FAIR VALUE MEASUREMENTS (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Assets:
Price risk management instruments, netting	$ (11)	$ (52)
TOTAL ASSETS	8,536	8,274
Liabilities:
Price risk management instruments, netting	(41)	(52)
TOTAL LIABILITIES	161	223
Amount primarily related to deferred taxes on appreciation of investment value	854	881
Self-insurance investments
Assets:
TOTAL ASSETS	1,000	1,000
Pacific Casualty Insurance Company, LLC
Assets:
TOTAL ASSETS	119	77
Short-term investments
Assets:
Short-term investments	1,016	634
Self-insurance investments
Assets:
Short-term investments	1,178	1,120
TOTAL ASSETS	1,178	1,120
Nuclear decommissioning trusts
Assets:
Short-term investments	53	94
Global equity securities	2,336	2,433
Fixed-income securities	2,625	2,558
Price risk management instruments, netting		0
TOTAL ASSETS	5,039	5,111
Customer credit trust
Assets:
Short-term investments	127	111
Global equity securities	0	0
Fixed-income securities	564	693
TOTAL ASSETS	691	804
Rabbi trusts
Assets:
Short-term investments	117	115
Global equity securities	5	5
Life insurance contracts	65	65
TOTAL ASSETS	187	185
Long-term disability trust
Assets:
Short-term investments	1	10
TOTAL ASSETS	128	137
Total price risk management instruments
Assets:
Price risk management instruments, netting	(11)	(52)
Price risk management instruments, assets	297	283
Electricity
Assets:
Price risk management instruments, netting	(9)	(6)
Price risk management instruments, assets	282	296
Liabilities:
Price risk management instruments, netting	(39)	(6)
Price risk management instruments, liabilities	160	204
Gas
Assets:
Price risk management instruments, netting	(2)	(46)
Price risk management instruments, assets	15	(13)
Liabilities:
Price risk management instruments, netting	(2)	(46)
Price risk management instruments, liabilities	1	19
Level 1
Assets:
TOTAL ASSETS	6,529	6,334
Liabilities:
TOTAL LIABILITIES	0	0
Level 1 | Short-term investments
Assets:
Short-term investments	1,016	634
Level 1 | Self-insurance investments
Assets:
Short-term investments	1,178	1,120
TOTAL ASSETS	1,178	1,120
Level 1 | Nuclear decommissioning trusts
Assets:
Short-term investments	53	94
Global equity securities	2,336	2,433
Fixed-income securities	1,518	1,445
TOTAL ASSETS	3,907	3,972
Level 1 | Customer credit trust
Assets:
Short-term investments	127	111
Global equity securities	0
Fixed-income securities	178	367
TOTAL ASSETS	305	478
Level 1 | Rabbi trusts
Assets:
Short-term investments	117	115
Global equity securities	5	5
Life insurance contracts	0	0
TOTAL ASSETS	122	120
Level 1 | Long-term disability trust
Assets:
Short-term investments	1	10
TOTAL ASSETS	1	10
Level 1 | Total price risk management instruments
Assets:
Price risk management instruments, gross subject to netting	0	0
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:
TOTAL ASSETS	1,606	1,556
Liabilities:
TOTAL LIABILITIES	34	145
Level 2 | Short-term investments
Assets:
Short-term investments	0	0
Level 2 | Self-insurance investments
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	1,107	1,113
TOTAL ASSETS	1,107	1,113
Level 2 | Customer credit trust
Assets:
Short-term investments	0	0
Global equity securities	0	0
Fixed-income securities	386	326
TOTAL ASSETS	386	326
Level 2 | Rabbi trusts
Assets:
Short-term investments	0	0
Global equity securities	0	0
Life insurance contracts	65	65
TOTAL ASSETS	65	65
Level 2 | Long-term disability trust
Assets:
Short-term investments	0	0
TOTAL ASSETS	0	0
Level 2 | Total price risk management instruments
Assets:
Price risk management instruments, gross subject to netting	48	52
Level 2 | Electricity
Assets:
Price risk management instruments, gross subject to netting	31	19
Liabilities:
Price risk management instruments, gross subject to netting	31	80
Level 2 | Gas
Assets:
Price risk management instruments, gross subject to netting	17	33
Liabilities:
Price risk management instruments, gross subject to netting	3	65
Level 3
Assets:
TOTAL ASSETS	260	283
Liabilities:
TOTAL LIABILITIES	168	130
Level 3 | Short-term investments
Assets:
Short-term investments	0	0
Level 3 | Self-insurance investments
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 | Total price risk management instruments
Assets:
Price risk management instruments, gross subject to netting	260	283
Level 3 | Electricity
Assets:
Price risk management instruments, gross subject to netting	260	283
Liabilities:
Price risk management instruments, gross subject to netting	168	130
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	25	26
Assets measured at NAV | Long-term disability trust
Assets:
Assets measured at NAV	$ 127	$ 127