DTE Energy (DTE) 10-Q 24 Oct 14 2014 Q3 Quarterly report Financial data

DEI_Document

DEI Document	9 Months Ended
	Sep. 30, 2014
Entity Registrant Name	'DTE ENERGY CO
Entity Central Index Key	'0000936340
Current Fiscal Year End Date	'--12-31
Entity Filer Category	'Large Accelerated Filer
Document Type	'10-Q
Document Period End Date	30-Sep-14
Document Fiscal Year Focus	'2014
Document Fiscal Period Focus	'Q3
Amendment Flag	'false
Entity Common Stock, Shares Outstanding	176,991,277

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Operating Revenues	$2,595	$2,387	$9,223	$7,128
Operating Expenses	'	'	'	'
Fuel, purchased power and gas	1,119	967	4,550	2,931
Operation and maintenance	860	728	2,512	2,168
Depreciation and amortization	293	284	855	811
Taxes other than income	86	84	268	262
Asset (gains) and losses, reserves and impairments, net	-2	-5	-10	-6
Total operating expenses	2,356	2,058	8,175	6,166
Operating Income	239	329	1,048	962
Other (Income) and Deductions	'	'	'	'
Interest expense	107	106	323	327
Interest income	-2	-2	-7	-7
Other income	-55	-58	-136	-148
Other expenses	11	7	29	23
Total Other (Income) and Deductions	61	53	209	195
Income Before Income Taxes	178	276	839	767
Income Tax Expense	21	76	229	225
Net Income	157	200	610	542
Less: Net Income Attributable to Noncontrolling Interests	1	2	4	5
Net Income Attributable to DTE Energy Company	$156	$198	$606	$537
Basic Earnings per Common Share	'	'	'	'
Total Basic Earnings per Common Share	$0.88	$1.13	$3.42	$3.07
Diluted Earnings per Common Share	'	'	'	'
Total Diluted Earnings per Common Share	$0.88	$1.13	$3.42	$3.07
Weighted Average Common Shares Outstanding	'	'	'	'
Basic	177	175	177	174
Diluted	177	176	177	175
Dividends Declared per Common Share	$0.69	$0.66	$2	$1.93

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Statement of Income and Comprehensive Income [Abstract]	'	'	'	'
Net Income	$157	$200	$610	$542
Other comprehensive income (loss), net of tax:	'	'	'	'
Benefit obligations, net of taxes of $1, $2, $2 and $4, respectively	2	2	3	7
Net unrealized gains on investments during the period, net of taxes of $—, $1, $— and $1, respectively	0	1	1	1
Foreign currency translation, net of taxes of $(1), $—, $(1) and $(1), respectively	-1	1	-1	-1
Other Comprehensive Income (Loss), Net of Tax	1	4	3	7
Comprehensive income	158	204	613	549
Less: Comprehensive income attributable to noncontrolling interests	1	2	4	5
Comprehensive income attributable to DTE Energy Company	$157	$202	$609	$544

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Benefit Plan Improvement, Tax	$1	$2	$2	$4
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	0	1	0	1
Other Comprehensive Income (Loss), Foreign Currency Translation Gain (Loss) Arising During Period, Tax	($1)	$0	($1)	($1)

Consolidated_Statements_of_Fin

Consolidated Statements of Financial Position (Unaudited) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Current Assets	'	'
Cash and cash equivalents	$60	$52
Restricted cash, principally Securitization	61	123
Accounts receivable (less allowance for doubtful accounts of $60 and $55, respectively)	'	'
Customer	1,257	1,542
Other	120	127
Inventories	'	'
Fuel and gas	511	363
Materials and supplies	282	265
Derivative assets	68	99
Regulatory assets	91	26
Other	305	209
Total Current Assets	2,755	2,806
Investments	'	'
Nuclear decommissioning trust funds	1,229	1,191
Other	618	603
Total Investments	1,847	1,794
Property	'	'
Property, plant and equipment	26,169	25,123
Less accumulated depreciation and amortization	-9,670	-9,323
Property, plant and equipment, net	16,499	15,800
Other Assets	'	'
Goodwill	2,018	2,018
Regulatory assets	2,704	2,837
Securitized regulatory assets	86	231
Intangible assets	108	122
Notes receivable	87	102
Derivative assets	29	27
Other	243	198
Total Noncurrent Assets	5,275	5,535
Total Assets	26,376	25,935
Current Liabilities	'	'
Accounts payable	873	962
Accrued interest	110	90
Dividends payable	122	116
Short-term borrowings	653	131
Current portion long-term debt, including capital leases	274	898
Derivative liabilities	134	195
Regulatory liabilities	164	302
Other	475	495
Total Current Liabilities	2,805	3,189
Long-Term Debt (net of current portion)	'	'
Mortgage bonds, notes and other	7,426	6,618
Securitization bonds, noncurrent	0	105
Junior subordinated debentures	480	480
Capital lease obligations	3	11
Total Long-Term Debt (net of current portion)	7,909	7,214
Other Liabilities	'	'
Deferred income taxes	3,546	3,321
Regulatory liabilities	715	862
Asset retirement obligations	1,911	1,827
Unamortized investment tax credit	43	47
Derivative liabilities	19	43
Accrued pension liability	499	653
Accrued postretirement liability	286	350
Nuclear decommissioning	179	178
Other	278	297
Total Noncurrent Liabilities	7,476	7,578
Commitments and Contingencies (Notes 7 and 11)	'	'
Equity	'	'
Common stock, without par value, 400,000,000 shares authorized, 176,991,277 and 177,087,230 shares issued and outstanding, respectively	3,900	3,907
Retained earnings	4,402	4,150
Accumulated other comprehensive loss	-133	-136
Total DTE Energy Company Equity	8,169	7,921
Noncontrolling interests	17	33
Total Equity	8,186	7,954
Total Liabilities and Equity	$26,376	$25,935

Consolidated_Statements_of_Fin1

Consolidated Statements of Financial Position (Unaudited) (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified
Current Assets:	'	'
Allowance for doubtful accounts	$60	$55
Stockholders' Equity:	'	'
Common stock, par value	$0	$0
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares issued	176,991,277	177,087,230
Common stock, shares outstanding	176,991,277	177,087,230

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (Unaudited) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Operating Activities	'	'
Net Income	$610	$542
Adjustments to reconcile net income to net cash from operating activities:	'	'
Depreciation and amortization	855	811
Nuclear fuel amortization	33	25
Allowance for equity funds used during construction	-16	-10
Deferred income taxes	244	162
Asset (gains) and losses, reserves and impairments, net	-10	-5
Changes in assets and liabilities:	'	'
Accounts receivable, net	273	177
Inventories	-165	35
Accounts payable	48	-16
Accrued pension obligation	-154	-44
Accrued postretirement obligation	-64	-191
Derivative assets and liabilities	-56	-23
Regulatory assets and liabilities	-211	327
Other assets	-66	-62
Other liabilities	-23	-13
Net cash from operating activities	1,298	1,715
Investing Activities	'	'
Plant and equipment expenditures b utility	-1,295	-1,101
Plant and equipment expenditures b non-utility	-207	-270
Proceeds from sale of assets	36	20
Restricted cash for debt redemption, principally Securitization	62	58
Proceeds from sale of nuclear decommissioning trust fund assets	652	477
Investment in nuclear decommissioning trust funds	-665	-489
Other	-40	-32
Net cash used for investing activities	-1,457	-1,337
Financing Activities	'	'
Issuance of long-term debt, net of issuance costs	1,289	768
Redemption of long-term debt	-1,222	-855
Short-term borrowings, net	522	31
Issuance of common stock	0	29
Repurchase of common stock	-52	0
Dividends on common stock	-348	-329
Other	-22	-16
Net cash from (used for) financing activities	167	-372
Net Increase (Decrease) in Cash and Cash Equivalents	8	6
Cash and Cash Equivalents at Beginning of Period	52	65
Cash and Cash Equivalents at End of Period	60	71
Supplemental Disclosure of Non-Cash Information	'	'
Plant and equipment expenditures in accounts payable	$192	$263

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Equity (Unaudited) (USD $)	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Loss	Accumulated Defined Benefit Plans Adjustment [Member]	Accumulated Net Unrealized Investment Gain (Loss) [Member]	Accumulated Translation Adjustment [Member]	Noncontrolling Interest
In Millions, except Share data
Stockholders' Equity, Including Portion Attributable to Noncontrolling interest at Dec. 31, 2013	$7,954	$3,907	$4,150	($136)	'	'	'	$33
Beginning Balance, shares at Dec. 31, 2013	177,087,230	177,087,000	'	'	'	'	'	'
Net Income	610	'	606	'	'	'	'	4
Dividends declared on common stock	-354	'	-354	'	'	'	'	'
Repurchase of common stock, Shares	'	-713,000	'	'	'	'	'	'
Repurchase of common stock, Value	-52	-52	'	'	'	'	'	'
Other Comprehensive Income (Loss), Net of Tax	3	'	'	'	3	1	-1	'
Stock-based compensation, distributions to noncontrolling interests and other, shares	'	617,000	'	'	'	'	'	'
Stock-based compensation, distributions to noncontrolling interests and other	25	45	'	'	'	'	'	-20
Stockholders' Equity, Including Portion Attributable to Noncontrolling interest at Sep. 30, 2014	$8,186	$3,900	$4,402	($133)	'	'	'	$17
Ending Balance, shares at Sep. 30, 2014	176,991,277	176,991,000	'	'	'	'	'	'

Organization_and_Basis_of_Pres

Organization and Basis of Presentation (Notes)	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	'
	ORGANIZATION AND BASIS OF PRESENTATION
	Corporate Structure
	DTE Energy owns the following businesses:
	•	DTE Electric, an electric utility engaged in the generation, purchase, distribution and sale of electricity to approximately 2.1 million customers in southeastern Michigan;
	•	DTE Gas, a natural gas utility engaged in the purchase, storage, transportation, distribution and sale of natural gas to approximately 1.2 million customers throughout Michigan and the sale of storage and transportation capacity; and
	•	Other businesses involved in 1) natural gas pipelines, gathering and storage; 2) power and industrial projects; and 3) energy marketing and trading operations.
	DTE Electric and DTE Gas are regulated by the MPSC. Certain activities of DTE Electric and DTE Gas, as well as various other aspects of businesses under DTE Energy are regulated by the FERC. In addition, the Company is regulated by other federal and state regulatory agencies including the NRC, the EPA, the MDEQ and the CFTC.
	References in this Report to “we”, “us”, “our”, “Company” or “DTE” are to DTE Energy and its subsidiaries, collectively.
	Basis of Presentation
	These Consolidated Financial Statements should be read in conjunction with the Notes to Consolidated Financial Statements included in the 2013 Annual Report on Form 10-K.
	The accompanying Consolidated Financial Statements are prepared using accounting principles generally accepted in the United States of America. These accounting principles require management to use estimates and assumptions that impact reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from the Company’s estimates.
	The Consolidated Financial Statements are unaudited, but in the Company's opinion include all adjustments necessary to present a fair statement of the results for the interim periods. All adjustments are of a normal recurring nature, except as otherwise disclosed in these Consolidated Financial Statements and Notes to Consolidated Financial Statements. Financial results for this interim period are not necessarily indicative of results that may be expected for any other interim period or for the fiscal year ending December 31, 2014.
	Prior year balances were revised to reflect an increase of $437 million in the Consolidated Statements of Cash Flows line items for (i) Proceeds from sale of nuclear decommissioning trust funds, and (ii) Investment in nuclear decommissioning trust funds for the nine months ended September 30, 2013. These revisions were needed to properly state the gross purchases and sales activity in the nuclear decommissioning trust fund for the nine months ended September 30, 2013. The total of Net cash used for investing activities for the nine months ended September 30, 2013 was unchanged by these revisions. The revisions noted above are not deemed material, individually or in the aggregate, to the prior period Consolidated Financial Statements.
	Principles of Consolidation
	The Company consolidates all majority-owned subsidiaries and investments in entities in which it has controlling influence. Non-majority owned investments are accounted for using the equity method when the Company is able to influence the operating policies of the investee. When the Company does not influence the operating policies of an investee, the cost method is used. These Consolidated Financial Statements also reflect the Company's proportionate interests in certain jointly owned utility plants. The Company eliminates all intercompany balances and transactions.
	The Company evaluates whether an entity is a VIE whenever reconsideration events occur. The Company consolidates VIEs for which it is the primary beneficiary. If the Company is not the primary beneficiary and an ownership interest is held, the VIE is accounted for under the equity method of accounting. When assessing the determination of the primary beneficiary, the Company considers all relevant facts and circumstances, including: the power, through voting or similar rights, to direct the activities of the VIE that most significantly impact the VIE's economic performance and the obligation to absorb the expected losses and/or the right to receive the expected returns of the VIE. The Company performs ongoing reassessments of all VIEs to determine if the primary beneficiary status has changed.
	Legal entities within the Company's Power and Industrial Projects segment enter into long-term contractual arrangements with customers to supply energy-related products or services. The entities are generally designed to pass-through the commodity risk associated with these contracts to the customers, with the Company retaining operational and customer default risk. These entities generally are VIEs and consolidated when the Company is the primary beneficiary. In addition, we have interests in certain VIEs through which we share control of all significant activities for those entities with our partners, and therefore are accounted for under the equity method.
	The Company has variable interests in VIEs through certain of its long-term purchase and sale contracts. As of September 30, 2014, the carrying amount of assets and liabilities in the Consolidated Statements of Financial Position that relate to its variable interests under long-term purchase and sale contracts are predominately related to working capital accounts and generally represent the amounts owed by or to the Company for the deliveries associated with the current billing cycle under the contracts. The Company has not provided any significant form of financial support associated with these long-term contracts. There is no significant potential exposure to loss as a result of its variable interests through these long-term purchase and sale contracts.
	In 2001, DTE Electric financed a regulatory asset related to Fermi 2 and certain other regulatory assets through the sale of rate reduction bonds by a wholly-owned special purpose entity, Securitization. DTE Electric performs servicing activities including billing and collecting surcharge revenue for Securitization. This entity is a VIE and is consolidated by the Company.
	The maximum risk exposure for consolidated VIEs is reflected on the Company's Consolidated Statements of Financial Position. For non-consolidated VIEs, the maximum risk exposure is generally limited to its investment and amounts which it has guaranteed.
	The following table summarizes the major balance sheet items for consolidated VIEs as of September 30, 2014 and December 31, 2013. All assets and liabilities of a consolidated VIE are presented where it has been determined that a consolidated VIE has either (1) assets that can be used only to settle obligations of the VIE or (2) liabilities for which creditors do not have recourse to the general credit of the primary beneficiary. VIEs, in which the Company holds a majority voting interest and is the primary beneficiary, that meet the definition of a business and whose assets can be used for purposes other than the settlement of the VIE's obligations have been excluded from the table below.
		September 30, 2014						December 31, 2013
		Securitization		Other		Total		Securitization		Other		Total
		(In millions)
	ASSETS
	Cash and cash equivalents	$	—	$	12	$	12	$	—	$	12	$	12
	Restricted cash	40		6		46		100		8		108
	Accounts receivable	40		15		55		34		16		50
	Inventories	—		34		34		—		118		118
	Property, plant and equipment, net	—		84		84		—		99		99
	Securitized regulatory assets	86		—		86		231		—		231
	Other current and long-term assets	2		7		9		4		9		13
		$	168	$	158	$	326	$	369	$	262	$	631
	LIABILITIES
	Accounts payable and accrued current liabilities	$	1	$	9	$	10	$	7	$	23	$	30
	Current portion long-term debt, including capital leases	105		9		114		196		9		205
	Current regulatory liabilities	44		—		44		43		—		43
	Mortgage bonds, notes and other	—		17		17		—		21		21
	Securitization bonds	—		—		—		105		—		105
	Capital lease obligations	—		3		3		—		7		7
	Other current and long-term liabilities	9		5		14		8		6		14
		$	159	$	43	$	202	$	359	$	66	$	425
	Amounts for non-consolidated VIEs as of September 30, 2014 and December 31, 2013 are as follows:
		30-Sep-14		31-Dec-13
		(In millions)
	Other investments	$	134	$	141
	Notes receivable	$	14	$	8

Significant_Accounting_Policie

Significant Accounting Policies (Notes)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Significant Accounting Policies [Text Block]	'
	SIGNIFICANT ACCOUNTING POLICIES
	Other Income
	Other income is recognized for non-operating income such as equity earnings, allowance for equity funds used during construction and contract services. Power & Industrial Projects also recognizes Other income in connection with the sale of membership interests in reduced emissions fuel facilities to investors. In exchange for the cash received, the investors will receive a portion of the economic attributes of the facilities, including income tax attributes. The transactions are not treated as a sale of membership interests for financial reporting purposes. Other income is considered earned when refined coal is produced and tax credits are generated. Power & Industrial Projects recognized approximately $25 million of Other income for the three months ended September 30, 2014 and 2013, respectively, and approximately $57 million and $60 million of Other income for the nine months ended September 30, 2014 and 2013, respectively.
	Changes in Accumulated Other Comprehensive Loss
	For the three and nine months ended September 30, 2014 and 2013, reclassifications out of accumulated other comprehensive loss for the Company were not material. Changes in accumulated other comprehensive loss are presented in the Consolidated Statements of Changes in Equity.
	Intangible Assets
	The Company has certain intangible assets relating to emission allowances, renewable energy credits and non-utility contracts as shown below:
		September 30, 2014		December 31, 2013
		(In millions)
	Emission allowances	$	1	$	2
	Renewable energy credits	50		51
	Contract intangible assets	123		126
		174		179
	Less accumulated amortization	54		45
	Intangible assets, net	120		134
	Less current intangible assets	12		12
		$	108	$	122
	Emission allowances and renewable energy credits are charged to expense, using average cost, as the allowances and credits are consumed in the operation of the business. The Company amortizes contract intangible assets on a straight-line basis over the expected period of benefit, ranging from 1 to 28 years.
	Income Taxes
	The Company's effective tax rate for the three months ended September 30, 2014 was 12% as compared to 28% for the three months ended September 30, 2013. The Company's effective tax rate for the nine months ended September 30, 2014 was 27% as compared to 29% for the nine months ended September 30, 2013. The 16% decrease in the effective tax rate for the three months ended September 30, 2014 is due to higher production tax credits. The 2% decrease in effective tax rate for the nine months ended September 30, 2014 is due to higher production tax credits, partially offset by $8 million of deferred tax expense resulting from New York state income tax reform enacted on March 31, 2014.
	The Company had $2 million of unrecognized tax benefits at September 30, 2014, that, if recognized, would favorably impact its effective tax rate. The Company believes that it is possible that there will be a decrease in the unrecognized tax benefits of up to $1 million in the next twelve months.

Accounting_Pronouncements_Note

Accounting Pronouncements (Notes)	9 Months Ended
	Sep. 30, 2014
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
Description of New Accounting Pronouncements Not yet Adopted [Text Block]	'
	NEW ACCOUNTING PRONOUNCEMENTS
	In May 2014, the FASB issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers. The objectives of this ASU are to improve upon revenue recognition requirements by providing a single comprehensive model to determine the measurement of revenue and timing of recognition. The core principle is that an entity will recognize revenue to depict the transfer of goods or services to customers at an amount that the entity expects to be entitled to in exchange for those goods or services. This ASU also requires expanded qualitative and quantitative disclosures regarding the nature, amount, timing, and uncertainty of revenues and cash flows arising from contracts with customers. The revenue standard is effective for the first interim period within annual reporting periods beginning after December 15, 2016 and is to be applied retrospectively. Early adoption is not permitted. The Company is currently assessing the impact of this ASU on its Consolidated Financial Statements.

