Fair Value of Financial Instruments - Schedule of Fair Value Liabilities on a Recurring Basis (Details) (Recurring, USD $) In Thousands, unless otherwise specified	May 03, 2015	Apr. 27, 2014
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	$ 221,406	$ 252,268
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	264,364	409,412
Level 1 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	264,364	409,430
Level 2 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	0	0
Level 3 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total	0	0
5.0% Convertible Senior Notes Due 2029 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Convertible debt	0	40,015
5.0% Convertible Senior Notes Due 2029 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Convertible debt	0	104,105
5.0% Convertible Senior Notes Due 2029 | Level 1 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Convertible debt	0	104,105
5.0% Convertible Senior Notes Due 2029 | Level 2 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Convertible debt	0	0
5.0% Convertible Senior Notes Due 2029 | Level 3 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Convertible debt	0	0
0.5% Convertible Senior Notes Due 2033 | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Convertible debt	221,406	212,253
0.5% Convertible Senior Notes Due 2033 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Convertible debt	264,364	305,307
0.5% Convertible Senior Notes Due 2033 | Level 1 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Convertible debt	264,364	305,325
0.5% Convertible Senior Notes Due 2033 | Level 2 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Convertible debt	0	0
0.5% Convertible Senior Notes Due 2033 | Level 3 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Convertible debt	$ 0	$ 0