Allowance for Credit Losses (Details) (USD $)	3 Months Ended
	Jul. 28, 2012	Jul. 30, 2011
Allowance for Credit Losses [Abstract]
Notes receivable, gross	$ 9,600,000
Number of customers with notes receivable balance	12
Allowance for credit losses	1,500,000
Notes receivable, current	1,400,000
Allowance for Credit Losses [Roll Forward]
Ending balance	1,500,000
Allowance for Credit Losses [Member]
Allowance for Credit Losses [Abstract]
Allowance for credit losses	1,519,000	2,309,000
Allowance for Credit Losses [Roll Forward]
Beginning balance	1,537,000	2,067,000
Recoveries	(18,000)	0
Provision for credit losses, net	0	268,000
Currency effect	0	(26,000)
Ending balance	$ 1,519,000	$ 2,309,000