Discontinued Operations (Narrative) (Details) $ / shares in Units, shares in Millions, $ in Millions	1 Months Ended			3 Months Ended		6 Months Ended		9 Months Ended		12 Months Ended
	Aug. 31, 2016 USD ($)	Jun. 30, 2016 USD ($)	Jul. 31, 2015 USD ($) shares	Sep. 30, 2016 USD ($)	Oct. 02, 2015 USD ($)	Jul. 01, 2016 USD ($)	Jul. 14, 2015 USD ($)	Sep. 30, 2016 USD ($)	Oct. 02, 2015 USD ($) shares	Dec. 31, 2015 USD ($) $ / shares	Dec. 31, 2014 USD ($)	Jun. 15, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Separation, Fortive shares distributed per Danaher share, ratio												0.5
Long-term debt				$ 8,312.2				$ 8,312.2		$ 12,870.4
Extinguishment of debt, amount	$ 1,900.0
Make-whole premiums to redeem borrowings prior to maturity	$ (188.0)			(188.0)				(188.1)	$ 0.0
Discontinued operations, sales				0.0	$ 1,524.6			3,029.8	$ 4,948.5
Shares held as Treasury shares | shares									26.0
Shares redeemed through the distribution of the communications business (26.0 shares held as Treasury shares)								0.0	$ (2,291.7)
Fortive
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Long-term debt		$ 3,400.0
Separation, Fortive's cash payments to Danaher prior to distribution date		3,000.0
Discontinued operations, sales						$ 3,000.0				6,100.0
Separation-related expenses				22.0				48.0
Discontinued operations | Communications business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued operations, sales							$ 346.0				$ 760.0
Shares held as Treasury shares | shares			26.0
Shares redeemed through the distribution of the communications business (26.0 shares held as Treasury shares)			$ (2,300.0)
Disposition of communications business, aggregate consideration number of Netscout shares received | shares			62.5
Disposition of communications business, percentage of investment ownership			60.00%
Aggregate after-tax gain on disposition										$ 767.0
After-tax gain on sale upon closing of transaction, per diluted share | $ / shares										$ 1.08
Senior notes | 2.3% senior unsecured notes due 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Long-term debt				$ 0.0				$ 0.0		$ 500.0
Debt Instrument, face value		$ 500.0
Interest rate of debt instrument		2.30%		2.30%				2.30%
Senior notes | 5.625% senior unsecured notes due 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Long-term debt				$ 0.0				$ 0.0		500.0
Interest rate of debt instrument				5.625%				5.625%
Senior notes | 5.4% senior unsecured notes due 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Long-term debt				$ 0.0				$ 0.0		750.0
Interest rate of debt instrument				5.40%				5.40%
Senior notes | 3.9% senior unsecured notes due 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Long-term debt				$ 0.0				$ 0.0		$ 600.0
Interest rate of debt instrument				3.90%				3.90%