Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net Income	$ 100,725	$ 152,121	$ 498,825	$ 273,962
Other Comprehensive (Loss) Income:
Actuarially Determined Long-Term Liability Adjustments (Net of tax: $274, ($508), $822, ($1,524))	901	(1,525)	2,702	(4,574)
Unrealized Loss on Investments in Available-for-Sale Securities (Net of tax: $2, $—, $15, $—)	(6)	0	(49)	0
Unrealized (Loss) Gain on Cash Flow Hedges (Net of tax: $—, $89, $—, ($116))	0	(214)	0	401
Other Comprehensive (Loss) Income	(907)	1,311	(2,751)	4,975
Comprehensive Income (Loss)	$ 99,818	$ 153,432	$ 496,074	$ 278,937