CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Total
Balance at Jul. 31, 2015	$ 240	$ 56,066	$ (3,725)	$ 485,687	$ 538,268
Balance (in shares) at Jul. 31, 2015	23,975,755
Comprehensive Income:
Net income	$ 0	0	0	189,299	189,299
Other comprehensive income, net of tax	0	0	(10,015)	0	(10,015)
Comprehensive income	0	0	(10,015)	189,299	179,284
Cash dividends declared	0	0	0	(186,505)	(186,505)
Share-based compensation	0	13,202	0	0	13,202
Issuance of share-based compensation awards, net of shares withheld for employee taxes	$ 1	(5,780)	0	0	(5,779)
Issuance of share-based compensation awards, net of shares withheld for employee taxes (in shares)	80,379
Tax benefit realized upon exercise of share-based compensation awards	$ 0	2,626	0	0	2,626
Purchases and retirement of common stock	$ (1)	(14,652)	0	0	$ (14,653)
Purchases and retirement of common stock (in shares)	(100,000)				(100,000)
Balance at Jul. 29, 2016	$ 240	51,462	(13,740)	488,481	$ 526,443
Balance (in shares) at Jul. 29, 2016	23,956,134
Comprehensive Income:
Net income	$ 0	0	0	201,899	201,899
Other comprehensive income, net of tax	0	0	9,511	0	9,511
Comprehensive income	0	0	9,511	201,899	211,410
Cash dividends declared	0	0	0	(197,544)	(197,544)
Share-based compensation	0	8,458	0	0	8,458
Issuance of share-based compensation awards, net of shares withheld for employee taxes	$ 1	(6,897)	0	0	(6,896)
Issuance of share-based compensation awards, net of shares withheld for employee taxes (in shares)	99,548
Tax benefit realized upon exercise of share-based compensation awards	$ 0	2,636	0	0	2,636
Purchases and retirement of common stock	$ 0	0	0	0	$ 0
Purchases and retirement of common stock (in shares)	0				0
Balance at Jul. 28, 2017	$ 241	55,659	(4,229)	492,836	$ 544,507
Balance (in shares) at Jul. 28, 2017	24,055,682				24,055,682
Comprehensive Income:
Net income	$ 0	0	0	247,620	$ 247,620
Other comprehensive income, net of tax	0	0	8,914	0	8,914
Comprehensive income	0	0	8,914	247,620	256,534
Cash dividends declared	0	0	0	(207,649)	(207,649)
Share-based compensation	0	6,977	0	0	6,977
Issuance of share-based compensation awards, net of shares withheld for employee taxes	$ 0	(3,816)	0	0	$ (3,816)
Issuance of share-based compensation awards, net of shares withheld for employee taxes (in shares)	55,868				55,868
Tax benefit realized upon exercise of share-based compensation awards	$ 0	0	0	0	$ 0
Purchases and retirement of common stock	$ (1)	(14,771)	0	0	$ (14,772)
Purchases and retirement of common stock (in shares)	(100,000)				(100,000)
Balance at Aug. 03, 2018	$ 240	$ 44,049	$ 4,685	$ 532,807	$ 581,781
Balance (in shares) at Aug. 03, 2018	24,011,550				24,011,550