DTE Energy (DTE) 10-Q 24 Apr 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015
Entity Registrant Name	DTE ENERGY CO
Entity Central Index Key	936340
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding	179,330,405
DTE Electric
Entity Registrant Name	DTE ELECTRIC CO
Entity Central Index Key	28385
Current Fiscal Year End Date	-19
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding	138,632,324

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Operating Revenues	$2,984	$3,930
Operating Expenses
Fuel, purchased power and gas	1,398	2,155
Operation and maintenance	826	841
Depreciation and amortization	209	280
Taxes other than income	100	95
Asset (gains) losses and impairments, net	-10	-1
Total operating expenses	2,523	3,370
Operating Income	461	560
Other (Income) and Deductions
Interest expense	110	110
Interest income	-4	-2
Other income	-51	-41
Other expenses	10	8
Total Other (Income) and Deductions	65	75
Income Before Income Taxes	396	485
Income Tax Expense	122	158
Net Income	274	327
Less: Net Income Attributable to Noncontrolling Interests	1	1
Net Income Attributable to DTE Energy Company/DTE Electric	273	326
Basic Earnings per Common Share
Total Basic Earnings per Common Share (in dollars per share)	$1.53	$1.84
Diluted Earnings per Common Share
Total Diluted Earnings per Common Share (in dollars per share)	$1.53	$1.84
Weighted Average Common Shares Outstanding
Basic (in shares)	178	177
Diluted (in shares)	178	177
Dividends Declared per Common Share	$0.69	$0.66
DTE Electric
Operating Revenues	1,203	1,410
Operating Expenses
Fuel, purchased power and gas	390	498
Operation and maintenance	317	342
Depreciation and amortization	155	228
Taxes other than income	73	71
Total operating expenses	935	1,139
Operating Income	268	271
Other (Income) and Deductions
Interest expense	63	63
Other income	-15	-13
Other expenses	9	7
Total Other (Income) and Deductions	57	57
Income Before Income Taxes	211	214
Income Tax Expense	74	77
Net Income Attributable to DTE Energy Company/DTE Electric	$137	$137

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Net Income	$274	$327
Net Income	273	326
Other comprehensive income (loss), net of tax:
Benefit obligations, net of taxes	3	0
Foreign currency translation	-3	-1
Other comprehensive income (loss)	0	-1
Comprehensive income	274	326
Less comprehensive income attributable to noncontrolling interests	1	1
Comprehensive income attributable to parent	273	325
DTE Electric
Net Income	137	137
Other comprehensive income (loss), net of tax:
Transfer of benefit obligations, net of taxes	28	0
Benefit obligations, net of taxes	0	-1
Comprehensive income attributable to parent	$165	$136

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Parentheticals) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Tax effect on benefit obligation	$2	$0
DTE Electric
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Transfer, Tax	18	0
Tax effect on benefit obligation	$0	($1)

Consolidated_Statements_of_Fin

Consolidated Statements of Financial Position (Unaudited) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Current Assets
Cash and cash equivalents	$99	$48
Restricted cash	24	120
Accounts receivable (less allowance for doubtful accounts)
Customer	1,534	1,504
Other	73	94
Inventories
Fuel and gas	333	512
Materials and supplies	300	292
Notes receivable
Derivative assets	74	128
Regulatory assets	39	76
Other	312	313
Total Current Assets	2,788	3,087
Investments
Nuclear decommissioning trust funds	1,262	1,241
Other	649	628
Total Investments	1,911	1,869
Property
Property, plant and equipment	27,124	26,538
Less accumulated depreciation and amortization	-9,889	-9,718
Property, plant and equipment, net	17,235	16,820
Other Assets
Goodwill	2,018	2,018
Regulatory assets	3,643	3,651
Securitized regulatory assets	0	34
Intangible assets	100	102
Notes receivable	88	90
Derivative assets	40	44
Other	245	259
Total Noncurrent Assets	6,134	6,198
Total Assets	28,068	27,974
Current Liabilities
Accounts payable	825	973
Accrued interest	116	86
Dividends payable	124	122
Short-term borrowings	0	398
Current portion long-term debt, including capital leases	166	274
Derivative liabilities	52	77
Gas inventory equalization	130	0
Regulatory liabilities	79	153
Other	347	494
Total Current Liabilities	1,839	2,577
Long-Term Debt (net of current portion)
Mortgage bonds, notes and other	8,348	7,860
Junior subordinated debentures	480	480
Capital lease obligations	10	3
Total Long-Term Debt (net of current portion)	8,838	8,343
Other Liabilities
Deferred income taxes	3,858	3,776
Regulatory liabilities	665	667
Asset retirement obligations	2,022	1,962
Unamortized investment tax credit	52	41
Derivative liabilities	23	8
Accrued pension liability	1,282	1,280
Accrued postretirement liability	380	515
Nuclear decommissioning	184	182
Other	247	281
Total Noncurrent Liabilities	8,713	8,712
Commitments and Contingencies (Notes 6 and 12)
Equity
Common stock, without par value, 400,000,000 shares authorized, and 179,330,405 and 176,991,231 shares issued and outstanding, respectively	4,093	3,904
Retained earnings	4,727	4,578
Accumulated other comprehensive loss	-155	-155
Total Equity Attributable to Parent	8,665	8,327
Noncontrolling interests	13	15
Total Equity	8,678	8,342
Total Liabilities and Equity	28,068	27,974
DTE Electric
Current Assets
Cash and cash equivalents	54	14
Restricted cash	0	96
Accounts receivable (less allowance for doubtful accounts)
Customer	664	688
Affiliates	53	31
Other	20	15
Inventories
Fuel and gas	260	269
Materials and supplies	240	231
Notes receivable
Affiliates	0	8
Other	2	8
Regulatory assets	38	46
Prepaid property tax	82	44
Other	26	31
Total Current Assets	1,439	1,481
Investments
Nuclear decommissioning trust funds	1,262	1,241
Other	36	172
Total Investments	1,298	1,413
Property
Property, plant and equipment	20,395	19,805
Less accumulated depreciation and amortization	-7,408	-7,216
Property, plant and equipment, net	12,987	12,589
Other Assets
Regulatory assets	2,914	2,913
Securitized regulatory assets	0	34
Intangible assets	37	37
Other	174	182
Total Noncurrent Assets	3,125	3,166
Total Assets	18,849	18,649
Current Liabilities
Accounts payable, affiliates	55	60
Accounts payable, other	356	366
Accrued interest	66	58
Accrued vacation	48	48
Current portion long-term debt, including capital leases	11	118
Regulatory liabilities	73	150
Deferred income taxes	8	0
Short-term borrowings, affiliates	35	84
Short-term borrowings, other	0	50
Other	74	103
Total Current Liabilities	726	1,037
Long-Term Debt (net of current portion)
Mortgage bonds, notes and other	5,634	5,144
Capital lease obligations	10	0
Total Long-Term Debt (net of current portion)	5,644	5,144
Other Liabilities
Deferred income taxes	3,275	3,188
Regulatory liabilities	245	245
Asset retirement obligations	1,854	1,796
Unamortized investment tax credit	47	36
Nuclear decommissioning	184	182
Accrued pension liability — affiliates	1,112	1,200
Accrued postretirement liability — affiliates	392	520
Other	108	105
Total Noncurrent Liabilities	7,217	7,272
Commitments and Contingencies (Notes 6 and 12)
Equity
Common stock, without par value, 400,000,000 shares authorized, and 179,330,405 and 176,991,231 shares issued and outstanding, respectively	3,786	3,786
Retained earnings	1,474	1,436
Accumulated other comprehensive loss	2	-26
Total Equity Attributable to Parent	5,262	5,196
Total Liabilities and Equity	$18,849	$18,649

Consolidated_Statements_of_Fin1

Consolidated Statements of Financial Position (Unaudited) (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, except Share data, unless otherwise specified
Allowance for doubtful accounts	$51	$54
Shareholder’s Equity
Common stock, par value (in dollars per share)	$0	$0
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	179,330,405	176,991,231
Common stock, shares outstanding (in shares)	179,330,405	176,991,231
DTE Electric
Allowance for doubtful accounts	$31	$29
Shareholder’s Equity
Common stock, par value (in dollars per share)	$10	$10
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	138,632,324	138,632,324
Common stock, shares outstanding (in shares)	138,632,324	138,632,324

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Operating Activities
Net Income	$274	$327
Net Income	273	326
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	209	280
Nuclear fuel amortization	13	5
Allowance for equity funds used during construction	-5	-5
Deferred income taxes	84	77
Asset (gains) losses and impairments, net	-10	-1
Changes in assets and liabilities:
Accounts receivable, net	-8	-270
Inventories	172	147
Accounts payable	-123	100
Gas inventory equalization	130	142
Accrued pension obligation	2	-23
Accrued postretirement obligation	-135	-22
Derivative assets and liabilities	49	-51
Regulatory assets and liabilities	-4	-222
Other assets	2	50
Other liabilities	97	-2
Net cash from operating activities	747	532
Investing Activities
Plant and equipment expenditures — utility	-366	-399
Plant and equipment expenditures — non-utility	-39	-98
Acquisition	-240	0
Proceeds from sale of assets	13	3
Restricted cash for debt redemption, principally Securitization	96	66
Proceeds from sale of nuclear decommissioning trust fund assets	246	271
Investment in nuclear decommissioning trust funds	-250	-275
Other	-16	-10
Net cash used for investing activities	-556	-442
Financing Activities
Issuance of long-term debt, net of issuance costs	495	0
Redemption of long-term debt	-117	-115
Short-term borrowings, net	-398	244
Issuance of common stock	9	0
Repurchase of common stock	0	-50
Dividends on common stock	-122	-116
Other	-7	-7
Net cash used for financing activities	-140	-44
Net Increase in Cash and Cash Equivalents	51	46
Cash and Cash Equivalents at Beginning of Period	48	52
Cash and Cash Equivalents at End of Period	99	98
Supplemental disclosure of non-cash investing and financing activities
Plant and equipment expenditures in accounts payable	186	212
DTE Electric
Operating Activities
Net Income	137	137
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	155	228
Nuclear fuel amortization	13	5
Allowance for equity funds used during construction	-5	-5
Deferred income taxes	76	42
Changes in assets and liabilities:
Accounts receivable, net	-3	6
Inventories	2	55
Accounts payable	-8	73
Accrued pension liability — affiliates	-88	-20
Accrued postretirement liability — affiliates	-128	-15
Regulatory assets and liabilities	-43	-135
Other assets	-38	-28
Other liabilities	103	-31
Net cash from operating activities	173	312
Investing Activities
Plant and equipment expenditures	-311	-354
Acquisition	-240	0
Restricted cash for debt redemption, principally Securitization	96	65
Notes receivable from affiliate	8	200
Proceeds from sale of nuclear decommissioning trust fund assets	246	271
Investment in nuclear decommissioning trust funds	-250	-275
Transfer of Rabbi Trust assets to affiliate	137	0
Other	2	-8
Net cash used for investing activities	-312	-101
Financing Activities
Issuance of long-term debt, net of issuance costs	496	0
Redemption of long-term debt	-115	-113
Short-term borrowings, net — other	-50	0
Short-term borrowings, net — affiliate	-49	5
Dividends on common stock	-99	-93
Other	-4	-3
Net cash used for financing activities	179	-204
Net Increase in Cash and Cash Equivalents	40	7
Cash and Cash Equivalents at Beginning of Period	14	27
Cash and Cash Equivalents at End of Period	54	34
Supplemental disclosure of non-cash investing and financing activities
Plant and equipment expenditures in accounts payable	$154	$176

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Equity (Unaudited) (USD $)	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Non-Controlling Interests	DTE Electric	DTE Electric	DTE Electric	DTE Electric	DTE Electric
In Millions, except Share data, unless otherwise specified							Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning Balance at Dec. 31, 2014	$8,327					$5,196	$1,386	$2,400	$1,436	($26)
Beginning Balance at Dec. 31, 2014	8,342	3,904	4,578	-155	15
Beginning Balance, shares at Dec. 31, 2014	176,991,231	176,991,000				138,632,324	138,632,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	274		273		1
Net Income	273					137			137
Dividends declared on common stock	-124		-124			-99			-99
Issuance of common stock, shares		105,000
Issuance of common stock	9	9
Contribution of common stock to VEBA Trust, shares		1,428,000
Contribution of common stock to VEBA Trust	117	117
Benefit obligations, net of taxes	3			3		0
Transfer of benefit obligations, net of taxes						28				28
Foreign currency translation	-3			-3
Stock-based compensation, distributions to noncontrolling interests and other, shares		806,000
Stock-based compensation, distributions to noncontrolling interests and other	60	63			-3
Ending Balance at Mar. 31, 2015	8,665					5,262	1,386	2,400	1,474	2
Ending Balance at Mar. 31, 2015	$8,678	$4,093	$4,727	($155)	$13
Ending Balance, shares at Mar. 31, 2015	179,330,405	179,330,000				138,632,324	138,632,000

Organization_and_Basis_of_Pres

Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	ORGANIZATION AND BASIS OF PRESENTATION
	Corporate Structure
	DTE Energy owns the following businesses:
	•	DTE Electric is an electric utility engaged in the generation, purchase, distribution and sale of electricity to approximately 2.1 million customers in southeastern Michigan;
	•	DTE Gas is 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 Registrants are regulated by other federal and state regulatory agencies including the NRC, the EPA, the MDEQ and the CFTC.
	Basis of Presentation
	The Consolidated Financial Statements should be read in conjunction with the Notes to Consolidated Financial Statements included in the DTE Energy 2014 Annual Report on Form 10-K and the Notes to Consolidated Financial Statements included in the DTE Electric 2014 Annual Report on Form 10-K.
	The accompanying Consolidated Financial Statements of the Registrants 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 Registrants' estimates.
	The Consolidated Financial Statements are unaudited, but in the Registrants' opinions 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 Combined 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, 2015.
	The information in these combined notes relates to each of the Registrants as noted in the Index of Combined Notes to Consolidated Financial Statements. However, DTE Electric does not make any representation as to information related solely to DTE Energy or the subsidiaries of DTE Energy other than itself.
	Certain prior year balances for DTE Electric were reclassified to match current year's financial statement presentation.
	Principles of Consolidation
	The Registrants consolidate all majority-owned subsidiaries and investments in entities in which they have controlling influence. Non-majority owned investments are accounted for using the equity method when the Registrants are able to influence the operating policies of the investee. When the Registrants do not influence the operating policies of an investee, the cost method is used. These Consolidated Financial Statements also reflect the Registrants' proportionate interests in certain jointly-owned utility plants. The Registrants eliminate all intercompany balances and transactions.
	The Registrants evaluate whether an entity is a VIE whenever reconsideration events occur. The Registrants consolidate VIEs for which they are the primary beneficiary. If a Registrant 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, a Registrant 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 Registrants perform ongoing reassessments of all VIEs to determine if the primary beneficiary status has changed.
	Legal entities within DTE Energy'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 DTE Energy retaining operational and customer default risk. These entities generally are VIEs and consolidated when DTE Energy is the primary beneficiary. In addition, DTE Energy has interests in certain VIEs through which control of all significant activities is shared with partners, and therefore are accounted for under the equity method.
	DTE Energy has variable interests in VIEs through certain of its long-term purchase and sale contracts. DTE Electric has variable interests in VIEs through certain of its long-term purchase contracts. As of March 31, 2015, the carrying amount of assets and liabilities in the Registrants' 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 Registrants for the deliveries associated with the current billing cycle under the contracts. The Registrants have 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 DTE Energy's variable interests through these long-term purchase and sale contracts. In addition, there is no significant potential exposure to loss as a result of DTE Electric's variable interests through these long-term purchase 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 performed servicing activities including billing and collecting surcharge revenue for Securitization. The remaining amounts due on the rate reduction bonds were paid in March 2015. The associated regulatory assets were fully amortized by March 31, 2015. Securitization has an over-recovery of funds which will be returned to customers after receipt of an order from the MPSC. Subsequent to the pay-down of the bonds, Securitization is no longer a VIE but continues to be consolidated by the Registrants as a voting interest entity.
	The maximum risk exposure for consolidated VIEs is reflected on the Registrants' 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 Consolidated Statements of Financial Position items for consolidated VIEs as of March 31, 2015 and December 31, 2014. 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. Securitization, included in the DTE Energy table below for December 31, 2014, also relates to DTE Electric. VIEs, in which DTE Energy 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.
		March 31, 2015		December 31, 2014
		Total		Securitization		Other		Total
		(In millions)
	ASSETS
	Cash and cash equivalents	$	12	$	—	$	7	$	7
	Restricted cash	9		96		8		104
	Accounts receivable	12		26		15		41
	Inventories	34		—		67		67
	Property, plant and equipment, net	77		—		81		81
	Securitized regulatory assets	—		34		—		34
	Other current and long-term assets	6		1		6		7
		$	150	$	157	$	184	$	341
	LIABILITIES
	Accounts payable and accrued current liabilities	$	11	$	3	$	8	$	11
	Current portion long-term debt, including capital leases	8		105		10		115
	Current regulatory liabilities	—		32		—		32
	Mortgage bonds, notes and other	14		—		15		15
	Capital lease obligations	1		—		3		3
	Other current and long-term liabilities	6		9		6		15
		$	40	$	149	$	42	$	191
	Amounts for DTE Energy's non-consolidated VIEs as of March 31, 2015 and December 31, 2014 are as follows:
		31-Mar-15		31-Dec-14
		(In millions)
	Other investments	$	136	$	134
	Notes receivable	$	15	$	15

