Enterprise Bancorp (EBTC) 10-K 15 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Mar. 04, 2016	Jun. 30, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	ENTERPRISE BANCORP INC /MA/
Entity Central Index Key	1,018,399
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		10,409,989
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 179,336,416

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Cash and cash equivalents:
Cash and due from banks	$ 32,318	$ 30,044
Interest-earning deposits	19,177	10,102
Total cash and cash equivalents	51,495	40,146
Investment securities at fair value	300,358	245,065
Federal Home Loan Bank Stock	3,050	3,357
Loans held for sale	1,709	2,371
Loans, less allowance for loan losses of $29,008 at December 31, 2015 and $27,121 at December 31, 2014	1,830,954	1,645,483
Premises and equipment	30,553	30,370
Accrued interest receivable	7,790	6,733
Deferred income taxes, net	14,111	12,852
Bank-owned life insurance	28,018	16,315
Prepaid income taxes	57	770
Prepaid expenses and other assets	11,780	13,110
Goodwill	5,656	5,656
Total assets	2,285,531	2,022,228
Liabilities
Deposits	2,018,148	1,768,546
Borrowed funds	53,671	58,900
Subordinated debt	14,822	10,825
Accrued expenses and other liabilities	18,287	16,441
Accrued interest payable	276	566
Total liabilities	$ 2,105,204	$ 1,855,278
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; 20,000,000 shares authorized; 10,377,787 shares issued and outstanding at December 31, 2015 (including 144,717 shares of unvested participating restricted awards) and 10,207,943 shares issued and outstanding at December 31, 2014 (including 157,694 shares of unvested participating restricted awards)	104	102
Additional paid-in capital	61,008	57,130
Retained earnings	116,941	105,951
Accumulated other comprehensive income	2,274	3,767
Total stockholders’ equity	180,327	166,950
Total liabilities and stockholders' equity	$ 2,285,531	$ 2,022,228

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Financial Position [Abstract]
Allowance for loan losses	$ 29,008	$ 27,121	$ 26,967	$ 24,254
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	10,377,787	10,207,943
Common stock, shares outstanding	10,377,787	10,207,943
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Unvested participating restricted stock awards	144,717	157,694

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Interest and dividend income:
Loans and loans held for sale	$ 77,946	$ 71,854	$ 67,673
Investment securities	5,346	4,504	3,381
Other interest-earning assets	179	115	68
Total interest and dividend income	83,471	76,473	71,122
Interest expense:
Deposits	4,068	4,028	4,058
Borrowed funds	38	38	96
Subordinated debt	1,071	1,177	1,177
Total interest expense	5,177	5,243	5,331
Net interest income	78,294	71,230	65,791
Provision for loan losses	3,267	1,395	3,279
Net interest income after provision for loan losses	75,027	69,835	62,512
Non-interest income:
Investment advisory fees	4,750	4,618	4,285
Deposit and interchange fees	4,879	5,036	4,788
Income on bank-owned life insurance,net	553	413	459
Net gains on sales of investment securities	1,828	1,619	1,239
Gains on sales of loans	492	406	792
Other income	2,465	2,340	2,229
Total non-interest income	14,967	14,432	13,792
Non-interest expense:
Salaries and employee benefits	40,285	38,029	33,551
Occupancy and equipment expenses	7,308	6,515	6,035
Technology and telecommunications expenses	5,710	5,167	4,647
Advertising and public relations expenses	2,719	2,928	2,708
Audit, legal and other professional fees	1,785	1,695	1,742
Deposit insurance premiums	1,214	1,169	1,118
Supplies and postage expenses	988	1,053	967
Investment advisory and custodial expenses	328	552	540
Other operating expenses	5,395	4,923	4,516
Total non-interest expense	65,732	62,031	55,824
Income before income taxes	24,262	22,236	20,480
Provision for income taxes	8,114	7,585	6,951
Net income	$ 16,148	$ 14,651	$ 13,529
Basic earnings per share	$ 1.56	$ 1.45	$ 1.37
Diluted earnings per share	$ 1.55	$ 1.44	$ 1.36
Basic weighted average common shares outstanding	10,323,016	10,118,762	9,862,678
Diluted weighted average common shares outstanding	10,389,934	10,209,243	9,950,609

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 16,148	$ 14,651	$ 13,529
Other comprehensive income (loss), net of taxes:
Gross unrealized holding (losses)/gains on investments arising during the period	(518)	4,225	(1,910)
Income tax benefit/(expense)	216	(1,553)	752
Net unrealized holding (losses)/gains, net of tax	(302)	2,672	(1,158)
Less: Reclassification adjustment for net gains included in net income
Net realized gains on sales of securities during the period	1,828	1,619	1,239
Income tax expense	(637)	(569)	(443)
Reclassification adjustment for gains realized, net of tax	1,191	1,050	796
Total other comprehensive income (loss)	(1,493)	1,622	(1,954)
Comprehensive income	$ 14,655	$ 16,273	$ 11,575

Consolidated Statement of Chang

Consolidated Statement of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated OtherComprehensive Income/(Loss)
Balance, beginning at Dec. 31, 2012	$ 139,549	$ 97	$ 48,194	$ 87,159	$ 4,099
Balance, beginning, shares, outstanding at Dec. 31, 2012		9,676,477
Increase (Decrease) in Stockholders' Equity
Net income	13,529			13,529
Other comprehensive (loss) income, net	(1,954)				(1,954)
Tax benefit from stock compensation	25		25
Common stock dividend paid	(4,535)			(4,535)
Common stock issued under dividend reinvestment plan, shares		69,633
Common stock issued under dividend reinvestment plan	1,239	$ 1	1,238
Stock-based compensation, shares, net		90,824
Stock-based compensation, net	1,652	$ 1	1,651
Stock options exercised, shares, net		155,626
Stock options exercised, net	1,829	$ 1	1,828
Balance, ending at Dec. 31, 2013	151,334	$ 100	52,936	96,153	2,145
Balance, ending, shares, outstanding at Dec. 31, 2013		9,992,560
Increase (Decrease) in Stockholders' Equity
Net income	14,651			14,651
Other comprehensive (loss) income, net	1,622				1,622
Tax benefit from stock compensation	320		320
Common stock dividend paid	(4,853)			(4,853)
Common stock issued under dividend reinvestment plan, shares		60,586
Common stock issued under dividend reinvestment plan	1,219	$ 1	1,218
Common stock issued, shares, other		2,917
Common stock issued, other	64	$ 0	64
Stock-based compensation, shares, net		69,926
Stock-based compensation, net	1,704	$ 1	1,703
Stock options exercised, shares, net		81,954
Stock options exercised, net	889	$ 0	889
Balance, ending at Dec. 31, 2014	$ 166,950	$ 102	57,130	105,951	3,767
Balance, ending, shares, outstanding at Dec. 31, 2014	10,207,943	10,207,943
Increase (Decrease) in Stockholders' Equity
Net income	$ 16,148			16,148
Other comprehensive (loss) income, net	(1,493)				(1,493)
Tax benefit from stock compensation	217		217
Common stock dividend paid	(5,158)			(5,158)
Common stock issued under dividend reinvestment plan, shares		58,529
Common stock issued under dividend reinvestment plan	1,277	$ 1	1,276
Common stock issued, shares, other		7,674
Common stock issued, other	171	$ 0	171
Stock-based compensation, shares, net		65,015
Stock-based compensation, net	1,784	$ 1	1,783
Stock options exercised, shares, net		38,626
Stock options exercised, net	431	$ 0	431
Balance, ending at Dec. 31, 2015	$ 180,327	$ 104	$ 61,008	$ 116,941	$ 2,274
Balance, ending, shares, outstanding at Dec. 31, 2015	10,377,787	10,377,787

Consolidated Statement of Chan7

Consolidated Statement of Changes in Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Stockholders' Equity [Abstract]
Common stock dividend paid, per share	$ 0.5	$ 0.48	$ 0.46

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income	$ 16,148,000	$ 14,651,000	$ 13,529,000
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	3,267,000	1,395,000	3,279,000
Depreciation and amortization	5,603,000	5,458,000	5,015,000
Stock-based compensation expense	1,803,000	1,752,000	1,662,000
Mortgage loans originated for sale	(23,673,000)	(20,864,000)	(35,284,000)
Proceeds from mortgage loans sold	24,827,000	20,154,000	43,378,000
Net gains on sales of loans	(492,000)	(406,000)	(792,000)
Net gains on sales of OREO	(154,000)	0	(121,000)
Net gains on sales of investment	(1,828,000)	(1,619,000)	(1,239,000)
Net gains on life insurance	(163,000)	0	0
Income on bank-owned life insurance, net	(553,000)	(413,000)	(459,000)
OREO fair value adjustment	0	0	23,000
Changes in:
Accrued interest receivable	(1,057,000)	(547,000)	(358,000)
Prepaid expenses and other assets	1,527,000	(6,597,000)	6,592,000
Deferred income taxes	(406,000)	90,000	(183,000)
Accrued expenses and other liabilities	1,342,000	85,000	780,000
Subordinated debt issuance costs	(178,000)	0	0
Accrued interest payable	(290,000)	1,000	(38,000)
Net cash provided by operating activities	25,723,000	13,140,000	35,784,000
Cash flows from investing activities:
Proceeds from sales of investment securities available-for-sale	25,115,000	25,371,000	9,564,000
Net proceeds (purchase) from FHLB capital stock	307,000	967,000	(64,000)
Proceeds from maturities, calls and pay-downs of investment securities	26,731,000	40,497,000	27,923,000
Purchase of investment securities	(108,962,000)	(90,918,000)	(70,663,000)
Net increase in loans	(188,738,000)	(150,079,000)	(165,135,000)
Additions to premises and equipment, net	(3,938,000)	(4,667,000)	(6,580,000)
Proceeds from OREO sales and payments	1,015,000	0	652,000
Purchase of OREO	0	(457,000)	0
Purchase of bank-owned life insurance	(11,390,000)	0	0
Net cash used in (provided by) investing activities	(259,860,000)	(179,286,000)	(204,303,000)
Cash flows from financing activities:
Net increase in deposits	249,602,000	132,554,000	160,965,000
Net (decrease) increase in borrowed funds	(5,229,000)	22,366,000	9,994,000
Repayment of subordinated debt	(10,825,000)	0	0
Proceeds from the issuance of subordinated debt	15,000,000	0	0
Cash dividends paid	(5,158,000)	(4,853,000)	(4,535,000)
Proceeds from issuance of common stock	1,448,000	1,283,000	1,239,000
Proceeds from exercise of stock options, net	431,000	889,000	1,829,000
Tax benefit from stock-based compensation	217,000	320,000	25,000
Net cash provided by (used in) financing activities	245,486,000	152,559,000	169,517,000
Net increase (decrease) in cash and cash equivalents	11,349,000	(13,587,000)	998,000
Cash and cash equivalents, beginning of year	40,146,000	53,733,000	52,735,000
Cash and cash equivalents, end of year	51,495,000	40,146,000	53,733,000
Supplemental financial data:
Cash paid for: Interest	5,467,000	5,242,000	5,369,000
Cash paid for: Income taxes	7,594,000	7,466,000	7,342,000
Supplemental schedule of non-cash activity:
Purchase of investment securities not yet settled	2,296,000	2,336,000	703,000
Transfer from loans to other real estate owned	0	290,000	168,000
Bank owned life insurance proceeds not yet received	403,000	0	0
Capital expenditures incurred not yet paid	$ 525,000	$ 0	$ 0

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies (a) Organization of Holding Company and Basis of Presentation The consolidated financial statements of Enterprise Bancorp, Inc. (the “Company” or “Enterprise”), a Massachusetts corporation, include the accounts of the Company and its wholly owned subsidiary Enterprise Bank and Trust Company (the “Bank”). The Bank is a Massachusetts trust company organized in 1989. Substantially all of the Company’s operations are conducted through the Bank. The Bank’s subsidiaries include Enterprise Insurance Services, LLC and Enterprise Investment Services, LLC, organized under the laws of the state of Delaware for the purposes of engaging in insurance sales activities and offering 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, which hold various types of qualifying securities. The security corporations are limited to conducting securities investment activities that the Bank itself would be allowed to conduct under applicable laws. The Company has 22 full-service branches serving the greater Merrimack Valley and North Central regions of Massachusetts and Southern New Hampshire. The Company also plans to open its second Nashua, NH branch in the second quarter of 2016. Through the Bank and its subsidiaries, the Company offers a range of commercial and consumer loan products, and deposit and cash management services. The Company also offers investment advisory and wealth management, trust, and insurance 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. Prior to March 2015 , pursuant to the Accounting Standards Codification (“ASC”) Topic 810 “Consolidation of Variable Interest Entities,” issued by the Financial Accounting Standards Board ("FASB"), the Company carried junior subordinated debentures as a liability on its consolidated financial statements, along with the related interest expense. The debentures were issued by a statutory business trust (the "Trust") created by the Company in March 2000 under the laws of the state of Delaware, and the trust preferred securities issued by the Trust, and the related non-interest expense, had been excluded from the Company’s consolidated financial statements. In March 2015 , the Company redeemed in full the junior subordinated debentures, which in turn allowed the Trust to redeem in full the trust preferred securities. The Company also dissolved the Trust in April 2015. See Note 7, "Borrowed Funds and Subordinated Debt," below for further information on the Company's subordinated debt. The Federal Deposit Insurance Corporation (“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 Commissioner also retains supervisory jurisdiction over the Company. The accompanying audited consolidated financial statements and notes thereto have been prepared in accordance with GAAP and the instructions for Form 10-K through the rules and interpretive releases of the SEC under federal securities law. In the opinion of management, the accompanying consolidated 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 consolidated financial statements. Certain previous years' amounts in the consolidated financial statements, and notes thereto, have been reclassified to conform to the current year's presentation. (b) Uses of estimates In preparing the financial statements in conformity with U.S. generally accepted accounting principles ("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 at the balance sheet date and income and expenses for the years 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 change over time due to changes in circumstances. Changes in those estimates resulting from continuing change in the economic environment and other factors will be reflected in the financial statements and results of operations in future periods. The three most significant areas in which management applies critical assumptions and estimates are the estimate of the allowance for loan losses, impairment review of investment securities and the impairment review of goodwill. (c) Cash and cash equivalents Cash equivalents are defined as highly liquid investments with original maturities of three months or less, that are readily convertible to known amounts of cash and present insignificant risk of changes in value due to changes in interest rates. The Company's cash and cash equivalents are comprised of cash on hand and cash items due from banks, interest-earning deposits (deposit accounts, excess cash balances, money market and money market mutual fund accounts) and overnight and term federal funds sold ("fed funds"). Balances in cash and cash equivalents will fluctuate resulting primarily from the timing of net deposit flows, borrowing and loan inflows and outflows, investment purchases and maturities, calls and sales proceeds, and the immediate liquidity needs of the Company. (d) Investments Investments that are intended to be held for indefinite periods of time but which may not be held to maturity or on a long-term basis are considered to be “available-for-sale” and are carried at fair value. Net unrealized appreciation and depreciation on investments available-for-sale, net of applicable income taxes, are reflected as a component of accumulated other comprehensive income. Included as available-for-sale are securities that are purchased in connection with the Company’s asset-liability risk management strategy and that may be sold in response to changes in interest rates, resultant prepayment risk and other related factors. In instances where the Company has the positive intent to hold investment securities to maturity, investment securities will be classified as held-to-maturity and carried at amortized cost. As of the balance sheet dates, all of the Company’s investment securities were classified as available-for-sale and carried at fair value. There are inherent risks associated with the Company’s investment activities that could adversely impact the fair market value and the ultimate collectability of the Company’s investments. Management regularly reviews the portfolio for securities with unrealized losses that are other than temporarily impaired. The determination of other-than-temporary impairment (“OTTI”) involves a high degree of judgment and requires management to make significant estimates of current market risks and future trends. Management's assessment, depending on the type of security includes: reviews of market pricing, evaluating the level and duration of the loss on individual securities; ongoing credit quality evaluations; determining if any individual security or mutual fund or other fund exhibits fundamental deterioration; and estimating whether it is unlikely that the individual security or fund will completely recover its unrealized loss within a reasonable period of time, or in the case of fixed income securities prior to maturity. While management uses available information to measure OTTI at the balance sheet date, future write-downs may be necessary based on extended duration of current unrealized losses, changing market conditions, or circumstances surrounding individual issuers and funds. Should an investment be deemed to have OTTI, the Company is required to write-down the carrying value of the investment. OTTI on equity securities are recognized through a charge to earnings. OTTI on fixed income securities are assessed in order to determine the impairment attributed to underlying credit quality of the issuer and the portion of noncredit impairment. When there are credit losses on a fixed income security that management does not intend to sell and it is more likely than not that the Company will not be required to sell prior to a marketplace recovery or maturity, the portion of the total impairment that is attributable to the credit loss would be recognized in earnings, and the remaining difference between the security’s amortized cost basis and its fair value would be included in other comprehensive income. Once written-down, a security may not be written-up in excess of its new cost basis to reflect future increases in market prices. Any OTTI charges, depending upon the magnitude of the charges, could have a material adverse effect on the Company’s financial condition and results of operations. Investment securities’ discounts are accreted and premiums are amortized over the period of estimated principal repayment using methods that approximate the interest method. Gains or losses on the sale of investment securities are recognized on the trade date on a specific identification basis. (e) Restricted Investments As a member of the Federal Home Loan Bank of Boston (“FHLB”), the Bank is required to purchase certain levels of FHLB stock in association with outstanding advances from the FHLB. This stock investment is classified as a restricted investment and carried at cost, which management believes approximates fair value. FHLB stock represents the only restricted investment held by the Company. In conjunction with the OTTI review noted above under investments, management also regularly reviews its holdings of FHLB stock for OTTI. Based on management’s ongoing 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. (f) Loans Held for Sale Depending on the current interest rate environment, management projections of future interest rates and the overall asset-liability management program of the Company, management may elect to sell those fixed and adjustable rate residential mortgage loans which are eligible for sale in the secondary market. Mortgage loans are generally not pooled for sale, but instead sold on an individual basis. Enterprise may retain or sell the servicing when selling the loans. Loans sold are subject to standard secondary market underwriting and eligibility representations and warranties over the life of the loan, and are subject to an early payment default period covering the first four payments for certain loan sales. Loans held for sale are carried at the lower of aggregate amortized cost or market value. Market value is based on comparable market prices for loans with similar rates and terms. When loans are sold, a gain or loss is recognized to the extent that the sales proceeds plus unamortized fees and costs exceed, or are less than, the carrying value of the loans. Gains and losses are determined using the specific identification method. (g) Loans Loans made by the Company to businesses include commercial mortgage loans, construction and land development loans, secured and unsecured commercial loans and lines of credit, and standby 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, secured and unsecured personal loans and lines of credit. Most loans granted by the Company are collateralized by real estate or equipment and/or are guaranteed by the principals of the borrower. The ability and willingness of the single family residential and consumer borrowers to honor their repayment commitments is generally dependent on the level of overall economic activity and real estate values within the borrowers’ geographic areas. The ability and willingness of commercial real estate, commercial and construction loan borrowers to honor their repayment commitments is generally dependent on the health of the real estate sector in the borrowers’ geographic areas and the general economy, among other factors. Loans are reported at the principal amount outstanding, net of deferred origination fees and costs. The aggregate amount of overdrawn deposit accounts are reclassified as loan balances. Loan origination fees received, offset by direct loan origination costs, are deferred and amortized using the straight line method over three to five years for lines of credit and demand notes or over the life of the related loans using the level-yield method for all other types of loans. When loans are paid off, the unamortized fees and costs are recognized as an adjustment to interest income. Loans acquired at a net premium are initially measured at fair value as of the acquisition date without carryover of historical allowance for loan losses. Credit discounts representing losses of unpaid loan principal balances expected over the life of the loans are included in the determination of acquisition date fair value. The fair-market valuation of loans acquired at a premium is amortized into interest income on a level-yield basis over the life of the loan. Subsequent to the purchase date, the methods utilized to estimate the required allowance for loan losses are similar to originated loans. (h) Allowance for Loan Losses The allowance for loan losses is an estimate of probable credit risk inherent in the loan portfolio as of the specified balance sheet dates. 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 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 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 uses a two-tiered approach that makes use of specific reserves for loans individually evaluated and deemed impaired and general reserves for larger groups of homogeneous loans. On a quarterly basis, the Company prepares an estimate of the allowance necessary to cover estimated credit risk inherent in the portfolio as of the specified balance sheet dates. The adequacy of the allowance for loan losses is reviewed and evaluated on a regular basis by an internal management committee, a sub-committee of the Board of Directors and the full Board itself. While management uses available information to recognize losses on loans, future additions to the allowance may be necessary. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Company’s allowance for loan losses. Such agencies may require the Company to recognize additions to the allowance based on judgments different from those of management. See Note 4, "Allowance for Loan Losses," for additional accounting policies related to non-accrual, impaired and troubled debt restructured loans and to the allowance for loan losses. (i) Other Real Estate Owned Real estate acquired by the Company through foreclosure proceedings or the acceptance of a deed in lieu of foreclosure is classified as Other Real Estate Owned (“OREO”). When property is acquired, it is generally recorded at the lesser of the loan’s remaining principal balance, net of unamortized deferred fees, or the estimated fair value of the property acquired, less estimated costs to sell. 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. (j) Premises and Equipment Land is carried at cost. Premises and equipment are stated at cost less accumulated depreciation and amortization. Depreciation or amortization is computed on a straight-line basis over the lesser of the estimated useful lives of the asset or the respective lease term (with reasonably assured renewal options) for leasehold improvements generally as follows: Bank premises and leasehold improvements 10 to 39 years Computer software and equipment 3 to 5 years Furniture, fixtures and equipment 3 to 10 years (k) Bank Owned Life Insurance The Company has purchased bank owned life insurance (“BOLI”) on certain current and former senior and executive officers. The cash surrender value carried on the balance sheet at December 31, 2015 and December 31, 2014 amounted to $28.0 million and $16.3 million , respectively. The increase over the prior year was primarily due to the purchase of additional BOLI investments. There are no associated surrender charges under the outstanding policies. (l) Impairment of Long-Lived Assets Other than Goodwill The Company reviews long-lived assets, including premises and equipment, for impairment on an ongoing basis or whenever events or changes in business circumstances indicate that the remaining useful life may warrant revision or that the carrying amount of the long-lived asset may not be fully recoverable. If impairment is determined to exist, any related impairment loss is recognized through a charge to earnings. Impairment losses on assets disposed of, if any, are based on the estimated proceeds to be received, less cost of disposal. (m) Goodwill Goodwill carried on the Company’s consolidated financial statements was $5.7 million at both December 31, 2015 and December 31, 2014 . This asset is related to the Company’s acquisition of two branch offices in July 2000. In accordance with generally accepted accounting principles, the Company does not amortize goodwill and instead, at least annually, evaluates whether the carrying value of goodwill has become impaired. Impairment of the goodwill may occur when the estimated fair value of the Company is less than its recorded book value. A determination that goodwill has become impaired results in an immediate write-down of goodwill to its determined value with a resulting charge to operations. The annual impairment test begins with a qualitative assessment of whether it is "more likely than not" that the reporting unit's fair value is less than its carrying amount. The assessment is performed at the operating unit level. If an entity concludes it is not "more likely than not" that the fair value of a reporting unit is less than its carrying amount, it need not perform a two-step impairment test. In the case of the Company, the services offered through the Bank and subsidiaries are managed as one strategic unit and represent the Company’s only reportable operating segment. Management's qualitative assessment takes into consideration macroeconomic conditions, industry and market considerations, cost or margin factors, financial performance and share price. Based on this assessment, the Company determined that it is not "more likely than not" that the Company's fair value is less than its carrying amount and therefore goodwill was not considered to be impaired at December 31, 2015 . If the Company's qualitative assessment concluded that it is "more likely than not" that the fair value of a reporting unit is less than its carrying amount, it must perform the two-step impairment test to identify potential goodwill impairment and measure the amount of goodwill impairment loss to be recognized, if any. The first step of the goodwill impairment test compares the estimated fair value of the reporting unit with its carrying amount, or the book value of the reporting unit, including goodwill. If the estimated fair value of the reporting unit equals or exceeds its book value, goodwill is considered not impaired, and the second step of the impairment test is unnecessary. The second step, if necessary, measures the amount of goodwill impairment loss to be recognized. The reporting unit must determine fair values for all assets and liabilities, excluding goodwill. The net of the assigned fair value of assets and liabilities is then compared to the book value of the reporting unit, and any excess book value becomes the implied fair value of goodwill. If the carrying amount of the goodwill exceeds the newly calculated implied fair value of that goodwill, an impairment loss is recognized in the amount required to write down the goodwill to the implied fair value. (n) Investment Assets Under Management Investment assets under management, consisting of assets managed through Enterprise Investment Advisors and Enterprise Investment Services and the commercial sweep product, totaled $678.4 million and $674.6 million at December 31, 2015 and 2014 , respectively. Fee income is recorded on an accrual basis and recognized over the period in which it is earned. Securities and other property held in a fiduciary or agency capacity are not included in the consolidated balance sheets because they are not assets of the Company. (o) Derivatives The Company recognizes all derivatives as either assets or liabilities on its balance sheet and measures those instruments at fair market value. 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 December 31, 2015 and 2014 , the estimated fair values of these derivative instruments were considered to be immaterial. Beginning in 2015, the Company implemented 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 counterparty. The transaction structure effectively minimizes the Bank’s net risk exposure resulting from such transactions. The customer interest-rate swap agreement allows commercial banking customers to convert a floating-rate loan payment to fixed-rate loan payment. 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 inverse relationship, are recognized directly in earnings. See Note 8, "Commitments, Contingencies and Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk" for more information about the Company's derivatives. (p) Stock Based Compensation The Company’s financial statements include stock-based compensation expense for the portion of stock option awards, net of estimated forfeitures, and stock awards for which the requisite service has been rendered during the period. The compensation expense has been estimated based on the estimated grant-date fair value of the awards, or in the case of stock awards, the market value of the common stock on the date of grant. The Company will recognize the remaining estimated compensation expense for the portion of outstanding awards and compensation expense for any future awards, net of estimated forfeitures, as the requisite service is rendered (i.e., on a straight-line basis over the remaining vesting period of each award) or as performance objectives are met. Stock awards that do not require future service (“vested awards”) will be expensed immediately. Stock-based compensation also includes Director stock compensation for stock awards and stock in lieu of cash fees, both included in other operating expenses, described in more detail in Note 11 "Stock-Based Compensation Plans." (q) Income Taxes 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 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. 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 tax-exempt interest from certain investment securities, loans and bank owned life insurance. The Company did not have any unrecognized tax benefits accrued as income tax liabilities or receivables or as deferred tax items at December 31, 2015 or December 31, 2014 . The Company is subject to U.S. federal and state income tax examinations by taxing authorities for the 2012 through 2015 tax years. (r) Earnings per Share Basic earnings per share are calculated by dividing net income 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. 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. (s) Reporting Comprehensive Income Comprehensive income is defined as all changes to 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. The Company’s only other comprehensive income component is the net unrealized holding gains or losses on investments available-for-sale, net of deferred income taxes. 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 securities are sold. When securities are sold, the reclassification of realized gains and losses on available-for-sale securities are included on the Consolidated Statements of Income under the "non-interest income" subheading on the line item "net gains on sales of investment securities" and the related income tax expense is included in the line item "provision for income taxes," both of which are also detailed on the Consolidated Statements of Comprehensive Income under the subheading "reclassification adjustment for net gains included in net income." (t) Recently Adopted Accounting Pronouncements In April 2015, the Financial Accounting Standards Board ("FASB") issued ASU No. 2015-03, Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs. The amendments in this ASU require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this ASU. Entities are required to apply the new guidance on a retrospective basis, wherein the balance sheet of each individual period presented should be adjusted to reflect the period-specific effects of applying the new guidance. For public business entities, the amendments are effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption of the amendments is permitted for financial statements that have not been previously issued. The Company early adopted this ASU as of January 1, 2015 in relation to the Company's Fixed-to-Floating Rate Subordinated Notes issued in January 2015. This adoption did not have a material impact on the Company's financial statements or results of operations. In January 2014, the FASB issued ASU No. 2014-04, Receivables - Troubled Debt Restructurings by Creditors (Subtopic 310-40) - Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure. The amendments are intended to reduce diversity of practice by clarifying when a creditor should be considered to have received physical possession of residential real estate property collateralizing a residential mortgage loan, such that the loan should be removed, and the real estate property recognized, on the financial statements. Additionally, the amendments require interim and annual disclosure of both the amount of foreclosed residential real estate property held by the creditor and the recorded investment in collateralized residential mortgage loans that are in the process of foreclosure according to local requirements of the applicable jurisdiction. The amendments in this ASU are effective for public business entities for annual periods and interim reporting periods beginning after December 15, 2014. As this ASU primarily offers clarification of existing standards and added disclosures, the adoption of this ASU in the first quarter of 2015 did not have a material impact on the Company's financial statements or results of operations. In January 2014, the FASB issued ASU No. 2014-01, Equity Method and Joint Ventures (Topic 323): Accounting for Investments in Qualified Affordable Housing Projects. The amendments in this ASU apply to all reporting entities that invest in qualified affordable housing projects through limited liability entities that are flow through entities for tax purposes. The amendments in this ASU eliminate the effective yield election and permit reporting entities to make an accounting policy election to account for such investments using the proportional amortization method if certain conditions are met. The investor must recognize any subsequent impairment loss when it is more likely than not that the carrying amount of the investment will not be realized. Those not electing the proportional amortization method would account for the investment using the equity method or cost method. The decision to apply the proportional amortization method of accounting is an accounting policy decision that must be applied consistently to all qualifying affordable housing project investments rather than a decision to be applied to individual investments. A reporting entity must disclose information that enables users of its financial statements to understand the nature of such investments and the effect of the measurement, and the related

