Contingencies - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Accrual for environmental loss contingencies, gross	$ 16.4	$ 18.4
Accrued environmental loss contingencies, current	4.1	7.0
Accrued environmental loss contingencies, noncurrent	$ 12.3	$ 11.4

Carrying value of the obligation (known or estimated) arising from requirements to perform activities to remediate one or more sites, payable in twelve months or in the next operating cycle if longer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant