Loans and Allowance for Loan Losses - Past due aging analysis (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Past due aging analysis of loans
Accruing Current	$ 2,045,533	$ 1,711,189
Nonaccrual	4,795	7,379
Loans and Leases Receivable, Gross, Total	2,058,419	1,721,279
30 - 89 Days Past Due
Past due aging analysis of loans
Past due	8,091	2,263
90 Days or More Past Due
Past due aging analysis of loans
Past due		448
Commercial
Past due aging analysis of loans
Accruing Current	1,347,650	992,858
Nonaccrual	4,169	6,302
Loans and Leases Receivable, Gross, Total	1,357,421	1,000,225
Commercial \| 30 - 89 Days Past Due
Past due aging analysis of loans
Past due	5,602	1,065
Commercial \| Commercial and industrial
Past due aging analysis of loans
Accruing Current	784,282	473,900
Nonaccrual	2,840	4,862
Loans and Leases Receivable, Gross, Total	789,036	479,144
Commercial \| Commercial and industrial \| 30 - 89 Days Past Due
Past due aging analysis of loans
Past due	1,914	382
Commercial \| Real estate construction
Past due aging analysis of loans
Accruing Current	32,384	26,251
Loans and Leases Receivable, Gross, Total	33,169	26,378
Commercial \| Real estate construction \| 30 - 89 Days Past Due
Past due aging analysis of loans
Past due	785	127
Commercial \| Commercial real estate
Past due aging analysis of loans
Accruing Current	530,984	492,707
Nonaccrual	1,329	1,440
Loans and Leases Receivable, Gross, Total	535,216	494,703
Commercial \| Commercial real estate \| 30 - 89 Days Past Due
Past due aging analysis of loans
Past due	2,903	556
Consumer
Past due aging analysis of loans
Accruing Current	697,883	718,331
Nonaccrual	626	1,077
Loans and Leases Receivable, Gross, Total	700,998	721,054
Consumer \| 30 - 89 Days Past Due
Past due aging analysis of loans
Past due	2,489	1,198
Consumer \| 90 Days or More Past Due
Past due aging analysis of loans
Past due		448
Consumer \| Residential \| Real estate first mortgage
Past due aging analysis of loans
Accruing Current	466,551	455,244
Nonaccrual	457	797
Loans and Leases Receivable, Gross, Total	469,050	457,155
Consumer \| Residential \| Real estate first mortgage \| 30 - 89 Days Past Due
Past due aging analysis of loans
Past due	2,042	666
Consumer \| Residential \| Real estate first mortgage \| 90 Days or More Past Due
Past due aging analysis of loans
Past due		448
Consumer \| Residential \| Real estate junior lien
Past due aging analysis of loans
Accruing Current	152,111	176,915
Nonaccrual	169	274
Loans and Leases Receivable, Gross, Total	152,487	177,373
Consumer \| Residential \| Real estate junior lien \| 30 - 89 Days Past Due
Past due aging analysis of loans
Past due	207	184
Consumer \| Other revolving and installment
Past due aging analysis of loans
Accruing Current	79,221	86,172
Nonaccrual		6
Loans and Leases Receivable, Gross, Total	79,461	86,526
Consumer \| Other revolving and installment \| 30 - 89 Days Past Due
Past due aging analysis of loans
Past due	$ 240	$ 348

Amount of financing receivable not past due.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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