Asset Retirement Obligations - EEGH - Change in Asset Retirement Obligations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	$ 1,341	$ 1,272
Change in estimated costs	81	46
Additions	15	51
Retirements	(144)	(201)
Accretion	47	51
Ending Balance	1,340	1,341
Current liabilities	130	184
Other long-term liabilities	1,210	1,157
Total ARO liability	1,340	1,341
EEGH
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning Balance	71	89
Change in estimated costs	0	(51)
Additions	0	48
Retirements	(17)	(3)
Disposal of Questar Pipeline Group	0	(16)
Accretion	1	4
Ending Balance	55	71
Current liabilities	33	36
Other long-term liabilities	22	35
Total ARO liability	$ 55	$ 71