Summary of Quarterly Results (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Apr. 28, 2012	Jan. 28, 2012	Oct. 29, 2011	Jul. 30, 2011	Apr. 30, 2011	Jan. 29, 2011	Oct. 30, 2010	Jul. 31, 2010	Apr. 28, 2012	Apr. 30, 2011	Apr. 24, 2010
Quarterly Financial Information [Line Items]
Net sales	$ 936,334	$ 895,030	$ 856,875	$ 847,422	$ 883,819	$ 824,650	$ 857,414	$ 849,787	$ 3,535,661	$ 3,415,670	$ 3,237,376
Gross profit	313,721	289,534	280,983	278,276	303,949	280,875	279,201	280,200	1,162,514	1,144,225	1,089,401
Operating income	102,851	89,906	83,259	81,993	104,125	92,707	90,152	89,024	358,009	376,008	355,291
Net income	$ 62,143	$ 53,108	$ 48,954	$ 48,610	$ 62,707	$ 55,396	$ 53,357	$ 53,925	$ 212,815	$ 225,385	$ 212,254
Earnings per share - basic	$ 0.59	$ 0.50	$ 0.43	$ 0.42	$ 0.52	$ 0.47	$ 0.45	$ 0.45	$ 1.93	$ 1.91	$ 1.79
Earnings per share - diluted	$ 0.58	$ 0.50	$ 0.43	$ 0.42	$ 0.52	$ 0.47	$ 0.45	$ 0.45	$ 1.92	$ 1.89	$ 1.78