Reportable Segments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Segment Reporting Information [Line Items]
Operating Revenue	$ 2,284	$ 2,374
Net income (loss) available to common stockholders	202	351
Plant, property, and equipment, gross	30,866		$ 30,491
Total assets	31,386		31,353
Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	2,210	2,283
Net income (loss) available to common stockholders	232	383
Plant, property, and equipment, gross	29,721		29,342
Total assets	29,772		29,916
Other reconciling items
Segment Reporting Information [Line Items]
Net income (loss) available to common stockholders	(29)	(40)
Plant, property, and equipment, gross	28		30
Total assets	228		109
Other reconciling items | Consumers Energy Company
Segment Reporting Information [Line Items]
Net income (loss) available to common stockholders	8	0
Plant, property, and equipment, gross	34		29
Total assets	43		30
Electric Utility | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	1,091	1,241
Net income (loss) available to common stockholders	70	167
Plant, property, and equipment, gross	18,056		17,870
Total assets	18,117		17,907
Electric Utility | Operating Segments | Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	1,091	1,241
Net income (loss) available to common stockholders	70	167
Plant, property, and equipment, gross	18,056		17,870
Total assets	18,177		17,968
Gas Utility | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	1,119	1,042
Net income (loss) available to common stockholders	154	216
Plant, property, and equipment, gross	11,631		11,443
Total assets	11,507		11,873
Gas Utility | Operating Segments | Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	1,119	1,042
Net income (loss) available to common stockholders	154	216
Plant, property, and equipment, gross	11,631		11,443
Total assets	11,552		11,918
NorthStar Clean Energy | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	74	91
Net income (loss) available to common stockholders	7	$ 8
Plant, property, and equipment, gross	1,151		1,148
Total assets	$ 1,534		$ 1,464