Fair Value Measurements (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions		Jan. 03, 2020	Dec. 28, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent Consideration, Liabilities	[1]	$ 19.9	$ 5.6
Level III
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent Consideration, Liabilities	[1]	19.9	5.6
Deferred Compensation Plan Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure	[2]	36.2	28.5
Deferred Compensation Plan Liabilities [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Financial Liabilities Fair Value Disclosure	[2]	36.2	28.5
Derivative Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	[3]	1.0	0.0
Derivative Liabilities [Member] | Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contracts, Liability, Fair Value Disclosure	[3]	1.0	0.0
Deferred Compensation Plan Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	[2]	36.2	28.5
Deferred Compensation Plan Assets [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets	[2]	36.2	28.5
Derivative Financial Instruments, Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	[3]	0.3	0.4
Derivative Financial Instruments, Assets [Member] | Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign Currency Contract, Asset, Fair Value Disclosure	[3]	0.3	0.4
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets		36.5	28.9
Financial Liabilities Fair Value Disclosure		57.1	34.1
Fair Value, Recurring [Member] | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets		36.2	28.5
Financial Liabilities Fair Value Disclosure		36.2	28.5
Fair Value, Recurring [Member] | Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets		0.3	0.4
Financial Liabilities Fair Value Disclosure		1.0	0.0
Fair Value, Recurring [Member] | Level III
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets			0.0
Financial Liabilities Fair Value Disclosure		$ 19.9	$ 5.6

[1] Contingent consideration liabilities represent arrangements to pay the former owners of certain companies that Trimble acquired. The undiscounted maximum payment under the arrangements is $33.7 million at the end of fiscal 2019. The fair values are estimated using scenario-based methods or option pricing methods based upon estimated future revenue, gross margin, or other milestones. At the end of fiscal 2019, the Company had $13.7 million included in Other current liabilities and $6.2 million included in Other non-current liabilities on the Company's Consolidated Balance Sheets.

[2] The Company maintains a self-directed, non-qualified deferred compensation plan for certain executives and other highly compensated employees. The plan assets and liabilities are invested in actively traded mutual funds and individual stocks valued using observable quoted prices in active markets. Deferred compensation plan assets and liabilities are included in Other non-current assets and Other non-current liabilities, respectively, on the Company's Consolidated Balance Sheets.

[3] Derivative assets and liabilities primarily represent forward currency exchange contracts. The Company typically enters into these contracts to minimize the short-term impact of foreign currency exchange rates on certain trade and inter-company receivables and payables. Derivative assets and liabilities are included in Other current assets and Other current liabilities on the Company's Consolidated Balance Sheets.