Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2017	Apr. 30, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net (loss) income	$ (59,664)	$ 4,970	$ (49,618)	$ 3,361
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment, net of tax	178	3,551	(2,415)	303
Unrecognized gain on pension benefits, net of tax	58	26	167	76
Unrealized (loss) gain on foreign currency forward contracts, net of tax	(324)	373	(153)	358
Total other comprehensive (loss) income, net of tax	(88)	3,950	(2,401)	737
Total comprehensive (loss) income	$ (59,752)	$ 8,920	$ (52,019)	$ 4,098