Restructuring and Other Charges - Reconciliation of Restructuring Liability (Detail) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Restructuring Cost and Reserve [Line Items]        
Beginning Balance     $ 10.9  
Provision $ 3.1 $ 1.8 12.4 $ 12.6
Cash Expenditures [1]     (18.0)  
Non-Cash Write-offs [2]     (0.4)  
Ending Balance 4.9   4.9  
Workforce Reduction Costs [Member]        
Restructuring Cost and Reserve [Line Items]        
Beginning Balance     10.4  
Provision     8.7  
Cash Expenditures [1]     (15.0)  
Non-Cash Write-offs [2]     0.2  
Ending Balance 4.3   4.3  
Other [Member]        
Restructuring Cost and Reserve [Line Items]        
Beginning Balance     0.5  
Provision     3.7  
Cash Expenditures [1]     (3.0)  
Non-Cash Write-offs [2]     (0.6)  
Ending Balance $ 0.6   $ 0.6  
[1] Cash expenditures primarily related to severance charges.
[2] Non-cash write-offs primarily include long-lived asset impairment charges attributable to restructuring actions.