Income Taxes - EGTS (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Federal statutory income tax rate	21.00%	21.00%	21.00%	21.00%
State income tax, net of federal income tax impacts	0.00%	(4.00%)	(2.00%)	0.00%
Other	0.00%	1.00%	3.00%	1.00%
Effective income tax rate	64.00%	(21.00%)	(178.00%)	(13.00%)
EGTS
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Federal statutory income tax rate	21.00%	21.00%	21.00%	21.00%
State income tax, net of federal income tax impacts	11.00%	6.00%	8.00%	7.00%
Effects of ratemaking	0.00%	(4.00%)	0.00%	(3.00%)
Debt exchange	0.00%	0.00%	0.00%	2.00%
Other	1.00%	1.00%	0.00%	(1.00%)
Effective income tax rate	33.00%	24.00%	29.00%	26.00%