Quarterly Results (unaudited) - Summary of Quarterly Results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2016	Jan. 30, 2016	Oct. 31, 2015	Aug. 01, 2015	Apr. 25, 2015	Jan. 24, 2015	Oct. 25, 2014	Jul. 26, 2014	Apr. 30, 2016	Apr. 25, 2015	Apr. 26, 2014
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 1,453,770	$ 1,400,853	$ 1,389,210	$ 1,142,870	$ 1,035,061	$ 958,628	$ 978,220	$ 938,956	$ 5,386,703	$ 3,910,865	$ 3,585,141
Gross profit	363,741	339,864	330,899	288,244	288,203	262,442	259,287	250,617	1,322,748	1,060,549	1,018,697
Operating income from continuing operations	106,344	95,729	83,463	62,177	89,073	77,377	72,140	65,996	347,713	304,586	293,726
Net income from continuing operations	65,620	57,190	42,563	20,311	53,459	46,434	41,865	38,325	185,684	180,083	171,332
Net income from discontinued operations	0	(750)	(7,142)	9,392	11,059	8,242	11,913	11,964
Net income	$ 65,620	$ 56,440	$ 35,421	$ 29,703	$ 64,518	$ 54,676	$ 53,778	$ 50,289	$ 187,184	$ 223,261	$ 200,612
Basic earnings (loss) per share:
Continuing operations (in usd per share)	$ 0.69	$ 0.60	$ 0.43	$ 0.20	$ 0.54	$ 0.47	$ 0.42	$ 0.39	$ 1.91	$ 1.82	$ 1.70
Discontinued operations (in usd per share)	0.00	(0.01)	(0.07)	0.10	0.11	0.08	0.12	0.12	0.02	0.44	0.29
Basic (in usd per share)	0.69	0.59	0.36	0.30	0.65	0.55	0.54	0.51	1.93	2.26	1.99
Diluted earnings (loss) per share:
Continuing operations (in usd per share)	0.68	0.60	0.43	0.20	0.54	0.47	0.42	0.38	1.90	1.81	1.69
Discontinued operations (in usd per share)	0.00	(0.01)	(0.07)	0.10	0.11	0.08	0.12	0.12	0.01	0.43	0.28
Diluted (in usd per share)	$ 0.68	$ 0.59	$ 0.36	$ 0.30	$ 0.65	$ 0.55	$ 0.54	$ 0.50	$ 1.91	$ 2.24	$ 1.97