Significant_Accounting_Policie

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES
	Other Income
	Other income for the Registrants is recognized for non-operating income such as equity earnings, allowance for equity funds used during construction and contract services. DTE Energy's Power & Industrial Projects segment 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 $19 million and $17 million of Other income for the three months ended March 31, 2015 and 2014, respectively.
	Changes in Accumulated Other Comprehensive Income (Loss)
	For the three months ended March 31, 2015 and 2014, reclassifications out of accumulated other comprehensive income (loss) for the Registrants were not material. Refer to Note 13 to the Consolidated Financial Statements, "Retirement Benefits and Trusteed Assets", regarding the transfer of a portion of DTE Electric benefit obligations during the year. Changes in accumulated other comprehensive income (loss) are presented in the Registrants' Consolidated Statements of Changes in Equity.
	Intangible Assets
	DTE Energy has certain intangible assets relating to emission allowances, renewable energy credits and non-utility contracts as shown below:
		March 31,			December 31,
		2015			2014
		(In millions)
	Emission allowances	$	1		$	1
	Renewable energy credits	46			45
	Contract intangible assets	123			122
		170			168
	Less accumulated amortization	60			57
	Intangible assets, net	110			111
	Less current intangible assets	10			9
		$	100		$	102
	DTE Electric has certain intangible assets relating to emission allowances and renewable energy credits as shown below:
		March 31,			December 31,
		2015			2014
		(In millions)
	Emission allowances	$	1		$	1
	Renewable energy credits	46			45
		47			46
	Less current intangible assets	10			9
		$	37		$	37
	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 by the Registrants. DTE Energy amortizes contract intangible assets on a straight-line basis over the expected period of benefit, ranging from 1 to 26 years.
	Income Taxes
	The effective tax rate and unrecognized tax benefits of the Registrants are as follows:
		Effective Tax Rate					Unrecognized
							Tax Benefits
		Three Months Ended March 31,					March 31,
		2015		2014			2015
							(In millions)
	DTE Energy	31	%	33	%		$	9
	DTE Electric	35	%	36	%		$	4
	The 2% decrease in DTE Energy's effective tax rate for the three months ended March 31, 2015 is primarily due to the inclusion in 2014 of $8 million of deferred tax expense resulting from New York state income tax reform enacted in March 2014. The 1% decrease in DTE Electric's effective tax rate for the three months ended March 31, 2015 is due to higher production tax credits.
	If recognized, $2 million of the unrecognized tax benefits of the Registrants would favorably impact their effective tax rates. DTE Energy believes that it is possible that there will be a decrease in the unrecognized tax benefits of up to $6 million in the next twelve months. DTE Electric does not anticipate any material changes to the unrecognized tax benefits in the next twelve months.
	DTE Electric had an income tax receivable with DTE Energy of $51 million and $29 million at March 31, 2015 and December 31, 2014, respectively.

New_Accounting_Pronouncements

New Accounting Pronouncements	3 Months Ended
	Mar. 31, 2015
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements	NEW ACCOUNTING PRONOUNCEMENTS
	In May 2014, the FASB issued 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 Registrants are currently assessing the impact of this ASU on their Consolidated Financial Statements.
	In April 2015, the FASB issued ASU No. 2015-03, Simplifying the Presentation of Debt Issuance Costs. This ASU requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. This ASU is effective for reporting periods beginning after December 15, 2015 and interim periods therein. It is to be applied retrospectively and early adoption is permitted. The Registrants are currently assessing the impact of this ASU on their Consolidated Financial Statements.

Acquisition

Acquisition	3 Months Ended
	Mar. 31, 2015
Business Combinations [Abstract]
Acquisition	ACQUISITION
	In October 2014, DTE Electric executed an agreement to purchase a 732 MW simple-cycle natural gas facility in Carson City, Michigan from The LS Power Group. The facility will serve to meet the needs of approximately 260,000 additional households during peak demand. DTE Electric closed on the acquisition of 100% equity interest in the facility on January 21, 2015.
	DTE Electric has completed its valuation analysis to arrive at the fair value of the assets acquired. The cash consideration and total purchase price of approximately $240 million was allocated based on the underlying fair value of the assets acquired, which was primarily property, plant and equipment.
	The pro forma results of operations have not been presented for DTE Electric as the effects of the acquisition were not material to either Registrant's consolidated results of operations.

Asset_Retirement_Obligations

Asset Retirement Obligations	3 Months Ended
	Mar. 31, 2015
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	ASSET RETIREMENT OBLIGATIONS
	A reconciliation of the asset retirement obligations for the three months ended March 31, 2015 follows:
		DTE Energy		DTE Electric
		(In millions)
	Asset retirement obligations at December 31, 2014	$	1,962	$	1,796
	Accretion	28		26
	Revision in estimated cash flows	32		32
	Asset retirement obligations at March 31, 2015	$	2,022	$	1,854

Regulatory_Matters

Regulatory Matters	3 Months Ended
	Mar. 31, 2015
Public Utilities, General Disclosures [Abstract]
Regulatory Matters	REGULATORY MATTERS
	2014 Electric Rate Case Filing
	DTE Electric filed a rate case with the MPSC on December 19, 2014 requesting an increase in base rates of $370 million based on a projected twelve-month period ending June 30, 2016. The requested increase in base rates is due primarily to an increase in net plant resulting from infrastructure investments, plant acquisitions, environmental compliance and reliability improvement projects. The rate filing also included projected changes in sales, working capital, operation and maintenance expenses, return on equity and capital structure. New rates could be self-implemented in July 2015, with a final order expected in December 2015.
	Refundable Revenue Decoupling / 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 DTE Electric'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. DTE Electric amortized one-half of the RDM regulatory liability in the first six months of 2014 and resumed amortization of the remainder beginning January 1, 2015. If DTE Electric's base rates are increased prior to July 1, 2015, DTE Electric will cease amortization and refund to customers the remaining unamortized balance of the regulatory liability.
	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 its 2012 PSCR reconciliation that included purchased power costs related to the manual shutdown of the 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 approximately 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 customers. Certain intervenors in the reconciliation case have challenged the recovery of up to $32 million of the Fermi 2 related purchased power costs. In April 2015, an MPSC Administrative Law Judge issued a Proposal for Decision that challenged the recovery of approximately $50 million of such costs. Resolution of this matter is expected in 2016.

Earnings_Per_Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE
	DTE Energy 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 months ended March 31:
		Three Months Ended March 31,
		2015		2014
		(In millions, except per share amounts)
	Basic Earnings per Share
	Net income attributable to DTE Energy Company	$	273	$	326
	Average number of common shares outstanding	178		177
	Dividends declared — common shares	$	123	$	116
	Dividends declared — net restricted shares	1		—
	Total distributed earnings	$	124	$	116
	Net income less distributed earnings	$	149	$	210
	Distributed (dividends per common share)	$	0.69	$	0.66
	Undistributed	0.84		1.18
	Total Basic Earnings per Common Share	$	1.53	$	1.84
	Diluted Earnings per Share
	Net income attributable to DTE Energy Company	$	273	$	326
	Average number of common shares outstanding	178		177
	Dividends declared — common shares	$	123	$	116
	Dividends declared — net restricted shares	1		—
	Total distributed earnings	$	124	$	116
	Net income less distributed earnings	$	149	$	210
	Distributed (dividends per common share)	$	0.69	$	0.66
	Undistributed	0.84		1.18
	Total Diluted Earnings per Common Share	$	1.53	$	1.84

Fair_Value

Fair Value	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value	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 Registrants make certain assumptions they believe 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 Registrants and their counterparties is incorporated in the valuation of assets and liabilities through the use of credit reserves, the impact of which was immaterial at March 31, 2015 and December 31, 2014. The Registrants believe they use 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 Registrants classify 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 Registrants have 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 for DTE Energy measured and recorded at fair value on a recurring basis as of March 31, 2015 and December 31, 2014:
		31-Mar-15																			31-Dec-14
		Level 1			Level 2				Level 3				Netting				Net Balance				Level 1				Level 2			Level 3			Netting			Net Balance
													(a)																		(a)
		(In millions)
	Assets:
	Cash equivalents (b)	$	14		$	3			$	—			$	—			$	17			$	13			$	99		$	—		$	—		$	112
	Nuclear decommissioning trusts	798			464				—				—				1,262				792				449			—			—			1,241
	Other investments (c)	100			51				—				—				151				100				50			—			—			150
	Derivative assets:
	Commodity Contracts:
	Natural Gas	315			87				41				(389		)		54				555				140			92			(681		)	106
	Electricity	—			234				36				(215		)		55				—				295			47			(280		)	62
	Other	42			—				1				(42		)		1				42				—			3			(42		)	3
	Other derivative contracts (d)	—			8				—				(4		)		4				—				4			—			(3		)	1
	Total derivative assets	357			329				78				(650		)		114				597				439			142			(1,006		)	172
	Total	$	1,269		$	847			$	78			$	(650	)		$	1,544			$	1,502			$	1,037		$	142		$	(1,006	)	$	1,675
	Liabilities:
	Derivative liabilities:
	Commodity Contracts:
	Natural Gas	$	(369	)	$	(45	)		$	(41	)		$	428			$	(27	)		$	(578	)		$	(78	)	$	(62	)	$	679		$	(39	)
	Electricity	—			(219		)		(43		)		217				(45		)		—				(290		)	(52		)	298			(44		)
	Other	(32		)	(8		)		(6		)		46				—				(32		)		(9		)	(4		)	45			—
	Other derivative contracts (d)	—			(7		)		—				4				(3		)		—				(5		)	—			3			(2		)
	Total derivative liabilities	(401		)	(279		)		(90		)		695				(75		)		(610		)		(382		)	(118		)	1,025			(85		)
	Total	$	(401	)	$	(279	)		$	(90	)		$	695			$	(75	)		$	(610	)		$	(382	)	$	(118	)	$	1,025		$	(85	)
	Net Assets (Liabilities) at the end of the period	$	868		$	568			$	(12	)		$	45			$	1,469			$	892			$	655		$	24		$	19		$	1,590
	Assets:
	Current	$	339		$	295			$	59			$	(602	)		$	91			$	582			$	504		$	109		$	(955	)	$	240
	Noncurrent (e)	930			552				19				(48		)		1,453				920				533			33			(51		)	1,435
	Total Assets	$	1,269		$	847			$	78			$	(650	)		$	1,544			$	1,502			$	1,037		$	142		$	(1,006	)	$	1,675
	Liabilities:
	Current	$	(353	)	$	(253	)		$	(74	)		$	628			$	(52	)		$	(572	)		$	(357	)	$	(112	)	$	964		$	(77	)
	Noncurrent	(48		)	(26		)		(16		)		67				(23		)		(38		)		(25		)	(6		)	61			(8		)
	Total Liabilities	$	(401	)	$	(279	)		$	(90	)		$	695			$	(75	)		$	(610	)		$	(382	)	$	(118	)	$	1,025		$	(85	)
	Net Assets (Liabilities) at the end of the period	$	868		$	568			$	(12	)		$	45			$	1,469			$	892			$	655		$	24		$	19		$	1,590
	_______________________________________
	(a)	Amounts represent the impact of master netting agreements that allow DTE Energy to net gain and loss positions and cash collateral held or placed with the same counterparties.
	(b)	At March 31, 2015, available-for-sale securities of $17 million included $9 million and $8 million of cash equivalents included in Restricted cash and Other investments on DTE Energy's Consolidated Statements of Financial Position, respectively. At December 31, 2014, available-for-sale securities of $112 million, included $105 million and $7 million of cash equivalents included in Restricted cash and Other investments on DTE Energy's Consolidated Statements of Financial Position, respectively.
	(c)	Excludes cash surrender value of life insurance investments.
	(d)	Primarily includes Foreign currency exchange contracts.
	(e)	Includes $151 million and $150 million at March 31, 2015 and December 31, 2014, respectively, of other investments that are included in DTE Energy's Consolidated Statements of Financial Position in Other investments.
	The following table presents assets for DTE Electric measured and recorded at fair value on a recurring basis as of March 31, 2015 and December 31, 2014:
		March 31, 2015															December 31, 2014
		Level 1			Level 2				Level 3				Net Balance				Level 1				Level 2				Level 3			Net Balance
		(In millions)
	Assets:
	Cash equivalents (a)	$	5		$	3			$	—			$	8			$	5			$	99			$	—		$	104
	Nuclear decommissioning trusts	798			464				—				1,262				792				449				—			1,241
	Other investments	10			—				—				10				97				50				—			147
	Derivative assets — FTRs	—			—				1				1				—				—				3			3
	Total	$	813		$	467			$	1			$	1,281			$	894			$	598			$	3		$	1,495
	Assets:
	Current	$	5		$	3			$	1			$	9			$	5			$	99			$	3		$	107
	Noncurrent	808			464				—				1,272				889				499				—			1,388
	Total Assets	$	813		$	467			$	1			$	1,281			$	894			$	598			$	3		$	1,495
	_______________________________________
	(a)	At March 31, 2015, available-for-sale securities of $8 million consisted of cash equivalents included in Other investments on DTE Electric's Consolidated Statements of Financial Position. At December 31, 2014, available-for-sale securities of $104 million included $96 million and $8 million of cash equivalents included in Restricted cash and Other investments, respectively, on DTE Electric's Consolidated Statements of Financial Position.
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 NAVs. 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. The Registrants have obtained an understanding of how these prices are derived, including the nature and observability of the inputs used in deriving such prices. Additionally, the Registrants selectively corroborate the fair value of securities by comparison of market-based price sources. Investment policies and procedures are determined by DTE Energy's Trust Investments Department which reports to DTE Energy'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. The Registrants consider 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. The Registrants monitor 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. The Registrants have obtained an understanding of how these prices are derived. Additionally, the Registrants selectively corroborate the fair value of their 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 Registrants have 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 the Registrants' forward price curves has been assigned to DTE Energy's Risk Management Department, which is separate and distinct from the trading functions within DTE Energy.
The following tables present the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for DTE Energy for the three months ended March 31, 2015 and 2014:
	Three Months Ended March 31, 2015															Three Months Ended March 31, 2014
	Natural Gas			Electricity				Other				Total				Natural Gas				Electricity				Other			Total
	(In millions)
Net Assets (Liabilities) as of December 31	$	30		$	(5	)		$	(1	)		$	24			$	(52	)		$	13			$	3		$	(36	)
Transfers into Level 3	—			—				(1		)		(1		)		—				—				—			—
Transfers out of Level 3	—			—				—				—				—				—				—			—
Total gains (losses):
Included in earnings	(29		)	7				(2		)		(24		)		(22		)		36				—			14
Recorded in regulatory assets/liabilities	—			—				(2		)		(2		)		—				—				4			4
Purchases, issuances and settlements:
Issuances	—			—				—				—				—				(1		)		—			(1		)
Settlements	(1		)	(9		)		1				(9		)		64				(82		)		(6		)	(24		)
Net Assets (Liabilities) as of March 31	$	—		$	(7	)		$	(5	)		$	(12	)		$	(10	)		$	(34	)		$	1		$	(43	)
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 March 31, 2015 and 2014 and reflected in Operating revenues and Fuel, purchased power and gas in DTE Energy's Consolidated Statements of Operations	$	(91	)	$	(3	)		$	(2	)		$	(96	)		$	—			$	(20	)		$	—		$	(20	)
The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for DTE Electric for three months ended March 31, 2015 and 2014:
	Three Months Ended March 31,
	2015			2014
	(In millions)
Net Assets as of beginning of period	$	3		$	3
Change in fair value recorded in regulatory assets/liabilities	(2		)	4
Purchases, issuances and settlements:
Settlements	—			(6		)
Net Assets as of March 31,	$	1		$	1
The amount of total gains (losses) included in Regulatory assets and liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31, 2015 and 2014 and reflected in DTE Electric's Consolidated Statements of Operations	$	—		$	—
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 for the Registrants during the three months ended March 31, 2015 and 2014, and there were no transfers between Level 3 for DTE Electric during the same periods.
The following table presents the unobservable inputs related to DTE Energy's Level 3 assets and liabilities as of March 31, 2015:
		March 31, 2015
Commodity Contracts		Derivative Assets			Derivative Liabilities				Valuation Techniques		Unobservable Input		Range								Weighted Average
		(In millions)
Natural Gas		$	41		$	(41	)		Discounted Cash Flow		Forward basis price (per MMBtu)		$	(2.46	) —		$	7	/MMBtu		$	(0.25	)/MMBtu
Electricity		$	36		$	(43	)		Discounted Cash Flow		Forward basis price (per MWh)		$	(7	) —		$	19	/MWh		$	3	/MWh
The following table presents the unobservable inputs related to DTE Energy's Level 3 assets and liabilities as of December 31, 2014:
		December 31, 2014
Commodity Contracts		Derivative Assets			Derivative Liabilities				Valuation Techniques		Unobservable Input		Range								Weighted Average
		(In millions)
Natural Gas		$	92		$	(62	)		Discounted Cash Flow		Forward basis price (per MMBtu)		$	(2.28	) —		$	7.83	/MMBtu		$	(0.22	)/MMBtu
Electricity		$	47		$	(52	)		Discounted Cash Flow		Forward basis price (per MWh)		$	(14	) —		$	15	/MWh		$	4	/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. The Registrants have obtained an understanding of how the fair values are derived. The Registrants also selectively corroborate the fair value of their 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 for the Registrants are determined by the DTE Energy's Treasury Department which reports to the DTE Energy's Vice President and Treasurer.
The following table presents the carrying amount and fair value of financial instruments for DTE Energy as of March 31, 2015 and December 31, 2014:
	March 31, 2015															December 31, 2014
	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	$	35		$	—			$	—			$	35			$	41			$	—			$	—		$	41
Dividends payable	$	124		$	124			$	—			$	—			$	122			$	122			$	—		$	—
Short-term borrowings	$	—		$	—			$	—			$	—			$	398			$	—			$	398		$	—
Long-term debt, excluding capital leases	$	8,989		$	500			$	8,581			$	1,051			$	8,606			$	489			$	8,308		$	706
The following table presents the carrying amount and fair value of financial instruments for DTE Electric as of March 31, 2015 and December 31, 2014:
	March 31, 2015															December 31, 2014
	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	$	6		$	—			$	—			$	6			$	12			$	—			$	—		$	12
Notes receivable — affiliates	$	—		$	—			$	—			$	—			$	8			$	—			$	—		$	8
Short-term borrowings — affiliates	$	35		$	—			$	—			$	35			$	84			$	—			$	—		$	84
Short-term borrowings — other	$	—		$	—			$	—			$	—			50				$	—			$	50		$	—
Long-term debt, excluding capital leases	$	5,643		$	—			$	5,682			$	735			$	5,259			$	—			$	5,341		$	496
For further fair value information on financial and derivative instruments see Note 9 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 Registrants' 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 DTE Electric's fair value of the nuclear decommissioning trust fund assets:
	31-Mar-15			31-Dec-14
	(In millions)
Fermi 2	$	1,241		$	1,221
Fermi 1	3			3
Low-level radioactive waste	18			17
Total	$	1,262		$	1,241
The costs of securities sold are determined on the basis of specific identification. The following table sets forth DTE Electric's gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds:
	Three Months Ended March 31,
	2015			2014
	(In millions)
Realized gains	$	9		$	9
Realized losses	$	(7	)	$	(7	)
Proceeds from sales of securities	$	246		$	271
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 DTE Electric's fair value and unrealized gains and losses for the nuclear decommissioning trust funds:
	31-Mar-15											31-Dec-14
	Fair			Unrealized				Unrealized				Fair				Unrealized				Unrealized
	Value			Gains				Losses				Value				Gains				Losses
	(In millions)
Equity securities	$	774		$	217			$	(41	)		$	756			$	204			$	(39	)
Debt securities	483			24				(1		)		474				21				(2		)
Cash and cash equivalents	5			—				—				11				—				—
	$	1,262		$	241			$	(42	)		$	1,241			$	225			$	(41	)
The debt securities at March 31, 2015 and December 31, 2014 had an average maturity of approximately 7 years. 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.
Other Securities
At March 31, 2015 and December 31, 2014, the Registrants' securities were comprised primarily of money market and equity securities. There were no unrealized losses on available-for-sale securities which were reclassified out of other comprehensive income and realized into net income for DTE Energy or DTE Electric during the three months ended March 31, 2015 and 2014. Gains related to trading securities held at March 31, 2015 and 2014 were $1 million and $2 million, respectively, for both DTE Energy and DTE Electric.

