Subsidiary Debt - NV Energy (Details) - USD ($) $ in Millions	1 Months Ended
	Feb. 21, 2025	Dec. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Par value		$ 55,471
NPC
Debt Instrument [Line Items]
Par value		3,434
Subsidiary debt		3,395	$ 3,392
Eligible property subject to lien of mortgages		11,500
SPPC
Debt Instrument [Line Items]
Par value		1,537
Subsidiary debt		1,527	1,293
Eligible property subject to lien of mortgages		5,200
3.70% Series CC, due 2029 | NPC
Debt Instrument [Line Items]
Par value		500
2.40% Series DD, due 2030 | NPC
Debt Instrument [Line Items]
Par value		425
6.65% Series N, due 2036 | NPC
Debt Instrument [Line Items]
Par value		367
6.75% Series R, due 2037 | NPC
Debt Instrument [Line Items]
Par value		349
5.375% Series X, due 2040 | NPC
Debt Instrument [Line Items]
Par value		250
5.45% Series Y, due 2041 | NPC
Debt Instrument [Line Items]
Par value		250
3.125% Series EE, due 2050 | NPC
Debt Instrument [Line Items]
Par value		300
5.90% Series GG, due 2053 | NPC
Debt Instrument [Line Items]
Par value		400
6.00% Series 2023A, due 2054 | NPC
Debt Instrument [Line Items]
Par value		500
4.125% Pollution Control Bonds Series 2017A, due 2032 | NPC
Debt Instrument [Line Items]
Par value		40
3.750% Pollution Control Bonds Series 2017, due 2036 | NPC
Debt Instrument [Line Items]
Par value		40
3.750% Pollution Control Bonds Series 2017B, due 2039 | NPC
Debt Instrument [Line Items]
Par value		13
2.60% Series U, due 2026 | SPPC
Debt Instrument [Line Items]
Par value		400
6.75% Series P, due 2037 | SPPC
Debt Instrument [Line Items]
Par value		252
4.71% Series W, due 2052 | SPPC
Debt Instrument [Line Items]
Par value		250
5.90% Series 2023A, due 2054 | SPPC
Debt Instrument [Line Items]
Par value		$ 400
3.550% Pollution Control Series 2016B, due 2029 | SPPC
Debt Instrument [Line Items]
Stated rate		3.55%
Par value		$ 30
Subject to mandatory sinking fund redemption		10
Junior Subordinated Notes due 2055 | NPC | Subsequent event
Debt Instrument [Line Items]
Stated rate	6.25%
Par value	$ 300
Debt instrument, term	5 years
Subsidiary debt
Debt Instrument [Line Items]
Par value		42,270
Subsidiary debt		42,150	38,971
Subsidiary debt | NPC
Debt Instrument [Line Items]
Par value		3,434
Subsidiary debt		3,395
Subsidiary debt | SPPC
Debt Instrument [Line Items]
Par value		1,537
Subsidiary debt		$ 1,527
Subsidiary debt | 3.70% Series CC, due 2029 | NPC
Debt Instrument [Line Items]
Stated rate		3.70%
Subsidiary debt		$ 498	498
Subsidiary debt | 2.40% Series DD, due 2030 | NPC
Debt Instrument [Line Items]
Stated rate		2.40%
Subsidiary debt		$ 423	423
Subsidiary debt | 6.65% Series N, due 2036 | NPC
Debt Instrument [Line Items]
Stated rate		6.65%
Subsidiary debt		$ 361	360
Subsidiary debt | 6.75% Series R, due 2037 | NPC
Debt Instrument [Line Items]
Stated rate		6.75%
Subsidiary debt		$ 347	346
Subsidiary debt | 5.375% Series X, due 2040 | NPC
Debt Instrument [Line Items]
Stated rate		5.375%
