Income Taxes - Income Tax Expense (Benefit) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Apr. 28, 2013	Jan. 27, 2013	Oct. 28, 2012	Jul. 29, 2012	Apr. 29, 2012	Jan. 29, 2012	Oct. 30, 2011	Jul. 31, 2011	Apr. 28, 2013	Apr. 29, 2012	May 01, 2011
current
federal										$ 79	$ (79)
state									19
foreign									2,297	2,505	2,367
current income tax expense (benefit)									2,316	2,584	2,288
deferred
federal									192	727	1,805
state									14	55	142
undistributed earnings - foreign subsidiaries									7,011
U.S. operating loss carryforwards									3,665	1,102	1,241
foreign									608	143	89
USD election for Canadian returns											(315)
valuation allowance									(11,834)	(3,709)	(6,352)
deferred income tax expense (benefit)									(344)	(1,682)	(3,390)
income tax expense (benefit)	$ 2,161	$ 1,700	$ (3,736)	$ 1,848	$ 2,071	$ 1,075	$ (3,389)	$ 1,145	$ 1,972	$ 902	$ (1,102)