Revisions to Previously Reported Financial Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 02, 2015	Oct. 03, 2014	Oct. 02, 2015	Oct. 03, 2014	Jan. 02, 2015	Jan. 03, 2014	Dec. 28, 2012
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Goodwill	$ 2,083.7		$ 2,083.7		$ 2,085.8
Total assets	3,719.9		3,719.9		3,858.9
Accumulated other comprehensive loss	(147.0)		(147.0)		(76.7)
Total Trimble Navigation Ltd. shareholders' equity	2,202.2		2,202.2		2,341.6
Total equity	2,203.2		2,203.2		2,353.4
Total Liabilities and Equity	3,719.9		3,719.9		3,858.9
Net income	37.0	$ 11.8	96.8	$ 158.0
Foreign currency translation adjustments	(15.3)	(63.9)	(70.5)	(64.6)
Net unrealized actuarial gain	0.0	0.1	0.2	0.1
Comprehensive Income (Loss)	21.7	(52.0)	26.5	93.5
Less: Comprehensive loss attributable to noncontrolling interests	(0.1)	0.0	(0.3)	(0.3)
Comprehensive Income (Loss) attributable to Trimble Navigation Ltd.	$ 21.8	(52.0)	$ 26.8	93.8
As previously reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Goodwill					2,101.2
Total assets					3,874.3
Accumulated other comprehensive loss					(61.3)
Total Trimble Navigation Ltd. shareholders' equity					2,357.0
Total equity					2,368.8
Total Liabilities and Equity					3,874.3
Net income		11.8		158.0
Foreign currency translation adjustments		(60.5)		(62.9)
Net unrealized actuarial gain		0.1		0.1
Comprehensive Income (Loss)		(48.6)		95.2
Less: Comprehensive loss attributable to noncontrolling interests		0.0		(0.3)
Comprehensive Income (Loss) attributable to Trimble Navigation Ltd.		(48.6)		95.5
Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Goodwill					(15.4)
Total assets					(15.4)
Accumulated other comprehensive loss					(15.4)
Total Trimble Navigation Ltd. shareholders' equity					(15.4)
Total equity					(15.4)
Total Liabilities and Equity					(15.4)
Net income		0.0		0.0
Foreign currency translation adjustments		(3.4)		(1.7)	$ (11.2)	$ (4.0)	$ 10.7
Net unrealized actuarial gain		0.0		0.0
Comprehensive Income (Loss)		(3.4)		(1.7)
Less: Comprehensive loss attributable to noncontrolling interests		0.0		0.0
Comprehensive Income (Loss) attributable to Trimble Navigation Ltd.		$ (3.4)		$ (1.7)