Allowance for Loan Losses - Allowance for Loan Loss Activity by Class (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 11,858	$ 11,490	$ 11,639	$ 11,232	$ 11,232
Charge offs	162	329	417	480	1,120
Recoveries	64	60	138	94	277
Provision (credit)	2,350	250	2,750	625	1,250
Ending balance	14,110	11,471	14,110	11,471	11,639
Ending balance specifically evaluated for impairment	917	1,830	917	1,830	2,213
Ending balance collectively evaluated for impairment	13,193	9,641	13,193	9,641	9,426
Total	1,451,623	1,249,132	1,451,623	1,249,132	1,297,075
Ending balance specifically evaluated for impairment	20,013	31,180	20,013	31,180	29,274
Ending balance collectively evaluated for impairment	1,431,610	1,217,952	1,431,610	1,217,952	1,267,801
Commercial \| Real estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,862	3,632	3,742	3,567	3,567
Charge offs	0	53	0	53	89
Recoveries	0	5	0	13	15
Provision (credit)	649	25	769	82	249
Ending balance	4,511	3,609	4,511	3,609	3,742
Ending balance specifically evaluated for impairment	199	196	199	196	251
Ending balance collectively evaluated for impairment	4,312	3,413	4,312	3,413	3,491
Total	397,155	359,581	397,155	359,581	372,810
Ending balance specifically evaluated for impairment	5,749	8,961	5,749	8,961	6,309
Ending balance collectively evaluated for impairment	391,406	350,620	391,406	350,620	366,501
Commercial \| Construction
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	424	325	365	255	255
Charge offs	0	0	0	0	0
Recoveries	0	0	0	0	0
Provision (credit)	100	(16)	159	54	110
Ending balance	524	309	524	309	365
Ending balance specifically evaluated for impairment	20	0	20	0	0
Ending balance collectively evaluated for impairment	504	309	504	309	365
Total	47,169	32,785	47,169	32,785	38,084
Ending balance specifically evaluated for impairment	934	982	934	982	958
Ending balance collectively evaluated for impairment	46,235	31,803	46,235	31,803	37,126
Commercial \| Other
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	2,427	3,430	3,329	3,541	3,541
Charge offs	17	108	17	109	179
Recoveries	0	1	20	2	73
Provision (credit)	1,279	(42)	357	(153)	(106)
Ending balance	3,689	3,281	3,689	3,281	3,329
Ending balance specifically evaluated for impairment	132	1,320	132	1,320	1,273
Ending balance collectively evaluated for impairment	3,557	1,961	3,557	1,961	2,056
Total	327,967	205,910	327,967	205,910	218,773
Ending balance specifically evaluated for impairment	853	7,582	853	7,582	7,075
Ending balance collectively evaluated for impairment	327,114	198,328	327,114	198,328	211,698
Municipal
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	29	25	27	24	24
Charge offs	0	0	0	0	0
Recoveries	0	0	0	0	0
Provision (credit)	81	0	83	1	3
Ending balance	110	25	110	25	27
Ending balance specifically evaluated for impairment	0	0	0	0	0
Ending balance collectively evaluated for impairment	110	25	110	25	27
Total	49,644	36,113	49,644	36,113	41,288
Ending balance specifically evaluated for impairment	0	0	0	0	0
Ending balance collectively evaluated for impairment	49,644	36,113	49,644	36,113	41,288
Residential \| Construction
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	32	30	25	34	34
Charge offs	0	0	0	0	0
Recoveries	0	0	0	0	0
Provision (credit)	32	(7)	39	(11)	(9)
Ending balance	64	23	64	23	25
Ending balance specifically evaluated for impairment	0	0	0	0	0
Ending balance collectively evaluated for impairment	64	23	64	23	25
Total	14,707	13,239	14,707	13,239	14,813
Ending balance specifically evaluated for impairment	0	0	0	0	0
Ending balance collectively evaluated for impairment	14,707	13,239	14,707	13,239	14,813
Residential \| Term
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,226	1,114	1,024	1,235	1,235
Charge offs	44	44	46	93	445
Recoveries	16	3	26	6	57
Provision (credit)	1,063	33	1,257	(42)	177
Ending balance	2,261	1,106	2,261	1,106	1,024
Ending balance specifically evaluated for impairment	269	305	269	305	237
Ending balance collectively evaluated for impairment	1,992	801	1,992	801	787
Total	499,693	481,349	499,693	481,349	492,455
Ending balance specifically evaluated for impairment	10,311	12,636	10,311	12,636	12,439
Ending balance collectively evaluated for impairment	489,382	468,713	489,382	468,713	480,016
Home equity line of credit
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,012	630	1,078	730	730
Charge offs	0	0	153	38	69
Recoveries	18	1	19	2	4
Provision (credit)	254	2	340	(61)	413
Ending balance	1,284	633	1,284	633	1,078
Ending balance specifically evaluated for impairment	292	9	292	9	447
Ending balance collectively evaluated for impairment	992	624	992	624	631
Total	87,019	94,763	87,019	94,763	92,349
Ending balance specifically evaluated for impairment	2,161	1,019	2,161	1,019	2,488
Ending balance collectively evaluated for impairment	84,858	93,744	84,858	93,744	89,861
Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	725	660	867	630	630
Charge offs	101	124	201	187	338
Recoveries	30	50	73	71	128
Provision (credit)	4	63	(81)	135	447
Ending balance	658	649	658	649	867
Ending balance specifically evaluated for impairment	5	0	5	0	5
Ending balance collectively evaluated for impairment	653	649	653	649	862
Total	28,269	25,392	28,269	25,392	26,503
Ending balance specifically evaluated for impairment	5	0	5	0	5
Ending balance collectively evaluated for impairment	28,264	25,392	28,264	25,392	26,498
Unallocated
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	2,121	1,644	1,182	1,216	1,216
Charge offs	0	0	0	0	0
Recoveries	0	0	0	0	0
Provision (credit)	(1,112)	192	(173)	620	(34)
Ending balance	1,009	1,836	1,009	1,836	1,182
Ending balance specifically evaluated for impairment	0	0	0	0	0
Ending balance collectively evaluated for impairment	1,009	1,836	1,009	1,836	1,182
Total	0	0	0	0	0
Ending balance specifically evaluated for impairment	0	0	0	0	0
Ending balance collectively evaluated for impairment	$ 0	$ 0	$ 0	$ 0	$ 0

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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The balance of financing receivables that were collectively evaluated for impairment.

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- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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- Definition

Amount of expense related to estimated loss from loan and lease transactions.

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