Regulatory Matters - EEGH - Regulatory Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Regulatory Liabilities [Line Items]
Total regulatory liabilities	$ 7,214	$ 7,475
Regulatory liabilities	254	254
Regulatory liabilities, noncurrent	6,960	7,221
Deferred income taxes
Regulatory Liabilities [Line Items]
Total regulatory liabilities	3,185	3,600
Other postretirement benefit costs
Regulatory Liabilities [Line Items]
Total regulatory liabilities	$ 243	187
Cost of removal
Regulatory Liabilities [Line Items]
Regulatory liability, amortization period	26 years
Total regulatory liabilities	$ 2,424	2,435
EEGH
Regulatory Liabilities [Line Items]
Total regulatory liabilities	685	709
Regulatory liabilities	40	40
Regulatory liabilities, noncurrent	645	669
EEGH | Deferred income taxes
Regulatory Liabilities [Line Items]
Total regulatory liabilities	468	473
EEGH | Other postretirement benefit costs
Regulatory Liabilities [Line Items]
Total regulatory liabilities	$ 116	115
EEGH | Cost of removal
Regulatory Liabilities [Line Items]
Regulatory liability, amortization period	44 years
Total regulatory liabilities	$ 73	88
Regulatory liabilities, noncurrent	73	88
EEGH | Other
Regulatory Liabilities [Line Items]
Total regulatory liabilities	$ 28	$ 33