CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock Class A Common Stock	Common Stock Class B Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Balance (in shares) at Jul. 29, 2017		10,562	4,304			477
Balance at Jul. 29, 2017	$ 286,820	$ 57,852	$ 699	$ 244,308	$ (7,406)	$ (8,633)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	25,080			25,080
Other comprehensive income, net of tax	815			1,594	(779)
Dividends	$ (12,878)			(12,878)
Exercise of stock options (in shares)	(8)					(8)
Exercise of stock options	$ 225	$ 111				$ 114
Treasury stock purchases (in shares)						27
Treasury stock purchases	(632)					$ (632)
Restricted shares forfeited (in shares)		(8)
Restricted shares forfeited	(59)	$ (59)
Share-based compensation expense (in shares)		21
Share-based compensation expense	3,774	$ 3,774
Balance (in shares) at Jul. 28, 2018		10,575	4,304			496
Balance at Jul. 28, 2018	303,145	$ 61,678	$ 699	258,104	(8,185)	$ (9,151)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	25,539			25,539
Other comprehensive income, net of tax	(157)				(157)
Dividends	$ (12,890)			(12,890)
Exercise of stock options (in shares)	(36)					(36)
Exercise of stock options	$ 1,007	$ 336				$ 671
Treasury stock purchases (in shares)						42
Treasury stock purchases	(1,070)					$ (1,070)
Restricted shares forfeited (in shares)		(15)
Restricted shares forfeited	(247)	$ (247)
Share-based compensation expense (in shares)		23
Share-based compensation expense	3,345	$ 3,345
Conversion of Class B shares to Class A shares (in shares)		10	(10)
Conversion of Class B shares to Class A shares	0	$ 2	$ (2)
Balance (in shares) at Jul. 27, 2019		10,593	4,294			502
Balance at Jul. 27, 2019	$ 318,672	$ 65,114	$ 697	$ 270,753	$ (8,342)	$ (9,550)