Fair_Value_Notes

Fair Value (Notes)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Disclosure	'
	FAIR VALUE
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date in a principal or most advantageous market. Fair value is a market-based measurement that is determined based on inputs, which refer broadly to assumptions that market participants use in pricing assets or liabilities. These inputs can be readily observable, market corroborated or generally unobservable inputs. The Company makes certain assumptions it believes that market participants would use in pricing assets or liabilities, including assumptions about risk, and the risks inherent in the inputs to valuation techniques. Credit risk of the Company and its counterparties is incorporated in the valuation of assets and liabilities through the use of credit reserves, the impact of which was immaterial at September 30, 2014 and December 31, 2013. The Company believes it uses valuation techniques that maximize the use of observable market-based inputs and minimize the use of unobservable inputs.
	A fair value hierarchy has been established that prioritizes the inputs to valuation techniques used to measure fair value in three broad levels. The fair value hierarchy gives the highest priority to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). In some cases, the inputs used to measure fair value might fall in different levels of the fair value hierarchy. All assets and liabilities are required to be classified in their entirety based on the lowest level of input that is significant to the fair value measurement in its entirety. Assessing the significance of a particular input may require judgment considering factors specific to the asset or liability, and may affect the valuation of the asset or liability and its placement within the fair value hierarchy. The Company classifies fair value balances based on the fair value hierarchy defined as follows:
	•	Level 1 — Consists of unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access as of the reporting date.
	•	Level 2 — Consists of inputs other than quoted prices included within Level 1 that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data.
	•	Level 3 — Consists of unobservable inputs for assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost-benefit constraints.
	The following table presents assets and liabilities measured and recorded at fair value on a recurring basis as of September 30, 2014 and December 31, 2013:
		30-Sep-14																			31-Dec-13
		Level 1			Level 2				Level 3				Netting (a)				Net Balance				Level 1				Level 2			Level 3			Netting (a)			Net Balance
		(In millions)
	Assets:
	Cash equivalents (b)	$	11		$	51			$	—			$	—			$	62			$	10			$	115		$	—		$	—		$	125
	Nuclear decommissioning trusts	789			440				—				—				1,229				779				412			—			—			1,191
	Other investments (c) (d)	95			51				—				—				146				92				44			—			—			136
	Derivative assets:
	Commodity Contracts:
	Natural Gas	118			98				38				(225		)		29				273				89			34			(382		)	14
	Electricity	—			312				74				(322		)		64				—				261			139			(291		)	109
	Other	46			2				4				(48		)		4				33				1			3			(34		)	3
	Other derivative contracts (e)	—			1				—				(1		)		—				—				—			—			—			—
	Total derivative assets	164			413				116				(596		)		97				306				351			176			(707		)	126
	Total	$	1,059		$	955			$	116			$	(596	)		$	1,534			$	1,187			$	922		$	176		$	(707	)	$	1,578
	Liabilities:
	Derivative liabilities:
	Commodity Contracts:
	Natural Gas	$	(129	)	$	(147	)		$	(66	)		$	268			$	(74	)		$	(277	)		$	(140	)	$	(86	)	$	395		$	(108	)
	Electricity	—			(303		)		(91		)		317				(77		)		—				(272		)	(126		)	269			(129		)
	Other	(39		)	(8		)		(1		)		48				—				(32		)		(2		)	—			34			—
	Other derivative contracts (e)	—			(3		)		—				1				(2		)		—				(1		)	—			—			(1		)
	Total derivative liabilities	(168		)	(461		)		(158		)		634				(153		)		(309		)		(415		)	(212		)	698			(238		)
	Total	$	(168	)	$	(461	)		$	(158	)		$	634			$	(153	)		$	(309	)		$	(415	)	$	(212	)	$	698		$	(238	)
	Net Assets (Liabilities) at the end of the period	$	891		$	494			$	(42	)		$	38			$	1,381			$	878			$	507		$	(36	)	$	(9	)	$	1,340
	Assets:
	Current	$	155		$	419			$	93			$	(537	)		$	130			$	277			$	400		$	139		$	(592	)	$	224
	Noncurrent (f)	904			536				23				(59		)		1,404				910				522			37			(115		)	1,354
	Total Assets	$	1,059		$	955			$	116			$	(596	)		$	1,534			$	1,187			$	922		$	176		$	(707	)	$	1,578
	Liabilities:
	Current	$	(146	)	$	(405	)		$	(145	)		$	562			$	(134	)		$	(268	)		$	(328	)	$	(177	)	$	578		$	(195	)
	Noncurrent	(22		)	(56		)		(13		)		72				(19		)		(41		)		(87		)	(35		)	120			(43		)
	Total Liabilities	$	(168	)	$	(461	)		$	(158	)		$	634			$	(153	)		$	(309	)		$	(415	)	$	(212	)	$	698		$	(238	)
	Net Assets (Liabilities) at the end of the period	$	891		$	494			$	(42	)		$	38			$	1,381			$	878			$	507		$	(36	)	$	(9	)	$	1,340
	_______________________________________
	(a)	Amounts represent the impact of master netting agreements that allow the Company to net gain and loss positions and cash collateral held or placed with the same counterparties.
	(b)	At September 30, 2014, available-for-sale securities of $62 million included $46 million and $16 million of cash equivalents included in Restricted cash and Other investments on the Consolidated Statements of Financial Position, respectively. At December 31, 2013, available-for-sale securities of $125 million, included $109 million and $16 million of cash equivalents included in Restricted cash and Other investments on the Consolidated Statements of Financial Position, respectively.
	(c)	Excludes cash surrender value of life insurance investments.
	(d)	Available-for-sale equity securities of $7 million at both September 30, 2014 and December 31, 2013, are included in Other investments on the Consolidated Statements of Financial Position.
	(e)	Primarily includes Foreign currency exchange contracts.
	(f)	Includes $146 million and $136 million at September 30, 2014 and December 31, 2013, respectively, of other investments that are included in the Consolidated Statements of Financial Position in Other investments.
	Cash Equivalents
	Cash equivalents include investments with maturities of three months or less when purchased. The cash equivalents shown in the fair value table are comprised of short-term investments and money market funds.
	Nuclear Decommissioning Trusts and Other Investments
	The nuclear decommissioning trusts and other investments hold debt and equity securities directly and indirectly through institutional mutual funds. Exchange-traded debt and equity securities held directly are valued using quoted market prices in actively traded markets. The institutional mutual funds hold exchange-traded equity or debt securities and are valued based on stated net asset values (NAV). Non-exchange-traded fixed income securities are valued based upon quotations available from brokers or pricing services. A primary price source is identified by asset type, class or issue for each security. The trustee monitors prices supplied by pricing services and may use a supplemental price source or change the primary price source of a given security if the trustee determines that another price source is considered to be preferable. DTE Energy has obtained an understanding of how these prices are derived, including the nature and observability of the inputs used in deriving such prices. Additionally, DTE Energy selectively corroborates the fair value of securities by comparison of market-based price sources. Investment policies and procedures are determined by the Company's Trust Investments Department which reports to the Company's Vice President and Treasurer.
	Derivative Assets and Liabilities
	Derivative assets and liabilities are comprised of physical and financial derivative contracts, including futures, forwards, options and swaps that are both exchange-traded and over-the-counter traded contracts. Various inputs are used to value derivatives depending on the type of contract and availability of market data. Exchange-traded derivative contracts are valued using quoted prices in active markets. DTE Energy considers the following criteria in determining whether a market is considered active: frequency in which pricing information is updated, variability in pricing between sources or over time and the availability of public information. Other derivative contracts are valued based upon a variety of inputs including commodity market prices, broker quotes, interest rates, credit ratings, default rates, market-based seasonality and basis differential factors. DTE Energy monitors the prices that are supplied by brokers and pricing services and may use a supplemental price source or change the primary price source of an index if prices become unavailable or another price source is determined to be more representative of fair value. DTE Energy has obtained an understanding of how these prices are derived. Additionally, DTE Energy selectively corroborates the fair value of its transactions by comparison of market-based price sources. Mathematical valuation models are used for derivatives for which external market data is not readily observable, such as contracts which extend beyond the actively traded reporting period. The Company has established a Risk Management Committee whose responsibilities include directly or indirectly ensuring all valuation methods are applied in accordance with predefined policies. The development and maintenance of our forward price curves has been assigned to our Risk Management Department, which is separate and distinct from the trading functions within the Company.
	The following tables present the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for the three and nine months ended September 30, 2014 and 2013:
		Three Months Ended September 30, 2014															Three Months Ended September 30, 2013
		Natural Gas			Electricity				Other				Total				Natural Gas				Electricity				Other			Total
		(In millions)
	Net Assets (Liabilities) as of June 30	$	(20	)	$	(27	)		$	7			$	(40	)		$	(30	)		$	12			$	2		$	(16	)
	Transfers into Level 3	1			—				—				1				—				—				—			—
	Transfers out of Level 3	(4		)	—				—				(4		)		—				(1		)		—			(1		)
	Total gains (losses):
	Included in earnings	(2		)	13				(1		)		10				8				17				—			25
Recorded in regulatory assets/liabilities	—			—				(3		)		(3		)		—				—				3			3
Purchases, issuances and settlements:
Settlements	(3		)	(3		)		—				(6		)		8				(23		)		—			(15		)
Net Assets (Liabilities) as of September 30	$	(28	)	$	(17	)		$	3			$	(42	)		$	(14	)		$	5			$	5		$	(4	)
The amount of total gains (losses) included in net income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2014 and 2013 and reflected in Operating revenues and Fuel, purchased power and gas in the Consolidated Statements of Operations	$	(7	)	$	14			$	(1	)		$	6			$	(8	)		$	8			$	—		$	—
	Nine Months Ended September 30, 2014															Nine Months Ended September 30, 2013
	Natural Gas			Electricity				Other				Total				Natural Gas				Electricity				Other			Total
	(In millions)
Net Assets (Liabilities) as of December 31	$	(52	)	$	13			$	3			$	(36	)		$	(38	)		$	23			$	2		$	(13	)
Transfers into Level 3	—			—				—				—				—				—				—			—
Transfers out of Level 3	2			—				—				2				(2		)		—				—			(2		)
Total gains (losses):
Included in earnings	(45		)	26				(2		)		(21		)		(1		)		44				—			43
Recorded in regulatory assets/liabilities	—			—				9				9				—				—				7			7
Purchases, issuances and settlements:
Purchases	—			1				—				1				—				(1		)		—			(1		)
Issuances	—			(2		)		—				(2		)		—				—				—			—
Settlements	67			(55		)		(7		)		5				27				(61		)		(4		)	(38		)
Net Assets (Liabilities) as of September 30	$	(28	)	$	(17	)		$	3			$	(42	)		$	(14	)		$	5			$	5		$	(4	)
The amount of total gains (losses) included in net income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2014 and 2013 and reflected in Operating revenues and Fuel, purchased power and gas in the Consolidated Statements of Operations	$	(23	)	$	(6	)		$	(1	)		$	(30	)		$	(14	)		$	36			$	—		$	22
Derivatives are transferred between levels primarily due to changes in the source data used to construct price curves as a result of changes in market liquidity. Transfers in and transfers out are reflected as if they had occurred at the beginning of the period. There were no transfers between levels 1 and 2 during the three and nine months ended September 30, 2014 and 2013.
The following table presents the unobservable inputs related to Level 3 assets and liabilities as of September 30, 2014:
		September 30, 2014
Commodity Contracts		Derivative Assets			Derivative Liabilities				Valuation Techniques		Unobservable Input		Range								Weighted Average
		(In millions)
Natural Gas		$	38		$	(66	)		Discounted Cash Flow		Forward basis price (per MMBtu)		$	(2.28	) —		$	9.97	/MMBtu		$	(0.13	)/MMBtu
Electricity		$	74		$	(91	)		Discounted Cash Flow		Forward basis price (per MWh)		$	(15	) —		$	24	/MWh		$	4	/MWh
The following table presents the unobservable inputs related to Level 3 assets and liabilities as of December 31, 2013:
		December 31, 2013
Commodity Contracts		Derivative Assets			Derivative Liabilities				Valuation Techniques		Unobservable Input		Range								Weighted Average
		(In millions)
Natural Gas		$	34		$	(86	)		Discounted Cash Flow		Forward basis price (per MMBtu)		$	(0.88	) —		$	5.07	/MMBtu		$	(0.16	)/MMBtu
Electricity		$	139		$	(126	)		Discounted Cash Flow		Forward basis price (per MWh)		$	(7	) —		$	15	/MWh		$	3	/MWh
The unobservable inputs used in the fair value measurement of the electricity and natural gas commodity types consist of inputs that are less observable due in part to lack of available broker quotes, supported by little, if any, market activity at the measurement date or are based on internally developed models. Certain basis prices (i.e. the difference in pricing between two locations) included in the valuation of natural gas and electricity contracts were deemed unobservable.
The inputs listed above would have a direct impact on the fair values of the above security types if they were adjusted. A significant increase (decrease) in the basis price would result in a higher (lower) fair value for long positions, with offsetting impacts to short positions.
Fair Value of Financial Instruments
The fair value of financial instruments included in the table below is determined by using quoted market prices when available. When quoted prices are not available, pricing services may be used to determine the fair value with reference to observable interest rate indexes. DTE Energy has obtained an understanding of how the fair values are derived. DTE Energy also selectively corroborates the fair value of its transactions by comparison of market-based price sources. Discounted cash flow analyses based upon estimated current borrowing rates are also used to determine fair value when quoted market prices are not available. The fair values of notes receivable, excluding capital leases, are estimated using discounted cash flow techniques that incorporate market interest rates as well as assumptions about the remaining life of the loans and credit risk. Depending on the information available, other valuation techniques may be used that rely on internal assumptions and models. Valuation policies and procedures are determined by DTE Energy's Treasury Department which reports to the Company's Vice President and Treasurer.
The following table presents the carrying amount and fair value of financial instruments as of September 30, 2014 and December 31, 2013:
	September 30, 2014															December 31, 2013
	Carrying			Fair Value												Carrying				Fair Value
	Amount			Level 1				Level 2				Level 3				Amount				Level 1				Level 2			Level 3
	(In millions)
Notes receivable, excluding capital leases	$	45		$	—			$	—			$	45			$	41			$	—			$	—		$	41
Dividends payable	$	122		$	122			$	—			$	—			$	116			$	116			$	—		$	—
Short-term borrowings	$	653		$	—			$	653			$	—			$	131			$	—			$	131		$	—
Long-term debt, excluding capital leases	$	8,171		$	474			$	7,107			$	1,412			$	8,094			$	425			$	7,551		$	499
For further fair value information on financial and derivative instruments see Note 5 to the Consolidated Financial Statements, "Financial and Other Derivative Instruments".
Nuclear Decommissioning Trust Funds
DTE Electric has a legal obligation to decommission its nuclear power plants following the expiration of their operating licenses. This obligation is reflected as an asset retirement obligation on the Consolidated Statements of Financial Position. Rates approved by the MPSC provide for the recovery of decommissioning costs of Fermi 2 and the disposal of low-level radioactive waste. DTE Electric is continuing to fund FERC jurisdictional amounts for decommissioning even though explicit provisions are not included in FERC rates.
The following table summarizes the fair value of the nuclear decommissioning trust fund assets:
	30-Sep-14			31-Dec-13
	(In millions)
Fermi 2	$	1,205		$	1,172
Fermi 1	3			3
Low level radioactive waste	21			16
Total	$	1,229		$	1,191
The costs of securities sold are determined on the basis of specific identification. The following table sets forth the gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds:
	Three Months Ended September 30,							Nine Months Ended September 30,
	2014			2013				2014				2013
	(In millions)
Realized gains	$	8		$	11			$	24			$	30
Realized losses	$	(3	)	$	(11	)		$	(14	)		$	(25	)
Proceeds from sales of securities	$	177		$	168			$	652			$	477
Realized gains and losses from the sale of securities for the Fermi 2 and the low-level radioactive waste funds are recorded to the Regulatory asset and Nuclear decommissioning liability. The following table sets forth the fair value and unrealized gains for the nuclear decommissioning trust funds:
	30-Sep-14							31-Dec-13
	Fair			Unrealized				Fair				Unrealized
	Value			Gains				Value				Gains
	(In millions)
Equity securities	$	748		$	209			$	730			$	201
Debt securities	465			18				442				12
Cash and cash equivalents	16			—				19				—
	$	1,229		$	227			$	1,191			$	213
The debt securities at September 30, 2014 and December 31, 2013 had an average maturity of approximately 7 years, respectively. Securities held in the nuclear decommissioning trust funds are classified as available-for-sale. As DTE Electric does not have the ability to hold impaired investments for a period of time sufficient to allow for the anticipated recovery of market value, all unrealized losses are considered to be other-than-temporary impairments.
Unrealized losses incurred by the Fermi 2 trust are recognized as a Regulatory asset. DTE Electric recognized $37 million and $31 million of unrealized losses as Regulatory assets at September 30, 2014 and December 31, 2013, respectively.
Other Securities
At September 30, 2014 and December 31, 2013, the securities were comprised primarily of money market and equity securities. During the three and nine months ended September 30, 2014 and 2013, no amounts of unrealized losses on available-for-sale securities were reclassified out of other comprehensive income and realized into net income for the periods. Gains related to trading securities held at September 30, 2014 and 2013 were $9 million and $14 million, respectively.

Financial_and_Other_Derivative

Financial and Other Derivative Instruments (Notes)	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Financial and other derivative instruments	'
	FINANCIAL AND OTHER DERIVATIVE INSTRUMENTS
	The Company recognizes all derivatives at their fair value as Derivative assets or liabilities on the Consolidated Statements of Financial Position unless they qualify for certain scope exceptions, including the normal purchases and normal sales exception. Further, derivatives that qualify and are designated for hedge accounting are classified as either hedges of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge), or as hedges of the fair value of a recognized asset or liability or of an unrecognized firm commitment (fair value hedge). For cash flow hedges, the portion of the derivative gain or loss that is effective in offsetting the change in the value of the underlying exposure is deferred in Accumulated other comprehensive income and later reclassified into earnings when the underlying transaction occurs. Gains or losses from the ineffective portion of cash flow hedges are recognized in earnings immediately. For fair value hedges, changes in fair values for the derivative and hedged item are recognized in earnings each period. For derivatives that do not qualify or are not designated for hedge accounting, changes in fair value are recognized in earnings each period.
	The Company’s primary market risk exposure is associated with commodity prices, credit, and interest rates. The Company has risk management policies to monitor and manage market risks. The Company uses derivative instruments to manage some of the exposure. The Company uses derivative instruments for trading purposes in its Energy Trading segment. Contracts classified as derivative instruments include electricity, natural gas, oil and certain coal forwards, futures, options and swaps, and foreign currency exchange contracts. Items not classified as derivatives include natural gas inventory, pipeline transportation contracts, renewable energy credits and natural gas storage assets.
	Electric — DTE Electric generates, purchases, distributes and sells electricity. DTE Electric uses forward energy contracts to manage changes in the price of electricity and fuel. Substantially all of these contracts meet the normal purchases and sales exemption and are therefore accounted for under the accrual method. Other derivative contracts are MTM and recoverable through the PSCR mechanism when settled. This results in the deferral of unrealized gains and losses as Regulatory assets or liabilities until realized.
	Gas — DTE Gas purchases, stores, transports, distributes and sells natural gas and sells storage and transportation capacity. DTE Gas has fixed-priced contracts for portions of its expected natural gas supply requirements through March 2017. Substantially all of these contracts meet the normal purchases and sales exemption and are therefore accounted for under the accrual method. DTE Gas may also sell forward transportation and storage capacity contracts. Forward transportation and storage contracts are generally not derivatives and are therefore accounted for under the accrual method.
	Gas Storage and Pipelines — This segment is primarily engaged in services related to the transportation and storage of natural gas. Primarily fixed-priced contracts are used in the marketing and management of transportation and storage services. Generally these contracts are not derivatives and are therefore accounted for under the accrual method.
	Power and Industrial Projects — This segment manages and operates energy and pulverized coal projects, coke batteries, reduced emissions fuel projects, landfill gas recovery and power generation assets. Primarily fixed-price contracts are used in the marketing and management of the segment assets. These contracts are generally not derivatives and are therefore accounted for under the accrual method.
	Energy Trading — Commodity Price Risk — Energy Trading markets and trades electricity, natural gas physical products and energy financial instruments, and provides energy and asset management services utilizing energy commodity derivative instruments. Forwards, futures, options and swap agreements are used to manage exposure to the risk of market price and volume fluctuations in its operations. These derivatives are accounted for by recording changes in fair value to earnings unless hedge accounting criteria are met.
	Energy Trading — Foreign Currency Exchange Risk — Energy Trading has foreign currency exchange forward contracts to economically hedge fixed Canadian dollar commitments existing under natural gas and power purchase and sale contracts and natural gas transportation contracts. The Company enters into these contracts to mitigate price volatility with respect to fluctuations of the Canadian dollar relative to the U.S. dollar. These derivatives are accounted for by recording changes in fair value to earnings unless hedge accounting criteria are met.
	Corporate and Other — Interest Rate Risk — The Company uses interest rate swaps, treasury locks and other derivatives to hedge the risk associated with interest rate market volatility.
	Credit Risk — The utility and non-utility businesses are exposed to credit risk if customers or counterparties do not comply with their contractual obligations. The Company maintains credit policies that significantly minimize overall credit risk. These policies include an evaluation of potential customers’ and counterparties’ financial condition, credit rating, collateral requirements or other credit enhancements such as letters of credit or guarantees. The Company generally uses standardized agreements that allow the netting of positive and negative transactions associated with a single counterparty. The Company maintains a provision for credit losses based on factors surrounding the credit risk of its customers, historical trends, and other information. Based on the Company’s credit policies and its September 30, 2014 provision for credit losses, the Company’s exposure to counterparty nonperformance is not expected to have a material adverse effect on the Company’s financial statements.
	Derivative Activities
	The Company manages its MTM risk on a portfolio basis based upon the delivery period of its contracts and the individual components of the risks within each contract. Accordingly, it records and manages the energy purchase and sale obligations under its contracts in separate components based on the commodity (e.g. electricity or natural gas), the product (e.g. electricity for delivery during peak or off-peak hours), the delivery location (e.g. by region), the risk profile (e.g. forward or option), and the delivery period (e.g. by month and year). The following describes the categories of activities represented by their operating characteristics and key risks:
	•	Asset Optimization — Represents derivative activity associated with assets owned and contracted by DTE Energy, including forward natural gas purchases and sales, natural gas transportation and storage capacity. Changes in the value of derivatives in this category typically economically offset changes in the value of underlying non-derivative positions, which do not qualify for fair value accounting. The difference in accounting treatment of derivatives in this category and the underlying non-derivative positions can result in significant earnings volatility.
	•	Marketing and Origination — Represents derivative activity transacted by originating substantially hedged positions with wholesale energy marketers, producers, end users, utilities, retail aggregators and alternative energy suppliers.
	•	Fundamentals Based Trading — Represents derivative activity transacted with the intent of taking a view, capturing market price changes, or putting capital at risk. This activity is speculative in nature as opposed to hedging an existing exposure.
	•	Other — Includes derivative activity at DTE Electric related to FTRs. Changes in the value of derivative contracts at DTE Electric are recorded as Derivative Assets or Liabilities, with an offset to Regulatory Assets or Liabilities as the settlement value of these contracts will be included in the PSCR mechanism when realized.
	The following tables present the fair value of derivative instruments as of September 30, 2014 and December 31, 2013:
		September 30, 2014								December 31, 2013
		Derivative				Derivative Liabilities				Derivative				Derivative Liabilities
		Assets								Assets
		(In millions)
	Derivatives not designated as hedging instruments:
	Foreign currency exchange contracts	$	1			$	(3	)		$	—			$	(1	)
	Commodity Contracts:
	Natural Gas	254				(342		)		396				(503		)
	Electricity	386				(394		)		400				(398		)
	Other	52				(48		)		37				(34		)
	Total derivatives not designated as hedging instruments:	$	693			$	(787	)		$	833			$	(936	)
	Total derivatives:
	Current	$	605			$	(696	)		$	691			$	(773	)
	Noncurrent	88				(91		)		142				(163		)
	Total derivatives	$	693			$	(787	)		$	833			$	(936	)
	Certain of the Company's derivative positions are subject to netting arrangements which provide for offsetting of asset and liability positions as well as related cash collateral. Such netting arrangements generally do not have restrictions. Under such netting arrangements, the Company offsets the fair value of derivative instruments with cash collateral received or paid for those contracts executed with the same counterparty, which reduces the Company's total assets and liabilities. Cash collateral is allocated between the fair value of derivative instruments and customer accounts receivable and payable with the same counterparty on a pro rata basis to the extent there is exposure. Any cash collateral remaining, after the exposure is netted to zero, is reflected in accounts receivable and accounts payable as collateral paid or received, respectively.
	The Company also provides and receives collateral in the form of letters of credit which can be offset against net derivative assets and liabilities as well as accounts receivable and payable. The Company had issued letters of credit of approximately $21 million and $19 million at September 30, 2014 and December 31, 2013, respectively, which could be used to offset net derivative liabilities. Letters of credit received from third parties which could be used to offset our net derivative assets were not material for the periods presented. Such balances of letters of credit are excluded from the tables below and are not netted with the recognized assets and liabilities in the Consolidated Statements of Financial Position.
	For contracts with certain clearing agents the fair value of derivative instruments is netted against realized positions with the net balance reflected as either 1) a derivative asset or liability or 2) an account receivable or payable. Other than certain clearing agents, accounts receivable and accounts payable that are subject to netting arrangements have not been offset against the fair value of derivative assets and liabilities. Certain contracts that have netting arrangements have not been offset in the Consolidated Statements of Financial Position. The impact of netting these derivative instruments and cash collateral related to such contracts is not material. Only the gross amounts for these derivative instruments are included in the table below.
	As of September 30, 2014, the total cash collateral posted, net of cash collateral received, was $40 million. As of December 31, 2013, the total cash collateral posted, net of cash collateral received, was $12 million. As of September 30, 2014, derivative assets and derivative liabilities are shown net of cash collateral of $4 million and $42 million, respectively. As of December 31, 2013, derivative assets and derivative liabilities are shown net of cash collateral of $26 million and $17 million, respectively. The Company recorded cash collateral paid of $4 million and cash collateral received of $2 million not related to unrealized derivative positions as of September 30, 2014. The Company recorded cash collateral paid of $34 million and cash collateral received of $13 million not related to unrealized derivative positions as of December 31, 2013. These amounts are included in accounts receivable and accounts payable and are recorded net by counterparty.
	The following table presents the netting offsets of derivative assets and liabilities at September 30, 2014 and December 31, 2013:
		30-Sep-14												31-Dec-13
		Gross Amounts of Recognized Assets (Liabilities)				Gross Amounts Offset in the Consolidated Statements of Financial Position				Net Amounts of Assets (Liabilities) Presented in the Consolidated Statements of Financial Position				Gross Amounts of Recognized Assets (Liabilities)				Gross Amounts Offset in the Consolidated Statements of Financial Position			Net Amounts of Assets (Liabilities) Presented in the Consolidated Statements of Financial Position
		(In millions)
	Derivative assets:
	Commodity Contracts:
	Natural Gas	$	254			$	(225	)		$	29			$	396			$	(382	)	$	14
	Electricity	386				(322		)		64				400				(291		)	109
	Other	52				(48		)		4				37				(34		)	3
	Other derivative contracts (a)	1				(1		)		—				—				—			—
	Total derivative assets	$	693			$	(596	)		$	97			$	833			$	(707	)	$	126
	Derivative liabilities:
	Commodity Contracts:
	Natural Gas	$	(342	)		$	268			$	(74	)		$	(503	)		$	395		$	(108	)
	Electricity	(394		)		317				(77		)		(398		)		269			(129		)
	Other	(48		)		48				—				(34		)		34			—
	Other derivative contracts (a)	(3		)		1				(2		)		(1		)		—			(1		)
	Total derivative liabilities	$	(787	)		$	634			$	(153	)		$	(936	)		$	698		$	(238	)
	_______________________________________
	(a)	Primarily includes Foreign currency exchange contracts.
	The following table presents the netting offsets of derivative assets and liabilities at September 30, 2014 and December 31, 2013:
		September 30, 2014																31-Dec-13
		Derivative Assets								Derivative Liabilities								Derivative Assets						Derivative Liabilities
		Current				Noncurrent				Current				Noncurrent				Current			Noncurrent			Current			Noncurrent
		(In millions)
	Reconciliation of derivative instruments to Consolidated Statements of Financial Position:
Total fair value of derivatives	$	605			$	88			$	(696	)		$	(91	)		$	691		$	142		$	(773	)	$	(163	)
Counterparty netting	(533		)		(59		)		533				59				(566		)	(115		)	566			115
Collateral adjustment	(4		)		—				29				13				(26		)	—			12			5
Total derivatives as reported	$	68			$	29			$	(134	)		$	(19	)		$	99		$	27		$	(195	)	$	(43	)
The effect of derivatives not designated as hedging instruments on the Consolidated Statements of Operations for the three and nine months ended September 30, 2014 and 2013 is as follows:
		Location of Gain		Gain (Loss)								Gain (Loss)
		(Loss) Recognized		Recognized in								Recognized in
		in Income on Derivatives		Income on								Income on
				Derivatives for								Derivatives for
				the Three Months Ended September 30,								the Nine Months Ended September 30,
Derivatives not Designated as Hedging Instruments				2014				2013				2014				2013
				(In millions)
Foreign currency exchange contracts		Operating Revenue		$	(1	)		$	—			$	(2	)		$	(1	)
Commodity Contracts:
Natural Gas		Operating Revenue		(38		)		1				(10		)		37
Natural Gas		Fuel, purchased power and gas		12				(1		)		23				(33		)
Electricity		Operating Revenue		12				22				100				52
Other		Operating Revenue		(1		)		1				(5		)		1
Total				$	(16	)		$	23			$	106			$	56
Revenues and energy costs related to trading contracts are presented on a net basis in the Consolidated Statements of Operations. Commodity derivatives used for trading purposes, and financial non-trading commodity derivatives, are accounted for using the mark-to-market method with unrealized and realized gains and losses recorded in Operating revenues. Non-trading physical commodity sale and purchase derivative contracts are generally accounted for using the mark-to-market method with unrealized and realized gains and losses for sales recorded in Operating revenue and purchases recorded in Fuel, purchased power and gas.
The following represents the cumulative gross volume of derivative contracts outstanding as of September 30, 2014:
Commodity		Number of Units
Natural Gas (MMBtu)		865,462,971
Electricity (MWh)		15,291,188
Oil (Gallons)		10,290,000
Foreign Currency Exchange (Canadian dollars)		81,310,582
Various subsidiaries of the Company have entered into contracts which contain ratings triggers and are guaranteed by DTE Energy. These contracts contain provisions which allow the counterparties to require that the Company post cash or letters of credit as collateral in the event that DTE Energy’s credit rating is downgraded below investment grade. Certain of these provisions (known as “hard triggers”) state specific circumstances under which the Company can be required to post collateral upon the occurrence of a credit downgrade, while other provisions (known as “soft triggers”) are not as specific. For contracts with soft triggers, it is difficult to estimate the amount of collateral which may be requested by counterparties and/or which the Company may ultimately be required to post. The amount of such collateral which could be requested fluctuates based on commodity prices (primarily natural gas, power and coal) and the provisions and maturities of the underlying transactions. As of September 30, 2014, DTE Energy's contractual obligation to post collateral in the form of cash or letter of credit in the event of a downgrade to below investment grade, under both hard trigger and soft trigger provisions, was approximately $327 million.
As of September 30, 2014, the Company had approximately $894 million of derivatives in net liability positions, for which hard triggers exist. Collateral of approximately $13 million has been posted against such liabilities, including cash and letters of credit. Associated derivative net asset positions for which contractual offset exists were approximately $744 million. The net remaining amount of approximately $137 million is derived from the $327 million noted above.

