Other Noncurrent Liabilities - Other Noncurrent Liabilities (Detail) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Other Noncurrent Liabilities [Line Items]
Reserve for uncertain tax positions	$ 28.9	$ 34.1
Asset retirement obligations	28.6	27.2
Deferred income	8.5	18.9
Employee benefits	7.4	8.1
Insurance claims and expenses	9.7	9.5
Deferred payment obligation	8.7	8.5
Accrued workforce reduction costs	3.0
Other	7.0	6.4
Total, Other noncurrent liabilities	104.0	$ 112.7
Interest Rate Swap Contract
Other Noncurrent Liabilities [Line Items]
Hedging liabilities	$ 2.2