Consolidated Statements of Changes in Equity - NPC - USD ($) $ in Millions	Total	Common Stock [Member]	Nevada Power Company [Member]	Nevada Power Company [Member] Common Stock [Member]	Nevada Power Company [Member] Additional Paid-in Capital [Member]	Nevada Power Company [Member] Retained Earnings [Member]	Nevada Power Company [Member] Accumulated Other Comprehensive (Loss) Income, Net [Member]
Balance (shares) at Dec. 31, 2017		77,000,000		1,000
Stockholders' Equity Attributable to Parent at Dec. 31, 2017			$ 2,678	$ 0	$ 2,308	$ 374	$ (4)
Net Income (Loss) Attributable to Parent	$ 513		0
Balance (shares) at Mar. 31, 2018		77,000,000		1,000
Stockholders' Equity Attributable to Parent at Mar. 31, 2018			$ 2,678	$ 0	2,308	374	(4)
Balance (shares) at Dec. 31, 2018	77,000,000	77,000,000	1,000	1,000
Stockholders' Equity Attributable to Parent at Dec. 31, 2018	$ 29,593		$ 2,904	$ 0	2,308	600	(4)
Net Income (Loss) Attributable to Parent	$ 622		6			6
Dividends, Common Stock, Cash			$ 75			75
Balance (shares) at Mar. 31, 2019	77,000,000	77,000,000	1,000	1,000
Stockholders' Equity Attributable to Parent at Mar. 31, 2019	$ 30,036		$ 2,835	$ 0	$ 2,308	$ 531	$ (4)