Loans and Allowance for Credit Losses - Summary of Loan Classes and Aging of Past Due Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 40,134,325	$ 38,779,408
Nonaccrual Loans	151,250	144,666
30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	40,260	81,511
Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	14,924	18,403
Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	206,434	244,580
Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	39,927,891	38,534,828
Commercial and Industrial Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	17,068,764	16,270,520
Nonaccrual Loans	55,975	26,633
Commercial and Industrial Portfolio [Member] \| 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	8,811	36,391
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	6,417
Commercial and Industrial Portfolio [Member] \| Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	64,787	69,441
Commercial and Industrial Portfolio [Member] \| Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	17,003,977	16,201,079
Specialty Lending Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	646,027	518,237
Specialty Lending Portfolio [Member] \| Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	646,027	518,237
Commercial Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	16,627,070	16,376,239
Nonaccrual Loans	63,436	86,838
Commercial Real Estate Portfolio [Member] \| 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	8,647	24,786
Commercial Real Estate Portfolio [Member] \| Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	959
Commercial Real Estate Portfolio [Member] \| Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	73,042	111,624
Commercial Real Estate Portfolio [Member] \| Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	16,554,028	16,264,615
Consumer Real Estate Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	4,429,728	4,436,468
Nonaccrual Loans	31,103	29,910
Consumer Real Estate Portfolio [Member] \| 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	11,631	10,451
Consumer Real Estate Portfolio [Member] \| Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans		244
Consumer Real Estate Portfolio [Member] \| Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	42,734	40,605
Consumer Real Estate Portfolio [Member] \| Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	4,386,994	4,395,863
Consumer Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	235,982	238,811
Nonaccrual Loans	147	777
Consumer Portfolio [Member] \| 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	568	689
Consumer Portfolio [Member] \| Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	5,182	5,237
Consumer Portfolio [Member] \| Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	5,897	6,703
Consumer Portfolio [Member] \| Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	230,085	232,108
Credit Cards Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	717,831	700,733
Nonaccrual Loans	589	508
Credit Cards Portfolio [Member] \| 30-89 Days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	10,603	9,194
Credit Cards Portfolio [Member] \| Greater than 90 days Past Due and Accruing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	8,782	6,505
Credit Cards Portfolio [Member] \| Total Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	19,974	16,207
Credit Cards Portfolio [Member] \| Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	697,857	684,526
Leases and Other Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	408,923	238,400
Leases and Other Portfolio [Member] \| Current [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 408,923	$ 238,400