Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Current Assets
Cash and cash equivalents	$ 358	$ 172
Restricted cash and cash equivalents	31	32
Accounts receivable and accrued revenue, less allowances	754	914
Notes receivable	88	63
Accounts receivable - related parties	11	10
Accrued power supply and gas revenue	152
Inventories at average cost
Gas in underground storage	582	660
Materials and supplies	109	107
Generating plant fuel stock	84	114
Deferred income taxes	29	126
Deferred property taxes	148	202
Regulatory assets	11	40
Prepayments and other current assets	108	86
Total current assets	2,465	2,526
Plant, Property, and Equipment
Plant, property, and equipment, gross	16,583	16,184
Less accumulated depreciation and amortization	5,242	5,087
Plant, property, and equipment, net	11,341	11,097
Construction work in progress	1,339	1,149
Total plant, property, and equipment	12,680	12,246
Other Non-current Assets
Regulatory assets	1,463	1,530
Accounts and notes receivable, less allowances	687	646
Investments	62	59
Other	362	409
Total other non-current assets	2,574	2,644
Total Assets	17,719	17,416
Current Liabilities
Current portion of long-term debt, capital and financing obligation	439	562
Notes payable		170
Accounts payable	587	585
Accounts payable - related parties	10	10
Accrued rate refunds		12
Accrued interest	103	96
Accrued taxes	225	297
Regulatory liabilities	70	67
Other current liabilities	129	146
Total current liabilities	1,563	1,945
Non-current Liabilities
Long-term debt	7,535	7,101
Non-current portion of capital and financing obligations	131	138
Regulatory liabilities	2,220	2,215
Postretirement benefits	241	239
Asset retirement obligations	329	325
Deferred investment tax credit	39	40
Deferred income taxes	1,676	1,616
Other non-current liabilities	303	306
Total non-current liabilities	12,474	11,980
Commitments and Contingencies (Notes 2 and 3)
Equity
Common stock	3	3
Other paid-in capital	4,761	4,715
Accumulated other comprehensive income (loss)	(20)	(22)
Retained earnings (Accumulated deficit)	(1,099)	(1,242)
Total common stockholder's equity	3,645	3,454
Noncontrolling interests	37	37
Total equity	3,682	3,491
Total Liabilities and Equity	17,719	17,416
Consumers Energy Company [Member]
Current Assets
Cash and cash equivalents	98	18
Restricted cash and cash equivalents	31	31
Accounts receivable and accrued revenue, less allowances	739	902
Notes receivable		14
Accounts receivable - related parties	1	4
Accrued power supply and gas revenue	152
Inventories at average cost
Gas in underground storage	582	653
Materials and supplies	104	103
Generating plant fuel stock	82	113
Deferred property taxes	148	202
Regulatory assets	11	40
Prepayments and other current assets	101	77
Total current assets	2,049	2,157
Plant, Property, and Equipment
Plant, property, and equipment, gross	16,441	16,044
Less accumulated depreciation and amortization	5,174	5,022
Plant, property, and equipment, net	11,267	11,022
Construction work in progress	1,337	1,147
Total plant, property, and equipment	12,604	12,169
Other Non-current Assets
Regulatory assets	1,463	1,530
Accounts and notes receivable, less allowances	4	11
Investments	34	29
Other	233	283
Total other non-current assets	1,734	1,853
Total Assets	16,387	16,179
Current Liabilities
Current portion of long-term debt, capital and financing obligation	67	64
Notes payable		170
Accounts payable	573	571
Accounts payable - related parties	14	13
Accrued rate refunds		12
Accrued interest	63	63
Accrued taxes	283	353
Deferred income taxes	121	55
Regulatory liabilities	70	67
Other current liabilities	97	112
Total current liabilities	1,288	1,480
Non-current Liabilities
Long-term debt	4,555	4,579
Non-current portion of capital and financing obligations	131	138
Regulatory liabilities	2,220	2,215
Postretirement benefits	182	179
Asset retirement obligations	328	324
Deferred investment tax credit	39	40
Deferred income taxes	2,143	2,115
Other non-current liabilities	251	252
Total non-current liabilities	9,849	9,842
Commitments and Contingencies (Notes 2 and 3)
Equity
Common stock	841	841
Other paid-in capital	3,572	3,257
Accumulated other comprehensive income (loss)	2	(2)
Retained earnings (Accumulated deficit)	798	724
Total common stockholder's equity	5,213	4,820
Preferred stock	37	37
Total equity	5,250	4,857
Total Liabilities and Equity	$ 16,387	$ 16,179