Enterprise Bancorp (EBTC) 10-Q 7 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	May 01, 2019
Document and Entity Information [Abstract]
Entity Registrant Name	ENTERPRISE BANCORP INC /MA/
Entity Central Index Key	0001018399
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		11,794,979
Entity Small Business	false
Entity Emerging Growth Company	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands		Mar. 31, 2019	Dec. 31, 2018
Cash and cash equivalents:
Cash and due from banks		$ 35,715	$ 43,865
Interest-earning deposits		99,547	19,255
Total cash and cash equivalents		135,262	63,120
Investments:
Debt securities at fair value		458,765	431,473
Equity securities at fair value		2,049	1,448
Total investment securities at fair value		460,814	432,921
Federal Home Loan Bank (FHLB) stock		1,491	5,357
Loans held for sale		332	701
Loans, less allowance for loan losses of $33,729 at March 31, 2019 and $33,849 at December 31, 2018		2,350,908	2,353,657
Premises and equipment, net		38,446	37,588
Lease right-of-use asset		18,851	0
Accrued interest receivable		12,619	11,462
Deferred income taxes, net		10,632	11,747
Bank-owned life insurance		30,300	30,138
Prepaid income taxes		0	732
Prepaid expenses and other assets		8,470	11,279
Goodwill		5,656	5,656
Total assets		3,073,781	2,964,358
Deposits:
Customer deposits		2,725,667	2,507,999
Brokered deposits	[1]	30,499	56,783
Total deposits		2,756,166	2,564,782
Borrowed funds		488	100,492
Subordinated debt		14,863	14,860
Lease liability		17,871	0
Accrued expenses and other liabilities		16,431	27,948
Income taxes payable		809	0
Accrued interest payable		1,092	979
Total liabilities		2,807,720	2,709,061
Commitments and Contingencies
Stockholders' Equity
Preferred stock, $0.01 par value per share; 1,000,000 shares authorized; no shares issued		0	0
Common stock, $0.01 par value per share; 40,000,000 shares authorized; 11,798,114 shares issued and outstanding at March 31, 2019 and 11,708,218 shares issued and outstanding at December 31, 2018		118	117
Additional paid-in capital		92,089	91,281
Retained earnings		172,004	165,183
Accumulated other comprehensive income (loss)		1,850	(1,284)
Total stockholders' equity		266,061	255,297
Total liabilities and stockholders' equity		$ 3,073,781	$ 2,964,358
[1]	Brokered CDs which are $250,000 and under.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for loan losses	$ 33,729	$ 33,849	$ 34,524	$ 32,915
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	11,798,114	11,708,218
Common Stock, Shares, Outstanding	11,798,114	11,708,218
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Interest and dividend income:
Loans and loans held for sale	$ 29,616	$ 26,150
Investment securities	3,222	2,487
Other interest-earning assets	459	134
Total interest and dividend income	33,297	28,771
Interest expense:
Deposits	4,706	2,236
Borrowed funds	279	292
Subordinated debt	228	228
Total interest expense	5,213	2,756
Net interest income	28,084	26,015
Provision for loan losses	(400)	1,600
Net interest income after provision for loan losses	28,484	24,415
Non-interest income:
Wealth management fees	1,299	1,408
Deposit and interchange fees	1,564	1,489
Income on bank-owned life insurance, net	162	168
Net (losses) gains on sales of investment securities	(1)	1
Net gains on sales of loans	36	84
Other income	776	641
Total non-interest income	3,836	3,791
Non-interest expense:
Salaries and employee benefits	13,471	12,108
Occupancy and equipment expenses	2,212	2,157
Technology and telecommunications expenses	1,726	1,553
Advertising and public relations expenses	715	720
Audit, legal and other professional fees	423	507
Deposit insurance premiums	351	500
Supplies and postage expenses	224	232
Other operating expenses	1,728	1,670
Total non-interest expense	20,850	19,447
Income before income taxes	11,470	8,759
Provision for income taxes	2,774	1,934
Net income	$ 8,696	$ 6,825
Basic earnings per share	$ 0.74	$ 0.59
Diluted earnings per share	$ 0.74	$ 0.58
Basic weighted average common shares outstanding	11,730,482	11,628,587
Diluted weighted average common shares outstanding	11,783,405	11,700,854

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 8,696	$ 6,825
Other comprehensive income (loss), net of taxes:
Gross unrealized holding gains (losses) on investments arising during the period	4,040	(8,069)
Income tax (expense) benefit	(907)	1,805
Net unrealized holding gains (losses), net of tax	3,133	(6,264)
Less: reclassification adjustment for net (losses) gains included in net income
Net realized (losses) gains on sales of securities during the period	(1)	1
Income tax benefit (expense)	0	(1)
Reclassification adjustment for (losses) gains realized, net of tax	(1)	0
Total other comprehensive income (loss), net	3,134	(6,264)
Comprehensive income	$ 11,830	$ 561

Consolidated Statement of Chang

Consolidated Statement of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated other comprehensive (loss)/income, net
Balance, beginning at Dec. 31, 2017	$ 231,810	$ 116	$ 88,205	$ 143,073	$ 416
Balance, beginning, shares, outstanding at Dec. 31, 2017		11,609,853
Increase (Decrease) in Stockholders' Equity
Net income	6,825			6,825
Other comprehensive income (loss), net	(6,264)				(6,264)
Common stock dividend paid	(1,686)			(1,686)
Common stock issued under dividend reinvestment plan, shares		12,765
Common stock issued under dividend reinvestment plan	397	$ 0	397
Common stock issued, shares, other		1,138
Common stock issued, other	38	$ 0	38
Stock-based compensation, shares		51,488
Stock-based compensation	591	$ 1	590
Net settlement for employee taxes on restricted stock and options, shares		(7,561)
Net settlement for employee taxes on restricted stock and options	(286)	$ 0	(286)
Stock options exercised, net, shares		15,231
Stock options exercised, net	215	$ 0	215
Balance, ending at Mar. 31, 2018	231,640	$ 117	89,159	148,212	(5,848)
Balance, ending, shares, outstanding at Mar. 31, 2018		11,682,914
Balance, beginning at Dec. 31, 2018	$ 255,297	$ 117	91,281	165,183	(1,284)
Balance, beginning, shares, outstanding at Dec. 31, 2018	11,708,218	11,708,218
Increase (Decrease) in Stockholders' Equity
Net income	$ 8,696			8,696
Other comprehensive income (loss), net	3,134				3,134
Common stock dividend paid	(1,875)			(1,875)
Common stock issued under dividend reinvestment plan, shares		9,341
Common stock issued under dividend reinvestment plan	298	$ 0	298
Common stock issued, shares, other		264
Common stock issued, other	8	$ 0	8
Stock-based compensation, shares		62,523
Stock-based compensation	599	$ 1	598
Net settlement for employee taxes on restricted stock and options, shares		(2,741)
Net settlement for employee taxes on restricted stock and options	(240)	$ 0	(240)
Stock options exercised, net, shares		20,509
Stock options exercised, net	144	$ 0	144
Balance, ending at Mar. 31, 2019	$ 266,061	$ 118	$ 92,089	$ 172,004	$ 1,850
Balance, ending, shares, outstanding at Mar. 31, 2019	11,798,114	11,798,114

Consolidated Statement of Cha_2

Consolidated Statement of Changes in Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Stockholders' Equity [Abstract]
Common stock dividend paid, per share	$ 0.16	$ 0.145

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Cash flows from operating activities:
Net income	$ 8,696	$ 6,825
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	(400)	1,600
Depreciation and amortization	1,476	1,740
Stock-based compensation expense	426	385
Income on bank-owned life insurance, net	(162)	(168)
Net losses (gains) on sales of investment securities	1	(1)
Mortgage loans originated for sale	(1,443)	(3,536)
Proceeds from mortgage loans sold	1,848	3,828
Net gains on sales of loans	(36)	(84)
Net fair value (gain) loss on equity securities	(186)	5
Changes in:
Increase in other assets	(902)	(1,952)
Decrease in other liabilities	(3,355)	(2,415)
Net cash provided by operating activities	5,963	6,227
Cash flows from investing activities:
Proceeds from sales of investment securities	3,648	12,705
Net proceeds from sales of FHLB capital stock	3,866	2,845
Proceeds from maturities, calls and pay-downs of investment securities	7,228	6,347
Purchase of investment securities	(39,203)	(44,126)
Net decrease (increase) in loans	2,894	(20,260)
Additions to premises and equipment, net	(1,969)	(1,371)
Net cash used in investing activities	(23,536)	(43,860)
Cash flows from financing activities:
Net increase in deposits	191,384	130,027
Net decrease in borrowed funds	(100,004)	(89,000)
Cash dividends paid	(1,875)	(1,686)
Proceeds from issuance of common stock, net of expenses	306	435
Net settlement for employee taxes on restricted stock and options	(240)	(286)
Proceeds from stock option exercises	144	215
Net cash provided by financing activities	89,715	39,705
Net increase in cash and cash equivalents	72,142	2,072
Cash and cash equivalents at beginning of period	63,120	54,806	$ 54,806
Cash and cash equivalents at end of period	$ 135,262	$ 56,878	$ 63,120

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies (a) Organization of the Company and Basis of Presentation The accompanying unaudited consolidated interim financial statements and these notes should be read in conjunction with the December 31, 2018 audited consolidated financial statements and notes thereto contained in the 2018 Annual Report on Form 10-K of Enterprise Bancorp, Inc. as filed with the Securities and Exchange Commission (the "SEC") on March 13, 2019 (the " 2018 Annual Report on Form 10-K"). The accompanying unaudited consolidated interim financial statements of Enterprise Bancorp, Inc. (the "Company," "Enterprise," "we," or "our"), a Massachusetts corporation, include the accounts of the Company and its wholly owned subsidiary, Enterprise Bank and Trust Company, commonly referred to as Enterprise Bank (the "Bank"). The Bank is a Massachusetts trust company and state chartered commercial bank organized in 1989. Substantially all of the Company's operations are conducted through the Bank and its subsidiaries. The Company has not materially changed its accounting policies from those disclosed in its 2018 Annual Report on Form 10-K. See Item (f) "Recent Accounting Pronouncements" under the subheading "Accounting pronouncements adopted by the Company" below in this Note 1. The Bank's subsidiaries Enterprise Insurance Services, LLC and Enterprise Wealth Services, LLC, both organized under the laws of the State of Delaware, engage in insurance sales activities and offer non-deposit investment products and services, respectively. In addition, the Bank has the following subsidiaries that are incorporated in the Commonwealth of Massachusetts and classified as security corporations in accordance with applicable Massachusetts General Laws: Enterprise Security Corporation; Enterprise Security Corporation II; and Enterprise Security Corporation III. The security corporations, which hold various types of qualifying securities, are limited to conducting securities investment activities that the Bank itself would be allowed to conduct under applicable laws. The Company's headquarters and the Bank's main office are located at 222 Merrimack Street in Lowell, Massachusetts. At March 31, 2019 , the Company had 24 full service branch banking offices serving the Greater Merrimack Valley, Nashoba Valley and North Central regions of Massachusetts and Southern New Hampshire (Southern Hillsborough and Rockingham counties). Through the Bank and its subsidiaries, the Company offers a range of commercial, residential and consumer loan products, deposit products and cash management services, electronic and digital banking options, and insurance services. The Company also provides a range of wealth management, wealth services and trust services delivered via two channels, Enterprise Wealth Management and Enterprise Wealth Services. The services offered through the Bank and its subsidiaries are managed as one strategic unit and represent the Company's only reportable operating segment. The Federal Deposit Insurance Corporation (the "FDIC") and the Massachusetts Division of Banks (the "Division") have regulatory authority over the Bank. The Bank is also subject to certain regulatory requirements of the Board of Governors of the Federal Reserve System (the "Federal Reserve Board") and, with respect to its New Hampshire branch operations, the New Hampshire Banking Department. The business and operations of the Company are subject to the regulatory oversight of the Federal Reserve Board. The Division also retains supervisory jurisdiction over the Company. The accompanying unaudited consolidated interim financial statements and notes thereto have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and the instructions for SEC Form 10-Q through the rules and interpretive releases of the SEC under federal securities law. In the opinion of management, the accompanying unaudited consolidated interim financial statements reflect all necessary adjustments consisting of normal recurring accruals for a fair presentation. All significant intercompany balances and transactions have been eliminated in the accompanying unaudited consolidated interim financial statements. Certain previous years' amounts in the audited consolidated financial statements, and notes thereto, have been reclassified to conform to the current year's presentation. Interim results are not necessarily indicative of results to be expected for the entire year, or any future period. The Company has evaluated subsequent events and transactions from March 31, 2019 through the date this Quarterly Report on Form 10-Q (this "Form 10-Q") was filed with the SEC for potential recognition or disclosure as required by GAAP and determined that there were no material subsequent events requiring recognition or disclosure. (b) Uses of Estimates In preparing the unaudited consolidated interim financial statements in conformity with GAAP, management is required to exercise judgment in determining many of the methodologies, assumptions and estimates to be utilized. These assumptions and estimates affect the reported values of assets and liabilities as of the balance sheet dates and income and expenses for the period then ended. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates should the assumptions and estimates used be incorrect or change over time due to changes in circumstances. Changes in those estimates resulting from continuing changes in the economic environment and other factors will be reflected in the consolidated financial statements and results of operations in future periods. As discussed in the Company's 2018 Annual Report on Form 10-K, the three most significant areas in which management applies critical assumptions and estimates are: the estimates of the allowance for loan losses, impairment review of investment securities, and the impairment review of goodwill. Refer to Note 1, "Summary of Significant Accounting Policies," to the Company's audited consolidated financial statements included in the Company's 2018 Annual Report on Form 10-K for accounting policies related to these significant estimates. The Company has not changed its significant accounting policies from those disclosed in its 2018 Annual Report on Form 10-K. (c) Restricted Cash and Investments Certain of the Company's derivative agreements contain provisions for collateral to be posted if the derivative exposure exceeds a threshold amount. When the Company has pledged cash as collateral for this purpose, the cash is carried as restricted cash within "Interest-earning Deposits." See Note 8, "Derivatives and Hedging Activities," to the Company's unaudited consolidated interim financial statements below for more information about the Company's collateral related to its derivatives. The Bank is also required by the Federal Reserve Bank of Boston ("FRB") to maintain in reserves certain amounts of vault cash and/or deposits with the FRB. The average daily cash balance on hand for reserve requirements included in "Cash and Due from Banks" was approximately $2.9 million , based on the two-week computation period encompassing March 31, 2019 . As a member of the FHLB, the Company is required to purchase certain levels of FHLB capital stock at par value in association with outstanding advances from the FHLB. From time-to-time, the FHLB may initiate the repurchase, at par value, of "excess" levels of its capital stock held by member banks. This stock is classified as a restricted investment and is carried at cost, which management believes approximates fair value. FHLB stock represents the only restricted investment held by the Company. Management regularly reviews its holdings of FHLB stock for other-than-temporary-impairment ("OTTI"). Based on management's periodic review, the Company has not recorded any OTTI charges on this investment to date. If it was determined that a write-down of FHLB stock was required, impairment would be recognized through a charge to earnings. See Note 2, "Investment Securities," to the Company's unaudited consolidated interim financial statements below for additional information on management's OTTI review. (d) Revenue Recognition-Accounting Standard Codification ("ASC") Topic 606 While the majority of the Company's revenue is generated from contracts with customers, our primary sources of revenue, interest and dividend income (primarily loan interest income), are outside of the scope of ASC 606, "Revenue from Contracts with Customers-Topic 606," and are accounted for under other ASC topics. The core principles of this standard require an entity to recognize revenue to depict the transfer of goods and services to customers as performance obligations are satisfied. The primary areas of income within the scope of ASC 606, which are also the first two lines of non-interest income on the Company's consolidated statements of income, are discussed below. Wealth management fees consist of income generated through Enterprise Wealth Management and Enterprise Wealth Services. Enterprise Wealth Management income is primarily generated by managing customers' financial assets. Revenue is recognized as our performance obligation is completed each month. Enterprise Wealth Services revenue is generated through a third-party arrangement to refer, manage and service customers. For new sales and referrals along with transactional type charges, the performance obligation is based on a point in time and the payment is received and revenue is recognized in the same month as the revenue-generating activity. For managing and servicing customers, revenue is recognized when our performance obligation is completed each month. Deposit and interchange fees are comprised of deposit account related charges and income generated from electronic payment interchanges. Deposit account charges consist of certain transactional analysis fees net of earning balance credits, monthly account service fees, and transactional fees such as overdraft fees. Analysis and monthly services fees are recognized over the period the service is performed. For transactional fees, the performance obligation and the revenue are recognized at a point of time and payment is typically received as the service is rendered. Interchange income is generated primarily from retail debit card transactions processed through the card payment network. The performance obligation and the revenue are recognized when the service is performed. The following non-interest income components are not subject to ASC 606: income on bank-owned life insurance ("BOLI"), net gains/losses on sales of investment securities, and net gains on sales of loans, and are covered under other ASC topics. The remaining revenue items in non-interest income are not material. See also Note 1, "Summary of Significant Accounting Policies," to the Company's audited consolidated financial statements in the Company's 2018 Annual Report on Form 10-K for additional accounting policies on revenue recognition related to income generated on investments, gains and losses on debt security sales, net gains on loans held for sale, and loans. (e) Income Taxes The Company and its subsidiaries file income tax returns in the U.S. federal jurisdiction and in the states of Massachusetts and New Hampshire within the directives of the respective enacted tax legislation. The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the future tax expense or benefit attributable to differences between the financial statement carrying amounts and the tax basis of assets and liabilities. The deferred tax assets and liabilities are reflected at currently-enacted income tax rates applicable to the period in which the deferred tax assets or liabilities are expected to be realized or settled. As changes in tax laws or rates are enacted, deferred tax assets and liabilities will be adjusted accordingly through the provision for income taxes in the period that includes the enactment date. The Company's policy is to classify interest resulting from underpayment of income taxes as income tax expense in the first period the interest would begin accruing according to the provisions of the relevant tax law. The Company classifies penalties resulting from underpayment of income taxes as income tax expense in the period for which the Company claims or expects to claim an uncertain tax position or in the period in which the Company's judgment changes regarding an uncertain tax position. The income tax provisions will differ from the expense that would result from applying the federal statutory rate to income before taxes, due primarily to the impact of state tax expense, tax-exempt interest from certain investment securities, loans and BOLI and tax benefits from equity compensation deductions. The Company did not have any unrecognized tax benefits accrued as income tax liabilities or receivables or as deferred tax items at March 31, 2019 . The Company is subject to U.S. federal and state income tax examinations by taxing authorities for the 2015 through 2018 tax years. (f) Recent Accounting Pronouncements Accounting pronouncements adopted by the Company In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, "Leases (Topic 842)," which supersedes previous leasing guidance in Topic 840. Under the new guidance, as amended, lessees are required to recognize lease (right-of-use or "ROU") assets and lease liabilities on the balance sheet for all leases with terms longer than 12 months. The Company adopted and is applying the new lease standard on leases existing on or after January 1, 2019. For the Company, this ASU primarily impacted operating leases on our facilities, mainly branch leases, and as a result the Company recorded, on its consolidated balance sheet a lease liability of $18.0 million and ROU asset of $19.0 million on January 1, 2019 related to these leases. The lease liability represents the present value of the future lease payments. The ROU asset includes the lease liability, lease prepayments and indirect costs, less accrued lease liabilities. See Note 5, "Leases," to the Company's unaudited consolidated interim financial statements, contained below, for further information regarding the Company's operating leases and associated expenses which are included in occupancy and equipment expenses on the Company's consolidated statement of income. In August 2017, the FASB issued ASU No. 2017-12, "Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities." The objective of the ASU is to better align hedge accounting with an organization's risk management activities in the financial statements. In addition, the ASU simplifies the application of hedge accounting guidance in areas where practice issues exist. The amendments expand the strategies that qualify for hedge accounting, change how many hedging relationships are presented in the financial statements and simplify the application of hedge accounting in certain situations, reducing the operational complexities associated with certain existing strategies. New or modified disclosures are required, primarily for fair value and cash flow hedges. For public business entities, the ASU was effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. The Company currently does not hold any instruments that meet hedge accounting requirements and therefore the adoption of this ASU, in January 2019, did not have an impact on the Company's unaudited consolidated interim financial statements, results of operations or disclosures, however, the Company may utilize hedging strategies in the future. In June 2018, the FASB issued ASU No. 2018-07, "Compensation-Stock-Based Compensation (Topic 718): Improvements to Nonemployee Shared-Based Payment Accounting." The amendments in the ASU expand the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees except for share-based payments used to effectively provide (1) financing to the issuer or (2) awards granted in conjunction with selling goods or services to customers as part of a contract. Additionally, Topic 718 has been updated for specific guidance on inputs to an option pricing model and the attribution of cost (that is, the period of time over which share-based payment awards vest and the pattern of cost recognition over that period). The amendments in this update were effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. From time to time, the Company issues shares to community members for consulting on regional advisory councils. These shares vest immediately and the cost, which is based on the market price on the date of grant and deemed to be immaterial, is expensed in the period in which the services are rendered. The adoption of this standard in January 2019 did not have a material impact on the Company's unaudited consolidated interim financial statements, results of operations or disclosures. Accounting pronouncements not yet adopted by the Company (in order of effective date of implementation) In June 2016, the FASB issued ASU No. 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments." The amendments in this ASU require a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. Previously, when credit losses were measured under GAAP, an entity generally only considered past events and current conditions in measuring the incurred loss and generally recognition of the full amount of credit losses was delayed until the loss was probable of occurring. The amendments in this ASU eliminate the probable initial recognition threshold in current GAAP and, instead, reflect an entity's current estimate of all expected credit losses (commonly known as "CECL"). The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. An entity must use judgment in determining the relevant information and estimation methods that are appropriate in its circumstances. The income statement reflects the measurement of credit losses for newly recognized financial assets, as well as the expected increases or decreases of expected credit losses that have taken place during the period. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial asset(s) to present the net carrying value at the amount expected to be collected on the financial asset. Credit losses on available-for-sale debt securities should be measured in a manner similar to current GAAP. However, the amendments in this ASU require that credit losses be presented as an allowance rather than as a write-down. Unlike current GAAP, the ASU provides for reversals of credit losses in future period net income in situations where the estimate of loss declines. An entity will apply the amendments in this ASU through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective (that is, a modified-retrospective approach). For public business entities that are SEC filers, such as the Company, the amendments in this ASU are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption for fiscal years beginning after December 15, 2018 is permitted. In April 2018, banking regulators issued a proposed revision to their capital rules that addresses the regulatory capital treatment of credit loss allowances under the CECL methodology and, if enacted as proposed, would allow banking organizations to phase in the day-one regulatory capital effects of CECL adoption over three years. The Company has established a project committee and an implementation plan for this ASU. The impact of the adoption of ASU No. 2016-13 on the Company's operations, financial results, disclosures, and controls is under evaluation. In January 2017, the FASB issued ASU No. 2017-04, "Intangibles-Goodwill and Other (Topic 350)-Simplifying the Test for Goodwill Impairment." The main provision in this ASU eliminated Step 2 of the goodwill impairment test and instead requires an entity to perform its annual, or interim, goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount. An impairment charge would be recognized for the amount the carrying value exceeds the reporting unit's fair value as long as the amount recognized does not exceed the amount of goodwill allocated to the reporting unit. For public business entities that are SEC filers, such as the Company, the amendments in this ASU are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for impairment tests performed on testing dates after January 1, 2017. Goodwill carried on the Company's consolidated financial statements was $5.7 million at both March 31, 2019 and December 31, 2018 . This asset is related to the Company’s acquisition of two branch offices in July 2000. The Company does not expect the adoption of ASU No. 2017-04 to have a material impact on the Company's consolidated financial statements and results of operations. In August 2018, the FASB issued ASU No. 2018-13, "Fair Value Measurement (Topic 820-Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement." The amendments in this ASU modify the disclosure requirements primarily related to level 3 fair value measurements of the fair value hierarchy. This amendment is effective for fiscal years beginning after December 15, 2019 and interim periods within those fiscal years. Early adoption is permitted. Because this ASU primarily relates to disclosure requirements, the Company does not expect the adoption of ASU No. 2018-13 to have a material impact on the Company's consolidated financial statements and results of operations. In August 2018, the FASB issued ASU No. 2018-15, "Intangibles-Goodwill and Other- Internal-use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract." The major provision in the amendments in this ASU require an entity to capitalize certain implementation costs incurred in a hosting arrangement that is a service contract in accordance with current GAAP for internal-use software and expense these costs over the term of the hosting arrangement. Additionally, these capitalized implementation costs are required to be reviewed for impairment in accordance with current GAAP for internal-use software. This amendment is effective for fiscal years beginning after December 15, 2019 and interim periods within those fiscal years. Early adoption is permitted. The amendments in this ASU should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. The Company does not expect the adoption of ASU No. 2018-15 to have a material impact on the Company's consolidated financial statements and results of operations. In August 2018, the FASB issued ASU No. 2018-14, "Compensation-Retirement Benefits-Defined Benefit Plans-General (Subtopic 715-20) -Disclosure Framework-Changes to the Disclosure Requirements for Defined Benefit Plans." The amendments in this ASU modify the disclosure requirements on defined benefit plans including requiring disclosures about significant gains and losses related to changes in the benefit obligation. This amendment is effective for fiscal years ending after December 15, 2020. Early adoption is permitted. Because this ASU primarily relates to disclosure requirements and the balances of the benefit plans impacted by this ASU are immaterial to the Company, the adoption of ASU No. 2018-14 will not have a material impact on the Company's consolidated financial statements and results of operations.

