Debt - Long-Term Debt Obligations (Details) - USD ($)	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Face value of long-term debt	$ 51,762,000,000	$ 33,174,000,000
Less current portion of long-term debt	(1,158,000,000)	(1,155,000,000)
Long-term debt	50,279,000,000	31,816,000,000
Senior Notes
Debt Instrument [Line Items]
Face value of long-term debt	50,700,000,000
Unamortized discount and issuance costs, net	$ (325,000,000)	(203,000,000)
Weighted average remaining lives term	15 years 1 month 6 days
Senior Notes | 2012 Notes issuance of $3.0 billion
Debt Instrument [Line Items]
Issuance amount	$ 3,000,000,000.0
Stated Interest Rates	2.50%
Effective Interest Rates	2.66%
Face value of long-term debt	$ 1,250,000,000	1,250,000,000
Weighted average remaining lives term	1 year 4 months 24 days
Senior Notes | 2014 Notes issuance of $6.0 billion
Debt Instrument [Line Items]
Issuance amount	$ 6,000,000,000.0
Face value of long-term debt	$ 5,000,000,000	5,000,000,000
Weighted average remaining lives term	11 years 3 months 18 days
Senior Notes | 2014 Notes issuance of $6.0 billion | Minimum
Debt Instrument [Line Items]
Stated Interest Rates	3.30%
Effective Interest Rates	3.43%
Senior Notes | 2014 Notes issuance of $6.0 billion | Maximum
Debt Instrument [Line Items]
Stated Interest Rates	4.95%
Effective Interest Rates	5.11%
Senior Notes | 2017 Notes issuance of $17.0 billion
Debt Instrument [Line Items]
Issuance amount	$ 17,000,000,000.0
Face value of long-term debt	$ 16,000,000,000	16,000,000,000
Weighted average remaining lives term	15 years 8 months 12 days
Senior Notes | 2017 Notes issuance of $17.0 billion | Minimum
Debt Instrument [Line Items]
Stated Interest Rates	2.40%
Effective Interest Rates	2.56%
Senior Notes | 2017 Notes issuance of $17.0 billion | Maximum
Debt Instrument [Line Items]
Stated Interest Rates	5.20%
Effective Interest Rates	4.33%
Senior Notes | 2020 Notes issuance of $10.0 billion
Debt Instrument [Line Items]
Issuance amount	$ 10,000,000,000.0
Face value of long-term debt	$ 10,000,000,000	10,000,000,000
Weighted average remaining lives term	18 years 2 months 12 days
Senior Notes | 2020 Notes issuance of $10.0 billion | Minimum
Debt Instrument [Line Items]
Stated Interest Rates	0.40%
Effective Interest Rates	0.56%
Senior Notes | 2020 Notes issuance of $10.0 billion | Maximum
Debt Instrument [Line Items]
Stated Interest Rates	2.70%
Effective Interest Rates	2.77%
Senior Notes | 2021 Notes issuance of $18.5 billion
Debt Instrument [Line Items]
Issuance amount	$ 18,500,000,000
Face value of long-term debt	$ 18,500,000,000	0
Weighted average remaining lives term	14 years 9 months 18 days
Senior Notes | 2021 Notes issuance of $18.5 billion | Green or social projects
Debt Instrument [Line Items]
Issuance amount	$ 1,000,000,000.0
Senior Notes | 2021 Notes issuance of $18.5 billion | Minimum
Debt Instrument [Line Items]
Stated Interest Rates	0.25%
Effective Interest Rates	0.35%
Senior Notes | 2021 Notes issuance of $18.5 billion | Maximum
Debt Instrument [Line Items]
Stated Interest Rates	3.25%
Effective Interest Rates	3.31%
Credit Facility | Revolving Credit Facility
Debt Instrument [Line Items]
Face value of long-term debt	$ 503,000,000	338,000,000
Other long-term debt
Debt Instrument [Line Items]
Face value of long-term debt	$ 509,000,000	$ 586,000,000