Acquisitions and Dispositions (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended					0 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012	Jun. 30, 2013 Five year 2012 senior notes	Jun. 30, 2013 Term loan	Apr. 10, 2013 Champion	Jun. 30, 2013 Champion	Dec. 31, 2012 Champion	Apr. 30, 2013 Champion Term loan
Acquisitions and Dispositions
Estimated annual sales pre-acquisition										$ 1,300
Cash consideration								1,429.9
Stock consideration
Ecolab shares issued to Champion shareholders								6.6
Ecolab's closing stock price on April 10, 2013 (in dollars per share)								$ 82.31
Total fair value of stock consideration								543.0
Total consideration transferred								1,972.9
Period of escrow deposit								2 years
Portion of consideration transferred and deposited in an escrow account to fund post-closing adjustments to the consideration and covenant and other indemnification obligations								100
Acquisition and integration costs									47.9
Inventories at FIFO cost	1,396.3		1,396.3		1,112.6				13.6
Special (gains) and charges related to merger and integration charges, closing costs and advisory fees	73.6	41.6	123.3	83.0					31.8
Net interest expense related to interest expense through the close date of the acquisition	68.8	66.1	133.8	154.8					2.5
Long-term debt, aggregate principal amount						$ 500	$ 900		$ 500	$ 500	$ 900
Interest rate (as a percent)						1.45%