Restatement and Revision of Previously Issued Consolidated Financial Statements (Details 5) (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 Previously Reported	Mar. 31, 2012 As Previously Reported	Mar. 31, 2012 Adjustments	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
Cash flows from operating activities:
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
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	48,967	51,766	52,277		44,419	45,968	6,310			6,589	6,310			758	(1,000)
Amortization of other intangible assets	17,771	23,571	27,198		23,571	27,198
Share-based compensation expense	25,546	25,198	31,529		25,198	31,529
Impairment of goodwill and other assets		216,688			216,688
Impairment of investments	624	3,600			3,600
Loss (gain) on disposal of property, plant and equipment	4,411	2,007	(6,533)			(8,967)								2,007	2,434
Gain on sales of available-for-sale securities		(831)	(6,109)		(831)	(6,109)
Inventory valuation adjustment						34,074						34,074
Excess tax benefits from share-based compensation	(2,246)	(26)	(37)		(26)	(37)
Deferred income taxes and other	(4,828)	(3,209)	(2,249)		11,552	137								(14,761)	(2,386)
Changes in assets and liabilities, net of acquisitions:
Accounts receivable	(219)	45,273	29,279		44,667	29,279								606
Inventories	49,471	23,109	(33,277)		23,954	(36,621)								(845)	3,344
Other assets	(1,388)	5,381	(2,570)		(1,420)	(4,621)								6,801	(2,051)
Accounts payable	(21,322)	(33,406)	3,327		(34,069)	3,622								663	(295)
Accrued and other liabilities	14,330	(9,214)	5,462		(14,594)	7,919							1,294	5,380	(3,751)
Net cash provided by operating activities	205,421	122,389	202,534		117,142	196,142		5,247	6,392
Cash flows from investing activities:
Purchases of property, plant and equipment	(46,658)	(54,487)	(54,199)		(49,240)	(47,807)				(5,247)	(6,392)
Purchase of strategic investment		(4,420)			(4,420)
Acquisitions, net of cash acquired	(650)		(18,814)			(18,814)
Proceeds from sales of available-for-sale securities		917	6,550		917	6,550
Proceeds from sales of property and plant			8,967			8,967
Purchases of trading investments	(8,450)	(4,196)	(7,505)		(4,196)	(7,505)
Proceeds from sales of trading investments	8,994	4,463	7,399		4,463	7,399
Net cash used in investing activities	(46,803)	(57,723)	(57,602)		(52,476)	(51,210)		(5,247)	(6,392)
Cash flows from financing activities:
Payment of cash dividends	(36,123)	(133,462)			(133,462)
Purchases of treasury shares		(87,812)	(156,036)		(87,812)	(156,036)
Proceeds from sales of shares upon exercise of options and purchase rights	16,914	15,982	17,591		15,982	17,591
Tax withholdings related to net share settlements of restricted stock units	(5,718)	(2,375)	(966)		(2,375)	(966)
Excess tax benefits from share-based compensation	2,246	26	37		26	37
Net cash used in financing activities	(22,681)	(207,641)	(139,374)		(207,641)	(139,374)
Effect of exchange rate changes on cash and cash equivalents	(349)	(1,571)	(5,119)		(1,571)	(5,119)
Net increase (decrease) in cash and cash equivalents	135,588	(144,546)	439		(144,546)	439
Cash and cash equivalents at beginning of period	333,824	478,370	477,931		478,370	477,931
Cash and cash equivalents at end of period	469,412	333,824	478,370		333,824	478,370
Non-cash investing activities:
Property, plant and equipment purchased during the period and included in period end liability accounts	5,204	4,828	5,454		4,828	5,454
Supplemental cash flow information:
Interest paid	1,080	1,293	110		1,293	110
Income taxes paid, net	$ 9,189	$ 14,108	$ 14,422		$ 14,108	$ 14,422