Derivatives and Risk Management - Schedule of Energy Commodity Derivative Volumes (Details) MWh in Thousands, MMBTU in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2026 MWh MMBTU	Dec. 31, 2025 MMBTU MWh
Physical Purchases [Member] \| Electric Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Remainder 2026 \| MWh	6
Year one \| MWh	0	6
Year two \| MWh	0	0
Year three \| MWh	0	0
Physical Purchases [Member] \| Gas Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Remainder 2026 \| MMBTU	12,492
Year one \| MMBTU	21,640	30,523
Year two \| MMBTU	9,218	14,558
Year three \| MMBTU	1,350	4,413
Financial Purchases [Member] \| Electric Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Remainder 2026 \| MWh	0
Year one \| MWh	0	0
Year two \| MWh	0	0
Year three \| MWh	0	0
Financial Purchases [Member] \| Gas Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Remainder 2026 \| MMBTU	12,805
Year one \| MMBTU	27,075	30,535
Year two \| MMBTU	14,828	14,443
Year three \| MMBTU	7,370	5,393
Physical Sales [Member] \| Electric Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Remainder 2026 \| MWh	123
Year one \| MWh	0	373
Year two \| MWh	0	0
Year three \| MWh	0	0
Physical Sales [Member] \| Gas Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Remainder 2026 \| MMBTU	531
Year one \| MMBTU	1,393	2,325
Year two \| MMBTU	1,013	1,393
Year three \| MMBTU	0	1,013
Financial Sales [Member] \| Electric Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Remainder 2026 \| MWh	112
Year one \| MWh	159	328
Year two \| MWh	0	0
Year three \| MWh	0	0
Financial Sales [Member] \| Gas Derivative [Member]
Energy Commodity Derivative Volumes [Line Items]
Remainder 2026 \| MMBTU	0
Year one \| MMBTU	78	543
Year two \| MMBTU	0	0
Year three \| MMBTU	0	0