Accounts Receivable (Tables)

6 Months Ended

Jan. 31, 2015

Accounts Receivable Additional Disclosures [Abstract]

Accounts receivable

Accounts receivable consist of the following at:

	January 31, 2015		July 31, 2014
Billed receivables from commercial customers	$	36,759,000	31,681,000
Billed receivables from the U.S. government and its agencies	10,285,000		10,316,000
Unbilled receivables on contracts-in-progress	22,552,000		13,517,000
Total accounts receivable	69,596,000		55,514,000
Less allowance for doubtful accounts	700,000		627,000
Accounts receivable, net	$	68,896,000	54,887,000