Segment Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Segment Reporting Information [Line Items]
Total operating revenues	$ 2,118	$ 2,943
Depreciation, depletion and amortization expense	313	275
Operating income	606	1,299
Interest expense	36	41
Gain on derivatives	1,401	(3,927)
Loss on early extinguishment of debt	(19)	(2)
Other income, net	(1)	0
Provision from income taxes	12	4
Assets	12,937	11,847	$ 12,926
Capital investments	665	544
Increase (decrease) in accrued expenditures	(6)	43
Merger-related expenses	0	25
Intersegment Revenues
Segment Reporting Information [Line Items]
Total operating revenues	1,352	1,886
E&P
Segment Reporting Information [Line Items]
Total operating revenues	1,439	2,077
Depreciation, depletion and amortization expense	312	274
Operating income	578	1,278
Interest expense	36	41
Gain on derivatives	1,401	(3,925)
Loss on early extinguishment of debt	0	0
Other income, net	(1)	0
Provision from income taxes	12	4
Assets	12,260	10,766
Capital investments	664	544
Merger-related expenses		25
E&P | Intersegment Revenues
Segment Reporting Information [Line Items]
Total operating revenues	(10)	(3)
Marketing
Segment Reporting Information [Line Items]
Total operating revenues	679	866
Depreciation, depletion and amortization expense	1	1
Operating income	28	21
Interest expense	0	0
Gain on derivatives	0	0
Loss on early extinguishment of debt	0	0
Other income, net	0	0
Provision from income taxes	0	0
Assets	552	969
Capital investments	0	0
Marketing | Intersegment Revenues
Segment Reporting Information [Line Items]
Total operating revenues	1,362	1,889
Other
Segment Reporting Information [Line Items]
Total operating revenues	0	0
Depreciation, depletion and amortization expense	0	0
Operating income	0	0
Interest expense	0	0
Gain on derivatives	0	(2)
Loss on early extinguishment of debt	(19)	(2)
Other income, net	0	0
Provision from income taxes	0	0
Assets	125	112
Capital investments	1	0
Other | Intersegment Revenues
Segment Reporting Information [Line Items]
Total operating revenues	$ 0	$ 0