Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (366,922)	$ (147,734)	$ 59,648
Other comprehensive income (loss):
Cumulative translation adjustments	(327)	(113)	(270)
Recognition of actuarial net gains (losses) from pension and other post-retirement plans, net of tax (benefit) of $277, ($823), and $2,448	653	(1,937)	5,759
Changes in market value of investments:
Changes in unrealized gains (losses), net of tax (benefit) of $9, ($15), and $14	27	(45)	42
Total net change in market value of investments	27	(45)	42
Changes in market value of derivatives:
Changes in market value of derivatives, net of benefit of $35, $9, and $116	(114)	(24)	(361)
Reclassification adjustment for net gain (loss) included in net income (loss), net of tax (benefit) of $83, ($15), and $137	262	(47)	427
Total net change in market value of derivatives	148	(71)	66
Other comprehensive income (loss)	501	(2,166)	5,597
Total comprehensive income (loss)	$ (366,421)	$ (149,900)	$ 65,245