Accumulated Other Comprehensive Income Items (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2019	Apr. 30, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 94,537	$ 128,697	$ 107,628	$ 62,971
Foreign currency translation adjustment	(608)	(1,411)	(276)	2,515
Net unrealized holding loss on securities	3	(26)	(86)	(10)
Pension liability adjustments	0	0	(64)	26
Other comprehensive gain (loss)	(605)	(1,437)	(426)	2,531
Ending balance	92,386	118,658	92,386	118,658
Foreign currency items
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			6,348
Foreign currency translation adjustment			(276)
Net unrealized holding loss on securities			0
Pension liability adjustments			0
Other comprehensive gain (loss)			(276)
Ending balance	6,072		6,072
Pension items
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			(3,795)
Foreign currency translation adjustment			0
Net unrealized holding loss on securities			0
Pension liability adjustments			(64)
Other comprehensive gain (loss)			(64)
Ending balance	(3,859)		(3,859)
Unrealized gains (losses) on securities
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance			181
Foreign currency translation adjustment
Net unrealized holding loss on securities			(86)
Pension liability adjustments			0
Other comprehensive gain (loss)			(86)
Ending balance	95		95
Accumulated Other Comprehensive Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	2,913	8,281	2,734	4,313
Other comprehensive gain (loss)	(605)	(1,437)	(426)	2,531
Ending balance	$ 2,308	$ 6,844	$ 2,308	$ 6,844