Loans and Allowance for Credit Losses - Financing Receivables Past Due (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Financing Receivable, Past Due
Nonaccruing	$ 4,387	$ 3,778
Total Past Due and Nonaccruing	29,079	29,696
Not Past Due	2,241,334	2,226,994
Total	2,270,413	2,256,690
Financial Receivable 30 to 59 Days Past Due
Financing Receivable, Past Due
Past due	18,655	16,027
Financial Receivable 60 to 89 Days Past Due
Financing Receivable, Past Due
Past due	5,230	8,807
Financing Receivables Greater Than 89 Days Past Due
Financing Receivable, Past Due
Past due	807	1,084
Commercial
Financing Receivable, Past Due
Nonaccruing	2,768	3,573
Commercial | Commercial and industrial
Financing Receivable, Past Due
Nonaccruing	2,756	3,531
Total Past Due and Nonaccruing	3,791	7,263
Not Past Due	869,539	945,542
Total	873,330	952,805
Commercial | Commercial real estate
Financing Receivable, Past Due
Nonaccruing	12	42
Total Past Due and Nonaccruing	7,823	4,407
Not Past Due	949,147	904,694
Total	956,970	909,101
Commercial | Construction and land
Financing Receivable, Past Due
Total Past Due and Nonaccruing	349	0
Not Past Due	180,148	145,595
Total	180,497	145,595
Commercial | Financial Receivable 30 to 59 Days Past Due | Commercial and industrial
Financing Receivable, Past Due
Past due	385	1,166
Commercial | Financial Receivable 30 to 59 Days Past Due | Commercial real estate
Financing Receivable, Past Due
Past due	7,811	4,008
Commercial | Financial Receivable 30 to 59 Days Past Due | Construction and land
Financing Receivable, Past Due
Past due	349
Commercial | Financial Receivable 60 to 89 Days Past Due | Commercial and industrial
Financing Receivable, Past Due
Past due		1,749
Commercial | Financial Receivable 60 to 89 Days Past Due | Commercial real estate
Financing Receivable, Past Due
Past due		357
Commercial | Financial Receivable 60 to 89 Days Past Due | Construction and land
Financing Receivable, Past Due
Past due		0
Commercial | Financing Receivables Greater Than 89 Days Past Due | Commercial and industrial
Financing Receivable, Past Due
Past due	650	817
Commercial | Financing Receivables Greater Than 89 Days Past Due | Commercial real estate
Financing Receivable, Past Due
Past due		0
Commercial | Financing Receivables Greater Than 89 Days Past Due | Construction and land
Financing Receivable, Past Due
Past due		0
Residential | Residential mortgages
Financing Receivable, Past Due
Nonaccruing	1,619	205
Total Past Due and Nonaccruing	2,848	1,876
Not Past Due	42,359	31,907
Total	45,207	33,783
Residential | Home equity
Financing Receivable, Past Due
Total Past Due and Nonaccruing		0
Not Past Due	24,972	25,443
Total	24,972	25,443
Residential | Financial Receivable 30 to 59 Days Past Due | Residential mortgages
Financing Receivable, Past Due
Past due	776	479
Residential | Financial Receivable 60 to 89 Days Past Due | Residential mortgages
Financing Receivable, Past Due
Past due	297	925
Residential | Financial Receivable 60 to 89 Days Past Due | Home equity
Financing Receivable, Past Due
Past due		0
Residential | Financing Receivables Greater Than 89 Days Past Due | Residential mortgages
Financing Receivable, Past Due
Past due	156	267
Residential | Financing Receivables Greater Than 89 Days Past Due | Home equity
Financing Receivable, Past Due
Past due		0
Consumer
Financing Receivable, Past Due
Total Past Due and Nonaccruing	14,268	16,150
Not Past Due	175,169	173,813
Total	189,437	189,963
Consumer | Financial Receivable 30 to 59 Days Past Due
Financing Receivable, Past Due
Past due	9,334	10,374
Consumer | Financial Receivable 60 to 89 Days Past Due
Financing Receivable, Past Due
Past due	4,933	5,776
Consumer | Financing Receivables Greater Than 89 Days Past Due
Financing Receivable, Past Due
Past due	$ 1	$ 0