v2.4.0.8
Property, Plant and Equipment - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
3 Months Ended 9 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Property, Plant and Equipment [Line Items]        
Interest cost paid $ 0.3 $ 0.2 $ 0.9 $ 0.6
Interest cost capitalized 0   0.4  
Maximum [Member]
       
Property, Plant and Equipment [Line Items]        
Interest cost capitalized   0.1   0.1
Property, Plant and Equipment [Member]
       
Property, Plant and Equipment [Line Items]        
Depreciation $ 1.4 $ 1.0 $ 4.0 $ 2.8