Business Combination, Goodwill and Intangible Assets - Narrative (Details) - USD ($)		3 Months Ended								12 Months Ended
	Oct. 31, 2018	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Aggregate purchase price, net of cash acquired										$ 0	$ 36,571,000	$ 0
Depreciation and amortization expense										(96,713,000)	(98,156,000)	(98,356,000)
Net income		$ 18,965,000	$ 24,253,000	$ 24,748,000	$ 18,954,000	$ 15,658,000	$ 25,817,000	$ 53,081,000	$ 26,754,000	86,920,000	121,310,000	64,860,000
Goodwill		77,341,000				55,546,000				$ 77,341,000	$ 55,546,000	58,180,000
Intangible assets acquired, weighted-average useful life										8 years 4 months 24 days	10 years 9 months 18 days
Amortization expense										$ 12,900,000	$ 20,000,000.0	21,400,000
Minimum
Business Acquisition [Line Items]
Estimated useful life										3 years
Maximum
Business Acquisition [Line Items]
Estimated useful life										15 years
Rubber
Business Acquisition [Line Items]
Goodwill		30,955,000				31,550,000				$ 30,955,000	31,550,000	33,037,000
Impairment charged against goodwill										0	0
Specialty
Business Acquisition [Line Items]
Goodwill		46,385,000				$ 23,996,000				46,385,000	23,996,000	$ 25,143,000
Impairment charged against goodwill										$ 0	$ 0
Société du Noir d'Acétylène de l'Aubette, SAS
Business Acquisition [Line Items]
Acquisition of shares of acetylene carbon black manufacturer (as a percent)	100.00%
Aggregate purchase price, net of cash acquired	$ 36,784,000
Intangible assets acquired	12,766,000
Acquired property, plant and equipment	5,317,000
Deferred tax liabilities	4,716,000
Provisional adjustment, deferred tax liabilities		9,000,000.0
Change in goodwill		23,000,000.0
Goodwill	23,014,000
Société du Noir d'Acétylène de l'Aubette, SAS | Fair Value Adjustment To Assets And Related Deferred Tax Liability
Business Acquisition [Line Items]
Depreciation and amortization expense		1,000,000.0
Net income		$ 700,000
Société du Noir d'Acétylène de l'Aubette, SAS | Previously Reported
Business Acquisition [Line Items]
Intangible assets acquired	44,300,000
Acquired property, plant and equipment	5,800,000
Deferred tax liabilities	$ 13,700,000