Quarterly Results (unaudited) - Summary of Quarterly Results (Details) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	Apr. 30, 2020	Apr. 24, 2021 USD ($) $ / shares	Jan. 23, 2021 USD ($) $ / shares	Oct. 24, 2020 USD ($) $ / shares	Jul. 25, 2020 USD ($) $ / shares	Apr. 25, 2020 USD ($) investment $ / shares	Jan. 25, 2020 USD ($) $ / shares	Oct. 26, 2019 USD ($) $ / shares	Jul. 27, 2019 USD ($) investment $ / shares	Apr. 24, 2021 USD ($) $ / shares	Apr. 25, 2020 USD ($) investment $ / shares	Apr. 27, 2019 USD ($) $ / shares
Quarterly Financial Information [Line Items]
Net sales		$ 1,561,793	$ 1,551,268	$ 1,553,168	$ 1,245,837	$ 1,286,461	$ 1,456,155	$ 1,418,744	$ 1,328,651	$ 5,912,066	$ 5,490,011	$ 5,574,523
Gross profit		304,405	324,541	320,368	253,816	294,032	311,830	301,494	290,054	1,203,130	1,197,410	1,190,775
Operating income (loss)		37,348	61,681	73,706	37,872	(614,463)	43,816	(18,146)	16,674	210,607	(572,119)	137,716
Net income (loss)		28,514	48,567	53,826	24,202	(608,797)	22,972	(33,349)	29,807	155,109	(589,367)	82,876
Net loss attributable to noncontrolling interests		(241)	(192)	(234)	(205)	(211)	(255)	(220)	(235)	(872)	(921)	(752)
Net income (loss) attributable to Patterson Companies, Inc.		$ 28,755	$ 48,759	$ 54,060	$ 24,407	$ (608,586)	$ 23,227	$ (33,129)	$ 30,042	$ 155,981	$ (588,446)	$ 83,628
Earnings (loss) per share attributable to Patterson Companies, Inc.:
Basic (in usd per share) | $ / shares		$ 0.30	$ 0.51	$ 0.57	$ 0.26	$ (6.44)	$ 0.25	$ (0.35)	$ 0.32	$ 1.63	$ (6.25)	$ 0.90
Diluted (in usd per share) | $ / shares		$ 0.30	$ 0.50	$ 0.56	$ 0.25	$ (6.44)	$ 0.24	$ (0.35)	$ 0.32	$ 1.61	$ (6.25)	$ 0.89
Investment gain									$ (34,334)	$ 0	$ 34,334	$ 0
Litigation settlement									$ 17,666
Goodwill impairment						$ 0				0	$ 675,055	0
Number of investments | investment						1			1		1
U.S. Attorney’s Office, Western District Of Virginia
Earnings (loss) per share attributable to Patterson Companies, Inc.:
Litigation settlement reserve						$ 58,300					$ 58,300
Dental net sales
Quarterly Financial Information [Line Items]
Net sales										2,327,021	2,101,922	2,191,790
Operating income (loss)										201,244	168,304	179,236
Earnings (loss) per share attributable to Patterson Companies, Inc.:
Revenue decrease, percentage	71.00%
Animal Health net sales
Quarterly Financial Information [Line Items]
Net sales										3,559,994	3,336,253	3,354,528
Operating income (loss)										$ 88,123	$ (594,743)	$ 81,472
Earnings (loss) per share attributable to Patterson Companies, Inc.:
Revenue decrease, percentage	9.00%
Goodwill impairment		$ 269,000				$ 675,055			$ 406,055