Consolidated Statements Of Income - USD ($) shares in Millions, $ in Millions		12 Months Ended
		Dec. 28, 2018	Dec. 29, 2017		Dec. 30, 2016
Revenue		$ 3,108.4	$ 2,646.5	[1]	$ 2,362.1	[1]
Cost of Sales		1,427.4	1,268.9	[1]	1,127.6	[1]
Amortization of purchased intangible assets		103.2	85.8	[1]	88.6	[1]
Gross margin		1,681.0	1,377.6	[1]	1,234.5	[1]
Operating expense:
Research and development		446.1	370.2	[1]	349.6	[1]
Sales and marketing		479.8	400.1	[1]	374.7	[1]
General and administrative		349.8	301.7	[1]	256.0	[1]
Restructuring charges		8.2	6.9	[1]	11.6	[1]
Amortization of purchased intangible assets		76.4	63.0	[1]	62.2	[1]
Total operating expense		1,360.3	1,141.9	[1]	1,054.1	[1]
Operating income		320.7	235.7	[1]	180.4	[1]
Non-operating income (expense), net:
Interest expense, net		(73.2)	(25.2)	[1]	(25.9)	[1]
Foreign currency transaction gain (loss), net		0.5	3.3	[1]	(1.9)	[1]
Income from equity method investments, net		28.7	29.5	[1]	17.6	[1]
Other income, net		1.3	4.9	[1]	5.9	[1]
Total non-operating income (expense), net		(42.7)	12.5	[1]	(4.3)	[1]
Income before taxes		278.0	248.2	[1]	176.1	[1]
Income tax provision (benefit)		(5.3)	129.7	[1]	43.9	[1]
Net income	[1]	283.3	118.5		132.2
Net gain (loss) attributable to noncontrolling interests		0.5	0.1	[1]	(0.2)	[1]
Net income attributable to Trimble Inc.		$ 282.8	$ 118.4	[1]	$ 132.4	[1]
Basic earnings per share		$ 1.13	$ 0.47	[1]	$ 0.53	[1]
Shares used in calculating basic earnings per share		250.0	252.1	[1]	250.5	[1]
Diluted earnings per share		$ 1.12	$ 0.46	[1]	$ 0.52	[1]
Shares used in calculating diluted earnings per share		253.4	256.7	[1]	253.9	[1]
Product [Member]
Revenue		$ 1,999.9	$ 1,763.8	[1]	$ 1,570.6	[1]
Cost of Sales		938.9	875.6	[1]	764.0	[1]
Service [Member]
Revenue		588.7	475.4	[1]	436.7	[1]
Cost of Sales		247.3	194.4	[1]	170.1	[1]
Subscription [Member]
Revenue		519.8	407.3	[1]	354.8	[1]
Cost of Sales		$ 138.0	$ 113.1	[1]	$ 104.9	[1]

[1] See Note 2 for a summary of adjustments