Segment Reporting - Information about Reportable Segments (Detail) $ in Thousands	3 Months Ended
	Jul. 30, 2016 USD ($) Segment	Aug. 01, 2015 USD ($)	Apr. 30, 2016 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | Segment	3
Segment Reporting Information [Line Items]
Net sales	$ 1,332,436	$ 1,142,870
Operating income (loss) from continuing operations	65,416	62,177
Total assets	3,499,267		$ 3,520,804
Operating Segments [Member] | Dental [Member]
Segment Reporting Information [Line Items]
Net sales	555,015	575,117
Operating income (loss) from continuing operations	60,295	67,252
Total assets	917,235		994,113
Operating Segments [Member] | Animal Health [Member]
Segment Reporting Information [Line Items]
Net sales	762,631	557,297
Operating income (loss) from continuing operations	14,829	12,972
Total assets	2,082,686		2,064,302
Operating Segments [Member] | Corporate [Member]
Segment Reporting Information [Line Items]
Net sales	14,790	10,456
Operating income (loss) from continuing operations	(9,708)	$ (18,047)
Total assets	$ 499,346		$ 462,389