Consolidated Statements Of Income (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Operating Revenue	$ 6,566		$ 6,253		$ 6,503
Operating Expenses
Fuel for electric generation	621		598		636
Purchased and interchange power	1,387		1,364		1,282
Purchased power - related parties	90		87		82
Cost of gas sold	1,228		1,150		1,512
Maintenance and other operating expenses	1,236		1,224		1,237
Depreciation and amortization	628		598		546
General taxes	234		229		205
Total operating expenses	5,424		5,250		5,500
Operating Income	1,142		1,003		1,003
Other Income (Expense)
Interest income	3		5		9
Allowance for equity funds used during construction	6		8		6
Income from equity method investees	13	[1]	17	[1]	9	[1]
Other income	10		11		16
Other expense	(20)		(33)		(22)
Total other income (expense)	12		8		18
Interest Charges
Interest on long-term debt	385		372		396
Other interest expense	16		21		23
Allowance for borrowed funds used during construction	(3)		(4)		(4)
Total interest charges	398		389		415
Income Before Income Taxes	756		622		606
Income Tax Expense	302		245		191
Income From Continuing Operations	454		377		415
Income From Discontinued Operations, Net			7	[2]	2	[3]
Net Income	454		384		417
Income Attributable to Noncontrolling Interests	2		2		2
Net Income Attributable to Common Stockholders
Amounts attributable to continuing operations	452		375		413
Amounts attributable to discontinued operations			7		2
Net Income Available to Common Stockholders	452		382		415
Income Attributable to Noncontrolling Interests
Amounts attributable to continuing operations	2		2		2
Amounts attributable to discontinued operations
Income attributable to noncontrolling interests	2		2		2
Basic Earnings Per Average Common Share
Basic earnings from continuing operations	$ 1.71		$ 1.43		$ 1.65
Basic earnings from discontinued operations			$ 0.03		$ 0.01
Basic earnings attributable to common stock	$ 1.71		$ 1.46		$ 1.66
Diluted Earnings Per Average Common Share
Diluted earnings from continuing operations	$ 1.66		$ 1.39		$ 1.57
Diluted earnings from discontinued operations			$ 0.03		$ 0.01
Diluted earnings attributable to common stock	$ 1.66		$ 1.42		$ 1.58
Dividends Declared Per Common Share	$ 1.02		$ 0.96		$ 0.84
Consumers Energy Company [Member]
Operating Revenue	6,321		6,013		6,253
Operating Expenses
Fuel for electric generation	541		517		559
Purchased and interchange power	1,361		1,339		1,267
Purchased power - related parties	89		86		81
Cost of gas sold	1,187		1,110		1,438
Maintenance and other operating expenses	1,174		1,162		1,175
Depreciation and amortization	622		592		542
General taxes	229		223		206
Total operating expenses	5,203		5,029		5,268
Operating Income	1,118		984		985
Other Income (Expense)
Interest income	2		4		7
Interest and dividend income - related parties	1		1		2
Allowance for equity funds used during construction	6		8		6
Other income	14		16		19
Other expense	(16)		(33)		(20)
Total other income (expense)	7		(4)		14
Interest Charges
Interest on long-term debt	237		232		251
Other interest expense	11		16		18
Allowance for borrowed funds used during construction	(3)		(4)		(4)
Total interest charges	245		244		265
Income Before Income Taxes	880		736		734
Income Tax Expense	346		297		267
Net Income	534		439		467
Preferred Stock Dividends and Distribution	2		2		2
Net Income Attributable to Common Stockholders
Net Income Available to Common Stockholders	$ 532		$ 437		$ 465

[1] Consumers had no significant equity method investments.

[2] Includes an $11 million ($7 million net of tax) reversal of a loss on disposal due to the elimination of a liability associated with the 2003 sale of Panhandle.

[3] Includes an operating gain of $3 million related to a litigation settlement at CMS Viron.