DERIVATIVES (Volumes of Outstanding Derivative Contracts) (Details)	Dec. 31, 2022 MWh MMBTU	Dec. 31, 2021 MWh MMBTU
Forwards, Futures and Swaps | Natural Gas (MMBtus)
Derivative [Line Items]
Contract Volume	171,212,813	173,361,635
Forwards, Futures and Swaps | Electricity (MWh)
Derivative [Line Items]
Contract Volume | MWh	10,814,728	10,283,639
Options | Natural Gas (MMBtus)
Derivative [Line Items]
Contract Volume	27,785,000	14,420,000
Options | Electricity (MWh)
Derivative [Line Items]
Contract Volume	215,600	288,000
Congestion revenue rights | Electricity (MWh)
Derivative [Line Items]
Contract Volume | MWh	205,743,505	239,857,610