Financial_and_Other_Derivative

Financial and Other Derivative Instruments	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial and Other Derivative Instruments	FINANCIAL AND OTHER DERIVATIVE INSTRUMENTS
	The Registrants recognize all derivatives at their fair value as Derivative assets or liabilities on their respective 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 Registrants’ primary market risk exposure is associated with commodity prices, credit and interest rates. The Registrants have risk management policies to monitor and manage market risks. The Registrants use derivative instruments to manage some of the exposure. DTE Energy 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.
	DTE 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 normal sales exception 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.
	DTE 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 2018. Substantially all of these contracts meet the normal purchases and normal sales exception 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. DTE Energy 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 — DTE Energy may use interest rate swaps, treasury locks and other derivatives to hedge the risk associated with interest rate market volatility.
	Credit Risk — DTE Energy 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. DTE Energy generally uses standardized agreements that allow the netting of positive and negative transactions associated with a single counterparty. DTE Energy maintains a provision for credit losses based on factors surrounding the credit risk of its customers, historical trends, and other information. Based on DTE Energy's credit policies and its March 31, 2015 provision for credit losses, DTE Energy’s exposure to counterparty nonperformance is not expected to have a material adverse effect on DTE Energy's Consolidated Financial Statements.
	Derivative Activities
	DTE Energy 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 March 31, 2015 and December 31, 2014 for DTE Energy:
		March 31, 2015								December 31, 2014
		Derivative				Derivative Liabilities				Derivative			Derivative Liabilities
		Assets								Assets
		(In millions)
	Derivatives not designated as hedging instruments:
	Foreign currency exchange contracts	$	8			$	(7	)		$	4		$	(5	)
	Commodity Contracts:
	Natural Gas	443				(455		)		787			(718		)
	Electricity	270				(262		)		342			(342		)
	Other	43				(46		)		45			(45		)
	Total derivatives not designated as hedging instruments:	$	764			$	(770	)		$	1,178		$	(1,110	)
	Total derivatives:
	Current	$	676			$	(680	)		$	1,083		$	(1,041	)
	Noncurrent	88				(90		)		95			(69		)
	Total derivatives	$	764			$	(770	)		$	1,178		$	(1,110	)
	The following table presents the fair value of derivative instruments as of March 31, 2015 and December 31, 2014 for DTE Electric:
		March 31, 2015				December 31, 2014
		(In millions)
	FTRs — Other current assets	$	1			$	3
	Total derivatives not designated as hedging instrument	$	1			$	3
	Certain of the DTE Energy'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, DTE Energy offsets the fair value of derivative instruments with cash collateral received or paid for those contracts executed with the same counterparty, which reduces DTE Energy'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.
	DTE Energy 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. DTE Energy had no letters of credit outstanding at March 31, 2015 and $7 million in letters of credit at December 31, 2014, which could be used to offset net derivative liabilities. Letters of credit received from third parties which could be used to offset net derivative assets were $1 million and $5 million at March 31, 2015 and December 31, 2014, respectively. Such balances of letters of credit are excluded from the tables below and are not netted with the recognized assets and liabilities in DTE Energy's 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 DTE Energy's 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.
	For DTE Energy, as of March 31, 2015, the total cash collateral posted, net of cash collateral received, was $85 million. As of December 31, 2014, the total cash collateral posted, net of cash collateral received, was $61 million. As of March 31, 2015, derivative assets and derivative liabilities are shown net of cash collateral of $1 million and $46 million, respectively. As of December 31, 2014, there was no cash collateral related to unrealized positions to net against derivative assets while derivative liabilities are shown net of cash collateral of $19 million. DTE Energy recorded cash collateral paid of $43 million and cash collateral received of $3 million not related to unrealized derivative positions as of March 31, 2015. DTE Energy recorded cash collateral paid of $44 million and cash collateral received of $2 million not related to unrealized derivative positions as of December 31, 2014. 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 for DTE Energy at March 31, 2015 and December 31, 2014:
		31-Mar-15											31-Dec-14
		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	$	443			$	(389	)		$	54		$	787		$	(681	)	$	106
	Electricity	270				(215		)		55			342			(280		)	62
	Other	43				(42		)		1			45			(42		)	3
	Other derivative contracts (a)	8				(4		)		4			4			(3		)	1
	Total derivative assets	$	764			$	(650	)		$	114		$	1,178		$	(1,006	)	$	172
	Derivative liabilities:
	Commodity Contracts:
	Natural Gas	$	(455	)		$	428			$	(27	)	$	(718	)	$	679		$	(39	)
	Electricity	(262		)		217				(45		)	(342		)	298			(44		)
	Other	(46		)		46				—			(45		)	45			—
	Other derivative contracts (a)	(7		)		4				(3		)	(5		)	3			(2		)
	Total derivative liabilities	$	(770	)		$	695			$	(75	)	$	(1,110	)	$	1,025		$	(85	)
	_______________________________________
	(a)	Primarily includes Foreign currency exchange contracts.
	The following table presents the netting offsets of derivative assets and liabilities for DTE Energy at March 31, 2015 and December 31, 2014:
		March 31, 2015														31-Dec-14
	Derivative Assets								Derivative Liabilities						Derivative Assets						Derivative Liabilities
	Current				Noncurrent				Current			Noncurrent			Current			Noncurrent			Current			Noncurrent
	(In millions)
Reconciliation of derivative instruments to DTE Energy's Consolidated Statements of Financial Position:
Total fair value of derivatives	$	676			$	88			$	(680	)	$	(90	)	$	1,083		$	95		$	(1,041	)	$	(69	)
Counterparty netting	(601		)		(48		)		601			48			(955		)	(51		)	955			51
Collateral adjustment	(1		)		—				27			19			—			—			9			10
Total derivatives as reported	$	74			$	40			$	(52	)	$	(23	)	$	128		$	44		$	(77	)	$	(8	)
The effect of derivatives not designated as hedging instruments on DTE Energy's Consolidated Statements of Operations for the three months ended March 31, 2015 and 2014 for DTE Energy is as follows:
		Location of Gain		Gain (Loss) Recognized in
		(Loss) Recognized		Income on Derivatives for
		in Income on Derivatives		the Three Months Ended March 31,
Derivatives not Designated as Hedging Instruments				2015				2014
				(In millions)
Foreign currency exchange contracts		Operating Revenue		$	1			$	(4	)
Commodity Contracts:
Natural Gas		Operating Revenue		(126		)		(127		)
Natural Gas		Fuel, purchased power and gas		21				20
Electricity		Operating Revenue		31				133
Other		Operating Revenue		(2		)		(1		)
Total				$	(75	)		$	21
Revenues and energy costs related to trading contracts are presented on a net basis in DTE Energy's Consolidated Statements of Operations. Commodity derivatives used for trading purposes, and financial non-trading commodity derivatives, are accounted for using the MTM 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 MTM 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 DTE Energy's derivative contracts outstanding as of March 31, 2015:
Commodity		Number of Units
Natural Gas (MMBtu)		935,928,277
Electricity (MWh)		13,667,643
Oil (Gallons)		27,048,000
Foreign Currency Exchange (Canadian dollars)		80,737,962
Various subsidiaries of DTE Energy 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 DTE Energy 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 DTE Energy 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 DTE Energy 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 March 31, 2015, 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 $416 million.
As of March 31, 2015, DTE Energy had approximately $726 million of derivatives in net liability positions, for which hard triggers exist. Collateral of approximately $4 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 $630 million. The net remaining amount of approximately $92 million is derived from the $416 million noted above.

