Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	$ 8,320	$ 7,075	$ 6,238
Leasing income	240	194	148
Financing income	16	15	17
Consumers alternative-revenue programs	57	45	43
Consumers revenues to be refunded	(37)		(28)
Total operating revenue	8,596	7,329	6,418
Electric Utility | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	5,395	4,915	4,348
Financing income	10	10	11
Consumers alternative-revenue programs	43	33	29
Consumers revenues to be refunded	(29)		(16)
Total operating revenue	5,419	4,958	4,372
Gas Utility | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	2,720	2,046	1,809
Financing income	6	5	6
Consumers alternative-revenue programs	14	12	14
Consumers revenues to be refunded	(8)		(12)
Total operating revenue	2,732	2,063	1,817
NorthStar Clean Energy | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	205	114	81
Leasing income	240	194	148
Total operating revenue	445	308	229
Consumers Energy Company
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	8,115	6,961	6,157
Financing income	16	15	17
Consumers alternative-revenue programs	57	45	43
Consumers revenues to be refunded	(37)		(28)
Total operating revenue	8,151	7,021	6,189
Consumers Energy Company | Electric Utility | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	5,395	4,915	4,348
Financing income	10	10	11
Consumers alternative-revenue programs	43	33	29
Consumers revenues to be refunded	(29)		(16)
Total operating revenue	5,419	4,958	4,372
Consumers Energy Company | Gas Utility | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	2,720	2,046	1,809
Financing income	6	5	6
Consumers alternative-revenue programs	14	12	14
Consumers revenues to be refunded	(8)		(12)
Total operating revenue	2,732	2,063	1,817
Residential | Consumers Energy Company
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	4,402	3,798	3,341
Residential | Consumers Energy Company | Electric Utility | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	2,523	2,402	2,109
Residential | Consumers Energy Company | Gas Utility | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	1,879	1,396	1,232
Commercial | Consumers Energy Company
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	2,292	1,969	1,781
Commercial | Consumers Energy Company | Electric Utility | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	1,733	1,573	1,444
Commercial | Consumers Energy Company | Gas Utility | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	559	396	337
Industrial | Consumers Energy Company
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	867	678	616
Industrial | Consumers Energy Company | Electric Utility | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	792	624	570
Industrial | Consumers Energy Company | Gas Utility | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	75	54	46
Other
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	205	114	81
Other | NorthStar Clean Energy | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	205	114	81
Other | Consumers Energy Company
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	554	516	419
Other | Consumers Energy Company | Electric Utility | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	347	316	225
Other | Consumers Energy Company | Gas Utility | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue recognized from contracts with customers	$ 207	$ 200	$ 194