Schedule I - Cash Dividends Received from Subsidiaries (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Standards Update 2016-15 \| Impact of ASU
Notes to parent company financial statements
Return of capital from subsidiaries			$ 9.0
WEC Energy Group
Notes to parent company financial statements
Cash dividends received from subsidiaries	$ 688.9	$ 548.6	725.4
Return of capital from subsidiaries	290.2	0.0	9.0
WEC Energy Group \| WE
Notes to parent company financial statements
Cash dividends received from subsidiaries	310.0	240.0	455.0
WEC Energy Group \| We Power
Notes to parent company financial statements
Cash dividends received from subsidiaries	223.0	181.0	188.9
WEC Energy Group \| ATC Holding LLC
Notes to parent company financial statements
Cash dividends received from subsidiaries	105.8	82.6	6.5
WEC Energy Group \| WG
Notes to parent company financial statements
Cash dividends received from subsidiaries	50.0	45.0	75.0
WEC Energy Group \| Wisvest
Notes to parent company financial statements
Cash dividends received from subsidiaries	$ 0.1	$ 0.0	$ 0.0

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This element represents disclosure of the aggregate cash dividends paid to the entity by consolidated subsidiaries.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(b))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690

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Amount of distribution received from equity method investee for return of investment, classified as investing activities. Excludes distribution for return on investment, classified as operating activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 21D
-URI http://asc.fasb.org/extlink&oid=109223946&loc=SL94080555-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585

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