The First Bancorp, Inc. (FNLC) 10-Q 9 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 01, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	First Bancorp, Inc /ME/
Entity Central Index Key	765,207
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		10,849,447
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Assets
Cash and cash equivalents	$ 16,559	$ 19,207	$ 17,600
Interest bearing deposits in other banks	280	860	3,272
Securities available for sale	303,769	300,172	312,624
Securities to be held to maturity (fair value of $255,851,000 at March 31, 2018, $259,655,000 at December 31, 2017 and $239,378,000 at March 31, 2017)	258,690	256,567	240,829
Restricted equity securities, at cost	11,947	10,358	13,363
Loans held for sale	284	386	979
Loans	1,188,002	1,164,139	1,089,735
Less allowance for loan losses	10,957	10,729	10,367
Net loans	1,177,045	1,153,410	1,079,368
Accrued interest receivable	7,222	5,867	6,854
Premises and equipment, net	22,043	22,502	21,760
Other real estate owned	1,121	1,012	525
Goodwill	29,805	29,805	29,805
Other assets	43,050	42,784	36,849
Total assets	1,871,815	1,842,930	1,763,828
Liabilities
Demand deposits	137,674	145,332	130,319
NOW deposits	314,587	318,043	323,919
Money market deposits	108,726	163,898	142,220
Savings deposits	232,458	232,605	222,976
Certificates of deposit	634,747	559,001	527,049
Total deposits	1,428,192	1,418,879	1,346,483
Borrowed funds – short term	129,112	113,638	106,342
Borrowed funds – long term	115,117	115,120	120,125
Other liabilities	18,022	13,972	16,025
Total liabilities	1,690,443	1,661,609	1,588,975
Shareholders' equity
Common stock, one cent par value per share	108	108	108
Additional paid-in capital	61,999	61,747	60,991
Retained earnings	123,876	121,144	113,697
Accumulated other comprehensive income (loss)
Net unrealized loss on securities available for sale	(6,210)	(2,901)	(934)
Net unrealized loss on securities transferred from available for sale to held to maturity	(182)	(174)	(133)
Net unrealized gain on cash flow hedging derivative instruments	1,928	1,544	1,226
Net unrealized loss on postretirement benefit costs	(147)	(147)	(102)
Total shareholders' equity	181,372	181,321	174,853
Total liabilities & shareholders' equity	$ 1,871,815	$ 1,842,930	$ 1,763,828
Common Stock
Number of shares authorized (in shares)	18,000,000	18,000,000	18,000,000
Number of shares issued (in shares)	10,846,562	10,829,918	10,814,132
Number of shares outstanding (in shares)	10,846,562	10,829,918	10,814,132
Book value per common share (usd per share)	$ 16.72	$ 16.74	$ 16.17
Tangible book value per common share (usd per share)	$ 13.95	$ 13.97	$ 13.39

Consolidated Balance Sheets (U3

Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Assets
Securities to be held to maturity, fair value	$ 255,851	$ 259,655	$ 239,378
Common stock, par value per share	$ 0.01	$ 0.01	$ 0.01

Consolidated Statements of Inco

Consolidated Statements of Income and Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest income
Interest and fees on loans (includes tax-exempt income of $211,000 as of March 31, 2018 and $186,000 as of March 31, 2017)	$ 12,391	$ 10,652
Interest on deposits with other banks	11	15
Interest and dividends on investments (includes tax-exempt income of $1,719,000 as of March 31, 2018 and $1,569,000 as of March 31, 2017)	4,049	3,824
Total interest income	16,451	14,491
Interest expense
Interest on deposits	3,099	1,994
Interest on borrowed funds	943	1,021
Total interest expense	4,042	3,015
Net interest income	12,409	11,476
Provision for loan losses	500	500
Net interest income after provision for loan losses	11,909	10,976
Non-interest income
Investment management and fiduciary income	740	631
Service charges on deposit accounts	527	502
Net securities gains	136	3
Mortgage origination and servicing income, net of amortization	331	332
Other operating income	1,398	1,375
Total non-interest income	3,132	2,843
Non-interest expense
Salaries and employee benefits	4,490	3,970
Occupancy expense	699	624
Furniture and equipment expense	929	870
FDIC insurance premiums	279	240
Amortization of identified intangibles	11	11
Other operating expense	2,171	1,983
Total non-interest expense	8,579	7,698
Income before income taxes	6,462	6,121
Income tax expense	956	1,484
NET INCOME	$ 5,506	$ 4,637
Basic earnings per common share (usd per share)	$ 0.51	$ 0.43
Diluted earnings per common share (usd per share)	$ 0.51	$ 0.43
Other comprehensive income (loss) net of tax
Net unrealized gain (loss) on securities available for sale	$ (3,309)	$ 1
Net unrealized loss on securities transferred from available for sale to held to maturity, net of amortization	(8)	(4)
Net unrealized gain on cash flow hedging derivative instruments	384	63
Other comprehensive income (loss)	(2,933)	60
Comprehensive income	$ 2,573	$ 4,697

Consolidated Statements of Inc5

Consolidated Statements of Income and Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Interest and fees on loans (tax-exempt income)	$ 211	$ 186
Interest and dividends on investments (tax-exempt income)	$ 1,719	$ 1,569

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common stock and additional paid-in capital	Retained earnings	Accumulated other comprehensive income (loss)
Beginning balance (in shares) at Dec. 31, 2016		10,793,946
Beginning balance at Dec. 31, 2016	$ 172,521	$ 60,831	$ 111,693	$ (3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,637		4,637
Net unrealized gain on securities available for sale, net of tax	1			1
Net unrealized gain on cash flow hedging derivative instruments, net of tax	63			63
Net unrealized loss on securities transferred from available for sale to held to maturity, net of tax	(4)			(4)
Comprehensive income	4,697		4,637	60
Cash dividends declared	(2,487)		(2,487)
Equity compensation expense	83	$ 83
Payment to repurchase of common stock (in shares)		(5,258)
Payment to repurchase common stock	$ (146)		(146)
Issuance of restricted stock (in shares)	0	18,850
Proceeds from sale of common stock (in shares)		6,594
Proceeds from sale of common stock	$ 185	$ 185
Ending balance (in shares) at Mar. 31, 2017	10,814,132	10,814,132
Ending balance at Mar. 31, 2017	$ 174,853	$ 61,099	113,697	57
Beginning balance (in shares) at Dec. 31, 2017	10,829,918	10,829,918
Beginning balance at Dec. 31, 2017	$ 181,321	$ 61,855	121,144	(1,678)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	5,506		5,506
Net unrealized gain on securities available for sale, net of tax	(3,309)			(3,309)
Net unrealized gain on cash flow hedging derivative instruments, net of tax	384			384
Net unrealized loss on securities transferred from available for sale to held to maturity, net of tax	(8)			(8)
Comprehensive income	2,573		5,506	(2,933)
Cash dividends declared	(2,607)		(2,607)
Equity compensation expense	95	$ 95
Payment to repurchase of common stock (in shares)		(5,725)
Payment to repurchase common stock	$ (167)		(167)
Issuance of restricted stock (in shares)	0	16,795
Proceeds from sale of common stock (in shares)		5,574
Proceeds from sale of common stock	$ 157	$ 157
Ending balance (in shares) at Mar. 31, 2018	10,846,562	10,846,562
Ending balance at Mar. 31, 2018	$ 181,372	$ 62,107	$ 123,876	$ (4,611)

Consolidated Statements of Cha7

Consolidated Statements of Changes in Shareholders' Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Stockholders' Equity [Abstract]
Cash dividends declared (usd per share)	$ 0.24	$ 0.23

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities
Net income	$ 5,506	$ 4,637
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation	464	457
Change in deferred taxes	(163)	80
Provision for loan losses	500	500
Loans originated for resale	(4,835)	(10,069)
Proceeds from sales and transfers of loans	5,016	10,024
Net gain on sales of loans	(79)	(152)
Net gain on sale or call of securities	(136)	(3)
Net amortization of premiums on investments	552	904
Net gain on sale of other real estate owned	(13)	(1)
Equity compensation expense	95	83
Net increase in other assets and accrued interest	(1,214)	(2,192)
Net increase (decrease) in other liabilities	5,014	(1,269)
Net loss on disposal of premises and equipment	127	7
Amortization of investment in limited partnership	43	45
Net acquisition amortization	11	11
Net cash provided by operating activities	10,888	3,062
Cash flows from investing activities
(Increase) decrease in interest-bearing deposits in other banks	580	(2,979)
Proceeds from sales of securities available for sale	459	3
Proceeds from maturities, payments and calls of securities available for sale	14,579	103,781
Proceeds from maturities, payments and calls of securities to be held to maturity	2,751	2,756
Proceeds from sales of other real estate owned	133	44
Purchases of securities available for sale	(23,262)	(117,017)
Purchases of securities to be held to maturity	(4,862)	(16,637)
Purchase of restricted equity securities	(1,589)	(1,433)
Net increase in loans	(24,364)	(18,673)
Capital expenditures	(132)	(22)
Net cash used by investing activities	(35,707)	(50,177)
Cash flows from financing activities
Net increase (decrease) in demand, savings, and money market accounts	(66,433)	53,097
Net increase in certificates of deposit	75,746	50,429
Net increase (decrease) in short-term borrowings	15,491	(52,434)
Repayment on long-term borrowings	(20)	0
Payment to repurchase common stock	(167)	(146)
Proceeds from sale of common stock	157	185
Dividends paid	(2,603)	(3,782)
Net cash provided by financing activities	22,171	47,349
Net increase (decrease) in cash and cash equivalents	(2,648)	234
Cash and cash equivalents at beginning of period	19,207	17,366
Cash and cash equivalents at end of period	16,559	17,600
Interest paid	3,925	2,975
Income taxes paid (refunded)	(8)	0
Non-cash transactions
Net transfer from loans to other real estate owned	$ 229	$ 193

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The First Bancorp, Inc. ("the Company") is a financial holding company that owns all of the common stock of First National Bank ("the Bank"). The accompanying unaudited consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of Management, all adjustments (consisting of normally recurring accruals) considered necessary for a fair presentation have been included. All significant intercompany transactions and balances are eliminated in consolidation. The income reported for the 2018 period is not necessarily indicative of the results that may be expected for the year ending December 31, 2018 . For further information, refer to the consolidated financial statements and notes included in the Company's annual report on Form 10-K for the year ended December 31, 2017 . Subsequent Events Events occurring subsequent to March 31, 2018 , have been evaluated as to their potential impact to the financial statements.

Investment Securities

Investment Securities	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Investment Securities	Investment Securities The following table summarizes the amortized cost and estimated fair value of investment securities at March 31, 2018 : Amortized Cost Unrealized Gains Unrealized Losses Fair Value (Estimated) Securities available for sale Mortgage-backed securities $ 302,935,000 $ 191,000 $ (7,798,000 ) $ 295,328,000 State and political subdivisions 5,765,000 3,000 (257,000 ) 5,511,000 Other equity securities 2,930,000 — — 2,930,000 $ 311,630,000 $ 194,000 $ (8,055,000 ) $ 303,769,000 Securities to be held to maturity U.S. Government-sponsored agencies $ 11,155,000 $ — $ (515,000 ) $ 10,640,000 Mortgage-backed securities 21,990,000 469,000 (289,000 ) 22,170,000 State and political subdivisions 221,245,000 1,497,000 (4,001,000 ) 218,741,000 Corporate securities 4,300,000 — — 4,300,000 $ 258,690,000 $ 1,966,000 $ (4,805,000 ) $ 255,851,000 Restricted equity securities Federal Home Loan Bank Stock $ 10,910,000 $ — $ — $ 10,910,000 Federal Reserve Bank Stock 1,037,000 — — 1,037,000 $ 11,947,000 $ — $ — $ 11,947,000 The following table summarizes the amortized cost and estimated fair value of investment securities at December 31, 2017 : Amortized Cost Unrealized Gains Unrealized Losses Fair Value (Estimated) Securities available for sale Mortgage-backed securities $ 293,689,000 $ 722,000 $ (4,422,000 ) $ 289,989,000 State and political subdivisions 6,860,000 16,000 (107,000 ) 6,769,000 Other equity securities 3,296,000 121,000 (3,000 ) 3,414,000 $ 303,845,000 $ 859,000 $ (4,532,000 ) $ 300,172,000 Securities to be held to maturity U.S. Government-sponsored agencies $ 11,155,000 $ — $ (180,000 ) $ 10,975,000 Mortgage-backed securities 23,284,000 568,000 (128,000 ) 23,724,000 State and political subdivisions 217,828,000 3,931,000 (1,103,000 ) 220,656,000 Corporate securities 4,300,000 — — 4,300,000 $ 256,567,000 $ 4,499,000 $ (1,411,000 ) $ 259,655,000 Restricted equity securities Federal Home Loan Bank Stock $ 9,321,000 $ — $ — $ 9,321,000 Federal Reserve Bank Stock 1,037,000 — — 1,037,000 $ 10,358,000 $ — $ — $ 10,358,000 The following table summarizes the amortized cost and estimated fair value of investment securities at March 31, 2017 : Amortized Cost Unrealized Gains Unrealized Losses Fair Value (Estimated) Securities available for sale Mortgage-backed securities $ 295,424,000 $ 1,407,000 $ (3,204,000 ) $ 293,627,000 State and political subdivisions 15,407,000 474,000 (176,000 ) 15,705,000 Other equity securities 3,229,000 67,000 (4,000 ) 3,292,000 $ 314,060,000 $ 1,948,000 $ (3,384,000 ) $ 312,624,000 Securities to be held to maturity U.S. Government-sponsored agencies $ 12,050,000 $ — $ (317,000 ) $ 11,733,000 Mortgage-backed securities 29,093,000 880,000 (135,000 ) 29,838,000 State and political subdivisions 195,386,000 2,079,000 (3,958,000 ) 193,507,000 Corporate securities 4,300,000 — — 4,300,000 $ 240,829,000 $ 2,959,000 $ (4,410,000 ) $ 239,378,000 Restricted equity securities Federal Home Loan Bank Stock $ 12,326,000 $ — $ — $ 12,326,000 Federal Reserve Bank Stock 1,037,000 — — 1,037,000 $ 13,363,000 $ — $ — $ 13,363,000 The following table summarizes the contractual maturities of investment securities at March 31, 2018 : Securities available for sale Securities to be held to maturity Amortized Cost Fair Value (Estimated) Amortized Cost Fair Value (Estimated) Due in 1 year or less $ 61,000 $ 61,000 $ 634,000 $ 635,000 Due in 1 to 5 years 6,502,000 6,492,000 25,692,000 25,796,000 Due in 5 to 10 years 66,434,000 65,234,000 145,297,000 144,211,000 Due after 10 years 235,703,000 229,052,000 87,067,000 85,209,000 Equity securities 2,930,000 2,930,000 — — $ 311,630,000 $ 303,769,000 $ 258,690,000 $ 255,851,000 The following table summarizes the contractual maturities of investment securities at December 31, 2017 : Securities available for sale Securities to be held to maturity Amortized Cost Fair Value (Estimated) Amortized Cost Fair Value (Estimated) Due in 1 year or less $ 111,000 $ 112,000 $ 635,000 $ 637,000 Due in 1 to 5 years 841,000 842,000 18,059,000 18,164,000 Due in 5 to 10 years 29,003,000 29,177,000 37,182,000 37,719,000 Due after 10 years 270,594,000 266,627,000 200,691,000 203,135,000 Equity securities 3,296,000 3,414,000 — — $ 303,845,000 $ 300,172,000 $ 256,567,000 $ 259,655,000 The following table summarizes the contractual maturities of investment securities at March 31, 2017 : Securities available for sale Securities to be held to maturity Amortized Cost Fair Value (Estimated) Amortized Cost Fair Value (Estimated) Due in 1 year or less $ 43,000 $ 43,000 $ 903,000 $ 908,000 Due in 1 to 5 years 1,909,000 1,953,000 12,213,000 12,477,000 Due in 5 to 10 years 31,835,000 32,471,000 42,819,000 43,562,000 Due after 10 years 277,044,000 274,865,000 184,894,000 182,431,000 Equity securities 3,229,000 3,292,000 — — $ 314,060,000 $ 312,624,000 $ 240,829,000 $ 239,378,000 At March 31, 2018 , securities with a fair value of $197,349,000 were pledged to secure public deposits, repurchase agreements, and for other purposes as required by law. This compares to securities with a fair value of $231,516,000 as of December 31, 2017 and $227,683,000 at March 31, 2017 , pledged for the same purposes. Gains and losses on the sale of securities available for sale are computed by subtracting the amortized cost at the time of sale from the security's selling price, net of accrued interest to be received. The following table shows securities gains and losses for the three months ended March 31, 2018 and 2017 : For the three months ended March 31, 2018 2017 Proceeds from sales of securities $ 459,000 $ 3,000 Gross realized gains 136,000 3,000 Gross realized losses — — Net gain $ 136,000 $ 3,000 Related income taxes $ 29,000 $ 1,000 Management reviews securities with unrealized losses for other than temporary impairment. As of March 31, 2018 , there were 457 securities with unrealized losses held in the Company's portfolio. These securities were temporarily impaired as a result of changes in interest rates reducing their fair value, of which 159 had been temporarily impaired for 12 months or more. At March 31, 2018 , there were no material changes in the credit quality of these securities resulting in other than temporary impairment, and in Management's opinion, no additional write-down for other-than-temporary impairment is warranted. Information regarding securities temporarily impaired as of March 31, 2018 is summarized below: Less than 12 months 12 months or more Total Fair Value (Estimated) Unrealized Losses Fair Value (Estimated) Unrealized Losses Fair Value (Estimated) Unrealized Losses U.S. Government-sponsored agencies $ 6,946,000 $ (309,000 ) $ 3,694,000 $ (206,000 ) $ 10,640,000 $ (515,000 ) Mortgage-backed securities 183,335,000 (4,332,000 ) 101,012,000 (3,755,000 ) 284,347,000 (8,087,000 ) State and political subdivisions 64,594,000 (1,533,000 ) 37,182,000 (2,725,000 ) 101,776,000 (4,258,000 ) $ 254,875,000 $ (6,174,000 ) $ 141,888,000 $ (6,686,000 ) $ 396,763,000 $ (12,860,000 ) As of December 31, 2017 , there were 241 securities with unrealized losses held in the Company's portfolio. These securities were temporarily impaired as a result of changes in interest rates reducing their fair value, of which 157 had been temporarily impaired for 12 months or more. Information regarding securities temporarily impaired as of December 31, 2017 is summarized below: Less than 12 months 12 months or more Total Fair Value (Estimated) Unrealized Losses Fair Value (Estimated) Unrealized Losses Fair Value (Estimated) Unrealized Losses U.S. Government-sponsored agencies $ 7,161,000 $ (94,000 ) $ 3,814,000 $ (86,000 ) $ 10,975,000 $ (180,000 ) Mortgage-backed securities 132,025,000 (1,857,000 ) 101,707,000 (2,693,000 ) 233,732,000 (4,550,000 ) State and political subdivisions 9,425,000 (149,000 ) 38,864,000 (1,061,000 ) 48,289,000 (1,210,000 ) Other equity securities — — 9,000 (3,000 ) 9,000 (3,000 ) $ 148,611,000 $ (2,100,000 ) $ 144,394,000 $ (3,843,000 ) $ 293,005,000 $ (5,943,000 ) As of March 31, 2017 , there were 311 securities with unrealized losses held in the Company's portfolio. These securities were temporarily impaired as a result of changes in interest rates reducing their fair value, of which 13 had been temporarily impaired for 12 months or more. Information regarding securities temporarily impaired as of March 31, 2017 is summarized below: Less than 12 months 12 months or more Total Fair Value (Estimated) Unrealized Losses Fair Value (Estimated) Unrealized Losses Fair Value (Estimated) Unrealized Losses U.S. Government-sponsored agencies $ 10,824,000 $ (317,000 ) $ — $ — $ 10,824,000 $ (317,000 ) Mortgage-backed securities 198,068,000 (3,193,000 ) 2,432,000 (146,000 ) 200,500,000 (3,339,000 ) State and political subdivisions 78,516,000 (4,134,000 ) — — 78,516,000 (4,134,000 ) Other equity securities — — 62,000 (4,000 ) 62,000 (4,000 ) $ 287,408,000 $ (7,644,000 ) $ 2,494,000 $ (150,000 ) $ 289,902,000 $ (7,794,000 ) During the third quarter of 2014, the Company transferred securities with a total amortized cost of $89,780,000 with a corresponding fair value of $89,757,000 from available for sale to held to maturity. The net unrealized loss, net of taxes, on these securities at the date of the transfer was $15,000 . The net unrealized holding loss at the time of transfer continues to be reported in accumulated other comprehensive income (loss), net of tax and is amortized over the remaining lives of the securities as an adjustment of the yield. The amortization of the net unrealized loss reported in accumulated other comprehensive income (loss) will offset the effect on interest income of the discount for the transferred securities. The remaining unamortized balance of the net unrealized losses for the securities transferred from available for sale to held to maturity was $182,000 at March 31, 2018 . These securities were transferred as a part of the Company's overall investment and balance sheet strategies. The Bank is a member of the Federal Home Loan Bank ("FHLB") of Boston, a cooperatively owned wholesale bank for housing and finance in the six New England States. As a requirement of membership in the FHLB, the Bank must own a minimum required amount of FHLB stock, calculated periodically based primarily on its level of borrowings from the FHLB. The Bank uses the FHLB for a portion of its wholesale funding needs. As of March 31, 2018 and 2017 , and December 31, 2017 , the Bank's investment in FHLB stock totaled $10,910,000 , $12,326,000 and $9,321,000 , respectively. FHLB stock is a non-marketable equity security and therefore is reported at cost, which equals par value. The Company periodically evaluates its investment in FHLB stock for impairment based on, among other factors, the capital adequacy of the FHLB and its overall financial condition. No impairment losses have been recorded through March 31, 2018 . The Company will continue to monitor its investment in FHLB stock.

