Intangible Assets and Goodwill (Details 3) (USD $)	9 Months Ended	12 Months Ended
	Apr. 30, 2015	Jul. 31, 2014	Jul. 31, 2013
Changes in Goodwill
Balance at the beginning of the period	$ 231,647,000	$ 211,618,000
Acquisitions	20,359,000	20,952,000
Foreign currency translation	(3,765,000)	(923,000)
Sale of business	(5,740,000)
Balance at the end of the period	242,501,000	231,647,000
Endoscopy
Changes in Goodwill
Balance at the beginning of the period	78,274,000	59,230,000
Acquisitions	11,299,000	19,225,000
Foreign currency translation	(2,398,000)	(181,000)
Balance at the end of the period	87,175,000	78,274,000
Water Purification and Filtration
Changes in Goodwill
Balance at the beginning of the period	56,838,000	57,179,000
Acquisitions	2,965,000
Foreign currency translation	(540,000)	(341,000)
Balance at the end of the period	59,263,000	56,838,000
Healthcare Disposables
Changes in Goodwill
Balance at the beginning of the period	81,835,000	80,108,000
Acquisitions	6,095,000	1,727,000
Balance at the end of the period	87,930,000	81,835,000
Dialysis
Changes in Goodwill
Balance at the beginning of the period			8,133,000
Balance at the end of the period	8,133,000	8,133,000	8,133,000
Other.
Changes in Goodwill
Balance at the beginning of the period	6,567,000	6,968,000
Foreign currency translation	(827,000)	(401,000)
Sale of business	(5,740,000)
Balance at the end of the period		$ 6,567,000