Consolidated Balance Sheets - USD ($) $ in Millions		Sep. 30, 2016	Dec. 31, 2015
Current Assets
Cash and cash equivalents		$ 339	$ 266
Restricted cash and cash equivalents		28	19
Accounts receivable and accrued revenue, less allowances		634	774
Notes receivable, less allowances		146	128
Notes receivable held for sale		41	16
Accounts receivable - related parties		12	11
Inventories at average cost
Gas in underground storage		553	568
Materials and supplies		119	126
Generating plant fuel stock		64	84
Deferred property taxes		152	235
Regulatory assets		16	16
Prepayments and other current assets		94	77
Total current assets		2,198	2,320
Plant, Property, and Equipment
Plant, property, and equipment, gross		20,698	18,943
Less accumulated depreciation and amortization		5,953	5,747
Plant, property, and equipment, net		14,745	13,196
Construction work in progress		698	1,509
Total plant, property, and equipment		15,443	14,705
Other Non-current Assets
Regulatory assets		1,765	1,840
Accounts and notes receivable		1,110	1,027
Investments		68	64
Other		258	343
Total other non-current assets		3,201	3,274
Total Assets	[1]	20,842	20,299
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation		1,005	706
Notes payable		75	249
Accounts payable		539	633
Accounts payable - related parties		9	9
Accrued rate refunds		33	26
Accrued interest		76	106
Accrued taxes		93	349
Regulatory liabilities		80	82
Other current liabilities		159	142
Total current liabilities		2,069	2,302
Non-current Liabilities
Long-term debt		8,722	8,400
Non-current portion of capital leases and financing obligation		110	118
Regulatory liabilities		2,053	2,088
Postretirement benefits		560	591
Asset retirement obligations		445	439
Deferred investment tax credit		74	56
Deferred income taxes		2,230	2,017
Other non-current liabilities		283	313
Total non-current liabilities		14,477	14,022
Commitments and Contingencies (Notes 2 and 3)
Common stockholder's equity
Common stock		3	3
Other paid-in capital		4,908	4,837
Accumulated other comprehensive loss		(45)	(47)
Retained earnings (Accumulated deficit)		(607)	(855)
Total common stockholders' equity		4,259	3,938
Noncontrolling interests		37	37
Total equity		4,296	3,975
Total Liabilities and Equity		20,842	20,299
Consumers Energy Company [Member]
Current Assets
Cash and cash equivalents		21	50
Restricted cash and cash equivalents		28	19
Accounts receivable and accrued revenue, less allowances		616	758
Accounts receivable - related parties		2	17
Inventories at average cost
Gas in underground storage		553	568
Materials and supplies		114	120
Generating plant fuel stock		60	80
Deferred property taxes		152	235
Regulatory assets		16	16
Prepayments and other current assets		85	66
Total current assets		1,647	1,929
Plant, Property, and Equipment
Plant, property, and equipment, gross		20,528	18,797
Less accumulated depreciation and amortization		5,893	5,676
Plant, property, and equipment, net		14,635	13,121
Construction work in progress		692	1,467
Total plant, property, and equipment		15,327	14,588
Other Non-current Assets
Regulatory assets		1,765	1,840
Accounts and notes receivable		56	10
Investments		34	29
Other		151	239
Total other non-current assets		2,006	2,118
Total Assets	[1]	18,980	18,635
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation		296	220
Notes payable		75	249
Accounts payable		521	613
Accounts payable - related parties		9	15
Accrued rate refunds		33	26
Accrued interest		48	65
Accrued taxes		114	352
Regulatory liabilities		80	82
Other current liabilities		127	109
Total current liabilities		1,303	1,731
Non-current Liabilities
Long-term debt		5,365	5,183
Non-current portion of capital leases and financing obligation		110	118
Regulatory liabilities		2,053	2,088
Postretirement benefits		500	529
Asset retirement obligations		444	438
Deferred investment tax credit		74	56
Deferred income taxes		2,958	2,710
Other non-current liabilities		212	236
Total non-current liabilities		11,716	11,358
Commitments and Contingencies (Notes 2 and 3)
Common stockholder's equity
Common stock		841	841
Other paid-in capital		3,999	3,724
Accumulated other comprehensive loss		(3)	(6)
Retained earnings (Accumulated deficit)		1,087	950
Total common stockholders' equity		5,924	5,509
Preferred stock		37	37
Total equity		5,961	5,546
Total Liabilities and Equity		$ 18,980	$ 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.