CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	12 Months Ended
	Apr. 01, 2017 USD ($)	Apr. 02, 2016 USD ($)	Mar. 28, 2015 USD ($)
Cash, Cash Equivalents, and Restricted Cash; At Carrying Value	$ 57,732	$ 42,413	$ 50,994
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income	(37,409)	(12,257)	(43,811)
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Depreciation and amortization	7,566	7,343	7,817
Amortization	1,530	1,376	1,502
Share-based compensation expense	7,095	5,103	4,542
Provision for (recovery of) doubtful accounts		329	53
Allowance for Doubtful Accounts Receivable, Recoveries	(429)
Gain on sale of property and equipment, net	1,323	862	(6)
Impairment of Intangible Assets, Finite-lived	2,349	0	0
Inventory Write-down	2,440	0	0
Other than temporary impairment of cost based investments	0	0	4,263
Goodwill, Impairment Loss	7,445	0	7,889
Decrease (increase) in deferred income taxes	(254)	(877)	(54)
Changes in operating accounts, net of acquisitions:
Decrease (increase) in trade receivables, net	2,571	2,984	(7,965)
Decrease (increase) in inventories	(6,252)	(7,303)	1,091
Decrease (increase) in shipped systems pending acceptance	(4,532)	1,631	(462)
Decrease (increase) in other current assets	(755)	1,154	(200)
Increase (decrease) in accounts payable and accrued liabilities	8,141	9,048	(4,013)
Increase (decrease) in deferred revenue	8,338	(4,691)	1,861
Net cash (usedin) provided by operating activities	(833)	4,702	(27,493)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of investments	(464,893)	(380,841)	(414,705)
Proceeds from sales and maturities of investments	473,842	369,700	450,507
Purchase of property, plant and equipment	(4,039)	(3,693)	(5,374)
Proceeds from sale of property, plant and equipment	7	232	154
Cash paid to acquire subsidiaries	2,010	0	7,737
Decrease (increase) in other assets	(293)	790	(2,638)
Net cash provided by (used in) investing activities	2,614	(13,812)	20,207
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from Issuance of Common Stock	1,398	1,362	1,863
Proceeds from Issuance of Other Long-term Debt	13,683	0	0
Repayments of Long-term Debt	(77)	0	0
Payments Related to Tax Withholding for Share-based Compensation	(839)	(638)	(1,850)
Cash dividends paid to shareholders	0	0	(7,266)
Stock Repurchased During Period, Value	0	0	(1,456)
Net cash (used in) provided by financing activities	14,165	724	(8,709)
Effect of exchange rate changes on cash	(627)	(195)	(1,472)
CashAndCashEquivalentsAndRestrictedCashPeriodIncreaseDecrease	15,319	(8,581)	(17,467)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	42,413
CASH AND CASH EQUIVALENTS AT END OF PERIOD	56,642	42,413
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid for interest	(121)	(57)	(109)
Cash paid for income taxes	(530)	(806)	(1,157)
Income tax refunds received	123	140	633
Property, Plant and Equipment, Gross, Period Increase (Decrease)	5,985	3,866	1,091
Property, Plant and Equipment, Additions	$ 40	$ 766	372
Retained Earnings [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income			$ (43,811)