Income Taxes - Deferred Income Taxes - Narrative (Detail) - USD ($) $ in Thousands	Aug. 02, 2015	May. 03, 2015		Aug. 03, 2014
Income Taxes [Line Items]
Current deferred tax asset	$ 6,986	$ 4,790	[1]	$ 6,203
Non-current deferred tax asset	412	447	[1]	973
Non-current deferred tax liability	4,064	1,050	[1]	1,013
U.S. Tax Authorities [Member]
Income Taxes [Line Items]
Current deferred tax asset	6,500	4,400		5,800
Non-current deferred tax asset				440
Non-current deferred tax liability	3,000	154
China [Member]
Income Taxes [Line Items]
Current deferred tax asset	502	421		405
Non-current deferred tax asset	412	447		533
Canada [Member]
Income Taxes [Line Items]
Non-current deferred tax liability	$ 1,100	$ 896		$ 1,000

[1] Derived from audited financial statements.