Accounts Receivable (Tables)

12 Months Ended

Jul. 31, 2013

Accounts Receivable Additional Disclosures [Abstract]

Accounts Receivable

	2013		2012
Billed receivables from commercial customers	$	40,005,000	41,139,000
Billed receivables from the U.S. government and its agencies	8,114,000		11,927,000
Unbilled receivables on contracts-in-progress	2,399,000		4,764,000
Total accounts receivable	50,518,000		57,830,000
Less allowance for doubtful accounts	603,000		1,588,000
Accounts receivable, net	$	49,915,000	56,242,000