Financial Instruments - Long-Term Debt (Details) - USD ($) $ in Millions		Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Net unamortized discounts, premiums and debt issuance costs		$ 0	$ (2)
Total long-term debt, carried at historical proceeds, as adjusted		36,195	37,133
Current portion of long-term debt, carried at historical proceeds, as adjusted (not included above (1.0% for 2021 and 2.6% for 2020))		$ 1,636	$ 2,002
Unsecured Debt [Member]
Debt Instrument [Line Items]
Interest rate, percentage		1.00%	2.60%
Total principal amount of long-term debt		$ 34,948	$ 35,774
Net fair value adjustments related to hedging and purchase accounting		1,438	1,562
Net unamortized discounts, premiums and debt issuance costs		(195)	(207)
Other long-term debt		4	4
Total long-term debt, carried at historical proceeds, as adjusted		36,195	37,133
Current portion of long-term debt, carried at historical proceeds, as adjusted (not included above (1.0% for 2021 and 2.6% for 2020))		1,636	$ 2,002
Unsecured Debt [Member] | Senior Unsecured Debt, Due 2022 [Member]
Debt Instrument [Line Items]
Interest rate, percentage			1.00%
Total principal amount of long-term debt	[1]	$ 0	$ 1,728
Unsecured Debt [Member] | Senior Unsecured Debt, Due 2023 [Member]
Debt Instrument [Line Items]
Interest rate, percentage		3.20%	3.20%
Total principal amount of long-term debt		$ 2,550	$ 2,550
Unsecured Debt [Member] | Senior Unsecured Debt, Due 2024 [Member]
Debt Instrument [Line Items]
Interest rate, percentage		3.90%	3.90%
Total principal amount of long-term debt		$ 2,250	$ 2,250
Unsecured Debt [Member] | Senior Unsecured Debt, Due 2025 [Member]
Debt Instrument [Line Items]
Interest rate, percentage		0.80%	0.80%
Total principal amount of long-term debt		$ 750	$ 750
Unsecured Debt [Member] | Senior Unsecured Debt, Due 2026 [Member]
Debt Instrument [Line Items]
Interest rate, percentage		2.90%	2.90%
Total principal amount of long-term debt		$ 3,000	$ 3,000
Unsecured Debt [Member] | Senior Unsecured Debt, Due 2027 [Member]
Debt Instrument [Line Items]
Interest rate, percentage		2.10%	2.00%
Total principal amount of long-term debt		$ 1,051	$ 1,121
Unsecured Debt [Member] | Senior Unsecured Debt, Due 2028-2032 [Member]
Debt Instrument [Line Items]
Interest rate, percentage		3.10%	3.40%
Total principal amount of long-term debt		$ 6,660	$ 5,660
Unsecured Debt [Member] | Senior Unsecured Debt, Due 2033-2037 [Member]
Debt Instrument [Line Items]
Interest rate, percentage		5.60%	5.60%
Total principal amount of long-term debt		$ 4,250	$ 4,250
Unsecured Debt [Member] | Senior Unsecured Debt, Due 2038-2042 [Member]
Debt Instrument [Line Items]
Interest rate, percentage		5.50%	5.50%
Total principal amount of long-term debt		$ 6,079	$ 6,086
Unsecured Debt [Member] | Senior Unsecured Debt, Due 2043-2047 [Member]
Debt Instrument [Line Items]
Interest rate, percentage		3.70%	3.70%
Total principal amount of long-term debt		$ 4,858	$ 4,878
Unsecured Debt [Member] | Senior Unsecured Debt, Due 2048-2050 [Member]
Debt Instrument [Line Items]
Interest rate, percentage		3.60%	3.60%
Total principal amount of long-term debt		$ 3,500	$ 3,500

[1] Reclassified to the current portion of long-term debt.