Loans and Allowance for Loan Losses - Summary of Changes in Allowance for Loan Losses Disaggregated by Loan Type (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	$ 16,768	$ 15,320	$ 15,261
Charge-offs	(1,656)	(109)	(323)
Recoveries	64	55	20
Provision for (Release of)	3,004	1,502	362
Allowance for loan losses, Ending balance	18,180	16,768	15,320
Residential Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	4,946	5,047	4,898
Provision for (Release of)	195	(101)	149
Allowance for loan losses, Ending balance	5,141	4,946	5,047
Commercial Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	9,626	8,289	8,451
Charge-offs	(1,270)
Provision for (Release of)	2,549	1,337	(162)
Allowance for loan losses, Ending balance	10,905	9,626	8,289
Home Equity
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	517	630	651
Provision for (Release of)	(56)	(113)	(21)
Allowance for loan losses, Ending balance	461	517	630
Commercial & Industrial
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	1,415	946	807
Charge-offs	(338)	(73)	(284)
Recoveries	53	48	13
Provision for (Release of)	258	494	410
Allowance for loan losses, Ending balance	1,388	1,415	946
Consumer
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance	264	315	264
Charge-offs	(48)	(36)	(39)
Recoveries	11	7	7
Provision for (Release of)	(29)	(22)	83
Allowance for loan losses, Ending balance	198	264	315
Impaired
Financing Receivable Allowance For Credit Losses [Line Items]
Allowance for loan losses, Beginning balance		93	190
Provision for (Release of)	87	$ (93)	(97)
Allowance for loan losses, Ending balance	$ 87		$ 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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