Gift Cards - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 27, 2012	Oct. 29, 2011	Oct. 27, 2012	Oct. 29, 2011	Apr. 28, 2012
Gift Cards [Line Items]
Gift card breakage	$ 6,015	$ 5,350	$ 12,060	$ 10,645
Gift card liabilities	$ 297,191	$ 287,268	$ 297,191	$ 287,268	$ 321,362