Condensed Consolidated Statements of Operations - USD ($)	3 Months Ended		9 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2016	Apr. 30, 2015
Income Statement [Abstract]
Net sales	$ 124,187,000	$ 71,633,000	$ 258,627,000	$ 229,826,000
Cost of sales	72,796,000	39,325,000	149,596,000	124,318,000
Gross profit	51,391,000	32,308,000	109,031,000	105,508,000
Expenses:
Selling, general and administrative	30,439,000	15,005,000	60,818,000	46,557,000
Research and development	12,613,000	8,582,000	28,216,000	28,267,000
Acquisition plan expenses	16,960,000	0	20,689,000	0
Amortization of intangibles	4,776,000	1,561,000	7,348,000	4,682,000
Total operating expenses	64,788,000	25,148,000	117,071,000	79,506,000
Operating (loss) income	(13,397,000)	7,160,000	(8,040,000)	26,002,000
Other expenses (income):
Interest expense and other	3,473,000	72,000	3,621,000	406,000
Interest income and other	(5,000)	(107,000)	(227,000)	(281,000)
(Loss) income before (benefit from) provision for income taxes	(16,865,000)	7,195,000	(11,434,000)	25,877,000
(Benefit from) provision for income taxes	(2,510,000)	2,235,000	(994,000)	8,107,000
Net (loss) income	$ (14,355,000)	$ 4,960,000	$ (10,440,000)	$ 17,770,000
Net (loss) income per share (See Note 5):
Basic (in dollars per share)	$ (0.89)	$ 0.31	$ (0.65)	$ 1.10
Diluted (in dollars per share)	$ (0.89)	$ 0.30	$ (0.65)	$ 1.08
Weighted average number of common shares outstanding – basic (in shares)	16,195,000	16,202,000	16,184,000	16,220,000
Weighted average number of common and common equivalent shares outstanding – diluted (in shares)	16,195,000	16,382,000	16,184,000	16,468,000
Dividends declared per issued and outstanding common share as of the applicable dividend record date (in dollars per share)	$ 0.30	$ 0.30	$ 0.90	$ 0.90