Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Apr. 30, 2016	Apr. 25, 2015
Accrued Expenses and Other Current Liabilities
Payroll and other compensation	$ 45,611	$ 40,711
Accrued product warranty, current portion	12,381	10,182
Customer deposits	20,961	23,722
Other current liabilities	33,523	33,711
Accrued expenses and other current liabilities	$ 112,476	108,326
Book overdraft		$ 7,300