Reportable Segments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Operating Revenue	$ 2,176	$ 2,284
Net income (loss) available to common stockholders	285	202
Plant, property, and equipment, gross	33,236		$ 33,135
Total assets	33,901		33,517
Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	2,097	2,210
Net income (loss) available to common stockholders	275	232
Plant, property, and equipment, gross	31,820		31,723
Total assets	32,209		31,852
Other reconciling items
Segment Reporting Information [Line Items]
Net income (loss) available to common stockholders	(12)	(29)
Plant, property, and equipment, gross	20		30
Total assets	222		202
Other reconciling items | Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	0	0
Net income (loss) available to common stockholders	9	8
Plant, property, and equipment, gross	28		38
Total assets	43		38
Electric Utility | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	1,132	1,091
Net income (loss) available to common stockholders	97	70
Plant, property, and equipment, gross	19,317		19,302
Total assets	19,759		19,358
Electric Utility | Operating Segments | Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	1,132	1,091
Net income (loss) available to common stockholders	97	70
Plant, property, and equipment, gross	19,317		19,302
Total assets	19,818		19,417
Gas Utility | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	965	1,119
Net income (loss) available to common stockholders	169	154
Plant, property, and equipment, gross	12,475		12,383
Total assets	12,305		12,353
Gas Utility | Operating Segments | Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	965	1,119
Net income (loss) available to common stockholders	169	154
Plant, property, and equipment, gross	12,475		12,383
Total assets	12,348		12,397
NorthStar Clean Energy | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	79	74
Net income (loss) available to common stockholders	31	$ 7
Plant, property, and equipment, gross	1,424		1,420
Total assets	$ 1,615		$ 1,604