Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (147,734)	$ 59,648	$ 35,874
Other comprehensive income (loss):
Cumulative translation adjustments	(113)	(270)	153
Recognition of actuarial net (losses) gains from pension and other post-retirement plans, net of (benefit) tax of ($823), $2,448, and $824	(1,937)	5,759	1,937
Changes in market value of investments:
Changes in unrealized (losses) gains, net of (benefit) tax of ($15), $14, and ($9)	(45)	42	(29)
Total net change in market value of investments	(45)	42	(29)
Changes in market value of derivatives:
Changes in market value of derivatives, net of (benefit) tax of ($9), ($116), and $19	(24)	(361)	63
Reclassification adjustment for net (loss) gain included in net income (loss), net of (benefit) tax of ($15), $137, and ($13)	(47)	427	(43)
Total net change in market value of derivatives	(71)	66	20
Other comprehensive income (loss)	(2,166)	5,597	2,081
Total comprehensive income (loss)	$ (149,900)	$ 65,245	$ 37,955