XML 108 R92.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Common Equity - Common Stock Dividends (Details) - $ / shares | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2018 | Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Dividends Paid and Payable [Line Items] |  |  |  |  |  |  |  |
Dividends per share (in dollars per share) |  | $ 0.52 | $ 0.52 | $ 0.52 | $ 0.52 | $ 2.08 | $ 1.98 | $ 1.74
Subsequent event |  |  |  |  |  |  |  |
Dividends Paid and Payable [Line Items] |  |  |  |  |  |  |  |
Dividends per share (in dollars per share) | $ 0.5525 |  |  |  |  |  |  |
Annualized dividend (in dollars per share) | $ 2.21 |  |  |  |  |  |  |
Subsequent event | Minimum |  |  |  |  |  |  |  |
Dividends Paid and Payable [Line Items] |  |  |  |  |  |  |  |
Target dividend payout ratio (as a percent) | 65.00% |  |  |  |  |  |  |
Subsequent event | Maximum |  |  |  |  |  |  |  |
Dividends Paid and Payable [Line Items] |  |  |  |  |  |  |  |
Target dividend payout ratio (as a percent) | 70.00% |  |  |  |  |  |  |

X
- Definition Aggregate dividends declared during the period for each share of common stock outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Annualized value of dividends declared + References No definition available. + Details
Name: | wec_Annualizeddividend
Namespace Prefix: | wec_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents dividends that have been declared and paid or not paid as of the financial reporting date. This information may contain the amount, amount per share, declared date, and date to be paid. + References No definition available. + Details
Name: | wec_DividendsPaidandPayableLineItems
Namespace Prefix: | wec_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Target dividend payout ratio as a percentage of earnings + References No definition available. + Details
Name: | wec_Targetdividendpayoutratio
Namespace Prefix: | wec_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |