Intangibles and Goodwill - Goodwill Rollforward (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2018	Jul. 31, 2017
Changes in Goodwill
Balance at the beginning of the period	$ 311,445	$ 280,318
Acquisitions	58,026	30,182
Foreign currency translation	(1,444)	945
Balance at the end of the period	368,027	311,445
Endoscopy
Changes in Goodwill
Balance at the beginning of the period	129,945	121,015
Acquisitions	58,026	8,193
Foreign currency translation	(1,281)	737
Balance at the end of the period	186,690	129,945
Water Purification and Filtration
Changes in Goodwill
Balance at the beginning of the period	59,088	58,880
Acquisitions	0	0
Foreign currency translation	(163)	208
Balance at the end of the period	58,925	59,088
Healthcare Disposables
Changes in Goodwill
Balance at the beginning of the period	114,279	92,290
Acquisitions	0	21,989
Foreign currency translation	0	0
Balance at the end of the period	114,279	114,279
Dialysis
Changes in Goodwill
Balance at the beginning of the period	8,133	8,133
Acquisitions	0	0
Foreign currency translation	0	0
Balance at the end of the period	$ 8,133	$ 8,133