Net Income Per Share - Computation Of Basic And Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net income attributable to Intuitive Surgical, Inc.	$ 292.5	$ 292.5	$ 255.3	$ 287.6	$ (31.5)	$ 298.6	$ 223.0	$ 180.8	$ 1,127.9	$ 670.9	$ 738.3
Weighted-average shares outstanding basic (shares)									113.7	111.7	114.9
Add: Dilutive potential shares									5.1	4.6	3.0
Weighted-average shares used in computing diluted net income per share (shares)									118.8	116.3	117.9
Basic net income per share (usd per share)	$ 2.56	$ 2.57	$ 2.25	$ 2.55	$ (0.28)	$ 2.67	$ 2.01	$ 1.62	$ 9.92	$ 6.01	$ 6.43
Diluted net income per share (usd per share)	$ 2.45	$ 2.45	$ 2.15	$ 2.44	$ (0.28)	$ 2.56	$ 1.94	$ 1.57	$ 9.49	$ 5.77	$ 6.26