Commitments and Contingencies - Additional Information (Detail)		9 Months Ended
	Sep. 21, 2015 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2015 EUR (€)
Operating Leased Assets [Line Items]
Fair value of contingent consideration		$ 24,300,000
ALF-X Surgical Robotic System Acquisition [Member]
Operating Leased Assets [Line Items]
Fair value of contingent consideration	$ 24,300,000	24,300,000
ALF-X Surgical Robotic System Acquisition [Member] | Maximum [Member]
Operating Leased Assets [Line Items]
Aggregate milestone payments | €			€ 27,500,000
ALF-X Surgical Robotic System Acquisition [Member] | License and Supply Agreements [Member]
Operating Leased Assets [Line Items]
Commitments under agreements, remainder of 2015		250,000
Commitments under agreements, in 2016		850,000
Commitments under agreements, in 2017		950,000
Commitments under agreements, in 2018		675,000
Commitments under agreements, thereafter until termination in 2027		$ 3,400,000