Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jan. 31, 2017	Jul. 31, 2016
Finite Lived Intangible Assets [Line Items]
Number of Years Weighted Average Amortization Period	13 years 7 months 6 days	13 years 7 months 6 days
Original Cost	$ 27,192	$ 27,192
Accumulated Amortization	(7,857)	(6,796)
Foreign Currency Translation Adjustment	(1,251)	(948)
Carrying Amount	18,084	19,448
Total intangible assets not subject to amortization	14,458	14,458
Total intangible assets, net	32,542	33,906
Other chemicals-penta product registrations
Finite Lived Intangible Assets [Line Items]
Total intangible assets not subject to amortization	8,765	8,765
Other chemicals-related trade name and trademark
Finite Lived Intangible Assets [Line Items]
Total intangible assets not subject to amortization	2,885	2,885
Other chemicals-proprietary manufacturing process
Finite Lived Intangible Assets [Line Items]
Total intangible assets not subject to amortization	$ 2,808	$ 2,808
Electronic chemicals-related contracts
Finite Lived Intangible Assets [Line Items]
Number of Years Weighted Average Amortization Period	6 years 7 months 6 days	6 years 7 months 6 days
Original Cost	$ 2,204	$ 2,204
Accumulated Amortization	(1,233)	(1,104)
Foreign Currency Translation Adjustment	(150)	(117)
Carrying Amount	$ 821	$ 983
Electronic chemicals-related trademarks and patents
Finite Lived Intangible Assets [Line Items]
Number of Years Weighted Average Amortization Period	12 years	12 years
Original Cost	$ 117	$ 117
Accumulated Amortization	(93)	(87)
Carrying Amount	$ 24	$ 30
Electronic chemicals-value of product qualifications
Finite Lived Intangible Assets [Line Items]
Number of Years Weighted Average Amortization Period	14 years 1 month 6 days	14 years 1 month 6 days
Original Cost	$ 14,100	$ 14,100
Accumulated Amortization	(5,049)	(4,616)
Foreign Currency Translation Adjustment	(1,092)	(831)
Carrying Amount	$ 7,959	$ 8,653
Other chemicals-customer relationships
Finite Lived Intangible Assets [Line Items]
Number of Years Weighted Average Amortization Period	15 years	15 years
Original Cost	$ 10,291	$ 10,291
Accumulated Amortization	(1,201)	(858)
Carrying Amount	$ 9,090	$ 9,433
Other chemicals-other related contracts
Finite Lived Intangible Assets [Line Items]
Number of Years Weighted Average Amortization Period	5 years	5 years
Original Cost	$ 152	$ 152
Accumulated Amortization	(53)	(38)
Carrying Amount	$ 99	$ 114
Electronic chemicals - Tolling/License Agreements
Finite Lived Intangible Assets [Line Items]
Number of Years Weighted Average Amortization Period	1 year 4 months 24 days	1 year 4 months 24 days
Original Cost	$ 328	$ 328
Accumulated Amortization	(228)	(93)
Foreign Currency Translation Adjustment	(9)
Carrying Amount	$ 91	$ 235