Income Taxes - Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets
Accrued liabilities and reserves	$ 55.2	$ 83.2
Pension and other post-retirement compensation and benefits	53.8	48.9
Employee compensation and benefits	43.5	76.6
Tax loss and credit carryforwards	811.7	391.0
Total deferred tax assets	964.2	599.7
Valuation allowance	792.4	380.8
Deferred tax assets, net of valuation allowance	171.8	218.9
Deferred tax liabilities
Property, plant and equipment	16.5	23.6
Goodwill and other intangibles	484.7	733.7
Other liabilities	22.4	32.1
Deferred Tax Liabilities, Gross	523.6	789.4
Total deferred tax liabilities	$ 351.8	$ 570.5