Segment Information - Depreciation and Amortization (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 25.6	$ 27.3	$ 50.5	$ 56.9
Performance Materials
Segment Reporting Information [Line Items]
Depreciation and amortization	9.9	9.7	19.8	19.3
Performance Chemicals
Segment Reporting Information [Line Items]
Depreciation and amortization	7.4	10.1	14.7	22.5
Advanced Polymer Technologies segment
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 8.3	$ 7.5	$ 16.0	$ 15.1