Employee Benefit Plans - Projected Benefit Obligation (Details) - USD ($) $ in Millions |
Dec. 31, 2019 |
Dec. 31, 2018 |
|---|---|---|
| Qualified Plan [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Projected benefit obligation | $ 2,073 | $ 1,871 |
| Accumulated benefit obligation | 1,919 | 1,737 |
| Fair values of pension plan assets | 1,635 | 1,373 |
| Nonqualified Plan [Member] | Unfunded Plan [Member] | ||
| Defined Benefit Plan Disclosure [Line Items] | ||
| Projected benefit obligation | 601 | 586 |
| Accumulated benefit obligation | $ 542 | $ 504 |
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- Definition Amount of actuarial present value of benefits attributed to employee service rendered, excluding assumptions about future compensation level. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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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. 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. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Amount of projected benefit obligation for defined benefit pension plan with accumulated benefit obligation in excess of plan assets. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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