Discontinued Operations - Summary of Results of Operations Under Discontinued Operation Activities (Details) - Patterson Medical [Member] - Discontinued Operations, Disposed of by Sale [Member] - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2016	Apr. 25, 2015	Apr. 26, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales	$ 168,504	$ 464,155	$ 478,574
Cost of sales	107,359	286,498	298,993
Operating expenses	54,954	108,816	127,551
Gain on sale	(24,328)	0	0
Other expense	150	488	381
Income before taxes	30,369	68,353	51,649
Income tax expense	28,869	25,175	22,369
Net income from discontinued operations	$ 1,500	$ 43,178	$ 29,280