Warranties (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2017	Jan. 31, 2016
Summary of activity in warranty reserves
Beginning balance	$ 2,831,000	$ 1,847,000	$ 2,575,000	$ 1,740,000
Acquisitions			121,000	28,000
Provisions	1,169,000	854,000	3,085,000	1,759,000
Settlements	(1,353,000)	(655,000)	(3,099,000)	(1,478,000)
Foreign currency translation	20,000	(79,000)	(15,000)	(82,000)
Ending balance	$ 2,667,000	$ 1,967,000	$ 2,667,000	$ 1,967,000