Investments

Investments	12 Months Ended
	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Investments	Investments The amortized cost and fair values of investments at December 31, 2015 and 2014 are summarized as follows: 2015 (Dollars in thousands) Amortized cost Unrealized gains Unrealized losses Fair Value Federal agency obligations (1) $ 78,626 $ 352 $ 153 $ 78,825 Residential federal agency MBS (1) 75,105 406 648 74,863 Commercial federal agency MBS (1) 23,908 — 363 23,545 Municipal securities 96,189 2,357 35 98,511 Corporate bonds 10,257 44 95 10,206 Certificates of Deposit (2) 2,753 — 2 2,751 Total fixed income securities 286,838 3,159 1,296 288,701 Equity investments 10,043 1,966 352 11,657 Total available-for-sale investments, at fair value $ 296,881 $ 5,125 $ 1,648 $ 300,358 2014 (Dollars in thousands) Amortized cost Unrealized gains Unrealized losses Fair Value Federal agency obligations (1) $ 59,518 $ 318 $ 24 $ 59,812 Residential federal agency MBS (1) 88,303 1,015 516 88,802 Municipal securities 72,113 2,157 66 74,204 Corporate bonds 7,937 61 26 7,972 Total fixed income securities 227,871 3,551 632 230,790 Equity investments 11,370 3,071 166 14,275 Total available-for-sales investments, at fair value $ 239,241 $ 6,622 $ 798 $ 245,065 (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, or one of several Federal Home Loan Banks, as well as, investments guaranteed by Ginnie Mae (GNMA), a wholly-owned government entity. (2) Certificates of deposit ("CDs") represent term deposits issued by banks that are subject to FDIC insurance and purchased on the open market. Included in the residential federal agency MBS category were collateralized mortgage obligations (“CMO’s”) totaling $20.8 million and $13.3 million at December 31, 2015 and 2014 respectively. All of the commercial MBS investments held by the Company were CMOs. At December 31, 2015 , the equity portfolio consisted primarily of investments in a diversified group of mutual funds, with a small portion of the portfolio (approximately 16% ) invested in individual common stock of entities in the financial services industry. Net unrealized appreciation and depreciation on investments available-for-sale, net of applicable income taxes, are reflected as a component of accumulated other comprehensive income. The net unrealized gain or loss in the Company's fixed income 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 fixed income investments will also decline as the securities approach maturity or if the issuer is credit impaired. Unrealized gains or losses will be recognized in the statements of income if the securities are sold. However, if an unrealized loss on the fixed income portfolio is deemed to be other than temporary, the credit loss portion is charged to earnings and the noncredit portion is recognized in accumulated other comprehensive income. The net unrealized gain or loss on equity securities will fluctuate based on changes in the market value of the mutual funds and individual securities held in the portfolio. Unrealized gains or losses will be recognized in the statements of income if the securities are sold. However, if an unrealized loss on an equity security is deemed to be other than temporary prior to a sale, the loss is charged to earnings. The following tables summarize investments (fixed income and equity) having temporary impairment, due to the fair market values having declined below the amortized costs of the individual investments, and the period that the investments have been temporarily impaired at December 31, 2015 and 2014 . 2015 Less than 12 months 12 months or longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair value Unrealized Losses Fair Value Unrealized Losses Federal agency obligations $ 27,420 $ 153 $ — $ — $ 27,420 $ 153 Residential federal agency MBS 20,517 276 10,935 373 31,452 649 Commercial federal agency MBS 23,545 363 — — 23,545 363 Municipal securities 6,988 32 261 2 7,249 34 Corporate bonds 4,574 78 419 17 4,993 95 Certificates of Deposit 1,976 2 — — 1,976 2 Equity investments 4,204 351 24 1 4,228 352 Total temporarily impaired investments $ 89,224 $ 1,255 $ 11,639 $ 393 $ 100,863 $ 1,648 2014 Less than 12 months 12 months or longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair value Unrealized Losses Fair Value Unrealized Losses Federal agency obligations $ 7,959 $ 24 $ — $ — $ 7,959 $ 24 Residential federal agency MBS — — 23,801 516 23,801 516 Municipal securities 3,597 31 2,794 35 6,391 66 Corporate bonds 2,704 12 871 14 3,575 26 Equity investments 2,008 162 21 4 2,029 166 Total temporarily impaired investments $ 16,268 $ 229 $ 27,487 $ 569 $ 43,755 $ 798 Management regularly reviews the portfolio for securities with unrealized losses that are other-than-temporarily impaired. During the years ended December 31, 2015 and 2014 , the Company did not record any fair value impairment charges on its investments. As of December 31, 2015 , there were 86 securities in an unrealized loss position in the Company's portfolio (fixed income and equity, excluding CDs). Management attributes these unrealized losses to increases in current market yields compared to the yields at the time the investments were purchased by the Company and the impact of market value fluctuations on the equity portion of our portfolio. Management does not consider these investments to be other-than-temporarily impaired at December 31, 2015 because (1) the decline in market value is not attributable to credit quality for fixed income securities, or a fundamental deterioration in the equity funds or issuers, and (2) the Company does not intend to, and it is more likely than not that it will not be required to, sell those investments prior to a market price recovery or maturity. In assessing the Company's investments in federal agency mortgage-backed securities and federal agency obligations, the contractual cash flows of these investments are guaranteed by the respective government sponsored enterprise (FHLMC, FNMA, FFCB, or FHLB) or wholly-owned government corporation (GNMA). Accordingly, it is expected that the securities would not be settled at a price less than the par value of the Company's investments. Management's assessment of other fixed income investments within the portfolio includes reviews of market pricing, ongoing credit quality evaluations, assessment of the investments' materiality, and duration of the investments' unrealized loss position. In addition, the Company utilizes an outside registered investment adviser to manage the corporate and municipal bond portfolios, within prescribed guidelines set by management, and to provide assistance in assessing the credit risk of those portfolios. At December 31, 2015 , the Company's corporate and municipal bond portfolios did not contain any securities below investment grade, as reported by major credit rating agencies. For equities and funds, management's assessment includes the severity of the declines, whether it is unlikely that the security or fund will completely recover its unrealized loss within a reasonable time period and if the equity security or fund exhibits fundamental deterioration. As noted in the table above, a small portion of the portfolio invested in CDs was also in an unrealized loss position at December 31, 2015 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 of total fixed income investments at December 31, 2015 is as follows: Within One Year After One, but within Five Years After Five, but within Ten Years After Ten Years (Dollars in thousands) Amount Yield Amount Yield Amount Yield Amount Yield At amortized cost: Federal agency obligations $ 7,048 0.91 % $ 62,024 1.59 % $ 9,554 2.22 % $ — — % Residential federal agency MBS — — % 3,576 3.15 % 1,299 1.90 % 70,230 2.11 % Commercial federal agency MBS — — % — — % 23,908 2.26 % — — % Municipal securities 5,052 2.74 % 23,948 3.38 % 34,749 3.69 % 32,440 3.91 % Corporate bonds 530 1.33 % 4,759 2.09 % 4,968 2.89 % — — % CDs 1,803 0.32 % 950 2.13 % — — % — — % Total fixed income securities $ 14,433 1.49 % $ 95,257 2.13 % $ 74,478 2.96 % $ 102,670 2.68 % At fair value: Total fixed income securities $ 14,477 $ 96,053 $ 75,015 $ 103,156 Scheduled contractual maturities 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 carrying value of fixed income investments above are callable securities, comprised of municipal securities and corporate bonds with amortized cost and fair values of $49.1 million and $50.3 million , respectively, at December 31, 2015 , 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 securities as collateral against deposit account balances of municipal deposit customers, and for borrowing capacity with the FHLB and the Federal Reserve Bank of Boston ("FRB"). The fair value of securities pledged as collateral for these purposes was $286.0 million at December 31, 2015 and $230.8 million at December 31, 2014 . Sales of investments for the years ended December 31, 2015 , 2014 , and 2013 are summarized as follows: (Dollars in thousands) 2015 2014 2013 Amortized cost of investments sold $ 23,287 $ 23,752 $ 8,325 Gross realized gains on sales 1,990 1,654 1,243 Gross realized losses on sales (162 ) (35 ) (4 ) Total proceeds from sales of investments $ 25,115 $ 25,371 $ 9,564 Tax-exempt interest earned on the municipal securities portfolio was $2.9 million for the year ended December 31, 2015 , $2.4 million for the year ended December 31, 2014 and $2.1 million for the year ended December 31, 2013 . See Item (d) “Investments,” contained in Note 1, “Summary of Significant Accounting Policies,” for additional information regarding the accounting for the Company’s investments portfolio. See also Note 14, “Fair Value Measurements,” for additional information regarding the Company’s fair value measurement of investments.

Loans

Loans	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Loans	Loans The Company specializes in lending to business entities, non-profit organizations, professionals 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 include commercial mortgage loans, construction and land development loans, secured and unsecured commercial loans and lines of credit, and standby 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 primary and secondary residences, and secured and unsecured personal loans and lines of credit. The Company seeks to manage its loan portfolio to avoid concentration by industry and loan size to lessen its credit risk exposure. See Note 4, "Allowance for Loan Losses," for information on the Company's credit risk management, non-accrual, impaired and troubled debt restructured loans and the allowance for loan losses. Major classifications of loans at the periods indicated, are as follows: (Dollars in thousands) December 31, 2015 December 31, 2014 Commercial real estate $ 936,921 $ 862,747 Commercial and industrial 458,553 402,994 Commercial construction 202,993 168,044 Total commercial loans 1,598,467 1,433,785 Residential mortgages 169,188 149,959 Home equity loans and lines 83,373 80,018 Consumer 10,747 10,708 Total retail loans 263,308 240,685 Gross loans 1,861,775 1,674,470 Deferred loan origination fees, net (1,813 ) (1,866 ) Total loans 1,859,962 1,672,604 Allowance for loan losses (29,008 ) (27,121 ) Net loans $ 1,830,954 $ 1,645,483 Loan Categories Commercial loans: Commercial real estate loans include loans secured by both owner-use and non-owner occupied real estate. These loans are typically secured by a variety of commercial and industrial property types including one-to-four family and multi-family apartment buildings, office, industrial or mixed-use facilities, strip shopping centers or other commercial properties and are generally guaranteed by the principals of the borrower. Commercial real estate loans generally have repayment periods of approximately fifteen to twenty-five years. Variable interest rate loans have a variety of adjustment terms and indices, and are generally fixed for an initial period before periodic rate adjustments begin. Commercial and industrial loans include seasonal revolving lines of credit, working capital loans, equipment financing (including equipment leases), and term loans. Also included in commercial and industrial loans are loans partially guaranteed by the U. S. Small Business Administration (SBA), and loans under various programs and agencies. Commercial and industrial credits may be unsecured loans and lines to financially strong borrowers, secured in whole or in part by real estate unrelated to the principal purpose of the loan or secured by inventories, equipment, or receivables, and are generally guaranteed by the principals of the borrower. Variable rate loans and lines in this portfolio have interest rates that are periodically adjusted, with loans generally having fixed initial periods. Commercial and industrial loans have average repayment periods of one to seven years. Commercial construction loans include the development of residential housing and condominium projects, the development of commercial and industrial use property, and loans for the purchase and improvement of raw land. These loans are secured in whole or in part by the underlying real estate collateral and are generally guaranteed by the principals of the borrowers. Construction lenders work to cultivate long-term relationships with established developers. The Company limits the amount of financing provided to any single developer for the construction of properties built on a speculative basis. Funds for construction projects are disbursed as pre-specified stages of construction are completed. Regular site inspections are performed, prior to advancing additional funds, at each construction phase, either by experienced construction lenders on staff or by independent outside inspection companies. Commercial construction loans generally are periodically adjusted variable rate loans and lines and generally have terms of one to three years. From time to time, the Company participates with other banks in the financing of certain commercial projects. Participating loans with other institutions provide banks the opportunity to retain customer relationships, while providing them with larger credit vehicles than the individual bank might be willing or able to offer independently, while reducing credit risk exposure among each participating bank. In some cases, the Company may act as the lead lender, originating and servicing the loans, but participating out a portion of the funding to other banks. In other cases, the Company may participate in loans originated by other institutions. In each case, the participating bank funds a percentage of the loan commitment and takes on the related pro-rata risk. In each case in which the Company participates in a loan, the rights and obligations of each participating bank are divided proportionately among the participating banks in an amount equal to their share of ownership and with equal priority among all banks. The balances participated out to other institutions are not carried as assets on the Company's financial statements. Loans originated by other banks in which the Company is the participating institution are carried in the loan portfolio at the Company's pro rata share of ownership. The Company performs an independent credit analysis of each commitment and a review of the participating institution prior to participation in the loan, and an annual review thereafter of each participating institution. Loans originated by other banks in which the Company is the participating institution amounted to $62.3 million at December 31, 2015 and $65.3 million at December 31, 2014 . Standby letters of credit are conditional commitments issued by the Company to guarantee the financial obligation or performance by a customer to a third-party. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. If the letter of credit is drawn upon, a loan is created for the customer, generally a commercial loan, with the same criteria associated with similar commercial loans. Residential loans: Enterprise originates conventional mortgage loans on one-to-four family residential properties. These properties may serve as the borrower's primary residence, or be vacation homes or investment properties. Loan to value limits vary, generally from 75% for multi-family owner occupied properties, up to 97% for single family, owner occupied properties, with mortgage insurance coverage required for loan-to-value ratios greater than 80% based on program parameters. In addition, financing is provided for the construction of owner occupied primary and secondary residences. Residential mortgage loans may have terms of up to 30 years at either fixed or adjustable rates of interest. Fixed and adjustable rate residential mortgage loans are generally originated using secondary market underwriting and documentation standards. Depending on the current interest rate environment, management projections of future interest rates and the overall asset-liability management program of the Company, management may elect to sell those fixed and adjustable rate residential mortgage loans which are eligible for sale in the secondary market, or hold some or all of this residential loan production for the Company's portfolio. Mortgage loans are generally not pooled for sale, but instead sold on an individual basis. The Company may retain or sell the servicing when selling the loans. Loans sold are subject to standard secondary market underwriting and eligibility representations and warranties over the life of the loan and are subject to an early payment default period covering the first four payments for certain loan sales. Loans classified as held for sale are carried as a separate line item on the balance sheet. Home equity loans and lines of credit: Home equity term loans are originated for one-to-four family residential properties with maximum original loan to value ratios generally up to 80% of the assessed or appraised value of the property securing the loan. Home equity loan payments consist of monthly principal and interest based on amortization ranging from three to fifteen years. The rates may also be fixed for three to fifteen years. The Company originates home equity revolving lines of credit for one-to-four family residential properties with maximum original loan to value ratios generally up to 80% of the appraised value of the property securing the loan. Home equity lines generally have interest rates that adjust monthly based on changes in the Prime Rate, although minimum rates may be applicable. Some home equity line rates may be fixed for a period of time and then adjusted monthly thereafter. The payment schedule for home equity lines requires interest only payments for the first ten years of the lines. Generally at the end of ten years, the line may be frozen to future advances, and principal plus interest payments are collected over a fifteen -year amortization schedule or, for eligible borrowers meeting certain requirements, the line availability may be extended for an additional interest only period. Consumer loans: Consumer loans primarily consist of secured or unsecured personal loans, energy efficiency financing programs in conjunction with Massachusetts public utilities, and overdraft protection lines on checking accounts extended to individual customers. The aggregate amounts of overdrawn deposit accounts are reclassified as loan balances. Related Party Loans Certain of the Company's directors, officers, principal stockholders and their associates are credit customers of the Company in the ordinary course of business. In addition, certain directors are also directors, trustees, officers or stockholders of corporations and non-profit entities or members of partnerships that are customers of the Bank and that enter into loan and other transactions with the Bank in the ordinary course of business. All loans and commitments included in such transactions are on such terms, including interest rates, repayment terms and collateral, as those prevailing at the time for comparable transactions with persons who are not affiliated with the Bank and do not involve more than a normal risk of collectability or present other features unfavorable to the Bank. As of December 31, 2015 and 2014 , the outstanding loan balances to directors, officers, principal stockholders and their associates were $17.5 million and $18.2 million , respectively. All loans to these related parties were current and accruing at those dates. Unadvanced portions of lines of credit available to these individuals were $10.6 million and $6.5 million , as of December 31, 2015 and 2014 , respectively. During 2015 , new loans and net increases in loan balances or lines of credit under existing commitments of $6.7 million were made and principal paydowns of $3.3 million were received. Loans Serviced for Others At December 31, 2015 and 2014 , the Company was servicing residential mortgage loans owned by investors amounting to $18.5 million and $19.3 million , respectively. Additionally, the Company was servicing commercial loans participated out to various other institutions amounting to $52.7 million and $44.8 million at December 31, 2015 and 2014 , respectively. See the discussion above for further information regarding commercial participations. Loans Serving as Collateral Loans designated as qualified collateral and pledged to the FHLB for borrowing capacity for the periods indicated are summarized below: (Dollars in thousands) December 31, 2015 December 31, 2014 Commercial real estate $ 281,802 $ 276,657 Residential mortgages 118,855 107,906 Home equity 13,972 15,677 Total loans pledged to FHLB $ 414,629 $ 400,240 Tax-exempt Interest Tax-exempt interest earned on qualified commercial loans was $1.6 million for the year ended December 31, 2015 and $1.4 million and $1.3 million for the years ended December 31, 2014 and 2013 , respectively. Average tax-exempt loan balances were $50.9 million and $38.3 million for the years ended December 31, 2015 and 2014 , respectively.

Allowance For Loan Losses

Allowance For Loan Losses	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Allowance for Loan Loss	Allowance for Loan Losses While the Company seeks to manage its loan portfolio to avoid concentration by industry and loan size to lessen its credit risk exposure, inherent in the lending process is the risk of loss due to customer non-payment, or “credit risk.” The Company endeavors to minimize this risk through sound underwriting practices and the risk management function, however, management recognizes that loan losses will occur and that the amount of these losses will fluctuate depending on the risk characteristics of the loan portfolio and economic conditions. The allowance for loan losses is an estimate of probable credit risk inherent in the loan portfolio as of the specified balance sheet dates. 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. In making its assessment on the adequacy of the allowance, management considers several quantitative and qualitative factors that could have an effect on the credit quality of the portfolio including, individual assessment of larger and high risk credits, delinquency trends and the level of non-performing loans, impaired and restructured loans, net charge-offs, the growth and composition of the loan portfolio, expansion in geographic market area, the experience level of lenders and changes in underwriting criteria, and the strength of the local and national economy, among other factors. Allowance for probable loan losses methodology On a quarterly basis, management prepares an estimate of the allowance necessary to cover estimated 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 groups of homogeneous loans, which are collectively evaluated relying on a combination of qualitative and quantitative factors that could have an impact on the credit quality of the portfolio. Specific Reserves for loans individually evaluated for impairment When a loan is deemed to be impaired, management estimates the credit loss by comparing the loan's carrying value against either 1) the present value of the expected future cash flows discounted at the loan's effective interest rate; 2) the loan's observable market price; or 3) the expected realizable fair value of the collateral, in the case of collateral dependent loans. A specific allowance is assigned to the impaired loan for the amount of estimated credit loss. Impaired loans are charged off, in whole or in part, when management believes that the recorded investment in the loan is uncollectible. General Reserves for loans collectively evaluated for impairment In assessing the general reserves management has segmented the portfolio for groups of loans with similar risk characteristics, by I. Non-classified loans, and II. Regulatory problem-asset segments. These groups are further subdivided by loan category or internal risk rating, respectively. The general loss allocation factors take into account the quantitative historic loss experience, qualitative or environmental factors such as those identified above, as well as regulatory guidance and industry data. I. Non-classified loans by credit type: Management has established the modified historic loss factor for non-classified loan segments by first calculating net charge-offs over a period of time, divided by the average loan balance over that same period. The time period utilized equates to the estimated loss emergence period for each loan segment. This average period may be changed from time to time to be reflective of the most appropriate corresponding conditions (market, economic, etc.). These historic loss factors are then adjusted up or down based on management’s assessment of current qualitative factors that are likely to cause estimated credit losses as of the evaluation date to differ from the segment’s historical loss experience. These key qualitative factors include the following broad categories: • Several key areas of expansion and growth, including geographic market, changes in lending staff, new or expanded product lines, changes in composition and portfolio concentrations; • Changes in the trend and current volume and severity of past due loans, non-accrual loans and the severity of adversely classified and impaired loans compared to historical levels; and • The current economic environment and conditions (local, state and national) and their general implications to each loan category. Management weighs the current effect of each of these areas on each particular non-classified loan segment in determining the allowance allocation factors. Management must exercise significant judgment when evaluating the effect of these qualitative factors on the amount of the allowance for loan losses on the non-classified segments because data may not be reasonably available or directly applicable to determine the precise impact of a factor on the collectability of the loan portfolio as of the evaluation date. The methodology contemplates a range of acceptable levels for these factors due to the subjective nature of the factors and the qualitative considerations related to the inherent credit risk in the portfolio. II. Regulatory problem-assets segments by credit rating: For determining the reserve percentages for problem-loans, management has segmented the portfolio following the regulatory problem-asset segments by risk rating: Criticized; Substandard; Doubtful; or Loss, after excluding loans that are individually evaluated for impairment. Management utilizes regulatory guidance and industry data in relation to the Company's own portfolio statistics as a basis for determining the allocation factors for each class of regulatory problem-assets. Management recognizes that additional issues may also impact the estimate of credit losses to some degree. From time to time management will re-evaluate the qualitative factors, regulatory guidance, and industry data in use in order to consider the impact of other issues which, based on changing circumstances, may become more significant in the future. The balances of loans as of December 31, 2015 by segment and evaluation method are summarized as follows: (Dollars in thousands) Loans individually evaluated for impairment Loans collectively evaluated for impairment Total Loans Commercial real estate $ 12,287 $ 924,634 $ 936,921 Commercial and industrial 7,810 450,743 458,553 Commercial construction 3,032 199,961 202,993 Residential 366 168,822 169,188 Home equity 169 83,204 83,373 Consumer 24 10,723 10,747 Deferred fees — (1,813 ) (1,813 ) Total loans $ 23,688 $ 1,836,274 $ 1,859,962 See the section titled "Impaired Loans" below, for information regarding the changes in impaired loans balances at December 31, 2015 compared to the prior year. The balances of loans as of December 31, 2014 by segment and evaluation method are summarized as follows: (Dollars in thousands) Loans individually evaluated for impairment Loans collectively evaluated for impairment Total Loans Commercial real estate $ 15,003 $ 847,744 $ 862,747 Commercial and industrial 10,901 392,093 402,994 Commercial construction 2,675 165,369 168,044 Residential 465 149,494 149,959 Home equity 180 79,838 80,018 Consumer 28 10,680 10,708 Deferred fees — (1,866 ) (1,866 ) Total loans $ 29,252 $ 1,643,352 $ 1,672,604 Credit Risk Management The level of adversely classified loans, delinquent and non-performing assets is largely a function of economic conditions, the overall banking environment, the Company's underwriting and credit risk management standards. The Company’s commercial lending focus may entail significant additional risks compared to long term financing on existing, owner-occupied residential real estate. The Company endeavors to minimize this risk through sound underwriting practices and the risk management function. The credit risk management function focuses on a wide variety of factors, including, among others, current and expected economic conditions, the real estate market, the financial condition of borrowers, the ability of borrowers to adapt to changing conditions or circumstances affecting their business and the continuity of borrowers’ management teams. Early detection of credit issues is critical to minimize credit losses. Accordingly, management regularly monitors these factors, among others, through ongoing credit reviews by the Credit Department, an external loan review service, reviews by members of senior management and the Loan Committee of the Board of Directors. This review includes the assessment of internal credit quality indicators such as the risk classification of individual loans, individual review of adversely classified loans, past due and non-accrual loans, impaired and restructured loans, and the level of foreclosure activity, as well as trends in the general levels of these indicators. However, despite prudent loan underwriting and ongoing credit risk management, adverse changes within the Company's market area or deterioration in the local, regional or national economic conditions could negatively impact the portfolio's credit risk profile and the Company's asset quality in the future. Management believes that the general credit profile of the portfolio and individual commercial relationships will continue to be affected by lagging effects that the economic environment has had on the regional and local commercial markets. Credit Quality Indicators 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, to the more severe adverse classifications of "substandard," "doubtful" and “loss” based on criteria established under banking regulations. Loans classified as substandard include those loans characterized by the distinct possibility that the Company will sustain some loss if the deficiencies are not corrected. These loans are inadequately protected by the sound net worth and paying capacity of the borrower; repayment has become increasingly reliant on collateral liquidation or reliance on guaranties; credit weaknesses are well-defined; borrower cash flow is insufficient to meet the required debt service specified in the loan terms and to meet other obligations, such as trade debt and tax payments. Loans classified as doubtful have all the weaknesses inherent in a substandard rated loan with the added characteristic that the weaknesses make collection or full payment from liquidation, on the basis of currently existing facts, conditions, and values, highly questionable and improbable. The probability of loss is extremely high, but because of certain important and reasonably specific pending factors which may work to the advantage and strengthening of the loan, its classification as an estimated loss is deferred until more exact status may be determined. Loans classified as loss are generally considered uncollectible at present, although long term recovery of part or all of loan proceeds may be possible. These “loss” loans would require a specific loss reserve or charge-off. Adversely classified loans may be accruing or in non-accrual status and may be additionally designated as impaired or restructured, or some combination thereof. Loans which are evaluated to be of weaker credit quality are reviewed on a more frequent basis by management. The following tables present the credit risk profile by internally assigned adverse risk rating category at the periods indicated. December 31, 2015 (Dollars in thousands) Adversely Classified Not Adversely Classified Gross Loans Substandard Doubtful Loss Commercial real estate $ 12,487 $ — $ — $ 924,434 $ 936,921 Commercial and industrial 8,670 — 3 449,880 458,553 Commercial construction 1,776 — — 201,217 202,993 Residential 1,278 — — 167,910 169,188 Home equity 503 — 5 82,865 83,373 Consumer 38 11 — 10,698 10,747 Total gross loans $ 24,752 $ 11 $ 8 $ 1,837,004 $ 1,861,775 December 31, 2014 (Dollars in thousands) Adversely Classified Not Adversely Classified Gross Loans Substandard Doubtful Loss Commercial real estate $ 11,409 $ 1,188 $ 19 $ 850,131 $ 862,747 Commercial and industrial 11,298 51 57 391,588 402,994 Commercial construction 2,759 — — 165,285 168,044 Residential 1,133 — — 148,826 149,959 Home equity 464 — — 79,554 80,018 Consumer 48 — — 10,660 10,708 Total gross loans $ 27,111 $ 1,239 $ 76 $ 1,646,044 $ 1,674,470 Total adversely classified loans amounted to 1.33% of total loans at December 31, 2015 , as compared to 1.70% at December 2014 . At December 31, 2015 , as compared to December 2014 , adversely classified balances declined $3.7 million , primarily due to several larger commercial loan payoffs, charge-offs, upgrades and principal payments within the commercial real estate and commercial and industrial loan segments, partially offset by additional credit downgrades within the commercial real estate, commercial and industrial, and commercial construction portfolio during the period. Past Due and Non-Accrual Loans Loans on which the accrual of interest has been discontinued are designated as non-accrual loans are credit downgraded to one of the adversely classified categories noted above. Accrual of interest on loans is generally discontinued when a loan becomes contractually past due, with respect to interest or principal, by 90 days, or when reasonable doubt exists as to the full and timely collection of interest or principal. When a loan is placed on non-accrual status, all interest previously accrued but not collected is reversed against current period interest income. Interest accruals are resumed on such loans only when payments are brought current and have remained current for a period of 180 days and when, in the judgment of management, the collectability of both principal and interest is reasonably assured. Interest payments received on loans in a non-accrual status are generally applied to principal on the books of the Company. Additionally, deposit accounts overdrawn for 90 or more days are included in the consumer non-accrual numbers below. The following table presents an age analysis of past due loans as of December 31, 2015 . (Dollars in thousands) Loans 30-59 Days Past Due Loans 60-89 Days Past Due Non-accrual Loans Total Past Due Loans Current Loans Gross Loans Commercial real estate $ 1,124 $ 1,140 $ 8,506 $ 10,770 $ 926,151 $ 936,921 Commercial and industrial 1,218 691 4,323 6,232 452,321 458,553 Commercial construction 581 — 335 916 202,077 202,993 Residential 250 180 366 796 168,392 169,188 Home equity 622 — 288 910 82,463 83,373 Consumer 35 10 27 72 10,675 10,747 Total gross loans $ 3,830 $ 2,021 $ 13,845 $ 19,696 $ 1,842,079 $ 1,861,775 The following table presents an age analysis of past due loans as of December 31, 2014 . (Dollars in thousands) Loans 30-59 Days Past Due Loans 60-89 Days Past Due Non-accrual Loans Total Past Due Loans Current Loans Gross Loans Commercial real estate $ 1,471 $ 1,235 $ 9,714 $ 12,420 $ 850,327 $ 862,747 Commercial and industrial 1,184 101 5,950 7,235 395,759 402,994 Commercial construction — — 447 447 167,597 168,044 Residential 1,328 370 763 2,461 147,498 149,959 Home equity 29 — 245 274 79,744 80,018 Consumer 94 1 17 112 10,596 10,708 Total gross loans $ 4,106 $ 1,707 $ 17,136 $ 22,949 $ 1,651,521 $ 1,674,470 At December 31, 2015 and December 31, 2014 , all loans 90 or more days past due were carried as non-accruing. Non-accrual loans which were not adversely classified amounted to $402 thousand at December 31, 2015 and $211 thousand at December 31, 2014 . These balances primarily represented the guaranteed portions of non-performing U.S. Small Business Administration loans. The majority of the non-accrual loan balances were also carried as impaired loans during the periods and are discussed further below. The ratio of non-accrual loans to total loans amounted to 0.74% and 1.02% at December 31, 2015 and December 31, 2014 , respectively. Reductions in non-accrual loans were seen in all commercial segments, led by commercial and industrial and commercial real estate loans as loan payoffs, charge-offs and principal payment continued during the period. At December 31, 2015 , additional funding commitments for loans on non-accrual status totaled $910 thousand . The Company's obligation to fulfill the additional funding commitments on non-accrual 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 reduction in interest income for the years ended December 31, associated with non-accruing loans is summarized as follows: (Dollars in thousands) 2015 2014 2013 Income in accordance with original loan terms $ 1,052 $ 1,007 $ 1,171 Less income recognized 426 323 680 Reduction in interest income $ 626 $ 684 $ 491 Impaired Loans Impaired loans are individually significant loans for which management considers it probable that not all amounts due (principal and interest) in accordance with original contractual terms will be collected. The majority of impaired loans are included within the non-accrual balances; however, not every loan in non-accrual status has been designated as impaired. Impaired loans include loans that have been modified in a troubled debt restructuring (or "TDR", see below). Impaired loans 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. Management does not set any minimum delay of payments as a factor in reviewing for impaired classification. Management considers the individual payment status, net worth and earnings potential of the borrower, and the value and cash flow of the collateral as factors to determine if a loan will be paid in accordance with its contractual terms. An impaired or TDR loan classification will be considered for upgrade based on the borrower's sustained performance over time and their improving financial condition, the expectation of the borrower's ability to continue to service the loan in accordance with the original or modified terms and the collectability of the remaining balance, and in the case of TDR loans, an interest rate at or greater than a market rate for a similar credit at the time of modification. Impaired loans are individually evaluated for credit loss and a specific reserve is assigned for the amount of the estimated credit loss. Refer to heading “Allowance for probable loan losses methodology” contained within this Note 4 for further discussion of management’s methodology used to estimate specific reserves for impaired loans. Total impaired loans amounted to $23.7 million and $29.3 million at December 31, 2015 and December 31, 2014 , respectively. Total accruing impaired loans amounted to $10.1 million and $12.5 million at December 31, 2015 and December 31, 2014 , respectively, while non-accrual impaired loans amounted to $13.6 million and $16.7 million as of December 31, 2015 and December 31, 2014 , respectively. The following table sets forth the recorded investment in impaired loans and the related specific allowance allocated as of December 31, 2015 . (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 $ 14,903 $ 12,287 $ 11,734 $ 553 $ 186 Commercial and industrial 9,816 7,810 5,253 2,557 1,078 Commercial construction 3,147 3,032 1,583 1,449 499 Residential 453 366 366 — — Home equity 308 169 164 5 5 Consumer 25 24 — 24 24 Total $ 28,652 $ 23,688 $ 19,100 $ 4,588 $ 1,792 The following table sets forth the recorded investment in impaired loans and the related specific allowance allocated as of December 31, 2014 . (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 $ 17,182 $ 15,003 $ 14,800 $ 203 $ 68 Commercial and industrial 11,991 10,901 5,461 5,440 1,516 Commercial construction 2,862 2,675 1,150 1,525 519 Residential 537 465 465 — — Home equity 183 180 — 180 26 Consumer 28 28 — 28 28 Total $ 32,783 $ 29,252 $ 21,876 $ 7,376 $ 2,157 The following table presents the average recorded investment in impaired loans and the related interest recognized during the year ends indicated. December 31, 2015 December 31, 2014 December 31, 2013 (Dollars in thousands) Average recorded investment Interest income recognized Average recorded investment Interest income recognized Average recorded investment Interest income recognized Commercial real estate $ 13,827 $ 196 $ 14,135 $ 223 $ 17,673 $ 237 Commercial and industrial 9,372 97 10,682 156 9,444 92 Commercial construction 2,202 83 3,158 105 3,227 77 Residential 449 — 1,082 3 745 9 Home equity 174 1 208 — 120 — Consumer 45 — 27 2 18 2 Total $ 26,069 $ 377 $ 29,292 $ 489 $ 31,227 $ 417 Interest income that was not recognized on loans that were deemed impaired as of December 31, 2015 , 2014 and 2013 , amounted to $688 thousand , $647 thousand , and $445 thousand , respectively. All payments received on impaired loans in non-accrual status are applied to principal. At December 31, 2015 , additional funding commitments for impaired loans totaled $749 thousand . 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, the Bank grants the borrower a concession on the terms, that would otherwise not be considered, as a result of financial difficulties of the borrower. Typically, such concessions consist of a reduction in interest rate to a below market rate, taking into account the credit quality of the note, 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 credit loss. Total TDR loans, included in the impaired loan figures above as of December 31, 2015 and December 31, 2014 , were $17.1 million and $19.5 million , respectively. TDR loans on accrual status amounted to $10.1 million and $11.9 million at December 31, 2015 and December 31, 2014 , respectively. TDR loans included in non-performing loans amounted to $7.1 million and $7.5 million at December 31, 2015 and December 31, 2014 , respectively. The Company continues to work with commercial relationships and enters into loan modifications to the extent deemed to be necessary or appropriate to ensure the best mutual outcome given the current economic environment. At December 31, 2015 , additional funding commitments for TDR loans totaled $469 thousand . The Company's obligation to fulfill the additional funding commitments on non-accrual 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 tables present certain information regarding loan modifications classified as troubled debt restructures. Troubled debt restructure agreements entered into during the year ended December 31, 2015 . (Dollars in thousands) Number of restructurings Pre-modification outstanding recorded investment Post-modification outstanding recorded investment Commercial real estate 4 $ 269 $ 371 Commercial and industrial 8 1,786 1,600 Commercial construction 2 1,339 1,339 Residential — — — Home equity — — — Consumer 1 4 3 Total 15 $ 3,398 $ 3,313 Loans modified as troubled debt restructuring within the previous twelve months for which there was a subsequent payment default during the year ended December 31, 2015 . (Dollars in thousands) Number of TDRs that defaulted Post-modification outstanding recorded investment Commercial real estate — $ — Commercial and industrial 3 759 Commercial construction — — Residential — — Home equity — — Consumer — — Total 3 $ 759 There were no subsequent charge-offs associated with TDRs modified during 2015 . At December 31, 2015 , specific reserves allocated to the 2015 TDRs amounted to $201 thousand , as management considers it likely the un-reserved principal will ultimately be collected. Interest payments received on non-accruing 2015 TDR loans which were applied to principal and not recognized as interest income amounted to $18 thousand . Troubled debt restructure agreements entered into during the year ended December 31, 2014 . (Dollars in thousands) Number of restructurings Pre-modification outstanding recorded investment Post-modification outstanding recorded investment Commercial real estate 3 $ 1,972 $ 1,972 Commercial and industrial 8 263 256 Commercial construction — — — Residential 1 124 121 Home equity 1 73 73 Consumer — — — Total 13 $ 2,432 $ 2,422 Loans modified as troubled debt restructuring within the previous twelve months for which there was a subsequent payment default during the year ended December 31, 2014 . (Dollars in thousands) Number of TDRs that defaulted Post-modification outstanding recorded investment Commercial real estate — $ — Commercial and industrial 1 64 Commercial construction — — Residential 1 121 Home equity — — Consumer — — Total 2 $ 185 There were $66 thousand in charge-offs associated with TDRs noted in the table above. At December 31, 2014 , specific reserves allocated to the 2014 TDRs amounted to $43 thousand as management considered it likely the principal would ultimately be collected. Interest payments received on non-accruing 2014 TDR loans which were applied to principal and not recognized as interest income amounted to $9 thousand . Other Real Estate Owned The Company carried no OREO at December 31, 2015 compared to $861 thousand at December 31, 2014 . During the year ended December 31, 2015 , the Company sold the three properties held at December 31, 2014 , recognizing net gains on OREO sales of $154 thousand ; there were no additions to OREO, or subsequent impairment write-downs during the period. During the year ended December 31, 2014 , there were no sales or subsequent impairment write-downs on OREO. Allowance for Loan Loss Activity 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 $29.0 million at December 31, 2015 compared to $27.1 million at December 31, 2014 . The allowance for loan losses to total loans ratio was 1.56% at December 31, 2015 , compared to 1.62% at December 31, 2014 . The decline in the overall allowance to total loan ratio at December 31, 2015 primarily resulted from the increase in the outstanding loan balances and a reduction in specific reserves and reflects the generally improving credit quality of the loan portfolio in the current period due, in part, to improved economic conditions. Specific reserves declined due to current charge-offs on commercial relationships for which management deemed collectability of amounts due was unlikely based on current realizable collateral values, partially offset by additional reserves for newly impaired loans during the period. Loan growth for the year ended December 31, 2015 was $187.4 million , compared to $148.5 million for 2014 . For the year ended December 31, 2015 , the Company recorded net charge-offs of $1.4 million compared to $1.2 million for 2014 . Provisions made to the allowance for loan losses amounted to $3.3 million and $1.4 million for the years ended December 31, 2015 and 2014 , respectively. The majority of the 2014 charge-offs were previously allocated specific reserves on commercial relationships, which contributed to the lower provision for loan losses in 2014 . Management continues to closely monitor the non-performing assets, charge-offs and necessary allowance levels, including specific reserves. 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 December 31, 2015 . Changes in the allowance for loan losses for the years ended December 31, are summarized as follows: (Dollars in thousands) 2015 2014 2013 Balance at beginning of year $ 27,121 $ 26,967 $ 24,254 Provision charged to operations 3,267 1,395 3,279 Loan recoveries 409 735 415 Less: Loans charged-off 1,789 1,976 981 Balance at end of year $ 29,008 $ 27,121 $ 26,967 Changes in the allowance for loan losses by segment for the year ended December 31, 2015 , are presented below: (Dollars in thousands) Cmml Real Estate Cmml and Industrial Cmml Constr Resid. Mortgage Home Equity Cnsmr Total Beg. Balance, 12/31/14 $ 12,664 $ 9,245 $ 3,384 $ 989 $ 608 $ 231 $ 27,121 Provision 909 1,805 496 72 (83 ) 68 3,267 Recoveries 74 279 25 — 15 16 409 Less: Charge offs 133 1,571 — — — 85 1,789 Ending Balance, 12/31/15 $ 13,514 $ 9,758 $ 3,905 $ 1,061 $ 540 $ 230 $ 29,008 Ending allowance balance allotted to: Loans individually evaluated for impairment $ 186 $ 1,078 $ 499 $ — $ 5 $ 24 $ 1,792 Loans collectively evaluated for impairment $ 13,328 $ 8,680 $ 3,406 $ 1,061 $ 535 $ 206 $ 27,216 Changes in the allowance for loan losses by segment for the year ended December 31, 2014 , are presented below: (Dollars in thousands) Cmml Real Estate Cmml and Industrial Cmml Constr Resid. Mortgage Home Equity Cnsmr Total Beg. Balance, 12/31/13 $ 13,174 $ 8,365 $ 3,493 $ 1,057 $ 653 $ 225 $ 26,967 Provision (186 ) 1,627 (41 ) (22 ) (19 ) 36 1,395 Recoveries 21 616 66 — 1 31 735 Less: Charge offs 345 1,363 134 46 27 61 1,976 Ending Balance, 12/31/14 $ 12,664 $ 9,245 $ 3,384 $ 989 $ 608 $ 231 $ 27,121 Ending allowance balance allotted to: Loans individually evaluated for impairment $ 68 $ 1,516 $ 519 $ — $ 26 $ 28 $ 2,157 Loans collectively evaluated for impairment $ 12,596 $ 7,729 $ 2,865 $ 989 $ 582 $ 203 $ 24,964 During 2012, the Company purchased a group of residential mortgage loans with a carrying value of $7.4 million at December 31, 2015 . These purchased loans were initially booked at fair market value and, in accordance with accounting guidance, do not carry an initial allowance for loan losses. Management will continue to closely monitor this portfolio of non-classified loans for estimated credit loss under general loss allocations taking into account the loss experience as well as the quantitative and qualitative factors identified above. To date this portfolio has paid down by approximately $19.0 million and no losses have been recorded.

