Income Taxes - Components of Net Deferred Tax Assets (Details) (USD $)	12 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Current
Inventory valuation and warranty costs	$ 11,779,000	$ 5,660,000
Receivables and other current assets	(217,000)	(257,000)
Payroll-related accruals	1,901,000	1,367,000
Accrued liabilities	2,226,000	1,097,000
Deferred revenue	3,182,000	3,897,000
Other	15,000	642,000
Total current deferred tax assets	18,886,000	12,406,000
Valuation allowance, current	(17,204,000)	(2,385,000)
Net current deferred tax assets	1,682,000	10,021,000
Non-current
Deferred compensation	6,745,000	6,497,000
Intangible assets and investments	(1,431,000)	(6,000)
Accrued liabilities	523,000	722,000
Property, plant and equipment	4,967,000	3,975,000
Other comprehensive income	(302,000)	(303,000)
Tax loss and credit carryforwards	36,442,000	32,408,000
Other	427,000	1,880,000
Total non-current deferred tax asset	47,371,000	45,173,000
Valuation allowance, non-current	(43,605,000)	(8,684,000)
Net non-current deferred tax assets	3,766,000	36,489,000
Total deferred tax assets	66,257,000	57,579,000
Total valuation allowance	60,809,000	11,069,000
Net deferred tax assets	5,448,000	46,510,000
Increase in valuation allowance	$ (49,700,000)