Equity Investees (Details Textual) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Schedule of Equity Method Investments [Line Items]
Income (loss) from affiliates and joint ventures	$ 5,566	$ (11,261)	$ 115
Equity Investees (Textual) [Abstract]
Equity method investments		0
Albagle Enterprise Limited [Member]
Schedule of Equity Method Investments [Line Items]
Income (loss) from affiliates and joint ventures		7,196
Ashapura AMCOL N.V. [Member]
Schedule of Equity Method Investments [Line Items]
Income (loss) from affiliates and joint ventures		6,875
Loss from sale of joint venture and affiliated entities	$ 2,104