Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingencies - Collective Bargaining Agreements (Detail)

v3.7.0.1
Commitments and Contingencies - Collective Bargaining Agreements (Detail) - Withdrawal from Multiemployer Defined Benefit Plan - Central States Plan - USD ($)
$ in Millions
33 Months Ended 49 Months Ended
Jun. 30, 2017
Jun. 30, 2017
Jan. 31, 2016
Jul. 31, 2014
Oct. 09, 2013
Dec. 31, 2011
Loss Contingencies [Line Items]            
Amount of withdrawal liability     $ 32.9 $ 39.6   $ 32.6
Payment of withdrawal liability assessment amount $ 20.7          
Acquired Company            
Loss Contingencies [Line Items]            
Amount of withdrawal liability     $ 4.8   $ 4.8  
Payment of withdrawal liability assessment amount   $ 3.9        
Amount of withdrawal liability, amount suggested by Plan which is different than amount recorded by company         $ 6.9  
Minimum            
Loss Contingencies [Line Items]            
Amount of withdrawal liability 40.1 40.1        
Maximum            
Loss Contingencies [Line Items]            
Amount of withdrawal liability $ 55.4 $ 55.4