 — Principal deferral 3 4,815 5,034 219 2 529 529 — Total 10 $ 4,937 $ 5,155 $ 218 11 $ 2,670 $ 2,665 $ (5 ) (1) Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end. (2) Chapter 7 bankruptcy loans where the debt has been legally discharged through the bankruptcy court and not reaffirmed. Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 (dollars in thousands) Number of Pre-Modification (1) Post-Modification (1) Total Difference Number of Pre-Modification ( 1) Post-Modification (1) Total Difference Totals by Loan Segment Commercial real estate Principal deferral — $ — $ — $ — 1 $ 100 $ 100 $ — Total Commercial Real Estate — — — — 1 100 100 — Commercial and industrial Maturity date extension 2 768 582 (186 ) — — — — Maturity date extension and interest rate reduction — — — — 2 1,800 1,800 — Principal deferral 3 4,815 5,034 219 1 429 429 — Principal deferral and maturity date extension 6 5,355 5,229 (126 ) — — — — Total Commercial and Industrial 11 10,938 10,845 (93 ) 3 2,229 2,229 — Commercial Construction . Total Commercial Construction — — — — — — — — Residential mortgage Chapter 7 bankruptcy (2) 3 199 196 (3 ) 1 33 33 — Total Residential Mortgage 3 199 196 (3 ) 1 33 33 — Home equity Chapter 7 bankruptcy (2) 11 605 574 (31 ) 9 309 304 (5 ) Maturity date extension — — — — 1 231 231 — Maturity date extension and interest rate reduction 2 47 47 — 1 173 172 (1 ) Total Home Equity 13 652 621 (31 ) 11 713 707 (6 ) Installment and other consumer Chapter 7 bankruptcy (2) 4 25 23 (2 ) 2 37 34 (3 ) Total Installment and Other Consumer 4 25 23 (2 ) 2 37 34 (3 ) Totals by Concession Type Chapter 7 bankruptcy (2) 18 829 793 (36 ) 12 379 371 (8 ) Maturity date extension 2 768 582 (186 ) 1 231 231 — Maturity date extension and interest rate reduction 2 47 47 — 3 1,973 1,972 (1 ) Principal deferral 3 4,815 5,034 219 2 529 529 — Principal deferral and maturity date extension 6 5,355 5,229 (126 ) — — — — Total 31 $ 11,814 $ 11,685 $ (129 ) 18 $ 3,112 $ 3,103 $ (9 ) (1) Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end. (2) Chapter 7 bankruptcy loans where the debt has been legally discharged through the bankruptcy court and not reaffirmed. As of June 30, 2018 , we had seven commitments to lend an additional $5.6 million on TDRs. Defaulted TDRs are defined as loans having a payment default of 90 days or more after the restructuring takes place. There were no TDRs that defaulted during the three and six months ended June 30, 2018 and 2017 that were restructured within the last 12 months prior to defaulting. The following table is a summary of nonperforming assets as of the dates presented: Nonperforming Assets (dollars in thousands) June 30, 2018 December 31, 2017 Nonperforming Assets Nonaccrual loans $ 13,977 $ 12,788 Nonaccrual TDRs 7,395 11,150 Total Nonaccrual Loans 21,372 23,938 OREO 2,999 469 Total Nonperforming Assets $ 24,371 $ 24,407 Other real estate owned, or OREO increased $2.5 million since December 31, 2017. This increase is related to two land lots that are no longer intended to be future branch locations. These land lots were reclassified from other assets to OREO during the three months ended March 31, 2018.

Allowance for Loan Losses

Allowance for Loan Losses	6 Months Ended
	Jun. 30, 2018
Receivables [Abstract]
ALLOWANCE FOR LOAN LOSSES	ALLOWANCE FOR LOAN LOSSES We maintain an allowance for loan losses, or ALLL, at a level determined to be adequate to absorb estimated probable credit losses inherent within the loan portfolio as of the balance sheet date. We develop and document a systematic ALLL methodology based on the following portfolio segments: 1) CRE, 2) Commercial and Industrial, or C&I, 3) Commercial Construction, 4) Consumer Real Estate and 5) Other Consumer. The following are key risks within each portfolio segment: CRE —Loans secured by commercial purpose real estate, including both owner-occupied properties and investment properties for various purposes such as hotels, strip malls and apartments. Operations of the individual projects and global cash flows of the debtors are the primary sources of repayment for these loans. The condition of the local economy is an important indicator of risk, but there are also more specific risks depending on the collateral type and the business prospects of the lessee, if the project is not owner-occupied. C&I —Loans made to operating companies or manufacturers for the purpose of production, operating capacity, accounts receivable, inventory or equipment financing. Cash flow from the operations of the company is the primary source of repayment for these loans. The condition of the local economy is an important indicator of risk, but there are also more specific risks depending on the industry of the company. Collateral for these types of loans often do not have sufficient value in a distressed or liquidation scenario to satisfy the outstanding debt. Commercial Construction —Loans made to finance construction of buildings or other structures, as well as to finance the acquisition and development of raw land for various purposes. While the risk of these loans is generally confined to the construction period, if there are problems, the project may not be completed, and as such, may not provide sufficient cash flow on its own to service the debt or have sufficient value in a liquidation to cover the outstanding principal. The condition of the local economy is an important indicator of risk, but there are also more specific risks depending on the type of project and the experience and resources of the developer. Consumer Real Estate —Loans secured by first and second liens such as home equity loans, home equity lines of credit and 1-4 family residential mortgages, including purchase money mortgages. The primary source of repayment for these loans is the income and assets of the borrower. The condition of the local economy, in particular the unemployment rate, is an important indicator of risk for this segment. The state of the local housing market can also have a significant impact on this segment because low demand and/or declining home values can limit the ability of borrowers to sell a property and satisfy the debt. Other Consumer —Loans made to individuals that may be secured by assets other than 1-4 family residences, as well as unsecured loans. This segment includes auto loans, unsecured loans and lines and credit cards. The primary source of repayment for these loans is the income and assets of the borrower. The condition of the local economy, in particular the unemployment rate, is an important indicator of risk for this segment. The value of the collateral, if there is any, is less likely to be a source of repayment due to less certain collateral values. We further assess risk within each portfolio segment by pooling loans with similar risk characteristics. For the commercial loan classes, the most important indicator of risk is the internally assigned risk rating, including pass, special mention and substandard. Consumer loans are pooled by type of collateral, lien position and loan to value, or LTV, for Consumer Real Estate loans. Historical loss rates are applied to these loan pools to determine the reserve for loans collectively evaluated for impairment. The ALLL methodology for groups of loans collectively evaluated for impairment is comprised of both a quantitative and qualitative analysis. A key assumption in the quantitative component of the reserve is the loss emergence period. The LEP is an estimate of the average amount of time from the point at which a loss is incurred on a loan to the point at which the loss is confirmed. Another key assumption is the look-back period which represents the historical data period utilized to calculate loss rates. Management monitors various credit quality indicators for both the commercial and consumer loan portfolios, including delinquency, nonperforming status and changes in risk ratings on a monthly basis. The following tables present the age analysis of past due loans segregated by class of loans as of the dates presented: June 30, 2018 (dollars in thousands) Current 30-59 Days Past Due 60-89 Days Past Due Non - performing Total Past Due Loans Total Loans Commercial real estate $ 2,781,239 $ 2,473 $ 312 $ 4,617 $ 7,402 $ 2,788,641 Commercial and industrial 1,450,174 432 119 4,853 5,404 1,455,578 Commercial construction 297,849 68 — 1,870 1,938 299,787 Residential mortgage 689,751 1,445 1,132 6,112 8,689 698,440 Home equity 465,261 1,906 584 3,871 6,361 471,622 Installment and other consumer 66,371 172 46 49 267 66,638 Consumer construction 5,412 — — — — 5,412 Loans held for sale 3,801 — — — — 3,801 Total $ 5,759,858 $ 6,496 $ 2,193 $ 21,372 $ 30,061 $ 5,789,919 December 31, 2017 (dollars in thousands) Current 30-59 Days Past Due 60-89 Days Past Due Non - performing Total Past Total Loans Commercial real estate $ 2,681,395 $ 997 $ 134 $ 3,468 $ 4,599 $ 2,685,994 Commercial and industrial 1,426,754 420 446 5,646 6,512 1,433,266 Commercial construction 377,968 2,473 20 3,873 6,366 384,334 Residential mortgage 687,195 2,975 1,439 7,165 11,579 698,774 Home equity 480,956 2,065 590 3,715 6,370 487,326 Installment and other consumer 66,770 193 170 71 434 67,204 Consumer construction 4,551 — — — — 4,551 Loans held for sale 4,485 — — — — 4,485 Total $ 5,730,074 $ 9,123 $ 2,799 $ 23,938 $ 35,860 $ 5,765,934 We continually monitor the commercial loan portfolio through an internal risk rating system. Loan risk ratings are assigned based upon the creditworthiness of the borrower and are reviewed on an ongoing basis according to our internal policies. Loans within the pass rating generally have a lower risk of loss than loans risk rated as special mention or substandard. Our risk ratings are consistent with regulatory guidance and are as follows: Pass —The loan is currently performing and is of high quality. Special Mention —A special mention loan has potential weaknesses that warrant management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects or in the strength of our credit position at some future date. Economic and market conditions, beyond the borrower’s control, may in the future necessitate this classification. Substandard —A substandard loan is not adequately protected by the net worth and/or paying capacity of the borrower or by the collateral pledged, if any. Substandard loans have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. These loans are characterized by the distinct possibility that we will sustain some loss if the deficiencies are not corrected. The following tables present the recorded investment in commercial loan classes by internally assigned risk ratings as of the dates presented: June 30, 2018 (dollars in thousands) Commercial Real Estate % of Total Commercial and Industrial % of Total Commercial Construction % of Total Total % of Total Pass $ 2,636,581 94.5 % $ 1,337,331 91.9 % $ 272,433 90.9 % $ 4,246,345 93.4 % Special mention 74,169 2.7 % 50,142 3.4 % 8,566 2.8 % 132,877 3.0 % Substandard 77,891 2.8 % 68,105 4.7 % 18,788 6.3 % 164,784 3.6 % Total $ 2,788,641 100.0 % $ 1,455,578 100.0 % $ 299,787 100.0 % $ 4,544,006 100.0 % December 31, 2017 (dollars in thousands) Commercial Real Estate % of Total Commercial and Industrial % of Total Commercial Construction % of Total Total % of Total Pass $ 2,588,847 96.4 % $ 1,345,810 93.9 % $ 368,105 95.8 % $ 4,302,762 95.5 % Special mention 66,436 2.5 % 54,320 3.8 % 9,345 2.4 % 130,101 2.9 % Substandard 30,711 1.1 % 33,136 2.3 % 6,884 1.8 % 70,731 1.6 % Total $ 2,685,994 100.0 % $ 1,433,266 100.0 % $ 384,334 100.0 % $ 4,503,594 100.0 % We monitor the delinquent status of the consumer portfolio on a monthly basis. Loans are considered nonperforming when interest and principal are 90 days or more past due or management has determined that a material deterioration in the borrower’s financial condition exists. The risk of loss is generally highest for nonperforming loans. The following tables present the recorded investment in consumer loan classes by performing and nonperforming status as of the dates presented: June 30, 2018 (dollars in thousands) Residential Mortgage % of Total Home Equity % of Total Installment and Other Consumer % of Total Consumer Construction % of Total Total % of Total Performing $ 692,328 99.1 % $ 467,751 99.2 % $ 66,589 99.9 % $ 5,412 100.0 % $ 1,232,080 99.2 % Nonperforming 6,112 0.9 % 3,871 0.8 % 49 0.1 % — — % 10,032 0.8 % Total $ 698,440 100.0 % $ 471,622 100.0 % $ 66,638 100.0 % $ 5,412 100.0 % $ 1,242,112 100.0 % December 31, 2017 (dollars in thousands) Residential Mortgage % of Total Home Equity % of Total Installment and Other Consumer % of Total Consumer Construction % of Total Total % of Total Performing $ 691,609 99.0 % $ 483,611 99.2 % $ 67,133 99.9 % $ 4,551 100.0 % $ 1,246,904 99.1 % Nonperforming 7,165 1.0 % 3,715 0.8 % 71 0.1 % — — % 10,951 0.9 % Total $ 698,774 100.0 % $ 487,326 100.0 % $ 67,204 100.0 % $ 4,551 100.0 % $ 1,257,855 100.0 % We individually evaluate all substandard and nonaccrual commercial loans greater than $0.5 million for impairment. Loans are considered to be impaired when based upon current information and events it is probable that we will be unable to collect all principal and interest payments due according to the original contractual terms of the loan agreement. All TDRs will be reported as an impaired loan for the remaining life of the loan, unless the restructuring agreement specifies an interest rate equal to or greater than the rate that would be accepted at the time of the restructuring for a new loan with comparable risk and it is expected that the remaining principal and interest will be fully collected according to the restructured agreement. For all TDRs and all other impaired loans, we conduct further analysis to determine the probable loss and assign a specific reserve to the loan if deemed appropriate. The following tables summarize investments in loans considered to be impaired and related information on those impaired loans as of the dates presented: June 30, 2018 December 31, 2017 (dollars in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance Related Allowance With a related allowance recorded: Commercial real estate $ — $ — $ — $ — $ — $ — Commercial and industrial — — — 1,735 1,787 29 Commercial construction — — — — — — Consumer real estate — — — 21 21 21 Other consumer 35 35 35 27 27 27 Total with a Related Allowance Recorded 35 35 35 1,783 1,835 77 Without a related allowance recorded: Commercial real estate 3,555 3,828 — 3,546 3,811 — Commercial and industrial 17,539 19,281 — 5,549 7,980 — Commercial construction 3,441 4,950 — 5,464 8,132 — Consumer real estate 9,186 10,132 — 10,467 11,357 — Other consumer 9 13 — 14 22 — Total without a Related Allowance Recorded 33,730 38,204 — 25,040 31,302 — Total: Commercial real estate 3,555 3,828 — 3,546 3,811 — Commercial and industrial 17,539 19,281 — 7,284 9,767 29 Commercial construction 3,441 4,950 — 5,464 8,132 — Consumer real estate 9,186 10,132 — 10,488 11,378 21 Other consumer 44 48 35 41 49 27 Total $ 33,765 $ 38,239 $ 35 $ 26,823 $ 33,137 $ 77 The following table summarizes average recorded investment in and interest income recognized on loans considered to be impaired for the periods presented: Three Months Ended June 30, 2018 June 30, 2017 (dollars in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized With a related allowance recorded: Commercial real estate $ — $ — $ — $ — Commercial and industrial — — 813 6 Commercial construction — — — — Consumer real estate — — 24 1 Other consumer 38 1 26 — Total with a Related Allowance Recorded 38 1 863 7 Without a related allowance recorded: Commercial real estate 3,609 54 6,934 35 Commercial and industrial 8,060 210 17,625 95 Commercial construction 3,443 33 4,262 42 Consumer real estate 9,483 118 11,280 125 Other consumer 10 — 11 1 Total without a Related Allowance Recorded 24,605 415 40,112 298 Total: Commercial real estate 3,609 54 6,934 35 Commercial and industrial 8,060 210 18,438 101 Commercial construction 3,443 33 4,262 42 Consumer real estate 9,483 118 11,304 126 Other consumer 48 1 37 1 Total $ 24,643 $ 416 $ 40,975 $ 305 Six Months Ended June 30, 2018 June 30, 2017 (dollars in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized With a related allowance recorded: Commercial real estate $ — $ — $ — $ — Commercial and industrial — — 628 11 Commercial construction — — — — Consumer real estate — — 25 1 Other consumer 40 2 27 1 Total with a Related Allowance Recorded 40 2 680 13 Without a related allowance recorded: Commercial real estate 3,712 85 7,028 70 Commercial and industrial 7,796 218 16,382 124 Commercial construction 3,445 73 4,267 79 Consumer real estate 10,128 253 11,514 255 Other consumer 11 — 12 — Total without a Related Allowance Recorded 25,092 629 39,203 528 Total: Commercial real estate 3,712 85 7,028 70 Commercial and industrial 7,796 218 17,010 135 Commercial construction 3,445 73 4,267 79 Consumer real estate 10,128 253 11,539 256 Other consumer 51 2 39 1 Total $ 25,132 $ 631 $ 39,883 $ 541 The following tables detail activity in the ALLL for the periods presented: Three Months Ended June 30, 2018 (dollars in thousands) Commercial Real Estate Commercial and Industrial Commercial Construction Consumer Real Estate Other Consumer Total Loans Balance at beginning of period $ 30,963 $ 10,472 $ 10,721 $ 5,418 $ 1,472 $ 59,046 Charge-offs (237 ) (7,392 ) (321 ) (268 ) (414 ) (8,632 ) Recoveries 185 362 1 85 125 758 Net (Charge-offs)/ Recoveries (52 ) (7,030 ) (320 ) (183 ) (289 ) (7,874 ) Provision for loan losses 321 7,432 1,275 6 311 9,345 Balance at End of Period $ 31,232 $ 10,874 $ 11,676 $ 5,241 $ 1,494 $ 60,517 Three Months Ended June 30, 2017 (dollars in thousands) Commercial Real Estate Commercial and Industrial Commercial Construction Consumer Real Estate Other Consumer Total Loans Balance at beginning of period $ 20,570 $ 13,244 $ 14,102 $ 5,956 $ 1,944 $ 55,816 Charge-offs (1,673 ) (2,682 ) — (1,097 ) (370 ) (5,822 ) Recoveries 155 69 113 76 75 488 Net (Charge-offs)/ Recoveries (1,518 ) (2,613 ) 113 (1,021 ) (295 ) (5,334 ) Provision for loan losses 5,306 (1,375 ) (271 ) 868 341 4,869 Balance at End of Period $ 24,358 $ 9,256 $ 13,944 $ 5,803 $ 1,990 $ 55,351 Six Months Ended June 30, 2018 (dollars in thousands) Commercial Real Estate Commercial and Industrial Commercial Construction Consumer Real Estate Other Consumer Total Loans Balance at beginning of period $ 27,235 $ 8,966 $ 13,167 $ 5,479 $ 1,543 $ 56,390 Charge-offs (232 ) (8,222 ) (321 ) (429 ) (872 ) (10,076 ) Recoveries 228 480 1,130 323 225 2,386 Net (Charge-offs)/Recoveries (4 ) (7,742 ) 809 (106 ) (647 ) (7,690 ) Provision for loan losses 4,001 9,650 (2,300 ) (132 ) 598 11,817 Balance at End of Period $ 31,232 $ 10,874 $ 11,676 $ 5,241 $ 1,494 $ 60,517 Six Months Ended June 30, 2017 (dollars in thousands) Commercial Real Estate Commercial and Industrial Commercial Construction Consumer Real Estate Other Consumer Total Loans Balance at beginning of period $ 19,976 $ 10,810 $ 13,999 $ 6,095 $ 1,895 $ 52,775 Charge-offs (2,063 ) (3,396 ) (644 ) (1,856 ) (804 ) (8,763 ) Recoveries 233 255 369 179 251 1,287 Net (Charge-offs)/Recoveries (1,830 ) (3,141 ) (275 ) (1,677 ) (553 ) (7,476 ) Provision for loan losses 6,212 1,587 220 1,385 648 10,052 Balance at End of Period $ 24,358 $ 9,256 $ 13,944 $ 5,803 $ 1,990 $ 55,351 Net charge-offs and provision for loan losses for the three and six months ended June 30, 2018 were significantly impacted by a $5.2 million loan charge-off for a commercial customer arising from a participation loan agreement with a lead bank and other participating banks. The loss resulted from fraudulent activities believed to be perpetrated by one or more executives employed by the borrower and its related entities. S&T’s total exposure consisted of the participation loan of $4.9 million and a direct exposure of $950 thousand which is secured by vehicles and equipment liens. The following tables present the ALLL and recorded investments in loans by category as of the periods presented: June 30, 2018 Allowance for Loan Losses Portfolio Loans (dollars in thousands) Individually Evaluated for Impairment Collectively Evaluated for Impairment Total Individually Evaluated for Impairment Collectively Evaluated for Impairment Total Commercial real estate $ — $ 31,232 $ 31,232 $ 3,555 $ 2,785,086 $ 2,788,641 Commercial and industrial — 10,874 10,874 17,539 1,438,039 1,455,578 Commercial construction — 11,676 11,676 3,441 296,346 299,787 Consumer real estate — 5,241 5,241 9,186 1,166,288 1,175,474 Other consumer 35 1,459 1,494 44 66,594 66,638 Total $ 35 $ 60,482 $ 60,517 $ 33,765 $ 5,752,353 $ 5,786,118 December 31, 2017 Allowance for Loan Losses Portfolio Loans (dollars in thousands) Individually Evaluated for Impairment Collectively Evaluated for Impairment Total Individually Evaluated for Impairment Collectively Evaluated for Impairment Total Commercial real estate $ — $ 27,235 $ 27,235 $ 3,546 $ 2,682,448 $ 2,685,994 Commercial and industrial 29 8,937 8,966 7,284 1,425,982 1,433,266 Commercial construction — 13,167 13,167 5,464 378,870 384,334 Consumer real estate 21 5,458 5,479 10,488 1,180,163 1,190,651 Other consumer 27 1,516 1,543 41 67,163 67,204 Total $ 77 $ 56,313 $ 56,390 $ 26,823 $ 5,734,626 $ 5,761,449

