Accounts Receivable (Tables)

9 Months Ended

Apr. 30, 2016

Accounts Receivable Additional Disclosures [Abstract]

Accounts receivable

Accounts receivable consist of the following at:

	April 30, 2016		July 31, 2015
Billed receivables from commercial and international customers	$	60,670,000	39,062,000
Billed receivables from the U.S. government and its agencies	29,086,000		8,375,000
Unbilled receivables from commercial and international customers	24,164,000		21,898,000
Unbilled receivables on U.S. government contracts-in-progress	21,964,000		1,126,000
Total accounts receivable	135,884,000		70,461,000
Less allowance for doubtful accounts	1,830,000		1,206,000
Accounts receivable, net	$	134,054,000	69,255,000