Investment Securities

Investment Securities	3 Months Ended
	Mar. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities As of March 31, 2019 , and December 31, 2018 , the investment portfolio was primarily comprised of debt securities, with a small portion of the portfolio invested in equity securities. See also item (c), "Restricted Cash and Investments," contained in Note 1, "Summary of Significant Accounting Policies," to the Company's unaudited consolidated interim financial statements, contained above, for further information regarding the Company's FHLB stock. See Note 13, "Fair Value Measurements," to the Company's unaudited consolidated interim financial statements, contained below, for further information regarding the Company's fair value measurements for investment securities. Debt Securities The amortized cost and fair values of debt securities at the dates specified are summarized as follows: March 31, 2019 (Dollars in thousands) Amortized cost Unrealized gains Unrealized losses Fair Value Federal agency obligations (1) $ 7,996 $ — $ 8 $ 7,988 Residential federal agency MBS (1) 169,682 713 2,009 168,386 Commercial federal agency MBS (1) 113,638 1,278 247 114,669 Municipal securities 150,141 2,725 197 152,669 Corporate bonds 14,003 156 54 14,105 Certificate of deposits (2) ("CDs") 950 — 2 948 Total debt securities, at fair value $ 456,410 $ 4,872 $ 2,517 $ 458,765 December 31, 2018 (Dollars in thousands) Amortized cost Unrealized gains Unrealized losses Fair Value Federal agency obligations (1) $ 7,994 $ — $ 19 $ 7,975 Residential federal agency MBS (1) 174,701 633 2,608 172,726 Commercial federal agency MBS (1) 93,800 609 430 93,979 Municipal securities 141,747 1,122 826 142,043 Corporate bonds 13,967 24 185 13,806 Certificates of deposits (2) 950 — 6 944 Total debt securities, at fair value $ 433,159 $ 2,388 $ 4,074 $ 431,473 __________________________________________ (1) These categories may include investments issued or guaranteed by government sponsored enterprises such as Fannie Mae ("FNMA"), Freddie Mac ("FHLMC"), Federal Farm Credit Bank ("FFCB"), or one of several Federal Home Loan Banks, as well as, investments guaranteed by Ginnie Mae ("GNMA"), a wholly-owned government entity. (2) CDs represent term deposits issued by banks that are subject to FDIC insurance and purchased on the open market. Included in the residential and commercial federal agency mortgage-backed securities ("MBS") categories were collateralized mortgage obligations ("CMOs") issued by U.S. agencies with fair values totaling $259.3 million and $242.8 million at March 31, 2019 and December 31, 2018 , respectively. Included in municipal securities were tax exempt municipal securities with fair values totaling $106.3 million and $107.3 million at March 31, 2019 and December 31, 2018 , respectively. As of the dates reflected in the tables above, all of the Company's debt securities were classified as available-for-sale and carried at fair value. Net unrealized appreciation and depreciation on debt securities available-for-sale, net of applicable income taxes, are reflected as a component of accumulated other comprehensive income (loss). The net unrealized gain or loss in the Company's debt security portfolio fluctuates as market interest rates rise and fall. Due to the fixed rate nature of this portfolio, as market rates fall, the value of the portfolio rises, and as market rates rise, the value of the portfolio declines. The unrealized gains or losses on debt securities will also decline as the securities approach maturity. Unrealized losses on debt securities that are deemed OTTI are generally charged to earnings, as described further in Note 1, "Summary of Significant Accounting Policies," under Item (e), "Investments," to the Company's audited consolidated financial statements contained in the Company's 2018 Annual Report on Form 10-K. Gains or losses will be recognized in the income statement if the securities are sold. The following tables summarize debt securities with unrealized losses, due to the fair values having declined below the amortized costs of the individual investments, by the duration of their continuous unrealized loss positions at March 31, 2019 and December 31, 2018 . March 31, 2019 Less than 12 months 12 months or longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses # of holdings Federal agency obligations $ — $ — $ 6,990 $ 8 $ 6,990 $ 8 2 Residential federal agency MBS 2,519 11 98,056 1,998 100,575 2,009 22 Commercial federal agency MBS 1,009 1 18,848 246 19,857 247 6 Municipal securities — — 14,350 197 14,350 197 24 Corporate bonds — — 5,743 54 5,743 54 35 CDs — — 948 2 948 2 4 Total temporarily impaired debt securities $ 3,528 $ 12 $ 144,935 $ 2,505 $ 148,463 $ 2,517 93 December 31, 2018 Less than 12 months 12 months or longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses # of holdings Federal agency obligations $ 997 $ 1 $ 6,978 $ 18 $ 7,975 $ 19 3 Residential federal agency MBS 26,147 597 81,158 2,011 107,305 2,608 25 Commercial federal agency MBS 3,258 11 18,717 419 21,975 430 9 Municipal securities 15,036 108 41,265 718 56,301 826 83 Corporate bonds 5,277 36 5,653 149 10,930 185 63 CDs — — 944 6 944 6 4 Total temporarily impaired debt securities $ 50,715 $ 753 $ 154,715 $ 3,321 $ 205,430 $ 4,074 187 During the three months ended March 31, 2019 and 2018 , the Company did not record any fair value impairment charges (Other than temporary impairment or "OTTI") on its investments in debt securities. At March 31, 2019 , management did not consider any debt securities to have OTTI. Management regularly reviews the portfolio for debt securities with unrealized losses that are other-than-temporarily impaired. There have been no material changes to the Company's process for assessing investments for OTTI as reported in the 2018 Annual Report on Form 10-K. For more information about the Company's assessment for OTTI, see Note 2, "Investment Securities," to the Company's audited consolidated financial statements contained in the Company's 2018 Annual Report on Form 10-K. As noted in the table above, a small portion of the portfolio was invested in CDs and was also in an unrealized loss position at March 31, 2019 and December 31, 2018 , due to market rates. The unrealized loss was not considered to be material and the securities are expected to mature at par value. The contractual maturity distribution at March 31, 2019 of total debt securities was as follows: (Dollars in thousands) Amortized Cost Fair Value Due in one year or less $ 11,919 $ 11,919 Due after one, but within five years 67,383 67,962 Due after five, but within ten years 175,158 177,764 Due after ten years 201,950 201,120 Total debt securities $ 456,410 $ 458,765 Scheduled contractual maturities shown above may not reflect the actual maturities of the investments. The actual MBS/CMO cash flows likely will be faster than presented above due to prepayments and amortization. Similarly, included in the table above are callable securities, comprised of municipal securities and corporate bonds, with a fair value of $83.9 million , which can be redeemed by the issuers prior to the maturity presented above. Management considers these factors when evaluating the interest-rate risk in the Company's asset-liability management program. From time to time, the Company may pledge debt securities as collateral for deposit account balances of municipal customers, and for borrowing capacity with the FHLB and the FRB. The fair value of debt securities pledged as collateral for these purposes was $ 456.3 million at March 31, 2019 . Sales of debt securities, including pending trades based on trade date, if applicable, for the three months ended March 31, 2019 and March 31, 2018 are summarized as follows: Three months ended March 31, (Dollars in thousands) 2019 2018 Amortized cost of debt securities sold (1) $ 1,793 $ 668 Gross realized gains on sales 2 3 Gross realized losses on sales (3 ) (2 ) Total proceeds from sales of debt securities $ 1,792 $ 669 _________________________________________ (1) Amortized cost of investments sold is determined on a specific identification basis. Equity Securities The Company held equity securities with a fair value of $2.0 million as of March 31, 2019 , compared to fair value of $1.4 million at December 31, 2018 . At March 31, 2019 , the equity portfolio consisted primarily of investments in a diversified group of mutual funds, with a portion of the portfolio invested in individual common stock of entities in the financial services industry. There were no sales of equity securities in either the three months ended March 31, 2019 or March 31, 2018 . During the three months ended March 31, 2019 , the fair value gain on equity securities recorded in the Other Income line of the Company's consolidated statement of income was $186 thousand , while during the three months ended March 31, 2018 , the recorded fair value loss was $5 thousand . The fair value changes of equity securities that will be recognized in net income in the future will depend on the amount of dollars invested in equities and the magnitude of changes in equity fair values.

Loans

Loans	3 Months Ended
	Mar. 31, 2019
Receivables [Abstract]
Loans	Loans The Company specializes in lending to business entities, non-profit organizations, professional practices and individuals. The Company's primary lending focus is on the development of high-quality commercial relationships achieved through active business development efforts, long-term relationships with established commercial developers, strong community involvement and focused marketing strategies. Loans made to businesses, non-profits, and professional practices may include commercial mortgage loans, construction and land development loans, secured and unsecured commercial loans and lines of credit, and letters of credit. The Company also originates equipment lease financing for businesses. Loans made to individuals include conventional residential mortgage loans, home equity loans and lines, residential construction loans on owner-occupied primary and secondary residences, and secured and unsecured personal loans and lines of credit. The Company manages its loan portfolio to avoid concentration by industry, relationship size and source of repayment to lessen its credit risk exposure. For additional information on the Company's lending products, see the heading "Lending Products" under Item 1, "Business," contained in the Company's 2018 Annual Report on Form 10-K. See also Note 4, "Allowance for Loan Losses," to the Company's unaudited consolidated interim financial statements, contained below, for information on the Company's credit risk management, non-accrual, impaired and troubled debt restructured loans and the allowance for loan losses. See Note 8, "Derivatives and Hedging Activities," to the Company's unaudited consolidated interim financial statements, contained below, for information regarding interest-rate swap agreements related to certain commercial loans, and see Note 13, "Fair Value Measurements," to the Company's unaudited consolidated interim financial statements, contained below, for further information regarding the Company's fair value measurements for loans. Loan Portfolio Classifications Major classifications of loans at the dates indicated were as follows: (Dollars in thousands) March 31, December 31, Commercial real estate $ 1,292,047 $ 1,303,879 Commercial and industrial 509,733 514,253 Commercial construction 244,978 234,430 Total commercial loans 2,046,758 2,052,562 Residential mortgages 233,129 231,501 Home equity loans and lines 97,798 96,116 Consumer 9,897 10,241 Total retail loans 340,824 337,858 Gross loans 2,387,582 2,390,420 Deferred loan origination fees, net (2,945 ) (2,914 ) Total loans 2,384,637 2,387,506 Allowance for loan losses (33,729 ) (33,849 ) Net loans $ 2,350,908 $ 2,353,657 Commercial loans originated by other banks in which the Company is a participating institution are carried at the pro-rata share of ownership and amounted to $65.5 million at March 31, 2019 and $63.5 million at December 31, 2018 . Loans serviced for others At March 31, 2019 and December 31, 2018 , the Company was servicing residential mortgage loans owned by investors amounting to $17.1 million and $17.2 million , respectively. Additionally, the Company was servicing commercial loans originated by the Company and participated out to various other institutions amounting to $73.1 million and $72.1 million at March 31, 2019 and December 31, 2018 , respectively. Loans serving as collateral Loans designated as qualified collateral and pledged to the FHLB for borrowing capacity for the dates indicated are summarized below: (Dollars in thousands) March 31, December 31, Commercial real estate $ 299,896 $ 311,024 Residential mortgages 220,827 220,815 Home equity 7,987 8,382 Total loans pledged to FHLB $ 528,710 $ 540,221

