Consolidated Balance Sheets - USD ($) $ in Millions		Jun. 30, 2016	Dec. 31, 2015
Current Assets
Cash and cash equivalents		$ 385	$ 266
Restricted cash and cash equivalents		18	19
Accounts receivable and accrued revenue, less allowances		603	774
Notes receivable, less allowances		142	128
Notes receivable held for sale		15	16
Accounts receivable - related parties		12	11
Inventories at average cost
Gas in underground storage		377	568
Materials and supplies		119	126
Generating plant fuel stock		77	84
Deferred property taxes		174	235
Regulatory assets		7	16
Prepayments and other current assets		102	77
Total current assets		2,031	2,320
Plant, Property, and Equipment
Plant, property, and equipment, gross		20,497	18,943
Less accumulated depreciation and amortization		5,922	5,747
Plant, property, and equipment, net		14,575	13,196
Construction work in progress		612	1,509
Total plant, property, and equipment		15,187	14,705
Other Non-current Assets
Regulatory assets		1,796	1,840
Accounts and notes receivable		1,098	1,027
Investments		66	64
Other		285	343
Total other non-current assets		3,245	3,274
Total Assets	[1]	20,463	20,299
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation		918	706
Notes payable			249
Accounts payable		559	633
Accounts payable - related parties		9	9
Accrued rate refunds		41	26
Accrued interest		107	106
Accrued taxes		252	349
Regulatory liabilities		78	82
Other current liabilities		127	142
Total current liabilities		2,091	2,302
Non-current Liabilities
Long-term debt		8,486	8,400
Non-current portion of capital leases and financing obligation		110	118
Regulatory liabilities		2,070	2,088
Postretirement benefits		570	591
Asset retirement obligations		442	439
Deferred investment tax credit		73	56
Deferred income taxes		2,127	2,017
Other non-current liabilities		301	313
Total non-current liabilities		14,179	14,022
Commitments and Contingencies (Notes 2 and 3)
Common stockholder's equity
Common stock		3	3
Other paid-in capital		4,906	4,837
Accumulated other comprehensive loss		(47)	(47)
Retained earnings (Accumulated deficit)		(706)	(855)
Total common stockholders' equity		4,156	3,938
Noncontrolling interests		37	37
Total equity		4,193	3,975
Total Liabilities and Equity		20,463	20,299
Consumers Energy Company [Member]
Current Assets
Cash and cash equivalents		117	50
Restricted cash and cash equivalents		18	19
Accounts receivable and accrued revenue, less allowances		585	758
Accounts receivable - related parties		1	17
Inventories at average cost
Gas in underground storage		377	568
Materials and supplies		114	120
Generating plant fuel stock		74	80
Deferred property taxes		174	235
Regulatory assets		7	16
Prepayments and other current assets		97	66
Total current assets		1,564	1,929
Plant, Property, and Equipment
Plant, property, and equipment, gross		20,326	18,797
Less accumulated depreciation and amortization		5,863	5,676
Plant, property, and equipment, net		14,463	13,121
Construction work in progress		609	1,467
Total plant, property, and equipment		15,072	14,588
Other Non-current Assets
Regulatory assets		1,796	1,840
Accounts and notes receivable		54	10
Investments		37	29
Other		179	239
Total other non-current assets		2,066	2,118
Total Assets	[1]	18,702	18,635
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation		469	220
Notes payable			249
Accounts payable		545	613
Accounts payable - related parties		15	15
Accrued rate refunds		41	26
Accrued interest		65	65
Accrued taxes		265	352
Regulatory liabilities		78	82
Other current liabilities		93	109
Total current liabilities		1,571	1,731
Non-current Liabilities
Long-term debt		4,922	5,183
Non-current portion of capital leases and financing obligation		110	118
Regulatory liabilities		2,070	2,088
Postretirement benefits		510	529
Asset retirement obligations		441	438
Deferred investment tax credit		73	56
Deferred income taxes		2,858	2,710
Other non-current liabilities		231	236
Total non-current liabilities		11,215	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		(1)	(6)
Retained earnings (Accumulated deficit)		1,040	950
Total common stockholders' equity		5,879	5,509
Preferred stock		37	37
Total equity		5,916	5,546
Total Liabilities and Equity		$ 18,702	$ 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.