Restatement and Revision of Previously Issued Consolidated Financial Statements (Details 3) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011 Property Plant and Equipment Capitalization Threshold Convention	Mar. 31, 2013 As Reported	Mar. 31, 2012 As Reported	Mar. 31, 2013 Adjustments Amounts not properly stated	Mar. 31, 2012 Adjustments Amounts not properly stated	Mar. 31, 2013 Adjustments Property Plant and Equipment Capitalization Threshold Convention	Mar. 31, 2012 Adjustments Property Plant and Equipment Capitalization Threshold Convention	Mar. 31, 2012 Adjustments Inventory Valuation Reserve	Mar. 31, 2012 Adjustments Legal Settlement	Mar. 31, 2013 Adjustments Other adjustments	Mar. 31, 2012 Adjustments Other adjustments
Consolidated Statements of Comprehensive Income (Loss)
Net income (loss)	$ 74,304	$ (227,518)	$ 104,237	$ (8,300)	$ (225,567)	$ 72,771	$ (1,951)	$ 31,466	$ (1,342)	$ 82	$ 30,730	$ (1,294)	$ (609)	$ 1,948
Foreign currency translation loss:
Foreign currency translation loss:	2,119	(6,381)	(8,232)		(6,333)	(8,213)							(48)	(19)
Defined benefit pension plans:
Net gain (loss) and prior service costs, net of taxes	5,551	3,873	(11,549)		4,794	(11,564)							(921)	15
Reclass of amortization included in operating expenses	2,017	3,633	260		4,252	275							(619)	(15)
Hedging gain (loss):
Unrealized hedging gain (loss)	(3,497)	(1,190)	3,337		(1,190)	3,337
Reclass of hedging loss (gain) included in cost of goods sold	2,472	1,756	(421)		1,756	(421)
Net change in unrealized investment loss:
Net unrealized loss on investments for the period			(342)			(342)
Reclass of investment gain included in other income (expense), net		(343)	(483)		(343)	(483)
Other comprehensive income (loss):	9,327	1,348	(17,430)		2,936	(17,411)	(1,588)	(19)
Total comprehensive income (loss)	$ 83,631	$ (226,170)	$ 86,807		$ (222,631)	$ 55,360	$ (3,539)	$ 31,447