Gift Cards - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Jan. 31, 2015	Jan. 25, 2014	Jan. 31, 2015	Jan. 25, 2014	May 03, 2014
Gift Cards [Line Items]
Additional gift card breakage during the period	$ 4,300,000
Gift card breakage	10,126,000	5,831,000	21,259,000	17,503,000
Gift card liabilities	$ 390,102,000	$ 392,244,000	$ 390,102,000	$ 392,244,000	$ 356,700,000