Allowance For Loan Loss

Allowance For Loan Loss	3 Months Ended
	Mar. 31, 2019
Receivables [Abstract]
Allowance for Loan Loss	Allowance for Loan Losses Allowance for probable loan losses methodology On a quarterly basis, management prepares an estimate of the allowance necessary to cover estimated probable credit losses. The Company uses a systematic methodology to measure the amount of estimated loan loss exposure inherent in the portfolio for purposes of establishing a sufficient allowance for loan losses. The methodology makes use of specific reserves for loans individually evaluated and deemed impaired, and general reserves for larger pools of homogeneous loans, which are collectively evaluated relying on a combination of qualitative and quantitative factors that may affect credit quality of the pool. There have been no material changes to the Company's underwriting practices, credit risk management system, or to the allowance assessment methodology used to estimate loan loss exposure as reported in Note 4, "Allowance for Loan Losses," to the Company's audited consolidated financial statements contained in the 2018 Annual Report on Form 10-K, The balances of loans as of March 31, 2019 by portfolio classification and evaluation method are summarized as follows: (Dollars in thousands) Loans individually evaluated for impairment Loans collectively evaluated for impairment Gross Loans Commercial real estate $ 15,622 $ 1,276,425 $ 1,292,047 Commercial and industrial 11,643 498,090 509,733 Commercial construction 1,732 243,246 244,978 Residential mortgages 883 232,246 233,129 Home equity loans and lines 502 97,296 97,798 Consumer 15 9,882 9,897 Total gross loans $ 30,397 $ 2,357,185 $ 2,387,582 The balances of loans as of December 31, 2018 by portfolio classification and evaluation method are summarized as follows: (Dollars in thousands) Loans individually evaluated for impairment Loans collectively evaluated for impairment Gross Loans Commercial real estate $ 16,318 $ 1,287,561 $ 1,303,879 Commercial and industrial 12,053 502,200 514,253 Commercial construction 1,736 232,694 234,430 Residential mortgages 893 230,608 231,501 Home equity loans and lines 514 95,602 96,116 Consumer 16 10,225 10,241 Total gross loans $ 31,530 $ 2,358,890 $ 2,390,420 See "Financial Condition" in Item 2, "Management's Discussion and Analysis," under the headings "Credit Risk" and "Allowance for Loan Losses" in this Form 10-Q for additional information about changes in the Company's credit quality indicators since December 31, 2018 . Credit quality indicators Early detection of credit issues is critical to minimize credit losses. Accordingly, management regularly monitors internal credit quality indicators such as, among others, the risk classification of adversely classified loans, past due and non-accrual loans, impaired and restructured loans, and the level of foreclosure activity. These credit quality indicators are discussed below. Adversely classified loans The Company's loan risk rating system classifies loans depending on risk of loss characteristics. The classifications range from "substantially risk free" for the highest quality loans and loans that are secured by cash collateral, through a satisfactory range of "minimal," "moderate," "better than average," and "average" risk, to the regulatory problem-asset classifications of "criticized," for loans that may need additional monitoring, and the more severe adverse classifications of "substandard," "doubtful," and "loss" based on criteria established under banking regulations. Loans which are evaluated to be of weaker credit quality are placed on the "watch credit list" and reviewed on a more frequent basis by management. Adversely classified loans may be accruing or in non-accrual status and may be additionally designated as impaired or restructured, or some combination thereof. The following tables present the Company's credit risk profile for each portfolio classification by internally assigned adverse risk rating category as of the periods indicated: March 31, 2019 Adversely Classified Not Adversely (Dollars in thousands) Substandard Doubtful Loss Classified Gross Loans Commercial real estate $ 17,323 $ — $ — $ 1,274,724 $ 1,292,047 Commercial and industrial 12,642 38 — 497,053 509,733 Commercial construction 2,254 — — 242,724 244,978 Residential mortgages 1,802 — — 231,327 233,129 Home equity loans and lines 549 — — 97,249 97,798 Consumer 33 8 — 9,856 9,897 Total gross loans $ 34,603 $ 46 $ — $ 2,352,933 $ 2,387,582 December 31, 2018 Adversely Classified Not Adversely (Dollars in thousands) Substandard Doubtful Loss Classified Gross Loans Commercial real estate $ 17,714 $ 240 $ — $ 1,285,925 $ 1,303,879 Commercial and industrial 12,821 — — 501,432 514,253 Commercial construction 2,262 — — 232,168 234,430 Residential mortgages 1,820 — — 229,681 231,501 Home equity loans and lines 561 — — 95,555 96,116 Consumer 35 8 — 10,198 10,241 Total gross loans $ 35,213 $ 248 $ — $ 2,354,959 $ 2,390,420 Total adversely classified loans amounted to 1.45% of total loans at March 31, 2019 , as compared to 1.49% at December 31, 2018 . Past due and non-accrual loans The following tables present an age analysis of past due loans by portfolio classification as of the dates indicated: Balance at March 31, 2019 (Dollars in thousands) 30-59 Days Past Due 60-89 Days Past Due Past Due 90 days or more Total Past Due Loans Current Loans Gross Loans Non-accrual Loans Commercial real estate $ 7,650 $ — $ 3,247 $ 10,897 $ 1,281,150 $ 1,292,047 $ 6,668 Commercial and industrial 1,939 121 1,774 3,834 505,899 509,733 2,936 Commercial construction 1,769 — 174 1,943 243,035 244,978 174 Residential mortgages 1,182 — 289 1,471 231,658 233,129 754 Home equity loans and lines 97 — 92 189 97,609 97,798 502 Consumer 38 — 2 40 9,857 9,897 15 Total gross loans $ 12,675 $ 121 $ 5,578 $ 18,374 $ 2,369,208 $ 2,387,582 $ 11,049 Balance at December 31, 2018 (Dollars in thousands) 30-59 Days Past Due 60-89 Days Past Due Past Due 90 days or more Total Past Due Loans Current Loans Gross Loans Non-accrual Loans Commercial real estate $ 7,596 $ 21 $ 3,821 $ 11,438 $ 1,292,441 $ 1,303,879 $ 6,894 Commercial and industrial 619 17 2,299 2,935 511,318 514,253 3,417 Commercial construction 4,319 — — 4,319 230,111 234,430 176 Residential mortgages 114 — 377 491 231,010 231,501 763 Home equity loans and lines 14 168 209 391 95,725 96,116 514 Consumer 23 31 6 60 10,181 10,241 20 Total gross loans $ 12,685 $ 237 $ 6,712 $ 19,634 $ 2,370,786 $ 2,390,420 $ 11,784 At March 31, 2019 and December 31, 2018 , all loans past due 90 days or more were carried as non-accrual, in addition to those loans less than 90 days past due where reasonable doubt existed as to the full and timely collection of interest or principal that have also been designated as non-accrual, despite their payment due status shown in the tables above. Non-accrual loans that were not adversely classified amounted to $80 thousand at March 31, 2019 and $81 thousand at December 31, 2018 . These balances primarily represented the guaranteed portions of non-performing SBA loans. The majority of the non-accrual loan balances were also carried as impaired loans during the periods noted and are discussed further below. The ratio of non-accrual loans to total loans amounted to 0.46% at March 31, 2019 and 0.49% at December 31, 2018 . At March 31, 2019 , additional funding commitments for non-accrual loans were not material. Impaired loans Impaired loans are individually significant loans for which management considers it probable that not all amounts due (principal and interest) will be collected in accordance with the original contractual terms. Impaired loans include loans that have been modified in a troubled debt restructuring ("TDR"), see "Troubled debt restructurings" below. Impaired loans are individually evaluated and exclude large groups of smaller-balance homogeneous loans, such as residential mortgage loans and consumer loans, which are collectively evaluated for impairment, and loans that are measured at fair value, unless the loan is amended in a TDR. The carrying value of impaired loans amounted to $30.4 million and $31.5 million at March 31, 2019 and December 31, 2018 , respectively. Total accruing impaired loans amounted to $19.3 million and $19.7 million at March 31, 2019 and December 31, 2018 , respectively, while non-accrual impaired loans amounted to $11.0 million and $11.8 million as of March 31, 2019 and December 31, 2018 , respectively. The following tables set forth the recorded investment in impaired loans and the related specific allowance allocated by portfolio classification as of the dates indicated: Balance at March 31, 2019 (Dollars in thousands) Unpaid contractual principal balance Total recorded investment in impaired loans Recorded investment with no allowance Recorded investment with allowance Related specific allowance Commercial real estate $ 16,491 $ 15,622 $ 15,454 $ 168 $ 6 Commercial and industrial 12,147 11,643 7,522 4,121 2,112 Commercial construction 1,802 1,732 1,732 — — Residential mortgages 967 883 464 419 12 Home equity loans and lines 679 502 502 — — Consumer 15 15 — 15 14 Total $ 32,101 $ 30,397 $ 25,674 $ 4,723 $ 2,144 Balance at December 31, 2018 (Dollars in thousands) Unpaid contractual principal balance Total recorded investment in impaired loans Recorded investment with no allowance Recorded investment with allowance Related specific allowance Commercial real estate $ 17,140 $ 16,318 $ 15,948 $ 370 $ 55 Commercial and industrial 12,538 12,053 7,752 4,301 2,140 Commercial construction 1,804 1,736 1,736 — — Residential mortgages 970 893 473 420 13 Home equity loans and lines 685 514 514 — — Consumer 16 16 — 16 16 Total $ 33,153 $ 31,530 $ 26,423 $ 5,107 $ 2,224 The following table presents the average recorded investment in impaired loans by portfolio classification and the related interest recognized during the three months indicated: Three Months Ended March 31, 2019 Three Months Ended March 31, 2018 (Dollars in thousands) Average recorded investment Interest income recognized Average recorded investment Interest income recognized Commercial real estate $ 15,803 $ 120 $ 13,715 $ 94 Commercial and industrial 11,919 115 10,647 77 Commercial construction 1,734 25 1,636 22 Residential mortgages 890 1 614 (1 ) Home equity loans and lines 507 — 475 — Consumer 19 — 32 — Total $ 30,872 $ 261 $ 27,119 $ 192 At March 31, 2019 , additional funding commitments for impaired loans was not material. The Company's obligation to fulfill the additional funding commitments on impaired loans is generally contingent on the borrower's compliance with the terms of the credit agreement. If the borrower is not in compliance, additional funding commitments may or may not be made at the Company's discretion. Troubled debt restructurings Loans are designated as a TDR when, as part of an agreement to modify the original contractual terms of the loan as a result of financial difficulties of the borrower, the Bank grants the borrower a concession on the terms, that would not otherwise be considered. Typically, such concessions may consist of one or a combination of the following: a reduction in interest rate to a below market rate, taking into account the credit quality of the note; extension of additional credit based on receipt of adequate collateral; or a deferment or reduction of payments (principal or interest) which materially alters the Bank's position or significantly extends the note's maturity date, such that the present value of cash flows to be received is materially less than those contractually established at the loan's origination. All loans that are modified are reviewed by the Company to identify if a TDR has occurred. TDR loans are included in the impaired loan category and, as such, these loans are individually reviewed and evaluated, and a specific reserve is assigned for the amount of the estimated probable credit loss. Total TDR loans, included in the impaired loan balances above, as of March 31, 2019 and December 31, 2018 , were $23.5 million and $23.1 million , respectively. TDR loans on accrual status amounted to $19.3 million and $19.4 million at March 31, 2019 and December 31, 2018 , respectively. TDR loans included in non-performing loans amounted to $4.2 million at March 31, 2019 and $3.7 million at December 31, 2018 . The Company continues to work with customers and enters into loan modifications (which may or may not be TDRs) to the extent deemed to be necessary or appropriate while attempting to achieve the best mutual outcome given the individual financial circumstances and future prospects of the borrower. At March 31, 2019 , additional funding commitments for TDR loans were not material. The Company's obligation to fulfill the additional funding commitments on TDR loans is generally contingent on the borrower's compliance with the terms of the credit agreement. If the borrower is not in compliance, additional funding commitments may or may not be made at the Company's discretion. The following table sets forth the post modification balances of TDRs listed by type of modification for TDRs that occurred during the periods indicated: Three months ended March 31, 2019 March 31, 2018 (Dollars in thousands) Number of restructurings Amount Number of restructurings Amount Temporary payment reduction and payment re-amortization of remaining principal over extended term 6 $ 607 2 $ 139 Temporary interest only payment plan — — 2 132 Other payment concessions 1 314 — — Total 7 $ 921 4 $ 271 Amount of specific reserves included in the allowance for loan losses associated with TDRs listed above $ 91 $ 120 Loans modified as TDRs during the three month periods ended March 31, 2019 and March 31, 2018 by portfolio classification are detailed below: Three months ended March 31, 2019 March 31, 2018 (Dollars in thousands) Number of restructurings Pre-modification outstanding recorded investment Post-modification outstanding recorded investment Number of restructurings Pre-modification outstanding recorded investment Post-modification outstanding recorded investment Commercial real estate 1 $ 421 $ 415 2 $ 131 $ 132 Commercial and industrial 5 194 192 2 142 139 Commercial construction — — — — — — Residential mortgages 1 315 314 — — — Home equity loans and lines — — — — — — Consumer — — — — — — Total 7 $ 930 $ 921 4 $ 273 $ 271 There were no subsequent charge-offs associated with the new TDRs noted in the table above during the three months ended March 31, 2019 or 2018 . Payment defaults by portfolio classification during the three month period ended March 31, 2019 on loans modified as TDRs within the preceding twelve months are detailed below: Three months ended March 31, 2019 (Dollars in thousands) Number of TDRs that defaulted Post- modification outstanding recorded investment Commercial real estate — $ — Commercial and industrial 2 174 Commercial construction — — Residential mortgages — — Home equity loans and lines — — Consumer — — Total 2 $ 174 For the three months ended March 31, 2018 , there were no payment defaults on loans modified as TDRs within the preceding twelve months. Other real estate owned ( " OREO " ) Real estate acquired by the Company through foreclosure proceedings or the acceptance of a deed in lieu of foreclosure is classified as OREO. When property is acquired, it is recorded at estimated fair value of the property acquired, less estimated costs to sell, establishing a new cost basis and carried on the consolidated balance sheet in the line item "Prepaid expenses and other assets". The estimated fair value is based on market appraisals and the Company’s internal analysis. Any loan balance in excess of the estimated realizable fair value on the date of transfer is charged to the allowance for loan losses on that date. All costs incurred thereafter in maintaining the property, as well as subsequent declines in fair value are charged to non-interest expense. The carrying value of OREO at March 31, 2019 was $255 thousand and consisted of one property added during the three months ended March 31, 2019 , compared to no OREO at December 31, 2018 or March 31, 2018 . There were no OREO sales or write downs of OREO during the three months ended March 31, 2019 . During the three months ended March 31, 2018 , there were no additions, sales or write downs on OREO. At both March 31, 2019 and December 31, 2018 , the Company had no consumer mortgage loans secured by residential real estate properties for which formal foreclosure proceedings were in process according to local requirements of the applicable jurisdictions. Allowance for loan loss activity The allowance for loan losses is an estimate of probable credit loss inherent in the loan portfolio as of the specified balance sheet dates. On a quarterly basis, management prepares an estimate of the allowance necessary to cover estimated probable credit losses. The Company maintains the allowance at a level that it deems adequate to absorb all reasonably anticipated probable losses from specifically known and other credit risks associated with the portfolio. The allowance for loan losses is established through a provision for loan losses, a direct charge to earnings. Loan losses are charged against the allowance when management believes that the collectability of the loan principal is unlikely. Recoveries on loans previously charged-off are credited to the allowance. The allowance for loan losses amounted to $33.7 million at March 31, 2019 , compared to $33.8 million at December 31, 2018 , and $34.5 million at March 31, 2018 . The allowance for loan losses to total loans ratio was 1.41% at March 31, 2019 , 1.42% at December 31, 2018 and 1.51% at March 31, 2018 . Based on management's judgment as to the existing credit risks inherent in the loan portfolio, as discussed above under the heading "Credit Quality Indicators," management believes that the Company's allowance for loan losses is adequate to absorb probable losses from specifically known and other probable credit risks associated with the portfolio as of March 31, 2019 . Changes in the allowance for loan losses by portfolio classification for the three months ended March 31, 2019 are presented below: (Dollars in thousands) Cmml Real Estate Cmml and Industrial Cmml Constr Resid. Mortgage Home Equity Consumer Total Beginning Balance at December 31, 2018 $ 18,014 $ 10,493 $ 3,307 $ 1,160 $ 629 $ 246 $ 33,849 Provision (188 ) (406 ) 145 24 (4 ) 29 (400 ) Recoveries — 316 — — 2 5 323 Less: Charge offs — — — — — 43 43 Ending Balance at March 31, 2019 $ 17,826 $ 10,403 $ 3,452 $ 1,184 $ 627 $ 237 $ 33,729 Ending allowance balance: Allocated to loans individually evaluated for impairment $ 6 $ 2,112 $ — $ 12 $ — $ 14 $ 2,144 Allocated to loans collectively evaluated for impairment $ 17,820 $ 8,291 $ 3,452 $ 1,172 $ 627 $ 223 $ 31,585 Changes in the allowance for loan losses by portfolio classification for the three months ended March 31, 2018 are presented below: (Dollars in thousands) Cmml Real Estate Cmml and Industrial Cmml Constr Resid. Mortgage Home Equity Consumer Total Beginning Balance at December 31, 2017 $ 17,545 $ 9,669 $ 3,947 $ 904 $ 608 $ 242 $ 32,915 Provision 755 1,435 (664 ) 10 20 44 1,600 Recoveries — 108 — — 1 5 114 Less: Charge offs — 41 — — — 64 105 Ending Balance at March 31, 2018 $ 18,300 $ 11,171 $ 3,283 $ 914 $ 629 $ 227 $ 34,524 Ending allowance balance: Allocated to loans individually evaluated for impairment $ 52 $ 2,776 $ — $ 4 $ — $ 22 $ 2,854 Allocated to loans collectively evaluated for impairment $ 18,248 $ 8,395 $ 3,283 $ 910 $ 629 $ 205 $ 31,670

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Lessee, Operating Leases	As of March 31, 2019 , the Company had 15 operating real estate leases. The Company's leased facilities are contracted under various non-cancelable operating leases, most of which provide options to the Company to extend the lease periods and include periodic rent adjustments. While the Company typically exercises its option to extend lease terms, clauses with its lease contracts allow the Company, upon notification, to terminate the lease at the end of the lease term, or any option period. Several leases also provide the Company the right of first refusal should the property be offered for sale or purchase options at specified periods mutually agreeable to the parties. The Company has an agreement to purchase one of the leased buildings in its main campus and anticipates this transaction will be completed during the second quarter of 2019. On January 1, 2019, the Company adopted ASU No. 2016-02, "Leases (Topic 842)." Under this ASU, as amended, lessees are required to recognize lease assets (right-of-use asset or "ROU") and lease liabilities on the balance sheet for all leases with terms longer than 12 months. For the Company, this ASU primarily impacted operating leases on our facilities, mainly branch leases, and as a result the Company recorded, on its consolidated balance sheet a lease liability of $18.0 million and ROU asset of $19.0 million on January 1, 2019 related to these leases. Upon adoption of this ASU, the Company elected the following practical expedients: • to not reassess, among other things, the historical lease classification, and • to use hindsight to assess lease terms and impairment of the ROU asset. The Company excludes leases with a term of 12 months or less from the recorded lease liability and ROU asset and accounts for lease and non-lease components separately. In order to calculate the lease liability, the Company used its incremental borrowing rate as the discount rate to determine the net present value of the lease liability. In determining the term of a lease, the Company included options renewal periods that it considered reasonably certain to exercise, which generally resulted in the inclusion of all lease option periods. The Company recognizes lease expense on a straight-line basis in the "Occupancy and Equipment Expenses" line item within the non-interest expense section of the consolidated income statement. Lease expenses, consisting of operating lease costs and variable lease costs, for the three months ended March 31, 2019 were $319 thousand . Variable lease costs and short-term lease expenses during this period were immaterial. The weighted average remaining lease term for operating leases at March 31, 2019 was 28.5 years, and the weighted average discount rate was 3.82% . At March 31, 2019 , the remaining undiscounted cash flows by year of these lease liabilities were as follows: (Dollars in thousands) Operating Leases 2019 (nine remaining months) $ 891 2020 1,179 2021 1,179 2022 1,181 2023 1,188 Thereafter 24,134 Total lease payments $ 29,752 Less: Imputed interest 11,881 Total $ 17,871 In addition, the Company currently collects rent through non-cancellable leases for a small portion of the overall square-footage within its Lowell, Massachusetts campus headquarters and at one of its branch locations. These leases are deemed immaterial.

Deposits

Deposits	3 Months Ended
	Mar. 31, 2019
Deposits [Abstract]
Deposits	Deposits Deposits are summarized as follows: (Dollars in thousands) March 31, 2019 December 31, 2018 Non-interest checking $ 743,151 $ 765,029 Interest-bearing checking 409,480 403,497 Savings 198,784 193,214 Money market 1,067,370 862,028 CDs $250,000 or less 228,585 215,200 CDs greater than $250,000 78,297 69,031 Total customer deposits 2,725,667 2,507,999 Brokered deposits (1) 30,499 56,783 Total deposits $ 2,756,166 $ 2,564,782 ___________________________________ (1) Brokered CDs which are $250,000 and under. Total customer deposits (deposits excluding brokered deposits) include reciprocal balances from checking, money market deposits and CDs received from participating banks in nationwide deposit networks as a result of our customers electing to participate in Company offered programs which allow for enhanced FDIC insurance. Essentially, the equivalent of the customers' original deposited funds comes back to the Company and are carried within the appropriate category under total customer deposits. The Company's balances in these reciprocal products were $510.5 million and $342.4 million at March 31, 2019 and December 31, 2018 , respectively. See Note 13, "Fair Value Measurements," to the Company's unaudited consolidated interim financial statements, contained below, for further information regarding the Company's fair value measurements for deposits.

Borrowed Funds and Subordinated

Borrowed Funds and Subordinated Debt	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Borrowed Funds and Subordinated Debt	Borrowed Funds and Subordinated Debt The Company had $488 thousand in borrowed funds at March 31, 2019 linked to outstanding commercial loans under various community reinvestment programs of the FHLB. At December 31, 2018 , borrowed funds consisted of FHLB borrowings amounting to $100.5 million . The Company had outstanding subordinated debt (net of deferred issuance costs) of $14.9 million at both March 31, 2019 and December 31, 2018 , which consisted of $15.0 million in aggregate principal amount of Fixed-to-Floating Rate Subordinated Notes (the "Notes") issued in January 2015 , with a 15 year term. Original debt issuance costs were $190 thousand and have been netted against the subordinated debt on the consolidated balance sheet in accordance with accounting guidance. These costs are being amortized to interest expense over the life of the Notes. The Notes are intended to qualify as Tier 2 capital for regulatory purposes and pay interest at a fixed rate of 6.00% per annum through January 30, 2025 , after which floating rates apply. Refer to Note 7, "Borrowed Funds and Subordinated Debt," to the Company's audited consolidated financial statements contained in the 2018 Annual Report on Form 10-K for additional information about the Company's subordinated debt. See Note 2, "Investments," and Note 3, "Loans" to the Company's unaudited consolidated interim financial statements, contained above, for further information regarding securities and loans pledged for borrowed funds. Refer to the "Liquidity" section and "Borrowed Funds" in the "Financial Condition" section in Item 2, "Management's Discussion and Analysis," for additional information about other sources of funding available to the Company and the Company's borrowing capacity.

Derivatives and Hedging Activit

Derivatives and Hedging Activities	3 Months Ended
	Mar. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Hedging Activities	Derivatives and Hedging Activities Interest-rate lock commitments related to the origination of mortgage loans that will be sold are considered derivative instruments. The commitments to sell loans are also considered derivative instruments. The Company generally does not pool mortgage loans for sale, but instead sells the loans on an individual basis. To reduce the net interest-rate exposure arising from its loan sale activity, the Company enters into the commitment to sell these loans at essentially the same time that the interest-rate lock commitment is quoted on the origination of the loan. The Company estimates the fair value of these derivatives based on current secondary mortgage market prices. At March 31, 2019 and December 31, 2018 , the estimated fair value of the Company's interest rate lock commitments and commitments to sell these mortgage loans were deemed immaterial. The Company may use interest-rate swaps as part of its interest rate risk management strategy. Interest-rate swap agreements may be entered into as hedges against future interest rate fluctuations on specifically identified assets or liabilities. The Company had no derivative fair value hedges or derivative cash flow hedges at March 31, 2019 or December 31, 2018 . The Company has a "Back-to-Back Swap" program whereby the Bank enters into an interest-rate swap with a qualified commercial banking customer and simultaneously enters into an equal and opposite interest-rate swap with a swap counterparty. The customer interest rate swap agreement allows commercial banking customers to convert a floating-rate loan payment to a fixed-rate payment. The transaction structure effectively minimizes the Bank's net risk exposure resulting from such transactions. Customer-related credit risk is minimized by the cross collateralization of the loan and the interest rate swap agreement. Back-to-Back swaps are not speculative; rather, the transactions result from a service the Company provides to certain commercial customers. Back-to-Back swaps do not meet hedge accounting requirements and therefore changes in the fair value of both the customer swaps and the counterparty swaps, which have an offsetting relationship, are recognized directly in earnings. As a result of this offsetting relationship, there were no net gains or losses recognized in income on Back-to-Back swaps during the three months ended March 31, 2019 or March 31, 2018 . Each Back-to-Back swap transaction consists of two interest-rate swaps (a customer swap and offsetting counterparty swap) and amounted to a total number of eight interest rate swaps outstanding at both March 31, 2019 and December 31, 2018 , with an aggregate notional amount of $37.4 million and $37.7 million on those respective dates. Asset derivatives are included in the line item prepaid expenses and other assets and liability derivatives are included in the accrued expenses and other liabilities line item on the consolidated balance sheets, respectively. Interest-rate swaps with the counterparty are subject to master netting agreements, while interest-rate swaps with customers are not. The table below presents the fair value and classification of the Company's derivative financial instruments for the periods presented: As of March 31, 2019 As of December 31, 2018 (Dollars in thousands) Asset Derivatives Liability Derivatives Asset Derivatives Liability Derivatives Interest rate contracts - pay floating, receive fixed $ 165 $ 434 $ 45 $ 723 Interest rate contracts - pay fixed, receive floating 269 — 678 — Total interest rate swaps $ 434 $ 434 $ 723 $ 723 By using derivative financial instruments, the Company exposes itself to counterparty-credit risk. Credit risk is the risk of failure by the counterparty to perform under the terms of the derivative contract. When the fair value of a derivative contract is positive, the counterparty owes the Company, which creates credit risk for the Company. When the fair value of a derivative is negative, the Company owes the counterparty and, therefore, it does not possess credit risk. The credit risk in derivative instruments is mitigated by entering into transactions with highly-rated counterparties that management believes to be creditworthy. The Company has one counterparty and it was rated A and A2 by Standard & Poor and Moody, respectively, at March 31, 2019 . Additionally, counterparty interest rate swaps contain provisions for collateral to be posted if the derivative exposure exceeds a threshold amount. The Company had credit risk exposure amounting to $269 thousand and $678 thousand at March 31, 2019 and December 31, 2018 , respectively, relating to interest rate swaps with counterparties. The Company held cash collateral of $200 thousand at March 31, 2019 and $850 thousand at December 31, 2018 . Collateral held by the Company is restricted and not considered an asset of the Company. Therefore, it is not carried on the Company's consolidated balance sheet. The table below presents the Company's asset derivative positions and the potential effect of those netting arrangements on its financial position, as of the periods presented. As noted above, interest-rate swaps with customers are not subject to master netting agreements and therefore are not included in the table below. As of March 31, 2019 (Dollars in thousands) Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Position Net Amounts of Assets Presented in the Statement of Financial Position Asset Derivatives Interest rate contracts - pay fixed, receive floating $ 434 $ 165 $ 269 As of December 31, 2018 (Dollars in thousands) Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Position Net Amounts of Assets Presented in the Statement of Financial Position Asset Derivatives Interest rate contracts - pay fixed, receive floating $ 723 $ 45 $ 678 The Company's interest-rate swaps with counterparties contain credit-risk-related contingent provisions. These provisions provide the counterparty with the right to terminate its derivative positions and require the Company to settle its obligations under the agreements if the Company defaults on certain of its indebtedness. The Company also participates in loans originated by third party banks, where the originating bank utilizes a back-to-back interest-rate swap structure; however, the Company is not a party to the swap agreements. Under the terms of the loan participations, the Company has accepted contingent liabilities that would only be realized if the swaps were terminated early and there were outstanding losses not covered by the underlying borrowers and the borrowers' pledged collateral. If applicable, the Company's swap-loss exposure would be equal to the percentage of the Company's participation in the underlying loan applied to the originating bank's swap loss. At both March 31, 2019 and December 31, 2018 , the Company had one such participation loan. At March 31, 2019 , management considers the risk of material swap-loss exposure related to this participation loan to be unlikely based on the swap market value, as well as the borrower's financial and collateral strength.