Asset_Retirement_Obligations_N

Asset Retirement Obligations (Notes)	9 Months Ended
	Sep. 30, 2014
Asset Retirement Obligation Disclosure [Abstract]	'
Asset Retirement Obligations	'
	ASSET RETIREMENT OBLIGATIONS
	A reconciliation of the asset retirement obligations for the nine months ended September 30, 2014 follows:
		(In millions)
	Asset retirement obligations at December 31, 2013	$	1,827
	Accretion	84
	Liabilities incurred	11
	Liabilities settled	(5		)
	Revision in estimated cash flows	(6		)
	Asset retirement obligations at September 30, 2014	$	1,911

Regulatory_Matters_Notes

Regulatory Matters (Notes)	9 Months Ended
	Sep. 30, 2014
Public Utilities, General Disclosures [Abstract]	'
Regulatory Matters	'
	REGULATORY MATTERS
	Refundable Revenue Decoupling (RDM)/ Deferred Gain Amortization
	In September 2012, the MPSC approved DTE Electric's accounting application to defer for future amortization the gain resulting from the reversal of the Company's $127 million regulatory liability associated with the operation of the RDM. The approved application provided for the amortization of the regulatory liability to income, at a monthly rate of approximately $10.6 million, beginning January 2014. On April 1, 2014, the MPSC approved DTE Electric's accounting application to suspend the amortization of the RDM regulatory liability as of June 30, 2014 and to complete the amortization over the period January 2015 to June 2015. If DTE Electric's base rates are increased prior to July 1, 2015, the Company will cease amortization and refund to customers the remaining unamortized balance of the regulatory liability.
	Transition of PLD Customers to DTE Electric's Distribution System
	On July 19, 2013, DTE Electric filed its TRM application proposing a transitional tariff option for certain former PLD customers and a modified line extension provision. The application also proposed a recovery mechanism for the deferred net incremental revenue requirement associated with the transition. The net incremental revenue requirement includes costs to install meters and attach customers; system and customer facility upgrades and repairs; and the difference between DTE Electric's tariff rates and any transitional rates approved in the future. On May 13, 2014, the MPSC approved the TRM as requested and also ordered DTE Electric to include in the TRM the PLD transmission delivery service costs incurred while DTE Electric is temporarily relying upon PLD to operate and maintain PLD's system during the system conversion period. The meter installation phase of the transition was completed in June 2014. On July 1, 2014, former PLD customers became customers of DTE Electric.
	PSCR Proceedings
	The PSCR process is designed to allow DTE Electric to recover all of its power supply costs if incurred under reasonable and prudent policies and practices. DTE Electric's power supply costs include fuel and related transportation costs, purchased and net interchange power costs, nitrogen oxide and sulfur dioxide emission allowances costs, urea costs, transmission costs and MISO costs. The MPSC reviews these costs, policies and practices for prudence in annual plan and reconciliation filings.
	2012 PSCR Year — In March 2013, DTE Electric filed the 2012 PSCR reconciliation calculating a net under-recovery of approximately $87 million that includes an under-recovery of approximately $148 million for the 2011 PSCR year. The reconciliation includes purchased power costs related to the manual shutdown of our Fermi 2 nuclear power plant in June 2012 caused by the failure of one of the plant's two non-safety related feed-water pumps. The plant was restarted on July 30, 2012, which restored production to nominal 68% of full capacity. In September 2013, the repair to the plant was completed and production was returned to full capacity. DTE Electric was able to purchase sufficient power from MISO to continue to provide uninterrupted service to our customers. Certain intervenors in the reconciliation case have challenged the recovery of up to $32 million of the Fermi 2 related purchased power costs. Resolution of this matter is expected by early 2015.

Earnings_Per_Share_Notes

Earnings Per Share (Notes)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Earnings per Share	'
	EARNINGS PER SHARE
	The Company reports both basic and diluted earnings per share. The calculation of diluted earnings per share assumes the issuance of potentially dilutive common shares outstanding during the period from the exercise of stock options. A reconciliation of both calculations is presented in the following table for the three and nine months ended September 30:
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
		(In millions, except per share amounts)
	Basic Earnings per Share
	Net income attributable to DTE Energy Company	$	156	$	198	$	606	$	537
	Average number of common shares outstanding	177		175		177		174
	Weighted average net restricted shares outstanding	—		—		—		1
	Dividends declared — common shares	$	122	$	115	$	353	$	337
	Dividends declared — net restricted shares	—		1		1		1
	Total distributed earnings	$	122	$	116	$	354	$	338
	Net income less distributed earnings	$	34	$	82	$	252	$	199
	Distributed (dividends per common share)	$	0.69	$	0.66	$	2	$	1.93
	Undistributed	0.19		0.47		1.42		1.14
	Total Basic Earnings per Common Share	$	0.88	$	1.13	$	3.42	$	3.07
	Diluted Earnings per Share
	Net income attributable to DTE Energy Company	$	156	$	198	$	606	$	537
	Average number of common shares outstanding	177		176		177		175
	Weighted average net restricted shares outstanding	—		—		—		1
	Dividends declared — common shares	$	122	$	115	$	353	$	337
	Dividends declared — net restricted shares	—		1		1		1
	Total distributed earnings	$	122	$	116	$	354	$	338
	Net income less distributed earnings	$	34	$	82	$	252	$	199
	Distributed (dividends per common share)	$	0.69	$	0.66	$	2	$	1.93
	Undistributed	0.19		0.47		1.42		1.14
	Total Diluted Earnings per Common Share	$	0.88	$	1.13	$	3.42	$	3.07

LongTerm_Debt_Notes

Long-Term Debt (Notes)	9 Months Ended
	Sep. 30, 2014
Long-term Debt, Unclassified [Abstract]	'
Long-term Debt [Text Block]	'
	LONG-TERM DEBT
	Debt Issuances
	In 2014, the following debt was issued:
	Company		Month	Type	Interest Rate	Maturity	Amount
							(In millions)
	DTE Energy		May	Senior Notes (a)	3.50%	2024	$	350
	DTE Electric		June	Mortgage Bonds (a)	3.77%	2026	100
	DTE Electric		June	Mortgage Bonds (a)	4.60%	2044	150
	DTE Electric		July	Mortgage Bonds (a)	3.38%	2025	350
	DTE Electric		July	Mortgage Bonds (a)	4.30%	2044	350
							$	1,300
	_______________________________________
	(a)	Proceeds were used for the redemption of long-term debt, for the repayment of short-term borrowings and for general corporate purposes.
	In September 2014, DTE Gas agreed to issue $150 million of 4.35% mortgage bonds due 2044 to a group of institutional investors in a private placement transaction. These bonds are expected to close and fund in December 2014. Proceeds will be used for general corporate purposes.
	Debt Redemptions
	In 2014, the following debt was redeemed:
	Company		Month	Type	Interest Rate	Maturity	Amount
							(In millions)
	DTE Electric		March	Mortgage Bonds	Various	2014	$	13
	DTE Electric		March	Securitization Bonds	6.62%	2014	100
	DTE Electric		April	Tax Exempt Revenue Bonds (a)	2.35%	2024	31
	DTE Electric		April	Tax Exempt Revenue Bonds (a)	4.65%	2028	32
	DTE Gas		May	Mortgage Bonds	8.25%	2014	80
	DTE Energy		May	Senior Notes	7.63%	2014	300
	DTE Electric		June	Tax Exempt Revenue Bonds (a)	4.88%	2029	36
	DTE Electric		June	Tax Exempt Revenue Bonds (a)	6.00%	2036	69
	DTE Electric		July	Senior Notes	4.80%	2015	200
	DTE Electric		August	Senior Notes	5.40%	2014	200
	DTE Electric		August	Tax Exempt Revenue Bonds (a)	5.25%	2029	60
	DTE Electric		September	Securitization Bonds	6.62%	2014	96
	DTE Energy		Various	Other Long Term Debt	Various	2014	5
							$	1,222
	_______________________________________
	(a)	DTE Electric Tax Exempt Revenue Bonds are issued by a public body that loans the proceeds to DTE Electric on terms substantially mirroring the Tax Exempt Revenue Bonds.

ShortTerm_Credit_Arrangements_

Short-Term Credit Arrangements and Borrowings (Notes)	9 Months Ended
	Sep. 30, 2014
Short-term Debt [Abstract]	'
Short-Term Credit Arrangements and Borrowings	'
	SHORT-TERM CREDIT ARRANGEMENTS AND BORROWINGS
	DTE Energy and its wholly owned subsidiaries, DTE Electric and DTE Gas, have unsecured revolving credit agreements with a syndicate of 19 banks that can be used for general corporate borrowings, but are intended to provide liquidity support for each of the companies’ commercial paper programs. No one bank provides more than 8.7% of the commitment in any facility. Borrowings under the facilities are available at prevailing short-term interest rates. Additionally, DTE Energy has other facilities to support letter of credit issuance.
	The agreements require the Company to maintain a total funded debt to capitalization ratio of no more than 0.65 to 1. In the agreements, “total funded debt” means all indebtedness of the Company and its consolidated subsidiaries, including capital lease obligations, hedge agreements and guarantees of third parties’ debt, but excluding contingent obligations, nonrecourse and junior subordinated debt and certain equity-linked securities and, except for calculations at the end of the second quarter, certain DTE Gas short-term debt. “Capitalization” means the sum of (a) total funded debt plus (b) “consolidated net worth,” which is equal to consolidated total stockholders’ equity of the Company and its consolidated subsidiaries (excluding pension effects under certain FASB statements), as determined in accordance with accounting principles generally accepted in the United States of America. At September 30, 2014, the total funded debt to total capitalization ratios for DTE Energy, DTE Electric and DTE Gas were 0.49 to 1, 0.52 to 1 and 0.45 to 1, respectively, and are in compliance with this financial covenant. The availability under the facilities in place at September 30, 2014 is shown in the following table:
		DTE Energy		DTE Electric		DTE Gas		Total
		(In millions)
	Unsecured letter of credit facility, expiring in February 2015	$	100	$	—	$	—	$	100
	Unsecured letter of credit facility, expiring in August 2015	125		—		—		125
	Unsecured revolving credit facility, expiring April 2018	1,200		300		300		1,800
		1,425		300		300		2,025
	Amounts outstanding at September 30, 2014:
	Commercial paper issuances	207		254		192		653
	Letters of credit	200		—		—		200
		407		254		192		853
	Net availability at September 30, 2014	$	1,018	$	46	$	108	$	1,172
	The Company has other outstanding letters of credit which are not included in the above described facilities totaling approximately $35 million which are used for various corporate purposes.
	In conjunction with maintaining certain exchange traded risk management positions, the Company may be required to post cash collateral with its clearing agent. The Company has a demand financing agreement for up to $100 million with its clearing agent. The agreement, as amended, also allows for up to $50 million of additional margin financing provided that the Company posts a letter of credit for the incremental amount. At September 30, 2014, a $50 million letter of credit was in place, raising the capacity under this facility to $150 million. The $50 million letter of credit is included in the table above. The amount outstanding under this agreement was $78 million and $138 million at September 30, 2014 and December 31, 2013, respectively.

