Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Contingencies And Commitments [Line Items]
Amount paid to implement remedial action work plan		$ 0.2	$ 0.4	$ 0.6
Other Accrued Liabilities and Other Non-current Liabilities [Member]
Contingencies And Commitments [Line Items]
Accrual for reasonably estimable remediation cost		$ 2.7
Discontinued Operations [Member]
Contingencies And Commitments [Line Items]
Accrual charge after remaining estimate of costs to complete remediation	$ 0.5