Stockholder's Equity

Stockholder's Equity	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity Shares Authorized and Share Issuance The Company's authorized capital is divided into common stock and preferred stock. The Company is authorized to issue 40,000,000 shares of common stock, with a par value of $0.01 , and as of March 31, 2019 had 11,798,114 shares of common stock issued and outstanding. The Company is authorized to issue 1,000,000 shares of preferred stock, with a par value of $0.01 . No preferred stock has been issued as of the date of this Form 10-Q. Holders of common stock are entitled to one vote per share and are entitled to receive dividends if and when declared by the Company's Board of Directors (the "Board"). Dividend and liquidation rights of the common stock may be subject to the rights of any outstanding preferred stock. The Company has a shareholders' rights plan. Under the plan, each share of common stock includes a right to purchase under certain circumstances one one-hundredth of a share of the Company's Series A Junior Participating Preferred Stock, par value $0.01 per share, at a purchase price of $122.50 per one one-hundredth of a preferred share, subject to adjustment, or, in certain circumstances, to receive cash, property, shares of common stock or other securities of the Company. The rights are not presently exercisable and remain attached to the shares of common stock until the occurrence of certain triggering events that would ordinarily be associated with an unsolicited acquisition or attempted acquisition of 10% or more of the Company's outstanding shares of common stock. The rights have no voting or dividend privileges, and unless and until they become exercisable, have no dilutive effect on the earnings of the Company. The rights will expire, unless earlier redeemed, exchanged, or otherwise rescinded by the Company, on January 13, 2028. The Company's stock incentive plans permit the Board to grant, under various terms, stock options (for the purchase of newly issued shares of common stock), common stock, restricted stock awards, restricted stock units and stock appreciation rights to officers and other employees, non-employee directors and consultants. The Company issues stock options and restricted stock awards to officers and other employees and restricted stock awards and stock compensation in lieu of cash fees to non-employee directors. The restricted stock awards allow for the non-forfeitable receipt of dividends, and the voting of all shares, whether or not vested, throughout the vesting periods at the same proportional level as common shares outstanding. The unvested restricted stock awards are the Company's only participating securities and are included in shares outstanding. Unvested participating restricted awards amounted to 124,938 shares and 91,708 shares as of March 31, 2019 and December 31, 2018 , respectively. See Note 12, "Earnings per Share," to the Company's unaudited consolidated interim financial statements, contained below, for additional information regarding unvested participating restricted awards and the Company's earnings per share calculation. Upon vesting, restricted stock awards may be net share-settled to cover payment for employee tax obligations, resulting in shares of common stock being reacquired by the Company and returned to the pool of shares reserved for issuance under the incentive plans. Chapter 156D of the Massachusetts General Laws, a statute known as the Massachusetts Business Corporation Act, which applies to Massachusetts corporations such as the Company, eliminates the concept of "treasury stock" and provides that shares reacquired by a Massachusetts company will be treated as authorized but unissued shares. The Company's stock incentive plans also allow for newly issued shares of common stock to be issued without restrictions to officers and other employees, non-employee directors and consultants. From time to time, the Company issues shares to community members for consulting on regional advisory councils and grants shares of fully vested stock as employee anniversary awards. These shares vest immediately and the cost, which is based on the market price on the date of grant and deemed to be immaterial, is expensed in the period in which the services are rendered. See Note 11, "Stock-Based Compensation," to the Company's unaudited consolidated interim financial statements, contained below, for additional information regarding the Company's stock incentive plans. In addition to shares issued to employees, non-employee directors and community members for consulting on regional advisory councils, and shares issued through equity offerings, the Company maintains a dividend reinvestment and direct stock purchase plan ("DRSPP") which enables stockholders, at their discretion, to elect to reinvest cash dividends paid on their shares of the Company's common stock by purchasing additional shares of common stock from the Company at a purchase price equal to fair market value. Under the DRSPP, stockholders and new investors also have the opportunity to purchase shares of the Company's common stock without brokerage fees, subject to monthly minimums and maximums. Comprehensive Income Comprehensive income is defined as all changes to stockholders' equity except investments by and distributions to stockholders. Net income is one component of comprehensive income, with other components referred to in the aggregate as other comprehensive income. At March 31, 2019 and March 31, 2018 , the Company's only other comprehensive income component is the net unrealized holding gains or losses on available-for-sale debt securities, net of deferred income taxes. Pursuant to GAAP, the Company initially excludes these unrealized holding gains and losses from net income; however, they are later reported as reclassifications out of accumulated other comprehensive income into net income when the debt securities are sold. See "Capital Resources" in Item 2, "Management's Discussion and Analysis," of this Form 10-Q for the Company's capital ratios and capital adequacy assessment as of March 31, 2019 . Refer to Note 10, "Stockholders' Equity," to the Company's audited consolidated financial statements included in the Company's 2018 Annual Report on Form 10-K for additional information relating to capital adequacy requirements, dividends and the DRSPP.

Supplemental Retirement Plan an

Supplemental Retirement Plan and Other Postretirement Benefit Obligations	3 Months Ended
	Mar. 31, 2019
Retirement Benefits [Abstract]
Employee Benefit Plans	Supplemental Retirement Plans and Other Post-Retirement Benefit Obligations Supplemental Employee Retirement Plan ("SERP") The Company has salary continuation agreements with two of its current executive officers and one former executive officer. These salary continuation agreements provide for predetermined fixed-cash supplemental retirement benefits to be provided for a period of 20 years after each individual reaches a defined "benefit age." The individuals covered under the SERP have reached the defined benefit age and are receiving payments under the plan. Additionally, the Company has not recognized service costs in the current or prior year as each officer had previously attained their individually defined benefit age and was fully vested under the plan. This non-qualified plan represents a direct liability of the Company, and as such has no specific assets set aside to settle the benefit obligation. The aggregate amount accrued, or the "accumulated benefit obligation," is equal to the present value of the benefits to be provided to the employee or any beneficiary. Because the Company's benefit obligations provide for predetermined fixed-cash payments, the Company does not have any unrecognized costs to be included as a component of accumulated other comprehensive income. Additionally, on December 11, 2018, the Board approved and adopted the Enterprise Bank Supplemental Executive Retirement and Deferred Compensation Plan. The plan is unfunded and is maintained for the purpose of providing deferred compensation to a certain group of management employees. Please refer to Exhibit 10.17 attached to the Company's 2018 Annual Report on Form 10-K and our Current Report on Form 8-K filed with the SEC on March 22, 2019 for a more complete description of the plan. Total expenses for these plans were $111 thousand for the three months ended March 31, 2019 , compared to $56 thousand for the three months ended March 31, 2018 . Benefits paid amounted to $69 thousand for both the three months ended March 31, 2019 and March 31, 2018 . The Company anticipates accruing an additional $314 thousand in total for these SERPs during the remainder of 2019 . Supplemental Life Insurance The Company has provided supplemental life insurance through split-dollar life insurance arrangements for certain executive and senior officers on whom the Bank owns BOLI. These arrangements provide a death benefit to the officer's designated beneficiaries that extend to postretirement periods for some of the supplemental life insurance plans. The Company has recognized a liability for these future postretirement benefits. These non-qualified plans represent a direct liability of the Company and, as such, the Company has no specific assets set aside to settle the benefit obligation. The funded status is the aggregate amount accrued, or the "accumulated postretirement benefit obligation," which is the present value of the post-retirement benefits associated with this arrangement. Total net periodic post-retirement benefit cost for supplemental life insurance plans, which consisted mainly of interest costs, were $50 thousand and $45 thousand for the three months ended March 31, 2019 and March 31, 2018 , respectively. See also Note 11, "Stock-Based Compensation," to the Company's unaudited consolidated interim financial statements, contained below, for further information regarding employee benefits offered in the form of stock options and stock awards.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Company currently has one active individual stock incentive plan: the Enterprise Bancorp, Inc. 2016 Stock Incentive Plan, as amended. As of March 31, 2019 , there remained 271,584 shares available for future grants under this plan. Additionally, the Enterprise Bancorp, Inc 2009 Stock Incentive Plan, as amended expired in March 2019 with 87,849 unissued shares. As such, this plan is closed for future grants, although awards previously granted under this plan remain outstanding and may be exercised through 2028. The Company's stock-based compensation expense related to these plans includes stock options and stock awards to officers and other employees included in salary and benefits expense, and stock awards and stock compensation in lieu of cash fees to non-employee directors both included in other operating expenses. Total stock-based compensation expense was $426 thousand for the three months ended March 31, 2019 , compared to $385 thousand for the three months ended March 31, 2018 . A tax benefit associated with employee exercises and vesting of stock compensation of approximately $111 thousand was recorded as a reduction of the Company's income tax expense for the three months ended March 31, 2019 , compared with $195 thousand for the three months ended March 31, 2018 . These amounts, treated as discrete tax items in the period in which they occur, will vary from year to year as a function of the volume of share-based payments vested or exercised and the then-current market price of the Company's stock in comparison to the compensation cost recognized in the Company's unaudited consolidated interim financial statements. Stock Option Awards The Company recognized stock-based compensation expense related to stock option awards of $48 thousand for the three months ended March 31, 2019 , compared to $51 thousand for the three months ended March 31, 2018 . The table below provides a summary of the options granted, including the weighted average fair value, the fair value as a percentage of the market value of the stock at the date of grant and the average assumptions used in the model for the periods indicated: Three Months Ended March 31, 2019 2018 Options granted 23,218 14,755 Term in years 10 10 Weighted average assumptions used in the fair value model: Expected volatility 33 % 37 % Expected dividend yield 2.75 % 2.10 % Expected life in years 6.5 6.5 Risk-free interest rate 2.58 % 2.86 % Weighted average market price on date of grants $ 29.84 $ 34.33 Per share weighted average fair value $ 8.70 $ 11.98 Fair value as a percentage of market value at grant date 29 % 35 % Options granted during the first three months of 2019 and 2018 generally vest 50% in year two and 50% in year four, on or about the anniversary date of the awards. The Company utilizes the Black-Scholes option valuation model in order to determine the per share grant date fair value of option grants. Restricted Stock Awards Stock-based compensation expense recognized in association with stock awards, mainly restricted stock awards, amounted to $301 thousand for the three months ended March 31, 2019 , compared to $259 thousand for the three months ended March 31, 2018 . Restricted stock awards are granted at the market price of the Company's common stock on the date of the grant. Employee awards generally vest over four years in equal portions beginning on or about the first anniversary date of the award or are performance-based awards that vest upon the Company achieving certain predefined performance objectives. Non-employee director awards generally vest over two years in equal portions beginning on or about the first anniversary date of the award. The table below provides a summary of restricted stock awards granted during the periods indicated: Three Months Ended March 31, Restricted Stock Awards (number of underlying shares) 2019 2018 Two year vesting 8,368 7,280 Four year vesting 22,403 16,666 Performance-based vesting 24,427 20,559 Total restricted stock awards granted 55,198 44,505 Weighted average grant date fair value $ 29.84 $ 34.33 Stock in Lieu of Directors' Fees In addition to restricted stock awards discussed above, the non-employee members of the Company's Board may opt to receive newly issued shares of the Company's common stock in lieu of cash compensation for attendance at Board and Board committee meetings. Stock-based compensation expense related to these directors' fees amounted to $77 thousand for the three months ended March 31, 2019 , compared to $75 thousand for the three months ended March 31, 2018 , and is included in other operating expenses. In January 2019 , non-employee directors were issued 7,470 shares of common stock in lieu of 2018 annual cash fees of $250 thousand at a market value price of $33.50 per share, the market value of the common stock on the opt-in measurement date of January 2, 2018 . For further information regarding the Company's stock awards, see Note 9, "Stockholders' Equity," to the Company's unaudited consolidated interim financial statements, contained above, under the caption "Shares Authorized and Share Issuance." There have been no material changes to the terms of the Company's stock incentive plans or the terms for vesting, forfeiture and settlement for options and restricted stock awards granted and outstanding under such plans as reported in the 2018 Annual Report on Form 10-K. Refer to Note 12, "Stock-Based Compensation Plans," to the Company's audited consolidated financial statements in the Company's 2018 Annual Report on Form 10-K for further information on the Company's stock incentive plans, stock options and restricted awards including descriptions of the assumptions used in the valuation model for stock options.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share	Earnings per Share Basic earnings per share are calculated by dividing net income available to common stockholders by the weighted average number of common shares outstanding (including participating securities) during the year. The Company's only participating securities are unvested restricted stock awards that contain non-forfeitable rights to dividends. See Note 9, "Stockholders' Equity," under the caption "Shares Authorized and Share Issuance," to the Company's unaudited consolidated interim financial statements above for further information regarding the Company's participating securities. Diluted earnings per share reflects the effect on weighted average shares outstanding of the number of additional shares outstanding if dilutive stock options were converted into common stock using the treasury stock method. The table below presents the increase in average shares outstanding, using the treasury stock method, for the diluted earnings per share calculation for the periods indicated: Three months ended March 31, 2019 2018 Basic weighted average common shares outstanding 11,730,482 11,628,587 Dilutive shares 52,923 72,267 Diluted weighted average common shares outstanding 11,783,405 11,700,854 There were 52,478 and 29,353 stock options outstanding at March 31, 2019 and March 31, 2018 , respectively that were determined to be anti-dilutive and therefore excluded from the calculation of dilutive shares for the three months ended March 31, 2019 and 2018 . These stock options, which were not dilutive at those dates, may potentially dilute earnings per share in subsequent periods.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The FASB defines the fair value of an asset or liability to be the price which a seller would receive in an orderly transaction between market participants (an exit price) and also establishes a fair value hierarchy segregating fair value measurements using three levels of inputs: (Level 1) quoted market prices in active markets for identical assets or liabilities; (Level 2) significant other observable inputs, including quoted prices for similar items in active markets, quoted prices for identical or similar items in markets that are not active, inputs such as interest rates and yield curves, volatilities, prepayment speeds, credit risks and default rates which provide a reasonable basis for fair value determination or inputs derived principally from observed market data; and (Level 3) significant unobservable inputs for situations in which there is little, if any, market activity for the asset or liability. Unobservable inputs must reflect reasonable assumptions that market participants would use in pricing the asset or liability, which are developed based on the best information available under the circumstances. The following tables summarize significant assets and liabilities carried at fair value and placement in the fair value hierarchy at the dates specified: March 31, 2019 Fair Value Measurements using: (Dollars in thousands) Fair Value (Level 1) (Level 2) (Level 3) Assets measured on a recurring basis: Debt securities $ 458,765 $ — $ 458,765 $ — Equity securities 2,049 2,049 — — FHLB stock 1,491 — — 1,491 Interest rate swaps 434 — 434 — Assets measured on a non-recurring basis: Impaired loans (collateral dependent) 2,556 — — 2,556 Other real estate owned 255 — — 255 Liabilities measured on a recurring basis: Interest rate swaps $ 434 $ — $ 434 $ — December 31, 2018 Fair Value Measurements using: (Dollars in thousands) Fair Value (Level 1) (Level 2) (Level 3) Assets measured on a recurring basis: Debt securities $ 431,473 $ — $ 431,473 $ — Equity securities 1,448 1,448 — — FHLB stock 5,357 — — 5,357 Interest rate swaps 723 — 723 — Assets measured on a non-recurring basis: Impaired loans (collateral dependent) 2,574 — — 2,574 Liabilities measured on a recurring basis: Interest rate swaps $ 723 $ — $ 723 $ — The Company did not transfer any assets between the fair value measurement levels during the three months ended March 31, 2019 or the year ended December 31, 2018 . All of the Company's debt securities are considered "available-for-sale" and are carried at fair value. The debt security category above includes federal agency obligations, commercial and residential federal agency MBS, municipal securities, corporate bonds, and CDs, as held at those dates. The Company utilizes third-party pricing vendors to provide valuations on its debt securities. Fair values provided by the vendors were generally determined based upon pricing matrices utilizing observable market data inputs for similar or benchmark securities in active markets and/or based on a matrix pricing methodology which employs The Bond Market Association's standard calculations for cash flow and price/yield analysis, live benchmark bond pricing and terms/condition data available from major pricing sources. Therefore, management regards the inputs and methods used by third-party pricing vendors to be "Level 2 inputs and methods" as defined in the "fair value hierarchy." The Company periodically obtains a second price from an impartial third party on debt securities to assess the reasonableness of prices provided by the primary independent pricing vendor. The Company's equity portfolio fair value is measured based on quoted market prices for the shares; therefore, these securities are categorized as Level 1 within the fair value hierarchy. The Bank is required to purchase FHLB stock at par value in association with advances from the FHLB. This stock is classified as a restricted investment and carried at cost which management believes approximates fair value; therefore, these securities are categorized as Level 3 measures. Impaired loan balances in the table above represent those collateral dependent impaired commercial loans where management has estimated the probable credit loss by comparing the loan's carrying value against the expected realizable fair value of the collateral (appraised value, or internal analysis, less estimated cost to sell, adjusted as necessary for changes in relevant valuation factors subsequent to the measurement date). Certain inputs used in these assessments, and possible subsequent adjustments, are not always observable, and therefore, collateral dependent impaired loans are categorized as Level 3 within the fair value hierarchy. A specific allowance is assigned to the collateral dependent impaired loan for the amount of management's estimated probable credit loss. The specific allowances assigned to the collateral dependent impaired loans amounted to $1.1 million at March 31, 2019 compared to $1.6 million at December 31, 2018 . Real estate acquired by the Company through foreclosure proceedings or the acceptance of a deed in lieu of foreclosure is classified as OREO. When property is acquired, it is recorded at the estimated fair value of the property acquired, less estimated costs to sell, establishing a new cost basis. The estimated fair value is based on market appraisals and the Company's internal analysis. Certain inputs used in appraisals or the Company's internal analysis, are not always observable, and therefore, OREO may be categorized as Level 3 within the fair value hierarchy. The fair values for the interest rate swap assets and liabilities represent a FASB Level 2 measurement and are based on settlement values adjusted for credit risks and observable market interest rate curves. The settlement values are based on discounted cash flow analysis, a widely accepted valuation technique, reflecting the contractual terms of the derivatives, including the period to maturity, and uses observable market-based inputs, including interest rate curves. Credit risk adjustments consider factors such as the likelihood of default by the Company and its counterparties, its net exposures and remaining contractual life. The change in value of interest rate swap assets and liabilities attributable to credit risk was not significant during the reported periods. Refer also to Note 8, "Derivatives and Hedging Activities," to the Company's unaudited consolidated interim financial statements, contained above, for additional information on the Company's interest rate swaps. Letters of credit are conditional commitments issued by the Company to guarantee the financial obligation or performance of a customer to a third party. The fair value of these commitments was estimated to be the fees charged to enter into similar agreements, and accordingly these fair value measures are deemed to be FASB Level 2 measurements. In accordance with the FASB, the estimated fair values of these commitments are carried on the consolidated balance sheet as a liability and amortized to income over the life of the letters of credit, which are typically one year. The estimated fair value of these commitments carried on the consolidated balance sheet at March 31, 2019 and December 31, 2018 were deemed immaterial. Interest rate lock commitments related to the origination of mortgage loans that will be sold are considered derivative instruments. The commitments to sell loans are also considered derivative instruments. The Company generally does not pool mortgage loans for sale, but instead sells the loans on an individual basis. To reduce the net interest rate exposure arising from its loan sale activity, the Company enters into the commitment to sell these loans at essentially the same time that the interest rate lock commitment is quoted on the origination of the loan. The Company estimates the fair value of these derivatives based on current secondary mortgage market prices. These commitments are accounted for in accordance with FASB guidance. The fair values of the Company's derivative instruments are deemed to be FASB Level 2 measurements. At March 31, 2019 and December 31, 2018 , the estimated fair value of the Company's interest rate lock commitments and commitments to sell these mortgage loans were deemed immaterial. The following table presents additional quantitative information about assets measured at fair value on a recurring and non-recurring basis for which the Company utilized Level 3 inputs (significant unobservable inputs for situations in which there is little, if any, market activity for the asset or liability) to determine fair value as of March 31, 2019 : (Dollars in thousands) Fair Value Valuation Technique Unobservable Input Unobservable Input Value or Range Assets measured on a recurring basis: FHLB stock $ 1,491 FHLB Stated Par Value N/A N/A Assets measured on a non-recurring basis: Impaired loans (collateral dependent) $ 2,556 Appraisal of collateral Appraisal adjustments (1) 5% - 50% Other real estate owned $ 255 Appraisal of collateral Appraisal adjustments (1) 0% - 30% __________________________________________ (1) Appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses. Estimated Fair Values of Assets and Liabilities In addition to disclosures regarding the measurement of assets and liabilities carried at fair value on the consolidated balance sheet, the Company is also required to disclose fair value information about financial instruments for which it is practicable to estimate that value, whether or not recognized on the consolidated balance sheet. The carrying values, estimated fair values and placement in the fair value hierarchy of the Company's consolidated financial instruments for which fair value is only disclosed but not recognized on the consolidated balance sheet at the dates indicated are summarized as follows: March 31, 2019 Fair value measurement (Dollars in thousands) Carrying Amount Fair Value Level 1 Inputs Level 2 Inputs Level 3 Inputs Financial assets: Loans held for sale $ 332 $ 335 $ — $ 335 $ — Loans, net 2,350,908 2,339,246 — — 2,339,246 Financial liabilities: CDs (including brokered) 337,381 336,679 — 336,679 — Borrowed funds 488 328 — 328 — Subordinated debt 14,863 14,680 — — 14,680 December 31, 2018 Fair value measurement (Dollars in thousands) Carrying Amount Fair Value Level 1 Inputs Level 2 Inputs Level 3 Inputs Financial assets: Loans held for sale $ 701 $ 710 $ — $ 710 $ — Loans, net 2,353,657 2,331,076 — — 2,331,076 Financial liabilities: CDs (including brokered) 341,014 339,308 — 339,308 — Borrowed funds 100,492 100,312 — 100,312 — Subordinated debt 14,860 14,300 — — 14,300 Excluded from the tables above are certain financial instruments with carrying values that approximated their fair value at the dates indicated, as they were short-term in nature or payable on demand. These include cash and cash equivalents and non-term deposit accounts. The respective carrying values of these instruments would all be classified within Level 1 of their fair value hierarchy. Also excluded from these tables are the fair values of commitments for unused portions of lines of credit and commitments to originate loans that were short-term, at current market rates and estimated to have no significant change in fair value.