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	6 Months Ended
	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	Interest Rate Swaps In accordance with applicable accounting guidance for derivatives and hedging, all derivatives are recognized as either assets or liabilities on the balance sheet at fair value. Interest rate swaps are contracts in which a series of interest rate flows (fixed and variable) are exchanged over a prescribed period. The notional amounts on which the interest payments are based are not exchanged. These derivative positions relate to transactions in which we enter into an interest rate swap with a commercial customer while at the same time entering into an offsetting interest rate swap with another financial institution. In connection with each transaction, we agree to pay interest to the customer on a notional amount at a variable interest rate and receive interest from the customer on the same notional amount at a fixed rate. At the same time, we agree to pay another financial institution the same fixed interest rate on the same notional amount and receive the same variable interest rate on the same notional amount. The transaction allows our customer to effectively convert a variable rate loan to a fixed rate loan with us receiving a variable rate. These agreements could have floors or caps on the contracted interest rates. Pursuant to our agreements with various financial institutions, we may receive collateral or may be required to post collateral based upon mark-to-market positions. Beyond unsecured threshold levels, collateral in the form of cash or securities may be made available to counterparties of interest rate swap transactions. Based upon our current positions and related future collateral requirements relating to them, we believe any effect on our cash flow or liquidity position to be immaterial. Derivatives contain an element of credit risk, the possibility that we will incur a loss because a counterparty, which may be a financial institution or a customer, fails to meet its contractual obligations. All derivative contracts with financial institutions may be executed only with counterparties approved by our Asset and Liability Committee, or ALCO, and derivatives with customers may only be executed with customers within credit exposure limits approved by our Senior Loan Committee. Interest rate swaps are considered derivatives, but are not accounted for using hedge accounting. As such, changes in the estimated fair value of the derivatives are recorded in current earnings and included in other noninterest income in the Consolidated Statements of Comprehensive Income. Interest Rate Lock Commitments and Forward Sale Contracts In the normal course of business, we sell originated mortgage loans into the secondary mortgage loan market. We also offer interest rate lock commitments to potential borrowers. The commitments are generally for a period of 60 days and guarantee a specified interest rate for a loan if underwriting standards are met, but the commitment does not obligate the potential borrower to close on the loan. Accordingly, some commitments expire prior to becoming loans. We may encounter pricing risks if interest rates increase significantly before the loan can be closed and sold. We may utilize forward sale contracts in order to mitigate this pricing risk. Whenever a customer desires these products, a mortgage originator quotes a secondary market rate guaranteed for that day by the investor. The rate lock is executed between the mortgagee and us and in turn a forward sale contract may be executed between us and the investor. Both the rate lock commitment and the corresponding forward sale contract for each customer are considered derivatives, but are not accounted for using hedge accounting. As such, changes in the estimated fair value of the derivatives during the commitment period are recorded in current earnings and included in mortgage banking in the Consolidated Statements of Comprehensive Income. The following tables indicate the amounts representing the value of derivative assets and derivative liabilities as of the dates presented: Derivatives (included in Other Assets) Derivatives (included in Other Liabilities) (dollars in thousands) June 30, 2018 December 31, 2017 June 30, 2018 December 31, 2017 Derivatives not Designated as Hedging Instruments: Interest Rate Swap Contracts - Commercial Loans Fair value $ 6,157 $ 3,074 $ 6,223 $ 3,055 Notional amount 246,494 263,841 246,494 263,841 Net collateral received/posted 2,560 — — 1,448 Interest Rate Lock Commitments - Mortgage Loans Fair value 398 226 — — Notional amount 12,711 6,860 — — Forward Sale Contracts - Mortgage Loans Fair value — — 39 5 Notional amount $ — $ — $ 12,250 $ 6,580 Presenting offsetting derivatives that are subject to legally enforceable netting arrangements with the same party is permitted. For example, we may have a derivative asset and a derivative liability with the same counterparty to a swap transaction and are permitted to offset the asset position and the liability position resulting in a net presentation. The following tables indicate the gross amounts of commercial loan swap derivative assets and derivative liabilities, the amounts offset and the carrying values in the Consolidated Balance Sheets as of the dates presented: Derivatives (included in Other Assets) Derivatives (included in Other Liabilities) (dollars in thousands) June 30, 2018 December 31, 2017 June 30, 2018 December 31, 2017 Derivatives not Designated as Hedging Instruments: Gross amounts recognized $ 7,258 $ 4,974 $ 7,324 $ 4,955 Gross amounts offset (1,101 ) (1,900 ) (1,101 ) (1,900 ) Net Amounts Presented in the Consolidated Balance Sheets 6,157 3,074 6,223 3,055 Gross amounts not offset (1) (2,560 ) — — (1,448 ) Net Amount $ 3,597 $ 3,074 $ 6,223 $ 1,607 (1) Amounts represent received/posted collateral. The following tables indicate the gain or loss recognized in income on derivatives for the periods presented: Three Months Ended June 30, Six Months Ended June 30, (dollars in thousands) 2018 2017 2018 2017 Derivatives not Designated as Hedging Instruments Interest rate swap contracts—commercial loans $ (201 ) $ (8 ) $ (85 ) $ 16 Interest rate lock commitments—mortgage loans 128 (13 ) 172 220 Forward sale contracts—mortgage loans (15 ) 76 (33 ) 40 Total Derivatives (Loss)/Gain $ (88 ) $ 55 $ 54 $ 276

Borrowings

Borrowings	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
BORROWINGS	BORROWINGS Short-term borrowings are for terms under or equal to one year and are comprised of securities sold under repurchase agreements, or REPOs, and Federal Home Loan Bank, or FHLB, advances. All REPOs are overnight short-term investments and are not insured by the Federal Deposit Insurance Corporation. Securities pledged as collateral under these REPO financing arrangements cannot be sold or repledged by the secured party and therefore, the REPOs are accounted for as a secured borrowing. Mortgage-backed securities with amortized cost of $51.4 million and carrying value of $49.9 million at June 30, 2018 and amortized cost of $57.5 million and carrying value of $56.8 million at December 31, 2017 were pledged as collateral for these secured transactions. The pledged securities are held in safekeeping at the Federal Reserve. Due to the overnight short-term nature of REPOs, potential risk due to a decline in the value of the pledged collateral is low. Collateral pledging requirements with REPOs are monitored daily. FHLB advances are for various terms and are secured by a blanket lien on residential mortgages and other real estate secured loans. Long-term borrowings are for original terms greater than one year and are comprised of FHLB advances, a capital lease and junior subordinated debt securities. Long-term FHLB advances are secured by the same loans as short-term FHLB advances. We had total long-term borrowings outstanding of $7.9 million at a fixed rate and $38.1 million at a variable rate at June 30, 2018 , excluding our capital lease. Information pertaining to borrowings is summarized in the table below as of the dates presented: June 30, 2018 December 31, 2017 (dollars in thousands) Balance Weighted Average Rate Balance Weighted Average Rate Short-term Borrowings Securities sold under repurchase agreements $ 44,724 0.46 % $ 50,161 0.39 % Short-term borrowings 600,000 2.16 % 540,000 1.47 % Total Short-term Borrowings 644,724 2.04 % 590,161 1.38 % Long-term Borrowings Long-term borrowings 46,062 2.31 % 47,301 1.88 % Junior subordinated debt securities 45,619 4.80 % 45,619 3.78 % Total Long-term Borrowings 91,681 3.55 % 92,920 2.81 % Total Borrowings $ 736,405 2.23 % $ 683,081 1.57 % We had total borrowings at June 30, 2018 and December 31, 2017 at the FHLB of Pittsburgh of $646 million and $587 million . The $646 million at June 30, 2018 consisted of $600 million in short-term borrowings and $46.1 million in long-term borrowings. Our maximum borrowing capacity with the FHLB of Pittsburgh was $2.5 billion at June 30, 2018 . We utilized $790 million of our borrowing capacity at June 30, 2018 consisting of $646 million for borrowings and $144 million for letters of credit to collateralize public funds. Our remaining borrowing availability at June 30, 2018 is $1.7 billion .

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	Commitments In the normal course of business, we offer off-balance sheet credit arrangements to enable our customers to meet their financing objectives. These instruments involve, to varying degrees, elements of credit and interest rate risk in excess of the amount recognized in the financial statements. Our exposure to credit loss, in the event the customer does not satisfy the terms of the agreement, equals the contractual amount of the obligation less the value of any collateral. We apply the same credit policies in making commitments and standby letters of credit that are used for the underwriting of loans to customers. Commitments generally have fixed expiration dates, annual renewals or other termination clauses and may require payment of a fee. Because many of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. Our allowance for unfunded commitments totaled $2.1 million at June 30, 2018 and $2.2 million at December 31, 2017 . The allowance for unfunded commitments is included in other liabilities in the Consolidated Balance Sheets. The allowance for unfunded commitments is determined using a similar methodology as our ALLL methodology. The reserve is calculated by applying historical loss rates and qualitative adjustments to our unfunded commitments. Estimates of the fair value of these off-balance sheet items were not made because of the short-term nature of these arrangements and the credit standing of the counterparties. The following table sets forth our commitments and letters of credit as of the dates presented: (dollars in thousands) June 30, 2018 December 31, 2017 Commitments to extend credit $ 1,413,700 $ 1,420,428 Standby letters of credit 80,709 80,918 Total $ 1,494,409 $ 1,501,346 Litigation In the normal course of business, we are subject to various legal and administrative proceedings and claims. While any type of litigation contains a level of uncertainty, we believe that the outcome of such proceedings or claims pending will not have a material adverse effect on our consolidated financial position or results of operations.

Other Comprehensive Income

Other Comprehensive Income	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
OTHER COMPREHENSIVE INCOME	The following tables present the change in components of other comprehensive income (loss) for the periods presented, net of tax effects. Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 (dollars in thousands) Pre-Tax Amount Tax (Expense) Benefit Net of Tax Amount Pre-Tax Amount Tax (Expense) Benefit Net of Tax Amount Change in net unrealized gains/(losses) on debt securities available-for-sale (1) $ (2,296 ) $ 487 $ (1,809 ) $ 2,672 $ (938 ) $ 1,734 Reclassification adjustment for net (gains)/losses on debt securities available-for-sale included in net income (2) — — — (3,617 ) 1,270 (2,347 ) Adjustment to funded status of employee benefit plans 702 (149 ) 553 539 (188 ) 351 Other Comprehensive (Loss)/Income $ (1,594 ) $ 338 $ (1,256 ) $ (406 ) $ 144 $ (262 ) (1) Due to the adoption of ASU No. 2016-01, net unrealized gains on marketable equity securities were reclassified from Accumulated Other Comprehensive Income to Retained Earnings during the three months ended March 31, 2018. The prior period data was not restated; as such, the change in unrealized gains on marketable securities is combined with the change in net unrealized gains on debit securities for the period ended June 30, 2017. (2) Reclassification adjustments are comprised of realized security gains or losses. The realized gains or losses have been reclassified out of accumulated other comprehensive income/(loss) and have affected certain lines in the Consolidated Statements of Comprehensive Income as follows; the pre-tax amount is included in securities gains/losses-net, the tax expense amount is included in the provision for income taxes and the net of tax amount is included in net income. Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 (dollars in thousands) Pre-Tax Amount Tax (Expense) Benefit Net of Tax Amount Pre-Tax Amount Tax (Expense) Benefit Net of Tax Amount Change in net unrealized gains/(losses) on securities available-for-sale (1) $ (11,770 ) $ 2,499 $ (9,271 ) $ 4,335 $ (1,523 ) $ 2,812 Reclassification adjustment for net (gains)/losses on securities available-for-sale included in net income (2) — — — (3,987 ) 1,400 (2,587 ) Adjustment to funded status of employee benefit plans 1,323 (281 ) 1,042 1,078 (377 ) 701 Other Comprehensive (Loss)/Income $ (10,447 ) $ 2,218 $ (8,229 ) $ 1,426 $ (500 ) $ 926 (1) Due to the adoption of ASU No. 2016-01, net unrealized gains on marketable equity securities were reclassified from Accumulated Other Comprehensive Income to Retained Earnings during the three months ended March 31, 2018. The prior period data was not restated; as such, the change in unrealized gains on marketable securities is combined with the change in net unrealized gains on debit securities for the period ended June 30, 2017. (2) Reclassification adjustments are comprised of realized security gains or losses. The realized gains or losses have been reclassified out of accumulated other comprehensive income/(loss) and have affected certain lines in the Consolidated Statements of Comprehensive Income as follows; the pre-tax amount is included in securities gains/losses-net, the tax expense amount is included in the provision for income taxes and the net of tax amount is included in net income.

Employee Benefits

Employee Benefits	6 Months Ended
	Jun. 30, 2018
Retirement Benefits [Abstract]
EMPLOYEE BENEFITS	Our qualified and nonqualified defined benefit plans were amended to freeze benefit accruals for all persons entitled to benefits under the plan in 2016. We will continue recording pension expense related to these plans, primarily representing interest costs on the accumulated benefit obligation and amortization of actuarial losses accumulated in the plan, as well as income from expected investment returns on pension assets. Since the plans have been frozen, no service costs are included in net periodic pension expense. The expected long-term rate of return on plan assets is 7.50 percent . The following table summarizes the components of net periodic pension cost for the periods presented: Three Months Ended June 30, Six Months Ended June 30, (dollars in thousands) 2018 2017 2018 2017 Components of Net Periodic Pension Cost Interest cost on projected benefit obligation $ 967 $ 1,025 $ 1,934 $ 2,050 Expected return on plan assets (1,567 ) (1,582 ) (3,134 ) (3,164 ) Amortization of prior service credit 545 475 1,089 949 Net Periodic Pension Expense $ (55 ) $ (82 ) $ (111 ) $ (165 )

Qualified Affordable Housing Pr

Qualified Affordable Housing Projects	6 Months Ended
	Jun. 30, 2018
Investments in Affordable Housing Projects [Abstract]
QUALIFIED AFFORDABLE HOUSING PROJECTS	QUALIFIED AFFORDABLE HOUSING PROJECTS We invest in affordable housing projects primarily to satisfy our Community Reinvestment Act requirements. As a limited partner in these operating partnerships, we receive tax credits and tax deductions for losses incurred by the underlying properties. We use the cost method to account for these partnerships. Our total investment in qualified affordable housing projects was $7.3 million at June 30, 2018 and $8.7 million at December 31, 2017 . Amortization expense, included in other noninterest expense in the Consolidated Statements of Comprehensive Income was $0.7 million and $1.4 million for the three and six months ended June 30, 2018 and $0.8 million and $1.6 million for the three and six months ended June 30, 2017. The amortization expense was offset by tax credits of $0.8 million and $1.5 million for the three and six months ended June 30, 2018 and $0.9 million and $1.7 million for the three and six months ended June 30, 2017 as a reduction to our federal tax provision.

Sale of a Majority Interest of

Sale of a Majority Interest of Insurance Business	6 Months Ended
	Jun. 30, 2018
Disposal Group, Not Discontinued Operation, Disposal Disclosures [Abstract]
SALE OF A MAJORITY INTEREST OF INSURANCE BUSINESS	SALE OF A MAJORITY INTEREST OF INSURANCE BUSINESS On November 9, 2017, we entered into an asset purchase agreement to sell a 70 percent ownership interest in the assets of our subsidiary, S&T Evergreen Insurance, LLC. The partial sale was accounted for as the sale of a business. At the date of the sale, January 1, 2018, we ceased to have a controlling financial interest, deconsolidated the subsidiary and recognized a gain of $1.9 million . We transferred our remaining 30 percent share of net assets from S&T Evergreen Insurance, LLC to a new entity for a 30 percent partnership interest in a new insurance entity. We use the equity method of accounting to recognize changes in the value of our investment in the new insurance entity for our proportional share of income and losses of the new insurance entity.

Share Repurchase Plan

Share Repurchase Plan	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
SHARE REPURCHASE PLAN	SHARE REPURCHASE PLAN On March 19, 2018, our Board of Directors authorized a $50 million share repurchase plan. This repurchase authorization, which is effective through August 31, 2019, permits us to repurchase from time to time up to $50 million in aggregate value of shares of our common stock through a combination of open market and privately negotiated repurchases. The specific timing, price and quantity of repurchases will be at our discretion and will depend on a variety of factors, including general market conditions, the trading price of the common stock, legal and contractual requirements and our financial performance. The repurchase plan does not obligate us to repurchase any particular number of shares. We expect to fund any repurchases from cash on hand and internally generated funds.

