Selected Quarterly Financial Data (Schedule Of Selected Quarterly Financial Data) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Jan. 01, 2016	Oct. 02, 2015	Jul. 03, 2015	Apr. 03, 2015	Jan. 02, 2015	Oct. 03, 2014	Jul. 04, 2014	Apr. 04, 2014	Jan. 01, 2016		Jan. 02, 2015		Jan. 03, 2014
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 559.7	$ 562.3	$ 585.8	$ 582.6	$ 563.8	$ 584.8	$ 642.2	$ 604.7	$ 2,290.4	[1]	$ 2,395.5	[1]	$ 2,288.1	[1]
Gross margin	293.1	298.0	303.9	307.2	292.5	316.8	354.6	326.9	1,202.2		1,290.8		1,203.8
Net income attributable to Trimble Navigation Limited	$ 24.0	$ 37.1	$ 25.9	$ 34.1	$ 55.8	$ 11.8	$ 77.9	$ 68.6	$ 121.1		$ 214.1		$ 218.9
Basic net income per share	$ 0.10	$ 0.15	$ 0.10	$ 0.13	$ 0.22	$ 0.05	$ 0.30	$ 0.26	$ 0.47		$ 0.82		$ 0.85
Diluted net income per share	$ 0.09	$ 0.14	$ 0.10	$ 0.13	$ 0.21	$ 0.04	$ 0.29	$ 0.26	$ 0.47		$ 0.81		$ 0.84

[1] Revenue is attributed to countries based on the location of the customer.