LongTerm_Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2015
Long-term Debt, Unclassified [Abstract]
Long-term Debt	LONG-TERM DEBT
	Debt Issuances
	In 2015, the following debt was issued:
	Company		Month	Type	Interest Rate	Maturity	Amount
							(In millions)
	DTE Electric		March	Mortgage Bonds (a)	3.70%	2045	$	500
							$	500
	_______________________________________
	(a)	Proceeds were used for the redemption of long-term debt, for the repayment of short-term borrowings and for general corporate purposes.
	Debt Redemptions
	In 2015, the following debt was redeemed:
	Company		Month	Type	Interest Rate	Maturity	Amount
							(In millions)
	DTE Electric		March	Securitization Bonds	6.62%	2015	$	105
	DTE Electric		March	Mortgage Bonds	7.90%	2016	10
	DTE Energy		Various	Other Long Term Debt	Various	2015	2
							$	117

ShortTerm_Credit_Arrangements_

Short-Term Credit Arrangements and Borrowings	3 Months Ended
	Mar. 31, 2015
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 that can be used for general corporate borrowings, but are intended to provide liquidity support for each of the companies’ commercial paper programs. 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 Registrants and DTE Gas to maintain a total funded debt to capitalization ratio of no more than 0.65 to 1. At March 31, 2015, the total funded debt to total capitalization ratios for DTE Energy, DTE Electric and DTE Gas were 0.50 to 1, 0.52 to 1 and 0.47 to 1, respectively, and are in compliance with this financial covenant. The availability under the facilities in place at March 31, 2015 is shown in the following table:
		DTE Energy		DTE Electric		DTE Gas		Total
		(In millions)
	Unsecured letter of credit facility, expiring in February 2017	$	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 March 31, 2015:
	Letters of credit	255		—		—		255
		255		—		—		255
	Net availability at March 31, 2015	$	1,170	$	300	$	300	$	1,770
	In February 2015, DTE Energy amended its $100 million letter of credit facility. The facility's maturity date was amended from February 2015 to February 2017.
	In April 2015, DTE Energy, DTE Electric and DTE Gas, entered into third amended and restated five-year unsecured revolving credit agreements. The agreements' expiration was amended from April 2018 to April 2020. As part of this amendment, DTE Electric increased its $300 million unsecured revolving credit facility to $400 million.
	DTE Energy 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, DTE Energy may be required to post cash collateral with its clearing agent. DTE Energy 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 DTE Energy posts a letter of credit for the incremental amount. At March 31, 2015, 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 $74 million and $37 million at March 31, 2015 and December 31, 2014, respectively.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES
	Environmental
	DTE 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. The EPA and the State of Michigan have issued emission reduction regulations relating to ozone, fine particulate, regional haze, mercury, and other air pollution. These rules have led to 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 $2.2 billion through 2014. DTE Electric estimates making capital expenditures of approximately $100 million in 2015 and up to approximately $30 million of additional capital expenditures through 2019 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), required further reductions of sulfur dioxide and nitrogen oxides emissions beginning in January 2015. DTE Electric expects to meet its obligations under CSAPR. Portions of CSAPR are being reviewed by the U.S. Court of Appeals. DTE Electric cannot predict the financial impact or outcome of that case at this time.
	The Mercury and Air Toxics Standards (MATS) rule, formerly known as the Electric Generating Unit Maximum Achievable Control Technology (EGU MACT) Rule was finalized in December 2011. The MATS rule requires reductions of mercury and other hazardous air pollutants beginning in April 2015. DTE Electric has requested and been granted compliance date extensions for all relevant units to April 2016. DTE Electric has tested several technologies as MATS compliance alternatives to Flue Gas Desulfurization (FGD) systems to determine technological and economic feasibility. Dry Sorbent Injection (DSI) and Activated Carbon Injection (ACI) technologies were deemed feasible and their implementation will allow several units that would not have been economical for FGD installations to continue operation in compliance with MATS. In November 2014, the Supreme Court agreed to review a challenge to the MATS rule based on a narrowly focused question of how the EPA considered costs in regulating air pollutants emitted by electric utilities. DTE Electric cannot predict the financial impact or outcome of this Supreme Court case at this time, or the timing of its resolution.
	The EPA proposed revised air quality standards for ground level ozone in November 2014 and the standards are expected to be finalized by October 2015. DTE Electric cannot predict the financial impact of the proposed ozone standards at this time.
	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. In August 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. In October 2011, the EPA caused to be filed a Notice of Appeal to the U.S. Court of Appeals for the Sixth Circuit. In March 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. In September 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. In March 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. In April 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. In June 2014, the EPA filed a motion requesting certification for appeal of the March 2014 summary judgment decision. In October 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.
	The Registrants believe that 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 Registrants cannot predict the financial impact or outcome of this matter, or the timing of its resolution.
	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. A final rule was issued in May 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. DTE Electric is 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.
	In April 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. 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, DTE Electric 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 March 31, 2015 and December 31, 2014, DTE Electric had $9 million and $10 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 DTE Electric’s financial position and cash flows. DTE Electric believes the likelihood of a material change to the accrued amount is remote based on current knowledge of the conditions at each site.
	In April 2015, the EPA published a final rule for the disposal of coal combustion residuals, commonly known as coal ash. The rule is based on the continued listing of coal ash as a non-hazardous waste, and relies on various self-implementation design and performance standards. DTE Electric owns and operates three permitted engineered coal ash storage facilities to dispose of coal ash from coal fired power plants and operates a number of smaller impoundments at its power plants. DTE Electric is currently evaluating the rule and will determine its impacts upon completion of the evaluation.
	DTE Gas
	Contaminated and Other Sites — DTE Gas owns or previously owned, 14 former MGP sites. Investigations have revealed contamination related to the by-products of gas manufacturing at each site. Cleanup of four of the MGP sites is complete and the sites are closed. DTE Gas has also completed partial closure of two additional sites. Cleanup activities associated with the remaining sites will continue 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, DTE Gas is also in the process of cleaning up other contaminated sites, including gate stations, gas pipeline releases and underground storage tank locations. As of March 31, 2015 and December 31, 2014, DTE Gas had $23 million and $24 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 DTE Gas’s financial position and cash flows. DTE Gas anticipates the cost amortization methodology approved by the MPSC, which allows for amortization of 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 DTE Gas’s results of operations.
	Non-utility
	DTE Energy’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 DTE Energy’s position of demonstrated compliance and has not initiated escalated enforcement. At this time, DTE Energy 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 DTE Energy self reporting to MDEQ questionable activities by an employee of a contractor hired by DTE Energy to perform the visible emissions readings. At this time, DTE Energy cannot predict the impact of this investigation.
	DTE Energy 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. DTE Energy settled the alleged violations by implementing best management practices to address the issues and repair/upgrade their wastewater treatment plant. DTE Energy recently received a permit to upgrade its existing waste water treatment system and is currently seeking a permit from the PADEP to further upgrade its wastewater treatment technology to biological treatment. DTE Energy expects to spend $1 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. DTE Energy will also spend up to an additional $15 million over the next few years to complete its upgrade of the treatment technology to biological treatment in order to meet future regulatory requirements and gain other operational improvement savings.
	DTE Energy 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, DTE Energy 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 DTE Energy'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, DTE Energy agreed to a Consent Order and Agreement with Allegheny County pursuant to which DTE Energy 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 in May 2014. DTE Energy believes that the GASP suit is without merit and filed a motion to dismiss in July 2014. In March 2015, the United States District Court granted DTE Energy's motion for dismissal.
	Other
	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. 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 DTE Energy's Michigan coke battery. As part of the state implementation plan process, DTE Energy has worked with MDEQ to develop proposed air permits reflecting significant SO2 emission reductions. Since several non-DTE Energy sources are also part of the proposed compliance plan, DTE Energy is unable to determine the final 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 $328 million of coverage for extra expenses over a two-year period.
	On January 13, 2015, the Terrorism Risk Insurance Program Reauthorization Act of 2015 was signed, extending TRIA through December 31, 2020. 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 NEIL policies, DTE Electric could be liable for maximum assessments of up to approximately $43 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 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 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's 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 1 mill per kWh DOE fee was reduced to zero effective May 16, 2014.
	DTE Electric currently employs a spent nuclear fuel storage strategy utilizing a fuel pool and a newly completed dry cask storage facility. 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.
	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.
	Synthetic Fuel Guarantees
	DTE Energy discontinued the operations of its synthetic fuel production facilities throughout the United States as of December 31, 2007. DTE Energy 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. DTE Energy estimates that its maximum potential liability under these guarantees at March 31, 2015 is approximately $850 million. Payment under these guarantees is considered remote.
	REF Guarantees
	DTE Energy 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. DTE Energy estimates that its maximum potential liability under these guarantees at March 31, 2015 is approximately $192 million. Payment under these guarantees is considered remote.
	Other Guarantees
	In certain limited circumstances, the Registrants enter into contractual guarantees. The Registrants may guarantee another entity’s obligation in the event it fails to perform and may provide guarantees in certain indemnification agreements. Finally, the Registrants may provide indirect guarantees for the indebtedness of others. DTE Energy’s guarantees are not individually material with maximum potential payments totaling $63 million at March 31, 2015. Payment under these guarantees is considered remote.
	DTE Energy 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 March 31, 2015, DTE Energy had approximately $49 million of performance bonds outstanding. In the event that such bonds are called for nonperformance, DTE Energy would be obligated to reimburse the issuer of the performance bond. DTE Energy 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 DTE Energy's approximately 4,900 represented employees, including DTE Electric's approximately 2,600 represented employees. The majority of the represented employees are under contracts that expire in 2016 and 2017.
	Purchase Commitments
	As of March 31, 2015, the Registrants were party to numerous long-term purchase commitments relating to a variety of goods and services required for the business. These agreements primarily consist of fuel supply commitments and renewable energy contracts for the Registrants, as well as energy trading contracts for DTE Energy. DTE Energy estimates that these commitments will be approximately $8.2 billion from 2015 through 2051. DTE Electric estimates that these commitments will be approximately $2.4 billion from 2015 through 2033. In addition, DTE Energy and DTE Electric have made certain commitments in connection with 2015 capital expenditures and contributions to equity method investees that are expected to be approximately $2.6 billion and $1.9 billion, respectively.
	Bankruptcies
	Certain of the Registrants' customers and suppliers have filed for bankruptcy protection under the U.S. Bankruptcy Code. The Registrants regularly review contingent matters relating to these customers and suppliers and their purchase and sale contracts and record provisions for amounts considered at risk of probable loss. The Registrants believe their accrued amounts are adequate for probable loss.
	Other Contingencies
	The Registrants are 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 Registrants cannot predict the final disposition of such proceedings. The Registrants regularly review legal matters and record provisions for claims that they can estimate and are considered probable of loss. The resolution of these pending proceedings is not expected to have a material effect on the Registrants' operations or financial statements in the periods they are resolved.
	For a discussion of contingencies related to regulatory matters and derivatives see Notes 6 and 9 to the Consolidated Financial Statements, "Regulatory Matters" and "Financial and Other Derivative Instruments", respectively.

Retirement_Benefits_and_Truste

Retirement Benefits and Trusteed Assets	3 Months Ended
	Mar. 31, 2015
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Retirement Benefits and Trusteed Assets	RETIREMENT BENEFITS AND TRUSTEED ASSETS
	The following table details the components of net periodic benefit costs for pension benefits and other postretirement benefits for DTE Energy:
		Pension Benefits							Other Postretirement Benefits
		2015				2014			2015			2014
	Three Months Ended March 31,	(In millions)
	Service cost	$	25			$	21		$	9		$	9
	Interest cost	53				53			20			23
	Expected return on plan assets	(74		)		(68		)	(33		)	(31		)
	Amortization of:
	Net actuarial loss	51				38			11			5
	Prior service credit	—				—			(31		)	(36		)
	Net periodic benefit cost (credit)	$	55			$	44		$	(24	)	$	(30	)
	The following table details the components of net periodic benefit costs for pension benefits and other postretirement benefits for DTE Electric:
		Pension Benefits							Other Postretirement Benefits
		2015				2014			2015			2014
	Three Months Ended March 31,	(In millions)
	Service cost	$	20			$	17		$	7		$	7
	Interest cost	40				40			16			17
	Expected return on plan assets	(53		)		(48		)	(23		)	(21		)
	Amortization of:
	Net actuarial loss	38				27			8			3
	Prior service cost (credit)	—				—			(24		)	(27		)
	Net periodic benefit cost (credit)	$	45			$	36		$	(16	)	$	(21	)
	Pension and Other Postretirement Contributions
	In April 2015, DTE Energy made contributions of $25 million, through contributions from DTE Electric, to its pension plans. At the discretion of management, and depending upon financial market conditions, DTE Energy may make up to $150 million of additional contributions, including up to $120 million of additional DTE Electric contributions, to its pension plans in 2015.
	During 2015, DTE Energy contributed the following amounts of DTE Energy common stock to the DTE Energy Company Master VEBA Trust:
	Date		Number of Shares		Price per Share		Amount
							(In millions)
	February 17, 2015		1,427,835		$81.91		$	117
							$	117
	The above contribution was made on behalf of DTE Electric, who paid DTE Energy cash consideration of $117 million in February 2015.
	At the discretion of management, DTE Energy may make up to $80 million of additional contributions, including up to $60 million of additional DTE Electric contributions, to its other postretirement benefit plans in 2015.
	Plan Changes
	In 2015, certain executive retirement benefit plans were amended to transfer the obligation for benefits as attributed to DTE Energy Corporate Services, LLC (LLC), a subsidiary of DTE Energy. The related plan liabilities were transferred from DTE Electric and DTE Gas to LLC. The related Rabbi Trust assets were also transferred to DTE Energy from DTE Electric.

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2015
Share-based Compensation [Abstract]
Stock-based Compensation	STOCK-BASED COMPENSATION
	The following table summarizes the components of stock-based compensation for DTE Energy:
		Three Months Ended March 31,
		2015			2014
		(In millions)
	Stock-based compensation expense	$	6		$	33
	Tax benefit	$	2		$	13
	Stock-based compensation cost capitalized in property, plant and equipment	$	1		$	5
	Stock Options
	The following table summarizes DTE Energy's stock option activity for the three months ended March 31, 2015:
		Number of		Weighted			Aggregate Intrinsic Value
		Options		Average			(In millions)
				Exercise Price
	Options outstanding at January 1, 2015	444,278		$	43.56
	Exercised	(150,317	)	$	45.37
	Forfeited or expired	(3,979	)	$	44.72
	Options outstanding and exercisable at March 31, 2015	289,982		$	42.61		$	12
	As of March 31, 2015, the weighted average remaining contractual life for the exercisable shares is 3.32 years. As of March 31, 2015, all options were vested.
	The intrinsic value of options exercised for the three months ended March 31, 2015 and 2014 was $6 million and $5 million, respectively. No option expense was recognized for the three months ended March 31, 2015 and 2014, respectively.
	Restricted Stock Awards
	The following table summarizes DTE Energy’s restricted stock awards activity for the three months ended March 31, 2015:
		Restricted		Weighted Average Grant Date Fair Value
		Stock
	Balance at January 1, 2015	416,318		$	62.82
	Grants	105,500		$	84.06
	Forfeitures	(260	)	$	67.23
	Vested and issued	(141,260	)	$	53.4
	Balance at March 31, 2015	380,298		$	72.2
	Performance Share Awards
	Performance shares awarded under the plan are for a specified number of shares of DTE Energy common stock that entitle the holder to receive a cash payment, shares of DTE Energy 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 and 2015 were primarily deemed to be equity awards. The DTE Energy 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 DTE Energy’s performance share activity for the three months ended March 31, 2015:
		Performance		Weighted Average Grant Date Fair Value
		Shares
	Balance at January 1, 2015	1,554,697		$	69.32
	Grants	429,151		$	84.04
	Forfeitures	(5,021	)	$	69.16
	Payouts	(532,700	)	$	—
	Balance at March 31, 2015	1,446,127		$	75.76
	Unrecognized Compensation Costs
	As of March 31, 2015, DTE Energy had $81 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 1.72 years.
	Allocated Stock-Based Compensation
	DTE Electric received an allocation of costs from DTE Energy associated with stock-based compensation of $4 million and $19 million for the three months ended March 31, 2015 and 2014, respectively.

