Pension And Postretirement Benefits (Change In The Value Of Plan Assets And The Plans' Funded Status) (Details) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
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| Pension Benefits | ||
| Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||
| Fair value of plan assets at beginning of year | $ 53,530 | $ 51,681 |
| Actual return on plan assets | 6,199 | 8,207 |
| Benefits paid | (5,124) | (6,356) |
| Contributions | 2 | 2 |
| Plan transfers | (1) | (4) |
| Fair value of plan assets at end of year | 54,606 | 53,530 |
| Unfunded status at end of year | (7,552) | (6,343) |
| Postretirement Benefits | ||
| Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] | ||
| Fair value of plan assets at beginning of year | 4,145 | 4,277 |
| Actual return on plan assets | 302 | 609 |
| Benefits paid | (1,029) | (941) |
| Contributions | 425 | 200 |
| Plan transfers | 0 | 0 |
| Fair value of plan assets at end of year | 3,843 | 4,145 |
| Unfunded status at end of year | $ (10,085) | $ (11,896) |
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- Definition Amount of increase (decrease) in plan assets of defined benefit plan from actual return (loss) determined by change in fair value of plan assets adjusted for contributions, benefit payments, and other expenses. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of increase (decrease) in plan assets of defined benefit plan from assets transferred into (from) plan. No definition available.
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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. No definition available.
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- Definition Amount of contribution received by defined benefit plan from employer which increases plan assets. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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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. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of funded (unfunded) status of defined benefit plan, measured as difference between fair value of plan assets and benefit obligation. Includes, but is not limited to, overfunded (underfunded) status. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Amount of payment to participant under defined benefit plan which decreases plan assets. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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