Fair Value - Quantitative Information about Inputs and Valuation Methodologies Used for Fair Value Measurements Classification (Detail) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($) $ / shares
Senhance Surgical Robotic System Acquisition | Significant Unobservable Inputs (Level 3) | Contingent Consideration | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.1075	0.1075
Senhance Surgical Robotic System Acquisition | Significant Unobservable Inputs (Level 3) | Contingent Consideration | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	0.1575	0.1575
Series B Warrant
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value | $	$ 0.1	$ 2.4
Share price (in dollars per share) | $ / shares	$ 0.35	$ 1.47
Probability of additional financing	100.00%	100.00%
Series B Warrant | Measurement Input, Expected Term
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Term	2 years 1 month 6 days	2 years 3 months 18 days
Series B Warrant | Measurement Input, Risk Free Interest Rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant fair value measurement input	0.0023	0.0159
Series B Warrant | Measurement Input, Expected Dividend Payment
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant fair value measurement input	0	0
Series B Warrant | Measurement Input, Price Volatility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant fair value measurement input	0.85	1.0980