Financings and Capitalization (Schedule of Revolving Credit Facilities) (Details)	Jun. 30, 2022 USD ($)
Consumers Energy Company | Revolving Credit Facilities June 5, 2024
Line of Credit Facility [Line Items]
Amount of Facility	$ 850,000,000
Amount Borrowed	0
Letters of Credit Outstanding	13,000,000
Amount Available	837,000,000
Consumers Energy Company | Revolving Credit Facilities November 19, 2023
Line of Credit Facility [Line Items]
Amount of Facility	250,000,000
Amount Borrowed	0
Letters of Credit Outstanding	61,000,000
Amount Available	189,000,000
CMS Energy | Revolving Credit Facilities June 5, 2024
Line of Credit Facility [Line Items]
Amount of Facility	550,000,000
Amount Borrowed	0
Letters of Credit Outstanding	14,000,000
Amount Available	536,000,000
CMS Energy | Revolving Credit Facilities September 23, 2022
Line of Credit Facility [Line Items]
Amount of Facility	50,000,000
Amount Borrowed	0
Letters of Credit Outstanding	50,000,000
Amount Available	0
CMS Enterprises Including Subsidiaries | Revolving Credit Facilities September 25, 2025
Line of Credit Facility [Line Items]
Amount of Facility	37,000,000
Amount Borrowed	0
Letters of Credit Outstanding	37,000,000
Amount Available	$ 0