Investments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2011 Joint Venture Saudi Organometallic Chemicals Company [Member]	Mar. 31, 2012 Stannica LLC [Member]	Dec. 31, 2011 Stannica LLC [Member]
Schedule of Investments [Line Items]
Carrying value of unconsolidated investment		$ 6.6	$ 7.3
Capital contributions in joint venture	$ 10.7
Ownership percentage, joint venture	50.00%