FAIR VALUE MEASUREMENTS (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Assets:
Short-term investments		$ 289
Price risk management instruments, netting	$ 46	143
Price risk management instruments, assets	292	370
TOTAL ASSETS	5,170	5,558
Liabilities:
Price risk management instruments, netting	(42)	(27)
TOTAL LIABILITIES	259	242
Amount primarily related to deferred taxes on appreciation of investment value	559	783
Short-term investments
Assets:
Short-term investments	197
Fixed-income securities
Assets:
Short-term investments	50
Nuclear decommissioning trusts
Assets:
Short-term investments	60	22
Global equity securities	1,826	2,504
Fixed-income securities	1,939	2,024
TOTAL ASSETS	3,850	4,581
Customer credit trust
Assets:
Short-term investments	98
Global equity securities	132
Fixed-income securities	248
TOTAL ASSETS	478
Rabbi trusts
Assets:
Fixed-income securities	96	104
Life insurance contracts	68	76
TOTAL ASSETS	164	180
Long-term disability trust
Assets:
Short-term investments	8	6
TOTAL ASSETS	139	138
Price Risk Derivative, Electricity
Assets:
Price risk management instruments, netting	25	6
Price risk management instruments, assets	256	229
Liabilities:
Price risk management instruments, netting	(29)	(24)
Price risk management instruments, liabilities	240	235
Price Risk Derivative, Gas
Assets:
Price risk management instruments, netting	21	137
Price risk management instruments, assets	36	141
Liabilities:
Price risk management instruments, netting	(13)	(3)
Price risk management instruments, liabilities	19	7
Level 1
Assets:
Short-term investments		289
Price risk management instruments, gross subject to netting	0	0
TOTAL ASSETS	3,456	3,979
Liabilities:
TOTAL LIABILITIES	0	0
Level 1 | Short-term investments
Assets:
Short-term investments	197
Level 1 | Fixed-income securities
Assets:
Short-term investments	0
Level 1 | Nuclear decommissioning trusts
Assets:
Short-term investments	60	22
Global equity securities	1,826	2,504
Fixed-income securities	1,089	1,158
TOTAL ASSETS	2,975	3,684
Level 1 | Customer credit trust
Assets:
Short-term investments	43
Global equity securities	132
Fixed-income securities	101
TOTAL ASSETS	276
Level 1 | Rabbi trusts
Assets:
Fixed-income securities	0	0
Life insurance contracts	0	0
TOTAL ASSETS	0	0
Level 1 | Long-term disability trust
Assets:
Short-term investments	8	6
TOTAL ASSETS	8	6
Level 1 | Price Risk Derivative, 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 | Price Risk Derivative, 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:
Short-term investments		0
Price risk management instruments, gross subject to netting	41	13
TOTAL ASSETS	1,307	1,059
Liabilities:
TOTAL LIABILITIES	107	21
Level 2 | Short-term investments
Assets:
Short-term investments	0
Level 2 | Fixed-income securities
Assets:
Short-term investments	50
Level 2 | Nuclear decommissioning trusts
Assets:
Short-term investments	0	0
Global equity securities	0	0
Fixed-income securities	850	866
TOTAL ASSETS	850	866
Level 2 | Customer credit trust
Assets:
Short-term investments	55
Global equity securities	0
Fixed-income securities	147
TOTAL ASSETS	202
Level 2 | Rabbi trusts
Assets:
Fixed-income securities	96	104
Life insurance contracts	68	76
TOTAL ASSETS	164	180
Level 2 | Long-term disability trust
Assets:
Short-term investments	0	0
TOTAL ASSETS	0	0
Level 2 | Price Risk Derivative, Electricity
Assets:
Price risk management instruments, gross subject to netting	26	9
Liabilities:
Price risk management instruments, gross subject to netting	75	11
Level 2 | Price Risk Derivative, Gas
Assets:
Price risk management instruments, gross subject to netting	15	4
Liabilities:
Price risk management instruments, gross subject to netting	32	10
Level 3
Assets:
Short-term investments		0
Price risk management instruments, gross subject to netting	205	214
TOTAL ASSETS	205	214
Liabilities:
TOTAL LIABILITIES	194	248
Level 3 | Short-term investments
Assets:
Short-term investments	0
Level 3 | Fixed-income securities
Assets:
Short-term investments	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
Global equity securities	0
Fixed-income securities	0
TOTAL ASSETS	0
Level 3 | Rabbi trusts
Assets:
Fixed-income 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 | Price Risk Derivative, Electricity
Assets:
Price risk management instruments, gross subject to netting	205	214
Liabilities:
Price risk management instruments, gross subject to netting	194	248
Level 3 | Price Risk Derivative, Gas
Assets:
Price risk management instruments, gross subject to netting	0	0
Liabilities:
Price risk management instruments, gross subject to netting	0	0
Fair Value Measured at Net Asset Value Per Share | Nuclear decommissioning trusts
Assets:
Assets measured at NAV	25	31
Fair Value Measured at Net Asset Value Per Share | Long-term disability trust
Assets:
Assets measured at NAV	$ 131	$ 132