Reportable Segments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Segment Reporting Information [Line Items]
Operating Revenue	$ 2,374	$ 2,013
Net income (loss) available to common stockholders	351	349
Plant, property, and equipment, gross	30,199		$ 29,893
Total assets	28,740		28,753
Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	2,283	1,937
Net income (loss) available to common stockholders	383	336
Plant, property, and equipment, gross	29,076		28,771
Total assets	27,114		27,140
Other reconciling items
Segment Reporting Information [Line Items]
Net income (loss) available to common stockholders	(40)	(1)
Plant, property, and equipment, gross	23		23
Total assets	444		431
Other reconciling items | Consumers Energy Company
Segment Reporting Information [Line Items]
Plant, property, and equipment, gross	23		23
Total assets	22		21
Electric Utility | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	1,241	1,134
Net income (loss) available to common stockholders	167	155
Plant, property, and equipment, gross	18,294		18,147
Total assets	16,650		16,493
Electric Utility | Operating Segments | Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	1,241	1,134
Net income (loss) available to common stockholders	167	155
Plant, property, and equipment, gross	18,294		18,147
Total assets	16,712		16,555
Gas Utility | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	1,042	803
Net income (loss) available to common stockholders	216	181
Plant, property, and equipment, gross	10,759		10,601
Total assets	10,334		10,517
Gas Utility | Operating Segments | Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	1,042	803
Net income (loss) available to common stockholders	216	181
Plant, property, and equipment, gross	10,759		10,601
Total assets	10,380		10,564
Enterprises | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	91	76
Net income (loss) available to common stockholders	8	$ 14
Plant, property, and equipment, gross	1,123		1,122
Total assets	$ 1,312		$ 1,312