Fair Value - Quantitative Information about Inputs and Valuation Methodologies Used for Fair Value Measurements Classified in Level 3 (Detail) - ALF-X Surgical Robotic System Acquisition [Member] - Fair Value, Inputs, Level 3 [Member] - Contingent Consideration [Member]	12 Months Ended
	Dec. 31, 2015
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Probability of occurrence	100.00%
Minimum [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Milestone dates	2016
Discount rate	7.50%
Maximum [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Milestone dates	2017
Discount rate	9.00%