CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 29, 2013	Jun. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income	$ (3,283)	$ (944)
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation, Depletion and Amortization	1,747	2,288
Amortization of acquired intangible assets	722	470
Share-based compensation expense	2,634	2,977
Loss on sale of property and equipment, net	(37)	0
Business Combination, Bargain Purchase, Gain Recognized, Amount	(464)	0
Decrease (increase) in deferred income taxes	(289)	(1,669)
Changes in operating accounts, net of acquisitions:
Decrease (increase) in trade receivables, net	(2,573)	4,915
Decrease (increase) in inventories	(2,676)	(1,902)
Decrease (increase) in shipped systems pending acceptance	(850)	1,003
Decrease in other current assets	(1,441)	456
Increase (decrease) in accounts payable and accrued liabilities	(2,655)	3,943
(Decrease) increase in deferred revenue	391	(185)
Net cash provided by operating activities	(8,700)	11,352
CASH FLOWS FROM INVESTING ACTIVITIES
Purchase of investments	(123,126)	(313,897)
Proceeds from sales and maturities of investments	129,015	330,312
Purchase of property, plant and equipment	(1,215)	(995)
Cash paid to acquire subsidiaries	(8,000)	(9,466)
Decrease (increase) in other assets	239	172
Net cash provided by (used in) investing activities	(3,087)	6,126
CASH FLOWS FROM FINANCING ACTIVITIES
Cash dividends paid to shareholders	(2,379)	(2,331)
Stock plan activity, net	(796)	(618)
Excess tax benefit of share-based compensation	0	54
Net cash (used in) provided by financing activities	(3,175)	(2,895)
Effect of exchange rate changes on cash	(186)	(47)
NET CHANGE IN CASH AND CASH EQUIVALENTS	(15,148)	14,536
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	88,913	69,780
CASH AND CASH EQUIVALENTS AT END OF PERIOD	73,765
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid for interest	0	0
Cash paid for income taxes	(338)	(306)
Income tax refunds received	2	131
Accrued acquisition purchase price adjustment	$ (1,600)	$ 0