Allowance for Loan Losses - Adversely Classified Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	$ 3,087,246	$ 2,568,562
Adversely classified loans to total loans	1.79%	1.45%
Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	$ 1,478,235	$ 1,394,179
Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	435,660	501,227
Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	373,309	317,477
SBA paycheck protection program
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	453,084	0
Residential mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	252,971	247,373
Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	85,006	98,252
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	8,981	10,054
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	52,386	34,749
Substandard | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	40,088	16,664
Substandard | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	7,901	10,900
Substandard | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	3,501	4,836
Substandard | SBA paycheck protection program
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	0
Substandard | Residential mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	474	1,825
Substandard | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	381	455
Substandard | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	41	69
Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	2,490	2,373
Doubtful | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	197	0
Doubtful | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	2,293	2,370
Doubtful | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	0	0
Doubtful | SBA paycheck protection program
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	0
Doubtful | Residential mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	0	0
Doubtful | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	0	0
Doubtful | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	0	3
Loss
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	0	0
Loss | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	0	0
Loss | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	0	0
Loss | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	0	0
Loss | SBA paycheck protection program
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	0
Loss | Residential mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	0	0
Loss | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	0	0
Loss | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	0	0
Not Adversely Classified
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	3,032,370	2,531,440
Not Adversely Classified | Commercial real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	1,437,950	1,377,515
Not Adversely Classified | Commercial and industrial
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	425,466	487,957
Not Adversely Classified | Commercial construction
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	369,808	312,641
Not Adversely Classified | SBA paycheck protection program
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	453,084
Not Adversely Classified | Residential mortgages
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	252,497	245,548
Not Adversely Classified | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	84,625	97,797
Not Adversely Classified | Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Gross Loans	$ 8,940	$ 9,982