Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash Flows from Operating Activities
Net income	$ 381	$ 292
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	483	459
Deferred income taxes and investment tax credit	60	132
Other non-cash operating activities and reconciling adjustments	22	47
Cash provided by (used in) changes in assets and liabilities
Accounts and notes receivable and accrued revenue	298	154
Inventories	101	44
Accounts payable and accrued refunds	(41)	37
Other current and non-current assets and liabilities	112	(46)
Net cash provided by operating activities	1,416	1,119
Cash Flows from Investing Activities
Capital expenditures (excludes assets placed under capital lease)	(872)	(746)
Increase in EnerBank notes receivable	(80)	(25)
Proceeds from the sale of EnerBank notes receivable	0	19
Cost to retire property and other investing activities	(56)	(54)
Net cash used in investing activities	(1,008)	(806)
Cash Flows from Financing Activities
Proceeds from issuance of debt	794	923
Retirement of debt	(660)	(488)
Increase (decrease) in EnerBank certificates of deposit	136
Increase (decrease) in EnerBank certificates of deposit		(27)
Decrease in notes payable	(170)	(398)
Issuance of common stock	36	76
Payment of dividends on common and preferred stock	(204)	(188)
Payment of capital lease obligations and other financing costs	(43)	(27)
Net cash used in financing activities	(111)	(129)
Net Increase in Cash and Cash Equivalents, Including Restricted Amounts	297	184
Cash and Cash Equivalents, Including Restricted Amounts, Beginning of Period	204	257
Cash and Cash Equivalents, Including Restricted Amounts, End of Period	501	441
Non-cash transactions
Capital expenditures not paid	140	146
Consumers Energy Company
Cash Flows from Operating Activities
Net income	394	315
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	478	455
Deferred income taxes and investment tax credit	35	157
Other non-cash operating activities and reconciling adjustments	15	44
Cash provided by (used in) changes in assets and liabilities
Accounts and notes receivable and accrued revenue	172	158
Inventories	98	43
Accounts payable and accrued refunds	(34)	38
Other current and non-current assets and liabilities	(60)	(85)
Net cash provided by operating activities	1,098	1,125
Cash Flows from Investing Activities
Capital expenditures (excludes assets placed under capital lease)	(859)	(741)
Cost to retire property and other investing activities	(55)	(61)
Net cash used in investing activities	(914)	(802)
Cash Flows from Financing Activities
Proceeds from issuance of debt	544	349
Retirement of debt	(330)	(263)
Decrease in notes payable	(170)	(398)
Stockholder contribution	250	450
Payment of dividends on common and preferred stock	(246)	(237)
Payment of capital lease obligations and other financing costs	(21)	(12)
Net cash used in financing activities	27	(111)
Net Increase in Cash and Cash Equivalents, Including Restricted Amounts	211	212
Cash and Cash Equivalents, Including Restricted Amounts, Beginning of Period	65	152
Cash and Cash Equivalents, Including Restricted Amounts, End of Period	276	364
Non-cash transactions
Capital expenditures not paid	$ 116	$ 133