Regulatory Matters - (Narrative) (Details) - Consumers Energy Company - USD ($) $ in Millions	1 Months Ended
	Apr. 24, 2024	Mar. 31, 2024	Sep. 30, 2023	May 31, 2023
Electric Rate Case
Public Utilities, General Disclosures [Line Items]
Requested annual rate increase			$ 169	$ 216
Requested annual rate increase, as a percent				10.25%
Surcharge for the recovery of excess distribution investments		$ 9
Additional annual rate increase authorized		$ 92
Rate of return on equity authorized		9.90%
Meter Investigation | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Settlement agreement penalty payment	$ 1
Minimum settlement returns to customers	$ 3