Condensed Consolidated Statements of Operations - USD ($)	3 Months Ended
	Oct. 31, 2018	Oct. 31, 2017
Income Statement [Abstract]
Net sales	$ 160,844,000	$ 121,569,000
Cost of sales	103,075,000	73,853,000
Gross profit	57,769,000	47,716,000
Expenses:
Selling, general and administrative	31,847,000	28,475,000
Research and development	13,210,000	13,750,000
Amortization of intangibles	4,289,000	5,269,000
Acquisition plan expenses	1,130,000	0
Total operating expenses	50,476,000	47,494,000
Operating income	7,293,000	222,000
Other expenses:
Interest expense	2,669,000	2,588,000
Write-off of deferred financing costs	3,217,000	0
Interest (income) and other	66,000	39,000
Income (loss) before benefit from income taxes	1,341,000	(2,405,000)
Benefit from income taxes	(2,127,000)	(745,000)
Net income (loss)	$ 3,468,000	$ (1,660,000)
Net income (loss) per share (See Note 5):
Basic (in dollars per share)	$ 0.14	$ (0.07)
Diluted (in dollars per share)	$ 0.14	$ (0.07)
Weighted average number of common shares outstanding – basic (in shares)	23,999,000	23,797,000
Weighted average number of common and common equivalent shares outstanding – diluted (in shares)	24,375,000	23,797,000