Goodwill, In-Process Research and Development and Intellectual Property - Additional Information (Detail) - USD ($)			1 Months Ended	3 Months Ended		12 Months Ended
	Oct. 31, 2018	Sep. 21, 2015	Nov. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2009
Goodwill And Intangible Assets [Line Items]
Goodwill						$ 80,131,000	$ 71,368,000	$ 68,697,000	$ 130,869,000
Accumulated impairment of goodwill						61,800,000	61,800,000
Goodwill impairment				$ 0	$ 61,800,000	0	0	61,784,000
In-Process Research and Development [Member]
Goodwill And Intangible Assets [Line Items]
Discount rate	15.00%	45.00%
Patents [Member]
Goodwill And Intangible Assets [Line Items]
Patent purchased amount										$ 5,000,000
Patents [Member] | SurgiBot System [Member]
Goodwill And Intangible Assets [Line Items]
Write-off of intellectual property						0	0	$ 1,600,000
Intellectual Property [Member]
Goodwill And Intangible Assets [Line Items]
Discount rate		45.00%
Patent purchased amount						66,813,000	66,813,000
Technology and Patents Purchased [Member]
Goodwill And Intangible Assets [Line Items]
Patent purchased amount						$ 400,000	400,000
Weighted average remaining useful life						8 years 3 months 18 days
Developed Technology [Member]
Goodwill And Intangible Assets [Line Items]
Patent purchased amount						$ 66,413,000	66,413,000
Weighted average remaining useful life						3 years 9 months 18 days
Safe Stitch Medical Inc [Member]
Goodwill And Intangible Assets [Line Items]
Goodwill						$ 93,800,000
Senhance Surgical Robotic System Acquisition [Member]
Goodwill And Intangible Assets [Line Items]
Goodwill		$ 38,348,000				38,300,000
Intellectual property		48,500,000
Acquisition price		92,577,000	$ 400,000
Senhance Surgical Robotic System Acquisition [Member] | In-Process Research and Development [Member]
Goodwill And Intangible Assets [Line Items]
In-process research and development		$ 17,100,000
Senhance Surgical Robotic System Acquisition [Member] | Technology and Patents Purchased [Member]
Goodwill And Intangible Assets [Line Items]
Acquisition price							$ 400,000
Medical Surgery Technologies Ltd. [Member]
Goodwill And Intangible Assets [Line Items]
Goodwill	$ 9,638,000					$ 9,600,000
Acquisition price	20,314,000
Medical Surgery Technologies Ltd. [Member] | In-Process Research and Development [Member]
Goodwill And Intangible Assets [Line Items]
In-process research and development	$ 10,600