CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 154,547	$ 175,013
Other comprehensive income (loss), net of tax:
Change in unrealized investment gains and losses	80,659	(270,938)
Benefit plan adjustments	5,353	393
Other comprehensive income (loss), net of tax	86,012	(270,545)
Comprehensive income (loss)	$ 240,559	$ (95,532)