Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating Activities:
Net Income	$ 26,037	$ 24,007
Items not affecting cash:
Depreciation and amortization	18,167	17,139
Deferred income taxes	1,433	(1,359)
Provision for doubtful receivables	734	634
Employee benefit plan (credit) cost	(940)	474
Equity earnings in ATC	(2,266)	(2,218)
Other items	(1,974)	32
Changes in working capital items:
Decrease in current assets	14,089	13,665
(Decrease) increase in current liabilities	(2,738)	3,182
Dividends from ATC	2,700	2,012
Cash contributions to pension and other postretirement plans	(1,470)	(957)
Other noncurrent items, net	47	(3,416)
Cash Provided by Operating Activities	53,819	53,195
Investing Activities:
Capital expenditures	(46,758)	(31,933)
Capital contributions to investments	(1,643)	(740)
Other	(398)	(206)
Cash Used for Investing Activities	(48,799)	(32,879)
Financing Activities:
Cash dividends paid on common stock	(12,221)	(11,701)
Repayment of long-term debt	(1,155)	(1,129)
Net proceeds from (repayments of) short-term debt	3,000	(7,000)
Other	(664)	(999)
Cash Used for Financing Activities	(11,040)	(20,829)
Change in cash, cash equivalents, and restricted cash	(6,020)	(513)
Cash, cash equivalents, and restricted cash at beginning of period	25,814	84,929
Cash, cash equivalents, and restricted cash at end of period	19,794	84,416
Significant noncash investing activities:
Accrued capital expenditures	8,129	3,428
MGE [Member]
Operating Activities:
Net Income	24,557	22,070
Items not affecting cash:
Depreciation and amortization	18,167	17,139
Deferred income taxes	976	(2,002)
Provision for doubtful receivables	734	634
Employee benefit plan (credit) cost	(940)	474
Other items	(1,721)	604
Changes in working capital items:
Decrease in current assets	12,953	13,737
(Decrease) increase in current liabilities	290	5,532
Cash contributions to pension and other postretirement plans	(1,470)	(957)
Other noncurrent items, net	(428)	(3,629)
Cash Provided by Operating Activities	53,118	53,602
Investing Activities:
Capital expenditures	(46,758)	(31,933)
Other	(406)	(228)
Cash Used for Investing Activities	(47,164)	(32,161)
Financing Activities:
Distributions to parent from noncontrolling interest	(7,000)	(7,500)
Repayment of long-term debt	(1,155)	(1,129)
Net proceeds from (repayments of) short-term debt	3,000	(7,000)
Other	(664)	(844)
Cash Used for Financing Activities	(5,819)	(16,473)
Change in cash, cash equivalents, and restricted cash	135	4,968
Cash, cash equivalents, and restricted cash at beginning of period	5,529	6,670
Cash, cash equivalents, and restricted cash at end of period	5,664	11,638
Significant noncash investing activities:
Accrued capital expenditures	$ 8,129	$ 3,428