CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)
Net income (loss)	$ 74,304	$ (227,518)	$ 104,237
Foreign currency translation gain (loss):
Foreign currency translation gain (loss)	2,119	(6,381)	(8,232)
Reclass of foreign currency translation loss included in other income, net	665	0	0
Defined benefit pension plans:
Net gain (loss) and prior service costs, net of taxes	5,551	3,873	(11,549)
Reclass of amortization included in operating expenses	2,017	3,633	260
Hedging gain (loss):
Unrealized hedging gain (loss)	(3,497)	(1,190)	3,337
Reclass of hedging loss (gain) included in cost of goods sold	2,472	1,756	(421)
Net change in unrealized investment loss:
Net unrealized loss on investments for the period			(342)
Reclass of investment loss included in other income (expense), net		(343)	(483)
Other comprehensive income (loss):	9,327	1,348	(17,430)
Total comprehensive income (loss)	$ 83,631	$ (226,170)	$ 86,807