Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Current Assets
Cash and cash equivalents	$ 150	$ 207
Restricted cash and cash equivalents	52	37
Accounts receivable and accrued revenue, less allowances	640	881
Notes receivable, less allowances	119	98
Notes receivable held for sale	17	41
Accounts receivable - related parties	12	11
Accrued power supply and gas revenue	10	27
Inventories at average cost
Gas in underground storage	652	681
Materials and supplies	119	117
Generating plant fuel stock	92	120
Deferred income taxes	12
Deferred property taxes	141	216
Regulatory assets	20	89
Prepayments and other current assets	87	72
Total current assets	2,123	2,597
Plant, Property, and Equipment
Plant, property, and equipment, gross	18,547	17,721
Less accumulated depreciation and amortization	5,697	5,415
Plant, property, and equipment, net	12,850	12,306
Construction work in progress	1,310	1,106
Total plant, property, and equipment	14,160	13,412
Other Non-current Assets
Regulatory assets	1,870	1,956
Accounts and notes receivable	950	807
Investments	61	61
Other	288	352
Total other non-current assets	3,169	3,176
Total Assets	19,452	19,185
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation	741	540
Notes payable	68	60
Accounts payable	586	678
Accounts payable - related parties	8	10
Accrued rate refunds	20	6
Accrued interest	64	108
Accrued taxes	90	316
Deferred income taxes		66
Regulatory liabilities	81	67
Other current liabilities	130	163
Total current liabilities	1,788	2,014
Non-current Liabilities
Long-term debt	7,903	8,016
Non-current portion of capital leases and financing obligation	111	123
Regulatory liabilities	2,110	2,095
Postretirement benefits	847	872
Asset retirement obligations	419	340
Deferred investment tax credit	56	37
Deferred income taxes	1,980	1,682
Other non-current liabilities	299	299
Total non-current liabilities	$ 13,725	$ 13,464
Commitments and Contingencies (Notes 2 and 3)
Common stockholder's equity
Common stock	$ 3	$ 3
Other paid-in capital	4,829	4,774
Accumulated other comprehensive loss	(49)	(49)
Retained earnings (Accumulated deficit)	(881)	(1,058)
Total common stockholders' equity	3,902	3,670
Noncontrolling interests	37	37
Total equity	3,939	3,707
Total Liabilities and Equity	19,452	19,185
Consumers Energy Company [Member]
Current Assets
Cash and cash equivalents	43	71
Restricted cash and cash equivalents	52	37
Accounts receivable and accrued revenue, less allowances	627	863
Accounts receivable - related parties	1	1
Accrued power supply and gas revenue	10	27
Inventories at average cost
Gas in underground storage	652	681
Materials and supplies	114	113
Generating plant fuel stock	87	112
Deferred property taxes	141	216
Regulatory assets	20	89
Prepayments and other current assets	79	63
Total current assets	1,826	2,273
Plant, Property, and Equipment
Plant, property, and equipment, gross	18,400	17,580
Less accumulated depreciation and amortization	5,626	5,346
Plant, property, and equipment, net	12,774	12,234
Construction work in progress	1,305	1,103
Total plant, property, and equipment	14,079	13,337
Other Non-current Assets
Regulatory assets	1,870	1,956
Accounts and notes receivable	9	7
Investments	28	38
Other	165	236
Total other non-current assets	2,072	2,237
Total Assets	17,977	17,847
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation	283	145
Notes payable	68	60
Accounts payable	571	662
Accounts payable - related parties	11	12
Accrued rate refunds	20	6
Accrued interest	44	70
Accrued taxes	78	149
Deferred income taxes	59	80
Regulatory liabilities	81	67
Other current liabilities	100	135
Total current liabilities	1,315	1,386
Non-current Liabilities
Long-term debt	4,969	5,154
Non-current portion of capital leases and financing obligation	111	123
Regulatory liabilities	2,110	2,095
Postretirement benefits	770	793
Asset retirement obligations	418	339
Deferred investment tax credit	56	37
Deferred income taxes	2,467	2,406
Other non-current liabilities	239	237
Total non-current liabilities	$ 11,140	$ 11,184
Commitments and Contingencies (Notes 2 and 3)
Common stockholder's equity
Common stock	$ 841	$ 841
Other paid-in capital	3,724	3,574
Accumulated other comprehensive loss	(11)	(7)
Retained earnings (Accumulated deficit)	931	832
Total common stockholders' equity	5,485	5,240
Preferred stock	37	37
Total equity	5,522	5,277
Total Liabilities and Equity	$ 17,977	$ 17,847