Accounts Receivable (Tables)

12 Months Ended

Jul. 31, 2020

Receivables [Abstract]

Accounts receivable

Accounts receivable consist of the following at July 31, 2020 and 2019:

	2020		2019
Receivables from commercial and international customers	$	67,109,000	85,556,000
Unbilled receivables from commercial and international customers	21,588,000		20,469,000
Receivables from the U.S. government and its agencies	32,870,000		38,856,000
Unbilled receivables from the U.S. government and its agencies	7,018,000		2,018,000
Total accounts receivable	128,585,000		146,899,000
Less allowance for doubtful accounts	1,769,000		1,867,000
Accounts receivable, net	$	126,816,000	145,032,000