Restructuring Expenses - Narrative (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2018 USD ($) plant	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) kmt
Restructuring Cost and Reserve [Line Items]
Restructuring income		$ 0	$ 40,253,000	$ 0
Restructuring expenses	$ 7,200,000	3,080,000	15,620,000	6,492,000
Number of plants consolidated | plant	2
Restructuring expenses (income), net		3,600,000	(24,600,000)	6,500,000
Personnel expenses
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 4,400,000	$ 2,801,000	$ 7,586,000	$ 2,975,000
Rubber Carbon Black
Restructuring Cost and Reserve [Line Items]
Standard rubber grade (kmt) | kmt					50
Impairment of property plant and equipment					$ 10,300,000
Estimated recoverable amount					$ 0