Fair Value Measurements - Additional Information (Detail)	3 Months Ended	9 Months Ended
	Apr. 30, 2017 USD ($)	Apr. 30, 2017 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Adjustments in contingent consideration		$ (10,238,000)
PocketSonics
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Adjustments in contingent consideration	$ 0	0
Contingent consideration paid for business acquisitions	2,000,000
Oncura
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Adjustments in contingent consideration	(2,100,000)	(10,200,000)
Fair value of contingent consideration obligation	$ 0	$ 0