Loans

Loans	3 Months Ended
	Mar. 31, 2018
Loans and Leases Receivable Disclosure [Abstract]
Loans	Loans The following table shows the composition of the Company's loan portfolio as of March 31, 2018 and 2017 and at December 31, 2017 : March 31, 2018 December 31, 2017 March 31, 2017 Commercial Real estate $ 339,306,000 28.6 % $ 323,809,000 27.8 % $ 304,663,000 28.0 % Construction 43,813,000 3.7 % 38,056,000 3.3 % 28,775,000 2.6 % Other 177,783,000 15.0 % 181,528,000 15.6 % 158,507,000 14.4 % Municipal 35,463,000 3.0 % 33,391,000 2.9 % 28,327,000 2.6 % Residential Term 439,984,000 37.0 % 432,661,000 37.1 % 421,202,000 38.7 % Construction 15,847,000 1.3 % 17,868,000 1.5 % 13,717,000 1.3 % Home equity line of credit 110,298,000 9.3 % 111,302,000 9.6 % 110,016,000 10.1 % Consumer 25,508,000 2.1 % 25,524,000 2.2 % 24,528,000 2.3 % Total $ 1,188,002,000 100.0 % $ 1,164,139,000 100.0 % $ 1,089,735,000 100.0 % Loan balances include net deferred loan costs of $5,990,000 as of March 31, 2018 , $5,748,000 as of December 31, 2017 , and $5,167,000 as of March 31, 2017 . Pursuant to collateral agreements, qualifying first mortgage loans, which totaled $237,239,000 at March 31, 2018 , $239,805,000 at December 31, 2017 , and $254,512,000 at March 31, 2017 , were used to collateralize borrowings from the FHLB. In addition, commercial, construction and home equity loans totaling $255,020,000 at March 31, 2018 , $290,247,000 at December 31, 2017 , and $285,464,000 at March 31, 2017 , were used to collateralize a standby line of credit at the Federal Reserve Bank of Boston that is currently unused. For all loan classes, loans over 30 days past due are considered delinquent. Information on the past-due status of loans by class of financing receivable as of March 31, 2018 , is presented in the following table: 30-59 Days Past Due 60-89 Days Past Due 90+ Days Past Due All Past Due Current Total 90+ Days & Accruing Commercial Real estate $ 963,000 $ 17,000 $ 202,000 $ 1,182,000 $ 338,124,000 $ 339,306,000 $ — Construction 347,000 — — 347,000 43,466,000 43,813,000 — Other 6,887,000 52,000 294,000 7,233,000 170,550,000 177,783,000 — Municipal — — — — 35,463,000 35,463,000 — Residential Term 3,175,000 345,000 1,880,000 5,400,000 434,584,000 439,984,000 — Construction — — — — 15,847,000 15,847,000 — Home equity line of credit 449,000 438,000 664,000 1,551,000 108,747,000 110,298,000 126,000 Consumer 119,000 8,000 27,000 154,000 25,354,000 25,508,000 11,000 Total $ 11,940,000 $ 860,000 $ 3,067,000 $ 15,867,000 $ 1,172,135,000 $ 1,188,002,000 $ 137,000 Information on the past-due status of loans by class of financing receivable as of December 31, 2017 , is presented in the following table: 30-59 Days Past Due 60-89 Days Past Due 90+ Days Past Due All Past Due Current Total 90+ Days & Accruing Commercial Real estate $ 574,000 $ 80,000 $ 220,000 $ 874,000 $ 322,935,000 $ 323,809,000 $ — Construction — — — — 38,056,000 38,056,000 — Other 542,000 6,663,000 574,000 7,779,000 173,749,000 181,528,000 — Municipal — — — — 33,391,000 33,391,000 — Residential Term 1,031,000 4,372,000 2,256,000 7,659,000 425,002,000 432,661,000 436,000 Construction 101,000 370,000 — 471,000 17,397,000 17,868,000 — Home equity line of credit 537,000 445,000 725,000 1,707,000 109,595,000 111,302,000 — Consumer 159,000 18,000 9,000 186,000 25,338,000 25,524,000 9,000 Total $ 2,944,000 $ 11,948,000 $ 3,784,000 $ 18,676,000 $ 1,145,463,000 $ 1,164,139,000 $ 445,000 Information on the past-due status of loans by class of financing receivable as of March 31, 2017 , is presented in the following table: 30-59 Days Past Due 60-89 Days Past Due 90+ Days Past Due All Past Due Current Total 90+ Days & Accruing Commercial Real estate $ 142,000 $ 772,000 $ 1,823,000 $ 2,737,000 $ 301,926,000 $ 304,663,000 $ — Construction 20,000 — — 20,000 28,755,000 28,775,000 — Other 199,000 154,000 439,000 792,000 157,715,000 158,507,000 — Municipal — — — — 28,327,000 28,327,000 — Residential Term 3,555,000 — 1,603,000 5,158,000 416,044,000 421,202,000 — Construction — — — — 13,717,000 13,717,000 — Home equity line of credit 392,000 167,000 773,000 1,332,000 108,684,000 110,016,000 — Consumer 328,000 34,000 11,000 373,000 24,155,000 24,528,000 11,000 Total $ 4,636,000 $ 1,127,000 $ 4,649,000 $ 10,412,000 $ 1,079,323,000 $ 1,089,735,000 $ 11,000 For all classes, loans are placed on non-accrual status when, based on current information and events, it is probable that the Company will be unable to collect all amounts due according to the contractual terms of the loan agreement or when principal and interest is 90 days or more past due unless the loan is both well secured and in the process of collection (in which case the loan may continue to accrue interest in spite of its past due status). A loan is "well secured" if it is secured (1) by collateral in the form of liens on or pledges of real or personal property, including securities, that have a realizable value sufficient to discharge the debt (including accrued interest) in full, or (2) by the guarantee of a financially responsible party. A loan is "in the process of collection" if collection of the loan is proceeding in due course either (1) through legal action, including judgment enforcement procedures, or, (2) in appropriate circumstances, through collection efforts not involving legal action which are reasonably expected to result in repayment of the debt or in its restoration to a current status in the near future. Cash payments received on non-accrual loans, which are included in impaired loans, are applied to reduce the loan's principal balance until the remaining principal balance is deemed collectible, after which interest is recognized when collected. As a general rule, a loan may be restored to accrual status when payments are current for a substantial period of time, generally six months, and repayment of the remaining contractual amounts is expected, or when it otherwise becomes well secured and in the process of collection. Information on nonaccrual loans as of March 31, 2018 and 2017 and at December 31, 2017 is presented in the following table: March 31, 2018 December 31, 2017 March 31, 2017 Commercial Real estate $ 1,021,000 $ 752,000 $ 2,625,000 Construction — — — Other 8,895,000 9,357,000 938,000 Municipal — — — Residential Term 3,654,000 3,778,000 4,028,000 Construction — — — Home equity line of credit 697,000 833,000 909,000 Consumer 16,000 16,000 — Total $ 14,283,000 $ 14,736,000 $ 8,500,000 Impaired loans include troubled debt restructured ("TDR") and loans placed on non-accrual. These loans are measured at the present value of expected future cash flows discounted at the loan's effective interest rate or at the fair value of the collateral if the loan is collateral dependent. If the measure of an impaired loan is lower than the recorded investment in the loan and estimated selling costs, a specific reserve is established for the difference, or, in certain situations, if the measure of an impaired loan is lower than the recorded investment in the loan and estimated selling costs, the difference is written off. A breakdown of impaired loans by class of financing receivable as of and for the period ended March 31, 2018 is presented in the following table: For the three months ended March 31, 2018 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Recognized Interest Income With No Related Allowance Commercial Real estate $ 5,054,000 $ 5,269,000 $ — $ 4,163,000 $ 54,000 Construction 741,000 741,000 — 741,000 10,000 Other 2,281,000 2,360,000 — 2,302,000 6,000 Municipal — — — — — Residential Term 9,594,000 10,733,000 — 9,700,000 71,000 Construction — — — — — Home equity line of credit 917,000 1,008,000 — 1,090,000 5,000 Consumer 16,000 29,000 — 16,000 — $ 18,603,000 $ 20,140,000 $ — $ 18,012,000 $ 146,000 With an Allowance Recorded Commercial Real estate $ 3,897,000 $ 4,002,000 $ 254,000 $ 3,889,000 $ 39,000 Construction — — — — — Other 7,159,000 7,324,000 1,664,000 7,182,000 — Municipal — — — — — Residential Term 1,934,000 2,146,000 272,000 1,968,000 24,000 Construction — — — — — Home equity line of credit 122,000 125,000 16,000 70,000 — Consumer — — — — — $ 13,112,000 $ 13,597,000 $ 2,206,000 $ 13,109,000 $ 63,000 Total Commercial Real estate $ 8,951,000 $ 9,271,000 $ 254,000 $ 8,052,000 $ 93,000 Construction 741,000 741,000 — 741,000 10,000 Other 9,440,000 9,684,000 1,664,000 9,484,000 6,000 Municipal — — — — — Residential Term 11,528,000 12,879,000 272,000 11,668,000 95,000 Construction — — — — — Home equity line of credit 1,039,000 1,133,000 16,000 1,160,000 5,000 Consumer 16,000 29,000 — 16,000 — $ 31,715,000 $ 33,737,000 $ 2,206,000 $ 31,121,000 $ 209,000 Substantially all interest income recognized on impaired loans for all classes of financing receivables was recognized on a cash basis as received. A breakdown of impaired loans by class of financing receivable as of and for the year ended December 31, 2017 is presented in the following table: Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Recognized Interest Income With No Related Allowance Commercial Real estate $ 3,791,000 $ 3,996,000 $ — $ 5,124,000 $ 164,000 Construction 741,000 741,000 — 62,000 38,000 Other 2,591,000 2,671,000 — 1,908,000 36,000 Municipal — — — — — Residential Term 9,769,000 10,909,000 — 10,770,000 297,000 Construction — — — — — Home equity line of credit 1,115,000 1,429,000 — 1,351,000 18,000 Consumer 16,000 29,000 — 12,000 — $ 18,023,000 $ 19,775,000 $ — $ 19,227,000 $ 553,000 With an Allowance Recorded Commercial Real estate $ 3,999,000 $ 4,116,000 $ 224,000 $ 4,460,000 $ 152,000 Construction — — — 699,000 — Other 7,327,000 7,371,000 1,309,000 2,584,000 — Municipal — — — — — Residential Term 1,979,000 2,144,000 255,000 2,106,000 79,000 Construction — — — — — Home equity line of credit 64,000 67,000 24,000 32,000 — Consumer — — — — — $ 13,369,000 $ 13,698,000 $ 1,812,000 $ 9,881,000 $ 231,000 Total Commercial Real estate $ 7,790,000 $ 8,112,000 $ 224,000 $ 9,584,000 $ 316,000 Construction 741,000 741,000 — 761,000 38,000 Other 9,918,000 10,042,000 1,309,000 4,492,000 36,000 Municipal — — — — — Residential Term 11,748,000 13,053,000 255,000 12,876,000 376,000 Construction — — — — — Home equity line of credit 1,179,000 1,496,000 24,000 1,383,000 18,000 Consumer 16,000 29,000 — 12,000 — $ 31,392,000 $ 33,473,000 $ 1,812,000 $ 29,108,000 $ 784,000 A breakdown of impaired loans by class of financing receivable as of and for the period ended March 31, 2017 is presented in the following table: For the three months ended March 31, 2017 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Recognized Interest Income With No Related Allowance Commercial Real estate $ 5,949,000 $ 6,450,000 $ — $ 5,444,000 $ 51,000 Construction — — — — — Other 1,476,000 1,636,000 — 1,595,000 22,000 Municipal — — — — — Residential Term 11,388,000 12,470,000 — 11,402,000 129,000 Construction — — — — — Home equity line of credit 1,422,000 1,752,000 — 1,376,000 9,000 Consumer — — — — — $ 20,235,000 $ 22,308,000 $ — $ 19,817,000 $ 211,000 With an Allowance Recorded Commercial Real estate $ 4,722,000 $ 4,908,000 $ 351,000 $ 4,741,000 $ 46,000 Construction 763,000 763,000 101,000 763,000 9,000 Other 234,000 272,000 39,000 125,000 4,000 Municipal — — — — — Residential Term 1,872,000 2,020,000 251,000 2,077,000 23,000 Construction — — — — — Home equity line of credit 26,000 27,000 26,000 26,000 — Consumer — — — — — $ 7,617,000 $ 7,990,000 $ 768,000 $ 7,732,000 $ 82,000 Total Commercial Real estate $ 10,671,000 $ 11,358,000 $ 351,000 $ 10,185,000 $ 97,000 Construction 763,000 763,000 101,000 763,000 9,000 Other 1,710,000 1,908,000 39,000 1,720,000 26,000 Municipal — — — — — Residential Term 13,260,000 14,490,000 251,000 13,479,000 152,000 Construction — — — — — Home equity line of credit 1,448,000 1,779,000 26,000 1,402,000 9,000 Consumer — — — — — $ 27,852,000 $ 30,298,000 $ 768,000 $ 27,549,000 $ 293,000 Troubled Debt Restructured A "TDR" constitutes a restructuring of debt if the Company, for economic or legal reasons related to the borrower's financial difficulties, grants a concession to the borrower that it would not otherwise consider. To determine whether or not a loan should be classified as a TDR, Management evaluates a loan based upon the following criteria: • The borrower demonstrates financial difficulty; common indicators include past due status with bank obligations, substandard credit bureau reports, or an inability to refinance with another lender, and • The Company has granted a concession; common concession types include maturity date extension, interest rate adjustments to below market pricing, and deferment of payments. As of March 31, 2018 , the Company had 69 loans with a balance of $18,709,000 that have been classified as TDRs. This compares to 62 loans with a balance of $17,801,000 and 70 loans with a balance of $21,121,000 classified as TDRs as of December 31, 2017 and March 31, 2017 , respectively. The impairment carried as a specific reserve in the allowance for loan losses is calculated by present valuing the expected cash flows on the loan at the original interest rate, or, for collateral-dependent loans, using the fair value of the collateral less costs to sell. The following table shows TDRs by class and the specific reserve as of March 31, 2018 : Number of Loans Balance Specific Reserves Commercial Real estate 15 $ 8,030,000 $ 132,000 Construction 1 741,000 — Other 4 546,000 — Municipal — — — Residential Term 46 8,883,000 271,000 Construction — — — Home equity line of credit 3 509,000 — Consumer — — — 69 $ 18,709,000 $ 403,000 The following table shows TDRs by class and the specific reserve as of December 31, 2017 : Number of Loans Balance Specific Reserves Commercial Real estate 8 $ 7,038,000 $ 90,000 Construction 1 741,000 — Other 4 561,000 — Municipal — — — Residential Term 46 8,948,000 233,000 Construction — — — Home equity line of credit 3 513,000 — Consumer — — — 62 $ 17,801,000 $ 323,000 The following table shows TDRs by class and the specific reserve as of March 31, 2017 : Number of Loans Balance Specific Reserves Commercial Real estate 10 $ 8,703,000 $ 82,000 Construction 1 763,000 101,000 Other 5 772,000 2,000 Municipal — — — Residential Term 51 10,344,000 201,000 Construction — — — Home equity line of credit 3 539,000 — Consumer — — — 70 $ 21,121,000 $ 386,000 As of March 31, 2018 , seven of the loans classified as TDRs with a total balance of $810,000 were more than 30 days past due. None of these loans had been placed on TDR status in the previous 12 months. The following table shows these TDRs by class and the associated specific reserves included in the allowance for loan losses as of March 31, 2018 : Number of Loans Balance Specific Reserves Commercial Real estate — $ — $ — Construction — — — Other — — — Municipal — — — Residential Term 6 643,000 45,000 Construction — — — Home equity line of credit 1 167,000 — Consumer — — — 7 $ 810,000 $ 45,000 As of March 31, 2017 , nine of the loans classified as TDRs with a total balance of $1,651,000 were more than 30 days past due. Of these loans, none had been placed on TDR status in the previous 12 months. The following table shows these TDRs by class and the associated specific reserves included in the allowance for loan losses as of March 31, 2017 : Number of Loans Balance Specific Reserves Commercial Real estate 1 $ 658,000 $ — Construction — — — Other — — — Municipal — — — Residential Term 7 826,000 — Construction — — — Home equity line of credit 1 167,000 — Consumer — — — 9 $ 1,651,000 $ — For the three months ended March 31, 2018 , seven loans were placed on TDR status. The following table shows these TDRs by class and the associated specific reserves included in the allowance for loan losses as of March 31, 2018 : For the quarter ended March 31, 2018 Number of Loans Pre-Modification Post-Modification Outstanding Specific Reserves Commercial Real estate 7 $ 1,056,000 $ 1,056,000 $ 36,000 Construction — — — — Other — — — — Municipal — — — — Residential Term — — — — Construction — — — — Home equity line of credit — — — — Consumer — — — — 7 $ 1,056,000 $ 1,056,000 $ 36,000 For the three months ended March 31, 2017 , no loans were placed on TDR status. As of March 31, 2018 , Management is aware of four loans classified as TDRs that are involved in bankruptcy with an outstanding balance of $684,000 . There were also 11 loans with an outstanding balance of $1,276,000 that were classified as TDRs and on non-accrual status, of which three loans with an outstanding balance of $456,000 were in the process of foreclosure. Residential Mortgage Loans in Process of Foreclosure As of March 31, 2018 , there were 13 mortgage loans collateralized by residential real estate in the process of foreclosure with a total balance of $ 1,388,000 . This compares to 12 mortgage loans collateralized by residential real estate in the process of foreclosure with a total balance of $1,773,000 as of March 31, 2017 .

Allowance for Loan Losses

Allowance for Loan Losses	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Allowance for Loan Losses	Allowance for Loan Losses The Company provides for loan losses through the establishment of an allowance for loan losses which represents an estimated reserve for existing losses in the loan portfolio. A systematic methodology is used for determining the allowance that includes a quarterly review process, risk rating changes, and adjustments to the allowance. The loan portfolio is classified in eight classes and credit risk is evaluated separately in each class. Major risk characteristics relevant to each portfolio segment are as follows: Commercial Real Estate - Commercial real estate loans are impacted by factors such as competitive market forces, vacancy rates, cap rates, net operating incomes, lease renewals and overall economic demand. In addition, loans in the recreational and tourism sector can be affected by weather conditions, such as unseasonably low winter snowfalls. Commercial real estate lending also carries a higher degree of environmental risk than other real estate lending. Commercial Construction - Commercial construction loans are impacted by factors similar to those for commercial real estate loans in addition to risks related to contractor financial capacity and ability to complete a project within acceptable time frames and within budget. Commercial Other - A weakened economy, soft consumer spending, and the rising cost of labor or raw materials are examples of issues that can impact the credit quality in this segment. Municipal Loans - The overall health of the economy, including unemployment rates and housing prices, has an impact on the credit quality of this segment. Residential Real Estate Term - The overall health of the economy, including unemployment rates and housing prices, has an impact on the credit quality of this segment. Residential Real Estate Construction - Residential construction are impacted by factors similar to those for residential real estate term in addition to risks related to contractor financial capacity and ability to complete a project within acceptable time frames and within budget. Home Equity Line of Credit - The overall health of the economy, including unemployment rates and housing prices, has an impact on the credit quality of this segment. Consumer - The overall health of the economy, including unemployment rates, has an impact on the credit quality of this segment. The appropriate level of the allowance is evaluated continually based on a review of significant loans, with a particular emphasis on nonaccruing, past due, and other loans that may require special attention. Other factors include general conditions in local and national economies; loan portfolio composition and asset quality indicators; and internal factors such as changes in underwriting policies, credit administration practices, experience, ability and depth of lending management, among others. The allowance consists of four elements: (1) specific reserves for loans evaluated individually for impairment; (2) general reserves for each portfolio segment based on historical loan loss experience, (3) qualitative reserves judgmentally adjusted for local and national economic conditions, concentrations, portfolio composition, volume and severity of delinquencies and nonaccrual loans, trends of criticized and classified loans, changes in credit policies and underwriting standards, credit administration practices, and other factors as applicable for each portfolio segment; and (4) unallocated reserves. All outstanding loans are considered in evaluating the appropriateness of the allowance. A breakdown of the allowance for loan losses as of March 31, 2018 , December 31, 2017 , and March 31, 2017 , by class of financing receivable and allowance element, is presented in the following tables: As of March 31, 2018 Specific Reserves on Loans Evaluated Individually for Impairment General Reserves on Loans Based on Historical Loss Experience Reserves for Qualitative Factors Unallocated Reserves Total Reserves Commercial Real estate $ 254,000 $ 1,039,000 $ 2,439,000 $ — $ 3,732,000 Construction — 81,000 315,000 — 396,000 Other 1,664,000 597,000 1,279,000 — 3,540,000 Municipal — — 21,000 — 21,000 Residential Term 272,000 303,000 554,000 — 1,129,000 Construction — 11,000 20,000 — 31,000 Home equity line of credit 16,000 297,000 403,000 — 716,000 Consumer — 265,000 316,000 — 581,000 Unallocated — — — 811,000 811,000 $ 2,206,000 $ 2,593,000 $ 5,347,000 $ 811,000 $ 10,957,000 As of December 31, 2017 Specific Reserves on Loans Evaluated Individually for Impairment General Reserves on Loans Based on Historical Loss Experience Reserves for Qualitative Factors Unallocated Reserves Total Reserves Commercial Real estate $ 224,000 $ 1,285,000 $ 2,363,000 $ — $ 3,872,000 Construction — 153,000 281,000 — 434,000 Other 1,309,000 723,000 1,326,000 — 3,358,000 Municipal — — 20,000 — 20,000 Residential Term 255,000 311,000 564,000 — 1,130,000 Construction — 13,000 23,000 — 36,000 Home equity line of credit 24,000 297,000 371,000 — 692,000 Consumer — 251,000 294,000 — 545,000 Unallocated — — — 642,000 642,000 $ 1,812,000 $ 3,033,000 $ 5,242,000 $ 642,000 $ 10,729,000 As of March 31, 2017 Specific Reserves on Loans Evaluated Individually for Impairment General Reserves on Loans Based on Historical Loss Experience Reserves for Qualitative Factors Unallocated Reserves Total Reserves Commercial Real estate $ 351,000 $ 1,631,000 $ 2,033,000 $ — $ 4,015,000 Construction 101,000 151,000 189,000 — 441,000 Other 39,000 840,000 1,046,000 — 1,925,000 Municipal — — 18,000 — 18,000 Residential Term 251,000 282,000 436,000 — 969,000 Construction — 9,000 15,000 — 24,000 Home equity line of credit 26,000 439,000 346,000 — 811,000 Consumer — 337,000 236,000 — 573,000 Unallocated — — — 1,591,000 1,591,000 $ 768,000 $ 3,689,000 $ 4,319,000 $ 1,591,000 $ 10,367,000 Qualitative adjustment factors are taken into consideration when determining reserve estimates. These adjustment factors are based upon Management's evaluation of various current conditions, including those listed below. • General economic conditions. • Credit quality trends with emphasis on loan delinquencies, nonaccrual levels and classified loans. • Recent loss experience in particular segments of the portfolio. • Loan volumes and concentrations, including changes in mix. • Other factors, including changes in quality of the loan origination; loan policy changes; changes in credit risk management processes; Bank regulatory and external loan review examination results. The qualitative portion of the allowance for loan losses was 0.45% of related loans as of March 31, 2018 and December 31, 2017 . The qualitative portion increased $105,000 between December 31, 2017 and March 31, 2018 due to loan growth and slippage in certain economic factors. The unallocated component of the allowance totaled $811,000 at March 31, 2018 , or 7.4% of the total reserve. This compares to $642,000 or 6.0% as of December 31, 2017 . The change results from a measure of imprecision owing to general portfolio activity. The allowance for loan losses as a percent of total loans stood at 0.92% as of March 31, 2018 and December 31, 2017 . This compares to 0.95% as of March 31, 2017 . Commercial loans are comprised of three major classes, commercial real estate loans, commercial construction loans and other commercial loans. Commercial real estate loans consist of mortgage loans to finance investments in real property such as multi-family residential, commercial/retail, office, industrial, hotels, educational and other specific or mixed use properties. Commercial real estate loans are typically written with amortizing payment structures. Collateral values are determined based on appraisals and evaluations in accordance with established policy and regulatory guidelines. Commercial real estate loans typically have a loan-to-value ratio of up to 80% based upon current valuation information at the time the loan is made. Commercial real estate loans are primarily paid by the cash flow generated from the real property, such as operating leases, rents, or other operating cash flows from the borrower. Commercial construction loans consist of loans to finance construction in a mix of owner- and non-owner occupied commercial real estate properties. Commercial construction loans typically have maturities of less than two years. Payment structures during the construction period are typically on an interest only basis, although principal payments may be established depending on the type of construction project being financed. During the construction phase, commercial construction loans are primarily paid by cash flow generated from the construction project or other operating cash flows from the borrower or guarantors, if applicable. At the end of the construction period, loan repayment typically comes from a third party source in the event that the Company will not be providing permanent term financing. Collateral valuation and loan-to-value guidelines follow those for commercial real estate loans. Other commercial loans consist of revolving and term loan obligations extended to business and corporate enterprises for the purpose of financing working capital and or capital investment. Collateral generally consists of pledges of business assets including, but not limited to, accounts receivable, inventory, plant and equipment, and/or real estate, if applicable. Commercial loans are primarily paid by the operating cash flow of the borrower. Commercial loans may be secured or unsecured. Municipal loans are comprised of loans to municipalities in Maine for capitalized expenditures, construction projects or tax anticipation notes. All municipal loans are considered general obligations of the municipality and are collateralized by the taxing ability of the municipality for repayment of debt. Residential loans are comprised of two classes: term loans and construction loans. Residential term loans consist of residential real estate loans held in the Company's loan portfolio made to borrowers who demonstrate the ability to make scheduled payments with full consideration to underwriting factors. Borrower qualifications include favorable credit history combined with supportive income requirements and loan-to-value ratios within established policy and regulatory guidelines. Collateral values are determined based on appraisals and evaluations in accordance with established policy and regulatory guidelines. Residential loans typically have a loan-to-value ratio of up to 80% based on appraisal information at the time the loan is made. Collateral consists of mortgage liens on one- to four-family residential properties. Loans are offered with fixed or adjustable rates with amortization terms of up to thirty years. Residential construction loans typically consist of loans for the purpose of constructing single family residences to be owned and occupied by the borrower. Borrower qualifications include favorable credit history combined with supportive income requirements and loan-to-value ratios within established policy and regulatory guidelines. Residential construction loans normally have construction terms of one year or less and payment during the construction term is typically on an interest only basis from sources including interest reserves, borrower liquidity and/or income. Residential construction loans will typically convert to permanent financing from the Company or have another financing commitment in place from an acceptable mortgage lender. Collateral valuation and loan-to-value guidelines are consistent with those for residential term loans. Home equity lines of credit are made to qualified individuals and are secured by senior or junior mortgage liens on owner occupied one- to four-family homes, condominiums, or vacation homes. The home equity line of credit typically has a variable interest rate and is billed as interest-only payments during the draw period. At the end of the draw period, the home equity line of credit is billed as a percentage of the principal balance plus all accrued interest. Loan maturities are normally 300 months. Borrower qualifications include favorable credit history combined with supportive income requirements and combined loan-to- value ratios usually not exceeding 80% inclusive of priority liens. Collateral valuation guidelines follow those for residential real state loans. Consumer loan products including personal lines of credit and amortizing loans made to qualified individuals for various purposes such as auto, recreational vehicles, debt consolidation, personal expenses or overdraft protection. Borrower qualifications include favorable credit history combined with supportive income and collateral requirements within established policy guidelines. Consumer loans may be secured or unsecured. Construction, land and land development loans, both commercial and residential, comprise a small portion of the portfolio, and at 36.0% of capital are below the regulatory guidance limit of 100.0% of capital at March 31, 2018 . Construction loans and non-owner-occupied commercial real estate loans are at 131.4% of total capital, below the regulatory limit of 300.0% of capital at March 31, 2018 . The process of establishing the allowance with respect to the commercial loan portfolio begins when a Loan Officer or Senior Officer (or designate) initially assigns each loan a risk rating, using established credit criteria. Approximately 50% of the outstanding loans and commitments are subject to review and validation annually by an independent consulting firm. Additionally, commercial loan relationships with exposure greater than or equal to $500,000 and lines of credit greater than $250,000 are subject to review annually by the Company's internal credit review function. The methodology employs Management's judgment as to the level of losses on existing loans based on internal review of the loan portfolio, including an analysis of a borrower's current financial position, and the consideration of current and anticipated economic conditions and their potential effects on specific borrowers and or lines of business. In determining the Company's ability to collect certain loans, Management also considers the fair value of underlying collateral. The risk rating system has eight levels, defined as follows: 1 Strong Credits rated "1" are characterized by borrowers fully responsible for the credit with excellent capacity to pay principal and interest. Loans rated "1" may be secured with acceptable forms of liquid collateral. 2 Above Average Credits rated "2" are characterized by borrowers that have better than average liquidity, capitalization, earnings and/or cash flow with a consistent record of solid financial performance. 3 Satisfactory Credits rated "3" are characterized by borrowers with favorable liquidity, profitability and financial condition with adequate cash flow to pay debt service. 4 Average Credits rated "4" are characterized by borrowers that present risk more than 1, 2 and 3 rated loans and merit an ordinary level of ongoing monitoring. Financial condition is on par or somewhat below industry averages while cash flow is generally adequate to meet debt service requirements. 5 Watch Credits rated "5" are characterized by borrowers that warrant greater monitoring due to financial condition or unresolved and identified risk factors. 6 Other Assets Especially Mentioned (OAEM) Loans in this category are currently protected but are potentially weak and constitute an undue and unwarranted credit risk, but not to the point of justifying a classification of substandard. OAEM have potential weaknesses which may, if not checked or corrected, weaken the asset or inadequately protect the Company's credit position at some future date. 7 Substandard Loans in this category are inadequately protected by the paying capacity of the borrower or of the collateral pledged, if any. Loans so classified have a well-defined weakness or weaknesses that jeopardize the liquidation of the debt. Substandard loans are characterized by the distinct possibility that the Company may sustain some loss if the deficiencies are not corrected. 8 Doubtful Loans classified "Doubtful" have the same weaknesses as those classified substandard with the added characteristic that the weaknesses make collection or liquidation in full, based on currently existing facts, conditions, and values, highly questionable and improbable. The possibility of loss is high, but because of certain important and reasonably specific pending factors which may work to the advantage and strengthening of the asset, its classification as an estimated loss is deferred until its more exact status may be determined. The following table summarizes the risk ratings for the Company's commercial real estate, commercial construction, commercial other, and municipal loans as of March 31, 2018 : Commercial Real Estate Commercial Construction Commercial Other Municipal Loans All Risk- Rated Loans 1 Strong $ — $ — $ 1,251,000 $ — $ 1,251,000 2 Above Average 12,308,000 40,000 5,528,000 33,875,000 51,751,000 3 Satisfactory 74,612,000 4,776,000 38,738,000 653,000 118,779,000 4 Average 183,675,000 21,585,000 79,751,000 935,000 285,946,000 5 Watch 46,918,000 17,412,000 35,743,000 — 100,073,000 6 OAEM 3,148,000 — 1,866,000 — 5,014,000 7 Substandard 18,522,000 — 14,906,000 — 33,428,000 8 Doubtful 123,000 — — — 123,000 Total $ 339,306,000 $ 43,813,000 $ 177,783,000 $ 35,463,000 $ 596,365,000 The following table summarizes the risk ratings for the Company's commercial real estate, commercial construction, commercial other, and municipal loans as of December 31, 2017 : Commercial Real Estate Commercial Construction Commercial Other Municipal Loans All Risk- Rated Loans 1 Strong $ — $ — $ 1,586,000 $ — $ 1,586,000 2 Above Average 12,534,000 40,000 5,776,000 32,673,000 51,023,000 3 Satisfactory 73,899,000 2,856,000 38,151,000 718,000 115,624,000 4 Average 173,956,000 22,446,000 84,360,000 — 280,762,000 5 Watch 41,652,000 12,714,000 33,934,000 — 88,300,000 6 OAEM 3,442,000 — 2,765,000 — 6,207,000 7 Substandard 18,203,000 — 14,956,000 — 33,159,000 8 Doubtful 123,000 — — — 123,000 Total $ 323,809,000 $ 38,056,000 $ 181,528,000 $ 33,391,000 $ 576,784,000 The following table summarizes the risk ratings for the Company's commercial real estate, commercial construction, commercial other, and municipal loans as of March 31, 2017 : Commercial Real Estate Commercial Construction Commercial Other Municipal Loans All Risk- Rated Loans 1 Strong $ 2,000 $ — $ 499,000 $ — $ 501,000 2 Above Average 14,213,000 45,000 8,222,000 27,479,000 49,959,000 3 Satisfactory 83,021,000 2,051,000 47,724,000 848,000 133,644,000 4 Average 138,865,000 18,283,000 72,791,000 — 229,939,000 5 Watch 45,053,000 8,239,000 14,280,000 — 67,572,000 6 OAEM 4,036,000 — 5,661,000 — 9,697,000 7 Substandard 19,473,000 157,000 9,330,000 — 28,960,000 8 Doubtful — — — — — Total $ 304,663,000 $ 28,775,000 $ 158,507,000 $ 28,327,000 $ 520,272,000 Commercial loans are generally charged off when all or a portion of the principal amount is determined to be uncollectible. This determination is based on circumstances specific to a borrower including repayment ability, analysis of collateral and other factors as applicable. Residential loans are comprised of two classes: term loans, which include traditional amortizing home mortgages, and construction loans, which include loans for owner-occupied residential construction. Residential loans typically have a 75% to 80% loan to value based upon current appraisal information at the time the loan is made. Home equity loans and lines of credit are typically written to the same underwriting standards. Consumer loans are primarily amortizing loans to individuals collateralized by automobiles, pleasure craft and recreation vehicles, typically with a maximum loan to value of 80% to 90% of the purchase price of the collateral. Consumer loans also include a small amount of unsecured short-term time notes to individuals. Residential loans, consumer loans and home equity lines of credit are segregated into homogeneous pools with similar risk characteristics. Trends and current conditions are analyzed and historical loss experience is adjusted accordingly. Quantitative and qualitative adjustment factors for these segments are consistent with those for the commercial and municipal classes. Certain loans in the residential, home equity lines of credit and consumer classes identified as having the potential for further deterioration are analyzed individually to confirm impairment status, and to determine the need for a specific reserve; however there is no formal rating system used for these classes. Consumer loans greater than 120 days past due are generally charged off. Residential loans 90 days or more past due are placed on non-accrual status unless the loans are both well secured and in the process of collection. One- to four-family residential real estate loans and home equity loans are written down or charged-off no later than 180 days past due, or for residential real estate secured loans having a borrower in bankruptcy, within 60 days of receipt of notification of filing from the bankruptcy court, whichever is sooner. This is subject to completion of a current assessment of the value of the collateral with any outstanding loan balance in excess of the fair value of the property, less costs to sell, written down or charged-off. There were no changes to the Company's accounting policies or methodology used to estimate the allowance for loan losses during the three months ended March 31, 2018 . The following table presents allowance for loan losses activity by class for the three months ended March 31, 2018 , and allowance for loan loss balances by class and related loan balances by class as of March 31, 2018 : Commercial Municipal Residential Home Equity Line of Credit Consumer Unallocated Total Real Estate Construction Other Term Construction For the three months ended March 31, 2018 Beginning balance $ 3,872,000 $ 434,000 $ 3,358,000 $ 20,000 $ 1,130,000 $ 36,000 $ 692,000 $ 545,000 $ 642,000 $ 10,729,000 Charge offs — — 17,000 — 81,000 — 115,000 105,000 — 318,000 Recoveries — — 6,000 — 4,000 — 11,000 25,000 — 46,000 Provision (credit) (140,000 ) (38,000 ) 193,000 1,000 76,000 (5,000 ) 128,000 116,000 169,000 500,000 Ending balance $ 3,732,000 $ 396,000 $ 3,540,000 $ 21,000 $ 1,129,000 $ 31,000 $ 716,000 $ 581,000 $ 811,000 $ 10,957,000 Allowance for loan losses as of March 31, 2018 Ending balance specifically evaluated for impairment $ 254,000 $ — $ 1,664,000 $ — $ 272,000 $ — $ 16,000 $ — $ — $ 2,206,000 Ending balance collectively evaluated for impairment $ 3,478,000 $ 396,000 $ 1,876,000 $ 21,000 $ 857,000 $ 31,000 $ 700,000 $ 581,000 $ 811,000 $ 8,751,000 Related loan balances as of March 31, 2018 Ending balance $ 339,306,000 $ 43,813,000 $ 177,783,000 $ 35,463,000 $ 439,984,000 $ 15,847,000 $ 110,298,000 $ 25,508,000 $ — $ 1,188,002,000 Ending balance specifically evaluated for impairment $ 8,951,000 $ 741,000 $ 9,440,000 $ — $ 11,528,000 $ — $ 1,039,000 $ 16,000 $ — $ 31,715,000 Ending balance collectively evaluated for impairment $ 330,355,000 $ 43,072,000 $ 168,343,000 $ 35,463,000 $ 428,456,000 $ 15,847,000 $ 109,259,000 $ 25,492,000 $ — $ 1,156,287,000 The following table presents allowance for loan losses activity by class for the year ended December 31, 2017 and allowance for loan loss balances by class and related loan balances by class as of December 31, 2017 : Municipal Residential Home Equity Line of Credit Consumer Unallocated Total Real Estate Construction Other Term Construction Beginning balance $ 3,988,000 $ 396,000 $ 1,780,000 $ 18,000 $ 1,288,000 $ 44,000 $ 807,000 $ 559,000 $ 1,258,000 $ 10,138,000 Charge offs 587,000 — 212,000 — 456,000 — 28,000 335,000 — 1,618,000 Recoveries — — 49,000 — 40,000 — 11,000 109,000 — 209,000 Provision (credit) 471,000 38,000 1,741,000 2,000 258,000 (8,000 ) (98,000 ) 212,000 (616,000 ) 2,000,000 Ending balance $ 3,872,000 $ 434,000 $ 3,358,000 $ 20,000 $ 1,130,000 $ 36,000 $ 692,000 $ 545,000 $ 642,000 $ 10,729,000 Ending balance specifically evaluated for impairment $ 224,000 $ — $ 1,309,000 $ — $ 255,000 $ — $ 24,000 $ — $ — $ 1,812,000 Ending balance collectively evaluated for impairment $ 3,648,000 $ 434,000 $ 2,049,000 $ 20,000 $ 875,000 $ 36,000 $ 668,000 $ 545,000 $ 642,000 $ 8,917,000 Ending balance $ 323,809,000 $ 38,056,000 $ 181,528,000 $ 33,391,000 $ 432,661,000 $ 17,868,000 $ 111,302,000 $ 25,524,000 $ — $ 1,164,139,000 Ending balance specifically evaluated for impairment $ 7,790,000 $ 741,000 $ 9,918,000 $ — $ 11,748,000 $ — $ 1,179,000 $ 16,000 $ — $ 31,392,000 Ending balance collectively evaluated for impairment $ 316,019,000 $ 37,315,000 $ 171,610,000 $ 33,391,000 $ 420,913,000 $ 17,868,000 $ 110,123,000 $ 25,508,000 $ — $ 1,132,747,000 The following table presents allowance for loan losses activity by class for the three months ended March 31, 2017 , and allowance for loan loss balances by class and related loan balances by class as of March 31, 2017 : Commercial Municipal Residential Home Equity Line of Credit Consumer Unallocated Total Real Estate Construction Other Term Construction For the three months ended March 31, 2017 Beginning balance $ 3,988,000 $ 396,000 $ 1,780,000 $ 18,000 $ 1,288,000 $ 44,000 $ 807,000 $ 559,000 $ 1,258,000 $ 10,138,000 Charge offs 164,000 — — — 53,000 — 7,000 103,000 — 327,000 Recoveries — — 11,000 — 14,000 — — 31,000 — 56,000 Provision (credit) 191,000 45,000 134,000 — (280,000 ) (20,000 ) 11,000 86,000 333,000 500,000 Ending balance $ 4,015,000 $ 441,000 $ 1,925,000 $ 18,000 $ 969,000 $ 24,000 $ 811,000 $ 573,000 $ 1,591,000 $ 10,367,000 Allowance for loan losses as of March 31, 2017 Ending balance specifically evaluated for impairment $ 351,000 $ 101,000 $ 39,000 $ — $ 251,000 $ — $ 26,000 $ — $ — $ 768,000 Ending balance collectively evaluated for impairment $ 3,664,000 $ 340,000 $ 1,886,000 $ 18,000 $ 718,000 $ 24,000 $ 785,000 $ 573,000 $ 1,591,000 $ 9,599,000 Related loan balances as of March 31, 2017 Ending balance $ 304,663,000 $ 28,775,000 $ 158,507,000 $ 28,327,000 $ 421,202,000 $ 13,717,000 $ 110,016,000 $ 24,528,000 $ — $ 1,089,735,000 Ending balance specifically evaluated for impairment $ 10,671,000 $ 763,000 $ 1,710,000 $ — $ 13,260,000 $ — $ 1,448,000 $ — $ — $ 27,852,000 Ending balance collectively evaluated for impairment $ 293,992,000 $ 28,012,000 $ 156,797,000 $ 28,327,000 $ 407,942,000 $ 13,717,000 $ 108,568,000 $ 24,528,000 $ — $ 1,061,883,000