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The interim Consolidated Financial Statements include the accounts of S&T Bancorp, Inc., or S&T, and its wholly owned subsidiaries. All significant intercompany transactions have been eliminated in consolidation. Investments of 20 percent to 50 percent of the outstanding common stock of investees are accounted for using the equity method of accounting.
Basis of Presentation	Basis of Presentation The accompanying unaudited interim Consolidated Financial Statements of S&T have been prepared in accordance with generally accepted accounting principles, or GAAP, in the United States for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements and should be read in conjunction with the audited consolidated financial statements included in our annual report on Form 10-K for the year ended December 31, 2017 , filed with the Securities and Exchange Commission, or SEC, on March 1, 2018. In the opinion of management, the accompanying interim financial information reflects all adjustments, consisting of normal recurring adjustments, necessary to present fairly our financial position and the results of operations for each of the interim periods presented. Results of operations for interim periods are not necessarily indicative of the results of operations that may be expected for a full year or any future period.
Reclassification	Reclassification A mounts in prior period financial statements and footnotes are reclassified whenever necessary to conform to the current period presentation. Reclassifications had no effect on our results of operations or financial condition.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates.
Recently Adopted Accounting Standards Updates, or ASU or Update and Accounting Standards Issued But Not Yet Adopted	Recently Adopted Accounting Standards Updates, or ASU or Update Income Statement - Reporting Comprehensive Income - Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income In February 2018, the FASB issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220), Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The amendments in this Update allow a reclassification from accumulated other comprehensive income, or AOCI, to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act, or Tax Act. The amendments eliminate the stranded tax effects resulting from the Tax Act and will improve the usefulness of information reported to financial statement users and will require certain disclosures about the stranded tax effects. This Update is effective for all entities for fiscal years beginning after December 15, 2018 and interim periods within those fiscal years. Early adoption is permitted, including adoption in any interim period, for public business entities for reporting periods for which financial statements have not been issued or made available for issuance. We have elected to reclassify all tax effects related to the Tax Act from AOCI to retained earnings as of January 1, 2018. As such, we have early adopted this Update and reclassified $3.4 million for the release of stranded income tax effects relating to unrealized gains and losses on our securities portfolio and our pension plan from AOCI to retained earnings as of March 31, 2018. The adoption of this ASU had no impact on our Consolidated Statements of Comprehensive Income. Our policy for releasing income tax effects from AOCI is to release them as investments are sold or mature and liabilities are extinguished. Compensation - Retirement Benefits - Improving the Presentation of Net Periodic Pension Costs and Net Periodic Post Retirement Benefit Costs In March 2017, the FASB issued ASU No. 2017-07, Compensation Retirement Benefits - Improving the Presentation of Net Periodic Pension Costs and Net Periodic Post Retirement Benefit Costs (Topic 715). The main objective of this ASU is to provide financial statement users with clearer and disaggregated information related to the components of net periodic benefit cost and improve transparency of the presentation of net periodic benefit cost in the financial statements. This Update was effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. Early adoption was permitted as of the beginning of an annual period for which financial statements have not been issued or made available for issuance. Effective March 31, 2016, our qualified and nonqualified defined benefit plans were amended to freeze benefit accruals for all persons entitled to benefits under the plan; as such, the adoption of this ASU had no impact on our Consolidated Balance Sheets or Consolidated Statements of Comprehensive Income. Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets - Clarifying the Scope of Assets Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets In February 2017, the FASB issued ASU No. 2017-05, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20). The main objective of this ASU is to provide greater detail on what types of transactions should be accounted for as partial sales of nonfinancial assets. This ASU, as originally issued in ASU No. 2014-09, is intended to reduce the complexity of current GAAP requirements by clarifying which accounting guidance applies to various types of contracts that transfer assets or ownership interest to another entity. This Update was effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017 and at the same time that ASU No. 2014-09 was effective. Early adoption was permitted, but only as of annual reporting periods beginning after December 15, 2016, including interim reporting periods within that reporting period. The adoption of this ASU was applied to the partial sale of our insurance subsidiary in January 2018. As such, the subsidiary is no longer included in our consolidated financial statements and we recognized a $1.9 million gain on the transaction. Business Combinations - Clarifying the Definition of a Business In January 2017, the FASB issued ASU No. 2017-01, Business Combinations - Clarifying the Definition of a Business (Topic 805). The main objective of this ASU is to help financial statement preparers evaluate whether a set of transferred assets and activities (either acquired or disposed of) is a business under Topic 805, Business Combinations by changing the definition of a business. The revised definition results in fewer acquisitions being accounted for as business combinations than under previous guidance. The definition of a business is significant because it affects the accounting for acquisitions, the identification of reporting units, consolidation evaluations and the accounting for dispositions. This Update was effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. Early adoption was permitted for transactions not yet reflected in financial statements that have been issued or made available for issuance. The adoption of this ASU had no impact on our Consolidated Balance Sheets or Consolidated Statements of Comprehensive Income. Income Taxes - Intra-Entity Transfers of Assets Other Than Inventory In October 2016, the FASB issued ASU No. 2016-16, Intra-Entity Transfers of Assets Other Than Inventory. The main objective of this ASU is to require companies to recognize the income tax effects of intercompany sales and transfers of assets other than inventory in the period in which the transfer occurs. This represents a change from previous guidance, which required companies to defer the income tax effects of intercompany transfers of assets until the asset has been sold to an outside party or otherwise recognized. The new guidance requires companies to defer the income tax effects only of intercompany transfers of inventory. This Update was effective for annual periods beginning after December 15, 2017. Early adoption was permitted as of the beginning of an annual period. If an entity chose to early adopt the amendments in the ASU, it had to do so in the first interim period of its annual financial statements. That is, an entity could not have adopted the amendments in the ASU in a later interim period and apply them as if they were in effect as of the beginning of the year. The adoption of this ASU had no impact on our Consolidated Balance Sheets or Consolidated Statements of Comprehensive Income. Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments In August 2016, the FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments. The main objective of this ASU is to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. The amendments in this Update provide guidance on the following eight specific cash flow issues: debt prepayment or debt extinguishment costs, settlement of zero-coupon debt instruments, contingent consideration payments made after a business combination, proceeds from the settlement of insurance claims, proceeds from the settlement of bank-owned life insurance (BOLI) policies, distributions received from equity method investments, beneficial interests in securitization transactions, and separately identifiable cash flows and application of the predominance principle. This Update was effective for interim and annual reporting periods in fiscal years beginning after December 15, 2017. Early adoption was permitted, provided that all of the amendments are adopted in the same period. The adoption of this ASU had no material impact to the presentation of activities in our Consolidated Statements of Cash Flows. Revenue from Contracts with Customers In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606). This revenue pronouncement established a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and superseded most previous revenue recognition guidance in GAAP. We adopted the new standard January 1, 2018. Our primary sources of revenue are derived from interest and dividends earned on loans, investment securities and other financial instruments that are not within the scope of ASU No. 2014-09. We evaluated the nature of our contracts with customers and related revenue streams, including service charges on deposit accounts, debit and credit cards and wealth management and determined that revenue recognition did not change significantly from current practice. We evaluated certain costs related to these revenue streams to determine whether such costs should be presented as expenses or contra-revenue. The adoption of this ASU had no material impact on our Consolidated Balance Sheets or Consolidated Statements of Comprehensive Income. Accounting for Financial Instruments - Overall: Classification and Measurement In January 2016, the FASB issued ASU No. 2016-01, Accounting for Financial Instruments - Overall: Classification and Measurement (Subtopic 825-10). The amendments in this ASU address the following: 1. require equity investments to be measured at fair value with changes in fair value recognized in net income; 2. simplify the impairment assessment of equity investments without readily-determinable fair values by requiring a qualitative assessment to identify impairment; 3. eliminate the requirement to disclose the method(s) and significant assumptions used to estimate the fair value that is required to be disclosed for financial instruments measured at amortized cost on the balance sheet; 4. require entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes; 5. require separate presentation in other comprehensive income for the portion of the total change in the fair value of a liability resulting from a change in the instrument-specific credit risk when the entity has elected to measure the liability at fair value in accordance with the fair value option for financial instruments; 6. require separate presentation of financial assets and financial liabilities by measurement category and form of financial asset (that is, securities or loans and receivables) on the balance sheet or in the accompanying notes to the financial statements; and 7. clarify that an entity should evaluate the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity's other deferred tax assets. This ASU was effective for annual and interim periods in fiscal years beginning after December 15, 2017. We adopted ASU No. 2016-01 as of January 1, 2018 and have concluded that the provisions of this ASU did not materially impact our Balance Sheets or Statements of Comprehensive Income. The new guidance resulted in a change in the fair value measurement of our loan portfolio as of March 31, 2018 using an exit price notion (see Note 3: Fair Value Measurements). The new guidance also resulted in a cumulative-effect adjustment of $0.9 million from AOCI to retained earnings at January 1, 2018 for net unrealized gains on our marketable equities portfolio. As a result of the new guidance, we recognized $0.3 million of net unrealized gains in our Consolidated Statements of Comprehensive Income during the six months ended June 30, 2018 on our marketable equity securities portfolio. Accounting Standards Issued But Not Yet Adopted Leases - Land Easement Practical Expedient for Transition to Topic 842 In January 2018, the FASB issued ASU No. 2018-01, Leases - Land Easement Practical Expedient for Transition to Topic 842. The amendments in this ASU permit an entity to elect an optional transition practical expedient to not evaluate under Topic 842 land easements, that existed or expired before the entity's adoption of Topic 842 and that were not previously accounted for as leases under Topic 840. This ASU is effective for annual and interim periods in fiscal years beginning after December 15, 2018. We are evaluating the amendments in this ASU; however, we do not anticipate that these amendments will materially impact our Consolidated Balance Sheets or Consolidated Statements of Comprehensive Income. Intangibles - Goodwill and Other - Simplifying the Test for Goodwill Impairment In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other - Simplifying the Test for Goodwill Impairment (Topic 350). The main objective of this ASU is intended to simplify the current requirements for testing goodwill for impairment by eliminating step two from the goodwill impairment test. The amendments are expected to reduce the complexity and costs associated with performing the goodwill impairment test, which could result in recording impairment charges sooner than under the current guidance. This Update is effective for any interim and annual impairment tests in reporting periods in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We are evaluating the provisions of this ASU; however, we do not anticipate that this ASU will materially impact our Consolidated Balance Sheets or Consolidated Statements of Comprehensive Income. Financial Instruments - Credit Losses In June 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments. The main objective of this ASU is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. The amendments of this Update replace the incurred loss impairment methodology in current GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to form credit loss estimates. The collective changes to the recognition and measurement accounting standards for financial instruments and their anticipated impact on the allowance for credit losses modeling have been universally referred to as CECL, or current expected credit loss, model. This Update is effective for interim and annual reporting periods in fiscal years beginning after December 15, 2019. Early adoption is permitted for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. We have created a CECL Committee to govern the implementation of these amendments consisting of key stakeholders from Credit Administration, Finance, Risk Management and Internal Audit. We have engaged a third-party to assist us in developing our CECL methodology. We continue to evaluate the provisions of this ASU to determine the potential impact on our Consolidated Balance Sheets and Consolidated Statements of Comprehensive Income. Leases - Section A-Amendments to the FASB Accounting Standards Codification, Section B-Conforming Amendments Related to Leases and Section C-Background Information and Basis for Conclusions In February 2016, the FASB issued ASU No. 2016-02, Leases, which requires lessees to recognize a right-to-use asset and a lease obligation for all leases on the balance sheet. Lessor accounting remains substantially similar to current GAAP. ASU No. 2016-02 supersedes Topic 840, Leases. This ASU is effective for annual and interim periods in fiscal years beginning after December 15, 2018. ASU No. 2016-02 mandates a modified retrospective transition method for all entities. Early adoption of this ASU is permitted. We anticipate that this ASU will impact our financial statements as it relates to the recognition of right-to-use assets and lease obligations on our Consolidated Balance Sheets. We have approximately 50 lease agreements for our branch and loan production offices, which are currently accounted for as operating leases. We expect the new guidance will require these lease agreements to be included on our Consolidated Balance Sheets as right-to-use assets with a corresponding lease liability. We expect that these changes to our Consolidated Balance Sheets will impact our regulatory capital ratios. We have compiled a preliminary inventory of our leases and continue to evaluate the standard. We anticipate that this ASU will impact total assets and total liabilities presented on our Balance Sheets; however, we do not believe that it will materially impact our Consolidated Statements of Comprehensive Income.
Fair Value Measurements	We use fair value measurements when recording and disclosing certain financial assets and liabilities. Debt securities, equity securities, trading assets and derivative financial instruments are recorded at fair value on a recurring basis. Additionally, from time to time, we may be required to record other assets at fair value on a nonrecurring basis, such as loans held for sale, impaired loans, other real estate owned, or OREO, and other repossessed assets, mortgage servicing rights, or MSRs, and certain other assets. Fair value is the price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market in an orderly transaction between market participants at the measurement date. An orderly transaction is a transaction that assumes exposure to the market for a period prior to the measurement date to allow for marketing activities that are usual and customary for transactions involving such assets or liabilities; it is not a forced transaction. In determining fair value, we use various valuation approaches, including market, income and cost approaches. The fair value standard establishes a hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that observable inputs be used when available. Observable inputs are inputs that market participants would use in pricing an asset or liability, which are developed based on market data that we have obtained from independent sources. Unobservable inputs reflect our estimates of assumptions that market participants would use in pricing an asset or liability, which are developed based on the best information available in the circumstances. The fair value hierarchy gives the highest priority to unadjusted quoted market prices in active markets for identical assets or liabilities (Level 1 measurement) and the lowest priority to unobservable inputs (Level 3 measurement). The fair value hierarchy is broken down into three levels based on the reliability of inputs as follows: Level 1: valuation is based upon unadjusted quoted market prices for identical instruments traded in active markets. Level 2: valuation is based upon quoted market prices for similar instruments traded in active markets, quoted market prices for identical or similar instruments traded in markets that are not active and model-based valuation techniques for which all significant assumptions are observable in the market or can be corroborated by market data. Level 3: valuation is derived from other valuation methodologies, including discounted cash flow models and similar techniques that use significant assumptions not observable in the market. These unobservable assumptions reflect estimates of assumptions that market participants would use in determining fair value. A financial instrument’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. Our policy is to recognize transfers between any of the fair value hierarchy levels at the end of the reporting period in which the transfer occurred. The following are descriptions of the valuation methodologies that we use for financial instruments recorded at fair value on either a recurring or nonrecurring basis. Recurring Basis Debt Securities Available-for-Sale We obtain fair values for debt securities from a third-party pricing service which utilizes several sources for valuing fixed-income securities. We validate prices received from our pricing service through comparison to a secondary pricing service and broker quotes. We review the methodologies of the pricing service which provide us with a sufficient understanding of the valuation models, assumptions, inputs and pricing to reasonably measure the fair value of our debt securities. The market evaluation sources for debt securities include observable inputs rather than significant unobservable inputs and are classified as Level 2. The service provider utilizes pricing models that vary by asset class and include available trade, bid and other market information. Generally, the methodologies include broker quotes, proprietary models, vast descriptive terms and conditions databases, and extensive quality control programs. Equity Securities Marketable equity securities that have an active, quotable market are classified as Level 1. Marketable equity securities that are quotable, but are thinly traded or inactive, are classified as Level 2. Marketable equity securities that are not readily traded and do not have a quotable market are classified as Level 3. Trading Assets We use quoted market prices to determine the fair value of our trading assets. Our trading assets are held in a Rabbi Trust under a deferred compensation plan and are invested in readily quoted mutual funds. Accordingly, these assets are classified as Level 1. Rabbi Trust assets are reported in other assets in the Consolidated Balance Sheets. Derivative Financial Instruments We use derivative instruments, including interest rate swaps for commercial loans with our customers, interest rate lock commitments and the sale of mortgage loans in the secondary market. We calculate the fair value for derivatives using widely accepted valuation techniques, including discounted cash flow analysis on the expected cash flows of each derivative. Each valuation considers the contractual terms of the derivative, including the period to maturity, and uses observable market-based inputs, such as interest rate curves and implied volatilities. Accordingly, derivatives are classified as Level 2. We incorporate credit valuation adjustments into the valuation models to appropriately reflect both our own nonperformance risk and the respective counterparties' nonperformance risk in calculating fair value measurements. In adjusting the fair value of our derivative contracts for the effect of nonperformance risk, we have considered the impact of netting and any applicable credit enhancements and collateral postings. Nonrecurring Basis Loans Held for Sale Loans held for sale consist of 1-4 family residential loans originated for sale in the secondary market and, from time to time, certain loans transferred from the loan portfolio to loans held for sale, all of which are carried at the lower of cost or fair value. The fair value of 1-4 family residential loans is based on the principal or most advantageous market currently offered for similar loans using observable market data. The fair value of the loans transferred from the loan portfolio is based on the amounts offered for these loans in currently pending sales transactions. Loans held for sale carried at fair value are classified as Level 3. Impaired Loans Impaired loans are carried at the lower of carrying value or fair value. Fair value is determined as the recorded investment balance less any specific reserve. We establish specific reserves based on the following three impairment methods: 1) the present value of expected future cash flows discounted at the loan’s original effective interest rate; 2) the loan’s observable market price; or 3) the fair value of the collateral less estimated selling costs when the loan is collateral dependent and we expect to liquidate the collateral. However, if repayment is expected to come from the operation of the collateral, rather than liquidation, then we do not consider estimated selling costs in determining the fair value of the collateral. Collateral values are generally based upon appraisals by approved, independent state certified appraisers. Appraisals may be discounted based on our historical knowledge, changes in market conditions from the time of appraisal or our knowledge of the borrower and the borrower’s business. Impaired loans carried at fair value are classified as Level 3. OREO and Other Repossessed Assets OREO and other repossessed assets obtained in partial or total satisfaction of a loan are recorded at the lower of recorded investment in the loan or fair value less cost to sell. Subsequent to foreclosure, these assets are carried at the lower of the amount recorded at acquisition date or fair value less cost to sell. Accordingly, it may be necessary to record nonrecurring fair value adjustments. Fair value, when recorded, is generally based upon appraisals by approved, independent state certified appraisers. Like impaired loans, appraisals on OREO may be discounted based on our historical knowledge, changes in market conditions from the time of appraisal or other information available to us. OREO and other repossessed assets carried at fair value are classified as Level 3. Mortgage Servicing Rights The fair value of MSRs is determined by calculating the present value of estimated future net servicing cash flows, considering expected mortgage loan prepayment rates, discount rates, servicing costs and other economic factors, which are determined based on current market conditions. The expected rate of mortgage loan prepayments is the most significant factor driving the value of MSRs. MSRs are considered impaired if the carrying value exceeds fair value. The valuation model includes significant unobservable inputs; therefore, MSRs are classified as Level 3. MSRs are reported in other assets in the Consolidated Balance Sheets and are amortized into noninterest income in the Consolidated Statements of Comprehensive Income. Other Assets We measure certain other assets at fair value on a nonrecurring basis. Fair value is based on the application of lower of cost or fair value accounting, or write-downs of individual assets. Valuation methodologies used to measure fair value are consistent with overall principles of fair value accounting and consistent with those described above. Financial Instruments In addition to financial instruments recorded at fair value in our financial statements, fair value accounting guidance requires disclosure of the fair value of all of an entity’s assets and liabilities that are considered financial instruments. The majority of our assets and liabilities are considered financial instruments. Many of these instruments lack an available trading market as characterized by a willing buyer and a willing seller engaged in an exchange transaction. Also, it is our general practice and intent to hold our financial instruments to maturity and to not engage in trading or sales activities with respect to such financial instruments. For fair value disclosure purposes, we substantially utilize the fair value measurement criteria as required and explained above. In cases where quoted fair values are not available, we use present value methods to determine the fair value of our financial instruments. Cash and Cash Equivalents The carrying amounts reported in the Consolidated Balance Sheets for cash and due from banks, including interest-bearing deposits, approximate fair value. Loans With the adoption of ASU No. 2016-01, Accounting for Financial Instruments - Overall: Classification and Measurement, on January 1, 2018, we refined our methodology to estimate the fair value of our loan portfolio to use the exit price notion as required by the standard. The guidance was applied on a prospective basis resulting in prior-periods no longer being comparable. The fair value of variable rate loans that may reprice frequently at short-term market rates is based on carrying values adjusted for liquidity and credit risk. The fair value of variable rate loans that reprice at intervals of one year or longer, such as adjustable rate mortgage products, is estimated using discounted cash flow analyses that utilize interest rates currently being offered for similar loans and adjusted for liquidity and credit risk. The fair value of fixed rate loans is estimated using a discounted cash flow analysis that utilizes interest rates currently being offered for similar loans adjusted for liquidity and credit risk. Bank Owned Life Insurance Fair value approximates net cash surrender value of bank owned life insurance, or BOLI. Federal Home Loan Bank, or FHLB, and Other Restricted Stock It is not practical to determine the fair value of our FHLB and other restricted stock due to the restrictions placed on the transferability of these stocks; it is presented at carrying value. Deposits The fair values disclosed for deposits without defined maturities (e.g., noninterest and interest-bearing demand, money market and savings accounts) are by definition equal to the amounts payable on demand. The carrying amounts for variable rate, fixed-term time deposits approximate their fair values. Estimated fair values for fixed rate and other time deposits are based on discounted cash flow analysis using interest rates currently offered for time deposits with similar terms. The carrying amount of accrued interest approximates fair value. Short-Term Borrowings The carrying amounts of securities sold under repurchase agreements, or REPOs, and other short-term borrowings approximate their fair values. Long-Term Borrowings The fair values disclosed for fixed rate long-term borrowings are determined by discounting their contractual cash flows using current interest rates for long-term borrowings of similar remaining maturities. The carrying amounts of variable rate long-term borrowings approximate their fair values. Junior Subordinated Debt Securities The interest rate on the variable rate junior subordinated debt securities is reset quarterly; therefore, the carrying values approximate their fair values. Loan Commitments and Standby Letters of Credit Off-balance sheet financial instruments consist of commitments to extend credit and letters of credit. Except for interest rate lock commitments, estimates of the fair value of these off-balance sheet items are not made because of the short-term nature of these arrangements and the credit standing of the counterparties. Other Estimates of fair value are not made for items that are not defined as financial instruments, including such items as our core deposit intangibles and the value of our trust operations.
Allowance for Loans Losses	We maintain an allowance for loan losses, or ALLL, at a level determined to be adequate to absorb estimated probable credit losses inherent within the loan portfolio as of the balance sheet date. We develop and document a systematic ALLL methodology based on the following portfolio segments: 1) CRE, 2) Commercial and Industrial, or C&I, 3) Commercial Construction, 4) Consumer Real Estate and 5) Other Consumer. The following are key risks within each portfolio segment: CRE —Loans secured by commercial purpose real estate, including both owner-occupied properties and investment properties for various purposes such as hotels, strip malls and apartments. Operations of the individual projects and global cash flows of the debtors are the primary sources of repayment for these loans. The condition of the local economy is an important indicator of risk, but there are also more specific risks depending on the collateral type and the business prospects of the lessee, if the project is not owner-occupied. C&I —Loans made to operating companies or manufacturers for the purpose of production, operating capacity, accounts receivable, inventory or equipment financing. Cash flow from the operations of the company is the primary source of repayment for these loans. The condition of the local economy is an important indicator of risk, but there are also more specific risks depending on the industry of the company. Collateral for these types of loans often do not have sufficient value in a distressed or liquidation scenario to satisfy the outstanding debt. Commercial Construction —Loans made to finance construction of buildings or other structures, as well as to finance the acquisition and development of raw land for various purposes. While the risk of these loans is generally confined to the construction period, if there are problems, the project may not be completed, and as such, may not provide sufficient cash flow on its own to service the debt or have sufficient value in a liquidation to cover the outstanding principal. The condition of the local economy is an important indicator of risk, but there are also more specific risks depending on the type of project and the experience and resources of the developer. Consumer Real Estate —Loans secured by first and second liens such as home equity loans, home equity lines of credit and 1-4 family residential mortgages, including purchase money mortgages. The primary source of repayment for these loans is the income and assets of the borrower. The condition of the local economy, in particular the unemployment rate, is an important indicator of risk for this segment. The state of the local housing market can also have a significant impact on this segment because low demand and/or declining home values can limit the ability of borrowers to sell a property and satisfy the debt. Other Consumer —Loans made to individuals that may be secured by assets other than 1-4 family residences, as well as unsecured loans. This segment includes auto loans, unsecured loans and lines and credit cards. The primary source of repayment for these loans is the income and assets of the borrower. The condition of the local economy, in particular the unemployment rate, is an important indicator of risk for this segment. The value of the collateral, if there is any, is less likely to be a source of repayment due to less certain collateral values. We further assess risk within each portfolio segment by pooling loans with similar risk characteristics. For the commercial loan classes, the most important indicator of risk is the internally assigned risk rating, including pass, special mention and substandard. Consumer loans are pooled by type of collateral, lien position and loan to value, or LTV, for Consumer Real Estate loans. Historical loss rates are applied to these loan pools to determine the reserve for loans collectively evaluated for impairment. The ALLL methodology for groups of loans collectively evaluated for impairment is comprised of both a quantitative and qualitative analysis. A key assumption in the quantitative component of the reserve is the loss emergence period. The LEP is an estimate of the average amount of time from the point at which a loss is incurred on a loan to the point at which the loss is confirmed. Another key assumption is the look-back period which represents the historical data period utilized to calculate loss rates. Management monitors various credit quality indicators for both the commercial and consumer loan portfolios, including delinquency, nonperforming status and changes in risk ratings on a monthly basis.
Loans Credit Risk Rating	We continually monitor the commercial loan portfolio through an internal risk rating system. Loan risk ratings are assigned based upon the creditworthiness of the borrower and are reviewed on an ongoing basis according to our internal policies. Loans within the pass rating generally have a lower risk of loss than loans risk rated as special mention or substandard. Our risk ratings are consistent with regulatory guidance and are as follows: Pass —The loan is currently performing and is of high quality. Special Mention —A special mention loan has potential weaknesses that warrant management’s close attention. If left uncorrected, these potential weaknesses may result in deterioration of the repayment prospects or in the strength of our credit position at some future date. Economic and market conditions, beyond the borrower’s control, may in the future necessitate this classification. Substandard —A substandard loan is not adequately protected by the net worth and/or paying capacity of the borrower or by the collateral pledged, if any. Substandard loans have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. These loans are characterized by the distinct possibility that we will sustain some loss if the deficiencies are not corrected.
Derivative Financial Instruments	Interest Rate Swaps In accordance with applicable accounting guidance for derivatives and hedging, all derivatives are recognized as either assets or liabilities on the balance sheet at fair value. Interest rate swaps are contracts in which a series of interest rate flows (fixed and variable) are exchanged over a prescribed period. The notional amounts on which the interest payments are based are not exchanged. These derivative positions relate to transactions in which we enter into an interest rate swap with a commercial customer while at the same time entering into an offsetting interest rate swap with another financial institution. In connection with each transaction, we agree to pay interest to the customer on a notional amount at a variable interest rate and receive interest from the customer on the same notional amount at a fixed rate. At the same time, we agree to pay another financial institution the same fixed interest rate on the same notional amount and receive the same variable interest rate on the same notional amount. The transaction allows our customer to effectively convert a variable rate loan to a fixed rate loan with us receiving a variable rate. These agreements could have floors or caps on the contracted interest rates. Pursuant to our agreements with various financial institutions, we may receive collateral or may be required to post collateral based upon mark-to-market positions. Beyond unsecured threshold levels, collateral in the form of cash or securities may be made available to counterparties of interest rate swap transactions. Based upon our current positions and related future collateral requirements relating to them, we believe any effect on our cash flow or liquidity position to be immaterial. Derivatives contain an element of credit risk, the possibility that we will incur a loss because a counterparty, which may be a financial institution or a customer, fails to meet its contractual obligations. All derivative contracts with financial institutions may be executed only with counterparties approved by our Asset and Liability Committee, or ALCO, and derivatives with customers may only be executed with customers within credit exposure limits approved by our Senior Loan Committee. Interest rate swaps are considered derivatives, but are not accounted for using hedge accounting. As such, changes in the estimated fair value of the derivatives are recorded in current earnings and included in other noninterest income in the Consolidated Statements of Comprehensive Income. Interest Rate Lock Commitments and Forward Sale Contracts In the normal course of business, we sell originated mortgage loans into the secondary mortgage loan market. We also offer interest rate lock commitments to potential borrowers. The commitments are generally for a period of 60 days and guarantee a specified interest rate for a loan if underwriting standards are met, but the commitment does not obligate the potential borrower to close on the loan. Accordingly, some commitments expire prior to becoming loans. We may encounter pricing risks if interest rates increase significantly before the loan can be closed and sold. We may utilize forward sale contracts in order to mitigate this pricing risk. Whenever a customer desires these products, a mortgage originator quotes a secondary market rate guaranteed for that day by the investor. The rate lock is executed between the mortgagee and us and in turn a forward sale contract may be executed between us and the investor. Both the rate lock commitment and the corresponding forward sale contract for each customer are considered derivatives, but are not accounted for using hedge accounting. As such, changes in the estimated fair value of the derivatives during the commitment period are recorded in current earnings and included in mortgage banking in the Consolidated Statements of Comprehensive Income.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Schedule of Reconciliation of Numerators and Denominators of Basic Earnings Per Share with Diluted Earnings Per Share	The following table reconciles the numerators and denominators of basic and diluted earnings per share for the periods presented: Three Months Ended June 30, Six Months Ended June 30, (in thousands, except share and per share data) 2018 2017 2018 2017 Numerator for Earnings per Share—Basic: Net income $ 21,436 $ 22,765 $ 47,599 $ 40,953 Less: Income allocated to participating shares 62 81 141 141 Net Income Allocated to Shareholders $ 21,374 $ 22,684 $ 47,458 $ 40,812 Numerator for Earnings per Share—Diluted: Net income $ 21,436 $ 22,765 $ 47,599 $ 40,953 Net Income Available to Shareholders $ 21,436 $ 22,765 $ 47,599 $ 40,953 Denominators for Earnings per Share: Weighted Average Shares Outstanding—Basic 34,793,160 34,724,925 34,775,043 34,707,683 Add: Potentially dilutive shares 264,416 181,571 267,998 199,693 Denominator for Treasury Stock Method—Diluted 35,057,576 34,906,496 35,043,041 34,907,376 Weighted Average Shares Outstanding—Basic 34,793,160 34,724,925 34,775,043 34,707,683 Add: Average participating shares outstanding 100,212 123,729 103,449 119,585 Denominator for Two-Class Method—Diluted 34,893,372 34,848,654 34,878,492 34,827,268 Earnings per share—basic $ 0.62 $ 0.66 $ 1.37 $ 1.18 Earnings per share—diluted $ 0.61 $ 0.65 $ 1.36 $ 1.17 Warrants considered anti-dilutive excluded from potentially dilutive shares - exercise price $31.53 per share, expires January 2019 374,314 466,554 386,747 456,749 Restricted stock considered anti-dilutive excluded from potentially dilutive shares 89,974 126,332 76,325 105,187

