Loans and Allowance for Credit Losses - Summary of Loan Classes and Aging of Past Due Loans (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 22,881,689	$ 21,031,189
Nonaccrual Loans	17,042	19,269
30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	21,126	8,775
Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	3,044	1,617
Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	41,212	29,661
Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	22,840,477	21,001,528
Commercial and Industrial Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	9,789,685	9,205,986
Nonaccrual Loans	8,784	11,356
Commercial and Industrial Portfolio [Member] | 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	11,748	2,456
Commercial and Industrial Portfolio [Member] | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	76	2
Commercial and Industrial Portfolio [Member] | Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	20,608	13,814
Commercial and Industrial Portfolio [Member] | Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	9,769,077	9,192,172
Specialty Lending Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	522,419	602,706
Specialty Lending Portfolio [Member] | Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	522,419	602,706
Commercial Real Estate Portfolio Segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	8,778,638	7,616,086
Nonaccrual Loans	2,324	2,505
Commercial Real Estate Portfolio Segment | 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	4,298	2,167
Commercial Real Estate Portfolio Segment | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans		191
Commercial Real Estate Portfolio Segment | Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	6,622	4,863
Commercial Real Estate Portfolio Segment | Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	8,772,016	7,611,223
Consumer Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	2,924,515	2,723,269
Nonaccrual Loans	5,706	4,882
Consumer Real Estate Portfolio [Member] | 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	286	10
Consumer Real Estate Portfolio [Member] | Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	5,992	4,892
Consumer Real Estate Portfolio [Member] | Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	2,918,523	2,718,377
Consumer Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	143,721	145,666
Nonaccrual Loans	37	61
Consumer Portfolio [Member] | 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	181	613
Consumer Portfolio [Member] | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans		20
Consumer Portfolio [Member] | Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	218	694
Consumer Portfolio [Member] | Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	143,503	144,972
Credit Cards Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	450,564	431,672
Nonaccrual Loans	191	441
Credit Cards Portfolio [Member] | 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	4,613	3,529
Credit Cards Portfolio [Member] | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	2,968	1,404
Credit Cards Portfolio [Member] | Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	7,772	5,374
Credit Cards Portfolio [Member] | Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	442,792	426,298
Leases and Other Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	272,147	305,804
Nonaccrual Loans		24
Leases and Other Portfolio [Member] | Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans		24
Leases and Other Portfolio [Member] | Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 272,147	$ 305,780