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation At the 2010 Annual Meeting, shareholders approved the 2010 Equity Incentive Plan (the "2010 Plan"). This reserves 400,000 shares of common stock for issuance in connection with stock options, restricted stock awards and other equity based awards to attract and retain the best available personnel, provide additional incentive to officers, employees and non-employee Directors and promote the success of our business. Such grants and awards will be structured in a manner that does not encourage the recipients to expose the Company to undue or inappropriate risk. Options issued under the 2010 Plan will qualify for treatment as incentive stock options for purposes of Section 422 of the Internal Revenue Code. Other compensation under the 2010 Plan will qualify as performance-based for purposes of Section 162(m) of the Internal Revenue Code, and will satisfy NASDAQ guidelines relating to equity compensation. As of March 31, 2018 , 144,355 shares of restricted stock had been granted under the 2010 Plan, of which 67,689 shares remain restricted as of March 31, 2018 as detailed in the following table: Year Granted Vesting Term (In Years) Shares Remaining Term (In Years) 2014 5.0 10,422 0.9 2015 5.0 12,023 1.9 2016 5.0 15,015 2.8 2017 3.0 4,902 1.9 2017 5.0 9,972 3.8 2018 1.0 300 0.9 2018 2.0 932 1.8 2018 3.0 2,400 2.9 2018 4.0 2,068 3.8 2018 5.0 9,655 4.8 67,689 2.6 The compensation cost related to these restricted stock grants is $1,489,000 and is recognized over the vesting terms of each grant. In the three months ended March 31, 2018 , $95,000 of expense was recognized for these restricted shares, leaving $964,000 in unrecognized expense as of March 31, 2018 . In the three months ended March 31, 2017 , $83,000 of expense was recognized for restricted shares, leaving $911,000 in unrecognized expense as of March 31, 2017 .

Preferred and Common Stock

Preferred and Common Stock	3 Months Ended
	Mar. 31, 2018
Stockholders' Equity Note [Abstract]
Preferred and Common Stock	Preferred and Common Stock Preferred Stock On January 9, 2009, the Company issued $25,000,000 in Fixed Rate Cumulative Perpetual Preferred Stock, Series A, to the U.S. Treasury ("Treasury') under the Capital Purchase Program ("the CPP Shares"). The CPP Shares qualified as Tier 1 capital on the Company's books for regulatory purposes and ranked senior to the Company's common stock and senior or at an equal level in the Company's capital structure to any other shares of preferred stock the Company may issue in the future. In three separate transactions in 2012 and 2013, the Company repurchased all of the CPP shares from the Treasury. Incident to such issuance of the CPP shares, the Company issued to the Treasury warrants (the "Warrants") to purchase up to 225,904 shares of the Company's common stock at a price per share of $16.60 (subject to adjustment). The Warrants (and any shares of common stock issuable pursuant to the Warrants) are freely transferable by the Treasury to third parties. The Warrants have a term of ten years and could be exercised by the Treasury or a subsequent holder at any time or from time to time during their term. To the extent they had not previously been exercised, the Warrants will expire after ten years . The Warrants were unchanged as a result of the CPP Shares repurchase transactions. In May 2015, the Treasury sold the Warrants to private parties. In accordance with the contractual terms of the Warrants, the number of shares issuable upon exercise and strike price were adjusted at the time of the sale. As a result of this transaction, the aggregate number of shares of common stock issuable under the Warrants were adjusted to 226,819 shares with a strike price of $16.53 per share. In November 2016, the Company repurchased all of the outstanding Warrants for an aggregate purchase price of $1,750,000 . Common Stock Proceeds from sale of common stock totaled $157,000 and $185,000 for the three months ended March 31, 2018 and 2017 , respectively.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following table sets forth the computation of basic and diluted earnings per share (EPS) for the three months ended March 31, 2018 and 2017 : Income (Numerator) Shares (Denominator) Per-Share Amount For the three months ended March 31, 2018 Net income as reported $ 5,506,000 Basic EPS: Income available to common shareholders 5,506,000 10,771,271 $ 0.51 Effect of dilutive securities: restricted stock 73,228 Diluted EPS: Income available to common shareholders plus assumed conversions $ 5,506,000 10,844,499 $ 0.51 For the three months ended March 31, 2017 Net income as reported $ 4,637,000 Basic EPS: Income available to common shareholders 4,637,000 10,734,281 $ 0.43 Effect of dilutive securities: restricted stock 73,623 Diluted EPS: Income available to common shareholders plus assumed conversions $ 4,637,000 10,807,904 $ 0.43 All earnings per share calculations have been made using the weighted average number of shares outstanding during the period. The potentially dilutive securities are unvested shares of restricted stock granted to certain key members of Management. The number of dilutive shares is calculated using the treasury method, assuming that all shares were vested.

Employee Benefit Plans

Employee Benefit Plans	3 Months Ended
	Mar. 31, 2018
Retirement Benefits, Description [Abstract]
Employee Benefit Plans	Employee Benefit Plans 401(k) Plan The Bank has a defined contribution plan available to substantially all employees who have completed 3 months of service. Employees may contribute up to Internal Revenue Service ("IRS") determined limits and the Bank may match employee contributions not to exceed 3.0% of compensation depending on contribution level. Subject to a vote of the Board of Directors, the Bank may also make a profit-sharing contribution to the Plan. Such contribution equaled 2.0% of each eligible employee's compensation in 2017 . The amount for 2018 has not been established. The expense related to the 401(k) plan was $164,000 and $130,000 for the three months ended March 31, 2018 and 2017 , respectively. Deferred Compensation and Supplemental Retirement Benefits The Bank also provides unfunded supplemental retirement benefits for certain officers, payable in installments over 20 years upon retirement or death. The agreements consist of individual contracts with differing characteristics that, when taken together, do not constitute a postretirement plan. The costs for these benefits are recognized over the service periods of the participating officers in accordance with Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") Topic 712 "Compensation – Nonretirement Postemployment Benefits". The expense of these supplemental retirement benefits was $43,000 for the three months ended March 31, 2018 and $54,000 for the the same period in 2017 . As of March 31, 2018 , the associated accrued liability included in other liabilities in the balance sheet was $3,031,000 compared to $3,060,000 and $3,045,000 at December 31, 2017 and March 31, 2017 , respectively. Post-Retirement Benefit Plans The Bank sponsors two post-retirement benefit plans. One plan currently provides a subsidy for health insurance premiums to certain retired employees and a future subsidy for six active employees who were age 50 and over in 1996. These subsidies are based on years of service and range between $40 and $1,200 per month per person. The other plan provides life insurance coverage to certain retired employees and health insurance for retired directors. None of these plans are pre-funded. The Company utilizes FASB ASC Topic 712 to recognize the overfunded or underfunded status of a defined benefit postretirement plan as an asset or liability in its balance sheet and to recognize changes in the funded status in the year in which the changes occur through comprehensive income (loss). The following table sets forth the accumulated postretirement benefit obligation and funded status: At or for the three months ended March 31, 2018 2017 Change in benefit obligation Benefit obligation at beginning of year $ 1,874,000 $ 1,870,000 Interest cost 19,000 19,000 Benefits paid (28,000 ) (32,000 ) Benefit obligation at end of period $ 1,865,000 $ 1,857,000 Funded status Benefit obligation at end of period $ (1,865,000 ) $ (1,857,000 ) Unamortized loss 186,000 102,000 Accrued benefit cost at end of period $ (1,679,000 ) $ (1,755,000 ) The following table sets forth the net periodic pension cost: For the three months ended March 31, 2018 2017 Components of net periodic benefit cost Interest cost $ 19,000 $ 19,000 Net periodic benefit cost $ 19,000 $ 19,000 Amounts not yet reflected in net periodic benefit cost and included in accumulated other comprehensive income (loss) are as follows: March 31, December 31, 2017 March 31, Unamortized net actuarial loss $ (186,000 ) $ (186,000 ) $ (156,000 ) Deferred tax benefit at 21% (for March 31, 2018 and December 31, 2017) and 35% (for March 31, 2017) 39,000 39,000 54,000 Net unrecognized postretirement benefits included in accumulated other comprehensive income (loss) $ (147,000 ) $ (147,000 ) $ (102,000 ) A weighted average discount rate of 4.25% was used in determining the accumulated benefit obligation and the net periodic benefit cost. The assumed health care cost trend rate is 7.0% . The measurement date for benefit obligations was as of year-end for prior years presented. The expected benefit payments for all of 2018 are $128,000 . Plan expense for 2018 is estimated to be $77,000 . A 1% change in trend assumptions would create an approximate change in the same direction of $100,000 in the accumulated benefit obligation, $7,000 in the interest cost and $1,000 in the service cost.

Other Comprehensive Income (Los

Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Other Comprehensive Income (Loss)	Other Comprehensive Income (Loss) The following table summarizes activity in the unrealized gain or loss on available for sale securities included in other comprehensive income (loss) for the three months ended March 31, 2018 and 2017 . For the three months ended March 31, 2018 2017 Balance at beginning of period $ (2,901,000 ) $ (935,000 ) Unrealized gains (losses) arising during the period (4,052,000 ) 5,000 Reclassification of realized gains during the period (136,000 ) (3,000 ) Related deferred taxes (at a Federal Income Tax rate of 21% for March 31, 2018 and 35% for March 31, 2017) 879,000 (1,000 ) Net change (3,309,000 ) 1,000 Balance at end of period $ (6,210,000 ) $ (934,000 ) The reclassification of realized gains is included in the net securities gains line of the consolidated statements of income and comprehensive income and the tax effect is included in the income tax expense line of the same statement. The following table summarizes activity in the unrealized loss on securities transferred from available for sale to held to maturity included in other comprehensive income (loss) for the three months ended March 31, 2018 and 2017 . For the three months ended March 31, 2018 2017 Balance at beginning of period $ (174,000 ) $ (129,000 ) Amortization of net unrealized losses (10,000 ) (6,000 ) Related deferred taxes (at a Federal Income Tax rate of 21% for March 31, 2018 and 35% for March 31, 2017) 2,000 2,000 Net change (8,000 ) (4,000 ) Balance at end of period $ (182,000 ) $ (133,000 ) The following table presents the effect of the Company's derivative financial instruments included in other comprehensive income (loss) for the three months ended March 31, 2018 and 2017 . For the three months ended March 31, 2018 2017 Balance at beginning of period $ 1,544,000 $ 1,163,000 Unrealized gains on cash flow hedging derivatives arising during the period 486,000 96,000 Related deferred taxes (at a Federal Income Tax rate of 21% for March 31, 2018 and 35% for March 31, 2017) (102,000 ) (33,000 ) Net change 384,000 63,000 Balance at end of period $ 1,928,000 $ 1,226,000 The following table summarizes activity in the unrealized gain or loss on postretirement benefits included in other comprehensive income (loss) for the three months ended March 31, 2018 and 2017 . For the three months ended March 31, 2018 2017 Unrecognized postretirement benefits at beginning of period $ (147,000 ) $ (102,000 ) Amortization of unrecognized transition obligation — — Change in unamortized net actuarial gain (loss) — — Related deferred taxes (at a Federal Income Tax rate of 21% for March 31, 2018 and 35% for March 31, 2017) — — Unrecognized postretirement benefits at end of period $ (147,000 ) $ (102,000 )

Financial Derivative Instrument

Financial Derivative Instruments	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial Derivative Instruments	Financial Derivative Instruments As part of its overall asset and liability management strategy, the Company periodically uses derivative instruments to minimize significant unplanned fluctuations in earnings and cash flows caused by interest rate volatility. The Company’s interest rate risk management strategy involves modifying the re-pricing characteristics of certain assets or liabilities so that changes in interest rates do not have a significant effect on net interest income. The Company recognizes its derivative instruments in the consolidated balance sheet at fair value. On the date the derivative instrument is entered into, the Company designates whether the derivative is part of a hedging relationship (i.e., cash flow or fair value hedge). The Company formally documents relationships between hedging instruments and hedged items, as well as its risk management objective and strategy for undertaking hedge transactions. The Company also assesses, both at the hedge’s inception and on an ongoing basis, whether the derivatives used in hedging transactions are highly effective in offsetting the changes in cash flows or fair values of hedged items. Changes in fair value of derivative instruments that are highly effective and qualify as cash flow hedges are recorded in other comprehensive income or loss. Any ineffective portion is recorded in earnings. The Company discontinues hedge accounting when it is determined that the derivative is no longer highly effective in offsetting changes of the hedged risk on the hedged item, or management determines that the designation of the derivative as a hedging instrument is no longer appropriate. In 2016, interest rate swaps were contracted to limit the Company’s exposure to rising interest rates on short-term liabilities indexed to one-month London Inter-bank Offered Rates (LIBOR). The interest rate swaps were designated as cash flow hedges. The details of the interest rate swap agreements are as follows: March 31, 2018 December 31, 2017 March 31, 2017 Notional Amount Effective Date Maturity Date Variable Index Received Fixed Rate Paid Fair Value (1) Fair Value (1) Fair Value (1) $ 30,000,000 June 28, 2016 June 28, 2021 1-Month USD LIBOR 0.940 % $ 1,447,000 $ 1,154,000 $ 1,108,000 20,000,000 June 27, 2016 June 27, 2021 1-Month USD LIBOR 0.893 % 994,000 801,000 778,000 $ 50,000,000 $ 2,441,000 $ 1,955,000 $ 1,886,000 (1) Presented within other assets in the consolidated balance sheet. The Company would reclassify unrealized gains or losses accounted for within accumulated other comprehensive income (loss) into earnings if the interest rate swaps were to become ineffective or the swaps were to terminate. In the next 12 months, the Company does not believe it will be required to reclassify any unrealized gains or losses accounted for within accumulated other comprehensive income (loss) into earnings as a result of ineffectiveness or swap termination. Amounts paid or received under the swaps are reported in interest expense in the statement of income, and in interest paid in the statement of cash flows.

Mortgage Servicing Rights

Mortgage Servicing Rights	3 Months Ended
	Mar. 31, 2018
Transfers and Servicing [Abstract]
Mortgage Servicing Rights	Mortgage Servicing Rights FASB ASC Topic 860 "Transfers and Servicing" requires all separately recognized servicing assets and servicing liabilities to be initially measured at fair value, if practicable. The Company's servicing assets and servicing liabilities are reported using the amortization method and carried at the lower of amortized cost or fair value by strata. In evaluating the carrying values of mortgage servicing rights, the Company obtains third party valuations based on loan level data including note rate, type and term of the underlying loans. The model utilizes several assumptions, the most significant of which is loan prepayments, calculated using a three -months moving average of weekly prepayment data published by the Public Securities Association (PSA) and modeled against the serviced loan portfolio, and the discount rate to discount future cash flows. As of March 31, 2018 , the prepayment assumption using the PSA model was 132 , which translates into an anticipated prepayment rate of 7.92% . The discount rate is 9.50% . Other assumptions include delinquency rates, foreclosure rates, servicing cost inflation, and annual unit loan cost. All assumptions are adjusted periodically to reflect current circumstances. Amortization of mortgage servicing rights, as well as write-offs due to prepayments of the related mortgage loans, are recorded as a charge against mortgage servicing fee income. For the three months ended March 31, 2018 and 2017 , servicing rights capitalized totaled $62,000 and $102,000 , respectively. Servicing rights amortized for the three-month periods ended March 31, 2018 and 2017 were $50,000 and $95,000 , respectively. The fair value of servicing rights was $2,518,000 , $2,321,000 and $1,853,000 at March 31, 2018 , December 31, 2017 and March 31, 2017 , respectively. The Bank serviced loans for others totaling $258,475,000 , $260,258,000 and $251,865,000 at March 31, 2018 , December 31, 2017 , and March 31, 2017 , respectively. Mortgage servicing rights are included in other assets and detailed in the following table: March 31, December 31, March 31, Mortgage servicing rights $ 5,489,000 $ 5,428,000 $ 4,491,000 Accumulated amortization (4,209,000 ) (4,160,000 ) (3,415,000 ) Impairment reserve — — (22,000 ) $ 1,280,000 $ 1,268,000 $ 1,054,000

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes FASB ASC Topic 740 "Income Taxes" defines the criteria that an individual tax position must satisfy for some or all of the benefits of that position to be recognized in a company's financial statements. Topic 740 prescribes a recognition threshold of more-likely-than-not, and a measurement attribute for all tax positions taken or expected to be taken on a tax return, in order for those tax positions to be recognized in the financial statements. The Company is currently open to audit under the statute of limitations by the IRS for the years ended December 31, 2015 through 2017.

Certificates of Deposit

Certificates of Deposit	3 Months Ended
	Mar. 31, 2018
Banking and Thrift [Abstract]
Certificates of Deposit	Certificates of Deposit The following table represents the breakdown of certificates of deposit at March 31, 2018 and 2017 , and at December 31, 2017 : March 31, 2018 December 31, 2017 March 31, 2017 Certificates of deposit < $100,000 $ 347,010,000 $ 284,066,000 $ 246,792,000 Certificates $100,000 to $250,000 240,492,000 232,759,000 236,971,000 Certificates $250,000 and over 47,245,000 42,176,000 43,286,000 $ 634,747,000 $ 559,001,000 $ 527,049,000

Reclassifications

Reclassifications	3 Months Ended
	Mar. 31, 2018
Accounting Changes and Error Corrections [Abstract]
Reclassifications	Reclassifications Certain items from the prior year were reclassified in the financial statements to conform with the current year presentation. These do not have a material impact on the consolidated balance sheet or statement of income and comprehensive income presentations.

