Business Combinations (Narrative) (Details) In Millions, except Per Share data, unless otherwise specified	3 Months Ended												12 Months Ended			9 Months Ended		12 Months Ended				9 Months Ended		6 Months Ended	12 Months Ended			6 Months Ended	5 Months Ended
	Sep. 30, 2012 USD ($)		Jun. 30, 2012 USD ($)		Mar. 31, 2012 USD ($)		Dec. 31, 2011 USD ($)		Sep. 30, 2011 USD ($)	Jun. 30, 2011 USD ($)	Mar. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Sep. 30, 2012 USD ($)	Sep. 30, 2011 USD ($)	Sep. 30, 2010 USD ($)	Jul. 03, 2012 Indura [Member] USD ($)	Jul. 03, 2012 Indura [Member] CLP	Sep. 30, 2012 Indura [Member] USD ($)	Jul. 01, 2012 Indura [Member]	Sep. 30, 2012 Indura [Member] Debt Issuance Cost [Member] USD ($)	Sep. 30, 2012 Indura [Member] Selling And Administrative Expense [Member] USD ($)	Jul. 03, 2012 Indura [Member] Customer Relationships [Member] USD ($)	Jul. 03, 2012 Indura [Member] Trade names and trademarks [Member] USD ($)	Apr. 02, 2012 DANanoMaterials [Member] USD ($)	Sep. 30, 2012 DANanoMaterials [Member] USD ($)	Dec. 31, 2011 DANanoMaterials [Member] USD ($)	Feb. 29, 2012 DANanoMaterials [Member]	Apr. 02, 2012 DANanoMaterials [Member] Customer Relationships [Member]	Mar. 01, 2010 SAGA [Member] USD ($)	Nov. 30, 2010 SAGA [Member] USD ($)	Nov. 30, 2010 SAGA [Member] EUR (€)	Sep. 30, 2010 SAGA [Member]	Mar. 01, 2010 SAGA [Member] EUR (€)
Business Acquisition [Line Items]
Percentage of shares purchased																13.00%	13.00%		51.80%								50.00%		51.47%			100.00%
Percentage of results consolidated																100.00%	100.00%
Cash consideration																$ 690.0	345,500.0													$ 62.0	€ 44.8
Acquired debt																227	113,800
Additional equity interest committed to purchase																2.00%	2.00%
Agreement to purchase additional equity interest under put option																30.50%	30.50%
Put option exercise period start date																1 July 2015	1 July 2015
Put option exercise period beginning 1 July 2015																2 years	2 years
Acquisition related costs																		11.4		4.9	6.5
Allocation to plant and equipment																402.3								26.0
Allocation to identified intangibles																382.1						287.8	92.6	100.0
Intangibles useful life																						23 years						22 years
Allocation to goodwill																620.8								125.0
Goodwill deductible for tax purposes																0								50.0
Allocation to other net assets																								27
Sales	2,605.8		2,340.1		2,344.3		2,321.5		2,506.2	2,472.0	2,403.0	2,292.5	9,611.7	9,673.7	8,616.1			140.0
Net income (loss) attributable to parent	138.7		484.5		296.0		248.1		324.8	326.5	304.3	268.6	1,167.3	1,224.2	1,029.1			(7.6)
Non-cash charge related to Chilean tax rate change																		14.1
Acquiree revenues for previous calendar year																										90
Purchase price of acquired entity																								158.0					47.2				34.5
Acquisitions, less cash acquired													863.4	10.8	37.2									147.0					25.0
Cash acquired from acquisition																								11.0					22.2
Previous percent ownership																								50.00%
Fair value of previously held equity interest																								120
Gain on previously held equity interest	0	[1]	85.9	[1]	0	[1]	0	[1]					85.9	0	0										85.9
Gain on previously held equity interest, after tax																									$ 54.6
Gain on previously held equity interest, per share																									$ 0.25

[1]   For additional information, see Note 5, Business Combinations.