Condensed Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Equity Method Investment	$ 22,324				$ 22,324		$ 20,354
Prior Period Reclassification Adjustment		$ 3,600
Revenue Recognized Under Net Reporting Arrangements	11,000		$ 12,200		22,100	$ 24,100
Kelko (Venezuela) [Member]
Schedule of Equity Method Investments [Line Items]
Effect Of Currency Conversion, Amount		$ 100		$ 2,800
Effect Of Currency Conversion, Per Diluted Share		$ 0.01		$ 0.21
Equity Method Investment	$ 100				$ 100		$ 200