Consolidated Balance Sheets (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Assets
Cash and cash equivalents	$ 994	$ 247
Restricted cash and cash equivalents	29	23
Accounts receivable and accrued revenue, less allowances	719	981
Notes receivables	57	70
Accounts receivable - related parties	10	10
Accrued power supply revenue	0	15
Inventories at average cost
Gas in underground storage	720	946
Materials and supplies	106	104
Generating plant fuel stock	143	125
Deferred property taxes	133	180
Regulatory assets	8	19
Assets held for sale	0	2
Prepayments and other current assets	37	37
Total current assets	2,956	2,759
Plant, Property & Equipment (at cost)
Plant, property, and equipment, gross	14,413	14,145
Less accumulated depreciation, depletion, and amortization	4,802	4,646
Plant, property & equipment, net	9,611	9,499
Construction work in progress	644	570
Total plant, property & equipment	10,255	10,069
Non-current Assets
Regulatory assets	2,050	2,093
Accounts and notes receivable, less allowances	398	397
Investments	52	49
Assets held for sale		4
Other non-current assets	234	245
Total non-current assets	2,734	2,788
Total Assets	15,945	15,616
Liabilities and Equity
Current portion of long-term debt, capital and finance lease obligations	1,123	750
Accounts payable	444	492
Accounts payable - related parties	8	9
Accrued rate refunds	43	19
Accrued interest	107	102
Accrued taxes	239	302
Deferred income taxes	154	180
Regulatory liabilities	1	22
Liabilities held for sale		1
Other current liabilities	122	144
Total current liabilities	2,241	2,021
Non-current Liabilities
Long-term debt	6,184	6,448
Non-current portion of capital and finance lease obligations	177	188
Regulatory liabilities	1,860	1,988
Postretirement benefits	1,136	1,135
Asset retirement obligations	252	245
Deferred investment tax credit	47	49
Deferred income taxes	768	438
Other non-current liabilities	278	267
Total non-current liabilities	10,702	10,758
Commitments and Contingencies (Notes 3, 4, 5, 7, and 8)
Equity
Common stock	3	2
Other paid-in capital	4,621	4,588
Accumulated other comprehensive loss	(38)	(40)
Retained earnings (Accumulated deficit)	(1,628)	(1,757)
Total common stockholders' equity	2,958	2,793
Noncontrolling interests	44	44
Total equity	3,002	2,837
Total Liabilities and Equity	15,945	15,616
Consumers Energy Company [Member]
Assets
Cash and cash equivalents	766	71
Restricted cash and cash equivalents	28	23
Accounts receivable and accrued revenue, less allowances	706	963
Notes receivables	43	55
Accounts receivable - related parties	1	1
Accrued power supply revenue	0	15
Inventories at average cost
Gas in underground storage	720	941
Materials and supplies	103	100
Generating plant fuel stock	141	124
Deferred property taxes	133	180
Regulatory assets	8	19
Prepayments and other current assets	30	27
Total current assets	2,679	2,519
Plant, Property & Equipment (at cost)
Plant, property, and equipment, gross	14,285	14,022
Less accumulated depreciation, depletion, and amortization	4,747	4,593
Plant, property & equipment, net	9,538	9,429
Construction work in progress	640	566
Total plant, property & equipment	10,178	9,995
Non-current Assets
Regulatory assets	2,050	2,093
Accounts and notes receivable, less allowances	13	22
Investments	31	34
Other non-current assets	150	176
Total non-current assets	2,244	2,325
Total Assets	15,101	14,839
Liabilities and Equity
Current portion of long-term debt, capital and finance lease obligations	362	61
Accounts payable	429	471
Accounts payable - related parties	11	11
Accrued rate refunds	43	19
Accrued interest	75	74
Accrued taxes	163	199
Deferred income taxes	194	209
Regulatory liabilities	1	22
Other current liabilities	85	95
Total current liabilities	1,363	1,161
Non-current Liabilities
Long-term debt	4,169	4,488
Non-current portion of capital and finance lease obligations	177	188
Regulatory liabilities	1,860	1,988
Postretirement benefits	1,078	1,076
Asset retirement obligations	251	244
Deferred investment tax credit	47	49
Deferred income taxes	1,617	1,289
Other non-current liabilities	186	176
Total non-current liabilities	9,385	9,498
Equity
Common stock	841	841
Other paid-in capital	2,957	2,832
Retained earnings (Accumulated deficit)	511	463
Total common stockholders' equity	4,309	4,136
Preferred stock	44	44
Total equity	4,353	4,180
Total Liabilities and Equity	$ 15,101	$ 14,839