Segment Reporting - Information about Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 29, 2022	Jan. 23, 2021	Jan. 29, 2022	Jan. 23, 2021	Apr. 24, 2021
Segment Reporting Information [Line Items]
Net sales	$ 1,596,596	$ 1,551,268	$ 4,860,633	$ 4,350,273
Operating income	60,833	61,681	84,164	173,259
Total assets	2,863,496		2,863,496		$ 2,751,511
Consumable
Segment Reporting Information [Line Items]
Net sales	1,237,127	1,199,102	3,923,613	3,485,669
Equipment and software
Segment Reporting Information [Line Items]
Net sales	276,446	266,628	683,711	616,286
Value-added services and other
Segment Reporting Information [Line Items]
Net sales	83,023	85,538	253,309	248,318
Dental
Segment Reporting Information [Line Items]
Net sales	650,633	648,946	1,879,715	1,710,989
Dental | Operating Segments
Segment Reporting Information [Line Items]
Operating income	64,125	61,291	118,609	172,017
Total assets	893,996		893,996		863,718
Dental | Consumable
Segment Reporting Information [Line Items]
Net sales	337,192	342,561	1,070,422	957,013
Dental | Equipment and software
Segment Reporting Information [Line Items]
Net sales	241,384	237,205	591,787	548,403
Dental | Value-added services and other
Segment Reporting Information [Line Items]
Net sales	72,057	69,180	217,506	205,573
Animal Health
Segment Reporting Information [Line Items]
Net sales	944,774	894,347	2,975,031	2,620,677
Animal Health | Operating Segments
Segment Reporting Information [Line Items]
Operating income	23,420	20,615	73,360	55,605
Total assets	1,527,152		1,527,152		1,391,892
Animal Health | Consumable
Segment Reporting Information [Line Items]
Net sales	899,935	856,541	2,853,191	2,528,656
Animal Health | Equipment and software
Segment Reporting Information [Line Items]
Net sales	35,062	29,423	91,924	67,883
Animal Health | Value-added services and other
Segment Reporting Information [Line Items]
Net sales	9,777	8,383	29,916	24,138
Corporate
Segment Reporting Information [Line Items]
Net sales	1,189	7,975	5,887	18,607
Corporate | Operating Segments
Segment Reporting Information [Line Items]
Operating income	(26,712)	(20,225)	(107,805)	(54,363)
Total assets	442,348		442,348		$ 495,901
Corporate | Value-added services and other
Segment Reporting Information [Line Items]
Net sales	1,189	7,975	5,887	18,607
United States
Segment Reporting Information [Line Items]
Net sales	1,329,051	1,272,696	4,006,576	3,586,674
United States | Dental
Segment Reporting Information [Line Items]
Net sales	591,397	584,868	1,694,044	1,553,097
United States | Animal Health
Segment Reporting Information [Line Items]
Net sales	736,465	679,853	2,306,645	2,014,970
United States | Corporate
Segment Reporting Information [Line Items]
Net sales	1,189	7,975	5,887	18,607
United Kingdom
Segment Reporting Information [Line Items]
Net sales	168,568	178,260	545,321	507,347
United Kingdom | Animal Health
Segment Reporting Information [Line Items]
Net sales	168,568	178,260	545,321	507,347
Canada
Segment Reporting Information [Line Items]
Net sales	98,977	100,312	308,736	256,252
Canada | Dental
Segment Reporting Information [Line Items]
Net sales	59,236	64,078	185,671	157,892
Canada | Animal Health
Segment Reporting Information [Line Items]
Net sales	$ 39,741	$ 36,234	$ 123,065	$ 98,360