Segment Information - Reconciliation of Segment Operating Income to Consolidated Income (Loss) Before Income Taxes (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income (loss)	$ 42,900,000	$ 101,800,000
Interest expense	(15,500,000)	(16,600,000)
Other income (expense), net	(30,400,000)	(22,600,000)
Cost-reduction (charges) benefit	(2,600,000)	0
Total income (loss) before income taxes	(3,000,000)	62,600,000
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income (loss)	44,600,000	99,100,000
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Cost-reduction (charges) benefit	(2,600,000)	2,900,000
Corporate and eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating income (loss)	$ 900,000	$ (200,000)