Loans and Allowance for Credit Losses for Loans - Summary of Activity in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Allowance for loan losses:
Beginning balance	$ 519,310	$ 442,175	$ 436,432	$ 446,080	$ 458,655	$ 458,655
Loans charged-off	(48,221)		(8,918)	(111,460)	(52,818)
Charged-off loans recovered	5,313		3,440	8,158	8,347
Net (charge-offs) recoveries	(42,908)		(5,478)	(103,302)	(44,471)
Provision for loan losses	71,925		11,221	205,549	29,359
Ending balance	548,327	446,080	442,175	548,327	442,175	446,080
Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses:
Beginning balance					(1,368)	(1,368)
Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses:
Beginning balance					457,287	457,287
Commercial and industrial
Allowance for loan losses:
Beginning balance	149,243	133,988	128,245	133,359	139,941	139,941
Loans charged-off	(7,501)		(7,487)	(36,515)	(37,399)
Charged-off loans recovered	3,162		3,043	4,586	6,615
Net (charge-offs) recoveries	(4,339)		(4,444)	(31,929)	(30,784)
Provision for loan losses	21,461		10,187	64,935	25,570
Ending balance	166,365	133,359	133,988	166,365	133,988	133,359
Commercial and industrial | Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses:
Beginning balance					(739)	(739)
Commercial and industrial | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses:
Beginning balance					139,202	139,202
Commercial Real Estate
Allowance for loan losses:
Beginning balance	301,093	245,047	239,695	249,598	259,408	259,408
Loans charged-off	(38,123)		(255)	(69,277)	(12,226)
Charged-off loans recovered	1,601		5	1,992	33
Net (charge-offs) recoveries	(36,522)		(250)	(67,285)	(12,193)
Provision for loan losses	44,457		5,602	126,715	(1,579)
Ending balance	309,028	249,598	245,047	309,028	245,047	249,598
Commercial Real Estate | Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses:
Beginning balance					(589)	(589)
Commercial Real Estate | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses:
Beginning balance					258,819	258,819
Residential Mortgage
Allowance for loan losses:
Beginning balance	47,697	44,621	44,153	42,957	39,020	39,020
Loans charged-off	0		(20)	0	(169)
Charged-off loans recovered	29		30	59	186
Net (charge-offs) recoveries	29		10	59	17
Provision for loan losses	3,819		458	8,529	5,596
Ending balance	51,545	42,957	44,621	51,545	44,621	42,957
Residential Mortgage | Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses:
Beginning balance					(12)	(12)
Residential Mortgage | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses:
Beginning balance					39,008	39,008
Consumer loans
Allowance for loan losses:
Beginning balance	21,277	18,519	24,339	20,166	20,286	20,286
Loans charged-off	(2,597)		(1,156)	(5,668)	(3,024)
Charged-off loans recovered	521		362	1,521	1,513
Net (charge-offs) recoveries	(2,076)		(794)	(4,147)	(1,511)
Provision for loan losses	2,188		(5,026)	5,370	(228)
Ending balance	$ 21,389	$ 20,166	$ 18,519	$ 21,389	18,519	20,166
Consumer loans | Cumulative Effect, Period of Adoption, Adjustment
Allowance for loan losses:
Beginning balance					(28)	(28)
Consumer loans | Cumulative Effect, Period of Adoption, Adjusted Balance
Allowance for loan losses:
Beginning balance					$ 20,258	$ 20,258