LONG-TERM DEBT - DEBT ISSUANCE, REPURCHASES, REPAYMENTS AND EXCHANGES (Details) - USD ($)		3 Months Ended			6 Months Ended	12 Months Ended
	Oct. 20, 2021	Dec. 31, 2021	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2020
Long-term Debt Rollforward [Roll Forward]
Total borrowings at face value as of December 31, 2020				$ 35,235,000,000		$ 37,401,000,000
Total borrowings at face value as of December 31, 2021		$ 28,493,000,000			$ 35,235,000,000	35,235,000,000
Variable rate bonds due 2021 | First quarter repayments
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments				(27,000,000)
Variable rate bonds due 2021 | July tender and purchase
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						(473,000,000)
Variable rate bonds due 2021 | August and September tender and purchase
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						(123,000,000)
Variable rate bonds due August 2022 | August and September tender and purchase
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (448,000,000)
6.500% note payable to WES due 2038 | August WES exchange | WES
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					6.50%	6.50%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (260,000,000)
2-year variable rate term loan due 2021
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments					$ (2,500,000,000)
2-year variable rate term loan due 2021 | September repayment
Debt Instrument [Line Items]
Debt instrument, term						2 years
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (500,000,000)
2-year variable rate bonds due August 2021 | October repayment
Debt Instrument [Line Items]
Debt instrument, term						2 years
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (377,000,000)
2-year variable rate term loan due September 2021 | October repayment
Debt Instrument [Line Items]
Debt instrument, term						2 years
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (1,010,000,000)
2-year variable rate term loan due September 2021 | November repayment
Debt Instrument [Line Items]
Debt instrument, term						2 years
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (232,000,000)
2-year variable rate term loan due September 2021 | December repayment
Debt Instrument [Line Items]
Debt instrument, term						2 years
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (214,000,000)
Senior notes
Long-term Debt Rollforward [Roll Forward]
Total borrowings at face value as of December 31, 2020				$ 7,000,000,000
Total borrowings at face value as of December 31, 2021					7,000,000,000	$ 7,000,000,000
Senior notes | 4.850% senior notes due 2021 | First quarter repayments
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage				4.85%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments				$ (147,000,000)
Senior notes | 2.700% senior notes due 2022
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments					(2,700,000,000)
Senior notes | 2.700% senior notes due 2022 | Third quarter repayments
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage			2.70%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments			$ (278,000,000)
Senior notes | 2.700% senior notes due 2022 | Fourth quarter issuances (repayments)
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (627,000,000)
Senior notes | 2.700% senior notes due 2023
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments					$ (264,000,000)
Senior notes | 2.700% senior notes due 2023 | Third quarter repayments
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage			2.70%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments			$ (484,000,000)
Senior notes | 3.450% senior notes due 2024 | Third quarter repayments
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage			3.45%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments			$ (81,000,000)
Senior notes | 3.450% senior notes due 2024 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		3.45%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (40,000,000)
Senior notes | 2.900% senior notes due 2024 | Third quarter repayments
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage			2.90%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments			$ (1,620,000,000)
Senior notes | 2.900% senior notes due 2024 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		2.90%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (431,000,000)
Senior notes | 3.500% senior notes due 2025 | Third quarter repayments
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage			3.50%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments			$ (229,000,000)
Senior notes | 3.500% senior notes due 2025 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		3.50%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (195,000,000)
Senior notes | 3.400% senior notes due 2026 | Third quarter repayments
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage			3.40%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments			$ (224,000,000)
Senior notes | 3.400% senior notes due 2026 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		3.40%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (148,000,000)
Senior notes | 3.200% senior notes due 2026 | Third quarter repayments
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage			3.20%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments			$ (110,000,000)
Senior notes | 3.200% senior notes due 2026 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		3.20%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (93,000,000)
Senior notes | 2.600% senior notes due 2021 | Third quarter repayments
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage			2.60%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments			$ (224,000,000)
Senior notes | Floating interest rate notes due August 2022 | Third quarter repayments
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments			$ (1,051,000,000)
Senior notes | 4.400% senior notes due 2046 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		4.40%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (224,000,000)
Senior notes | 4.400% senior notes due 2049 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		4.40%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (46,000,000)
Senior notes | 7.730% debentures due 2096 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		7.73%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (3,000,000)
Senior notes | 7.500% debentures due 2026 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		7.50%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (18,000,000)
Senior notes | 7.250% debentures due 2096 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		7.25%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (44,000,000)
Senior notes | 6.600% senior notes due 2046 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage	6.60%	6.60%
Long-term Debt Rollforward [Roll Forward]
Issuances	$ 57,200,000	$ 57,000,000