Segment_and_Related_Informatio

Segment and Related Information	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Segment and Related Information	SEGMENT AND RELATED INFORMATION
	DTE Energy 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 renewable 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 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 March 31,
		2015			2014
		(In millions)
	Inter-segment Revenues
	Electric	$	9		$	7
	Gas	1			2
	Gas Storage and Pipelines	1			1
	Power and Industrial Projects	180			206
	Energy Trading	9			9
	Corporate and Other	1			2
		$	201		$	227
	Financial data of the DTE Energy business segments follows:
		Three Months Ended March 31,
		2015			2014
		(In millions)
	Operating Revenues
	Electric	$	1,203		$	1,412
	Gas	647			804
	Gas Storage and Pipelines	57			52
	Power and Industrial Projects	567			575
	Energy Trading	711			1,314
	Corporate and Other	—			—
	Reconciliation and Eliminations	(201		)	(227		)
	Total	$	2,984		$	3,930
	Net Income (Loss) Attributable to DTE Energy by Segment:
	Electric	$	136		$	136
	Gas	111			129
	Gas Storage and Pipelines	27			21
	Power and Industrial Projects	33			15
	Energy Trading	(9		)	42
	Corporate and Other	(25		)	(17		)
	Net Income Attributable to DTE Energy Company	$	273		$	326

Significant_Accounting_Policie1

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation	The accompanying Consolidated Financial Statements of the Registrants 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 Registrants' estimates.
Principles of Consolidation	The Registrants consolidate all majority-owned subsidiaries and investments in entities in which they have controlling influence. Non-majority owned investments are accounted for using the equity method when the Registrants are able to influence the operating policies of the investee. When the Registrants do not influence the operating policies of an investee, the cost method is used. These Consolidated Financial Statements also reflect the Registrants' proportionate interests in certain jointly-owned utility plants. The Registrants eliminate all intercompany balances and transactions.
	The Registrants evaluate whether an entity is a VIE whenever reconsideration events occur. The Registrants consolidate VIEs for which they are the primary beneficiary. If a Registrant 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, a Registrant 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 Registrants perform ongoing reassessments of all VIEs to determine if the primary beneficiary status has changed.
	Legal entities within DTE Energy'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 DTE Energy retaining operational and customer default risk. These entities generally are VIEs and consolidated when DTE Energy is the primary beneficiary. In addition, DTE Energy has interests in certain VIEs through which control of all significant activities is shared with partners, and therefore are accounted for under the equity method.
	DTE Energy has variable interests in VIEs through certain of its long-term purchase and sale contracts. DTE Electric has variable interests in VIEs through certain of its long-term purchase contracts. As of March 31, 2015, the carrying amount of assets and liabilities in the Registrants' 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 Registrants for the deliveries associated with the current billing cycle under the contracts. The Registrants have 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 DTE Energy's variable interests through these long-term purchase and sale contracts. In addition, there is no significant potential exposure to loss as a result of DTE Electric's variable interests through these long-term purchase 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 performed servicing activities including billing and collecting surcharge revenue for Securitization. The remaining amounts due on the rate reduction bonds were paid in March 2015. The associated regulatory assets were fully amortized by March 31, 2015. Securitization has an over-recovery of funds which will be returned to customers after receipt of an order from the MPSC. Subsequent to the pay-down of the bonds, Securitization is no longer a VIE but continues to be consolidated by the Registrants as a voting interest entity.
	The maximum risk exposure for consolidated VIEs is reflected on the Registrants' 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.
Comprehensive Income	Changes in accumulated other comprehensive income (loss) are presented in the Registrants' Consolidated Statements of Changes in Equity.
Intangible Assets	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 by the Registrants. DTE Energy amortizes contract intangible assets on a straight-line basis over the expected period of benefit, ranging from 1 to 26 years.
Fair Value Measurement	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 Registrants make certain assumptions they believe 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 Registrants and their counterparties is incorporated in the valuation of assets and liabilities through the use of credit reserves, the impact of which was immaterial at March 31, 2015 and December 31, 2014. The Registrants believe they use 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 Registrants classify 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 Registrants have 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	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 NAVs. 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. The Registrants have obtained an understanding of how these prices are derived, including the nature and observability of the inputs used in deriving such prices. Additionally, the Registrants selectively corroborate the fair value of securities by comparison of market-based price sources. Investment policies and procedures are determined by DTE Energy's Trust Investments Department which reports to DTE Energy's Vice President and Treasurer.
Derivatives Reporting of Derivative Activity	The Registrants consider 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. The Registrants monitor 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. The Registrants have obtained an understanding of how these prices are derived. Additionally, the Registrants selectively corroborate the fair value of their 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 Registrants have 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 the Registrants' forward price curves has been assigned to DTE Energy's Risk Management Department, which is separate and distinct from the trading functions within DTE Energy.
Fair Value Transfer	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	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. The Registrants have obtained an understanding of how the fair values are derived. The Registrants also selectively corroborate the fair value of their 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 for the Registrants are determined by the DTE Energy's Treasury Department which reports to the DTE Energy's Vice President and Treasurer.
Derivatives	The Registrants recognize all derivatives at their fair value as Derivative assets or liabilities on their respective 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 Registrants’ primary market risk exposure is associated with commodity prices, credit and interest rates. The Registrants have risk management policies to monitor and manage market risks. The Registrants use derivative instruments to manage some of the exposure. DTE Energy 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	Certain of the DTE Energy'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, DTE Energy offsets the fair value of derivative instruments with cash collateral received or paid for those contracts executed with the same counterparty, which reduces DTE Energy'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.
	DTE Energy 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. DTE Energy had no letters of credit outstanding at March 31, 2015 and $7 million in letters of credit at December 31, 2014, which could be used to offset net derivative liabilities. Letters of credit received from third parties which could be used to offset net derivative assets were $1 million and $5 million at March 31, 2015 and December 31, 2014, respectively. Such balances of letters of credit are excluded from the tables below and are not netted with the recognized assets and liabilities in DTE Energy's 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 DTE Energy's 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	Revenues and energy costs related to trading contracts are presented on a net basis in DTE Energy's Consolidated Statements of Operations. Commodity derivatives used for trading purposes, and financial non-trading commodity derivatives, are accounted for using the MTM 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 MTM 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	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 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)	3 Months Ended
	Mar. 31, 2015
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Schedule of Variable Interest Entities	The following table summarizes the major Consolidated Statements of Financial Position items for consolidated VIEs as of March 31, 2015 and December 31, 2014. 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. Securitization, included in the DTE Energy table below for December 31, 2014, also relates to DTE Electric. VIEs, in which DTE Energy 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.
		March 31, 2015		December 31, 2014
		Total		Securitization		Other		Total
		(In millions)
	ASSETS
	Cash and cash equivalents	$	12	$	—	$	7	$	7
	Restricted cash	9		96		8		104
	Accounts receivable	12		26		15		41
	Inventories	34		—		67		67
	Property, plant and equipment, net	77		—		81		81
	Securitized regulatory assets	—		34		—		34
	Other current and long-term assets	6		1		6		7
		$	150	$	157	$	184	$	341
	LIABILITIES
	Accounts payable and accrued current liabilities	$	11	$	3	$	8	$	11
	Current portion long-term debt, including capital leases	8		105		10		115
	Current regulatory liabilities	—		32		—		32
	Mortgage bonds, notes and other	14		—		15		15
	Capital lease obligations	1		—		3		3
	Other current and long-term liabilities	6		9		6		15
		$	40	$	149	$	42	$	191
Summary of Amounts for Non-Consolidated Variable Interest Entities	Amounts for DTE Energy's non-consolidated VIEs as of March 31, 2015 and December 31, 2014 are as follows:
		31-Mar-15		31-Dec-14
		(In millions)
	Other investments	$	136	$	134
	Notes receivable	$	15	$	15

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Schedule of Finite-Lived Intangible Assets	DTE Energy has certain intangible assets relating to emission allowances, renewable energy credits and non-utility contracts as shown below:
		March 31,			December 31,
		2015			2014
		(In millions)
	Emission allowances	$	1		$	1
	Renewable energy credits	46			45
	Contract intangible assets	123			122
		170			168
	Less accumulated amortization	60			57
	Intangible assets, net	110			111
	Less current intangible assets	10			9
		$	100		$	102
	DTE Electric has certain intangible assets relating to emission allowances and renewable energy credits as shown below:
		March 31,			December 31,
		2015			2014
		(In millions)
	Emission allowances	$	1		$	1
	Renewable energy credits	46			45
		47			46
	Less current intangible assets	10			9
		$	37		$	37
Schedule of Effective Tax Rate and Unrecognized Tax Benefits	The effective tax rate and unrecognized tax benefits of the Registrants are as follows:
		Effective Tax Rate					Unrecognized
							Tax Benefits
		Three Months Ended March 31,					March 31,
		2015		2014			2015
							(In millions)
	DTE Energy	31	%	33	%		$	9
	DTE Electric	35	%	36	%		$	4

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	3 Months Ended
	Mar. 31, 2015
Asset Retirement Obligation Disclosure [Abstract]
Schedule of Change in Asset Retirement Obligation	A reconciliation of the asset retirement obligations for the three months ended March 31, 2015 follows:
		DTE Energy		DTE Electric
		(In millions)
	Asset retirement obligations at December 31, 2014	$	1,962	$	1,796
	Accretion	28		26
	Revision in estimated cash flows	32		32
	Asset retirement obligations at March 31, 2015	$	2,022	$	1,854

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	A reconciliation of both calculations is presented in the following table for the three months ended March 31:
		Three Months Ended March 31,
		2015		2014
		(In millions, except per share amounts)
	Basic Earnings per Share
	Net income attributable to DTE Energy Company	$	273	$	326
	Average number of common shares outstanding	178		177
	Dividends declared — common shares	$	123	$	116
	Dividends declared — net restricted shares	1		—
	Total distributed earnings	$	124	$	116
	Net income less distributed earnings	$	149	$	210
	Distributed (dividends per common share)	$	0.69	$	0.66
	Undistributed	0.84		1.18
	Total Basic Earnings per Common Share	$	1.53	$	1.84
	Diluted Earnings per Share
	Net income attributable to DTE Energy Company	$	273	$	326
	Average number of common shares outstanding	178		177
	Dividends declared — common shares	$	123	$	116
	Dividends declared — net restricted shares	1		—
	Total distributed earnings	$	124	$	116
	Net income less distributed earnings	$	149	$	210
	Distributed (dividends per common share)	$	0.69	$	0.66
	Undistributed	0.84		1.18
	Total Diluted Earnings per Common Share	$	1.53	$	1.84

Fair_Value_Tables

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Assets and liabilities measured and recorded at fair value on a recurring basis	The following table presents assets and liabilities for DTE Energy measured and recorded at fair value on a recurring basis as of March 31, 2015 and December 31, 2014:
		31-Mar-15																			31-Dec-14
		Level 1			Level 2				Level 3				Netting				Net Balance				Level 1				Level 2			Level 3			Netting			Net Balance
													(a)																		(a)
		(In millions)
	Assets:
	Cash equivalents (b)	$	14		$	3			$	—			$	—			$	17			$	13			$	99		$	—		$	—		$	112
	Nuclear decommissioning trusts	798			464				—				—				1,262				792				449			—			—			1,241
	Other investments (c)	100			51				—				—				151				100				50			—			—			150
	Derivative assets:
	Commodity Contracts:
	Natural Gas	315			87				41				(389		)		54				555				140			92			(681		)	106
	Electricity	—			234				36				(215		)		55				—				295			47			(280		)	62
	Other	42			—				1				(42		)		1				42				—			3			(42		)	3
	Other derivative contracts (d)	—			8				—				(4		)		4				—				4			—			(3		)	1
	Total derivative assets	357			329				78				(650		)		114				597				439			142			(1,006		)	172
	Total	$	1,269		$	847			$	78			$	(650	)		$	1,544			$	1,502			$	1,037		$	142		$	(1,006	)	$	1,675
	Liabilities:
	Derivative liabilities:
	Commodity Contracts:
	Natural Gas	$	(369	)	$	(45	)		$	(41	)		$	428			$	(27	)		$	(578	)		$	(78	)	$	(62	)	$	679		$	(39	)
	Electricity	—			(219		)		(43		)		217				(45		)		—				(290		)	(52		)	298			(44		)
	Other	(32		)	(8		)		(6		)		46				—				(32		)		(9		)	(4		)	45			—
	Other derivative contracts (d)	—			(7		)		—				4				(3		)		—				(5		)	—			3			(2		)
	Total derivative liabilities	(401		)	(279		)		(90		)		695				(75		)		(610		)		(382		)	(118		)	1,025			(85		)
	Total	$	(401	)	$	(279	)		$	(90	)		$	695			$	(75	)		$	(610	)		$	(382	)	$	(118	)	$	1,025		$	(85	)
	Net Assets (Liabilities) at the end of the period	$	868		$	568			$	(12	)		$	45			$	1,469			$	892			$	655		$	24		$	19		$	1,590
	Assets:
	Current	$	339		$	295			$	59			$	(602	)		$	91			$	582			$	504		$	109		$	(955	)	$	240
	Noncurrent (e)	930			552				19				(48		)		1,453				920				533			33			(51		)	1,435
	Total Assets	$	1,269		$	847			$	78			$	(650	)		$	1,544			$	1,502			$	1,037		$	142		$	(1,006	)	$	1,675
	Liabilities:
	Current	$	(353	)	$	(253	)		$	(74	)		$	628			$	(52	)		$	(572	)		$	(357	)	$	(112	)	$	964		$	(77	)
	Noncurrent	(48		)	(26		)		(16		)		67				(23		)		(38		)		(25		)	(6		)	61			(8		)
	Total Liabilities	$	(401	)	$	(279	)		$	(90	)		$	695			$	(75	)		$	(610	)		$	(382	)	$	(118	)	$	1,025		$	(85	)
	Net Assets (Liabilities) at the end of the period	$	868		$	568			$	(12	)		$	45			$	1,469			$	892			$	655		$	24		$	19		$	1,590
	_______________________________________
	(a)	Amounts represent the impact of master netting agreements that allow DTE Energy to net gain and loss positions and cash collateral held or placed with the same counterparties.
	(b)	At March 31, 2015, available-for-sale securities of $17 million included $9 million and $8 million of cash equivalents included in Restricted cash and Other investments on DTE Energy's Consolidated Statements of Financial Position, respectively. At December 31, 2014, available-for-sale securities of $112 million, included $105 million and $7 million of cash equivalents included in Restricted cash and Other investments on DTE Energy's Consolidated Statements of Financial Position, respectively.
	(c)	Excludes cash surrender value of life insurance investments.
	(d)	Primarily includes Foreign currency exchange contracts.
	(e)	Includes $151 million and $150 million at March 31, 2015 and December 31, 2014, respectively, of other investments that are included in DTE Energy's Consolidated Statements of Financial Position in Other investments.
	The following table presents assets for DTE Electric measured and recorded at fair value on a recurring basis as of March 31, 2015 and December 31, 2014:
		March 31, 2015															December 31, 2014
		Level 1			Level 2				Level 3				Net Balance				Level 1				Level 2				Level 3			Net Balance
		(In millions)
	Assets:
	Cash equivalents (a)	$	5		$	3			$	—			$	8			$	5			$	99			$	—		$	104
	Nuclear decommissioning trusts	798			464				—				1,262				792				449				—			1,241
	Other investments	10			—				—				10				97				50				—			147
	Derivative assets — FTRs	—			—				1				1				—				—				3			3
	Total	$	813		$	467			$	1			$	1,281			$	894			$	598			$	3		$	1,495
	Assets:
	Current	$	5		$	3			$	1			$	9			$	5			$	99			$	3		$	107
	Noncurrent	808			464				—				1,272				889				499				—			1,388
	Total Assets	$	813		$	467			$	1			$	1,281			$	894			$	598			$	3		$	1,495
	_______________________________________
	(a)	At March 31, 2015, available-for-sale securities of $8 million consisted of cash equivalents included in Other investments on DTE Electric's Consolidated Statements of Financial Position. At December 31, 2014, available-for-sale securities of $104 million included $96 million and $8 million of cash equivalents included in Restricted cash and Other investments, respectively, on DTE Electric's Consolidated Statements of Financial Position.
Fair value reconciliation of level 3 assets and liabilities measured at fair value on a recurring basis	The following tables present the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for DTE Energy for the three months ended March 31, 2015 and 2014:
		Three Months Ended March 31, 2015															Three Months Ended March 31, 2014
		Natural Gas			Electricity				Other				Total				Natural Gas				Electricity				Other			Total
		(In millions)
	Net Assets (Liabilities) as of December 31	$	30		$	(5	)		$	(1	)		$	24			$	(52	)		$	13			$	3		$	(36	)
	Transfers into Level 3	—			—				(1		)		(1		)		—				—				—			—
	Transfers out of Level 3	—			—				—				—				—				—				—			—
	Total gains (losses):
	Included in earnings	(29		)	7				(2		)		(24		)		(22		)		36				—			14
	Recorded in regulatory assets/liabilities	—			—				(2		)		(2		)		—				—				4			4
	Purchases, issuances and settlements:
	Issuances	—			—				—				—				—				(1		)		—			(1		)
	Settlements	(1		)	(9		)		1				(9		)		64				(82		)		(6		)	(24		)
	Net Assets (Liabilities) as of March 31	$	—		$	(7	)		$	(5	)		$	(12	)		$	(10	)		$	(34	)		$	1		$	(43	)
	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 March 31, 2015 and 2014 and reflected in Operating revenues and Fuel, purchased power and gas in DTE Energy's Consolidated Statements of Operations	$	(91	)	$	(3	)		$	(2	)		$	(96	)		$	—			$	(20	)		$	—		$	(20	)
	The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for DTE Electric for three months ended March 31, 2015 and 2014:
		Three Months Ended March 31,
		2015			2014
		(In millions)
	Net Assets as of beginning of period	$	3		$	3
	Change in fair value recorded in regulatory assets/liabilities	(2		)	4
	Purchases, issuances and settlements:
	Settlements	—			(6		)
	Net Assets as of March 31,	$	1		$	1
	The amount of total gains (losses) included in Regulatory assets and liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31, 2015 and 2014 and reflected in DTE Electric's Consolidated Statements of Operations	$	—		$	—
Unobservable inputs related to Level 3 assets and liabilities	The following table presents the unobservable inputs related to DTE Energy's Level 3 assets and liabilities as of March 31, 2015:
			March 31, 2015
	Commodity Contracts		Derivative Assets			Derivative Liabilities				Valuation Techniques		Unobservable Input		Range								Weighted Average
			(In millions)
	Natural Gas		$	41		$	(41	)		Discounted Cash Flow		Forward basis price (per MMBtu)		$	(2.46	) —		$	7	/MMBtu		$	(0.25	)/MMBtu
	Electricity		$	36		$	(43	)		Discounted Cash Flow		Forward basis price (per MWh)		$	(7	) —		$	19	/MWh		$	3	/MWh
	The following table presents the unobservable inputs related to DTE Energy's Level 3 assets and liabilities as of December 31, 2014:
			December 31, 2014
	Commodity Contracts		Derivative Assets			Derivative Liabilities				Valuation Techniques		Unobservable Input		Range								Weighted Average
			(In millions)
	Natural Gas		$	92		$	(62	)		Discounted Cash Flow		Forward basis price (per MMBtu)		$	(2.28	) —		$	7.83	/MMBtu		$	(0.22	)/MMBtu
	Electricity		$	47		$	(52	)		Discounted Cash Flow		Forward basis price (per MWh)		$	(14	) —		$	15	/MWh		$	4	/MWh
Carrying amount of fair value of financial instruments	The following table presents the carrying amount and fair value of financial instruments for DTE Energy as of March 31, 2015 and December 31, 2014:
		March 31, 2015															December 31, 2014
		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	$	35		$	—			$	—			$	35			$	41			$	—			$	—		$	41
	Dividends payable	$	124		$	124			$	—			$	—			$	122			$	122			$	—		$	—
	Short-term borrowings	$	—		$	—			$	—			$	—			$	398			$	—			$	398		$	—
	Long-term debt, excluding capital leases	$	8,989		$	500			$	8,581			$	1,051			$	8,606			$	489			$	8,308		$	706
	The following table presents the carrying amount and fair value of financial instruments for DTE Electric as of March 31, 2015 and December 31, 2014:
		March 31, 2015															December 31, 2014
		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	$	6		$	—			$	—			$	6			$	12			$	—			$	—		$	12
	Notes receivable — affiliates	$	—		$	—			$	—			$	—			$	8			$	—			$	—		$	8
	Short-term borrowings — affiliates	$	35		$	—			$	—			$	35			$	84			$	—			$	—		$	84
	Short-term borrowings — other	$	—		$	—			$	—			$	—			50				$	—			$	50		$	—
	Long-term debt, excluding capital leases	$	5,643		$	—			$	5,682			$	735			$	5,259			$	—			$	5,341		$	496
Fair value of nuclear decommissioning trust fund assets	The following table summarizes DTE Electric's fair value of the nuclear decommissioning trust fund assets:
		31-Mar-15			31-Dec-14
		(In millions)
	Fermi 2	$	1,241		$	1,221
	Fermi 1	3			3
	Low-level radioactive waste	18			17
	Total	$	1,262		$	1,241
Schedule of realized gain (loss)	The following table sets forth DTE Electric's gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds:
		Three Months Ended March 31,
		2015			2014
		(In millions)
	Realized gains	$	9		$	9
	Realized losses	$	(7	)	$	(7	)
	Proceeds from sales of securities	$	246		$	271
Fair value and unrealized gains for nuclear decommissioning trust fund	The following table sets forth DTE Electric's fair value and unrealized gains and losses for the nuclear decommissioning trust funds:
		31-Mar-15											31-Dec-14
		Fair			Unrealized				Unrealized				Fair				Unrealized				Unrealized
		Value			Gains				Losses				Value				Gains				Losses
		(In millions)
	Equity securities	$	774		$	217			$	(41	)		$	756			$	204			$	(39	)
	Debt securities	483			24				(1		)		474				21				(2		)
	Cash and cash equivalents	5			—				—				11				—				—
		$	1,262		$	241			$	(42	)		$	1,241			$	225			$	(41	)