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis	The following tables present our assets and liabilities that are measured at fair value on a recurring basis by fair value hierarchy level at June 30, 2018 and December 31, 2017 . There were no transfers between Level 1 and Level 2 for items measured at fair value on a recurring basis during the periods presented. June 30, 2018 (dollars in thousands) Level 1 Level 2 Level 3 Total ASSETS Debt securities available-for-sale: U.S. Treasury securities $ — $ 9,619 $ — $ 9,619 Obligations of U.S. government corporations and agencies — 155,069 — 155,069 Collateralized mortgage obligations of U.S. government corporations and agencies — 118,742 — 118,742 Residential mortgage-backed securities of U.S. government corporations and agencies — 28,442 — 28,442 Commercial mortgage-backed securities of U.S. government corporations and agencies — 247,128 — 247,128 Obligations of states and political subdivisions — 123,916 — 123,916 Total Debt Securities Available-for-Sale — 682,916 — 682,916 Marketable equity securities (1) — 5,425 — 5,425 Total Securities — 688,341 — 688,341 Trading securities held in a Rabbi Trust 4,988 — — 4,988 Derivative financial assets: Interest rate swaps — 6,157 — 6,157 Interest rate lock commitments — 398 — 398 Total Assets $ 4,988 $ 694,896 $ — $ 699,884 LIABILITIES Derivative financial liabilities: Interest rate swaps $ — $ 6,223 $ — $ 6,223 Forward sale contracts — 39 — 39 Total Liabilities $ — $ 6,262 $ — $ 6,262 (1) ASU No. 2016-01 was adopted January 1, 2018, resulting in separate classification of our marketable equity securities previously included in available-for-sale securities. December 31, 2017 (dollars in thousands) Level 1 Level 2 Level 3 Total ASSETS Debt securities available-for-sale: U.S. Treasury securities $ — $ 19,789 $ — $ 19,789 Obligations of U.S. government corporations and agencies — 162,193 — 162,193 Collateralized mortgage obligations of U.S. government corporations and agencies — 108,688 — 108,688 Residential mortgage-backed securities of U.S. government corporations and agencies — 32,854 — 32,854 Commercial mortgage-backed securities of U.S. government corporations and agencies — 242,221 — 242,221 Obligations of states and political subdivisions — 127,402 — 127,402 Total Debt Securities Available-for-Sale — 693,147 — 693,147 Marketable equity securities — 5,144 — 5,144 Total Securities — 698,291 — 698,291 Trading securities held in a Rabbi Trust 5,080 — — 5,080 Derivative financial assets: Interest rate swaps — 3,074 — 3,074 Interest rate lock commitments — 226 — 226 Total Assets $ 5,080 $ 701,591 $ — $ 706,671 LIABILITIES Derivative financial liabilities: Interest rate swaps $ — $ 3,055 $ — $ 3,055 Forward sale contracts — 5 — 5 Total Liabilities $ — $ 3,060 $ — $ 3,060 (1) ASU No. 2016-01 was adopted January 1, 2018, resulting in separate classification of our marketable equity securities previously included in available-for-sale securities.
Schedule of Assets Measured at Estimated Fair Value on Nonrecurring Basis by Fair Value Hierarchy	The following table presents our assets that are measured at fair value on a nonrecurring basis by the fair value hierarchy level as of the dates presented: June 30, 2018 December 31, 2017 (dollars in thousands) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total ASSETS (1) Impaired loans $ — $ — $ 5,487 $ 5,487 $ — $ — $ 6,759 $ 6,759 Other real estate owned — — 2,719 2,719 — — 444 444 Mortgage servicing rights — — 89 89 — — 178 178 Total Assets $ — $ — $ 8,295 $ 8,295 $ — $ — $ 7,381 $ 7,381 (1) This table presents only the nonrecurring items that are recorded at fair value in our financial statements.
Schedule of Carrying Values and Fair Values of Financial Instruments	The carrying values and fair values of our financial instruments at June 30, 2018 and December 31, 2017 are presented in the following tables: Carrying Value (1) Fair Value Measurements at June 30, 2018 (dollars in thousands) Total Level 1 Level 2 Level 3 ASSETS Cash and due from banks, including interest-bearing deposits $ 137,933 $ 137,933 $ 137,933 $ — $ — Securities 688,341 688,341 — 688,341 — Loans held for sale 3,801 3,927 — — 3,927 Portfolio loans, net 5,725,601 5,558,333 — — 5,558,333 Bank owned life insurance 73,122 73,122 — 73,122 — FHLB and other restricted stock 35,782 35,782 — — 35,782 Trading securities held in a Rabbi Trust 4,988 4,988 4,988 — — Mortgage servicing rights 4,296 5,198 — — 5,198 Interest rate swaps 6,157 6,157 — 6,157 — Interest rate lock commitments 398 398 — 398 — LIABILITIES Deposits $ 5,393,533 $ 5,378,467 $ — $ — $ 5,378,467 Securities sold under repurchase agreements 44,724 44,724 — — 44,724 Short-term borrowings 600,000 600,000 — — 600,000 Long-term borrowings 46,062 46,226 — — 46,226 Junior subordinated debt securities 45,619 45,619 — — 45,619 Interest rate swaps 6,223 6,223 — 6,223 — Forward sales contracts 39 39 — 39 — (1) As reported in the Consolidated Balance Sheets Carrying Value (1) Fair Value Measurements at December 31, 2017 (dollars in thousands) Total Level 1 Level 2 Level 3 ASSETS Cash and due from banks, including interest-bearing deposits $ 117,152 $ 117,152 $ 117,152 $ — $ — Securities 698,291 698,291 — 698,291 — Loans held for sale 4,485 4,583 — — 4,583 Portfolio loans, net 5,705,059 5,690,292 — — 5,690,292 Bank owned life insurance 72,150 72,150 — 72,150 — FHLB and other restricted stock 29,270 29,270 — — 29,270 Trading securities held in a Rabbi Trust 5,080 5,080 5,080 — — Mortgage servicing rights 4,133 4,571 — — 4,571 Interest rate swaps 3,074 3,074 — 3,074 — Interest rate lock commitments 226 226 — 226 — LIABILITIES Deposits $ 5,427,891 $ 5,426,928 $ — $ — $ 5,426,928 Securities sold under repurchase agreements 50,161 50,161 — — 50,161 Short-term borrowings 540,000 540,000 — — 540,000 Long-term borrowings 47,301 47,618 — — 47,618 Junior subordinated debt securities 45,619 45,619 — — 45,619 Interest rate swaps 3,055 3,055 — 3,055 — Forward sales contracts 5 5 — 5 — (1) As reported in the Consolidated Balance Sheets.

Securities (Tables)

Securities (Tables)	6 Months Ended
	Jun. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of Composition of Securities	The following table presents the fair values of our securities portfolio at the dates presented: (dollars in thousands) June 30, 2018 December 31, 2017 Debt securities available for sale $ 682,916 $ 693,147 Marketable equity securities 5,425 5,144 Total Securities $ 688,341 $ 698,291 Debt Securities Available for Sale The following tables present the amortized cost and fair value of debt securities available for sale as of June 30, 2018 and debt and equity securities available for sale as of December 31, 2017: June 30, 2018 December 31, 2017 (dollars in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value U.S. Treasury securities $ 9,953 $ — $ (334 ) $ 9,619 $ 19,943 $ — $ (154 ) $ 19,789 Obligations of U.S. government corporations and agencies 156,812 16 (1,759 ) 155,069 162,045 341 (193 ) 162,193 Collateralized mortgage obligations of U.S. government corporations and agencies 121,631 61 (2,950 ) 118,742 109,916 93 (1,321 ) 108,688 Residential mortgage-backed securities of U.S. government corporations and agencies 28,662 309 (529 ) 28,442 32,388 679 (213 ) 32,854 Commercial mortgage-backed securities of U.S. government corporations and agencies (1) 254,458 — (7,330 ) 247,128 244,018 247 (2,044 ) 242,221 Obligations of states and political subdivisions 121,492 2,472 (48 ) 123,916 123,159 4,285 (42 ) 127,402 Total Debt Securities Available-for-Sale 693,008 2,858 (12,950 ) 682,916 691,469 5,645 (3,967 ) 693,147 Total equity securities (2) — — — — 3,815 1,330 (1 ) 5,144 Total Securities $ 693,008 $ 2,858 $ (12,950 ) $ 682,916 $ 695,284 $ 6,975 $ (3,968 ) $ 698,291 (1) Includes a $5.9 million security purchase that was pending settlement as of December 31, 2017. (2) ASU No. 2016-01 was adopted January 1, 2018, resulting in separate classification of our marketable equity securities previously included in available-for-sale securities.
Schedule of Temporally Impaired Debt Securities	The following tables present the fair value and the age of gross unrealized losses on debt securities available for sale by investment category as of the dates presented: June 30, 2018 Less Than 12 Months 12 Months or More Total (dollars in thousands) Number of Securities Fair Value Unrealized Number of Securities Fair Value Unrealized Number of Securities Fair Value Unrealized U.S. Treasury securities 1 $ 9,618 $ (334 ) — $ — $ — 1 $ 9,618 $ (334 ) Obligations of U.S. government corporations and agencies 16 129,180 (1,728 ) 2 10,993 (31 ) 18 140,173 (1,759 ) Collateralized mortgage obligations of U.S. government corporations and agencies 10 66,019 (1,067 ) 7 41,018 (1,883 ) 17 107,037 (2,950 ) Residential mortgage-backed securities of U.S. government corporations and agencies 3 4,803 (131 ) 2 7,721 (398 ) 5 12,524 (529 ) Commercial mortgage-backed securities of U.S. government corporations and agencies 22 199,634 (5,190 ) 5 47,494 (2,140 ) 27 247,128 (7,330 ) Obligations of states and political subdivisions 5 23,109 (48 ) — — — 5 23,109 (48 ) Total Temporarily Impaired Debt Securities 57 $ 432,363 $ (8,498 ) 16 $ 107,226 $ (4,452 ) 73 $ 539,589 $ (12,950 ) December 31, 2017 Less Than 12 Months 12 Months or More Total (dollars in thousands) Number of Securities Fair Value Unrealized Number of Securities Fair Value Unrealized Number of Securities Fair Value Unrealized U.S. Treasury securities 3 $ 19,789 $ (154 ) — $ — $ — 3 $ 19,789 $ (154 ) Obligations of U.S. government corporations and agencies 9 63,635 (144 ) 1 10,017 (49 ) 10 73,652 (193 ) Collateralized mortgage obligations of U.S. government corporations and agencies 7 47,465 (248 ) 7 45,809 (1,073 ) 14 93,274 (1,321 ) Residential mortgage-backed securities of U.S. government corporations and agencies 1 2,333 (10 ) 2 8,638 (203 ) 3 10,971 (213 ) Commercial mortgage-backed securities of U.S. government corporations and agencies 14 128,300 (775 ) 5 48,746 (1,269 ) 19 177,046 (2,044 ) Obligations of states and political subdivisions 2 10,330 (42 ) — — — 2 10,330 (42 ) Total Temporarily Impaired Debt Securities 36 $ 271,852 $ (1,373 ) 15 $ 113,210 $ (2,594 ) 51 $ 385,062 $ (3,967 )
Schedule of Unrealized Gains and Losses, Net of Tax, of Debt Securities Available for Sale	The following table presents net unrealized gains and losses, net of tax, on debt securities available-for-sale included in accumulated other comprehensive income/(loss), for the periods presented: June 30, 2018 December 31, 2017 (dollars in thousands) Gross Unrealized Gains Gross Unrealized Losses Net Unrealized Gains/ (Losses) Gross Unrealized Gains Gross Unrealized Losses Net Unrealized Gains/ (Losses) Total unrealized gains (losses) on debt securities available-for-sale $ 2,858 $ (12,950 ) $ (10,092 ) $ 5,645 $ (3,967 ) $ 1,678 Income tax (expense) benefit (607 ) 2,750 2,143 (1,982 ) 1,393 (589 ) Net Unrealized Gains/(Losses), Net of Tax Included in Accumulated Other Comprehensive Income/(Loss) $ 2,251 $ (10,200 ) $ (7,949 ) $ 3,663 $ (2,574 ) $ 1,089
Schedule of Contractual Maturity of Debt Securities Available-for-Sale Securities	The amortized cost and fair value of debt securities available-for-sale at June 30, 2018 by contractual maturity are included in the table below. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations with or without call or prepayment penalties. June 30, 2018 (dollars in thousands) Amortized Cost Fair Value Obligations of the U.S. Treasury, U.S. government corporations and agencies, and obligations of states and political subdivisions Due in one year or less $ 33,878 $ 33,888 Due after one year through five years 152,588 152,374 Due after five years through ten years 73,099 72,961 Due after ten years 28,692 29,381 288,257 288,604 Collateralized mortgage obligations of U.S. government corporations and agencies 121,631 118,742 Residential mortgage-backed securities of U.S. government corporations and agencies 28,662 28,442 Commercial mortgage-backed securities of U.S. government corporations and agencies 254,458 247,128 Total Debt Securities Available-for-Sale $ 693,008 $ 682,916
Schedule of Unrealized Gains and Losses on Marketable Securities	The following table presents realized and unrealized net gains and losses for our marketable equity securities for the periods presented: Three Months Ended Six Months Ended (dollars in thousands) 2018 2017 2018 2017 Marketable Equity Securities Net market gains/(losses) recognized $ 230 $ 4,121 $ 282 $ 5,224 Less: Net gains/(losses) recognized for equity securities sold — 3,617 — 3,987 Unrealized Gains/(Losses) on Equity Securities Still Held $ 230 $ 504 $ 282 $ 1,237

Loans and Loans Held for Sale (

Loans and Loans Held for Sale (Tables)	6 Months Ended
	Jun. 30, 2018
Receivables [Abstract]
Schedule of Composition of Loans	The following table indicates the composition of loans as of the dates presented: (dollars in thousands) June 30, 2018 December 31, 2017 Commercial Commercial real estate $ 2,788,641 $ 2,685,994 Commercial and industrial 1,455,578 1,433,266 Commercial construction 299,787 384,334 Total Commercial Loans 4,544,006 4,503,594 Consumer Residential mortgage 698,440 698,774 Home equity 471,622 487,326 Installment and other consumer 66,638 67,204 Consumer construction 5,412 4,551 Total Consumer Loans 1,242,112 1,257,855 Total Portfolio Loans 5,786,118 5,761,449 Loans held for sale 3,801 4,485 Total Loans $ 5,789,919 $ 5,765,934
Schedule of Restructured Loans for Periods Presented	The following tables present the restructured loans by loan segment and by type of concession for the three and six months ended June 30, 2018 and 2017: Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 (dollars in thousands) Number of Pre-Modification (1) Post-Modification (1) Total Difference Number of Pre-Modification ( 1) Post-Modification (1) Total Difference Totals by Loan Segment Commercial real estate Principal deferral — $ — $ — $ — 1 $ 100 $ 100 $ — Total Commercial Real Estate — — — — 1 100 100 — Commercial and industrial Maturity date extension and interest rate reduction — — — — 2 1,800 1,800 — Principal deferral 3 4,815 5,034 219 1 429 429 — Total Commercial and Industrial 3 4,815 5,034 219 3 2,229 2,229 — Commercial Construction . Total Commercial Construction — — — — — — — — Residential mortgage Chapter 7 bankruptcy (2) 1 41 41 — 1 33 33 — Total Residential Mortgage 1 41 41 — 1 33 33 — Home equity Chapter 7 bankruptcy (2) 2 26 26 — 3 40 38 (2 ) Maturity date extension — — — — 1 231 231 — Maturity date extension and interest rate reduction 2 47 47 — — — — — Total Home Equity 4 73 73 — 4 271 269 (2 ) Installment and other consumer Chapter 7 bankruptcy (2) 2 8 7 (1 ) 2 37 34 (3 ) Total Installment and Other Consumer 2 8 7 (1 ) 2 37 34 (3 ) Totals by Concession Type Chapter 7 bankruptcy (2) 5 75 74 (1 ) 6 110 105 $ (5 ) Maturity date extension and interest rate reduction 2 47 47 — 2 1,800 1,800 — Maturity date extension — — — — 1 231 231 — Principal deferral 3 4,815 5,034 219 2 529 529 — Total 10 $ 4,937 $ 5,155 $ 218 11 $ 2,670 $ 2,665 $ (5 ) (1) Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end. (2) Chapter 7 bankruptcy loans where the debt has been legally discharged through the bankruptcy court and not reaffirmed. Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 (dollars in thousands) Number of Pre-Modification (1) Post-Modification (1) Total Difference Number of Pre-Modification ( 1) Post-Modification (1) Total Difference Totals by Loan Segment Commercial real estate Principal deferral — $ — $ — $ — 1 $ 100 $ 100 $ — Total Commercial Real Estate — — — — 1 100 100 — Commercial and industrial Maturity date extension 2 768 582 (186 ) — — — — Maturity date extension and interest rate reduction — — — — 2 1,800 1,800 — Principal deferral 3 4,815 5,034 219 1 429 429 — Principal deferral and maturity date extension 6 5,355 5,229 (126 ) — — — — Total Commercial and Industrial 11 10,938 10,845 (93 ) 3 2,229 2,229 — Commercial Construction . Total Commercial Construction — — — — — — — — Residential mortgage Chapter 7 bankruptcy (2) 3 199 196 (3 ) 1 33 33 — Total Residential Mortgage 3 199 196 (3 ) 1 33 33 — Home equity Chapter 7 bankruptcy (2) 11 605 574 (31 ) 9 309 304 (5 ) Maturity date extension — — — — 1 231 231 — Maturity date extension and interest rate reduction 2 47 47 — 1 173 172 (1 ) Total Home Equity 13 652 621 (31 ) 11 713 707 (6 ) Installment and other consumer Chapter 7 bankruptcy (2) 4 25 23 (2 ) 2 37 34 (3 ) Total Installment and Other Consumer 4 25 23 (2 ) 2 37 34 (3 ) Totals by Concession Type Chapter 7 bankruptcy (2) 18 829 793 (36 ) 12 379 371 (8 ) Maturity date extension 2 768 582 (186 ) 1 231 231 — Maturity date extension and interest rate reduction 2 47 47 — 3 1,973 1,972 (1 ) Principal deferral 3 4,815 5,034 219 2 529 529 — Principal deferral and maturity date extension 6 5,355 5,229 (126 ) — — — — Total 31 $ 11,814 $ 11,685 $ (129 ) 18 $ 3,112 $ 3,103 $ (9 ) (1) Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end. (2) Chapter 7 bankruptcy loans where the debt has been legally discharged through the bankruptcy court and not reaffirmed. The following table summarizes restructured loans as of the dates presented: June 30, 2018 December 31, 2017 (dollars in thousands) Performing TDRs Nonperforming TDRs Total TDRs Performing TDRs Nonperforming TDRs Total TDRs Commercial real estate $ 2,136 $ 925 $ 3,061 $ 2,579 $ 967 $ 3,546 Commercial and industrial 14,149 2,599 16,748 3,946 3,197 7,143 Commercial construction 2,400 410 2,810 2,420 2,413 4,833 Residential mortgage 2,157 1,924 4,081 2,039 3,585 5,624 Home equity 3,569 1,536 5,105 3,885 979 4,864 Installment and other consumer 43 1 44 32 9 41 Total $ 24,454 $ 7,395 $ 31,849 $ 14,901 $ 11,150 $ 26,051
Schedule of Summary of Nonperforming Assets	The following table is a summary of nonperforming assets as of the dates presented: Nonperforming Assets (dollars in thousands) June 30, 2018 December 31, 2017 Nonperforming Assets Nonaccrual loans $ 13,977 $ 12,788 Nonaccrual TDRs 7,395 11,150 Total Nonaccrual Loans 21,372 23,938 OREO 2,999 469 Total Nonperforming Assets $ 24,371 $ 24,407