Supplemental Cash Flow (Notes)

Supplemental Cash Flow (Notes)	3 Months Ended
	Mar. 31, 2019
Supplemental Cash Flow [Abstract]
Cash Flow, Supplemental Disclosures [Text Block]	Supplemental Cash Flow Information The supplemental cash flow information for the three months ended March 31, 2019 and March 31, 2018 is as follows: Three months ended March 31, (Dollars in thousands) 2019 2018 Supplemental financial data: Cash paid for: interest $ 5,100 $ 2,638 Cash paid for: income taxes 1,012 868 Cash paid for: lease liability 288 — Supplemental schedule of non-cash activity: Net purchases of investment securities not yet settled 1,500 — Transfer from loans to other real estate owned 255 — ROU lease assets: operating leases (1) $ 19,002 $ — _________________________________________ (1) This represents the ROU lease asset that was recorded upon adoption of ASC 842 and was primarily offset by a corresponding lease liability.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Principles of Consolidation	The accompanying unaudited consolidated interim financial statements and these notes should be read in conjunction with the December 31, 2018 audited consolidated financial statements and notes thereto contained in the 2018 Annual Report on Form 10-K of Enterprise Bancorp, Inc. as filed with the Securities and Exchange Commission (the "SEC") on March 13, 2019 (the " 2018 Annual Report on Form 10-K"). The accompanying unaudited consolidated interim financial statements of Enterprise Bancorp, Inc. (the "Company," "Enterprise," "we," or "our"), a Massachusetts corporation, include the accounts of the Company and its wholly owned subsidiary, Enterprise Bank and Trust Company, commonly referred to as Enterprise Bank (the "Bank"). The Bank is a Massachusetts trust company and state chartered commercial bank organized in 1989. Substantially all of the Company's operations are conducted through the Bank and its subsidiaries. The Company has not materially changed its accounting policies from those disclosed in its 2018 Annual Report on Form 10-K. See Item (f) "Recent Accounting Pronouncements" under the subheading "Accounting pronouncements adopted by the Company" below in this Note 1. The Bank's subsidiaries Enterprise Insurance Services, LLC and Enterprise Wealth Services, LLC, both organized under the laws of the State of Delaware, engage in insurance sales activities and offer non-deposit investment products and services, respectively. In addition, the Bank has the following subsidiaries that are incorporated in the Commonwealth of Massachusetts and classified as security corporations in accordance with applicable Massachusetts General Laws: Enterprise Security Corporation; Enterprise Security Corporation II; and Enterprise Security Corporation III. The security corporations, which hold various types of qualifying securities, are limited to conducting securities investment activities that the Bank itself would be allowed to conduct under applicable laws. The Company's headquarters and the Bank's main office are located at 222 Merrimack Street in Lowell, Massachusetts. At March 31, 2019 , the Company had 24 full service branch banking offices serving the Greater Merrimack Valley, Nashoba Valley and North Central regions of Massachusetts and Southern New Hampshire (Southern Hillsborough and Rockingham counties). Through the Bank and its subsidiaries, the Company offers a range of commercial, residential and consumer loan products, deposit products and cash management services, electronic and digital banking options, and insurance services. The Company also provides a range of wealth management, wealth services and trust services delivered via two channels, Enterprise Wealth Management and Enterprise Wealth Services. The services offered through the Bank and its subsidiaries are managed as one strategic unit and represent the Company's only reportable operating segment. The Federal Deposit Insurance Corporation (the "FDIC") and the Massachusetts Division of Banks (the "Division") have regulatory authority over the Bank. The Bank is also subject to certain regulatory requirements of the Board of Governors of the Federal Reserve System (the "Federal Reserve Board") and, with respect to its New Hampshire branch operations, the New Hampshire Banking Department. The business and operations of the Company are subject to the regulatory oversight of the Federal Reserve Board. The Division also retains supervisory jurisdiction over the Company.
Basis of Accounting	Interim results are not necessarily indicative of results to be expected for the entire year, or any future period. The accompanying unaudited consolidated interim financial statements and notes thereto have been prepared in accordance with U.S. generally accepted accounting principles ("GAAP") for interim financial information and the instructions for SEC Form 10-Q through the rules and interpretive releases of the SEC under federal securities law. In the opinion of management, the accompanying unaudited consolidated interim financial statements reflect all necessary adjustments consisting of normal recurring accruals for a fair presentation. All significant intercompany balances and transactions have been eliminated in the accompanying unaudited consolidated interim financial statements.
Reclassifications	Certain previous years' amounts in the audited consolidated financial statements, and notes thereto, have been reclassified to conform to the current year's presentation.
Subsequent events	The Company has evaluated subsequent events and transactions from March 31, 2019 through the date this Quarterly Report on Form 10-Q (this "Form 10-Q") was filed with the SEC for potential recognition or disclosure as required by GAAP and determined that there were no material subsequent events requiring recognition or disclosure.
Uses of Estimates	In preparing the unaudited consolidated interim financial statements in conformity with GAAP, management is required to exercise judgment in determining many of the methodologies, assumptions and estimates to be utilized. These assumptions and estimates affect the reported values of assets and liabilities as of the balance sheet dates and income and expenses for the period then ended. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates should the assumptions and estimates used be incorrect or change over time due to changes in circumstances. Changes in those estimates resulting from continuing changes in the economic environment and other factors will be reflected in the consolidated financial statements and results of operations in future periods. As discussed in the Company's 2018 Annual Report on Form 10-K, the three most significant areas in which management applies critical assumptions and estimates are: the estimates of the allowance for loan losses, impairment review of investment securities, and the impairment review of goodwill. Refer to Note 1, "Summary of Significant Accounting Policies," to the Company's audited consolidated financial statements included in the Company's 2018 Annual Report on Form 10-K for accounting policies related to these significant estimates. The Company has not changed its significant accounting policies from those disclosed in its 2018 Annual Report on Form 10-K.
Restricted Cash and Investments	Restricted Cash and Investments Certain of the Company's derivative agreements contain provisions for collateral to be posted if the derivative exposure exceeds a threshold amount. When the Company has pledged cash as collateral for this purpose, the cash is carried as restricted cash within "Interest-earning Deposits." See Note 8, "Derivatives and Hedging Activities," to the Company's unaudited consolidated interim financial statements below for more information about the Company's collateral related to its derivatives. The Bank is also required by the Federal Reserve Bank of Boston ("FRB") to maintain in reserves certain amounts of vault cash and/or deposits with the FRB. The average daily cash balance on hand for reserve requirements included in "Cash and Due from Banks" was approximately $2.9 million , based on the two-week computation period encompassing March 31, 2019 . As a member of the FHLB, the Company is required to purchase certain levels of FHLB capital stock at par value in association with outstanding advances from the FHLB. From time-to-time, the FHLB may initiate the repurchase, at par value, of "excess" levels of its capital stock held by member banks. This stock is classified as a restricted investment and is carried at cost, which management believes approximates fair value. FHLB stock represents the only restricted investment held by the Company. Management regularly reviews its holdings of FHLB stock for other-than-temporary-impairment ("OTTI"). Based on management's periodic review, the Company has not recorded any OTTI charges on this investment to date. If it was determined that a write-down of FHLB stock was required, impairment would be recognized through a charge to earnings. See Note 2, "Investment Securities," to the Company's unaudited consolidated interim financial statements below for additional information on management's OTTI review.
Revenue Recognition	Revenue Recognition-Accounting Standard Codification ("ASC") Topic 606 While the majority of the Company's revenue is generated from contracts with customers, our primary sources of revenue, interest and dividend income (primarily loan interest income), are outside of the scope of ASC 606, "Revenue from Contracts with Customers-Topic 606," and are accounted for under other ASC topics. The core principles of this standard require an entity to recognize revenue to depict the transfer of goods and services to customers as performance obligations are satisfied. The primary areas of income within the scope of ASC 606, which are also the first two lines of non-interest income on the Company's consolidated statements of income, are discussed below. Wealth management fees consist of income generated through Enterprise Wealth Management and Enterprise Wealth Services. Enterprise Wealth Management income is primarily generated by managing customers' financial assets. Revenue is recognized as our performance obligation is completed each month. Enterprise Wealth Services revenue is generated through a third-party arrangement to refer, manage and service customers. For new sales and referrals along with transactional type charges, the performance obligation is based on a point in time and the payment is received and revenue is recognized in the same month as the revenue-generating activity. For managing and servicing customers, revenue is recognized when our performance obligation is completed each month. Deposit and interchange fees are comprised of deposit account related charges and income generated from electronic payment interchanges. Deposit account charges consist of certain transactional analysis fees net of earning balance credits, monthly account service fees, and transactional fees such as overdraft fees. Analysis and monthly services fees are recognized over the period the service is performed. For transactional fees, the performance obligation and the revenue are recognized at a point of time and payment is typically received as the service is rendered. Interchange income is generated primarily from retail debit card transactions processed through the card payment network. The performance obligation and the revenue are recognized when the service is performed. The following non-interest income components are not subject to ASC 606: income on bank-owned life insurance ("BOLI"), net gains/losses on sales of investment securities, and net gains on sales of loans, and are covered under other ASC topics. The remaining revenue items in non-interest income are not material. See also Note 1, "Summary of Significant Accounting Policies," to the Company's audited consolidated financial statements in the Company's 2018 Annual Report on Form 10-K for additional accounting policies on revenue recognition related to income generated on investments, gains and losses on debt security sales, net gains on loans held for sale, and loans.
Income Taxes	Income Taxes The Company and its subsidiaries file income tax returns in the U.S. federal jurisdiction and in the states of Massachusetts and New Hampshire within the directives of the respective enacted tax legislation. The Company uses the asset and liability method of accounting for income taxes. Under this method, deferred tax assets and liabilities are recognized for the future tax expense or benefit attributable to differences between the financial statement carrying amounts and the tax basis of assets and liabilities. The deferred tax assets and liabilities are reflected at currently-enacted income tax rates applicable to the period in which the deferred tax assets or liabilities are expected to be realized or settled. As changes in tax laws or rates are enacted, deferred tax assets and liabilities will be adjusted accordingly through the provision for income taxes in the period that includes the enactment date. The Company's policy is to classify interest resulting from underpayment of income taxes as income tax expense in the first period the interest would begin accruing according to the provisions of the relevant tax law. The Company classifies penalties resulting from underpayment of income taxes as income tax expense in the period for which the Company claims or expects to claim an uncertain tax position or in the period in which the Company's judgment changes regarding an uncertain tax position. The income tax provisions will differ from the expense that would result from applying the federal statutory rate to income before taxes, due primarily to the impact of state tax expense, tax-exempt interest from certain investment securities, loans and BOLI and tax benefits from equity compensation deductions. The Company did not have any unrecognized tax benefits accrued as income tax liabilities or receivables or as deferred tax items at March 31, 2019 . The Company is subject to U.S. federal and state income tax examinations by taxing authorities for the 2015 through 2018 tax years.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Accounting pronouncements adopted by the Company In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, "Leases (Topic 842)," which supersedes previous leasing guidance in Topic 840. Under the new guidance, as amended, lessees are required to recognize lease (right-of-use or "ROU") assets and lease liabilities on the balance sheet for all leases with terms longer than 12 months. The Company adopted and is applying the new lease standard on leases existing on or after January 1, 2019. For the Company, this ASU primarily impacted operating leases on our facilities, mainly branch leases, and as a result the Company recorded, on its consolidated balance sheet a lease liability of $18.0 million and ROU asset of $19.0 million on January 1, 2019 related to these leases. The lease liability represents the present value of the future lease payments. The ROU asset includes the lease liability, lease prepayments and indirect costs, less accrued lease liabilities. See Note 5, "Leases," to the Company's unaudited consolidated interim financial statements, contained below, for further information regarding the Company's operating leases and associated expenses which are included in occupancy and equipment expenses on the Company's consolidated statement of income. In August 2017, the FASB issued ASU No. 2017-12, "Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities." The objective of the ASU is to better align hedge accounting with an organization's risk management activities in the financial statements. In addition, the ASU simplifies the application of hedge accounting guidance in areas where practice issues exist. The amendments expand the strategies that qualify for hedge accounting, change how many hedging relationships are presented in the financial statements and simplify the application of hedge accounting in certain situations, reducing the operational complexities associated with certain existing strategies. New or modified disclosures are required, primarily for fair value and cash flow hedges. For public business entities, the ASU was effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. The Company currently does not hold any instruments that meet hedge accounting requirements and therefore the adoption of this ASU, in January 2019, did not have an impact on the Company's unaudited consolidated interim financial statements, results of operations or disclosures, however, the Company may utilize hedging strategies in the future. In June 2018, the FASB issued ASU No. 2018-07, "Compensation-Stock-Based Compensation (Topic 718): Improvements to Nonemployee Shared-Based Payment Accounting." The amendments in the ASU expand the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees except for share-based payments used to effectively provide (1) financing to the issuer or (2) awards granted in conjunction with selling goods or services to customers as part of a contract. Additionally, Topic 718 has been updated for specific guidance on inputs to an option pricing model and the attribution of cost (that is, the period of time over which share-based payment awards vest and the pattern of cost recognition over that period). The amendments in this update were effective for public business entities for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. From time to time, the Company issues shares to community members for consulting on regional advisory councils. These shares vest immediately and the cost, which is based on the market price on the date of grant and deemed to be immaterial, is expensed in the period in which the services are rendered. The adoption of this standard in January 2019 did not have a material impact on the Company's unaudited consolidated interim financial statements, results of operations or disclosures. Accounting pronouncements not yet adopted by the Company (in order of effective date of implementation) In June 2016, the FASB issued ASU No. 2016-13, "Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments." The amendments in this ASU require a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. Previously, when credit losses were measured under GAAP, an entity generally only considered past events and current conditions in measuring the incurred loss and generally recognition of the full amount of credit losses was delayed until the loss was probable of occurring. The amendments in this ASU eliminate the probable initial recognition threshold in current GAAP and, instead, reflect an entity's current estimate of all expected credit losses (commonly known as "CECL"). The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. An entity must use judgment in determining the relevant information and estimation methods that are appropriate in its circumstances. The income statement reflects the measurement of credit losses for newly recognized financial assets, as well as the expected increases or decreases of expected credit losses that have taken place during the period. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial asset(s) to present the net carrying value at the amount expected to be collected on the financial asset. Credit losses on available-for-sale debt securities should be measured in a manner similar to current GAAP. However, the amendments in this ASU require that credit losses be presented as an allowance rather than as a write-down. Unlike current GAAP, the ASU provides for reversals of credit losses in future period net income in situations where the estimate of loss declines. An entity will apply the amendments in this ASU through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective (that is, a modified-retrospective approach). For public business entities that are SEC filers, such as the Company, the amendments in this ASU are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption for fiscal years beginning after December 15, 2018 is permitted. In April 2018, banking regulators issued a proposed revision to their capital rules that addresses the regulatory capital treatment of credit loss allowances under the CECL methodology and, if enacted as proposed, would allow banking organizations to phase in the day-one regulatory capital effects of CECL adoption over three years. The Company has established a project committee and an implementation plan for this ASU. The impact of the adoption of ASU No. 2016-13 on the Company's operations, financial results, disclosures, and controls is under evaluation. In January 2017, the FASB issued ASU No. 2017-04, "Intangibles-Goodwill and Other (Topic 350)-Simplifying the Test for Goodwill Impairment." The main provision in this ASU eliminated Step 2 of the goodwill impairment test and instead requires an entity to perform its annual, or interim, goodwill impairment test by comparing the fair value of the reporting unit with its carrying amount. An impairment charge would be recognized for the amount the carrying value exceeds the reporting unit's fair value as long as the amount recognized does not exceed the amount of goodwill allocated to the reporting unit. For public business entities that are SEC filers, such as the Company, the amendments in this ASU are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for impairment tests performed on testing dates after January 1, 2017. Goodwill carried on the Company's consolidated financial statements was $5.7 million at both March 31, 2019 and December 31, 2018 . This asset is related to the Company’s acquisition of two branch offices in July 2000. The Company does not expect the adoption of ASU No. 2017-04 to have a material impact on the Company's consolidated financial statements and results of operations. In August 2018, the FASB issued ASU No. 2018-13, "Fair Value Measurement (Topic 820-Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement." The amendments in this ASU modify the disclosure requirements primarily related to level 3 fair value measurements of the fair value hierarchy. This amendment is effective for fiscal years beginning after December 15, 2019 and interim periods within those fiscal years. Early adoption is permitted. Because this ASU primarily relates to disclosure requirements, the Company does not expect the adoption of ASU No. 2018-13 to have a material impact on the Company's consolidated financial statements and results of operations. In August 2018, the FASB issued ASU No. 2018-15, "Intangibles-Goodwill and Other- Internal-use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract." The major provision in the amendments in this ASU require an entity to capitalize certain implementation costs incurred in a hosting arrangement that is a service contract in accordance with current GAAP for internal-use software and expense these costs over the term of the hosting arrangement. Additionally, these capitalized implementation costs are required to be reviewed for impairment in accordance with current GAAP for internal-use software. This amendment is effective for fiscal years beginning after December 15, 2019 and interim periods within those fiscal years. Early adoption is permitted. The amendments in this ASU should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. The Company does not expect the adoption of ASU No. 2018-15 to have a material impact on the Company's consolidated financial statements and results of operations. In August 2018, the FASB issued ASU No. 2018-14, "Compensation-Retirement Benefits-Defined Benefit Plans-General (Subtopic 715-20) -Disclosure Framework-Changes to the Disclosure Requirements for Defined Benefit Plans." The amendments in this ASU modify the disclosure requirements on defined benefit plans including requiring disclosures about significant gains and losses related to changes in the benefit obligation. This amendment is effective for fiscal years ending after December 15, 2020. Early adoption is permitted. Because this ASU primarily relates to disclosure requirements and the balances of the benefit plans impacted by this ASU are immaterial to the Company, the adoption of ASU No. 2018-14 will not have a material impact on the Company's consolidated financial statements and results of operations.

