Post-Employment Benefits - Funding and Payments (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plans
Defined benefit plans disclosures
Company contributions	$ 418	$ 400
Defined benefit plan, expected contributions in 2022	415
Total benefit payments expected to be paid to participants
2022	350
2023	365
2024	387
2025	408
2026	429
2027 to 2031	2,485
Medical and Dental Plans
Defined benefit plans disclosures
Company contributions	35	$ 20
Total benefit payments expected to be paid to participants
2022	75
2023	75
2024	77
2025	78
2026	79
2027 to 2031	$ 410

Amount of contribution received by defined benefit plan from employer which increases plan assets.

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