Goodwill and Other Intangible Assets - Changes in Carrying Value of Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended			12 Months Ended
	Apr. 24, 2021	Apr. 25, 2020	Jul. 27, 2019	Apr. 24, 2021	Apr. 25, 2020	Apr. 27, 2019
Goodwill [Roll Forward]
Beginning Balance				$ 138,724
Impairment		$ 0		0	$ (675,055)	$ 0
Other Activity				1,208
Ending Balance	$ 139,932	138,724		139,932	138,724
Animal Health net sales
Goodwill [Roll Forward]
Impairment	(269,000)	(675,055)	$ (406,055)
Operating Segments | Dental net sales
Goodwill [Roll Forward]
Beginning Balance				138,724
Other Activity				1,208
Ending Balance	139,932	138,724		139,932	138,724
Operating Segments | Animal Health net sales
Goodwill [Roll Forward]
Beginning Balance				0
Other Activity				0
Ending Balance	0	0		0	0
Operating Segments | Corporate net sales
Goodwill [Roll Forward]
Beginning Balance				0
Other Activity				0
Ending Balance	$ 0	$ 0		$ 0	$ 0