Condensed Consolidated Balance Sheet Parenthetical - USD ($) $ in Thousands	Jan. 31, 2022	Jul. 31, 2021
Allowance for doubtful accounts	$ 1,093	$ 1,174
Accumulated amortization of other intangibles	471	385
Accumulated amortization of customer lists	7,464	7,321
Net unamortized debt issuance costs	$ 222	$ 122
Common Stock
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares issued	8,667,968	8,561,311
Treasury stock, common shares	3,380,955	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