Condensed Consolidated Statements of Operations - USD ($)	3 Months Ended		9 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2017	Apr. 30, 2016
Income Statement [Abstract]
Net sales	$ 127,792,000	$ 124,187,000	$ 402,606,000	$ 258,627,000
Cost of sales	75,331,000	72,796,000	244,833,000	149,596,000
Gross profit	52,461,000	51,391,000	157,773,000	109,031,000
Expenses:
Selling, general and administrative	25,923,000	30,439,000	89,596,000	60,818,000
Research and development	12,961,000	12,613,000	40,371,000	28,216,000
Amortization of intangibles	5,468,000	4,776,000	17,555,000	7,348,000
Settlement of intellectual property litigation	(2,041,000)	0	(12,020,000)	0
Acquisition plan expenses	0	16,960,000	0	20,689,000
Total operating expenses	42,311,000	64,788,000	135,502,000	117,071,000
Operating income (loss)	10,150,000	(13,397,000)	22,271,000	(8,040,000)
Other expenses (income):
Interest expense and other	2,761,000	3,473,000	8,938,000	3,621,000
Interest income and other	(88,000)	5,000	(12,000)	227,000
Income (loss) before provision for (benefit from) income taxes	7,301,000	(16,865,000)	13,321,000	(11,434,000)
Provision for (benefit from) income taxes	2,884,000	(2,510,000)	4,808,000	(994,000)
Net income (loss)	$ 4,417,000	$ (14,355,000)	$ 8,513,000	$ (10,440,000)
Net income (loss) per share (See Note 5):
Basic (in dollars per share)	$ 0.19	$ (0.89)	$ 0.36	$ (0.65)
Diluted (in dollars per share)	$ 0.19	$ (0.89)	$ 0.36	$ (0.65)
Weighted average number of common shares outstanding – basic (in shares)	23,449,000	16,195,000	23,420,000	16,184,000
Weighted average number of common and common equivalent shares outstanding – diluted (in shares)	23,503,000	16,195,000	23,449,000	16,184,000
Dividends declared per issued and outstanding common share as of the applicable dividend record date (in dollars per share)	$ 0.1	$ 0.30	$ 0.5	$ 0.90