Commitments_and_Contingencies_

Commitments and Contingencies (Notes)	9 Months Ended
	Sep. 30, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	COMMITMENTS AND CONTINGENCIES
	Environmental
	Electric
	Air - DTE Electric is subject to the EPA ozone and fine particulate transport and acid rain regulations that limit power plant emissions of sulfur dioxide and nitrogen oxides. Since 2005, the EPA and the State of Michigan have issued additional emission reduction regulations relating to ozone, fine particulate, regional haze, mercury, and other air pollution. These rules have led to additional controls on fossil-fueled power plants to reduce nitrogen oxide, sulfur dioxide, mercury and other emissions. To comply with these requirements, DTE Electric spent approximately $2 billion through 2013. The Company estimates DTE Electric will make capital expenditures of approximately $200 million in 2014 and up to approximately $1.2 billion of additional capital expenditures through 2021 based on current regulations.
	Additional rulemakings are expected over the next few years which could require additional controls for sulfur dioxide, nitrogen oxides and other hazardous air pollutants. The Cross State Air Pollution Rule (CSAPR), finalized in July 2011, required further reductions of sulfur dioxide and nitrogen oxides emissions beginning in 2012. On December 30, 2011, the COA granted the motions to stay the rule, leaving DTE Electric temporarily subject to the previously existing Clean Air Interstate Rule (CAIR). On August 21, 2012, the COA issued its decision, vacating CSAPR and leaving CAIR in place. The EPA's petition seeking a rehearing of the COA's decision regarding the CSAPR was denied on January 24, 2013. On June 24, 2013, the U.S. Supreme Court granted EPA's petition for a review of the COA's decision on CSAPR. On April 29, 2014, the U.S. Supreme Court issued its ruling reversing the COA's stay decision and remanding the case for further proceedings. The EPA has since requested the COA to lift the stay on CSAPR and proposed that phase one of the rule would start effective January 2015. Notwithstanding the U.S. Supreme Court remand decision and potential decision by the COA to lift the stay, DTE Electric expects to meet its obligations under CSAPR beginning in 2015. Furthermore, the EPA and a number of states, including Michigan, have started working on the framework of revised CSAPR regulations which may still be proposed in the next few years to address other challenges to the existing CSAPR regulations. DTE Electric will continue to monitor these developments and adjust its compliance strategy accordingly.
	The Mercury and Air Toxics Standard (MATS) rule, formerly known as the Electric Generating Unit Maximum Achievable Control Technology (EGU MACT) Rule was finalized on December 16, 2011. The MATS rule requires reductions of mercury and other hazardous air pollutants beginning in April 2015, with a potential extension to April 2016. DTE Electric has requested and been granted compliance date extensions for all relevant units to April 2016, with the exception of Monroe Power Plant. All Monroe Power Plant units will be in compliance with MATS requirements by April 2015. DTE Electric has tested technologies to determine technological and economic feasibility as MATS compliance alternatives to Flue Gas Desulfurization (FGD) systems. Implementation of Dry Sorbent Injection (DSI) and Activated Carbon Injection (ACI) technologies will allow several units that would not have been economical for FGD installations to continue operation in compliance with MATS.
	In July 2009, DTE Energy received a NOV/FOV from the EPA alleging, among other things, that five DTE Electric power plants violated New Source Performance standards, Prevention of Significant Deterioration requirements, and operating permit requirements under the Clean Air Act. In June 2010, the EPA issued a NOV/FOV making similar allegations related to a project and outage at Unit 2 of the Monroe Power Plant. In March 2013, DTE Energy received a supplemental NOV from the EPA relating to the July 2009 NOV/FOV. The supplemental NOV alleged additional violations relating to the New Source Review provisions under the Clean Air Act, among other things.
	In August 2010, the U.S. Department of Justice, at the request of the EPA, brought a civil suit in the U.S. District Court for the Eastern District of Michigan against DTE Energy and DTE Electric, related to the June 2010 NOV/FOV and the outage work performed at Unit 2 of the Monroe Power Plant, but not relating to the July 2009 NOV/FOV. Among other relief, the EPA requested the court to require DTE Electric to install and operate the best available control technology at Unit 2 of the Monroe Power Plant. Further, the EPA requested the court to issue a preliminary injunction to require DTE Electric to (i) begin the process of obtaining the necessary permits for the Monroe Unit 2 modification and (ii) offset the pollution from Monroe Unit 2 through emissions reductions from DTE Electric's fleet of coal-fired power plants until the new control equipment is operating. On August 23, 2011, the U.S. District Court judge granted DTE Energy's motion for summary judgment in the civil case, dismissing the case and entering judgment in favor of DTE Energy and DTE Electric. On October 20, 2011, the EPA caused to be filed a Notice of Appeal to the U.S. Court of Appeals for the Sixth Circuit. On March 28, 2013, the Court of Appeals remanded the case to the U.S. District Court for review of the procedural component of the New Source Review notification requirements. On September 3, 2013, the EPA caused to be filed a motion seeking leave to amend their complaint regarding the June 2010 NOV/FOV adding additional claims related to outage work performed at the Trenton Channel and Belle River power plants as well as additional claims related to work performed at the Monroe Power Plant. In addition, the Sierra Club caused to be filed a motion to add a claim regarding the River Rouge Power Plant. On March 3, 2014, the U.S. District Court judge granted again DTE Energy's motion for summary judgment dismissing the civil case related to Monroe Unit 2. On April 3, 2014, the U.S. District Court judge granted motions filed by the EPA and the Sierra Club to amend their New Source Review complaint adding additional claims for Monroe Units 1, 2 and 3, Belle River Units 1 and 2, Trenton Channel Unit 9 and denied the claims related to River Rouge that were brought by the Sierra Club. On June 30, 2014, the EPA filed a motion requesting certification for appeal of the March 3, 2014 summary judgment decision. On October 3, 2014, the EPA and the U.S. Department of Justice filed the anticipated notice of appeal of the U.S. District Court judge's dismissal of the Monroe Unit 2 case. This will officially start the appellate process. The amended New Source Review claims are all stayed until the appeal is resolved by the U.S. Court of Appeals for the Sixth Circuit.
	DTE Energy and DTE Electric believe that all the plants and generating units identified by the EPA and the Sierra Club have complied with all applicable federal environmental regulations. Depending upon the outcome of discussions with the EPA regarding the two NOVs/FOVs, DTE Electric could be required to install additional pollution control equipment at some or all of the power plants in question, implement early retirement of facilities where control equipment is not economical, engage in supplemental environmental programs, and/or pay fines. The Company cannot predict the financial impact or outcome of this matter, or the timing of its resolution.
	In March 2013, the Sierra Club filed suit against DTE Energy and DTE Electric alleging violations of the Clean Air Act at four of DTE Electric's coal-fired power plants. The plaintiffs alleged 1,499 six-minute periods of excess opacity of air emissions from 2007-2012 at those facilities. The suit asks that the court enjoin DTE Energy and DTE Electric from operating the power plants except in complete compliance with applicable laws and permit requirements, pay civil penalties, conduct beneficial environmental mitigation projects, pay attorney fees and require the installation of any necessary pollution controls or to convert and/or operate the plants' boilers on natural gas to avoid additional violations and to off-set historic unlawful emissions. In December 2013, a U.S. District Court judge issued an order dismissing, without prejudice, the plaintiff's complaint allowing them to file an amended complaint by January 17, 2014. The order dismissing the complaint resulted from a considerable number of plaintiff's claims being time barred based on the statute of limitations. On January 17, 2014, the plaintiffs filed an amended complaint for the period January 13, 2008 - June 30, 2012, reducing the total number of six-minute periods from 1,499 to 1,139. DTE Energy and DTE Electric filed an answer to the amended complaint on March 11, 2014. On October 16, 2014, the Sierra Club, DTE Energy and DTE Electric filed a stipulation to voluntary dismiss the litigation in its entirety.
	Water — In response to an EPA regulation, DTE Electric would be required to examine alternatives for reducing the environmental impacts of the cooling water intake structures at several of its facilities. Based on the results of completed studies and expected future studies, DTE Electric may be required to install technologies to reduce the impacts of the water intake structures. The initial rule published in 2004 was subsequently remanded and a proposed rule published in 2011. The final rule was issued on May 19, 2014. The final rule specifies a time period exceeding three years to complete studies to determine the type of technology needed to reduce impacts to fish. Final compliance for the installation of the required technology will be determined by each state on a case by case basis. We are currently evaluating the compliance options and working with the State of Michigan on evaluating whether any controls are needed. These evaluations/studies may require modifications to some existing intake structures. It is not possible to quantify the impact of this rulemaking at this time.
	On April 19, 2013, the EPA proposed revised steam electric effluent guidelines regulating wastewater streams from coal-fired power plants including multiple possible options for compliance. The rules are expected to be finalized by September 2015. DTE Electric has provided comments to the EPA. However, it is not possible at this time to quantify the impacts of these developing requirements.
	Contaminated and Other Sites — Prior to the construction of major interstate natural gas pipelines, gas for heating and other uses was manufactured locally from processes involving coal, coke or oil. The facilities, which produced gas, have been designated as MGP sites. DTE Electric conducted remedial investigations at contaminated sites, including three former MGP sites. The investigations have revealed contamination related to the by-products of gas manufacturing at each MGP site. In addition to the MGP sites, the Company is also in the process of cleaning up other contaminated sites, including the area surrounding an ash landfill, electrical distribution substations, electric generating power plants, and underground and aboveground storage tank locations. The findings of these investigations indicated that the estimated cost to remediate these sites is expected to be incurred over the next several years. At September 30, 2014 and December 31, 2013, the Company had $10 million and $8 million accrued for remediation, respectively. Any change in assumptions, such as remediation techniques, nature and extent of contamination and regulatory requirements, could impact the estimate of remedial action costs for the sites and affect the Company’s financial position and cash flows. The Company believes the likelihood of a material change to the accrued amount is remote based on current knowledge of the conditions at each site.
	DTE Electric owns and operates three permitted engineered ash storage facilities to dispose of fly ash from the coal fired power plants. The EPA has published proposed rules to regulate coal ash under the authority of the Resources Conservation and Recovery Act (RCRA). The proposed rule published in June 2010 contains two primary regulatory options to regulate coal ash residue. The EPA is currently considering either designating coal ash as a “Hazardous Waste” as defined by RCRA or regulating coal ash as non-hazardous waste under RCRA. Agencies and legislatures have urged the EPA to regulate coal ash as a non-hazardous waste. If the EPA designates coal ash as a hazardous waste, the agency could apply some, or all, of the disposal and reuse standards that have been applied to other existing hazardous wastes to disposal and reuse of coal ash. Some of the regulatory actions currently being contemplated could have a significant impact on our operations and financial position and the rates we charge our customers. The rules are expected to be finalized by December 2014. It is not possible to quantify the impact of those expected rulemakings at this time.
	Gas
	Contaminated and Other Sites — Gas segment owns or previously owned, 15 former MGP sites. Investigations have revealed contamination related to the by-products of gas manufacturing at each site. Cleanup of two of the MGP sites is complete and the sites are closed. We expect complete closure of two additional sites and partial closure of two sites by the end of 2014. Cleanup activities associated with the remaining sites will be continued over the next several years. The MPSC has established a cost deferral and rate recovery mechanism for investigation and remediation costs incurred at former MGP sites. In addition to the MGP sites, the Company is also in the process of cleaning up other contaminated sites, including gate stations, gas pipeline releases and underground storage tank locations. As of September 30, 2014 and December 31, 2013, the Company had $26 million and $28 million accrued for remediation, respectively. Any change in assumptions, such as remediation techniques, nature and extent of contamination and regulatory requirements, could impact the estimate of remedial action costs for the sites and affect the Company’s financial position and cash flows. The Company anticipates the cost amortization methodology approved by the MPSC for DTE Gas, which allows DTE Gas to amortize the MGP costs over a ten-year period beginning with the year subsequent to the year the MGP costs were incurred will prevent environmental costs from having a material adverse impact on the Company’s results of operations.
	Non-utility
	The Company’s non-utility businesses are subject to a number of environmental laws and regulations dealing with the protection of the environment from various pollutants.
	The Michigan coke battery facility received and responded to information requests from the EPA that resulted in the issuance of a NOV in June 2007 alleging potential maximum achievable control technologies and new source review violations. The EPA is in the process of reviewing the Company’s position of demonstrated compliance and has not initiated escalated enforcement. At this time, the Company cannot predict the impact of this issue. Furthermore, the Michigan coke battery facility is the subject of an investigation by the MDEQ concerning visible emissions readings that resulted from the Company self reporting to MDEQ questionable activities by an employee of a contractor hired by the Company to perform the visible emissions readings. At this time, the Company cannot predict the impact of this investigation.
	The Company received two NOVs from the Pennsylvania Department of Environmental Protection (PADEP) in 2010 alleging violations of the permit for the Pennsylvania coke battery facility in connection with coal pile storm water runoff. The Company settled the alleged violations by implementing best management practices to address the issues and repair/upgrade their wastewater treatment plant. The Company recently received a permit to upgrade its existing waste water treatment system and is currently seeking a permit from the PADEP to upgrade its wastewater treatment technology to a biological treatment facility. The Company expects to spend $2 million on the existing waste water treatment system to comply with existing water discharge requirements and to upgrade its coal pile storm water runoff management program. The Company will also spend up to an additional $13 million over the next few years to upgrade the treatment technology to biological treatment to meet future regulatory requirements and gain other operational improvement savings.
	The Company also received an NOV from the Allegheny County (PA) Health Department pertaining to excessive opacity readings from fugitive sources (mainly pushing emissions) in excess of its opacity standards for the Pennsylvania coke battery facility. Fugitive sources at the plant are in full compliance with the applicable Federal Opacity Standards. In February 2014, the Company received from the Group Against Smog & Pollution (GASP) a 60 day Notice of Intent to sue letter under the Federal Clean Air Act and/or Article XXI of the Allegheny County (PA) Health Department's Rules and Regulations. GASP alleged in the letter that the Company's coke battery facility in Pennsylvania was in violation of visible emissions limits from charging activities, door leaks, the combustion stack and pushing operations and hydrogen sulfide emission limits on flared, mixed or combusted coke oven gas. To resolve these issues, the Company agreed to a Consent Order and Agreement with Allegheny County pursuant to which the Company paid a fine of $300,000 and will spend $300,000 for a supplemental environmental project to enhance particulate collection efficiency from the coke battery's quench tower. Notwithstanding the agreement reached with the County, GASP proceeded with the filing of their complaint. The Company believes that the GASP suit is without merit and filed a motion to dismiss on June 18, 2014.
	The Company believes that its non-utility businesses are substantially in compliance with all environmental requirements, other than as noted above.
	Other
	In December 2012, the EPA finalized a new set of regulations regarding the identification of non-hazardous secondary materials that are considered solid waste, industrial boiler and process heater maximum achievable control technologies (IBMACT) for major and area sources, and commercial/industrial solid waste incinerator new source performance standard and emission guidelines (CISWI). Capital costs for pollution controls and/or boiler conversions and the expenses for the one-time energy assessments are not expected to be material.
	In 2010, the EPA finalized a new 1-hour sulfur dioxide ambient air quality standard that requires states to submit plans for non-attainment areas to be in compliance by 2017. Michigan's non-attainment area includes DTE Energy facilities in southwest Detroit and areas of Wayne County. Preliminary modeling runs by the MDEQ suggest that emission reductions may be required by significant sources of sulfur dioxide emissions in these areas, including DTE Electric power plants and our Michigan coke battery. The state implementation plan process is in the information gathering stage, and DTE Energy is unable to estimate any required emissions reductions at this time.
	Nuclear Operations
	Property Insurance
	DTE Electric maintains property insurance policies specifically for the Fermi 2 plant. These policies cover such items as replacement power and property damage. NEIL is the primary supplier of the insurance policies.
	DTE Electric maintains a policy for extra expenses, including replacement power costs necessitated by Fermi 2’s unavailability due to an insured event. This policy has a 12-week waiting period and provides an aggregate $490 million of coverage over a three-year period.
	DTE Electric has $1.5 billion in primary coverage and $1.25 billion of excess coverage for stabilization, decontamination, debris removal, repair and/or replacement of property and decommissioning. The combined coverage limit for total property damage is $2.75 billion, subject to a $1 million deductible. The total limit for property damage for non-nuclear events is $2 billion and an aggregate of $327 million of coverage for extra expenses over a two-year period.
	In 2007, the TRIA was extended through December 31, 2014. A major change in the extension is the inclusion of “domestic” acts of terrorism in the definition of covered or “certified” acts. For multiple terrorism losses caused by acts of terrorism not covered under the TRIA occurring within one year after the first loss from terrorism, the NEIL policies would make available to all insured entities up to $3.2 billion, plus any amounts recovered from reinsurance, government indemnity, or other sources to cover losses.
	Under the NEIL policies, DTE Electric could be liable for maximum assessments of up to approximately $35 million per event if the loss associated with any one event at any nuclear plant should exceed the accumulated funds available to NEIL.
	Public Liability Insurance
	As required by federal law, DTE Electric maintains $375 million of public liability insurance for a nuclear incident. For liabilities arising from a terrorist act outside the scope of TRIA, the policy is subject to one industry aggregate limit of $300 million. Further, under the Price-Anderson Amendments Act of 2005, deferred premium charges up to $127.3 million could be levied against each licensed nuclear facility, but not more than $19 million per year per facility. Thus, deferred premium charges could be levied against all owners of licensed nuclear facilities in the event of a nuclear incident at any of these facilities.
	Nuclear Fuel Disposal Costs
	In accordance with the Federal Nuclear Waste Policy Act of 1982, DTE Electric has a contract with the DOE for the future storage and disposal of spent nuclear fuel from Fermi 2 that required DTE Electric to pay the DOE a fee of 1 mill per kWh of Fermi 2 electricity generated and sold. The fee was a component of nuclear fuel expense. The DOE's Yucca Mountain Nuclear Waste Repository program for the acceptance and disposal of spent nuclear fuel was terminated in 2011. DTE Electric currently employs a spent nuclear fuel storage strategy utilizing a fuel pool and a newly completed dry cask storage facility. The initial dry cask loading campaign planned for 2014 has been completed. The dry cask storage facility is expected to provide sufficient spent fuel storage capability for the life of the plant as defined by the original operating license.
	DTE Electric is a party in the litigation against the DOE for both past and future costs associated with the DOE's failure to accept spent nuclear fuel under the timetable set forth in the Federal Nuclear Waste Policy Act of 1982. In July 2012, DTE Electric executed a settlement agreement with the federal government for costs associated with the DOE's delay in acceptance of spent nuclear fuel from Fermi 2 for permanent storage. The settlement agreement, including extensions, provides for a claims process and payment of delay-related costs experienced by DTE Electric through 2016. DTE Electric has begun the claims process and claims are being settled and paid on a timely basis. The settlement proceeds reduce the cost of the dry cask storage facility assets and provide reimbursement for related operating expenses. The federal government continues to maintain its legal obligation to accept spent nuclear fuel from Fermi 2 for permanent storage. Issues relating to long-term waste disposal policy and to the disposition of funds contributed by DTE Electric ratepayers to the federal waste fund await future governmental action.
	In February 2013, the COA granted a motion to reopen the fee adequacy litigation to review the DOE's latest fee adequacy report which was released in January 2013. In November 2013, the COA issued a decision ordering the DOE to submit a proposal to Congress to reduce the nuclear waste fee to zero until the DOE enacts an alternative nuclear waste management plan. In January 2014, the DOE submitted such a proposal to Congress that was scheduled to take effect in 90 legislative calendar days, absent legislative action to the contrary. Simultaneously, the DOE filed a petition for rehearing of the November 2013 decision with the COA. In March 2014, the COA denied DOE's petition for rehearing. The 1 mill per kWh fee was reduced to zero effective May 16, 2014.
	Synthetic Fuel Guarantees
	The Company discontinued the operations of its synthetic fuel production facilities throughout the United States as of December 31, 2007. The Company provided certain guarantees and indemnities in conjunction with the sales of interests in its synfuel facilities. The guarantees cover potential commercial, environmental, oil price and tax-related obligations and will survive until 90 days after expiration of all applicable statutes of limitations. The Company estimates that its maximum potential liability under these guarantees at September 30, 2014 is approximately $1 billion. Payment under these guarantees is considered remote.
	REF Guarantees
	The Company has provided certain guarantees and indemnities in conjunction with the sales of interests in its REF facilities. The guarantees cover potential commercial, environmental, and tax-related obligations and will survive until 90 days after expiration of all applicable statutes of limitations. The Company estimates that its maximum potential liability under these guarantees at September 30, 2014 is approximately $150 million. Payment under these guarantees is considered remote.
	Other Guarantees
	In certain limited circumstances, the Company enters into contractual guarantees. The Company may guarantee another entity’s obligation in the event it fails to perform. The Company may provide guarantees in certain indemnification agreements. Finally, the Company may provide indirect guarantees for the indebtedness of others. The Company’s guarantees are not individually material with maximum potential payments totaling $60 million at September 30, 2014. Payment under these guarantees is considered remote.
	The Company is periodically required to obtain performance surety bonds in support of obligations to various governmental entities and other companies in connection with its operations. As of September 30, 2014, the Company had approximately $46 million of performance bonds outstanding. In the event that such bonds are called for nonperformance, the Company would be obligated to reimburse the issuer of the performance bond. The Company is released from the performance bonds as the contractual performance is completed and does not believe that a material amount of any currently outstanding performance bonds will be called.
	Labor Contracts
	There are several bargaining units for the Company's approximately 4,900 represented employees. The majority of the represented employees are under contracts that expire in 2016 and 2017.
	Purchase Commitments
	As of September 30, 2014, the Company was party to numerous long-term purchase commitments relating to a variety of goods and services required for the Company’s business. These agreements primarily consist of fuel supply commitments, renewable energy contracts and energy trading contracts. The Company estimates that these commitments will be approximately $8.3 billion from 2014 through 2051.
	The Company also estimates that 2014 capital expenditures will be approximately $2.2 billion. The Company has made certain commitments in connection with expected capital expenditures.
	Bankruptcies
	The Company purchases and sells electricity, natural gas, coal, coke and other energy products from and to governmental entities and numerous companies operating in the steel, automotive, energy, retail, financial and other industries. Certain of its customers have filed for bankruptcy protection under the U.S. Bankruptcy Code. The Company regularly reviews contingent matters relating to these customers and its purchase and sale contracts and records provisions for amounts considered at risk of probable loss. The Company believes its accrued amounts are adequate for probable loss.
	Other Contingencies
	The Company is involved in certain other legal, regulatory, administrative and environmental proceedings before various courts, arbitration panels and governmental agencies concerning claims arising in the ordinary course of business. These proceedings include certain contract disputes, additional environmental reviews and investigations, audits, inquiries from various regulators, and pending judicial matters. The Company cannot predict the final disposition of such proceedings. The Company regularly reviews legal matters and records provisions for claims that it can estimate and are considered probable of loss. The resolution of these pending proceedings is not expected to have a material effect on the Company’s operations or financial statements in the periods they are resolved.
	For a discussion of contingencies related to derivatives and regulatory matters see Notes 5 and 7 to the Consolidated Financial Statements, "Financial and Other Derivative Instruments" and "Regulatory Matters".

Retirement_Benefits_and_Truste

Retirement Benefits and Trusteed Assets (Notes)	9 Months Ended
	Sep. 30, 2014
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]	'
Pension and Other Postretirement Benefits Disclosure [Text Block]	'
	RETIREMENT BENEFITS AND TRUSTEED ASSETS
	The following table details the components of net periodic benefit costs for pension benefits and other postretirement benefits:
		Pension Benefits						Other Postretirement Benefits
		2014			2013			2014			2013
	Three Months Ended September 30	(In millions)
	Service cost	$	19		$	22		$	8		$	9
	Interest cost	54			49			22			21
	Expected return on plan assets	(69		)	(67		)	(31		)	(28		)
	Amortization of:
	Net actuarial loss	42			55			4			16
	Prior service credit	—			—			(36		)	(36		)
	Net periodic benefit cost (credit)	$	46		$	59		$	(33	)	$	(18	)
		Pension Benefits						Other Postretirement Benefits
		2014			2013			2014			2013
	Nine Months Ended September 30	(In millions)
	Service cost	$	62		$	71		$	26		$	37
	Interest cost	159			144			67			66
	Expected return on plan assets	(205		)	(200		)	(92		)	(82		)
	Amortization of:
	Net actuarial loss	118			156			15			48
	Prior service credit	—			—			(108		)	(95		)
	Net periodic benefit cost (credit)	$	134		$	171		$	(92	)	$	(26	)
	Pension and Other Postretirement Contributions
	During the first nine months of 2014, the Company contributed $167 million to its pension plans. At the discretion of management, and depending upon financial market conditions, the Company may make up to an additional $20 million contribution to its pension plans in 2014.
	At the discretion of management, the Company may make up to a $145 million contribution to its other postretirement benefit plans in 2014.

StockBased_Compensation_Notes

Stock-Based Compensation (Notes)	9 Months Ended
	Sep. 30, 2014
Share-based Compensation [Abstract]	'
Stock-based Compensation	'
	STOCK-BASED COMPENSATION
	The following table summarizes the components of stock-based compensation:
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014		2013
		(In millions)
	Stock-based compensation expense	$	22		$	18		$	72	$	81
	Tax benefit	$	8		$	7		$	27	$	31
	Stock-based compensation cost capitalized in property, plant and equipment	$	4		$	1		$	11	$	5
	Stock Options
	The following table summarizes our stock option activity for the nine months ended September 30, 2014:
		Number of		Weighted			Aggregate
		Options		Average			Intrinsic Value
				Exercise Price			(In millions)
	Options outstanding at January 1, 2014	723,697		$	42.6
	Exercised	(232,751	)	$	41.44
	Forfeited or expired	(10,730	)	$	39.41
	Options outstanding and exercisable at September 30, 2014	480,216		$	43.24		$	16
	As of September 30, 2014, the weighted average remaining contractual life for the exercisable shares is 3.57 years. As of September 30, 2014, all options were vested.
	The intrinsic value of options exercised for the nine months ended September 30, 2014 and 2013 was $7 million and $11 million, respectively. No option expense was recognized for the nine months ended September 30, 2014 and 2013, respectively.
	Restricted Stock Awards
	The following table summarizes the Company’s restricted stock awards activity for the nine months ended September 30, 2014:
		Restricted		Weighted Average Grant Date Fair Value
		Stock
	Balance at January 1, 2014	492,329		$	53.76
	Grants	158,390		$	70.03
	Forfeitures	(16,014	)	$	62.34
	Vested and issued	(217,603	)	$	47.71
	Balance at September 30, 2014	417,102		$	62.76
	Performance Share Awards
	Performance shares awarded under the plan are for a specified number of shares of common stock that entitle the holder to receive a cash payment, shares of common stock or a combination thereof. The final value of the award is determined by the achievement of certain performance objectives and market conditions. The awards vest at the end of a specified period, usually three years. Awards granted in 2014 were primarily deemed to be equity awards. The stock price and number of probable shares attributable to market conditions for such equity awards are fair valued only at the grant date. Performance shares awarded prior to 2014 are liability awards and are remeasured to fair value at each reporting period.
	The following table summarizes the Company’s performance share activity for the nine months ended September 30, 2014:
		Performance Shares		Weighted Average Grant Date Fair Value
	Balance at January 1, 2014	1,608,789		$	—
	Grants	548,892		$	69.24
	Forfeitures	(36,471	)	$	69.13
	Payouts	(571,177	)	$	—
	Balance at September 30, 2014	1,550,033		$	69.24
	Unrecognized Compensation Costs
	As of September 30, 2014, there was $72 million of total unrecognized compensation cost related to non-vested stock incentive plan arrangements. That cost is expected to be recognized over a weighted-average period of 1.24 years.

Segment_Information_Notes

Segment Information (Notes)	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Segment Information	'
	SEGMENT AND RELATED INFORMATION
	The Company sets strategic goals, allocates resources and evaluates performance based on the following structure:
	Electric segment consists principally of DTE Electric, which is engaged in the generation, purchase, distribution and sale of electricity to approximately 2.1 million residential, commercial and industrial customers in southeastern Michigan.
	Gas segment consists principally of DTE Gas, which is engaged in the purchase, storage, transportation, distribution and sale of natural gas to approximately 1.2 million residential, commercial and industrial customers throughout Michigan and the sale of storage and transportation capacity.
	Gas Storage and Pipelines consists of natural gas pipeline, gathering and storage businesses.
	Power and Industrial Projects is comprised primarily of projects that deliver energy and utility-type products and services to industrial, commercial and institutional customers; produce REF and sell electricity from biomass-fired energy projects.
	Energy Trading consists of energy marketing and trading operations.
	Corporate and Other, includes various holding company activities, holds certain non-utility debt and energy-related investments.
	The federal income tax provisions or benefits of DTE Energy’s subsidiaries are determined on an individual company basis and recognize the tax benefit of production tax credits and net operating losses if applicable. The state and local income tax provisions of the utility subsidiaries are determined on an individual company basis and recognize the tax benefit of various tax credits and net operating losses, if applicable. The subsidiaries record federal, state and local income taxes payable to or receivable from DTE Energy based on the federal, state and local tax provisions of each company.
	Inter-segment billing for goods and services exchanged between segments is based upon tariffed or market-based prices of the provider and primarily consists of the sale of reduced emissions fuel, power sales and natural gas sales in the following segments:
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
		(In millions)
	Inter-segment Revenues
	Electric	$	8		$	6		$	22		$	19
	Gas	1			2			5			4
	Gas Storage and Pipelines	1			(2		)	9			2
	Power and Industrial Projects	211			231			593			621
	Energy Trading	8			13			24			36
	Corporate and Other	1			(8		)	2			(23		)
		$	230		$	242		$	655		$	659
	Financial data of the business segments follows:
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
		(In millions)
	Operating Revenues
	Electric	$	1,358		$	1,458		$	4,049		$	3,942
	Gas	149			161			1,182			1,013
	Gas Storage and Pipelines	49			34			146			92
	Power and Industrial Projects	605			512			1,703			1,431
	Energy Trading	664			463			2,797			1,307
	Corporate and Other	—			1			1			2
	Reconciliation & Eliminations	(230		)	(242		)	(655		)	(659		)
	Total	$	2,595		$	2,387		$	9,223		$	7,128
	Net Income (Loss) Attributable to DTE Energy by Segment:
	Electric	$	135		$	179		$	400		$	383
	Gas	(16		)	(13		)	109			91
	Gas Storage and Pipelines	20			16			59			49
	Power and Industrial Projects	38			27			66			46
	Energy Trading	(22		)	(6		)	6			(1		)
	Corporate and Other	1			(5		)	(34		)	(31		)
	Net Income Attributable to DTE Energy Company	$	156		$	198		$	606		$	537

