OEM Partner Agreements (Details) $ in Thousands	12 Months Ended
	Jul. 31, 2015 USD ($) Partner	Jul. 31, 2014 USD ($)	Jul. 31, 2013 USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of U.S. based national and international marketing partners | Partner	2
Net sales	$ 75,019	$ 64,769	$ 62,796
Codman Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Numbers of years a product was sold	30 years
Net sales	$ 17,323	$ 15,173	$ 14,097
percent of net sales (in hundredths)	23.10%	23.40%	22.40%
Codman Collaborative Arrangement [Member] | Bipolar Generators and Related Disposables and Accessories [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement time frame	3 years
Collaborative arrangements extension	3 years
Codman Collaborative Arrangement [Member] | Malis Spetzler Trademark [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaborative arrangement time frame	3 years
Collaborative arrangements extension	3 years
Stryker Collaborative Arrangement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Net sales	$ 13,507	$ 10,779	$ 10,815
percent of net sales (in hundredths)	18.00%	16.60%	17.20%