Accounts Receivable (Tables)

3 Months Ended

Oct. 31, 2020

Receivables [Abstract]

Accounts receivable

Accounts receivable consist of the following at:

	October 31, 2020		July 31, 2020
Receivables from commercial and international customers	$	64,461,000	67,109,000
Unbilled receivables from commercial and international customers	28,806,000		21,588,000
Receivables from the U.S. government and its agencies	37,345,000		32,870,000
Unbilled receivables from the U.S. government and its agencies	3,446,000		7,018,000
Total accounts receivable	134,058,000		128,585,000
Less allowance for doubtful accounts	1,988,000		1,769,000
Accounts receivable, net	$	132,070,000	126,816,000