Revenue Recognition (Disaggregation of Revenue by Segment) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 4,541	$ 1,598	$ 11,622	$ 3,720
E&P
Disaggregation of Revenue [Line Items]
Total operating revenues	3,243	1,179	8,251	2,616
Marketing
Disaggregation of Revenue [Line Items]
Total operating revenues	1,298	419	3,371	1,104
Operating Segments | E&P
Disaggregation of Revenue [Line Items]
Total operating revenues	3,247	1,165	8,250	2,574
Operating Segments | Marketing
Disaggregation of Revenue [Line Items]
Total operating revenues	4,436	1,366	11,214	3,346
Intersegment Revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	3,142	933	7,842	2,200
Intersegment Revenues | E&P
Disaggregation of Revenue [Line Items]
Total operating revenues	4	(14)	(1)	(42)
Intersegment Revenues | Marketing
Disaggregation of Revenue [Line Items]
Total operating revenues	3,138	947	7,843	2,242
Gas sales
Disaggregation of Revenue [Line Items]
Total operating revenues	2,884	811	7,061	1,708
Gas sales | Operating Segments | E&P
Disaggregation of Revenue [Line Items]
Total operating revenues	2,889	799	7,064	1,671
Gas sales | Operating Segments | Marketing
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Gas sales | Intersegment Revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	(5)	12	(3)	37
Oil sales
Disaggregation of Revenue [Line Items]
Total operating revenues	100	110	349	297
Oil sales | Operating Segments | E&P
Disaggregation of Revenue [Line Items]
Total operating revenues	99	108	345	293
Oil sales | Operating Segments | Marketing
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Oil sales | Intersegment Revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	1	2	4	4
NGL sales
Disaggregation of Revenue [Line Items]
Total operating revenues	260	255	842	607
NGL sales | Operating Segments | E&P
Disaggregation of Revenue [Line Items]
Total operating revenues	260	255	842	606
NGL sales | Operating Segments | Marketing
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
NGL sales | Intersegment Revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	1
Marketing
Disaggregation of Revenue [Line Items]
Total operating revenues	1,298	418	3,371	1,102
Marketing | Operating Segments | E&P
Disaggregation of Revenue [Line Items]
Total operating revenues	0	0	0	0
Marketing | Operating Segments | Marketing
Disaggregation of Revenue [Line Items]
Total operating revenues	4,436	1,365	11,214	3,344
Marketing | Intersegment Revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	3,138	947	7,843	2,242
Other
Disaggregation of Revenue [Line Items]
Total operating revenues	(1)	4	(1)	6
Other | Operating Segments | E&P
Disaggregation of Revenue [Line Items]
Total operating revenues	(1)	3	(1)	4
Other | Operating Segments | Marketing
Disaggregation of Revenue [Line Items]
Total operating revenues	0	1	0	2
Other | Intersegment Revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 0	$ 0	$ 0	$ 0