Loans and Allowance for Credit Losses - Narrative (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2026 USD ($)	Mar. 31, 2025 USD ($)	Dec. 31, 2025 USD ($)
Certain Loans Acquired in Transfer Accounted for as Debt Securities Accretable Yield Movement Schedule [Line Items]
Accrued interest receivable	$ 46,500,000		$ 45,900,000
Loans acquired	0		0
Loans held for investment	$ 11,532,570,000		$ 11,434,605,000
Nonaccrual	51,364,000		44,663,000
Non-accrual business loans, no allowance	15,200,000		16,900,000
Interest income	200,000	$ 300,000
Commitment to lend	1,200,000		$ 600,000
Related Party
Certain Loans Acquired in Transfer Accounted for as Debt Securities Accretable Yield Movement Schedule [Line Items]
Loans held for investment	$ 305,700,000