Madison Gas and Electric Company Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Items not affecting cash:
Depreciation and amortization	$ 44,646	$ 44,225	$ 40,695
Deferred income taxes	22,421	21,927	49,884
Provision for doubtful receivables	1,196	596	1,898
Employee benefit plan expenses	295	3,333	(1,080)
Equity earnings in MGE Transco	(8,428)	(7,728)	(9,150)
Other items	1,426	721	729
Changes in working capital items:
Trade and other receivables (change)	(5,666)	4,508	2,115
Inventories (change)	7,273	(2,646)	(10,399)
Unbilled revenues (change)	(4,838)	6,254	720
Prepaid taxes (change)	8,616	3,658	(19,804)
Other current assets (change)	700	978	(5,693)
Accounts payable (change)	9,881	(3,499)	2,756
Other current liabilities (change)	(1,738)	(597)	(4,195)
Dividend income from MGE Transco	7,926	6,645	7,740
Cash contributions to pension and other postretirement plans	(14,452)	(13,676)	(3,321)
Other noncurrent items, net	2,695	5,143	(4,452)
Cash Provided by Operating Activities	147,513	141,185	128,762
Investing Activities:
Capital expenditures	(83,659)	(72,030)	(92,676)
Capital contributions to MGE Transco	(2,958)	(1,053)	(2,185)
Other investing	(209)	(230)	(1,297)
Cash Used for Investing Activities	(86,826)	(73,313)	(96,158)
Financing Activities:
Repayment of long-term debt	(4,267)	(4,182)	(4,103)
(Decrease) increase in short-term debt	0	(7,000)	7,000
Other financing	(70)	(1,018)	(130)
Cash Used for Financing Activities	(46,112)	(52,243)	(35,662)
Change in cash and cash equivalents:	14,575	15,629	(3,058)
Cash and cash equivalents at beginning of period	81,384	65,755	68,813
Cash and cash equivalents at end of period	95,959	81,384	65,755
Supplemental disclosures of cash flow information:
Interest paid	19,415	19,636	20,478
Income taxes paid	21,831	23,800	19,579
Income taxes received	(10,000)	(10,130)	(644)
Significant noncash investing activities:
Accrued capital expenditures	16,376	3,963	1,569
MGE [Member]
Operating Activities:
Net Income	74,592	71,465	81,938
Items not affecting cash:
Depreciation and amortization	44,622	44,178	40,648
Deferred income taxes	20,876	18,843	49,603
Provision for doubtful receivables	1,196	596	1,898
Employee benefit plan expenses	295	3,333	(1,080)
Equity earnings in MGE Transco	(6,366)	(7,728)	(9,150)
Other items	1,954	1,223	1,280
Changes in working capital items:
Trade and other receivables (change)	(3,583)	11,079	(4,455)
Inventories (change)	7,273	(2,647)	(10,398)
Unbilled revenues (change)	(4,838)	6,254	720
Prepaid taxes (change)	8,481	4,824	(15,169)
Other current assets (change)	699	976	(5,693)
Accounts payable (change)	9,941	(3,587)	2,741
Accrued interest and taxes (change)	419	(18)	(1,001)
Other current liabilities (change)	(2,137)	1,885	(3,144)
Dividend income from MGE Transco	5,032	6,645	7,740
Cash contributions to pension and other postretirement plans	(14,452)	(13,677)	(3,321)
Other noncurrent items, net	2,497	4,816	(4,619)
Cash Provided by Operating Activities	146,501	148,460	128,538
Investing Activities:
Capital expenditures	(83,659)	(72,030)	(92,676)
Capital contributions to MGE Transco	(1,598)	(710)	(1,775)
Other investing	(391)	(180)	(1,146)
Cash Used for Investing Activities	(85,648)	(72,920)	(95,597)
Financing Activities:
Cash dividends paid to parent by MGE	(50,000)	(30,000)	(26,500)
Distributions to parent from noncontrolling interest	(24,113)	(14,708)	(21,359)
Equity contribution received by noncontrolling interest	1,598	3,230	1,775
Repayment of long-term debt	(4,267)	(4,182)	(4,103)
(Decrease) increase in short-term debt	0	(7,000)	7,000
Other financing	(63)	(682)	0
Cash Used for Financing Activities	(76,845)	(53,342)	(43,187)
Change in cash and cash equivalents:	(15,992)	22,198	(10,246)
Cash and cash equivalents at beginning of period	26,760	4,562	14,808
Cash and cash equivalents at end of period	10,768	26,760	4,562
Supplemental disclosures of cash flow information:
Interest paid	19,415	19,636	20,478
Income taxes paid	29	29	67
Income taxes received	0	0	(644)
Significant noncash investing activities:
Accrued capital expenditures	16,376	3,963	1,569
Dividend in kind to parent	$ 15,822	$ 0	$ 0