Condensed Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Equity Method Investment	$ 20,078			$ 20,078		$ 21,751
Revenue Recognized Under Net Reporting Arrangements	12,188		$ 10,926	24,053	$ 21,499
Kelko (Venezuela) [Member]
Schedule of Equity Method Investments [Line Items]
Effect Of Currency Conversion, Amount		$ 2,806	$ 321
Effect Of Currency Conversion, Per Diluted Share		$ 0.21	$ 0.02
Equity Method Investment	$ 143			$ 143