Employee Benefit Plans - NPC (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Other Postretirement
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	$ 14,000,000	$ 3,000,000
Other assets	60,000,000	20,000,000
Other current liabilities	0	0
Other long-term liabilities	(5,000,000)	(34,000,000)
United States | Pension
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	13,000,000	13,000,000
Other assets	204,000,000	43,000,000
Other current liabilities	(13,000,000)	(13,000,000)
Other long-term liabilities	(173,000,000)	(283,000,000)
United States | Other Postretirement | NPC
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	0	0	$ 0
United States | Other Postretirement | NPC | Other non-current assets | NV Energy
Defined Benefit Plan Disclosure [Line Items]
Other assets	8,000,000	4,000,000
United States | Qualified Plan | Pension | NPC
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	0	0	0
United States | Qualified Plan | Pension | NPC | Other non-current assets | NV Energy
Defined Benefit Plan Disclosure [Line Items]
Other assets	42,000,000	8,000,000
United States | Nonqualified Plan | Other Pension Plan | NPC
Defined Benefit Plan Disclosure [Line Items]
Employer contributions	1,000,000	1,000,000	$ 1,000,000
United States | Nonqualified Plan | Other Pension Plan | NPC | Other current liabilities | NV Energy
Defined Benefit Plan Disclosure [Line Items]
Other current liabilities	(1,000,000)	(1,000,000)
United States | Nonqualified Plan | Other Pension Plan | NPC | Other long-term liabilities | NV Energy
Defined Benefit Plan Disclosure [Line Items]
Other long-term liabilities	$ (8,000,000)	$ (9,000,000)