Consolidated Balance Sheets - USD ($) $ in Millions		Mar. 31, 2016	Dec. 31, 2015
Current Assets
Cash and cash equivalents		$ 177	$ 266
Restricted cash and cash equivalents		28	19
Accounts receivable and accrued revenue, less allowances		730	774
Notes receivable, less allowances		135	128
Notes receivable held for sale		16	16
Accounts receivable - related parties		11	11
Inventories at average cost
Gas in underground storage		314	568
Materials and supplies		120	126
Generating plant fuel stock		64	84
Deferred property taxes		193	235
Regulatory assets		11	16
Prepayments and other current assets		91	77
Total current assets		1,890	2,320
Plant, Property, and Equipment
Plant, property, and equipment, gross		19,334	18,943
Less accumulated depreciation and amortization		5,878	5,747
Plant, property, and equipment, net		13,456	13,196
Construction work in progress		1,451	1,509
Total plant, property, and equipment		14,907	14,705
Other Non-current Assets
Regulatory assets		1,827	1,840
Accounts and notes receivable		1,034	1,027
Investments		64	64
Other		315	343
Total other non-current assets		3,240	3,274
Total Assets	[1]	20,037	20,299
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation		950	706
Notes payable			249
Accounts payable		534	633
Accounts payable - related parties		9	9
Accrued rate refunds		34	26
Accrued interest		72	106
Accrued taxes		254	349
Regulatory liabilities		76	82
Other current liabilities		118	142
Total current liabilities		2,047	2,302
Non-current Liabilities
Long-term debt		8,170	8,400
Non-current portion of capital leases and financing obligation		114	118
Regulatory liabilities		2,092	2,088
Postretirement benefits		581	591
Asset retirement obligations		440	439
Deferred investment tax credit		55	56
Deferred income taxes		2,078	2,017
Other non-current liabilities		314	313
Total non-current liabilities		$ 13,844	$ 14,022
Commitments and Contingencies (Notes 2 and 3)
Common stockholder's equity
Common stock		$ 3	$ 3
Other paid-in capital		4,897	4,837
Accumulated other comprehensive loss		(47)	(47)
Retained earnings (Accumulated deficit)		(744)	(855)
Total common stockholders' equity		4,109	3,938
Noncontrolling interests		37	37
Total equity		4,146	3,975
Total Liabilities and Equity		20,037	20,299
Consumers Energy Company [Member]
Current Assets
Cash and cash equivalents		27	50
Restricted cash and cash equivalents		28	19
Accounts receivable and accrued revenue, less allowances		713	758
Accounts receivable - related parties		1	17
Inventories at average cost
Gas in underground storage		314	568
Materials and supplies		115	120
Generating plant fuel stock		63	80
Deferred property taxes		193	235
Regulatory assets		11	16
Prepayments and other current assets		84	66
Total current assets		1,549	1,929
Plant, Property, and Equipment
Plant, property, and equipment, gross		19,165	18,797
Less accumulated depreciation and amortization		5,821	5,676
Plant, property, and equipment, net		13,344	13,121
Construction work in progress		1,449	1,467
Total plant, property, and equipment		14,793	14,588
Other Non-current Assets
Regulatory assets		1,827	1,840
Accounts and notes receivable		10	10
Investments		34	29
Other		209	239
Total other non-current assets		2,080	2,118
Total Assets	[1]	18,422	18,635
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation		469	220
Notes payable			249
Accounts payable		521	613
Accounts payable - related parties		15	15
Accrued rate refunds		34	26
Accrued interest		47	65
Accrued taxes		262	352
Regulatory liabilities		76	82
Other current liabilities		87	109
Total current liabilities		1,511	1,731
Non-current Liabilities
Long-term debt		4,934	5,183
Non-current portion of capital leases and financing obligation		114	118
Regulatory liabilities		2,092	2,088
Postretirement benefits		519	529
Asset retirement obligations		439	438
Deferred investment tax credit		55	56
Deferred income taxes		2,799	2,710
Other non-current liabilities		243	236
Total non-current liabilities		$ 11,195	$ 11,358
Commitments and Contingencies (Notes 2 and 3)
Common stockholder's equity
Common stock		$ 841	$ 841
Other paid-in capital		3,874	3,724
Accumulated other comprehensive loss		(3)	(6)
Retained earnings (Accumulated deficit)		967	950
Total common stockholders' equity		5,679	5,509
Preferred stock		37	37
Total equity		5,716	5,546
Total Liabilities and Equity		$ 18,422	$ 18,635

[1] CMS Energy and Consumers changed the reporting of debt issuance costs on their consolidated balance sheets in accordance with ASU 2015-03, Simplifying the Presentation of Debt Issuance Costs, as of January 1, 2016, and retrospectively adjusted prior-period amounts for comparability. For further details on the implementation of this standard, see Note 1, New Accounting Standards.