Regulatory Matters Regulatory Matters - NPC (Details) - Nevada Power Company [Member] - General Rate Case [Member] - Public Utilities Commission, Nevada [Member] - USD ($) $ in Millions	1 Months Ended
	Oct. 31, 2020	Sep. 30, 2020	Jun. 30, 2020
Schedule Of Regulatory Assets and Liabilities [Line Items]
Public Utilities, Interim Rate increase (Decrease), Amount			$ 96
Public Utilities, Requested Rate Increase (Decrease), Amount			$ 120
Public Utilities, Approved Rate Increase (Decrease), Amount		$ 93
Subsequent Event [Member]
Schedule Of Regulatory Assets and Liabilities [Line Items]
Public Utilities, Approved Bill Credit, Amount	$ 120