Gift Cards - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jan. 26, 2013	Jan. 28, 2012	Jan. 26, 2013	Jan. 28, 2012	Apr. 28, 2012
Gift Cards [Line Items]
Gift card breakage	$ 6,001	$ 12,554	$ 18,061	$ 23,199
Gift card liabilities	$ 386,704	$ 367,555	$ 386,704	$ 367,555	$ 321,362