Financings and Capitalization (Schedule of Revolving Credit Facilities) (Details)	Mar. 31, 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	12,000,000
Amount Available	838,000,000
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	8,000,000
Amount Available	242,000,000
Consumers Energy Company | Revolving Credit Facilities April 18, 2022
Line of Credit Facility [Line Items]
Amount of Facility	30,000,000
Amount Borrowed	0
Letters of Credit Outstanding	30,000,000
Amount Available	0
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	24,000,000
Amount Available	526,000,000
CMS Energy | Revolving Credit Facilities September 23, 2022
Line of Credit Facility [Line Items]
Amount of Facility	42,000,000
Amount Borrowed	0
Letters of Credit Outstanding	42,000,000
Amount Available	0
CMS Energy | Revolving Credit Facilities September 23, 2022 | Letter of Credit
Line of Credit Facility [Line Items]
Amount of Facility	50,000,000
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
CMS Enterprises Including Subsidiaries | Revolving Credit Facilities September 30, 2025
Line of Credit Facility [Line Items]
Amount of Facility	18,000,000
Amount Borrowed	0
Letters of Credit Outstanding	8,000,000
Amount Available	10,000,000
Letter of Credit | CMS Enterprises Including Subsidiaries | Revolving Credit Facilities September 30, 2025
Line of Credit Facility [Line Items]
Amount Available	$ 8,000,000