Pension and Other Postemployment Benefits (Details 6) $ in Millions	Dec. 31, 2019 USD ($)
Pension
Estimated Future Benefit Payments
2020	$ 547
2021	564
2022	573
2023	586
2024	593
Years 2025-2029	3,099
OPEB
Estimated Future Benefit Payments
2020	52
2021	49
2022	48
2023	47
2024	46
Years 2025-2029	208
Subsidy Receipts
2020	(1)
2021	(1)
2022	(1)
2023	(1)
2024	(1)
Years 2025-2029	$ (3)

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