Consolidated Balance Sheets - USD ($) $ in Millions		Dec. 31, 2015	Dec. 31, 2014
Current Assets
Cash and cash equivalents		$ 266	$ 207
Restricted cash and cash equivalents		19	37
Accounts receivable and accrued revenue, less allowances		774	881
Notes receivable, less allowances		128	98
Notes receivable held for sale		16	41
Accounts receivable - related parties		$ 11	11
Accrued gas revenue			27
Inventories at average cost
Gas in underground storage		$ 568	681
Materials and supplies		126	117
Generating plant fuel stock		84	120
Deferred property taxes		235	216
Regulatory assets		16	89
Prepayments and other current assets		77	72
Total current assets		2,320	2,597
Plant, Property, and Equipment
Plant, property, and equipment, gross		18,943	17,721
Less accumulated depreciation and amortization		5,747	5,415
Plant, property, and equipment, net		13,196	12,306
Construction work in progress		1,509	1,106
Total plant, property, and equipment	[1]	14,705	13,412
Other Non-current Assets
Regulatory assets		1,840	1,956
Accounts and notes receivable		1,027	807
Investments	[2]	64	61
Other		384	352
Total other non-current assets		3,315	3,176
Total Assets		20,340	19,185
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation		706	540
Notes payable		249	60
Accounts payable		633	678
Accounts payable - related parties, current		9	10
Accrued rate refunds		26	6
Accrued interest		106	108
Accrued taxes		349	316
Regulatory liabilities		82	67
Other current liabilities		142	163
Total current liabilities		2,302	1,948
Non-current Liabilities
Long-term debt		8,441	8,016
Non-current portion of capital leases and financing obligation		118	123
Regulatory liabilities		2,088	2,095
Postretirement benefits		591	872
Asset retirement obligations		439	340
Deferred investment tax credit		56	37
Deferred income taxes		2,017	1,748
Other non-current liabilities		313	299
Total non-current liabilities		$ 14,063	$ 13,530
Commitments and Contingencies (Notes 3, 4, and 5)
Common stockholder's equity
Common stock		$ 3	$ 3
Other paid-in capital		4,837	4,774
Accumulated other comprehensive loss		(47)	(49)
Retained earnings (Accumulated deficit)		(855)	(1,058)
Total common stockholders' equity		3,938	3,670
Noncontrolling interests		37	37
Total equity		3,975	3,707
Total Liabilities and Equity		20,340	19,185
Consumers Energy Company [Member]
Current Assets
Cash and cash equivalents		50	71
Restricted cash and cash equivalents		19	37
Accounts receivable and accrued revenue, less allowances		758	863
Accounts receivable - related parties		17	1
Accrued gas revenue			27
Inventories at average cost
Gas in underground storage		568	681
Materials and supplies		120	113
Generating plant fuel stock		80	112
Deferred property taxes		235	216
Regulatory assets		16	89
Prepayments and other current assets		66	63
Total current assets		1,929	2,273
Plant, Property, and Equipment
Plant, property, and equipment, gross		18,797	17,580
Less accumulated depreciation and amortization		5,676	5,346
Plant, property, and equipment, net		13,121	12,234
Construction work in progress		1,467	1,103
Total plant, property, and equipment	[1]	14,588	13,337
Other Non-current Assets
Regulatory assets		1,840	1,956
Accounts and notes receivable		10	7
Investments		29	38
Other		262	236
Total other non-current assets		2,141	2,237
Total Assets		18,658	17,847
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation		220	145
Notes payable		249	60
Accounts payable		613	662
Accounts payable - related parties, current		15	12
Accrued rate refunds		26	6
Accrued interest		65	70
Accrued taxes		352	149
Regulatory liabilities		82	67
Other current liabilities		109	135
Total current liabilities		1,731	1,306
Non-current Liabilities
Long-term debt		5,206	5,154
Non-current portion of capital leases and financing obligation		118	123
Regulatory liabilities		2,088	2,095
Postretirement benefits		529	793
Asset retirement obligations		438	339
Deferred investment tax credit		56	37
Deferred income taxes		2,710	2,486
Other non-current liabilities		236	237
Total non-current liabilities		$ 11,381	$ 11,264
Commitments and Contingencies (Notes 3, 4, and 5)
Common stockholder's equity
Common stock		$ 841	$ 841
Other paid-in capital		3,724	3,574
Accumulated other comprehensive loss		(6)	(7)
Retained earnings (Accumulated deficit)		950	832
Total common stockholders' equity		5,509	5,240
Preferred stock		37	37
Total equity		5,546	5,277
Total Liabilities and Equity		$ 18,658	$ 17,847

[1] For the year ended December 31, 2015, utility plant additions were $1.4 billion and utility plant retirements were $187 million. For the year ended December 31, 2014, utility plant additions were $1.6 billion and utility plant retirements were $126 million.

[2] Consumers had no significant equity method investments.