Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net Income	$ 167,723	$ 126,291	$ 398,100	$ 121,841
Other Comprehensive (Loss) Income:
Actuarially Determined Long-Term Liability Adjustments (Net of tax: $274, ($508), $548, ($1,016))	900	(1,524)	1,801	(3,049)
Unrealized Loss on Investments in Available-for-Sale Securities (Net of tax: $77, $—, $13, $—)	(255)	0	(43)	0
Unrealized Gain on Cash Flow Hedges (Net of tax: $—, ($75), $—, ($205))	0	224	0	615
Other Comprehensive (Loss) Income	(1,155)	1,748	(1,844)	3,664
Comprehensive Income	$ 166,568	$ 128,039	$ 396,256	$ 125,505