Certain Financial Statement Information (Details 3) (USD $) In Thousands, unless otherwise specified				6 Months Ended
	Sep. 30, 2012	Mar. 31, 2012		Sep. 30, 2012 Machinery and Equipment [Member] Minimum [Member]	Sep. 30, 2012 Machinery and Equipment [Member] Maximum [Member]	Sep. 30, 2012 Leasehold Improvements [Member] Minimum [Member]	Sep. 30, 2012 Leasehold Improvements [Member] Maximum [Member]	Sep. 30, 2012 Computers, Office Furniture and Equipment [Member] Minimum [Member]	Sep. 30, 2012 Computers, Office Furniture and Equipment [Member] Maximum [Member]	Sep. 30, 2012 Buildings [Member]
Schedule of Property and equipment
Useful Life				5 years	7 years	1 year	15 years	3 years	7 years	31 years 6 months
Machinery and equipment	$ 36,732	$ 36,600
Leasehold improvements	17,405	14,228
Computers, office furniture and equipment	43,031	43,929
Buildings	2,756	2,756
Land	9,800	9,800
Property and equipment, gross	109,724	107,313
Less: accumulated depreciation and amortization	(71,866)	(69,213)
Property and equipment, total	$ 37,858	$ 38,100	[1]

[1] Note: Amounts have been derived from the March 31, 2012 audited consolidated financial statements.