Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2019

Commitments And Contingencies Disclosure [Abstract]

Change in Accrued Environmental Remediation and Related Costs

The table below presents a summary of the activity in our accrued environmental costs during the past three years.  The amount charged to expense is included in corporate expense on our Consolidated Statements of Operations.

	Years ended December 31,
	2017			2018			2019
	(In thousands)
Balance at the beginning of the year	$	116,658		$	111,909		$	98,211
Additions charged (credited) to expense, net		3,376			2,735			(579	)
Payments, net		(8,125	)		(16,433	)		(3,124	)
Balance at the end of the year	$	111,909		$	98,211		$	94,508
Amounts recognized in the balance sheet:
Current liability	$	5,302		$	5,027		$	3,065
Noncurrent liability		106,607			93,184			91,443
Balance at the end of the year	$	111,909		$	98,211		$	94,508