Income Taxes (Effective Income Tax Rate Reconciliation) (Details)	12 Months Ended
	Apr. 26, 2013		Apr. 27, 2012		Apr. 29, 2011
Income Taxes [Abstract]
U.S. statutory rate	35.00%		35.00%		35.00%
Change in deferred tax valuation allowance	(0.10%)		0.00%		0.00%
Shortfall on settle of options and restricted stock	0.00%		1.40%		2.60%
Reduction in valuation allowance due to shortfall	0.00%		0.00%		(1.70%)
Foreign taxes	0.10%		0.20%		0.10%
State and local tax provision, net of federal benefit	2.30%		2.60%		2.80%
Research and development tax credit	(1.40%)	[1]	(1.10%)	[1]	(1.20%)	[1]
Gain on warrant liability	(0.60%)		0.00%		0.00%
Contingency for uncertain tax positions	1.80%	[2]	0.00%	[2]	4.50%	[2]
Other, net	1.30%		2.20%		1.30%
Discrete item	0.00%	[3]	0.00%	[3]	(39.50%)	[3]
Effective tax rate	38.40%		40.30%		3.90%

[1] The research and development tax credit (“R&D tax credit”) expired as of December 31, 2011 and January 2, 2013 and was extended by the United States Congress on January 1, 2013 to December 31, 2013 prior to our fiscal year end of April 26, 2013. Therefore, the R&D tax credit recognized for the 52 weeks ended April 26, 2013 included the impact of the retroactive enactment of the R&D Tax Credit covering the period January 1, 2012 to April 26, 2013, which includes four months from the prior fiscal year ended April 27, 2012.

[2] The contingency in fiscal year 2013 related to the uncertain tax position associated with the NeuroVista debt obligation impairment. The contingency in fiscal year 2011 related to the uncertain tax position associated with the worthless stock deduction.

[3] The discrete items in fiscal year 2011 were a worthless stock deduction and the release of valuation allowance against our regular net operating loss carryforward deferred tax asset. Significant components of our deferred tax assets are as follows: