Goodwill and Other Intangible Assets - Goodwill Balances and Related Activity by Business Segment (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Apr. 26, 2014	Aug. 16, 2013
Goodwill [Line Items]
Beginning Balance	$ 823,740	$ 23,374
Acquisition Activity	24,023
Other Activity	(3,330)
Ending Balance	844,433	23,374
Dental supply [Member]
Goodwill [Line Items]
Beginning Balance	137,867
Acquisition Activity	649
Other Activity	(1,053)
Ending Balance	137,463
Rehabilitation supply [Member]
Goodwill [Line Items]
Beginning Balance	549,020
Other Activity	(4,013)
Ending Balance	545,007
Veterinary supply [Member]
Goodwill [Line Items]
Beginning Balance	136,853
Acquisition Activity	23,374
Other Activity	1,736
Ending Balance	$ 161,963