Financial_and_Other_Derivative1

Financial and Other Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair value of derivative instruments	The following tables present the fair value of derivative instruments as of March 31, 2015 and December 31, 2014 for DTE Energy:
		March 31, 2015								December 31, 2014
		Derivative				Derivative Liabilities				Derivative			Derivative Liabilities
		Assets								Assets
		(In millions)
	Derivatives not designated as hedging instruments:
	Foreign currency exchange contracts	$	8			$	(7	)		$	4		$	(5	)
	Commodity Contracts:
	Natural Gas	443				(455		)		787			(718		)
	Electricity	270				(262		)		342			(342		)
	Other	43				(46		)		45			(45		)
	Total derivatives not designated as hedging instruments:	$	764			$	(770	)		$	1,178		$	(1,110	)
	Total derivatives:
	Current	$	676			$	(680	)		$	1,083		$	(1,041	)
	Noncurrent	88				(90		)		95			(69		)
	Total derivatives	$	764			$	(770	)		$	1,178		$	(1,110	)
	The following table presents the fair value of derivative instruments as of March 31, 2015 and December 31, 2014 for DTE Electric:
		March 31, 2015				December 31, 2014
		(In millions)
	FTRs — Other current assets	$	1			$	3
	Total derivatives not designated as hedging instrument	$	1			$	3
Netting Offsets of Derivative Assets and Liabilities	The following table presents the netting offsets of derivative assets and liabilities for DTE Energy at March 31, 2015 and December 31, 2014:
		31-Mar-15											31-Dec-14
		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	$	443			$	(389	)		$	54		$	787		$	(681	)	$	106
	Electricity	270				(215		)		55			342			(280		)	62
	Other	43				(42		)		1			45			(42		)	3
	Other derivative contracts (a)	8				(4		)		4			4			(3		)	1
	Total derivative assets	$	764			$	(650	)		$	114		$	1,178		$	(1,006	)	$	172
	Derivative liabilities:
	Commodity Contracts:
	Natural Gas	$	(455	)		$	428			$	(27	)	$	(718	)	$	679		$	(39	)
	Electricity	(262		)		217				(45		)	(342		)	298			(44		)
	Other	(46		)		46				—			(45		)	45			—
	Other derivative contracts (a)	(7		)		4				(3		)	(5		)	3			(2		)
	Total derivative liabilities	$	(770	)		$	695			$	(75	)	$	(1,110	)	$	1,025		$	(85	)
	_______________________________________
	(a)	Primarily includes Foreign currency exchange contracts.
Netting Offsets of Derivative Assets and Liabilities Reconciliation to the Statements of Financial Position	The following table presents the netting offsets of derivative assets and liabilities for DTE Energy at March 31, 2015 and December 31, 2014:
		March 31, 2015														31-Dec-14
		Derivative Assets								Derivative Liabilities						Derivative Assets						Derivative Liabilities
		Current				Noncurrent				Current			Noncurrent			Current			Noncurrent			Current			Noncurrent
		(In millions)
	Reconciliation of derivative instruments to DTE Energy's Consolidated Statements of Financial Position:
	Total fair value of derivatives	$	676			$	88			$	(680	)	$	(90	)	$	1,083		$	95		$	(1,041	)	$	(69	)
	Counterparty netting	(601		)		(48		)		601			48			(955		)	(51		)	955			51
	Collateral adjustment	(1		)		—				27			19			—			—			9			10
	Total derivatives as reported	$	74			$	40			$	(52	)	$	(23	)	$	128		$	44		$	(77	)	$	(8	)
Gain (Loss) Recognized in Income on Derivative	The effect of derivatives not designated as hedging instruments on DTE Energy's Consolidated Statements of Operations for the three months ended March 31, 2015 and 2014 for DTE Energy is as follows:
			Location of Gain		Gain (Loss) Recognized in
			(Loss) Recognized		Income on Derivatives for
			in Income on Derivatives		the Three Months Ended March 31,
	Derivatives not Designated as Hedging Instruments				2015				2014
					(In millions)
	Foreign currency exchange contracts		Operating Revenue		$	1			$	(4	)
	Commodity Contracts:
	Natural Gas		Operating Revenue		(126		)		(127		)
	Natural Gas		Fuel, purchased power and gas		21				20
	Electricity		Operating Revenue		31				133
	Other		Operating Revenue		(2		)		(1		)
	Total				$	(75	)		$	21
Volume of Commodity Contracts	The following represents the cumulative gross volume of DTE Energy's derivative contracts outstanding as of March 31, 2015:
	Commodity		Number of Units
	Natural Gas (MMBtu)		935,928,277
	Electricity (MWh)		13,667,643
	Oil (Gallons)		27,048,000
	Foreign Currency Exchange (Canadian dollars)		80,737,962

LongTerm_Debt_Tables

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2015
Long-term Debt, Unclassified [Abstract]
Schedule of Issued Debt	In 2015, the following debt was issued:
	Company		Month	Type	Interest Rate	Maturity	Amount
							(In millions)
	DTE Electric		March	Mortgage Bonds (a)	3.70%	2045	$	500
							$	500
	_______________________________________
	(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	In 2015, the following debt was redeemed:
	Company		Month	Type	Interest Rate	Maturity	Amount
							(In millions)
	DTE Electric		March	Securitization Bonds	6.62%	2015	$	105
	DTE Electric		March	Mortgage Bonds	7.90%	2016	10
	DTE Energy		Various	Other Long Term Debt	Various	2015	2
							$	117

ShortTerm_Credit_Arrangements_1

Short-Term Credit Arrangements and Borrowings (Tables)	3 Months Ended
	Mar. 31, 2015
Short-term Debt [Abstract]
Schedule of Line of Credit Facilities	The availability under the facilities in place at March 31, 2015 is shown in the following table:
		DTE Energy		DTE Electric		DTE Gas		Total
		(In millions)
	Unsecured letter of credit facility, expiring in February 2017	$	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 March 31, 2015:
	Letters of credit	255		—		—		255
		255		—		—		255
	Net availability at March 31, 2015	$	1,170	$	300	$	300	$	1,770

Retirement_Benefits_and_Truste1

Retirement Benefits and Trusteed Assets (Tables)	3 Months Ended
	Mar. 31, 2015
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Schedule of Net Benefit Costs	The following table details the components of net periodic benefit costs for pension benefits and other postretirement benefits for DTE Energy:
		Pension Benefits							Other Postretirement Benefits
		2015				2014			2015			2014
	Three Months Ended March 31,	(In millions)
	Service cost	$	25			$	21		$	9		$	9
	Interest cost	53				53			20			23
	Expected return on plan assets	(74		)		(68		)	(33		)	(31		)
	Amortization of:
	Net actuarial loss	51				38			11			5
	Prior service credit	—				—			(31		)	(36		)
	Net periodic benefit cost (credit)	$	55			$	44		$	(24	)	$	(30	)
	The following table details the components of net periodic benefit costs for pension benefits and other postretirement benefits for DTE Electric:
		Pension Benefits							Other Postretirement Benefits
		2015				2014			2015			2014
	Three Months Ended March 31,	(In millions)
	Service cost	$	20			$	17		$	7		$	7
	Interest cost	40				40			16			17
	Expected return on plan assets	(53		)		(48		)	(23		)	(21		)
	Amortization of:
	Net actuarial loss	38				27			8			3
	Prior service cost (credit)	—				—			(24		)	(27		)
	Net periodic benefit cost (credit)	$	45			$	36		$	(16	)	$	(21	)
Schedule of Contributions	During 2015, DTE Energy contributed the following amounts of DTE Energy common stock to the DTE Energy Company Master VEBA Trust:
	Date		Number of Shares		Price per Share		Amount
							(In millions)
	February 17, 2015		1,427,835		$81.91		$	117
							$	117

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Share-based Compensation [Abstract]
Schedule of Stock-based Compensation	The following table summarizes the components of stock-based compensation for DTE Energy:
		Three Months Ended March 31,
		2015			2014
		(In millions)
	Stock-based compensation expense	$	6		$	33
	Tax benefit	$	2		$	13
	Stock-based compensation cost capitalized in property, plant and equipment	$	1		$	5
Schedule of Stock Option Activity	The following table summarizes DTE Energy's stock option activity for the three months ended March 31, 2015:
		Number of		Weighted			Aggregate Intrinsic Value
		Options		Average			(In millions)
				Exercise Price
	Options outstanding at January 1, 2015	444,278		$	43.56
	Exercised	(150,317	)	$	45.37
	Forfeited or expired	(3,979	)	$	44.72
	Options outstanding and exercisable at March 31, 2015	289,982		$	42.61		$	12
Schedule of Restricted Stock Activitiy	The following table summarizes DTE Energy’s restricted stock awards activity for the three months ended March 31, 2015:
		Restricted		Weighted Average Grant Date Fair Value
		Stock
	Balance at January 1, 2015	416,318		$	62.82
	Grants	105,500		$	84.06
	Forfeitures	(260	)	$	67.23
	Vested and issued	(141,260	)	$	53.4
	Balance at March 31, 2015	380,298		$	72.2
Schedule of Performance Share Activity	The following table summarizes DTE Energy’s performance share activity for the three months ended March 31, 2015:
		Performance		Weighted Average Grant Date Fair Value
		Shares
	Balance at January 1, 2015	1,554,697		$	69.32
	Grants	429,151		$	84.04
	Forfeitures	(5,021	)	$	69.16
	Payouts	(532,700	)	$	—
	Balance at March 31, 2015	1,446,127		$	75.76

Segment_Information_Tables

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	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 March 31,
		2015			2014
		(In millions)
	Inter-segment Revenues
	Electric	$	9		$	7
	Gas	1			2
	Gas Storage and Pipelines	1			1
	Power and Industrial Projects	180			206
	Energy Trading	9			9
	Corporate and Other	1			2
		$	201		$	227
	Financial data of the DTE Energy business segments follows:
		Three Months Ended March 31,
		2015			2014
		(In millions)
	Operating Revenues
	Electric	$	1,203		$	1,412
	Gas	647			804
	Gas Storage and Pipelines	57			52
	Power and Industrial Projects	567			575
	Energy Trading	711			1,314
	Corporate and Other	—			—
	Reconciliation and Eliminations	(201		)	(227		)
	Total	$	2,984		$	3,930
	Net Income (Loss) Attributable to DTE Energy by Segment:
	Electric	$	136		$	136
	Gas	111			129
	Gas Storage and Pipelines	27			21
	Power and Industrial Projects	33			15
	Energy Trading	(9		)	42
	Corporate and Other	(25		)	(17		)
	Net Income Attributable to DTE Energy Company	$	273		$	326

Organization_and_Basis_of_Pres2

Organization and Basis of Presentation (Details Textuals) (USD $)	Mar. 31, 2015
	customers
Number of electric utility customers	2,100,000
Number of gas utility customers	1,200,000
Significant Potential Exposure to Loss Due to VIE Long-Term Purchase Contracts	$0
DTE Electric
Significant Potential Exposure to Loss Due to VIE Long-Term Purchase Contracts	$0

