Loans and Allowance for Credit Losses - Schedule of Types of Collateral (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 13,786,479	$ 12,117,524
Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	101,194
Blanket Lien
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	21,654
Investment Securities/Cash
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	6,581
Auto
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	3,292
Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	14,607
Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	3,956,422	2,890,296
Commercial | Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	8,976
Commercial | Blanket Lien
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	19,253
Commercial | Investment Securities/Cash
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	5,379
Commercial | Auto
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	394
Commercial | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	893
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	5,946,512	5,166,792
Commercial real estate | Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	60,844
Commercial real estate | Blanket Lien
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	472
Commercial real estate | Investment Securities/Cash
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,137
Commercial real estate | Auto
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0
Commercial real estate | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	13,685
BBCC | Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,425
BBCC | Blanket Lien
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,929
BBCC | Investment Securities/Cash
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	63
BBCC | Auto
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	134
BBCC | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0
Residential real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	2,248,422	$ 2,334,289
Residential real estate | Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	24,794
Residential real estate | Blanket Lien
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0
Residential real estate | Investment Securities/Cash
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0
Residential real estate | Auto
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0
Residential real estate | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0
Indirect
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	913,902
Indirect | Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0
Indirect | Blanket Lien
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0
Indirect | Investment Securities/Cash
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0
Indirect | Auto
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	2,529
Indirect | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0
Direct
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	164,807
Direct | Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	901
Direct | Blanket Lien
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0
Direct | Investment Securities/Cash
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	2
Direct | Auto
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	235
Direct | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	29
Home equity
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	556,414
Home equity | Real Estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	4,254
Home equity | Blanket Lien
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0
Home equity | Investment Securities/Cash
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0
Home equity | Auto
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0
Home equity | Other
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 0