Postretirement Benefit Plans - Components of Net Periodic Pension Costs (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
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| Pension and Other Postretirement Benefits Cost (Reversal of Cost) [Abstract] | |||
| Service cost | $ 17 | $ 14 | $ 16 |
| Interest cost on the projected benefit obligation | 7 | 12 | 12 |
| Expected return on plan assets | (5) | (6) | (6) |
| Amortization of net (gain) loss | 8 | 4 | 4 |
| Curtailments & settlements | 0 | 0 | 0 |
| Net periodic cost | $ 27 | $ 24 | $ 26 |
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- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of cost recognized for passage of time related to defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of net periodic benefit cost (credit) for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of gain (loss) recognized in net periodic benefit (cost) credit from settlement and curtailment. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- References No definition available.
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