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	6 Months Ended
	Jun. 30, 2018
Receivables [Abstract]
Schedule of Age Analysis of Past Due Loans Segregated by Class of Loans	The following tables present the age analysis of past due loans segregated by class of loans as of the dates presented: June 30, 2018 (dollars in thousands) Current 30-59 Days Past Due 60-89 Days Past Due Non - performing Total Past Due Loans Total Loans Commercial real estate $ 2,781,239 $ 2,473 $ 312 $ 4,617 $ 7,402 $ 2,788,641 Commercial and industrial 1,450,174 432 119 4,853 5,404 1,455,578 Commercial construction 297,849 68 — 1,870 1,938 299,787 Residential mortgage 689,751 1,445 1,132 6,112 8,689 698,440 Home equity 465,261 1,906 584 3,871 6,361 471,622 Installment and other consumer 66,371 172 46 49 267 66,638 Consumer construction 5,412 — — — — 5,412 Loans held for sale 3,801 — — — — 3,801 Total $ 5,759,858 $ 6,496 $ 2,193 $ 21,372 $ 30,061 $ 5,789,919 December 31, 2017 (dollars in thousands) Current 30-59 Days Past Due 60-89 Days Past Due Non - performing Total Past Total Loans Commercial real estate $ 2,681,395 $ 997 $ 134 $ 3,468 $ 4,599 $ 2,685,994 Commercial and industrial 1,426,754 420 446 5,646 6,512 1,433,266 Commercial construction 377,968 2,473 20 3,873 6,366 384,334 Residential mortgage 687,195 2,975 1,439 7,165 11,579 698,774 Home equity 480,956 2,065 590 3,715 6,370 487,326 Installment and other consumer 66,770 193 170 71 434 67,204 Consumer construction 4,551 — — — — 4,551 Loans held for sale 4,485 — — — — 4,485 Total $ 5,730,074 $ 9,123 $ 2,799 $ 23,938 $ 35,860 $ 5,765,934
Schedule of Recorded Investment in Commercial Loan Classes by Internally Assigned Risk Ratings	The following tables present the recorded investment in commercial loan classes by internally assigned risk ratings as of the dates presented: June 30, 2018 (dollars in thousands) Commercial Real Estate % of Total Commercial and Industrial % of Total Commercial Construction % of Total Total % of Total Pass $ 2,636,581 94.5 % $ 1,337,331 91.9 % $ 272,433 90.9 % $ 4,246,345 93.4 % Special mention 74,169 2.7 % 50,142 3.4 % 8,566 2.8 % 132,877 3.0 % Substandard 77,891 2.8 % 68,105 4.7 % 18,788 6.3 % 164,784 3.6 % Total $ 2,788,641 100.0 % $ 1,455,578 100.0 % $ 299,787 100.0 % $ 4,544,006 100.0 % December 31, 2017 (dollars in thousands) Commercial Real Estate % of Total Commercial and Industrial % of Total Commercial Construction % of Total Total % of Total Pass $ 2,588,847 96.4 % $ 1,345,810 93.9 % $ 368,105 95.8 % $ 4,302,762 95.5 % Special mention 66,436 2.5 % 54,320 3.8 % 9,345 2.4 % 130,101 2.9 % Substandard 30,711 1.1 % 33,136 2.3 % 6,884 1.8 % 70,731 1.6 % Total $ 2,685,994 100.0 % $ 1,433,266 100.0 % $ 384,334 100.0 % $ 4,503,594 100.0 %
Schedule of Recorded Investment in Consumer Loan Classes by Performing and Nonperforming Status	The following tables present the recorded investment in consumer loan classes by performing and nonperforming status as of the dates presented: June 30, 2018 (dollars in thousands) Residential Mortgage % of Total Home Equity % of Total Installment and Other Consumer % of Total Consumer Construction % of Total Total % of Total Performing $ 692,328 99.1 % $ 467,751 99.2 % $ 66,589 99.9 % $ 5,412 100.0 % $ 1,232,080 99.2 % Nonperforming 6,112 0.9 % 3,871 0.8 % 49 0.1 % — — % 10,032 0.8 % Total $ 698,440 100.0 % $ 471,622 100.0 % $ 66,638 100.0 % $ 5,412 100.0 % $ 1,242,112 100.0 % December 31, 2017 (dollars in thousands) Residential Mortgage % of Total Home Equity % of Total Installment and Other Consumer % of Total Consumer Construction % of Total Total % of Total Performing $ 691,609 99.0 % $ 483,611 99.2 % $ 67,133 99.9 % $ 4,551 100.0 % $ 1,246,904 99.1 % Nonperforming 7,165 1.0 % 3,715 0.8 % 71 0.1 % — — % 10,951 0.9 % Total $ 698,774 100.0 % $ 487,326 100.0 % $ 67,204 100.0 % $ 4,551 100.0 % $ 1,257,855 100.0 %
Schedule of Investments in Loans Considered to be Impaired and Related Information on Impaired Loans	Six Months Ended June 30, 2018 June 30, 2017 (dollars in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized With a related allowance recorded: Commercial real estate $ — $ — $ — $ — Commercial and industrial — — 628 11 Commercial construction — — — — Consumer real estate — — 25 1 Other consumer 40 2 27 1 Total with a Related Allowance Recorded 40 2 680 13 Without a related allowance recorded: Commercial real estate 3,712 85 7,028 70 Commercial and industrial 7,796 218 16,382 124 Commercial construction 3,445 73 4,267 79 Consumer real estate 10,128 253 11,514 255 Other consumer 11 — 12 — Total without a Related Allowance Recorded 25,092 629 39,203 528 Total: Commercial real estate 3,712 85 7,028 70 Commercial and industrial 7,796 218 17,010 135 Commercial construction 3,445 73 4,267 79 Consumer real estate 10,128 253 11,539 256 Other consumer 51 2 39 1 Total $ 25,132 $ 631 $ 39,883 $ 541 The following table summarizes average recorded investment in and interest income recognized on loans considered to be impaired for the periods presented: Three Months Ended June 30, 2018 June 30, 2017 (dollars in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized With a related allowance recorded: Commercial real estate $ — $ — $ — $ — Commercial and industrial — — 813 6 Commercial construction — — — — Consumer real estate — — 24 1 Other consumer 38 1 26 — Total with a Related Allowance Recorded 38 1 863 7 Without a related allowance recorded: Commercial real estate 3,609 54 6,934 35 Commercial and industrial 8,060 210 17,625 95 Commercial construction 3,443 33 4,262 42 Consumer real estate 9,483 118 11,280 125 Other consumer 10 — 11 1 Total without a Related Allowance Recorded 24,605 415 40,112 298 Total: Commercial real estate 3,609 54 6,934 35 Commercial and industrial 8,060 210 18,438 101 Commercial construction 3,443 33 4,262 42 Consumer real estate 9,483 118 11,304 126 Other consumer 48 1 37 1 Total $ 24,643 $ 416 $ 40,975 $ 305 Six Months Ended June 30, 2018 June 30, 2017 (dollars in thousands) Average Recorded Investment Interest Income Recognized Average Recorded Investment Interest Income Recognized With a related allowance recorded: Commercial real estate $ — $ — $ — $ — Commercial and industrial — — 628 11 Commercial construction — — — — Consumer real estate — — 25 1 Other consumer 40 2 27 1 Total with a Related Allowance Recorded 40 2 680 13 Without a related allowance recorded: Commercial real estate 3,712 85 7,028 70 Commercial and industrial 7,796 218 16,382 124 Commercial construction 3,445 73 4,267 79 Consumer real estate 10,128 253 11,514 255 Other consumer 11 — 12 — Total without a Related Allowance Recorded 25,092 629 39,203 528 Total: Commercial real estate 3,712 85 7,028 70 Commercial and industrial 7,796 218 17,010 135 Commercial construction 3,445 73 4,267 79 Consumer real estate 10,128 253 11,539 256 Other consumer 51 2 39 1 Total $ 25,132 $ 631 $ 39,883 $ 541 The following tables summarize investments in loans considered to be impaired and related information on those impaired loans as of the dates presented: June 30, 2018 December 31, 2017 (dollars in thousands) Recorded Investment Unpaid Principal Balance Related Allowance Recorded Investment Unpaid Principal Balance Related Allowance With a related allowance recorded: Commercial real estate $ — $ — $ — $ — $ — $ — Commercial and industrial — — — 1,735 1,787 29 Commercial construction — — — — — — Consumer real estate — — — 21 21 21 Other consumer 35 35 35 27 27 27 Total with a Related Allowance Recorded 35 35 35 1,783 1,835 77 Without a related allowance recorded: Commercial real estate 3,555 3,828 — 3,546 3,811 — Commercial and industrial 17,539 19,281 — 5,549 7,980 — Commercial construction 3,441 4,950 — 5,464 8,132 — Consumer real estate 9,186 10,132 — 10,467 11,357 — Other consumer 9 13 — 14 22 — Total without a Related Allowance Recorded 33,730 38,204 — 25,040 31,302 — Total: Commercial real estate 3,555 3,828 — 3,546 3,811 — Commercial and industrial 17,539 19,281 — 7,284 9,767 29 Commercial construction 3,441 4,950 — 5,464 8,132 — Consumer real estate 9,186 10,132 — 10,488 11,378 21 Other consumer 44 48 35 41 49 27 Total $ 33,765 $ 38,239 $ 35 $ 26,823 $ 33,137 $ 77
Schedule of Summary of Allowance for Loan Losses	The following tables detail activity in the ALLL for the periods presented: Three Months Ended June 30, 2018 (dollars in thousands) Commercial Real Estate Commercial and Industrial Commercial Construction Consumer Real Estate Other Consumer Total Loans Balance at beginning of period $ 30,963 $ 10,472 $ 10,721 $ 5,418 $ 1,472 $ 59,046 Charge-offs (237 ) (7,392 ) (321 ) (268 ) (414 ) (8,632 ) Recoveries 185 362 1 85 125 758 Net (Charge-offs)/ Recoveries (52 ) (7,030 ) (320 ) (183 ) (289 ) (7,874 ) Provision for loan losses 321 7,432 1,275 6 311 9,345 Balance at End of Period $ 31,232 $ 10,874 $ 11,676 $ 5,241 $ 1,494 $ 60,517 Three Months Ended June 30, 2017 (dollars in thousands) Commercial Real Estate Commercial and Industrial Commercial Construction Consumer Real Estate Other Consumer Total Loans Balance at beginning of period $ 20,570 $ 13,244 $ 14,102 $ 5,956 $ 1,944 $ 55,816 Charge-offs (1,673 ) (2,682 ) — (1,097 ) (370 ) (5,822 ) Recoveries 155 69 113 76 75 488 Net (Charge-offs)/ Recoveries (1,518 ) (2,613 ) 113 (1,021 ) (295 ) (5,334 ) Provision for loan losses 5,306 (1,375 ) (271 ) 868 341 4,869 Balance at End of Period $ 24,358 $ 9,256 $ 13,944 $ 5,803 $ 1,990 $ 55,351 Six Months Ended June 30, 2018 (dollars in thousands) Commercial Real Estate Commercial and Industrial Commercial Construction Consumer Real Estate Other Consumer Total Loans Balance at beginning of period $ 27,235 $ 8,966 $ 13,167 $ 5,479 $ 1,543 $ 56,390 Charge-offs (232 ) (8,222 ) (321 ) (429 ) (872 ) (10,076 ) Recoveries 228 480 1,130 323 225 2,386 Net (Charge-offs)/Recoveries (4 ) (7,742 ) 809 (106 ) (647 ) (7,690 ) Provision for loan losses 4,001 9,650 (2,300 ) (132 ) 598 11,817 Balance at End of Period $ 31,232 $ 10,874 $ 11,676 $ 5,241 $ 1,494 $ 60,517 Six Months Ended June 30, 2017 (dollars in thousands) Commercial Real Estate Commercial and Industrial Commercial Construction Consumer Real Estate Other Consumer Total Loans Balance at beginning of period $ 19,976 $ 10,810 $ 13,999 $ 6,095 $ 1,895 $ 52,775 Charge-offs (2,063 ) (3,396 ) (644 ) (1,856 ) (804 ) (8,763 ) Recoveries 233 255 369 179 251 1,287 Net (Charge-offs)/Recoveries (1,830 ) (3,141 ) (275 ) (1,677 ) (553 ) (7,476 ) Provision for loan losses 6,212 1,587 220 1,385 648 10,052 Balance at End of Period $ 24,358 $ 9,256 $ 13,944 $ 5,803 $ 1,990 $ 55,351
Schedule of Summary of Allowance for Loan Losses and Recorded Investments	The following tables present the ALLL and recorded investments in loans by category as of the periods presented: June 30, 2018 Allowance for Loan Losses Portfolio Loans (dollars in thousands) Individually Evaluated for Impairment Collectively Evaluated for Impairment Total Individually Evaluated for Impairment Collectively Evaluated for Impairment Total Commercial real estate $ — $ 31,232 $ 31,232 $ 3,555 $ 2,785,086 $ 2,788,641 Commercial and industrial — 10,874 10,874 17,539 1,438,039 1,455,578 Commercial construction — 11,676 11,676 3,441 296,346 299,787 Consumer real estate — 5,241 5,241 9,186 1,166,288 1,175,474 Other consumer 35 1,459 1,494 44 66,594 66,638 Total $ 35 $ 60,482 $ 60,517 $ 33,765 $ 5,752,353 $ 5,786,118 December 31, 2017 Allowance for Loan Losses Portfolio Loans (dollars in thousands) Individually Evaluated for Impairment Collectively Evaluated for Impairment Total Individually Evaluated for Impairment Collectively Evaluated for Impairment Total Commercial real estate $ — $ 27,235 $ 27,235 $ 3,546 $ 2,682,448 $ 2,685,994 Commercial and industrial 29 8,937 8,966 7,284 1,425,982 1,433,266 Commercial construction — 13,167 13,167 5,464 378,870 384,334 Consumer real estate 21 5,458 5,479 10,488 1,180,163 1,190,651 Other consumer 27 1,516 1,543 41 67,163 67,204 Total $ 77 $ 56,313 $ 56,390 $ 26,823 $ 5,734,626 $ 5,761,449

Derivative Instruments and He28

Derivative Instruments and Hedging Activities (Tables)	6 Months Ended
	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Value of Derivative Assets and Derivative Liabilities	The following tables indicate the amounts representing the value of derivative assets and derivative liabilities as of the dates presented: Derivatives (included in Other Assets) Derivatives (included in Other Liabilities) (dollars in thousands) June 30, 2018 December 31, 2017 June 30, 2018 December 31, 2017 Derivatives not Designated as Hedging Instruments: Interest Rate Swap Contracts - Commercial Loans Fair value $ 6,157 $ 3,074 $ 6,223 $ 3,055 Notional amount 246,494 263,841 246,494 263,841 Net collateral received/posted 2,560 — — 1,448 Interest Rate Lock Commitments - Mortgage Loans Fair value 398 226 — — Notional amount 12,711 6,860 — — Forward Sale Contracts - Mortgage Loans Fair value — — 39 5 Notional amount $ — $ — $ 12,250 $ 6,580
Schedule of Offsetting Derivative Assets	The following tables indicate the gross amounts of commercial loan swap derivative assets and derivative liabilities, the amounts offset and the carrying values in the Consolidated Balance Sheets as of the dates presented: Derivatives (included in Other Assets) Derivatives (included in Other Liabilities) (dollars in thousands) June 30, 2018 December 31, 2017 June 30, 2018 December 31, 2017 Derivatives not Designated as Hedging Instruments: Gross amounts recognized $ 7,258 $ 4,974 $ 7,324 $ 4,955 Gross amounts offset (1,101 ) (1,900 ) (1,101 ) (1,900 ) Net Amounts Presented in the Consolidated Balance Sheets 6,157 3,074 6,223 3,055 Gross amounts not offset (1) (2,560 ) — — (1,448 ) Net Amount $ 3,597 $ 3,074 $ 6,223 $ 1,607 (1) Amounts represent received/posted collateral.
Schedule of Offsetting Liabilities	The following tables indicate the gross amounts of commercial loan swap derivative assets and derivative liabilities, the amounts offset and the carrying values in the Consolidated Balance Sheets as of the dates presented: Derivatives (included in Other Assets) Derivatives (included in Other Liabilities) (dollars in thousands) June 30, 2018 December 31, 2017 June 30, 2018 December 31, 2017 Derivatives not Designated as Hedging Instruments: Gross amounts recognized $ 7,258 $ 4,974 $ 7,324 $ 4,955 Gross amounts offset (1,101 ) (1,900 ) (1,101 ) (1,900 ) Net Amounts Presented in the Consolidated Balance Sheets 6,157 3,074 6,223 3,055 Gross amounts not offset (1) (2,560 ) — — (1,448 ) Net Amount $ 3,597 $ 3,074 $ 6,223 $ 1,607 (1) Amounts represent received/posted collateral.
Amount of Gain or Loss Recognized in Income on Derivatives	The following tables indicate the gain or loss recognized in income on derivatives for the periods presented: Three Months Ended June 30, Six Months Ended June 30, (dollars in thousands) 2018 2017 2018 2017 Derivatives not Designated as Hedging Instruments Interest rate swap contracts—commercial loans $ (201 ) $ (8 ) $ (85 ) $ 16 Interest rate lock commitments—mortgage loans 128 (13 ) 172 220 Forward sale contracts—mortgage loans (15 ) 76 (33 ) 40 Total Derivatives (Loss)/Gain $ (88 ) $ 55 $ 54 $ 276

Borrowings (Tables)

Borrowings (Tables)	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Schedule of Information Pertaining to Borrowings	Information pertaining to borrowings is summarized in the table below as of the dates presented: June 30, 2018 December 31, 2017 (dollars in thousands) Balance Weighted Average Rate Balance Weighted Average Rate Short-term Borrowings Securities sold under repurchase agreements $ 44,724 0.46 % $ 50,161 0.39 % Short-term borrowings 600,000 2.16 % 540,000 1.47 % Total Short-term Borrowings 644,724 2.04 % 590,161 1.38 % Long-term Borrowings Long-term borrowings 46,062 2.31 % 47,301 1.88 % Junior subordinated debt securities 45,619 4.80 % 45,619 3.78 % Total Long-term Borrowings 91,681 3.55 % 92,920 2.81 % Total Borrowings $ 736,405 2.23 % $ 683,081 1.57 %

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Letters of Credit	The following table sets forth our commitments and letters of credit as of the dates presented: (dollars in thousands) June 30, 2018 December 31, 2017 Commitments to extend credit $ 1,413,700 $ 1,420,428 Standby letters of credit 80,709 80,918 Total $ 1,494,409 $ 1,501,346

Other Comprehensive Income (Tab

Other Comprehensive Income (Tables)	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Tax Effects of Components of Other Comprehensive Income	The following tables present the change in components of other comprehensive income (loss) for the periods presented, net of tax effects. Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 (dollars in thousands) Pre-Tax Amount Tax (Expense) Benefit Net of Tax Amount Pre-Tax Amount Tax (Expense) Benefit Net of Tax Amount Change in net unrealized gains/(losses) on debt securities available-for-sale (1) $ (2,296 ) $ 487 $ (1,809 ) $ 2,672 $ (938 ) $ 1,734 Reclassification adjustment for net (gains)/losses on debt securities available-for-sale included in net income (2) — — — (3,617 ) 1,270 (2,347 ) Adjustment to funded status of employee benefit plans 702 (149 ) 553 539 (188 ) 351 Other Comprehensive (Loss)/Income $ (1,594 ) $ 338 $ (1,256 ) $ (406 ) $ 144 $ (262 ) (1) Due to the adoption of ASU No. 2016-01, net unrealized gains on marketable equity securities were reclassified from Accumulated Other Comprehensive Income to Retained Earnings during the three months ended March 31, 2018. The prior period data was not restated; as such, the change in unrealized gains on marketable securities is combined with the change in net unrealized gains on debit securities for the period ended June 30, 2017. (2) Reclassification adjustments are comprised of realized security gains or losses. The realized gains or losses have been reclassified out of accumulated other comprehensive income/(loss) and have affected certain lines in the Consolidated Statements of Comprehensive Income as follows; the pre-tax amount is included in securities gains/losses-net, the tax expense amount is included in the provision for income taxes and the net of tax amount is included in net income. Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 (dollars in thousands) Pre-Tax Amount Tax (Expense) Benefit Net of Tax Amount Pre-Tax Amount Tax (Expense) Benefit Net of Tax Amount Change in net unrealized gains/(losses) on securities available-for-sale (1) $ (11,770 ) $ 2,499 $ (9,271 ) $ 4,335 $ (1,523 ) $ 2,812 Reclassification adjustment for net (gains)/losses on securities available-for-sale included in net income (2) — — — (3,987 ) 1,400 (2,587 ) Adjustment to funded status of employee benefit plans 1,323 (281 ) 1,042 1,078 (377 ) 701 Other Comprehensive (Loss)/Income $ (10,447 ) $ 2,218 $ (8,229 ) $ 1,426 $ (500 ) $ 926 (1) Due to the adoption of ASU No. 2016-01, net unrealized gains on marketable equity securities were reclassified from Accumulated Other Comprehensive Income to Retained Earnings during the three months ended March 31, 2018. The prior period data was not restated; as such, the change in unrealized gains on marketable securities is combined with the change in net unrealized gains on debit securities for the period ended June 30, 2017. (2) Reclassification adjustments are comprised of realized security gains or losses. The realized gains or losses have been reclassified out of accumulated other comprehensive income/(loss) and have affected certain lines in the Consolidated Statements of Comprehensive Income as follows; the pre-tax amount is included in securities gains/losses-net, the tax expense amount is included in the provision for income taxes and the net of tax amount is included in net income.

Employee Benefits (Tables)

Employee Benefits (Tables)	6 Months Ended
	Jun. 30, 2018
Retirement Benefits [Abstract]
Components of Net Periodic Pension Cost and Other Changes in Plan Assets and Benefit	The following table summarizes the components of net periodic pension cost for the periods presented: Three Months Ended June 30, Six Months Ended June 30, (dollars in thousands) 2018 2017 2018 2017 Components of Net Periodic Pension Cost Interest cost on projected benefit obligation $ 967 $ 1,025 $ 1,934 $ 2,050 Expected return on plan assets (1,567 ) (1,582 ) (3,134 ) (3,164 ) Amortization of prior service credit 545 475 1,089 949 Net Periodic Pension Expense $ (55 ) $ (82 ) $ (111 ) $ (165 )

Basis of Presentation (Details)

Basis of Presentation (Details)		Jan. 01, 2018USD ($)	Jun. 30, 2018USD ($)lease	Mar. 31, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)lease	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Schedule of Equity Method Investments [Line Items]
Provisional estimate for reclassification of AOCI to retain earnings for other income tax effects of Tax Act				$ 3,400,000
Gain on sale of a majority interest of insurance business			$ 0		$ 0	$ 1,873,000	$ 0
Unrealized gains on marketable equity securities			$ 230,000		$ 504,000	$ 282,000	$ 1,237,000
Number of operating lease agreements | lease			50			50
ASU No. 2018-02
Schedule of Equity Method Investments [Line Items]
Effect of new accounting pronouncement on Consolidated Financial Statements								$ 0
ASU No. 2018-02 | AOCI
Schedule of Equity Method Investments [Line Items]
Provisional estimate for reclassification of AOCI to retain earnings for other income tax effects of Tax Act	[1]					$ (3,427,000)
ASU No. 2018-02 | Retained Earnings
Schedule of Equity Method Investments [Line Items]
Provisional estimate for reclassification of AOCI to retain earnings for other income tax effects of Tax Act	[1]					3,427,000
ASU No. 2017-07
Schedule of Equity Method Investments [Line Items]
Effect of new accounting pronouncement on Consolidated Financial Statements								0
ASU No. 2017-01
Schedule of Equity Method Investments [Line Items]
Effect of new accounting pronouncement on Consolidated Financial Statements								0
ASU No. 2016-16
Schedule of Equity Method Investments [Line Items]
Effect of new accounting pronouncement on Consolidated Financial Statements								0
ASU No. 2016-15
Schedule of Equity Method Investments [Line Items]
Effect of new accounting pronouncement on Consolidated Financial Statements								0
ASU No. 2014-09
Schedule of Equity Method Investments [Line Items]
Effect of new accounting pronouncement on Consolidated Financial Statements		$ 0
ASU No. 2016-01
Schedule of Equity Method Investments [Line Items]
Unrealized gains on marketable equity securities						$ 300,000
ASU No. 2016-01 | AOCI
Schedule of Equity Method Investments [Line Items]
Effect of new accounting pronouncement on Consolidated Financial Statements		(900,000)						(862,000)	[2]
ASU No. 2016-01 | Retained Earnings
Schedule of Equity Method Investments [Line Items]
Effect of new accounting pronouncement on Consolidated Financial Statements		$ 900,000						$ 862,000	[2]
New Partnership
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage		30.00%
Subsidiaries | S&T Evergreen Insurance LLC
Schedule of Equity Method Investments [Line Items]
Percentage of ownership in subsidiary sold		70.00%
Gain on sale of a majority interest of insurance business		$ 1,900,000
[1]	Reclassification due to the adoption of ASU No. 2018-02 - $(3,660) relates to funded status of pension and $233 relates to net unrealized gains on available-for-sale securities.
[2]	Reclassification due to the adoption of ASU No. 2016-01.

