v3.22.0.1

Pension and Other Postretirement Benefits - Expected Benefit Payments (Details) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Apr. 30, 2021 USD ($) plan	Jun. 30, 2021 plan	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Pension benefits​
Pension benefits and Net other postretirement benefits
2022			$ 164
2023			162
2024			160
2025			158
2026			158
2027 through 2031			763
Expected benefit payments			1,565
Other postretirement benefits
Contributions by employer			458	$ 271
Pension benefits​ | United States
Other postretirement benefits
Contributions by employer	$ 250
Number of defined benefit pension plans | plan	2	2
Other postretirement benefits
Other postretirement benefits
2022			29
2023			28
2024			27
2025			27
2026			27
2027 through 2031			128
Expected benefit payments			266
Contributions by employer			$ 0	$ 0

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