Accounts Receivable (Tables)

3 Months Ended

Oct. 31, 2021

Receivables [Abstract]

Accounts receivable

Accounts receivable consist of the following at:

	October 31, 2021		July 31, 2021
Receivables from commercial and international customers	$	72,311,000	86,890,000
Unbilled receivables from commercial and international customers	34,210,000		36,131,000
Receivables from the U.S. government and its agencies	28,758,000		33,381,000
Unbilled receivables from the U.S. government and its agencies	3,010,000		3,356,000
Total accounts receivable	138,289,000		159,758,000
Less allowance for doubtful accounts	1,467,000		1,648,000
Accounts receivable, net	$	136,822,000	158,110,000