Senior notes | 3.000% senior notes due 2027 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		3.00%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (116,000,000)
Senior notes | 3.500% senior notes due 2029 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		3.50%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (23,000,000)
Senior notes | 4.100% senior notes due 2047 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		4.10%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (87,000,000)
Senior notes | 4.200% senior notes due 2048 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		4.20%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (39,000,000)
Senior notes | 4.300% senior notes due 2039 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		4.30%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (57,000,000)
Senior notes | 4.500% senior notes due 2044 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		4.50%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (17,000,000)
Senior notes | 4.625% senior notes due 2045 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		4.625%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (116,000,000)
Senior notes | 3.125% senior notes due 2022 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		3.125%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (276,000,000)
Senior notes | 2.700% senior notes due 2022 | Fourth quarter issuances (repayments)
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		2.70%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments		$ (351,000,000)
Senior notes | 8.000% senior notes due 2025 | Issuance of July 2020 notes
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					8.00%	8.00%
Long-term Debt Rollforward [Roll Forward]
Issuances						$ 500,000,000
Senior notes | 8.500% senior notes due 2027 | Issuance of July 2020 notes
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					8.50%	8.50%
Long-term Debt Rollforward [Roll Forward]
Issuances						$ 500,000,000
Senior notes | 8.875% senior notes due 2030 | Issuance of July 2020 notes
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					8.875%	8.875%
Long-term Debt Rollforward [Roll Forward]
Issuances						$ 1,000,000,000
Senior notes | 4.100% senior notes due February 2021 | July tender and purchase
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					4.10%	4.10%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (943,000,000)
Senior notes | 4.100% senior notes due February 2021 | August and September tender and purchase
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					4.10%	4.10%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (139,000,000)
Senior notes | 4.100% senior notes due February 2021 | December repayment
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					4.10%	4.10%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (167,000,000)
Senior notes | 4.850% senior notes due March 2021 | July tender and purchase
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					4.85%	4.85%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (530,000,000)
Senior notes | 2.600% senior notes due August 2021 | July tender and purchase
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					2.60%	2.60%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (51,000,000)
Senior notes | 2.600% senior notes due August 2021 | August and September tender and purchase
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					2.60%	2.60%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (1,099,000,000)
Senior notes | 2.600% senior notes due August 2021 | December tender and purchase
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					2.60%	2.60%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (126,000,000)
Senior notes | 5.875% senior notes due 2025 | Issuance of August 2020 notes
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					5.875%	5.875%
Long-term Debt Rollforward [Roll Forward]
Issuances						$ 900,000,000
Senior notes | 6.375% senior notes due 2028 | Issuance of August 2020 notes
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					6.375%	6.375%
Long-term Debt Rollforward [Roll Forward]
Issuances						$ 600,000,000
Senior notes | 6.625% senior notes due 2030 | Issuance of August 2020 notes
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					6.625%	6.625%
Long-term Debt Rollforward [Roll Forward]
Issuances						$ 1,500,000,000
Senior notes | 2.600% senior notes due April 2022 | August and September tender and purchase
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					2.60%	2.60%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (171,000,000)
Senior notes | 2.600% senior notes due April 2022 | December tender and purchase
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					2.60%	2.60%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (128,000,000)
Senior notes | 2.700% senior notes due August 2022 | August and September tender and purchase
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					2.70%	2.70%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (102,000,000)
Senior notes | 2.700% senior notes due August 2022 | December tender and purchase
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					2.70%	2.70%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (1,269,000,000)
Senior notes | 2.700% senior notes due February 2023 | August and September tender and purchase
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					2.70%	2.70%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (52,000,000)
Senior notes | 2.700% senior notes due February 2023 | December tender and purchase
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					2.70%	2.70%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (212,000,000)
Senior notes | 0.00% senior notes due October 2036
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments					$ (2,000,000)
Senior notes | 0.00% senior notes due October 2036 | October repayment
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					0.00%	0.00%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (2,000,000)
Senior notes | 5.500% senior notes due 2025
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		5.50%			5.50%	5.50%
Senior notes | 5.500% senior notes due 2025 | Issuance of December 2020 notes
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					5.50%	5.50%
Long-term Debt Rollforward [Roll Forward]
Issuances						$ 750,000,000
Senior notes | 6.125% senior notes due 2031
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage		6.125%			6.125%	6.125%
Senior notes | 6.125% senior notes due 2031 | Issuance of December 2020 notes
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					6.125%	6.125%
Long-term Debt Rollforward [Roll Forward]
Issuances						$ 1,250,000,000
Senior notes | 3.125% senior notes due February 2022 | December tender and purchase
Debt Instrument [Line Items]
Debt instrument interest rate stated percentage					3.125%	3.125%
Long-term Debt Rollforward [Roll Forward]
Tender, purchase and repayments						$ (538,000,000)