Lease Commitments - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
Apr. 29, 2017	Apr. 30, 2016	Apr. 25, 2015
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 24,502	$ 23,315	$ 16,909

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

No definition available.

Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration