Goodwill (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Dec. 31, 2010
Summary of Goodwill
At January 1 Gross cost			$ 674.0	$ 674.1
Exchange effect			0.1	0.2
At September 30 Gross cost	674.1	674.3	674.1	674.3
Accumulated impairment of Octane Additives segment goodwill at January 1			(234.0)	(232.0)
Impairment of Octane Additives segment goodwill	(0.3)	(0.6)	(0.9)	(1.7)
Accumulated impairment of Octane Additives segment goodwill at September 30	(234.9)	(233.7)	(234.9)	(233.7)
Total	439.2	440.6	439.2	440.6	440.0	442.1
Accumulated amortization at January 1			(298.5)	(298.5)
Exchange effect			(0.2)	(0.2)
Accumulated amortization at September 30	(298.7)	(298.7)	(298.7)	(298.7)
Goodwill	140.5	141.9	140.5	141.9	141.5
Octane Additives [Member]
Summary of Goodwill
Goodwill	1.5	2.9	1.5	2.9
Fuel Specialties and Performance Chemicals Segments [Member]
Summary of Goodwill
Goodwill	$ 139.0	$ 139.0	$ 139.0	$ 139.0