Fair Value

Fair Value	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value	Fair Value Certain assets and liabilities are recorded at fair value to provide additional insight into the Company's quality of earnings. Some of these assets and liabilities are measured on a recurring basis while others are measured on a nonrecurring basis, with the determination based upon applicable existing accounting pronouncements. For example, securities available for sale are recorded at fair value on a recurring basis. Other assets, such as, other real estate owned and impaired loans, are recorded at fair value on a nonrecurring basis using the lower of cost or market methodology to determine impairment of individual assets. The Company groups assets and liabilities which are recorded at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. A financial instrument's level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement (with level 1 considered highest and level 3 considered lowest). A brief description of each level follows: Level 1 - Valuation is based upon quoted prices for identical instruments in active markets. Level 2 - Valuation is based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market. Level 3 - Valuation is generated from model-based techniques that use at least one significant assumption not observable in the market. These unobservable assumptions reflect estimates that market participants would use in pricing the asset or liability. Valuation includes use of discounted cash flow models and similar techniques. The fair value methods and assumptions for the Company's financial instruments and other assets measured at fair value are set forth below. Cash, Cash Equivalents and Interest-Bearing Deposits in Other Banks The carrying values of cash equivalents, due from banks and federal funds sold approximate their relative fair values. As such, the Company classifies these financial instruments as Level 1. Investment Securities The fair values of investment securities are estimated by independent providers using a market approach with observable inputs, including matrix pricing and recent transactions. In obtaining such valuation information from third parties, the Company has evaluated their valuation methodologies used to develop the fair values in order to determine whether the valuations are representative of an exit price in the Company's principal markets. The Company's principal markets for its securities portfolios are the secondary institutional markets, with an exit price that is predominantly reflective of bid level pricing in those markets. Fair values are calculated based on the value of one unit without regard to any premium or discount that may result from concentrations of ownership of a financial instrument, possible tax ramifications, or estimated transaction costs. If these considerations had been incorporated into the fair value estimates, the aggregate fair value could have been changed. The carrying values of restricted equity securities approximate fair values. As such, the Company classifies investment securities as Level 2. Loans Held for Sale Loans held for sale are recorded at the lower of aggregate carrying value or fair value. The fair value of mortgage loans held for sale is based on what secondary markets are currently offering for portfolios with similar characteristics. As such, the Company classifies mortgage loans held for sale as Level 2. Loans Fair values are estimated for portfolios of loans with similar financial characteristics. The fair values of performing loans are calculated by discounting scheduled cash flows through the estimated maturity using estimated market discount rates that reflect the credit and interest risk inherent in the loan. The estimates of maturity are based on the Company's historical experience with repayments for each loan classification, modified, as required, by an estimate of the effect of current economic and lending conditions, and the effects of estimated prepayments. Assumptions regarding credit risk, cash flows, and discount rates are judgmentally determined using available market information and specific borrower information. Management has made estimates of fair value using discount rates that it believes to be reasonable. However, because there is no market for many of these financial instruments, Management has no basis to determine whether the fair value presented above would be indicative of the value negotiated in an actual sale. As such, the Company classifies loans as Level 3, except for certain collateral-dependent impaired loans. Fair values of impaired loans are based on estimated cash flows and are discounted using a rate commensurate with the risk associated with the estimated cash flows, or if collateral dependent, discounted to the appraised value of the collateral as determined by reference to sale prices of similar properties, less costs to sell. As such, the Company classifies collateral dependent impaired loans for which a specific reserve results in a fair value measure as Level 2. All other impaired loans are classified as Level 3. Other Real Estate Owned Real estate acquired through foreclosure is initially recorded at fair value. The fair value of other real estate owned is based on property appraisals and an analysis of similar properties currently available. As such, the Company records other real estate owned as nonrecurring Level 2. Mortgage Servicing Rights Mortgage servicing rights represent the value associated with servicing residential mortgage loans. Servicing assets and servicing liabilities are reported using the amortization method and compared to fair value for impairment. In evaluating the fair values of mortgage servicing rights, the Company obtains third party valuations based on loan level data including note rate, type and term of the underlying loans. As such, the Company classifies mortgage servicing rights as Level 2. Accrued Interest Receivable The fair value estimate of this financial instrument approximates the carrying value as this financial instrument has a short maturity. It is the Company's policy to stop accruing interest on loans for which it is probable that the interest is not collectible. Therefore, this financial instrument has been adjusted for estimated credit loss. As such, the Company classifies accrued interest receivable as Level 2. Deposits The fair value of deposits is based on the discounted value of contractual cash flows. The discount rate is estimated using the rates currently offered for deposits of similar remaining maturities. As such, the Company classifies deposits as Level 2. The fair value estimates do not include the benefit that results from the low-cost funding provided by the deposits compared to the cost of borrowing funds in the market. If that value were considered, the fair value of the Company's net assets could increase. Borrowed Funds The fair value of borrowed funds is based on the discounted value of contractual cash flows. The discount rate is estimated using the rates currently available for borrowings of similar remaining maturities. As such, the Company classifies borrowed funds as Level 2. Derivatives The fair value of interest rate swaps is determined using inputs that are observable in the market place obtained from third parties including yield curves, publicly available volatilities, and floating indexes and, accordingly, are classified as Level 2 inputs. The credit value adjustments associated with derivatives utilize Level 3 inputs, such as estimates of current credit spreads to evaluate the likelihood of default by the Company and its counterparties. As of March 31, 2018 and 2017 , and December 31, 2017 , the Company has assessed the significance of the impact of the credit valuation adjustments on the overall valuation of its derivative positions and has determined that the credit valuation adjustments are not significant to the overall valuation of its derivatives due to collateral postings. Accrued Interest Payable The fair value estimate approximates the carrying amount as this financial instrument has a short maturity. The Company classifies accrued interest payable as Level 2. Off-Balance-Sheet Instruments Off-balance-sheet instruments include loan commitments. Fair values for loan commitments have not been presented as the future revenue derived from such financial instruments is not significant. Limitations Fair value estimates are made at a specific point in time, based on relevant market information and information about the financial instrument. These values 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. Because no market exists for a significant portion of the Company's financial instruments, fair value estimates are based on Management's 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 are based on existing on- and off-balance-sheet financial instruments without attempting to estimate the value of anticipated future business and the value of assets and liabilities that are not considered financial instruments. Other significant assets and liabilities that are not considered financial instruments include the deferred tax asset, premises and equipment, and other real estate owned. In addition, tax ramifications related to the realization of the unrealized gains and losses can have a significant effect on fair value estimates and have not been considered in any of the estimates. Assets Recorded at Fair Value on a Recurring Basis The following tables present the balances of assets that were measured at fair value on a recurring basis as of March 31, 2018 , December 31, 2017 and March 31, 2017 . At March 31, 2018 Level 1 Level 2 Level 3 Total Securities available for sale Mortgage-backed securities $ — $ 295,328,000 $ — $ 295,328,000 State and political subdivisions — 5,511,000 — 5,511,000 Other equity securities — 2,930,000 — 2,930,000 Total securities available for sale — 303,769,000 — 303,769,000 Interest rate swap agreements — 2,441,000 — 2,441,000 Total assets $ — $ 306,210,000 $ — $ 306,210,000 At December 31, 2017 Level 1 Level 2 Level 3 Total Securities available for sale Mortgage-backed securities $ — $ 289,989,000 $ — $ 289,989,000 State and political subdivisions — 6,769,000 — 6,769,000 Other equity securities — 3,414,000 — 3,414,000 Total securities available for sale — 300,172,000 — 300,172,000 Interest rate swap agreements — 1,955,000 — 1,955,000 Total assets $ — $ 302,127,000 $ — $ 302,127,000 At March 31, 2017 Level 1 Level 2 Level 3 Total Securities available for sale Mortgage-backed securities $ — $ 293,627,000 $ — $ 293,627,000 State and political subdivisions — 15,705,000 — 15,705,000 Other equity securities — 3,292,000 — 3,292,000 Total securities available for sale — 312,624,000 — 312,624,000 Interest rate swap agreements — 1,886,000 — 1,886,000 Total assets $ — $ 314,510,000 $ — $ 314,510,000 Assets Recorded at Fair Value on a Non-Recurring Basis The following tables include assets measured at fair value on a nonrecurring basis that have had a fair value adjustment since their initial recognition. Other real estate owned is presented net of an allowance of $53,000 and $78,000 at, December 31, 2017 , and March 31, 2017 , respectively. There was no allowance at March 31, 2018. Only collateral-dependent impaired loans with a related specific allowance for loan losses or a partial charge off are included in impaired loans for purposes of fair value disclosures. Impaired loans below are presented net of specific allowances of $1,924,000 , $1,531,000 and $356,000 at March 31, 2018 , December 31, 2017 , and March 31, 2017 , respectively. At March 31, 2018 Level 1 Level 2 Level 3 Total Other real estate owned $ — $ 1,121,000 $ — $ 1,121,000 Impaired loans — 5,938,000 — 5,938,000 Total assets $ — $ 7,059,000 $ — $ 7,059,000 At December 31, 2017 Level 1 Level 2 Level 3 Total Other real estate owned $ — $ 1,012,000 $ — $ 1,012,000 Impaired loans — 6,521,000 — 6,521,000 Total assets $ — $ 7,533,000 $ — $ 7,533,000 At March 31, 2017 Level 1 Level 2 Level 3 Total Other real estate owned $ — $ 525,000 $ — $ 525,000 Impaired loans — 718,000 — 718,000 Total assets $ — $ 1,243,000 $ — $ 1,243,000 Fair Value of Financial Instruments FASB ASC Topic 825 "Financial Instruments" requires disclosures of fair value information about financial instruments, whether or not recognized in the balance sheet, if the fair values can be reasonably determined. Fair value is best determined based upon quoted market prices. However, in many instances, there are no quoted market prices for the Company's various financial instruments. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques using observable inputs when available. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. Accordingly, the fair value estimates may not be realized in an immediate settlement of the instrument. Topic 825 excludes certain financial instruments and all nonfinancial instruments from its disclosure requirements. Accordingly, the aggregate fair value amounts presented may not necessarily represent the underlying fair value of the Company. The carrying amount and estimated fair values for financial instruments as of March 31, 2018 were as follows: Carrying value Estimated fair value Level 1 Level 2 Level 3 Financial assets Cash and cash equivalents $ 16,559,000 $ 16,559,000 $ 16,559,000 $ — $ — Interest bearing deposits in other banks 280,000 280,000 280,000 — — Securities available for sale 303,769,000 303,769,000 — 303,769,000 — Securities to be held to maturity 258,690,000 255,851,000 — 255,851,000 — Restricted equity securities 11,947,000 11,947,000 — 11,947,000 — Loans held for sale 284,000 284,000 — 284,000 — Loans (net of allowance for loan losses) Commercial Real estate 335,275,000 326,030,000 — 3,000 326,027,000 Construction 43,385,000 42,189,000 — — 42,189,000 Other 173,960,000 171,045,000 — 5,495,000 165,550,000 Municipal 35,440,000 34,972,000 — — 34,972,000 Residential Term 438,765,000 430,023,000 — 334,000 429,689,000 Construction 15,814,000 15,587,000 — — 15,587,000 Home equity line of credit 109,525,000 108,047,000 — 106,000 107,941,000 Consumer 24,881,000 24,178,000 — — 24,178,000 Total loans 1,177,045,000 1,152,071,000 — 5,938,000 1,146,133,000 Mortgage servicing rights 1,280,000 2,518,000 — 2,518,000 — Interest rate swap agreements 2,441,000 2,441,000 — 2,441,000 — Accrued interest receivable 7,222,000 7,222,000 — 7,222,000 — Financial liabilities Demand deposits $ 137,674,000 $ 128,525,000 $ — $ 128,525,000 $ — NOW deposits 314,587,000 286,661,000 — 286,661,000 — Money market deposits 108,726,000 102,196,000 — 102,196,000 — Savings deposits 232,458,000 198,171,000 — 198,171,000 — Local certificates of deposit 260,450,000 255,579,000 — 255,579,000 — National certificates of deposit 374,297,000 374,095,000 — 374,095,000 — Total deposits 1,428,192,000 1,345,227,000 — 1,345,227,000 — Repurchase agreements 67,182,000 64,361,000 — 64,361,000 — Federal Home Loan Bank advances 177,047,000 175,308,000 — 175,308,000 — Total borrowed funds 244,229,000 239,669,000 — 239,669,000 — Accrued interest payable 760,000 760,000 — 760,000 — The carrying amounts and estimated fair values for financial instruments as of December 31, 2017 were as follows: Carrying value Estimated fair value Level 1 Level 2 Level 3 Financial assets Cash and cash equivalents $ 19,207,000 $ 19,207,000 $ 19,207,000 $ — $ — Interest bearing deposits in other banks 860,000 860,000 860,000 — — Securities available for sale 300,172,000 300,172,000 — 300,172,000 — Securities to be held to maturity 256,567,000 259,655,000 — 259,655,000 — Restricted equity securities 10,358,000 10,358,000 — 10,358,000 — Loans held for sale 386,000 386,000 — 386,000 — Loans (net of allowance for loan losses) Commercial Real estate 319,691,000 311,321,000 — 72,000 311,249,000 Construction 37,594,000 36,610,000 — — 36,610,000 Other 177,956,000 175,455,000 — 6,018,000 169,437,000 Municipal 33,370,000 33,280,000 — — 33,280,000 Residential Term 431,459,000 431,028,000 — 391,000 430,637,000 Construction 17,830,000 17,613,000 — — 17,613,000 Home equity line of credit 110,566,000 109,012,000 — 40,000 108,972,000 Consumer 24,944,000 24,408,000 — — 24,408,000 Total loans 1,153,410,000 1,138,727,000 — 6,521,000 1,132,206,000 Mortgage servicing rights 1,268,000 2,321,000 — 2,321,000 — Interest rate swap agreements 1,955,000 1,955,000 — 1,955,000 — Accrued interest receivable 5,867,000 5,867,000 — 5,867,000 — Financial liabilities Demand deposits $ 145,332,000 $ 139,350,000 $ — $ 139,350,000 $ — NOW deposits 318,043,000 295,775,000 — 295,775,000 — Money market deposits 163,898,000 153,497,000 — 153,497,000 — Savings deposits 232,605,000 203,799,000 — 203,799,000 — Local certificates of deposit 223,074,000 220,734,000 — 220,734,000 — National certificates of deposit 335,927,000 335,775,000 — 335,775,000 — Total deposits 1,418,879,000 1,348,930,000 — 1,348,930,000 — Repurchase agreements 70,564,000 67,976,000 — 67,976,000 — Federal Home Loan Bank advances 158,194,000 156,396,000 — 156,396,000 — Total borrowed funds 228,758,000 224,372,000 — 224,372,000 — Accrued interest payable 642,000 642,000 — 642,000 — The carrying amount and estimated fair values for financial instruments as of March 31, 2017 were as follows: Carrying value Estimated fair value Level 1 Level 2 Level 3 Financial assets Cash and cash equivalents $ 17,600,000 $ 17,600,000 $ 17,600,000 $ — $ — Interest bearing deposits in other banks 3,272,000 3,272,000 3,272,000 — — Securities available for sale 312,624,000 312,624,000 — 312,624,000 — Securities to be held to maturity 240,829,000 239,378,000 — 239,378,000 — Restricted equity securities 13,363,000 13,363,000 — 13,363,000 — Loans held for sale 979,000 979,000 — 979,000 — Loans (net of allowance for loan losses) Commercial Real estate 299,920,000 295,039,000 — 424,000 294,615,000 Construction 28,254,000 27,794,000 — — 27,794,000 Other 156,233,000 154,823,000 — 33,000 154,790,000 Municipal 28,306,000 28,737,000 — — 28,737,000 Residential Term 420,057,000 420,393,000 — 261,000 420,132,000 Construction 13,689,000 13,593,000 — — 13,593,000 Home equity line of credit 109,058,000 107,823,000 — — 107,823,000 Consumer 23,851,000 23,519,000 — — 23,519,000 Total loans 1,079,368,000 1,071,721,000 — 718,000 1,071,003,000 Mortgage servicing rights 1,054,000 1,853,000 — 1,853,000 — Interest rate swap agreements 1,886,000 1,886,000 — 1,886,000 — Accrued interest receivable 6,854,000 6,854,000 — 6,854,000 — Financial liabilities Demand deposits $ 130,319,000 $ 123,696,000 $ — $ 123,696,000 $ — NOW deposits 323,919,000 296,958,000 — 296,958,000 — Money market deposits 142,220,000 130,374,000 — 130,374,000 — Savings deposits 222,976,000 193,142,000 — 193,142,000 — Local certificates of deposit 213,296,000 212,337,000 — 212,337,000 — National certificates of deposit 313,753,000 313,833,000 — 313,833,000 — Total deposits 1,346,483,000 1,270,340,000 — 1,270,340,000 — Repurchase agreements 76,342,000 72,399,000 — 72,399,000 — Federal Home Loan Bank advances 150,125,000 149,358,000 — 149,358,000 — Total borrowed funds 226,467,000 221,757,000 — 221,757,000 — Accrued interest payable 519,000 519,000 — 519,000 —

Impact of Recently Issued Accou

Impact of Recently Issued Accounting Standards	3 Months Ended
	Mar. 31, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Impact of Recently Issued Accounting Standards	Impact of Recently Issued Accounting Standards The FASB issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers, in 2014 to replace the current plethora of industry-specific rules with a broad, principles-based framework for recognizing and measuring revenue. Due to the complexity of the new pronouncement and the anticipated effort required by entities in many industries to implement ASU No. 2014-09, FASB delayed the effective date. Public business entities, certain not-for-profit entities, and certain employee benefit plans should apply the guidance to annual reporting periods beginning after December 15, 2017, and all other entities should apply the guidance to annual reporting periods beginning after December 15, 2018. FASB formed a Transition Resource Group to assist it in identifying implementation issues that may require further clarification or amendment to ASU No. 2014-09. As a result of that group’s deliberations, FASB has issued the following amendments, which will be effective concurrently with ASU No. 2014-09: ASU No. 2016-08, Principal versus Agent Considerations, which clarifies whether an entity should record the gross amount of revenue or only its ultimate share when a third party is also involved in providing goods or services to a customer; ASU No. 2016-10, Identifying Performance Obligations and Licensing, which clarifies and simplifies the process for determining whether performance obligations to a customer should be segregated and accounted for individually, and clarifies how the new revenue rules apply to licenses of intellectual property; and ASU No. 2016-12, Narrow-Scope Improvements and Practical Expedients, which clarifies and simplifies the process of assessing collectability of consideration under a contract, presentation of sales taxes, accounting for noncash consideration received, and certain transitional issues. The new standard does not apply to revenue associated with financial instruments, including loans and securities that are accounted for under other U.S. GAAP. The Company has reviewed its various other revenue streams and concluded that the new standard will have minimal impact upon its consolidated financial statements. Adoption of ASU No. 2014-09 was made on January 1, 2018 utilizing the modified retrospective approach. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall: Recognition and Measurement of Financial Assets and Financial Liabilities. The ASU was issued to enhance the reporting model for financial instruments to provide users of financial statements with more decision-useful information. This ASU changes how entities account for equity investments that do not result in consolidation and are not accounted for under the equity method of accounting. The ASU also changes certain disclosure requirements and other aspects of U.S. GAAP, including a requirement for public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes. The ASU became effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The adoption of the ASU did not have a material effect on the Company's consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The ASU was issued to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The ASU is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2018. Management is reviewing the guidance in the ASU to determine whether it will have a material effect on the Company’s consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. Under the new guidance, which will replace the existing incurred loss model for recognizing credit losses, banks and other lending institutions will be required to recognize the full amount of expected credit losses. The new guidance, which is referred to as the current expected credit loss model, requires that expected credit losses for financial assets held at the reporting date that are accounted for at amortized cost be measured and recognized based on historical experience and current and reasonably supportable forecasted conditions to reflect the full amount of expected credit losses. A modified version of these requirements also applies to debt securities classified as available for sale. The ASU is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for fiscal years beginning after December 15, 2018, including interim periods within such years. The Company is currently evaluating the impact of the adoption of the ASU on its consolidated financial statements, and anticipates it may have a material impact. The Bank has formed an implementation committee for ASU No. 2016-13. To date, committee members have participated in educational seminars on the new standards, begun the process of identifying the historical data sets that will be necessary to implement the new standard, and have chosen a third-party vendor who provides software solutions for ASU No. 2016-13 modeling and calculation. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. The ASU was issued to reduce the cost and complexity of the goodwill impairment test. To simplify the subsequent measurement of goodwill, step two of the goodwill impairment test was eliminated. Instead, a Company will recognize an impairment of goodwill should the carrying value of a reporting unit exceed its fair value (i.e. step one). The ASU will be effective for the Company on January 1, 2020 and will be applied prospectively. The Company does not expect the implementation to have a material effect on the Company's consolidated financial statements. In March 2017, the FASB issued ASU No. 2017-08, Premium Amortization on Purchased Callable Debt Securities. This ASU shortens the amortization period for the premium on certain purchased callable debt securities to the earliest call date. Today, many entities amortize the premium over the contractual life of the security. The new guidance does not change the accounting for purchased callable debt securities held at a discount; the discount continues to be accreted to maturity. The ASU is effective for interim and annual reporting periods beginning after December 15, 2018; early adoption is permitted. The guidance calls for a modified retrospective transition approach under which a cumulative-effect adjustment will be made to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The Company's current practice aligns with the ASU therefore Management believes there will be no impact on the Company's consolidated financial statements. In May 2017, the FASB issued ASU No. 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting. The ASU was issued to provide clarity and reduce both 1) diversity in practice and 2) cost and complexity when applying the guidance in Topic 718, Compensation-Stock Compensation, to a change to the terms or conditions of a shared-based payment award. The ASU includes guidance on determining which changes to the terms and conditions of share-based payment awards require and entity to apply modification accounting under Topic 718. The ASU is effective for the annual period, and interim periods within the annual periods, beginning after December 15, 2017. Early adoption is permitted, including adoption in any interim period. The ASU should be applied prospectively to an award modified on or after the adoption date. Adoption of the ASU did not have a material effect on the Company's consolidated financial statements. In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 815). The amendments in this ASU improve the financial reporting of hedging relationships to better portray the economic results of an entity's risk management activities in its financial statements. In addition, this ASU makes certain targeted improvements to simplify the application of the hedge accounting guidance in current US GAAP. The amendments in this ASU are effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early application is permitted in any interim period after issuance of the ASU. Management is reviewing the guidance in this ASU to determine whether it will have a material effect on the Company's consolidated financial statements. In February 2018, the FASB issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income (Loss). This ASU was issued to allow a reclassification from accumulated other comprehensive income (loss) to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. Consequently, the amendments eliminate the stranded tax effects resulting from the Tax Cuts and Jobs Act and will improve the usefulness of information reported to financial statement users. However, because the amendments only relate to the reclassification of the income tax effects of the Tax Cuts and Jobs Act, the underlying guidance that requires that the effect of a change in tax laws or rates be included in income from continuing operations is not affected. The ASU is effective for fiscal years beginning after December 15, 2018, with early adoption permitted for financial statements which have not yet been issued. The Company adopted the ASU for the December 31, 2017 consolidated financial statements, which resulted in a reclassification adjustment on the Consolidated Statements of Changes in Shareholders' Equity of $297,000 from accumulated other comprehensive income (loss) to retained earnings. Refer to Note 9, Income Taxes, in the Company's December 31, 2017 Form 10-K for additional information.

Basis of Presentation (Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Financial Derivative Instruments	As part of its overall asset and liability management strategy, the Company periodically uses derivative instruments to minimize significant unplanned fluctuations in earnings and cash flows caused by interest rate volatility. The Company’s interest rate risk management strategy involves modifying the re-pricing characteristics of certain assets or liabilities so that changes in interest rates do not have a significant effect on net interest income. The Company recognizes its derivative instruments in the consolidated balance sheet at fair value. On the date the derivative instrument is entered into, the Company designates whether the derivative is part of a hedging relationship (i.e., cash flow or fair value hedge). The Company formally documents relationships between hedging instruments and hedged items, as well as its risk management objective and strategy for undertaking hedge transactions. The Company also assesses, both at the hedge’s inception and on an ongoing basis, whether the derivatives used in hedging transactions are highly effective in offsetting the changes in cash flows or fair values of hedged items. Changes in fair value of derivative instruments that are highly effective and qualify as cash flow hedges are recorded in other comprehensive income or loss. Any ineffective portion is recorded in earnings. The Company discontinues hedge accounting when it is determined that the derivative is no longer highly effective in offsetting changes of the hedged risk on the hedged item, or management determines that the designation of the derivative as a hedging instrument is no longer appropriate. In 2016, interest rate swaps were contracted to limit the Company’s exposure to rising interest rates on short-term liabilities indexed to one-month London Inter-bank Offered Rates (LIBOR). The interest rate swaps were designated as cash flow hedges.
Reclassifications	Certain items from the prior year were reclassified in the financial statements to conform with the current year presentation. These do not have a material impact on the consolidated balance sheet or statement of income and comprehensive income presentations.
Fair Value	Certain assets and liabilities are recorded at fair value to provide additional insight into the Company's quality of earnings. Some of these assets and liabilities are measured on a recurring basis while others are measured on a nonrecurring basis, with the determination based upon applicable existing accounting pronouncements. For example, securities available for sale are recorded at fair value on a recurring basis. Other assets, such as, other real estate owned and impaired loans, are recorded at fair value on a nonrecurring basis using the lower of cost or market methodology to determine impairment of individual assets. The Company groups assets and liabilities which are recorded at fair value in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. A financial instrument's level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement (with level 1 considered highest and level 3 considered lowest). A brief description of each level follows: Level 1 - Valuation is based upon quoted prices for identical instruments in active markets. Level 2 - Valuation is based upon quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market. Level 3 - Valuation is generated from model-based techniques that use at least one significant assumption not observable in the market. These unobservable assumptions reflect estimates that market participants would use in pricing the asset or liability. Valuation includes use of discounted cash flow models and similar techniques.
Fair Value of Financial Instruments	Fair Value of Financial Instruments FASB ASC Topic 825 "Financial Instruments" requires disclosures of fair value information about financial instruments, whether or not recognized in the balance sheet, if the fair values can be reasonably determined. Fair value is best determined based upon quoted market prices. However, in many instances, there are no quoted market prices for the Company's various financial instruments. In cases where quoted market prices are not available, fair values are based on estimates using present value or other valuation techniques using observable inputs when available. Those techniques are significantly affected by the assumptions used, including the discount rate and estimates of future cash flows. Accordingly, the fair value estimates may not be realized in an immediate settlement of the instrument. Topic 825 excludes certain financial instruments and all nonfinancial instruments from its disclosure requirements. Accordingly, the aggregate fair value amounts presented may not necessarily represent the underlying fair value of the Company.
Impact of Recently Issued Accounting Standards	Impact of Recently Issued Accounting Standards The FASB issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers, in 2014 to replace the current plethora of industry-specific rules with a broad, principles-based framework for recognizing and measuring revenue. Due to the complexity of the new pronouncement and the anticipated effort required by entities in many industries to implement ASU No. 2014-09, FASB delayed the effective date. Public business entities, certain not-for-profit entities, and certain employee benefit plans should apply the guidance to annual reporting periods beginning after December 15, 2017, and all other entities should apply the guidance to annual reporting periods beginning after December 15, 2018. FASB formed a Transition Resource Group to assist it in identifying implementation issues that may require further clarification or amendment to ASU No. 2014-09. As a result of that group’s deliberations, FASB has issued the following amendments, which will be effective concurrently with ASU No. 2014-09: ASU No. 2016-08, Principal versus Agent Considerations, which clarifies whether an entity should record the gross amount of revenue or only its ultimate share when a third party is also involved in providing goods or services to a customer; ASU No. 2016-10, Identifying Performance Obligations and Licensing, which clarifies and simplifies the process for determining whether performance obligations to a customer should be segregated and accounted for individually, and clarifies how the new revenue rules apply to licenses of intellectual property; and ASU No. 2016-12, Narrow-Scope Improvements and Practical Expedients, which clarifies and simplifies the process of assessing collectability of consideration under a contract, presentation of sales taxes, accounting for noncash consideration received, and certain transitional issues. The new standard does not apply to revenue associated with financial instruments, including loans and securities that are accounted for under other U.S. GAAP. The Company has reviewed its various other revenue streams and concluded that the new standard will have minimal impact upon its consolidated financial statements. Adoption of ASU No. 2014-09 was made on January 1, 2018 utilizing the modified retrospective approach. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments - Overall: Recognition and Measurement of Financial Assets and Financial Liabilities. The ASU was issued to enhance the reporting model for financial instruments to provide users of financial statements with more decision-useful information. This ASU changes how entities account for equity investments that do not result in consolidation and are not accounted for under the equity method of accounting. The ASU also changes certain disclosure requirements and other aspects of U.S. GAAP, including a requirement for public business entities to use the exit price notion when measuring the fair value of financial instruments for disclosure purposes. The ASU became effective for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The adoption of the ASU did not have a material effect on the Company's consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The ASU was issued to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The ASU is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2018. Management is reviewing the guidance in the ASU to determine whether it will have a material effect on the Company’s consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. Under the new guidance, which will replace the existing incurred loss model for recognizing credit losses, banks and other lending institutions will be required to recognize the full amount of expected credit losses. The new guidance, which is referred to as the current expected credit loss model, requires that expected credit losses for financial assets held at the reporting date that are accounted for at amortized cost be measured and recognized based on historical experience and current and reasonably supportable forecasted conditions to reflect the full amount of expected credit losses. A modified version of these requirements also applies to debt securities classified as available for sale. The ASU is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. Early adoption is permitted for fiscal years beginning after December 15, 2018, including interim periods within such years. The Company is currently evaluating the impact of the adoption of the ASU on its consolidated financial statements, and anticipates it may have a material impact. The Bank has formed an implementation committee for ASU No. 2016-13. To date, committee members have participated in educational seminars on the new standards, begun the process of identifying the historical data sets that will be necessary to implement the new standard, and have chosen a third-party vendor who provides software solutions for ASU No. 2016-13 modeling and calculation. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. The ASU was issued to reduce the cost and complexity of the goodwill impairment test. To simplify the subsequent measurement of goodwill, step two of the goodwill impairment test was eliminated. Instead, a Company will recognize an impairment of goodwill should the carrying value of a reporting unit exceed its fair value (i.e. step one). The ASU will be effective for the Company on January 1, 2020 and will be applied prospectively. The Company does not expect the implementation to have a material effect on the Company's consolidated financial statements. In March 2017, the FASB issued ASU No. 2017-08, Premium Amortization on Purchased Callable Debt Securities. This ASU shortens the amortization period for the premium on certain purchased callable debt securities to the earliest call date. Today, many entities amortize the premium over the contractual life of the security. The new guidance does not change the accounting for purchased callable debt securities held at a discount; the discount continues to be accreted to maturity. The ASU is effective for interim and annual reporting periods beginning after December 15, 2018; early adoption is permitted. The guidance calls for a modified retrospective transition approach under which a cumulative-effect adjustment will be made to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The Company's current practice aligns with the ASU therefore Management believes there will be no impact on the Company's consolidated financial statements. In May 2017, the FASB issued ASU No. 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting. The ASU was issued to provide clarity and reduce both 1) diversity in practice and 2) cost and complexity when applying the guidance in Topic 718, Compensation-Stock Compensation, to a change to the terms or conditions of a shared-based payment award. The ASU includes guidance on determining which changes to the terms and conditions of share-based payment awards require and entity to apply modification accounting under Topic 718. The ASU is effective for the annual period, and interim periods within the annual periods, beginning after December 15, 2017. Early adoption is permitted, including adoption in any interim period. The ASU should be applied prospectively to an award modified on or after the adoption date. Adoption of the ASU did not have a material effect on the Company's consolidated financial statements. In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 815). The amendments in this ASU improve the financial reporting of hedging relationships to better portray the economic results of an entity's risk management activities in its financial statements. In addition, this ASU makes certain targeted improvements to simplify the application of the hedge accounting guidance in current US GAAP. The amendments in this ASU are effective for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Early application is permitted in any interim period after issuance of the ASU. Management is reviewing the guidance in this ASU to determine whether it will have a material effect on the Company's consolidated financial statements. In February 2018, the FASB issued ASU No. 2018-02, Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income (Loss). This ASU was issued to allow a reclassification from accumulated other comprehensive income (loss) to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. Consequently, the amendments eliminate the stranded tax effects resulting from the Tax Cuts and Jobs Act and will improve the usefulness of information reported to financial statement users. However, because the amendments only relate to the reclassification of the income tax effects of the Tax Cuts and Jobs Act, the underlying guidance that requires that the effect of a change in tax laws or rates be included in income from continuing operations is not affected. The ASU is effective for fiscal years beginning after December 15, 2018, with early adoption permitted for financial statements which have not yet been issued. The Company adopted the ASU for the December 31, 2017 consolidated financial statements, which resulted in a reclassification adjustment on the Consolidated Statements of Changes in Shareholders' Equity of $297,000 from accumulated other comprehensive income (loss) to retained earnings. Refer to Note 9, Income Taxes, in the Company's December 31, 2017 Form 10-K for additional information.

