Commitments and Contingencies Personal Injury (Details) - Personal Injury - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019
Loss Contingency Accrual [Roll Forward]
Beginning balance	$ 275	$ 308
Accruals / changes in estimates	36	69
Payments	(34)	(88)
Ending balance	277	289
Current portion of ending balance	75	$ 85
Minimum
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss	235
Maximum
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss	$ 330

Amount of expense for newly incurred loss contingencies and revisions to previously reported estimates

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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Amount of loss contingency liability.

+ References

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-Topic 450
-SubTopic 20
-Section 50
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- Definition

Amount of loss contingency liability expected to be resolved within one year or the normal operating cycle, if longer.

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Amount of cash outflow reducing loss contingency liability.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Reflects the estimated amount of loss from the specified contingency as of the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Topic 450
-SubTopic 20
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-Publisher FASB
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