Income Taxes - Deferred Taxes (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Other current assets	$ 0.0	$ 34.4
Other non-current assets	39.0	2.2
Deferred tax liabilities	609.5	670.2
Total deferred tax liabilities	$ 570.5	$ 633.6