Income Taxes (Details) (USD $)	12 Months Ended
	May 03, 2015	Apr. 27, 2014	Apr. 28, 2013
Operating Loss Carryforwards
Percentage of total deferred assets maintained as a valuation allowance	94.00%
Increase (decrease) in valuation allowance	$ 7,700,000	$ (74,200,000)	$ 5,000,000
Deferred tax assets	42,700,000
Tax Holiday affect on net income (in usd)	5,600,000
Tax Holiday affect on net income (in usd per share)	$ 0.05
Undistributed earnings of foreign subsidiaries	190,600,000
Federal statutory tax rate	35.00%	35.00%	35.00%
Unrecognized tax benefits that would impact fffective tax rate	12,600,000
Accrued interest or penalties	0
Federal
Operating Loss Carryforwards
Net operating loss carryforwards	375,300,000
Tax credit carryforwards	27,000,000
State
Operating Loss Carryforwards
Net operating loss carryforwards	50,100,000
Tax credit carryforwards	20,500,000
Foreign
Operating Loss Carryforwards
Net operating loss carryforwards	$ 40,300,000