CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data	Total	Common Stock	Treasury Stock	Additional Paid in Capital	Unallocated Shares of ESOP	Accumulated Other Comprehensive (Loss) Income	Retained Earnings	Comprehensive Income
Balances at Aug. 02, 2008	$ 480,050	$ 431	$ (6,092)	$ 169,238	$ (1,040)	$ (753)	$ 318,266
Balances (in shares) at Aug. 02, 2008		43,100,000	229,000
Increase (Decrease) in Stockholders' Equity
Allocation of shares to ESOP	163				163
Issuance of common stock pursuant to secondary offering, net of direct offering costs	1,039	1		1,038
Issuance of common stock pursuant to secondary offering, net of direct offering costs (in shares)		137,000
Share-based compensation	5,504			5,504
Tax benefit (expense) associated with stock plans	(598)			(598)
Fair value of swap agreements, net of tax	(870)					(870)		(870)
Net income	59,184						59,184	59,184
Total comprehensive income	58,314							58,314
Balances at Aug. 01, 2009	544,472	432	(6,092)	175,182	(877)	(1,623)	377,450
Balances (in shares) at Aug. 01, 2009		43,237,000	229,000
Increase (Decrease) in Stockholders' Equity
Allocation of shares to ESOP	164				164
Issuance of common stock pursuant to secondary offering, net of direct offering costs	7,143	3	5,384	3,666			(1,910)
Issuance of common stock pursuant to secondary offering, net of direct offering costs (in shares)		321,000	(202,000)
Share-based compensation	8,057			8,057
Tax benefit (expense) associated with stock plans	1,822			1,822
Fair value of swap agreements, net of tax	128					128		128
Foreign currency translation	340					340		340
Net income	68,321						68,321	68,321
Total comprehensive income	68,789							68,789
Balances at Jul. 31, 2010	630,447	435	(708)	188,727	(713)	(1,155)	443,861
Balances (in shares) at Jul. 31, 2010		43,558,000	27,000
Increase (Decrease) in Stockholders' Equity
Allocation of shares to ESOP	171				171
Issuance of common stock pursuant to secondary offering, net of direct offering costs	138,301	44		138,257
Issuance of common stock pursuant to secondary offering, net of direct offering costs (in shares)		4,428,000
Stock option exercises and restricted stock vestings, net	7,354	6	0	7,348
Stock option exercises and restricted stock vestings, net (in shares)		534,000	0
Share-based compensation	9,159			9,159
Tax benefit (expense) associated with stock plans	1,545			1,545
Fair value of swap agreements, net of tax	732					732		732
Foreign currency translation	5,285					5,285		5,285
Net income	76,673						76,673	76,673
Total comprehensive income	82,690							82,690
Balances at Jul. 30, 2011	$ 869,667	$ 485	$ (708)	$ 345,036	$ (542)	$ 4,862	$ 520,534
Balances (in shares) at Jul. 30, 2011		48,520,000	27,000