Organization_and_Basis_of_Pres3

Organization and Basis of Presentation (Consolidated Variable Interest Entities) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
ASSETS
Cash and cash equivalents	$99	$48	$98	$52
Restricted cash	24	120
Accounts receivable	1,534	1,504
Property, plant and equipment, net	17,235	16,820
Securitized regulatory assets	0	34
Total Assets	28,068	27,974
Liabilities [Abstract]
Current portion long-term debt, including capital leases	166	274
Current regulatory liabilities	79	153
Mortgage bonds, notes and other	8,348	7,860
Capital lease obligations	10	3
Variable Interest Entity, Primary Beneficiary [Member]
ASSETS
Cash and cash equivalents	12	7
Restricted cash	9	104
Accounts receivable	12	41
Inventories	34	67
Property, plant and equipment, net	77	81
Securitized regulatory assets	0	34
Other current and long-term assets	6	7
Total Assets	150	341
Liabilities [Abstract]
Accounts payable and accrued current liabilities	11	11
Current portion long-term debt, including capital leases	8	115
Current regulatory liabilities	0	32
Mortgage bonds, notes and other	14	15
Capital lease obligations	1	3
Other current and long-term liabilities	6	15
Total Liabilities	40	191
Variable Interest Entity, Primary Beneficiary Securitization [Member]
ASSETS
Cash and cash equivalents		0
Restricted cash		96
Accounts receivable		26
Inventories		0
Property, plant and equipment, net		0
Securitized regulatory assets		34
Other current and long-term assets		1
Total Assets		157
Liabilities [Abstract]
Accounts payable and accrued current liabilities		3
Current portion long-term debt, including capital leases		105
Current regulatory liabilities		32
Mortgage bonds, notes and other		0
Capital lease obligations		0
Other current and long-term liabilities		9
Total Liabilities		149
Variable Interest Entity, Primary Beneficiary Other [Member]
ASSETS
Cash and cash equivalents		7
Restricted cash		8
Accounts receivable		15
Inventories		67
Property, plant and equipment, net		81
Securitized regulatory assets		0
Other current and long-term assets		6
Total Assets		184
Liabilities [Abstract]
Accounts payable and accrued current liabilities		8
Current portion long-term debt, including capital leases		10
Current regulatory liabilities		0
Mortgage bonds, notes and other		15
Capital lease obligations		3
Other current and long-term liabilities		6
Total Liabilities		$42

Organization_and_Basis_of_Pres4

Organization and Basis of Presentation (Non Consolidated Variable Interest Entities) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Variable Interest Entity [Line Items]
Notes receivable	$88	$90
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Other investments	136	134
Notes receivable	$15	$15

Significant_Accounting_Policie3

Significant Accounting Policies (Details Textuals) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Significant Accounting Policies [Line Items]
Other income	$51	$41
Increase (decrease) in effective tax rate from prior year	-2.00%
Deferred tax expense	8
Unrecognized tax benefits that would impact effective tax rate	2
Change in unrecognized tax benefits is reasonably possible	6
DTE Electric
Significant Accounting Policies [Line Items]
Other income	15	13
Increase (decrease) in effective tax rate from prior year	-1.00%
DTE Electric | DTE Energy
Significant Accounting Policies [Line Items]
Income Taxes Receivable	51		29
Minimum
Significant Accounting Policies [Line Items]
Useful life	1 year
Maximum
Significant Accounting Policies [Line Items]
Useful life	26 years
Power and Industrial Projects
Significant Accounting Policies [Line Items]
Other income	$19	$17

Significant_Accounting_Policie4

Significant Accounting Policies (Intangible Assets) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$170	$168
Less accumulated amortization	60	57
Intangible assets, net	110	111
Less current intangible assets	10	9
Intangible assets	100	102
DTE Electric
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	47	46
Less current intangible assets	10	9
Intangible assets	37	37
Renewable energy credits
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	46	45
Renewable energy credits | DTE Electric
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	46	45
Contract intangible assets
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	123	122
Emission allowances
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets, gross	1	1
Emission allowances | DTE Electric
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets, gross	$1	$1

Significant_Accounting_Policie5

Significant Accounting Policies (Income Taxes) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Schedule of Income Taxes [Line Items]
Effective Tax Rate	31.00%	33.00%
Unrecognized Tax Benefits	$9
DTE Electric
Schedule of Income Taxes [Line Items]
Effective Tax Rate	35.00%	36.00%
Unrecognized Tax Benefits	$4

Acquisition_Details

Acquisition (Details) (USD $)	3 Months Ended		0 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Jan. 21, 2015
Business Acquisition [Line Items]
Total purchase price	$240	$0
DTE Electric
Business Acquisition [Line Items]
Total purchase price	240	0
DTE Electric | Natural Gas Facility in Carson City Michigan
Business Acquisition [Line Items]
Gas facility capacity			732
Number of additional households served			260,000
Equity interest acquired			100.00%
Total purchase price			$240

Asset_Retirement_Obligations_D

Asset Retirement Obligations (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations, beginning balance	$1,962
Accretion	28
Revision in estimated cash flows	32
Asset retirement obligations, ending balance	2,022
DTE Electric
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations, beginning balance	1,796
Accretion	26
Revision in estimated cash flows	32
Asset retirement obligations, ending balance	$1,854

Regulatory_Matters_Details_Tex

Regulatory Matters (Details Textuals) (DTE Electric, USD $)	0 Months Ended
	Dec. 19, 2014	Sep. 30, 2013	Jul. 30, 2012	Jan. 01, 2014	Sep. 30, 2012	Apr. 24, 2015
Public Utilities, General Disclosures [Line Items]
Fermi 2 production level of full capacity			68.00%
Maximum of challenged Fermi 2 outage charges		$32,000,000
MPSC
Public Utilities, General Disclosures [Line Items]
Public utilities, requested rate increase (decrease)	370,000,000
MPSC | Refundable Revenue Decoupling
Public Utilities, General Disclosures [Line Items]
Regulatory liability					127,000,000
Monthly amount to amortize from liability to income				10,600,000
Subsequent Event | MPSC
Public Utilities, General Disclosures [Line Items]
Maximum of challenged Fermi 2 outage charges						$50,000,000

Earnings_Per_Share_Details

Earnings Per Share (Details) (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Basic Earnings per Share
Net Income Attributable to DTE Energy Company/DTE Electric	$273	$326
Average number of common shares outstanding (in shares)	178	177
Dividends declared — common shares	123	116
Dividends declared — net restricted shares	1	0
Total distributed earnings	124	116
Net income less distributed earnings	149	210
Distributed (dividends per common share) (dollars per share)	$0.69	$0.66
Undistributed (in dollars per share)	$0.84	$1.18
Total Basic Earnings per Common Share (dollars per share)	$1.53	$1.84
Diluted Earnings per Share
Net Income Attributable to DTE Energy Company/DTE Electric	273	326
Average number of common shares outstanding (in shares)	178	177
Dividends declared — common shares	123	116
Dividends declared — net restricted shares	1	0
Total distributed earnings	124	116
Net income less distributed earnings	$149	$210
Distributed (dividends per common share) (dollars per share)	$0.69	$0.66
Undistributed (dollars per share)	$0.84	$1.18
Total Diluted Earnings per Common Share (dollars per share)	$1.53	$1.84

Fair_Value_Assets_and_Liabilit

Fair Value (Assets and Liabilities Recorded at Fair Value on a Recurring Basis) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Derivative Assets
Derivative asset, gross	$764	$1,178
Derivative asset, netting	-650	-1,006
Derivative assets, net	114	172
Derivative Liabilities
Derivative liability, gross	-770	-1,110
Derivative liability, netting	695	1,025
Derivative liabilities, net	-75	-85
DTE Electric
ASSETS
Nuclear decommissioning trusts	1,262	1,241
Current derivative liability
Derivative Liabilities
Derivative liability, gross	-680	-1,041
Noncurrent derivative liability
Derivative Liabilities
Derivative liability, gross	-90	-69
Natural Gas
Derivative Assets
Derivative asset, gross	443	787
Derivative asset, netting	-389	-681
Derivative assets, net	54	106
Derivative Liabilities
Derivative liability, gross	-455	-718
Derivative liability, netting	428	679
Derivative liabilities, net	-27	-39
Electricity
Derivative Assets
Derivative asset, gross	270	342
Derivative asset, netting	-215	-280
Derivative assets, net	55	62
Derivative Liabilities
Derivative liability, gross	-262	-342
Derivative liability, netting	217	298
Derivative liabilities, net	-45	-44
Other
Derivative Assets
Derivative asset, gross	43	45
Derivative asset, netting	-42	-42
Derivative assets, net	1	3
Derivative Liabilities
Derivative liability, gross	-46	-45
Derivative liability, netting	46	45
Derivative liabilities, net	0	0
Other derivative contract
Derivative Assets
Derivative asset, gross	8	4
Derivative asset, netting	-4	-3
Derivative assets, net	4	1
Derivative Liabilities
Derivative liability, gross	-7	-5
Derivative liability, netting	4	3
Derivative liabilities, net	-3	-2
Recurring
ASSETS
Cash and cash equivalents	17	112
Nuclear decommissioning trusts	1,262	1,241
Other investments	151	150
Derivative Assets
Derivative asset, netting	-650	-1,006
Derivative assets, net	114	172
Total assets	1,544	1,675
Derivative Liabilities
Derivative liability, netting	695	1,025
Derivative liabilities, net	-75	-85
Net asset (liability)	1,469	1,590
Net assets (liabilities), netting	45	19
Recurring | DTE Electric
ASSETS
Cash and cash equivalents	8	104
Nuclear decommissioning trusts	1,262	1,241
Other investments	10	147
Derivative Assets
Total assets	1,281	1,495
Recurring | Current asset
Derivative Assets
Derivative asset, netting	-602	-955
Total assets	91	240
Recurring | Current asset | DTE Electric
Derivative Assets
Total assets	9	107
Recurring | Noncurrent asset
Derivative Assets
Derivative asset, netting	-48	-51
Total assets	1,453	1,435
Recurring | Noncurrent asset | DTE Electric
Derivative Assets
Total assets	1,272	1,388
Recurring | Current derivative liability
Derivative Liabilities
Derivative liability, netting	628	964
Derivative liabilities, net	-52	-77
Recurring | Noncurrent derivative liability
Derivative Liabilities
Derivative liability, netting	67	61
Derivative liabilities, net	-23	-8
Recurring | Natural Gas
Derivative Assets
Derivative asset, netting	-389	-681
Derivative assets, net	54	106
Derivative Liabilities
Derivative liability, netting	428	679
Derivative liabilities, net	-27	-39
Recurring | Electricity
Derivative Assets
Derivative asset, netting	-215	-280
Derivative assets, net	55	62
Derivative Liabilities
Derivative liability, netting	217	298
Derivative liabilities, net	-45	-44
Recurring | Other
Derivative Assets
Derivative asset, netting	-42	-42
Derivative assets, net	1	3
Derivative Liabilities
Derivative liability, netting	46	45
Derivative liabilities, net	0	0
Recurring | Other derivative contract
Derivative Assets
Derivative asset, netting	-4	-3
Derivative assets, net	4	1
Derivative Liabilities
Derivative liability, netting	4	3
Derivative liabilities, net	-3	-2
Recurring | Financial transmission rights | DTE Electric
Derivative Assets
Derivative assets, net	1	3
Recurring | Level 1
ASSETS
Cash and cash equivalents	14	13
Nuclear decommissioning trusts	798	792
Other investments	100	100
Derivative Assets
Derivative asset, gross	357	597
Total assets	1,269	1,502
Derivative Liabilities
Derivative liability, gross	-401	-610
Net asset (liability)	868	892
Recurring | Level 1 | DTE Electric
ASSETS
Cash and cash equivalents	5	5
Nuclear decommissioning trusts	798	792
Other investments	10	97
Derivative Assets
Total assets	813	894
Recurring | Level 1 | Current asset
Derivative Assets
Total assets	339	582
Recurring | Level 1 | Current asset | DTE Electric
Derivative Assets
Total assets	5	5
Recurring | Level 1 | Noncurrent asset
Derivative Assets
Total assets	930	920
Recurring | Level 1 | Noncurrent asset | DTE Electric
Derivative Assets
Total assets	808	889
Recurring | Level 1 | Current derivative liability
Derivative Liabilities
Derivative liability, gross	-353	-572
Recurring | Level 1 | Noncurrent derivative liability
Derivative Liabilities
Derivative liability, gross	-48	-38
Recurring | Level 1 | Natural Gas
Derivative Assets
Derivative asset, gross	315	555
Derivative Liabilities
Derivative liability, gross	-369	-578
Recurring | Level 1 | Electricity
Derivative Assets
Derivative asset, gross	0	0
Derivative Liabilities
Derivative liability, gross	0	0
Recurring | Level 1 | Other
Derivative Assets
Derivative asset, gross	42	42
Derivative Liabilities
Derivative liability, gross	-32	-32
Recurring | Level 1 | Other derivative contract
Derivative Assets
Derivative asset, gross	0	0
Derivative Liabilities
Derivative liability, gross	0	0
Recurring | Level 1 | Financial transmission rights | DTE Electric
Derivative Assets
Derivative assets, net	0	0
Recurring | Level 2
ASSETS
Cash and cash equivalents	3	99
Nuclear decommissioning trusts	464	449
Other investments	51	50
Derivative Assets
Derivative asset, gross	329	439
Total assets	847	1,037
Derivative Liabilities
Derivative liability, gross	-279	-382
Net asset (liability)	568	655
Recurring | Level 2 | DTE Electric
ASSETS
Cash and cash equivalents	3	99
Nuclear decommissioning trusts	464	449
Other investments	0	50
Derivative Assets
Total assets	467	598
Recurring | Level 2 | Current asset
Derivative Assets
Total assets	295	504
Recurring | Level 2 | Current asset | DTE Electric
Derivative Assets
Total assets	3	99
Recurring | Level 2 | Noncurrent asset
Derivative Assets
Total assets	552	533
Recurring | Level 2 | Noncurrent asset | DTE Electric
Derivative Assets
Total assets	464	499
Recurring | Level 2 | Current derivative liability
Derivative Liabilities
Derivative liability, gross	-253	-357
Recurring | Level 2 | Noncurrent derivative liability
Derivative Liabilities
Derivative liability, gross	-26	-25
Recurring | Level 2 | Natural Gas
Derivative Assets
Derivative asset, gross	87	140
Derivative Liabilities
Derivative liability, gross	-45	-78
Recurring | Level 2 | Electricity
Derivative Assets
Derivative asset, gross	234	295
Derivative Liabilities
Derivative liability, gross	-219	-290
Recurring | Level 2 | Other
Derivative Assets
Derivative asset, gross	0	0
Derivative Liabilities
Derivative liability, gross	-8	-9
Recurring | Level 2 | Other derivative contract
Derivative Assets
Derivative asset, gross	8	4
Derivative Liabilities
Derivative liability, gross	-7	-5
Recurring | Level 2 | Financial transmission rights | DTE Electric
Derivative Assets
Derivative assets, net	0	0
Recurring | Level 3
ASSETS
Cash and cash equivalents	0	0
Nuclear decommissioning trusts	0	0
Other investments	0	0
Derivative Assets
Derivative asset, gross	78	142
Total assets	78	142
Derivative Liabilities
Derivative liability, gross	-90	-118
Net asset (liability)	-12	24
Recurring | Level 3 | DTE Electric
ASSETS
Cash and cash equivalents	0	0
Nuclear decommissioning trusts	0	0
Other investments	0	0
Derivative Assets
Total assets	1	3
Recurring | Level 3 | Current asset
Derivative Assets
Total assets	59	109
Recurring | Level 3 | Current asset | DTE Electric
Derivative Assets
Total assets	1	3
Recurring | Level 3 | Noncurrent asset
Derivative Assets
Total assets	19	33
Recurring | Level 3 | Noncurrent asset | DTE Electric
Derivative Assets
Total assets	0	0
Recurring | Level 3 | Current derivative liability
Derivative Liabilities
Derivative liability, gross	-74	-112
Recurring | Level 3 | Noncurrent derivative liability
Derivative Liabilities
Derivative liability, gross	-16	-6
Recurring | Level 3 | Natural Gas
Derivative Assets
Derivative asset, gross	41	92
Derivative Liabilities
Derivative liability, gross	-41	-62
Recurring | Level 3 | Electricity
Derivative Assets
Derivative asset, gross	36	47
Derivative Liabilities
Derivative liability, gross	-43	-52
Recurring | Level 3 | Other
Derivative Assets
Derivative asset, gross	1	3
Derivative Liabilities
Derivative liability, gross	-6	-4
Recurring | Level 3 | Other derivative contract
Derivative Assets
Derivative asset, gross	0	0
Derivative Liabilities
Derivative liability, gross	0	0
Recurring | Level 3 | Financial transmission rights | DTE Electric
Derivative Assets
Derivative assets, net	$1	$3