Subsidiary debt		$ 248	248
Subsidiary debt | 5.45% Series Y, due 2041 | NPC
Debt Instrument [Line Items]
Stated rate		5.45%
Subsidiary debt		$ 240	240
Subsidiary debt | 3.125% Series EE, due 2050 | NPC
Debt Instrument [Line Items]
Stated rate		3.125%
Subsidiary debt		$ 298	298
Subsidiary debt | 5.90% Series GG, due 2053 | NPC
Debt Instrument [Line Items]
Subsidiary debt		$ 394	394
Subsidiary debt | 6.00% Series 2023A, due 2054 | NPC
Debt Instrument [Line Items]
Stated rate		6.00%
Subsidiary debt		$ 495	494
Subsidiary debt | 4.125% Pollution Control Bonds Series 2017A, due 2032 | NPC
Debt Instrument [Line Items]
Stated rate		4.125%
Subsidiary debt		$ 39	39
Subsidiary debt | 3.750% Pollution Control Bonds Series 2017, due 2036 | NPC
Debt Instrument [Line Items]
Stated rate		3.75%
Subsidiary debt		$ 39	39
Subsidiary debt | 3.750% Pollution Control Bonds Series 2017B, due 2039 | NPC
Debt Instrument [Line Items]
Stated rate		3.75%
Subsidiary debt		$ 13	13
Subsidiary debt | 2.60% Series U, due 2026 | SPPC
Debt Instrument [Line Items]
Stated rate		2.60%
Subsidiary debt		$ 399	398
Subsidiary debt | 6.75% Series P, due 2037 | SPPC
Debt Instrument [Line Items]
Stated rate		6.75%
Subsidiary debt		$ 254	254
Subsidiary debt | 4.71% Series W, due 2052 | SPPC
Debt Instrument [Line Items]
Stated rate		4.71%
Subsidiary debt		$ 248	248
Subsidiary debt | 5.90% Series 2023A, due 2054 | SPPC
Debt Instrument [Line Items]
Stated rate		5.90%
Subsidiary debt		$ 394	393
Subsidiary debt | 3.550% Pollution Control Series 2016B, due 2029 | SPPC
Debt Instrument [Line Items]
Subsidiary debt		29	0
NV Energy | NPC
Debt Instrument [Line Items]
Eligible property subject to lien of mortgages		11,500
NV Energy | SPPC
Debt Instrument [Line Items]
Eligible property subject to lien of mortgages		5,200
NV Energy | Subsidiary debt
Debt Instrument [Line Items]
Par value		4,971
Subsidiary debt		4,932	4,695
Debt, net of fair value adjustments		4,932	4,695
NV Energy | Subsidiary debt | NPC
Debt Instrument [Line Items]
Par value		3,434
Subsidiary debt		3,395	3,392
Fair value adjustments		9	9
Debt, net of fair value adjustments		3,404	3,401
NV Energy | Subsidiary debt | SPPC
Debt Instrument [Line Items]
Par value		1,537
Subsidiary debt		1,527	1,293
Fair value adjustments		1	1
Debt, net of fair value adjustments		$ 1,528	1,294
NV Energy | Subsidiary debt | 3.70% Series CC, due 2029 | NPC
Debt Instrument [Line Items]
Stated rate		3.70%
Par value		$ 500
Subsidiary debt		$ 498	498
NV Energy | Subsidiary debt | 2.40% Series DD, due 2030 | NPC
Debt Instrument [Line Items]
Stated rate		2.40%
Par value		$ 425
Subsidiary debt		$ 423	423
NV Energy | Subsidiary debt | 6.65% Series N, due 2036 | NPC
Debt Instrument [Line Items]
Stated rate		6.65%
Par value		$ 367
Subsidiary debt		$ 361	360
NV Energy | Subsidiary debt | 6.75% Series R, due 2037 | NPC
Debt Instrument [Line Items]
Stated rate		6.75%
Par value		$ 349
Subsidiary debt		$ 347	346
