Loans and Allowance for Credit Losses - Schedule of Composition of Loans and Impact of Adoption (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	$ 32,991,927	$ 31,123,641
Allowance for credit losses on loans	(307,610)	(303,671)	$ (107,341)	$ (131,388)
Net loans	32,684,317	30,819,970
Taxable	1,815,390	1,177,816	490,042
Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	0	0
Portfolio Segment After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	32,991,927	31,123,641
Allowance for credit losses on loans	(307,610)	(303,671)
Net loans	32,684,317	30,819,970
Taxable	93,700	126,700
Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	9,512,230	9,508,904
Allowance for credit losses on loans	(118,333)	(120,612)	(27,232)	(30,567)
Commercial | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	(232,764)	(210,280)
Commercial | Portfolio Segment After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	9,279,466	9,298,624
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	14,140,629	12,457,070
Allowance for credit losses on loans	(155,099)	(138,244)	(64,004)	(75,810)
Commercial real estate | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	(169,058)	(158,322)
Commercial real estate | Portfolio Segment After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	13,971,571	12,298,748
BBCC
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses on loans	(2,887)	(2,431)	(2,458)	(6,120)
BBCC | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	401,822	368,602
BBCC | Portfolio Segment After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	401,822	368,602
Residential real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	6,699,443	6,460,441
Allowance for credit losses on loans	(20,837)	(21,916)	(9,347)	(12,608)
Residential real estate | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	0	0
Residential real estate | Portfolio Segment After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	6,699,443	6,460,441
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	2,639,625	2,697,226
Consumer | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	(2,639,625)	(2,697,226)
Indirect
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	1,050,982	1,034,257
Allowance for credit losses on loans	(1,236)	(1,532)	(1,743)	(3,580)
Indirect | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	1,050,982	1,034,257
Indirect | Portfolio Segment After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	1,050,982	1,034,257
Direct
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	523,172	629,186
Allowance for credit losses on loans	(3,169)	(12,116)	(528)	(855)
Direct | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	523,172	629,186
Direct | Portfolio Segment After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	523,172	629,186
Home equity
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	1,065,471	1,033,783
Allowance for credit losses on loans	(6,049)	(6,820)	$ (2,029)	$ (1,848)
Home equity | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	1,065,471	1,033,783
Home equity | Portfolio Segment After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	1,065,471	1,033,783
Direct Finance Leases
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans, net of unearned income	$ 169,700	$ 188,100