Consolidated Statements Of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Operating Revenue	$ 1,587	$ 1,486	$ 4,759	$ 4,947
Operating Expenses
Fuel for electric generation	145	161	367	462
Purchased and interchange power	454	392	1,165	1,082
Purchased power - related parties	22	21	65	61
Cost of gas sold	45	52	490	754
Maintenance and other operating expenses	290	311	859	906
Depreciation and amortization	183	173	597	564
General taxes	62	59	209	200
Total operating expenses	1,201	1,169	3,752	4,029
Operating Income	386	317	1,007	918
Other Income (Expense)
Interest income	1	1	4	3
Allowance for equity funds used during construction	3	3	9	7
Income from equity method investees	5	4	12	9
Other income	2	2	7	8
Other expense	(6)	(3)	(13)	(11)
Total other income	5	7	19	16
Interest Charges
Interest on long-term debt	103	95	306	288
Other interest expense	8	7	22	20
Allowance for borrowed funds used during construction	(1)	(1)	(4)	(3)
Total interest charges	110	101	324	305
Income Before Income Taxes	281	223	702	629
Income Tax Expense	95	75	227	211
Net Income	186	148	475	418
Income Attributable to Noncontrolling Interests			1	1
Net Income Available to Common Stockholders	$ 186	$ 148	$ 474	$ 417
Basic Earnings Per Average Common Share	$ 0.67	$ 0.53	$ 1.71	$ 1.51
Diluted Earnings Per Average Common Share	0.67	0.53	1.70	1.51
Dividends Declared Per Common Share	$ 0.31	$ 0.29	$ 0.93	$ 0.87
Consumers Energy Company [Member]
Operating Revenue	$ 1,498	$ 1,417	$ 4,514	$ 4,726
Operating Expenses
Fuel for electric generation	118	138	290	381
Purchased and interchange power	445	389	1,148	1,072
Purchased power - related parties	23	21	66	61
Cost of gas sold	39	46	477	737
Maintenance and other operating expenses	265	289	788	845
Depreciation and amortization	182	172	592	560
General taxes	61	57	207	194
Total operating expenses	1,133	1,112	3,568	3,850
Operating Income	365	305	946	876
Other Income (Expense)
Interest income	1	1	3	3
Interest and dividend income - related parties			1
Allowance for equity funds used during construction	3	3	9	7
Other income	2	2	7	17
Other expense	(6)	(3)	(13)	(11)
Total other income		3	7	16
Interest Charges
Interest on long-term debt	65	62	195	188
Other interest expense	3	4	9	11
Allowance for borrowed funds used during construction	(1)	(1)	(4)	(3)
Total interest charges	67	65	200	196
Income Before Income Taxes	298	243	753	696
Income Tax Expense	103	83	254	237
Net Income	195	160	499	459
Preferred Stock Dividends			1	1
Net Income Available to Common Stockholders	$ 195	$ 160	$ 498	$ 458