Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Percentage of sales	100.00%	100.00%
Sales	$ 302,713	$ 314,895
United States
Disaggregation of Revenue [Line Items]
Sales	230,443	257,642
International
Disaggregation of Revenue [Line Items]
Sales	$ 72,270	$ 57,253
Nylon
Disaggregation of Revenue [Line Items]
Percentage of sales	26.00%	31.00%
Caprolactam
Disaggregation of Revenue [Line Items]
Percentage of sales	22.00%	20.00%
Ammonium Sulfate Fertilizers
Disaggregation of Revenue [Line Items]
Percentage of sales	23.00%	21.00%
Chemical Intermediates
Disaggregation of Revenue [Line Items]
Percentage of sales	29.00%	28.00%