Revenue Recognition (Disaggregation of Revenue on Geographic Basis) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 2,118	$ 2,943
E&P
Disaggregation of Revenue [Line Items]
Total operating revenues	1,439	2,077
Operating Segments | E&P
Disaggregation of Revenue [Line Items]
Total operating revenues	1,429	2,074
Operating Segments | E&P | Appalachia
Disaggregation of Revenue [Line Items]
Total operating revenues	923	1,321
Operating Segments | E&P | Haynesville
Disaggregation of Revenue [Line Items]
Total operating revenues	$ 506	$ 753