Income Taxes - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jan. 25, 2014	Jan. 26, 2013	Jan. 25, 2014	Jan. 26, 2013
Income Taxes [Line Items]
Income Tax Expense (Benefit)	$ 47,725	$ (1,432)	$ 64,453	$ (22,524)
Income (Loss) before taxes	110,955	(5,115)	53,889	(65,534)
Effective income tax rate	43.00%	28.00%	119.60%	34.40%
Increase in income tax provision	44,245
Unrecognized tax benefits, all of which, if recognized, would affect effective tax rate	26,898		26,898
Accrued interest and penalties included in unrecognized tax benefits	10,394		10,394
Unrecognized tax benefits	26,898		26,898
Decrease in unrecognized tax benefits in next twelve months	$ 10,376