Fair Value Measurements - Level 3 Liabilities (Details) - Level 3 - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3
Beginning balance	$ 1,298	$ 1,138	$ 1,579
Original fair value of contingent consideration		1,292
Loss included in general and administrative expense	113	6	(265)
Net purchases, issuances, sales and settlements		(1,138)	(176)
Ending balance	1,411	1,298	1,138
Contingent Consideration | Aexis Medical
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3
Beginning balance	1,298	0	0
Original fair value of contingent consideration		1,292
Loss included in general and administrative expense	113	6	0
Net purchases, issuances, sales and settlements		0	0
Ending balance	1,411	1,298	0
Assumed Contingent Obligation | Jet Prep Ltd.
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3
Beginning balance	0	1,138	1,138
Original fair value of contingent consideration		0
Loss included in general and administrative expense	0	0	0
Net purchases, issuances, sales and settlements		(1,138)	0
Ending balance	0	0	1,138
Contingent Guaranteed Obligation | Cantel Medical (UK)
Reconciliation of liability measured and recorded at fair value on a recurring basis using Level 3
Beginning balance	0	0	441
Original fair value of contingent consideration		0
Loss included in general and administrative expense	0	0	(265)
Net purchases, issuances, sales and settlements		0	(176)
Ending balance	$ 0	$ 0	$ 0