Commitments and Contingencies - Narrative (Detail) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2019 Facility
Commitments And Contingencies Disclosure [Abstract]
Number of sites cited as potentially responsible party			2
Number of previously and currently owned sites with potential remediation obligations			6
Rend expense for facilities in use and equipment \| $	$ 28.0	$ 57.4

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

No definition available.

Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration