Goodwill and Other Intangible Assets (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Acquired Finite-Lived Intangible Assets [Line Items]
Other intangible assets	$ 7,585	$ 8,950	$ 32,264	$ 130,612
SemMexico [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Other intangible assets	7,549	8,907
Corporate and other [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Other intangible assets	$ 36	$ 43