Schedule I - Short-Term Notes Receivable from Related Parties (Details) - WEC Energy Group - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Notes to parent company financial statements
Short-term notes receivable from related parties	$ 29.0	$ 110.8
UMERC
Notes to parent company financial statements
Short-term notes receivable from related parties	22.0	30.7
Bluewater
Notes to parent company financial statements
Short-term notes receivable from related parties	7.0	0.0
Integrys
Notes to parent company financial statements
Short-term notes receivable from related parties	0.0	68.1
Wispark
Notes to parent company financial statements
Short-term notes receivable from related parties	$ 0.0	$ 12.0

Amounts due from parties associated with the reporting entity as evidenced by a written promise to pay, due within 1 year (or 1 business cycle).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(k)(1))
-URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.3(a)(2))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_NotesReceivableRelatedPartiesCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant