Restatement and Revision of Previously Issued Consolidated Financial Statements (Details 2) In Thousands, except Per Share data, unless otherwise specified	1 Months Ended				12 Months Ended
	Sep. 30, 2013 USD ($)	Sep. 30, 2013 CHF	Sep. 30, 2012 USD ($)	Sep. 30, 2012 CHF	Mar. 31, 2014 USD ($)	Mar. 31, 2013 USD ($)	Mar. 31, 2012 USD ($)	Mar. 31, 2011 Property Plant and Equipment Capitalization Threshold Convention USD ($)	Mar. 31, 2013 As Previously Reported USD ($)	Mar. 31, 2012 As Previously Reported USD ($)	Mar. 31, 2013 Adjustments USD ($)	Mar. 31, 2012 Adjustments USD ($)	Mar. 31, 2013 Adjustments Amounts not properly stated USD ($)	Mar. 31, 2012 Adjustments Amounts not properly stated USD ($)	Mar. 31, 2013 Adjustments Property Plant and Equipment Capitalization Threshold Convention USD ($)	Mar. 31, 2012 Adjustments Property Plant and Equipment Capitalization Threshold Convention USD ($)	Mar. 31, 2012 Adjustments Inventory Valuation Reserve USD ($)	Mar. 31, 2012 Adjustments Legal Settlement USD ($)	Mar. 31, 2013 Adjustments Other adjustments USD ($)	Mar. 31, 2012 Adjustments Other adjustments USD ($)
Condensed Consolidated Statements of Operations
Net sales					$ 2,128,713	$ 2,099,277	$ 2,316,203		$ 2,099,883	$ 2,316,203									$ (606)
Cost of goods sold					1,400,844	1,389,643	1,508,670		1,389,726	1,537,921					408	(25)	(30,730)	1,294	(491)	210
Gross profit					727,869	709,634	807,533		710,157	778,282			(523)	29,251
Operating expenses:
Marketing and selling					379,747	431,886	422,116		431,598	423,854					396	(24)			(108)	(1,714)
Research and development					139,385	155,012	162,159		154,207	162,711					324	(20)			481	(532)
General and administrative					118,940	114,381	109,260		113,824	109,456					214	(13)			343	(183)
Impairment of goodwill and other assets						216,688			216,688
Restructuring charges					13,811	43,704			43,704
Total operating expenses					651,883	961,671	693,535		960,021	696,021			1,650	(2,486)	1,300	(100)
Operating income (loss)					75,986	(252,037)	113,998		(249,864)	82,261			(2,173)	31,737	(1,300)	100
Interest income, net					(397)	907	2,674		907	2,674
Other income (expense), net					1,993	(2,198)	7,655		(2,198)	7,655
Income (loss) before income taxes					77,582	(253,328)	124,327		(251,155)	92,590			(2,173)	31,737
Provision for (benefit from) income taxes					3,278	(25,810)	20,090		(25,588)	19,819									(222)	271
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
Net income (loss) per share:
Basic (in dollars per share)					$ 0.46	$ (1.44)	$ 0.60		$ (1.42)	$ 0.42	$ (0.02)	$ 0.18
Diluted (in dollars per share)					$ 0.46	$ (1.44)	$ 0.59		$ (1.42)	$ 0.41	$ (0.02)	$ 0.18
Shares used to compute net income (loss) per share :
Basic (in shares)					160,619	158,468	174,648		158,468	174,648
Diluted (in shares)					162,526	158,468	175,591		158,468	175,591
Cash dividends per share (in dollars per share)	$ 0.22	0.21	$ 0.85	0.79	$ 0.22	$ 0.85			$ 0.85