FAIR VALUE MEASUREMENTS (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Assets:
Price risk management instruments, netting	$ (8)	$ 42
Price risk management instruments, assets	348	456
TOTAL ASSETS	7,051	5,501
Liabilities:
Price risk management instruments, netting	(17)	(54)
TOTAL LIABILITIES	275	278
Amount primarily related to deferred taxes on appreciation of investment value	822	717
Short-term investments
Assets:
Short-term investments	459	203
PERS
Assets:
Short-term investments	761
TOTAL ASSETS	761
Nuclear decommissioning trusts
Assets:
Short-term investments	42	52
Global equity securities	2,347	2,144
Fixed-income securities	2,323	2,077
TOTAL ASSETS	4,734	4,291
Customer credit trust
Assets:
Short-term investments	5	49
Global equity securities	223	71
Fixed-income securities	218	113
TOTAL ASSETS	446	233
Rabbi trusts
Assets:
Short-term investments	106	102
Global equity securities	6	5
Life insurance contracts	66	65
TOTAL ASSETS	178	172
Long-term disability trust
Assets:
Short-term investments	4	7
TOTAL ASSETS	125	146
Electricity
Assets:
Price risk management instruments, netting	(3)	(1)
Price risk management instruments, assets	341	410
Liabilities:
Price risk management instruments, netting	(9)	(6)
Price risk management instruments, liabilities	269	250
Gas
Assets:
Price risk management instruments, netting	(5)	43
Price risk management instruments, assets	7	46
Liabilities:
Price risk management instruments, netting	(8)	(48)
Price risk management instruments, liabilities	6	28
Level 1
Assets:
Price risk management instruments, gross subject to netting	0	0
TOTAL ASSETS	5,335	3,830
Liabilities:
TOTAL LIABILITIES	0	0
Level 1 | Short-term investments
Assets:
Short-term investments	459	203
Level 1 | PERS
Assets:
Short-term investments	761
TOTAL ASSETS	761
Level 1 | Nuclear decommissioning trusts
Assets:
Short-term investments	42	52
Global equity securities	2,347	2,144
Fixed-income securities	1,306	1,168
TOTAL ASSETS	3,695	3,364
Level 1 | Customer credit trust
Assets:
Short-term investments	5	49
Global equity securities	223	71
Fixed-income securities	76	29
TOTAL ASSETS	304	149
Level 1 | Rabbi trusts
Assets:
Short-term investments	106	102
Global equity securities	6	5
Life insurance contracts	0	0
TOTAL ASSETS	112	107
Level 1 | Long-term disability trust
Assets:
Short-term investments	4	7
TOTAL ASSETS	4	7
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	40	10
TOTAL ASSETS	1,265	1,068
Liabilities:
TOTAL LIABILITIES	107	119
Level 2 | Short-term investments
Assets:
Short-term investments	0	0
Level 2 | PERS
Assets:
Short-term investments	0
TOTAL ASSETS	0
Level 2 | Nuclear decommissioning trusts
Assets:
Short-term investments	0	0
Global equity securities	0	0
Fixed-income securities	1,017	909
TOTAL ASSETS	1,017	909
Level 2 | Customer credit trust
Assets:
Short-term investments	0	0
Global equity securities	0	0
Fixed-income securities	142	84
TOTAL ASSETS	142	84
Level 2 | Rabbi trusts
Assets:
Short-term investments	0	0
Global equity securities	0	0
Life insurance contracts	66	65
TOTAL ASSETS	66	65
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	28	7
Liabilities:
Price risk management instruments, gross subject to netting	93	43
Level 2 | Gas
Assets:
Price risk management instruments, gross subject to netting	12	3
Liabilities:
Price risk management instruments, gross subject to netting	14	76
Level 3
Assets:
Price risk management instruments, gross subject to netting	316	404
TOTAL ASSETS	316	404
Liabilities:
TOTAL LIABILITIES	185	213
Level 3 | Short-term investments
Assets:
Short-term investments	0	0
Level 3 | PERS
Assets:
Short-term investments	0
TOTAL ASSETS	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	316	404
Liabilities:
Price risk management instruments, gross subject to netting	185	213
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	22	18
Assets measured at NAV | Long-term disability trust
Assets:
Assets measured at NAV	$ 121	$ 139