Investment Securities (Tables)

Investment Securities (Tables)	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of Available For Sale, Held-to-Maturity, and Restricted Equity Securities	The following table summarizes the amortized cost and estimated fair value of investment securities at March 31, 2018 : Amortized Cost Unrealized Gains Unrealized Losses Fair Value (Estimated) Securities available for sale Mortgage-backed securities $ 302,935,000 $ 191,000 $ (7,798,000 ) $ 295,328,000 State and political subdivisions 5,765,000 3,000 (257,000 ) 5,511,000 Other equity securities 2,930,000 — — 2,930,000 $ 311,630,000 $ 194,000 $ (8,055,000 ) $ 303,769,000 Securities to be held to maturity U.S. Government-sponsored agencies $ 11,155,000 $ — $ (515,000 ) $ 10,640,000 Mortgage-backed securities 21,990,000 469,000 (289,000 ) 22,170,000 State and political subdivisions 221,245,000 1,497,000 (4,001,000 ) 218,741,000 Corporate securities 4,300,000 — — 4,300,000 $ 258,690,000 $ 1,966,000 $ (4,805,000 ) $ 255,851,000 Restricted equity securities Federal Home Loan Bank Stock $ 10,910,000 $ — $ — $ 10,910,000 Federal Reserve Bank Stock 1,037,000 — — 1,037,000 $ 11,947,000 $ — $ — $ 11,947,000 The following table summarizes the amortized cost and estimated fair value of investment securities at December 31, 2017 : Amortized Cost Unrealized Gains Unrealized Losses Fair Value (Estimated) Securities available for sale Mortgage-backed securities $ 293,689,000 $ 722,000 $ (4,422,000 ) $ 289,989,000 State and political subdivisions 6,860,000 16,000 (107,000 ) 6,769,000 Other equity securities 3,296,000 121,000 (3,000 ) 3,414,000 $ 303,845,000 $ 859,000 $ (4,532,000 ) $ 300,172,000 Securities to be held to maturity U.S. Government-sponsored agencies $ 11,155,000 $ — $ (180,000 ) $ 10,975,000 Mortgage-backed securities 23,284,000 568,000 (128,000 ) 23,724,000 State and political subdivisions 217,828,000 3,931,000 (1,103,000 ) 220,656,000 Corporate securities 4,300,000 — — 4,300,000 $ 256,567,000 $ 4,499,000 $ (1,411,000 ) $ 259,655,000 Restricted equity securities Federal Home Loan Bank Stock $ 9,321,000 $ — $ — $ 9,321,000 Federal Reserve Bank Stock 1,037,000 — — 1,037,000 $ 10,358,000 $ — $ — $ 10,358,000 The following table summarizes the amortized cost and estimated fair value of investment securities at March 31, 2017 : Amortized Cost Unrealized Gains Unrealized Losses Fair Value (Estimated) Securities available for sale Mortgage-backed securities $ 295,424,000 $ 1,407,000 $ (3,204,000 ) $ 293,627,000 State and political subdivisions 15,407,000 474,000 (176,000 ) 15,705,000 Other equity securities 3,229,000 67,000 (4,000 ) 3,292,000 $ 314,060,000 $ 1,948,000 $ (3,384,000 ) $ 312,624,000 Securities to be held to maturity U.S. Government-sponsored agencies $ 12,050,000 $ — $ (317,000 ) $ 11,733,000 Mortgage-backed securities 29,093,000 880,000 (135,000 ) 29,838,000 State and political subdivisions 195,386,000 2,079,000 (3,958,000 ) 193,507,000 Corporate securities 4,300,000 — — 4,300,000 $ 240,829,000 $ 2,959,000 $ (4,410,000 ) $ 239,378,000 Restricted equity securities Federal Home Loan Bank Stock $ 12,326,000 $ — $ — $ 12,326,000 Federal Reserve Bank Stock 1,037,000 — — 1,037,000 $ 13,363,000 $ — $ — $ 13,363,000
Contractual Maturities of Investment Securities	The following table summarizes the contractual maturities of investment securities at March 31, 2018 : Securities available for sale Securities to be held to maturity Amortized Cost Fair Value (Estimated) Amortized Cost Fair Value (Estimated) Due in 1 year or less $ 61,000 $ 61,000 $ 634,000 $ 635,000 Due in 1 to 5 years 6,502,000 6,492,000 25,692,000 25,796,000 Due in 5 to 10 years 66,434,000 65,234,000 145,297,000 144,211,000 Due after 10 years 235,703,000 229,052,000 87,067,000 85,209,000 Equity securities 2,930,000 2,930,000 — — $ 311,630,000 $ 303,769,000 $ 258,690,000 $ 255,851,000 The following table summarizes the contractual maturities of investment securities at December 31, 2017 : Securities available for sale Securities to be held to maturity Amortized Cost Fair Value (Estimated) Amortized Cost Fair Value (Estimated) Due in 1 year or less $ 111,000 $ 112,000 $ 635,000 $ 637,000 Due in 1 to 5 years 841,000 842,000 18,059,000 18,164,000 Due in 5 to 10 years 29,003,000 29,177,000 37,182,000 37,719,000 Due after 10 years 270,594,000 266,627,000 200,691,000 203,135,000 Equity securities 3,296,000 3,414,000 — — $ 303,845,000 $ 300,172,000 $ 256,567,000 $ 259,655,000 The following table summarizes the contractual maturities of investment securities at March 31, 2017 : Securities available for sale Securities to be held to maturity Amortized Cost Fair Value (Estimated) Amortized Cost Fair Value (Estimated) Due in 1 year or less $ 43,000 $ 43,000 $ 903,000 $ 908,000 Due in 1 to 5 years 1,909,000 1,953,000 12,213,000 12,477,000 Due in 5 to 10 years 31,835,000 32,471,000 42,819,000 43,562,000 Due after 10 years 277,044,000 274,865,000 184,894,000 182,431,000 Equity securities 3,229,000 3,292,000 — — $ 314,060,000 $ 312,624,000 $ 240,829,000 $ 239,378,000
Schedule of Securities Gains and Losses	The following table shows securities gains and losses for the three months ended March 31, 2018 and 2017 : For the three months ended March 31, 2018 2017 Proceeds from sales of securities $ 459,000 $ 3,000 Gross realized gains 136,000 3,000 Gross realized losses — — Net gain $ 136,000 $ 3,000 Related income taxes $ 29,000 $ 1,000
Schedule of Securities Temporarily Impaired	Information regarding securities temporarily impaired as of March 31, 2018 is summarized below: Less than 12 months 12 months or more Total Fair Value (Estimated) Unrealized Losses Fair Value (Estimated) Unrealized Losses Fair Value (Estimated) Unrealized Losses U.S. Government-sponsored agencies $ 6,946,000 $ (309,000 ) $ 3,694,000 $ (206,000 ) $ 10,640,000 $ (515,000 ) Mortgage-backed securities 183,335,000 (4,332,000 ) 101,012,000 (3,755,000 ) 284,347,000 (8,087,000 ) State and political subdivisions 64,594,000 (1,533,000 ) 37,182,000 (2,725,000 ) 101,776,000 (4,258,000 ) $ 254,875,000 $ (6,174,000 ) $ 141,888,000 $ (6,686,000 ) $ 396,763,000 $ (12,860,000 ) As of December 31, 2017 , there were 241 securities with unrealized losses held in the Company's portfolio. These securities were temporarily impaired as a result of changes in interest rates reducing their fair value, of which 157 had been temporarily impaired for 12 months or more. Information regarding securities temporarily impaired as of December 31, 2017 is summarized below: Less than 12 months 12 months or more Total Fair Value (Estimated) Unrealized Losses Fair Value (Estimated) Unrealized Losses Fair Value (Estimated) Unrealized Losses U.S. Government-sponsored agencies $ 7,161,000 $ (94,000 ) $ 3,814,000 $ (86,000 ) $ 10,975,000 $ (180,000 ) Mortgage-backed securities 132,025,000 (1,857,000 ) 101,707,000 (2,693,000 ) 233,732,000 (4,550,000 ) State and political subdivisions 9,425,000 (149,000 ) 38,864,000 (1,061,000 ) 48,289,000 (1,210,000 ) Other equity securities — — 9,000 (3,000 ) 9,000 (3,000 ) $ 148,611,000 $ (2,100,000 ) $ 144,394,000 $ (3,843,000 ) $ 293,005,000 $ (5,943,000 ) As of March 31, 2017 , there were 311 securities with unrealized losses held in the Company's portfolio. These securities were temporarily impaired as a result of changes in interest rates reducing their fair value, of which 13 had been temporarily impaired for 12 months or more. Information regarding securities temporarily impaired as of March 31, 2017 is summarized below: Less than 12 months 12 months or more Total Fair Value (Estimated) Unrealized Losses Fair Value (Estimated) Unrealized Losses Fair Value (Estimated) Unrealized Losses U.S. Government-sponsored agencies $ 10,824,000 $ (317,000 ) $ — $ — $ 10,824,000 $ (317,000 ) Mortgage-backed securities 198,068,000 (3,193,000 ) 2,432,000 (146,000 ) 200,500,000 (3,339,000 ) State and political subdivisions 78,516,000 (4,134,000 ) — — 78,516,000 (4,134,000 ) Other equity securities — — 62,000 (4,000 ) 62,000 (4,000 ) $ 287,408,000 $ (7,644,000 ) $ 2,494,000 $ (150,000 ) $ 289,902,000 $ (7,794,000 )

Loans (Tables)

Loans (Tables)	3 Months Ended
	Mar. 31, 2018
Loans and Leases Receivable Disclosure [Abstract]
Composition of Loan Portfolio	The following table shows the composition of the Company's loan portfolio as of March 31, 2018 and 2017 and at December 31, 2017 : March 31, 2018 December 31, 2017 March 31, 2017 Commercial Real estate $ 339,306,000 28.6 % $ 323,809,000 27.8 % $ 304,663,000 28.0 % Construction 43,813,000 3.7 % 38,056,000 3.3 % 28,775,000 2.6 % Other 177,783,000 15.0 % 181,528,000 15.6 % 158,507,000 14.4 % Municipal 35,463,000 3.0 % 33,391,000 2.9 % 28,327,000 2.6 % Residential Term 439,984,000 37.0 % 432,661,000 37.1 % 421,202,000 38.7 % Construction 15,847,000 1.3 % 17,868,000 1.5 % 13,717,000 1.3 % Home equity line of credit 110,298,000 9.3 % 111,302,000 9.6 % 110,016,000 10.1 % Consumer 25,508,000 2.1 % 25,524,000 2.2 % 24,528,000 2.3 % Total $ 1,188,002,000 100.0 % $ 1,164,139,000 100.0 % $ 1,089,735,000 100.0 %
Past Due Loans Aging	Information on the past-due status of loans by class of financing receivable as of March 31, 2018 , is presented in the following table: 30-59 Days Past Due 60-89 Days Past Due 90+ Days Past Due All Past Due Current Total 90+ Days & Accruing Commercial Real estate $ 963,000 $ 17,000 $ 202,000 $ 1,182,000 $ 338,124,000 $ 339,306,000 $ — Construction 347,000 — — 347,000 43,466,000 43,813,000 — Other 6,887,000 52,000 294,000 7,233,000 170,550,000 177,783,000 — Municipal — — — — 35,463,000 35,463,000 — Residential Term 3,175,000 345,000 1,880,000 5,400,000 434,584,000 439,984,000 — Construction — — — — 15,847,000 15,847,000 — Home equity line of credit 449,000 438,000 664,000 1,551,000 108,747,000 110,298,000 126,000 Consumer 119,000 8,000 27,000 154,000 25,354,000 25,508,000 11,000 Total $ 11,940,000 $ 860,000 $ 3,067,000 $ 15,867,000 $ 1,172,135,000 $ 1,188,002,000 $ 137,000 Information on the past-due status of loans by class of financing receivable as of December 31, 2017 , is presented in the following table: 30-59 Days Past Due 60-89 Days Past Due 90+ Days Past Due All Past Due Current Total 90+ Days & Accruing Commercial Real estate $ 574,000 $ 80,000 $ 220,000 $ 874,000 $ 322,935,000 $ 323,809,000 $ — Construction — — — — 38,056,000 38,056,000 — Other 542,000 6,663,000 574,000 7,779,000 173,749,000 181,528,000 — Municipal — — — — 33,391,000 33,391,000 — Residential Term 1,031,000 4,372,000 2,256,000 7,659,000 425,002,000 432,661,000 436,000 Construction 101,000 370,000 — 471,000 17,397,000 17,868,000 — Home equity line of credit 537,000 445,000 725,000 1,707,000 109,595,000 111,302,000 — Consumer 159,000 18,000 9,000 186,000 25,338,000 25,524,000 9,000 Total $ 2,944,000 $ 11,948,000 $ 3,784,000 $ 18,676,000 $ 1,145,463,000 $ 1,164,139,000 $ 445,000 Information on the past-due status of loans by class of financing receivable as of March 31, 2017 , is presented in the following table: 30-59 Days Past Due 60-89 Days Past Due 90+ Days Past Due All Past Due Current Total 90+ Days & Accruing Commercial Real estate $ 142,000 $ 772,000 $ 1,823,000 $ 2,737,000 $ 301,926,000 $ 304,663,000 $ — Construction 20,000 — — 20,000 28,755,000 28,775,000 — Other 199,000 154,000 439,000 792,000 157,715,000 158,507,000 — Municipal — — — — 28,327,000 28,327,000 — Residential Term 3,555,000 — 1,603,000 5,158,000 416,044,000 421,202,000 — Construction — — — — 13,717,000 13,717,000 — Home equity line of credit 392,000 167,000 773,000 1,332,000 108,684,000 110,016,000 — Consumer 328,000 34,000 11,000 373,000 24,155,000 24,528,000 11,000 Total $ 4,636,000 $ 1,127,000 $ 4,649,000 $ 10,412,000 $ 1,079,323,000 $ 1,089,735,000 $ 11,000
Nonaccrual Loans	Information on nonaccrual loans as of March 31, 2018 and 2017 and at December 31, 2017 is presented in the following table: March 31, 2018 December 31, 2017 March 31, 2017 Commercial Real estate $ 1,021,000 $ 752,000 $ 2,625,000 Construction — — — Other 8,895,000 9,357,000 938,000 Municipal — — — Residential Term 3,654,000 3,778,000 4,028,000 Construction — — — Home equity line of credit 697,000 833,000 909,000 Consumer 16,000 16,000 — Total $ 14,283,000 $ 14,736,000 $ 8,500,000
Impaired Loans by Class of Financing Receivable	A breakdown of impaired loans by class of financing receivable as of and for the period ended March 31, 2018 is presented in the following table: For the three months ended March 31, 2018 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Recognized Interest Income With No Related Allowance Commercial Real estate $ 5,054,000 $ 5,269,000 $ — $ 4,163,000 $ 54,000 Construction 741,000 741,000 — 741,000 10,000 Other 2,281,000 2,360,000 — 2,302,000 6,000 Municipal — — — — — Residential Term 9,594,000 10,733,000 — 9,700,000 71,000 Construction — — — — — Home equity line of credit 917,000 1,008,000 — 1,090,000 5,000 Consumer 16,000 29,000 — 16,000 — $ 18,603,000 $ 20,140,000 $ — $ 18,012,000 $ 146,000 With an Allowance Recorded Commercial Real estate $ 3,897,000 $ 4,002,000 $ 254,000 $ 3,889,000 $ 39,000 Construction — — — — — Other 7,159,000 7,324,000 1,664,000 7,182,000 — Municipal — — — — — Residential Term 1,934,000 2,146,000 272,000 1,968,000 24,000 Construction — — — — — Home equity line of credit 122,000 125,000 16,000 70,000 — Consumer — — — — — $ 13,112,000 $ 13,597,000 $ 2,206,000 $ 13,109,000 $ 63,000 Total Commercial Real estate $ 8,951,000 $ 9,271,000 $ 254,000 $ 8,052,000 $ 93,000 Construction 741,000 741,000 — 741,000 10,000 Other 9,440,000 9,684,000 1,664,000 9,484,000 6,000 Municipal — — — — — Residential Term 11,528,000 12,879,000 272,000 11,668,000 95,000 Construction — — — — — Home equity line of credit 1,039,000 1,133,000 16,000 1,160,000 5,000 Consumer 16,000 29,000 — 16,000 — $ 31,715,000 $ 33,737,000 $ 2,206,000 $ 31,121,000 $ 209,000 Substantially all interest income recognized on impaired loans for all classes of financing receivables was recognized on a cash basis as received. A breakdown of impaired loans by class of financing receivable as of and for the year ended December 31, 2017 is presented in the following table: Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Recognized Interest Income With No Related Allowance Commercial Real estate $ 3,791,000 $ 3,996,000 $ — $ 5,124,000 $ 164,000 Construction 741,000 741,000 — 62,000 38,000 Other 2,591,000 2,671,000 — 1,908,000 36,000 Municipal — — — — — Residential Term 9,769,000 10,909,000 — 10,770,000 297,000 Construction — — — — — Home equity line of credit 1,115,000 1,429,000 — 1,351,000 18,000 Consumer 16,000 29,000 — 12,000 — $ 18,023,000 $ 19,775,000 $ — $ 19,227,000 $ 553,000 With an Allowance Recorded Commercial Real estate $ 3,999,000 $ 4,116,000 $ 224,000 $ 4,460,000 $ 152,000 Construction — — — 699,000 — Other 7,327,000 7,371,000 1,309,000 2,584,000 — Municipal — — — — — Residential Term 1,979,000 2,144,000 255,000 2,106,000 79,000 Construction — — — — — Home equity line of credit 64,000 67,000 24,000 32,000 — Consumer — — — — — $ 13,369,000 $ 13,698,000 $ 1,812,000 $ 9,881,000 $ 231,000 Total Commercial Real estate $ 7,790,000 $ 8,112,000 $ 224,000 $ 9,584,000 $ 316,000 Construction 741,000 741,000 — 761,000 38,000 Other 9,918,000 10,042,000 1,309,000 4,492,000 36,000 Municipal — — — — — Residential Term 11,748,000 13,053,000 255,000 12,876,000 376,000 Construction — — — — — Home equity line of credit 1,179,000 1,496,000 24,000 1,383,000 18,000 Consumer 16,000 29,000 — 12,000 — $ 31,392,000 $ 33,473,000 $ 1,812,000 $ 29,108,000 $ 784,000 A breakdown of impaired loans by class of financing receivable as of and for the period ended March 31, 2017 is presented in the following table: For the three months ended March 31, 2017 Recorded Investment Unpaid Principal Balance Related Allowance Average Recorded Investment Recognized Interest Income With No Related Allowance Commercial Real estate $ 5,949,000 $ 6,450,000 $ — $ 5,444,000 $ 51,000 Construction — — — — — Other 1,476,000 1,636,000 — 1,595,000 22,000 Municipal — — — — — Residential Term 11,388,000 12,470,000 — 11,402,000 129,000 Construction — — — — — Home equity line of credit 1,422,000 1,752,000 — 1,376,000 9,000 Consumer — — — — — $ 20,235,000 $ 22,308,000 $ — $ 19,817,000 $ 211,000 With an Allowance Recorded Commercial Real estate $ 4,722,000 $ 4,908,000 $ 351,000 $ 4,741,000 $ 46,000 Construction 763,000 763,000 101,000 763,000 9,000 Other 234,000 272,000 39,000 125,000 4,000 Municipal — — — — — Residential Term 1,872,000 2,020,000 251,000 2,077,000 23,000 Construction — — — — — Home equity line of credit 26,000 27,000 26,000 26,000 — Consumer — — — — — $ 7,617,000 $ 7,990,000 $ 768,000 $ 7,732,000 $ 82,000 Total Commercial Real estate $ 10,671,000 $ 11,358,000 $ 351,000 $ 10,185,000 $ 97,000 Construction 763,000 763,000 101,000 763,000 9,000 Other 1,710,000 1,908,000 39,000 1,720,000 26,000 Municipal — — — — — Residential Term 13,260,000 14,490,000 251,000 13,479,000 152,000 Construction — — — — — Home equity line of credit 1,448,000 1,779,000 26,000 1,402,000 9,000 Consumer — — — — — $ 27,852,000 $ 30,298,000 $ 768,000 $ 27,549,000 $ 293,000
Troubled Debt Restructurings on Financing Receivables	The following table shows these TDRs by class and the associated specific reserves included in the allowance for loan losses as of March 31, 2017 : Number of Loans Balance Specific Reserves Commercial Real estate 1 $ 658,000 $ — Construction — — — Other — — — Municipal — — — Residential Term 7 826,000 — Construction — — — Home equity line of credit 1 167,000 — Consumer — — — 9 $ 1,651,000 $ — For the three months ended March 31, 2018 , seven loans were placed on TDR status. The following table shows these TDRs by class and the associated specific reserves included in the allowance for loan losses as of March 31, 2018 : For the quarter ended March 31, 2018 Number of Loans Pre-Modification Post-Modification Outstanding Specific Reserves Commercial Real estate 7 $ 1,056,000 $ 1,056,000 $ 36,000 Construction — — — — Other — — — — Municipal — — — — Residential Term — — — — Construction — — — — Home equity line of credit — — — — Consumer — — — — 7 $ 1,056,000 $ 1,056,000 $ 36,000 The following table shows these TDRs by class and the associated specific reserves included in the allowance for loan losses as of March 31, 2018 : Number of Loans Balance Specific Reserves Commercial Real estate — $ — $ — Construction — — — Other — — — Municipal — — — Residential Term 6 643,000 45,000 Construction — — — Home equity line of credit 1 167,000 — Consumer — — — 7 $ 810,000 $ 45,000 The following table shows TDRs by class and the specific reserve as of March 31, 2018 : Number of Loans Balance Specific Reserves Commercial Real estate 15 $ 8,030,000 $ 132,000 Construction 1 741,000 — Other 4 546,000 — Municipal — — — Residential Term 46 8,883,000 271,000 Construction — — — Home equity line of credit 3 509,000 — Consumer — — — 69 $ 18,709,000 $ 403,000 The following table shows TDRs by class and the specific reserve as of December 31, 2017 : Number of Loans Balance Specific Reserves Commercial Real estate 8 $ 7,038,000 $ 90,000 Construction 1 741,000 — Other 4 561,000 — Municipal — — — Residential Term 46 8,948,000 233,000 Construction — — — Home equity line of credit 3 513,000 — Consumer — — — 62 $ 17,801,000 $ 323,000 The following table shows TDRs by class and the specific reserve as of March 31, 2017 : Number of Loans Balance Specific Reserves Commercial Real estate 10 $ 8,703,000 $ 82,000 Construction 1 763,000 101,000 Other 5 772,000 2,000 Municipal — — — Residential Term 51 10,344,000 201,000 Construction — — — Home equity line of credit 3 539,000 — Consumer — — — 70 $ 21,121,000 $ 386,000

