v3.5.0.2
Restructuring and Divestiture Costs - Chlorovinyls - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Feb. 24, 2016
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Restructuring Cost and Reserve [Line Items]          
Loss on sale of business       $ (19.9) $ 0.1
Solucor Business [Member]          
Restructuring Cost and Reserve [Line Items]          
Severance cost   $ 0.9      
Concord Ontario [Member]          
Restructuring Cost and Reserve [Line Items]          
Severance cost       20.8  
Specialty Phosgene [Member]          
Restructuring Cost and Reserve [Line Items]          
Severance cost     $ 0.4   $ 0.4
Solucor [Member]          
Restructuring Cost and Reserve [Line Items]          
Proceeds from sale of assets $ 9.2        
Chlorovinyls [Member]          
Restructuring Cost and Reserve [Line Items]          
Severance cost   0.3   10.4  
Chlorovinyls [Member] | Solucor [Member]          
Restructuring Cost and Reserve [Line Items]          
Loss on sale of business       (15.5)  
Building Products [Member]          
Restructuring Cost and Reserve [Line Items]          
Severance cost   $ 0.6   2.7  
Building Products [Member] | Concord Ontario [Member]          
Restructuring Cost and Reserve [Line Items]          
Loss on sale of business       $ (4.0)