Regulatory Environment - MGU 2021 Rate Order (Details) - MPSC - MGU - USD ($) $ in Millions		1 Months Ended
	Aug. 30, 2023	Sep. 30, 2021	Jul. 31, 2020
Public Utilities, General Disclosures
Depreciation and interest expense approved for deferral			$ 5.0
Approved rate increase	$ 9.9	$ 9.3
Approved rate increase (as a percent)	4.70%	6.35%
Approved return on equity (as a percent)	9.80%	9.85%
Approved common equity component average (as a percent)	51.00%	51.50%