CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jan. 31, 2021	Jul. 31, 2020
Accounts Receivable, Allowance for Credit Loss, Current	$ 7,450	$ 7,157
Class A nonvoting common stock
Common stock, shares outstanding	48,486,758	48,456,954
Treasury stock, shares	2,774,729	2,804,533
Common stock, shares issued	51,261,487	51,261,487
Common Class B [Member]
Common stock, shares outstanding	3,538,628	3,538,628
Common stock, shares issued	3,538,628	3,538,628