Income Taxes - Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of income taxes computed at the United States federal statutory tax rates
Tax at U.S. statutory rate	$ 44,375	$ 46,794	$ 21,733
Increase (decrease) in taxes resulting from:
Tax-exempt interest income	(1,832)	(1,669)	(1,431)
BOLI income	(1,946)	(1,547)	(1,182)
Investment tax credits	(928)	(988)	(1,494)
Amortization of investment in low-income housing tax credits	683	817	1,280
State income tax expense, net of federal benefit	3,241	2,479	469
Other items, net	1,647	1,049	465
Total income tax expense	$ 45,240	$ 46,935	$ 19,840