Loans and Allowance for Credit Losses - Schedule of Past Due Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Total loans	$ 31,822,374	$ 31,123,641
Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	31,822,374	31,123,641
Commercial
Financing Receivable, Past Due [Line Items]
Total loans	9,751,875	9,508,904
Commercial | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	9,538,688	9,298,624
Commercial real estate
Financing Receivable, Past Due [Line Items]
Total loans	12,908,380	12,457,070
Commercial real estate | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	12,748,339	12,298,748
BBCC | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	373,228	368,602
Residential real estate
Financing Receivable, Past Due [Line Items]
Total loans	6,568,666	6,460,441
Residential real estate | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	6,568,666	6,460,441
Indirect
Financing Receivable, Past Due [Line Items]
Total loans	1,003,287	1,034,257
Indirect | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	1,003,287	1,034,257
Direct
Financing Receivable, Past Due [Line Items]
Total loans	580,726	629,186
Direct | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	580,726	629,186
Home equity
Financing Receivable, Past Due [Line Items]
Total loans	1,009,440	1,033,783
Home equity | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	1,009,440	1,033,783
Total Past Due | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	119,996	186,223
Total Past Due | Commercial | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	21,193	30,028
Total Past Due | Commercial real estate | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	41,563	81,444
Total Past Due | BBCC | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	2,600	1,698
Total Past Due | Residential real estate | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	29,530	40,967
Total Past Due | Indirect | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	5,881	9,378
Total Past Due | Direct | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	6,225	9,450
Total Past Due | Home equity | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	13,004	13,258
30-59 Days Past Due | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	58,491	104,589
30-59 Days Past Due | Commercial | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	8,463	14,147
30-59 Days Past Due | Commercial real estate | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	14,648	47,240
30-59 Days Past Due | BBCC | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	1,618	730
30-59 Days Past Due | Residential real estate | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	19,495	24,181
30-59 Days Past Due | Indirect | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	4,229	6,302
30-59 Days Past Due | Direct | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	3,759	5,404
30-59 Days Past Due | Home equity | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	6,279	6,585
60-89 Days Past Due | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	8,534	17,713
60-89 Days Past Due | Commercial | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	3,397	4,801
60-89 Days Past Due | Commercial real estate | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	256	1,312
60-89 Days Past Due | BBCC | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	552	365
60-89 Days Past Due | Residential real estate | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	310	5,033
60-89 Days Past Due | Indirect | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	1,141	2,118
60-89 Days Past Due | Direct | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	955	2,118
60-89 Days Past Due | Home equity | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	1,923	1,966
Past Due 90 Days or More | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	52,971	63,921
Past Due 90 Days or More | Commercial | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	9,333	11,080
Past Due 90 Days or More | Commercial real estate | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	26,659	32,892
Past Due 90 Days or More | BBCC | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	430	603
Past Due 90 Days or More | Residential real estate | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	9,725	11,753
Past Due 90 Days or More | Indirect | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	511	958
Past Due 90 Days or More | Direct | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	1,511	1,928
Past Due 90 Days or More | Home equity | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	4,802	4,707
Current | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	31,702,378	30,937,418
Current | Commercial | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	9,517,495	9,268,596
Current | Commercial real estate | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	12,706,776	12,217,304
Current | BBCC | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	370,628	366,904
Current | Residential real estate | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	6,539,136	6,419,474
Current | Indirect | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	997,406	1,024,879
Current | Direct | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	574,501	619,736
Current | Home equity | Segment Portfolio Reclassification, Adjusted Balance
Financing Receivable, Past Due [Line Items]
Total loans	$ 996,436	$ 1,020,525