Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2021

Commitments And Contingencies Disclosure [Abstract]

Changes in Accrued Environmental Remediation and Related Costs

	Years ended December 31,
	2019		2020		2021
	(In thousands)
Balance at the beginning of the period	$	98,211	$	94,508	$	93,416
Additions charged (credited) to expense, net		(579)		82		788
Payments, net		(3,124)		(1,174)		(1,264)
Balance at the end of the year	$	94,508	$	93,416	$	92,940
Amounts recognized in the balance sheet:
Current liability	$	3,065	$	2,027	$	2,643
Noncurrent liability		91,443		91,389		90,297
Balance at the end of the period	$	94,508	$	93,416	$	92,940