Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Accounting Policies [Abstract]
Percentage Of Outstanding Stock Of All Subsidiaries Owned	100.00%
Deferred revenue on shipments to distributors	$ 222,800,000	$ 201,800,000
Deferred cost of sales on shipments to distributors	75,000,000	62,800,000
Deferred income on shipments to distributors	147,798,000	138,952,000
Property, Plant and Equipment [Line Items]
Amount of distributor advances, included in deferred income on shipments to distributors in consolidated balance sheets	$ 92,800,000	$ 70,100,000
Number of days requiring distributor to settle receivable balances (in days)	30
Minimum [Member] | Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	10 years
Minimum [Member] | Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Maximum [Member] | Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	30 years
Maximum [Member] | Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Useful Life	8 years