Consolidated Balance Sheets - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Current Assets
Cash and cash equivalents	$ 477	$ 207
Restricted cash and cash equivalents	40	37
Accounts receivable and accrued revenue, less allowances	669	881
Notes receivable	114	98
Notes receivable held for sale		41
Accounts receivable - related parties	12	11
Accrued gas revenue		27
Inventories at average cost
Gas in underground storage	459	681
Materials and supplies	118	117
Generating plant fuel stock	106	120
Deferred income taxes	17
Deferred property taxes	159	216
Regulatory assets	31	89
Prepayments and other current assets	89	72
Total current assets	2,291	2,597
Plant, Property, and Equipment
Plant, property, and equipment, gross	18,217	17,721
Less accumulated depreciation and amortization	5,633	5,415
Plant, property, and equipment, net	12,584	12,306
Construction work in progress	1,191	1,106
Total plant, property, and equipment	13,775	13,412
Other Non-current Assets
Regulatory assets	1,908	1,956
Accounts and notes receivable, less allowances	884	807
Investments	61	61
Other	319	352
Total other non-current assets	3,172	3,176
Total Assets	19,238	19,185
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation	519	540
Notes payable		60
Accounts payable	558	678
Accounts payable - related parties	6	10
Accrued rate refunds	27	6
Accrued interest	103	108
Accrued taxes	235	316
Deferred income taxes		66
Regulatory liabilities	69	67
Other current liabilities	123	163
Total current liabilities	1,640	2,014
Non-current Liabilities
Long-term debt	8,040	8,016
Non-current portion of capital leases and financing obligation	113	123
Regulatory liabilities	2,136	2,095
Postretirement benefits	846	872
Asset retirement obligations	348	340
Deferred investment tax credit	57	37
Deferred income taxes	1,899	1,682
Other non-current liabilities	304	299
Total non-current liabilities	$ 13,743	$ 13,464
Commitments and Contingencies (Notes 2 and 3)
Equity
Common stock	$ 3	$ 3
Other paid-in capital	4,812	4,774
Accumulated other comprehensive loss	(48)	(49)
Retained earnings (Accumulated deficit)	(949)	(1,058)
Total common stockholders' equity	3,818	3,670
Noncontrolling interests	37	37
Total equity	3,855	3,707
Total Liabilities and Equity	19,238	19,185
Consumers Energy Company [Member]
Current Assets
Cash and cash equivalents	397	71
Restricted cash and cash equivalents	40	37
Accounts receivable and accrued revenue, less allowances	655	863
Accounts receivable - related parties	1	1
Accrued gas revenue		27
Inventories at average cost
Gas in underground storage	459	681
Materials and supplies	113	113
Generating plant fuel stock	100	112
Deferred property taxes	159	216
Regulatory assets	31	89
Prepayments and other current assets	83	63
Total current assets	2,038	2,273
Plant, Property, and Equipment
Plant, property, and equipment, gross	18,074	17,580
Less accumulated depreciation and amortization	5,564	5,346
Plant, property, and equipment, net	12,510	12,234
Construction work in progress	1,184	1,103
Total plant, property, and equipment	13,694	13,337
Other Non-current Assets
Regulatory assets	1,908	1,956
Accounts and notes receivable, less allowances	7	7
Investments	26	38
Other	194	236
Total other non-current assets	2,135	2,237
Total Assets	17,867	17,847
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation	122	145
Notes payable		60
Accounts payable	540	662
Accounts payable - related parties	11	12
Accrued rate refunds	27	6
Accrued interest	64	70
Accrued taxes	166	149
Deferred income taxes	54	80
Regulatory liabilities	69	67
Other current liabilities	93	135
Total current liabilities	1,146	1,386
Non-current Liabilities
Long-term debt	5,141	5,154
Non-current portion of capital leases and financing obligation	113	123
Regulatory liabilities	2,136	2,095
Postretirement benefits	768	793
Asset retirement obligations	347	339
Deferred investment tax credit	57	37
Deferred income taxes	2,450	2,406
Other non-current liabilities	243	237
Total non-current liabilities	$ 11,255	$ 11,184
Commitments and Contingencies (Notes 2 and 3)
Equity
Common stock	$ 841	$ 841
Other paid-in capital	3,724	3,574
Accumulated other comprehensive loss	(12)	(7)
Retained earnings (Accumulated deficit)	876	832
Total common stockholders' equity	5,429	5,240
Preferred stock	37	37
Total equity	5,466	5,277
Total Liabilities and Equity	$ 17,867	$ 17,847