Stockholder's Equity (Policies)

Stockholder's Equity (Policies)	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Comprehensive Income	Comprehensive income is defined as all changes to stockholders' equity except investments by and distributions to stockholders. Net income is one component of comprehensive income, with other components referred to in the aggregate as other comprehensive income. At March 31, 2019 and March 31, 2018 , the Company's only other comprehensive income component is the net unrealized holding gains or losses on available-for-sale debt securities, net of deferred income taxes. Pursuant to GAAP, the Company initially excludes these unrealized holding gains and losses from net income; however, they are later reported as reclassifications out of accumulated other comprehensive income into net income when the debt securities are sold.

Investment Securities (Tables)

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2019
Investments, Debt and Equity Securities [Abstract]
Schedule of Debt Securities, Available-for-Sale Investments Reconciliation	The amortized cost and fair values of debt securities at the dates specified are summarized as follows: March 31, 2019 (Dollars in thousands) Amortized cost Unrealized gains Unrealized losses Fair Value Federal agency obligations (1) $ 7,996 $ — $ 8 $ 7,988 Residential federal agency MBS (1) 169,682 713 2,009 168,386 Commercial federal agency MBS (1) 113,638 1,278 247 114,669 Municipal securities 150,141 2,725 197 152,669 Corporate bonds 14,003 156 54 14,105 Certificate of deposits (2) ("CDs") 950 — 2 948 Total debt securities, at fair value $ 456,410 $ 4,872 $ 2,517 $ 458,765 December 31, 2018 (Dollars in thousands) Amortized cost Unrealized gains Unrealized losses Fair Value Federal agency obligations (1) $ 7,994 $ — $ 19 $ 7,975 Residential federal agency MBS (1) 174,701 633 2,608 172,726 Commercial federal agency MBS (1) 93,800 609 430 93,979 Municipal securities 141,747 1,122 826 142,043 Corporate bonds 13,967 24 185 13,806 Certificates of deposits (2) 950 — 6 944 Total debt securities, at fair value $ 433,159 $ 2,388 $ 4,074 $ 431,473 __________________________________________ (1) These categories may include investments issued or guaranteed by government sponsored enterprises such as Fannie Mae ("FNMA"), Freddie Mac ("FHLMC"), Federal Farm Credit Bank ("FFCB"), or one of several Federal Home Loan Banks, as well as, investments guaranteed by Ginnie Mae ("GNMA"), a wholly-owned government entity. (2) CDs represent term deposits issued by banks that are subject to FDIC insurance and purchased on the open market.
Schedule of Unrealized Loss on Debt Securities, Available-for-Sale Investments	The following tables summarize debt securities with unrealized losses, due to the fair values having declined below the amortized costs of the individual investments, by the duration of their continuous unrealized loss positions at March 31, 2019 and December 31, 2018 . March 31, 2019 Less than 12 months 12 months or longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses # of holdings Federal agency obligations $ — $ — $ 6,990 $ 8 $ 6,990 $ 8 2 Residential federal agency MBS 2,519 11 98,056 1,998 100,575 2,009 22 Commercial federal agency MBS 1,009 1 18,848 246 19,857 247 6 Municipal securities — — 14,350 197 14,350 197 24 Corporate bonds — — 5,743 54 5,743 54 35 CDs — — 948 2 948 2 4 Total temporarily impaired debt securities $ 3,528 $ 12 $ 144,935 $ 2,505 $ 148,463 $ 2,517 93 December 31, 2018 Less than 12 months 12 months or longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses # of holdings Federal agency obligations $ 997 $ 1 $ 6,978 $ 18 $ 7,975 $ 19 3 Residential federal agency MBS 26,147 597 81,158 2,011 107,305 2,608 25 Commercial federal agency MBS 3,258 11 18,717 419 21,975 430 9 Municipal securities 15,036 108 41,265 718 56,301 826 83 Corporate bonds 5,277 36 5,653 149 10,930 185 63 CDs — — 944 6 944 6 4 Total temporarily impaired debt securities $ 50,715 $ 753 $ 154,715 $ 3,321 $ 205,430 $ 4,074 187
Debt Securities, Available-for-Sale Investments Classified by Contractual Maturity Date	The contractual maturity distribution at March 31, 2019 of total debt securities was as follows: (Dollars in thousands) Amortized Cost Fair Value Due in one year or less $ 11,919 $ 11,919 Due after one, but within five years 67,383 67,962 Due after five, but within ten years 175,158 177,764 Due after ten years 201,950 201,120 Total debt securities $ 456,410 $ 458,765
Schedule of Realized Gain (Loss) on Sales of Debt Securities, Available-for-Sale Investments	Sales of debt securities, including pending trades based on trade date, if applicable, for the three months ended March 31, 2019 and March 31, 2018 are summarized as follows: Three months ended March 31, (Dollars in thousands) 2019 2018 Amortized cost of debt securities sold (1) $ 1,793 $ 668 Gross realized gains on sales 2 3 Gross realized losses on sales (3 ) (2 ) Total proceeds from sales of debt securities $ 1,792 $ 669 _________________________________________ (1) Amortized cost of investments sold is determined on a specific identification basis.

Loans (Tables)

Loans (Tables)	3 Months Ended
	Mar. 31, 2019
Receivables [Abstract]
Schedule of Loans by Loan Classification	Major classifications of loans at the dates indicated were as follows: (Dollars in thousands) March 31, December 31, Commercial real estate $ 1,292,047 $ 1,303,879 Commercial and industrial 509,733 514,253 Commercial construction 244,978 234,430 Total commercial loans 2,046,758 2,052,562 Residential mortgages 233,129 231,501 Home equity loans and lines 97,798 96,116 Consumer 9,897 10,241 Total retail loans 340,824 337,858 Gross loans 2,387,582 2,390,420 Deferred loan origination fees, net (2,945 ) (2,914 ) Total loans 2,384,637 2,387,506 Allowance for loan losses (33,729 ) (33,849 ) Net loans $ 2,350,908 $ 2,353,657
Schedule of Loans Pledged as Collateral	Loans designated as qualified collateral and pledged to the FHLB for borrowing capacity for the dates indicated are summarized below: (Dollars in thousands) March 31, December 31, Commercial real estate $ 299,896 $ 311,024 Residential mortgages 220,827 220,815 Home equity 7,987 8,382 Total loans pledged to FHLB $ 528,710 $ 540,221

Allowance For Loan Loss (Tables

Allowance For Loan Loss (Tables)	3 Months Ended
	Mar. 31, 2019
Receivables [Abstract]
Financing Receivables by Evaluation Method	The balances of loans as of March 31, 2019 by portfolio classification and evaluation method are summarized as follows: (Dollars in thousands) Loans individually evaluated for impairment Loans collectively evaluated for impairment Gross Loans Commercial real estate $ 15,622 $ 1,276,425 $ 1,292,047 Commercial and industrial 11,643 498,090 509,733 Commercial construction 1,732 243,246 244,978 Residential mortgages 883 232,246 233,129 Home equity loans and lines 502 97,296 97,798 Consumer 15 9,882 9,897 Total gross loans $ 30,397 $ 2,357,185 $ 2,387,582 The balances of loans as of December 31, 2018 by portfolio classification and evaluation method are summarized as follows: (Dollars in thousands) Loans individually evaluated for impairment Loans collectively evaluated for impairment Gross Loans Commercial real estate $ 16,318 $ 1,287,561 $ 1,303,879 Commercial and industrial 12,053 502,200 514,253 Commercial construction 1,736 232,694 234,430 Residential mortgages 893 230,608 231,501 Home equity loans and lines 514 95,602 96,116 Consumer 16 10,225 10,241 Total gross loans $ 31,530 $ 2,358,890 $ 2,390,420
Financing Receivable Credit Quality Indicators	The following tables present the Company's credit risk profile for each portfolio classification by internally assigned adverse risk rating category as of the periods indicated: March 31, 2019 Adversely Classified Not Adversely (Dollars in thousands) Substandard Doubtful Loss Classified Gross Loans Commercial real estate $ 17,323 $ — $ — $ 1,274,724 $ 1,292,047 Commercial and industrial 12,642 38 — 497,053 509,733 Commercial construction 2,254 — — 242,724 244,978 Residential mortgages 1,802 — — 231,327 233,129 Home equity loans and lines 549 — — 97,249 97,798 Consumer 33 8 — 9,856 9,897 Total gross loans $ 34,603 $ 46 $ — $ 2,352,933 $ 2,387,582 December 31, 2018 Adversely Classified Not Adversely (Dollars in thousands) Substandard Doubtful Loss Classified Gross Loans Commercial real estate $ 17,714 $ 240 $ — $ 1,285,925 $ 1,303,879 Commercial and industrial 12,821 — — 501,432 514,253 Commercial construction 2,262 — — 232,168 234,430 Residential mortgages 1,820 — — 229,681 231,501 Home equity loans and lines 561 — — 95,555 96,116 Consumer 35 8 — 10,198 10,241 Total gross loans $ 35,213 $ 248 $ — $ 2,354,959 $ 2,390,420
Past Due Financing Receivables	The following tables present an age analysis of past due loans by portfolio classification as of the dates indicated: Balance at March 31, 2019 (Dollars in thousands) 30-59 Days Past Due 60-89 Days Past Due Past Due 90 days or more Total Past Due Loans Current Loans Gross Loans Non-accrual Loans Commercial real estate $ 7,650 $ — $ 3,247 $ 10,897 $ 1,281,150 $ 1,292,047 $ 6,668 Commercial and industrial 1,939 121 1,774 3,834 505,899 509,733 2,936 Commercial construction 1,769 — 174 1,943 243,035 244,978 174 Residential mortgages 1,182 — 289 1,471 231,658 233,129 754 Home equity loans and lines 97 — 92 189 97,609 97,798 502 Consumer 38 — 2 40 9,857 9,897 15 Total gross loans $ 12,675 $ 121 $ 5,578 $ 18,374 $ 2,369,208 $ 2,387,582 $ 11,049 Balance at December 31, 2018 (Dollars in thousands) 30-59 Days Past Due 60-89 Days Past Due Past Due 90 days or more Total Past Due Loans Current Loans Gross Loans Non-accrual Loans Commercial real estate $ 7,596 $ 21 $ 3,821 $ 11,438 $ 1,292,441 $ 1,303,879 $ 6,894 Commercial and industrial 619 17 2,299 2,935 511,318 514,253 3,417 Commercial construction 4,319 — — 4,319 230,111 234,430 176 Residential mortgages 114 — 377 491 231,010 231,501 763 Home equity loans and lines 14 168 209 391 95,725 96,116 514 Consumer 23 31 6 60 10,181 10,241 20 Total gross loans $ 12,685 $ 237 $ 6,712 $ 19,634 $ 2,370,786 $ 2,390,420 $ 11,784
Impaired Financing Receivables	The following tables set forth the recorded investment in impaired loans and the related specific allowance allocated by portfolio classification as of the dates indicated: Balance at March 31, 2019 (Dollars in thousands) Unpaid contractual principal balance Total recorded investment in impaired loans Recorded investment with no allowance Recorded investment with allowance Related specific allowance Commercial real estate $ 16,491 $ 15,622 $ 15,454 $ 168 $ 6 Commercial and industrial 12,147 11,643 7,522 4,121 2,112 Commercial construction 1,802 1,732 1,732 — — Residential mortgages 967 883 464 419 12 Home equity loans and lines 679 502 502 — — Consumer 15 15 — 15 14 Total $ 32,101 $ 30,397 $ 25,674 $ 4,723 $ 2,144 Balance at December 31, 2018 (Dollars in thousands) Unpaid contractual principal balance Total recorded investment in impaired loans Recorded investment with no allowance Recorded investment with allowance Related specific allowance Commercial real estate $ 17,140 $ 16,318 $ 15,948 $ 370 $ 55 Commercial and industrial 12,538 12,053 7,752 4,301 2,140 Commercial construction 1,804 1,736 1,736 — — Residential mortgages 970 893 473 420 13 Home equity loans and lines 685 514 514 — — Consumer 16 16 — 16 16 Total $ 33,153 $ 31,530 $ 26,423 $ 5,107 $ 2,224 The following table presents the average recorded investment in impaired loans by portfolio classification and the related interest recognized during the three months indicated: Three Months Ended March 31, 2019 Three Months Ended March 31, 2018 (Dollars in thousands) Average recorded investment Interest income recognized Average recorded investment Interest income recognized Commercial real estate $ 15,803 $ 120 $ 13,715 $ 94 Commercial and industrial 11,919 115 10,647 77 Commercial construction 1,734 25 1,636 22 Residential mortgages 890 1 614 (1 ) Home equity loans and lines 507 — 475 — Consumer 19 — 32 — Total $ 30,872 $ 261 $ 27,119 $ 192
Troubled Debt Restructurings on Financing Receivables	Payment defaults by portfolio classification during the three month period ended March 31, 2019 on loans modified as TDRs within the preceding twelve months are detailed below: Three months ended March 31, 2019 (Dollars in thousands) Number of TDRs that defaulted Post- modification outstanding recorded investment Commercial real estate — $ — Commercial and industrial 2 174 Commercial construction — — Residential mortgages — — Home equity loans and lines — — Consumer — — Total 2 $ 174 For the three months ended March 31, 2018 , there were no payment defaults on loans modified as TDRs within the preceding twelve months. The following table sets forth the post modification balances of TDRs listed by type of modification for TDRs that occurred during the periods indicated: Three months ended March 31, 2019 March 31, 2018 (Dollars in thousands) Number of restructurings Amount Number of restructurings Amount Temporary payment reduction and payment re-amortization of remaining principal over extended term 6 $ 607 2 $ 139 Temporary interest only payment plan — — 2 132 Other payment concessions 1 314 — — Total 7 $ 921 4 $ 271 Amount of specific reserves included in the allowance for loan losses associated with TDRs listed above $ 91 $ 120 Loans modified as TDRs during the three month periods ended March 31, 2019 and March 31, 2018 by portfolio classification are detailed below: Three months ended March 31, 2019 March 31, 2018 (Dollars in thousands) Number of restructurings Pre-modification outstanding recorded investment Post-modification outstanding recorded investment Number of restructurings Pre-modification outstanding recorded investment Post-modification outstanding recorded investment Commercial real estate 1 $ 421 $ 415 2 $ 131 $ 132 Commercial and industrial 5 194 192 2 142 139 Commercial construction — — — — — — Residential mortgages 1 315 314 — — — Home equity loans and lines — — — — — — Consumer — — — — — — Total 7 $ 930 $ 921 4 $ 273 $ 271
Allowance for Credit Losses on Financing Receivables	Changes in the allowance for loan losses by portfolio classification for the three months ended March 31, 2019 are presented below: (Dollars in thousands) Cmml Real Estate Cmml and Industrial Cmml Constr Resid. Mortgage Home Equity Consumer Total Beginning Balance at December 31, 2018 $ 18,014 $ 10,493 $ 3,307 $ 1,160 $ 629 $ 246 $ 33,849 Provision (188 ) (406 ) 145 24 (4 ) 29 (400 ) Recoveries — 316 — — 2 5 323 Less: Charge offs — — — — — 43 43 Ending Balance at March 31, 2019 $ 17,826 $ 10,403 $ 3,452 $ 1,184 $ 627 $ 237 $ 33,729 Ending allowance balance: Allocated to loans individually evaluated for impairment $ 6 $ 2,112 $ — $ 12 $ — $ 14 $ 2,144 Allocated to loans collectively evaluated for impairment $ 17,820 $ 8,291 $ 3,452 $ 1,172 $ 627 $ 223 $ 31,585 Changes in the allowance for loan losses by portfolio classification for the three months ended March 31, 2018 are presented below: (Dollars in thousands) Cmml Real Estate Cmml and Industrial Cmml Constr Resid. Mortgage Home Equity Consumer Total Beginning Balance at December 31, 2017 $ 17,545 $ 9,669 $ 3,947 $ 904 $ 608 $ 242 $ 32,915 Provision 755 1,435 (664 ) 10 20 44 1,600 Recoveries — 108 — — 1 5 114 Less: Charge offs — 41 — — — 64 105 Ending Balance at March 31, 2018 $ 18,300 $ 11,171 $ 3,283 $ 914 $ 629 $ 227 $ 34,524 Ending allowance balance: Allocated to loans individually evaluated for impairment $ 52 $ 2,776 $ — $ 4 $ — $ 22 $ 2,854 Allocated to loans collectively evaluated for impairment $ 18,248 $ 8,395 $ 3,283 $ 910 $ 629 $ 205 $ 31,670

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Operating lease liability maturity table as lessee	At March 31, 2019 , the remaining undiscounted cash flows by year of these lease liabilities were as follows: (Dollars in thousands) Operating Leases 2019 (nine remaining months) $ 891 2020 1,179 2021 1,179 2022 1,181 2023 1,188 Thereafter 24,134 Total lease payments $ 29,752 Less: Imputed interest 11,881 Total $ 17,871

Deposits (Tables)

Deposits (Tables)	3 Months Ended
	Mar. 31, 2019
Deposits [Abstract]
Schedule of Deposit Liabilities	Deposits are summarized as follows: (Dollars in thousands) March 31, 2019 December 31, 2018 Non-interest checking $ 743,151 $ 765,029 Interest-bearing checking 409,480 403,497 Savings 198,784 193,214 Money market 1,067,370 862,028 CDs $250,000 or less 228,585 215,200 CDs greater than $250,000 78,297 69,031 Total customer deposits 2,725,667 2,507,999 Brokered deposits (1) 30,499 56,783 Total deposits $ 2,756,166 $ 2,564,782 ___________________________________ (1) Brokered CDs which are $250,000 and under.

Derivatives and Hedging Activ_2

Derivatives and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivatives, Fair Value and Classification	The table below presents the fair value and classification of the Company's derivative financial instruments for the periods presented: As of March 31, 2019 As of December 31, 2018 (Dollars in thousands) Asset Derivatives Liability Derivatives Asset Derivatives Liability Derivatives Interest rate contracts - pay floating, receive fixed $ 165 $ 434 $ 45 $ 723 Interest rate contracts - pay fixed, receive floating 269 — 678 — Total interest rate swaps $ 434 $ 434 $ 723 $ 723
Schedule of Derivatives - Offsetting Assets and Liabilities	The table below presents the Company's asset derivative positions and the potential effect of those netting arrangements on its financial position, as of the periods presented. As noted above, interest-rate swaps with customers are not subject to master netting agreements and therefore are not included in the table below. As of March 31, 2019 (Dollars in thousands) Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Position Net Amounts of Assets Presented in the Statement of Financial Position Asset Derivatives Interest rate contracts - pay fixed, receive floating $ 434 $ 165 $ 269 As of December 31, 2018 (Dollars in thousands) Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Position Net Amounts of Assets Presented in the Statement of Financial Position Asset Derivatives Interest rate contracts - pay fixed, receive floating $ 723 $ 45 $ 678

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	The table below provides a summary of the options granted, including the weighted average fair value, the fair value as a percentage of the market value of the stock at the date of grant and the average assumptions used in the model for the periods indicated: Three Months Ended March 31, 2019 2018 Options granted 23,218 14,755 Term in years 10 10 Weighted average assumptions used in the fair value model: Expected volatility 33 % 37 % Expected dividend yield 2.75 % 2.10 % Expected life in years 6.5 6.5 Risk-free interest rate 2.58 % 2.86 % Weighted average market price on date of grants $ 29.84 $ 34.33 Per share weighted average fair value $ 8.70 $ 11.98 Fair value as a percentage of market value at grant date 29 % 35 %
Schedule of Restricted Stock Awards Granted	The table below provides a summary of restricted stock awards granted during the periods indicated: Three Months Ended March 31, Restricted Stock Awards (number of underlying shares) 2019 2018 Two year vesting 8,368 7,280 Four year vesting 22,403 16,666 Performance-based vesting 24,427 20,559 Total restricted stock awards granted 55,198 44,505 Weighted average grant date fair value $ 29.84 $ 34.33

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Schedule of Weighted Average Number of Shares	The table below presents the increase in average shares outstanding, using the treasury stock method, for the diluted earnings per share calculation for the periods indicated: Three months ended March 31, 2019 2018 Basic weighted average common shares outstanding 11,730,482 11,628,587 Dilutive shares 52,923 72,267 Diluted weighted average common shares outstanding 11,783,405 11,700,854

