Condensed Consolidated Balance Sheet Parenthetical - USD ($) $ in Thousands	Apr. 30, 2022	Jul. 31, 2021
Allowance for doubtful accounts	$ 1,149	$ 1,174
Accumulated amortization of other intangibles	497	385
Accumulated amortization of customer lists	7,536	7,321
Net unamortized debt issuance costs	$ 212	$ 122
Common Stock
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares issued	8,682,968	8,561,311
Treasury stock, common shares	3,535,568	3,192,702
Common Class B
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares issued	2,397,056	2,397,056
Treasury stock, common shares	351,641	346,491