Consolidated Balance Sheets - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015
Current Assets
Cash and cash equivalents		$ 235	$ 266
Restricted cash and cash equivalents		19	19
Accounts receivable and accrued revenue, less allowances		821	774
Notes receivable, less allowances		180	128
Notes receivable held for sale		39	16
Accounts receivable - related parties		12	11
Inventories at average cost
Gas in underground storage		446	568
Materials and supplies		119	126
Generating plant fuel stock		61	84
Deferred property taxes		250	235
Regulatory assets		17	16
Prepayments and other current assets		81	77
Total current assets		2,280	2,320
Plant, Property, and Equipment
Plant, property, and equipment, gross		21,010	18,943
Less accumulated depreciation and amortization		6,056	5,747
Plant, property, and equipment, net		14,954	13,196
Construction work in progress		761	1,509
Total plant, property, and equipment	[1]	15,715	14,705
Other Non-current Assets
Regulatory assets		2,091	1,840
Accounts and notes receivable		1,118	1,027
Investments	[2]	65	64
Other		353	343
Total other non-current assets		3,627	3,274
Total Assets		21,622	20,299
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation		886	706
Notes payable		398	249
Accounts payable		598	633
Accounts payable - related parties		12	9
Accrued rate refunds		21	26
Accrued interest		98	106
Accrued taxes		348	349
Regulatory liabilities		95	82
Other current liabilities		199	142
Total current liabilities		2,655	2,302
Non-current Liabilities
Long-term debt		8,640	8,400
Non-current portion of capital leases and financing obligation		110	118
Regulatory liabilities		2,041	2,088
Postretirement benefits		789	591
Asset retirement obligations		447	439
Deferred investment tax credit		73	56
Deferred income taxes		2,287	2,017
Other non-current liabilities		290	313
Total non-current liabilities		14,677	14,022
Commitments and Contingencies (Notes 3, 4, and 5)
Common stockholder's equity
Common stock		3	3
Other paid-in capital		4,916	4,837
Accumulated other comprehensive loss		(50)	(47)
Retained earnings (Accumulated deficit)		(616)	(855)
Total common stockholders' equity		4,253	3,938
Noncontrolling interests		37	37
Total equity		4,290	3,975
Total Liabilities and Equity		21,622	20,299
Consumers Energy Company [Member]
Current Assets
Cash and cash equivalents		131	50
Restricted cash and cash equivalents		19	19
Accounts receivable and accrued revenue, less allowances		800	758
Notes receivable, less allowances		29
Accounts receivable - related parties		9	17
Inventories at average cost
Gas in underground storage		446	568
Materials and supplies		114	120
Generating plant fuel stock		57	80
Deferred property taxes		250	235
Regulatory assets		17	16
Prepayments and other current assets		70	66
Total current assets		1,942	1,929
Plant, Property, and Equipment
Plant, property, and equipment, gross		20,838	18,797
Less accumulated depreciation and amortization		5,994	5,676
Plant, property, and equipment, net		14,844	13,121
Construction work in progress		759	1,467
Total plant, property, and equipment	[1]	15,603	14,588
Other Non-current Assets
Regulatory assets		2,091	1,840
Accounts and notes receivable		27	10
Investments		33	29
Other		250	239
Total other non-current assets		2,401	2,118
Total Assets		19,946	18,635
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation		397	220
Notes payable		398	249
Accounts payable		580	613
Accounts payable - related parties		18	15
Accrued rate refunds		21	26
Accrued interest		67	65
Accrued taxes		354	352
Regulatory liabilities		95	82
Other current liabilities		164	109
Total current liabilities		2,094	1,731
Non-current Liabilities
Long-term debt		5,253	5,183
Non-current portion of capital leases and financing obligation		110	118
Regulatory liabilities		2,041	2,088
Postretirement benefits		730	529
Asset retirement obligations		446	438
Deferred investment tax credit		73	56
Deferred income taxes		3,042	2,710
Other non-current liabilities		218	236
Total non-current liabilities		11,913	11,358
Commitments and Contingencies (Notes 3, 4, and 5)
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)		1,065	950
Total common stockholders' equity		5,902	5,509
Preferred stock		37	37
Total equity		5,939	5,546
Total Liabilities and Equity		$ 19,946	$ 18,635

[1] For the year ended December 31, 2016, Consumers' plant additions were $2.3 billion and plant retirements were $285 million. For the year ended December 31, 2015, Consumers' plant additions were $1.4 billion and plant retirements were $187 million.

[2] Consumers had no significant equity method investments.