Goodwill - Additional Disclosures (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013 segment
Goodwill [Line Items]
Goodwill acquired	$ 39,328
Number of Operating Segments with Goodwill Balance	2
Chemical Technologies [Member]
Goodwill [Line Items]
Goodwill acquired	18,686
Non-Energy Chemical Technologies [Member]
Goodwill [Line Items]
Goodwill acquired	$ 20,642