Postretirement Benefit Plans (Rollforward of Fair Value Measurements) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning Balance	$ 567
Ending Balance	605	$ 567
Other \| Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning Balance	12	17
Purchases, sales, settlements	1	(5)
Impact on currency	0	0
Ending Balance	$ 13	$ 12

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

No definition available.

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- Definition

Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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+ Details

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- Definition

Amount of foreign currency translation gain (loss) which increases (decreases) plan assets of defined benefit plan.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Amount, measured using unobservable input, of increase (decrease) in plan asset of defined benefit plan from purchase, sale and settlement of trade associated with underlying investment.

+ References

+ Details

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- Details

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