Schedule I - Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Future maturities of long-term debt outstanding
2020	$ 686.9
2021	1,338.8
Thereafter	7,918.2
Total	10,387.6
WEC Energy Group
Future maturities of long-term debt outstanding
2020	400.0
2021	600.0
Thereafter	1,200.0
Total	2,200.0
Long-term notes outstanding	2,190.8	$ 1,592.3
WEC Energy Group \| WECC \| Support agreement related to WECC debt
Future maturities of long-term debt outstanding
Long-term notes outstanding	$ 50.0

Face (par) amount of debt instrument at time of issuance.

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