Goodwill and Other Intangible Assets (Details) (USD $)	3 Months Ended
	Mar. 31, 2013 Segment	Mar. 31, 2012
Goodwill and Other Intangible Assets
Impairment of goodwill	$ 0
Number of operating segments	10
Number of reportable segments	4
Changes in the carrying amount of goodwill
Beginning goodwill, net	5,920,500,000
Current year business acquisitions	33,300,000
Effect of foreign currency translation	(45,300,000)
Ending goodwill, net	5,908,500,000
Total amortization expense related to other intangible assets	60,500,000	59,300,000
Future estimated expense related to amortizable other identifiable intangible assets
2013 (Remainder: nine-month period)	182,000,000
2014	227,000,000
2015	225,000,000
2016	220,000,000
2017	217,000,000
Nalco Holding Company ("Nalco")
Changes in the carrying amount of goodwill
Ending goodwill, net	4,500,000,000
Nalco Holding Company ("Nalco") | Trademarks
Changes in the carrying amount of goodwill
Carrying value of asset subject to impairment testing	1,200,000,000
Impairment of indefinite life intangible asset	0
Global Industrial
Changes in the carrying amount of goodwill
Beginning goodwill, net	2,750,000,000
Current year business acquisitions	33,300,000
Effect of foreign currency translation	(21,200,000)
Ending goodwill, net	2,762,100,000
Global Institutional
Changes in the carrying amount of goodwill
Beginning goodwill, net	725,000,000
Effect of foreign currency translation	(5,500,000)
Ending goodwill, net	719,500,000
Global Energy
Changes in the carrying amount of goodwill
Beginning goodwill, net	2,325,300,000
Effect of foreign currency translation	(17,700,000)
Ending goodwill, net	2,307,600,000
Other
Changes in the carrying amount of goodwill
Beginning goodwill, net	120,200,000
Effect of foreign currency translation	(900,000)
Ending goodwill, net	$ 119,300,000