Condensed Consolidated Statements of Operations - USD ($)	3 Months Ended		6 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2017	Jan. 31, 2016
Income Statement [Abstract]
Net sales	$ 139,028,000	$ 70,323,000	$ 274,814,000	$ 134,440,000
Cost of sales	85,824,000	40,885,000	169,502,000	76,800,000
Gross profit	53,204,000	29,438,000	105,312,000	57,640,000
Expenses:
Selling, general and administrative	30,988,000	17,390,000	63,673,000	34,108,000
Research and development	13,314,000	7,663,000	27,410,000	15,603,000
Settlement of intellectual property litigation	(9,979,000)	0	(9,979,000)	0
Amortization of intangibles	6,032,000	1,196,000	12,087,000	2,572,000
Total operating expenses	40,355,000	26,249,000	93,191,000	52,283,000
Operating income	12,849,000	3,189,000	12,121,000	5,357,000
Other expenses (income):
Interest expense and other	2,852,000	73,000	6,177,000	148,000
Interest income and other	(74,000)	(110,000)	(76,000)	(222,000)
Income before provision for income taxes	10,071,000	3,226,000	6,020,000	5,431,000
Provision for income taxes	3,486,000	750,000	1,924,000	1,516,000
Net income	$ 6,585,000	$ 2,476,000	$ 4,096,000	$ 3,915,000
Net income per share (See Note 5):
Basic (in dollars per share)	$ 0.28	$ 0.15	$ 0.17	$ 0.24
Diluted (in dollars per share)	$ 0.28	$ 0.15	$ 0.17	$ 0.24
Weighted average number of common shares outstanding – basic (in shares)	23,428,000	16,186,000	23,406,000	16,178,000
Weighted average number of common and common equivalent shares outstanding – diluted (in shares)	23,445,000	16,205,000	23,427,000	16,201,000
Dividends declared per issued and outstanding common share as of the applicable dividend record date (in dollars per share)	$ 0.1	$ 0.3	$ 0.4	$ 0.6