Stockholders' Equity (Deficit), Accumulated Other Comprehensive Income (Loss) and Noncontrolling Interest - Changes in Accumulated Other Comprehensive Income/(Loss) Net of Tax by Component (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) net of tax, beginning balance	$ (302.0)
Accumulated other comprehensive income (loss) net of tax, ending balance	(312.2)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) net of tax, beginning balance	(48.6)
Other comprehensive income (loss) before reclassifications	(8.5)
Net current-period other comprehensive income (loss)	(8.5)
Accumulated other comprehensive income (loss) net of tax, ending balance	(57.1)
Benefit Plan Liabilities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) net of tax, beginning balance	(253.1)
Amounts reclassified from accumulated other comprehensive income into net income	1.8
Net current-period other comprehensive income (loss)	1.8
Accumulated other comprehensive income (loss) net of tax, ending balance	(251.3)
Cash Flow Hedge - Interest Rate Swap [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss) net of tax, beginning balance	(0.3)
Other comprehensive income (loss) before reclassifications	(3.6)
Amounts reclassified from accumulated other comprehensive income into net income	0.1
Net current-period other comprehensive income (loss)	(3.5)
Accumulated other comprehensive income (loss) net of tax, ending balance	$ (3.8)