Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Amount
Income tax expense at federal statutory rate	$ 106,375	$ 82,681
Tax-exempt interest	(2,517)	(2,165)
Other tax-exempt income	(143)	(134)
Dividend exclusion	(35)	(41)
State income taxes, net of federal income tax and the excluding state credits	12,553	10,103
Nondeductible expenses	1,433	819
Partnership Amortization	3,993	6,189
Tax credits	(5,689)	(9,528)
Changes in unrecognized tax benefits	0	100
Other, net	(265)	(114)
Total income tax expense on operations	$ 115,705	$ 87,910
Percent
Income tax expense at federal statutory rate	21.00%	21.00%
Tax-exempt interest	(0.50%)	(0.60%)
Other tax-exempt income	0.00%	0.00%
Dividend exclusion	0.00%	0.00%
State income taxes, net of federal income tax and the excluding state credits	2.50%	2.60%
Nondeductible expenses	0.30%	0.20%
Partnership Amortization	0.80%	1.60%
Tax credits	(1.10%)	(2.40%)
Changes in unrecognized tax benefits	0.00%	0.00%
Other, net	(0.10%)	0.00%
Total income tax expense	22.80%	22.30%
Low income housing tax credit	$ 4,600	$ 8,800