Goodwill and Other Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended			9 Months Ended								9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 02, 2011	Sep. 30, 2012 Minimum	Sep. 30, 2012 Maximum	Sep. 30, 2012 Nalco Holding Company ("Nalco")	Sep. 30, 2012 Nalco Holding Company ("Nalco") Trademarks	Sep. 30, 2012 U.S. Cleaning and Sanitizing	Dec. 31, 2011 U.S. Cleaning and Sanitizing	Sep. 30, 2012 U.S. Other Services	Dec. 31, 2011 U.S. Other Services	Sep. 30, 2012 Int'l Cleaning, Sanitizing & Other Services	Sep. 30, 2012 Global Water	Sep. 30, 2012 Global Paper	Sep. 30, 2012 Global Energy
Changes in the carrying amount of goodwill
Goodwill impairment test, discount rate used (as a percent)						9.60%	10.40%
Discount rate used in the purchase price allocation (as a percent)					11.50%
Beginning goodwill, net			$ 5,855.3					$ 4,400.0		$ 543.6	$ 543.6	$ 50.5	$ 50.5	$ 857.3	$ 1,933.0	$ 179.3	$ 2,291.6
Current year business acquisitions			23.3											17.2	6.1
Prior year business acquisitions			54.6												24.0	2.2	28.4
Effect of Foreign currency translation			(39.5)											(38.6)	(0.4)		(0.5)
Ending goodwill, net	5,893.7		5,893.7					4,400.0		543.6	543.6	50.5	50.5	835.9	1,962.7	181.5	2,319.5
Carrying value of asset subject to impairment testing									1,200.0
Total amortization expense related to other intangible assets	59.3	13.7	178.0	39.0
Future estimated amortization expense related to amortizable other identifiable intangible assets
2012 (Remainder: three-month period)	60		60
2013	236		236
2014	225		225
2015	222		222
2016	$ 217		$ 217