Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Reconciliation of income taxes computed at the United States federal statutory tax rates
Tax at U.S. statutory rate	$ 51,443	$ 37,209	$ 44,375
Increase (decrease) in taxes resulting from:
Tax-exempt interest income	(1,750)	(1,505)	(1,832)
BOLI income	(1,178)	(2,197)	(1,946)
Investment tax credits	(3,950)	(1,901)	(928)
Amortization of investment in low-income housing tax credits	2,851	1,741	683
State income tax expense, net of federal benefit	(262)	(1,929)	3,241
Nondeductible transaction costs	1,060	0	0
Other items, net	1,294	1,091	1,647
Total income tax expense	$ 49,508	$ 32,509	$ 45,240