Condensed Consolidated Statements of Operations - USD ($)	3 Months Ended
	Oct. 31, 2019	Oct. 31, 2018
Income Statement [Abstract]
Net sales	$ 170,267,000	$ 160,844,000
Cost of sales	106,700,000	103,075,000
Gross profit	63,567,000	57,769,000
Expenses:
Selling, general and administrative	31,851,000	31,847,000
Research and development	14,861,000	13,210,000
Amortization of intangibles	5,206,000	4,289,000
Acquisition plan expenses	2,389,000	1,130,000
Total operating expenses	54,307,000	50,476,000
Operating income	9,260,000	7,293,000
Other expenses:
Interest expense	1,804,000	2,669,000
Write-off of deferred financing costs	0	3,217,000
Interest (income) and other	(77,000)	66,000
Income before provision for (benefit from) income taxes	7,533,000	1,341,000
Provision for (benefit from) income taxes	1,145,000	(2,127,000)
Net income	$ 6,388,000	$ 3,468,000
Net income per share (See Note 6):
Basic (in dollars per share)	$ 0.26	$ 0.14
Diluted (in dollars per share)	$ 0.26	$ 0.14
Weighted average number of common shares outstanding – basic (in shares)	24,555,000	23,999,000
Weighted average number of common and common equivalent shares outstanding – diluted (in shares)	24,737,000	24,375,000