Long-Term Debt - Debt Maturing Within One Year (Details) $ in Millions	Dec. 31, 2020 USD ($)
Long-term debt maturing within one year
Total principal amount	$ 777.7
2.95% WE debentures \| WE
Long-term debt maturing within one year
Interest rate	2.95%
Principal amount of unsecured debt	$ 300.0
3.35% WPS senior notes \| WPS
Long-term debt maturing within one year
Interest rate	3.35%
Principal amount of senior notes	$ 400.0
3.76% Bluewater Gas Storage senior notes \| Bluewater Gas Storage
Long-term debt maturing within one year
Interest rate	3.76%
Principal amount of senior notes	$ 2.6
4.91% We Power subsidiaries notes - PWGS \| We Power
Long-term debt maturing within one year
Interest rate	4.91%
Principal amount of secured debt	$ 6.9
5.209% We Power subsidiaries notes - ERGS \| We Power
Long-term debt maturing within one year
Interest rate	5.209%
Principal amount of secured debt	$ 13.2
4.673% We Power subsidiaries notes - ERGS \| We Power
Long-term debt maturing within one year
Interest rate	4.673%
Principal amount of secured debt	$ 10.2
6.00% We Power subsidiaries notes - PWGS \| We Power
Long-term debt maturing within one year
Interest rate	6.00%
Principal amount of secured debt	$ 5.9
2.75% WECI Wind Holding I senior notes \| WECI Wind Holding I
Long-term debt maturing within one year
Interest rate	2.75%
Principal amount of senior notes	$ 38.9

Contractual interest rate for funds borrowed, under the debt agreement.

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