Allowance for Loan Losses - Activity by Class (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 17,034	$ 14,110	$ 16,253	$ 11,639	$ 11,639
Charge offs	158	576	637	993	1,661
Recoveries	106	37	316	175	225
Provision (credit)	525	1,800	1,575	4,550	6,050
Ending balance	17,507	15,371	17,507	15,371	16,253
Ending balance specifically evaluated for impairment	682	890	682	890	462
Ending balance collectively evaluated for impairment	16,825	14,481	16,825	14,481	15,791
Ending balance	1,617,212	1,436,646	1,617,212	1,436,646	1,476,761
Ending balance specifically evaluated for impairment	14,549	19,341	14,549	19,341	16,039
Ending balance collectively evaluated for impairment	1,602,663	1,417,305	1,602,663	1,417,305	1,460,722
Commercial \| Real estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	6,088	4,511	5,178	3,742	3,742
Charge offs	66	532	71	532	1,088
Recoveries	0	0	95	0	0
Provision (credit)	477	782	1,297	1,551	2,524
Ending balance	6,499	4,761	6,499	4,761	5,178
Ending balance specifically evaluated for impairment	138	135	138	135	112
Ending balance collectively evaluated for impairment	6,361	4,626	6,361	4,626	5,066
Ending balance	550,077	407,128	550,077	407,128	442,121
Ending balance specifically evaluated for impairment	2,800	4,753	2,800	4,753	3,029
Ending balance collectively evaluated for impairment	547,277	402,375	547,277	402,375	439,092
Commercial \| Construction
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	750	524	662	365	365
Charge offs	0	0	0	0	0
Recoveries	0	0	0	0	0
Provision (credit)	129	83	217	242	297
Ending balance	879	607	879	607	662
Ending balance specifically evaluated for impairment	18	19	18	19	18
Ending balance collectively evaluated for impairment	861	588	861	588	644
Ending balance	73,302	52,038	73,302	52,038	56,565
Ending balance specifically evaluated for impairment	705	1,009	705	1,009	770
Ending balance collectively evaluated for impairment	72,597	51,029	72,597	51,029	55,795
Commercial \| Other
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,757	3,689	3,438	3,329	3,329
Charge offs	0	7	286	24	27
Recoveries	81	4	83	24	37
Provision (credit)	(111)	(44)	492	313	99
Ending balance	3,727	3,642	3,727	3,642	3,438
Ending balance specifically evaluated for impairment	397	128	397	128	169
Ending balance collectively evaluated for impairment	3,330	3,514	3,330	3,514	3,269
Ending balance	288,121	309,297	288,121	309,297	285,015
Ending balance specifically evaluated for impairment	1,755	1,023	1,755	1,023	1,779
Ending balance collectively evaluated for impairment	286,366	308,274	286,366	308,274	283,236
Municipal
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	187	110	171	27	27
Charge offs	0	0	0	0	0
Recoveries	0	0	0	0	0
Provision (credit)	2	29	18	112	144
Ending balance	189	139	189	139	171
Ending balance specifically evaluated for impairment	0	0	0	0	0
Ending balance collectively evaluated for impairment	189	139	189	139	171
Ending balance	40,616	44,110	40,616	44,110	43,783
Ending balance specifically evaluated for impairment	0	0	0	0	0
Ending balance collectively evaluated for impairment	40,616	44,110	40,616	44,110	43,783
Residential \| Construction
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	160	64	102	25	25
Charge offs	0	0	0	0	0
Recoveries	0	0	0	0	0
Provision (credit)	(18)	17	40	56	77
Ending balance	142	81	142	81	102
Ending balance specifically evaluated for impairment	0	0	0	0	0
Ending balance collectively evaluated for impairment	142	81	142	81	102
Ending balance	29,358	16,101	29,358	16,101	21,600
Ending balance specifically evaluated for impairment	0	0	0	0	0
Ending balance collectively evaluated for impairment	29,358	16,101	29,358	16,101	21,600
Residential \| Term
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	2,896	2,261	2,579	1,024	1,024
Charge offs	0	0	41	46	66
Recoveries	3	5	12	31	34
Provision (credit)	(138)	250	211	1,507	1,587
Ending balance	2,761	2,516	2,761	2,516	2,579
Ending balance specifically evaluated for impairment	129	204	129	204	163
Ending balance collectively evaluated for impairment	2,632	2,312	2,632	2,312	2,416
Ending balance	537,811	497,667	537,811	497,667	522,070
Ending balance specifically evaluated for impairment	8,782	10,182	8,782	10,182	9,414
Ending balance collectively evaluated for impairment	529,029	487,485	529,029	487,485	512,656
Home equity line of credit
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	959	1,284	1,211	1,078	1,078
Charge offs	0	0	0	153	153
Recoveries	12	1	60	20	22
Provision (credit)	(15)	172	(315)	512	264
Ending balance	956	1,457	956	1,457	1,211
Ending balance specifically evaluated for impairment	0	403	0	403	0
Ending balance collectively evaluated for impairment	956	1,054	956	1,054	1,211
Ending balance	74,594	82,982	74,594	82,982	79,750
Ending balance specifically evaluated for impairment	503	2,364	503	2,364	1,039
Ending balance collectively evaluated for impairment	74,091	80,618	74,091	80,618	78,711
Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	892	658	778	867	867
Charge offs	92	37	239	238	327
Recoveries	10	27	66	100	132
Provision (credit)	57	(56)	262	(137)	106
Ending balance	867	592	867	592	778
Ending balance specifically evaluated for impairment	0	1	0	1	0
Ending balance collectively evaluated for impairment	867	591	867	591	778
Ending balance	23,333	27,323	23,333	27,323	25,857
Ending balance specifically evaluated for impairment	4	10	4	10	8
Ending balance collectively evaluated for impairment	23,329	27,313	23,329	27,313	25,849
Unallocated
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,345	1,009	2,134	1,182	1,182
Charge offs	0	0	0	0	0
Recoveries	0	0	0	0	0
Provision (credit)	142	567	(647)	394	952
Ending balance	1,487	1,576	1,487	1,576	2,134
Ending balance specifically evaluated for impairment	0	0	0	0	0
Ending balance collectively evaluated for impairment	1,487	1,576	1,487	1,576	2,134
Ending balance	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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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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Amount excluding accrued interest, of allowance for credit loss on financing receivable.

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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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Amount, before allowance for credit loss, of financing receivable.

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