Jointly Owned Facilities (Tables)

12 Months Ended

Dec. 31, 2024

Regulated Operations [Abstract]

Schedule of Jointly Owned Utility Plants

At December 31, the Company's share of the cost of utility plant in service, construction work in progress and related accumulated depreciation for the jointly owned facilities was as follows:

	Ownership Percentage		2024		2023
			(In thousands)
Big Stone Station:	22.7	%
Utility plant in service			$	155,302	$	159,437
CWIP			318		197
Less accumulated depreciation			55,327		52,264
			$	100,293	$	107,370
BSSE:	50.0	%
Utility plant in service			$	111,043	$	107,260
CWIP			—		—
Less accumulated depreciation			10,359		8,111
			$	100,684	$	99,149
Coyote Station:	25.0	%
Utility plant in service			$	160,343	$	160,208
CWIP			755		159
Less accumulated depreciation			115,133		113,187
			$	45,965	$	47,180
JETx:	50.0	%
Utility plant in service			$	—	$	—
CWIP			6,112		1,372
Less accumulated depreciation			—		—
			$	6,112	$	1,372
Wygen III:	25.0	%
Utility plant in service			$	67,851	$	66,852
CWIP			97		127
Less accumulated depreciation			15,340		13,728
			$	52,608	$	53,251