Loans and Credit Quality - Narrative (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2020 USD ($) financing_commitment contract	Dec. 31, 2019 USD ($) contract
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable	$ 1,448,208,000	$ 1,048,456,000
Unearned origination fees, net of origination costs	15,007,000	5,085,000
Net nonaccrual loans	12,730,000	13,951,000
Total loans classified as troubled debt restructurings	$ 10,636,000	$ 10,100,000
Number of commitments on TDR | financing_commitment	0
Charge offs on loans later classified as TDRs	$ 0
TDR with specific impairment | contract	0	0
Small Business Administration (SBA), CARES Act, Paycheck Protection Program
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unearned origination fees, net of origination costs	$ 9,800,000
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable	780,160,000	$ 412,690,000
Commercial | Small Business Administration (SBA), CARES Act, Paycheck Protection Program
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable	$ 353,500,000