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on Recurring and Nonrecurring Basis	The following tables summarize significant assets and liabilities carried at fair value and placement in the fair value hierarchy at the dates specified: March 31, 2019 Fair Value Measurements using: (Dollars in thousands) Fair Value (Level 1) (Level 2) (Level 3) Assets measured on a recurring basis: Debt securities $ 458,765 $ — $ 458,765 $ — Equity securities 2,049 2,049 — — FHLB stock 1,491 — — 1,491 Interest rate swaps 434 — 434 — Assets measured on a non-recurring basis: Impaired loans (collateral dependent) 2,556 — — 2,556 Other real estate owned 255 — — 255 Liabilities measured on a recurring basis: Interest rate swaps $ 434 $ — $ 434 $ — December 31, 2018 Fair Value Measurements using: (Dollars in thousands) Fair Value (Level 1) (Level 2) (Level 3) Assets measured on a recurring basis: Debt securities $ 431,473 $ — $ 431,473 $ — Equity securities 1,448 1,448 — — FHLB stock 5,357 — — 5,357 Interest rate swaps 723 — 723 — Assets measured on a non-recurring basis: Impaired loans (collateral dependent) 2,574 — — 2,574 Liabilities measured on a recurring basis: Interest rate swaps $ 723 $ — $ 723 $ —
Quantitative Information About Significant Unobservable Inputs for Fair Value Measurements	The following table presents additional quantitative information about assets measured at fair value on a recurring and non-recurring basis for which the Company utilized Level 3 inputs (significant unobservable inputs for situations in which there is little, if any, market activity for the asset or liability) to determine fair value as of March 31, 2019 : (Dollars in thousands) Fair Value Valuation Technique Unobservable Input Unobservable Input Value or Range Assets measured on a recurring basis: FHLB stock $ 1,491 FHLB Stated Par Value N/A N/A Assets measured on a non-recurring basis: Impaired loans (collateral dependent) $ 2,556 Appraisal of collateral Appraisal adjustments (1) 5% - 50% Other real estate owned $ 255 Appraisal of collateral Appraisal adjustments (1) 0% - 30% __________________________________________ (1) Appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses.
Fair Value, by Balance Sheet Grouping	The carrying values, estimated fair values and placement in the fair value hierarchy of the Company's consolidated financial instruments for which fair value is only disclosed but not recognized on the consolidated balance sheet at the dates indicated are summarized as follows: March 31, 2019 Fair value measurement (Dollars in thousands) Carrying Amount Fair Value Level 1 Inputs Level 2 Inputs Level 3 Inputs Financial assets: Loans held for sale $ 332 $ 335 $ — $ 335 $ — Loans, net 2,350,908 2,339,246 — — 2,339,246 Financial liabilities: CDs (including brokered) 337,381 336,679 — 336,679 — Borrowed funds 488 328 — 328 — Subordinated debt 14,863 14,680 — — 14,680 December 31, 2018 Fair value measurement (Dollars in thousands) Carrying Amount Fair Value Level 1 Inputs Level 2 Inputs Level 3 Inputs Financial assets: Loans held for sale $ 701 $ 710 $ — $ 710 $ — Loans, net 2,353,657 2,331,076 — — 2,331,076 Financial liabilities: CDs (including brokered) 341,014 339,308 — 339,308 — Borrowed funds 100,492 100,312 — 100,312 — Subordinated debt 14,860 14,300 — — 14,300

Supplemental Cash Flow (Tables)

Supplemental Cash Flow (Tables)	3 Months Ended
	Mar. 31, 2019
Supplemental Cash Flow [Abstract]
Schedule of Cash Flow, Supplemental Disclosures [Table Text Block]	The supplemental cash flow information for the three months ended March 31, 2019 and March 31, 2018 is as follows: Three months ended March 31, (Dollars in thousands) 2019 2018 Supplemental financial data: Cash paid for: interest $ 5,100 $ 2,638 Cash paid for: income taxes 1,012 868 Cash paid for: lease liability 288 — Supplemental schedule of non-cash activity: Net purchases of investment securities not yet settled 1,500 — Transfer from loans to other real estate owned 255 — ROU lease assets: operating leases (1) $ 19,002 $ — _________________________________________ (1) This represents the ROU lease asset that was recorded upon adoption of ASC 842 and was primarily offset by a corresponding lease liability.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)branchessegment	Jan. 01, 2019USD ($)	Dec. 31, 2018USD ($)	Jul. 31, 2000branches
Summary of Significant Accounting Policies [Line Items]
Number of branches | branches	24
Reportable operating segments | segment	1
Federal Reserve Bank Average Daily Reserve Requirement included in Cash and Due from Banks	$ 2,900
Lease liability	17,871		$ 0
Lease right-of-use asset	18,851		0
Goodwill	$ 5,656		$ 5,656
Number of offices related to the goodwill in acquisition | branches				2
Accounting Standards Update 2016-02
Summary of Significant Accounting Policies [Line Items]
Lease liability		$ 18,000
Lease right-of-use asset		$ 19,000

Investment Securities Available

Investment Securities Available-for-Sale (Details) - USD ($) $ in Thousands		Mar. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Debt securities at fair value		$ 458,765	$ 431,473
Debt securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost		456,410	433,159
Debt Securities,Gross Unrealized Gains		4,872	2,388
Debt Securities, Gross Unrealized Loss		2,517	4,074
Debt securities at fair value		458,765	431,473
Federal agency obligations
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	[1]	7,996	7,994
Debt Securities,Gross Unrealized Gains	[1]	0	0
Debt Securities, Gross Unrealized Loss	[1]	8	19
Debt securities at fair value	[1]	7,988	7,975
Residential federal agency MBS
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	[1]	169,682	174,701
Debt Securities,Gross Unrealized Gains	[1]	713	633
Debt Securities, Gross Unrealized Loss	[1]	2,009	2,608
Debt securities at fair value	[1]	168,386	172,726
Commercial federal agency MBS
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	[1]	113,638	93,800
Debt Securities,Gross Unrealized Gains	[1]	1,278	609
Debt Securities, Gross Unrealized Loss	[1]	247	430
Debt securities at fair value	[1]	114,669	93,979
Collateralized Mortgage Obligations
Debt Securities, Available-for-sale [Line Items]
Debt securities at fair value		259,300	242,800
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost		150,141	141,747
Debt Securities,Gross Unrealized Gains		2,725	1,122
Debt Securities, Gross Unrealized Loss		197	826
Debt securities at fair value		152,669	142,043
Tax-exempt municipal securities
Debt Securities, Available-for-sale [Line Items]
Debt securities at fair value		106,300	107,300
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost		14,003	13,967
Debt Securities,Gross Unrealized Gains		156	24
Debt Securities, Gross Unrealized Loss		54	185
Debt securities at fair value		14,105	13,806
Certificates of Deposit
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale, Amortized Cost	[2]	950	950
Debt Securities,Gross Unrealized Gains	[2]	0	0
Debt Securities, Gross Unrealized Loss	[2]	2	6
Debt securities at fair value	[2]	948	$ 944
Collateral Pledged
Debt Securities, Available-for-sale [Line Items]
Debt securities, pledged as collateral		$ 456,300
[1]	These categories may include investments issued or guaranteed by government sponsored enterprises such as Fannie Mae ("FNMA"), Freddie Mac ("FHLMC"), Federal Farm Credit Bank ("FFCB"), or one of several Federal Home Loan Banks, as well as, investments guaranteed by Ginnie Mae ("GNMA"), a wholly-owned government entity.
[2]	CDs represent term deposits issued by banks that are subject to FDIC insurance and purchased on the open market.

Investment Securities Availab_2

Investment Securities Available-for-Sale - Continuous Loss Position (Details) $ in Thousands	Mar. 31, 2019USD ($)investments	Dec. 31, 2018USD ($)investments
Debt Securities, Available-for-sale [Line Items]
Debt Securities, temporarily impaired, Less than 12 Months, fair value	$ 3,528	$ 50,715
Debt Securities, temporarily impaired,less than 12 months, unrealized loss	12	753
Debt securities,temporarily impaired, 12 months or longer, fair value	144,935	154,715
Debt securities, temporarily impaired, 12 months or longer, unrealized loss	2,505	3,321
Debt securities, temporarily impaired, fair value	148,463	205,430
Debt securities,temporarily impaired, unrealized loss	$ 2,517	$ 4,074
Number of debt securities in loss positions | investments	93	187
Federal agency obligations
Debt Securities, Available-for-sale [Line Items]
Debt Securities, temporarily impaired, Less than 12 Months, fair value	$ 0	$ 997
Debt Securities, temporarily impaired,less than 12 months, unrealized loss	0	1
Debt securities,temporarily impaired, 12 months or longer, fair value	6,990	6,978
Debt securities, temporarily impaired, 12 months or longer, unrealized loss	8	18
Debt securities, temporarily impaired, fair value	6,990	7,975
Debt securities,temporarily impaired, unrealized loss	$ 8	$ 19
Number of debt securities in loss positions | investments	2	3
Residential federal agency MBS
Debt Securities, Available-for-sale [Line Items]
Debt Securities, temporarily impaired, Less than 12 Months, fair value	$ 2,519	$ 26,147
Debt Securities, temporarily impaired,less than 12 months, unrealized loss	11	597
Debt securities,temporarily impaired, 12 months or longer, fair value	98,056	81,158
Debt securities, temporarily impaired, 12 months or longer, unrealized loss	1,998	2,011
Debt securities, temporarily impaired, fair value	100,575	107,305
Debt securities,temporarily impaired, unrealized loss	$ 2,009	$ 2,608
Number of debt securities in loss positions | investments	22	25
Commercial federal agency MBS
Debt Securities, Available-for-sale [Line Items]
Debt Securities, temporarily impaired, Less than 12 Months, fair value	$ 1,009	$ 3,258
Debt Securities, temporarily impaired,less than 12 months, unrealized loss	1	11
Debt securities,temporarily impaired, 12 months or longer, fair value	18,848	18,717
Debt securities, temporarily impaired, 12 months or longer, unrealized loss	246	419
Debt securities, temporarily impaired, fair value	19,857	21,975
Debt securities,temporarily impaired, unrealized loss	$ 247	$ 430
Number of debt securities in loss positions | investments	6	9
Municipal securities
Debt Securities, Available-for-sale [Line Items]
Debt Securities, temporarily impaired, Less than 12 Months, fair value	$ 0	$ 15,036
Debt Securities, temporarily impaired,less than 12 months, unrealized loss	0	108
Debt securities,temporarily impaired, 12 months or longer, fair value	14,350	41,265
Debt securities, temporarily impaired, 12 months or longer, unrealized loss	197	718
Debt securities, temporarily impaired, fair value	14,350	56,301
Debt securities,temporarily impaired, unrealized loss	$ 197	$ 826
Number of debt securities in loss positions | investments	24	83
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Debt Securities, temporarily impaired, Less than 12 Months, fair value	$ 0	$ 5,277
Debt Securities, temporarily impaired,less than 12 months, unrealized loss	0	36
Debt securities,temporarily impaired, 12 months or longer, fair value	5,743	5,653
Debt securities, temporarily impaired, 12 months or longer, unrealized loss	54	149
Debt securities, temporarily impaired, fair value	5,743	10,930
Debt securities,temporarily impaired, unrealized loss	$ 54	$ 185
Number of debt securities in loss positions | investments	35	63
Certificates of Deposit
Debt Securities, Available-for-sale [Line Items]
Debt Securities, temporarily impaired, Less than 12 Months, fair value	$ 0	$ 0
Debt Securities, temporarily impaired,less than 12 months, unrealized loss	0	0
Debt securities,temporarily impaired, 12 months or longer, fair value	948	944
Debt securities, temporarily impaired, 12 months or longer, unrealized loss	2	6
Debt securities, temporarily impaired, fair value	948	944
Debt securities,temporarily impaired, unrealized loss	$ 2	$ 6
Number of debt securities in loss positions | investments	4	4

Investment Securities Availab_3

Investment Securities Available-for-Sale -Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Debt Securities at fair value	$ 458,765	$ 431,473
Debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost, Within One Year	11,919
Fair Value, Within One Year	11,919
Amortized Cost Basis, After One, But Within Five Years	67,383
Fair Value, After One, But Within Five Years	67,962
Amortized Cost, After Five, But Within Ten Years	175,158
Fair Value, After Five but Within Ten Years	177,764
Amortized Cost Basis, After Ten Years	201,950
Fair Value, After Ten Years	201,120
Debt Securities, Available-for-sale, Amortized Cost	456,410	433,159
Debt Securities at fair value	458,765	$ 431,473
Callable debt securities, fair value	$ 83,900

Investment Securities Availab_4

Investment Securities Available-for-Sale -Sales (Details) - Debt securities - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Gain (Loss) on Securities [Line Items]
Amortized cost of debt securities sold, including pending trades	$ 1,793	$ 668
Debt Securities, Available-for-sale, Realized Gain	2	3
Debt Securities, Available-for-sale, Realized Loss	(3)	(2)
Proceeds from sale of debt securities, including pending trades	$ 1,792	$ 669

Investment Securities Equity Se

Investment Securities Equity Securities (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Marketable Securities [Line Items]
Equity securities	$ 2,049,000		$ 1,448,000
Marketable Securities, Amortized Cost Basis, Investments Sold, Including Pending Trades	0	$ 0
Net fair value gain (loss) on equity securities	$ 186,000	$ (5,000)

Loans - Balance by Class of Loa

Loans - Balance by Class of Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Schedule of Loans by Loan Classification [Line Items]
Gross loans	$ 2,387,582	$ 2,390,420
Deferred loan origination fees, net	(2,945)	(2,914)
Total loans	2,384,637	2,387,506
Allowance for loan losses	(33,729)	(33,849)	$ (34,524)	$ (32,915)
Net Loans	2,350,908	2,353,657
Commercial
Schedule of Loans by Loan Classification [Line Items]
Gross loans	2,046,758	2,052,562
Commercial real estate
Schedule of Loans by Loan Classification [Line Items]
Gross loans	1,292,047	1,303,879
Allowance for loan losses	(17,826)	(18,014)	(18,300)	(17,545)
Commercial and industrial
Schedule of Loans by Loan Classification [Line Items]
Gross loans	509,733	514,253
Allowance for loan losses	(10,403)	(10,493)	(11,171)	(9,669)
Commercial construction
Schedule of Loans by Loan Classification [Line Items]
Gross loans	244,978	234,430
Allowance for loan losses	(3,452)	(3,307)	(3,283)	(3,947)
Retail
Schedule of Loans by Loan Classification [Line Items]
Gross loans	340,824	337,858
Residential
Schedule of Loans by Loan Classification [Line Items]
Gross loans	233,129	231,501
Allowance for loan losses	(1,184)	(1,160)	(914)	(904)
Home Equity
Schedule of Loans by Loan Classification [Line Items]
Gross loans	97,798	96,116
Allowance for loan losses	(627)	(629)	(629)	(608)
Consumer
Schedule of Loans by Loan Classification [Line Items]
Gross loans	9,897	10,241
Allowance for loan losses	$ (237)	$ (246)	$ (227)	$ (242)

Loans - Loan Categories Narrati

Loans - Loan Categories Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Commercial
Schedule of Loans by Loan Classification [Line Items]
Participation loans amount	$ 65.5	$ 63.5
Participations loans sold that are still serviced amount	73.1	72.1
Residential
Schedule of Loans by Loan Classification [Line Items]
Amount of loans serviced for others	$ 17.1	$ 17.2

Loans - Loans Serving as Collat

Loans - Loans Serving as Collateral (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Financial Instruments Owned and Pledged as Collateral [Line Items]
Loans pledged to the FHLB for borrowing capacity	$ 528,710	$ 540,221
Commercial real estate
Financial Instruments Owned and Pledged as Collateral [Line Items]
Loans pledged to the FHLB for borrowing capacity	299,896	311,024
Residential
Financial Instruments Owned and Pledged as Collateral [Line Items]
Loans pledged to the FHLB for borrowing capacity	220,827	220,815
Home Equity
Financial Instruments Owned and Pledged as Collateral [Line Items]
Loans pledged to the FHLB for borrowing capacity	$ 7,987	$ 8,382

Allowance For Loan Loss - Evalu

Allowance For Loan Loss - Evaluation Method (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Schedule of Financing Receivable by Evaluation Method [Line Items]
Loans individually evaluated for impairment	$ 30,397	$ 31,530
Loans collectively evaluated for impairment	2,357,185	2,358,890
Gross loans	2,387,582	2,390,420
Commercial real estate
Schedule of Financing Receivable by Evaluation Method [Line Items]
Loans individually evaluated for impairment	15,622	16,318
Loans collectively evaluated for impairment	1,276,425	1,287,561
Gross loans	1,292,047	1,303,879
Commercial and industrial
Schedule of Financing Receivable by Evaluation Method [Line Items]
Loans individually evaluated for impairment	11,643	12,053
Loans collectively evaluated for impairment	498,090	502,200
Gross loans	509,733	514,253
Commercial construction
Schedule of Financing Receivable by Evaluation Method [Line Items]
Loans individually evaluated for impairment	1,732	1,736
Loans collectively evaluated for impairment	243,246	232,694
Gross loans	244,978	234,430
Residential
Schedule of Financing Receivable by Evaluation Method [Line Items]
Loans individually evaluated for impairment	883	893
Loans collectively evaluated for impairment	232,246	230,608
Gross loans	233,129	231,501
Home Equity
Schedule of Financing Receivable by Evaluation Method [Line Items]
Loans individually evaluated for impairment	502	514
Loans collectively evaluated for impairment	97,296	95,602
Gross loans	97,798	96,116
Consumer
Schedule of Financing Receivable by Evaluation Method [Line Items]
Loans individually evaluated for impairment	15	16
Loans collectively evaluated for impairment	9,882	10,225
Gross loans	$ 9,897	$ 10,241

Allowance For Loan Loss - Adver

Allowance For Loan Loss - Adversely Classified Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment [Line Items]
Gross loans	$ 2,387,582	$ 2,390,420
Adversely classified loans to total loans	1.45%	1.49%
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	$ 1,292,047	$ 1,303,879
Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Gross loans	509,733	514,253
Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Gross loans	244,978	234,430
Residential
Financing Receivable, Recorded Investment [Line Items]
Gross loans	233,129	231,501
Home Equity
Financing Receivable, Recorded Investment [Line Items]
Gross loans	97,798	96,116
Consumer
Financing Receivable, Recorded Investment [Line Items]
Gross loans	9,897	10,241
Substandard
Financing Receivable, Recorded Investment [Line Items]
Gross loans	34,603	35,213
Substandard | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	17,323	17,714
Substandard | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Gross loans	12,642	12,821
Substandard | Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Gross loans	2,254	2,262
Substandard | Residential
Financing Receivable, Recorded Investment [Line Items]
Gross loans	1,802	1,820
Substandard | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Gross loans	549	561
Substandard | Consumer
Financing Receivable, Recorded Investment [Line Items]
Gross loans	33	35
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Gross loans	46	248
Doubtful | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	240
Doubtful | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Gross loans	38	0
Doubtful | Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	0
Doubtful | Residential
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	0
Doubtful | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	0
Doubtful | Consumer
Financing Receivable, Recorded Investment [Line Items]
Gross loans	8	8
Loss
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	0
Loss | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	0
Loss | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	0
Loss | Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	0
Loss | Residential
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	0
Loss | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	0
Loss | Consumer
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	0
Not Adversely Classified
Financing Receivable, Recorded Investment [Line Items]
Gross loans	2,352,933	2,354,959
Not Adversely Classified | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	1,274,724	1,285,925
Not Adversely Classified | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Gross loans	497,053	501,432
Not Adversely Classified | Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Gross loans	242,724	232,168
Not Adversely Classified | Residential
Financing Receivable, Recorded Investment [Line Items]
Gross loans	231,327	229,681
Not Adversely Classified | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Gross loans	97,249	95,555
Not Adversely Classified | Consumer
Financing Receivable, Recorded Investment [Line Items]
Gross loans	$ 9,856	$ 10,198

Allowance For Loan Loss - Past

Allowance For Loan Loss - Past Due and Non-Accrual Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	$ 2,387,582	$ 2,390,420
Total Past Due Loans	18,374	19,634
Current Loans	2,369,208	2,370,786
Non-accrual loans	$ 11,049	$ 11,784
The ratio of non-accrual loans to total loans	0.46%	0.49%
Commercial real estate
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	$ 1,292,047	$ 1,303,879
Total Past Due Loans	10,897	11,438
Current Loans	1,281,150	1,292,441
Non-accrual loans	6,668	6,894
Commercial and industrial
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	509,733	514,253
Total Past Due Loans	3,834	2,935
Current Loans	505,899	511,318
Non-accrual loans	2,936	3,417
Commercial construction
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	244,978	234,430
Total Past Due Loans	1,943	4,319
Current Loans	243,035	230,111
Non-accrual loans	174	176
Residential
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	233,129	231,501
Total Past Due Loans	1,471	491
Current Loans	231,658	231,010
Non-accrual loans	754	763
Home Equity
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	97,798	96,116
Total Past Due Loans	189	391
Current Loans	97,609	95,725
Non-accrual loans	502	514
Consumer
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	9,897	10,241
Total Past Due Loans	40	60
Current Loans	9,857	10,181
Non-accrual loans	15	20
Loans 30-59 Days Past Due
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	12,675	12,685
Loans 30-59 Days Past Due | Commercial real estate
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	7,650	7,596
Loans 30-59 Days Past Due | Commercial and industrial
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	1,939	619
Loans 30-59 Days Past Due | Commercial construction
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	1,769	4,319
Loans 30-59 Days Past Due | Residential
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	1,182	114
Loans 30-59 Days Past Due | Home Equity
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	97	14
Loans 30-59 Days Past Due | Consumer
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	38	23
Loans 60-89 Days Past Due
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	121	237
Loans 60-89 Days Past Due | Commercial real estate
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	0	21
Loans 60-89 Days Past Due | Commercial and industrial
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	121	17
Loans 60-89 Days Past Due | Commercial construction
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	0	0
Loans 60-89 Days Past Due | Residential
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	0	0
Loans 60-89 Days Past Due | Home Equity
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	0	168
Loans 60-89 Days Past Due | Consumer
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	0	31
Loans equal to or greater than 90 days past due
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	5,578	6,712
Loans equal to or greater than 90 days past due | Commercial real estate
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	3,247	3,821
Loans equal to or greater than 90 days past due | Commercial and industrial
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	1,774	2,299
Loans equal to or greater than 90 days past due | Commercial construction
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	174	0
Loans equal to or greater than 90 days past due | Residential
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	289	377
Loans equal to or greater than 90 days past due | Home Equity
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	92	209
Loans equal to or greater than 90 days past due | Consumer
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	2	6
Not Adversely Classified
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	2,352,933	2,354,959
Non-accrual loans not adversely classified	80	81
Not Adversely Classified | Commercial real estate
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	1,274,724	1,285,925
Not Adversely Classified | Commercial and industrial
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	497,053	501,432
Not Adversely Classified | Commercial construction
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	242,724	232,168
Not Adversely Classified | Residential
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	231,327	229,681
Not Adversely Classified | Home Equity
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	97,249	95,555
Not Adversely Classified | Consumer
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	$ 9,856	$ 10,198