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Basis of Accounting, Policy [Policy Text Block]	'
	The accompanying Consolidated Financial Statements are prepared using accounting principles generally accepted in the United States of America. These accounting principles require management to use estimates and assumptions that impact reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from the Company’s estimates.
Comprehensive Income [Policy Text Block]	'
	Changes in accumulated other comprehensive loss are presented in the Consolidated Statements of Changes in Equity.
Intangible Assets [Policy Text Block]	'
	Emission allowances and renewable energy credits are charged to expense, using average cost, as the allowances and credits are consumed in the operation of the business. The Company amortizes contract intangible assets on a straight-line basis over the expected period of benefit
Fair Value Measurement, Policy [Policy Text Block]	'
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date in a principal or most advantageous market. Fair value is a market-based measurement that is determined based on inputs, which refer broadly to assumptions that market participants use in pricing assets or liabilities. These inputs can be readily observable, market corroborated or generally unobservable inputs. The Company makes certain assumptions it believes that market participants would use in pricing assets or liabilities, including assumptions about risk, and the risks inherent in the inputs to valuation techniques. Credit risk of the Company and its counterparties is incorporated in the valuation of assets and liabilities through the use of credit reserves, the impact of which was immaterial at September 30, 2014 and December 31, 2013. The Company believes it uses valuation techniques that maximize the use of observable market-based inputs and minimize the use of unobservable inputs.
	A fair value hierarchy has been established that prioritizes the inputs to valuation techniques used to measure fair value in three broad levels. The fair value hierarchy gives the highest priority to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). In some cases, the inputs used to measure fair value might fall in different levels of the fair value hierarchy. All assets and liabilities are required to be classified in their entirety based on the lowest level of input that is significant to the fair value measurement in its entirety. Assessing the significance of a particular input may require judgment considering factors specific to the asset or liability, and may affect the valuation of the asset or liability and its placement within the fair value hierarchy. The Company classifies fair value balances based on the fair value hierarchy defined as follows:
	•	Level 1 — Consists of unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access as of the reporting date.
	•	Level 2 — Consists of inputs other than quoted prices included within Level 1 that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data.
	•	Level 3 — Consists of unobservable inputs for assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost-benefit constraints.
Nuclear Decommissioning Trust and Other Investments, Policy [Policy Text Block]	'
	The nuclear decommissioning trusts and other investments hold debt and equity securities directly and indirectly through institutional mutual funds. Exchange-traded debt and equity securities held directly are valued using quoted market prices in actively traded markets. The institutional mutual funds hold exchange-traded equity or debt securities and are valued based on stated net asset values (NAV). Non-exchange-traded fixed income securities are valued based upon quotations available from brokers or pricing services. A primary price source is identified by asset type, class or issue for each security. The trustee monitors prices supplied by pricing services and may use a supplemental price source or change the primary price source of a given security if the trustee determines that another price source is considered to be preferable. DTE Energy has obtained an understanding of how these prices are derived, including the nature and observability of the inputs used in deriving such prices. Additionally, DTE Energy selectively corroborates the fair value of securities by comparison of market-based price sources. Investment policies and procedures are determined by the Company's Trust Investments Department which reports to the Company's Vice President and Treasurer.
Derivatives, Reporting of Derivative Activity [Policy Text Block]	'
	DTE Energy considers the following criteria in determining whether a market is considered active: frequency in which pricing information is updated, variability in pricing between sources or over time and the availability of public information. Other derivative contracts are valued based upon a variety of inputs including commodity market prices, broker quotes, interest rates, credit ratings, default rates, market-based seasonality and basis differential factors. DTE Energy monitors the prices that are supplied by brokers and pricing services and may use a supplemental price source or change the primary price source of an index if prices become unavailable or another price source is determined to be more representative of fair value. DTE Energy has obtained an understanding of how these prices are derived. Additionally, DTE Energy selectively corroborates the fair value of its transactions by comparison of market-based price sources. Mathematical valuation models are used for derivatives for which external market data is not readily observable, such as contracts which extend beyond the actively traded reporting period. The Company has established a Risk Management Committee whose responsibilities include directly or indirectly ensuring all valuation methods are applied in accordance with predefined policies. The development and maintenance of our forward price curves has been assigned to our Risk Management Department, which is separate and distinct from the trading functions within the Company.
Fair Value Transfer, Policy [Policy Text Block]	'
	Derivatives are transferred between levels primarily due to changes in the source data used to construct price curves as a result of changes in market liquidity. Transfers in and transfers out are reflected as if they had occurred at the beginning of the period.
Fair Value of Financial Instruments, Policy [Policy Text Block]	'
	The fair value of financial instruments included in the table below is determined by using quoted market prices when available. When quoted prices are not available, pricing services may be used to determine the fair value with reference to observable interest rate indexes. DTE Energy has obtained an understanding of how the fair values are derived. DTE Energy also selectively corroborates the fair value of its transactions by comparison of market-based price sources. Discounted cash flow analyses based upon estimated current borrowing rates are also used to determine fair value when quoted market prices are not available. The fair values of notes receivable, excluding capital leases, are estimated using discounted cash flow techniques that incorporate market interest rates as well as assumptions about the remaining life of the loans and credit risk. Depending on the information available, other valuation techniques may be used that rely on internal assumptions and models. Valuation policies and procedures are determined by DTE Energy's Treasury Department which reports to the Company's Vice President and Treasurer.
Derivatives, Policy [Policy Text Block]	'
	The Company recognizes all derivatives at their fair value as Derivative assets or liabilities on the Consolidated Statements of Financial Position unless they qualify for certain scope exceptions, including the normal purchases and normal sales exception. Further, derivatives that qualify and are designated for hedge accounting are classified as either hedges of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge), or as hedges of the fair value of a recognized asset or liability or of an unrecognized firm commitment (fair value hedge). For cash flow hedges, the portion of the derivative gain or loss that is effective in offsetting the change in the value of the underlying exposure is deferred in Accumulated other comprehensive income and later reclassified into earnings when the underlying transaction occurs. Gains or losses from the ineffective portion of cash flow hedges are recognized in earnings immediately. For fair value hedges, changes in fair values for the derivative and hedged item are recognized in earnings each period. For derivatives that do not qualify or are not designated for hedge accounting, changes in fair value are recognized in earnings each period.
	The Company’s primary market risk exposure is associated with commodity prices, credit, and interest rates. The Company has risk management policies to monitor and manage market risks. The Company uses derivative instruments to manage some of the exposure. The Company uses derivative instruments for trading purposes in its Energy Trading segment. Contracts classified as derivative instruments include electricity, natural gas, oil and certain coal forwards, futures, options and swaps, and foreign currency exchange contracts. Items not classified as derivatives include natural gas inventory, pipeline transportation contracts, renewable energy credits and natural gas storage assets.
Derivatives, Offsetting Fair Value Amounts, Policy [Policy Text Block]	'
	Certain of the Company's derivative positions are subject to netting arrangements which provide for offsetting of asset and liability positions as well as related cash collateral. Such netting arrangements generally do not have restrictions. Under such netting arrangements, the Company offsets the fair value of derivative instruments with cash collateral received or paid for those contracts executed with the same counterparty, which reduces the Company's total assets and liabilities. Cash collateral is allocated between the fair value of derivative instruments and customer accounts receivable and payable with the same counterparty on a pro rata basis to the extent there is exposure. Any cash collateral remaining, after the exposure is netted to zero, is reflected in accounts receivable and accounts payable as collateral paid or received, respectively.
	The Company also provides and receives collateral in the form of letters of credit which can be offset against net derivative assets and liabilities as well as accounts receivable and payable. The Company had issued letters of credit of approximately $21 million and $19 million at September 30, 2014 and December 31, 2013, respectively, which could be used to offset net derivative liabilities. Letters of credit received from third parties which could be used to offset our net derivative assets were not material for the periods presented. Such balances of letters of credit are excluded from the tables below and are not netted with the recognized assets and liabilities in the Consolidated Statements of Financial Position.
	For contracts with certain clearing agents the fair value of derivative instruments is netted against realized positions with the net balance reflected as either 1) a derivative asset or liability or 2) an account receivable or payable. Other than certain clearing agents, accounts receivable and accounts payable that are subject to netting arrangements have not been offset against the fair value of derivative assets and liabilities. Certain contracts that have netting arrangements have not been offset in the Consolidated Statements of Financial Position. The impact of netting these derivative instruments and cash collateral related to such contracts is not material. Only the gross amounts for these derivative instruments are included in the table below.
Derivatives, Methods of Accounting, Derivatives Not Designated or Qualifying as Hedges [Policy Text Block]	'
	Revenues and energy costs related to trading contracts are presented on a net basis in the Consolidated Statements of Operations. Commodity derivatives used for trading purposes, and financial non-trading commodity derivatives, are accounted for using the mark-to-market method with unrealized and realized gains and losses recorded in Operating revenues. Non-trading physical commodity sale and purchase derivative contracts are generally accounted for using the mark-to-market method with unrealized and realized gains and losses for sales recorded in Operating revenue and purchases recorded in Fuel, purchased power and gas.
Income Tax, Policy [Policy Text Block]	'
	The federal income tax provisions or benefits of DTE Energy’s subsidiaries are determined on an individual company basis and recognize the tax benefit of production tax credits and net operating losses if applicable. The state and local income tax provisions of the utility subsidiaries are determined on an individual company basis and recognize the tax benefit of various tax credits and net operating losses, if applicable. The subsidiaries record federal, state and local income taxes payable to or receivable from DTE Energy based on the federal, state and local tax provisions of each company.

Organization_and_Basis_of_Pres1

Organization and Basis of Presentation (Tables)	9 Months Ended
	Sep. 30, 2014
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]	'
Schedule of Variable Interest Entities [Table Text Block]	'
	The following table summarizes the major balance sheet items for consolidated VIEs as of September 30, 2014 and December 31, 2013. All assets and liabilities of a consolidated VIE are presented where it has been determined that a consolidated VIE has either (1) assets that can be used only to settle obligations of the VIE or (2) liabilities for which creditors do not have recourse to the general credit of the primary beneficiary. VIEs, in which the Company holds a majority voting interest and is the primary beneficiary, that meet the definition of a business and whose assets can be used for purposes other than the settlement of the VIE's obligations have been excluded from the table below.
		September 30, 2014						December 31, 2013
		Securitization		Other		Total		Securitization		Other		Total
		(In millions)
	ASSETS
	Cash and cash equivalents	$	—	$	12	$	12	$	—	$	12	$	12
	Restricted cash	40		6		46		100		8		108
	Accounts receivable	40		15		55		34		16		50
	Inventories	—		34		34		—		118		118
	Property, plant and equipment, net	—		84		84		—		99		99
	Securitized regulatory assets	86		—		86		231		—		231
	Other current and long-term assets	2		7		9		4		9		13
		$	168	$	158	$	326	$	369	$	262	$	631
	LIABILITIES
	Accounts payable and accrued current liabilities	$	1	$	9	$	10	$	7	$	23	$	30
	Current portion long-term debt, including capital leases	105		9		114		196		9		205
	Current regulatory liabilities	44		—		44		43		—		43
	Mortgage bonds, notes and other	—		17		17		—		21		21
	Securitization bonds	—		—		—		105		—		105
	Capital lease obligations	—		3		3		—		7		7
	Other current and long-term liabilities	9		5		14		8		6		14
		$	159	$	43	$	202	$	359	$	66	$	425
Summary of Amounts for Non-Consolidated Variable Interest Entities [Table Text Block]	'
	Amounts for non-consolidated VIEs as of September 30, 2014 and December 31, 2013 are as follows:
		30-Sep-14		31-Dec-13
		(In millions)
	Other investments	$	134	$	141
	Notes receivable	$	14	$	8

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2014
Accounting Policies [Abstract]	'
Schedule of Finite-Lived Intangible Assets by Major Class [Table Text Block]	'
	The Company has certain intangible assets relating to emission allowances, renewable energy credits and non-utility contracts as shown below:
		September 30, 2014		December 31, 2013
		(In millions)
	Emission allowances	$	1	$	2
	Renewable energy credits	50		51
	Contract intangible assets	123		126
		174		179
	Less accumulated amortization	54		45
	Intangible assets, net	120		134
	Less current intangible assets	12		12
		$	108	$	122

Fair_Value_Tables

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Assets and liabilities measured and recorded at fair value on a recurring basis	'
	The following table presents assets and liabilities measured and recorded at fair value on a recurring basis as of September 30, 2014 and December 31, 2013:
		30-Sep-14																			31-Dec-13
		Level 1			Level 2				Level 3				Netting (a)				Net Balance				Level 1				Level 2			Level 3			Netting (a)			Net Balance
		(In millions)
	Assets:
	Cash equivalents (b)	$	11		$	51			$	—			$	—			$	62			$	10			$	115		$	—		$	—		$	125
	Nuclear decommissioning trusts	789			440				—				—				1,229				779				412			—			—			1,191
	Other investments (c) (d)	95			51				—				—				146				92				44			—			—			136
	Derivative assets:
	Commodity Contracts:
	Natural Gas	118			98				38				(225		)		29				273				89			34			(382		)	14
	Electricity	—			312				74				(322		)		64				—				261			139			(291		)	109
	Other	46			2				4				(48		)		4				33				1			3			(34		)	3
	Other derivative contracts (e)	—			1				—				(1		)		—				—				—			—			—			—
	Total derivative assets	164			413				116				(596		)		97				306				351			176			(707		)	126
	Total	$	1,059		$	955			$	116			$	(596	)		$	1,534			$	1,187			$	922		$	176		$	(707	)	$	1,578
	Liabilities:
	Derivative liabilities:
	Commodity Contracts:
	Natural Gas	$	(129	)	$	(147	)		$	(66	)		$	268			$	(74	)		$	(277	)		$	(140	)	$	(86	)	$	395		$	(108	)
	Electricity	—			(303		)		(91		)		317				(77		)		—				(272		)	(126		)	269			(129		)
	Other	(39		)	(8		)		(1		)		48				—				(32		)		(2		)	—			34			—
	Other derivative contracts (e)	—			(3		)		—				1				(2		)		—				(1		)	—			—			(1		)
	Total derivative liabilities	(168		)	(461		)		(158		)		634				(153		)		(309		)		(415		)	(212		)	698			(238		)
	Total	$	(168	)	$	(461	)		$	(158	)		$	634			$	(153	)		$	(309	)		$	(415	)	$	(212	)	$	698		$	(238	)
	Net Assets (Liabilities) at the end of the period	$	891		$	494			$	(42	)		$	38			$	1,381			$	878			$	507		$	(36	)	$	(9	)	$	1,340
	Assets:
	Current	$	155		$	419			$	93			$	(537	)		$	130			$	277			$	400		$	139		$	(592	)	$	224
	Noncurrent (f)	904			536				23				(59		)		1,404				910				522			37			(115		)	1,354
	Total Assets	$	1,059		$	955			$	116			$	(596	)		$	1,534			$	1,187			$	922		$	176		$	(707	)	$	1,578
	Liabilities:
	Current	$	(146	)	$	(405	)		$	(145	)		$	562			$	(134	)		$	(268	)		$	(328	)	$	(177	)	$	578		$	(195	)
	Noncurrent	(22		)	(56		)		(13		)		72				(19		)		(41		)		(87		)	(35		)	120			(43		)
	Total Liabilities	$	(168	)	$	(461	)		$	(158	)		$	634			$	(153	)		$	(309	)		$	(415	)	$	(212	)	$	698		$	(238	)
	Net Assets (Liabilities) at the end of the period	$	891		$	494			$	(42	)		$	38			$	1,381			$	878			$	507		$	(36	)	$	(9	)	$	1,340
	_______________________________________
	(a)	Amounts represent the impact of master netting agreements that allow the Company to net gain and loss positions and cash collateral held or placed with the same counterparties.
	(b)	At September 30, 2014, available-for-sale securities of $62 million included $46 million and $16 million of cash equivalents included in Restricted cash and Other investments on the Consolidated Statements of Financial Position, respectively. At December 31, 2013, available-for-sale securities of $125 million, included $109 million and $16 million of cash equivalents included in Restricted cash and Other investments on the Consolidated Statements of Financial Position, respectively.
	(c)	Excludes cash surrender value of life insurance investments.
	(d)	Available-for-sale equity securities of $7 million at both September 30, 2014 and December 31, 2013, are included in Other investments on the Consolidated Statements of Financial Position.
	(e)	Primarily includes Foreign currency exchange contracts.
	(f)	Includes $146 million and $136 million at September 30, 2014 and December 31, 2013, respectively, of other investments that are included in the Consolidated Statements of Financial Position in Other investments.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	'
	The following tables present the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for the three and nine months ended September 30, 2014 and 2013:
		Three Months Ended September 30, 2014															Three Months Ended September 30, 2013
		Natural Gas			Electricity				Other				Total				Natural Gas				Electricity				Other			Total
		(In millions)
	Net Assets (Liabilities) as of June 30	$	(20	)	$	(27	)		$	7			$	(40	)		$	(30	)		$	12			$	2		$	(16	)
	Transfers into Level 3	1			—				—				1				—				—				—			—
	Transfers out of Level 3	(4		)	—				—				(4		)		—				(1		)		—			(1		)
	Total gains (losses):
	Included in earnings	(2		)	13				(1		)		10				8				17				—			25
	Recorded in regulatory assets/liabilities	—			—				(3		)		(3		)		—				—				3			3
	Purchases, issuances and settlements:
	Settlements	(3		)	(3		)		—				(6		)		8				(23		)		—			(15		)
	Net Assets (Liabilities) as of September 30	$	(28	)	$	(17	)		$	3			$	(42	)		$	(14	)		$	5			$	5		$	(4	)
	The amount of total gains (losses) included in net income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2014 and 2013 and reflected in Operating revenues and Fuel, purchased power and gas in the Consolidated Statements of Operations	$	(7	)	$	14			$	(1	)		$	6			$	(8	)		$	8			$	—		$	—
		Nine Months Ended September 30, 2014															Nine Months Ended September 30, 2013
		Natural Gas			Electricity				Other				Total				Natural Gas				Electricity				Other			Total
		(In millions)
	Net Assets (Liabilities) as of December 31	$	(52	)	$	13			$	3			$	(36	)		$	(38	)		$	23			$	2		$	(13	)
	Transfers into Level 3	—			—				—				—				—				—				—			—
	Transfers out of Level 3	2			—				—				2				(2		)		—				—			(2		)
	Total gains (losses):
	Included in earnings	(45		)	26				(2		)		(21		)		(1		)		44				—			43
	Recorded in regulatory assets/liabilities	—			—				9				9				—				—				7			7
	Purchases, issuances and settlements:
	Purchases	—			1				—				1				—				(1		)		—			(1		)
	Issuances	—			(2		)		—				(2		)		—				—				—			—
	Settlements	67			(55		)		(7		)		5				27				(61		)		(4		)	(38		)
	Net Assets (Liabilities) as of September 30	$	(28	)	$	(17	)		$	3			$	(42	)		$	(14	)		$	5			$	5		$	(4	)
	The amount of total gains (losses) included in net income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2014 and 2013 and reflected in Operating revenues and Fuel, purchased power and gas in the Consolidated Statements of Operations	$	(23	)	$	(6	)		$	(1	)		$	(30	)		$	(14	)		$	36			$	—		$	22
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Table Text Block]	'
	The following table presents the unobservable inputs related to Level 3 assets and liabilities as of September 30, 2014:
			September 30, 2014
	Commodity Contracts		Derivative Assets			Derivative Liabilities				Valuation Techniques		Unobservable Input		Range								Weighted Average
			(In millions)
	Natural Gas		$	38		$	(66	)		Discounted Cash Flow		Forward basis price (per MMBtu)		$	(2.28	) —		$	9.97	/MMBtu		$	(0.13	)/MMBtu
	Electricity		$	74		$	(91	)		Discounted Cash Flow		Forward basis price (per MWh)		$	(15	) —		$	24	/MWh		$	4	/MWh
	The following table presents the unobservable inputs related to Level 3 assets and liabilities as of December 31, 2013:
			December 31, 2013
	Commodity Contracts		Derivative Assets			Derivative Liabilities				Valuation Techniques		Unobservable Input		Range								Weighted Average
			(In millions)
	Natural Gas		$	34		$	(86	)		Discounted Cash Flow		Forward basis price (per MMBtu)		$	(0.88	) —		$	5.07	/MMBtu		$	(0.16	)/MMBtu
	Electricity		$	139		$	(126	)		Discounted Cash Flow		Forward basis price (per MWh)		$	(7	) —		$	15	/MWh		$	3	/MWh
Fair Value of Financial Instruments [Table Text Block]	'
	The following table presents the carrying amount and fair value of financial instruments as of September 30, 2014 and December 31, 2013:
		September 30, 2014															December 31, 2013
		Carrying			Fair Value												Carrying				Fair Value
		Amount			Level 1				Level 2				Level 3				Amount				Level 1				Level 2			Level 3
		(In millions)
	Notes receivable, excluding capital leases	$	45		$	—			$	—			$	45			$	41			$	—			$	—		$	41
	Dividends payable	$	122		$	122			$	—			$	—			$	116			$	116			$	—		$	—
	Short-term borrowings	$	653		$	—			$	653			$	—			$	131			$	—			$	131		$	—
	Long-term debt, excluding capital leases	$	8,171		$	474			$	7,107			$	1,412			$	8,094			$	425			$	7,551		$	499
Fair Value of Nuclear Decommissioning Trust Fund Assets [Table Text Block]	'
	The following table summarizes the fair value of the nuclear decommissioning trust fund assets:
		30-Sep-14			31-Dec-13
		(In millions)
	Fermi 2	$	1,205		$	1,172
	Fermi 1	3			3
	Low level radioactive waste	21			16
	Total	$	1,229		$	1,191
Schedule of Realized Gain (Loss) [Table Text Block]	'
	The following table sets forth the gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds:
		Three Months Ended September 30,							Nine Months Ended September 30,
		2014			2013				2014				2013
		(In millions)
	Realized gains	$	8		$	11			$	24			$	30
	Realized losses	$	(3	)	$	(11	)		$	(14	)		$	(25	)
	Proceeds from sales of securities	$	177		$	168			$	652			$	477
Fair Value and Unrealized Gains for Nuclear Decommissioning Trust Fund [Table Text Block]	'
	The following table sets forth the fair value and unrealized gains for the nuclear decommissioning trust funds:
		30-Sep-14							31-Dec-13
		Fair			Unrealized				Fair				Unrealized
		Value			Gains				Value				Gains
		(In millions)
	Equity securities	$	748		$	209			$	730			$	201
	Debt securities	465			18				442				12
	Cash and cash equivalents	16			—				19				—
		$	1,229		$	227			$	1,191			$	213

Financial_and_Other_Derivative1

Financial and Other Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Fair value of derivative instruments	'
	The following tables present the fair value of derivative instruments as of September 30, 2014 and December 31, 2013:
		September 30, 2014								December 31, 2013
		Derivative				Derivative Liabilities				Derivative				Derivative Liabilities
		Assets								Assets
		(In millions)
	Derivatives not designated as hedging instruments:
	Foreign currency exchange contracts	$	1			$	(3	)		$	—			$	(1	)
	Commodity Contracts:
	Natural Gas	254				(342		)		396				(503		)
	Electricity	386				(394		)		400				(398		)
	Other	52				(48		)		37				(34		)
	Total derivatives not designated as hedging instruments:	$	693			$	(787	)		$	833			$	(936	)
	Total derivatives:
	Current	$	605			$	(696	)		$	691			$	(773	)
	Noncurrent	88				(91		)		142				(163		)
	Total derivatives	$	693			$	(787	)		$	833			$	(936	)
Netting Offsets of Derivative Assets and Liabilities [Table Text Block]	'
	The following table presents the netting offsets of derivative assets and liabilities at September 30, 2014 and December 31, 2013:
		30-Sep-14												31-Dec-13
		Gross Amounts of Recognized Assets (Liabilities)				Gross Amounts Offset in the Consolidated Statements of Financial Position				Net Amounts of Assets (Liabilities) Presented in the Consolidated Statements of Financial Position				Gross Amounts of Recognized Assets (Liabilities)				Gross Amounts Offset in the Consolidated Statements of Financial Position			Net Amounts of Assets (Liabilities) Presented in the Consolidated Statements of Financial Position
		(In millions)
	Derivative assets:
	Commodity Contracts:
	Natural Gas	$	254			$	(225	)		$	29			$	396			$	(382	)	$	14
	Electricity	386				(322		)		64				400				(291		)	109
	Other	52				(48		)		4				37				(34		)	3
	Other derivative contracts (a)	1				(1		)		—				—				—			—
	Total derivative assets	$	693			$	(596	)		$	97			$	833			$	(707	)	$	126
	Derivative liabilities:
	Commodity Contracts:
	Natural Gas	$	(342	)		$	268			$	(74	)		$	(503	)		$	395		$	(108	)
	Electricity	(394		)		317				(77		)		(398		)		269			(129		)
	Other	(48		)		48				—				(34		)		34			—
	Other derivative contracts (a)	(3		)		1				(2		)		(1		)		—			(1		)
	Total derivative liabilities	$	(787	)		$	634			$	(153	)		$	(936	)		$	698		$	(238	)
	_______________________________________
	(a)	Primarily includes Foreign currency exchange contracts.
Netting Offsets of Derivative Assets and Liabilities Reconciliation to the Statements of Financial Position [Table Text Block]	'
	The following table presents the netting offsets of derivative assets and liabilities at September 30, 2014 and December 31, 2013:
		September 30, 2014																31-Dec-13
		Derivative Assets								Derivative Liabilities								Derivative Assets						Derivative Liabilities
		Current				Noncurrent				Current				Noncurrent				Current			Noncurrent			Current			Noncurrent
		(In millions)
	Reconciliation of derivative instruments to Consolidated Statements of Financial Position:
	Total fair value of derivatives	$	605			$	88			$	(696	)		$	(91	)		$	691		$	142		$	(773	)	$	(163	)
	Counterparty netting	(533		)		(59		)		533				59				(566		)	(115		)	566			115
	Collateral adjustment	(4		)		—				29				13				(26		)	—			12			5
	Total derivatives as reported	$	68			$	29			$	(134	)		$	(19	)		$	99		$	27		$	(195	)	$	(43	)
Gain (Loss) Recognized in Income on Derivative	'
	The effect of derivatives not designated as hedging instruments on the Consolidated Statements of Operations for the three and nine months ended September 30, 2014 and 2013 is as follows:
			Location of Gain		Gain (Loss)								Gain (Loss)
			(Loss) Recognized		Recognized in								Recognized in
			in Income on Derivatives		Income on								Income on
					Derivatives for								Derivatives for
					the Three Months Ended September 30,								the Nine Months Ended September 30,
	Derivatives not Designated as Hedging Instruments				2014				2013				2014				2013
					(In millions)
	Foreign currency exchange contracts		Operating Revenue		$	(1	)		$	—			$	(2	)		$	(1	)
	Commodity Contracts:
	Natural Gas		Operating Revenue		(38		)		1				(10		)		37
	Natural Gas		Fuel, purchased power and gas		12				(1		)		23				(33		)
	Electricity		Operating Revenue		12				22				100				52
	Other		Operating Revenue		(1		)		1				(5		)		1
	Total				$	(16	)		$	23			$	106			$	56
Volume of Commodity Contracts [Table Text Block]	'
	The following represents the cumulative gross volume of derivative contracts outstanding as of September 30, 2014:
	Commodity		Number of Units
	Natural Gas (MMBtu)		865,462,971
	Electricity (MWh)		15,291,188
	Oil (Gallons)		10,290,000
	Foreign Currency Exchange (Canadian dollars)		81,310,582

