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Property, Plant and Equipment - Additional Information (Detail) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Dec. 31, 2017
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Property, Plant and Equipment [Line Items]        
Depreciation and amortization expenses   $ 12.6 $ 13.2 $ 11.4
Costs related to terminated manufacturing obligations $ 0.9      
Manufacturing Equipment [Member]        
Property, Plant and Equipment [Line Items]        
Original cost of impaired equipment 23.4 23.4    
Net book value of impaired equipment $ 15.1 $ 15.1