Consolidated Statements of Comprehensive (Loss) Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Statement of Comprehensive Income [Abstract]
Net (Loss) Income	$ (153,216)	$ 286,405	$ 655,892
Actuarially Determined Long-Term Liability Adjustments:
Recognition of Benefit Plan Credits (Costs) (net of tax: ($441), ($395), $1,049)	1,506	1,371	(3,650)
Unrecognized Benefit Plan Gains Arising During the Period (net of tax: ($2,888), ($3,792), ($1,232))	9,676	13,157	4,150
Available-for-Sale Securities:
Unrealized Gain (Loss) on Investments in Available-for-Sale Securities (net of tax: ($165), $12, ($23))	562	(41)	80
Other Comprehensive Income	11,744	14,487	580
Comprehensive (Loss) Income	$ (141,472)	$ 300,892	$ 656,472