Commitments and Contingencies - Summary of Credit Related Financial Instruments With Off-Balance Sheet Risk (Detail) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	$ 12,921,970	$ 12,237,964
Standby letters of credit
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	608,752	578,912
Commercial letters of credit
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	27,842	28,287
Commitments to extend credit
Loss Contingencies [Line Items]
Total credit-related financial instruments with off-balance sheet risk	$ 12,285,376	$ 11,630,765