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	9 Months Ended
	Sep. 30, 2014
Asset Retirement Obligation Disclosure [Abstract]	'
Schedule of Change in Asset Retirement Obligation [Table Text Block]	'
	A reconciliation of the asset retirement obligations for the nine months ended September 30, 2014 follows:
		(In millions)
	Asset retirement obligations at December 31, 2013	$	1,827
	Accretion	84
	Liabilities incurred	11
	Liabilities settled	(5		)
	Revision in estimated cash flows	(6		)
	Asset retirement obligations at September 30, 2014	$	1,911

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings Per Share [Abstract]	'
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	'
	A reconciliation of both calculations is presented in the following table for the three and nine months ended September 30:
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
		(In millions, except per share amounts)
	Basic Earnings per Share
	Net income attributable to DTE Energy Company	$	156	$	198	$	606	$	537
	Average number of common shares outstanding	177		175		177		174
	Weighted average net restricted shares outstanding	—		—		—		1
	Dividends declared — common shares	$	122	$	115	$	353	$	337
	Dividends declared — net restricted shares	—		1		1		1
	Total distributed earnings	$	122	$	116	$	354	$	338
	Net income less distributed earnings	$	34	$	82	$	252	$	199
	Distributed (dividends per common share)	$	0.69	$	0.66	$	2	$	1.93
	Undistributed	0.19		0.47		1.42		1.14
	Total Basic Earnings per Common Share	$	0.88	$	1.13	$	3.42	$	3.07
	Diluted Earnings per Share
	Net income attributable to DTE Energy Company	$	156	$	198	$	606	$	537
	Average number of common shares outstanding	177		176		177		175
	Weighted average net restricted shares outstanding	—		—		—		1
	Dividends declared — common shares	$	122	$	115	$	353	$	337
	Dividends declared — net restricted shares	—		1		1		1
	Total distributed earnings	$	122	$	116	$	354	$	338
	Net income less distributed earnings	$	34	$	82	$	252	$	199
	Distributed (dividends per common share)	$	0.69	$	0.66	$	2	$	1.93
	Undistributed	0.19		0.47		1.42		1.14
	Total Diluted Earnings per Common Share	$	0.88	$	1.13	$	3.42	$	3.07

LongTerm_Debt_Tables

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2014
Long-term Debt, Unclassified [Abstract]	'
Schedule of Issued Debt [Table Text Block]	'
	In 2014, the following debt was issued:
	Company		Month	Type	Interest Rate	Maturity	Amount
							(In millions)
	DTE Energy		May	Senior Notes (a)	3.50%	2024	$	350
	DTE Electric		June	Mortgage Bonds (a)	3.77%	2026	100
	DTE Electric		June	Mortgage Bonds (a)	4.60%	2044	150
	DTE Electric		July	Mortgage Bonds (a)	3.38%	2025	350
	DTE Electric		July	Mortgage Bonds (a)	4.30%	2044	350
							$	1,300
	_______________________________________
	(a)	Proceeds were used for the redemption of long-term debt, for the repayment of short-term borrowings and for general corporate purposes.
Schedule of Debt Redemptions [Table Text Block]	'
	In 2014, the following debt was redeemed:
	Company		Month	Type	Interest Rate	Maturity	Amount
							(In millions)
	DTE Electric		March	Mortgage Bonds	Various	2014	$	13
	DTE Electric		March	Securitization Bonds	6.62%	2014	100
	DTE Electric		April	Tax Exempt Revenue Bonds (a)	2.35%	2024	31
	DTE Electric		April	Tax Exempt Revenue Bonds (a)	4.65%	2028	32
	DTE Gas		May	Mortgage Bonds	8.25%	2014	80
	DTE Energy		May	Senior Notes	7.63%	2014	300
	DTE Electric		June	Tax Exempt Revenue Bonds (a)	4.88%	2029	36
	DTE Electric		June	Tax Exempt Revenue Bonds (a)	6.00%	2036	69
	DTE Electric		July	Senior Notes	4.80%	2015	200
	DTE Electric		August	Senior Notes	5.40%	2014	200
	DTE Electric		August	Tax Exempt Revenue Bonds (a)	5.25%	2029	60
	DTE Electric		September	Securitization Bonds	6.62%	2014	96
	DTE Energy		Various	Other Long Term Debt	Various	2014	5
							$	1,222
	_______________________________________
	(a)	DTE Electric Tax Exempt Revenue Bonds are issued by a public body that loans the proceeds to DTE Electric on terms substantially mirroring the Tax Exempt Revenue Bonds.

ShortTerm_Credit_Arrangements_1

Short-Term Credit Arrangements and Borrowings (Tables)	9 Months Ended
	Sep. 30, 2014
Short-term Debt [Abstract]	'
Schedule of Line of Credit Facilities [Table Text Block]	'
	The availability under the facilities in place at September 30, 2014 is shown in the following table:
		DTE Energy		DTE Electric		DTE Gas		Total
		(In millions)
	Unsecured letter of credit facility, expiring in February 2015	$	100	$	—	$	—	$	100
	Unsecured letter of credit facility, expiring in August 2015	125		—		—		125
	Unsecured revolving credit facility, expiring April 2018	1,200		300		300		1,800
		1,425		300		300		2,025
	Amounts outstanding at September 30, 2014:
	Commercial paper issuances	207		254		192		653
	Letters of credit	200		—		—		200
		407		254		192		853
	Net availability at September 30, 2014	$	1,018	$	46	$	108	$	1,172

Retirement_Benefits_and_Truste1

Retirement Benefits and Trusteed Assets (Tables)	9 Months Ended
	Sep. 30, 2014
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]	'
Schedule of Costs of Retirement Plans [Table Text Block]	'
	The following table details the components of net periodic benefit costs for pension benefits and other postretirement benefits:
		Pension Benefits						Other Postretirement Benefits
		2014			2013			2014			2013
	Three Months Ended September 30	(In millions)
	Service cost	$	19		$	22		$	8		$	9
	Interest cost	54			49			22			21
	Expected return on plan assets	(69		)	(67		)	(31		)	(28		)
	Amortization of:
	Net actuarial loss	42			55			4			16
	Prior service credit	—			—			(36		)	(36		)
	Net periodic benefit cost (credit)	$	46		$	59		$	(33	)	$	(18	)
		Pension Benefits						Other Postretirement Benefits
		2014			2013			2014			2013
	Nine Months Ended September 30	(In millions)
	Service cost	$	62		$	71		$	26		$	37
	Interest cost	159			144			67			66
	Expected return on plan assets	(205		)	(200		)	(92		)	(82		)
	Amortization of:
	Net actuarial loss	118			156			15			48
	Prior service credit	—			—			(108		)	(95		)
	Net periodic benefit cost (credit)	$	134		$	171		$	(92	)	$	(26	)

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2014
Share-based Compensation [Abstract]	'
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]	'
	The following table summarizes the components of stock-based compensation:
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014		2013
		(In millions)
	Stock-based compensation expense	$	22		$	18		$	72	$	81
	Tax benefit	$	8		$	7		$	27	$	31
	Stock-based compensation cost capitalized in property, plant and equipment	$	4		$	1		$	11	$	5
Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]	'
	The following table summarizes our stock option activity for the nine months ended September 30, 2014:
		Number of		Weighted			Aggregate
		Options		Average			Intrinsic Value
				Exercise Price			(In millions)
	Options outstanding at January 1, 2014	723,697		$	42.6
	Exercised	(232,751	)	$	41.44
	Forfeited or expired	(10,730	)	$	39.41
	Options outstanding and exercisable at September 30, 2014	480,216		$	43.24		$	16
Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]	'
	The following table summarizes the Company’s restricted stock awards activity for the nine months ended September 30, 2014:
		Restricted		Weighted Average Grant Date Fair Value
		Stock
	Balance at January 1, 2014	492,329		$	53.76
	Grants	158,390		$	70.03
	Forfeitures	(16,014	)	$	62.34
	Vested and issued	(217,603	)	$	47.71
	Balance at September 30, 2014	417,102		$	62.76
	Performance Share Awards
	Performance shares awarded under the plan are for a specified number of shares of common stock that entitle the holder to receive a cash payment, shares of common stock or a combination thereof. The final value of the award is determined by the achievement of certain performance objectives and market conditions. The awards vest at the end of a specified period, usually three years. Awards granted in 2014 were primarily deemed to be equity awards. The stock price and number of probable shares attributable to market conditions for such equity awards are fair valued only at the grant date. Performance shares awarded prior to 2014 are liability awards and are remeasured to fair value at each reporting period.
	The following table summarizes the Company’s performance share activity for the nine months ended September 30, 2014:
		Performance Shares		Weighted Average Grant Date Fair Value
	Balance at January 1, 2014	1,608,789		$	—
	Grants	548,892		$	69.24
	Forfeitures	(36,471	)	$	69.13
	Payouts	(571,177	)	$	—
	Balance at September 30, 2014	1,550,033		$	69.24

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Reconciliation of Revenue from Segments to Consolidated [Table Text Block]	'
	Inter-segment billing for goods and services exchanged between segments is based upon tariffed or market-based prices of the provider and primarily consists of the sale of reduced emissions fuel, power sales and natural gas sales in the following segments:
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
		(In millions)
	Inter-segment Revenues
	Electric	$	8		$	6		$	22		$	19
	Gas	1			2			5			4
	Gas Storage and Pipelines	1			(2		)	9			2
	Power and Industrial Projects	211			231			593			621
	Energy Trading	8			13			24			36
	Corporate and Other	1			(8		)	2			(23		)
		$	230		$	242		$	655		$	659
	Financial data of the business segments follows:
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
		(In millions)
	Operating Revenues
	Electric	$	1,358		$	1,458		$	4,049		$	3,942
	Gas	149			161			1,182			1,013
	Gas Storage and Pipelines	49			34			146			92
	Power and Industrial Projects	605			512			1,703			1,431
	Energy Trading	664			463			2,797			1,307
	Corporate and Other	—			1			1			2
	Reconciliation & Eliminations	(230		)	(242		)	(655		)	(659		)
	Total	$	2,595		$	2,387		$	9,223		$	7,128
Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table Text Block]	'
	Net Income (Loss) Attributable to DTE Energy by Segment:
	Electric	$	135		$	179		$	400		$	383
	Gas	(16		)	(13		)	109			91
	Gas Storage and Pipelines	20			16			59			49
	Power and Industrial Projects	38			27			66			46
	Energy Trading	(22		)	(6		)	6			(1		)
	Corporate and Other	1			(5		)	(34		)	(31		)
	Net Income Attributable to DTE Energy Company	$	156		$	198		$	606		$	537

Organization_and_Basis_of_Pres2

Organization and Basis of Presentation (Consolidated Variable Interest Entities) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Assets [Abstract]	'	'	'	'
Cash and cash equivalents	$60	$52	$71	$65
Restricted cash	61	123	'	'
Accounts receivable	1,257	1,542	'	'
Property, plant and equipment, net	16,499	15,800	'	'
Securitized regulatory assets, noncurrent	86	231	'	'
Total Assets	26,376	25,935	'	'
Liabilities [Abstract]	'	'	'	'
Current portion long-term debt, including, capital leases	274	898	'	'
Current regulatory liabilities	164	302	'	'
Mortgage bonds, notes and other	7,426	6,618	'	'
Capital lease obligations	3	11	'	'
Variable Interest Entity, Primary Beneficiary Securitization [Member]	'	'	'	'
Assets [Abstract]	'	'	'	'
Cash and cash equivalents	0	0	'	'
Restricted cash	40	100	'	'
Accounts receivable	40	34	'	'
Inventories	0	0	'	'
Property, plant and equipment, net	0	0	'	'
Securitized regulatory assets, noncurrent	86	231	'	'
Other current and long-term assets	2	4	'	'
Total Assets	168	369	'	'
Liabilities [Abstract]	'	'	'	'
Accounts payable and accrued current liabilities	1	7	'	'
Current portion long-term debt, including, capital leases	105	196	'	'
Current regulatory liabilities	44	43	'	'
Mortgage bonds, notes and other	0	0	'	'
Securitization bonds	0	105	'	'
Capital lease obligations	0	0	'	'
Other current and long-term liabilities	9	8	'	'
Total Liabilities	159	359	'	'
Variable Interest Entity, Primary Beneficiary Other [Member]	'	'	'	'
Assets [Abstract]	'	'	'	'
Cash and cash equivalents	12	12	'	'
Restricted cash	6	8	'	'
Accounts receivable	15	16	'	'
Inventories	34	118	'	'
Property, plant and equipment, net	84	99	'	'
Securitized regulatory assets, noncurrent	0	0	'	'
Other current and long-term assets	7	9	'	'
Total Assets	158	262	'	'
Liabilities [Abstract]	'	'	'	'
Accounts payable and accrued current liabilities	9	23	'	'
Current portion long-term debt, including, capital leases	9	9	'	'
Current regulatory liabilities	0	0	'	'
Mortgage bonds, notes and other	17	21	'	'
Securitization bonds	0	0	'	'
Capital lease obligations	3	7	'	'
Other current and long-term liabilities	5	6	'	'
Total Liabilities	43	66	'	'
Variable Interest Entity, Primary Beneficiary [Member]	'	'	'	'
Assets [Abstract]	'	'	'	'
Cash and cash equivalents	12	12	'	'
Restricted cash	46	108	'	'
Accounts receivable	55	50	'	'
Inventories	34	118	'	'
Property, plant and equipment, net	84	99	'	'
Securitized regulatory assets, noncurrent	86	231	'	'
Other current and long-term assets	9	13	'	'
Total Assets	326	631	'	'
Liabilities [Abstract]	'	'	'	'
Accounts payable and accrued current liabilities	10	30	'	'
Current portion long-term debt, including, capital leases	114	205	'	'
Current regulatory liabilities	44	43	'	'
Mortgage bonds, notes and other	17	21	'	'
Securitization bonds	0	105	'	'
Capital lease obligations	3	7	'	'
Other current and long-term liabilities	14	14	'	'
Total Liabilities	$202	$425	'	'

Organization_and_Basis_of_Pres3

Organization and Basis of Presentation (Non Consolidated Variable Interest Entities) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Variable Interest Entity [Line Items]	'	'
Notes receivable	$87	$102
Variable Interest Entity, Not Primary Beneficiary [Member]	'	'
Variable Interest Entity [Line Items]	'	'
Other Investments	134	141
Notes receivable	$14	$8

Organization_and_Basis_of_Pres4

Organization and Basis of Presentation (Details Textuals) (USD $)	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2013
In Millions, unless otherwise specified	customers	Proceeds from sale of nuclear decommissioning trust funds [Member]	Investment in nuclear decommissioning trust funds [Member]
Number of Electric Customers	2,100,000	'	'
Number of Gas Customers	1,200,000	'	'
Prior Period Reclassification Adjustment	'	$437	($437)
Significant Potential Exposure to Loss Due to VIE Long-Term Purchase Contracts	$0	'	'

Significant_Accounting_Policie3

Significant Accounting Policies (Intangible Assets) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Gross	$174	$179
Less: Accumulated Amortization	54	45
Intangible Assets, Net	120	134
Less current intangible assets	12	12
Finite-Lived Intangible Assets, Net	108	122
Emission Allowances [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Gross	1	2
Renewable Energy Credits [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Gross	50	51
Contract Intangible Assets [Member]	'	'
Finite-Lived Intangible Assets [Line Items]	'	'
Intangible Assets, Gross	$123	$126

Significant_Accounting_Policie4

Significant Accounting Policies (Details Textuals) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Significant Accounting Policies [Line Items]	'	'	'	'
Other Nonoperating Income	$55	$58	$136	$148
Effective Income Tax Rate, Continuing Operations	12.00%	28.00%	27.00%	29.00%
Other Information Pertaining to Income Taxes	'	'	'The 16% decrease in the effective tax rate for the three months ended September 30, 2014 is due to higher production tax credits. The 2% decrease in effective tax rate for the nine months ended September 30, 2014 is due to higher production tax credits, partially offset by $8 million of deferred tax expense resulting from New York state income tax reform enacted on March 31, 2014.	'
Unrecognized Tax Benefits that would impact Effective Tax Rate	2	'	2	'
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecognized Benefit	1	'	1	'
Minimum [Member]	'	'	'	'
Significant Accounting Policies [Line Items]	'	'	'	'
Finite Lived Asset Useful Life	'	'	'1 year	'
Maximum [Member]	'	'	'	'
Significant Accounting Policies [Line Items]	'	'	'	'
Finite Lived Asset Useful Life	'	'	'28 years	'
Power and Industrial Projects [Member]	'	'	'	'
Significant Accounting Policies [Line Items]	'	'	'	'
Other Nonoperating Income	$25	$25	$57	$60

Fair_Value_Assets_and_Liabilit

Fair Value (Assets and Liabilities Recorded at Fair Value on a Recurring Basis) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets [Abstract]	'	'
Nuclear decommissioning trusts	$1,229	$1,191
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	693	833
Derivative Assets, Net	97	126
Liabilities [Abstract]	'	'
Derivative Liability, Gross	787	936
Derivative Liabilities, Net	-153	-238
Fair Value, Measurements, Recurring [Member]	'	'
Assets [Abstract]	'	'
Cash and Cash Equivalents	62	125
Nuclear decommissioning trusts	1,229	1,191
Other Investments	146	136
Derivative assets [Abstract]	'	'
Derivative Assets, Net	97	126
Assets, Fair Value Disclosure	1,534	1,578
Liabilities [Abstract]	'	'
Derivative Liabilities, Net	-153	-238
Fair Value, Net Asset (Liability)	1,381	1,340
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]	'	'
Assets [Abstract]	'	'
Cash and Cash Equivalents	11	10
Nuclear decommissioning trusts	789	779
Other Investments	95	92
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	164	306
Assets, Fair Value Disclosure	1,059	1,187
Liabilities [Abstract]	'	'
Derivative Liability, Gross	168	309
Fair Value, Net Asset (Liability)	891	878
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Assets [Abstract]	'	'
Cash and Cash Equivalents	51	115
Nuclear decommissioning trusts	440	412
Other Investments	51	44
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	413	351
Assets, Fair Value Disclosure	955	922
Liabilities [Abstract]	'	'
Derivative Liability, Gross	461	415
Fair Value, Net Asset (Liability)	494	507
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Assets [Abstract]	'	'
Cash and Cash Equivalents	0	0
Nuclear decommissioning trusts	0	0
Other Investments	0	0
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	116	176
Assets, Fair Value Disclosure	116	176
Liabilities [Abstract]	'	'
Derivative Liability, Gross	158	212
Fair Value, Net Asset (Liability)	-42	-36
Current Asset [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Derivative assets [Abstract]	'	'
Assets, Fair Value Disclosure	130	224
Current Asset [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]	'	'
Derivative assets [Abstract]	'	'
Assets, Fair Value Disclosure	155	277
Current Asset [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Derivative assets [Abstract]	'	'
Assets, Fair Value Disclosure	419	400
Current Asset [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Derivative assets [Abstract]	'	'
Assets, Fair Value Disclosure	93	139
Non Current Asset [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Derivative assets [Abstract]	'	'
Assets, Fair Value Disclosure	1,404	1,354
Non Current Asset [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]	'	'
Derivative assets [Abstract]	'	'
Assets, Fair Value Disclosure	904	910
Non Current Asset [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Derivative assets [Abstract]	'	'
Assets, Fair Value Disclosure	536	522
Non Current Asset [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Derivative assets [Abstract]	'	'
Assets, Fair Value Disclosure	23	37
Current Derivative Liability [Member]	'	'
Liabilities [Abstract]	'	'
Derivative Liability, Gross	696	773
Current Derivative Liability [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Liabilities [Abstract]	'	'
Derivative Liabilities, Net	-134	-195
Current Derivative Liability [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]	'	'
Liabilities [Abstract]	'	'
Derivative Liability, Gross	146	268
Current Derivative Liability [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Liabilities [Abstract]	'	'
Derivative Liability, Gross	405	328
Current Derivative Liability [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Liabilities [Abstract]	'	'
Derivative Liability, Gross	145	177
Noncurrent Derivative Liability [Member]	'	'
Liabilities [Abstract]	'	'
Derivative Liability, Gross	91	163
Noncurrent Derivative Liability [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Liabilities [Abstract]	'	'
Derivative Liabilities, Net	-19	-43
Noncurrent Derivative Liability [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]	'	'
Liabilities [Abstract]	'	'
Derivative Liability, Gross	22	41
Noncurrent Derivative Liability [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Liabilities [Abstract]	'	'
Derivative Liability, Gross	56	87
Noncurrent Derivative Liability [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Liabilities [Abstract]	'	'
Derivative Liability, Gross	13	35
Fair Value, Master Netting Arrangements [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	-596	-707
Liabilities [Abstract]	'	'
Derivative Liability, Gross	-634	-698
Fair Value, Master Netting Arrangements [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	-596	-707
Assets, Fair Value Disclosure	-596	-707
Liabilities [Abstract]	'	'
Derivative Liability, Gross	-634	-698
Fair Value, Net Asset (Liability)	-38	9
Fair Value, Master Netting Arrangements [Member] | Current Asset [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Derivative assets [Abstract]	'	'
Assets, Fair Value Disclosure	-537	-592
Fair Value, Master Netting Arrangements [Member] | Non Current Asset [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Derivative assets [Abstract]	'	'
Assets, Fair Value Disclosure	-59	-115
Fair Value, Master Netting Arrangements [Member] | Current Derivative Liability [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Liabilities [Abstract]	'	'
Derivative Liability, Gross	-562	-578
Fair Value, Master Netting Arrangements [Member] | Noncurrent Derivative Liability [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Liabilities [Abstract]	'	'
Derivative Liability, Gross	-72	-120
Natural Gas Commodity Contract [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	254	396
Derivative Assets, Net	29	14
Liabilities [Abstract]	'	'
Derivative Liability, Gross	342	503
Derivative Liabilities, Net	-74	-108
Natural Gas Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Assets, Net	29	14
Liabilities [Abstract]	'	'
Derivative Liabilities, Net	-74	-108
Natural Gas Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	118	273
Liabilities [Abstract]	'	'
Derivative Liability, Gross	129	277
Natural Gas Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	98	89
Liabilities [Abstract]	'	'
Derivative Liability, Gross	147	140
Natural Gas Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	38	34
Liabilities [Abstract]	'	'
Derivative Liability, Gross	66	86
Natural Gas Commodity Contract [Member] | Fair Value, Master Netting Arrangements [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	-225	-382
Liabilities [Abstract]	'	'
Derivative Liability, Gross	-268	-395
Natural Gas Commodity Contract [Member] | Fair Value, Master Netting Arrangements [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	-225	-382
Liabilities [Abstract]	'	'
Derivative Liability, Gross	-268	-395
Electricity Commodity Contract [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	386	400
Derivative Assets, Net	64	109
Liabilities [Abstract]	'	'
Derivative Liability, Gross	394	398
Derivative Liabilities, Net	-77	-129
Electricity Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Assets, Net	64	109
Liabilities [Abstract]	'	'
Derivative Liabilities, Net	-77	-129
Electricity Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	0	0
Liabilities [Abstract]	'	'
Derivative Liability, Gross	0	0
Electricity Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	312	261
Liabilities [Abstract]	'	'
Derivative Liability, Gross	303	272
Electricity Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	74	139
Liabilities [Abstract]	'	'
Derivative Liability, Gross	91	126
Electricity Commodity Contract [Member] | Fair Value, Master Netting Arrangements [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	-322	-291
Liabilities [Abstract]	'	'
Derivative Liability, Gross	-317	-269
Electricity Commodity Contract [Member] | Fair Value, Master Netting Arrangements [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	-322	-291
Liabilities [Abstract]	'	'
Derivative Liability, Gross	-317	-269
Other Commodity Contract [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	52	37
Derivative Assets, Net	4	3
Liabilities [Abstract]	'	'
Derivative Liability, Gross	48	34
Derivative Liabilities, Net	0	0
Other Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Assets, Net	4	3
Liabilities [Abstract]	'	'
Derivative Liabilities, Net	0	0
Other Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	46	33
Liabilities [Abstract]	'	'
Derivative Liability, Gross	39	32
Other Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	2	1
Liabilities [Abstract]	'	'
Derivative Liability, Gross	8	2
Other Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	4	3
Liabilities [Abstract]	'	'
Derivative Liability, Gross	1	0
Other Commodity Contract [Member] | Fair Value, Master Netting Arrangements [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	-48	-34
Liabilities [Abstract]	'	'
Derivative Liability, Gross	-48	-34
Other Commodity Contract [Member] | Fair Value, Master Netting Arrangements [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	-48	-34
Liabilities [Abstract]	'	'
Derivative Liability, Gross	-48	-34
Other Derivative Contract [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	1	0
Derivative Assets, Net	0	0
Liabilities [Abstract]	'	'
Derivative Liability, Gross	3	1
Derivative Liabilities, Net	-2	-1
Other Derivative Contract [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Assets, Net	0	0
Liabilities [Abstract]	'	'
Derivative Liabilities, Net	-2	-1
Other Derivative Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	0	0
Liabilities [Abstract]	'	'
Derivative Liability, Gross	0	0
Other Derivative Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	1	0
Liabilities [Abstract]	'	'
Derivative Liability, Gross	3	1
Other Derivative Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	0	0
Liabilities [Abstract]	'	'
Derivative Liability, Gross	0	0
Other Derivative Contract [Member] | Fair Value, Master Netting Arrangements [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	-1	0
Liabilities [Abstract]	'	'
Derivative Liability, Gross	-1	0
Other Derivative Contract [Member] | Fair Value, Master Netting Arrangements [Member] | Fair Value, Measurements, Recurring [Member]	'	'
Derivative assets [Abstract]	'	'
Derivative Asset, Gross	-1	0
Liabilities [Abstract]	'	'
Derivative Liability, Gross	($1)	$0