Premises and Equipment

Premises and Equipment	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and Equipment Premises and equipment at December 31, are summarized as follows: (Dollars in thousands) 2015 2014 Land $ 4,614 $ 4,594 Bank premises and leasehold improvements 33,597 32,556 Computer software and equipment 9,014 6,764 Furniture, fixtures and equipment 16,649 15,548 Total premises and equipment, before accumulated depreciation 63,874 59,462 Less accumulated depreciation (33,321 ) (29,092 ) Total premises and equipment, net of accumulated depreciation $ 30,553 $ 30,370 Total depreciation expense related to premises and equipment amounted to $4.3 million , $4.2 million and $3.9 million for the years ended December 31, 2015 , 2014 and 2013 , respectively. Total rent expense for the years ended December 31, 2015 , 2014 and 2013 amounted to $1.2 million , $1.1 million and $910 thousand , respectively. The Company's leased facilities are contracted under various non-cancelable operating leases, most of which provide options to extend lease periods and periodic rent adjustments. Several leases 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. At December 31, 2015 , minimum lease payments for these operating leases were as follows: (Dollars in thousands) Payable in: 2016 $ 1,476 2017 1,454 2018 1,133 2019 695 2020 606 Thereafter 5,100 Total minimum lease payments $ 10,464 The Company currently collects rent through leases for a small portion of the overall square-footage within its Lowell, MA campus headquarters. Rental income was $153 thousand for both the years ended December 31, 2015 and 2014 , and $150 thousand for the year ended December 31, 2013 .

Deposits

Deposits	12 Months Ended
	Dec. 31, 2015
Deposits [Abstract]
Deposits	Deposits Deposits at December 31, are summarized as follows: (Dollars in thousands) 2015 2014 Non-interest bearing demand deposits $ 570,589 $ 470,025 Interest bearing checking 313,674 253,126 Savings 167,304 149,940 Money market 692,114 631,676 Certificates of deposit $250,000 or less 129,993 141,379 Certificates of deposit more than $250,000 37,704 37,215 Total non-brokered deposits (1) 1,911,378 1,683,361 Brokered deposits (2) 106,770 85,185 Total deposits $ 2,018,148 $ 1,768,546 (1) Includes reciprocal money market deposits and CDs received from participating banks in nationwide networks as a result of our customers electing to participate in programs to obtain full FDIC insurance. Essentially, the equivalent of the original deposit comes back to the Company as non-brokered deposits within the appropriate category under total deposits on the balance sheet. (2) Primarily brokered CDs $250,000 and under. The aggregate amount of overdrawn deposits that have been reclassified as loan balances were $407 thousand and $1.1 million at December 31, 2015 and 2014 , respectively. The following table shows the scheduled maturities of certificates of deposit (including brokered deposits with a weighted average remaining life of approximately 1.4 years): (Dollars in thousands) December 31, 2015 December 31, 2014 Due in less than twelve months $ 176,792 $ 166,325 Due in over one year through two years 37,729 30,043 Due in over two years through three years 23,429 22,776 Due in over three years through four years 26,501 17,618 Due in over four years through five years 5,983 26,140 Due in over five years 4,033 877 Total certificates of deposit $ 274,467 $ 263,779

Borrowed Funds and Subordinated

Borrowed Funds and Subordinated Debt	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Borrowed Funds and Subordinated Debt	Borrowed Funds and Subordinated Debt Borrowed funds and subordinated debt outstanding at December 31, are summarized as follows: 2015 2014 2013 (Dollars in thousands) Amount Average Rate Amount Average Rate Amount Average Rate FHLB borrowings $ 40,671 0.51 % $ 58,900 0.30 % $ 36,534 0.30 % Other borrowings 13,000 0.60 % — — % — — % Total borrowed funds $ 53,671 0.53 % $ 58,900 0.30 % $ 36,534 0.30 % Subordinated debt 14,822 6.16 % 10,825 10.88 % 10,825 10.88 % Total borrowed funds and subordinated debt $ 68,493 1.75 % $ 69,725 1.94 % $ 47,359 2.72 % The contractual maturity distribution as of December 31, 2015 , of borrowed funds with the weighted average cost for each category is set forth below: Overnight Within 12 months (Dollars in thousands) Balance Rate Balance Rate FHLB borrowings $ 40,000 0.51 % $ 671 0.70 % Other borrowings 13,000 0.60 % — — % Total borrowed funds $ 53,000 0.53 % $ 671 0.70 % The FHLB borrowings due within 12 months had original maturities of one to two years, and are linked to certain outstanding commercial loans under various community investment programs of the FHLB. Maximum FHLB and other borrowings outstanding at any month end during 2015 , 2014 , and 2013 were $53.7 million , $58.9 million , and $57.4 million , respectively. The following table summarizes the average balance and average cost of borrowed funds for the years ended December 31, Year ended December 31, 2015 2014 2013 (Dollars in thousands) Average Balance Average Cost Average Balance Average Cost Average Balance Average Cost FHLB advances $ 10,731 0.36 % $ 12,085 0.31 % $ 24,385 0.39 % Other borrowings 36 0.61 % 28 0.56 % 14 0.46 % Total borrowed funds $ 10,767 0.36 % $ 12,113 0.31 % $ 24,399 0.39 % The Company’s primary borrowing source is the FHLB, but the Company may choose to borrow from other established business partners. “Other borrowings” represents overnight advances from the FRB or federal funds purchased from correspondent banks. At December 31, 2015, other borrowings was comprised of an overnight borrowing with a correspondent bank. As a member of the FHLB, the Bank has the potential capacity to borrow an amount up to the value of its discounted qualified collateral. Borrowings from the FHLB are secured by certain securities from the Company’s investment portfolio not otherwise pledged and certain residential and commercial real estate loans. At December 31, 2015 , based on qualifying collateral less outstanding advances, the Bank had the capacity to borrow additional funds from the FHLB of up to approximately $370 million . In addition, based on qualifying collateral, the Bank had the capacity to borrow funds from the FRB Discount Window up to approximately $100 million . The Bank also has pre-approved borrowing arrangements with large correspondent banks in order to provide overnight and short-term borrowing capacity. See Note 2, "Investments," and Note 3, "Loans" above to these consolidated financial statements for further information regarding securities and loans pledged for borrowed funds. The Company also carried subordinated debt of $14.8 million at December 31, 2015 , and $10.8 million at December 31, 2014 . The subordinated debt carried at December 31, 2015 consisted of $15.0 million in aggregate principal amount of Fixed-to-Floating Rate Subordinated Notes (the "Notes"), issued in January 2015 , in a private placement to an accredited investor. The Notes, which are intended to qualify as Tier 2 capital for regulatory purposes, mature on January 30, 2030 (the "Maturity Date") and are callable by the Company, subject to regulatory approval, at a premium beginning January 30, 2020 , and at par beginning January 30, 2025 . The Notes pay interest at a fixed rate of 6.00% per annum through January 30, 2025 , and beginning on January 31, 2025 through the Maturity Date, or any early redemption date, the interest rate on the Notes will adjust monthly at an interest rate of 3.90% plus 30-day LIBOR. Original note issuance costs were $190 thousand and have been netted against the subordinated debt on the balance sheet in accordance with recent accounting guidance which the Company adopted in the first quarter of 2015. These costs are being amortized over the life of the Notes. The subordinated debt balance carried at December 31, 2014 consisted of $10.8 million in Junior Subordinated Debt Securities (the "Debt"). In March 2000, Enterprise (MA) Capital Trust I (the "Trust"), a subsidiary of Enterprise Bancorp, issued $10.5 million of 10.875% trust preferred securities that were to mature in 2030 and were callable at a premium. The proceeds from the sale of the trust preferred securities were used by the Trust, along with the Company's $325 thousand capital contribution, to acquire $10.8 million in aggregate principal amount of the Company's 10.875% Debt that was to mature in 2030 and was callable. In March 2015 , the Company redeemed the Debt in full using proceeds from the $15.0 million in Notes issued in January 2015 , which in turned allowed the Trust to redeem in full the trust preferred securities. The Company dissolved the Trust in April 2015.

Commitments, Contingencies and

Commitments, Contingencies and Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingencies and Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk	Commitments, Contingencies and Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk The Company is party to financial instruments with off-balance sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to originate loans, standby letters of credit, unadvanced portions of loans and lines of credit and derivative instruments. The instruments involve, to varying degrees, elements of credit risk in excess of the amount recognized in the balance sheets. The contract amounts of these instruments reflect the extent of involvement the Company has in the particular classes of financial instruments. The Company’s exposure to credit loss in the event of nonperformance by the other party to the financial instrument for loan commitments and standby letters of credit is represented by the contractual amounts of those instruments. The Company uses the same credit policies in making commitments and conditional obligations as it does for on-balance sheet instruments. Financial instruments with off-balance sheet credit risk at December 31, 2015 and 2014 are as follows: (Dollars in thousands) 2015 2014 Commitments to originate loans $ 48,641 $ 33,870 Commitments to originate residential mortgages loans for sale 1,516 1,471 Commitments to sell residential mortgage loans 3,225 3,842 Standby letters of credit 22,712 19,359 Unadvanced portions of commercial real estate loans 13,128 27,335 Unadvanced portions of commercial loans and lines 337,970 306,745 Unadvanced portions of construction loans (commercial & residential) 138,162 143,016 Unadvanced portions of home equity lines 73,397 64,337 Unadvanced portions of consumer loans 2,999 3,017 Commitments to originate loans are agreements to lend to a customer provided there is no violation of any condition established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee by the customer. Since some of the commitments are expected to expire without being drawn upon, the total commitment amounts do not necessarily represent future cash requirements. The Company evaluates each customer’s credit worthiness on a case-by-case basis. The amount of collateral obtained, if deemed necessary by the Company upon extension of credit, is based on management’s credit evaluation of the borrower. The Company originates residential mortgage loans under agreements to sell such loans, and may retain or sell the servicing when selling the loans. Loans sold are subject to standard secondary market underwriting and eligibility representations and warranties over the life of the loan, and are subject to an early payment default period covering the first four payments for certain loan sales. Standby letters of credit are conditional commitments issued by the Company to guarantee the financial obligation or performance by a customer to a third-party. The credit risk involved in issuing letters of credit is essentially the same as that involved in extending loan facilities to customers. If the letter of credit is drawn upon, the Company creates a loan for the customer with the same criteria associated with similar loans. Unadvanced portions of loans and lines of credit represent credit extended to customers but not yet drawn upon, and are secured or guaranteed under preexisting loan agreements. Commercial loans and lines may be collateralized by the assets underlying the borrower’s business such as accounts receivable, equipment, inventory and real property or may be unsecured loans and lines to financially strong borrowers and are generally guaranteed by the principals of the borrower. Commercial real estate loans are generally secured by the underlying real property and rental agreements. Residential mortgage and home equity loans are secured by the real property financed. Consumer loans such as installment loans are generally secured by the personal property financed, while credit card loans and overdraft protection lines are generally unsecured. The Company seeks to manage its loan portfolio to avoid concentration by industry or loan size to minimize its credit risk exposure. The Bank is required by the FRB to maintain in reserves certain amounts of vault cash and/or deposits with the FRB. The average daily reserve requirement included in “Cash and Due from Banks” was approximately $7.4 million and $14.3 million , based on the two week computation periods encompassing December 31, 2015 and 2014 , respectively. There are no material pending legal proceedings to which the Company or its subsidiaries are a party or to which any of its property is subject, other than ordinary routine litigation incidental to the business of the Company. Management does not believe resolution of any present litigation will have a material adverse effect on the financial condition or results of operations of the Company. 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 December 31, 2015 and 2014 , the estimated fair values of these derivative instruments were considered to be immaterial. The Company may use interest-rate contract swaps as part of its interest-rate risk management strategy. Interest-rate swap agreements are entered into as hedges against future interest-rate fluctuations on specifically identified assets or liabilities. The Company did not have derivative fair value hedges or derivative cash flow hedges at December 31, 2015 and 2014 . Derivatives not designated as hedges, such as Back-to-Back Swaps as detailed in Note 1 are not speculative but rather, result from a service the Company provides to certain customers. The Company had two interest-rate swaps with an aggregate notional amount of $10.1 million at December 31, 2015 . There were no interest-rate swaps related to this program at December 31, 2014 . Asset derivatives and liability derivatives are included in other assets and accrued expenses and other liabilities on the consolidated balance sheets, respectively. The table below presents the fair value and classification of the Company’s derivative financial instruments at December 31, 2015 . As of December 31, 2015 (Dollars in thousands) Asset Derivatives Liability Derivatives Back-to-Back Swaps $ 16 $ 16 There was no gain or loss recognized in income on derivatives during the year ended December 31, 2015 . By using derivative financial instruments, the Company exposes itself to 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. As the swaps are subject to master netting agreements, the Company had limited exposure relating to interest rate swaps with institutional counterparties at December 31, 2015 . The Company did not have any credit risk exposure for derivative financial instruments at December 31, 2015 . Certain derivative agreements contain provisions that require the Company to post collateral if the derivative exposure exceeds a threshold amount. The Company did not have any collateral posted as of December 31, 2015 . The table below presents the offsetting of derivatives and amounts subject to master netting agreements not offset in the consolidated balance sheet at the dates indicated. As of December 31, 2015 Gross Amounts of Recognized Asset/Liabilities Gross Amounts Offset in the Statement of Financial Position Net Amounts of Assets Presented in the Statement of Financial Position Gross amounts not offset in the Statement of Financial Position (Dollars in thousands) Financial Instruments Cash collateral (Received)/Posted Net Amount Asset Derivatives Back-to-Back Swaps $ 16 — $ 16 — — $ 16 Liability Derivatives Back-to-Back Swaps $ 16 — $ 16 — — $ 16 The Company has agreements with certain derivative counterparties that 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.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity The Company’s authorized capital is divided into common stock and preferred stock. The Company is authorized to issue 20,000,000 shares of common stock and 1,000,000 shares of preferred stock. Holders of common stock are entitled to one vote per share, and are entitled to receive dividends if and when declared by the Board of Directors. 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 $52.00 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 will expire, unless earlier redeemed, exchanged, or otherwise rescinded by the Company, on January 13, 2018 . 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 Company issues restricted stock awards that upon vesting, may be net share-settled to cover payment for employee tax obligations, resulting in shares of common stock being reaquired by the Company. See Note 11, "Stock-Based Compensation Plans," below for further information about stock-based compensation issued by the Company and net share-settlement. Capital Adequacy Requirements Capital planning by the Company and the Bank considers current needs and anticipated future growth. The primary sources of capital have been common stock issuances and proceeds from the issuance of subordinated debt. Ongoing sources of capital include the retention of earnings less dividends paid since the Bank commenced operations, proceeds from the exercise of employee stock options and proceeds from purchases of shares pursuant to the Company’s dividend reinvestment plan and direct stock purchase plan. Although management believes its current capital is adequate to support ongoing operations, on July 18, 2013, the Company filed a shelf registration of common stock, rights or preferred stock with the Securities and Exchange Commission for the flexibility to raise, over a three year period, up to $40 million in capital to position the Company to take advantage of future growth and market share opportunities. As of December 31, 2015 , the Company has not utilized this shelf registration. In July 2013, the Federal Reserve, the FDIC and OCC, adopted a final rule that implements the Basel III changes to the international regulatory capital framework and revises the U.S. risk-based and leverage capital requirements for U.S. banking organizations. As a result of these regulatory changes, that became effective January 1, 2015, with a phase in period that extends to January 2019, the Company is subject to increased capital ratios, changes in the capital ratio calculations and the methodology used to calculate such ratios. The Company began implementing the new regulatory requirements under Basel III in 2015 . Management believes, as of December 31, 2015 , that the Company and the Bank meet all capital adequacy requirements to which they were subject. As of December 31, 2015 , both the Company and the Bank qualified as “well capitalized” under then applicable Federal Reserve Board and FDIC regulations. The current regulatory requirements, and the Company's and the Bank's actual capital amounts and ratios are presented as of December 31, 2015 in the table below. Actual Minimum Capital for Capital Adequacy Purposes Minimum Capital To Be Well Capitalized* (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio As of December 31, 2015 The Company Total Capital (to risk weighted assets) $ 212,871 10.70 % $ 159,198 8.00 % $ 198,997 10.00 % Tier 1 Capital (to risk weighted assets) 172,397 8.66 % 119,398 6.00 % 159,198 8.00 % Tier 1 Capital (to average assets)* 172,397 7.73 % 89,173 4.00 % N/A N/A Common equity tier 1 capital to risk-weighted assets 172,397 8.66 % 89,549 4.50 % $ 129,348 6.50 % The Bank Total Capital (to risk weighted assets) $ 209,670 10.54 % $ 159,189 8.00 % $ 198,987 10.00 % Tier 1 Capital (to risk weighted assets) 184,019 9.25 % 119,392 6.00 % 159,189 8.00 % Tier 1 Capital (to average assets) 184,019 8.25 % 89,172 4.00 % 111,465 5.00 % Common equity tier 1 capital to risk-weighted assets 184,019 9.25 % 89,544 4.50 % 129,341 6.50 % ____________________ *For the Bank to qualify as “well capitalized," it must maintain a leverage capital ratio (Tier 1 capital to average assets) of at least 5% . This requirement does not apply to the Company. Under Basel III, capital ratio requirements for all banking organizations have increased and include a "capital conservation buffer," of 2.5% above the regulatory minimum risk-based capital requirements shown above. Both the Company's and the Bank's actual ratios, as outlined in the table above, would exceed this Basel III "Adequate" Ratio with full Capital Conservation Buffer as of December 31, 2015 . The capital conservation buffer requirement began to be phased in beginning in January 2016 at 0.625% of risk-weighted assets and will increase by that amount each year until fully implemented in January 2019. If a banking organization dips into its capital conservation buffer it may be restricted in its ability to pay dividends and discretionary bonus payments to its executive officers. Although community banks began complying with the Basel III rules on January 1, 2015, as previously noted above, there is a phase in period for several aspects, including the capital conservation buffer, which began in January 2016 and extends to January 2019. For further information on the Basel III requirements see the “Supervision and Regulation” contained in Item 1, "Business" in this Form 10-K. The Basel III minimum capital ratio requirements as applicable to the Company and the Bank in 2019 after the full phase-in period are summarized in the table below: Basel III Minimum for Capital Adequacy Purposes Basel III Additional Capital Conservation Buffer Basel III "Adequate" Ratio with Capital Conservation Buffer Total Risk Based Capital (total capital to risk weighted assets) 8.0% 2.5% 10.5% Tier 1 Risk Based Capital (tier 1 to risk weighted assets) 6.0% 2.5% 8.5% Tier 1 Leverage Ratio (tier 1 to average assets) 4.0% —% 4.0% Common Equity Tier 1 Risk Based to risk weighted assets 4.5% 2.5% 7.0% Failure to meet minimum capital requirements can initiate or result in certain mandatory and possibly additional discretionary actions by regulators that, if undertaken, could have a material adverse effect on the Company’s financial statements. Under applicable capital adequacy requirements and the regulatory framework for prompt corrective action applicable to the Bank, the Company must meet specific capital guidelines that involve quantitative measures of the Company’s assets, liabilities and certain off-balance sheet items as calculated under regulatory accounting practices. The Company’s capital amounts and classifications are also subject to qualitative judgments by the regulators about components, risk weightings, and other factors. As noted above, capital ratios for 2015 are based on the Basel III regulatory capital framework implemented at the beginning of 2015. The capital ratios presented below for 2014 are based on the capital requirements in effect before the implementation of Basel III. As of December 31, 2014 , the Company and the Bank met all capital adequacy requirements to which they were subject. As of December 31, 2014 , both the Company and the Bank qualified as “well capitalized” under then applicable Federal Reserve Board and FDIC regulations. Prior to 2015, to have been categorized as "well capitalized" under the prompt corrective action framework, the Company and the Bank were required to maintain minimum Total and Tier 1 capital ratios, and in the case of the Bank, leverage capital ratios, as set forth in the table below. Actual Minimum Capital for Capital Adequacy Purposes Minimum Capital To Be Well Capitalized* (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio As of December 31, 2014 The Company Total Capital (to risk weighted assets) $ 189,733 11.27 % $ 134,732 8.00 % $ 168,415 10.00 % Tier 1 Capital (to risk weighted assets) 167,299 9.93 % 67,366 4.00 % 101,049 6.00 % Tier 1 Capital (to average assets)* 167,299 8.41 % 79,578 4.00 % N/A N/A The Bank Total Capital (to risk weighted assets) $ 188,446 11.19 % $ 134,726 8.00 % $ 168,407 10.00 % Tier 1 Capital (to risk weighted assets) 166,013 9.86 % 67,363 4.00 % 101,044 6.00 % Tier 1 Capital (to average assets) 166,013 8.35 % 79,544 4.00 % 99,430 5.00 % _____________________ *For the Bank to qualify as “well capitalized," it must maintain a leverage capital ratio (Tier 1 capital to average assets) of at least 5% . This requirement does not apply to the Company. Dividends Neither the Company nor the Bank may declare or pay dividends on its stock if the effect thereof would cause stockholders’ equity to be reduced below applicable regulatory capital requirements or if such declaration and payment would otherwise violate regulatory requirements. As the principal asset of the Company, the Bank currently provides the only source of cash for the payment of dividends by the Company. Under Massachusetts law, trust companies such as the Bank may pay dividends only out of “net profits” and only to the extent that such payments will not impair the Bank’s capital stock. Any dividend payment that would exceed the total of the Bank’s net profits for the current year plus its retained net profits of the preceding two years would require the Massachusetts Division of Banks' approval. Applicable provisions of the FDIC Improvement Act also prohibits a bank from paying any dividends on its capital stock if the bank is in default on the payment of any assessment to the FDIC or if the payment of dividends would otherwise cause the bank to become undercapitalized. Any restrictions, regulatory or otherwise, on the ability of the Bank to pay dividends to the Company may restrict the ability of the Company to pay dividends to the holders of its common stock. The statutory term “net profits” essentially equates with the accounting term “net income” and is defined under the Massachusetts banking statutes to mean the remainder of all earnings from current operations plus actual recoveries on loans and investments and other assets after deducting from such total all current operating expenses, actual losses, accrued dividends on any preferred stock and all federal and state taxes. The Company previously maintained a dividend reinvestment plan (the “DRP”). In July 2014, the DRP was terminated and the Company adopted a new dividend reinvestment plan and direct stock purchase plan (the "DRSPP"). The DRSPP enables stockholders, at their discretion, to continue 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. For the year ended December 31, 2015 , the Company paid $5.2 million in cash dividends. Stockholders utilized the dividend reinvestment portion of the DRSPP to purchase an aggregate of 58,529 shares of the Company's common stock totaling $1.3 million . The direct purchase component of the DRSPP was used to purchase 6,700 shares of the Company's common stock totaling $150 thousand during the year ended December 31, 2015 . In 2014 , the Company paid $4.9 million in cash dividends. Stockholders utilized the dividend reinvestment portion of the DRSPP to purchase 60,586 shares of the Company’s common stock totaling $1.2 million . The direct purchase component of the DRSPP was used to purchase 2,917 shares of the Company's common stock totaling $64 thousand during the year ended December 31, 2014 .

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Employee Benefit Plans	Employee Benefit Plans 401(k) Defined Contribution Plan and Profit Sharing The Company has a 401(k) defined contribution employee benefit plan. The 401(k) plan allows eligible employees to contribute a percentage of their earnings to the plan. A portion of the employee contribution, as determined by the Compensation Committee of the Board of Directors, is matched by the Company. The Company’s current percentage match has been 60% up to the first 6% contributed by the employee. All eligible employees, at least 18 years of age and completing 1 hour of service, may participate in the 401(k) plan. Vesting for the Company’s 401(k) plan matching contribution is based on years of service with participants becoming 20% vested on January 1st of the year following their date of hire and each subsequent January 1st increasing pro-rata to 100% vesting on January1st following five years of service. Amounts not distributable to an employee following termination of employment are used to offset plan expenses and the Company's contributions. Prior to 2014, the Company also had a profit sharing component to the 401(k) plan. In 2014, the profit sharing component of the 401(k) plan was replaced by combining this component with an existing cash-based variable compensation vehicle. For the year ended December 31, 2013 , the Company’s expense for the profit sharing contribution to the 401(k) plan was $458 thousand . The Company’s expense for the 401(k) plan match (excluding the profit sharing component) was $859 thousand , $792 thousand and $692 thousand , respectively, for the years ended December 31, 2015 , 2014 , and 2013 . Supplemental 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 a predetermined fixed-cash supplemental retirement benefit to be provided for a period of 20 years after the 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 cost 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 funded status is the aggregate amount accrued, or the “Accumulated Benefit Obligation,” which 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. The amounts charged to expense for this plan are included in the table below. The Company anticipates accruing an additional $124 thousand to the plan for the year ending December 31, 2016 . The following table provides a reconciliation of the changes in the supplemental retirement benefit obligation and the net periodic benefit cost for the years ended December 31: (Dollars in thousands) 2015 2014 2013 Reconciliation of benefit obligation: Benefit obligation at beginning of year $ 2,844 $ 2,889 $ 3,181 Net periodic benefit cost: Interest cost 133 128 157 Actuarial loss (gain) (47 ) 103 (173 ) Net periodic benefit costs $ 86 $ 231 $ (16 ) Benefits paid (276 ) (276 ) (276 ) Benefit obligation at end of year $ 2,654 $ 2,844 $ 2,889 Funded status: Accrued liability as of December 31 $ (2,654 ) $ (2,844 ) $ (2,889 ) Discount rate used for benefit obligation (1) 4.75 % 4.50 % 5.00 % (1) Management utilizes the Moody’s 20 year AA corporate bond rates to establish the reasonableness of the discount rate used. The Company reviews and periodically updates the discount rate to reflect changes in bond market rates. The impact of the discount rate change is reflected as the actuarial gain or loss. Benefits expected to be paid in each of the next five years and in the aggregate five years thereafter: (Dollars in thousands) 2016 $ 276 2017 276 2018 276 2019 276 2020 276 2021-2025 1,379 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 bank-owned life insurance ("BOLI"). See Item (k) "Bank Owned Life Insurance" in Note 1, "Summary of Significant Accounting Policies," for further information regarding 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 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 future retirement benefits associated with this arrangement. The following table provides a reconciliation of the changes in the supplemental life insurance plan obligation and the net periodic benefit cost for the years ended December 31: (Dollars in thousands) 2015 2014 2013 Reconciliation of benefit obligation: Benefit obligation at beginning of year $ 1,723 $ 1,576 $ 1,664 Net periodic benefit cost: Service cost (56 ) (38 ) 2 Interest cost 86 74 74 Actuarial loss (gain) 39 111 (164 ) Total net period cost (benefit) $ 69 $ 147 $ (88 ) Benefit obligation at end of year $ 1,792 $ 1,723 $ 1,576 Funded status: Accrued liability as of December 31 $ (1,792 ) $ (1,723 ) $ (1,576 ) Discount rate used for benefit obligation (1) 4.75 % 4.50 % 5.00 % (1) Management utilizes the Moody’s 20 year AA corporate bond rates to establish the reasonableness of the discount rate used. The Company reviews and periodically updates the discount rate to reflect changes in bond market rates. The impact of the discount rate change is reflected as the actuarial gain or loss. The amounts charged to expense for the postretirement cost of insurance for split dollar insurance coverage are included in the table above. The Company anticipates accruing an additional $76 thousand to the plan for the year ending December 31, 2016 . See Note 11, “Stock-Based Compensation Plans” below, for additional information regarding employee benefits offered in the form of stock option and stock awards.

