Segments - Reconciliation of Operating Profit (Loss) from Segments to Consolidated (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted EBIT	$ (37.8)	$ 168.0	$ 67.4	$ 280.8
Interest expense, net	36.1	41.0	72.6	82.3
Debt extinguishment and refinancing related costs	0.0	0.2	2.4	0.2
Termination benefits and other employee related costs	15.2	2.8	34.7	4.1
Strategic review and retention costs	6.7	0.8	18.2	0.8
Offering and transactional costs	0.1	0.2	0.2	0.8
Loss (gain) on divestiture and impairments	2.7	(1.3)	3.2	3.9
Pension special event	(0.6)	0.0	(1.8)	0.0
Accelerated depreciation	0.4	6.7	8.5	12.8
(Loss) income before income taxes	(98.4)	117.8	(70.6)	176.1
Indemnity income	0.0	(0.2)	0.0	(0.2)
Performance Coatings
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted EBIT	1.5	127.6	80.9	206.2
Transportation Coatings
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Adjusted EBIT	$ (39.3)	$ 40.4	$ (13.5)	$ 74.6
Minimum
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Retention payment terms	18 months
Maximum
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Retention payment terms	24 months