Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 27, 2013	Oct. 28, 2012	Oct. 27, 2013	Oct. 28, 2012
Income Taxes
Federal taxes at the statutory rate	$ 3,289	$ (1,933)	$ 2,081	$ 189
State taxes	233	(218)	516	29
Permanent differences	277	405	536	661
Tax credits	(263)	(355)	(525)	(710)
Other	49	(94)	101	20
Valuation allowance	(2,226)	1,013	61	(53)
Income tax provision (benefit) from continuing operations	$ 1,359	$ (1,182)	$ 2,770	$ 136