Contingencies - Roll-forward of Remediation Reserves Included in Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Balance at beginning of period	$ 11,444	$ 11,274	$ 17,067
Remediation expense	2,769	2,602	1,182
Remediation payments	(3,639)	(2,455)	(6,967)
Other activity	68	23	(8)
Balance at end of the period	$ 10,642	$ 11,444	$ 11,274