Balance Sheet Detail (Details) (USD $)	3 Months Ended			6 Months Ended		12 Months Ended								3 Months Ended		6 Months Ended
	Sep. 28, 2014		Jun. 29, 2014	Sep. 28, 2014		Mar. 30, 2014		Sep. 28, 2014 Land	Mar. 30, 2014 Land	Sep. 28, 2014 Machinery and equipment	Mar. 30, 2014 Machinery and equipment	Sep. 28, 2014 Building and leasehold improvements	Mar. 30, 2014 Building and leasehold improvements	Sep. 28, 2014 High-Speed Converter Business	Sep. 29, 2013 High-Speed Converter Business	Sep. 28, 2014 High-Speed Converter Business	Sep. 29, 2013 High-Speed Converter Business	May 30, 2014 High-Speed Converter Business	Mar. 30, 2014 High-Speed Converter Business
Inventories, net
Raw materials	$ 5,473,000			$ 5,473,000		$ 7,745,000
Work-in-process	14,400,000			14,400,000		18,436,000
Finished goods	17,766,000			17,766,000		23,441,000
Total inventories, net	37,639,000			37,639,000		49,622,000
Property, plant and equipment, net
Total property, plant and equipment, gross	351,644,000			351,644,000		349,675,000		11,716,000	11,724,000	291,566,000	289,393,000	48,362,000	48,558,000
Less: accumulated depreciation	(285,879,000)			(285,879,000)		(279,848,000)
Total property, plant and equipment, net	65,765,000	[1]		65,765,000	[1]	69,827,000	[1]
Other accrued liabilities
Short-term portion of supplier obligations	248,000			248,000		762,000
Accrued severance costs (3)	7,201,000			7,201,000		638,000
Other	7,156,000			7,156,000		10,125,000
Total other accrued liabilities	14,605,000			14,605,000		11,525,000
Other long-term obligations
Deferred compensation related liabilities	13,638,000			13,638,000		13,786,000
Other	4,806,000			4,806,000		4,897,000
Total other long-term liabilities	18,444,000			18,444,000		18,683,000
Fixed assets held for sale																		2,900,000	2,900,000
Intangible assets held for sale														0		0		5,600,000	6,600,000
Restructuring Charges	$ 300,000		$ 400,000	$ 6,775,000		$ 5,500,000								$ 6,775,000	$ 0	$ 6,775,000	$ 0

[1] As of March 30, 2014, total property, plant and equipment, net includes the HSC business assets held for sale of $2.9 million.