Earnings Per Share - Reconciles

Earnings Per Share - Reconciles Numerators and Denominators of Basic Earnings Per Share with Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Numerator for Earnings per Share Basic and Diluted:
Net income	$ 21,436	$ 22,765	$ 47,599	$ 40,953
Less: Income allocated to participating shares	62	81	141	141
Net Income Allocated to Shareholders	21,374	22,684	47,458	40,812
Net Income Available to Shareholders	$ 21,436	$ 22,765	$ 47,599	$ 40,953
Denominators for Earnings per Share:
Weighted Average Shares Outstanding—Basic (in shares)	34,793,160	34,724,925	34,775,043	34,707,683
Add: Potentially dilutive shares (in shares)	264,416	181,571	267,998	199,693
Denominator for Treasury Stock Method—Diluted (in shares)	35,057,576	34,906,496	35,043,041	34,907,376
Weighted Average Shares Outstanding—Basic (in shares)	34,793,160	34,724,925	34,775,043	34,707,683
Add: Average participating shares outstanding (in shares)	100,212	123,729	103,449	119,585
Denominator for Two-Class Method—Diluted (in shares)	34,893,372	34,848,654	34,878,492	34,827,268
Earnings per share—basic (in dollars per share)	$ 0.62	$ 0.66	$ 1.37	$ 1.18
Earnings per share—diluted (in dollars per share)	0.61	0.65	1.36	1.17
Anti-dilutive warrants—exercise price (in dollars per share)	$ 31.53	$ 31.53	$ 31.53	$ 31.53
Warrants
Denominators for Earnings per Share:
Anti-dilutive excluded from potentially dilutive shares (in shares)	374,314	466,554	386,747	456,749
Restricted Stock
Denominators for Earnings per Share:
Anti-dilutive excluded from potentially dilutive shares (in shares)	89,974	126,332	76,325	105,187

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($)		Jun. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers between Level 1 to Level 2		$ 0	$ 0
ASSETS
Debt securities available-for-sale:		682,916,000	693,147,000
Marketable equity securities		5,425,000	5,144,000
U.S. Treasury securities
ASSETS
Debt securities available-for-sale:		9,619,000	19,789,000
Obligations of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		155,069,000	162,193,000
Collateralized mortgage obligations of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		118,742,000	108,688,000
Residential mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		28,442,000	32,854,000
Commercial mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		247,128,000	242,221,000	[1]
Obligations of states and political subdivisions
ASSETS
Debt securities available-for-sale:		123,916,000	127,402,000
Fair Value Measurements, Recurring
ASSETS
Debt securities available-for-sale:		682,916,000	693,147,000
Marketable equity securities	[2]	5,425,000	5,144,000
Total securities		688,341,000	698,291,000
Trading securities held in a Rabbi Trust		4,988,000	5,080,000
Total Assets		699,884,000	706,671,000
LIABILITIES
Total Liabilities		6,262,000	3,060,000
Fair Value Measurements, Recurring | U.S. Treasury securities
ASSETS
Debt securities available-for-sale:		9,619,000	19,789,000
Fair Value Measurements, Recurring | Obligations of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		155,069,000	162,193,000
Fair Value Measurements, Recurring | Collateralized mortgage obligations of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		118,742,000	108,688,000
Fair Value Measurements, Recurring | Residential mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		28,442,000	32,854,000
Fair Value Measurements, Recurring | Commercial mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		247,128,000	242,221,000
Fair Value Measurements, Recurring | Obligations of states and political subdivisions
ASSETS
Debt securities available-for-sale:		123,916,000	127,402,000
Fair Value Measurements, Recurring | Interest rate swaps
ASSETS
Derivative financial assets		6,157,000	3,074,000
LIABILITIES
Derivative financial liabilities		6,223,000	3,055,000
Fair Value Measurements, Recurring | Interest rate lock commitments
ASSETS
Derivative financial assets		398,000	226,000
Fair Value Measurements, Recurring | Forward sale contracts
LIABILITIES
Derivative financial liabilities		39,000	5,000
Fair Value Measurements, Recurring | Level 1
ASSETS
Debt securities available-for-sale:		0	0
Marketable equity securities	[2]	0	0
Total securities		0	0
Trading securities held in a Rabbi Trust		4,988,000	5,080,000
Total Assets		4,988,000	5,080,000
LIABILITIES
Total Liabilities		0	0
Fair Value Measurements, Recurring | Level 1 | U.S. Treasury securities
ASSETS
Debt securities available-for-sale:		0	0
Fair Value Measurements, Recurring | Level 1 | Obligations of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		0	0
Fair Value Measurements, Recurring | Level 1 | Collateralized mortgage obligations of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		0	0
Fair Value Measurements, Recurring | Level 1 | Residential mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		0	0
Fair Value Measurements, Recurring | Level 1 | Commercial mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		0	0
Fair Value Measurements, Recurring | Level 1 | Obligations of states and political subdivisions
ASSETS
Debt securities available-for-sale:		0	0
Fair Value Measurements, Recurring | Level 1 | Interest rate swaps
ASSETS
Derivative financial assets		0	0
LIABILITIES
Derivative financial liabilities		0	0
Fair Value Measurements, Recurring | Level 1 | Interest rate lock commitments
ASSETS
Derivative financial assets		0	0
Fair Value Measurements, Recurring | Level 1 | Forward sale contracts
LIABILITIES
Derivative financial liabilities		0	0
Fair Value Measurements, Recurring | Level 2
ASSETS
Debt securities available-for-sale:		682,916,000	693,147,000
Marketable equity securities	[2]	5,425,000	5,144,000
Total securities		688,341,000	698,291,000
Trading securities held in a Rabbi Trust		0	0
Total Assets		694,896,000	701,591,000
LIABILITIES
Total Liabilities		6,262,000	3,060,000
Fair Value Measurements, Recurring | Level 2 | U.S. Treasury securities
ASSETS
Debt securities available-for-sale:		9,619,000	19,789,000
Fair Value Measurements, Recurring | Level 2 | Obligations of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		155,069,000	162,193,000
Fair Value Measurements, Recurring | Level 2 | Collateralized mortgage obligations of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		118,742,000	108,688,000
Fair Value Measurements, Recurring | Level 2 | Residential mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		28,442,000	32,854,000
Fair Value Measurements, Recurring | Level 2 | Commercial mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		247,128,000	242,221,000
Fair Value Measurements, Recurring | Level 2 | Obligations of states and political subdivisions
ASSETS
Debt securities available-for-sale:		123,916,000	127,402,000
Fair Value Measurements, Recurring | Level 2 | Interest rate swaps
ASSETS
Derivative financial assets		6,157,000	3,074,000
LIABILITIES
Derivative financial liabilities		6,223,000	3,055,000
Fair Value Measurements, Recurring | Level 2 | Interest rate lock commitments
ASSETS
Derivative financial assets		398,000	226,000
Fair Value Measurements, Recurring | Level 2 | Forward sale contracts
LIABILITIES
Derivative financial liabilities		39,000	5,000
Fair Value Measurements, Recurring | Level 3
ASSETS
Debt securities available-for-sale:		0	0
Marketable equity securities	[2]	0	0
Total securities		0	0
Trading securities held in a Rabbi Trust		0	0
Total Assets		0	0
LIABILITIES
Total Liabilities		0	0
Fair Value Measurements, Recurring | Level 3 | U.S. Treasury securities
ASSETS
Debt securities available-for-sale:		0	0
Fair Value Measurements, Recurring | Level 3 | Obligations of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		0	0
Fair Value Measurements, Recurring | Level 3 | Collateralized mortgage obligations of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		0	0
Fair Value Measurements, Recurring | Level 3 | Residential mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		0	0
Fair Value Measurements, Recurring | Level 3 | Commercial mortgage-backed securities of U.S. government corporations and agencies
ASSETS
Debt securities available-for-sale:		0	0
Fair Value Measurements, Recurring | Level 3 | Obligations of states and political subdivisions
ASSETS
Debt securities available-for-sale:		0	0
Fair Value Measurements, Recurring | Level 3 | Interest rate swaps
ASSETS
Derivative financial assets		0	0
LIABILITIES
Derivative financial liabilities		0	0
Fair Value Measurements, Recurring | Level 3 | Interest rate lock commitments
ASSETS
Derivative financial assets		0	0
Fair Value Measurements, Recurring | Level 3 | Forward sale contracts
LIABILITIES
Derivative financial liabilities		$ 0	$ 0
[1]	Includes a $5.9 million security purchase that was pending settlement as of December 31, 2017.
[2]	ASU No. 2016-01 was adopted January 1, 2018, resulting in separate classification of our marketable equity securities previously included in available-for-sale securities.

Fair Value Measurements - Ass36

Fair Value Measurements - Assets Measured at Estimated Fair Value on Nonrecurring Basis by Fair Value Hierarchy (Details) - Fair Value, Measurements, Nonrecurring - USD ($)		Jun. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities measured at fair value on a nonrecurring basis		$ 0	$ 0
ASSETS
Impaired loans	[1]	5,487,000	6,759,000
Other real estate owned	[1]	2,719,000	444,000
Mortgage servicing rights	[1]	89,000	178,000
Total Assets	[1]	8,295,000	7,381,000
Level 1
ASSETS
Impaired loans	[1]	0	0
Other real estate owned	[1]	0	0
Mortgage servicing rights	[1]	0	0
Total Assets	[1]	0	0
Level 2
ASSETS
Impaired loans	[1]	0	0
Other real estate owned	[1]	0	0
Mortgage servicing rights	[1]	0	0
Total Assets	[1]	0	0
Level 3
ASSETS
Impaired loans	[1]	5,487,000	6,759,000
Other real estate owned	[1]	2,719,000	444,000
Mortgage servicing rights	[1]	89,000	178,000
Total Assets	[1]	$ 8,295,000	$ 7,381,000
[1]	This table represents only the nonrecurring items that are recorded at fair value in our financial statements.

Fair Value Measurements - Carry

Fair Value Measurements - Carrying Values and Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands		Jun. 30, 2018	Dec. 31, 2017
ASSETS
Securities, at fair value		$ 688,341	$ 698,291
Portfolio loans, net		5,725,601	5,705,059
FHLB and other restricted stock		35,782	29,270
Carrying Value
ASSETS
Cash and due from banks, including interest-bearing deposits	[1]	137,933	117,152
Securities, at fair value	[1]	688,341	698,291
Loans held for sale	[1]	3,801	4,485
Portfolio loans, net	[1]	5,725,601	5,705,059
Bank owned life insurance	[1]	73,122	72,150
FHLB and other restricted stock	[1]	35,782	29,270
Trading securities held in a Rabbi Trust	[1]	4,988	5,080
Mortgage servicing rights	[1]	4,296	4,133
LIABILITIES
Deposits	[1]	5,393,533	5,427,891
Securities sold under repurchase agreements	[1]	44,724	50,161
Short-term borrowings	[1]	600,000	540,000
Long-term borrowings	[1]	46,062	47,301
Junior subordinated debt securities	[1]	45,619	45,619
Carrying Value | Interest rate swaps
ASSETS
Derivative financial assets	[1]	6,157	3,074
LIABILITIES
Derivative financial liabilities	[1]	6,223	3,055
Carrying Value | Interest rate lock commitments
ASSETS
Derivative financial assets	[1]	398	226
Carrying Value | Forward sale contracts
LIABILITIES
Derivative financial liabilities	[1]	39	5
Fair Value Measurements
ASSETS
Cash and due from banks, including interest-bearing deposits		137,933	117,152
Securities, at fair value		688,341	698,291
Loans held for sale		3,927	4,583
Portfolio loans, net		5,558,333	5,690,292
Bank owned life insurance		73,122	72,150
FHLB and other restricted stock		35,782	29,270
Trading securities held in a Rabbi Trust		4,988	5,080
Mortgage servicing rights		5,198	4,571
LIABILITIES
Deposits		5,378,467	5,426,928
Securities sold under repurchase agreements		44,724	50,161
Short-term borrowings		600,000	540,000
Long-term borrowings		46,226	47,618
Junior subordinated debt securities		45,619	45,619
Fair Value Measurements | Interest rate swaps
ASSETS
Derivative financial assets		6,157	3,074
LIABILITIES
Derivative financial liabilities		6,223	3,055
Fair Value Measurements | Interest rate lock commitments
ASSETS
Derivative financial assets		398	226
Fair Value Measurements | Forward sale contracts
LIABILITIES
Derivative financial liabilities		39	5
Fair Value Measurements | Level 1
ASSETS
Cash and due from banks, including interest-bearing deposits		137,933	117,152
Securities, at fair value		0	0
Loans held for sale		0	0
Portfolio loans, net		0	0
Bank owned life insurance		0	0
FHLB and other restricted stock		0	0
Trading securities held in a Rabbi Trust		4,988	5,080
Mortgage servicing rights		0	0
LIABILITIES
Deposits		0	0
Securities sold under repurchase agreements		0	0
Short-term borrowings		0	0
Long-term borrowings		0	0
Junior subordinated debt securities		0	0
Fair Value Measurements | Level 1 | Interest rate swaps
ASSETS
Derivative financial assets		0	0
LIABILITIES
Derivative financial liabilities		0	0
Fair Value Measurements | Level 1 | Interest rate lock commitments
ASSETS
Derivative financial assets		0	0
Fair Value Measurements | Level 1 | Forward sale contracts
LIABILITIES
Derivative financial liabilities		0	0
Fair Value Measurements | Level 2
ASSETS
Cash and due from banks, including interest-bearing deposits		0	0
Securities, at fair value		688,341	698,291
Loans held for sale		0	0
Portfolio loans, net		0	0
Bank owned life insurance		73,122	72,150
FHLB and other restricted stock		0	0
Trading securities held in a Rabbi Trust		0	0
Mortgage servicing rights		0	0
LIABILITIES
Deposits		0	0
Securities sold under repurchase agreements		0	0
Short-term borrowings		0	0
Long-term borrowings		0	0
Junior subordinated debt securities		0	0
Fair Value Measurements | Level 2 | Interest rate swaps
ASSETS
Derivative financial assets		6,157	3,074
LIABILITIES
Derivative financial liabilities		6,223	3,055
Fair Value Measurements | Level 2 | Interest rate lock commitments
ASSETS
Derivative financial assets		398	226
Fair Value Measurements | Level 2 | Forward sale contracts
LIABILITIES
Derivative financial liabilities		39	5
Fair Value Measurements | Level 3
ASSETS
Cash and due from banks, including interest-bearing deposits		0	0
Securities, at fair value		0	0
Loans held for sale		3,927	4,583
Portfolio loans, net		5,558,333	5,690,292
Bank owned life insurance		0	0
FHLB and other restricted stock		35,782	29,270
Trading securities held in a Rabbi Trust		0	0
Mortgage servicing rights		5,198	4,571
LIABILITIES
Deposits		5,378,467	5,426,928
Securities sold under repurchase agreements		44,724	50,161
Short-term borrowings		600,000	540,000
Long-term borrowings		46,226	47,618
Junior subordinated debt securities		45,619	45,619
Fair Value Measurements | Level 3 | Interest rate swaps
ASSETS
Derivative financial assets		0	0
LIABILITIES
Derivative financial liabilities		0	0
Fair Value Measurements | Level 3 | Interest rate lock commitments
ASSETS
Derivative financial assets		0	0
Fair Value Measurements | Level 3 | Forward sale contracts
LIABILITIES
Derivative financial liabilities		$ 0	$ 0
[1]	As reported in the Consolidated Balance Sheets.

Securities - Fair Values and Am

Securities - Fair Values and Amortized Costs Securities (Details) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost		$ 693,008
Debt Securities, Available-for-Sale, Gross Unrealized Gains		2,858		$ 5,645
Debt Securities, Available-for-Sale, Gross Unrealized Losses		(12,950)		(3,967)
Debt Securities, Available-for-Sale, Fair Value		682,916		693,147
Equity Securities, Fair Value		5,425		5,144
Total Securities, Amortized Cost				695,284
Total Securities, Gross Unrealized Gains				6,975
Total Securities, Gross Unrealized Losses				(3,968)
Total Securities, Fair Value		688,341		698,291
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost		9,953		19,943
Debt Securities, Available-for-Sale, Gross Unrealized Gains		0		0
Debt Securities, Available-for-Sale, Gross Unrealized Losses		(334)		(154)
Debt Securities, Available-for-Sale, Fair Value		9,619		19,789
Obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost		156,812		162,045
Debt Securities, Available-for-Sale, Gross Unrealized Gains		16		341
Debt Securities, Available-for-Sale, Gross Unrealized Losses		(1,759)		(193)
Debt Securities, Available-for-Sale, Fair Value		155,069		162,193
Collateralized mortgage obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost		121,631		109,916
Debt Securities, Available-for-Sale, Gross Unrealized Gains		61		93
Debt Securities, Available-for-Sale, Gross Unrealized Losses		(2,950)		(1,321)
Debt Securities, Available-for-Sale, Fair Value		118,742		108,688
Residential mortgage-backed securities of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost		28,662		32,388
Debt Securities, Available-for-Sale, Gross Unrealized Gains		309		679
Debt Securities, Available-for-Sale, Gross Unrealized Losses		(529)		(213)
Debt Securities, Available-for-Sale, Fair Value		28,442		32,854
Commercial mortgage-backed securities of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost		254,458		244,018	[1]
Debt Securities, Available-for-Sale, Gross Unrealized Gains		0		247	[1]
Debt Securities, Available-for-Sale, Gross Unrealized Losses		(7,330)		(2,044)	[1]
Debt Securities, Available-for-Sale, Fair Value		247,128		242,221	[1]
Securities purchased pending settlement				5,900
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost		121,492		123,159
Debt Securities, Available-for-Sale, Gross Unrealized Gains		2,472		4,285
Debt Securities, Available-for-Sale, Gross Unrealized Losses		(48)		(42)
Debt Securities, Available-for-Sale, Fair Value		123,916		127,402
Total Debt Securities Available-for-Sale
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-Sale, Amortized Cost		693,008		691,469
Debt Securities, Available-for-Sale, Gross Unrealized Gains		2,858		5,645
Debt Securities, Available-for-Sale, Gross Unrealized Losses		(12,950)		(3,967)
Debt Securities, Available-for-Sale, Fair Value		682,916		693,147
Marketable equity securities
Debt Securities, Available-for-sale [Line Items]
Equity Securities, FV-NI, Cost	[2]	0		3,815
Equity Securities, FV-NI, Unrealized Gain	[2]	0	$ 1,330
Equity Securities, FV-NI, Unrealized Loss	[2]	0	$ (1)
Equity Securities, Fair Value	[2]	$ 0		$ 5,144
[1]	Includes a $5.9 million security purchase that was pending settlement as of December 31, 2017.
[2]	ASU No. 2016-01 was adopted January 1, 2018, resulting in separate classification of our marketable equity securities previously included in available-for-sale securities

Securities - Fair Value and Age

Securities - Fair Value and Age of Gross Unrealized Losses of Debt Securities (Details) $ in Thousands	Jun. 30, 2018USD ($)security	Dec. 31, 2017USD ($)security
Debt Securities, Available-for-sale [Line Items]
Temporarily Impaired Debt Securities, Less Than 12 Months, Number of Securities | security	57	36
Temporarily Impaired Debt Securities, Less Than 12 Months, Fair Value	$ 432,363	$ 271,852
Temporarily Impaired Debt Securities, Less Than 12 Months, Unrealized Losses	$ (8,498)	$ (1,373)
Temporarily Impaired Debt Securities, 12 Months or More, Number of Securities | security	16	15
Temporarily Impaired Debt Securities, 12 Months or More, Fair Value	$ 107,226	$ 113,210
Temporarily Impaired Debt Securities, 12 Months or More, Unrealized Losses	$ (4,452)	$ (2,594)
Temporarily Impaired Debt Securities, Number of Securities | security	73	51
Temporarily Impaired Debt Securities, Fair Value, Total	$ 539,589	$ 385,062
Temporarily Impaired Debt Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (12,950)	$ (3,967)
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Temporarily Impaired Debt Securities, Less Than 12 Months, Number of Securities | security	1	3
Temporarily Impaired Debt Securities, Less Than 12 Months, Fair Value	$ 9,618	$ 19,789
Temporarily Impaired Debt Securities, Less Than 12 Months, Unrealized Losses	$ (334)	$ (154)
Temporarily Impaired Debt Securities, 12 Months or More, Number of Securities | security	0	0
Temporarily Impaired Debt Securities, 12 Months or More, Fair Value	$ 0	$ 0
Temporarily Impaired Debt Securities, 12 Months or More, Unrealized Losses	$ 0	$ 0
Temporarily Impaired Debt Securities, Number of Securities | security	1	3
Temporarily Impaired Debt Securities, Fair Value, Total	$ 9,618	$ 19,789
Temporarily Impaired Debt Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (334)	$ (154)
Obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Temporarily Impaired Debt Securities, Less Than 12 Months, Number of Securities | security	16	9
Temporarily Impaired Debt Securities, Less Than 12 Months, Fair Value	$ 129,180	$ 63,635
Temporarily Impaired Debt Securities, Less Than 12 Months, Unrealized Losses	$ (1,728)	$ (144)
Temporarily Impaired Debt Securities, 12 Months or More, Number of Securities | security	2	1
Temporarily Impaired Debt Securities, 12 Months or More, Fair Value	$ 10,993	$ 10,017
Temporarily Impaired Debt Securities, 12 Months or More, Unrealized Losses	$ (31)	$ (49)
Temporarily Impaired Debt Securities, Number of Securities | security	18	10
Temporarily Impaired Debt Securities, Fair Value, Total	$ 140,173	$ 73,652
Temporarily Impaired Debt Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (1,759)	$ (193)
Collateralized mortgage obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Temporarily Impaired Debt Securities, Less Than 12 Months, Number of Securities | security	10	7
Temporarily Impaired Debt Securities, Less Than 12 Months, Fair Value	$ 66,019	$ 47,465
Temporarily Impaired Debt Securities, Less Than 12 Months, Unrealized Losses	$ (1,067)	$ (248)
Temporarily Impaired Debt Securities, 12 Months or More, Number of Securities | security	7	7
Temporarily Impaired Debt Securities, 12 Months or More, Fair Value	$ 41,018	$ 45,809
Temporarily Impaired Debt Securities, 12 Months or More, Unrealized Losses	$ (1,883)	$ (1,073)
Temporarily Impaired Debt Securities, Number of Securities | security	17	14
Temporarily Impaired Debt Securities, Fair Value, Total	$ 107,037	$ 93,274
Temporarily Impaired Debt Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (2,950)	$ (1,321)
Residential mortgage-backed securities of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Temporarily Impaired Debt Securities, Less Than 12 Months, Number of Securities | security	3	1
Temporarily Impaired Debt Securities, Less Than 12 Months, Fair Value	$ 4,803	$ 2,333
Temporarily Impaired Debt Securities, Less Than 12 Months, Unrealized Losses	$ (131)	$ (10)
Temporarily Impaired Debt Securities, 12 Months or More, Number of Securities | security	2	2
Temporarily Impaired Debt Securities, 12 Months or More, Fair Value	$ 7,721	$ 8,638
Temporarily Impaired Debt Securities, 12 Months or More, Unrealized Losses	$ (398)	$ (203)
Temporarily Impaired Debt Securities, Number of Securities | security	5	3
Temporarily Impaired Debt Securities, Fair Value, Total	$ 12,524	$ 10,971
Temporarily Impaired Debt Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (529)	$ (213)
Commercial mortgage-backed securities of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Temporarily Impaired Debt Securities, Less Than 12 Months, Number of Securities | security	22	14
Temporarily Impaired Debt Securities, Less Than 12 Months, Fair Value	$ 199,634	$ 128,300
Temporarily Impaired Debt Securities, Less Than 12 Months, Unrealized Losses	$ (5,190)	$ (775)
Temporarily Impaired Debt Securities, 12 Months or More, Number of Securities | security	5	5
Temporarily Impaired Debt Securities, 12 Months or More, Fair Value	$ 47,494	$ 48,746
Temporarily Impaired Debt Securities, 12 Months or More, Unrealized Losses	$ (2,140)	$ (1,269)
Temporarily Impaired Debt Securities, Number of Securities | security	27	19
Temporarily Impaired Debt Securities, Fair Value, Total	$ 247,128	$ 177,046
Temporarily Impaired Debt Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (7,330)	$ (2,044)
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Temporarily Impaired Debt Securities, Less Than 12 Months, Number of Securities | security	5	2
Temporarily Impaired Debt Securities, Less Than 12 Months, Fair Value	$ 23,109	$ 10,330
Temporarily Impaired Debt Securities, Less Than 12 Months, Unrealized Losses	$ (48)	$ (42)
Temporarily Impaired Debt Securities, 12 Months or More, Number of Securities | security	0	0
Temporarily Impaired Debt Securities, 12 Months or More, Fair Value	$ 0	$ 0
Temporarily Impaired Debt Securities, 12 Months or More, Unrealized Losses	$ 0	$ 0
Temporarily Impaired Debt Securities, Number of Securities | security	5	2
Temporarily Impaired Debt Securities, Fair Value, Total	$ 23,109	$ 10,330
Temporarily Impaired Debt Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ (48)	$ (42)

Securities - Additional Informa

Securities - Additional Information (Details) $ in Thousands	Jun. 30, 2018USD ($)security	Jan. 01, 2018USD ($)	Dec. 31, 2017USD ($)security
Debt Securities, Available-for-sale [Line Items]
Number of debt securities in unrealized loss position | security	73		51
Securities pledged for regulatory and legal requirements	$ 231,000		$ 249,000
ASU No. 2016-01 | AOCI
Debt Securities, Available-for-sale [Line Items]
Reclassification of net unrealized gains on equity securities (from) AOCI to Retained Earnings		$ (900)	(862)	[1]
ASU No. 2016-01 | Retained Earnings
Debt Securities, Available-for-sale [Line Items]
Reclassification of net unrealized gains on equity securities (from) AOCI to Retained Earnings		$ 900	$ 862	[1]
[1]	Reclassification due to the adoption of ASU No. 2016-01.