Stock-Based Compensation Plans

Stock-Based Compensation Plans	12 Months Ended
	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation Plans	Stock-Based Compensation Plans The Company currently has two individual stock incentive plans: the 2003 plan as amended in 2009, and the 2009 plan as amended in 2012. The plans permit the Board of Directors to grant, under various terms, both incentive and non-qualified stock options (for the purchase of newly issued shares of common stock), restricted stock, restricted stock units and stock appreciation rights to officers and other employees, directors and consultants. These plans also allow for newly issued shares of common stock to be issued without restrictions, to officers and other employees, directors and consultants. As of December 31, 2015 , 210,683 shares remain available for future grants under the 2009 plan. The 2003 plan is closed to future grants, although several awards previously granted under this plan remain outstanding and may be exercised in the future. Total 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 directors both included in other operating expenses, and was $1.8 million for both the years ended December 31, 2015 and 2014 and $1.7 million for the year ended December 31, 2013 . The total tax benefit recognized related to the stock-based compensation expense was $720 thousand , $700 thousand and $660 thousand for the years ended 2015 , 2014 and 2013 , respectively. The actual tax benefit arising during the period for the tax deduction from stock-based compensation was $217 thousand , $320 thousand and $25 thousand in 2015 , 2014 , and 2013 , respectively. Stock Option Awards Options granted since 2013 vest 50% in year two and 50% in year four, on the anniversary date of the awards. Options that are outstanding and have been granted under the plans prior to 2013 generally vest ratably over four years . Vested options are only exercisable while the employee remains employed with the Bank and for a limited period thereafter. For all awards, if a grantee’s employment or other service relationship, such as service as a director, is terminated for any reason, then any stock options granted that have not vested as of the time of such termination generally must be forfeited, unless the Compensation Committee or the Board of Directors, as the case may be, waives such forfeiture requirement. Under the terms of the plans, stock options may not be granted at less than 100% of the fair market value of the shares on the date of grant and may not have a term of more than ten years. Any shares of common stock reserved for issuance pursuant to options granted under the 2009 plan that are returned to the Company unexercised shall remain available for issuance under such plan, while the plan is open. For participants owning 10% or more of the Company’s outstanding common stock (of which there are currently none), incentive stock options may not be granted at less than 110% of the fair market value of the shares on the date of grant and may not have an expiration term of more than five years. The Company utilizes the Black-Scholes option valuation model in order to determine the per share grant date fair value of option grants. The table below provides a summary of the options granted, including the 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 years indicated. Stock Option Awards 2015 2014 2013 Options granted 27,376 31,229 47,684 Term in years 10.0 10.0 10.0 Average assumptions used in the model: Expected volatility 47 % 47 % 48 % Expected dividend yield 2.90 % 2.88 % 2.96 % Expected life in years 7.0 7.0 7.0 Risk-free interest rate 1.95 % 2.19 % 1.35 % Market price on date of grant $ 21.03 $ 20.29 $ 16.61 Per share weighted average fair value $ 8.51 $ 8.32 $ 6.66 Fair value as a percentage of market value at grant date 40 % 41 % 40 % The expected volatility is the anticipated variability in the Company’s share price over the expected life of the option base on the Company's historical volatility. The expected dividend yield is the Company’s projected dividends based on historical annualized dividend yield to coincide with volatility divided by its share price at the date of grant. The expected life represents the period of time that the option is expected to be outstanding. The Company utilized the simplified method and under this method, the expected term equals the vesting term plus the contractual term divided by 2. The risk-free interest rate is based on the U.S. Treasury rate in effect at the time of grant for a period equivalent to the expected life of the option. Stock option transactions during the year ended December 31, 2015 are summarized as follows: (Dollars in thousands, except per share data) Options Weighted Average Exercise Price Per Share Weighted Average Remaining Life in Years Aggregate Intrinsic Value Outstanding December 31, 2014 319,884 $ 14.92 4.1 $ 3,303 Granted 27,376 21.03 Exercised 43,923 12.47 Forfeited/Expired 2,368 17.56 Outstanding December 31, 2015 300,969 $ 15.82 4.2 $ 2,116 Vested and Exercisable at December 31, 2015 204,344 $ 14.35 2.6 $ 1,738 The aggregate intrinsic value in the table above represents the difference between the closing price of the Company’s common stock on December 31, 2015 and the exercise price, multiplied by the number of options. If the closing price was less than the exercise price of the option, no intrinsic value was assigned to the grant. At December 31, 2015 , all of the vested and exercisable options were in-the money. The intrinsic value of options vested and exercisable represents the total pretax intrinsic value that would have been received by the option holders had all in-the-money vested option holders exercised their options on December 31, 2015 . The intrinsic value will change based on the fair market value of the Company’s stock. Cash received from option exercises was $431 thousand , $889 thousand and $1.8 million in 2015 , 2014 and 2013 , respectively, net of payments to cover employee tax obligations. The total intrinsic value of options exercised was $396 thousand , $867 thousand and $1.1 million in 2015 , 2014 and 2013 , respectively. Accounting guidance requires that the stock-based compensation expense recognized in earnings be based on the amount of awards ultimately expected to vest; therefore, a forfeiture assumption must be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. The Company has estimated forfeitures based on historical experience for the portion of the grant which had vested and/or grants already vested based on similarities in the type of options and employee group. Compensation expense recognized in association with the stock option awards amounted to $318 thousand , $363 thousand and $422 thousand for the years ended 2015 , 2014 and 2013 , respectively. The total tax benefit recognized related to the stock option expense was $127 thousand , $145 thousand , and $165 thousand for the years ended 2015 , 2014 , and 2013 , respectively. As of December 31, 2015 , there was $451 thousand of unrecognized stock-based compensation expense, net of estimated forfeitures, related to non-vested stock options. That cost is expected to be recognized over the remaining weighted average vesting period of 1.9 years. Stock Awards Stock-based compensation expense recognized in association with the stock awards amounted to $1.2 million for the year ended December 31, 2015 , $1.1 million for the year ended December 31, 2014 , and $1.0 million for the year ended December 31, 2013 . The total tax benefit recognized related to stock award compensation expense was $491 thousand , $458 thousand , and $418 thousand for the years ended 2015 , 2014 , and 2013 , respectively. In 2015 , the Company granted 105 shares of fully vested stock as employee anniversary awards at a grant date fair market value of $23.64 per share. In 2014 , the Company granted 2,142 shares of fully vested stock as employee anniversary awards at a grant date fair market value of 20.95 per share. There were no fully vested stock awards granted in 2013 . Restricted stock awards are granted at the market price 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. Employee performance based awards vest upon the Company achieving certain predefined performance objectives. 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 in the years indicated. Restricted Stock Awards 2015 2014 2013 Two Year Vesting 7,276 6,660 6,146 Four Year Vesting 17,775 19,167 26,660 Performance-Based Vesting 30,262 33,017 47,735 Total Restricted Stock Awards 55,313 58,844 80,541 Weighted average grant date fair value $ 21.03 $ 20.29 $ 16.43 If a grantee’s employment or other service relationship, such as service as a director, is terminated for any reason, then any shares of restricted stock that have not vested as of the time of such termination generally must be forfeited, unless the Compensation Committee or the Board of Directors, as the case may be, waives such forfeiture requirement. The restricted stock awards allow for the 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. Upon vesting, restricted stock awards may be net share-settled to cover payment for employee tax obligations, resulting in shares of common stock being reaquired by the Company. In accordance with 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 a Massachusetts company reacquires will be treated as authorized but unissued shares. Any shares that are returned to the Company prior to vesting or as payment for employee tax obligations upon vesting shall remain available for issuance under such plan, while the plan is still open. The following table sets forth a summary of the activity for the Company’s restricted stock awards. (Dollars in thousands, except per share data) Restricted Stock Weighted Average Grant Price Per Share Weighted Average Remaining Life In Years Aggregate Intrinsic Value Unvested December 31, 2014 157,694 $ 17.71 2.2 $ 3,982 Granted 55,313 21.03 Vested/released 66,588 17.17 Forfeited 1,702 18.58 Unvested December 31, 2015 144,717 $ 19.22 1.0 $ 3,304 As of December 31, 2015 , there remained $1.7 million of unrecognized compensation expense related to the restricted stock awards. That cost is expected to be recognized over the remaining weighted average vesting period of 1.6 years. Director Stock Compensation in Lieu of Fees In addition to restricted stock awards discussed above, the members of the Company’s Board of Directors 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. Directors must make an irrevocable election to receive shares of common stock in lieu of cash fees prior to December 31st of the preceding year. Directors are granted shares of common stock in lieu of cash fees at a per share price which reflects the market value of the common stock on the first business day of the year. Total directors' fee expense, included in other operating expenses, amounted to $424 thousand , $444 thousand and $356 thousand for the years ended December 31, 2015 , 2014 and 2013 , respectively. Included in the 2015 expense was stock compensation in lieu of cash fees of $254 thousand , which represented 10,657 shares issued to Directors in January 2016 , at a fair market value price of $23.86 per share, which reflected the fair value of the common stock on January 2, 2015 . Included in the 2014 expense was stock compensation of $242 thousand , which represented 11,612 shares issued to Directors in January 2015 , at a fair market value price of $20.84 per share, which reflected the fair value of the common stock on January 2, 2014 . Included in the 2013 expense was stock compensation of $194 thousand , which represented 11,136 shares issued to Directors in January 2014 , at a fair market value price of $17.43 per share, which reflected the fair value of the common stock on January 2, 2013 . The total tax benefit recognized related to the expense of Director stock compensation for attendance was $102 thousand , $97 thousand and $77 thousand , for the years ended 2015 , 2014 and 2013 , respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The components of income tax expense for the years ended December 31, were calculated using the asset and liability method as follows: (Dollars in thousands) 2015 2014 2013 Current tax expense: Federal $ 6,808 $ 5,814 $ 5,492 State 1,712 1,681 1,642 Total current tax expense 8,520 7,495 7,134 Deferred tax (benefit)/ expense: Federal (284 ) 85 (100 ) State (122 ) 5 (83 ) Total deferred tax (benefit)/ expense (406 ) 90 (183 ) Total income tax expense $ 8,114 $ 7,585 $ 6,951 The provision for income taxes differs from the amount computed by applying the statutory U.S. federal income tax rate ( 35% ) for 2015 and ( 34% ) for prior years to income before taxes as follows: (Dollars in thousands) 2015 2014 2013 Computed income tax expense at statutory rate $ 8,492 $ 7,560 $ 6,963 State income taxes, net of federal tax benefit 1,034 1,113 1,029 Tax-exempt income, net of disallowance (1,226 ) (1,060 ) (988 ) Bank-owned life insurance income, net (251 ) (140 ) (156 ) Other 65 112 103 Total income tax expense $ 8,114 $ 7,585 $ 6,951 Effective income tax rate 33.4 % 34.1 % 33.9 % At December 31, the tax effects of each type of income and expense item that give rise to deferred taxes are: (Dollars in thousands) 2015 2014 Deferred tax asset: Allowance for loan losses $ 11,800 $ 11,026 Depreciation 3,103 3,033 Other-than-temporary impairment on equity securities 22 168 Supplemental employee retirement plans 1,080 1,156 Non-accrual interest 1,393 1,440 Stock-based compensation expense 873 751 Other 163 97 Total 18,434 17,671 Deferred tax liability: Goodwill 2,300 2,140 Net unrealized gains on investments securities 1,204 2,057 Deferred origination costs 812 622 Other 7 — Total 4,323 4,819 Net deferred tax asset $ 14,111 $ 12,852 Management believes that it is more likely than not that current recoverable income taxes and the expectation of future taxable income, based on the Company’s history of reporting taxable income, will generate sufficient taxable income to realize the deferred tax asset existing at December 31, 2015 . However, factors, beyond management’s control, such as the general state of the economy can affect future levels of taxable income and there can be no assurances that sufficient taxable income will be generated to fully realize the deferred tax assets in the future. In addition, management has the ability to sell any of the equity securities affected by the OTTI charge. A sale of the equity securities would ensure that, for tax purposes, a portion of the losses on sales could be applied against investment gains realized on the portfolio during the past three years, before the ability to carry back losses against these gains expires. The Company paid total income taxes in 2015 , 2014 , and 2013 of $7.6 million , $7.5 million , and $7.3 million , respectively. The Company did not have any unrecognized tax benefits accrued as income tax liabilities or receivables or as deferred tax items at December 31, 2015 or December 31, 2014 . The Company and its subsidiaries file income tax returns in the U.S. federal jurisdiction and in the states of Massachusetts and New Hampshire. The Company is subject to U.S. federal and state income tax examinations by taxing authorities for the 2012 through 2015 tax years. The Company invests in qualified affordable housing projects as a limited partner. In 2015 , the Company estimated approximately $71 thousand of Federal Low Income Housing tax credits to be recognized. In both 2014 and 2013 , the Company recognized $71 thousand of Federal Low Income Housing tax credits. The Company anticipates that it will receive additional tax credits related to the Federal Low Income Housing Tax Credit program in the amount of $460 thousand which are expected to be realized over the next 7 years.

Earnings per share

Earnings per share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Earnings per share	Earnings per share The table below presents the increase in average shares outstanding, using the treasury stock method, for the diluted earnings per share calculation for the years ended December 31st: 2015 2014 2013 Basic weighted average common shares outstanding 10,323,016 10,118,762 9,862,678 Dilutive shares 66,918 90,481 87,931 Diluted weighted average common shares outstanding 10,389,934 10,209,243 9,950,609 For the year ended December 31, 2015 , all options outstanding were included in the year-to-date calculation of diluted earnings per share, as they were all considered "in the money" under the treasury stock method. See Item (r) “Earnings per Share,” contained in Note 1, “Summary of Significant Accounting Policies,” for additional information regarding the earnings per share calculation.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2015
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 on the basis of 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: December 31, 2015 Fair Value Measurements using: (Dollars in thousands) Fair Value (level 1) (level 2) (level 3) Assets measured on a recurring basis: Fixed income securities $ 288,701 $ — $ 288,701 $ — Equity securities 11,657 11,657 — — FHLB Stock 3,050 — — 3,050 Interest-rate swaps 16 — 16 — Assets measured on a non-recurring basis: Impaired loans (collateral dependent) 2,516 — — 2,516 Liabilities measured on a recurring basis: Interest-rate swaps 16 — 16 — December 31, Fair Value Measurements using: (Dollars in thousands) Fair Value (level 1) (level 2) (level 3) Assets measured on a recurring basis: Fixed income securities $ 230,790 $ — $ 230,790 $ — Equity securities 14,275 14,275 — — FHLB Stock 3,357 — — 3,357 Assets measured on a non-recurring basis: Impaired loans (collateral dependent) 5,174 — — 5,174 Other real estate owned 861 — — 861 The Company did not have cause to transfer any assets between the fair value measurement levels during the year ended December 31, 2015 or the year ended December 31, 2014 . There were no liabilities measured at fair value on a recurring or non-recurring basis as of December 31, 2014 . All of the Company's fixed income investments and equity securities that are considered “available-for-sale” are carried at fair value. The fixed income category above includes federal agency obligations, commercial and residential federal agency MBS, municipal securities, corporate bonds, and certificates of deposits as held at those dates. The Company utilizes third-party pricing vendors to provide valuations on its fixed income 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 fixed income 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. See Note 1, “Summary of Significant Accounting Policies,” under Item (e) "Restricted Investments," above, for further information regarding the Company’s fair value assessment of FHLB capital stock. Impaired loan balances in the table above represent those collateral dependent impaired commercial loans where management has estimated the 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 credit loss. The specific allowances assigned to the collateral dependent impaired loans at December 31, 2015 amounted to $1.4 million compared to $1.7 million at December 31, 2014 . When OREO property is acquired, it is generally recorded at the lesser of the loan’s remaining principal balance, net of unamortized deferred fees, or the estimated fair value of the property acquired, less estimated costs to sell. 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 Company carried no OREO at December 31, 2015 compared to $861 thousand at December 31, 2014 . The Company sold the three properties held at December 31, 2014 , recognizing net gains on OREO sales of $154 thousand , during the year ended December 31, 2015 ; there were no additions to OREO, or subsequent impairment write-downs during the period. There were no sales or subsequent write downs of OREO during the year ended December 31, 2014 . 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 associated with the counterparties and the Company 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, "Commitments, Contingencies and Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk," for additional information on the Company's interest-rate swaps. Standby letters of credit are conditional commitments issued by the Company to guarantee the financial obligation or performance by 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 balance sheet as a liability and amortized to income over the life of the letters of credit, which is typically one year. The estimated fair value of these commitments carried on the balance sheet at December 31, 2015 and December 31, 2014 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 December 31, 2015 and December 31, 2014 , the estimated fair value of the Company’s interest-rate lock commitments and commitments to sell these mortgages loans were considered to be 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 December 31, 2015 . (Dollars in thousands) Fair Value Valuation Technique Unobservable Input Unobservable Input Value or Range Assets measured on a recurring basis: FHLB Stock $3,050 FHLB Stated Par Value N/A N/A Assets measured on a non-recurring basis: Impaired loans (collateral dependent) $2,516 Appraisal of collateral Appraisal adjustments (1) 5% - 50% (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 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 balance sheet. The carrying values, estimated fair values and placement in the fair value hierarchy of the Company’s financial instruments for which fair value is only disclosed but not recognized on the balance sheet at the dates indicated are summarized as follows: December 31, 2015 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 $ 1,709 $ 1,709 $ — $ 1,709 $ — Loans, net 1,830,954 1,845,009 — — 1,845,009 Financial liabilities: Certificates of deposit (including brokered) 274,467 273,419 — 273,419 — Borrowed funds 53,671 53,670 — 53,670 — Subordinated debt 14,822 13,961 — — 13,961 December 31, 2014 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 $ 2,371 $ 2,381 $ — $ 2,381 $ — Loans, net 1,645,483 1,668,863 — — 1,668,863 Financial liabilities: Certificates of deposit (including brokered) 263,779 262,774 — 262,774 — Borrowed funds 58,900 58,899 — 58,899 — Subordinated debt 10,825 13,017 — — 13,017 Excluded from this table 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, accrued interest receivable, non-term deposit accounts, and accrued interest payable. The respective carrying values of these instruments would all be considered to be classified within Level 1 of their fair value hierarchy. Also excluded from these tables are the fair values of the unused portion of lines of credit and letters of credit which were estimated to be the fees currently charged to enter into similar agreements and are deemed immaterial, as well as, commitments to originate non-mortgage loans that were short-term, were at current market rates and estimated to have no significant change in fair value. In cases where quoted fair values are not available, fair values are based upon estimates using various valuation techniques. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. The following methods and assumptions were used by the Company in estimating fair values of its financial instruments: Loans held for sale: Loans held for sale are recorded at the lower of aggregate amortized cost or market value. The fair value is based on comparable market prices for loans with similar rates and terms. Loans: The fair value of loans was determined using discounted cash flow analysis, using interest rates currently being offered by the Company. The incremental credit risk for adversely classified loans was considered in the determination of the fair value of the loans. This method of estimating fair value does not incorporate the exit price concept of fair value. Financial liabilities: The fair values of certificates of deposit and borrowings were estimated using discounted cash flow analysis using rates offered by the Bank, or advance rates offered by the FHLB on December 31, 2015 and December 31, 2014 for similar instruments. The fair value of subordinated debt was estimated using discounted cash flow analysis using a market rate of interest at December 31, 2015 and December 31, 2014 . Limitations: The estimates of fair value of financial instruments were based on information available at December 31, 2015 and December 31, 2014 and are not indicative of the fair market value of those instruments as of the date of this report. These estimates do not reflect any premium or discount that could result from offering for sale at one time the Company’s entire holdings of a particular financial instrument. The fair value of the Company's time deposit liabilities do not take into consideration the value of the Company's long-term relationships with depositors, which may have significant value. Because no active market exists for a portion of the Company’s financial instruments, fair value estimates were based on judgments regarding future expected loss experience, current economic conditions, risk characteristics of various financial instruments, and other factors. These estimates are subjective in nature and involve uncertainties and matters of significant judgment and therefore cannot be determined with precision. Changes in assumptions could significantly affect the estimates. Fair value estimates were based on existing on- and off-balance sheet financial instruments without an attempt to estimate the value of anticipated future business and the value of assets and liabilities that are not considered financial instruments, including premises and equipment and foreclosed real estate. In addition, the tax ramifications related to the realization of the unrealized appreciation and depreciation can have a significant effect on fair value estimates and have not been considered in any of the estimates. Accordingly, the aggregate fair value amounts presented do not represent the underlying value of the Company.

Parent Company Only Financial S

Parent Company Only Financial Statements	12 Months Ended
	Dec. 31, 2015
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Parent Company Only Financial Statements	Parent Company Only Financial Statements Balance Sheets December 31, (Dollars in thousands) 2015 2014 Assets Cash $ 2,737 $ 699 Investment in subsidiaries 191,949 176,946 Other assets 546 510 Total assets $ 195,232 $ 178,155 Liabilities and Stockholders’ Equity Liabilities Subordinated debt $ 14,822 $ 10,825 Accrued interest payable 78 370 Other liabilities 5 10 Total liabilities 14,905 11,205 Stockholders' equity: Preferred stock, $0.01 par value per share; 1,000,000 shares authorized; no shares issued — — Common stock $0.01 par value per share; 20,000,000 shares authorized; 10,377,787 shares issued and outstanding at December 31, 2015 (including 144,717 shares of unvested participating restricted awards) and 10,207,943 shares issued and outstanding at December 31, 2014 (including 157,694 shares of unvested participating restricted awards) 104 102 Additional paid-in capital 61,008 57,130 Retained earnings 116,941 105,951 Accumulated other comprehensive income 2,274 3,767 Total stockholders’ equity 180,327 166,950 Total liabilities and stockholders’ equity $ 195,232 $ 178,155 Statements of Income For the years ended December 31, (Dollars in thousands) 2015 2014 2013 Equity in undistributed net income of subsidiaries $ 17,277 $ 13,744 $ 13,571 Dividends distributed by subsidiaries — 1,850 950 Loss distributed by divested subsidiary (210 ) — — Other income 17 — — Total income 17,084 15,594 14,521 Interest expense 1,071 1,177 1,177 Other operating expenses 500 194 225 Total operating expenses 1,571 1,371 1,402 Income before income taxes 15,513 14,223 13,119 Benefit from income taxes (635 ) (428 ) (410 ) Net income $ 16,148 $ 14,651 $ 13,529 Parent Company Only Financial Statements Statements of Cash Flows For the years ended December 31, (Dollars in thousands) 2015 2014 2013 Cash flows from operating activities: Net income $ 16,148 $ 14,651 $ 13,529 Adjustments to reconcile net income to net cash provided by operating activities: Equity in undistributed net income of subsidiaries (17,277 ) (13,744 ) (13,571 ) Payment from subsidiary bank for stock compensation expense 1,791 1,704 1,652 Changes in: Other assets (36 ) (277 ) 9 Other liabilities (12 ) (3 ) 10 Subordinated debt issuance costs (178 ) — — Accrued interest payable (292 ) — — Net cash provided by operating activities 144 2,331 1,629 Cash flows from investing activities Investment in subsidiary 781 — — Net cash provided by investing activities 781 — — Cash flows from financing activities: Repayment of subordinated debt (10,825 ) — — Proceeds from the issuance of subordinated debt 15,000 — — Cash dividends paid (5,158 ) (4,853 ) (4,535 ) Proceeds from issuance of common stock 1,448 1,283 1,239 Proceeds from exercise of stock options 431 889 1,829 Tax benefit from stock-based compensation 217 320 25 Net cash provided by financing activities 1,113 (2,361 ) (1,442 ) Net increase (decrease) in cash and cash equivalents 2,038 (30 ) 187 Cash and cash equivalents, beginning of year 699 729 542 Cash and cash equivalents, end of year $ 2,737 $ 699 $ 729 See Note 1, “Summary of Significant Accounting Policies,” under Item (a) "Organization of Holding Company and Basis of Presentation" and Note 7, "Borrowed Funds and Subordinated Debt," above, for further information regarding changes in both the Company's investment in the Capital Trust and in subordinated debt. The Parent Company’s Statements of Comprehensive Income and Statements of Changes in Stockholders’ Equity are identical to the Consolidated Statements of Comprehensive Income and the Consolidated Statements of Changes in Stockholders’ Equity and therefore are not presented here.

Quarterly Results of Operations

Quarterly Results of Operations (Unaudited)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Quarterly Results of Operations (Unaudited)	Quarterly Results of Operations (Unaudited) 2015 (Dollars in thousands, except share data) First Quarter Second Quarter Third Quarter Fourth Quarter Interest and dividend income $ 19,839 $ 20,437 $ 21,224 $ 21,971 Interest expense 1,385 1,253 1,264 1,275 Net interest income 18,454 19,184 19,960 20,696 Provision for loan losses 625 1,225 250 1,167 Net interest income after provision for loan losses 17,829 17,959 19,710 19,529 Non-interest income 3,125 3,222 3,177 3,615 Net gains on sales of investment securities 900 456 7 465 Non-interest expense 16,210 16,267 16,548 16,707 Income before income taxes 5,644 5,370 6,346 6,902 Provision for income taxes 2,024 1,855 2,054 2,181 Net income $ 3,620 $ 3,515 $ 4,292 $ 4,721 Basic earnings per share $ 0.35 $ 0.34 $ 0.41 $ 0.46 Diluted earnings per share $ 0.35 $ 0.34 $ 0.41 $ 0.45 2014 (Dollars in thousands, except share data) First Quarter Second Quarter Third Quarter Fourth Quarter Interest and dividend income $ 18,231 $ 18,780 $ 19,394 $ 20,068 Interest expense 1,317 1,328 1,302 1,296 Net interest income 16,914 17,452 18,092 18,772 Provision for loan losses 200 200 765 230 Net interest income after provision for loan losses 16,714 17,252 17,327 18,542 Non-interest income 2,991 3,137 3,325 3,360 Net gains on sales of investment securities 488 127 215 789 Non-interest expense 14,825 15,445 15,115 16,646 Income before income taxes 5,368 5,071 5,752 6,045 Provision for income taxes 1,862 1,757 1,921 2,045 Net income $ 3,506 $ 3,314 $ 3,831 $ 4,000 Basic earnings per share $ 0.35 $ 0.33 $ 0.38 $ 0.39 Diluted earnings per share $ 0.35 $ 0.32 $ 0.37 $ 0.39

