Credit Facility - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified			1 Months Ended	6 Months Ended
	Oct. 27, 2012	Oct. 29, 2011	Apr. 29, 2011 Amended Credit Agreement Y	Oct. 27, 2012 Amended Credit Agreement	Oct. 27, 2012 2009 Credit Facility
Line of Credit Facility [Line Items]
Credit facility, borrowing capacity			$ 1,000,000
Credit facility maturity term, in years			5
Increase in commitments under credit agreement, maximum			300,000
Percentage of Loan Cap under Amended Credit Agreement			10.00%
Amount of Loan Cap under Amended Credit Agreement			50,000
Amortization of deferred financing fees				10,180	6,580
Unamortized deferred costs					16,341
Deferred financing amortization term				5 years
Line of credit facility, amount outstanding	338,400	274,900
Letters of credit, outstanding amount	$ 34,567	$ 30,964