Loans and Allowance for Credit Losses for Loans - Summary of Allocation of Allowance for Loan Losses and Related Loans by Loan Portfolio Segment Disaggregated Based on Allowance Measurement Methodology (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for credit losses	$ 66,577	$ 74,215
Collectively evaluated for credit losses	402,671	371,865
Total	469,248	446,080	$ 436,898	$ 458,655
Individually evaluated for credit losses	262,429	264,678
Collectively evaluated for credit losses	49,659,613	49,945,617
Total	49,922,042	50,210,295
Commercial and industrial
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for credit losses	52,002	55,993
Collectively evaluated for credit losses	86,591	77,366
Total	138,593	133,359	127,992	139,941
Individually evaluated for credit losses	98,069	96,827
Collectively evaluated for credit losses	9,006,124	9,133,716
Total	9,104,193	9,230,543
Commercial Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for credit losses	14,545	17,987
Collectively evaluated for credit losses	251,302	231,611
Total	265,847	249,598	243,332	259,408
Individually evaluated for credit losses	139,778	145,419
Collectively evaluated for credit losses	31,565,686	31,824,628
Total	31,705,464	31,970,047
Residential Mortgage
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for credit losses	30	235
Collectively evaluated for credit losses	44,347	42,722
Total	44,377	42,957	41,708	39,020
Individually evaluated for credit losses	23,666	21,843
Collectively evaluated for credit losses	5,594,689	5,547,167
Total	5,618,355	5,569,010
Consumer loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Individually evaluated for credit losses	0	0
Collectively evaluated for credit losses	20,431	20,166
Total	20,431	20,166	$ 23,866	$ 20,286
Individually evaluated for credit losses	916	589
Collectively evaluated for credit losses	3,493,114	3,440,106
Total	$ 3,494,030	$ 3,440,695