Consolidated Statements Of Cash Flows (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2014	Jun. 30, 2013
Cash Flows from Operating Activities
Net income	$ 288	$ 225
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	350	318
Deferred income taxes and investment tax credit	137	135
Postretirement benefits expense	11	95
Other non-cash operating activities	38	32
Postretirement benefits contributions	(4)	(88)
Proceeds from government grant		69
Cash provided by (used in) changes in assets and liabilities
Decrease (increase) in accounts receivable, notes receivable, and accrued revenue	(14)	85
Decrease (increase) in inventories	108	253
Increase (decrease) in accounts payable	2	12
Other current and non-current assets and liabilities	21	(41)
Net cash provided by operating activities	937	1,095
Cash Flows from Investing Activities
Capital expenditures (excludes assets placed under capital lease)	(663)	(580)
Cost to retire property	(36)	(23)
Other investing activities	(84)	(13)
Net cash used in investing activities	(783)	(616)
Cash Flows from Financing Activities
Proceeds from issuance of long-term debt	550	675
Proceeds from (retirements of) EnerBank notes, net	78	(28)
Issuance of common stock	37	28
Retirement of long-term debt	(301)	(445)
Payment of common and preferred stock dividends	146	135
Increase (decrease) in notes payable	(170)	(110)
Payment of capital lease obligations and other financing costs	(16)	(20)
Net cash provided by (used in) financing activities	32	(35)
Net Increase (Decrease) in Cash and Cash Equivalents	186	444
Cash and Cash Equivalents, Beginning of Period	172	93
Cash and Cash Equivalents, End of Period	358	537
Consumers Energy Company [Member]
Cash Flows from Operating Activities
Net income	330	262
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	346	316
Deferred income taxes and investment tax credit	66	87
Postretirement benefits expense	12	93
Other non-cash operating activities	32	31
Postretirement benefits contributions	(2)	(86)
Proceeds from government grant		69
Cash provided by (used in) changes in assets and liabilities
Decrease (increase) in accounts receivable, notes receivable, and accrued revenue	(6)	85
Decrease (increase) in inventories	101	249
Increase (decrease) in accounts payable	10	16
Other current and non-current assets and liabilities	27	(37)
Net cash provided by operating activities	916	1,085
Cash Flows from Investing Activities
Capital expenditures (excludes assets placed under capital lease)	(660)	(579)
Cost to retire property	(36)	(23)
Other investing activities	2	(11)
Net cash used in investing activities	(694)	(613)
Cash Flows from Financing Activities
Proceeds from issuance of long-term debt		425
Retirement of long-term debt	(21)	(445)
Payment of common and preferred stock dividends	256	195
Stockholder contribution	315	150
Increase (decrease) in notes payable	(170)	(110)
Payment of capital lease obligations and other financing costs	(10)	(16)
Net cash provided by (used in) financing activities	(142)	(191)
Net Increase (Decrease) in Cash and Cash Equivalents	80	281
Cash and Cash Equivalents, Beginning of Period	18	5
Cash and Cash Equivalents, End of Period	$ 98	$ 286

Cash grant received from government during the current period.

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The aggregate amount of adjustments to net income or loss necessary to remove the effects of all items whose cash effects are investing or financing cash flows. The aggregate amount also includes all noncash expenses and income items which reduce or increase net income and are thus added back or deducted when calculating cash provided by or used in operating activities.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Amount of increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Includes effect from exchange rate changes.

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Amount of deferred income tax expense (benefit) and income tax credits.

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The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

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The increase (decrease) during the reporting period in the amount due from customers for the credit sale of goods and services; includes accounts receivable and other types of receivables.

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