General and Summary of Significant Accounting Policies (Detail) (USD $)	12 Months Ended
	Apr. 28, 2013	Apr. 29, 2012	May 01, 2011	May 02, 2010
Organization And Summary Of Significant Accounting Policies [Line Items]
cash and cash equivalents	$ 23,530,000	$ 25,023,000	$ 23,181,000	$ 18,295,000
Unrealized gains on short-term bond funds	54,000	16,000
Short-term bond funds at fair value	5,300,000	5,100,000
short-term investments	5,286,000	5,941,000
Inventory aging categories	Inventory aging categories are six, nine, twelve, and fifteen months.
Interest costs			17,000
Foreign currency exchange gain (loss)	(222,000)	215,000	115,000
goodwill	11,462,000	11,462,000	11,462,000	11,462,000
Mattress Fabrics [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
goodwill	11,462,000	11,462,000
Selling, general and administrative expense [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Handling costs	3,200,000	2,600,000	2,400,000
United States [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
short-term investments	1,000,000	1,000,000
Subsidiaries [Member] | China [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
cash and cash equivalents	10,200,000	15,600,000
short-term investments		796,000
Foreign currency exchange gain (loss)	(158,000)	320,000	222,000
Subsidiaries [Member] | Canada [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
cash and cash equivalents	5,000,000	5,600,000
short-term investments	4,200,000	4,100,000
Foreign currency exchange gain (loss)	(10,000)	(19,000)	(24,000)
Subsidiaries [Member] | Poland [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
cash and cash equivalents	100,000	158,000
Foreign currency exchange gain (loss)	$ (40,000)	$ (145,000)	$ 26,000