FAIR VALUE MEASUREMENTS (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Assets:
Price risk management instruments, netting	$ (9)	$ (16)
Price risk management instruments, assets	416	403
TOTAL ASSETS	9,087	7,404
Liabilities:
Price risk management instruments, netting	(12)	(16)
TOTAL LIABILITIES	269	303
Amount primarily related to deferred taxes on appreciation of investment value	744	747
Short-term investments
Assets:
Short-term investments	1,870	826
PERS
Assets:
Short-term investments	939	905
TOTAL ASSETS	939	905
Nuclear decommissioning trusts
Assets:
Short-term investments	60	53
Global equity securities	2,184	2,228
Fixed-income securities	2,333	2,277
TOTAL ASSETS	4,598	4,580
Customer credit trust
Assets:
Short-term investments	16	1
Global equity securities	465	186
Fixed-income securities	468	190
TOTAL ASSETS	949	377
Rabbi trusts
Assets:
Short-term investments	109	107
Global equity securities	5	6
Life insurance contracts	67	66
TOTAL ASSETS	181	179
Long-term disability trust
Assets:
Short-term investments	6	4
TOTAL ASSETS	134	134
Electricity
Assets:
Price risk management instruments, netting	(2)	(6)
Price risk management instruments, assets	407	403
Liabilities:
Price risk management instruments, netting	(5)	(6)
Price risk management instruments, liabilities	269	279
Gas
Assets:
Price risk management instruments, netting	(7)	(10)
Price risk management instruments, assets	9	0
Liabilities:
Price risk management instruments, netting	(7)	(10)
Price risk management instruments, liabilities	0	24
Level 1
Assets:
Price risk management instruments, gross subject to netting	0	0
TOTAL ASSETS	7,126	5,612
Liabilities:
TOTAL LIABILITIES	0	0
Level 1 | Short-term investments
Assets:
Short-term investments	1,870	826
Level 1 | PERS
Assets:
Short-term investments	939	905
TOTAL ASSETS	939	905
Level 1 | Nuclear decommissioning trusts
Assets:
Short-term investments	60	53
Global equity securities	2,184	2,228
Fixed-income securities	1,271	1,250
TOTAL ASSETS	3,515	3,531
Level 1 | Customer credit trust
Assets:
Short-term investments	16	1
Global equity securities	465	186
Fixed-income securities	201	46
TOTAL ASSETS	682	233
Level 1 | Rabbi trusts
Assets:
Short-term investments	109	107
Global equity securities	5	6
Life insurance contracts	0	0
TOTAL ASSETS	114	113
Level 1 | Long-term disability trust
Assets:
Short-term investments	6	4
TOTAL ASSETS	6	4
Level 1 | Electricity
Assets:
Price risk management instruments, gross subject to netting	0	0
Liabilities:
Price risk management instruments, gross subject to netting	0	0
Level 1 | Gas
Assets:
Price risk management instruments, gross subject to netting	0	0
Liabilities:
Price risk management instruments, gross subject to netting	0	0
Level 2
Assets:
Price risk management instruments, gross subject to netting	55	36
TOTAL ASSETS	1,451	1,273
Liabilities:
TOTAL LIABILITIES	37	71
Level 2 | Short-term investments
Assets:
Short-term investments	0	0
Level 2 | PERS
Assets:
Short-term investments	0	0
TOTAL ASSETS	0	0
Level 2 | Nuclear decommissioning trusts
Assets:
Short-term investments	0	0
Global equity securities	0	0
Fixed-income securities	1,062	1,027
TOTAL ASSETS	1,062	1,027
Level 2 | Customer credit trust
Assets:
Short-term investments	0	0
Global equity securities	0	0
Fixed-income securities	267	144
TOTAL ASSETS	267	144
Level 2 | Rabbi trusts
Assets:
Short-term investments	0	0
Global equity securities	0	0
Life insurance contracts	67	66
TOTAL ASSETS	67	66
Level 2 | Long-term disability trust
Assets:
Short-term investments	0	0
TOTAL ASSETS	0	0
Level 2 | Electricity
Assets:
Price risk management instruments, gross subject to netting	39	26
Liabilities:
Price risk management instruments, gross subject to netting	30	37
Level 2 | Gas
Assets:
Price risk management instruments, gross subject to netting	16	10
Liabilities:
Price risk management instruments, gross subject to netting	7	34
Level 3
Assets:
Price risk management instruments, gross subject to netting	370	383
TOTAL ASSETS	370	383
Liabilities:
TOTAL LIABILITIES	244	248
Level 3 | Short-term investments
Assets:
Short-term investments	0	0
Level 3 | PERS
Assets:
Short-term investments	0	0
TOTAL ASSETS	0	0
Level 3 | Nuclear decommissioning trusts
Assets:
Short-term investments	0	0
Global equity securities	0	0
Fixed-income securities	0	0
TOTAL ASSETS	0	0
Level 3 | Customer credit trust
Assets:
Short-term investments	0	0
Global equity securities	0	0
Fixed-income securities	0	0
TOTAL ASSETS	0	0
Level 3 | Rabbi trusts
Assets:
Short-term investments	0	0
Global equity securities	0	0
Life insurance contracts	0	0
TOTAL ASSETS	0	0
Level 3 | Long-term disability trust
Assets:
Short-term investments	0	0
TOTAL ASSETS	0	0
Level 3 | Electricity
Assets:
Price risk management instruments, gross subject to netting	370	383
Liabilities:
Price risk management instruments, gross subject to netting	244	248
Level 3 | Gas
Assets:
Price risk management instruments, gross subject to netting	0	0
Liabilities:
Price risk management instruments, gross subject to netting	0	0
Assets measured at NAV | Nuclear decommissioning trusts
Assets:
Assets measured at NAV	21	22
Assets measured at NAV | Long-term disability trust
Assets:
Assets measured at NAV	$ 128	$ 130