Securities - Unrealized Gains (

Securities - Unrealized Gains (Losses) of Debt Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Total unrealized gains (losses) on debt securities available-for-sale, Gross Unrealized Gains	$ 2,858	$ 5,645
Total unrealized gains (losses) on debt securities available-for-sale, Gross Unrealized Losses	(12,950)	(3,967)
Total unrealized gains (losses) on debt securities available-for-sale, Net Unrealized Gains/(Losses)	(10,092)	1,678
Income tax (expense) benefit, Gross Unrealized Gains	(607)	(1,982)
Income tax (expense) benefit, Gross Unrealized Losses	2,750	1,393
Income tax (expense) benefit, Net Unrealized Gains/(Losses)	2,143	(589)
Net Unrealized Gains/(Losses), Net of Tax Included in Accumulated Other Comprehensive Income/(Loss), Gross Unrealized Gains	2,251	3,663
Net Unrealized Gains/(Losses), Net of Tax Included in Accumulated Other Comprehensive Income/(Loss), Gross Unrealized Losses	(10,200)	(2,574)
Net Unrealized Gains/(Losses), Net of Tax Included in Accumulated Other Comprehensive Income/(Loss), Net Unrealized Gains/(Losses)	$ (7,949)	$ 1,089

Securities - Contractual Maturi

Securities - Contractual Maturities of Debt Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Amortized Cost
Debt Securities, Available-for-Sale, Amortized Cost	$ 693,008
Fair Value
Debt Securities, Available-for-Sale, Fair Value	682,916	$ 693,147
Obligations of the U.S. Treasury, U.S. government corporations and agencies, and obligations of states and political subdivisions
Amortized Cost
Due in one year or less	33,878
Due after one year through five years	152,588
Due after five years through ten years	73,099
Due after ten years	28,692
Debt Securities Available-for-sale, Maturity, Amortized Cost	288,257
Fair Value
Due in one year or less	33,888
Due after one year through five years	152,374
Due after five years through ten years	72,961
Due after ten years	29,381
Debt Securities Available-for-sale, Maturity, Fair Value	288,604
Collateralized mortgage obligations of U.S. government corporations and agencies
Amortized Cost
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Amortized Cost	121,631
Debt Securities, Available-for-Sale, Amortized Cost	121,631	109,916
Fair Value
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Fair Value	118,742
Debt Securities, Available-for-Sale, Fair Value	118,742	108,688
Residential mortgage-backed securities of U.S. government corporations and agencies
Amortized Cost
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Amortized Cost	28,662
Debt Securities, Available-for-Sale, Amortized Cost	28,662	32,388
Fair Value
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Fair Value	28,442
Debt Securities, Available-for-Sale, Fair Value	28,442	32,854
Commercial mortgage-backed securities of U.S. government corporations and agencies
Amortized Cost
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Amortized Cost	254,458
Debt Securities, Available-for-Sale, Amortized Cost	254,458	244,018	[1]
Fair Value
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Fair Value	247,128
Debt Securities, Available-for-Sale, Fair Value	$ 247,128	$ 242,221	[1]
[1]	Includes a $5.9 million security purchase that was pending settlement as of December 31, 2017.

Securities - Unrealized Gains43

Securities - Unrealized Gains (Losses) on Marketable Securities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Net market gains/(losses) recognized	$ 230	$ 4,121	$ 282	$ 5,224
Less: Net gains/(losses) recognized for equity securities sold	0	3,617	0	3,987
Unrealized Gains/(Losses) on Equity Securities Still Held	$ 230	$ 504	$ 282	$ 1,237

Loans and Loans Held for Sale -

Loans and Loans Held for Sale - Additional Information (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018USD ($)loan	Jun. 30, 2017USD ($)loan	Jun. 30, 2018USD ($)loan	Jun. 30, 2017USD ($)loan	Dec. 31, 2017USD ($)	Mar. 31, 2018Property
Accounts, Notes, Loans and Financing Receivable [Line Items]
Change-off arising from participation loan agreement	$ 8,632	$ 5,822	$ 10,076	$ 8,763
Loans, net of unearned income	$ 5,400		$ 5,400		$ 5,200
Threshold period of satisfactory performance for troubled debt restructuring to be restored to accruing status			6 months
Number of troubled debt restructuring loans returned back to accruing status | loan	0	1	0	1
Number of commitments to lend additional funds on TDRs | loan	7		7
Commitments to lend additional funds on TDRs	$ 5,600		$ 5,600
Minimum period of loan payment defaults following restructure for TDRs to be in default			90 days
Number of defaulted troubled debt restructuring loans restructured within twelve months prior to defaulting | loan	0	0	0	0
Amount of defaulted troubled debt restructuring loans restructured within twelve months prior to defaulting		$ 2,000		$ 2,000
Land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Increase in other real estate			$ 2,500
Other real estate owned, number | Property						2
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of commercial loans in total portfolio loans	79.00%		79.00%		78.00%
Commercial loans	$ 4,544,006		$ 4,544,006		$ 4,503,594
Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Change-off arising from participation loan agreement	414	$ 370	872	$ 804
Commercial real estate and commercial construction | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial loans	$ 3,100,000		$ 3,100,000		$ 3,100,000
Combined percentage of commercial real estate and commercial construction in total commercial loans	68.00%		68.00%		68.00%
Combined percentage of commercial real estate and commercial construction in total portfolio loans	53.00%		53.00%		53.00%
Concentration risk percentage of commercial real estate and commercial construction			0.00%		0.00%
Maximum concentration of commercial real estate and commercial construction portfolio in loans (in excess of)	13.00%		13.00%		14.00%
Out of market exposure of combined portfolio (percent)	5.30%		5.30%		5.20%
Percentage of total loans out-of-state excluding contiguous states	2.80%		2.80%		2.80%
Vehicles and Equipment Liens | Other consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Change-off arising from participation loan agreement	$ 5,200		$ 5,200

Loans and Loans Held for Sale45

Loans and Loans Held for Sale - Composition of Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Composition of the loans
Portfolio loans, net of unearned income	$ 5,786,118	$ 5,761,449
Loans held for sale	3,801	4,485
Total Loans	5,789,919	5,765,934
Commercial real estate
Composition of the loans
Portfolio loans, net of unearned income		2,685,994
Total Loans	2,788,641	2,685,994
Commercial and industrial
Composition of the loans
Portfolio loans, net of unearned income		1,433,266
Total Loans	1,455,578	1,433,266
Commercial construction
Composition of the loans
Portfolio loans, net of unearned income		384,334
Total Loans	299,787	384,334
Residential mortgage
Composition of the loans
Total Loans	698,440	698,774
Home equity
Composition of the loans
Total Loans	471,622	487,326
Installment and other consumer
Composition of the loans
Total Loans	66,638	67,204
Consumer construction
Composition of the loans
Total Loans	5,412	4,551
Commercial
Composition of the loans
Portfolio loans, net of unearned income	4,544,006	4,503,594
Commercial | Commercial real estate
Composition of the loans
Portfolio loans, net of unearned income	2,788,641	2,685,994
Commercial | Commercial and industrial
Composition of the loans
Portfolio loans, net of unearned income	1,455,578	1,433,266
Commercial | Commercial construction
Composition of the loans
Portfolio loans, net of unearned income	299,787	384,334
Consumer
Composition of the loans
Portfolio loans, net of unearned income	1,242,112	1,257,855
Consumer | Residential mortgage
Composition of the loans
Portfolio loans, net of unearned income	698,440	698,774
Consumer | Home equity
Composition of the loans
Portfolio loans, net of unearned income	471,622	487,326
Consumer | Installment and other consumer
Composition of the loans
Portfolio loans, net of unearned income	66,638	67,204
Consumer | Consumer construction
Composition of the loans
Portfolio loans, net of unearned income	$ 5,412	$ 4,551

Loans and Loans Held for Sale46

Loans and Loans Held for Sale - Summary of Restructured Loans (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Financing Receivable, Modifications [Line Items]
Restructured loans	[1]	$ 5,155	$ 2,665	$ 11,685	$ 3,103
Commercial real estate
Financing Receivable, Modifications [Line Items]
Restructured loans	[1]	0	100	0	100
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Restructured loans	[1]	5,034	2,229	10,845	2,229
Commercial construction
Financing Receivable, Modifications [Line Items]
Restructured loans	[1]	0	0	0	0
Residential mortgage
Financing Receivable, Modifications [Line Items]
Restructured loans	[1]	41	33	196	33
Home equity
Financing Receivable, Modifications [Line Items]
Restructured loans	[1]	73	269	621	707
Installment and other consumer
Financing Receivable, Modifications [Line Items]
Restructured loans	[1]	$ 7	$ 34	23	$ 34
Performing TDRs
Financing Receivable, Modifications [Line Items]
Restructured loans				24,454		$ 14,901
Performing TDRs | Commercial real estate
Financing Receivable, Modifications [Line Items]
Restructured loans				2,136		2,579
Performing TDRs | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Restructured loans				14,149		3,946
Performing TDRs | Commercial construction
Financing Receivable, Modifications [Line Items]
Restructured loans				2,400		2,420
Performing TDRs | Residential mortgage
Financing Receivable, Modifications [Line Items]
Restructured loans				2,157		2,039
Performing TDRs | Home equity
Financing Receivable, Modifications [Line Items]
Restructured loans				3,569		3,885
Performing TDRs | Installment and other consumer
Financing Receivable, Modifications [Line Items]
Restructured loans				43		32
Nonperforming TDRs
Financing Receivable, Modifications [Line Items]
Restructured loans				7,395		11,150
Nonperforming TDRs | Commercial real estate
Financing Receivable, Modifications [Line Items]
Restructured loans				925		967
Nonperforming TDRs | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Restructured loans				2,599		3,197
Nonperforming TDRs | Commercial construction
Financing Receivable, Modifications [Line Items]
Restructured loans				410		2,413
Nonperforming TDRs | Residential mortgage
Financing Receivable, Modifications [Line Items]
Restructured loans				1,924		3,585
Nonperforming TDRs | Home equity
Financing Receivable, Modifications [Line Items]
Restructured loans				1,536		979
Nonperforming TDRs | Installment and other consumer
Financing Receivable, Modifications [Line Items]
Restructured loans				1		9
Total TDRs
Financing Receivable, Modifications [Line Items]
Restructured loans				31,849		26,051
Total TDRs | Commercial real estate
Financing Receivable, Modifications [Line Items]
Restructured loans				3,061		3,546
Total TDRs | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Restructured loans				16,748		7,143
Total TDRs | Commercial construction
Financing Receivable, Modifications [Line Items]
Restructured loans				2,810		4,833
Total TDRs | Residential mortgage
Financing Receivable, Modifications [Line Items]
Restructured loans				4,081		5,624
Total TDRs | Home equity
Financing Receivable, Modifications [Line Items]
Restructured loans				5,105		4,864
Total TDRs | Installment and other consumer
Financing Receivable, Modifications [Line Items]
Restructured loans				$ 44		$ 41
[1]	Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.

Loans and Loans Held for Sale47

Loans and Loans Held for Sale - Restructured Loans By Segment and Type of Concession (Details) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018USD ($)loan	Jun. 30, 2017USD ($)loan	Jun. 30, 2018USD ($)loan	Jun. 30, 2017USD ($)loan
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		10	11	31	18
Pre-Modification Outstanding Recorded Investment	[1]	$ 4,937	$ 2,670	$ 11,814	$ 3,112
Post-Modification Outstanding Recorded Investment	[1]	5,155	2,665	11,685	3,103
Total Difference in Recorded Investment		$ 218	$ (5)	$ (129)	$ (9)
Principal deferral
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		3	2	3	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 4,815	$ 529	$ 4,815	$ 529
Post-Modification Outstanding Recorded Investment	[1]	5,034	529	5,034	529
Total Difference in Recorded Investment		$ 219	$ 0	$ 219	$ 0
Maturity date extension and interest rate reduction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		2	2	2	3
Pre-Modification Outstanding Recorded Investment	[1]	$ 47	$ 1,800	$ 47	$ 1,973
Post-Modification Outstanding Recorded Investment	[1]	47	1,800	47	1,972
Total Difference in Recorded Investment		$ 0	$ 0	$ 0	$ (1)
Principal deferral and maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | loan				6	0
Pre-Modification Outstanding Recorded Investment	[1]			$ 5,355	$ 0
Post-Modification Outstanding Recorded Investment	[1]			5,229	0
Total Difference in Recorded Investment				$ (126)	$ 0
Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	[2]	5	6	18	12
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 75	$ 110	$ 829	$ 379
Post-Modification Outstanding Recorded Investment	[1],[2]	74	105	793	371
Total Difference in Recorded Investment	[2]	$ (1)	$ (5)	$ (36)	$ (8)
Maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	1	2	1
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 231	$ 768	$ 231
Post-Modification Outstanding Recorded Investment	[1]	0	231	582	231
Total Difference in Recorded Investment		$ 0	$ 0	$ (186)	$ 0
Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	1	0	1
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 100	$ 0	$ 100
Post-Modification Outstanding Recorded Investment	[1]	0	100	0	100
Total Difference in Recorded Investment		$ 0	$ 0	$ 0	$ 0
Commercial real estate | Principal deferral
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	1	0	1
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 100	$ 0	$ 100
Post-Modification Outstanding Recorded Investment	[1]	0	100	0	100
Total Difference in Recorded Investment		$ 0	$ 0	$ 0	$ 0
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		3	3	11	3
Pre-Modification Outstanding Recorded Investment	[1]	$ 4,815	$ 2,229	$ 10,938	$ 2,229
Post-Modification Outstanding Recorded Investment	[1]	5,034	2,229	10,845	2,229
Total Difference in Recorded Investment		$ 219	$ 0	$ (93)	$ 0
Commercial and industrial | Principal deferral
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		3	1	3	1
Pre-Modification Outstanding Recorded Investment	[1]	$ 4,815	$ 429	$ 4,815	$ 429
Post-Modification Outstanding Recorded Investment	[1]	5,034	429	5,034	429
Total Difference in Recorded Investment		$ 219	$ 0	$ 219	$ 0	[1]
Commercial and industrial | Maturity date extension and interest rate reduction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	2	0	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 1,800	$ 0	$ 1,800
Post-Modification Outstanding Recorded Investment	[1]	0	1,800	0	1,800
Total Difference in Recorded Investment		$ 0	$ 0	$ 0	$ 0
Commercial and industrial | Principal deferral and maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | loan				6	0
Pre-Modification Outstanding Recorded Investment	[1]			$ 5,355	$ 0
Post-Modification Outstanding Recorded Investment	[1]			5,229	0
Total Difference in Recorded Investment				$ (126)	$ 0	[1]
Commercial and industrial | Maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | loan				2	0
Pre-Modification Outstanding Recorded Investment	[1]			$ 768	$ 0
Post-Modification Outstanding Recorded Investment	[1]			582	0
Total Difference in Recorded Investment				$ (186)	$ 0
Commercial construction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	0	0	0
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 0	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	[1]	0	0	0	0
Total Difference in Recorded Investment		$ 0	$ 0	$ 0	$ 0
Residential mortgage
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		1	1	3	1
Pre-Modification Outstanding Recorded Investment	[1]	$ 41	$ 33	$ 199	$ 33
Post-Modification Outstanding Recorded Investment	[1]	41	33	196	33
Total Difference in Recorded Investment		$ 0	$ 0	$ (3)	$ 0
Residential mortgage | Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	[2]	1	1	3	1
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 41	$ 33	$ 199	$ 33
Post-Modification Outstanding Recorded Investment	[1],[2]	41	33	196	33
Total Difference in Recorded Investment	[2]	$ 0	$ 0	$ (3)	$ 0
Home equity
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		4	4	13	11
Pre-Modification Outstanding Recorded Investment	[1]	$ 73	$ 271	$ 652	$ 713
Post-Modification Outstanding Recorded Investment	[1]	73	269	621	707
Total Difference in Recorded Investment		$ 0	$ (2)	$ (31)	$ (6)
Home equity | Maturity date extension and interest rate reduction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		2	0	2	1
Pre-Modification Outstanding Recorded Investment	[1]	$ 47	$ 0	$ 47	$ 173
Post-Modification Outstanding Recorded Investment	[1]	47	0	47	172
Total Difference in Recorded Investment		$ 0	$ 0	$ 0	$ (1)
Home equity | Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	[2]	2	3	11	9
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 26	$ 40	$ 605	$ 309
Post-Modification Outstanding Recorded Investment	[1],[2]	26	38	574	304
Total Difference in Recorded Investment	[2]	$ 0	$ (2)	$ (31)	$ (5)
Home equity | Maturity date extension
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		0	1	0	1
Pre-Modification Outstanding Recorded Investment	[1]	$ 0	$ 231	$ 0	$ 231
Post-Modification Outstanding Recorded Investment	[1]	0	231	0	231
Total Difference in Recorded Investment		$ 0	$ 0	$ 0	$ 0
Installment and other consumer
Financing Receivable, Modifications [Line Items]
Number of Loans | loan		2	2	4	2
Pre-Modification Outstanding Recorded Investment	[1]	$ 8	$ 37	$ 25	$ 37
Post-Modification Outstanding Recorded Investment	[1]	7	34	23	34
Total Difference in Recorded Investment		$ (1)	$ (3)	$ (2)	$ (3)
Installment and other consumer | Chapter 7 bankruptcy
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	[2]	2	2	4	2
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 8	$ 37	$ 25	$ 37
Post-Modification Outstanding Recorded Investment	[1],[2]	7	34	23	34
Total Difference in Recorded Investment	[2]	$ (1)	$ (3)	$ (2)	$ (3)
[1]	Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.
[2]	Chapter 7 bankruptcy loans where the debt has been legally discharged through the bankruptcy court and not reaffirmed.

Loans and Loans Held for Sale48

Loans and Loans Held for Sale - Nonperforming Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Nonperforming Assets
Nonaccrual loans	$ 13,977	$ 12,788
Nonaccrual TDRs	7,395	11,150
Total Nonaccrual Loans	21,372	23,938
OREO	2,999	469
Total Nonperforming Assets	$ 24,371	$ 24,407

Allowance for Loan Losses - Age

Allowance for Loan Losses - Age Analysis of Past Due Loans Segregated by Class of Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	$ 5,759,858	$ 5,730,074
Non - performing	21,372	23,938
Past due	30,061	35,860
Total Loans	5,789,919	5,765,934
Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	2,781,239	2,681,395
Non - performing	4,617	3,468
Past due	7,402	4,599
Total Loans	2,788,641	2,685,994
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	1,450,174	1,426,754
Non - performing	4,853	5,646
Past due	5,404	6,512
Total Loans	1,455,578	1,433,266
Commercial construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	297,849	377,968
Non - performing	1,870	3,873
Past due	1,938	6,366
Total Loans	299,787	384,334
Residential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	689,751	687,195
Non - performing	6,112	7,165
Past due	8,689	11,579
Total Loans	698,440	698,774
Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	465,261	480,956
Non - performing	3,871	3,715
Past due	6,361	6,370
Total Loans	471,622	487,326
Installment and other consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	66,371	66,770
Non - performing	49	71
Past due	267	434
Total Loans	66,638	67,204
Consumer construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	5,412	4,551
Non - performing	0	0
Past due	0	0
Total Loans	5,412	4,551
Loans Held for Sale
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current	3,801	4,485
Non - performing	0	0
Past due	0	0
Total Loans	3,801	4,485
30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	6,496	9,123
30 to 59 Days Past Due | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	2,473	997
30 to 59 Days Past Due | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	432	420
30 to 59 Days Past Due | Commercial construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	68	2,473
30 to 59 Days Past Due | Residential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,445	2,975
30 to 59 Days Past Due | Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,906	2,065
30 to 59 Days Past Due | Installment and other consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	172	193
30 to 59 Days Past Due | Consumer construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	0
30 to 59 Days Past Due | Loans Held for Sale
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	0
60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	2,193	2,799
60 to 89 Days Past Due | Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	312	134
60 to 89 Days Past Due | Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	119	446
60 to 89 Days Past Due | Commercial construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	20
60 to 89 Days Past Due | Residential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	1,132	1,439
60 to 89 Days Past Due | Home equity
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	584	590
60 to 89 Days Past Due | Installment and other consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	46	170
60 to 89 Days Past Due | Consumer construction
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	0	0
60 to 89 Days Past Due | Loans Held for Sale
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due	$ 0	$ 0

Allowance for Loan Losses - Rec

Allowance for Loan Losses - Recorded Investment in Commercial Loan Classes by Internally Assigned Risk Ratings (Details) - Commercial - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 4,544,006	$ 4,503,594
Total percentage of recorded investment in commercial loan	100.00%	100.00%
Pass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 4,246,345	$ 4,302,762
Total percentage of recorded investment in commercial loan	93.40%	95.50%
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 132,877	$ 130,101
Total percentage of recorded investment in commercial loan	3.00%	2.90%
Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 164,784	$ 70,731
Total percentage of recorded investment in commercial loan	3.60%	1.60%
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 2,788,641	$ 2,685,994
Total percentage of recorded investment in commercial loan	100.00%	100.00%
Commercial real estate | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 2,636,581	$ 2,588,847
Total percentage of recorded investment in commercial loan	94.50%	96.40%
Commercial real estate | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 74,169	$ 66,436
Total percentage of recorded investment in commercial loan	2.70%	2.50%
Commercial real estate | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 77,891	$ 30,711
Total percentage of recorded investment in commercial loan	2.80%	1.10%
Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 1,455,578	$ 1,433,266
Total percentage of recorded investment in commercial loan	100.00%	100.00%
Commercial and industrial | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 1,337,331	$ 1,345,810
Total percentage of recorded investment in commercial loan	91.90%	93.90%
Commercial and industrial | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 50,142	$ 54,320
Total percentage of recorded investment in commercial loan	3.40%	3.80%
Commercial and industrial | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 68,105	$ 33,136
Total percentage of recorded investment in commercial loan	4.70%	2.30%
Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 299,787	$ 384,334
Total percentage of recorded investment in commercial loan	100.00%	100.00%
Commercial construction | Pass
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 272,433	$ 368,105
Total percentage of recorded investment in commercial loan	90.90%	95.80%
Commercial construction | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 8,566	$ 9,345
Total percentage of recorded investment in commercial loan	2.80%	2.40%
Commercial construction | Substandard
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 18,788	$ 6,884
Total percentage of recorded investment in commercial loan	6.30%	1.80%

