Segments - Recon. of Net Income to Segment Adjusted EBITDA (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	May 03, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Income (loss) before income taxes		$ 156.3	$ (27.2)	$ 242.2	$ (54.4)
Interest expense, net		(21.6)	(11.7)	(33.6)	(22.0)
Depreciation and amortization				61.2	48.6
Adjusted EBITDA addbacks		23.1	8.0	86.4	38.5
Adjusted EBITDA		263.0	34.3	469.8	94.2
Loss on extinguishment of long-term debt		0.5		0.5
Net (gain) loss on disposition of businesses and assets				(0.2)	(0.4)
Restructuring and other charges		6.3	5.4	6.7	7.2
Acquisition transactions and integration net costs (benefit)		43.2	(0.4)	49.2	(0.3)
Acquisition purchase price hedge gain		(33.0)		22.0
Asset impairment charges or write-offs		1.8		1.8	10.3
Other items		4.3	3.0	6.4	21.7
Arkema
Segment Reporting Information [Line Items]
Acquisition-related costs		18.2		19.8
Integration costs		10.4		14.8
Inventory adjustment	$ 10.1	10.1		10.1
Jurisdictional asset transfer taxes		4.5		4.5
Operating Segments [Member]
Segment Reporting Information [Line Items]
Income (loss) before income taxes		156.3	(27.2)	242.2	(54.4)
Interest expense, net		21.6	11.7	33.6	22.0
Depreciation and amortization		38.1	24.3	61.2	48.6
Corporate Unallocated [Member]
Segment Reporting Information [Line Items]
Corporate Unallocated		$ 23.9	$ 17.5	$ 46.4	$ 39.5