Pension and Other Postretirement Benefit Plans - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 01, 2014 Employee	Oct. 26, 2013	Nov. 01, 2014 Employee	Oct. 26, 2013
Pension and Other Postretirement Benefit Plans [Line Items]
Pension expense	$ 778	$ 709	$ 1,385	$ 1,331
Increase in pension liability and other comprehensive loss, before tax			15,747
Pension plan, expected termination period			18 months
Pension plan, expected termination period			24 months
Number of terminated vested participants elected to receive lump sum payments	640
Lump sum payments made to plan participants	15,000
Number of remaining active and terminated vested participants elected to receive lump sum payments			2,350
Company contributions, employee benefit expenses	3,830	3,579	8,475	8,537
Company contributions for postretirement plan	38	38	75	75
Selling and Administrative Expenses
Pension and Other Postretirement Benefit Plans [Line Items]
Pension plan expected settlement charge			$ 6,800