Fair_Value_Reconciliation_of_L

Fair Value (Reconciliation of Level 3 Assets and Liabilities at Fair Value on a Recurring Basis) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis	'	'	'	'
Beginning Balance	($40)	($16)	($36)	($13)
Transfers into Level 3	1	0	0	0
Transfer out of Level 3	-4	-1	2	-2
Total gains (losses): [Abstract]	'	'	'	'
Included in earnings	10	25	-21	43
Recorded in regulatory assets/liabilities	-3	3	9	7
Purchases issuances and settlements [Abstract]	'	'	'	'
Purchases	'	'	1	-1
Issuances	'	'	-2	0
Settlements	-6	-15	5	-38
Ending Balance	-42	-4	-42	-4
The amount of total gains (losses) included in net income attributed to the change in unrealized gains or losses related to assets still held at the end of the period	6	0	-30	22
Natural Gas Commodity Contract [Member]	'	'	'	'
Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis	'	'	'	'
Beginning Balance	-20	-30	-52	-38
Transfers into Level 3	1	0	0	0
Transfer out of Level 3	-4	0	2	-2
Total gains (losses): [Abstract]	'	'	'	'
Included in earnings	-2	8	-45	-1
Recorded in regulatory assets/liabilities	0	0	0	0
Purchases issuances and settlements [Abstract]	'	'	'	'
Purchases	'	'	0	0
Issuances	'	'	0	0
Settlements	-3	8	67	27
Ending Balance	-28	-14	-28	-14
The amount of total gains (losses) included in net income attributed to the change in unrealized gains or losses related to assets still held at the end of the period	-7	-8	-23	-14
Electricity Commodity Contract [Member]	'	'	'	'
Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis	'	'	'	'
Beginning Balance	-27	12	13	23
Transfers into Level 3	0	0	0	0
Transfer out of Level 3	0	-1	0	0
Total gains (losses): [Abstract]	'	'	'	'
Included in earnings	13	17	26	44
Recorded in regulatory assets/liabilities	0	0	0	0
Purchases issuances and settlements [Abstract]	'	'	'	'
Purchases	'	'	1	-1
Issuances	'	'	-2	0
Settlements	-3	-23	-55	-61
Ending Balance	-17	5	-17	5
The amount of total gains (losses) included in net income attributed to the change in unrealized gains or losses related to assets still held at the end of the period	14	8	-6	36
Other Commodity Contract [Member]	'	'	'	'
Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis	'	'	'	'
Beginning Balance	7	2	3	2
Transfers into Level 3	0	0	0	0
Transfer out of Level 3	0	0	0	0
Total gains (losses): [Abstract]	'	'	'	'
Included in earnings	-1	0	-2	0
Recorded in regulatory assets/liabilities	-3	3	9	7
Purchases issuances and settlements [Abstract]	'	'	'	'
Purchases	'	'	0	0
Issuances	'	'	0	0
Settlements	0	0	-7	-4
Ending Balance	3	5	3	5
The amount of total gains (losses) included in net income attributed to the change in unrealized gains or losses related to assets still held at the end of the period	($1)	$0	($1)	$0

Fair_Value_Unobservable_Inputs

Fair Value (Unobservable Inputs related to Level 3 Assets and Liabilities) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Unobservable Inputs Valuation Techniques [Line Items]	'	'
Derivative Asset, Gross	$693	$833
Derivative Liability, Gross	-787	-936
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Unobservable Inputs Valuation Techniques [Line Items]	'	'
Derivative Asset, Gross	116	176
Derivative Liability, Gross	-158	-212
Electricity Commodity Contract [Member]	'	'
Unobservable Inputs Valuation Techniques [Line Items]	'	'
Derivative Asset, Gross	386	400
Derivative Liability, Gross	-394	-398
Electricity Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Unobservable Inputs Valuation Techniques [Line Items]	'	'
Derivative Asset, Gross	74	139
Derivative Liability, Gross	-91	-126
Natural Gas Commodity Contract [Member]	'	'
Unobservable Inputs Valuation Techniques [Line Items]	'	'
Derivative Asset, Gross	254	396
Derivative Liability, Gross	-342	-503
Natural Gas Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Unobservable Inputs Valuation Techniques [Line Items]	'	'
Derivative Asset, Gross	38	34
Derivative Liability, Gross	($66)	($86)
Discounted cash flow valuation technique [Member] | Electricity Commodity Contract [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Unobservable Inputs Valuation Techniques [Line Items]	'	'
Forward basis price	-15	-7
Discounted cash flow valuation technique [Member] | Electricity Commodity Contract [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Unobservable Inputs Valuation Techniques [Line Items]	'	'
Forward basis price	24	15
Discounted cash flow valuation technique [Member] | Electricity Commodity Contract [Member] | Weighted Average [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Unobservable Inputs Valuation Techniques [Line Items]	'	'
Forward basis price	4	3
Discounted cash flow valuation technique [Member] | Natural Gas Commodity Contract [Member] | Minimum [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Unobservable Inputs Valuation Techniques [Line Items]	'	'
Forward basis price	-2.28	-0.88
Discounted cash flow valuation technique [Member] | Natural Gas Commodity Contract [Member] | Maximum [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Unobservable Inputs Valuation Techniques [Line Items]	'	'
Forward basis price	9.97	5.07
Discounted cash flow valuation technique [Member] | Natural Gas Commodity Contract [Member] | Weighted Average [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Unobservable Inputs Valuation Techniques [Line Items]	'	'
Forward basis price	-0.13	-0.16

Fair_Value_Fair_Value_of_Finan

Fair Value (Fair Value of Financial Instruments) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Notes Receivable, Excluding Capital Leases	$45	$41
Dividends payable	122	116
Short-term Debt	653	131
Long-term Debt, excluding capital leases	8,171	8,094
Fair Value, Inputs, Level 1 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Notes Receivable, excluding capital leases, Fair Value	0	0
Dividends Payable Fair Value	122	116
Short-term Debt, Fair Value	0	0
Long-term Debt, excluding capital leases, Fair Value	474	425
Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Notes Receivable, excluding capital leases, Fair Value	0	0
Dividends Payable Fair Value	0	0
Short-term Debt, Fair Value	653	131
Long-term Debt, excluding capital leases, Fair Value	7,107	7,551
Fair Value, Inputs, Level 3 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Notes Receivable, excluding capital leases, Fair Value	45	41
Dividends Payable Fair Value	0	0
Short-term Debt, Fair Value	0	0
Long-term Debt, excluding capital leases, Fair Value	$1,412	$499

Fair_Value_Fair_Value_of_Nucle

Fair Value (Fair Value of Nuclear Decommissioning Trust Fund Assets) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]	'	'
Decommissioning Fund Investments	$1,229	$1,191
Fermi 2 [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Decommissioning Fund Investments	1,205	1,172
Fermi 1 [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Decommissioning Fund Investments	3	3
Low Level Radioactive Waste [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Decommissioning Fund Investments	21	16
Nuclear Decommissioning Trust Fund [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Decommissioning Fund Investments	$1,229	$1,191

Fair_Value_Gains_and_Losses_an

Fair Value (Gains and Losses and Proceeds from the Sale of Securities by the Nuclear Trust Funds) (Details) (Nuclear Decommissioning Trust Fund [Member], USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Nuclear Decommissioning Trust Fund [Member]	'	'	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Realized gains	$8	$11	$24	$30
Realized losses	-3	-11	-14	-25
Proceeds from sales of securities	$177	$168	$652	$477

Fair_Value_Fair_Value_and_Unre

Fair Value (Fair Value and Unrealized Gains for the Nuclear Decommissioning Trust Funds) (Details) (USD $)	9 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]	'	'
Nuclear decommissioning trusts	$1,229	$1,191
Unrealized Gains	227	213
Nuclear Decommissioning Trust Fund [Member]	'	'
Schedule of Available-for-sale Securities [Line Items]	'	'
Equity securities	748	730
Debt securities	465	442
Cash and Cash Equivalents	16	19
Available-for-sale Equity Securities, Gross Unrealized Gain	209	201
Available-for-sale Debt Securities Gross Unrealized Gain	$18	$12

Fair_Value_Details_Textuals

Fair Value (Details Textuals) (USD $)

9 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Accumulated Net Unrealized Investment Gain (Loss) [Member]

Fermi 2 [Member]

Fermi 2 [Member]

Nuclear Decommissioning Trust Fund [Member]

Nuclear Decommissioning Trust Fund [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Restricted Assets [Member]

Restricted Assets [Member]

Other Investments [Member]

Other Investments [Member]

Other Investments [Member]

Other Investments [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Fair Value, Measurements, Recurring [Member]

Equity [Member]

Equity [Member]

Fair Value, Option, Quantitative Disclosures [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Cash and Cash Equivalents, Fair Value Disclosure

'

'

'

'

'

'

'

'

$16

$19

$62

$125

$46

$109

$16

$16

'

'

Available-for-sale Securities, Fair Value Disclosure

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7

7

Other investments

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

146

136

Fair Value, Assets, Level 1 to Level 2 Transfers, Amount

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair Value, Assets, Level 2 to Level 1 Transfers, Amount

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair Value, Liabilities, Level 1 to Level 2 Transfers, Amount

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair Value, Liabilities, Level 2 to Level 1 Transfers, Amount

0

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Average Maturity of Debt Securities

'

'

'

'

'

'

'

'

'7 years

'7 years

'

'

'

'

'

'

'

'

Unrealized losses recognized as regulatory assets

'

'

'

'

'

'

37

31

'

'

'

'

'

'

'

'

'

'

Unrealized losses on Available for Sale Securities

'

'

0

0

0

0

'

'

'

'

'

'

'

'

'

'

'

'

Trading Securities, Realized Gain (Loss)

$9

$14

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Financial_and_Other_Derivative2

Financial and Other Derivative Instruments (Fair Value of Derivative Instruments) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Gross	$693	$833
Derivative Liability, Gross	-787	-936
Natural Gas Commodity Contract [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Gross	254	396
Derivative Liability, Gross	-342	-503
Electricity Commodity Contract [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Gross	386	400
Derivative Liability, Gross	-394	-398
Other Commodity Contract [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Gross	52	37
Derivative Liability, Gross	-48	-34
Not Designated as Hedging Instrument [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Gross	693	833
Derivative Liability, Gross	-787	-936
Not Designated as Hedging Instrument [Member] | Foreign currency exchange contracts [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Gross	1	0
Derivative Liability, Gross	-3	-1
Not Designated as Hedging Instrument [Member] | Natural Gas Commodity Contract [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Gross	254	396
Derivative Liability, Gross	-342	-503
Not Designated as Hedging Instrument [Member] | Electricity Commodity Contract [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Gross	386	400
Derivative Liability, Gross	-394	-398
Not Designated as Hedging Instrument [Member] | Other Commodity Contract [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Gross	52	37
Derivative Liability, Gross	-48	-34
Current Derivative Asset [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Gross	605	691
Current Derivative Liability [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Liability, Gross	-696	-773
Noncurrent Derivative Asset [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Asset, Gross	88	142
Noncurrent Derivative Liability [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative Liability, Gross	($91)	($163)

Financial_and_Other_Derivative3

Financial and Other Derivative Instruments Financial and Other Derivative Instruments (Netting Offsets of Derivative Assets and Liabilities) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Offsetting Assets [Line Items]	'	'
Fair Value, Gross Amount of Recognized Asset	$693	$833
Net Amounts of Assets Presented in the Statements of Financial Position	97	126
Fair Value Gross Amounts of Recognized (Liabilities)	-787	-936
Net Amounts of (Liabilities) Presented in the Statements of Financial Position	-153	-238
Natural Gas Commodity Contract [Member]	'	'
Offsetting Assets [Line Items]	'	'
Fair Value, Gross Amount of Recognized Asset	254	396
Net Amounts of Assets Presented in the Statements of Financial Position	29	14
Fair Value Gross Amounts of Recognized (Liabilities)	-342	-503
Net Amounts of (Liabilities) Presented in the Statements of Financial Position	-74	-108
Electricity Commodity Contract [Member]	'	'
Offsetting Assets [Line Items]	'	'
Fair Value, Gross Amount of Recognized Asset	386	400
Net Amounts of Assets Presented in the Statements of Financial Position	64	109
Fair Value Gross Amounts of Recognized (Liabilities)	-394	-398
Net Amounts of (Liabilities) Presented in the Statements of Financial Position	-77	-129
Other Commodity Contract [Member]	'	'
Offsetting Assets [Line Items]	'	'
Fair Value, Gross Amount of Recognized Asset	52	37
Net Amounts of Assets Presented in the Statements of Financial Position	4	3
Fair Value Gross Amounts of Recognized (Liabilities)	-48	-34
Net Amounts of (Liabilities) Presented in the Statements of Financial Position	0	0
Other Derivative Contract [Member]	'	'
Offsetting Assets [Line Items]	'	'
Fair Value, Gross Amount of Recognized Asset	1	0
Net Amounts of Assets Presented in the Statements of Financial Position	0	0
Fair Value Gross Amounts of Recognized (Liabilities)	-3	-1
Net Amounts of (Liabilities) Presented in the Statements of Financial Position	-2	-1
Fair Value, Master Netting Arrangements [Member]	'	'
Offsetting Assets [Line Items]	'	'
Fair Value, Gross Amount of Recognized Asset	-596	-707
Fair Value Gross Amounts of Recognized (Liabilities)	634	698
Fair Value, Master Netting Arrangements [Member] | Natural Gas Commodity Contract [Member]	'	'
Offsetting Assets [Line Items]	'	'
Fair Value, Gross Amount of Recognized Asset	-225	-382
Fair Value Gross Amounts of Recognized (Liabilities)	268	395
Fair Value, Master Netting Arrangements [Member] | Electricity Commodity Contract [Member]	'	'
Offsetting Assets [Line Items]	'	'
Fair Value, Gross Amount of Recognized Asset	-322	-291
Fair Value Gross Amounts of Recognized (Liabilities)	317	269
Fair Value, Master Netting Arrangements [Member] | Other Commodity Contract [Member]	'	'
Offsetting Assets [Line Items]	'	'
Fair Value, Gross Amount of Recognized Asset	-48	-34
Fair Value Gross Amounts of Recognized (Liabilities)	48	34
Fair Value, Master Netting Arrangements [Member] | Other Derivative Contract [Member]	'	'
Offsetting Assets [Line Items]	'	'
Fair Value, Gross Amount of Recognized Asset	-1	0
Fair Value Gross Amounts of Recognized (Liabilities)	$1	$0

Financial_and_Other_Derivative4

Financial and Other Derivative Instruments Financial and Other Derivative Instruments (Netting Offsets Reconciliation to Balance Sheet) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Derivative [Line Items]	'	'
Derivative Asset, Gross	$693	$833
Derivative Liability, Gross	-787	-936
Derivative Assets, Current	68	99
Derivative Assets, Noncurrent	29	27
Derivative Liabilities, Current	-134	-195
Derivative Liabilities, Noncurrent	-19	-43
Current Derivative Asset [Member]	'	'
Derivative [Line Items]	'	'
Derivative Asset, Gross	605	691
Noncurrent Derivative Asset [Member]	'	'
Derivative [Line Items]	'	'
Derivative Asset, Gross	88	142
Current Derivative Liability [Member]	'	'
Derivative [Line Items]	'	'
Derivative Liability, Gross	-696	-773
Noncurrent Derivative Liability [Member]	'	'
Derivative [Line Items]	'	'
Derivative Liability, Gross	-91	-163
Collateral Adjustment [Member] | Current Derivative Asset [Member]	'	'
Derivative [Line Items]	'	'
Derivative Asset, Gross	-4	-26
Collateral Adjustment [Member] | Noncurrent Derivative Asset [Member]	'	'
Derivative [Line Items]	'	'
Derivative Asset, Gross	0	0
Collateral Adjustment [Member] | Current Derivative Liability [Member]	'	'
Derivative [Line Items]	'	'
Derivative Liability, Gross	29	12
Collateral Adjustment [Member] | Noncurrent Derivative Liability [Member]	'	'
Derivative [Line Items]	'	'
Derivative Liability, Gross	13	5
Counterparty Netting [Member] | Current Derivative Asset [Member]	'	'
Derivative [Line Items]	'	'
Derivative Asset, Gross	-533	-566
Counterparty Netting [Member] | Noncurrent Derivative Asset [Member]	'	'
Derivative [Line Items]	'	'
Derivative Asset, Gross	-59	-115
Counterparty Netting [Member] | Current Derivative Liability [Member]	'	'
Derivative [Line Items]	'	'
Derivative Liability, Gross	533	566
Counterparty Netting [Member] | Noncurrent Derivative Liability [Member]	'	'
Derivative [Line Items]	'	'
Derivative Liability, Gross	$59	$115

Financial_and_Other_Derivative5

Financial and Other Derivative Instruments (Effect of Derviatives not Designated as Hedging Instruments on the Consolidated Statement of Operations) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	($16)	$23	$106	$56
Foreign currency exchange contracts [Member] | Operating Revenue [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	-1	0	-2	-1
Natural Gas Commodity Contract [Member] | Operating Revenue [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	-38	1	-10	37
Natural Gas Commodity Contract [Member] | Fuel, purchased power and gas [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	12	-1	23	-33
Electricity Commodity Contract [Member] | Operating Revenue [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	12	22	100	52
Other Commodity Contract [Member] | Operating Revenue [Member]	'	'	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'	'	'
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	($1)	$1	($5)	$1

Financial_and_Other_Derivative6

Financial and Other Derivative Instruments (Cumulative Gross Volume of Derivative Contracts Outstanding) (Details)	Sep. 30, 2014
	MMBTU
Natural Gas Commodity Contract [Member]	'
Derivative [Line Items]	'
Derivative, Number of Instruments Held	865,462,971
Electricity Commodity Contract [Member]	'
Derivative [Line Items]	'
Derivative, Number of Instruments Held	15,291,188
Oil Commodity Contract [Member]	'
Derivative [Line Items]	'
Derivative, Number of Instruments Held	10,290,000
Foreign currency exchange contracts [Member]	'
Derivative [Line Items]	'
Derivative, Number of Instruments Held	81,310,582

Financial_and_Other_Derivative7

Financial and Other Derivative Instruments (Details Textuals) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'	'
Letters of credit that could be used to offset net derivative liabilities	$21	$19
Cash Collateral Posted Net of Cash Collateral Received	40	12
Cash Collateral Paid or Received for Derivative Assets	4	26
Cash Collateral Paid or Received for Derivative Liabilities	42	17
Cash Collateral Received	2	13
Cash Collateral Paid	4	34
Derivative, Net Liability Position, Aggregate Fair Value	894	'
Collateral Already Posted, Aggregate Fair Value	13	'
Derivative, Net Asset Position, Aggregate Fair Value	744	'
Remaining amount of offsets to derivative net liability positions for hard and soft trigger provisions	137	'
Additional Collateral, Aggregate Fair Value	$327	'

Asset_Retirement_Obligations_D

Asset Retirement Obligations (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
Asset Retirement Obligation Disclosure [Abstract]	'
Asset retirement obligations	$1,827
Accretion	84
Liabilities Incurred	11
Liabilities Settled	-5
Revision in estimated cash flows	-6
Asset retirement obligations	$1,911

Regulatory_Matters_Details_Tex

Regulatory Matters (Details Textuals) (Electric [Member], USD $)	Sep. 30, 2014	Jul. 30, 2012	Mar. 31, 2013	Jan. 02, 2014	Sep. 30, 2012
In Millions, unless otherwise specified			MPSC [Member]	MPSC [Member]	Refundable Revenue Decoupling [Member]
Public Utilities, General Disclosures [Line Items]	'	'	'	'	'
Defer the Reversal of RDM Liability	'	'	'	'	$127
Monthly Amount to Amortize from Liability to Income	'	'	'	10.6	'
PSCR Under-Recovery from Two Plan Years Prior	'	'	87	'	'
PSCR under-recovery from Three Plan Years Prior	'	'	148	'	'
Fermi 2 Production Level of Full Capacity	'	68.00%	'	'	'
Maximum of challenged Fermi 2 outage charges	$32	'	'	'	'

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Basic Earnings per Share	'	'	'	'
Net Income Attributable to DTE Energy Company	$156	$198	$606	$537
Average number of common shares outstanding	177	175	177	174
Weighted average net restricted shares outstanding	0	0	0	1
Dividends declared - common shares	122	115	353	337
Dividends declared - net restricted shares	0	1	1	1
Total distributed earnings	122	116	354	338
Net income less distributed earnings	34	82	252	199
Distributed (dividends per common share)	$0.69	$0.66	$2	$1.93
Undistributed	$0.19	$0.47	$1.42	$1.14
Total Basic Earnings per Common Share	$0.88	$1.13	$3.42	$3.07
Diluted Earnings per Share	'	'	'	'
Net Income Attributable to DTE Energy Company	156	198	606	537
Common shares for dilutive calculation	177	176	177	175
Weighted average net restricted shares outstanding	0	0	0	1
Dividends declared - common shares	122	115	353	337
Dividends declared - net restricted shares	0	1	1	1
Total distributed earnings	122	116	354	338
Net income less distributed earnings	$34	$82	$252	$199
Distributed (dividends per common share)	$0.69	$0.66	$2	$1.93
Undistributed	$0.19	$0.47	$1.42	$1.14
Total Diluted Earnings per Common Share	$0.88	$1.13	$3.42	$3.07

LongTerm_Debt_Debt_Issuances_D

Long-Term Debt (Debt Issuances) (Details) (USD $)	Sep. 30, 2014
In Millions, unless otherwise specified
Debt Instrument [Line Items]	'
Debt Instrument, Face Amount	$1,300
DTE Energy [Member] | Senior Notes [Member] | May 2014 3.50% Senior Notes Maturing in 2024 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	3.50%
Debt Instrument, Face Amount	350
Electric [Member] | Mortgages [Member] | June 2014 3.77% Mortgage Bonds Maturing in 2026 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	3.77%
Debt Instrument, Face Amount	100
Electric [Member] | Mortgages [Member] | June 2014 4.60% Mortgage Bonds Maturing in 2044 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	4.60%
Debt Instrument, Face Amount	150
Electric [Member] | Mortgages [Member] | July 2014 3.375% Mortgage Bonds Maturing in 2025 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	3.38%
Debt Instrument, Face Amount	350
Electric [Member] | Mortgages [Member] | July 2014 4.30% Mortgage Bonds Maturing in 2044 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	4.30%
Debt Instrument, Face Amount	$350

