Reportable Segments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Operating Revenue	$ 1,743	$ 1,673	$ 5,526	$ 5,512
Net income (loss) available to common stockholders	251	174	731	571
Plant, property, and equipment, gross	34,156		34,156		$ 33,135
Total assets	34,817		34,817		33,517
Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	1,661	1,596	5,291	5,291
Net income (loss) available to common stockholders	273	178	725	576
Plant, property, and equipment, gross	32,695		32,695		31,723
Total assets	33,160		33,160		31,852
Other reconciling items
Segment Reporting Information [Line Items]
Net income (loss) available to common stockholders	(39)	(33)	(57)	(40)
Plant, property, and equipment, gross	21		21		30
Total assets	75		75		202
Other reconciling items | Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	0	1	0	1
Net income (loss) available to common stockholders	(11)	(13)	(10)	(9)
Plant, property, and equipment, gross	29		29		38
Total assets	29		29		38
Electric Utility | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	1,448	1,351	3,806	3,570
Net income (loss) available to common stockholders	273	187	540	404
Plant, property, and equipment, gross	19,826		19,826		19,302
Total assets	20,222		20,222		19,358
Electric Utility | Operating Segments | Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	1,448	1,351	3,806	3,570
Net income (loss) available to common stockholders	273	187	540	404
Plant, property, and equipment, gross	19,826		19,826		19,302
Total assets	20,279		20,279		19,417
Gas Utility | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	213	244	1,485	1,720
Net income (loss) available to common stockholders	11	4	195	181
Plant, property, and equipment, gross	12,840		12,840		12,383
Total assets	12,809		12,809		12,353
Gas Utility | Operating Segments | Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	213	244	1,485	1,720
Net income (loss) available to common stockholders	11	4	195	181
Plant, property, and equipment, gross	12,840		12,840		12,383
Total assets	12,852		12,852		12,397
NorthStar Clean Energy | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	82	78	235	222
Net income (loss) available to common stockholders	6	$ 16	53	$ 26
Plant, property, and equipment, gross	1,469		1,469		1,420
Total assets	$ 1,711		$ 1,711		$ 1,604