Allowance for Loan Losses (Tabl

Allowance for Loan Losses (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Allowance for Loan Losses by Class of Financing Receivable and Allowance	A breakdown of the allowance for loan losses as of March 31, 2018 , December 31, 2017 , and March 31, 2017 , by class of financing receivable and allowance element, is presented in the following tables: As of March 31, 2018 Specific Reserves on Loans Evaluated Individually for Impairment General Reserves on Loans Based on Historical Loss Experience Reserves for Qualitative Factors Unallocated Reserves Total Reserves Commercial Real estate $ 254,000 $ 1,039,000 $ 2,439,000 $ — $ 3,732,000 Construction — 81,000 315,000 — 396,000 Other 1,664,000 597,000 1,279,000 — 3,540,000 Municipal — — 21,000 — 21,000 Residential Term 272,000 303,000 554,000 — 1,129,000 Construction — 11,000 20,000 — 31,000 Home equity line of credit 16,000 297,000 403,000 — 716,000 Consumer — 265,000 316,000 — 581,000 Unallocated — — — 811,000 811,000 $ 2,206,000 $ 2,593,000 $ 5,347,000 $ 811,000 $ 10,957,000 As of December 31, 2017 Specific Reserves on Loans Evaluated Individually for Impairment General Reserves on Loans Based on Historical Loss Experience Reserves for Qualitative Factors Unallocated Reserves Total Reserves Commercial Real estate $ 224,000 $ 1,285,000 $ 2,363,000 $ — $ 3,872,000 Construction — 153,000 281,000 — 434,000 Other 1,309,000 723,000 1,326,000 — 3,358,000 Municipal — — 20,000 — 20,000 Residential Term 255,000 311,000 564,000 — 1,130,000 Construction — 13,000 23,000 — 36,000 Home equity line of credit 24,000 297,000 371,000 — 692,000 Consumer — 251,000 294,000 — 545,000 Unallocated — — — 642,000 642,000 $ 1,812,000 $ 3,033,000 $ 5,242,000 $ 642,000 $ 10,729,000 As of March 31, 2017 Specific Reserves on Loans Evaluated Individually for Impairment General Reserves on Loans Based on Historical Loss Experience Reserves for Qualitative Factors Unallocated Reserves Total Reserves Commercial Real estate $ 351,000 $ 1,631,000 $ 2,033,000 $ — $ 4,015,000 Construction 101,000 151,000 189,000 — 441,000 Other 39,000 840,000 1,046,000 — 1,925,000 Municipal — — 18,000 — 18,000 Residential Term 251,000 282,000 436,000 — 969,000 Construction — 9,000 15,000 — 24,000 Home equity line of credit 26,000 439,000 346,000 — 811,000 Consumer — 337,000 236,000 — 573,000 Unallocated — — — 1,591,000 1,591,000 $ 768,000 $ 3,689,000 $ 4,319,000 $ 1,591,000 $ 10,367,000
Summary of Risk Ratings for Loans	The following table summarizes the risk ratings for the Company's commercial real estate, commercial construction, commercial other, and municipal loans as of March 31, 2018 : Commercial Real Estate Commercial Construction Commercial Other Municipal Loans All Risk- Rated Loans 1 Strong $ — $ — $ 1,251,000 $ — $ 1,251,000 2 Above Average 12,308,000 40,000 5,528,000 33,875,000 51,751,000 3 Satisfactory 74,612,000 4,776,000 38,738,000 653,000 118,779,000 4 Average 183,675,000 21,585,000 79,751,000 935,000 285,946,000 5 Watch 46,918,000 17,412,000 35,743,000 — 100,073,000 6 OAEM 3,148,000 — 1,866,000 — 5,014,000 7 Substandard 18,522,000 — 14,906,000 — 33,428,000 8 Doubtful 123,000 — — — 123,000 Total $ 339,306,000 $ 43,813,000 $ 177,783,000 $ 35,463,000 $ 596,365,000 The following table summarizes the risk ratings for the Company's commercial real estate, commercial construction, commercial other, and municipal loans as of December 31, 2017 : Commercial Real Estate Commercial Construction Commercial Other Municipal Loans All Risk- Rated Loans 1 Strong $ — $ — $ 1,586,000 $ — $ 1,586,000 2 Above Average 12,534,000 40,000 5,776,000 32,673,000 51,023,000 3 Satisfactory 73,899,000 2,856,000 38,151,000 718,000 115,624,000 4 Average 173,956,000 22,446,000 84,360,000 — 280,762,000 5 Watch 41,652,000 12,714,000 33,934,000 — 88,300,000 6 OAEM 3,442,000 — 2,765,000 — 6,207,000 7 Substandard 18,203,000 — 14,956,000 — 33,159,000 8 Doubtful 123,000 — — — 123,000 Total $ 323,809,000 $ 38,056,000 $ 181,528,000 $ 33,391,000 $ 576,784,000 The following table summarizes the risk ratings for the Company's commercial real estate, commercial construction, commercial other, and municipal loans as of March 31, 2017 : Commercial Real Estate Commercial Construction Commercial Other Municipal Loans All Risk- Rated Loans 1 Strong $ 2,000 $ — $ 499,000 $ — $ 501,000 2 Above Average 14,213,000 45,000 8,222,000 27,479,000 49,959,000 3 Satisfactory 83,021,000 2,051,000 47,724,000 848,000 133,644,000 4 Average 138,865,000 18,283,000 72,791,000 — 229,939,000 5 Watch 45,053,000 8,239,000 14,280,000 — 67,572,000 6 OAEM 4,036,000 — 5,661,000 — 9,697,000 7 Substandard 19,473,000 157,000 9,330,000 — 28,960,000 8 Doubtful — — — — — Total $ 304,663,000 $ 28,775,000 $ 158,507,000 $ 28,327,000 $ 520,272,000
Allowance for Loan Losses Transactions	The following table presents allowance for loan losses activity by class for the three months ended March 31, 2018 , and allowance for loan loss balances by class and related loan balances by class as of March 31, 2018 : Commercial Municipal Residential Home Equity Line of Credit Consumer Unallocated Total Real Estate Construction Other Term Construction For the three months ended March 31, 2018 Beginning balance $ 3,872,000 $ 434,000 $ 3,358,000 $ 20,000 $ 1,130,000 $ 36,000 $ 692,000 $ 545,000 $ 642,000 $ 10,729,000 Charge offs — — 17,000 — 81,000 — 115,000 105,000 — 318,000 Recoveries — — 6,000 — 4,000 — 11,000 25,000 — 46,000 Provision (credit) (140,000 ) (38,000 ) 193,000 1,000 76,000 (5,000 ) 128,000 116,000 169,000 500,000 Ending balance $ 3,732,000 $ 396,000 $ 3,540,000 $ 21,000 $ 1,129,000 $ 31,000 $ 716,000 $ 581,000 $ 811,000 $ 10,957,000 Allowance for loan losses as of March 31, 2018 Ending balance specifically evaluated for impairment $ 254,000 $ — $ 1,664,000 $ — $ 272,000 $ — $ 16,000 $ — $ — $ 2,206,000 Ending balance collectively evaluated for impairment $ 3,478,000 $ 396,000 $ 1,876,000 $ 21,000 $ 857,000 $ 31,000 $ 700,000 $ 581,000 $ 811,000 $ 8,751,000 Related loan balances as of March 31, 2018 Ending balance $ 339,306,000 $ 43,813,000 $ 177,783,000 $ 35,463,000 $ 439,984,000 $ 15,847,000 $ 110,298,000 $ 25,508,000 $ — $ 1,188,002,000 Ending balance specifically evaluated for impairment $ 8,951,000 $ 741,000 $ 9,440,000 $ — $ 11,528,000 $ — $ 1,039,000 $ 16,000 $ — $ 31,715,000 Ending balance collectively evaluated for impairment $ 330,355,000 $ 43,072,000 $ 168,343,000 $ 35,463,000 $ 428,456,000 $ 15,847,000 $ 109,259,000 $ 25,492,000 $ — $ 1,156,287,000 The following table presents allowance for loan losses activity by class for the year ended December 31, 2017 and allowance for loan loss balances by class and related loan balances by class as of December 31, 2017 : Municipal Residential Home Equity Line of Credit Consumer Unallocated Total Real Estate Construction Other Term Construction Beginning balance $ 3,988,000 $ 396,000 $ 1,780,000 $ 18,000 $ 1,288,000 $ 44,000 $ 807,000 $ 559,000 $ 1,258,000 $ 10,138,000 Charge offs 587,000 — 212,000 — 456,000 — 28,000 335,000 — 1,618,000 Recoveries — — 49,000 — 40,000 — 11,000 109,000 — 209,000 Provision (credit) 471,000 38,000 1,741,000 2,000 258,000 (8,000 ) (98,000 ) 212,000 (616,000 ) 2,000,000 Ending balance $ 3,872,000 $ 434,000 $ 3,358,000 $ 20,000 $ 1,130,000 $ 36,000 $ 692,000 $ 545,000 $ 642,000 $ 10,729,000 Ending balance specifically evaluated for impairment $ 224,000 $ — $ 1,309,000 $ — $ 255,000 $ — $ 24,000 $ — $ — $ 1,812,000 Ending balance collectively evaluated for impairment $ 3,648,000 $ 434,000 $ 2,049,000 $ 20,000 $ 875,000 $ 36,000 $ 668,000 $ 545,000 $ 642,000 $ 8,917,000 Ending balance $ 323,809,000 $ 38,056,000 $ 181,528,000 $ 33,391,000 $ 432,661,000 $ 17,868,000 $ 111,302,000 $ 25,524,000 $ — $ 1,164,139,000 Ending balance specifically evaluated for impairment $ 7,790,000 $ 741,000 $ 9,918,000 $ — $ 11,748,000 $ — $ 1,179,000 $ 16,000 $ — $ 31,392,000 Ending balance collectively evaluated for impairment $ 316,019,000 $ 37,315,000 $ 171,610,000 $ 33,391,000 $ 420,913,000 $ 17,868,000 $ 110,123,000 $ 25,508,000 $ — $ 1,132,747,000 The following table presents allowance for loan losses activity by class for the three months ended March 31, 2017 , and allowance for loan loss balances by class and related loan balances by class as of March 31, 2017 : Commercial Municipal Residential Home Equity Line of Credit Consumer Unallocated Total Real Estate Construction Other Term Construction For the three months ended March 31, 2017 Beginning balance $ 3,988,000 $ 396,000 $ 1,780,000 $ 18,000 $ 1,288,000 $ 44,000 $ 807,000 $ 559,000 $ 1,258,000 $ 10,138,000 Charge offs 164,000 — — — 53,000 — 7,000 103,000 — 327,000 Recoveries — — 11,000 — 14,000 — — 31,000 — 56,000 Provision (credit) 191,000 45,000 134,000 — (280,000 ) (20,000 ) 11,000 86,000 333,000 500,000 Ending balance $ 4,015,000 $ 441,000 $ 1,925,000 $ 18,000 $ 969,000 $ 24,000 $ 811,000 $ 573,000 $ 1,591,000 $ 10,367,000 Allowance for loan losses as of March 31, 2017 Ending balance specifically evaluated for impairment $ 351,000 $ 101,000 $ 39,000 $ — $ 251,000 $ — $ 26,000 $ — $ — $ 768,000 Ending balance collectively evaluated for impairment $ 3,664,000 $ 340,000 $ 1,886,000 $ 18,000 $ 718,000 $ 24,000 $ 785,000 $ 573,000 $ 1,591,000 $ 9,599,000 Related loan balances as of March 31, 2017 Ending balance $ 304,663,000 $ 28,775,000 $ 158,507,000 $ 28,327,000 $ 421,202,000 $ 13,717,000 $ 110,016,000 $ 24,528,000 $ — $ 1,089,735,000 Ending balance specifically evaluated for impairment $ 10,671,000 $ 763,000 $ 1,710,000 $ — $ 13,260,000 $ — $ 1,448,000 $ — $ — $ 27,852,000 Ending balance collectively evaluated for impairment $ 293,992,000 $ 28,012,000 $ 156,797,000 $ 28,327,000 $ 407,942,000 $ 13,717,000 $ 108,568,000 $ 24,528,000 $ — $ 1,061,883,000

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Nonvested Restricted Stock Units Activity	As of March 31, 2018 , 144,355 shares of restricted stock had been granted under the 2010 Plan, of which 67,689 shares remain restricted as of March 31, 2018 as detailed in the following table: Year Granted Vesting Term (In Years) Shares Remaining Term (In Years) 2014 5.0 10,422 0.9 2015 5.0 12,023 1.9 2016 5.0 15,015 2.8 2017 3.0 4,902 1.9 2017 5.0 9,972 3.8 2018 1.0 300 0.9 2018 2.0 932 1.8 2018 3.0 2,400 2.9 2018 4.0 2,068 3.8 2018 5.0 9,655 4.8 67,689 2.6

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Basic and Diluted Earnings per Share (EPS)	The following table sets forth the computation of basic and diluted earnings per share (EPS) for the three months ended March 31, 2018 and 2017 : Income (Numerator) Shares (Denominator) Per-Share Amount For the three months ended March 31, 2018 Net income as reported $ 5,506,000 Basic EPS: Income available to common shareholders 5,506,000 10,771,271 $ 0.51 Effect of dilutive securities: restricted stock 73,228 Diluted EPS: Income available to common shareholders plus assumed conversions $ 5,506,000 10,844,499 $ 0.51 For the three months ended March 31, 2017 Net income as reported $ 4,637,000 Basic EPS: Income available to common shareholders 4,637,000 10,734,281 $ 0.43 Effect of dilutive securities: restricted stock 73,623 Diluted EPS: Income available to common shareholders plus assumed conversions $ 4,637,000 10,807,904 $ 0.43

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2018
Retirement Benefits, Description [Abstract]
Accumulated post-retirement benefit obligation and funded status	The following table sets forth the accumulated postretirement benefit obligation and funded status: At or for the three months ended March 31, 2018 2017 Change in benefit obligation Benefit obligation at beginning of year $ 1,874,000 $ 1,870,000 Interest cost 19,000 19,000 Benefits paid (28,000 ) (32,000 ) Benefit obligation at end of period $ 1,865,000 $ 1,857,000 Funded status Benefit obligation at end of period $ (1,865,000 ) $ (1,857,000 ) Unamortized loss 186,000 102,000 Accrued benefit cost at end of period $ (1,679,000 ) $ (1,755,000 )
Schedule of net pension costs	The following table sets forth the net periodic pension cost: For the three months ended March 31, 2018 2017 Components of net periodic benefit cost Interest cost $ 19,000 $ 19,000 Net periodic benefit cost $ 19,000 $ 19,000
Schedule of net periodic benefit cost not yet recognized	Amounts not yet reflected in net periodic benefit cost and included in accumulated other comprehensive income (loss) are as follows: March 31, December 31, 2017 March 31, Unamortized net actuarial loss $ (186,000 ) $ (186,000 ) $ (156,000 ) Deferred tax benefit at 21% (for March 31, 2018 and December 31, 2017) and 35% (for March 31, 2017) 39,000 39,000 54,000 Net unrecognized postretirement benefits included in accumulated other comprehensive income (loss) $ (147,000 ) $ (147,000 ) $ (102,000 )

Other Comprehensive Income (L32

Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes activity in the unrealized loss on securities transferred from available for sale to held to maturity included in other comprehensive income (loss) for the three months ended March 31, 2018 and 2017 . For the three months ended March 31, 2018 2017 Balance at beginning of period $ (174,000 ) $ (129,000 ) Amortization of net unrealized losses (10,000 ) (6,000 ) Related deferred taxes (at a Federal Income Tax rate of 21% for March 31, 2018 and 35% for March 31, 2017) 2,000 2,000 Net change (8,000 ) (4,000 ) Balance at end of period $ (182,000 ) $ (133,000 ) The following table presents the effect of the Company's derivative financial instruments included in other comprehensive income (loss) for the three months ended March 31, 2018 and 2017 . For the three months ended March 31, 2018 2017 Balance at beginning of period $ 1,544,000 $ 1,163,000 Unrealized gains on cash flow hedging derivatives arising during the period 486,000 96,000 Related deferred taxes (at a Federal Income Tax rate of 21% for March 31, 2018 and 35% for March 31, 2017) (102,000 ) (33,000 ) Net change 384,000 63,000 Balance at end of period $ 1,928,000 $ 1,226,000 The following table summarizes activity in the unrealized gain or loss on postretirement benefits included in other comprehensive income (loss) for the three months ended March 31, 2018 and 2017 . For the three months ended March 31, 2018 2017 Unrecognized postretirement benefits at beginning of period $ (147,000 ) $ (102,000 ) Amortization of unrecognized transition obligation — — Change in unamortized net actuarial gain (loss) — — Related deferred taxes (at a Federal Income Tax rate of 21% for March 31, 2018 and 35% for March 31, 2017) — — Unrecognized postretirement benefits at end of period $ (147,000 ) $ (102,000 ) The following table summarizes activity in the unrealized gain or loss on available for sale securities included in other comprehensive income (loss) for the three months ended March 31, 2018 and 2017 . For the three months ended March 31, 2018 2017 Balance at beginning of period $ (2,901,000 ) $ (935,000 ) Unrealized gains (losses) arising during the period (4,052,000 ) 5,000 Reclassification of realized gains during the period (136,000 ) (3,000 ) Related deferred taxes (at a Federal Income Tax rate of 21% for March 31, 2018 and 35% for March 31, 2017) 879,000 (1,000 ) Net change (3,309,000 ) 1,000 Balance at end of period $ (6,210,000 ) $ (934,000 )

Financial Derivative Instrume33

Financial Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments	The details of the interest rate swap agreements are as follows: March 31, 2018 December 31, 2017 March 31, 2017 Notional Amount Effective Date Maturity Date Variable Index Received Fixed Rate Paid Fair Value (1) Fair Value (1) Fair Value (1) $ 30,000,000 June 28, 2016 June 28, 2021 1-Month USD LIBOR 0.940 % $ 1,447,000 $ 1,154,000 $ 1,108,000 20,000,000 June 27, 2016 June 27, 2021 1-Month USD LIBOR 0.893 % 994,000 801,000 778,000 $ 50,000,000 $ 2,441,000 $ 1,955,000 $ 1,886,000 (1) Presented within other assets in the consolidated balance sheet.

Mortgage Servicing Rights (Tabl

Mortgage Servicing Rights (Tables)	3 Months Ended
	Mar. 31, 2018
Transfers and Servicing [Abstract]
Reconciliation of Mortgage Servicing Assets	Mortgage servicing rights are included in other assets and detailed in the following table: March 31, December 31, March 31, Mortgage servicing rights $ 5,489,000 $ 5,428,000 $ 4,491,000 Accumulated amortization (4,209,000 ) (4,160,000 ) (3,415,000 ) Impairment reserve — — (22,000 ) $ 1,280,000 $ 1,268,000 $ 1,054,000

Certificates of Deposit (Tables

Certificates of Deposit (Tables)	3 Months Ended
	Mar. 31, 2018
Banking and Thrift [Abstract]
Certificates of Deposit	The following table represents the breakdown of certificates of deposit at March 31, 2018 and 2017 , and at December 31, 2017 : March 31, 2018 December 31, 2017 March 31, 2017 Certificates of deposit < $100,000 $ 347,010,000 $ 284,066,000 $ 246,792,000 Certificates $100,000 to $250,000 240,492,000 232,759,000 236,971,000 Certificates $250,000 and over 47,245,000 42,176,000 43,286,000 $ 634,747,000 $ 559,001,000 $ 527,049,000

Fair Value (Tables)

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Assets Measured on Recurring Basis Measured at Fair Value	The following tables present the balances of assets that were measured at fair value on a recurring basis as of March 31, 2018 , December 31, 2017 and March 31, 2017 . At March 31, 2018 Level 1 Level 2 Level 3 Total Securities available for sale Mortgage-backed securities $ — $ 295,328,000 $ — $ 295,328,000 State and political subdivisions — 5,511,000 — 5,511,000 Other equity securities — 2,930,000 — 2,930,000 Total securities available for sale — 303,769,000 — 303,769,000 Interest rate swap agreements — 2,441,000 — 2,441,000 Total assets $ — $ 306,210,000 $ — $ 306,210,000 At December 31, 2017 Level 1 Level 2 Level 3 Total Securities available for sale Mortgage-backed securities $ — $ 289,989,000 $ — $ 289,989,000 State and political subdivisions — 6,769,000 — 6,769,000 Other equity securities — 3,414,000 — 3,414,000 Total securities available for sale — 300,172,000 — 300,172,000 Interest rate swap agreements — 1,955,000 — 1,955,000 Total assets $ — $ 302,127,000 $ — $ 302,127,000 At March 31, 2017 Level 1 Level 2 Level 3 Total Securities available for sale Mortgage-backed securities $ — $ 293,627,000 $ — $ 293,627,000 State and political subdivisions — 15,705,000 — 15,705,000 Other equity securities — 3,292,000 — 3,292,000 Total securities available for sale — 312,624,000 — 312,624,000 Interest rate swap agreements — 1,886,000 — 1,886,000 Total assets $ — $ 314,510,000 $ — $ 314,510,000
Assets Measured on Nonrecurring Basis Measured at Fair Value	The following tables include assets measured at fair value on a nonrecurring basis that have had a fair value adjustment since their initial recognition. Other real estate owned is presented net of an allowance of $53,000 and $78,000 at, December 31, 2017 , and March 31, 2017 , respectively. There was no allowance at March 31, 2018. Only collateral-dependent impaired loans with a related specific allowance for loan losses or a partial charge off are included in impaired loans for purposes of fair value disclosures. Impaired loans below are presented net of specific allowances of $1,924,000 , $1,531,000 and $356,000 at March 31, 2018 , December 31, 2017 , and March 31, 2017 , respectively. At March 31, 2018 Level 1 Level 2 Level 3 Total Other real estate owned $ — $ 1,121,000 $ — $ 1,121,000 Impaired loans — 5,938,000 — 5,938,000 Total assets $ — $ 7,059,000 $ — $ 7,059,000 At December 31, 2017 Level 1 Level 2 Level 3 Total Other real estate owned $ — $ 1,012,000 $ — $ 1,012,000 Impaired loans — 6,521,000 — 6,521,000 Total assets $ — $ 7,533,000 $ — $ 7,533,000 At March 31, 2017 Level 1 Level 2 Level 3 Total Other real estate owned $ — $ 525,000 $ — $ 525,000 Impaired loans — 718,000 — 718,000 Total assets $ — $ 1,243,000 $ — $ 1,243,000
Estimated Fair Value of Financial Instruments	The carrying amount and estimated fair values for financial instruments as of March 31, 2018 were as follows: Carrying value Estimated fair value Level 1 Level 2 Level 3 Financial assets Cash and cash equivalents $ 16,559,000 $ 16,559,000 $ 16,559,000 $ — $ — Interest bearing deposits in other banks 280,000 280,000 280,000 — — Securities available for sale 303,769,000 303,769,000 — 303,769,000 — Securities to be held to maturity 258,690,000 255,851,000 — 255,851,000 — Restricted equity securities 11,947,000 11,947,000 — 11,947,000 — Loans held for sale 284,000 284,000 — 284,000 — Loans (net of allowance for loan losses) Commercial Real estate 335,275,000 326,030,000 — 3,000 326,027,000 Construction 43,385,000 42,189,000 — — 42,189,000 Other 173,960,000 171,045,000 — 5,495,000 165,550,000 Municipal 35,440,000 34,972,000 — — 34,972,000 Residential Term 438,765,000 430,023,000 — 334,000 429,689,000 Construction 15,814,000 15,587,000 — — 15,587,000 Home equity line of credit 109,525,000 108,047,000 — 106,000 107,941,000 Consumer 24,881,000 24,178,000 — — 24,178,000 Total loans 1,177,045,000 1,152,071,000 — 5,938,000 1,146,133,000 Mortgage servicing rights 1,280,000 2,518,000 — 2,518,000 — Interest rate swap agreements 2,441,000 2,441,000 — 2,441,000 — Accrued interest receivable 7,222,000 7,222,000 — 7,222,000 — Financial liabilities Demand deposits $ 137,674,000 $ 128,525,000 $ — $ 128,525,000 $ — NOW deposits 314,587,000 286,661,000 — 286,661,000 — Money market deposits 108,726,000 102,196,000 — 102,196,000 — Savings deposits 232,458,000 198,171,000 — 198,171,000 — Local certificates of deposit 260,450,000 255,579,000 — 255,579,000 — National certificates of deposit 374,297,000 374,095,000 — 374,095,000 — Total deposits 1,428,192,000 1,345,227,000 — 1,345,227,000 — Repurchase agreements 67,182,000 64,361,000 — 64,361,000 — Federal Home Loan Bank advances 177,047,000 175,308,000 — 175,308,000 — Total borrowed funds 244,229,000 239,669,000 — 239,669,000 — Accrued interest payable 760,000 760,000 — 760,000 — The carrying amounts and estimated fair values for financial instruments as of December 31, 2017 were as follows: Carrying value Estimated fair value Level 1 Level 2 Level 3 Financial assets Cash and cash equivalents $ 19,207,000 $ 19,207,000 $ 19,207,000 $ — $ — Interest bearing deposits in other banks 860,000 860,000 860,000 — — Securities available for sale 300,172,000 300,172,000 — 300,172,000 — Securities to be held to maturity 256,567,000 259,655,000 — 259,655,000 — Restricted equity securities 10,358,000 10,358,000 — 10,358,000 — Loans held for sale 386,000 386,000 — 386,000 — Loans (net of allowance for loan losses) Commercial Real estate 319,691,000 311,321,000 — 72,000 311,249,000 Construction 37,594,000 36,610,000 — — 36,610,000 Other 177,956,000 175,455,000 — 6,018,000 169,437,000 Municipal 33,370,000 33,280,000 — — 33,280,000 Residential Term 431,459,000 431,028,000 — 391,000 430,637,000 Construction 17,830,000 17,613,000 — — 17,613,000 Home equity line of credit 110,566,000 109,012,000 — 40,000 108,972,000 Consumer 24,944,000 24,408,000 — — 24,408,000 Total loans 1,153,410,000 1,138,727,000 — 6,521,000 1,132,206,000 Mortgage servicing rights 1,268,000 2,321,000 — 2,321,000 — Interest rate swap agreements 1,955,000 1,955,000 — 1,955,000 — Accrued interest receivable 5,867,000 5,867,000 — 5,867,000 — Financial liabilities Demand deposits $ 145,332,000 $ 139,350,000 $ — $ 139,350,000 $ — NOW deposits 318,043,000 295,775,000 — 295,775,000 — Money market deposits 163,898,000 153,497,000 — 153,497,000 — Savings deposits 232,605,000 203,799,000 — 203,799,000 — Local certificates of deposit 223,074,000 220,734,000 — 220,734,000 — National certificates of deposit 335,927,000 335,775,000 — 335,775,000 — Total deposits 1,418,879,000 1,348,930,000 — 1,348,930,000 — Repurchase agreements 70,564,000 67,976,000 — 67,976,000 — Federal Home Loan Bank advances 158,194,000 156,396,000 — 156,396,000 — Total borrowed funds 228,758,000 224,372,000 — 224,372,000 — Accrued interest payable 642,000 642,000 — 642,000 — The carrying amount and estimated fair values for financial instruments as of March 31, 2017 were as follows: Carrying value Estimated fair value Level 1 Level 2 Level 3 Financial assets Cash and cash equivalents $ 17,600,000 $ 17,600,000 $ 17,600,000 $ — $ — Interest bearing deposits in other banks 3,272,000 3,272,000 3,272,000 — — Securities available for sale 312,624,000 312,624,000 — 312,624,000 — Securities to be held to maturity 240,829,000 239,378,000 — 239,378,000 — Restricted equity securities 13,363,000 13,363,000 — 13,363,000 — Loans held for sale 979,000 979,000 — 979,000 — Loans (net of allowance for loan losses) Commercial Real estate 299,920,000 295,039,000 — 424,000 294,615,000 Construction 28,254,000 27,794,000 — — 27,794,000 Other 156,233,000 154,823,000 — 33,000 154,790,000 Municipal 28,306,000 28,737,000 — — 28,737,000 Residential Term 420,057,000 420,393,000 — 261,000 420,132,000 Construction 13,689,000 13,593,000 — — 13,593,000 Home equity line of credit 109,058,000 107,823,000 — — 107,823,000 Consumer 23,851,000 23,519,000 — — 23,519,000 Total loans 1,079,368,000 1,071,721,000 — 718,000 1,071,003,000 Mortgage servicing rights 1,054,000 1,853,000 — 1,853,000 — Interest rate swap agreements 1,886,000 1,886,000 — 1,886,000 — Accrued interest receivable 6,854,000 6,854,000 — 6,854,000 — Financial liabilities Demand deposits $ 130,319,000 $ 123,696,000 $ — $ 123,696,000 $ — NOW deposits 323,919,000 296,958,000 — 296,958,000 — Money market deposits 142,220,000 130,374,000 — 130,374,000 — Savings deposits 222,976,000 193,142,000 — 193,142,000 — Local certificates of deposit 213,296,000 212,337,000 — 212,337,000 — National certificates of deposit 313,753,000 313,833,000 — 313,833,000 — Total deposits 1,346,483,000 1,270,340,000 — 1,270,340,000 — Repurchase agreements 76,342,000 72,399,000 — 72,399,000 — Federal Home Loan Bank advances 150,125,000 149,358,000 — 149,358,000 — Total borrowed funds 226,467,000 221,757,000 — 221,757,000 — Accrued interest payable 519,000 519,000 — 519,000 —

Investment Securities - Amortiz

Investment Securities - Amortized Cost and Estimated Fair Value of Available for Sale Securities (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 6,686,000	$ 3,843,000	$ 150,000
Amortized Cost	311,630,000	303,845,000	314,060,000
Unrealized Gains	194,000	859,000	1,948,000
Unrealized Losses	(8,055,000)	(4,532,000)	(3,384,000)
Fair Value (Estimated)	303,769,000	300,172,000	312,624,000
U.S. Government-sponsored agencies
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	206,000	86,000	0
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	3,755,000	2,693,000	146,000
Amortized Cost	302,935,000	293,689,000	295,424,000
Unrealized Gains	191,000	722,000	1,407,000
Unrealized Losses	(7,798,000)	(4,422,000)	(3,204,000)
Fair Value (Estimated)	295,328,000	289,989,000	293,627,000
State and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	2,725,000	1,061,000	0
Amortized Cost	5,765,000	6,860,000	15,407,000
Unrealized Gains	3,000	16,000	474,000
Unrealized Losses	(257,000)	(107,000)	(176,000)
Fair Value (Estimated)	5,511,000	6,769,000	15,705,000
Other equity securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		3,000	4,000
Amortized Cost	2,930,000	3,296,000	3,229,000
Unrealized Gains	0	121,000	67,000
Unrealized Losses	0	(3,000)	(4,000)
Fair Value (Estimated)	$ 2,930,000	$ 3,414,000	$ 3,292,000

Investment Securities - Amort38

Investment Securities - Amortized Cost and Estimated Fair Value of Held to Maturity Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 258,690	$ 256,567	$ 240,829
Unrealized Gains	1,966	4,499	2,959
Unrealized Losses	(4,805)	(1,411)	(4,410)
Fair Value (Estimated)	255,851	259,655	239,378
U.S. Government-sponsored agencies
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	11,155	11,155	12,050
Unrealized Gains	0	0	0
Unrealized Losses	(515)	(180)	(317)
Fair Value (Estimated)	10,640	10,975	11,733
Mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	21,990	23,284	29,093
Unrealized Gains	469	568	880
Unrealized Losses	(289)	(128)	(135)
Fair Value (Estimated)	22,170	23,724	29,838
State and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	221,245	217,828	195,386
Unrealized Gains	1,497	3,931	2,079
Unrealized Losses	(4,001)	(1,103)	(3,958)
Fair Value (Estimated)	218,741	220,656	193,507
Corporate securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	4,300	4,300	4,300
Unrealized Gains	0	0	0
Unrealized Losses	0	0	0
Fair Value (Estimated)	$ 4,300	$ 4,300	$ 4,300

Investment Securities - Amort39

Investment Securities - Amortized Cost and Estimated Fair Value of Restricted Equity Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Restricted Equity Securities [Line Items]
Amortized Cost	$ 11,947	$ 10,358	$ 13,363
Unrealized Gains	0	0	0
Unrealized Losses	0	0	0
Fair Value (Estimated)	11,947	10,358	13,363
Federal Home Loan Bank Stock
Restricted Equity Securities [Line Items]
Amortized Cost	10,910	9,321	12,326
Unrealized Gains	0	0	0
Unrealized Losses	0	0	0
Fair Value (Estimated)	10,910	9,321	12,326
Federal Reserve Bank Stock
Restricted Equity Securities [Line Items]
Amortized Cost	1,037	1,037	1,037
Unrealized Gains	0	0	0
Unrealized Losses	0	0	0
Fair Value (Estimated)	$ 1,037	$ 1,037	$ 1,037

Investment Securities - Contrac

Investment Securities - Contractual Maturities of Investment Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Due in 1 year or less, Securities available for sale, Amortized Cost	$ 61	$ 111	$ 43
Due in 1 to 5 years, Securities available for sale, Amortized Cost	6,502	841	1,909
Due in 5 to 10 years, Securities available for sale, Amortized Cost	66,434	29,003	31,835
Due after 10 years, Securities available for sale, Amortized Cost	235,703	270,594	277,044
Equity securities, Amortized Cost	2,930	3,296	3,229
Amortized Cost	311,630	303,845	314,060
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Due in 1 year or less, Securities available for sale, Fair Value (Estimated)	61	112	43
Due in 1 to 5 years, Securities available for sale, Fair Value (Estimated)	6,492	842	1,953
Due in 5 to 10 years, Securities available for sale, Fair Value (Estimated)	65,234	29,177	32,471
Due after 10 years, Securities available for sale, Fair Value (Estimated)	229,052	266,627	274,865
Equity securities, Fair Value (Estimated)	2,930	3,414	3,292
Securities available for sale, Fair Value (Estimated)	303,769	300,172	312,624
Held-to-maturity Securities, Debt Maturities, Net Carrying Amount [Abstract]
Due in 1 year or less, Securities to be held to maturity, Amortized Cost	634	635	903
Due in 1 to 5 years, Securities to be held to maturity, Amortized Cost	25,692	18,059	12,213
Due in 5 to 10 years, Securities to be held to maturity, Amortized Cost	145,297	37,182	42,819
Due after 10 years, Securities to be held to maturity, Amortized Cost	87,067	200,691	184,894
Securities to be held to maturity, Amortized Cost	258,690	256,567	240,829
Held-to-maturity Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Due in 1 year or less, Securities to be held to maturity, Fair Value (Estimated)	635	637	908
Due in 1 to 5 years, Securities to be held to maturity, Fair Value (Estimated)	25,796	18,164	12,477
Due in 5 to 10 years, Securities to be held to maturity, Fair Value (Estimated)	144,211	37,719	43,562
Due after 10 years, Securities to be held to maturity, Fair Value (Estimated)	85,209	203,135	182,431
Securities to be held to maturity, Fair Value (Estimated)	$ 255,851	$ 259,655	$ 239,378

