Earnings Per Share (Schedule Of Computation Of Earnings Per Share And Effect On Weighted-Average Number Of Shares) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Oct. 02, 2020	Sep. 27, 2019	Oct. 02, 2020	Sep. 27, 2019
Numerator:
Net income attributable to Trimble Inc.	$ 84.7		$ 209.6	$ 235.0
Denominator:
Weighted average number of common shares used in basic earnings per share (in shares)	250.7	250.4	250.4	251.2
Effect of dilutive securities (in shares)	2.1	1.7	1.5	2.2
Weighted average number of common shares and dilutive potential common shares used in diluted earnings per share (in shares)	252.8	252.1	251.9	253.4
Basic earnings per share (in dollars per share)	$ 0.34	$ 0.31	$ 0.84	$ 0.94
Diluted (in dollars per share)	$ 0.34	$ 0.31	$ 0.83	$ 0.93
Antidilutive shares (in shares)	0.3	0.1	1.1	0.3