Reportable Segments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Operating Revenue	$ 8,596	$ 7,329	$ 6,418
Depreciation and amortization	1,126	1,114	1,043
Income from equity method investees	3	10	5
Interest charges	519	500	505
Income tax expense (benefit)	93	95	115
Net income (loss) available to common stockholders	827	1,348	755
Plant, property, and equipment, gross	30,491	29,893	27,870
Investments in equity method investees	71	71	70
Total assets	31,353	28,753	29,666
Capital expenditures	2,393	2,161	2,275
Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	8,151	7,021	6,189
Depreciation and amortization	1,088	1,077	1,023
Interest charges	335	311	320
Income tax expense (benefit)	140	156	173
Net income (loss) available to common stockholders	943	866	814
Plant, property, and equipment, gross	29,342	28,771	26,757
Total assets	29,916	27,140	25,399
Capital expenditures	2,280	2,144	2,167
Other reconciling items
Segment Reporting Information [Line Items]
Depreciation and amortization	1	1	1
Interest charges	182	183	179
Income tax expense (benefit)	(51)	(59)	(54)
Net income (loss) available to common stockholders	(152)	458	(96)
Plant, property, and equipment, gross	30	23	21
Total assets	109	431	3,132
Capital expenditures	7	2	1
Other reconciling items | Consumers Energy Company
Segment Reporting Information [Line Items]
Depreciation and amortization	1	1	1
Interest charges	1	0	1
Income tax expense (benefit)	(1)	0	0
Net income (loss) available to common stockholders	(2)	(1)	(1)
Plant, property, and equipment, gross	29	23	21
Total assets	30	21	29
Capital expenditures	7	2	1
Electric Utility | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	5,419	4,958	4,372
Depreciation and amortization	757	772	739
Interest charges	218	207	217
Income tax expense (benefit)	109	117	115
Net income (loss) available to common stockholders	567	565	554
Plant, property, and equipment, gross	17,870	18,147	17,155
Total assets	17,907	16,493	15,829
Capital expenditures	1,265	1,153	1,281
Electric Utility | Operating Segments | Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	5,419	4,958	4,372
Depreciation and amortization	757	772	739
Interest charges	218	207	217
Income tax expense (benefit)	109	117	115
Net income (loss) available to common stockholders	567	565	554
Plant, property, and equipment, gross	17,870	18,147	17,155
Total assets	17,968	16,555	15,893
Capital expenditures	1,265	1,153	1,281
Gas Utility | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	2,732	2,063	1,817
Depreciation and amortization	330	304	283
Interest charges	116	104	102
Income tax expense (benefit)	32	39	58
Net income (loss) available to common stockholders	378	302	261
Plant, property, and equipment, gross	11,443	10,601	9,581
Total assets	11,873	10,517	9,429
Capital expenditures	1,008	989	885
Gas Utility | Operating Segments | Consumers Energy Company
Segment Reporting Information [Line Items]
Operating Revenue	2,732	2,063	1,817
Depreciation and amortization	330	304	283
Interest charges	116	104	102
Income tax expense (benefit)	32	39	58
Net income (loss) available to common stockholders	378	302	261
Plant, property, and equipment, gross	11,443	10,601	9,581
Total assets	11,918	10,564	9,477
Capital expenditures	1,008	989	885
NorthStar Clean Energy | Operating Segments
Segment Reporting Information [Line Items]
Operating Revenue	445	308	229
Depreciation and amortization	38	37	20
Income from equity method investees	3	10	5
Interest charges	3	6	7
Income tax expense (benefit)	3	(2)	(4)
Net income (loss) available to common stockholders	34	23	36
Plant, property, and equipment, gross	1,148	1,122	1,113
Investments in equity method investees	71	71	70
Total assets	1,464	1,312	1,276
Capital expenditures	$ 113	$ 17	$ 108