Investment Securities - Additio

Investment Securities - Additional Information (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018USD ($)securitystate	Mar. 31, 2017USD ($)security	Dec. 31, 2017USD ($)security	Sep. 30, 2014USD ($)
Investments, Debt and Equity Securities [Abstract]
Fair value of securities pledged as collateral	$ 197,349	$ 227,683	$ 231,516
Number of securities temporarily impaired (security) | security	457	311	241
Number of securities temporarily impaired for twelve months or more (security) | security	159	13	157
Length of time securities temporarily impaired (months)	12 months	12 months	12 months
Amortized cost of transferred securities from available-for-sale to held-to-maturity				$ 89,780
Fair value of transferred securities from available-for-sale to held-to-maturity				89,757
Net unrealized loss, net of taxes on transferred securities				$ 15
Unamortized balance of net unrealized losses	$ 182	$ 133	$ 174
Number of states in New England where FHLB serve (state) | state	6
Federal Home Loan Bank stock	$ 10,910	$ 12,326	$ 9,321

Investment Securities - Gains a

Investment Securities - Gains and Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Proceeds from sales of securities	$ 459	$ 3
Gross realized gains	136	3
Gross realized losses	0	0
Net gain	136	3
Related income taxes	$ 29	$ 1

Investment Securities - Tempora

Investment Securities - Temporarily Impaired Securities (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Fair Value (Estimated) (Less than 12 months)	$ 254,875,000	$ 148,611,000	$ 287,408,000
Unrealized Losses (Less than 12 months)	(6,174,000)	(2,100,000)	(7,644,000)
Fair Value (Estimated) (12 months or more)	141,888,000	144,394,000	2,494,000
Unrealized Losses (12 months or more)	(6,686,000)	(3,843,000)	(150,000)
Fair Value (Estimated)	396,763,000	293,005,000	289,902,000
Unrealized Losses	(12,860,000)	(5,943,000)	(7,794,000)
U.S. Government-sponsored agencies
Schedule of Available-for-sale Securities [Line Items]
Fair Value (Estimated) (Less than 12 months)	6,946,000	7,161,000	10,824,000
Unrealized Losses (Less than 12 months)	(309,000)	(94,000)	(317,000)
Fair Value (Estimated) (12 months or more)	3,694,000	3,814,000	0
Unrealized Losses (12 months or more)	(206,000)	(86,000)	0
Fair Value (Estimated)	10,640,000	10,975,000	10,824,000
Unrealized Losses	(515,000)	(180,000)	(317,000)
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Fair Value (Estimated) (Less than 12 months)	183,335,000	132,025,000	198,068,000
Unrealized Losses (Less than 12 months)	(4,332,000)	(1,857,000)	(3,193,000)
Fair Value (Estimated) (12 months or more)	101,012,000	101,707,000	2,432,000
Unrealized Losses (12 months or more)	(3,755,000)	(2,693,000)	(146,000)
Fair Value (Estimated)	284,347,000	233,732,000	200,500,000
Unrealized Losses	(8,087,000)	(4,550,000)	(3,339,000)
State and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Fair Value (Estimated) (Less than 12 months)	64,594,000	9,425,000	78,516,000
Unrealized Losses (Less than 12 months)	(1,533,000)	(149,000)	(4,134,000)
Fair Value (Estimated) (12 months or more)	37,182,000	38,864,000	0
Unrealized Losses (12 months or more)	(2,725,000)	(1,061,000)	0
Fair Value (Estimated)	101,776,000	48,289,000	78,516,000
Unrealized Losses	$ (4,258,000)	(1,210,000)	(4,134,000)
Other equity securities
Schedule of Available-for-sale Securities [Line Items]
Fair Value (Estimated) (Less than 12 months)		0	0
Unrealized Losses (Less than 12 months)		0	0
Fair Value (Estimated) (12 months or more)		9,000	62,000
Unrealized Losses (12 months or more)		(3,000)	(4,000)
Fair Value (Estimated)		9,000	62,000
Unrealized Losses		$ (3,000)	$ (4,000)

Loans - Loan Portfolio (Details

Loans - Loan Portfolio (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Schedule of Financing Receivables [Line Items]
Loans	$ 1,188,002	$ 1,164,139	$ 1,089,735
Percentage of loans receivable, by type	100.00%	100.00%	100.00%
Commercial | Real estate
Schedule of Financing Receivables [Line Items]
Loans	$ 339,306	$ 323,809	$ 304,663
Percentage of loans receivable, by type	28.60%	27.80%	28.00%
Commercial | Construction
Schedule of Financing Receivables [Line Items]
Loans	$ 43,813	$ 38,056	$ 28,775
Percentage of loans receivable, by type	3.70%	3.30%	2.60%
Commercial | Other
Schedule of Financing Receivables [Line Items]
Loans	$ 177,783	$ 181,528	$ 158,507
Percentage of loans receivable, by type	15.00%	15.60%	14.40%
Municipal
Schedule of Financing Receivables [Line Items]
Loans	$ 35,463	$ 33,391	$ 28,327
Percentage of loans receivable, by type	3.00%	2.90%	2.60%
Residential | Construction
Schedule of Financing Receivables [Line Items]
Loans	$ 15,847	$ 17,868	$ 13,717
Percentage of loans receivable, by type	1.30%	1.50%	1.30%
Residential | Term
Schedule of Financing Receivables [Line Items]
Loans	$ 439,984	$ 432,661	$ 421,202
Percentage of loans receivable, by type	37.00%	37.10%	38.70%
Home equity line of credit
Schedule of Financing Receivables [Line Items]
Loans	$ 110,298	$ 111,302	$ 110,016
Percentage of loans receivable, by type	9.30%	9.60%	10.10%
Consumer
Schedule of Financing Receivables [Line Items]
Loans	$ 25,508	$ 25,524	$ 24,528
Percentage of loans receivable, by type	2.10%	2.20%	2.30%

Loans - Narrative (Details)

Loans - Narrative (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018USD ($)loan	Mar. 31, 2017USD ($)loan	Dec. 31, 2017USD ($)loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Net deferred loan costs	$ 5,990	$ 5,167	$ 5,748
Qualifying first mortgage loans	237,239	254,512	239,805
Loans pledged as collateral	$ 255,020	$ 285,464	$ 290,247
Loans classified as TDR (loan) | loan	69	70	62
Value of loans classified as TDR	$ 18,709	$ 21,121	$ 17,801
Number of Loans | loan	7	9
Value of TDR loans more than 30 days past due	$ 810	$ 1,651
Number of TDR loans more than 30 days past due (loan) | loan		0
Number of loans placed on TDR status (loan) | loan	7	0
Number of TDR loans involved in bankruptcy (loan) | loan	4
Value of TDR loans involved in bankruptcy	$ 684
Number of TDR loans on non-accrual status (loan) | loan	11
Value of TDR loans on non-accrual status	$ 1,276
Number of TDR loans in the process of foreclosure (loan) | loan	3
Loans classified as TDRs in process of foreclosure	$ 456
Number of mortgage loans in the process of foreclosure (loan) | loan	13	12
Value of mortgage loans in the process of foreclosure	$ 1,388	$ 1,773
Unallocated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of days past due	30 days	30 days

Loans - Past-due Status of Loan

Loans - Past-due Status of Loans by Class (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Schedule of Financing Receivables [Line Items]
All Past Due	$ 15,867	$ 18,676	$ 10,412
Current	1,172,135	1,145,463	1,079,323
Total	1,188,002	1,164,139	1,089,735
90 Days or More & Accruing	137	445	11
30-59 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	11,940	2,944	4,636
60-89 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	860	11,948	1,127
90 Days or More Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	3,067	3,784	4,649
Commercial | Real estate
Schedule of Financing Receivables [Line Items]
All Past Due	1,182	874	2,737
Current	338,124	322,935	301,926
Total	339,306	323,809	304,663
90 Days or More & Accruing	0	0	0
Commercial | Real estate | 30-59 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	963	574	142
Commercial | Real estate | 60-89 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	17	80	772
Commercial | Real estate | 90 Days or More Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	202	220	1,823
Commercial | Construction
Schedule of Financing Receivables [Line Items]
All Past Due	347	0	20
Current	43,466	38,056	28,755
Total	43,813	38,056	28,775
90 Days or More & Accruing	0	0	0
Commercial | Construction | 30-59 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	347	0	20
Commercial | Construction | 60-89 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	0	0	0
Commercial | Construction | 90 Days or More Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	0	0	0
Commercial | Other
Schedule of Financing Receivables [Line Items]
All Past Due	7,233	7,779	792
Current	170,550	173,749	157,715
Total	177,783	181,528	158,507
90 Days or More & Accruing	0	0	0
Commercial | Other | 30-59 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	6,887	542	199
Commercial | Other | 60-89 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	52	6,663	154
Commercial | Other | 90 Days or More Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	294	574	439
Municipal
Schedule of Financing Receivables [Line Items]
All Past Due	0	0	0
Current	35,463	33,391	28,327
Total	35,463	33,391	28,327
90 Days or More & Accruing	0	0	0
Municipal | 30-59 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	0	0	0
Municipal | 60-89 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	0	0	0
Municipal | 90 Days or More Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	0	0	0
Residential | Construction
Schedule of Financing Receivables [Line Items]
All Past Due	0	471	0
Current	15,847	17,397	13,717
Total	15,847	17,868	13,717
90 Days or More & Accruing	0	0	0
Residential | Construction | 30-59 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	0	101	0
Residential | Construction | 60-89 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	0	370	0
Residential | Construction | 90 Days or More Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	0	0	0
Residential | Term
Schedule of Financing Receivables [Line Items]
All Past Due	5,400	7,659	5,158
Current	434,584	425,002	416,044
Total	439,984	432,661	421,202
90 Days or More & Accruing	0	436	0
Residential | Term | 30-59 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	3,175	1,031	3,555
Residential | Term | 60-89 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	345	4,372	0
Residential | Term | 90 Days or More Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	1,880	2,256	1,603
Home equity line of credit
Schedule of Financing Receivables [Line Items]
All Past Due	1,551	1,707	1,332
Current	108,747	109,595	108,684
Total	110,298	111,302	110,016
90 Days or More & Accruing	126	0	0
Home equity line of credit | 30-59 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	449	537	392
Home equity line of credit | 60-89 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	438	445	167
Home equity line of credit | 90 Days or More Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	664	725	773
Consumer
Schedule of Financing Receivables [Line Items]
All Past Due	154	186	373
Current	25,354	25,338	24,155
Total	25,508	25,524	24,528
90 Days or More & Accruing	11	9	11
Consumer | 30-59 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	119	159	328
Consumer | 60-89 Days Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	8	18	34
Consumer | 90 Days or More Past Due
Schedule of Financing Receivables [Line Items]
All Past Due	$ 27	$ 9	$ 11

Loans - Nonaccrual Loans (Detai

Loans - Nonaccrual Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Schedule of Financing Receivables [Line Items]
Nonaccrual loans	$ 14,283	$ 14,736	$ 8,500
Commercial | Real estate
Schedule of Financing Receivables [Line Items]
Nonaccrual loans	1,021	752	2,625
Commercial | Construction
Schedule of Financing Receivables [Line Items]
Nonaccrual loans	0	0	0
Commercial | Other
Schedule of Financing Receivables [Line Items]
Nonaccrual loans	8,895	9,357	938
Municipal
Schedule of Financing Receivables [Line Items]
Nonaccrual loans	0	0	0
Residential | Construction
Schedule of Financing Receivables [Line Items]
Nonaccrual loans	0	0	0
Residential | Term
Schedule of Financing Receivables [Line Items]
Nonaccrual loans	3,654	3,778	4,028
Home equity line of credit
Schedule of Financing Receivables [Line Items]
Nonaccrual loans	697	833	909
Consumer
Schedule of Financing Receivables [Line Items]
Nonaccrual loans	$ 16	$ 16	$ 0

Loans - Impaired Loans by Class

Loans - Impaired Loans by Class (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded investment, with no related allowance	$ 18,603	$ 20,235	$ 18,023
Recorded investment, with related allowance	13,112	7,617	13,369
Recorded Investment	31,715	27,852	31,392
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no related allowance	20,140	22,308	19,775
Unpaid principal balance with related allowance	13,597	7,990	13,698
Unpaid Principal Balance	33,737	30,298	33,473
Related Allowance	2,206	768	1,812
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average recorded investment, with no related allowance	18,012	19,817	19,227
Average recorded investment, with related allowance	13,109	7,732	9,881
Average Recorded Investment	31,121	27,549	29,108
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized interest income, with no related allowance	146	211	553
Recognized interest income, with related allowance	63	82	231
Recognized Interest Income	209	293	784
Commercial | Real estate
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded investment, with no related allowance	5,054	5,949	3,791
Recorded investment, with related allowance	3,897	4,722	3,999
Recorded Investment	8,951	10,671	7,790
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no related allowance	5,269	6,450	3,996
Unpaid principal balance with related allowance	4,002	4,908	4,116
Unpaid Principal Balance	9,271	11,358	8,112
Related Allowance	254	351	224
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average recorded investment, with no related allowance	4,163	5,444	5,124
Average recorded investment, with related allowance	3,889	4,741	4,460
Average Recorded Investment	8,052	10,185	9,584
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized interest income, with no related allowance	54	51	164
Recognized interest income, with related allowance	39	46	152
Recognized Interest Income	93	97	316
Commercial | Construction
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded investment, with no related allowance	741	0	741
Recorded investment, with related allowance	0	763	0
Recorded Investment	741	763	741
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no related allowance	741	0	741
Unpaid principal balance with related allowance	0	763	0
Unpaid Principal Balance	741	763	741
Related Allowance	0	101	0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average recorded investment, with no related allowance	741	0	62
Average recorded investment, with related allowance	0	763	699
Average Recorded Investment	741	763	761
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized interest income, with no related allowance	10	0	38
Recognized interest income, with related allowance	0	9	0
Recognized Interest Income	10	9	38
Commercial | Other
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded investment, with no related allowance	2,281	1,476	2,591
Recorded investment, with related allowance	7,159	234	7,327
Recorded Investment	9,440	1,710	9,918
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no related allowance	2,360	1,636	2,671
Unpaid principal balance with related allowance	7,324	272	7,371
Unpaid Principal Balance	9,684	1,908	10,042
Related Allowance	1,664	39	1,309
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average recorded investment, with no related allowance	2,302	1,595	1,908
Average recorded investment, with related allowance	7,182	125	2,584
Average Recorded Investment	9,484	1,720	4,492
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized interest income, with no related allowance	6	22	36
Recognized interest income, with related allowance	0	4	0
Recognized Interest Income	6	26	36
Municipal
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded investment, with no related allowance	0	0	0
Recorded investment, with related allowance	0	0	0
Recorded Investment	0	0	0
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no related allowance	0	0	0
Unpaid principal balance with related allowance	0	0	0
Unpaid Principal Balance	0	0	0
Related Allowance	0	0	0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average recorded investment, with no related allowance	0	0	0
Average recorded investment, with related allowance	0	0	0
Average Recorded Investment	0	0	0
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized interest income, with no related allowance	0	0	0
Recognized interest income, with related allowance	0	0	0
Recognized Interest Income	0	0	0
Residential | Construction
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded investment, with no related allowance	0	0	0
Recorded investment, with related allowance	0	0	0
Recorded Investment	0	0	0
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no related allowance	0	0	0
Unpaid principal balance with related allowance	0	0	0
Unpaid Principal Balance	0	0	0
Related Allowance	0	0	0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average recorded investment, with no related allowance	0	0	0
Average recorded investment, with related allowance	0	0	0
Average Recorded Investment	0	0	0
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized interest income, with no related allowance	0	0	0
Recognized interest income, with related allowance	0	0	0
Recognized Interest Income	0	0	0
Residential | Term
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded investment, with no related allowance	9,594	11,388	9,769
Recorded investment, with related allowance	1,934	1,872	1,979
Recorded Investment	11,528	13,260	11,748
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no related allowance	10,733	12,470	10,909
Unpaid principal balance with related allowance	2,146	2,020	2,144
Unpaid Principal Balance	12,879	14,490	13,053
Related Allowance	272	251	255
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average recorded investment, with no related allowance	9,700	11,402	10,770
Average recorded investment, with related allowance	1,968	2,077	2,106
Average Recorded Investment	11,668	13,479	12,876
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized interest income, with no related allowance	71	129	297
Recognized interest income, with related allowance	24	23	79
Recognized Interest Income	95	152	376
Home equity line of credit
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded investment, with no related allowance	917	1,422	1,115
Recorded investment, with related allowance	122	26	64
Recorded Investment	1,039	1,448	1,179
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no related allowance	1,008	1,752	1,429
Unpaid principal balance with related allowance	125	27	67
Unpaid Principal Balance	1,133	1,779	1,496
Related Allowance	16	26	24
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average recorded investment, with no related allowance	1,090	1,376	1,351
Average recorded investment, with related allowance	70	26	32
Average Recorded Investment	1,160	1,402	1,383
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized interest income, with no related allowance	5	9	18
Recognized interest income, with related allowance	0	0	0
Recognized Interest Income	5	9	18
Consumer
Impaired Financing Receivable, Recorded Investment [Abstract]
Recorded investment, with no related allowance	16	0	16
Recorded investment, with related allowance	0	0	0
Recorded Investment	16	0	16
Impaired Financing Receivable, Unpaid Principal Balance [Abstract]
Unpaid principal balance, with no related allowance	29	0	29
Unpaid principal balance with related allowance	0	0	0
Unpaid Principal Balance	29	0	29
Related Allowance	0	0	0
Impaired Financing Receivable, Average Recorded Investment [Abstract]
Average recorded investment, with no related allowance	16	0	12
Average recorded investment, with related allowance	0	0	0
Average Recorded Investment	16	0	12
Impaired Financing Receivable, Interest Income, Cash Basis Method [Abstract]
Recognized interest income, with no related allowance	0	0	0
Recognized interest income, with related allowance	0	0	0
Recognized Interest Income	$ 0	$ 0	$ 0

Loans - TDR's by Class and Spec

Loans - TDR's by Class and Specific Reserves (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018USD ($)loan	Mar. 31, 2017USD ($)loan	Dec. 31, 2017USD ($)loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	69	70	62
Balance	$ 18,709	$ 21,121	$ 17,801
Specific Reserves	$ 403	$ 386	$ 323
Commercial | Real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	15	10	8
Balance	$ 8,030	$ 8,703	$ 7,038
Specific Reserves	$ 132	$ 82	$ 90
Commercial | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	1	1	1
Balance	$ 741	$ 763	$ 741
Specific Reserves	$ 0	$ 101	$ 0
Commercial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	4	5	4
Balance	$ 546	$ 772	$ 561
Specific Reserves	$ 0	$ 2	$ 0
Municipal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	0	0	0
Balance	$ 0	$ 0	$ 0
Specific Reserves	$ 0	$ 0	$ 0
Residential | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	0	0	0
Balance	$ 0	$ 0	$ 0
Specific Reserves	$ 0	$ 0	$ 0
Residential | Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	46	51	46
Balance	$ 8,883	$ 10,344	$ 8,948
Specific Reserves	$ 271	$ 201	$ 233
Home equity line of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	3	3	3
Balance	$ 509	$ 539	$ 513
Specific Reserves	$ 0	$ 0	$ 0
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	0	0	0
Balance	$ 0	$ 0	$ 0
Specific Reserves	$ 0	$ 0	$ 0

Loans - TDR's by Class and Sp50

Loans - TDR's by Class and Specific Reserves More Than 30 Days Past Due (Details)	Mar. 31, 2018USD ($)loan	Mar. 31, 2017USD ($)loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	7	9
Balance	$ 810,000	$ 1,651,000
Specific Reserves	$ 45,000	$ 0
Commercial | Real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	0	1
Balance	$ 0	$ 658,000
Specific Reserves	$ 0	$ 0
Commercial | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	0	0
Balance	$ 0	$ 0
Specific Reserves	$ 0	$ 0
Commercial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	0	0
Balance	$ 0	$ 0
Specific Reserves	$ 0	$ 0
Municipal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	0	0
Balance	$ 0	$ 0
Specific Reserves	$ 0	$ 0
Residential | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	0	0
Balance	$ 0	$ 0
Specific Reserves	$ 0	$ 0
Residential | Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	6	7
Balance	$ 643,000	$ 826,000
Specific Reserves	$ 45,000	$ 0
Home equity line of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	1	1
Balance	$ 167,000	$ 167,000
Specific Reserves	$ 0	$ 0
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Loans | loan	0	0
Balance	$ 0	$ 0
Specific Reserves	$ 0	$ 0

Loans - Pre-Modification and Po

Loans - Pre-Modification and Post-Modification Outstanding Recorded Investment (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)loan	Mar. 31, 2017loan
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	7	0
Pre-Modification Outstanding Recorded Investment	$ 1,056
Post-Modification Outstanding Recorded Investment	1,056
Specific Reserves	$ 36
Commercial | Real estate
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	7
Pre-Modification Outstanding Recorded Investment	$ 1,056
Post-Modification Outstanding Recorded Investment	1,056
Specific Reserves	$ 36
Commercial | Construction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0
Pre-Modification Outstanding Recorded Investment	$ 0
Post-Modification Outstanding Recorded Investment	0
Specific Reserves	$ 0
Commercial | Other
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0
Pre-Modification Outstanding Recorded Investment	$ 0
Post-Modification Outstanding Recorded Investment	0
Specific Reserves	$ 0
Municipal
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0
Pre-Modification Outstanding Recorded Investment	$ 0
Post-Modification Outstanding Recorded Investment	0
Specific Reserves	$ 0
Residential | Construction
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0
Pre-Modification Outstanding Recorded Investment	$ 0
Post-Modification Outstanding Recorded Investment	0
Specific Reserves	$ 0
Residential | Term
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0
Pre-Modification Outstanding Recorded Investment	$ 0
Post-Modification Outstanding Recorded Investment	0
Specific Reserves	$ 0
Home equity line of credit
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0
Pre-Modification Outstanding Recorded Investment	$ 0
Post-Modification Outstanding Recorded Investment	0
Specific Reserves	$ 0
Consumer
Financing Receivable, Modifications [Line Items]
Number of Loans | loan	0
Pre-Modification Outstanding Recorded Investment	$ 0
Post-Modification Outstanding Recorded Investment	0
Specific Reserves	$ 0

Allowance for Loan Losses - Nar

Allowance for Loan Losses - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)loan_class	Dec. 31, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of classes in the loan portfolio (loan class) | loan_class	8
Allowance for loan and lease losses (percent)	0.45%
Allowance for loan and lease losses, period increase (decrease)	$ 105
Allowance for loan losses	$ 10,957	$ 10,729	$ 10,367	$ 10,138
Allowance for loan losses as a percent of total loans	0.92%		0.95%
Number of classes in the commercial loan portfolio (loan class) | loan_class	3
Residential loans typical loan to value range, maximum (percent)	80.00%
Construction loans accrual to company capital	36.00%
Constructions loan portfolio maximum to company capital	100.00%
Construction and non owner occupied commercial real estate	131.40%
Maximum loan portfolio to company capital	300.00%
Outstanding loans and commitments subject by independent consulting firm	50.00%
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	$ 581	545	$ 573	$ 559
Delinquent period before consumer loans charged off (days)	120 days
Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Delinquent period before residential loans placed on non accrual status (days)	90 days
Delinquent period for loans charged off (days)	180 days
Delinquency period for loans charged off after receipt of notification from bankruptcy court (days)	60 days
Unallocated Reserves
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	$ 811	$ 642	$ 1,591
Total reserve allowance accounted for by loan loss allowances (percent)	7.40%	6.00%

Allowance for Loan Losses - Fin

Allowance for Loan Losses - Financing Receivable and Allowance Element by Class (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	$ 10,957	$ 10,729	$ 10,367	$ 10,138
Specific Reserves on Loans Evaluated Individually for Impairment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	2,206	1,812	768
General Reserves on Loans Based on Historical Loss Experience
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	2,593	3,033	3,689
Reserves for Qualitative Factors
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	5,347	5,242	4,319
Unallocated Reserves
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	811	642	1,591
Commercial | Real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	3,732	3,872	4,015	3,988
Commercial | Real estate | Specific Reserves on Loans Evaluated Individually for Impairment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	254	224	351
Commercial | Real estate | General Reserves on Loans Based on Historical Loss Experience
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	1,039	1,285	1,631
Commercial | Real estate | Reserves for Qualitative Factors
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	2,439	2,363	2,033
Commercial | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	396	434	441	396
Commercial | Construction | Specific Reserves on Loans Evaluated Individually for Impairment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	0	0	101
Commercial | Construction | General Reserves on Loans Based on Historical Loss Experience
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	81	153	151
Commercial | Construction | Reserves for Qualitative Factors
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	315	281	189
Commercial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	3,540	3,358	1,925	1,780
Commercial | Other | Specific Reserves on Loans Evaluated Individually for Impairment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	1,664	1,309	39
Commercial | Other | General Reserves on Loans Based on Historical Loss Experience
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	597	723	840
Commercial | Other | Reserves for Qualitative Factors
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	1,279	1,326	1,046
Municipal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	21	20	18	18
Municipal | Specific Reserves on Loans Evaluated Individually for Impairment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	0	0	0
Municipal | General Reserves on Loans Based on Historical Loss Experience
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	0	0	0
Municipal | Reserves for Qualitative Factors
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	21	20	18
Residential | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	31	36	24	44
Residential | Construction | Specific Reserves on Loans Evaluated Individually for Impairment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	0	0	0
Residential | Construction | General Reserves on Loans Based on Historical Loss Experience
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	11	13	9
Residential | Construction | Reserves for Qualitative Factors
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	20	23	15
Residential | Term
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	1,129	1,130	969	1,288
Residential | Term | Specific Reserves on Loans Evaluated Individually for Impairment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	272	255	251
Residential | Term | General Reserves on Loans Based on Historical Loss Experience
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	303	311	282
Residential | Term | Reserves for Qualitative Factors
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	554	564	436
Home equity line of credit
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	716	692	811	807
Home equity line of credit | Specific Reserves on Loans Evaluated Individually for Impairment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	16	24	26
Home equity line of credit | General Reserves on Loans Based on Historical Loss Experience
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	297	297	439
Home equity line of credit | Reserves for Qualitative Factors
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	403	371	346
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	581	545	573	559
Consumer | Specific Reserves on Loans Evaluated Individually for Impairment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	0	0	0
Consumer | General Reserves on Loans Based on Historical Loss Experience
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	265	251	337
Consumer | Reserves for Qualitative Factors
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	316	294	236
Unallocated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	811	642	1,591	$ 1,258
Unallocated | Unallocated Reserves
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for loan losses	$ 811	$ 642	$ 1,591