Summary of Significant Accoun25

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Principles of Consolidation	The consolidated financial statements of Enterprise Bancorp, Inc. (the “Company” or “Enterprise”), a Massachusetts corporation, include the accounts of the Company and its wholly owned subsidiary Enterprise Bank and Trust Company (the “Bank”). The Bank is a Massachusetts trust company organized in 1989. Substantially all of the Company’s operations are conducted through the Bank. The Bank’s subsidiaries include Enterprise Insurance Services, LLC and Enterprise Investment Services, LLC, organized under the laws of the state of Delaware for the purposes of engaging in insurance sales activities and offering 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, which hold various types of qualifying securities. The security corporations are limited to conducting securities investment activities that the Bank itself would be allowed to conduct under applicable laws. The Company has 22 full-service branches serving the greater Merrimack Valley and North Central regions of Massachusetts and Southern New Hampshire. The Company also plans to open its second Nashua, NH branch in the second quarter of 2016. Through the Bank and its subsidiaries, the Company offers a range of commercial and consumer loan products, and deposit and cash management services. The Company also offers investment advisory and wealth management, trust, and insurance 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. Prior to March 2015 , pursuant to the Accounting Standards Codification (“ASC”) Topic 810 “Consolidation of Variable Interest Entities,” issued by the Financial Accounting Standards Board ("FASB"), the Company carried junior subordinated debentures as a liability on its consolidated financial statements, along with the related interest expense. The debentures were issued by a statutory business trust (the "Trust") created by the Company in March 2000 under the laws of the state of Delaware, and the trust preferred securities issued by the Trust, and the related non-interest expense, had been excluded from the Company’s consolidated financial statements. In March 2015 , the Company redeemed in full the junior subordinated debentures, which in turn allowed the Trust to redeem in full the trust preferred securities. The Company also dissolved the Trust in April 2015. See Note 7, "Borrowed Funds and Subordinated Debt," below for further information on the Company's subordinated debt. The Federal Deposit Insurance Corporation (“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 Commissioner also retains supervisory jurisdiction over the Company.
Basis of Accounting	The accompanying audited consolidated financial statements and notes thereto have been prepared in accordance with GAAP and the instructions for Form 10-K through the rules and interpretive releases of the SEC under federal securities law. In the opinion of management, the accompanying consolidated 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 consolidated financial statements.
Reclassification	Certain previous years' amounts in the consolidated financial statements, and notes thereto, have been reclassified to conform to the current year's presentation.
Use of Estimates	Uses of estimates In preparing the financial statements in conformity with U.S. generally accepted accounting principles ("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 at the balance sheet date and income and expenses for the years 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 change over time due to changes in circumstances. Changes in those estimates resulting from continuing change in the economic environment and other factors will be reflected in the financial statements and results of operations in future periods. The three most significant areas in which management applies critical assumptions and estimates are the estimate of the allowance for loan losses, impairment review of investment securities and the impairment review of goodwill.
Cash and Cash Equivalents	Cash and cash equivalents Cash equivalents are defined as highly liquid investments with original maturities of three months or less, that are readily convertible to known amounts of cash and present insignificant risk of changes in value due to changes in interest rates. The Company's cash and cash equivalents are comprised of cash on hand and cash items due from banks, interest-earning deposits (deposit accounts, excess cash balances, money market and money market mutual fund accounts) and overnight and term federal funds sold ("fed funds"). Balances in cash and cash equivalents will fluctuate resulting primarily from the timing of net deposit flows, borrowing and loan inflows and outflows, investment purchases and maturities, calls and sales proceeds, and the immediate liquidity needs of the Company.
Investments	Investments Investments that are intended to be held for indefinite periods of time but which may not be held to maturity or on a long-term basis are considered to be “available-for-sale” and are carried at fair value. Net unrealized appreciation and depreciation on investments available-for-sale, net of applicable income taxes, are reflected as a component of accumulated other comprehensive income. Included as available-for-sale are securities that are purchased in connection with the Company’s asset-liability risk management strategy and that may be sold in response to changes in interest rates, resultant prepayment risk and other related factors. In instances where the Company has the positive intent to hold investment securities to maturity, investment securities will be classified as held-to-maturity and carried at amortized cost. As of the balance sheet dates, all of the Company’s investment securities were classified as available-for-sale and carried at fair value. There are inherent risks associated with the Company’s investment activities that could adversely impact the fair market value and the ultimate collectability of the Company’s investments. Management regularly reviews the portfolio for securities with unrealized losses that are other than temporarily impaired. The determination of other-than-temporary impairment (“OTTI”) involves a high degree of judgment and requires management to make significant estimates of current market risks and future trends. Management's assessment, depending on the type of security includes: reviews of market pricing, evaluating the level and duration of the loss on individual securities; ongoing credit quality evaluations; determining if any individual security or mutual fund or other fund exhibits fundamental deterioration; and estimating whether it is unlikely that the individual security or fund will completely recover its unrealized loss within a reasonable period of time, or in the case of fixed income securities prior to maturity. While management uses available information to measure OTTI at the balance sheet date, future write-downs may be necessary based on extended duration of current unrealized losses, changing market conditions, or circumstances surrounding individual issuers and funds. Should an investment be deemed to have OTTI, the Company is required to write-down the carrying value of the investment. OTTI on equity securities are recognized through a charge to earnings. OTTI on fixed income securities are assessed in order to determine the impairment attributed to underlying credit quality of the issuer and the portion of noncredit impairment. When there are credit losses on a fixed income security that management does not intend to sell and it is more likely than not that the Company will not be required to sell prior to a marketplace recovery or maturity, the portion of the total impairment that is attributable to the credit loss would be recognized in earnings, and the remaining difference between the security’s amortized cost basis and its fair value would be included in other comprehensive income. Once written-down, a security may not be written-up in excess of its new cost basis to reflect future increases in market prices. Any OTTI charges, depending upon the magnitude of the charges, could have a material adverse effect on the Company’s financial condition and results of operations. Investment securities’ discounts are accreted and premiums are amortized over the period of estimated principal repayment using methods that approximate the interest method. Gains or losses on the sale of investment securities are recognized on the trade date on a specific identification basis. (e) Restricted Investments As a member of the Federal Home Loan Bank of Boston (“FHLB”), the Bank is required to purchase certain levels of FHLB stock in association with outstanding advances from the FHLB. This stock investment is classified as a restricted investment and carried at cost, which management believes approximates fair value. FHLB stock represents the only restricted investment held by the Company. In conjunction with the OTTI review noted above under investments, management also regularly reviews its holdings of FHLB stock for OTTI. Based on management’s ongoing 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.
Loans Held for Sale	Loans Held for Sale Depending on the current interest rate environment, management projections of future interest rates and the overall asset-liability management program of the Company, management may elect to sell those fixed and adjustable rate residential mortgage loans which are eligible for sale in the secondary market. Mortgage loans are generally not pooled for sale, but instead sold on an individual basis. Enterprise may retain or sell the servicing when selling the loans. Loans sold are subject to standard secondary market underwriting and eligibility representations and warranties over the life of the loan, and are subject to an early payment default period covering the first four payments for certain loan sales. Loans held for sale are carried at the lower of aggregate amortized cost or market value. Market value is based on comparable market prices for loans with similar rates and terms. When loans are sold, a gain or loss is recognized to the extent that the sales proceeds plus unamortized fees and costs exceed, or are less than, the carrying value of the loans. Gains and losses are determined using the specific identification method.
Loans	Loans Loans made by the Company to businesses include commercial mortgage loans, construction and land development loans, secured and unsecured commercial loans and lines of credit, and standby 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, secured and unsecured personal loans and lines of credit. Most loans granted by the Company are collateralized by real estate or equipment and/or are guaranteed by the principals of the borrower. The ability and willingness of the single family residential and consumer borrowers to honor their repayment commitments is generally dependent on the level of overall economic activity and real estate values within the borrowers’ geographic areas. The ability and willingness of commercial real estate, commercial and construction loan borrowers to honor their repayment commitments is generally dependent on the health of the real estate sector in the borrowers’ geographic areas and the general economy, among other factors. Loans are reported at the principal amount outstanding, net of deferred origination fees and costs. The aggregate amount of overdrawn deposit accounts are reclassified as loan balances. Loan origination fees received, offset by direct loan origination costs, are deferred and amortized using the straight line method over three to five years for lines of credit and demand notes or over the life of the related loans using the level-yield method for all other types of loans. When loans are paid off, the unamortized fees and costs are recognized as an adjustment to interest income. Loans acquired at a net premium are initially measured at fair value as of the acquisition date without carryover of historical allowance for loan losses. Credit discounts representing losses of unpaid loan principal balances expected over the life of the loans are included in the determination of acquisition date fair value. The fair-market valuation of loans acquired at a premium is amortized into interest income on a level-yield basis over the life of the loan. Subsequent to the purchase date, the methods utilized to estimate the required allowance for loan losses are similar to originated loans.
Allowance for Loan Losses	Allowance for Loan Losses The allowance for loan losses is an estimate of probable credit risk inherent in the loan portfolio as of the specified balance sheet dates. 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 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 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 uses a two-tiered approach that makes use of specific reserves for loans individually evaluated and deemed impaired and general reserves for larger groups of homogeneous loans. On a quarterly basis, the Company prepares an estimate of the allowance necessary to cover estimated credit risk inherent in the portfolio as of the specified balance sheet dates. The adequacy of the allowance for loan losses is reviewed and evaluated on a regular basis by an internal management committee, a sub-committee of the Board of Directors and the full Board itself. While management uses available information to recognize losses on loans, future additions to the allowance may be necessary. In addition, various regulatory agencies, as an integral part of their examination process, periodically review the Company’s allowance for loan losses. Such agencies may require the Company to recognize additions to the allowance based on judgments different from those of management. See Note 4, "Allowance for Loan Losses," for additional accounting policies related to non-accrual, impaired and troubled debt restructured loans and to the allowance for loan losses.
Other Real Estate Owned	Other Real Estate Owned Real estate acquired by the Company through foreclosure proceedings or the acceptance of a deed in lieu of foreclosure is classified as Other Real Estate Owned (“OREO”). When property is acquired, it is generally recorded at the lesser of the loan’s remaining principal balance, net of unamortized deferred fees, or the estimated fair value of the property acquired, less estimated costs to sell. 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.
Premises and Equipment	Premises and Equipment Land is carried at cost. Premises and equipment are stated at cost less accumulated depreciation and amortization. Depreciation or amortization is computed on a straight-line basis over the lesser of the estimated useful lives of the asset or the respective lease term (with reasonably assured renewal options) for leasehold improvements generally as follows: Bank premises and leasehold improvements 10 to 39 years Computer software and equipment 3 to 5 years Furniture, fixtures and equipment 3 to 10 years
Bank Owned Life Insurance	Bank Owned Life Insurance The Company has purchased bank owned life insurance (“BOLI”) on certain current and former senior and executive officers. The cash surrender value carried on the balance sheet at December 31, 2015 and December 31, 2014 amounted to $28.0 million and $16.3 million , respectively. The increase over the prior year was primarily due to the purchase of additional BOLI investments. There are no associated surrender charges under the outstanding policies.
Impairment of Long-Lived Assets Other than Goodwill	Impairment of Long-Lived Assets Other than Goodwill The Company reviews long-lived assets, including premises and equipment, for impairment on an ongoing basis or whenever events or changes in business circumstances indicate that the remaining useful life may warrant revision or that the carrying amount of the long-lived asset may not be fully recoverable. If impairment is determined to exist, any related impairment loss is recognized through a charge to earnings. Impairment losses on assets disposed of, if any, are based on the estimated proceeds to be received, less cost of disposal.
Goodwill	Goodwill Goodwill carried on the Company’s consolidated financial statements was $5.7 million at both December 31, 2015 and December 31, 2014 . This asset is related to the Company’s acquisition of two branch offices in July 2000. In accordance with generally accepted accounting principles, the Company does not amortize goodwill and instead, at least annually, evaluates whether the carrying value of goodwill has become impaired. Impairment of the goodwill may occur when the estimated fair value of the Company is less than its recorded book value. A determination that goodwill has become impaired results in an immediate write-down of goodwill to its determined value with a resulting charge to operations. The annual impairment test begins with a qualitative assessment of whether it is "more likely than not" that the reporting unit's fair value is less than its carrying amount. The assessment is performed at the operating unit level. If an entity concludes it is not "more likely than not" that the fair value of a reporting unit is less than its carrying amount, it need not perform a two-step impairment test. In the case of the Company, the services offered through the Bank and subsidiaries are managed as one strategic unit and represent the Company’s only reportable operating segment. Management's qualitative assessment takes into consideration macroeconomic conditions, industry and market considerations, cost or margin factors, financial performance and share price. Based on this assessment, the Company determined that it is not "more likely than not" that the Company's fair value is less than its carrying amount and therefore goodwill was not considered to be impaired at December 31, 2015 . If the Company's qualitative assessment concluded that it is "more likely than not" that the fair value of a reporting unit is less than its carrying amount, it must perform the two-step impairment test to identify potential goodwill impairment and measure the amount of goodwill impairment loss to be recognized, if any. The first step of the goodwill impairment test compares the estimated fair value of the reporting unit with its carrying amount, or the book value of the reporting unit, including goodwill. If the estimated fair value of the reporting unit equals or exceeds its book value, goodwill is considered not impaired, and the second step of the impairment test is unnecessary. The second step, if necessary, measures the amount of goodwill impairment loss to be recognized. The reporting unit must determine fair values for all assets and liabilities, excluding goodwill. The net of the assigned fair value of assets and liabilities is then compared to the book value of the reporting unit, and any excess book value becomes the implied fair value of goodwill. If the carrying amount of the goodwill exceeds the newly calculated implied fair value of that goodwill, an impairment loss is recognized in the amount required to write down the goodwill to the implied fair value.
Investment Assets Under Management	Investment Assets Under Management Investment assets under management, consisting of assets managed through Enterprise Investment Advisors and Enterprise Investment Services and the commercial sweep product, totaled $678.4 million and $674.6 million at December 31, 2015 and 2014 , respectively. Fee income is recorded on an accrual basis and recognized over the period in which it is earned. Securities and other property held in a fiduciary or agency capacity are not included in the consolidated balance sheets because they are not assets of the Company.
Derivatives	Derivatives The Company recognizes all derivatives as either assets or liabilities on its balance sheet and measures those instruments at fair market value. 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 December 31, 2015 and 2014 , the estimated fair values of these derivative instruments were considered to be immaterial. Beginning in 2015, the Company implemented 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 counterparty. The transaction structure effectively minimizes the Bank’s net risk exposure resulting from such transactions. The customer interest-rate swap agreement allows commercial banking customers to convert a floating-rate loan payment to fixed-rate loan payment. 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 inverse relationship, are recognized directly in earnings. See Note 8, "Commitments, Contingencies and Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk" for more information about the Company's derivatives.
Stock Based Compensation	Stock Based Compensation The Company’s financial statements include stock-based compensation expense for the portion of stock option awards, net of estimated forfeitures, and stock awards for which the requisite service has been rendered during the period. The compensation expense has been estimated based on the estimated grant-date fair value of the awards, or in the case of stock awards, the market value of the common stock on the date of grant. The Company will recognize the remaining estimated compensation expense for the portion of outstanding awards and compensation expense for any future awards, net of estimated forfeitures, as the requisite service is rendered (i.e., on a straight-line basis over the remaining vesting period of each award) or as performance objectives are met. Stock awards that do not require future service (“vested awards”) will be expensed immediately. Stock-based compensation also includes Director stock compensation for stock awards and stock in lieu of cash fees, both included in other operating expenses, described in more detail in Note 11 "Stock-Based Compensation Plans."
Income Taxes	Income Taxes 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 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. 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 tax-exempt interest from certain investment securities, loans and bank owned life insurance. The Company did not have any unrecognized tax benefits accrued as income tax liabilities or receivables or as deferred tax items at December 31, 2015 or December 31, 2014 . The Company is subject to U.S. federal and state income tax examinations by taxing authorities for the 2012 through 2015 tax years.
Earnings Per Share	Earnings per Share Basic earnings per share are calculated by dividing net income 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. 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.
Reporting Comprehensive Income	Reporting Comprehensive Income Comprehensive income is defined as all changes to 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. The Company’s only other comprehensive income component is the net unrealized holding gains or losses on investments available-for-sale, net of deferred income taxes. 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 securities are sold. When securities are sold, the reclassification of realized gains and losses on available-for-sale securities are included on the Consolidated Statements of Income under the "non-interest income" subheading on the line item "net gains on sales of investment securities" and the related income tax expense is included in the line item "provision for income taxes," both of which are also detailed on the Consolidated Statements of Comprehensive Income under the subheading "reclassification adjustment for net gains included in net income."
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In April 2015, the Financial Accounting Standards Board ("FASB") issued ASU No. 2015-03, Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs. The amendments in this ASU require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this ASU. Entities are required to apply the new guidance on a retrospective basis, wherein the balance sheet of each individual period presented should be adjusted to reflect the period-specific effects of applying the new guidance. For public business entities, the amendments are effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. Early adoption of the amendments is permitted for financial statements that have not been previously issued. The Company early adopted this ASU as of January 1, 2015 in relation to the Company's Fixed-to-Floating Rate Subordinated Notes issued in January 2015. This adoption did not have a material impact on the Company's financial statements or results of operations. In January 2014, the FASB issued ASU No. 2014-04, Receivables - Troubled Debt Restructurings by Creditors (Subtopic 310-40) - Reclassification of Residential Real Estate Collateralized Consumer Mortgage Loans upon Foreclosure. The amendments are intended to reduce diversity of practice by clarifying when a creditor should be considered to have received physical possession of residential real estate property collateralizing a residential mortgage loan, such that the loan should be removed, and the real estate property recognized, on the financial statements. Additionally, the amendments require interim and annual disclosure of both the amount of foreclosed residential real estate property held by the creditor and the recorded investment in collateralized residential mortgage loans that are in the process of foreclosure according to local requirements of the applicable jurisdiction. The amendments in this ASU are effective for public business entities for annual periods and interim reporting periods beginning after December 15, 2014. As this ASU primarily offers clarification of existing standards and added disclosures, the adoption of this ASU in the first quarter of 2015 did not have a material impact on the Company's financial statements or results of operations. In January 2014, the FASB issued ASU No. 2014-01, Equity Method and Joint Ventures (Topic 323): Accounting for Investments in Qualified Affordable Housing Projects. The amendments in this ASU apply to all reporting entities that invest in qualified affordable housing projects through limited liability entities that are flow through entities for tax purposes. The amendments in this ASU eliminate the effective yield election and permit reporting entities to make an accounting policy election to account for such investments using the proportional amortization method if certain conditions are met. The investor must recognize any subsequent impairment loss when it is more likely than not that the carrying amount of the investment will not be realized. Those not electing the proportional amortization method would account for the investment using the equity method or cost method. The decision to apply the proportional amortization method of accounting is an accounting policy decision that must be applied consistently to all qualifying affordable housing project investments rather than a decision to be applied to individual investments. A reporting entity must disclose information that enables users of its financial statements to understand the nature of such investments and the effect of the measurement, and the related tax credits, on its financial position and results of operations. The amendments in this ASU are to be applied retrospectively to all periods presented. A reporting entity that uses the effective yield method to account for its investments in qualified affordable housing projects before the date of adoption may continue to apply the effective yield method for those preexisting investments. The amendments in this ASU are effective for public business entities for annual periods and interim reporting periods beginning after December 15, 2014. The adoption of this ASU in the first quarter of 2015 did not have a material impact on the Company's financial statements or results of operations. For information regarding recent accounting pronouncements not yet adopted by the Company, see Item 2, "Management's Discussion and Analysis of Financial Condition and Results of Operations," under the heading "Recent Accounting Pronouncements Not Yet Adopted."

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Property, Plant and Equipment, Useful Lives	Depreciation or amortization is computed on a straight-line basis over the lesser of the estimated useful lives of the asset or the respective lease term (with reasonably assured renewal options) for leasehold improvements generally as follows: Bank premises and leasehold improvements 10 to 39 years Computer software and equipment 3 to 5 years Furniture, fixtures and equipment 3 to 10 years

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-sale Securities Reconciliation	The amortized cost and fair values of investments at December 31, 2015 and 2014 are summarized as follows: 2015 (Dollars in thousands) Amortized cost Unrealized gains Unrealized losses Fair Value Federal agency obligations (1) $ 78,626 $ 352 $ 153 $ 78,825 Residential federal agency MBS (1) 75,105 406 648 74,863 Commercial federal agency MBS (1) 23,908 — 363 23,545 Municipal securities 96,189 2,357 35 98,511 Corporate bonds 10,257 44 95 10,206 Certificates of Deposit (2) 2,753 — 2 2,751 Total fixed income securities 286,838 3,159 1,296 288,701 Equity investments 10,043 1,966 352 11,657 Total available-for-sale investments, at fair value $ 296,881 $ 5,125 $ 1,648 $ 300,358 2014 (Dollars in thousands) Amortized cost Unrealized gains Unrealized losses Fair Value Federal agency obligations (1) $ 59,518 $ 318 $ 24 $ 59,812 Residential federal agency MBS (1) 88,303 1,015 516 88,802 Municipal securities 72,113 2,157 66 74,204 Corporate bonds 7,937 61 26 7,972 Total fixed income securities 227,871 3,551 632 230,790 Equity investments 11,370 3,071 166 14,275 Total available-for-sales investments, at fair value $ 239,241 $ 6,622 $ 798 $ 245,065 (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, or one of several Federal Home Loan Banks, as well as, investments guaranteed by Ginnie Mae (GNMA), a wholly-owned government entity. (2) Certificates of deposit ("CDs") represent term deposits issued by banks that are subject to FDIC insurance and purchased on the open market.
Schedule of Unrealized Loss on Investments	The following tables summarize investments (fixed income and equity) having temporary impairment, due to the fair market values having declined below the amortized costs of the individual investments, and the period that the investments have been temporarily impaired at December 31, 2015 and 2014 . 2015 Less than 12 months 12 months or longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair value Unrealized Losses Fair Value Unrealized Losses Federal agency obligations $ 27,420 $ 153 $ — $ — $ 27,420 $ 153 Residential federal agency MBS 20,517 276 10,935 373 31,452 649 Commercial federal agency MBS 23,545 363 — — 23,545 363 Municipal securities 6,988 32 261 2 7,249 34 Corporate bonds 4,574 78 419 17 4,993 95 Certificates of Deposit 1,976 2 — — 1,976 2 Equity investments 4,204 351 24 1 4,228 352 Total temporarily impaired investments $ 89,224 $ 1,255 $ 11,639 $ 393 $ 100,863 $ 1,648 2014 Less than 12 months 12 months or longer Total (Dollars in thousands) Fair Value Unrealized Losses Fair value Unrealized Losses Fair Value Unrealized Losses Federal agency obligations $ 7,959 $ 24 $ — $ — $ 7,959 $ 24 Residential federal agency MBS — — 23,801 516 23,801 516 Municipal securities 3,597 31 2,794 35 6,391 66 Corporate bonds 2,704 12 871 14 3,575 26 Equity investments 2,008 162 21 4 2,029 166 Total temporarily impaired investments $ 16,268 $ 229 $ 27,487 $ 569 $ 43,755 $ 798
Investments Classified by Contractual Maturity Date	The contractual maturity distribution of total fixed income investments at December 31, 2015 is as follows: Within One Year After One, but within Five Years After Five, but within Ten Years After Ten Years (Dollars in thousands) Amount Yield Amount Yield Amount Yield Amount Yield At amortized cost: Federal agency obligations $ 7,048 0.91 % $ 62,024 1.59 % $ 9,554 2.22 % $ — — % Residential federal agency MBS — — % 3,576 3.15 % 1,299 1.90 % 70,230 2.11 % Commercial federal agency MBS — — % — — % 23,908 2.26 % — — % Municipal securities 5,052 2.74 % 23,948 3.38 % 34,749 3.69 % 32,440 3.91 % Corporate bonds 530 1.33 % 4,759 2.09 % 4,968 2.89 % — — % CDs 1,803 0.32 % 950 2.13 % — — % — — % Total fixed income securities $ 14,433 1.49 % $ 95,257 2.13 % $ 74,478 2.96 % $ 102,670 2.68 % At fair value: Total fixed income securities $ 14,477 $ 96,053 $ 75,015 $ 103,156
Schedule of Realized Gain (Loss) on Sales of Investments	Sales of investments for the years ended December 31, 2015 , 2014 , and 2013 are summarized as follows: (Dollars in thousands) 2015 2014 2013 Amortized cost of investments sold $ 23,287 $ 23,752 $ 8,325 Gross realized gains on sales 1,990 1,654 1,243 Gross realized losses on sales (162 ) (35 ) (4 ) Total proceeds from sales of investments $ 25,115 $ 25,371 $ 9,564

Loans (Tables)

Loans (Tables)	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Schedule of Loans by Loan Classification	Major classifications of loans at the periods indicated, are as follows: (Dollars in thousands) December 31, 2015 December 31, 2014 Commercial real estate $ 936,921 $ 862,747 Commercial and industrial 458,553 402,994 Commercial construction 202,993 168,044 Total commercial loans 1,598,467 1,433,785 Residential mortgages 169,188 149,959 Home equity loans and lines 83,373 80,018 Consumer 10,747 10,708 Total retail loans 263,308 240,685 Gross loans 1,861,775 1,674,470 Deferred loan origination fees, net (1,813 ) (1,866 ) Total loans 1,859,962 1,672,604 Allowance for loan losses (29,008 ) (27,121 ) Net loans $ 1,830,954 $ 1,645,483
Schedule of Loans Pledged as Collateral	Loans designated as qualified collateral and pledged to the FHLB for borrowing capacity for the periods indicated are summarized below: (Dollars in thousands) December 31, 2015 December 31, 2014 Commercial real estate $ 281,802 $ 276,657 Residential mortgages 118,855 107,906 Home equity 13,972 15,677 Total loans pledged to FHLB $ 414,629 $ 400,240

Allowance For Loan Losses (Tabl

Allowance For Loan Losses (Tables)	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Financing Receivables by Evaluation Method	The balances of loans as of December 31, 2014 by segment and evaluation method are summarized as follows: (Dollars in thousands) Loans individually evaluated for impairment Loans collectively evaluated for impairment Total Loans Commercial real estate $ 15,003 $ 847,744 $ 862,747 Commercial and industrial 10,901 392,093 402,994 Commercial construction 2,675 165,369 168,044 Residential 465 149,494 149,959 Home equity 180 79,838 80,018 Consumer 28 10,680 10,708 Deferred fees — (1,866 ) (1,866 ) Total loans $ 29,252 $ 1,643,352 $ 1,672,604 The balances of loans as of December 31, 2015 by segment and evaluation method are summarized as follows: (Dollars in thousands) Loans individually evaluated for impairment Loans collectively evaluated for impairment Total Loans Commercial real estate $ 12,287 $ 924,634 $ 936,921 Commercial and industrial 7,810 450,743 458,553 Commercial construction 3,032 199,961 202,993 Residential 366 168,822 169,188 Home equity 169 83,204 83,373 Consumer 24 10,723 10,747 Deferred fees — (1,813 ) (1,813 ) Total loans $ 23,688 $ 1,836,274 $ 1,859,962
Financing Receivable Credit Quality Indicators	The following tables present the credit risk profile by internally assigned adverse risk rating category at the periods indicated. December 31, 2015 (Dollars in thousands) Adversely Classified Not Adversely Classified Gross Loans Substandard Doubtful Loss Commercial real estate $ 12,487 $ — $ — $ 924,434 $ 936,921 Commercial and industrial 8,670 — 3 449,880 458,553 Commercial construction 1,776 — — 201,217 202,993 Residential 1,278 — — 167,910 169,188 Home equity 503 — 5 82,865 83,373 Consumer 38 11 — 10,698 10,747 Total gross loans $ 24,752 $ 11 $ 8 $ 1,837,004 $ 1,861,775 December 31, 2014 (Dollars in thousands) Adversely Classified Not Adversely Classified Gross Loans Substandard Doubtful Loss Commercial real estate $ 11,409 $ 1,188 $ 19 $ 850,131 $ 862,747 Commercial and industrial 11,298 51 57 391,588 402,994 Commercial construction 2,759 — — 165,285 168,044 Residential 1,133 — — 148,826 149,959 Home equity 464 — — 79,554 80,018 Consumer 48 — — 10,660 10,708 Total gross loans $ 27,111 $ 1,239 $ 76 $ 1,646,044 $ 1,674,470
Past Due Financing Receivables	The following table presents an age analysis of past due loans as of December 31, 2015 . (Dollars in thousands) Loans 30-59 Days Past Due Loans 60-89 Days Past Due Non-accrual Loans Total Past Due Loans Current Loans Gross Loans Commercial real estate $ 1,124 $ 1,140 $ 8,506 $ 10,770 $ 926,151 $ 936,921 Commercial and industrial 1,218 691 4,323 6,232 452,321 458,553 Commercial construction 581 — 335 916 202,077 202,993 Residential 250 180 366 796 168,392 169,188 Home equity 622 — 288 910 82,463 83,373 Consumer 35 10 27 72 10,675 10,747 Total gross loans $ 3,830 $ 2,021 $ 13,845 $ 19,696 $ 1,842,079 $ 1,861,775 The following table presents an age analysis of past due loans as of December 31, 2014 . (Dollars in thousands) Loans 30-59 Days Past Due Loans 60-89 Days Past Due Non-accrual Loans Total Past Due Loans Current Loans Gross Loans Commercial real estate $ 1,471 $ 1,235 $ 9,714 $ 12,420 $ 850,327 $ 862,747 Commercial and industrial 1,184 101 5,950 7,235 395,759 402,994 Commercial construction — — 447 447 167,597 168,044 Residential 1,328 370 763 2,461 147,498 149,959 Home equity 29 — 245 274 79,744 80,018 Consumer 94 1 17 112 10,596 10,708 Total gross loans $ 4,106 $ 1,707 $ 17,136 $ 22,949 $ 1,651,521 $ 1,674,470
Schedule of Interest Lost on Nonaccrual Loans	The reduction in interest income for the years ended December 31, associated with non-accruing loans is summarized as follows: (Dollars in thousands) 2015 2014 2013 Income in accordance with original loan terms $ 1,052 $ 1,007 $ 1,171 Less income recognized 426 323 680 Reduction in interest income $ 626 $ 684 $ 491
Impaired Financing Receivables	The following table sets forth the recorded investment in impaired loans and the related specific allowance allocated as of December 31, 2015 . (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 $ 14,903 $ 12,287 $ 11,734 $ 553 $ 186 Commercial and industrial 9,816 7,810 5,253 2,557 1,078 Commercial construction 3,147 3,032 1,583 1,449 499 Residential 453 366 366 — — Home equity 308 169 164 5 5 Consumer 25 24 — 24 24 Total $ 28,652 $ 23,688 $ 19,100 $ 4,588 $ 1,792 The following table sets forth the recorded investment in impaired loans and the related specific allowance allocated as of December 31, 2014 . (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 $ 17,182 $ 15,003 $ 14,800 $ 203 $ 68 Commercial and industrial 11,991 10,901 5,461 5,440 1,516 Commercial construction 2,862 2,675 1,150 1,525 519 Residential 537 465 465 — — Home equity 183 180 — 180 26 Consumer 28 28 — 28 28 Total $ 32,783 $ 29,252 $ 21,876 $ 7,376 $ 2,157 The following table presents the average recorded investment in impaired loans and the related interest recognized during the year ends indicated. December 31, 2015 December 31, 2014 December 31, 2013 (Dollars in thousands) Average recorded investment Interest income recognized Average recorded investment Interest income recognized Average recorded investment Interest income recognized Commercial real estate $ 13,827 $ 196 $ 14,135 $ 223 $ 17,673 $ 237 Commercial and industrial 9,372 97 10,682 156 9,444 92 Commercial construction 2,202 83 3,158 105 3,227 77 Residential 449 — 1,082 3 745 9 Home equity 174 1 208 — 120 — Consumer 45 — 27 2 18 2 Total $ 26,069 $ 377 $ 29,292 $ 489 $ 31,227 $ 417
Troubled Debt Restructurings on Financing Receivables	Troubled debt restructure agreements entered into during the year ended December 31, 2014 . (Dollars in thousands) Number of restructurings Pre-modification outstanding recorded investment Post-modification outstanding recorded investment Commercial real estate 3 $ 1,972 $ 1,972 Commercial and industrial 8 263 256 Commercial construction — — — Residential 1 124 121 Home equity 1 73 73 Consumer — — — Total 13 $ 2,432 $ 2,422 Loans modified as troubled debt restructuring within the previous twelve months for which there was a subsequent payment default during the year ended December 31, 2014 . (Dollars in thousands) Number of TDRs that defaulted Post-modification outstanding recorded investment Commercial real estate — $ — Commercial and industrial 1 64 Commercial construction — — Residential 1 121 Home equity — — Consumer — — Total 2 $ 185 The following tables present certain information regarding loan modifications classified as troubled debt restructures. Troubled debt restructure agreements entered into during the year ended December 31, 2015 . (Dollars in thousands) Number of restructurings Pre-modification outstanding recorded investment Post-modification outstanding recorded investment Commercial real estate 4 $ 269 $ 371 Commercial and industrial 8 1,786 1,600 Commercial construction 2 1,339 1,339 Residential — — — Home equity — — — Consumer 1 4 3 Total 15 $ 3,398 $ 3,313 Loans modified as troubled debt restructuring within the previous twelve months for which there was a subsequent payment default during the year ended December 31, 2015 . (Dollars in thousands) Number of TDRs that defaulted Post-modification outstanding recorded investment Commercial real estate — $ — Commercial and industrial 3 759 Commercial construction — — Residential — — Home equity — — Consumer — — Total 3 $ 759
Allowance for Credit Losses on Financing Receivables	Changes in the allowance for loan losses for the years ended December 31, are summarized as follows: (Dollars in thousands) 2015 2014 2013 Balance at beginning of year $ 27,121 $ 26,967 $ 24,254 Provision charged to operations 3,267 1,395 3,279 Loan recoveries 409 735 415 Less: Loans charged-off 1,789 1,976 981 Balance at end of year $ 29,008 $ 27,121 $ 26,967 Changes in the allowance for loan losses by segment for the year ended December 31, 2015 , are presented below: (Dollars in thousands) Cmml Real Estate Cmml and Industrial Cmml Constr Resid. Mortgage Home Equity Cnsmr Total Beg. Balance, 12/31/14 $ 12,664 $ 9,245 $ 3,384 $ 989 $ 608 $ 231 $ 27,121 Provision 909 1,805 496 72 (83 ) 68 3,267 Recoveries 74 279 25 — 15 16 409 Less: Charge offs 133 1,571 — — — 85 1,789 Ending Balance, 12/31/15 $ 13,514 $ 9,758 $ 3,905 $ 1,061 $ 540 $ 230 $ 29,008 Ending allowance balance allotted to: Loans individually evaluated for impairment $ 186 $ 1,078 $ 499 $ — $ 5 $ 24 $ 1,792 Loans collectively evaluated for impairment $ 13,328 $ 8,680 $ 3,406 $ 1,061 $ 535 $ 206 $ 27,216 Changes in the allowance for loan losses by segment for the year ended December 31, 2014 , are presented below: (Dollars in thousands) Cmml Real Estate Cmml and Industrial Cmml Constr Resid. Mortgage Home Equity Cnsmr Total Beg. Balance, 12/31/13 $ 13,174 $ 8,365 $ 3,493 $ 1,057 $ 653 $ 225 $ 26,967 Provision (186 ) 1,627 (41 ) (22 ) (19 ) 36 1,395 Recoveries 21 616 66 — 1 31 735 Less: Charge offs 345 1,363 134 46 27 61 1,976 Ending Balance, 12/31/14 $ 12,664 $ 9,245 $ 3,384 $ 989 $ 608 $ 231 $ 27,121 Ending allowance balance allotted to: Loans individually evaluated for impairment $ 68 $ 1,516 $ 519 $ — $ 26 $ 28 $ 2,157 Loans collectively evaluated for impairment $ 12,596 $ 7,729 $ 2,865 $ 989 $ 582 $ 203 $ 24,964

Premises and Equipment (Tables)

Premises and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Premises and Equipment	Premises and equipment at December 31, are summarized as follows: (Dollars in thousands) 2015 2014 Land $ 4,614 $ 4,594 Bank premises and leasehold improvements 33,597 32,556 Computer software and equipment 9,014 6,764 Furniture, fixtures and equipment 16,649 15,548 Total premises and equipment, before accumulated depreciation 63,874 59,462 Less accumulated depreciation (33,321 ) (29,092 ) Total premises and equipment, net of accumulated depreciation $ 30,553 $ 30,370
Schedule of Future Minimum Rental Payments for Operating Leases	At December 31, 2015 , minimum lease payments for these operating leases were as follows: (Dollars in thousands) Payable in: 2016 $ 1,476 2017 1,454 2018 1,133 2019 695 2020 606 Thereafter 5,100 Total minimum lease payments $ 10,464

Deposits (Tables)

Deposits (Tables)	12 Months Ended
	Dec. 31, 2015
Deposits [Abstract]
Schedule of Deposit Liabilities	Deposits at December 31, are summarized as follows: (Dollars in thousands) 2015 2014 Non-interest bearing demand deposits $ 570,589 $ 470,025 Interest bearing checking 313,674 253,126 Savings 167,304 149,940 Money market 692,114 631,676 Certificates of deposit $250,000 or less 129,993 141,379 Certificates of deposit more than $250,000 37,704 37,215 Total non-brokered deposits (1) 1,911,378 1,683,361 Brokered deposits (2) 106,770 85,185 Total deposits $ 2,018,148 $ 1,768,546 (1) Includes reciprocal money market deposits and CDs received from participating banks in nationwide networks as a result of our customers electing to participate in programs to obtain full FDIC insurance. Essentially, the equivalent of the original deposit comes back to the Company as non-brokered deposits within the appropriate category under total deposits on the balance sheet. (2) Primarily brokered CDs $250,000 and under.
Schedule of Maturities of Time Deposits	The following table shows the scheduled maturities of certificates of deposit (including brokered deposits with a weighted average remaining life of approximately 1.4 years): (Dollars in thousands) December 31, 2015 December 31, 2014 Due in less than twelve months $ 176,792 $ 166,325 Due in over one year through two years 37,729 30,043 Due in over two years through three years 23,429 22,776 Due in over three years through four years 26,501 17,618 Due in over four years through five years 5,983 26,140 Due in over five years 4,033 877 Total certificates of deposit $ 274,467 $ 263,779

