Accounts Receivable

9 Months Ended

Apr. 30, 2018

Accounts Receivable Additional Disclosures [Abstract]

Accounts Receivable

Accounts Receivable

Accounts receivable consist of the following at:

	April 30, 2018		July 31, 2017
Billed receivables from commercial and international customers	$	72,889,000	71,404,000
Unbilled receivables from commercial and international customers	18,184,000		24,668,000
Billed receivables from the U.S. government and its agencies	22,020,000		18,497,000
Unbilled receivables from the U.S. government and its agencies	15,780,000		11,693,000
Total accounts receivable	128,873,000		126,262,000
Less allowance for doubtful accounts	1,606,000		1,300,000
Accounts receivable, net	$	127,267,000	124,962,000

Unbilled receivables relate to contracts-in-progress for which revenue has been recognized but we have not yet billed the customer for work performed. We had $130,000 and $118,000 of retainage included in unbilled receivables at April 30, 2018 and July 31, 2017, respectively, and management estimates that substantially all of the unbilled receivables at April 30, 2018 will be billed and collected within one year. Of the unbilled receivables from commercial and international customers at April 30, 2018 and July 31, 2017, approximately $1,049,000 and $2,995,000, respectively, relates to a large over-the-horizon microwave system contract with our large U.S. prime contractor customer (all of which related to our North African country end-customer).

As of April 30, 2018, the U.S. government (and its agencies) and Verizon Communications Inc. (through various divisions and, collectively, "Verizon") represented 29.3% and 14.5%, respectively, of total accounts receivable. As of July 31, 2017, except for the U.S. government (and its agencies), which represented 23.9% of total accounts receivable, there were no other customers which accounted for greater than 10.0% of total accounts receivable.