Warrants (Details) (USD $)	1 Months Ended	3 Months Ended		12 Months Ended
	Sep. 30, 2005	Jan. 25, 2013	Oct. 26, 2012	Apr. 26, 2013 item	Apr. 27, 2012	Apr. 29, 2011
Warrants [Line Items]
Proceeds from warrants sold, September 2005	$ 25,200,000
Number of common stock a warrant entitles holders to purchase	3,012,050
Exercise price of warrant (in Dollars per Unit)	50.00
Total settlement measurement period (in Duration)				60 days
Approximate share basis for each group (in Shares)				50,000
Total number of tranches split into three groups for settlement (in Tranches)				60
Number of tranches per settlement group (in Tranches)				20
Cash settlement election for the first two groups (in Tranches)				40
Warrant equity of first 40 tranches reclassed to additional paid-in capital			13,200,000
Reclassification from common stock warrants to treasury stock and additional paid-in-capital				21,550,363	0	0
Warrants' liability revalued			2,321,951
Shares issued - warrant conversion		27,919
Gain on warrants' liability				1,325,574	0	0
Balance in common stock warrants reclassed to additional paid-in-capital		8,400,000
Convertible Subordinated Debt [Member]
Warrants [Line Items]
Senior Notes	$ 125,000,000