Restructuring - Additional Information (Detail) - Headcount, Discontinued Efforts and Cancellation of Contracts [Member] - SurgiBot System [Member] $ in Millions	1 Months Ended
	May 31, 2016 USD ($)
Restructuring Cost And Reserve [Line Items]
Restructuring charges	$ 5.7
Inventory write-down related to restructuring	2.6
Restructuring and other charges	3.1
Restructuring amount paid in cash	0.5
Employee severance costs	0.4
Restructuring and other charges related to cancellation of contracts	0.1
Restructuring and other charges related to other non-cash charges	2.6
Disposal of long-lived assets	1.0
Patents [Member]
Restructuring Cost And Reserve [Line Items]
Write-off of intellectual property	$ 1.6