Segment and Geographic Data - Information about Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 25, 2020	Jan. 25, 2020	Oct. 26, 2019	Jul. 27, 2019	Apr. 27, 2019	Jan. 26, 2019	Oct. 27, 2018	Jul. 28, 2018	Apr. 25, 2020	Apr. 27, 2019	Apr. 28, 2018
Segment Reporting Information [Line Items]
Operating (loss) income	$ (614,463)	$ 43,816	$ (18,146)	$ 16,674	$ 46,623	$ 45,363	$ 41,216	$ 4,514	$ (572,119)	$ 137,716	$ 219,889
Depreciation and amortization									82,182	82,773	83,816
Total assets	2,715,350				3,269,269				2,715,350	3,269,269
Dental net sales
Segment Reporting Information [Line Items]
Operating (loss) income									168,304	179,236	229,201
Depreciation and amortization									8,434	8,792	7,435
Total assets	704,216				641,721				704,216	641,721
Animal Health net sales
Segment Reporting Information [Line Items]
Operating (loss) income									(594,743)	81,472	78,058
Depreciation and amortization									49,958	49,362	50,892
Total assets	1,485,284				2,156,723				1,485,284	2,156,723
Corporate net sales
Segment Reporting Information [Line Items]
Operating (loss) income									(145,680)	(122,992)	(87,370)
Depreciation and amortization									23,790	24,619	$ 25,489
Total assets	$ 525,850				$ 470,825				$ 525,850	$ 470,825