Contingencies - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2019 USD ($)
Contingencies And Commitments [Line Items]
Amount paid to implement remedial action work plan	$ 0.2
Accrual for reasonably estimable remediation cost	3.1
Short-term Other Accrued Liabilities [Member]
Contingencies And Commitments [Line Items]
Accrual for reasonably estimable remediation cost	1.1
Other Non-current Liabilities [Member]
Contingencies And Commitments [Line Items]
Accrual for reasonably estimable remediation cost	$ 2.0