Loans - Loan Categories and Past Due Loans (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Financing Receivable, Past Due [Line Items]
Loans receivable held-for-sale, net, not part of disposal group	$ 2,169	$ 11,085	$ 10,580
Total	2,654,751	2,595,030	2,592,455
Loans 90 or More Days Past Due and Still Accruing Interest	555	228	121
Nonaccrual Loans	10,723	6,033	6,004
Nonaccrual With No Allowance for Credit Loss	7,940
Interest Income on Nonaccrual Loans	111
Commercial
Financing Receivable, Past Due [Line Items]
Total	188,191	240,554	275,921
Loans 90 or More Days Past Due and Still Accruing Interest	0	0	0
Nonaccrual Loans	91	78	72
Nonaccrual With No Allowance for Credit Loss	91
Interest Income on Nonaccrual Loans	0
Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Total	615,081	571,787	541,233
Loans 90 or More Days Past Due and Still Accruing Interest	0	184	0
Nonaccrual Loans	7,766	1,475	1,475
Nonaccrual With No Allowance for Credit Loss	4,983
Interest Income on Nonaccrual Loans	111
Consumer
Financing Receivable, Past Due [Line Items]
Total	921,189	859,768	849,526
Loans 90 or More Days Past Due and Still Accruing Interest	0	0	0
Nonaccrual Loans	1,101	1,470	1,559
Nonaccrual With No Allowance for Credit Loss	1,101
Interest Income on Nonaccrual Loans	0
Residential
Financing Receivable, Past Due [Line Items]
Total	930,290	922,921	925,775
Loans 90 or More Days Past Due and Still Accruing Interest	555	44	121
Nonaccrual Loans	1,765	3,010	2,898
Nonaccrual With No Allowance for Credit Loss	1,765
Interest Income on Nonaccrual Loans	0
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Total	14,484	13,783	12,808
Financial Asset, Past Due | Commercial
Financing Receivable, Past Due [Line Items]
Total	867	293	144
Financial Asset, Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Total	1,641	1,658	1,560
Financial Asset, Past Due | Consumer
Financing Receivable, Past Due [Line Items]
Total	8,362	9,068	8,394
Financial Asset, Past Due | Residential
Financing Receivable, Past Due [Line Items]
Total	3,614	2,764	2,710
Financing Receivables, 30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	5,906	5,339	4,709
Financing Receivables, 30 to 59 Days Past Due | Commercial
Financing Receivable, Past Due [Line Items]
Total	729	102	43
Financing Receivables, 30 to 59 Days Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Total	0	0	0
Financing Receivables, 30 to 59 Days Past Due | Consumer
Financing Receivable, Past Due [Line Items]
Total	4,809	4,976	4,238
Financing Receivables, 30 to 59 Days Past Due | Residential
Financing Receivable, Past Due [Line Items]
Total	368	261	428
Financing Receivables, 60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	3,901	4,105	3,782
Financing Receivables, 60 to 89 Days Past Due | Commercial
Financing Receivable, Past Due [Line Items]
Total	63	113	79
Financing Receivables, 60 to 89 Days Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Total	0	0	85
Financing Receivables, 60 to 89 Days Past Due | Consumer
Financing Receivable, Past Due [Line Items]
Total	2,543	2,713	2,853
Financing Receivables, 60 to 89 Days Past Due | Residential
Financing Receivable, Past Due [Line Items]
Total	1,295	1,279	765
Financing Receivables, Equal to Greater than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Total	4,677	4,339	4,317
Financing Receivables, Equal to Greater than 90 Days Past Due | Commercial
Financing Receivable, Past Due [Line Items]
Total	75	78	22
Financing Receivables, Equal to Greater than 90 Days Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Total	1,641	1,658	1,475
Financing Receivables, Equal to Greater than 90 Days Past Due | Consumer
Financing Receivable, Past Due [Line Items]
Total	1,010	1,379	1,303
Financing Receivables, Equal to Greater than 90 Days Past Due | Residential
Financing Receivable, Past Due [Line Items]
Total	1,951	1,224	1,517
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Total	2,640,267	2,581,247	2,579,647
Financial Asset, Not Past Due | Commercial
Financing Receivable, Past Due [Line Items]
Total	187,324	240,261	275,777
Financial Asset, Not Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Total	613,440	570,129	539,673
Financial Asset, Not Past Due | Consumer
Financing Receivable, Past Due [Line Items]
Total	912,827	850,700	841,132
Financial Asset, Not Past Due | Residential
Financing Receivable, Past Due [Line Items]
Total	$ 926,676	$ 920,157	$ 923,065