Allowance For Loan Loss - Impai

Allowance For Loan Loss - Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Total recorded investment in impaired loans	$ 30,397		$ 31,530
Total accruing impaired loans	19,300		19,700
Impaired non-accrual loans	11,000		11,800
Unpaid contractual principal balance	32,101		33,153
Recorded investment with no allowance	25,674		26,423
Recorded investment with allowance	4,723		5,107
Related allowance	2,144		2,224
Average recorded investment	30,872	$ 27,119
Interest income recognized	261	192
Commercial real estate
Financing Receivable, Impaired [Line Items]
Total recorded investment in impaired loans	15,622		16,318
Unpaid contractual principal balance	16,491		17,140
Recorded investment with no allowance	15,454		15,948
Recorded investment with allowance	168		370
Related allowance	6		55
Average recorded investment	15,803	13,715
Interest income recognized	120	94
Commercial and industrial
Financing Receivable, Impaired [Line Items]
Total recorded investment in impaired loans	11,643		12,053
Unpaid contractual principal balance	12,147		12,538
Recorded investment with no allowance	7,522		7,752
Recorded investment with allowance	4,121		4,301
Related allowance	2,112		2,140
Average recorded investment	11,919	10,647
Interest income recognized	115	77
Commercial construction
Financing Receivable, Impaired [Line Items]
Total recorded investment in impaired loans	1,732		1,736
Unpaid contractual principal balance	1,802		1,804
Recorded investment with no allowance	1,732		1,736
Recorded investment with allowance	0		0
Related allowance	0		0
Average recorded investment	1,734	1,636
Interest income recognized	25	22
Residential
Financing Receivable, Impaired [Line Items]
Total recorded investment in impaired loans	883		893
Unpaid contractual principal balance	967		970
Recorded investment with no allowance	464		473
Recorded investment with allowance	419		420
Related allowance	12		13
Average recorded investment	890	614
Interest income recognized	1	(1)
Home Equity
Financing Receivable, Impaired [Line Items]
Total recorded investment in impaired loans	502		514
Unpaid contractual principal balance	679		685
Recorded investment with no allowance	502		514
Recorded investment with allowance	0		0
Related allowance	0		0
Average recorded investment	507	475
Interest income recognized	0	0
Consumer
Financing Receivable, Impaired [Line Items]
Total recorded investment in impaired loans	15		16
Unpaid contractual principal balance	15		16
Recorded investment with no allowance	0		0
Recorded investment with allowance	15		16
Related allowance	14		$ 16
Average recorded investment	19	32
Interest income recognized	$ 0	$ 0

Allowance For Loan Loss - Troub

Allowance For Loan Loss - Troubled Debt Restructures (Details)	3 Months Ended
	Mar. 31, 2019USD ($)restructuring	Mar. 31, 2018USD ($)restructuring	Dec. 31, 2018USD ($)
Financing Receivable, Modifications [Line Items]
Total Troubled Debt Restructure (TDR) loans	$ 23,500,000		$ 23,100,000
TDR loans on accrual status	19,300,000		19,400,000
TDR loans included in non-performing loans	$ 4,200,000		$ 3,700,000
Number of restructurings | restructuring	7	4
Post-modification recorded investment	$ 921,000	$ 271,000
Specific reserves allocated to TDRs	91,000	120,000
Pre-modification outstanding recorded investment	930,000	273,000
Charge-offs associated with TDRs	$ 0	$ 0
Number of TDRs that defaulted | restructuring	2	0
Post-modification outstanding recorded investment, TDRs that defaulted	$ 174,000
Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	1	2
Post-modification recorded investment	$ 415,000	$ 132,000
Pre-modification outstanding recorded investment	$ 421,000	$ 131,000
Number of TDRs that defaulted | restructuring	0
Post-modification outstanding recorded investment, TDRs that defaulted	$ 0
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	5	2
Post-modification recorded investment	$ 192,000	$ 139,000
Pre-modification outstanding recorded investment	$ 194,000	$ 142,000
Number of TDRs that defaulted | restructuring	2
Post-modification outstanding recorded investment, TDRs that defaulted	$ 174,000
Commercial construction
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	0	0
Post-modification recorded investment	$ 0	$ 0
Pre-modification outstanding recorded investment	$ 0	$ 0
Number of TDRs that defaulted | restructuring	0
Post-modification outstanding recorded investment, TDRs that defaulted	$ 0
Residential
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	1	0
Post-modification recorded investment	$ 314,000	$ 0
Pre-modification outstanding recorded investment	$ 315,000	$ 0
Number of TDRs that defaulted | restructuring	0
Post-modification outstanding recorded investment, TDRs that defaulted	$ 0
Home Equity
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	0	0
Post-modification recorded investment	$ 0	$ 0
Pre-modification outstanding recorded investment	$ 0	$ 0
Number of TDRs that defaulted | restructuring	0
Post-modification outstanding recorded investment, TDRs that defaulted	$ 0
Consumer
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	0	0
Post-modification recorded investment	$ 0	$ 0
Pre-modification outstanding recorded investment	$ 0	$ 0
Number of TDRs that defaulted | restructuring	0
Post-modification outstanding recorded investment, TDRs that defaulted	$ 0
Temporary payment reduction and payment re-amortization of remaining principal over extended term
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	6	2
Post-modification recorded investment	$ 607,000	$ 139,000
Temporary interest only payment plan
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	0	2
Post-modification recorded investment	$ 0	$ 132,000
Other payment concessions
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	1	0
Post-modification recorded investment	$ 314,000	$ 0

Allowance For Loan Loss - Other

Allowance For Loan Loss - Other Real Estate Owned (Details)	3 Months Ended
	Mar. 31, 2019USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value of OREO	$ 255,000	$ 0	$ 0
Net gains on sales of OREO	0	$ 0
Consumer Mortgage Loans in Process of Foreclosure, Amount	$ 0		$ 0
Other real estate owned
Accounts, Notes, Loans and Financing Receivable [Line Items]
OREO Additions	1	0
OREO fair value adjustment	$ 0	$ 0

Allowance For Loan Loss - Allow

Allowance For Loan Loss - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses to total loans ratio	1.41%	1.51%	1.42%
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	$ 33,849	$ 32,915
Provision for loan losses	(400)	1,600
Recoveries	323	114
Less: Charge offs	43	105
Ending Balance	33,729	34,524
Allocated to loans individually evaluated for impairment	2,144	2,854
Allocated to loans collectively evaluated for impairment	31,585	31,670
Commercial real estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	18,014	17,545
Provision for loan losses	(188)	755
Recoveries	0	0
Less: Charge offs	0	0
Ending Balance	17,826	18,300
Allocated to loans individually evaluated for impairment	6	52
Allocated to loans collectively evaluated for impairment	17,820	18,248
Commercial and industrial
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	10,493	9,669
Provision for loan losses	(406)	1,435
Recoveries	316	108
Less: Charge offs	0	41
Ending Balance	10,403	11,171
Allocated to loans individually evaluated for impairment	2,112	2,776
Allocated to loans collectively evaluated for impairment	8,291	8,395
Commercial construction
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	3,307	3,947
Provision for loan losses	145	(664)
Recoveries	0	0
Less: Charge offs	0	0
Ending Balance	3,452	3,283
Allocated to loans individually evaluated for impairment	0	0
Allocated to loans collectively evaluated for impairment	3,452	3,283
Residential
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	1,160	904
Provision for loan losses	24	10
Recoveries	0	0
Less: Charge offs	0	0
Ending Balance	1,184	914
Allocated to loans individually evaluated for impairment	12	4
Allocated to loans collectively evaluated for impairment	1,172	910
Home Equity
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	629	608
Provision for loan losses	(4)	20
Recoveries	2	1
Less: Charge offs	0	0
Ending Balance	627	629
Allocated to loans individually evaluated for impairment	0	0
Allocated to loans collectively evaluated for impairment	627	629
Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance	246	242
Provision for loan losses	29	44
Recoveries	5	5
Less: Charge offs	43	64
Ending Balance	237	227
Allocated to loans individually evaluated for impairment	14	22
Allocated to loans collectively evaluated for impairment	$ 223	$ 205

Leases Narrative (Details)

Leases Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)property	Jan. 01, 2019USD ($)	Dec. 31, 2018USD ($)
Lessee, Lease, Description [Line Items]
Number of operating leases | property	15
Operating lease under agreement to be purchased | property	1
Lease liability	$ 17,871		$ 0
Lease right-of-use asset	18,851		$ 0
Operating lease expense	$ 319
Weighted average remaining lease term on operating leases	28 years 6 months
Weighted average discount rate for operating leases	3.82%
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Lease liability		$ 18,000
Lease right-of-use asset		$ 19,000

Leases Maturities (Details)

Leases Maturities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019 (nine remaining months)	$ 891
2020	1,179
2021	1,179
2022	1,181
2023	1,188
After 2023	24,134
Total lease payments	29,752
Less: Imputed interest	11,881
Total lease liability	$ 17,871	$ 0

Deposits (Details)

Deposits (Details) - USD ($) $ in Thousands		Mar. 31, 2019	Dec. 31, 2018
Deposits [Abstract]
Non-interest checking		$ 743,151	$ 765,029
Interest-bearing checking		409,480	403,497
Savings		198,784	193,214
Money market		1,067,370	862,028
CDs $250,000 or less		228,585	215,200
CDs greater than $250,000		78,297	69,031
Total customer deposits		2,725,667	2,507,999
Brokered deposits	[1]	30,499	56,783
Total deposits		2,756,166	2,564,782
Reciprocal deposits		$ 510,500	$ 342,400
[1]	Brokered CDs which are $250,000 and under.

Borrowed Funds and Subordinat_2

Borrowed Funds and Subordinated Debt (Details) - USD ($)	1 Months Ended	3 Months Ended
	Jan. 31, 2015	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Borrowed funds		$ 488,000	$ 100,492,000
Subordinated debt		$ 14,863,000	$ 14,860,000
Fixed-to Floating Rate Subordinated Notes
Debt Instrument [Line Items]
Subordinated debt	$ 15,000,000
Subordinated debt, term		15 years
Original debt issuance costs	$ 190,000
Subordinated debt, rate until January 30, 2025		6.00%

Derivatives and Hedging Activ_3

Derivatives and Hedging Activities (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2019USD ($)instrumentloan	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)instrumentloan
Derivative [Line Items]
Number of Participation Loans with Swap Contingent Liabilities | loan	1		1
Interest-rate swaps
Derivative [Line Items]
Gain (Loss) on Interest Rate Swaps	$ 0	$ 0
Number of Interest Rate Swaps | instrument	8		8
Aggregate notional value of interest-rate swaps	$ 37,400,000		$ 37,700,000
Fair Value of Interest-Rate Swap Assets	434,000		723,000
Fair Value of Interest-Rate Swap Liabilities	434,000		723,000
Counterparty Credit Risk Exposure on Interest Rate Swaps	269,000		678,000
Collateral received for interest-rate swaps	200,000		850,000
Receive Fixed Pay Variable | Interest-rate swaps
Derivative [Line Items]
Fair Value of Interest-Rate Swap Assets	165,000		45,000
Fair Value of Interest-Rate Swap Liabilities	434,000		723,000
Pay Fixed Receive Variable | Interest-rate swaps
Derivative [Line Items]
Fair Value of Interest-Rate Swap Assets	269,000		678,000
Fair Value of Interest-Rate Swap Liabilities	0		0
Gross Amount Interest Rate Swap Asset Recognized	434,000		723,000
Gross Amount Interest-Rate offset in the Statement of Financial Position	$ 165,000		$ 45,000

Stockholder's Equity (Details)

Stockholder's Equity (Details) - $ / shares	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Common stock, shares authorized	40,000,000	40,000,000
Common stock, par value	$ 0.01	$ 0.01
Common Stock, Shares, Outstanding	11,798,114	11,708,218
Common stock, shares issued	11,798,114	11,708,218
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares issued	0	0
Unvested participating restricted stock awards	124,938	91,708
Common Stock
Class of Stock [Line Items]
Votes Per Share, Number	1
Series A Junior Participating Preferred Stock
Class of Stock [Line Items]
Price per one one-hundredth of a share	$ 122.50
Minimum acquisition percentage to trigger the exercise of the right to purchase	10.00%
Amount of a share allowed to be purchased under right to purchase	0.01

Supplemental Retirement Plan _2

Supplemental Retirement Plan and Other Postretirement Benefit Obligations (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)officer	Mar. 31, 2018USD ($)
Supplemental Employee Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Number of Active Executive Officers under Plan | officer	2
Number of Former Executive Officers under Plan | officer	1
Term of SERP benefits	20 years
SERP expenses	$ 111	$ 56
Benefits Paid	69	69
Remaining expected SERP accrual in current year	314
Supplemental Life Insurance Benefit
Defined Benefit Plan Disclosure [Line Items]
Net periodic benefit cost	$ 50	$ 45

Stock-Based Compensation Summar

Stock-Based Compensation Summary Information for Options Granted (Details) - $ / shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted	23,218	14,755
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term in years	10 years	10 years
Expected volatility	33.00%	37.00%
Weighted average market price on date of grants	$ 29.84	$ 34.33
Options granted, per share weighted average fair value	$ 8.70	$ 11.98
Weighted Average | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	2.75%	2.10%
Expected life in years	6 years 6 months	6 years 6 months
Risk-free interest rate	2.58%	2.86%
Fair Value as a percentage of market value at grant date	29.00%	35.00%

Stock-Based Compensation Stock

Stock-Based Compensation Stock Options, Stock Awards, and Stock in Lieu of Directors' Fees (Details) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Jan. 31, 2019shares	Mar. 31, 2019USD ($)plansshares	Mar. 31, 2018USD ($)	Dec. 31, 2018USD ($)	Jan. 02, 2018$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of individual stock incentive plans | plans		1
Stock-based compensation expense		$ 426	$ 385
Income tax benefit for stock compensation in Income Statement		111	195
Number of shares issued in lieu of cash to directors | shares	7,470
Fair market share price | $ / shares					$ 33.50
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$ 48	51
Restricted stock | Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		4 years
Restricted stock | Non-Employee Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		2 years
Restricted stock and common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$ 301	259
Common stock in lieu of cash | Non-Employee Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$ 77	$ 75	$ 250
Vesting, Year Two | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted, vesting percentage		50.00%	50.00%
Vesting, Year Four | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted, vesting percentage		50.00%	50.00%
2016 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares remain available for future grants | shares		271,584
2009 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of unissued expired shares | shares		87,849

Stock-Based Compensation Restri

Stock-Based Compensation Restricted Stock Grants (Details) - Restricted stock - $ / shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards in the period	55,198	44,505
Weighted Average Grant Date Fair Value, Stock Awards	$ 29.84	$ 34.33
Non-Employee Director | Two year vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards in the period	8,368	7,280
Employee | Four year vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards in the period	22,403	16,666
Employee | Performance-based vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards in the period	24,427	20,559

Earnings Per Share (Details)

Earnings Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Basic weighted average common shares outstanding	11,730,482	11,628,587
Dilutive shares	52,923	72,267
Diluted weighted average common shares outstanding	11,783,405	11,700,854
Antidilutive shares excluded from EPS	52,478	29,353

Fair Value Measurements - Recur

Fair Value Measurements - Recurring and Nonrecurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Specific allowance for collateral dependent impaired loans	$ 1,100	$ 1,600
Letter of Credit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortization period of estimated fair value on letters of credit	1 year
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Interest-rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities	$ 0	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	0	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	2,049	1,448
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | FHLB Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	0	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Interest-rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	0	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | Interest-rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities	434	723
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | Debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	458,765	431,473
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	0	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | FHLB Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	0	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | Interest-rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	434	723
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Interest-rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities	0	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	0	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	0	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | FHLB Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	1,491	5,357
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Interest-rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	0	0
Fair Value, Measurements, Nonrecurring | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans (collateral dependent), Fair Value	0	0
Fair Value, Measurements, Nonrecurring | Fair Value, Inputs, Level 1 | Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	0
Fair Value, Measurements, Nonrecurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans (collateral dependent), Fair Value	0	0
Fair Value, Measurements, Nonrecurring | Fair Value, Inputs, Level 2 | Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	0
Fair Value, Measurements, Nonrecurring | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans (collateral dependent), Fair Value	2,556	2,574
Fair Value, Measurements, Nonrecurring | Fair Value, Inputs, Level 3 | Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	255
Fair Value | Fair Value, Measurements, Recurring | Interest-rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities	434	723
Fair Value | Fair Value, Measurements, Recurring | Debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	458,765	431,473
Fair Value | Fair Value, Measurements, Recurring | Equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	2,049	1,448
Fair Value | Fair Value, Measurements, Recurring | FHLB Stock
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	1,491	5,357
Fair Value | Fair Value, Measurements, Recurring | Interest-rate swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	434	723
Fair Value | Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans (collateral dependent), Fair Value	2,556	$ 2,574
Fair Value | Fair Value, Measurements, Nonrecurring | Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	$ 255

Fair Value Measurements - Quant

Fair Value Measurements - Quantitative (Details) - Fair Value, Inputs, Level 3 $ in Thousands		Mar. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Fair Value, Measurements, Recurring | FHLB Stock
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of assets		$ 1,491	$ 5,357
Fair Value, Measurements, Recurring | FHLB Stock | FHLB stated par value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of assets		1,491
Fair Value, Measurements, Nonrecurring
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans (collateral dependent), Fair Value		2,556	$ 2,574
Fair Value, Measurements, Nonrecurring | Impaired loans (collateral dependent) | Appraisal of collateral
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans (collateral dependent), Fair Value	[1]	2,556
Fair Value, Measurements, Nonrecurring | Other real estate owned
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of assets		255
Fair Value, Measurements, Nonrecurring | Other real estate owned | Appraisal of collateral
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of assets	[1]	$ 255
Appraisal adjustments | Fair Value, Measurements, Nonrecurring | Impaired loans (collateral dependent) | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans, unobservable input value or range		0.05
Appraisal adjustments | Fair Value, Measurements, Nonrecurring | Impaired loans (collateral dependent) | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans, unobservable input value or range		0.5
Appraisal adjustments | Fair Value, Measurements, Nonrecurring | Other real estate owned | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other real estate owned, unobservable input value or range		0
Appraisal adjustments | Fair Value, Measurements, Nonrecurring | Other real estate owned | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Other real estate owned, unobservable input value or range		0.3
[1]	Appraisals may be adjusted by management for qualitative factors such as economic conditions and estimated liquidation expenses.

Fair Value Measurements - Balan

Fair Value Measurements - Balance Sheet Grouping (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Carrying Amount
Financial assets:
Loans held for sale	$ 332	$ 701
Loans, net	2,350,908	2,353,657
Financial liabilities:
Borrowed Funds	488	100,492
Subordinated debt	14,863	14,860
Carrying Amount | Certificates of Deposit
Financial liabilities:
Certificates of deposit	337,381	341,014
Fair Value
Financial assets:
Loans held for sale	335	710
Loans, net	2,339,246	2,331,076
Financial liabilities:
Borrowed Funds	328	100,312
Subordinated debt	14,680	14,300
Fair Value | Certificates of Deposit
Financial liabilities:
Certificates of deposit	336,679	339,308
Fair Value, Inputs, Level 1
Financial assets:
Loans held for sale	0	0
Loans, net	0	0
Financial liabilities:
Borrowed Funds	0	0
Subordinated debt	0	0
Fair Value, Inputs, Level 1 | Certificates of Deposit
Financial liabilities:
Certificates of deposit	0	0
Fair Value, Inputs, Level 2
Financial assets:
Loans held for sale	335	710
Loans, net	0	0
Financial liabilities:
Borrowed Funds	328	100,312
Subordinated debt	0	0
Fair Value, Inputs, Level 2 | Certificates of Deposit
Financial liabilities:
Certificates of deposit	336,679	339,308
Fair Value, Inputs, Level 3
Financial assets:
Loans held for sale	0	0
Loans, net	2,339,246	2,331,076
Financial liabilities:
Borrowed Funds	0	0
Subordinated debt	14,680	14,300
Fair Value, Inputs, Level 3 | Certificates of Deposit
Financial liabilities:
Certificates of deposit	$ 0	$ 0

Supplemental Cash Flow (Details

Supplemental Cash Flow (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Supplemental financial data:
Cash paid for: interest		$ 5,100	$ 2,638
Cash paid for: income taxes		1,012	868
Cash paid for: lease liability		288	0
Supplemental schedule of non-cash activity:
Net purchases of investment securities not yet settled		1,500	0
Transfer from loans to other real estate owned		255	0
Right-of-use lease assets: operating leases(1)	[1]	$ 19,002	$ 0
[1]	This represents the ROU lease asset that was recorded upon adoption of ASC 842 and was primarily offset by a corresponding lease liability