Income Per Share (Schedule Of Computation Of Earnings Per Share And Effect On Weighted-Average Number Of Shares) (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 03, 2014	Sep. 27, 2013	Oct. 03, 2014	Sep. 27, 2013
Income Per Share [Line Items]
Net income attributable to Trimble Navigation Ltd.	$ 11,832	$ 54,469	$ 158,290	$ 158,858
Weighted average number of common shares used in basic income per share	260,329	257,037	260,398	256,135
Effect of dilutive securities	4,090	4,100	4,655	4,529
Weighted average number of common shares and dilutive potential common shares used in diluted income per share	264,419	261,137	265,053	260,664
Basic income per share	$ 0.05	$ 0.21	$ 0.61	$ 0.62
Diluted income per share	$ 0.04	$ 0.21	$ 0.60	$ 0.61