Loans and the Allowance for Loan Losses - Summary of Changes in Allowance for Loan Losses Disaggregated by Loan Type (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	$ 16,652	$ 15,732	$ 16,768	$ 15,320
Charge-offs	(164)	(23)	(205)	(32)
Recoveries	16	15	33	27
Provision for (Release of)	595	(79)	503	330
Allowance for loan losses, Ending balance	17,099	15,645	17,099	15,645
Residential Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	5,256	4,692	4,946	5,047
Provision for (Release of)	207	187	517	(168)
Allowance for loan losses, Ending balance	5,463	4,879	5,463	4,879
Commercial Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	9,369	8,937	9,626	8,289
Charge-offs	(55)		(55)
Provision for (Release of)	115	(263)	(142)	385
Allowance for loan losses, Ending balance	9,429	8,674	9,429	8,674
Home Equity
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	534	570	517	630
Provision for (Release of)	(3)	31	14	(29)
Allowance for loan losses, Ending balance	531	601	531	601
Commercial & Industrial
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	1,245	1,145	1,415	946
Charge-offs	(100)	(6)	(130)	(11)
Recoveries	12	12	25	22
Provision for (Release of)	288	44	135	238
Allowance for loan losses, Ending balance	1,445	1,195	1,445	1,195
Consumer
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	248	298	264	315
Charge-offs	(9)	(17)	(20)	(21)
Recoveries	4	3	8	5
Provision for (Release of)	(12)	12	(21)	(3)
Allowance for loan losses, Ending balance	$ 231	296	$ 231	296
Impaired
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance		90		93
Provision for (Release of)		$ (90)		$ (93)

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 increase (decrease) of allowance reserve for credit loss.

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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 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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