Borrowed Funds and Subordinat32

Borrowed Funds and Subordinated Debt (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Schedule of Borrowed Funds and Debentures	Borrowed funds and subordinated debt outstanding at December 31, are summarized as follows: 2015 2014 2013 (Dollars in thousands) Amount Average Rate Amount Average Rate Amount Average Rate FHLB borrowings $ 40,671 0.51 % $ 58,900 0.30 % $ 36,534 0.30 % Other borrowings 13,000 0.60 % — — % — — % Total borrowed funds $ 53,671 0.53 % $ 58,900 0.30 % $ 36,534 0.30 % Subordinated debt 14,822 6.16 % 10,825 10.88 % 10,825 10.88 % Total borrowed funds and subordinated debt $ 68,493 1.75 % $ 69,725 1.94 % $ 47,359 2.72 %
Borrowings Maturity Schedule	The contractual maturity distribution as of December 31, 2015 , of borrowed funds with the weighted average cost for each category is set forth below: Overnight Within 12 months (Dollars in thousands) Balance Rate Balance Rate FHLB borrowings $ 40,000 0.51 % $ 671 0.70 % Other borrowings 13,000 0.60 % — — % Total borrowed funds $ 53,000 0.53 % $ 671 0.70 %
Schedule of Average Balances and Rates for Borrowed Funds	The following table summarizes the average balance and average cost of borrowed funds for the years ended December 31, Year ended December 31, 2015 2014 2013 (Dollars in thousands) Average Balance Average Cost Average Balance Average Cost Average Balance Average Cost FHLB advances $ 10,731 0.36 % $ 12,085 0.31 % $ 24,385 0.39 % Other borrowings 36 0.61 % 28 0.56 % 14 0.46 % Total borrowed funds $ 10,767 0.36 % $ 12,113 0.31 % $ 24,399 0.39 %

Commitments, Contingencies an33

Commitments, Contingencies and Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Schedule of Financial Instruments with Off-Balance Sheet Risk	Financial instruments with off-balance sheet credit risk at December 31, 2015 and 2014 are as follows: (Dollars in thousands) 2015 2014 Commitments to originate loans $ 48,641 $ 33,870 Commitments to originate residential mortgages loans for sale 1,516 1,471 Commitments to sell residential mortgage loans 3,225 3,842 Standby letters of credit 22,712 19,359 Unadvanced portions of commercial real estate loans 13,128 27,335 Unadvanced portions of commercial loans and lines 337,970 306,745 Unadvanced portions of construction loans (commercial & residential) 138,162 143,016 Unadvanced portions of home equity lines 73,397 64,337 Unadvanced portions of consumer loans 2,999 3,017
Schedule of Derivatives, Fair Value and Classification	The table below presents the fair value and classification of the Company’s derivative financial instruments at December 31, 2015 . As of December 31, 2015 (Dollars in thousands) Asset Derivatives Liability Derivatives Back-to-Back Swaps $ 16 $ 16
Schedule of Derivatives-Offsetting Assets and Liabilities	The table below presents the offsetting of derivatives and amounts subject to master netting agreements not offset in the consolidated balance sheet at the dates indicated. As of December 31, 2015 Gross Amounts of Recognized Asset/Liabilities Gross Amounts Offset in the Statement of Financial Position Net Amounts of Assets Presented in the Statement of Financial Position Gross amounts not offset in the Statement of Financial Position (Dollars in thousands) Financial Instruments Cash collateral (Received)/Posted Net Amount Asset Derivatives Back-to-Back Swaps $ 16 — $ 16 — — $ 16 Liability Derivatives Back-to-Back Swaps $ 16 — $ 16 — — $ 16

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations	The Company began implementing the new regulatory requirements under Basel III in 2015 . Management believes, as of December 31, 2015 , that the Company and the Bank meet all capital adequacy requirements to which they were subject. As of December 31, 2015 , both the Company and the Bank qualified as “well capitalized” under then applicable Federal Reserve Board and FDIC regulations. The current regulatory requirements, and the Company's and the Bank's actual capital amounts and ratios are presented as of December 31, 2015 in the table below. Actual Minimum Capital for Capital Adequacy Purposes Minimum Capital To Be Well Capitalized* (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio As of December 31, 2015 The Company Total Capital (to risk weighted assets) $ 212,871 10.70 % $ 159,198 8.00 % $ 198,997 10.00 % Tier 1 Capital (to risk weighted assets) 172,397 8.66 % 119,398 6.00 % 159,198 8.00 % Tier 1 Capital (to average assets)* 172,397 7.73 % 89,173 4.00 % N/A N/A Common equity tier 1 capital to risk-weighted assets 172,397 8.66 % 89,549 4.50 % $ 129,348 6.50 % The Bank Total Capital (to risk weighted assets) $ 209,670 10.54 % $ 159,189 8.00 % $ 198,987 10.00 % Tier 1 Capital (to risk weighted assets) 184,019 9.25 % 119,392 6.00 % 159,189 8.00 % Tier 1 Capital (to average assets) 184,019 8.25 % 89,172 4.00 % 111,465 5.00 % Common equity tier 1 capital to risk-weighted assets 184,019 9.25 % 89,544 4.50 % 129,341 6.50 % ____________________ *For the Bank to qualify as “well capitalized," it must maintain a leverage capital ratio (Tier 1 capital to average assets) of at least 5% . This requirement does not apply to the Company. As noted above, capital ratios for 2015 are based on the Basel III regulatory capital framework implemented at the beginning of 2015. The capital ratios presented below for 2014 are based on the capital requirements in effect before the implementation of Basel III. As of December 31, 2014 , the Company and the Bank met all capital adequacy requirements to which they were subject. As of December 31, 2014 , both the Company and the Bank qualified as “well capitalized” under then applicable Federal Reserve Board and FDIC regulations. Prior to 2015, to have been categorized as "well capitalized" under the prompt corrective action framework, the Company and the Bank were required to maintain minimum Total and Tier 1 capital ratios, and in the case of the Bank, leverage capital ratios, as set forth in the table below. Actual Minimum Capital for Capital Adequacy Purposes Minimum Capital To Be Well Capitalized* (Dollars in thousands) Amount Ratio Amount Ratio Amount Ratio As of December 31, 2014 The Company Total Capital (to risk weighted assets) $ 189,733 11.27 % $ 134,732 8.00 % $ 168,415 10.00 % Tier 1 Capital (to risk weighted assets) 167,299 9.93 % 67,366 4.00 % 101,049 6.00 % Tier 1 Capital (to average assets)* 167,299 8.41 % 79,578 4.00 % N/A N/A The Bank Total Capital (to risk weighted assets) $ 188,446 11.19 % $ 134,726 8.00 % $ 168,407 10.00 % Tier 1 Capital (to risk weighted assets) 166,013 9.86 % 67,363 4.00 % 101,044 6.00 % Tier 1 Capital (to average assets) 166,013 8.35 % 79,544 4.00 % 99,430 5.00 % _____________________ *For the Bank to qualify as “well capitalized," it must maintain a leverage capital ratio (Tier 1 capital to average assets) of at least 5% . This requirement does not apply to the Company.
Schedule of Basel III Minimum Requirements at Full Phase In [Table Text Block]	The Basel III minimum capital ratio requirements as applicable to the Company and the Bank in 2019 after the full phase-in period are summarized in the table below: Basel III Minimum for Capital Adequacy Purposes Basel III Additional Capital Conservation Buffer Basel III "Adequate" Ratio with Capital Conservation Buffer Total Risk Based Capital (total capital to risk weighted assets) 8.0% 2.5% 10.5% Tier 1 Risk Based Capital (tier 1 to risk weighted assets) 6.0% 2.5% 8.5% Tier 1 Leverage Ratio (tier 1 to average assets) 4.0% —% 4.0% Common Equity Tier 1 Risk Based to risk weighted assets 4.5% 2.5% 7.0%

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2015
Supplemental Retirement Plan
Defined Benefit Plan Disclosure [Line Items]
Schedule of Changes in Projected Benefit Obligations	The following table provides a reconciliation of the changes in the supplemental retirement benefit obligation and the net periodic benefit cost for the years ended December 31: (Dollars in thousands) 2015 2014 2013 Reconciliation of benefit obligation: Benefit obligation at beginning of year $ 2,844 $ 2,889 $ 3,181 Net periodic benefit cost: Interest cost 133 128 157 Actuarial loss (gain) (47 ) 103 (173 ) Net periodic benefit costs $ 86 $ 231 $ (16 ) Benefits paid (276 ) (276 ) (276 ) Benefit obligation at end of year $ 2,654 $ 2,844 $ 2,889 Funded status: Accrued liability as of December 31 $ (2,654 ) $ (2,844 ) $ (2,889 ) Discount rate used for benefit obligation (1) 4.75 % 4.50 % 5.00 % (1) Management utilizes the Moody’s 20 year AA corporate bond rates to establish the reasonableness of the discount rate used. The Company reviews and periodically updates the discount rate to reflect changes in bond market rates. The impact of the discount rate change is reflected as the actuarial gain or loss.
Schedule of Expected Benefit Payments	Benefits expected to be paid in each of the next five years and in the aggregate five years thereafter: (Dollars in thousands) 2016 $ 276 2017 276 2018 276 2019 276 2020 276 2021-2025 1,379
Supplemental Life Insurance Benefit
Defined Benefit Plan Disclosure [Line Items]
Schedule of Changes in Projected Benefit Obligations	The following table provides a reconciliation of the changes in the supplemental life insurance plan obligation and the net periodic benefit cost for the years ended December 31: (Dollars in thousands) 2015 2014 2013 Reconciliation of benefit obligation: Benefit obligation at beginning of year $ 1,723 $ 1,576 $ 1,664 Net periodic benefit cost: Service cost (56 ) (38 ) 2 Interest cost 86 74 74 Actuarial loss (gain) 39 111 (164 ) Total net period cost (benefit) $ 69 $ 147 $ (88 ) Benefit obligation at end of year $ 1,792 $ 1,723 $ 1,576 Funded status: Accrued liability as of December 31 $ (1,792 ) $ (1,723 ) $ (1,576 ) Discount rate used for benefit obligation (1) 4.75 % 4.50 % 5.00 % (1) Management utilizes the Moody’s 20 year AA corporate bond rates to establish the reasonableness of the discount rate used. The Company reviews and periodically updates the discount rate to reflect changes in bond market rates. The impact of the discount rate change is reflected as the actuarial gain or loss.

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2015
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 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 years indicated. Stock Option Awards 2015 2014 2013 Options granted 27,376 31,229 47,684 Term in years 10.0 10.0 10.0 Average assumptions used in the model: Expected volatility 47 % 47 % 48 % Expected dividend yield 2.90 % 2.88 % 2.96 % Expected life in years 7.0 7.0 7.0 Risk-free interest rate 1.95 % 2.19 % 1.35 % Market price on date of grant $ 21.03 $ 20.29 $ 16.61 Per share weighted average fair value $ 8.51 $ 8.32 $ 6.66 Fair value as a percentage of market value at grant date 40 % 41 % 40 %
Schedule of Share-based Compensation, Stock Options, Activity	Stock option transactions during the year ended December 31, 2015 are summarized as follows: (Dollars in thousands, except per share data) Options Weighted Average Exercise Price Per Share Weighted Average Remaining Life in Years Aggregate Intrinsic Value Outstanding December 31, 2014 319,884 $ 14.92 4.1 $ 3,303 Granted 27,376 21.03 Exercised 43,923 12.47 Forfeited/Expired 2,368 17.56 Outstanding December 31, 2015 300,969 $ 15.82 4.2 $ 2,116 Vested and Exercisable at December 31, 2015 204,344 $ 14.35 2.6 $ 1,738
Schedule of Restricted Stock Awards Granted	The table below provides a summary of restricted stock awards granted in the years indicated. Restricted Stock Awards 2015 2014 2013 Two Year Vesting 7,276 6,660 6,146 Four Year Vesting 17,775 19,167 26,660 Performance-Based Vesting 30,262 33,017 47,735 Total Restricted Stock Awards 55,313 58,844 80,541 Weighted average grant date fair value $ 21.03 $ 20.29 $ 16.43
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	he following table sets forth a summary of the activity for the Company’s restricted stock awards. (Dollars in thousands, except per share data) Restricted Stock Weighted Average Grant Price Per Share Weighted Average Remaining Life In Years Aggregate Intrinsic Value Unvested December 31, 2014 157,694 $ 17.71 2.2 $ 3,982 Granted 55,313 21.03 Vested/released 66,588 17.17 Forfeited 1,702 18.58 Unvested December 31, 2015 144,717 $ 19.22 1.0 $ 3,304

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The components of income tax expense for the years ended December 31, were calculated using the asset and liability method as follows: (Dollars in thousands) 2015 2014 2013 Current tax expense: Federal $ 6,808 $ 5,814 $ 5,492 State 1,712 1,681 1,642 Total current tax expense 8,520 7,495 7,134 Deferred tax (benefit)/ expense: Federal (284 ) 85 (100 ) State (122 ) 5 (83 ) Total deferred tax (benefit)/ expense (406 ) 90 (183 ) Total income tax expense $ 8,114 $ 7,585 $ 6,951
Schedule of Effective Income Tax Rate Reconciliation	The provision for income taxes differs from the amount computed by applying the statutory U.S. federal income tax rate ( 35% ) for 2015 and ( 34% ) for prior years to income before taxes as follows: (Dollars in thousands) 2015 2014 2013 Computed income tax expense at statutory rate $ 8,492 $ 7,560 $ 6,963 State income taxes, net of federal tax benefit 1,034 1,113 1,029 Tax-exempt income, net of disallowance (1,226 ) (1,060 ) (988 ) Bank-owned life insurance income, net (251 ) (140 ) (156 ) Other 65 112 103 Total income tax expense $ 8,114 $ 7,585 $ 6,951 Effective income tax rate 33.4 % 34.1 % 33.9 %
Schedule of Deferred Tax Assets and Liabilities	At December 31, the tax effects of each type of income and expense item that give rise to deferred taxes are: (Dollars in thousands) 2015 2014 Deferred tax asset: Allowance for loan losses $ 11,800 $ 11,026 Depreciation 3,103 3,033 Other-than-temporary impairment on equity securities 22 168 Supplemental employee retirement plans 1,080 1,156 Non-accrual interest 1,393 1,440 Stock-based compensation expense 873 751 Other 163 97 Total 18,434 17,671 Deferred tax liability: Goodwill 2,300 2,140 Net unrealized gains on investments securities 1,204 2,057 Deferred origination costs 812 622 Other 7 — Total 4,323 4,819 Net deferred tax asset $ 14,111 $ 12,852

Earnings per share (Tables)

Earnings per share (Tables)	12 Months Ended
	Dec. 31, 2015
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 years ended December 31st: 2015 2014 2013 Basic weighted average common shares outstanding 10,323,016 10,118,762 9,862,678 Dilutive shares 66,918 90,481 87,931 Diluted weighted average common shares outstanding 10,389,934 10,209,243 9,950,609

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2015
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: December 31, 2015 Fair Value Measurements using: (Dollars in thousands) Fair Value (level 1) (level 2) (level 3) Assets measured on a recurring basis: Fixed income securities $ 288,701 $ — $ 288,701 $ — Equity securities 11,657 11,657 — — FHLB Stock 3,050 — — 3,050 Interest-rate swaps 16 — 16 — Assets measured on a non-recurring basis: Impaired loans (collateral dependent) 2,516 — — 2,516 Liabilities measured on a recurring basis: Interest-rate swaps 16 — 16 — December 31, Fair Value Measurements using: (Dollars in thousands) Fair Value (level 1) (level 2) (level 3) Assets measured on a recurring basis: Fixed income securities $ 230,790 $ — $ 230,790 $ — Equity securities 14,275 14,275 — — FHLB Stock 3,357 — — 3,357 Assets measured on a non-recurring basis: Impaired loans (collateral dependent) 5,174 — — 5,174 Other real estate owned 861 — — 861
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 December 31, 2015 . (Dollars in thousands) Fair Value Valuation Technique Unobservable Input Unobservable Input Value or Range Assets measured on a recurring basis: FHLB Stock $3,050 FHLB Stated Par Value N/A N/A Assets measured on a non-recurring basis: Impaired loans (collateral dependent) $2,516 Appraisal of collateral Appraisal adjustments (1) 5% - 50% (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 financial instruments for which fair value is only disclosed but not recognized on the balance sheet at the dates indicated are summarized as follows: December 31, 2015 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 $ 1,709 $ 1,709 $ — $ 1,709 $ — Loans, net 1,830,954 1,845,009 — — 1,845,009 Financial liabilities: Certificates of deposit (including brokered) 274,467 273,419 — 273,419 — Borrowed funds 53,671 53,670 — 53,670 — Subordinated debt 14,822 13,961 — — 13,961 December 31, 2014 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 $ 2,371 $ 2,381 $ — $ 2,381 $ — Loans, net 1,645,483 1,668,863 — — 1,668,863 Financial liabilities: Certificates of deposit (including brokered) 263,779 262,774 — 262,774 — Borrowed funds 58,900 58,899 — 58,899 — Subordinated debt 10,825 13,017 — — 13,017 Excluded from this table 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, accrued interest receivable, non-term deposit accounts, and accrued interest payable. The respective carrying values of these instruments would all be considered to be classified within Level 1 of their fair value hierarchy.

Parent Company Only Financial40

Parent Company Only Financial Statements (Tables)	12 Months Ended
	Dec. 31, 2015
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Schedule of Condensed Balance Sheet	Balance Sheets December 31, (Dollars in thousands) 2015 2014 Assets Cash $ 2,737 $ 699 Investment in subsidiaries 191,949 176,946 Other assets 546 510 Total assets $ 195,232 $ 178,155 Liabilities and Stockholders’ Equity Liabilities Subordinated debt $ 14,822 $ 10,825 Accrued interest payable 78 370 Other liabilities 5 10 Total liabilities 14,905 11,205 Stockholders' equity: Preferred stock, $0.01 par value per share; 1,000,000 shares authorized; no shares issued — — Common stock $0.01 par value per share; 20,000,000 shares authorized; 10,377,787 shares issued and outstanding at December 31, 2015 (including 144,717 shares of unvested participating restricted awards) and 10,207,943 shares issued and outstanding at December 31, 2014 (including 157,694 shares of unvested participating restricted awards) 104 102 Additional paid-in capital 61,008 57,130 Retained earnings 116,941 105,951 Accumulated other comprehensive income 2,274 3,767 Total stockholders’ equity 180,327 166,950 Total liabilities and stockholders’ equity $ 195,232 $ 178,155
Schedule of Condensed Income Statement	Statements of Income For the years ended December 31, (Dollars in thousands) 2015 2014 2013 Equity in undistributed net income of subsidiaries $ 17,277 $ 13,744 $ 13,571 Dividends distributed by subsidiaries — 1,850 950 Loss distributed by divested subsidiary (210 ) — — Other income 17 — — Total income 17,084 15,594 14,521 Interest expense 1,071 1,177 1,177 Other operating expenses 500 194 225 Total operating expenses 1,571 1,371 1,402 Income before income taxes 15,513 14,223 13,119 Benefit from income taxes (635 ) (428 ) (410 ) Net income $ 16,148 $ 14,651 $ 13,529
Schedule of Condensed Cash Flow Statement	Parent Company Only Financial Statements Statements of Cash Flows For the years ended December 31, (Dollars in thousands) 2015 2014 2013 Cash flows from operating activities: Net income $ 16,148 $ 14,651 $ 13,529 Adjustments to reconcile net income to net cash provided by operating activities: Equity in undistributed net income of subsidiaries (17,277 ) (13,744 ) (13,571 ) Payment from subsidiary bank for stock compensation expense 1,791 1,704 1,652 Changes in: Other assets (36 ) (277 ) 9 Other liabilities (12 ) (3 ) 10 Subordinated debt issuance costs (178 ) — — Accrued interest payable (292 ) — — Net cash provided by operating activities 144 2,331 1,629 Cash flows from investing activities Investment in subsidiary 781 — — Net cash provided by investing activities 781 — — Cash flows from financing activities: Repayment of subordinated debt (10,825 ) — — Proceeds from the issuance of subordinated debt 15,000 — — Cash dividends paid (5,158 ) (4,853 ) (4,535 ) Proceeds from issuance of common stock 1,448 1,283 1,239 Proceeds from exercise of stock options 431 889 1,829 Tax benefit from stock-based compensation 217 320 25 Net cash provided by financing activities 1,113 (2,361 ) (1,442 ) Net increase (decrease) in cash and cash equivalents 2,038 (30 ) 187 Cash and cash equivalents, beginning of year 699 729 542 Cash and cash equivalents, end of year $ 2,737 $ 699 $ 729

Quarterly Results of Operatio41

Quarterly Results of Operations (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	2015 (Dollars in thousands, except share data) First Quarter Second Quarter Third Quarter Fourth Quarter Interest and dividend income $ 19,839 $ 20,437 $ 21,224 $ 21,971 Interest expense 1,385 1,253 1,264 1,275 Net interest income 18,454 19,184 19,960 20,696 Provision for loan losses 625 1,225 250 1,167 Net interest income after provision for loan losses 17,829 17,959 19,710 19,529 Non-interest income 3,125 3,222 3,177 3,615 Net gains on sales of investment securities 900 456 7 465 Non-interest expense 16,210 16,267 16,548 16,707 Income before income taxes 5,644 5,370 6,346 6,902 Provision for income taxes 2,024 1,855 2,054 2,181 Net income $ 3,620 $ 3,515 $ 4,292 $ 4,721 Basic earnings per share $ 0.35 $ 0.34 $ 0.41 $ 0.46 Diluted earnings per share $ 0.35 $ 0.34 $ 0.41 $ 0.45 2014 (Dollars in thousands, except share data) First Quarter Second Quarter Third Quarter Fourth Quarter Interest and dividend income $ 18,231 $ 18,780 $ 19,394 $ 20,068 Interest expense 1,317 1,328 1,302 1,296 Net interest income 16,914 17,452 18,092 18,772 Provision for loan losses 200 200 765 230 Net interest income after provision for loan losses 16,714 17,252 17,327 18,542 Non-interest income 2,991 3,137 3,325 3,360 Net gains on sales of investment securities 488 127 215 789 Non-interest expense 14,825 15,445 15,115 16,646 Income before income taxes 5,368 5,071 5,752 6,045 Provision for income taxes 1,862 1,757 1,921 2,045 Net income $ 3,506 $ 3,314 $ 3,831 $ 4,000 Basic earnings per share $ 0.35 $ 0.33 $ 0.38 $ 0.39 Diluted earnings per share $ 0.35 $ 0.32 $ 0.37 $ 0.39

Summary of Significant Accoun42

Summary of Significant Accounting Policies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)branchespaymentsegment	Dec. 31, 2014USD ($)	Jul. 31, 2000branches
Summary of Significant Accounting Policies [Line Items]
Number of branches | branches	22
Reportable operating segments | segment	1
Bank-owned life insurance	$ 28,018	$ 16,315
Goodwill	5,656	5,656
Number of offices related to the goodwill in acquisition | branches			2
Investment assets under management	$ 678,400	$ 674,600
Buildings, renovations, and leasehold improvements | Minimum
Summary of Significant Accounting Policies [Line Items]
Estimated useful lives	10 years
Buildings, renovations, and leasehold improvements | Maximum
Summary of Significant Accounting Policies [Line Items]
Estimated useful lives	39 years
Computer software and equipment | Minimum
Summary of Significant Accounting Policies [Line Items]
Estimated useful lives	3 years
Computer software and equipment | Maximum
Summary of Significant Accounting Policies [Line Items]
Estimated useful lives	5 years
Furniture, fixtures and equipment | Minimum
Summary of Significant Accounting Policies [Line Items]
Estimated useful lives	3 years
Furniture, fixtures and equipment | Maximum
Summary of Significant Accounting Policies [Line Items]
Estimated useful lives	10 years
Residential
Summary of Significant Accounting Policies [Line Items]
Early payment default period | payment	4
Lines of Credit and Demand Notes | Minimum
Summary of Significant Accounting Policies [Line Items]
Period that loan deferred income is amortized	3 years
Lines of Credit and Demand Notes | Maximum
Summary of Significant Accounting Policies [Line Items]
Period that loan deferred income is amortized	5 years

Investments (Details)

Investments (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Available-for-sale Securities, Gross Unrealized Gain (Loss) [Abstract]
Fair Value		$ 300,358	$ 245,065
Securities pledged as collateral		286,000	230,800
Total fixed income securities
Available-for-sale Securities, Gross Unrealized Gain (Loss) [Abstract]
Amortized cost		286,838	227,871
Unrealized gains		3,159	3,551
Unrealized losses		1,296	632
Fair Value		288,701	230,790
Federal agency obligations
Available-for-sale Securities, Gross Unrealized Gain (Loss) [Abstract]
Amortized cost	[1]	78,626	59,518
Unrealized gains	[1]	352	318
Unrealized losses	[1]	153	24
Fair Value	[1]	78,825	59,812
Residential Mortgage Backed Securities
Available-for-sale Securities, Gross Unrealized Gain (Loss) [Abstract]
Amortized cost	[1]	75,105	88,303
Unrealized gains	[1]	406	1,015
Unrealized losses	[1]	648	516
Fair Value	[1]	74,863	88,802
Collateralized Mortgage Obligations (CMOs)
Available-for-sale Securities, Gross Unrealized Gain (Loss) [Abstract]
Fair Value		20,800	13,300
Commercial Mortgage Backed Securities
Available-for-sale Securities, Gross Unrealized Gain (Loss) [Abstract]
Amortized cost	[1]	23,908
Unrealized gains	[1]	0
Unrealized losses	[1]	363
Fair Value	[1]	23,545
Municipal securities
Available-for-sale Securities, Gross Unrealized Gain (Loss) [Abstract]
Amortized cost		96,189	72,113
Unrealized gains		2,357	2,157
Unrealized losses		35	66
Fair Value		98,511	74,204
Tax exempt interest earned on municipal securities		2,900	2,400	$ 2,100
Corporate bonds
Available-for-sale Securities, Gross Unrealized Gain (Loss) [Abstract]
Amortized cost		10,257	7,937
Unrealized gains		44	61
Unrealized losses		95	26
Fair Value		10,206	7,972
Certificates of Deposit
Available-for-sale Securities, Gross Unrealized Gain (Loss) [Abstract]
Amortized cost	[2]	2,753
Unrealized gains	[2]	0
Unrealized losses	[2]	2
Fair Value	[2]	2,751
Equity investments
Available-for-sale Securities, Gross Unrealized Gain (Loss) [Abstract]
Amortized cost		10,043	11,370
Unrealized gains		1,966	3,071
Unrealized losses		352	166
Fair Value		$ 11,657	14,275
Percent of portfolio invested in financial services		16.00%
Total available for sale securities, at fair value
Available-for-sale Securities, Gross Unrealized Gain (Loss) [Abstract]
Amortized cost		$ 296,881	239,241
Unrealized gains		5,125	6,622
Unrealized losses		1,648	798
Fair Value		$ 300,358	$ 245,065
[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, or one of several Federal Home Loan Banks, as well as, investments guaranteed by Ginnie Mae (GNMA), a wholly-owned government entity.
[2]	Certificates of deposit ("CDs") represent term deposits issued by banks that are subject to FDIC insurance and purchased on the open market.

Investments - Continuous Loss P

Investments - Continuous Loss Position (Details) $ in Thousands	Dec. 31, 2015USD ($)investments	Dec. 31, 2014USD ($)
Schedule of Available-for-sale Securities [Line Items]
Investments Temporarily Impaired, Less than 12 months, Fair Value	$ 89,224	$ 16,268
Investments Temporarily Impaired, Less than 12 months, Unrealized Losses	1,255	229
Investments Temporarily Impaired, 12 months or longer, Fair Value	11,639	27,487
Investments Temporarily Impaired,12 months or longer, Unrealized Losses	393	569
Investments Temporarily Impaired, Fair Value	100,863	43,755
Investments Temporarily Impaired, Unrealized Losses	1,648	798
Federal agency obligations
Schedule of Available-for-sale Securities [Line Items]
Investments Temporarily Impaired, Less than 12 months, Fair Value	27,420	7,959
Investments Temporarily Impaired, Less than 12 months, Unrealized Losses	153	24
Investments Temporarily Impaired, 12 months or longer, Fair Value	0	0
Investments Temporarily Impaired,12 months or longer, Unrealized Losses	0	0
Investments Temporarily Impaired, Fair Value	27,420	7,959
Investments Temporarily Impaired, Unrealized Losses	153	24
Residential Mortgage Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Investments Temporarily Impaired, Less than 12 months, Fair Value	20,517	0
Investments Temporarily Impaired, Less than 12 months, Unrealized Losses	276	0
Investments Temporarily Impaired, 12 months or longer, Fair Value	10,935	23,801
Investments Temporarily Impaired,12 months or longer, Unrealized Losses	373	516
Investments Temporarily Impaired, Fair Value	31,452	23,801
Investments Temporarily Impaired, Unrealized Losses	649	516
Commercial Mortgage Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Investments Temporarily Impaired, Less than 12 months, Fair Value	23,545
Investments Temporarily Impaired, Less than 12 months, Unrealized Losses	363
Investments Temporarily Impaired, 12 months or longer, Fair Value	0
Investments Temporarily Impaired,12 months or longer, Unrealized Losses	0
Investments Temporarily Impaired, Fair Value	23,545
Investments Temporarily Impaired, Unrealized Losses	363
Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Investments Temporarily Impaired, Less than 12 months, Fair Value	6,988	3,597
Investments Temporarily Impaired, Less than 12 months, Unrealized Losses	32	31
Investments Temporarily Impaired, 12 months or longer, Fair Value	261	2,794
Investments Temporarily Impaired,12 months or longer, Unrealized Losses	2	35
Investments Temporarily Impaired, Fair Value	7,249	6,391
Investments Temporarily Impaired, Unrealized Losses	34	66
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Investments Temporarily Impaired, Less than 12 months, Fair Value	4,574	2,704
Investments Temporarily Impaired, Less than 12 months, Unrealized Losses	78	12
Investments Temporarily Impaired, 12 months or longer, Fair Value	419	871
Investments Temporarily Impaired,12 months or longer, Unrealized Losses	17	14
Investments Temporarily Impaired, Fair Value	4,993	3,575
Investments Temporarily Impaired, Unrealized Losses	95	26
Certificates of Deposit
Schedule of Available-for-sale Securities [Line Items]
Investments Temporarily Impaired, Less than 12 months, Fair Value	1,976
Investments Temporarily Impaired, Less than 12 months, Unrealized Losses	2
Investments Temporarily Impaired, 12 months or longer, Fair Value	0
Investments Temporarily Impaired,12 months or longer, Unrealized Losses	0
Investments Temporarily Impaired, Fair Value	1,976
Investments Temporarily Impaired, Unrealized Losses	2
Equity investments
Schedule of Available-for-sale Securities [Line Items]
Investments Temporarily Impaired, Less than 12 months, Fair Value	4,204	2,008
Investments Temporarily Impaired, Less than 12 months, Unrealized Losses	351	162
Investments Temporarily Impaired, 12 months or longer, Fair Value	24	21
Investments Temporarily Impaired,12 months or longer, Unrealized Losses	1	4
Investments Temporarily Impaired, Fair Value	4,228	2,029
Investments Temporarily Impaired, Unrealized Losses	$ 352	$ 166
Fixed Income and Equity Securities, Excluding CDs [Member]
Schedule of Available-for-sale Securities [Line Items]
Number of securities in loss position | investments	86

