Net Sales by Geographic Area along with Long-Lived Assets by Location (Detail) (USD $)	3 Months Ended													12 Months Ended
	Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014		Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Segment Reporting Information [Line Items]
Sales to unaffiliated customers	$ 124,327,000	$ 105,424,000	$ 68,356,000	[1]	$ 32,767,000	$ 37,521,000	$ 36,257,000	$ 35,016,000	$ 43,188,000	$ 43,463,000	$ 30,837,000	$ 24,082,000	$ 33,752,000	$ 330,874,000	$ 151,982,000	$ 132,134,000
Long-lived assets	40,883,000					16,647,000								40,883,000	16,647,000
Top Ten Customers
Segment Reporting Information [Line Items]
Accounts receivable from top ten customers (in millions)	48,600,000					21,200,000				22,800,000				48,600,000	21,200,000	22,800,000
Sales Revenue, Net | Top Ten Customers
Segment Reporting Information [Line Items]
Revenue														50.00%	70.00%	68.00%
Sales Revenue, Net | Spirox
Segment Reporting Information [Line Items]
Revenue														15.00%	27.00%	22.00%
Sales Revenue, Net | Texas Instruments
Segment Reporting Information [Line Items]
Revenue														10.00%	12.00%	21.00%
US
Segment Reporting Information [Line Items]
Sales to unaffiliated customers														80,587,000	25,999,000	30,486,000
Long-lived assets	25,300,000					14,844,000								25,300,000	14,844,000
Philippines
Segment Reporting Information [Line Items]
Sales to unaffiliated customers														33,873,000	23,106,000	25,117,000
Long-lived assets	391,000					517,000								391,000	517,000
Singapore
Segment Reporting Information [Line Items]
Sales to unaffiliated customers														30,412,000	9,221,000	5,302,000
Long-lived assets	689,000					311,000								689,000	311,000
Japan
Segment Reporting Information [Line Items]
Long-lived assets	446,000					311,000								446,000	311,000
All Other Countries
Segment Reporting Information [Line Items]
Sales to unaffiliated customers														38,753,000	12,983,000	14,793,000
Long-lived assets	443,000					520,000								443,000	520,000
Taiwan
Segment Reporting Information [Line Items]
Sales to unaffiliated customers														52,123,000	39,913,000	26,308,000
Long-lived assets	107,000													107,000
Malaysia
Segment Reporting Information [Line Items]
Sales to unaffiliated customers														23,604,000	15,935,000	10,959,000
Long-lived assets	3,598,000					3,000								3,598,000	3,000
Thailand
Segment Reporting Information [Line Items]
Sales to unaffiliated customers														19,190,000	4,597,000	1,743,000
Hong Kong / China
Segment Reporting Information [Line Items]
Sales to unaffiliated customers														28,286,000	13,373,000	8,392,000
Germany
Segment Reporting Information [Line Items]
Sales to unaffiliated customers														24,046,000	6,855,000	9,034,000
Long-lived assets	9,198,000					141,000								9,198,000	141,000
China
Segment Reporting Information [Line Items]
Long-lived assets	$ 711,000													$ 711,000

[1] The results for the second quarter of 2014, as presented here, reflect the impact of retroactive accounting treatment for $2.6 million of bargain purchase gain, ($1.4) million of which was recorded in the third quarter of 2014 and $4 million of which was recorded in the fourth quarter of 2014.