Business Overview - Narrative (Details) $ in Millions			3 Months Ended		9 Months Ended
	Oct. 09, 2020	Jan. 01, 2020 USD ($)	Sep. 25, 2020 USD ($)	Sep. 27, 2019 USD ($)	Sep. 25, 2020 USD ($)	Sep. 27, 2019 USD ($)	Oct. 15, 2020 JPY (¥)	Sep. 25, 2020 JPY (¥)	Dec. 31, 2019 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
(Loss) gain in OCI related to net investment hedge			$ (2.0)	$ 10.3	$ 2.0	$ 10.4
Accounting Standards Update [Extensible List]		us-gaap:AccountingStandardsUpdate201613Member
Allowance for accounts, unbilled and financing receivables			126.3		126.3				$ 82.1
Retained earnings			$ 4,372.7		$ 4,372.7				4,128.8
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for accounts, unbilled and financing receivables		$ 40.0							$ 40.0
Retained earnings		$ (31.3)
Yen variable interest rate term loan due 2022
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Term loan facility, aggregate amount | ¥								¥ 13,800,000,000
Subsequent Event | Vontier
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Percentage of shares distributed in separation	80.10%
Distribution ratio of Voniter shares	0.4
ftv_DiscontinuedOperationEquityInvestmentRetainedAfterDisposalOwnershipInterestAfterDisposal	19.90%
Subsequent Event | Yen variable interest rate term loan due 2022
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Term loan facility, aggregate amount | ¥							¥ 13,800,000,000