Investments - Maturities (Detai

Investments - Maturities (Details) $ in Thousands	Dec. 31, 2015USD ($)
Schedule of Available-for-sale Securities [Line Items]
Callable debt securities, amortized cost	$ 49,100
Callable debt securities, fair value	50,300
Total fixed income securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One Year	$ 14,433
Amortized Cost, Within One Year, Yield	1.49%
Fair Value, Within One Year	$ 14,477
Amortized Cost Basis, After One, But Within Five Years	$ 95,257
Amortized Cost Basis, After One, But Within Five Years, Yield	2.13%
Fair Value, After One, But Within Five Years	$ 96,053
Amortized Cost, After Five, But Within Ten Years	$ 74,478
Amortized Cost, After Five, But Within Ten Years, Yield	2.96%
Fair Value, After Five, But Within Ten Years	$ 75,015
Amortized Cost Basis, After Ten Years	$ 102,670
Amortized Cost Basis, After Ten Years, Yield	2.68%
Fair Value, After Ten Years	$ 103,156
Federal agency obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One Year	$ 7,048
Amortized Cost, Within One Year, Yield	0.91%
Amortized Cost Basis, After One, But Within Five Years	$ 62,024
Amortized Cost Basis, After One, But Within Five Years, Yield	1.59%
Amortized Cost, After Five, But Within Ten Years	$ 9,554
Amortized Cost, After Five, But Within Ten Years, Yield	2.22%
Amortized Cost Basis, After Ten Years	$ 0
Amortized Cost Basis, After Ten Years, Yield	0.00%
Residential Mortgage Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One Year	$ 0
Amortized Cost, Within One Year, Yield	0.00%
Amortized Cost Basis, After One, But Within Five Years	$ 3,576
Amortized Cost Basis, After One, But Within Five Years, Yield	3.15%
Amortized Cost, After Five, But Within Ten Years	$ 1,299
Amortized Cost, After Five, But Within Ten Years, Yield	1.90%
Amortized Cost Basis, After Ten Years	$ 70,230
Amortized Cost Basis, After Ten Years, Yield	2.11%
Commercial Mortgage Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One Year	$ 0
Amortized Cost, Within One Year, Yield	0.00%
Amortized Cost Basis, After One, But Within Five Years	$ 0
Amortized Cost Basis, After One, But Within Five Years, Yield	0.00%
Amortized Cost, After Five, But Within Ten Years	$ 23,908
Amortized Cost, After Five, But Within Ten Years, Yield	2.26%
Amortized Cost Basis, After Ten Years	$ 0
Amortized Cost Basis, After Ten Years, Yield	0.00%
Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One Year	$ 5,052
Amortized Cost, Within One Year, Yield	2.74%
Amortized Cost Basis, After One, But Within Five Years	$ 23,948
Amortized Cost Basis, After One, But Within Five Years, Yield	3.38%
Amortized Cost, After Five, But Within Ten Years	$ 34,749
Amortized Cost, After Five, But Within Ten Years, Yield	3.69%
Amortized Cost Basis, After Ten Years	$ 32,440
Amortized Cost Basis, After Ten Years, Yield	3.91%
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One Year	$ 530
Amortized Cost, Within One Year, Yield	1.33%
Amortized Cost Basis, After One, But Within Five Years	$ 4,759
Amortized Cost Basis, After One, But Within Five Years, Yield	2.09%
Amortized Cost, After Five, But Within Ten Years	$ 4,968
Amortized Cost, After Five, But Within Ten Years, Yield	2.89%
Amortized Cost Basis, After Ten Years	$ 0
Amortized Cost Basis, After Ten Years, Yield	0.00%
Certificates of Deposit
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost, Within One Year	$ 1,803
Amortized Cost, Within One Year, Yield	0.32%
Amortized Cost Basis, After One, But Within Five Years	$ 950
Amortized Cost Basis, After One, But Within Five Years, Yield	2.13%
Amortized Cost, After Five, But Within Ten Years	$ 0
Amortized Cost, After Five, But Within Ten Years, Yield	0.00%
Amortized Cost Basis, After Ten Years	$ 0
Amortized Cost Basis, After Ten Years, Yield	0.00%

Investments - Sales (Details)

Investments - Sales (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]
Amortized cost of investments sold	$ 23,287	$ 23,752	$ 8,325
Gross realized gains on sales	1,990	1,654	1,243
Gross realized losses on sales	(162)	(35)	(4)
Proceeds from sales of investment securities available-for-sale	$ 25,115	$ 25,371	$ 9,564

Loans - Balance by Class of Loa

Loans - Balance by Class of Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule of Loans by Loan Classification [Line Items]
Gross loans	$ 1,861,775	$ 1,674,470
Deferred loan origination fees, net	(1,813)	(1,866)
Total loans	1,859,962	1,672,604
Allowance for loan losses	(29,008)	(27,121)	$ (26,967)	$ (24,254)
Net loans	1,830,954	1,645,483
Commercial
Schedule of Loans by Loan Classification [Line Items]
Gross loans	1,598,467	1,433,785
Commercial real estate
Schedule of Loans by Loan Classification [Line Items]
Gross loans	936,921	862,747
Allowance for loan losses	(13,514)	(12,664)	(13,174)
Commercial and industrial
Schedule of Loans by Loan Classification [Line Items]
Gross loans	458,553	402,994
Allowance for loan losses	(9,758)	(9,245)	(8,365)
Commercial construction
Schedule of Loans by Loan Classification [Line Items]
Gross loans	202,993	168,044
Allowance for loan losses	(3,905)	(3,384)	(3,493)
Retail
Schedule of Loans by Loan Classification [Line Items]
Gross loans	263,308	240,685
Residential
Schedule of Loans by Loan Classification [Line Items]
Gross loans	169,188	149,959
Allowance for loan losses	(1,061)	(989)	(1,057)
Home Equity
Schedule of Loans by Loan Classification [Line Items]
Gross loans	83,373	80,018
Allowance for loan losses	(540)	(608)	(653)
Consumer
Schedule of Loans by Loan Classification [Line Items]
Gross loans	10,747	10,708
Allowance for loan losses	$ (230)	$ (231)	$ (225)

Loans - Loan Categories Narrati

Loans - Loan Categories Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)payment	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Schedule of Loans by Loan Classification [Line Items]
Outstanding loan balances to related parties	$ 17.5	$ 18.2
Unadvanced lines of credit available to related parties	10.6	6.5
New loans and net increases to loan balances to related parties during period	6.7
Principal paydowns on related party loans	$ 3.3
Commercial real estate | Minimum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	15 years
Commercial real estate | Maximum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	25 years
Commercial and industrial | Minimum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	1 year
Commercial and industrial | Maximum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	7 years
Commercial construction | Minimum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	1 year
Commercial construction | Maximum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	3 years
Commercial
Schedule of Loans by Loan Classification [Line Items]
Participation loans amount	$ 62.3	65.3
Participations loans sold that are still serviced	52.7	44.8
Tax exempt interest income on qualified commercial loans	1.6	1.4	$ 1.3
Average tax exempt loan balances	$ 50.9	38.3
Residential
Schedule of Loans by Loan Classification [Line Items]
Early payment default period | payment	4
Amount of loans serviced for others	$ 18.5	$ 19.3
Residential | Maximum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	30 years
Home Equity | Maximum
Schedule of Loans by Loan Classification [Line Items]
Loan-to-value ratio	80.00%
Home equity loans | Minimum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	3 years
Period a loan has a fixed rate	3 years
Home equity loans | Maximum
Schedule of Loans by Loan Classification [Line Items]
Repayment period, term of loan	15 years
Period a loan has a fixed rate	15 years
Home equity lines of credit
Schedule of Loans by Loan Classification [Line Items]
Term of interest only payments	10 years
Term of principal and interest payments after Interest only term	15 years
Multi-family owner occupied residential property | Minimum
Schedule of Loans by Loan Classification [Line Items]
Loan-to-value ratio	75.00%
Single family owner occupied residential property | Maximum
Schedule of Loans by Loan Classification [Line Items]
Loan-to-value ratio	97.00%

Loans - Loans Serving as Collat

Loans - Loans Serving as Collateral (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financial Instruments Owned and Pledged as Collateral [Line Items]
Loans pledged to the FHLB for borrowing capacity	$ 414,629	$ 400,240
Commercial real estate
Financial Instruments Owned and Pledged as Collateral [Line Items]
Loans pledged to the FHLB for borrowing capacity	281,802	276,657
Residential
Financial Instruments Owned and Pledged as Collateral [Line Items]
Loans pledged to the FHLB for borrowing capacity	118,855	107,906
Home Equity
Financial Instruments Owned and Pledged as Collateral [Line Items]
Loans pledged to the FHLB for borrowing capacity	$ 13,972	$ 15,677

Allowance For Loan Losses - Eva

Allowance For Loan Losses - Evaluation Method (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule of Financing Receivable by Evaluation Method [Line Items]
Loans individually evaluated for impairment	$ 23,688	$ 29,252
Loans collectively evaluated for impairment	1,836,274	1,643,352
Gross loans	1,861,775	1,674,470
Deferred loan origination fees, net	(1,813)	(1,866)
Total loans	1,859,962	1,672,604
Commercial real estate
Schedule of Financing Receivable by Evaluation Method [Line Items]
Loans individually evaluated for impairment	12,287	15,003
Loans collectively evaluated for impairment	924,634	847,744
Gross loans	936,921	862,747
Commercial and industrial
Schedule of Financing Receivable by Evaluation Method [Line Items]
Loans individually evaluated for impairment	7,810	10,901
Loans collectively evaluated for impairment	450,743	392,093
Gross loans	458,553	402,994
Commercial construction
Schedule of Financing Receivable by Evaluation Method [Line Items]
Loans individually evaluated for impairment	3,032	2,675
Loans collectively evaluated for impairment	199,961	165,369
Gross loans	202,993	168,044
Residential
Schedule of Financing Receivable by Evaluation Method [Line Items]
Loans individually evaluated for impairment	366	465
Loans collectively evaluated for impairment	168,822	149,494
Gross loans	169,188	149,959
Home Equity
Schedule of Financing Receivable by Evaluation Method [Line Items]
Loans individually evaluated for impairment	169	180
Loans collectively evaluated for impairment	83,204	79,838
Gross loans	83,373	80,018
Consumer
Schedule of Financing Receivable by Evaluation Method [Line Items]
Loans individually evaluated for impairment	24	28
Loans collectively evaluated for impairment	10,723	10,680
Gross loans	$ 10,747	$ 10,708

Allowance For Loan Losses - Adv

Allowance For Loan Losses - Adversely Classified Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment [Line Items]
Gross loans	$ 1,861,775	$ 1,674,470
Adversely classified loans to total loans	1.33%	1.70%
Increase (decrease) in loans	$ 187,400	$ 148,500
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	936,921	862,747
Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Gross loans	458,553	402,994
Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Gross loans	202,993	168,044
Residential
Financing Receivable, Recorded Investment [Line Items]
Gross loans	169,188	149,959
Home Equity
Financing Receivable, Recorded Investment [Line Items]
Gross loans	83,373	80,018
Consumer
Financing Receivable, Recorded Investment [Line Items]
Gross loans	10,747	10,708
Criticized
Financing Receivable, Recorded Investment [Line Items]
Increase (decrease) in loans	(3,700)
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Gross loans	11	1,239
Doubtful | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	1,188
Doubtful | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	51
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	11	0
Substandard
Financing Receivable, Recorded Investment [Line Items]
Gross loans	24,752	27,111
Substandard | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	12,487	11,409
Substandard | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Gross loans	8,670	11,298
Substandard | Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Gross loans	1,776	2,759
Substandard | Residential
Financing Receivable, Recorded Investment [Line Items]
Gross loans	1,278	1,133
Substandard | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Gross loans	503	464
Substandard | Consumer
Financing Receivable, Recorded Investment [Line Items]
Gross loans	38	48
Loss
Financing Receivable, Recorded Investment [Line Items]
Gross loans	8	76
Loss | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	19
Loss | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Gross loans	3	57
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	5	0
Loss | Consumer
Financing Receivable, Recorded Investment [Line Items]
Gross loans	0	0
Not Adversely Classified
Financing Receivable, Recorded Investment [Line Items]
Gross loans	1,837,004	1,646,044
Not Adversely Classified | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Gross loans	924,434	850,131
Not Adversely Classified | Commercial and industrial
Financing Receivable, Recorded Investment [Line Items]
Gross loans	449,880	391,588
Not Adversely Classified | Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Gross loans	201,217	165,285
Not Adversely Classified | Residential
Financing Receivable, Recorded Investment [Line Items]
Gross loans	167,910	148,826
Not Adversely Classified | Home Equity
Financing Receivable, Recorded Investment [Line Items]
Gross loans	82,865	79,554
Not Adversely Classified | Consumer
Financing Receivable, Recorded Investment [Line Items]
Gross loans	$ 10,698	$ 10,660

Allowance For Loan Losses - Pas

Allowance For Loan Losses - Past Due and Non-Accrual Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Schedule of Aging of Financing Receivables [Line Items]
Number of days a loan must be paid current before accrual of interest is resumed	180 days
Non-accrual loans	$ 13,845	$ 17,136
Total Past Due Loans	19,696	22,949
Current Loans	1,842,079	1,651,521
Gross loans	$ 1,861,775	$ 1,674,470
The ratio of non-accrual loans to total loans	0.74%	1.02%
Additional funding commitments for loans on non-accrual	$ 910
Commercial real estate
Schedule of Aging of Financing Receivables [Line Items]
Non-accrual loans	8,506	$ 9,714
Total Past Due Loans	10,770	12,420
Current Loans	926,151	850,327
Gross loans	936,921	862,747
Commercial and industrial
Schedule of Aging of Financing Receivables [Line Items]
Non-accrual loans	4,323	5,950
Total Past Due Loans	6,232	7,235
Current Loans	452,321	395,759
Gross loans	458,553	402,994
Commercial construction
Schedule of Aging of Financing Receivables [Line Items]
Non-accrual loans	335	447
Total Past Due Loans	916	447
Current Loans	202,077	167,597
Gross loans	202,993	168,044
Residential
Schedule of Aging of Financing Receivables [Line Items]
Non-accrual loans	366	763
Total Past Due Loans	796	2,461
Current Loans	168,392	147,498
Gross loans	169,188	149,959
Home Equity
Schedule of Aging of Financing Receivables [Line Items]
Non-accrual loans	288	245
Total Past Due Loans	910	274
Current Loans	82,463	79,744
Gross loans	83,373	80,018
Consumer
Schedule of Aging of Financing Receivables [Line Items]
Non-accrual loans	27	17
Total Past Due Loans	72	112
Current Loans	10,675	10,596
Gross loans	10,747	10,708
Loans 30-59 Days Past Due
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	3,830	4,106
Loans 30-59 Days Past Due | Commercial real estate
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	1,124	1,471
Loans 30-59 Days Past Due | Commercial and industrial
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	1,218	1,184
Loans 30-59 Days Past Due | Commercial construction
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	581	0
Loans 30-59 Days Past Due | Residential
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	250	1,328
Loans 30-59 Days Past Due | Home Equity
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	622	29
Loans 30-59 Days Past Due | Consumer
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	35	94
Loans 60-89 Days Past Due
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	2,021	1,707
Loans 60-89 Days Past Due | Commercial real estate
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	1,140	1,235
Loans 60-89 Days Past Due | Commercial and industrial
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	691	101
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	180	370
Loans 60-89 Days Past Due | Home Equity
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	0	0
Loans 60-89 Days Past Due | Consumer
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	10	1
Not Adversely Classified
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	1,837,004	1,646,044
Non-accrual loans not adversely classified	402	211
Not Adversely Classified | Commercial real estate
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	924,434	850,131
Not Adversely Classified | Commercial and industrial
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	449,880	391,588
Not Adversely Classified | Commercial construction
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	201,217	165,285
Not Adversely Classified | Residential
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	167,910	148,826
Not Adversely Classified | Home Equity
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	82,865	79,554
Not Adversely Classified | Consumer
Schedule of Aging of Financing Receivables [Line Items]
Gross loans	$ 10,698	$ 10,660

Allowance For Loan Losses - Int

Allowance For Loan Losses - Interest Income Lost on Nonaccrual Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Receivables [Abstract]
Income in accordance with original loan terms	$ 1,052	$ 1,007	$ 1,171
Less income recognized	426	323	680
Reduction in interest income	$ 626	$ 684	$ 491

Allowance For Loan Losses - Imp

Allowance For Loan Losses - Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Financing Receivable, Impaired [Line Items]
Total accruing impaired loans	$ 10,100	$ 12,500
Impaired non-accrual loans	13,600	16,700
Interest income that was not recognized on loans that were deem impaired	688	647	$ 445
Additional funding commitments on impaired loans	749
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	28,652	32,783
Total recorded investment in impaired loans	23,688	29,252
Recorded investment with no allowance	19,100	21,876
Recorded investment with allowance	4,588	7,376
Related allowance	1,792	2,157
Average recorded investment	26,069	29,292	31,227
Interest income recognized	377	489	417
Commercial real estate
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	14,903	17,182
Total recorded investment in impaired loans	12,287	15,003
Recorded investment with no allowance	11,734	14,800
Recorded investment with allowance	553	203
Related allowance	186	68
Average recorded investment	13,827	14,135	17,673
Interest income recognized	196	223	237
Commercial and industrial
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	9,816	11,991
Total recorded investment in impaired loans	7,810	10,901
Recorded investment with no allowance	5,253	5,461
Recorded investment with allowance	2,557	5,440
Related allowance	1,078	1,516
Average recorded investment	9,372	10,682	9,444
Interest income recognized	97	156	92
Commercial construction
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	3,147	2,862
Total recorded investment in impaired loans	3,032	2,675
Recorded investment with no allowance	1,583	1,150
Recorded investment with allowance	1,449	1,525
Related allowance	499	519
Average recorded investment	2,202	3,158	3,227
Interest income recognized	83	105	77
Residential
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	453	537
Total recorded investment in impaired loans	366	465
Recorded investment with no allowance	366	465
Recorded investment with allowance	0	0
Related allowance	0	0
Average recorded investment	449	1,082	745
Interest income recognized	0	3	9
Home Equity
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	308	183
Total recorded investment in impaired loans	169	180
Recorded investment with no allowance	164	0
Recorded investment with allowance	5	180
Related allowance	5	26
Average recorded investment	174	208	120
Interest income recognized	1	0	0
Consumer
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	25	28
Total recorded investment in impaired loans	24	28
Recorded investment with no allowance	0	0
Recorded investment with allowance	24	28
Related allowance	24	28
Average recorded investment	45	27	18
Interest income recognized	$ 0	$ 2	$ 2

Allowance For Loan Losses - Tro

Allowance For Loan Losses - Troubled Debt Restructures (Details)	12 Months Ended
	Dec. 31, 2015USD ($)restructuring	Dec. 31, 2014USD ($)restructuring
Financing Receivable, Modifications [Line Items]
Total Troubled Debt Restructure (TDR) loans	$ 17,100,000	$ 19,500,000
TDR loans on accrual status	10,100,000	11,900,000
TDR loans included in non-performing loans	7,100,000	$ 7,500,000
Additional funding commitment on TDRs	$ 469,000
Number of restructurings | restructuring	15	13
Pre-modification outstanding recorded investment	$ 3,398,000	$ 2,432,000
Post-modification recorded investment	$ 3,313,000	$ 2,422,000
Number of TDR's that defaulted | restructuring	3	2
Post-modification outstanding recorded investment	$ 759,000	$ 185,000
Charge-offs associated with TDRs	0	66,000
Specific reserves allocated to TDRs	201,000	43,000
Interest payments received on nonaccruing loans excluded from income	$ 18,000	$ 9,000
Commercial real estate
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	4	3
Pre-modification outstanding recorded investment	$ 269,000	$ 1,972,000
Post-modification recorded investment	$ 371,000	$ 1,972,000
Number of TDR's that defaulted | restructuring	0	0
Post-modification outstanding recorded investment	$ 0	$ 0
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	8	8
Pre-modification outstanding recorded investment	$ 1,786,000	$ 263,000
Post-modification recorded investment	$ 1,600,000	$ 256,000
Number of TDR's that defaulted | restructuring	3	1
Post-modification outstanding recorded investment	$ 759,000	$ 64,000
Commercial construction
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	2	0
Pre-modification outstanding recorded investment	$ 1,339,000	$ 0
Post-modification recorded investment	$ 1,339,000	$ 0
Number of TDR's that defaulted | restructuring	0	0
Post-modification outstanding recorded investment	$ 0	$ 0
Residential
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	0	1
Pre-modification outstanding recorded investment	$ 0	$ 124,000
Post-modification recorded investment	$ 0	$ 121,000
Number of TDR's that defaulted | restructuring	0	1
Post-modification outstanding recorded investment	$ 0	$ 121,000
Home Equity
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	0	1
Pre-modification outstanding recorded investment	$ 0	$ 73,000
Post-modification recorded investment	$ 0	$ 73,000
Number of TDR's that defaulted | restructuring	0	0
Post-modification outstanding recorded investment	$ 0	$ 0
Consumer
Financing Receivable, Modifications [Line Items]
Number of restructurings | restructuring	1	0
Pre-modification outstanding recorded investment	$ 4,000	$ 0
Post-modification recorded investment	$ 3,000	$ 0
Number of TDR's that defaulted | restructuring	0	0
Post-modification outstanding recorded investment	$ 0	$ 0

Allowance For Loan Losses - Oth

Allowance For Loan Losses - Other Real Estate Owned (Details)	12 Months Ended
	Dec. 31, 2015USD ($)property	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying value of OREO	$ 0	$ 861,000
Net gains on sales of OREO	154,000	0	$ 121,000
OREO fair value adjustment	$ 0	0	$ 23,000
Other real estate owned
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of OREO properties held in prior year that sold | property	3
Number of OREO properties added | property	0
OREO fair value adjustment	$ 0	$ 0

Allowance For Loan Losses - All

Allowance For Loan Losses - Allowance for Loan Losses (Details) - USD ($)	3 Months Ended								12 Months Ended			48 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses to total loans ratio	1.56%				1.62%				1.56%	1.62%		1.56%
Increase (decrease) in loans									$ 187,400,000	$ 148,500,000
Net charge-offs on loans									1,400,000	1,200,000
Gross loans	$ 1,861,775,000				$ 1,674,470,000				1,861,775,000	1,674,470,000		$ 1,861,775,000
Paydowns on loans									188,738,000	150,079,000	$ 165,135,000
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				$ 27,121,000				$ 26,967,000	27,121,000	26,967,000	24,254,000
Provision for loan losses	1,167,000	$ 250,000	$ 1,225,000	625,000	230,000	$ 765,000	$ 200,000	200,000	3,267,000	1,395,000	3,279,000
Recoveries									409,000	735,000	415,000
Less: Charge offs									1,789,000	1,976,000	981,000
Ending Balance	29,008,000				27,121,000				29,008,000	27,121,000	26,967,000	29,008,000
Allotted to loans individually evaluated for impairment	1,792,000				2,157,000				1,792,000	2,157,000		1,792,000
Allotted to loans collectively evaluated for impairment	27,216,000				24,964,000				27,216,000	24,964,000		27,216,000
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Gross loans	936,921,000				862,747,000				936,921,000	862,747,000		936,921,000
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				12,664,000				13,174,000	12,664,000	13,174,000
Provision for loan losses									909,000	(186,000)
Recoveries									74,000	21,000
Less: Charge offs									133,000	345,000
Ending Balance	13,514,000				12,664,000				13,514,000	12,664,000	13,174,000	13,514,000
Allotted to loans individually evaluated for impairment	186,000				68,000				186,000	68,000		186,000
Allotted to loans collectively evaluated for impairment	13,328,000				12,596,000				13,328,000	12,596,000		13,328,000
Commercial and industrial
Financing Receivable, Allowance for Credit Losses [Line Items]
Gross loans	458,553,000				402,994,000				458,553,000	402,994,000		458,553,000
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				9,245,000				8,365,000	9,245,000	8,365,000
Provision for loan losses									1,805,000	1,627,000
Recoveries									279,000	616,000
Less: Charge offs									1,571,000	1,363,000
Ending Balance	9,758,000				9,245,000				9,758,000	9,245,000	8,365,000	9,758,000
Allotted to loans individually evaluated for impairment	1,078,000				1,516,000				1,078,000	1,516,000		1,078,000
Allotted to loans collectively evaluated for impairment	8,680,000				7,729,000				8,680,000	7,729,000		8,680,000
Commercial construction
Financing Receivable, Allowance for Credit Losses [Line Items]
Gross loans	202,993,000				168,044,000				202,993,000	168,044,000		202,993,000
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				3,384,000				3,493,000	3,384,000	3,493,000
Provision for loan losses									496,000	(41,000)
Recoveries									25,000	66,000
Less: Charge offs									0	134,000
Ending Balance	3,905,000				3,384,000				3,905,000	3,384,000	3,493,000	3,905,000
Allotted to loans individually evaluated for impairment	499,000				519,000				499,000	519,000		499,000
Allotted to loans collectively evaluated for impairment	3,406,000				2,865,000				3,406,000	2,865,000		3,406,000
Residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Gross loans	169,188,000				149,959,000				169,188,000	149,959,000		169,188,000
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				989,000				1,057,000	989,000	1,057,000
Provision for loan losses									72,000	(22,000)
Recoveries									0	0
Less: Charge offs									0	46,000
Ending Balance	1,061,000				989,000				1,061,000	989,000	1,057,000	1,061,000
Allotted to loans individually evaluated for impairment	0				0				0	0		0
Allotted to loans collectively evaluated for impairment	1,061,000				989,000				1,061,000	989,000		1,061,000
Home Equity
Financing Receivable, Allowance for Credit Losses [Line Items]
Gross loans	83,373,000				80,018,000				83,373,000	80,018,000		83,373,000
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				608,000				653,000	608,000	653,000
Provision for loan losses									(83,000)	(19,000)
Recoveries									15,000	1,000
Less: Charge offs									0	27,000
Ending Balance	540,000				608,000				540,000	608,000	653,000	540,000
Allotted to loans individually evaluated for impairment	5,000				26,000				5,000	26,000		5,000
Allotted to loans collectively evaluated for impairment	535,000				582,000				535,000	582,000		535,000
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Gross loans	10,747,000				10,708,000				10,747,000	10,708,000		10,747,000
Allowance for Loan and Lease Losses [Roll Forward]
Beginning Balance				$ 231,000				$ 225,000	231,000	225,000
Provision for loan losses									68,000	36,000
Recoveries									16,000	31,000
Less: Charge offs									85,000	61,000
Ending Balance	230,000				231,000				230,000	231,000	$ 225,000	230,000
Allotted to loans individually evaluated for impairment	24,000				28,000				24,000	28,000		24,000
Allotted to loans collectively evaluated for impairment	206,000				$ 203,000				206,000	$ 203,000		206,000
Purchased Loans [Member] | Residential
Financing Receivable, Allowance for Credit Losses [Line Items]
Gross loans	$ 7,400,000								$ 7,400,000			7,400,000
Paydowns on loans												(19,000,000)
Allowance for Loan and Lease Losses [Roll Forward]
Less: Charge offs												$ 0

Premises and Equipment (Details

Premises and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Gross premises and equipment	$ 63,874	$ 59,462
Less accumulated depreciation	(33,321)	(29,092)
Total premises and equipment, net of accumulated depreciation	30,553	30,370
Depreciation expense	4,300	4,200	$ 3,900
Land
Property, Plant and Equipment [Line Items]
Gross premises and equipment	4,614	4,594
Buildings, renovations, and leasehold improvements
Property, Plant and Equipment [Line Items]
Gross premises and equipment	33,597	32,556
Computer software and equipment
Property, Plant and Equipment [Line Items]
Gross premises and equipment	9,014	6,764
Furniture, fixtures and equipment
Property, Plant and Equipment [Line Items]
Gross premises and equipment	$ 16,649	$ 15,548

Premises and Equipment - Operat

Premises and Equipment - Operating Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Abstract]
2,016	$ 1,476
2,017	1,454
2,018	1,133
2,019	695
2,020	606
Thereafter	5,100
Total minimum lease payments	10,464
Operating Leases, Rent Expense	1,200	$ 1,100	$ 910
Rental income	$ 153	$ 153	$ 150

Deposits (Details)

Deposits (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Deposits [Abstract]
Non-interest bearing demand deposits		$ 570,589	$ 470,025
Interest bearing checking		313,674	253,126
Savings		167,304	149,940
Money market		692,114	631,676
Certificates of deposit $250,000 or less		129,993	141,379
Certificates of deposit more than $250,000		37,704	37,215
Total non-brokered deposits	[1]	1,911,378	1,683,361
Brokered deposits	[2]	106,770	85,185
Total deposits		2,018,148	1,768,546
Overdrawn deposits reclassified as loans		$ 407	$ 1,100
[1]	Includes reciprocal money market deposits and CDs received from participating banks in nationwide networks as a result of our customers electing to participate in programs to obtain full FDIC insurance. Essentially, the equivalent of the original deposit comes back to the Company as non-brokered deposits within the appropriate category under total deposits on the balance sheet.
[2]	Primarily brokered CDs $250,000 and under.

Deposits - Maturities (Details)

Deposits - Maturities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Deposits [Abstract]
Weighted average remaining life, brokered deposits	1 year 4 months 24 days
Due in less than twelve months	$ 176,792	$ 166,325
Due in over one year through two years	37,729	30,043
Due in over two years through three years,	23,429	22,776
Due in over three years through four years	26,501	17,618
Due in over four years through five years	5,983	26,140
Due in over five years	4,033	877
Total certificates of deposit	$ 274,467	$ 263,779

Borrowed Funds and Subordinat62

Borrowed Funds and Subordinated Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Disclosure [Abstract]
Federal Home Loan Bank Borrowings	$ 40,671	$ 58,900	$ 36,534
Federal Home Loan Bank Borrowings, Average Rate	0.51%	0.30%	0.30%
Other Borrowings	$ 13,000	$ 0	$ 0
Other Borrowings, Weighted Average interest Rate	0.60%	0.00%	0.00%
Borrowed Funds	$ 53,671	$ 58,900	$ 36,534
Borrowed Funds, Weighted Average Interest Rate	0.53%	0.30%	0.30%
Subordinated debt	$ 14,822	$ 10,825	$ 10,825
Subordinated Debt, Weighted Average Interest Rate	6.16%	10.88%	10.88%
Total borrowed funds and subordinated debt, amount	$ 68,493	$ 69,725	$ 47,359
Total borrowed funds and subordinated debt, Average Rate	1.75%	1.94%	2.72%

Borrowed Funds and Subordinat63

Borrowed Funds and Subordinated Debt - Textual (Details) - USD ($)	1 Months Ended		12 Months Ended
	Jan. 31, 2015	Mar. 31, 2000	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Maximum FHLB and other borrowings outstanding at any month end			$ 53,700,000	$ 58,900,000	$ 57,400,000
Proceeds from capital contribution		$ 325,000
Junior subordinated debt, Amount		$ 10,800,000
Subordinated debt			$ 14,822,000	$ 10,825,000	$ 10,825,000
Junior Subordinated Debt
Debt Instrument [Line Items]
Subordinated debt, rate		10.875%
Fixed-to Floating Rate Subordinated Notes
Debt Instrument [Line Items]
Subordinated debt, rate			6.00%
Subordinated debt	$ 15,000,000
Original debt issuance costs	$ 190,000
Minimum | Federal Home Loan Bank of Boston borrowings
Debt Instrument [Line Items]
Term for FHLB borrowings			1 year
Maximum | Federal Home Loan Bank of Boston borrowings
Debt Instrument [Line Items]
Term for FHLB borrowings			2 years
Line of credit | FHLB
Debt Instrument [Line Items]
Remaining borrowing capacity at FHLB			$ 370,000,000
Line of credit | Federal Reserve Bank of Boston
Debt Instrument [Line Items]
Remaining borrowing capacity at FRB			$ 100,000,000
Enterprise (MA) Capital Trust I
Debt Instrument [Line Items]
Trust preferred securities, value		$ 10,500,000
Trust preferred securities, stated interest rate		10.875%
London Interbank Offered Rate (LIBOR) [Member] | Fixed-to Floating Rate Subordinated Notes
Debt Instrument [Line Items]
Fixed to Floating Rate Conversion Date			Jan. 31, 2025
Spread over LIBOR fixed to floating rate note, rate			3.90%

Borrowed Funds and Subordinat64

Borrowed Funds and Subordinated Debt - Maturities (Details) $ in Thousands	Dec. 31, 2015USD ($)
Short-Term maturities [Abstract]
FHLB overnight borrowings	$ 40,000
FHLB overnight borrowings, weighted average rate	0.51%
Other overnight borrowings	$ 13,000
Other overnight borrowings, weighted average rate	0.60%
Overnight borrowed funds	$ 53,000
Overnight borrowed funds, weighted average rate	0.53%
FHLB borrowings, due within twelve months	$ 671
FHLB borrowings, due within twelve months, weighted average rate	0.70%
Other Borrowings, due within twelve months	$ 0
Other borrowings,due within twelve months, weighted average rate	0.00%
Borrowed funds, due within one year	$ 671
Borrowed funds, due within one year, weighted average rate	0.70%

Borrowed Funds and Subordinat65

Borrowed Funds and Subordinated Debt - Average Balances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Debt Disclosure [Abstract]
FHLB advances, Average Balance	$ 10,731	$ 12,085	$ 24,385
FHLB advances, Average Rate	0.36%	0.31%	0.39%
Other borrowings, Average Balance	$ 36	$ 28	$ 14
Other borrowings, Average Rate	0.61%	0.56%	0.46%
Total borrowed funds, Average Balance	$ 10,767	$ 12,113	$ 24,399
Total borrowed funds, Average Rate	0.36%	0.31%	0.39%

