Allowance for Loan Losses - Impaired Loans (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Impaired [Line Items]
Total accruing impaired loans	$ 10,300	$ 17,100
Impaired non-accrual loans	38,000	14,800
Interest income that was not recognized on loans that were deem impaired	1,400	1,000	$ 1,100
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	52,736	35,333
Total recorded investment in impaired loans	48,318	31,878
Recorded investment with no allowance	23,400	29,521
Recorded investment with allowance	24,918	2,357
Related specific allowance	6,185	1,049
Average recorded investment	35,536	31,825	28,661
Interest income (loss) recognized	337	993	851
Commercial real estate
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	37,184	18,537
Total recorded investment in impaired loans	35,915	17,515
Recorded investment with no allowance	14,728	17,129
Recorded investment with allowance	21,187	386
Related specific allowance	3,454	31
Average recorded investment	19,606	17,033	13,971
Interest income (loss) recognized	138	509	385
Commercial and industrial
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	10,628	11,455
Total recorded investment in impaired loans	8,409	9,332
Recorded investment with no allowance	4,696	7,405
Recorded investment with allowance	3,713	1,927
Related specific allowance	2,713	974
Average recorded investment	8,639	11,135	11,801
Interest income (loss) recognized	168	385	373
Commercial construction
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	3,668	3,359
Total recorded investment in impaired loans	2,999	3,347
Recorded investment with no allowance	2,999	3,347
Recorded investment with allowance	0	0
Related specific allowance	0	0
Average recorded investment	5,991	2,158	1,691
Interest income (loss) recognized	22	81	93
SBA paycheck protection program
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	0
Total recorded investment in impaired loans	0
Recorded investment with no allowance	0
Recorded investment with allowance	0
Related specific allowance	0
Average recorded investment	0	0	0
Interest income (loss) recognized	0	0	0
Residential mortgages
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	699	1,331
Total recorded investment in impaired loans	596	1,229
Recorded investment with no allowance	596	1,229
Recorded investment with allowance	0	0
Related specific allowance	0	0
Average recorded investment	854	1,024	644
Interest income (loss) recognized	8	18	0
Home equity
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	539	607
Total recorded investment in impaired loans	381	411
Recorded investment with no allowance	381	411
Recorded investment with allowance	0	0
Related specific allowance	0	0
Average recorded investment	410	447	498
Interest income (loss) recognized	(1)	0	0
Consumer
Impaired Financing Receivable, Recorded Investment [Abstract]
Unpaid contractual principal balance	18	44
Total recorded investment in impaired loans	18	44
Recorded investment with no allowance	0	0
Recorded investment with allowance	18	44
Related specific allowance	18	44
Average recorded investment	36	28	56
Interest income (loss) recognized	$ 2	$ 0	$ 0

Financing Receivable, Recorded Investment, Impaired and Nonaccrual Status

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- Definition

Reflects the carrying amount of impaired loans on which interest is continuing to be earned or accrued.

+ References

No definition available.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
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Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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Amount of allowance for credit losses related to recorded investment.

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Amount of unpaid principal balance of impaired financing receivables with related allowance for credit losses and without related allowance for credit losses.

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- Definition

Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-SubTopic 40
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