Summary of Significant Accounting Policies - Warranties (Details)	12 Months Ended
	Jul. 31, 2017
Most products
Product Warranties Disclosures [Abstract]
Warranty period	1 year
Endoscopy, Water Purification and Filtration products
Product Warranties Disclosures [Abstract]
Warranty period	24 months
Consumables, accessories and parts
Product Warranties Disclosures [Abstract]
Warranty period	90 days