Accumulated Other Comprehensive Income Items (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			$ 62,971
Foreign currency translation adjustment	$ 3,654	$ (734)	3,926	$ (2,003)
Net unrealized holding gain on securities	29	(10)	16
Pension liability adjustments		353	26	750
Other comprehensive income	3,683	$ (391)	3,968	$ (1,253)
Balance	133,968		133,968
Foreign currency items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			7,522
Foreign currency translation adjustment			3,926
Other comprehensive income			3,926
Balance	11,448		11,448
Pension items
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(3,376)
Pension liability adjustments			26
Other comprehensive income			26
Balance	(3,350)		(3,350)
Unrealized gains (losses) on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			167
Net unrealized holding gain on securities			16
Other comprehensive income			16
Balance	183		183
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			4,313
Balance	$ 8,281		$ 8,281