Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating Activities:
Net Income	$ 76,622	$ 70,212
Items not affecting cash:
Depreciation and amortization	55,193	53,423
Deferred income taxes	8,464	4,864
Provision for doubtful receivables	1,078	978
Employee benefit plan credit	(2,813)	(2,866)
Equity earnings in investments	(7,780)	(6,879)
Other items	382	692
Changes in working capital items:
Decrease in current assets	5,494	14,307
Decrease in current liabilities	(8,808)	(24,088)
Dividends from investments	6,929	5,526
Cash contributions to pension and other postretirement plans	(4,576)	(3,707)
Other noncurrent items, net	5,826	(760)
Cash Provided by Operating Activities	136,011	111,702
Investing Activities:
Capital expenditures	(139,055)	(128,389)
Capital contributions to investments	(4,007)	(5,894)
Other	(1,298)	(248)
Cash Used for Investing Activities	(144,360)	(134,531)
Financing Activities:
Issuance of common stock, net	79,635	0
Cash dividends paid on common stock	(38,349)	(35,622)
Repayments of long-term debt	(22,784)	(3,405)
Issuance of long-term debt	19,300	0
Net proceeds from short-term debt	0	41,500
Other	(1,175)	(1,331)
Cash Provided by Financing Activities	36,627	1,142
Change in cash, cash equivalents, and restricted cash	28,278	(21,687)
Cash, cash equivalents, and restricted cash at beginning of period	25,814	84,929
Cash, cash equivalents, and restricted cash at end of period	54,092	63,242
Significant noncash investing activities:
Accrued capital expenditures	23,594	16,819
MGE [Member]
Operating Activities:
Net Income	71,191	64,764
Items not affecting cash:
Depreciation and amortization	55,193	53,423
Deferred income taxes	7,334	3,653
Provision for doubtful receivables	1,078	978
Employee benefit plan credit	(2,813)	(2,866)
Other items	1,234	1,653
Changes in working capital items:
Decrease in current assets	3,352	14,236
Decrease in current liabilities	(5,212)	(22,234)
Cash contributions to pension and other postretirement plans	(4,576)	(3,707)
Other noncurrent items, net	5,090	(880)
Cash Provided by Operating Activities	131,871	109,020
Investing Activities:
Capital expenditures	(139,055)	(128,389)
Other	(1,512)	(477)
Cash Used for Investing Activities	(140,567)	(128,866)
Financing Activities:
Distributions to parent from noncontrolling interest	(16,000)	(17,000)
Capital contributions from parent	30,000	0
Repayments of long-term debt	(22,784)	(3,405)
Issuance of long-term debt	19,300	0
Net proceeds from short-term debt	0	41,500
Other	(1,144)	(1,133)
Cash Provided by Financing Activities	9,372	19,962
Change in cash, cash equivalents, and restricted cash	676	116
Cash, cash equivalents, and restricted cash at beginning of period	5,529	6,670
Cash, cash equivalents, and restricted cash at end of period	6,205	6,786
Significant noncash investing activities:
Accrued capital expenditures	$ 23,594	$ 16,819