XML 95 R80.htm IDEA: XBRL DOCUMENT v3.20.4
Commitments and Contingencies - Changes in Accrued Environmental Remediation and Related Costs (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Commitments And Contingencies Disclosure [Abstract]      
Balance at the beginning of the year $ 94,508 $ 98,211 $ 111,909
Additions charged (credited) to expense, net 82 (579) 2,735
Payments, net (1,174) (3,124) (16,433)
Balance at the end of the year 93,416 94,508 98,211
Amounts recognized in the balance sheet:      
Current liability 2,027 3,065 5,027
Noncurrent liability $ 91,389 $ 91,443 $ 93,184