LongTerm_Debt_Debt_Redemptions

Long-Term Debt (Debt Redemptions) (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
Debt Instrument [Line Items]	'
Extinguishment of Debt, Amount	$1,222
Mortgages [Member] | Electric [Member] | March 2014 Mortgage Bonds Various Interest Rates Maturing in 2014 [Member]	'
Debt Instrument [Line Items]	'
Extinguishment of Debt, Amount	13
Mortgages [Member] | Gas [Member] | May 2014 Mortgage Bonds 8.25% Maturing in 2014 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	8.25%
Extinguishment of Debt, Amount	80
Securitization Bonds [Member] | Electric [Member] | March 2014 Securitization Bonds 6.62% Maturing in 2014 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	6.62%
Extinguishment of Debt, Amount	100
Securitization Bonds [Member] | Electric [Member] | September 2014 Securitization Bonds 6.62% Maturing in 2014 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	6.62%
Extinguishment of Debt, Amount	96
Tax Exempt Revenue Bonds [Member] | Electric [Member] | April 2014 Tax Exempt Revenue Bonds 2.35% Maturing in 2024 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	2.35%
Extinguishment of Debt, Amount	31
Tax Exempt Revenue Bonds [Member] | Electric [Member] | April 2014 Tax Exempt Revenue Bonds 4.65% Maturing in 2028 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	4.65%
Extinguishment of Debt, Amount	32
Tax Exempt Revenue Bonds [Member] | Electric [Member] | June 2014 Tax Exempt Revenue Bonds 4.875% Maturing in 2029 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	4.88%
Extinguishment of Debt, Amount	36
Tax Exempt Revenue Bonds [Member] | Electric [Member] | June 2014 Tax Exempt Revenue Bonds 6.00% Maturing in 2036 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	6.00%
Extinguishment of Debt, Amount	69
Tax Exempt Revenue Bonds [Member] | Electric [Member] | August 2014 Tax Exempt Revenue Bonds 5.25% Maturing in 2029 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	5.25%
Extinguishment of Debt, Amount	60
Senior Notes [Member] | DTE Energy [Member] | May 2014 Senior Notes 7.625% Maturing in 2014 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	7.63%
Extinguishment of Debt, Amount	300
Senior Notes [Member] | Electric [Member] | July 2014 Senior Notes 4.80% Maturing in 2015 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	4.80%
Extinguishment of Debt, Amount	200
Senior Notes [Member] | Electric [Member] | August 2014 Senior Notes 5.40% Maturing in 2014 [Member]	'
Debt Instrument [Line Items]	'
Debt Instrument, Interest Rate, Stated Percentage	5.40%
Extinguishment of Debt, Amount	200
Long Term Debt, Other [Member] | DTE Energy [Member]	'
Debt Instrument [Line Items]	'
Extinguishment of Debt, Amount	$5

LongTerm_Debt_Details_Textuals

Long-Term Debt (Details Textuals) (USD $)	Sep. 30, 2014	Dec. 31, 2014
In Millions, unless otherwise specified		December 2014 4.35% Mortgage Bonds Maturing in 2044 [Member]
		Subsequent Event [Member]
		Gas [Member]
		Mortgages [Member]
Debt Instrument [Line Items]	'	'
Debt Instrument, Face Amount	$1,300	$150
Debt Instrument, Interest Rate, Stated Percentage	'	4.35%

ShortTerm_Credit_Arrangements_2

Short-Term Credit Arrangements and Borrowings (Details) (USD $)	Sep. 30, 2014
In Millions, unless otherwise specified
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	$2,025
Amounts Outstanding	853
Net availability	1,172
DTE Energy [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	1,425
Amounts Outstanding	407
Net availability	1,018
Electric [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	300
Amounts Outstanding	254
Net availability	46
Gas [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	300
Amounts Outstanding	192
Net availability	108
Letter of Credit [Member]	'
Availability under combined facilities	'
Amounts Outstanding	200
Letter of Credit [Member] | Unsecured letter of credit, expiring in February 2015 [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	100
Letter of Credit [Member] | Unsecured letter of credit facility expiring in August 2015 [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	125
Letter of Credit [Member] | DTE Energy [Member]	'
Availability under combined facilities	'
Amounts Outstanding	200
Letter of Credit [Member] | DTE Energy [Member] | Unsecured letter of credit, expiring in February 2015 [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	100
Letter of Credit [Member] | DTE Energy [Member] | Unsecured letter of credit facility expiring in August 2015 [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	125
Letter of Credit [Member] | Electric [Member]	'
Availability under combined facilities	'
Amounts Outstanding	0
Letter of Credit [Member] | Electric [Member] | Unsecured letter of credit, expiring in February 2015 [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	0
Letter of Credit [Member] | Electric [Member] | Unsecured letter of credit facility expiring in August 2015 [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	0
Letter of Credit [Member] | Gas [Member]	'
Availability under combined facilities	'
Amounts Outstanding	0
Letter of Credit [Member] | Gas [Member] | Unsecured letter of credit, expiring in February 2015 [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	0
Letter of Credit [Member] | Gas [Member] | Unsecured letter of credit facility expiring in August 2015 [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	0
Revolving Credit Facility [Member] | Unsecured revolving credit facility expiring in April 2018 [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	1,800
Revolving Credit Facility [Member] | DTE Energy [Member] | Unsecured revolving credit facility expiring in April 2018 [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	1,200
Revolving Credit Facility [Member] | Electric [Member] | Unsecured revolving credit facility expiring in April 2018 [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	300
Revolving Credit Facility [Member] | Gas [Member] | Unsecured revolving credit facility expiring in April 2018 [Member]	'
Availability under combined facilities	'
Line of Credit Facility, Maximum Borrowing Capacity	300
Commercial Paper [Member]	'
Availability under combined facilities	'
Amounts Outstanding	653
Commercial Paper [Member] | DTE Energy [Member]	'
Availability under combined facilities	'
Amounts Outstanding	207
Commercial Paper [Member] | Electric [Member]	'
Availability under combined facilities	'
Amounts Outstanding	254
Commercial Paper [Member] | Gas [Member]	'
Availability under combined facilities	'
Amounts Outstanding	$192

ShortTerm_Credit_Arrangements_3

Short-Term Credit Arrangements and Borrowings (Details Textuals) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Short-term Debt [Line Items]	'	'
Revolving Credit Facilities with a Syndicate Number of Banks	19	'
Number of Banks that Provide Percentage of Commitment in any Facility	1	'
Maximum Percentage of Commitment to Bank in any Facility	8.70%	'
Maximum Total Funded Debt to Total Capitalization Ratio	0.65	'
Other outstanding letters of credit	$853	'
DTE Energy [Member]	'	'
Short-term Debt [Line Items]	'	'
Total Funded Debt to Total Capitalization Ratio, Amount	0.49	'
Other outstanding letters of credit	407	'
Electric [Member]	'	'
Short-term Debt [Line Items]	'	'
Total Funded Debt to Total Capitalization Ratio, Amount	0.52	'
Other outstanding letters of credit	254	'
Gas [Member]	'	'
Short-term Debt [Line Items]	'	'
Total Funded Debt to Total Capitalization Ratio, Amount	0.45	'
Other outstanding letters of credit	192	'
Letter of Credit [Member]	'	'
Short-term Debt [Line Items]	'	'
Other outstanding letters of credit	200	'
Letter of Credit [Member] | DTE Energy [Member]	'	'
Short-term Debt [Line Items]	'	'
Other outstanding letters of credit	200	'
Letter of Credit [Member] | Electric [Member]	'	'
Short-term Debt [Line Items]	'	'
Other outstanding letters of credit	0	'
Letter of Credit [Member] | Gas [Member]	'	'
Short-term Debt [Line Items]	'	'
Other outstanding letters of credit	0	'
Demand Financing Agreement with Newedge plus letter of credit [Member] | DTE Energy [Member]	'	'
Short-term Debt [Line Items]	'	'
Financing Agreement, Maximum Borrowing Capacity	150	'
Demand Financing Agreement with Newedge [Member] | DTE Energy [Member]	'	'
Short-term Debt [Line Items]	'	'
Financing Agreement, Maximum Borrowing Capacity	100	'
Maximum Additional Margin Financing	50	'
Financing Agreement, Amount Outstanding	78	138
Other outstanding letters of credit [Member] | Letter of Credit [Member] | DTE Energy [Member]	'	'
Short-term Debt [Line Items]	'	'
Other outstanding letters of credit	35	'
Demand Financing Agreement with Newedge letter of credit to raise capacity [Member] | Letter of Credit [Member] | DTE Energy [Member]	'	'
Short-term Debt [Line Items]	'	'
Financing Agreement, Maximum Borrowing Capacity	$50	'

Commitments_and_Contingencies_1

Commitments and Contingencies (Details Textuals) (USD $)

1 Months Ended

9 Months Ended

0 Months Ended

3 Months Ended

5 Months Ended

4 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

Apr. 30, 2014

Sep. 30, 2014

Dec. 31, 2010

19-May-14

Dec. 30, 2013

Dec. 31, 2013

Sep. 30, 2014

15-May-14

Sep. 30, 2014

Mar. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 30, 2014

dte_instances

Electric [Member]

Electric [Member]

Electric [Member]

Electric [Member]

Electric [Member]

Electric [Member]

Electric [Member]

Gas [Member]

Gas [Member]

Cleanup completed and site closed [Member]

Complete closure expected by end of fiscal year [Member]

Partial closure expected by end of fiscal year [Member]

Synthetic Fuel [Member]

Emissions [Member]

Guarantee Type, Other [Member]

Performance Surety Bonds [Member]

Represented Employees [Member]

kWh

kWh

facilities

dte_instances

facilities

Gas [Member]

Gas [Member]

Gas [Member]

employees

facilities

dte_instances

facilities

facilities

facilities

dte_instances

Loss Contingencies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Environmental Capital Expenditures Through Prior Year End

'

'

'

'

'

'

'

'

$2,000,000,000

'

'

'

'

'

'

'

'

'

'

'

Environmental Capital Expenditures in Current Year

'

'

'

'

'

'

'

'

200,000,000

'

'

'

'

'

'

'

'

'

'

'

Environmental Capital Expenditures In Future Years

'

'

'

'

'

'

'

'

1,200,000,000

'

'

'

'

'

'

'

'

'

'

'

EPA is Alleging Detroit Edison Power Plants Violated New Source Performance Standards

'

'

'

'

'

'

5

'

5

'

'

'

'

'

'

'

'

'

'

'

Number of NOVs/FOVs currently being discussed with the EPA

'

'

'

'

'

'

2

'

2

'

'

'

'

'

'

'

'

'

'

'

Sierra Club is Alleging DTE Electric Coal Fired Power Plants Violated the Clean Air Act

'

'

'

'

'

'

4

'

4

'

'

'

'

'

'

'

'

'

'

'

Exceedances of Opacity Standard

'

'

'

'

'

'

1,139

'

1,139

1,499

'

'

'

'

'

'

'

'

'

'

Period of excess opacity of air emissions at alleged facilities

'

'

'

'

'

'

'

'

'6 minutes

'

'

'

'

'

'

'

'

'

'

'

Time period to complete studies on cooling water intake structures impacts on fish - EPA ruling

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of Former MGP Sites

'

'

'

'

'

'

'

'

3

'

15

'

2

2

2

'

'

'

'

'

Accrual for Environmental Loss Contingencies, Gross

'

'

'

'

'

8,000,000

10,000,000

'

10,000,000

'

26,000,000

28,000,000

'

'

'

'

'

'

'

'

Number of Options to Regulate Coal Ash Residue

'

'

'

'

'

'

2

'

2

'

'

'

'

'

'

'

'

'

'

'

Period Gas Utility Can Amortize MGP Costs

'

'

'

'

'

'

'

'

'

'

'10 years

'

'

'

'

'

'

'

'

'

Number of NOVs

'

'

2

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Possible Environmental Capital Expenditures to Comply with Requirements

'

2,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Estimated maximum spend to upgrade treatment technology to biological treatment to meet future requirements

'

13,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Length of Notice of Intent to sue from the Group Against Smog and Pollution

'

'60 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fine related to consent order and agreement with Allegheny County related to NOV

300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Estimated expenditures for a supplemental environmental project to enhance particulate collection efficiency

'

300,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

EPA Sulfur Dioxide Ambient Air Quality Standard

'

'1 hour

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Waiting Period of Policy

'

'84 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Insurance Coverage for Extra ExpenseWhen to Necessitate Power Plant when Unavailable

'

'

'

'

'

'

'

'

490,000,000

'

'

'

'

'

'

'

'

'

'

'

Period of Coverage of Policy for Extra Expenses

'

'

'

'

'

'

'

'

'3 years

'

'

'

'

'

'

'

'

'

'

'

Primary Coverage

'

'

'

'

'

'

'

'

1,500,000,000

'

'

'

'

'

'

'

'

'

'

'

Coverage for Stabilization Decontamination Debris Removal Repair and Replacement of Property and Decommissioning

'

'

'

'

'

'

'

'

1,250,000,000

'

'

'

'

'

'

'

'

'

'

'

Combined Coverage Limit for Total Property Damage

'

'

'

'

'

'

'

'

2,750,000,000

'

'

'

'

'

'

'

'

'

'

'

Insurance Deductible for Nuclear Power Plant

'

'

'

'

'

'

1,000,000

'

1,000,000

'

'

'

'

'

'

'

'

'

'

'

Total Limit for Property Damage for Non-Nuclear Events

'

'

'

'

'

'

2,000,000,000

'

2,000,000,000

'

'

'

'

'

'

'

'

'

'

'

Limit for Property Damage for Non-Nuclear Events Aggregate of Extra Expenses

'

'

'

'

'

'

'

'

327,000,000

'

'

'

'

'

'

'

'

'

'

'

Limit for Property Damage for Non-Nuclear Events Aggregate of Extra Expenses of Period

'

'

'

'

'

'

'

'

'2 years

'

'

'

'

'

'

'

'

'

'

'

Time Period for TRIA Insurance After the First Loss from Terrorism

'

'

'

'

'

'

'

'

'1 year

'

'

'

'

'

'

'

'

'

'

'

NEIL Policies Against Terrorism Loss

'

'

'

'

'

'

'

'

3,200,000,000

'

'

'

'

'

'

'

'

'

'

'

Amount per Event Loss Associated with Nuclear Power Plants

'

'

'

'

'

'

'

'

35,000,000

'

'

'

'

'

'

'

'

'

'

'

Maintenance of Public Liability Insurance for Nuclear Power Plants

'

'

'

'

'

'

'

'

375,000,000

'

'

'

'

'

'

'

'

'

'

'

Aggregate Limit of Liabilities Arises From Terrorist Act Outside Scope of Trials Subject to One Industry

'

'

'

'

'

'

'

'

300,000,000

'

'

'

'

'

'

'

'

'

'

'

Deferred Premium Charged Leviied Against Each Licensed Nuclear Facility

'

'

'

'

'

'

'

'

127,300,000

'

'

'

'

'

'

'

'

'

'

'

Limit Deferred Premium Charges Per Year

'

'

'

'

'

'

'

'

19,000,000

'

'

'

'

'

'

'

'

'

'

'

Company Obligated to Pay DOE Fee of Fermi 2 Electricity Generated and Sold

'

'

'

'

'

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

New DOE fee for nuclear waste

'

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

Court of Appeals proposal to congress to reduce nuclear waste fee, amount

'

'

'

'

'

0

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Time period after which the Court of Appeals proposal to Congress for nuclear waste fee reduction will take effect duration

'

'

'

'

'90 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Guarantor Obligations, Maximum Exposure, Undiscounted

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1,000,000,000

150,000,000

60,000,000

'

'

Performance Bonds Outstanding

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

46,000,000

'

Entity Number of Employees

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

4,900

Long-term Purchase Commitment, Amount

'

8,300,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Purchase Obligation, Future Minimum Payments, Remainder of Fiscal Year

'

$2,200,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Retirement_Benefits_and_Truste2

Retirement Benefits and Trusteed Assets (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Pension Plan, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'	'	'
Service Cost	$19	$22	$62	$71
Interest Cost	54	49	159	144
Expected Return on Plan Assets	-69	-67	-205	-200
Amortization of Net Actuarial Losses	42	55	118	156
Amortization of Prior Service Cost (Credit)	0	0	0	0
Net Periodic Benefit Cost (Credit)	46	59	134	171
Other Postretirement Benefit Plan, Defined Benefit [Member]	'	'	'	'
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]	'	'	'	'
Service Cost	8	9	26	37
Interest Cost	22	21	67	66
Expected Return on Plan Assets	-31	-28	-92	-82
Amortization of Net Actuarial Losses	4	16	15	48
Amortization of Prior Service Cost (Credit)	-36	-36	-108	-95
Net Periodic Benefit Cost (Credit)	($33)	($18)	($92)	($26)

Retirement_Benefits_and_Truste3

Retirement Benefits and Trusteed Assets (Details Textuals) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014
Pension Plan, Defined Benefit [Member]	'
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]	'
Contributions by Employer	$167
Estimated Future Employer Contributions in Current Fiscal Year	20
Other Postretirement Benefit Plan, Defined Benefit [Member]	'
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]	'
Estimated Future Employer Contributions in Current Fiscal Year	$145

StockBased_Compensation_Compon

Stock-Based Compensation (Components of Stock Based Compensation) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Components of stock-based compensation [Abstract]	'	'	'	'
Stock based compensation expense	$22	$18	$72	$81
Tax Benefit	8	7	27	31
Stock based compensation cost capitalized in property, plant and equipment	$4	$1	$11	$5

StockBased_Compensation_Stock_

Stock-Based Compensation (Stock Option Activity) (Details) (USD $)	9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2014
Stock option activity [Abstract]	'
Options outstanding	723,697
Exercised	-232,751
Forfeitures or expired	-10,730
Options outstanding	480,216
Options exercisable	480,216
Weighted Average Exercise Price Per Share - Options outstanding	$42.60
Weighted Average Exercise Price - Exercised	$41.44
Weighted Average Exercise Price Per Share - Forfeitured or expired	$39.41
Weighted Average Exercise Price Per Share - Options outstanding	$43.24
Weighted Average Exercise Price - Options exercisable	$43.24
Aggregate Intrinsic Value - Options outstanding	$16
Aggregate Intrinsic Value - Options exercisable	$16

StockBased_Compensation_Restri

Stock-Based Compensation (Restricted Stock and Performance Share Awards) (Details) (USD $)	9 Months Ended
	Sep. 30, 2014
Restricted Stock Awards [Abstract]	'
Forfeitures	-10,730
Restricted Stock [Member]	'
Restricted Stock Awards [Abstract]	'
Restricted Stock Awards, Beginning Balance, Number	492,329
Grants	158,390
Forfeitures	-16,014
Vested and Issued	-217,603
Restricted Stock Awards, Ending Balance, Number	417,102
Weighted Average Grant Date Fair Value Per Share Balance	53.76
Weighted Average Grant Date Fair Value, Grants	70.03
Weighted Average Grant Date Fair Value, Forfeitures	62.34
Weighted Average Fair Value Per Share, Vested and issued	47.71
Weighted Average Grant Date Fair Value Per Share Balance	62.76
Performance Stock Awards [Abstract]	'
Weighted Average Grant Date Fair Value Per Share Balance	53.76
Weighted Average Grant Date Fair Value, Grants	70.03
Weighted Average Grant Date Fair Value, Forfeitures	62.34
Weighted Average Grant Date Fair Value Per Share Balance	62.76
Performance Shares [Member]	'
Restricted Stock Awards [Abstract]	'
Weighted Average Grant Date Fair Value Per Share Balance	0
Weighted Average Grant Date Fair Value, Grants	69.24
Weighted Average Grant Date Fair Value, Forfeitures	69.13
Weighted Average Grant Date Fair Value Per Share Balance	69.24
Performance Stock Awards [Abstract]	'
Performance Share Awards, Beginning Balance, Number	1,608,789
Grants	548,892
Forfeitures	-36,471
Payouts	-571,177
Performance Share Awards, Ending Balance, Number	1,550,033
Weighted Average Grant Date Fair Value Per Share Balance	0
Weighted Average Grant Date Fair Value, Grants	69.24
Weighted Average Grant Date Fair Value, Forfeitures	69.13
Weighted Average Grant Date Fair Value, Payouts	0
Weighted Average Grant Date Fair Value Per Share Balance	69.24

StockBased_Compensation_Detail

Stock-Based Compensation (Details Textuals) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation [Abstract]	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	'3 years 6 months 25 days	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	$7	$11
Stock Option Plan Expense	0	0
Unrecognized Compensation Cost	$72	'
Weighted Average Period for unrecognized compensation cost to be recognized	'1 year 2 months 27 days	'

Segment_Information_Financial_

Segment Information (Financial Data - Operating Revenues including inter segment revenues) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'
Operating Revenues	$2,595	$2,387	$9,223	$7,128
Operating Segments [Member] | Electric [Member]	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'
Operating Revenues	1,358	1,458	4,049	3,942
Operating Segments [Member] | Gas [Member]	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'
Operating Revenues	149	161	1,182	1,013
Operating Segments [Member] | Gas Storage and Pipelines [Member]	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'
Operating Revenues	49	34	146	92
Operating Segments [Member] | Power and Industrial Projects [Member]	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'
Operating Revenues	605	512	1,703	1,431
Operating Segments [Member] | Energy Trading [Member]	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'
Operating Revenues	664	463	2,797	1,307
Operating Segments [Member] | Corporate and Other [Member]	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'
Operating Revenues	0	1	1	2
Intersegment Eliminations [Member]	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'
Operating Revenues	-230	-242	-655	-659
Intersegment Eliminations [Member] | Electric [Member]	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'
Operating Revenues	-8	-6	-22	-19
Intersegment Eliminations [Member] | Gas [Member]	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'
Operating Revenues	-1	-2	-5	-4
Intersegment Eliminations [Member] | Gas Storage and Pipelines [Member]	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'
Operating Revenues	-1	2	-9	-2
Intersegment Eliminations [Member] | Power and Industrial Projects [Member]	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'
Operating Revenues	-211	-231	-593	-621
Intersegment Eliminations [Member] | Energy Trading [Member]	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'
Operating Revenues	-8	-13	-24	-36
Intersegment Eliminations [Member] | Corporate and Other [Member]	'	'	'	'
Segment Reporting, Revenue Reconciling Item [Line Items]	'	'	'	'
Operating Revenues	($1)	$8	($2)	$23

Segment_Information_Financial_1

Segment Information (Financial Data - Net Income or Loss) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]	'	'	'	'
Net Income (Loss) Attributable to Parent	$156	$198	$606	$537
Electric [Member]	'	'	'	'
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]	'	'	'	'
Net Income (Loss) Attributable to Parent	135	179	400	383
Gas [Member]	'	'	'	'
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]	'	'	'	'
Net Income (Loss) Attributable to Parent	-16	-13	109	91
Gas Storage and Pipelines [Member]	'	'	'	'
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]	'	'	'	'
Net Income (Loss) Attributable to Parent	20	16	59	49
Power and Industrial Projects [Member]	'	'	'	'
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]	'	'	'	'
Net Income (Loss) Attributable to Parent	38	27	66	46
Energy Trading [Member]	'	'	'	'
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]	'	'	'	'
Net Income (Loss) Attributable to Parent	-22	-6	6	-1
Corporate and Other [Member]	'	'	'	'
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]	'	'	'	'
Net Income (Loss) Attributable to Parent	$1	($5)	($34)	($31)

Segment_Information_Details_Te

Segment Information (Details Textuals)	Sep. 30, 2014
	customers
Segment Reporting [Abstract]	'
Number of Electric Customers	2,100,000
Number of Gas Customers	1,200,000