Warranties (Details) - USD ($)
3 Months Ended 6 Months Ended
Jan. 31, 2016
Jan. 31, 2015
Jan. 31, 2016
Jan. 31, 2015
Summary of activity in warranty reserves        
Beginning balance $ 1,847,000 $ 1,689,000 $ 1,740,000 $ 1,589,000
Acquisitions   117,000 28,000 117,000
Provisions 854,000 593,000 1,759,000 1,306,000
Settlements (655,000) (681,000) (1,478,000) (1,281,000)
Foreign currency translation (79,000) (21,000) (82,000) (34,000)
Ending balance $ 1,967,000 $ 1,697,000 $ 1,967,000 $ 1,697,000