Allowance for Loan Losses - Ris

Allowance for Loan Losses - Risk Ratings by Segment (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	$ 596,365	$ 576,784	$ 520,272
1 Strong
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	1,251	1,586	501
2 Above Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	51,751	51,023	49,959
3 Satisfactory
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	118,779	115,624	133,644
4 Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	285,946	280,762	229,939
5 Watch
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	100,073	88,300	67,572
6 OAEM
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	5,014	6,207	9,697
7 Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	33,428	33,159	28,960
8 Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	123	123	0
Commercial | Real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	339,306	323,809	304,663
Commercial | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	43,813	38,056	28,775
Commercial | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	177,783	181,528	158,507
Commercial | 1 Strong | Real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	0	0	2
Commercial | 1 Strong | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	0	0	0
Commercial | 1 Strong | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	1,251	1,586	499
Commercial | 2 Above Average | Real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	12,308	12,534	14,213
Commercial | 2 Above Average | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	40	40	45
Commercial | 2 Above Average | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	5,528	5,776	8,222
Commercial | 3 Satisfactory | Real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	74,612	73,899	83,021
Commercial | 3 Satisfactory | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	4,776	2,856	2,051
Commercial | 3 Satisfactory | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	38,738	38,151	47,724
Commercial | 4 Average | Real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	183,675	173,956	138,865
Commercial | 4 Average | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	21,585	22,446	18,283
Commercial | 4 Average | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	79,751	84,360	72,791
Commercial | 5 Watch | Real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	46,918	41,652	45,053
Commercial | 5 Watch | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	17,412	12,714	8,239
Commercial | 5 Watch | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	35,743	33,934	14,280
Commercial | 6 OAEM | Real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	3,148	3,442	4,036
Commercial | 6 OAEM | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	0	0	0
Commercial | 6 OAEM | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	1,866	2,765	5,661
Commercial | 7 Substandard | Real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	18,522	18,203	19,473
Commercial | 7 Substandard | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	0	0	157
Commercial | 7 Substandard | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	14,906	14,956	9,330
Commercial | 8 Doubtful | Real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	123	123	0
Commercial | 8 Doubtful | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	0	0	0
Commercial | 8 Doubtful | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	0	0	0
Municipal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	35,463	33,391	28,327
Municipal | 1 Strong
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	0	0	0
Municipal | 2 Above Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	33,875	32,673	27,479
Municipal | 3 Satisfactory
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	653	718	848
Municipal | 4 Average
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	935	0	0
Municipal | 5 Watch
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	0	0	0
Municipal | 6 OAEM
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	0	0	0
Municipal | 7 Substandard
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	0	0	0
Municipal | 8 Doubtful
Accounts, Notes, Loans and Financing Receivable [Line Items]
Commercial and municipal risk-rated loans receivable	$ 0	$ 0	$ 0

Allowance for Loan Losses - All

Allowance for Loan Losses - Allowance for Loan Loss Activity by Class (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 10,729	$ 10,138	$ 10,138
Charge offs	318	327	1,618
Recoveries	46	56	209
Provision for loan losses	500	500	2,000
Ending balance	10,957	10,367	10,729
Ending balance specifically evaluated for impairment	2,206	768	1,812
Ending balance collectively evaluated for impairment	8,751	9,599	8,917
Total	1,188,002	1,089,735	1,164,139
Ending balance specifically evaluated for impairment	31,715	27,852	31,392
Ending balance collectively evaluated for impairment	1,156,287	1,061,883	1,132,747
Commercial | Real estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,872	3,988	3,988
Charge offs	0	164	587
Recoveries	0	0	0
Provision for loan losses	(140)	191	471
Ending balance	3,732	4,015	3,872
Ending balance specifically evaluated for impairment	254	351	224
Ending balance collectively evaluated for impairment	3,478	3,664	3,648
Total	339,306	304,663	323,809
Ending balance specifically evaluated for impairment	8,951	10,671	7,790
Ending balance collectively evaluated for impairment	330,355	293,992	316,019
Commercial | Construction
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	434	396	396
Charge offs	0	0	0
Recoveries	0	0	0
Provision for loan losses	(38)	45	38
Ending balance	396	441	434
Ending balance specifically evaluated for impairment	0	101	0
Ending balance collectively evaluated for impairment	396	340	434
Total	43,813	28,775	38,056
Ending balance specifically evaluated for impairment	741	763	741
Ending balance collectively evaluated for impairment	43,072	28,012	37,315
Commercial | Other
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,358	1,780	1,780
Charge offs	17	0	212
Recoveries	6	11	49
Provision for loan losses	193	134	1,741
Ending balance	3,540	1,925	3,358
Ending balance specifically evaluated for impairment	1,664	39	1,309
Ending balance collectively evaluated for impairment	1,876	1,886	2,049
Total	177,783	158,507	181,528
Ending balance specifically evaluated for impairment	9,440	1,710	9,918
Ending balance collectively evaluated for impairment	168,343	156,797	171,610
Municipal
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	20	18	18
Charge offs	0	0	0
Recoveries	0	0	0
Provision for loan losses	1	0	2
Ending balance	21	18	20
Ending balance specifically evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	21	18	20
Total	35,463	28,327	33,391
Ending balance specifically evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	35,463	28,327	33,391
Residential | Construction
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	36	44	44
Charge offs	0	0	0
Recoveries	0	0	0
Provision for loan losses	(5)	(20)	(8)
Ending balance	31	24	36
Ending balance specifically evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	31	24	36
Total	15,847	13,717	17,868
Ending balance specifically evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	15,847	13,717	17,868
Residential | Term
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,130	1,288	1,288
Charge offs	81	53	456
Recoveries	4	14	40
Provision for loan losses	76	(280)	258
Ending balance	1,129	969	1,130
Ending balance specifically evaluated for impairment	272	251	255
Ending balance collectively evaluated for impairment	857	718	875
Total	439,984	421,202	432,661
Ending balance specifically evaluated for impairment	11,528	13,260	11,748
Ending balance collectively evaluated for impairment	428,456	407,942	420,913
Home equity line of credit
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	692	807	807
Charge offs	115	7	28
Recoveries	11	0	11
Provision for loan losses	128	11	(98)
Ending balance	716	811	692
Ending balance specifically evaluated for impairment	16	26	24
Ending balance collectively evaluated for impairment	700	785	668
Total	110,298	110,016	111,302
Ending balance specifically evaluated for impairment	1,039	1,448	1,179
Ending balance collectively evaluated for impairment	109,259	108,568	110,123
Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	545	559	559
Charge offs	105	103	335
Recoveries	25	31	109
Provision for loan losses	116	86	212
Ending balance	581	573	545
Ending balance specifically evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	581	573	545
Total	25,508	24,528	25,524
Ending balance specifically evaluated for impairment	16	0	16
Ending balance collectively evaluated for impairment	25,492	24,528	25,508
Unallocated
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	642	1,258	1,258
Charge offs	0	0	0
Recoveries	0	0	0
Provision for loan losses	169	333	(616)
Ending balance	811	1,591	642
Ending balance specifically evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	811	1,591	642
Total	0	0	0
Ending balance specifically evaluated for impairment	0	0	0
Ending balance collectively evaluated for impairment	$ 0	$ 0	$ 0

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		87 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share based compensation cost	$ 1,489		$ 1,489
Compensation expense recognized	95	$ 83
Share-based compensation expense not yet recognized	$ 964	$ 911	$ 964
Plan 2,010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Capital shares reserved for future issuance (in shares)				400,000
Plan 2010 | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants during the period (in shares)			144,355
Shares	67,689		67,689

Stock-Based Compensation - Shar

Stock-Based Compensation - Shares of Restricted Stock Granted under 2010 Plan (Details) - Plan 2010 - Restricted Stock - shares	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares	67,689
Remaining Term (In Years)	2 years 7 months 10 days
2014 | Five Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term (In Years)				5 years
Shares	10,422
Remaining Term (In Years)				10 months 24 days
2015 | Five Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term (In Years)			5 years
Shares	12,023
Remaining Term (In Years)			1 year 10 months 10 days
2016 | Five Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term (In Years)			5 years
Shares	15,015
Remaining Term (In Years)			2 years 9 months 18 days
2017 | Five Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term (In Years)		5 years
Shares	9,972
Remaining Term (In Years)		3 years 9 months 18 days
2017 | Three Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term (In Years)		3 years
Shares	4,902
Remaining Term (In Years)		1 year 10 months 21 days
2018 | Five Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term (In Years)	5 years
Shares	9,655
Remaining Term (In Years)	4 years 9 months 18 days
2018 | Three Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term (In Years)	3 years
Shares	2,400
Remaining Term (In Years)	2 years 10 months 24 days
2018 | One Year
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term (In Years)	1 year
Shares	300
Remaining Term (In Years)	10 months 24 days
2018 | Two Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term (In Years)	2 years
Shares	932
Remaining Term (In Years)	1 year 9 months 18 days
2018 | Four Years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting Term (In Years)	4 years
Shares	2,068
Remaining Term (In Years)	3 years 9 months 18 days

Preferred and Common Stock (Det

Preferred and Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 09, 2009	Nov. 30, 2016	Mar. 31, 2018	Mar. 31, 2017	May 31, 2015
Class of Stock [Line Items]
Number of shares of common stock issuable pursuant to the Warrants, maximum (in shares)	225,904				226,819
Exercise price of the Warrants (in dollars per share)	$ 16.60				$ 16.53
Term of warrants (years)	10 years
Repurchase of warrants		$ 1,750
Proceeds from sale of common stock			$ 157	$ 185
Capital Purchase Program
Class of Stock [Line Items]
Proceeds from sale of common stock			$ 157	$ 185
Series A Preferred Stock
Class of Stock [Line Items]
Proceeds from issuance of CPP Shares	$ 25,000

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income (Numerator) [Abstract]
Net income as reported	$ 5,506	$ 4,637
Basic EPS: Income available to common shareholders	5,506	4,637
Diluted EPS: Income available to common shareholders plus assumed conversions	$ 5,506	$ 4,637
Shares (Denominator) [Abstract]
Basic EPS: Income available to common shareholders (in shares)	10,771,271	10,734,281
Effect of dilutive securities: restricted stock (in shares)	73,228	73,623
Diluted EPS: Income available to common shareholders plus assumed conversions (in shares)	10,844,499	10,807,904
Per-Share Amount [Abstract]
Basic EPS: Income available to common shareholders (in dollars per share)	$ 0.51	$ 0.43
Diluted EPS: Income available to common shareholders plus assumed conversions (in dollars per share)	$ 0.51	$ 0.43

Employee Benefit Plans - Narrat

Employee Benefit Plans - Narrative (Details)	3 Months Ended
	Mar. 31, 2018USD ($)post_retirement_benefit_planemployee	Mar. 31, 2017USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)
Retirement Benefits, Description [Abstract]
Requisite period of service (months)	3 months
Defined contribution plan employer maximum percentage match of annual salary based on employee contribution	3.00%
Defined contribution plan employer maximum percentage of annual profit-sharing contribution to plan for benefit of employee				2.00%
Expense related to 401(k) plan	$ 164,000	$ 130,000
Unfunded, supplemental retirement benefits payable period (years)	20 years
Pension expense	$ 43,000	54,000	$ 43,000
Accrued pension liability	$ 3,031,000	$ 3,045,000		$ 3,060,000
Number of post retirement benefit plans (post retirement benefit plan) | post_retirement_benefit_plan	2
Number of employees currently eligible (employee) | employee	6
Requisite age (in years)	50 years
Post-retirement benefit plan health insurance subsidy range minimum per month per person	$ 40
Post-retirement benefit plan health insurance subsidy range maximum per month per person	$ 1,200
Discount rate	4.25%
Assumed health care cost trend rate	7.00%
Expected future benefit payments, current year	$ 128,000
Estimated plan expense	77,000
Effect of one percentage point increase on accumulated benefit obligation	100,000
Effect of one percentage point increase on interest cost	7,000
Effect of one percentage point increase on service cost	$ 1,000

Employee Benefit Plans - Accumu

Employee Benefit Plans - Accumulated Post-Retirement Benefit Obligation, Funded Status, and Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Change in benefit obligation
Benefit obligation at beginning of year	$ 1,874	$ 1,870
Interest cost	19	19
Benefits paid	(28)	(32)
Benefit obligation at end of period	1,865	1,857
Funded status
Benefit obligation at end of period	(1,874)	(1,870)	$ (1,865)	$ (1,857)
Unamortized loss			186	102
Accrued benefit cost at end of period			$ (1,679)	$ (1,755)
Components of net periodic benefit cost
Interest cost	19	19
Net periodic benefit cost	$ 19	$ 19

Employee Benefit Plans - Schedu

Employee Benefit Plans - Schedule of Net Periodic Benefit Cost Not Yet Recognized (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Retirement Benefits, Description [Abstract]
Unamortized net actuarial loss	$ (186)	$ (156)	$ (186)
Deferred tax benefit at 21% (for March 31, 2018 and December 31, 2017) and 35% (for March 31, 2017)	39	54	39
Net unrecognized postretirement benefits included in accumulated other comprehensive income (loss)	$ (147)	$ (102)	$ (147)
Deferred tax benefit, percentage	21.00%	35.00%	21.00%

Other Comprehensive Income (L63

Other Comprehensive Income (Loss) - Summary of Available for Sale Securities Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 181,321	$ 172,521
Other comprehensive income (loss)	(2,933)	60
Ending balance	181,372	174,853
Accumulated Net Investment Gain (Loss) Attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(2,901)	(935)
Unrealized gains (losses) arising during the period	(4,052)	5
Reclassification of realized gains during the period	(136)	(3)
Related deferred taxes (at a Federal Income Tax rate of 21% for March 31, 2018 and 35% for March 31, 2017)	879	(1)
Other comprehensive income (loss)	(3,309)	1
Ending balance	$ (6,210)	$ (934)

Other Comprehensive Income (L64

Other Comprehensive Income (Loss) - Reclassification of Available-for-Sale Securities to Held-to-Maturity Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reclassification of Available-for-Sale Securities to Held-to-maturity Roll Forward [Roll Forward]
Beginning balance	$ 181,321	$ 172,521
Other comprehensive income (loss)	(2,933)	60
Ending balance	181,372	174,853
Accumulated Net Gain (Loss) on Securities Transferred from Available-for-Sale to Held-to-Maturity
Reclassification of Available-for-Sale Securities to Held-to-maturity Roll Forward [Roll Forward]
Beginning balance	(174)	(129)
Amortization of net unrealized losses	10	6
Related deferred taxes (at a Federal Income Tax rate of 21% for March 31, 2018 and 35% for March 31, 2017)	2	2
Other comprehensive income (loss)	(8)	(4)
Ending balance	$ (182)	$ (133)

Other Comprehensive Income (L65

Other Comprehensive Income (Loss) - Derivative Instruments Included in Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 181,321	$ 172,521
Other comprehensive income (loss)	(2,933)	60
Ending balance	181,372	174,853
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	1,544	1,163
Unrealized gains (losses) arising during the period	486	96
Related deferred taxes (at a Federal Income Tax rate of 21% for March 31, 2018 and 35% for March 31, 2017)	(102)	(33)
Other comprehensive income (loss)	384	63
Ending balance	$ 1,928	$ 1,226

Other Comprehensive Income (L66

Other Comprehensive Income (Loss) - Reclassification out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	$ 181,321	$ 172,521
Ending balance	181,372	174,853
Accumulated Defined Benefit Plans Adjustment Attributable to Parent
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(147)	(102)
Amortization of unrecognized transition obligation	0	0
Change in unamortized net actuarial gain (loss)	0	0
Related deferred taxes (at a Federal Income Tax rate of 21% for March 31, 2018 and 35% for March 31, 2017)	0	0
Ending balance	$ (147)	$ (102)

Financial Derivative Instrume67

Financial Derivative Instruments (Details) - Cash Flow Hedging - Designated as Hedging Instrument - USD ($)	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Interest Rate Swap June 28 2016
Derivative [Line Items]
Notional Amount	$ 30,000,000
Fixed Rate Paid	0.94%
Fair Value	$ 1,447,000	$ 1,154,000	$ 1,108,000
Interest Rate Swap June 27 2016
Derivative [Line Items]
Notional Amount	$ 20,000,000
Fixed Rate Paid	0.893%
Fair Value	$ 994,000	801,000	778,000
Interest Rate Swap
Derivative [Line Items]
Notional Amount	50,000,000
Fair Value	$ 2,441,000	$ 1,955,000	$ 1,886,000

Mortgage Servicing Rights - Nar

Mortgage Servicing Rights - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Transfers and Servicing [Abstract]
Moving average of weekly prepayment assumption (months)	3 months
Prepayment speed	7.92%
Discount rate adjustment rate	9.50%
Servicing rights capitalized	$ 62	$ 102
Servicing rights amortized	50	95
Mortgage servicing rights	2,518	1,853	$ 2,321
Residential mortgage loans serviced for others, principal	$ 258,475	$ 251,865	$ 260,258

Mortgage Servicing Rights - Sch

Mortgage Servicing Rights - Schedule of Mortgage Servicing Rights (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Transfers and Servicing [Abstract]
Mortgage servicing rights	$ 5,489	$ 5,428	$ 4,491
Accumulated amortization	(4,209)	(4,160)	(3,415)
Impairment reserve	0	0	(22)
Total servicing asset at fair value	$ 1,280	$ 1,268	$ 1,054

Certificates of Deposit (Detail

Certificates of Deposit (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Banking and Thrift [Abstract]
Certificates of deposit of less than $100,000	$ 347,010	$ 284,066	$ 246,792
Certificates $100,000 to $250,000	240,492	232,759	236,971
Certificates $250,000 and over	47,245	42,176	43,286
Total certificates of deposit	$ 634,747	$ 559,001	$ 527,049

Fair Value - Assets Recorded at

Fair Value - Assets Recorded at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	$ 303,769	$ 300,172	$ 312,624
Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	295,328	289,989	293,627
State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	5,511	6,769	15,705
Other equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	2,930	3,414	3,292
Total Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	303,769	300,172	312,624
Derivative asset	2,441	1,955	1,886
Total Fair Value | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0	0
Derivative asset	0	0	0
Total Fair Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	303,769	300,172	312,624
Derivative asset	2,441	1,955	1,886
Total Fair Value | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0	0
Derivative asset	0	0	0
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0	0
Total assets	0	0	0
Fair Value, Measurements, Recurring | Level 1 | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0	0
Fair Value, Measurements, Recurring | Level 1 | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0	0
Fair Value, Measurements, Recurring | Level 1 | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0	0
Fair Value, Measurements, Recurring | Level 1 | Other equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0	0
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	303,769	300,172	312,624
Total assets	306,210	302,127	314,510
Fair Value, Measurements, Recurring | Level 2 | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	2,441	1,955	1,886
Fair Value, Measurements, Recurring | Level 2 | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	295,328	289,989	293,627
Fair Value, Measurements, Recurring | Level 2 | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	5,511	6,769	15,705
Fair Value, Measurements, Recurring | Level 2 | Other equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	2,930	3,414	3,292
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0	0
Total assets	0	0	0
Fair Value, Measurements, Recurring | Level 3 | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	0	0	0
Fair Value, Measurements, Recurring | Level 3 | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0	0
Fair Value, Measurements, Recurring | Level 3 | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0	0
Fair Value, Measurements, Recurring | Level 3 | Other equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0	0	0
Fair Value, Measurements, Recurring | Total Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	303,769	300,172	312,624
Total assets	306,210	302,127	314,510
Fair Value, Measurements, Recurring | Total Fair Value | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset	2,441	1,955	1,886
Fair Value, Measurements, Recurring | Total Fair Value | Mortgage-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	295,328	289,989	293,627
Fair Value, Measurements, Recurring | Total Fair Value | State and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	5,511	6,769	15,705
Fair Value, Measurements, Recurring | Total Fair Value | Other equity securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	$ 2,930	$ 3,414	$ 3,292

Fair Value - Additional Informa

Fair Value - Additional Information (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Valuation allowance on real estate owned	$ 0	$ 53,000	$ 78,000
Valuation allowance on impaired financing receivable	$ 1,924,000	$ 1,531,000	$ 356,000

Fair Value - Assets Recorded 73

Fair Value - Assets Recorded at Fair Value on a Non-Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	$ 1,121	$ 1,012	$ 525
Fair Value, Measurements, Nonrecurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	0	0	0
Impaired loans	0	0	0
Total assets	0	0	0
Fair Value, Measurements, Nonrecurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	1,121	1,012	525
Impaired loans	5,938	6,521	718
Total assets	7,059	7,533	1,243
Fair Value, Measurements, Nonrecurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	0	0	0
Impaired loans	0	0	0
Total assets	0	0	0
Fair Value, Measurements, Nonrecurring | Total Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned	1,121	1,012	525
Impaired loans	5,938	6,521	718
Total assets	$ 7,059	$ 7,533	$ 1,243

Fair Value - Assets and Liabili

Fair Value - Assets and Liabilities at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, carrying value	$ 16,559	$ 19,207	$ 17,600	$ 17,366
Interest bearing deposits in other banks	280	860	3,272
Securities available for sale	303,769	300,172	312,624
Securities to be held to maturity, carrying value	258,690	256,567	240,829
Securities to be held to maturity	255,851	259,655	239,378
Restricted equity securities	11,947	10,358	13,363
Loans held for sale, carrying value	284	386	979
Mortgage servicing rights	2,518	2,321	1,853
Demand deposits	137,674	145,332	130,319
NOW deposits	314,587	318,043	323,919
Money market deposits	108,726	163,898	142,220
Savings deposits	232,458	232,605	222,976
Total deposits	1,428,192	1,418,879	1,346,483
Carrying value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents, carrying value	16,559	19,207	17,600
Interest bearing deposits in other banks	280	860	3,272
Securities available for sale	303,769	300,172	312,624
Securities to be held to maturity, carrying value	258,690	256,567	240,829
Restricted equity securities	11,947	10,358	13,363
Loans held for sale, carrying value	284	386	979
Loans	1,177,045	1,153,410	1,079,368
Mortgage servicing rights, carrying value	1,280	1,268	1,054
Interest rate swap agreements	2,441	1,955	1,886
Accrued interest receivable	7,222	5,867	6,854
Demand deposits	137,674	145,332	130,319
NOW deposits	314,587	318,043	323,919
Money market deposits	108,726	163,898	142,220
Savings deposits	232,458	232,605	222,976
Local certificates of deposit	260,450	223,074	213,296
National certificates of deposit	374,297	335,927	313,753
Total deposits	1,428,192	1,418,879	1,346,483
Repurchase agreements	67,182	70,564	76,342
Federal Home Loan Bank advances	177,047	158,194	150,125
Total borrowed funds	244,229	228,758	226,467
Accrued interest payable	760	642	519
Carrying value | Commercial | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	335,275	319,691	299,920
Carrying value | Commercial | Construction
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	43,385	37,594	28,254
Carrying value | Commercial | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	173,960	177,956	156,233
Carrying value | Municipal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	35,440	33,370	28,306
Carrying value | Residential | Construction
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	15,814	17,830	13,689
Carrying value | Residential | Term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	438,765	431,459	420,057
Carrying value | Home equity line of credit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	109,525	110,566	109,058
Carrying value | Consumer
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	24,881	24,944	23,851
Total Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	16,559	19,207	17,600
Interest bearing deposits in other banks	280	860	3,272
Securities available for sale	303,769	300,172	312,624
Securities to be held to maturity	255,851	259,655	239,378
Restricted equity securities	11,947	10,358	13,363
Loans held for sale	284	386	979
Loans	1,152,071	1,138,727	1,071,721
Mortgage servicing rights	2,518	2,321	1,853
Interest rate swap agreements	2,441	1,955	1,886
Accrued interest receivable	7,222	5,867	6,854
Demand deposits	128,525	139,350	123,696
NOW deposits	286,661	295,775	296,958
Money market deposits	102,196	153,497	130,374
Savings deposits	198,171	203,799	193,142
Local certificates of deposit	255,579	220,734	212,337
National certificates of deposit	374,095	335,775	313,833
Total deposits	1,345,227	1,348,930	1,270,340
Repurchase agreements	64,361	67,976	72,399
Federal Home Loan Bank advances	175,308	156,396	149,358
Total borrowed funds	239,669	224,372	221,757
Accrued interest payable	760	642	519
Total Fair Value | Commercial | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	326,030	311,321	295,039
Total Fair Value | Commercial | Construction
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	42,189	36,610	27,794
Total Fair Value | Commercial | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	171,045	175,455	154,823
Total Fair Value | Municipal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	34,972	33,280	28,737
Total Fair Value | Residential | Construction
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	15,587	17,613	13,593
Total Fair Value | Residential | Term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	430,023	431,028	420,393
Total Fair Value | Home equity line of credit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	108,047	109,012	107,823
Total Fair Value | Consumer
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	24,178	24,408	23,519
Total Fair Value | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	16,559	19,207	17,600
Interest bearing deposits in other banks	280	860	3,272
Securities available for sale	0	0	0
Securities to be held to maturity	0	0	0
Restricted equity securities	0	0	0
Loans held for sale	0	0	0
Loans	0	0	0
Mortgage servicing rights	0	0	0
Interest rate swap agreements	0	0	0
Accrued interest receivable	0	0	0
Demand deposits	0	0	0
NOW deposits	0	0	0
Money market deposits	0	0	0
Savings deposits	0	0	0
Local certificates of deposit	0	0	0
National certificates of deposit	0	0	0
Total deposits	0	0	0
Repurchase agreements	0	0	0
Federal Home Loan Bank advances	0	0	0
Total borrowed funds	0	0	0
Accrued interest payable	0	0	0
Total Fair Value | Level 1 | Commercial | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	0	0	0
Total Fair Value | Level 1 | Commercial | Construction
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	0	0	0
Total Fair Value | Level 1 | Commercial | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	0	0	0
Total Fair Value | Level 1 | Municipal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	0	0	0
Total Fair Value | Level 1 | Residential | Construction
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	0	0	0
Total Fair Value | Level 1 | Residential | Term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	0	0	0
Total Fair Value | Level 1 | Home equity line of credit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	0	0	0
Total Fair Value | Level 1 | Consumer
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	0	0	0
Total Fair Value | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0	0
Interest bearing deposits in other banks	0	0	0
Securities available for sale	303,769	300,172	312,624
Securities to be held to maturity	255,851	259,655	239,378
Restricted equity securities	11,947	10,358	13,363
Loans held for sale	284	386	979
Loans	5,938	6,521	718
Mortgage servicing rights	2,518	2,321	1,853
Interest rate swap agreements	2,441	1,955	1,886
Accrued interest receivable	7,222	5,867	6,854
Demand deposits	128,525	139,350	123,696
NOW deposits	286,661	295,775	296,958
Money market deposits	102,196	153,497	130,374
Savings deposits	198,171	203,799	193,142
Local certificates of deposit	255,579	220,734	212,337
National certificates of deposit	374,095	335,775	313,833
Total deposits	1,345,227	1,348,930	1,270,340
Repurchase agreements	64,361	67,976	72,399
Federal Home Loan Bank advances	175,308	156,396	149,358
Total borrowed funds	239,669	224,372	221,757
Accrued interest payable	760	642	519
Total Fair Value | Level 2 | Commercial | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	3	72	424
Total Fair Value | Level 2 | Commercial | Construction
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	0	0	0
Total Fair Value | Level 2 | Commercial | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	5,495	6,018	33
Total Fair Value | Level 2 | Municipal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	0	0	0
Total Fair Value | Level 2 | Residential | Construction
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	0	0	0
Total Fair Value | Level 2 | Residential | Term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	334	391	261
Total Fair Value | Level 2 | Home equity line of credit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	106	40	0
Total Fair Value | Level 2 | Consumer
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	0	0	0
Total Fair Value | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0	0
Interest bearing deposits in other banks	0	0	0
Securities available for sale	0	0	0
Securities to be held to maturity	0	0	0
Restricted equity securities	0	0	0
Loans held for sale	0	0	0
Loans	1,146,133	1,132,206	1,071,003
Mortgage servicing rights	0	0	0
Interest rate swap agreements	0	0	0
Accrued interest receivable	0	0	0
Demand deposits	0	0	0
NOW deposits	0	0	0
Money market deposits	0	0	0
Savings deposits	0	0	0
Local certificates of deposit	0	0	0
National certificates of deposit	0	0	0
Total deposits	0	0	0
Repurchase agreements	0	0	0
Federal Home Loan Bank advances	0	0	0
Total borrowed funds	0	0	0
Accrued interest payable	0	0	0
Total Fair Value | Level 3 | Commercial | Real estate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	326,027	311,249	294,615
Total Fair Value | Level 3 | Commercial | Construction
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	42,189	36,610	27,794
Total Fair Value | Level 3 | Commercial | Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	165,550	169,437	154,790
Total Fair Value | Level 3 | Municipal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	34,972	33,280	28,737
Total Fair Value | Level 3 | Residential | Construction
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	15,587	17,613	13,593
Total Fair Value | Level 3 | Residential | Term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	429,689	430,637	420,132
Total Fair Value | Level 3 | Home equity line of credit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	107,941	108,972	107,823
Total Fair Value | Level 3 | Consumer
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans	$ 24,178	$ 24,408	$ 23,519

Impact of Recently Issued Acc75

Impact of Recently Issued Accounting Standards (Details)	12 Months Ended
	Dec. 31, 2017USD ($)
Retained earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification adjustment for effect of enacted tax law changes	$ 297,000