Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (2,754)	$ (73,324)	$ 79,812
Other comprehensive income (loss):
Cumulative translation adjustments	(1,644)	(3,229)	4,889
Recognition of actuarial net gain (loss) from pension and other post-retirement plans, net of taxes (benefit) of $590, ($976), and $435	1,054	(2,278)	1,353
Changes in market value of investments:
Changes in unrealized gains (losses), net of taxes of $39, $19, and $15	126	60	(6)
Total net change in market value of investments	126	60	(6)
Changes in market value of derivatives:
Changes in market value of derivatives, net of (benefits) tax of ($25), ($172), and $267	(78)
Changes in market value of derivatives, net of (benefits) tax of ($25), ($172), and $267		(524)	812
Reclassification adjustment for net gains (losses) included in net income (loss), net of taxes (benefit) of $7, $138, and ($219)	21
Reclassification adjustment for net gains (losses) included in net income (loss), net of taxes (benefit) of $7, $138, and ($219)		437	(681)
Total net change in market value of derivatives	(57)
Total net change in market value of derivatives	(57)	(87)	131
Other comprehensive income (loss)	(521)	(5,534)	6,367
Total comprehensive income (loss)	$ (3,275)	$ (78,858)	$ 86,179