Consolidated Statements Of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Operating Revenue	$ 2,523	$ 1,979
Operating Expenses
Fuel for electric generation	219	154
Purchased and interchange power	498	333
Purchased power - related parties	24	23
Cost of gas sold	834	607
Maintenance and other operating expenses	266	282
Depreciation and amortization	199	181
General taxes	75	70
Total operating expenses	2,115	1,650
Operating Income	408	329
Other Income (Expense)
Allowance for equity funds used during construction	2	3
Income from equity method investees	4	5
Other income	3	3
Other expense	(7)	(3)
Total other income (expense)	2	8
Interest Charges
Interest on long-term debt	97	94
Other interest expense	5	5
Allowance for borrowed funds used during construction	(1)	(1)
Total interest charges	101	98
Income Before Income Taxes	309	239
Income Tax Expense	105	95
Net Income Available to Common Stockholders	204	144
Basic Earnings Per Average Common Share	$ 0.77	$ 0.55
Diluted Earnings Per Average Common Share	$ 0.75	$ 0.53
Dividends Declared Per Common Share	$ 0.27	$ 0.255
Consumers Energy Company [Member]
Operating Revenue	2,382	1,919
Operating Expenses
Fuel for electric generation	186	133
Purchased and interchange power	484	329
Purchased power - related parties	24	23
Cost of gas sold	768	600
Maintenance and other operating expenses	250	266
Depreciation and amortization	197	180
General taxes	74	69
Total operating expenses	1,983	1,600
Operating Income	399	319
Other Income (Expense)
Allowance for equity funds used during construction	2	3
Other income	3	7
Other expense	(6)	(3)
Total other income (expense)	(1)	7
Interest Charges
Interest on long-term debt	59	59
Other interest expense	3	3
Allowance for borrowed funds used during construction	(1)	(1)
Total interest charges	61	61
Income Before Income Taxes	337	265
Income Tax Expense	116	103
Net Income Available to Common Stockholders	$ 221	$ 162