Loans and Lease Finance Receivables and Allowance for Credit Losses - Summary of Components of Loans and Lease Finance Receivables, Including PCI Loans (Detail) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	$ 12,017,055	$ 8,699,193
Total loans, at amortized cost	12,017,055	8,699,193
Less: Allowance for credit losses	(126,661)	(77,161)
Net loans and lease finance receivables	11,890,394	8,622,032
Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	8,983,934	6,574,395
Construction Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	209,993	37,812
Construction	209,993	37,812
SBA Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	441,572	282,401
Commercial And Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	1,478,884	973,631
Dairy And Livestock And Agribusiness [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	280,994	431,577
Municipal Lease Finance Receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	56,086	59,542
Total loans, at amortized cost	56,086	59,542
SFR mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	341,340	281,766
Consumer and Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Notes receivable gross	$ 224,252	$ 58,069