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Loans and Allowance for Credit Losses on Loans - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 19,100		$ 22,874
Provision (reversal) - CECL	1,800		(2,049)
Initial allowance for PCD loans	1,505		1,505
Charge-offs	(2)		(2)
Recoveries	11		86
Ending balance	22,414		22,414
Beginning balance		$ 20,868		$ 16,677
Provision - incurred loss		1,250	(2,049)	5,450
Charge-offs		(10)		(30)
Recoveries		5		16
Ending balance		22,113		22,113
Commercial loans | Commercial and industrial
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,590		2,530
Provision (reversal) - CECL	126		(821)
Initial allowance for PCD loans	405		405
Charge-offs	0		0
Recoveries	3		10
Ending balance	2,124		2,124
Beginning balance		2,609		2,334
Provision - incurred loss		(79)		208
Charge-offs		(10)		(30)
Recoveries		5		13
Ending balance		2,525		2,525
Commercial real estate loans | Commercial owner-occupied
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	2,037		2,778
Provision (reversal) - CECL	(30)		(771)
Initial allowance for PCD loans	559		559
Charge-offs	0		0
Recoveries	0		0
Ending balance	2,566		2,566
Beginning balance		2,910		2,462
Provision - incurred loss		225		673
Charge-offs		0		0
Recoveries		0		0
Ending balance		3,135		3,135
Commercial real estate loans | Commercial investor-owned
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	10,761		12,682
Provision (reversal) - CECL	1,011		(910)
Initial allowance for PCD loans	533		533
Charge-offs	0		0
Recoveries	0		0
Ending balance	12,305		12,305
Beginning balance		10,403		8,483
Provision - incurred loss		1,221		3,141
Charge-offs		0		0
Recoveries		0		0
Ending balance		11,624		11,624
Commercial real estate loans | Construction
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,142		1,557
Provision (reversal) - CECL	77		(356)
Initial allowance for PCD loans	0		0
Charge-offs	0		0
Recoveries	8		26
Ending balance	1,227		1,227
Beginning balance		836		638
Provision - incurred loss		24		219
Charge-offs		0		0
Recoveries		0		3
Ending balance		860		860
Residential loans | Home equity
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	412		738
Provision (reversal) - CECL	247		(129)
Initial allowance for PCD loans	0		0
Charge-offs	0		0
Recoveries	0		50
Ending balance	659		659
Beginning balance		1,044		850
Provision - incurred loss		(6)		188
Charge-offs		0		0
Recoveries		0		0
Ending balance		1,038		1,038
Residential loans | Other residential
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	613		998
Provision (reversal) - CECL	4		(381)
Initial allowance for PCD loans	6		6
Charge-offs	0		0
Recoveries	0		0
Ending balance	623		623
Beginning balance		1,266		973
Provision - incurred loss		(6)		287
Charge-offs		0		0
Recoveries		0		0
Ending balance		1,260		1,260
Consumer loans | Installment and other consumer loans
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	238		291
Provision (reversal) - CECL	384		331
Initial allowance for PCD loans	2		2
Charge-offs	(2)		(2)
Recoveries	0		0
Ending balance	622		622
Beginning balance		426		284
Provision - incurred loss		(20)		122
Charge-offs		0		0
Recoveries		0		0
Ending balance		406		406
Unallocated
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	2,307		1,300
Provision (reversal) - CECL	(19)		988
Initial allowance for PCD loans	0		0
Charge-offs	0		0
Recoveries	0		0
Ending balance	$ 2,288		$ 2,288
Beginning balance		1,374		653
Provision - incurred loss		(109)		612
Charge-offs		0		0
Recoveries		0		0
Ending balance		$ 1,265		$ 1,265

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- Definition

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

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