Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jan. 31, 2022	Jul. 31, 2021
Accounts Receivable, Allowance for Credit Loss, Current	$ 4,896	$ 4,438
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Common Class A [Member]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	35,000,000	35,000,000
Common stock, shares issued	3,272,000	3,272,000
Common stock, shares outstanding	1,574,000	1,574,000
Treasury Stock, Shares	1,698,000	1,698,000
Common Class B [Member]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	26,684,000	26,379,000
Common stock, shares outstanding	24,292,000	24,187,000
Treasury Stock, Shares	2,392,000	2,192,000