CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 204,228	$ 191,054	$ 378,325	$ 345,601
Other comprehensive income (loss), net of tax:
Change in unrealized investment gains and losses	(7,459)	(30,234)	(17,851)	50,425
Benefit plan adjustments	538	846	1,077	6,199
Other comprehensive income (loss), net of tax	(6,921)	(29,388)	(16,774)	56,624
Comprehensive income (loss)	$ 197,307	$ 161,666	$ 361,551	$ 402,225