CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest and dividend income
Interest and fees on loans	$ 33,090	$ 32,050	$ 31,791
Interest on debt securities
Taxable	1,566	1,183	1,179
Tax exempt	380	927	1,431
Other interest and dividends	485	294	209
Total interest and dividend income	35,521	34,454	34,610
Interest expense
Deposits	2,483	2,181	1,844
Repurchase agreements	5	6	7
Capital lease	96	70	70
Note payable	18	21	6
Subordinated debt	624	624	35
Federal Home Loan Bank of Boston advances	1,012	947	1,064
Total interest expense	4,238	3,849	3,026
Net interest and dividend income	31,283	30,605	31,584
Provision for loan losses	1,020	1,835	917
Net interest and dividend income after provision for loan losses	30,263	28,770	30,667
Non-interest income
Trust and wealth advisory	3,477	3,338	3,265
Service charges and fees	3,718	3,133	2,986
Gains on sales of mortgage loans, net	125	229	274
Mortgage servicing, net	255	156	47
Gains on securities, net	178	584	192
Other	483	451	510
Total non-interest income	8,236	7,891	7,274
Non-interest expense
Salaries	11,135	10,926	10,301
Employee benefits	3,767	3,891	3,729
Premises and equipment	3,831	3,375	3,541
Data processing	2,057	2,106	1,677
Professional fees	2,499	1,933	2,150
Collections, OREO and appraisals	2,179	999	567
FDIC insurance	497	606	658
Marketing and community support	793	686	593
Amortization of intangibles	533	601	652
Other	2,038	2,264	2,053
Total non-interest expense	29,329	27,387	25,921
Income before income taxes	9,170	9,274	12,020
Income tax provision	2,914	2,589	3,563
Net income	6,256	6,685	8,457
Net income allocated to common stock	$ 6,201	$ 6,633	$ 8,227
Basic earnings per common share	$ 2.25	$ 2.43	$ 3.04
Weighted average common shares outstanding, to calculate basic earnings per share	2,755	2,733	2,706
Diluted earnings per common share	$ 2.24	$ 2.41	$ 3.02
Weighted average common shares outstanding, to calculate diluted earnings per share	2,774	2,749	2,723
Common dividends per share	$ 1.12	$ 1.12	$ 1.12