Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Current Assets
Cash and cash equivalents	$ 433	$ 235
Restricted cash and cash equivalents	30	19
Accounts receivable and accrued revenue, less allowance	775	821
Notes receivable, less allowance	186	180
Notes receivable held for sale	19	39
Accounts receivable - related parties	12	12
Inventories at average cost
Gas in underground storage	243	446
Materials and supplies	118	119
Generating plant fuel stock	64	61
Deferred property taxes	203	250
Regulatory assets	12	17
Prepayments and other current assets	120	81
Total current assets	2,215	2,280
Plant, Property, and Equipment
Plant, property, and equipment, gross	21,265	21,010
Less accumulated depreciation and amortization	6,206	6,056
Plant, property, and equipment, net	15,059	14,954
Construction work in progress	798	761
Total plant, property, and equipment	15,857	15,715
Other Non-current Assets
Regulatory assets	2,072	2,091
Accounts and notes receivable	1,092	1,118
Investments	66	65
Other	321	353
Total other non-current assets	3,551	3,627
Total Assets	21,623	21,622
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation	812	886
Notes payable		398
Accounts payable	479	598
Accounts payable - related parties	9	12
Accrued rate refunds	73	21
Accrued interest	73	98
Accrued taxes	260	348
Regulatory liabilities	85	95
Other current liabilities	135	199
Total current liabilities	1,926	2,655
Non-current Liabilities
Long-term debt	9,129	8,640
Non-current portion of capital leases and financing obligation	104	110
Regulatory liabilities	2,068	2,041
Postretirement benefits	781	789
Asset retirement obligations	451	447
Deferred investment tax credit	72	73
Deferred income taxes	2,390	2,287
Other non-current liabilities	295	290
Total non-current liabilities	15,290	14,677
Commitments and Contingencies (Notes 2 and 3)
Common stockholder's equity
Common stock	3	3
Other paid-in capital	4,927	4,916
Accumulated other comprehensive loss	(49)	(50)
Retained earnings (Accumulated deficit)	(511)	(616)
Total common stockholders' equity	4,370	4,253
Noncontrolling interests	37	37
Total equity	4,407	4,290
Total Liabilities and Equity	21,623	21,622
Consumers Energy Company [Member]
Current Assets
Cash and cash equivalents	182	131
Restricted cash and cash equivalents	30	19
Accounts receivable and accrued revenue, less allowance	755	800
Notes receivable, less allowance	29	29
Accounts receivable - related parties	2	9
Inventories at average cost
Gas in underground storage	243	446
Materials and supplies	113	114
Generating plant fuel stock	63	57
Deferred property taxes	203	250
Regulatory assets	12	17
Prepayments and other current assets	114	70
Total current assets	1,746	1,942
Plant, Property, and Equipment
Plant, property, and equipment, gross	21,092	20,838
Less accumulated depreciation and amortization	6,143	5,994
Plant, property, and equipment, net	14,949	14,844
Construction work in progress	794	759
Total plant, property, and equipment	15,743	15,603
Other Non-current Assets
Regulatory assets	2,072	2,091
Accounts and notes receivable	25	27
Investments	20	33
Other	218	250
Total other non-current assets	2,335	2,401
Total Assets	19,824	19,946
Current Liabilities
Current portion of long-term debt, capital leases, and financing obligation	327	397
Notes payable		398
Accounts payable	465	580
Accounts payable - related parties	13	18
Accrued rate refunds	73	21
Accrued interest	47	67
Accrued taxes	291	354
Regulatory liabilities	85	95
Other current liabilities	99	164
Total current liabilities	1,400	2,094
Non-current Liabilities
Long-term debt	5,419	5,253
Non-current portion of capital leases and financing obligation	104	110
Regulatory liabilities	2,068	2,041
Postretirement benefits	723	730
Asset retirement obligations	450	446
Deferred investment tax credit	72	73
Deferred income taxes	3,119	3,042
Other non-current liabilities	223	218
Total non-current liabilities	12,178	11,913
Commitments and Contingencies (Notes 2 and 3)
Common stockholder's equity
Common stock	841	841
Other paid-in capital	4,249	3,999
Accumulated other comprehensive loss	(9)	(3)
Retained earnings (Accumulated deficit)	1,128	1,065
Total common stockholders' equity	6,209	5,902
Preferred stock	37	37
Total equity	6,246	5,939
Total Liabilities and Equity	$ 19,824	$ 19,946