Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Increase (Decrease) in Stockholders' Equity
Beginning Balance	$ 608,867	$ 523,932	$ 454,370
Total other comprehensive (loss) income:	(10,741)	(1,556)	1,895
Ending Balance	661,537	608,867	523,932
Total
Increase (Decrease) in Stockholders' Equity
Beginning Balance	(11,456)	(9,900)	(11,795)
Total other comprehensive (loss) income:	(10,741)	(1,556)	1,895
Ending Balance	(22,197)	(11,456)	(9,900)
Foreign Currency Translation Adjustments
Increase (Decrease) in Stockholders' Equity
Beginning Balance	(11,456)	(9,900)	(11,795)
Other comprehensive (loss) income, before tax	(13,287)	(1,556)	1,895
Ending Balance	(24,743)	(11,456)	(9,900)
Changes in Fair Value of Interest Rate Swaps
Increase (Decrease) in Stockholders' Equity
Beginning Balance	0	0	0
Other comprehensive (loss) income, before tax	3,312	0	0
Ending Balance	3,312	0	0
Tax effects
Increase (Decrease) in Stockholders' Equity
Beginning Balance	0	0	0
Other comprehensive (loss) income, tax	(766)	0	0
Ending Balance	$ (766)	$ 0	$ 0