Loans and Allowance for Credit Losses - Schedule of Composition of Loans and Impact of Adoption (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 31,822,374	$ 31,123,641
Allowance for credit losses on loans	(298,711)	(303,671)	$ (280,507)	$ (107,341)
Net loans	31,523,663	30,819,970
Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0	0
After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	31,822,374	31,123,641
Allowance for credit losses on loans	(298,711)	(303,671)
Net loans	31,523,663	30,819,970
Commercial
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	9,751,875	9,508,904
Allowance for credit losses on loans	(125,768)	(120,612)	(99,471)	(27,232)
Commercial | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	(213,187)	(210,280)
Commercial | After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	9,538,688	9,298,624
Commercial real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	12,908,380	12,457,070
Allowance for credit losses on loans	(135,348)	(138,244)	(140,490)	(64,004)
Commercial real estate | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	(160,041)	(158,322)
Commercial real estate | After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	12,748,339	12,298,748
BBCC
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for credit losses on loans	(2,316)	(2,431)	(2,069)	(2,458)
BBCC | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	373,228	368,602
BBCC | After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	373,228	368,602
Residential real estate
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	6,568,666	6,460,441
Allowance for credit losses on loans	(20,207)	(21,916)	(17,252)	(9,347)
Residential real estate | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	0	0
Residential real estate | After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	6,568,666	6,460,441
Consumer
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	2,593,453	2,697,226
Consumer | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	(2,593,453)	(2,697,226)
Indirect
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,003,287	1,034,257
Allowance for credit losses on loans	(1,434)	(1,532)	(1,648)	(1,743)
Indirect | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,003,287	1,034,257
Indirect | After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,003,287	1,034,257
Direct
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	580,726	629,186
Allowance for credit losses on loans	(6,766)	(12,116)	(14,450)	(528)
Direct | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	580,726	629,186
Direct | After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	580,726	629,186
Home equity
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,009,440	1,033,783
Allowance for credit losses on loans	(6,872)	(6,820)	$ (5,127)	$ (2,029)
Home equity | Portfolio Segment Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,009,440	1,033,783
Home equity | After Reclassifications
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	1,009,440	1,033,783
Direct Finance Leases
Financing Receivable, Allowance for Credit Losses [Line Items]
Total loans	$ 178,700	$ 188,100