Loans and Allowance for Credit Losses - Summary of Loan Classes and Aging of Past Due Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 17,731,700	$ 17,170,871
Nonaccrual Loans	110,356	92,300
30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	17,159	6,509
Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	3,600	2,633
Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	131,115	101,442
Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	17,600,585	17,069,429
Commercial and Industrial Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	7,613,899	7,258,120
Nonaccrual Loans	91,053	82,845
Commercial and Industrial Portfolio [Member] | 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	4,564	2,827
Commercial and Industrial Portfolio [Member] | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	1,375	896
Commercial and Industrial Portfolio [Member] | Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	96,992	86,568
Commercial and Industrial Portfolio [Member] | Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	7,516,907	7,171,552
Specialty Lending Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	505,860	522,362
Nonaccrual Loans	11,797
Specialty Lending Portfolio [Member] | Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	11,797
Specialty Lending Portfolio [Member] | Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	494,063	522,362
Commercial Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	6,419,510	6,267,544
Nonaccrual Loans	2,651	4,688
Commercial Real Estate Portfolio [Member] | 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	9,470	962
Commercial Real Estate Portfolio [Member] | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	463
Commercial Real Estate Portfolio [Member] | Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	12,584	5,650
Commercial Real Estate Portfolio [Member] | Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	6,406,926	6,261,894
Consumer Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	2,393,314	2,320,033
Nonaccrual Loans	3,892	4,210
Consumer Real Estate Portfolio [Member] | 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	1,397	246
Consumer Real Estate Portfolio [Member] | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans		489
Consumer Real Estate Portfolio [Member] | Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	5,289	4,945
Consumer Real Estate Portfolio [Member] | Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	2,388,025	2,315,088
Consumer Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	132,815	129,135
Nonaccrual Loans	572	75
Consumer Portfolio [Member] | 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	49	105
Consumer Portfolio [Member] | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	1	2
Consumer Portfolio [Member] | Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	622	182
Consumer Portfolio [Member] | Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	132,193	128,953
Credit Cards Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	397,100	391,389
Nonaccrual Loans	366	457
Credit Cards Portfolio [Member] | 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	1,679	2,369
Credit Cards Portfolio [Member] | Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	1,761	1,246
Credit Cards Portfolio [Member] | Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	3,806	4,072
Credit Cards Portfolio [Member] | Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	393,294	387,317
Leases and Other Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	269,202	282,288
Nonaccrual Loans	25	25
Leases and Other Portfolio [Member] | Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	25	25
Leases and Other Portfolio [Member] | Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 269,177	$ 282,263