NV Energy | Subsidiary debt | 5.375% Series X, due 2040 | NPC
Debt Instrument [Line Items]
Stated rate		5.375%
Par value		$ 250
Subsidiary debt		$ 248	248
NV Energy | Subsidiary debt | 5.45% Series Y, due 2041 | NPC
Debt Instrument [Line Items]
Stated rate		5.45%
Par value		$ 250
Subsidiary debt		$ 240	240
NV Energy | Subsidiary debt | 3.125% Series EE, due 2050 | NPC
Debt Instrument [Line Items]
Stated rate		3.125%
Par value		$ 300
Subsidiary debt		$ 298	298
NV Energy | Subsidiary debt | 5.90% Series GG, due 2053 | NPC
Debt Instrument [Line Items]
Stated rate		5.90%
Par value		$ 400
Subsidiary debt		$ 394	394
NV Energy | Subsidiary debt | 6.00% Series 2023A, due 2054 | NPC
Debt Instrument [Line Items]
Stated rate		6.00%
Par value		$ 500
Subsidiary debt		$ 495	494
NV Energy | Subsidiary debt | 4.125% Pollution Control Bonds Series 2017A, due 2032 | NPC
Debt Instrument [Line Items]
Stated rate		4.125%
Par value		$ 40
Subsidiary debt		$ 39	39
NV Energy | Subsidiary debt | 3.750% Pollution Control Bonds Series 2017, due 2036 | NPC
Debt Instrument [Line Items]
Stated rate		3.75%
Par value		$ 40
Subsidiary debt		$ 39	39
NV Energy | Subsidiary debt | 3.750% Pollution Control Bonds Series 2017B, due 2039 | NPC
Debt Instrument [Line Items]
Stated rate		3.75%
Par value		$ 13
Subsidiary debt		$ 13	13
NV Energy | Subsidiary debt | 2.60% Series U, due 2026 | SPPC
Debt Instrument [Line Items]
Stated rate		2.60%
Par value		$ 400
Subsidiary debt		$ 399	398
NV Energy | Subsidiary debt | 6.75% Series P, due 2037 | SPPC
Debt Instrument [Line Items]
Stated rate		6.75%
Par value		$ 252
Subsidiary debt		$ 254	254
NV Energy | Subsidiary debt | 4.71% Series W, due 2052 | SPPC
Debt Instrument [Line Items]
Stated rate		4.71%
Par value		$ 250
Subsidiary debt		$ 248	248
NV Energy | Subsidiary debt | 5.90% Series 2023A, due 2054 | SPPC
Debt Instrument [Line Items]
Stated rate		5.90%
Par value		$ 400
Subsidiary debt		$ 394	393
NV Energy | Subsidiary debt | 3.55% Pollution Control Series 2016A, due 2029 | SPPC
Debt Instrument [Line Items]
Stated rate		3.55%
Par value		$ 20
Subsidiary debt		$ 20	0
NV Energy | Subsidiary debt | 3.550% Pollution Control Series 2016B, due 2029 | SPPC
Debt Instrument [Line Items]
Stated rate		3.55%
Par value		$ 30
Subsidiary debt		$ 29	0
NV Energy | Subsidiary debt | 3.625% Gas and Water Series 2016B, due 2036 | SPPC
Debt Instrument [Line Items]
Stated rate		3.625%
Par value		$ 60
Subsidiary debt		$ 59	0
NV Energy | Subsidiary debt | 4.125% Water Facilities Series 2016C, due 2036 | SPPC
Debt Instrument [Line Items]
Stated rate		4.125%
Par value		$ 30
Subsidiary debt		$ 30	0
NV Energy | Subsidiary debt | 4.125% Water Facilities Series 2016F, due 2036 | SPPC
Debt Instrument [Line Items]
Stated rate		4.125%
Par value		$ 75
Subsidiary debt		$ 74	0
NV Energy | Subsidiary debt | 3.625% Water Facilities Series 2016G, due 2036 | SPPC
Debt Instrument [Line Items]
Stated rate		3.625%
Par value		$ 20
Subsidiary debt		$ 20	$ 0