Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Operating Activities:
Net Income	$ 57,608	$ 59,759
Items not affecting cash:
Depreciation and amortization	53,532	49,730
Deferred income taxes	(1,351)	12,713
Provision for doubtful receivables	4,400	882
Employee benefit plan cost (credit)	323	(1,227)
Equity earnings in investments	(5,526)	(5,240)
Other items	930	(885)
Changes in working capital items:
Decrease in current assets	22,086	34,098
Decrease in accounts payable	(9,646)	(20,508)
Increase (decrease) in current liabilities	3,718	(2,105)
Dividends from investments	4,238	4,248
Cash contributions to pension and other postretirement plans	(3,634)	(3,540)
Other noncurrent items, net	3,756	(934)
Cash Provided by Operating Activities	130,434	126,991
Investing Activities:
Capital expenditures	(111,622)	(107,701)
Capital contributions to investments	(3,159)	(3,376)
Other	1,272	(682)
Cash Used for Investing Activities	(113,509)	(111,759)
Financing Activities:
Cash dividends paid on common stock	(30,930)	(29,473)
Repayments of long-term debt	(2,556)	(21,791)
Issuance of long-term debt	0	69,300
Proceeds from (repayments of) short-term debt	21,800	(28,500)
Other	(728)	(1,479)
Cash Used for Financing Activities	(12,414)	(11,943)
Change in cash, cash equivalents, and restricted cash	4,511	3,289
Cash, cash equivalents, and restricted cash at beginning of period	15,026	17,968
Cash, cash equivalents, and restricted cash at end of period	19,537	21,257
Significant noncash investing activities:
Accrued capital expenditures	11,416	6,446
MGE [Member]
Operating Activities:
Net Income	53,954	57,250
Items not affecting cash:
Depreciation and amortization	53,532	49,730
Deferred income taxes	(1,287)	11,955
Provision for doubtful receivables	4,400	882
Employee benefit plan cost (credit)	323	(1,227)
Other items	1,446	(1,344)
Changes in working capital items:
Decrease in current assets	22,098	33,520
Decrease in accounts payable	(9,642)	(20,560)
Increase (decrease) in current liabilities	4,774	(188)
Cash contributions to pension and other postretirement plans	(3,634)	(3,540)
Other noncurrent items, net	2,465	(1,428)
Cash Provided by Operating Activities	128,429	125,050
Investing Activities:
Capital expenditures	(111,622)	(107,701)
Other	(894)	(805)
Cash Used for Investing Activities	(112,516)	(108,506)
Financing Activities:
Cash dividends paid to parent by MGE	(24,000)	(21,000)
Distributions to parent from noncontrolling interest	(10,000)	(10,250)
Repayments of long-term debt	(2,556)	(21,791)
Issuance of long-term debt	0	69,300
Proceeds from (repayments of) short-term debt	21,800	(28,500)
Other	(728)	(1,479)
Cash Used for Financing Activities	(15,484)	(13,720)
Change in cash, cash equivalents, and restricted cash	429	2,824
Cash, cash equivalents, and restricted cash at beginning of period	6,705	10,500
Cash, cash equivalents, and restricted cash at end of period	7,134	13,324
Significant noncash investing activities:
Accrued capital expenditures	$ 11,416	$ 6,446