Acquisitions - Additional Information (Detail)						1 Months Ended	3 Months Ended		12 Months Ended
	Mar. 31, 2019 EUR (€)	Oct. 31, 2018 USD ($) shares	Dec. 30, 2016 shares	Sep. 21, 2015 USD ($) shares	Sep. 21, 2015 EUR (€) shares	Jan. 31, 2017 EUR (€)	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)	Mar. 31, 2019 EUR (€)
Business Acquisition [Line Items]
Additional consideration payable in cash, stock or cash and stock							$ 11,635,000		$ 10,637,000
Revenue							2,181,000	$ 4,767,000
Net loss							(22,525,000)	$ (882,000)
Medical Surgery Technologies Ltd. [Member]
Business Acquisition [Line Items]
Cash consideration		$ 5,800,000
Acquisition agreement, description		The Lock-Up Agreement further provides that the Seller may sell, transfer or convey: (i) no more than 50% of the Securities Consideration during the period commencing on the six-month anniversary of the Closing Date and ending on the twelve-month anniversary of the Closing Date; and (ii) no more than 75% of the Securities Consideration during the period commencing on the twelve-month anniversary of the Closing Date and ending on the eighteen-month anniversary of the Closing Date. The restrictions on transfer contained in the Lock-Up Agreement cease to apply to the Securities Consideration following the eighteen-month anniversary of the closing date of the MST Acquisition, or earlier upon certain other conditions.
In-process research and development		$ 10,633,000
Revenue							0
Net loss							600,000
Medical Surgery Technologies Ltd. [Member] | Ending on Twelve Month Anniversary [Member] | Maximum [Member]
Business Acquisition [Line Items]
Percentage of securities consideration		50.00%
Medical Surgery Technologies Ltd. [Member] | Ending on Eighteen Month Anniversary [Member] | Maximum [Member]
Business Acquisition [Line Items]
Percentage of securities consideration		75.00%
Medical Surgery Technologies Ltd. [Member] | First Tranche [Member]
Business Acquisition [Line Items]
Cash consideration		$ 5,800,000
Common shares issued | shares		3,150,000
Medical Surgery Technologies Ltd. [Member] | Second Tranche [Member]
Business Acquisition [Line Items]
Additional consideration payable in cash, stock or cash and stock		$ 6,600,000
Senhance Surgical Robotic System Acquisition [Member]
Business Acquisition [Line Items]
Common shares issued | shares				15,543,413	15,543,413
Additional consideration payable in cash, stock or cash and stock							11,600,000		$ 10,600,000
Senhance Surgical Robotic System Acquisition [Member] | U.S. Dollars [Member]
Business Acquisition [Line Items]
Cash consideration				$ 25,000,000
Senhance Surgical Robotic System Acquisition [Member] | Euro [Member]
Business Acquisition [Line Items]
Cash consideration | €					€ 27,500,000
Senhance Surgical Robotic System Acquisition [Member] | Second Tranche [Member]
Business Acquisition [Line Items]
Cash consideration | €	€ 15,100,000
Common shares issued | shares			3,722,685
Aggregate fair market value | €						€ 5,000,000
Senhance Surgical Robotic System Acquisition [Member] | Second Tranche [Member] | U.S. Dollars [Member]
Business Acquisition [Line Items]
Cash consideration payable							$ 25,000,000
Senhance Surgical Robotic System Acquisition [Member] | Second Tranche [Member] | Euro [Member]
Business Acquisition [Line Items]
Cash consideration payable | €										€ 22,500,000
Senhance Surgical Robotic System Acquisition [Member] | Third Tranche [Member]
Business Acquisition [Line Items]
Cash consideration payable | €										15,000,000
Senhance Surgical Robotic System Acquisition [Member] | Third Tranche [Member] | Minimum [Member]
Business Acquisition [Line Items]
Target revenue to be achieved | €										€ 25,000,000