Contingent Liabilities - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Accrual for Environmental Loss Contingencies	$ 6,104	$ 13,302
Gain (Loss) Related to Litigation Settlement	$ 8,000
Loss Contingency, Receivable		$ 6,277

Total costs accrued as of the balance sheet date for environmental loss contingencies.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
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-Name Accounting Standards Codification
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-SubTopic 30
-Section 50
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No definition available.

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Amount of gain (loss) recognized in settlement of litigation and insurance claims. Excludes claims within an insurance entity's normal claims settlement process.

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Amount of receivable related to a loss contingency accrual. For example, an insurance recovery receivable.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
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