Allowance for Loan Losses - Add

Allowance for Loan Losses - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans considered nonperforming (in days)			90 days
Threshold for evaluation for impairment of substandard and nonaccrual commercial loans	$ 500,000		$ 500,000
Change-off arising from participation loan agreement	8,632,000	$ 5,822,000	10,076,000	$ 8,763,000
Other consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Change-off arising from participation loan agreement	414,000	$ 370,000	872,000	$ 804,000
Other consumer | Vehicles and Equipment Liens
Financing Receivable, Allowance for Credit Losses [Line Items]
Change-off arising from participation loan agreement	5,200,000		5,200,000
Participating loans, total exposure	4,900,000		4,900,000
Participating loans, direct exposure	$ 950,000		$ 950,000

Allowance for Loan Losses - R52

Allowance for Loan Losses - Recorded Investment in Consumer Loan Classes by Performing and Nonperforming Status (Details) - Consumer - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 1,242,112	$ 1,257,855
Percentage of Total	100.00%	100.00%
Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 1,232,080	$ 1,246,904
Percentage of Total	99.20%	99.10%
Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 10,032	$ 10,951
Percentage of Total	0.80%	0.90%
Residential mortgage
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 698,440	$ 698,774
Percentage of Total	100.00%	100.00%
Residential mortgage | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 692,328	$ 691,609
Percentage of Total	99.10%	99.00%
Residential mortgage | Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 6,112	$ 7,165
Percentage of Total	0.90%	1.00%
Home equity
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 471,622	$ 487,326
Percentage of Total	100.00%	100.00%
Home equity | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 467,751	$ 483,611
Percentage of Total	99.20%	99.20%
Home equity | Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 3,871	$ 3,715
Percentage of Total	0.80%	0.80%
Installment and other consumer
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 66,638	$ 67,204
Percentage of Total	100.00%	100.00%
Installment and other consumer | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 66,589	$ 67,133
Percentage of Total	99.90%	99.90%
Installment and other consumer | Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 49	$ 71
Percentage of Total	0.10%	0.10%
Consumer construction
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 5,412	$ 4,551
Percentage of Total	100.00%	100.00%
Consumer construction | Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 5,412	$ 4,551
Percentage of Total	100.00%	100.00%
Consumer construction | Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and leases receivables, recorded investment	$ 0	$ 0
Percentage of Total	0.00%	0.00%

Allowance for Loan Losses - Inv

Allowance for Loan Losses - Investments in Loans Considered to be Impaired and Related Information on Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	$ 35		$ 35		$ 1,783
With a related allowance recorded, Unpaid Principal Balance	35		35		1,835
Impaired financing receivable, Related Allowance	35		35		77
Without a related allowance recorded, Recorded Investment	33,730		33,730		25,040
Without a related allowance, Unpaid Principal Balance	38,204		38,204		31,302
Impaired Financing Receivable, Recorded Investment, Total	33,765		33,765		26,823
Impaired Financing Receivable, Total Unpaid Principal Balance, Total	38,239		38,239		33,137
With a related allowance recorded, Average Recorded Investment	38	$ 863	25,092	$ 39,203
With a related allowance recorded, Interest Income Recognized	1	7	629	528
Without a related allowance recorded, Average Recorded Investment	24,605	40,112	40	680
Without a related allowance recorded, Interest Income Recognized	415	298	2	13
Impaired financing receivable, Average Recorded Investment, Total	24,643	40,975	25,132	39,883
Impaired financing Receivable, Interest Income Recognized, Total	416	305	631	541
Commercial real estate
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	0		0		0
With a related allowance recorded, Unpaid Principal Balance	0		0		0
Impaired financing receivable, Related Allowance	0		0		0
Without a related allowance recorded, Recorded Investment	3,555		3,555		3,546
Without a related allowance, Unpaid Principal Balance	3,828		3,828		3,811
Impaired Financing Receivable, Recorded Investment, Total	3,555		3,555		3,546
Impaired Financing Receivable, Total Unpaid Principal Balance, Total	3,828		3,828		3,811
With a related allowance recorded, Average Recorded Investment	0	0	3,712	7,028
With a related allowance recorded, Interest Income Recognized	0	0	85	70
Without a related allowance recorded, Average Recorded Investment	3,609	6,934	0	0
Without a related allowance recorded, Interest Income Recognized	54	35	0	0
Impaired financing receivable, Average Recorded Investment, Total	3,609	6,934	3,712	7,028
Impaired financing Receivable, Interest Income Recognized, Total	54	35	85	70
Commercial and industrial
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	0		0		1,735
With a related allowance recorded, Unpaid Principal Balance	0		0		1,787
Impaired financing receivable, Related Allowance	0		0		29
Without a related allowance recorded, Recorded Investment	17,539		17,539		5,549
Without a related allowance, Unpaid Principal Balance	19,281		19,281		7,980
Impaired Financing Receivable, Recorded Investment, Total	17,539		17,539		7,284
Impaired Financing Receivable, Total Unpaid Principal Balance, Total	19,281		19,281		9,767
With a related allowance recorded, Average Recorded Investment	0	813	7,796	16,382
With a related allowance recorded, Interest Income Recognized	0	6	218	124
Without a related allowance recorded, Average Recorded Investment	8,060	17,625	0	628
Without a related allowance recorded, Interest Income Recognized	210	95	0	11
Impaired financing receivable, Average Recorded Investment, Total	8,060	18,438	7,796	17,010
Impaired financing Receivable, Interest Income Recognized, Total	210	101	218	135
Commercial construction
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	0		0		0
With a related allowance recorded, Unpaid Principal Balance	0		0		0
Impaired financing receivable, Related Allowance	0		0		0
Without a related allowance recorded, Recorded Investment	3,441		3,441		5,464
Without a related allowance, Unpaid Principal Balance	4,950		4,950		8,132
Impaired Financing Receivable, Recorded Investment, Total	3,441		3,441		5,464
Impaired Financing Receivable, Total Unpaid Principal Balance, Total	4,950		4,950		8,132
With a related allowance recorded, Average Recorded Investment	0	0	3,445	4,267
With a related allowance recorded, Interest Income Recognized	0	0	73	79
Without a related allowance recorded, Average Recorded Investment	3,443	4,262	0	0
Without a related allowance recorded, Interest Income Recognized	33	42	0	0
Impaired financing receivable, Average Recorded Investment, Total	3,443	4,262	3,445	4,267
Impaired financing Receivable, Interest Income Recognized, Total	33	42	73	79
Consumer real estate
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	0		0		21
With a related allowance recorded, Unpaid Principal Balance	0		0		21
Impaired financing receivable, Related Allowance	0		0		21
Without a related allowance recorded, Recorded Investment	9,186		9,186		10,467
Without a related allowance, Unpaid Principal Balance	10,132		10,132		11,357
Impaired Financing Receivable, Recorded Investment, Total	9,186		9,186		10,488
Impaired Financing Receivable, Total Unpaid Principal Balance, Total	10,132		10,132		11,378
With a related allowance recorded, Average Recorded Investment	0	24	10,128	11,514
With a related allowance recorded, Interest Income Recognized	0	1	253	255
Without a related allowance recorded, Average Recorded Investment	9,483	11,280	0	25
Without a related allowance recorded, Interest Income Recognized	118	125	0	1
Impaired financing receivable, Average Recorded Investment, Total	9,483	11,304	10,128	11,539
Impaired financing Receivable, Interest Income Recognized, Total	118	126	253	256
Other consumer
Financing Receivable, Impaired [Line Items]
With a related allowance recorded, Recorded Investment	35		35		27
With a related allowance recorded, Unpaid Principal Balance	35		35		27
Impaired financing receivable, Related Allowance	35		35		27
Without a related allowance recorded, Recorded Investment	9		9		14
Without a related allowance, Unpaid Principal Balance	13		13		22
Impaired Financing Receivable, Recorded Investment, Total	44		44		41
Impaired Financing Receivable, Total Unpaid Principal Balance, Total	48		48		$ 49
With a related allowance recorded, Average Recorded Investment	38	26	11	12
With a related allowance recorded, Interest Income Recognized	1	0	0	0
Without a related allowance recorded, Average Recorded Investment	10	11	40	27
Without a related allowance recorded, Interest Income Recognized	0	1	2	1
Impaired financing receivable, Average Recorded Investment, Total	48	37	51	39
Impaired financing Receivable, Interest Income Recognized, Total	$ 1	$ 1	$ 2	$ 1

Allowance for Loan Losses - Sum

Allowance for Loan Losses - Summary of Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	$ 59,046	$ 55,816	$ 56,390	$ 52,775
Charge-offs	(8,632)	(5,822)	(10,076)	(8,763)
Recoveries	758	488	2,386	1,287
Net (Charge-offs)/ Recoveries	(7,874)	(5,334)	(7,690)	(7,476)
Provision for loan losses	9,345	4,869	11,817	10,052
Balance at End of Period	60,517	55,351	60,517	55,351
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	30,963	20,570	27,235	19,976
Charge-offs	(237)	(1,673)	(232)	(2,063)
Recoveries	185	155	228	233
Net (Charge-offs)/ Recoveries	(52)	(1,518)	(4)	(1,830)
Provision for loan losses	321	5,306	4,001	6,212
Balance at End of Period	31,232	24,358	31,232	24,358
Commercial and industrial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	10,472	13,244	8,966	10,810
Charge-offs	(7,392)	(2,682)	(8,222)	(3,396)
Recoveries	362	69	480	255
Net (Charge-offs)/ Recoveries	(7,030)	(2,613)	(7,742)	(3,141)
Provision for loan losses	7,432	(1,375)	9,650	1,587
Balance at End of Period	10,874	9,256	10,874	9,256
Commercial construction
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	10,721	14,102	13,167	13,999
Charge-offs	(321)	0	(321)	(644)
Recoveries	1	113	1,130	369
Net (Charge-offs)/ Recoveries	(320)	113	809	(275)
Provision for loan losses	1,275	(271)	(2,300)	220
Balance at End of Period	11,676	13,944	11,676	13,944
Consumer real estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	5,418	5,956	5,479	6,095
Charge-offs	(268)	(1,097)	(429)	(1,856)
Recoveries	85	76	323	179
Net (Charge-offs)/ Recoveries	(183)	(1,021)	(106)	(1,677)
Provision for loan losses	6	868	(132)	1,385
Balance at End of Period	5,241	5,803	5,241	5,803
Other consumer
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	1,472	1,944	1,543	1,895
Charge-offs	(414)	(370)	(872)	(804)
Recoveries	125	75	225	251
Net (Charge-offs)/ Recoveries	(289)	(295)	(647)	(553)
Provision for loan losses	311	341	598	648
Balance at End of Period	$ 1,494	$ 1,990	$ 1,494	$ 1,990

Allowance for Loan Losses - S55

Allowance for Loan Losses - Summary of Allowance for Loan Losses and Recorded Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	$ 35		$ 77
Allowance for Loan Losses, Collectively Evaluated for Impairment	60,482		56,313
Total Allowance for Loan Losses	60,517	$ 59,046	56,390	$ 55,351	$ 55,816	$ 52,775
Portfolio Loans, Individually Evaluated for Impairment	33,765		26,823
Portfolio Loans, Collectively Evaluated for Impairment	5,752,353		5,734,626
Total Portfolio Loans	5,786,118		5,761,449
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses, Collectively Evaluated for Impairment	31,232		27,235
Total Allowance for Loan Losses	31,232	30,963	27,235	24,358	20,570	19,976
Portfolio Loans, Individually Evaluated for Impairment	3,555		3,546
Portfolio Loans, Collectively Evaluated for Impairment	2,785,086		2,682,448
Total Portfolio Loans			2,685,994
Commercial and industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		29
Allowance for Loan Losses, Collectively Evaluated for Impairment	10,874		8,937
Total Allowance for Loan Losses	10,874	10,472	8,966	9,256	13,244	10,810
Portfolio Loans, Individually Evaluated for Impairment	17,539		7,284
Portfolio Loans, Collectively Evaluated for Impairment	1,438,039		1,425,982
Total Portfolio Loans			1,433,266
Commercial construction
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses, Collectively Evaluated for Impairment	11,676		13,167
Total Allowance for Loan Losses	11,676	10,721	13,167	13,944	14,102	13,999
Portfolio Loans, Individually Evaluated for Impairment	3,441		5,464
Portfolio Loans, Collectively Evaluated for Impairment	296,346		378,870
Total Portfolio Loans			384,334
Consumer real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		21
Allowance for Loan Losses, Collectively Evaluated for Impairment	5,241		5,458
Total Allowance for Loan Losses	5,241	5,418	5,479	5,803	5,956	6,095
Portfolio Loans, Individually Evaluated for Impairment	9,186		10,488
Portfolio Loans, Collectively Evaluated for Impairment	1,166,288		1,180,163
Total Portfolio Loans	1,175,474		1,190,651
Other consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	35		27
Allowance for Loan Losses, Collectively Evaluated for Impairment	1,459		1,516
Total Allowance for Loan Losses	1,494	$ 1,472	1,543	$ 1,990	$ 1,944	$ 1,895
Portfolio Loans, Individually Evaluated for Impairment	44		41
Portfolio Loans, Collectively Evaluated for Impairment	66,594		67,163
Total Portfolio Loans	$ 66,638		$ 67,204

Derivative Instruments and He56

Derivative Instruments and Hedging Activities - Additional Information (Details)	6 Months Ended
	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Period for commitments	60 days

Derivative Instruments and He57

Derivative Instruments and Hedging Activities - Value of Derivative Assets and Derivative Liabilities (Details) - Not Designated as Hedging Instruments - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Other Assets
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Assets)	$ 6,157	$ 3,074
Other Assets | Interest rate swap contracts—commercial loans
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Assets)	6,157	3,074
Notional amount, Derivatives (included in Other Assets)	246,494	263,841
Net collateral received/posted, Derivatives	2,560	0
Other Assets | Interest rate lock commitments—mortgage loans
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Assets)	398	226
Notional amount, Derivatives (included in Other Assets)	12,711	6,860
Other Assets | Forward sale contracts—mortgage loans
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Assets)	0	0
Notional amount, Derivatives (included in Other Assets)	0	0
Other Liabilities
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Liabilities)	6,223	3,055
Other Liabilities | Interest rate swap contracts—commercial loans
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Liabilities)	6,223	3,055
Notional amount, Derivatives (included in Other Liabilities)	246,494	263,841
Net collateral received/posted, Derivatives	0	1,448
Other Liabilities | Interest rate lock commitments—mortgage loans
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Liabilities)	0	0
Notional amount, Derivatives (included in Other Liabilities)	0	0
Other Liabilities | Forward sale contracts—mortgage loans
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Liabilities)	39	5
Notional amount, Derivatives (included in Other Liabilities)	$ 12,250	$ 6,580

Derivative Instruments and He58

Derivative Instruments and Hedging Activities - Schedule of Gross Amounts of Derivative Assets and Derivative Liabilities (Details) - Not Designated as Hedging Instruments - USD ($) $ in Thousands		Jun. 30, 2018	Dec. 31, 2017
Other Assets
Derivatives (included in Other Assets)
Gross amounts recognized		$ 7,258	$ 4,974
Gross amounts offset		(1,101)	(1,900)
Net Amounts Presented in the Consolidated Balance Sheets		6,157	3,074
Gross amounts not offset	[1]	(2,560)	0
Net Amount		3,597	3,074
Other Liabilities
Derivatives (included in Other Liabilities)
Gross amounts recognized		7,324	4,955
Gross amounts offset		(1,101)	(1,900)
Net Amounts Presented in the Consolidated Balance Sheets		6,223	3,055
Gross amounts not offset	[1]	0	(1,448)
Net Amount		$ 6,223	$ 1,607
[1]	Amounts represent received/posted collateral.

Derivative Instruments and He59

Derivative Instruments and Hedging Activities - Amount of Gain or Loss Recognized in Income on Derivatives (Details) - Not Designated as Hedging Instruments - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives (Loss)/Gain	$ (88)	$ 55	$ 54	$ 276
Interest rate swap contracts—commercial loans
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives (Loss)/Gain	(201)	(8)	(85)	16
Interest rate lock commitments—mortgage loans
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives (Loss)/Gain	128	(13)	172	220
Forward sale contracts—mortgage loans
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives (Loss)/Gain	$ (15)	$ 76	$ (33)	$ 40

Borrowings - Additional Informa

Borrowings - Additional Information (Details) - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Long Term And Short Term Debt [Line Items]
Total long-term debt outstanding at a fixed rate	$ 7,900,000
Total long-term debt outstanding at a variable rate	38,100,000
Federal Home Loan Bank Advance
Long Term And Short Term Debt [Line Items]
Total borrowings	646,000,000	$ 587,000,000
Short-term borrowings	600,000,000
Long-term borrowings	46,100,000
Maximum borrowing capacity	2,500,000,000
Borrowing capacity utilized	790,000,000
Letter of credit to collateralize public funds	144,000,000
Remaining borrowing capacity	1,700,000,000
Mortgage Backed Securities
Long Term And Short Term Debt [Line Items]
Amortized cost of securities pledged as collateral	51,400,000	57,500,000
Carrying value of securities pledged as collateral	$ 49,900,000	$ 56,800,000

Borrowings - Summary of Informa

Borrowings - Summary of Information Pertaining to Borrowings (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Long Term And Short Term Debt [Line Items]
Short-term borrowings, Balance	$ 644,724	$ 590,161
Long-term borrowings, Balance	91,681	92,920
Total Borrowings, Balance	$ 736,405	$ 683,081
Short-term borrowings, Weighted Average Rate	2.04%	1.38%
Long-term borrowings, Weighted Average Rate	3.55%	2.81%
Total Borrowings, Weighted Average Rate	2.23%	1.57%
Securities sold under repurchase agreements
Long Term And Short Term Debt [Line Items]
Short-term borrowings, Balance	$ 44,724	$ 50,161
Short-term borrowings, Weighted Average Rate	0.46%	0.39%
Short-term borrowings
Long Term And Short Term Debt [Line Items]
Short-term borrowings, Balance	$ 600,000	$ 540,000
Short-term borrowings, Weighted Average Rate	2.16%	1.47%
Long-term borrowings
Long Term And Short Term Debt [Line Items]
Long-term borrowings, Balance	$ 46,062	$ 47,301
Long-term borrowings, Weighted Average Rate	2.31%	1.88%
Junior subordinated debt securities
Long Term And Short Term Debt [Line Items]
Long-term borrowings, Balance	$ 45,619	$ 45,619
Long-term borrowings, Weighted Average Rate	4.80%	3.78%

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Commitments to extend credit
Other Commitments [Line Items]
Allowance for unfunded commitments	$ 2.1	$ 2.2

Commitments and Contingencies63

Commitments and Contingencies - Commitments and Letters of Credit (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Other Commitments [Line Items]
Commitments and letters of credit	$ 1,494,409	$ 1,501,346
Commitments to extend credit
Other Commitments [Line Items]
Commitments and letters of credit	1,413,700	1,420,428
Standby letters of credit
Other Commitments [Line Items]
Commitments and letters of credit	$ 80,709	$ 80,918

Other Comprehensive Income (Det

Other Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Pre-Tax Amount
Other Comprehensive (Loss)/Income, Before tax		$ (1,594)	$ (406)	$ (10,447)	$ 1,426
Tax (Expense) Benefit
Other Comprehensive (Loss)/Income, Tax		338	144	2,218	(500)
Net of Tax Amount
Other Comprehensive (Loss)/Income		(1,256)	(262)	(8,229)	926
Accumulated Net Investment Gain (Loss) Attributable to Parent
Pre-Tax Amount
Change in net unrealized gains/(losses) on debt securities available-for-sale	[1]	(2,296)	2,672	(11,770)	4,335
Reclassification adjustment for net (gains)/losses on securities available-for-sale included in net income	[2]	0	(3,617)	0	(3,987)
Tax (Expense) Benefit
Change in net unrealized gains/(losses) on debt securities available-for-sale	[1]	487	(938)	2,499	(1,523)
Reclassification adjustment for net (gains)/losses on securities available-for-sale included in net income	[2]	0	1,270	0	1,400
Net of Tax Amount
Change in net unrealized gains/(losses) on debt securities available-for-sale	[1]	(1,809)	1,734	(9,271)	2,812
Reclassification adjustment for net (gains)/losses on securities available-for-sale included in net income	[2]	0	(2,347)	0	(2,587)
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent
Pre-Tax Amount
Other Comprehensive (Loss)/Income, Before tax		702	539	1,323	1,078
Tax (Expense) Benefit
Other Comprehensive (Loss)/Income, Tax		(149)	(188)	(281)	(377)
Net of Tax Amount
Other Comprehensive (Loss)/Income		$ 553	$ 351	$ 1,042	$ 701
[1]	Due to the adoption of ASU No. 2016-01, net unrealized gains on marketable equity securities were reclassified from Accumulated Other Comprehensive Income to Retained Earnings during the three months ended March 31, 2018. The prior period data was not restated; as such, the change in unrealized gains on marketable securities is combined with the change in net unrealized gains on debit securities for the period ended June 30, 2017.
[2]	Reclassification adjustments are comprised of realized security gains or losses. The realized gains or losses have been reclassified out of accumulated other comprehensive income/(loss) and have affected certain lines in the Consolidated Statements of Comprehensive Income as follows; the pre-tax amount is included in securities gains/losses-net, the tax expense amount is included in the provision for income taxes and the net of tax amount is included in net income.

Employee Benefits - Additional

Employee Benefits - Additional Information (Details) - USD ($)	6 Months Ended	29 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Retirement Benefits [Abstract]
Service costs included in net periodic pension expense		$ 0
Expected long-term rate of return on plan assets	7.50%

Employee Benefits - Components

Employee Benefits - Components of Net Periodic Pension Cost and Other Changes in Plan Assets and Benefit (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Components of Net Periodic Pension Cost
Interest cost on projected benefit obligation	$ 967	$ 1,025	$ 1,934	$ 2,050
Expected return on plan assets	(1,567)	(1,582)	(3,134)	(3,164)
Amortization of prior service credit	545	475	1,089	949
Net Periodic Pension Expense	$ (55)	$ (82)	$ (111)	$ (165)

Qualified Affordable Housing 67

Qualified Affordable Housing Projects (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Investments in Affordable Housing Projects [Abstract]
Investment in qualified affordable housing projects	$ 7.3		$ 7.3		$ 8.7
Amortization expense included in noninterest expense	0.7	$ 0.8	1.4	$ 1.6
Tax credits	$ 0.8	$ 0.9	$ 1.5	$ 1.7

Sale of a Majority Interest o68

Sale of a Majority Interest of Insurance Business (Details) - USD ($) $ in Thousands	Jan. 01, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale of a majority interest of insurance business		$ 0	$ 0	$ 1,873	$ 0
New Partnership
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Equity method investment, ownership percentage	30.00%
Subsidiaries | S&T Evergreen Insurance LLC
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of ownership in subsidiary sold	70.00%
Gain on sale of a majority interest of insurance business	$ 1,900

Share Repurchase Plan (Details)

Share Repurchase Plan (Details)	Mar. 19, 2018USD ($)
Equity [Abstract]
Stock repurchase program, authorized amount	$ 50,000,000