Selected Quarterly Financial Data (Schedule Of Selected Quarterly Financial Data) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 28, 2012	Sep. 28, 2012	Jun. 29, 2012	Mar. 30, 2012	Dec. 30, 2011	Sep. 30, 2011	Jul. 01, 2011	Apr. 01, 2011	Dec. 28, 2012		Dec. 30, 2011		Dec. 31, 2010
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 515,523	$ 504,763	$ 517,560	$ 502,267	$ 435,170	$ 417,433	$ 407,169	$ 384,293	$ 2,040,113	[1]	$ 1,644,065	[1]	$ 1,293,937	[1]
Gross margin	256,463	262,867	267,696	259,150	217,758	211,559	208,734	191,530	1,046,177		829,581		645,501
Net income attributable to Trimble Navigation Ltd.	$ 33,185	$ 53,364	$ 53,692	$ 50,818	$ 29,403	$ 27,971	$ 53,678	$ 39,703	$ 191,060		$ 150,755		$ 103,660
Basic net income per share	$ 0.26	$ 0.42	$ 0.43	$ 0.41	$ 0.24	$ 0.23	$ 0.44	$ 0.33	$ 1.52		$ 1.23		$ 0.86
Diluted net income per share	$ 0.26	$ 0.42	$ 0.42	$ 0.40	$ 0.23	$ 0.22	$ 0.43	$ 0.32	$ 1.49		$ 1.20		$ 0.84

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