Accounts Receivable (Tables)

3 Months Ended

Oct. 31, 2016

Accounts Receivable Additional Disclosures [Abstract]

Accounts receivable

Accounts receivable consist of the following at:

	October 31, 2016		July 31, 2016
Billed receivables from commercial and international customers	$	73,217,000	90,185,000
Unbilled receivables from commercial and international customers	22,259,000		19,333,000
Billed receivables from the U.S. government and its agencies	21,441,000		21,465,000
Unbilled receivables from the U.S. government and its agencies	21,399,000		21,013,000
Total accounts receivable	138,316,000		151,996,000
Less allowance for doubtful accounts	1,368,000		1,029,000
Accounts receivable, net	$	136,948,000	150,967,000