Fair Value Measurements - Level 3 Liabilities (Details) - USD ($)	12 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3
Beginning balance	$ 2,777,000	$ 5,869,000	$ 45,000
Total net unrealized (gains) losses included in general and administrative expense in earnings	(687,000)	(2,585,000)	219,000
Net purchases, issuances, sales and settlements	(511,000)	(507,000)	5,605,000
Ending balance	1,579,000	2,777,000	5,869,000
Byrne Medical Business | Price floor
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3
Beginning balance			45,000
Total net unrealized (gains) losses included in general and administrative expense in earnings			(45,000)
Contingent Consideration | Jet Prep Ltd.
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3
Beginning balance	751,000	2,722,000
Total net unrealized (gains) losses included in general and administrative expense in earnings	(751,000)	(1,971,000)	232,000
Net purchases, issuances, sales and settlements			2,490,000
Ending balance		751,000	2,722,000
Assumed contingent liability | Jet Prep Ltd.
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3
Beginning balance	1,138,000	1,752,000
Total net unrealized (gains) losses included in general and administrative expense in earnings		(614,000)	32,000
Net purchases, issuances, sales and settlements			1,720,000
Ending balance	1,138,000	1,138,000	1,752,000
Contingent guaranteed obligation | Cantel Medical (UK) - PuriCore International Limited
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3
Beginning balance	888,000	1,395,000
Total net unrealized (gains) losses included in general and administrative expense in earnings	64,000
Net purchases, issuances, sales and settlements	(511,000)	(507,000)	1,395,000
Ending balance	$ 441,000	$ 888,000	$ 1,395,000