Industry Segment and Foreign Operations - Goodwill (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)
Goodwill [Roll Forward]
Balance at January 1, 2020	$ 375,061
Foreign currency translation	(2,144)
Balance at September 30, 2020	372,917
Polymer
Goodwill [Roll Forward]
Balance at January 1, 2020	0
Balance at September 30, 2020	0
Chemical
Goodwill [Roll Forward]
Balance at January 1, 2020	375,061
Balance at September 30, 2020	$ 372,917