Fair Value - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2016	Jul. 31, 2015	Jul. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Adjustments in contingent consideration	$ 141	$ (62)	$ 125
Fair value of contingent consideration obligation, short-term	4,534
Fair value of contingent consideration obligation, long-term	7,705	2,000
PocketSonics
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Adjustments in contingent consideration	0	(100)
Fair value of contingent consideration obligation, short-term	2,000	2,000
Fair value of contingent consideration obligation, long-term	2,000	$ 2,000
Oncura
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Adjustments in contingent consideration	100
Fair value of contingent consideration obligation, short-term	2,500
Fair value of contingent consideration obligation, long-term	$ 7,700