Consolidated Statements of Income (USD $) In Millions, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Operating Revenue	$ 1,364	$ 1,340	$ 3,419	$ 3,307
Operating Expenses
Fuel for electric generation	153	151	305	289
Purchased and interchange power	303	314	603	592
Purchased power - related parties	20	21	41	42
Cost of gas sold	220	178	988	956
Maintenance and other operating expenses	288	296	567	571
Depreciation and amortization	122	131	284	303
General taxes	51	41	118	107
Insurance settlement	0	(50)	0	(50)
Gain on asset sales, net	0	(4)	0	(4)
Total operating expenses	1,157	1,078	2,906	2,806
Operating Income	207	262	513	501
Other Income (Expense)
Interest income	2	4	4	9
Allowance for equity funds used during construction	2	2	3	3
Income from equity method investees	2	2	6	5
Other income	5	9	9	18
Other expense	(3)	(3)	(5)	(5)
Total other income	8	14	17	30
Interest Charges
Interest on long-term debt	99	98	199	196
Other interest expense	6	20	12	28
Allowance for borrowed funds used during construction	(1)	(1)	(2)	(2)
Total interest charges	104	117	209	222
Income Before Income Taxes	111	159	321	309
Income Tax Expense	10	59	87	120
Income from Continuing Operations	101	100	234	189
Income (Loss) From Discontinued Operations, Net of Tax	0	(16)	2	(17)
Net Income	101	84	236	172
Income Attributable to Noncontrolling Interests	1	2	1	2
Net Income Attributable to CMS Energy	100	82	235	170
Preferred Stock Dividends	0	2	0	5
Net Income Available to Common Stockholders	100	80	235	165
Net Income Attributable to Common Stockholders
Amounts Attributable to Continuing Operations	100	96	233	182
Amounts Attributable to Discontinued Operations	0	(16)	2	(17)
Net Income Available to Common Stockholders	100	80	235	165
Income Attributable to Noncontrolling Interests
Amounts Attributable to Continuing Operations	1	2	1	2
Loss from Discontinued Operations	0	0	0	0
Income Attributable to Noncontrolling Interests	1	2	1	2
Basic Earnings Per Average Common Share
Basic Earnings from Continuing Operations	$ 0.40	$ 0.42	$ 0.93	$ 0.80
Basic Earnings (Loss) from Discontinued Operations	$ 0.00	$ (0.07)	$ 0.01	$ (0.08)
Basic Earnings Attributable to Common Stock	$ 0.40	$ 0.35	$ 0.94	$ 0.72
Diluted Earnings Per Average Common Share
Diluted Earnings from Continuing Operations	$ 0.38	$ 0.39	$ 0.89	$ 0.74
Diluted Earnings (Loss) from Discontinued Operations	$ 0.00	$ (0.07)	$ 0.01	$ (0.07)
Diluted Earnings Attributable to Common Stock	$ 0.38	$ 0.32	$ 0.90	$ 0.67
Dividends Declared Per Common Share	$ 0.21	$ 0.15	$ 0.42	$ 0.3
Consumers Energy Company [Member]
Operating Revenue	1,303	1,276	3,291	3,166
Operating Expenses
Fuel for electric generation	138	125	267	250
Purchased and interchange power	299	310	592	587
Purchased power - related parties	19	20	40	41
Cost of gas sold	197	163	950	909
Maintenance and other operating expenses	273	281	538	543
Depreciation and amortization	121	130	282	301
General taxes	49	40	115	104
Total operating expenses	1,096	1,069	2,784	2,735
Operating Income	207	207	507	431
Other Income (Expense)
Interest income	2	4	4	9
Allowance for equity funds used during construction	2	2	3	3
Other income	5	9	13	18
Other expense	(3)	(3)	(5)	(5)
Total other income	6	12	15	25
Interest Charges
Interest on long-term debt	63	60	126	123
Other interest expense	5	19	9	25
Allowance for borrowed funds used during construction	(1)	(1)	(2)	(2)
Total interest charges	67	78	133	146
Income Before Income Taxes	146	141	389	310
Income Tax Expense	54	53	144	115
Net Income	92	88	245	195
Preferred Stock Dividends	1	1	1	1
Net Income Available to Common Stockholders	91	87	244	194
Net Income Attributable to Common Stockholders
Net Income Available to Common Stockholders	$ 91	$ 87	$ 244	$ 194