Goodwill - Schedule of Goodwill (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Goodwill [Roll Forward]
Goodwill, beginning balance			$ 71,500,000	$ 76,100,000	$ 76,100,000
Impairment	$ (80,800,000)	$ 0	(80,800,000)	0
Foreign currency impact			9,300,000		(4,600,000)
Goodwill, ending balance	0		0		71,500,000
Accumulated goodwill impairment	80,800,000		80,800,000
Rubber
Goodwill [Roll Forward]
Goodwill, beginning balance			28,600,000	30,500,000	30,500,000
Impairment			(32,300,000)
Foreign currency impact			3,700,000		(1,900,000)
Goodwill, ending balance	0		0		28,600,000
Specialty
Goodwill [Roll Forward]
Goodwill, beginning balance			42,900,000	$ 45,600,000	45,600,000
Impairment			(48,500,000)
Foreign currency impact			5,600,000		(2,700,000)
Goodwill, ending balance	$ 0		$ 0		$ 42,900,000