Segment Information - Reconciliation of Segment Operating Income (Loss) to Consolidated Income (Loss) From Continuing Operations Before Income Taxes (Detail) - 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]
Operating income (loss)	$ (8.5)	$ 53.0	$ 11.6	$ 78.2
Interest expense	(4.6)	(16.2)	(18.5)	(31.7)
Other expense, net	(53.7)	(28.9)	(101.8)	(59.3)
Cost-reduction charges	(7.9)	(2.6)	(35.4)	(5.2)
Total income (loss) from continuing operations before income taxes	(66.8)	7.9	(108.7)	(12.8)
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income (loss)	(0.6)	60.3	27.6	87.2
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Cost-reduction charges	(8.5)	(2.6)	(17.0)	(5.2)
Corporate and eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income (loss)	$ 0.6	$ (4.7)	$ 1.0	$ (3.8)