Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (28,369)	$ 61,192	$ 49,106
Other comprehensive income (loss):
Cumulative translation adjustments	1,446	(6,311)	1,887
Recognition of actuarial net gain from pension and other post-retirement plans, net of taxes of $215, $0 and $0	632	0	0
Changes in market value of investments:
Changes in unrealized (losses) gains, net of taxes of $0, $0 and $0	3	(12)	5
Total net change in market value of investments	3	(12)	5
Changes in market value of derivatives:
Changes in market value of derivatives, net of (benefit) taxes of ($329), ($1,113) and $33	(523)	(1,937)	62
Reclassification adjustment for net gains included in net income, net of taxes of $915, $497 and $62	1,586	843	147
Total net change in market value of derivatives	1,063	(1,094)	209
Other comprehensive income (loss)	3,144	(7,417)	2,101
Total comprehensive income (loss)	$ (25,225)	$ 53,775	$ 51,207