Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Jul. 27, 2013	Apr. 30, 2013
Current assets:
Cash and cash equivalents	$ 64,339	$ 75,332
Short-term investments	64,474	73,241
Accounts receivable, net of allowance for doubtful accounts of $731 at July 27, 2013 and $936 at April 30, 2013	19,604	19,770
Unbilled receivables and retentions	9,719	11,304
Inventories, net	68,663	62,561
Income tax receivable	14,812	11,777
Deferred income taxes	5,189	5,166
Prepaid expenses and other current assets	3,765	4,303
Total current assets	250,565	263,454
Long-term investments	67,595	68,916
Property and equipment, net	26,725	24,429
Deferred income taxes	5,638	5,606
Other assets	1,036	1,060
Total assets	351,559	363,465
Current liabilities:
Accounts payable	13,545	16,144
Wages and related accruals	9,109	12,116
Customer advances	7,005	7,519
Other current liabilities	7,194	6,408
Total current liabilities	36,853	42,187
Deferred rent	696	771
Liability for uncertain tax positions	5,211	5,321
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.0001 par value: Authorized shares - 10,000,000; none issued or outstanding
Common stock, $0.0001 par value: Authorized shares - 100,000,000 Issued and outstanding shares - 22,672,762 at July 27, 2013 and 22,614,315 at April 30, 2013	2	2
Additional paid-in capital	131,398	130,527
Accumulated other comprehensive loss	(753)	(705)
Retained earnings	178,152	185,362
Total stockholders' equity	308,799	315,186
Total liabilities and stockholders' equity	$ 351,559	$ 363,465