Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Oct. 26, 2013	Oct. 27, 2012
Operating activities
Net (loss) income	$ (5,555)	$ 7,352
Adjustments to reconcile net (loss) income to cash (used in) provided by operating activities:
Depreciation and amortization	4,504	5,937
Provision for doubtful accounts	309	566
Deferred income taxes	(233)	(130)
Stock-based compensation	1,840	1,642
Change in fair value of conversion feature of convertible bonds	5,711
Tax benefit from exercise of stock options	151	1,529
Changes in operating assets and liabilities:
Accounts receivable	(16,777)	7,521
Unbilled receivables and retentions	4,048	5,970
Inventories	1,932	(1,208)
Income tax receivable	3,657
Other assets	9	(836)
Accounts payable	(4,370)	(4,783)
Other liabilities	(4,899)	(18,772)
Net cash (used in) provided by operating activities	(9,673)	4,788
Investing activities
Acquisitions of property and equipment	(6,047)	(4,559)
Acquisitions of distribution and licensing rights	(750)
Net redemptions of held-to-maturity investments	6,934	5,911
Net sales of available-for-sale investments	175	250
Net cash provided by investing activities	312	1,602
Financing activities
Exercise of stock options	155	160
Net cash provided by financing activities	155	160
Net (decrease) increase in cash and cash equivalents	(9,206)	6,550
Cash and cash equivalents at beginning of period	75,332	64,220
Cash and cash equivalents at end of period	66,126	70,770
Supplemental disclosure:
Unrealized gain on long-term investments recorded in other comprehensive income (loss), net of deferred taxes of $18 and $17, respectively	29	27
Reclassification from share-based liability compensation to equity		$ 401