Commiments and Contingencies Commiments and Contingencies (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Total contingencies	$ 13	$ 13
Accrual for Environmental Loss Contingencies, Gross	14	14
Current portion (included in Accrued liabilities)	(1)	(1)
Long-term portion (included in Other long-term liabilities)	13	13
Environmental reserves
Loss Contingencies [Line Items]
Total contingencies	14	14
Other reserves
Loss Contingencies [Line Items]
Total contingencies	$ 0	$ 0

Undiscounted amount of the accrual for environmental loss contingencies.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 30
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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