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Property, Plant and Equipment - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Property, Plant and Equipment [Line Items]      
Amounts of assets held under finance leases $ 198.7 $ 196.4  
Depreciation charges 23.6 22.6 $ 21.4
Assets Held under Capital Leases [Member]      
Property, Plant and Equipment [Line Items]      
Amounts of assets held under finance leases $ 1.8 $ 3.6