Pension And Other Retirement Benefits - Accumulated Benefit Obligation in Excess of Plan Assets (Detail) - Pension Plans - U.S. Plans - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Aggregate projected benefit obligation	$ 589	$ 508
Aggregate accumulated benefit obligation	529	458
Aggregate fair value of plan assets	$ 395	$ 348

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Amount of accumulated benefit obligation for defined benefit plan with accumulated benefit obligation in excess of plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount of plan asset for defined benefit plan with accumulated benefit obligation in excess of plan assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Amount of projected benefit obligation for defined benefit pension plan with accumulated benefit obligation in excess of plan assets.

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