Restructuring Of Operations (Aggregate Pre-Tax Restructuring Charges (Credits) In Consolidated Statements Of Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Restructuring Cost And Reserve [Line Items]
Restructuring charges (credits)	$ 3.3	$ (0.7)	$ 21.6
Manufacturing Cost Of Sales [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges (credits)	1.2	(0.1)
Selling And Technical Services [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges (credits)	1.6	0
Research And Process Development [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges (credits)	0.4	(0.4)
Administrative And General [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges (credits)	$ 0.1	$ (0.2)