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v3.24.2

LONG-TERM DEBT (Details) |  | 1 Months Ended | 3 Months Ended | 6 Months Ended
--- | --- | --- | --- | ---
Feb. 07, 2024 USD ($) | May 31, 2024 USD ($) | Mar. 31, 2024 USD ($) | Jun. 30, 2024 USD ($) d $ / shares | Jun. 30, 2023 USD ($) | Jun. 30, 2024 USD ($) $ / shares shares | Jun. 30, 2023 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest expense |  |  |  | $ 200,600,000 | $ 178,700,000 | $ 392,600,000 | $ 350,900,000
5.00% WE Debentures due 05/15/2029 | WE |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate on long-term debt |  | 5.00% |  |  |  |  |
Proceeds from issuance of debt |  | $ 350,000,000.0 |  |  |  |  |
WEC Energy Group | Floating Rate WEC Energy Group Junior Notes Due 2067 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Extinguishment of debt | $ 122,100,000 | 19,000,000.0 |  |  |  |  |
Unsecured debt | 500,000,000 | 377,900,000 |  |  |  |  |
Repayment of long-term debt | 115,200,000 | $ 18,700,000 |  |  |  |  |
Gain on early extinguishment of debt | $ 6,900,000 |  |  |  |  |  |
WEC Energy Group | WEC 0.80% Senior Notes $600M due March 15, 2024 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Repayment of long-term debt |  |  | $ 600,000,000.0 |  |  |  |
Interest rate on long-term debt |  |  | 0.80% |  |  |  |
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2027 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate on long-term debt |  |  |  | 4.375% |  | 4.375% |
Proceeds from issuance of debt |  |  |  | $ 862,500,000 |  |  |
Initial conversion ratio |  |  |  | 10.1243 |  |  |
Principal amount conversion rate applied to |  |  |  | $ 1,000 |  | $ 1,000 |
Initial conversion price, per share | $ / shares |  |  |  | $ 98.77 |  | $ 98.77 |
Senior Notes |  |  |  | $ 862,500,000 |  | $ 862,500,000 |
Unamortized debt issuance costs |  |  |  | (9,000,000.0) |  | (9,000,000.0) |
Net carrying amount |  |  |  | 853,500,000 |  | 853,500,000 |
Fair value amount |  |  |  | 856,400,000 |  | 856,400,000 |
Contractual interest expense |  |  |  | 3,500,000 |  | 3,500,000 |
Amortization of debt issuance costs |  |  |  | 300,000 |  | 300,000 |
Interest expense |  |  |  | $ 3,800,000 |  | $ 3,800,000 |
Number of shares outstanding related to the potential conversion of the Notes included in diluted eps | shares |  |  |  |  |  | 0 |
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2027 | Early redemption terms |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt instrument, redemption price, percentage |  |  |  | 100.00% |  |  |
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2027 | Debt conversion terms one |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Threshold percentage of trigger |  |  |  | 130.00% |  |  |
Trading days | d |  |  |  | 20 |  |  |
Consecutive trading days | d |  |  |  | 30 |  |  |
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2027 | Debt conversion terms two |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Threshold percentage of trigger |  |  |  | 98.00% |  |  |
Trading days | d |  |  |  | 5 |  |  |
Consecutive trading days | d |  |  |  | 10 |  |  |
Principal amount conversion rate applied to |  |  |  | $ 1,000 |  | $ 1,000 |
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2027 | Debt conversion terms four |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Trading days prior to maturity | d |  |  |  | 2 |  |  |
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2029 |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Interest rate on long-term debt |  |  |  | 4.375% |  | 4.375% |
Proceeds from issuance of debt |  |  |  | $ 862,500,000 |  |  |
Initial conversion ratio |  |  |  | 10.1243 |  |  |
Principal amount conversion rate applied to |  |  |  | $ 1,000 |  | $ 1,000 |
Initial conversion price, per share | $ / shares |  |  |  | $ 98.77 |  | $ 98.77 |
Senior Notes |  |  |  | $ 862,500,000 |  | $ 862,500,000 |
Unamortized debt issuance costs |  |  |  | (9,200,000) |  | (9,200,000) |
Net carrying amount |  |  |  | 853,300,000 |  | 853,300,000 |
Fair value amount |  |  |  | 856,500,000 |  | 856,500,000 |
Contractual interest expense |  |  |  | 3,500,000 |  | 3,500,000 |
Amortization of debt issuance costs |  |  |  | 200,000 |  | 200,000 |
Interest expense |  |  |  | $ 3,700,000 |  | $ 3,700,000 |
Number of shares outstanding related to the potential conversion of the Notes included in diluted eps | shares |  |  |  |  |  | 0 |
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2029 | Early redemption terms |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Trading days prior to early redemption | d |  |  |  | 41 |  |  |
Threshold percentage of trigger |  |  |  | 130.00% |  |  |
Trading days | d |  |  |  | 20 |  |  |
Consecutive trading days | d |  |  |  | 30 |  |  |
Debt instrument, redemption price, percentage |  |  |  | 100.00% |  |  |
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2029 | Debt conversion terms one |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Threshold percentage of trigger |  |  |  | 130.00% |  |  |
Trading days | d |  |  |  | 20 |  |  |
Consecutive trading days | d |  |  |  | 30 |  |  |
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2029 | Debt conversion terms two |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Threshold percentage of trigger |  |  |  | 98.00% |  |  |
Trading days | d |  |  |  | 5 |  |  |
Consecutive trading days | d |  |  |  | 10 |  |  |
Principal amount conversion rate applied to |  |  |  | $ 1,000 |  | $ 1,000 |
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2029 | Debt conversion terms three |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Trading days prior to redemption | d |  |  |  | 2 |  |  |
WEC Energy Group | WEC 4.375% Convertible Notes due June 1, 2029 | Debt conversion terms four |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Trading days prior to maturity | d |  |  |  | 2 |  |  |

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