v3.20.2

Pension and Other Postretirement Benefits - Narrative (Details) $ in Millions |  | 1 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Jan. 01, 2020 USD ($) | Jun. 30, 2020 USD ($) participants | Jun. 30, 2020 USD ($) participants | Jun. 30, 2019 USD ($) | Jun. 30, 2020 USD ($) participants | Jun. 30, 2019 USD ($) | Dec. 31, 2020 USD ($) | Jun. 01, 2020 participants | Apr. 01, 2020 USD ($) | Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |  |  |  |  |  |
Retirement plans, liability | $ 1,920 |  |  |  |  |  |  |  |  |
Retirement plans, current liability | 60 |  |  |  |  |  |  |  |  |
Retirement plans, benefit obligation | 4,255 |  |  |  |  |  |  |  |  |
Retirement plans, plan assets | 2,335 |  |  |  |  |  |  |  |  |
Establishment of retirement plans, AOCI | $ 1,752 |  | $ 50 |  |  |  |  |  |  |
Expected employer contributions, 2020 |  | $ 280 | $ 280 |  | $ 280 |  |  |  |  |
Liability, Defined Benefit Plan, Noncurrent |  |  |  |  |  |  |  |  | $ 15 |
asset, defined benefit plan |  |  |  |  |  |  |  |  | $ 65 |
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate |  | 1.55% | 1.55% |  | 1.55% |  |  |  |  | 2.05%
U.K. Defined Benefit Plan [Member] |  |  |  |  |  |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement |  |  |  |  | $ 250 |  |  |  |  |
Forecast |  |  |  |  |  |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |  |  |  |  |  |
Net periodic benefit cost |  |  |  |  |  |  | $ 100 |  |  |
Service cost |  |  |  |  |  |  | $ 25 |  |  |
Pension benefits |  |  |  |  |  |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |  |  |  |  |  |
Net periodic benefit cost |  |  | $ 73 | $ 2 | 94 | $ 3 |  |  |  |
Service cost |  |  | 5 | 1 | 10 | 1 |  |  |  |
Multiemployer contribution expense |  |  | 0 | 14 | 0 | 30 |  |  |  |
Expected employer contributions, 2020 |  | $ 260 | 260 |  | 260 |  |  |  |  |
Other postretirement benefits |  |  |  |  |  |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |  |  |  |  |  |
Net periodic benefit cost |  |  | 6 | 0 | 12 | 0 |  |  |  |
Service cost |  |  | 1 | 0 | 2 | 0 |  |  |  |
Multiemployer contribution expense |  |  | 0 | $ 6 | 0 | $ 11 |  |  |  |
Expected employer contributions, 2020 |  | 55 | 55 |  | 55 |  |  |  |  |
Other Pension Plan [Member] |  |  |  |  |  |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |  |  |  |  |  |
Expected employer contributions, 2020 |  | 10 | 10 |  | 10 |  |  |  |  |
U.K. Defined Benefit Plan [Member] |  |  |  |  |  |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |  |  |  |  |  |
Retirement plans, benefit obligation |  | 240 | 240 |  | 240 |  |  |  |  |
Retirement plans, plan assets |  | $ 260 | $ 260 |  | $ 260 |  |  |  |  |
Defined Benefit Plan, Participants | participants |  | 1,050 | 1,050 |  | 1,050 |  |  | 1,800 |  |
Defined Benefit Plan, Plan Assets, Contributions by Employer |  |  | $ 10 |  |  |  |  |  |  |
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Remeasurement due to Settlement |  |  | $ 55 |  |  |  |  |  |  |
U.K. Defined Benefit Plan [Member] | ParentCo |  |  |  |  |  |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |  |  |  |  |  |
Defined Benefit Plan, Participants | participants |  |  |  |  |  |  |  | 3,350 |  |
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement |  | $ 400 |  |  |  |  |  |  |  |
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Assets Transferred to (from) Plan |  | $ 460 |  |  |  |  |  |  |  |

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