Warranties (Details) - USD ($)	3 Months Ended		9 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2017	Apr. 30, 2016
Summary of activity in warranty reserves
Beginning balance	$ 2,667,000	$ 1,967,000	$ 2,575,000	$ 1,740,000
Acquisitions			121,000	28,000
Provisions	1,336,000	1,505,000	4,421,000	3,264,000
Settlements	(1,245,000)	(887,000)	(4,344,000)	(2,365,000)
Foreign currency translation	5,000	9,000	(10,000)	(73,000)
Ending balance	$ 2,763,000	$ 2,594,000	$ 2,763,000	$ 2,594,000