Reportable Segments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Operating Revenue	$ 1,607	$ 1,555	$ 3,783	$ 3,839
Net income (loss) available to common stockholders	195	195	480	397
Plant, property, and equipment, gross	33,680		33,680		$ 33,135
Total assets	34,355		34,355		33,517
Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	1,533	1,485	3,630	3,695
Net income (loss) available to common stockholders	177	166	452	398
Plant, property, and equipment, gross	32,224		32,224		31,723
Total assets	32,718		32,718		31,852
Other reconciling items
Segment Reporting Information [Line Items]
Net income (loss) available to common stockholders	(6)	22	(18)	(7)
Plant, property, and equipment, gross	21		21		30
Total assets	105		105		202
Other reconciling items | Consumers Energy Company
Segment Reporting Information [Line Items]
Net income (loss) available to common stockholders	(8)	(4)	1	4
Plant, property, and equipment, gross	29		29		38
Total assets	26		26		38
Electric Utility | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	1,226	1,128	2,358	2,219
Net income (loss) available to common stockholders	170	147	267	217
Plant, property, and equipment, gross	19,557		19,557		19,302
Total assets	20,122		20,122		19,358
Electric Utility | Operating Segments | Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	1,226	1,128	2,358	2,219
Net income (loss) available to common stockholders	170	147	267	217
Plant, property, and equipment, gross	19,557		19,557		19,302
Total assets	20,180		20,180		19,417
Gas Utility | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	307	357	1,272	1,476
Net income (loss) available to common stockholders	15	23	184	177
Plant, property, and equipment, gross	12,638		12,638		12,383
Total assets	12,469		12,469		12,353
Gas Utility | Operating Segments | Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	307	357	1,272	1,476
Net income (loss) available to common stockholders	15	23	184	177
Plant, property, and equipment, gross	12,638		12,638		12,383
Total assets	12,512		12,512		12,397
NorthStar Clean Energy | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	74	70	153	144
Net income (loss) available to common stockholders	16	$ 3	47	$ 10
Plant, property, and equipment, gross	1,464		1,464		1,420
Total assets	$ 1,659		$ 1,659		$ 1,604