Commitments, Contingencies an66

Commitments, Contingencies and Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)payment	Dec. 31, 2014USD ($)
Other Commitments [Line Items]
Commitments to Originate Loans	$ 48,641	$ 33,870
Commitments to Sell Residential Mortgage Loans	3,225	3,842
Standby Letters of Credit	22,712	19,359
Federal Reserve Bank average daily reserve requirement included in Cash and Due from Banks	7,400	14,300
Residential
Other Commitments [Line Items]
Commitments to Originate Loans for Sale	$ 1,516	1,471
Early payment default period | payment	4
Commercial real estate
Other Commitments [Line Items]
Financial instruments with off-balance sheet credit risk	$ 13,128	27,335
Commercial and industrial
Other Commitments [Line Items]
Financial instruments with off-balance sheet credit risk	337,970	306,745
Commercial and residential construction
Other Commitments [Line Items]
Financial instruments with off-balance sheet credit risk	138,162	143,016
Home Equity
Other Commitments [Line Items]
Financial instruments with off-balance sheet credit risk	73,397	64,337
Consumer
Other Commitments [Line Items]
Financial instruments with off-balance sheet credit risk	$ 2,999	$ 3,017

Commitments, Contingencies an67

Commitments, Contingencies and Financial Instruments with Off-Balance Sheet Risk and Concentrations of Credit Risk Derivatives and Hedging Activities (Details) - Interest Rate Swap	12 Months Ended
	Dec. 31, 2015USD ($)instrument	Dec. 31, 2014instrument
Derivative [Line Items]
Number of Interest Rate Swaps | instrument	2	0
Aggregate notional value of interest-rate swaps	$ 10,100,000
Fair Value of Interest-Rate Swap Asset	16,000
Fair Value of Interest-Rate Swap Liability	16,000
Gain (Loss) on Interest Rate Swaps	0
Gross Amount Interest Rate Swap Asset Recognized	16,000
Net Asset Amount, Interest Rate Swap	16,000
Gross Amount Interest Rate Swap Liability Recognized	16,000
Net Liability Amount, Interest Rate Swap	$ 16,000

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jul. 18, 2013
Class of Stock [Line Items]
Common stock, shares authorized	20,000,000	20,000,000
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, par value	$ 0.01	$ 0.01
Maximum amount available to be raised under 2013 shelf registration				$ 40,000,000
Dividends, Common Stock	$ 5,158,000	$ 4,853,000	$ 4,535,000
Common stock issued under dividend reinvestment plan	1,277,000	1,219,000	1,239,000
Common stock issued under direct stock purchase plan, value	150,000	64,000
Retained Earnings
Class of Stock [Line Items]
Dividends, Common Stock	$ 5,158,000	$ 4,853,000	$ 4,535,000
Common Stock
Class of Stock [Line Items]
Common stock issued under dividend reinvestment plan, shares	58,529	60,586	69,633
Common stock issued under dividend reinvestment plan	$ 1,000	$ 1,000	$ 1,000
Common stock issued under direct stock purchase plan, shares	6,700	2,917
Common Stock
Class of Stock [Line Items]
Votes Per Share, Number	1
Series A Junior Participating Preferred Stock
Class of Stock [Line Items]
Amount of a share allowed to be purchased under right to purchase	0.01
Price per one one-hundredth of a share	$ 52
Minimum acquisition percentage to trigger the exercise of the right to purchase	10.00%

Stockholders' Equity - Regulato

Stockholders' Equity - Regulatory Capital Requirements (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital, Actual, Amount		$ 212,871	$ 189,733
Total Capital (to risk weighted assets), Actual, Ratio		10.70%	11.27%
Total Capital, Minimum Capital for Capital Adequacy Purposes, Amount		$ 159,198	$ 134,732
Total Capital (to risk weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio		8.00%	8.00%
Total Capital, Minimum Capital To Be Well Capitalized, Amount		$ 198,997	$ 168,415
Total Capital (to risk weighted assets), Minimum Capital To Be Well Capitalized, Ratio		10.00%	10.00%
Tier 1 Risk Based Capital, Actual, Amount		$ 172,397	$ 167,299
Tier 1 Risk Based Capital (to risk weighted assets), Actual, Ratio		8.66%	9.93%
Tier 1 Risk Based Capital, Minimum Capital for Capital Adequacy Purposes, Amount		$ 119,398	$ 67,366
Tier 1 Risk Based Capital (to risk weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio		6.00%	4.00%
Tier 1 Risk Based Capital, Minimum Capital To Be Well Capitalized, Amount		$ 159,198	$ 101,049
Tier 1 Risk Based Capital (to risk weighted assets), Minimum Capital To Be Well Capitalized, Ratio		8.00%	6.00%
Tier 1 Leverage Capital, Actual, Amount		$ 172,397	$ 167,299
Tier 1 Leverage Capital (to average assets), Actual, Ratio		7.73%	8.41%
Tier 1 Leverage Capital, Minimum Capital for Capital Adequacy Purposes, Amount		$ 89,173	$ 79,578
Tier 1 Leverage Capital (to average assets), Minimum Capital for Capital Adequacy Purposes, Ratio		4.00%	4.00%
Common Equity Tier 1 Risk Based Capital, Actual, Amount		$ 172,397
Common Equity Tier 1 Risk Based Capital (to risk weighted assets), Actual, Ratio		8.66%
Common Equity Tier 1 Risk Based Capital, Minimum Capital for Capital Adequacy Purposes, Amount		$ 89,549
Common Equity Tier 1 Risk Based Capital (to risk weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio		4.50%
Common Equity Tier 1 Risk Based Capital, Minimum Capital To Be Well Capitalized, Amount		$ 129,348
Common Equity Tier 1 Risk Based Capital (to risk weighted assets), Minimum Capital To Be Well Capitalized, Ratio		6.50%
The Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital, Actual, Amount		$ 209,670	$ 188,446
Total Capital (to risk weighted assets), Actual, Ratio		10.54%	11.19%
Total Capital, Minimum Capital for Capital Adequacy Purposes, Amount		$ 159,189	$ 134,726
Total Capital (to risk weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio		8.00%	8.00%
Total Capital, Minimum Capital To Be Well Capitalized, Amount		$ 198,987	$ 168,407
Total Capital (to risk weighted assets), Minimum Capital To Be Well Capitalized, Ratio		10.00%	10.00%
Tier 1 Risk Based Capital, Actual, Amount		$ 184,019	$ 166,013
Tier 1 Risk Based Capital (to risk weighted assets), Actual, Ratio		9.25%	9.86%
Tier 1 Risk Based Capital, Minimum Capital for Capital Adequacy Purposes, Amount		$ 119,392	$ 67,363
Tier 1 Risk Based Capital (to risk weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio		6.00%	4.00%
Tier 1 Risk Based Capital, Minimum Capital To Be Well Capitalized, Amount		$ 159,189	$ 101,044
Tier 1 Risk Based Capital (to risk weighted assets), Minimum Capital To Be Well Capitalized, Ratio		8.00%	6.00%
Tier 1 Leverage Capital, Actual, Amount		$ 184,019	$ 166,013
Tier 1 Leverage Capital (to average assets), Actual, Ratio		8.25%	8.35%
Tier 1 Leverage Capital, Minimum Capital for Capital Adequacy Purposes, Amount		$ 89,172	$ 79,544
Tier 1 Leverage Capital (to average assets), Minimum Capital for Capital Adequacy Purposes, Ratio		4.00%	4.00%
Tier 1 Leverage Capital, Minimum Capital To Be Well Capitalized, Amount		$ 111,465	$ 99,430
Tier 1 Leverage Capital (to average assets), Minimum Capital To Be Well Capitalized, Ratio	[1]	5.00%	5.00%
Common Equity Tier 1 Risk Based Capital, Actual, Amount		$ 184,019
Common Equity Tier 1 Risk Based Capital (to risk weighted assets), Actual, Ratio		9.25%
Common Equity Tier 1 Risk Based Capital, Minimum Capital for Capital Adequacy Purposes, Amount		$ 89,544
Common Equity Tier 1 Risk Based Capital (to risk weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio		4.50%
Common Equity Tier 1 Risk Based Capital, Minimum Capital To Be Well Capitalized, Amount		$ 129,341
Common Equity Tier 1 Risk Based Capital (to risk weighted assets), Minimum Capital To Be Well Capitalized, Ratio		6.50%
[1]	For the Bank to qualify as “well capitalized," it must maintain a leverage capital ratio (Tier 1 capital to average assets) of at least 5%. This requirement does not apply to the Company.

Stockholders' Equity - Basel II

Stockholders' Equity - Basel III Minimum Capital Adequacy Requirements after Full Phase In (Details)	Dec. 31, 2019	Jan. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital (to risk weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio			8.00%	8.00%
Tier 1 Risk Based Capital (to risk weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio			6.00%	4.00%
Tier 1 Leverage Capital (to average assets), Minimum Capital for Capital Adequacy Purposes, Ratio			4.00%	4.00%
Common Equity Tier 1 Risk Based Capital (to risk weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio			4.50%
Basel III Minimum Requirements Forecast [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital Conservation Buffer Percent, 2016		0.625%
Total Capital (to risk weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio	10.50%
Tier 1 Risk Based Capital (to risk weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio	8.50%
Tier 1 Leverage Capital (to average assets), Minimum Capital for Capital Adequacy Purposes, Ratio	4.00%
Common Equity Tier 1 Risk Based Capital (to risk weighted assets), Minimum Capital for Capital Adequacy Purposes, Ratio	7.00%
Basel III Additional Capital Conservation Buffer (percent)	2.50%

Employee Benefit Plans - Define

Employee Benefit Plans - Defined Contribution Plan and Profit Sharing (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)yrh	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Compensation and Retirement Disclosure [Abstract]
Company's percent match on 401(K) defined contribution plan	60.00%
Maximum percentage of employee contribution matched by the Company	6.00%
Minimum age to be eligible for 401(k) plan | yr	18
Number of minimum hours required to work for 401(k) plan eligibility | h	1
Employer's matching contribution, annual vesting percentage for 401(k) plan	20.00%
Number of years to be fully vested for 401(k) plan	5 years
Expense for profit sharing contributions to the 401(k) plan			$ 458
Expense for the 401(k) plan match (excluding profit sharing component)	$ 859	$ 792	$ 692

Employee Benefit Plans - Supple

Employee Benefit Plans - Supplemental Retirement Plan (SERP) (Details) - Supplemental Retirement Plan $ in Thousands		12 Months Ended
		Dec. 31, 2015USD ($)officer	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
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
Accrual for benefit obligation for following year		$ 124
Benefit obligation at beginning of year		2,844	$ 2,889	$ 3,181
Interest cost		133	128	157
Actuarial loss(gain)		(47)	103	(173)
Net periodic benefit cost(benefit)		86	231	(16)
Benefits paid		(276)	(276)	(276)
Benefit obligation at end of year		2,654	2,844	2,889
Accrued liability at end of year		$ (2,654)	$ (2,844)	$ (2,889)
Discount rate used for benefit obligation	[1]	4.75%	4.50%	5.00%
[1]	Management utilizes the Moody’s 20 year AA corporate bond rates to establish the reasonableness of the discount rate used. The Company reviews and periodically updates the discount rate to reflect changes in bond market rates. The impact of the discount rate change is reflected as the actuarial gain or loss.

Employee Benefit Plans - Expect

Employee Benefit Plans - Expected Future Benefit Payments for SERP (Details) $ in Thousands	Dec. 31, 2015USD ($)
Compensation and Retirement Disclosure [Abstract]
2,016	$ 276
2,017	276
2,018	276
2,019	276
2,020	276
2021-2025	$ 1,379

Employee Benefit Plans - Supp74

Employee Benefit Plans - Supplemental Life Insurance (Details) - Supplemental Life Insurance Benefit - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Postretirement Benefit Plan Disclosures [Line Items]
Benefit obligation at beginning of year		$ 1,723	$ 1,576	$ 1,664
Service cost		(56)	(38)	2
Interest cost		86	74	74
Actuarial loss(gain)		39	111	(164)
Net periodic benefit cost(benefit)		69	147	(88)
Benefit obligation at end of year		1,792	1,723	1,576
Accrued liability at end of year		$ (1,792)	$ (1,723)	$ (1,576)
Discount rate used for benefit obligation	[1]	4.75%	4.50%	5.00%
Accrual for benefit obligation for following year		$ 76
[1]	Management utilizes the Moody’s 20 year AA corporate bond rates to establish the reasonableness of the discount rate used. The Company reviews and periodically updates the discount rate to reflect changes in bond market rates. The impact of the discount rate change is reflected as the actuarial gain or loss.

Stock-Based Compensation Plan75

Stock-Based Compensation Plans - Stock Options, Stock Awards, and Stock in Lieu of Directors' Fees (Details) $ / shares in Units, $ in Thousands	1 Months Ended			12 Months Ended
	Jan. 31, 2016shares	Jan. 31, 2015shares	Jan. 31, 2014shares	Dec. 31, 2015USD ($)plans$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2013USD ($)$ / sharesshares	Jan. 02, 2015$ / shares	Jan. 02, 2014$ / shares	Jan. 02, 2013$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of individual stock incentive plans | plans				2
Shares remain available for future grants under the 2009 plan | shares				210,683
Stock-based compensation expense				$ 1,803	$ 1,752	$ 1,662
Tax benefit recognized related to stock-based compensation expense				720	700	660
Tax benefit from stock compensation				$ 217	320	25
Price as a percentage of fair market value that stock options may not be granted below				100.00%
Percentage of ownership of common stock by participants that if greater causes greater grant price				10.00%
Price as a percentage of fair market value that stock options may not be granted below for anyone who owns more than 10% common stock				110.00%
Expiration period of options granted for those who own more than 10% common stock				5 years
Proceeds from exercise of stock options, net				$ 431	889	1,829
Total intrinsic value of options exercised				396	867	1,100
Directors fee expense				424	444	356
Number of shares issued in lieu of cash to directors | shares		11,612	11,136
Fair market share price | $ / shares							$ 23.86	$ 20.84	$ 17.43
Additional Paid-in Capital
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax benefit from stock compensation				217	320	25
Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued in lieu of cash to directors | shares	10,657
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax benefit recognized related to stock-based compensation expense				102	97	77
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense				318	363	422
Tax benefit recognized related to stock-based compensation expense				$ 127	$ 145	$ 165
Term in years				10 years	10 years	10 years
Unrecognized stock-based compensation expense, net of estimated forfeitures				$ 451
Remaining vesting period unrecognized compensation expense is to be recognized				1 year 10 months 24 days
Stock options | Options Granted 2012 and Earlier
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				4 years
Restricted Stock and Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense				$ 1,200	$ 1,100	$ 1,000
Tax benefit recognized related to stock-based compensation expense				491	$ 458	$ 418
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense, net of estimated forfeitures				$ 1,700
Remaining vesting period unrecognized compensation expense is to be recognized				1 year 7 months 6 days
Stock awards in the period | shares				55,313	58,844	80,541
Granted, Weighted Average Grant Price Per Share | $ / shares				$ 21.03	$ 20.29	$ 16.43
Restricted Stock | Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				4 years
Restricted Stock | Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				2 years
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards in the period | shares						0
Common Stock | Employee
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards in the period | shares				105	2,142
Granted, Weighted Average Grant Price Per Share | $ / shares				$ 23.64	$ 20.95
Common stock in lieu of cash | Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense				$ 254	$ 242	$ 194
Vesting, Year Two | Stock options | Options Granted after 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted, vesting percentage				50.00%
Vesting, Year Four | Stock options | Options Granted after 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted, vesting percentage				50.00%

Stock-Based Compensation Plan76

Stock-Based Compensation Plans - Summary of Options Granted (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted	27,376	31,229	47,684
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term in years	10 years	10 years	10 years
Expected volatility	47.00%	47.00%	48.00%
Market price on date of grant	$ 21.03	$ 20.29	$ 16.61
Per share weighted average fair value	$ 8.51	$ 8.32	$ 6.66
Weighted Average | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	2.90%	2.88%	2.96%
Expected life in years	7 years	7 years	7 years
Risk-free interest rate	1.95%	2.19%	1.35%
Fair Value as a percentage of market value at grant date	40.00%	41.00%	40.00%

Stock-Based Compensation Plan77

Stock-Based Compensation Plans - Stock Options Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Outstanding Options, beginning balance	319,884
Granted, Options	27,376	31,229	47,684
Exercised, Options	43,923
Forfeited/Expired, Options	2,368
Outstanding Options, ending balance	300,969	319,884
Outstanding Options, Weighted Average Exercise Price, beginning balance	$ 14.92
Granted, Weighted Average Exercise Price	21.03
Exercised, Weighted Average Exercise Price	12.47
Forfeited/Expired, Weighted Average Exercise Price	17.56
Outstanding Options, Weighted Average Exercise Price, ending balance	$ 15.82	$ 14.92
Outstanding Options, Weighted Average Remaining Life	4 years 2 months 12 days	4 years 1 month 6 days
Options Outstanding, Aggregate Intrinsic Value, beginning balance	$ 3,303
Options Outstanding, Aggregate Intrinsic Value, ending balance	$ 2,116	$ 3,303
Vested and Exercisable, ending balance, Options	204,344
Vested and Exercisable, ending balance, Weighted Average Exercise Price	$ 14.35
Vested and Exercisable, ending balance, Weighted Average Remaining Life	2 years 7 months 6 days
Vested and Exercisable, ending balance, Aggregate Intrinsic Value	$ 1,738

Stock-Based Compensation Plan78

Stock-Based Compensation Plans - Restricted Stock Grants (Details) - Restricted Stock - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards in the period	55,313	58,844	80,541
Granted, Weighted Average Grant Price Per Share	$ 21.03	$ 20.29	$ 16.43
Director | Two year vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards in the period	7,276	6,660	6,146
Employee | Four year vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards in the period	17,775	19,167	26,660
Employee | Performance-based vesting
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards in the period	30,262	33,017	47,735

Stock-Based Compensation Plan79

Stock-Based Compensation Plans - Restricted Stock Award Activity and Weighted Average Price (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested, beginning balance, Restricted Stock	157,694
Unvested, ending balance, Restricted Stock	144,717	157,694
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested, beginning balance, Restricted Stock	157,694
Granted, Restricted Stock	55,313	58,844	80,541
Vested/released, Restricted Stock	66,588
Forfeited, Restricted Stock	1,702
Unvested, ending balance, Restricted Stock	144,717	157,694
Unvested, beginning balance, Weighted Average Grant Price Per Share	$ 17.71
Granted, Weighted Average Grant Price Per Share	21.03	$ 20.29	$ 16.43
Vested/released, Weighted Average Grant Price Per Share	17.17
Forfeited, Weighted Average Grant Price Per Share	18.58
Unvested, ending balance, Weighted Average Grant Price Per Share	$ 19.22	$ 17.71
Unvested, Weighted Average Remaining Life In Years	1 year	2 years 2 months 12 days
Unvested, Aggregate Intrinsic Value	$ 3,304,000	$ 3,982,000

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current tax expense:
Federal									$ 6,808	$ 5,814	$ 5,492
State									1,712	1,681	1,642
Total current tax expense									8,520	7,495	7,134
Deferred tax expense (benefit):
Federal									(284)	85	(100)
State									(122)	5	(83)
Total deferred tax expense/ (benefit)									(406)	90	(183)
Total income tax expense	$ 2,181	$ 2,054	$ 1,855	$ 2,024	$ 2,045	$ 1,921	$ 1,757	$ 1,862	$ 8,114	$ 7,585	$ 6,951

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Rate (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate									35.00%	34.00%	34.00%
Computed income tax expense at statutory rate									$ 8,492	$ 7,560	$ 6,963
State income taxes, net of federal tax benefit									1,034	1,113	1,029
Tax exempt income, net of disallowance									(1,226)	(1,060)	(988)
Bank Owned Life Insurance, net									(251)	(140)	(156)
Other									65	112	103
Total income tax expense	$ 2,181	$ 2,054	$ 1,855	$ 2,024	$ 2,045	$ 1,921	$ 1,757	$ 1,862	$ 8,114	$ 7,585	$ 6,951
Effective income tax rate									33.40%	34.10%	33.90%

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Asset and Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Components of Deferred Tax Assets [Abstract]
Allowance for loan losses	$ 11,800	$ 11,026
Depreciation	3,103	3,033
Other-than-temporary impairment on equity securities	22	168
Supplemental employee retirement plans	1,080	1,156
Non-accrual interest	1,393	1,440
Stock-based compensation expense	873	751
Other	163	97
Total	18,434	17,671
Components of Deferred Tax Liabilities [Abstract]
Goodwill	2,300	2,140
Net unrealized gains on investments securities	1,204	2,057
Deferred origination costs	812	622
Other	7	0
Total	4,323	4,819
Net deferred tax asset	14,111	12,852
Total income taxes paid, net	7,594	7,466	$ 7,342
Federal Low Income Housing Tax Credit
Components of Deferred Tax Liabilities [Abstract]
Tax credit carryforward recognized during period	71	$ 71	$ 71
Anticipated additional tax credits	$ 460
Number of years tax credit to be recognized over	7 years

Earnings per share (Details)

Earnings per share (Details) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Basic weighted average common shares outstanding	10,323,016	10,118,762	9,862,678
Dilutive shares	66,918	90,481	87,931
Diluted weighted average common shares outstanding	10,389,934	10,209,243	9,950,609

Fair Value Measurements - Recur

Fair Value Measurements - Recurring and Nonrecurring Basis (Details)	12 Months Ended
	Dec. 31, 2015USD ($)property	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Specific allowance for collateral dependent impaired loans	$ 1,400,000	$ 1,700,000
Carrying value of OREO	0	861,000
Net gains on sales of OREO	154,000	0	$ 121,000
OREO fair value adjustment	$ 0	0	$ 23,000
Financial Standby Letter of Credit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortization period of estimated fair value on standby letters of credit	1 year
Other real estate owned
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of OREO properties added | property	0
Number of OREO properties held in prior year that sold | property	3
OREO fair value adjustment	$ 0	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial liabilities	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1 | Fixed income 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	11,657,000	14,275,000
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 Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial liabilities	16,000
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2 | Fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	288,701,000	230,790,000
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 Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	16,000
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial liabilities	0
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Fixed income 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	3,050,000	3,357,000
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3 | Interest Rate Swap
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 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans (collateral dependent), Fair Value	0	0
Other real estate owned, Fair Value		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
Other real estate owned, Fair Value		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	2,516,000	5,174,000
Other real estate owned, Fair Value		861,000
Fair Value | Fair Value, Measurements, Recurring | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial liabilities	16,000
Fair Value | Fair Value, Measurements, Recurring | Fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	288,701,000	230,790,000
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	11,657,000	14,275,000
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	3,050,000	3,357,000
Fair Value | Fair Value, Measurements, Recurring | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets	16,000
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	$ 2,516,000	5,174,000
Other real estate owned, Fair Value		$ 861,000

Fair Value Measurements - Quant

Fair Value Measurements - Quantitative (Details) - Fair Value, Inputs, Level 3 - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Fair Value, Measurements, Recurring | FHLB Stock
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value of assets		$ 3,050	$ 3,357
Fair Value, Measurements, Recurring | FHLB Stock | FHLB Stated Par Value
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value of assets		3,050
Fair Value, Measurements, Nonrecurring
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans (collateral dependent), Fair Value		2,516	$ 5,174
Fair Value, Measurements, Nonrecurring | Impaired loans (collateral dependent) | Appraisal of collateral
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Impaired loans (collateral dependent), Fair Value	[1]	$ 2,516
Fair Value, Measurements, Nonrecurring | Impaired loans (collateral dependent) | Appraisal of collateral | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Unobservable Input Value or Range		5.00%
Fair Value, Measurements, Nonrecurring | Impaired loans (collateral dependent) | Appraisal of collateral | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Unobservable Input Value or Range		50.00%
[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	Dec. 31, 2015	Dec. 31, 2014
Carrying Amount
Financial assets:
Loans held for sale	$ 1,709	$ 2,371
Loans, net	1,830,954	1,645,483
Financial liabilities:
Borrowed funds	53,671	58,900
Subordinated debt	14,822	10,825
Carrying Amount | Certificates of Deposit
Financial liabilities:
Certificates of deposit	274,467	263,779
Fair Value
Financial assets:
Loans held for sale	1,709	2,381
Loans, net	1,845,009	1,668,863
Financial liabilities:
Borrowed funds	53,670	58,899
Subordinated debt	13,961	13,017
Fair Value | Certificates of Deposit
Financial liabilities:
Certificates of deposit	273,419	262,774
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	1,709	2,381
Loans, net	0	0
Financial liabilities:
Borrowed funds	53,670	58,899
Subordinated debt	0	0
Fair Value, Inputs, Level 2 | Certificates of Deposit
Financial liabilities:
Certificates of deposit	273,419	262,774
Fair Value, Inputs, Level 3
Financial assets:
Loans held for sale	0	0
Loans, net	1,845,009	1,668,863
Financial liabilities:
Borrowed funds	0	0
Subordinated debt	13,961	13,017
Fair Value, Inputs, Level 3 | Certificates of Deposit
Financial liabilities:
Certificates of deposit	$ 0	$ 0

Parent Company Only Financial87

Parent Company Only Financial Statements - Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets
Cash	$ 51,495	$ 40,146	$ 53,733	$ 52,735
Total assets	2,285,531	2,022,228
Liabilities
Subordinated debt	14,822	10,825	10,825
Accrued interest payable	276	566
Other liabilities	18,287	16,441
Total liabilities	2,105,204	1,855,278
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; 20,000,000 shares authorized; 10,377,787 shares issued and outstanding at December 31, 2015 (including 144,717 shares of unvested participating restricted awards) and 10,207,943 shares issued and outstanding at December 31, 2014 (including 157,694 shares of unvested participating restricted awards)	104	102
Additional paid-in capital	61,008	57,130
Retained earnings	116,941	105,951
Accumulated other comprehensive income	2,274	3,767
Total stockholders’ equity	180,327	166,950	151,334	139,549
Total liabilities and stockholders’ equity	2,285,531	2,022,228
Parent
Assets
Cash	2,737	699	$ 729	$ 542
Investment in subsidiaries	191,949	176,946
Other assets	546	510
Total assets	195,232	178,155
Liabilities
Subordinated debt	14,822	10,825
Accrued interest payable	78	370
Other liabilities	5	10
Total liabilities	14,905	11,205
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; 20,000,000 shares authorized; 10,377,787 shares issued and outstanding at December 31, 2015 (including 144,717 shares of unvested participating restricted awards) and 10,207,943 shares issued and outstanding at December 31, 2014 (including 157,694 shares of unvested participating restricted awards)	104	102
Additional paid-in capital	61,008	57,130
Retained earnings	116,941	105,951
Accumulated other comprehensive income	2,274	3,767
Total stockholders’ equity	180,327	166,950
Total liabilities and stockholders’ equity	$ 195,232	$ 178,155

Parent Company Only Financial88

Parent Company Only Financial Statements - Balance Sheet (Additional) (Details) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	10,377,787	10,207,943
Common stock, shares outstanding	10,377,787	10,207,943
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Unvested participating restricted stock awards	144,717	157,694
Parent
Condensed Financial Statements, Captions [Line Items]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	20,000,000	20,000,000
Common stock, shares issued	10,377,787	10,207,943
Common stock, shares outstanding	10,377,787	10,207,943
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued	0	0
Unvested participating restricted stock awards	144,717	157,694

Parent Company Only Financial89

Parent Company Only Financial Statements - Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
Other income									$ 2,465	$ 2,340	$ 2,229
Interest expense	$ 1,275	$ 1,264	$ 1,253	$ 1,385	$ 1,296	$ 1,302	$ 1,328	$ 1,317	5,177	5,243	5,331
Income before income taxes	6,902	6,346	5,370	5,644	6,045	5,752	5,071	5,368	24,262	22,236	20,480
Provision for (benefit from) income tax	2,181	2,054	1,855	2,024	2,045	1,921	1,757	1,862	8,114	7,585	6,951
Net income	$ 4,721	$ 4,292	$ 3,515	$ 3,620	$ 4,000	$ 3,831	$ 3,314	$ 3,506	16,148	14,651	13,529
Parent
Condensed Financial Statements, Captions [Line Items]
Equity in undistributed net income of subsidiaries									17,277	13,744	13,571
Dividend distributed by subsidiaries									0	1,850	950
Loss distributed by divested subsidiary									(210)	0	0
Other income									17	0	0
Total income									17,084	15,594	14,521
Interest expense									1,071	1,177	1,177
Other operating expenses									500	194	225
Total operating expenses									1,571	1,371	1,402
Income before income taxes									15,513	14,223	13,119
Provision for (benefit from) income tax									(635)	(428)	(410)
Net income									$ 16,148	$ 14,651	$ 13,529

Parent Company Only Financial90

Parent Company Only Financial Statements - Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net income	$ 4,721	$ 4,292	$ 3,515	$ 3,620	$ 4,000	$ 3,831	$ 3,314	$ 3,506	$ 16,148	$ 14,651	$ 13,529
Changes in:
Subordinated debt issuance costs									(178)	0	0
Accrued interest payable									(290)	1	(38)
Net cash provided by operating activities									25,723	13,140	35,784
Cash flows from investing activities:
Net cash used in (provided by) investing activities									(259,860)	(179,286)	(204,303)
Cash flows from financing activities:
Repayment of subordinated debt									(10,825)	0	0
Proceeds from the issuance of subordinated debt									15,000	0	0
Cash dividends paid									(5,158)	(4,853)	(4,535)
Proceeds from issuance of common stock									1,448	1,283	1,239
Proceeds from exercise of stock options, net									431	889	1,829
Tax benefit from stock-based compensation									217	320	25
Net cash provided by (used in) financing activities									245,486	152,559	169,517
Net (decrease) increase in cash and cash equivalents									11,349	(13,587)	998
Cash and cash equivalents, beginning of year				40,146				53,733	40,146	53,733	52,735
Cash and cash equivalents, end of year	51,495				40,146				51,495	40,146	53,733
Parent
Cash flows from operating activities:
Net income									16,148	14,651	13,529
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in undistributed net income of subsidiaries									(17,277)	(13,744)	(13,571)
Payment from subsidiary bank for stock compensation expense									1,791	1,704	1,652
Changes in:
Other assets									(36)	(277)	9
Other liabilities									(12)	(3)	10
Subordinated debt issuance costs									(178)	0	0
Accrued interest payable									(292)	0	0
Net cash provided by operating activities									144	2,331	1,629
Cash flows from investing activities:
Investment in subsidiary									781	0	0
Net cash used in (provided by) investing activities									781	0	0
Cash flows from financing activities:
Repayment of subordinated debt									(10,825)	0	0
Proceeds from the issuance of subordinated debt									15,000	0	0
Cash dividends paid									(5,158)	(4,853)	(4,535)
Proceeds from issuance of common stock									1,448	1,283	1,239
Proceeds from exercise of stock options, net									431	889	1,829
Tax benefit from stock-based compensation									217	320	25
Net cash provided by (used in) financing activities									1,113	(2,361)	(1,442)
Net (decrease) increase in cash and cash equivalents									2,038	(30)	187
Cash and cash equivalents, beginning of year				$ 699				$ 729	699	729	542
Cash and cash equivalents, end of year	$ 2,737				$ 699				$ 2,737	$ 699	$ 729

Quarterly Results of Operatio91

Quarterly Results of Operations (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Interest and dividend income	$ 21,971	$ 21,224	$ 20,437	$ 19,839	$ 20,068	$ 19,394	$ 18,780	$ 18,231	$ 83,471	$ 76,473	$ 71,122
Interest expense	1,275	1,264	1,253	1,385	1,296	1,302	1,328	1,317	5,177	5,243	5,331
Net interest income	20,696	19,960	19,184	18,454	18,772	18,092	17,452	16,914	78,294	71,230	65,791
Provision for loan losses	1,167	250	1,225	625	230	765	200	200	3,267	1,395	3,279
Net interest income after provision for loan losses	19,529	19,710	17,959	17,829	18,542	17,327	17,252	16,714	75,027	69,835	62,512
Non-interest income	3,615	3,177	3,222	3,125	3,360	3,325	3,137	2,991
Net gains on sales of investment securities	465	7	456	900	789	215	127	488	1,828	1,619	1,239
Non-interest expense	16,707	16,548	16,267	16,210	16,646	15,115	15,445	14,825	65,732	62,031	55,824
Income before income taxes	6,902	6,346	5,370	5,644	6,045	5,752	5,071	5,368	24,262	22,236	20,480
Provision for income taxes	2,181	2,054	1,855	2,024	2,045	1,921	1,757	1,862	8,114	7,585	6,951
Net income	$ 4,721	$ 4,292	$ 3,515	$ 3,620	$ 4,000	$ 3,831	$ 3,314	$ 3,506	$ 16,148	$ 14,651	$ 13,529
Basic earnings per share	$ 0.46	$ 0.41	$ 0.34	$ 0.35	$ 0.39	$ 0.38	$ 0.33	$ 0.35	$ 1.56	$ 1.45	$ 1.37
Diluted earnings per share	$ 0.45	$ 0.41	$ 0.34	$ 0.35	$ 0.39	$ 0.37	$ 0.32	$ 0.35	$ 1.55	$ 1.44	$ 1.36