Retirement Plan and Postretirement Benefits (Tables)

12 Months Ended

Dec. 31, 2020

Nevada Power Company [Member]

Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]

Schedule of Amounts Recognized in Balance Sheet [Table Text Block]

Amounts receivable from (payable to) NV Energy are included on the Consolidated Balance Sheets and consist of the following as of December 31 (in millions):

	2020		2019
Qualified Pension Plan:
Other non-current assets	$	8	$	—
Other long-term liabilities	—		(18)
Non-Qualified Pension Plans:
Other current liabilities	(1)		(1)
Other long-term liabilities	(9)		(9)
Other Postretirement Plans:
Other non-current assets	4		—
Other long-term liabilities	—		(2)

Sierra Pacific Power Company [Member]

Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]

Schedule of Amounts Recognized in Balance Sheet [Table Text Block]

Amounts receivable from (payable to) NV Energy are included on the Balance Sheets and consist of the following as of December 31 (in millions):

	2020		2019
Qualified Pension Plan:
Other non-current assets	$	26	$	—
Other long-term liabilities	—		(4)
Non-Qualified Pension Plans:
Other current liabilities	(1)		(1)
Other long-term liabilities	(8)		(8)
Other Postretirement Plans -
Other long-term liabilities	(13)		(7)