Employee Benefit Plans - EEGH - Voluntary Retirement Program (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Jun. 30, 2019
Other Postretirement
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.24%	2.95%	2.59%
EEGH | Voluntary Retirement Program
Defined Benefit Plan Disclosure [Line Items]
Cost of providing special and contractual termination benefits	$ 74
Cost of providing special and contractual termination benefits, after-tax	58
EEGH | Voluntary Retirement Program | Operations and maintenance expense
Defined Benefit Plan Disclosure [Line Items]
Cost of providing special and contractual termination benefits	41
EEGH | Voluntary Retirement Program | Other nonoperating income (expense)
Defined Benefit Plan Disclosure [Line Items]
Cost of providing special and contractual termination benefits	1
EEGH | Voluntary Retirement Program | Income (loss) from discontinued operations, net
Defined Benefit Plan Disclosure [Line Items]
Cost of providing special and contractual termination benefits	$ 32
EEGH | Pension
Defined Benefit Plan Disclosure [Line Items]
Discount rate				4.10%
EEGH | Other Postretirement
Defined Benefit Plan Disclosure [Line Items]
Discount rate				4.05%