Certain Financial Statement Information - Schedule of Property and equipment (Details) - USD ($)	12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Property, Plant and Equipment [Line Items]
Fully depreciated assets written off	$ 3,800,000	$ 24,000,000
Impairment of capitalized mask costs		2,600,000
Capitalized mask costs	0	5,900,000
Schedule of Property and equipment
Property and equipment, gross	78,268,000	80,097,000
Less: accumulated depreciation and amortization	(64,975,000)	(63,348,000)
Property and equipment, net	$ 13,293,000	16,749,000
Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	1 year
Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years
Machinery and Equipment
Schedule of Property and equipment
Property and equipment, gross	$ 36,723,000	37,286,000
Machinery and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years
Machinery and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years
Leasehold Improvements
Schedule of Property and equipment
Property and equipment, gross	$ 7,529,000	9,909,000
Leasehold Improvements | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	1 year
Leasehold Improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years
Computers, Office Furniture and Equipment
Schedule of Property and equipment
Property and equipment, gross	$ 34,016,000	$ 32,902,000
Computers, Office Furniture and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life (in years)	3 years
Computers, Office Furniture and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life (in years)	5 years