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
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis
Net Assets (Liabilities) as of December 31	$24	($36)
Transfers into Level 3	-1	0
Transfers out of Level 3	0	0
Total gains (losses):
Included in earnings	-24	14
Recorded in regulatory assets/liabilities	-2	4
Purchases, issuances and settlements:
Issuances	0	-1
Settlements	-9	-24
Net Assets (Liabilities) as of March 31	-12	-43
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 March 31, 2015 and 2014 and reflected in Operating revenues and Fuel, purchased power and gas in DTE Energy's Consolidated Statements of Operations	-96	-20
DTE Electric
Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis
Net Assets (Liabilities) as of December 31	3	3
Total gains (losses):
Recorded in regulatory assets/liabilities	-2	4
Purchases, issuances and settlements:
Settlements	0	-6
Net Assets (Liabilities) as of March 31	1	1
The amount of total gains (losses) included in Regulatory assets and liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31, 2015 and 2014 and reflected in DTE Electric's Consolidated Statements of Operations	0	0
Natural Gas
Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis
Net Assets (Liabilities) as of December 31	30	-52
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Total gains (losses):
Included in earnings	-29	-22
Recorded in regulatory assets/liabilities	0	0
Purchases, issuances and settlements:
Issuances	0	0
Settlements	-1	64
Net Assets (Liabilities) as of March 31	0	-10
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 March 31, 2015 and 2014 and reflected in Operating revenues and Fuel, purchased power and gas in DTE Energy's Consolidated Statements of Operations	-91	0
Electricity
Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis
Net Assets (Liabilities) as of December 31	-5	13
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Total gains (losses):
Included in earnings	7	36
Recorded in regulatory assets/liabilities	0	0
Purchases, issuances and settlements:
Issuances	0	-1
Settlements	-9	-82
Net Assets (Liabilities) as of March 31	-7	-34
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 March 31, 2015 and 2014 and reflected in Operating revenues and Fuel, purchased power and gas in DTE Energy's Consolidated Statements of Operations	-3	-20
Other
Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis
Net Assets (Liabilities) as of December 31	-1	3
Transfers into Level 3	-1	0
Transfers out of Level 3	0	0
Total gains (losses):
Included in earnings	-2	0
Recorded in regulatory assets/liabilities	-2	4
Purchases, issuances and settlements:
Issuances	0	0
Settlements	1	-6
Net Assets (Liabilities) as of March 31	-5	1
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 March 31, 2015 and 2014 and reflected in Operating revenues and Fuel, purchased power and gas in DTE Energy's Consolidated Statements of Operations	($2)	$0

Fair_Value_Unobservable_Inputs

Fair Value (Unobservable Inputs related to Level 3 Assets and Liabilities) (Details) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Unobservable Inputs Valuation Techniques [Line Items]
Derivative asset, gross	$764	$1,178
Derivative liability, gross	-770	-1,110
Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative asset, gross	78	142
Derivative liability, gross	-90	-118
Natural Gas
Unobservable Inputs Valuation Techniques [Line Items]
Derivative asset, gross	443	787
Derivative liability, gross	-455	-718
Natural Gas | Level 3 | Discounted cash flow valuation technique | Minimum
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price	-2.46	-2.28
Natural Gas | Level 3 | Discounted cash flow valuation technique | Maximum
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price	7	7.83
Natural Gas | Level 3 | Discounted cash flow valuation technique | Weighted Average
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price	-0.25	-0.22
Natural Gas | Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative asset, gross	41	92
Derivative liability, gross	-41	-62
Electricity
Unobservable Inputs Valuation Techniques [Line Items]
Derivative asset, gross	270	342
Derivative liability, gross	-262	-342
Electricity | Level 3 | Discounted cash flow valuation technique | Minimum
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price	-7	-14
Electricity | Level 3 | Discounted cash flow valuation technique | Maximum
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price	19	15
Electricity | Level 3 | Discounted cash flow valuation technique | Weighted Average
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price	3	4
Electricity | Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative asset, gross	36	47
Derivative liability, gross	($43)	($52)

Fair_Value_Fair_Value_of_Finan

Fair Value (Fair Value of Financial Instruments) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	$35	$41
Dividends payable	124	122
Short-term borrowings	0	398
Long-term debt, excluding capital leases	8,989	8,606
Carrying Amount | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	6	12
Short-term borrowings	0	50
Long-term debt, excluding capital leases	5,643	5,259
Carrying Amount | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	8
Short-term borrowings	35	84
Fair Value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Dividends payable	124	122
Short-term borrowings	0	0
Long-term debt, excluding capital leases	500	489
Fair Value | Level 1 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Short-term borrowings	0	0
Long-term debt, excluding capital leases	0	0
Fair Value | Level 1 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Short-term borrowings	0	0
Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Dividends payable	0	0
Short-term borrowings	0	398
Long-term debt, excluding capital leases	8,581	8,308
Fair Value | Level 2 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Short-term borrowings	0	50
Long-term debt, excluding capital leases	5,682	5,341
Fair Value | Level 2 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Short-term borrowings	0	0
Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	35	41
Dividends payable	0	0
Short-term borrowings	0	0
Long-term debt, excluding capital leases	1,051	706
Fair Value | Level 3 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	6	12
Short-term borrowings	0	0
Long-term debt, excluding capital leases	735	496
Fair Value | Level 3 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	8
Short-term borrowings	$35	$84

Fair_Value_Fair_Value_of_Nucle

Fair Value (Fair Value of Nuclear Decommissioning Trust Fund Assets) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	$1,262	$1,241
DTE Electric
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	1,262	1,241
DTE Electric | Fermi 2
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	1,241	1,221
DTE Electric | Fermi 1
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	3	3
DTE Electric | Low-level radioactive waste
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	18	17
DTE Electric | Nuclear decommissioning trust fund
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	$1,262	$1,241

Fair_Value_Gains_and_Losses_an

Fair Value (Gains and Losses and Proceeds from the Sale of Securities by the Nuclear Trust Funds) (Details) (DTE Electric, Nuclear decommissioning trust fund, USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
DTE Electric | Nuclear decommissioning trust fund
Schedule of Available-for-sale Securities [Line Items]
Realized gains	$9	$9
Realized losses	-7	-7
Proceeds from sales of securities	$246	$271

Fair_Value_Fair_Value_and_Unre

Fair Value (Fair Value and Unrealized Gains for the Nuclear Decommissioning Trust Funds) (Details) (DTE Electric, USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$1,262	$1,241
Unrealized Gains	241	225
Unrealized Losses	-42	-41
Nuclear decommissioning trust fund
Schedule of Available-for-sale Securities [Line Items]
Equity securities	774	756
Debt securities	483	474
Cash and cash equivalents	5	11
Equity securities, unrealized gains	217	204
Equity securities, unrealized losses	-41	-39
Debt securities, unrealized gains	24	21
Debt securities, unrealized losses	($1)	($2)

Fair_Value_Details_Textuals

Fair Value (Details Textuals) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2014
Fair Value, Option, Quantitative Disclosures [Line Items]
Assets Level 1 to Level 2	$0	$0
Assets Level 2 to Level 1	0	0
Liabilities Level 1 to Level 2	0	0
Liabilities Level 2 to Level 1	0	0
Trading securities realized gain (loss)	1,000,000	2,000,000
Accumulated Net Unrealized Investment Gain (Loss)
Fair Value, Option, Quantitative Disclosures [Line Items]
Unrealized losses on available for sale securities	0	0
Nuclear decommissioning trust fund
Fair Value, Option, Quantitative Disclosures [Line Items]
Average maturity of debt securities			7 years
DTE Electric
Fair Value, Option, Quantitative Disclosures [Line Items]
Transfers between Level 3	0	0
Trading securities realized gain (loss)	1,000,000	2,000,000
DTE Electric | Accumulated Net Unrealized Investment Gain (Loss)
Fair Value, Option, Quantitative Disclosures [Line Items]
Unrealized losses on available for sale securities	0
DTE Electric | Nuclear decommissioning trust fund
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash and cash equivalents	5,000,000			11,000,000
Average maturity of debt securities	7 years
Recurring
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash and cash equivalents	17,000,000			112,000,000
Recurring | DTE Electric
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash and cash equivalents	8,000,000			104,000,000
Restricted assets | Recurring
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash and cash equivalents	9,000,000			105,000,000
Restricted assets | Recurring | DTE Electric
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash and cash equivalents				96,000,000
Other investments | Recurring
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash and cash equivalents	8,000,000			7,000,000
Other investments | Recurring | DTE Electric
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash and cash equivalents				8,000,000
Other investments | Recurring | Equity
Fair Value, Option, Quantitative Disclosures [Line Items]
Other investments	$151,000,000			$150,000,000

Financial_and_Other_Derivative2

Financial and Other Derivative Instruments (Fair Value of Derivative Instruments) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Derivatives, Fair Value [Line Items]
Derivative asset, gross	$764	$1,178
Derivative liability, gross	-770	-1,110
Natural Gas
Derivatives, Fair Value [Line Items]
Derivative asset, gross	443	787
Derivative liability, gross	-455	-718
Electricity
Derivatives, Fair Value [Line Items]
Derivative asset, gross	270	342
Derivative liability, gross	-262	-342
Other
Derivatives, Fair Value [Line Items]
Derivative asset, gross	43	45
Derivative liability, gross	-46	-45
Current derivative asset
Derivatives, Fair Value [Line Items]
Derivative asset, gross	676	1,083
Current derivative liability
Derivatives, Fair Value [Line Items]
Derivative liability, gross	-680	-1,041
Noncurrent derivative asset
Derivatives, Fair Value [Line Items]
Derivative asset, gross	88	95
Noncurrent derivative liability
Derivatives, Fair Value [Line Items]
Derivative liability, gross	-90	-69
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative asset, gross	764	1,178
Derivative liability, gross	-770	-1,110
Not Designated as Hedging Instrument | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative asset, gross	1	3
Not Designated as Hedging Instrument | Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative asset, gross	8	4
Derivative liability, gross	-7	-5
Not Designated as Hedging Instrument | Natural Gas
Derivatives, Fair Value [Line Items]
Derivative asset, gross	443	787
Derivative liability, gross	-455	-718
Not Designated as Hedging Instrument | Electricity
Derivatives, Fair Value [Line Items]
Derivative asset, gross	270	342
Derivative liability, gross	-262	-342
Not Designated as Hedging Instrument | Other
Derivatives, Fair Value [Line Items]
Derivative asset, gross	43	45
Derivative liability, gross	-46	-45
Not Designated as Hedging Instrument | Financial transmission rights | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative asset, gross	$1	$3

Financial_and_Other_Derivative3

Financial and Other Derivative Instruments Financial and Other Derivative Instruments (Netting Offsets of Derivative Assets and Liabilities) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Millions, unless otherwise specified
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	$764	$1,178
Gross Amounts Offset in the Consolidated Statements of Financial Position	-650	-1,006
Net Amounts of Assets Presented in the Statements of Financial Position	114	172
Gross Amounts of Recognized (Liabilities)	-770	-1,110
Gross Amounts Offset in the Consolidated Statements of Financial Position	695	1,025
Net Amounts of (Liabilities) Presented in the Statements of Financial Position	-75	-85
Natural Gas
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	443	787
Gross Amounts Offset in the Consolidated Statements of Financial Position	-389	-681
Net Amounts of Assets Presented in the Statements of Financial Position	54	106
Gross Amounts of Recognized (Liabilities)	-455	-718
Gross Amounts Offset in the Consolidated Statements of Financial Position	428	679
Net Amounts of (Liabilities) Presented in the Statements of Financial Position	-27	-39
Electricity
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	270	342
Gross Amounts Offset in the Consolidated Statements of Financial Position	-215	-280
Net Amounts of Assets Presented in the Statements of Financial Position	55	62
Gross Amounts of Recognized (Liabilities)	-262	-342
Gross Amounts Offset in the Consolidated Statements of Financial Position	217	298
Net Amounts of (Liabilities) Presented in the Statements of Financial Position	-45	-44
Other
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	43	45
Gross Amounts Offset in the Consolidated Statements of Financial Position	-42	-42
Net Amounts of Assets Presented in the Statements of Financial Position	1	3
Gross Amounts of Recognized (Liabilities)	-46	-45
Gross Amounts Offset in the Consolidated Statements of Financial Position	46	45
Net Amounts of (Liabilities) Presented in the Statements of Financial Position	0	0
Other derivative contract
Offsetting Assets [Line Items]
Gross Amounts of Recognized Assets	8	4
Gross Amounts Offset in the Consolidated Statements of Financial Position	-4	-3
Net Amounts of Assets Presented in the Statements of Financial Position	4	1
Gross Amounts of Recognized (Liabilities)	-7	-5
Gross Amounts Offset in the Consolidated Statements of Financial Position	4	3
Net Amounts of (Liabilities) Presented in the Statements of Financial Position	($3)	($2)

Financial_and_Other_Derivative4

Financial and Other Derivative Instruments Financial and Other Derivative Instruments (Netting Offsets Reconciliation to Balance Sheet) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Derivative Assets
Derivative asset, gross	$764,000,000	$1,178,000,000
Collateral adjustment	-1,000,000	0
Derivative assets, current	74,000,000	128,000,000
Derivative assets, noncurrent	40,000,000	44,000,000
Derivative Liabilities
Derivative liability, gross	-770,000,000	-1,110,000,000
Collateral adjustment	46,000,000	19,000,000
Derivative liabilities, current	-52,000,000	-77,000,000
Derivative liabilities, noncurrent	-23,000,000	-8,000,000
Current derivative asset
Derivative Assets
Derivative asset, gross	676,000,000	1,083,000,000
Counterparty netting	-601,000,000	-955,000,000
Collateral adjustment	-1,000,000	0
Noncurrent derivative asset
Derivative Assets
Derivative asset, gross	88,000,000	95,000,000
Counterparty netting	-48,000,000	-51,000,000
Collateral adjustment	0	0
Current derivative liability
Derivative Liabilities
Derivative liability, gross	-680,000,000	-1,041,000,000
Counterparty netting	601,000,000	955,000,000
Collateral adjustment	27,000,000	9,000,000
Noncurrent derivative liability
Derivative Liabilities
Derivative liability, gross	-90,000,000	-69,000,000
Counterparty netting	48,000,000	51,000,000
Collateral adjustment	$19,000,000	$10,000,000

Financial_and_Other_Derivative5

Financial and Other Derivative Instruments (Effect of Derivatives not Designated as Hedging Instruments on the Consolidated Statement of Operations) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives for the Three Months Ended March 31,	($75)	$21
Foreign currency exchange contracts | Operating Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives for the Three Months Ended March 31,	1	-4
Natural Gas | Operating Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives for the Three Months Ended March 31,	-126	-127
Natural Gas | Fuel, purchased power and gas
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives for the Three Months Ended March 31,	21	20
Electricity | Operating Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives for the Three Months Ended March 31,	31	133
Other | Operating Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives for the Three Months Ended March 31,	($2)	($1)

Financial_and_Other_Derivative6

Financial and Other Derivative Instruments (Cumulative Gross Volume of Derivative Contracts Outstanding) (Details) (CAD)	Mar. 31, 2015
	MMBTU
Natural Gas
Derivative [Line Items]
Number of units	935,928,277
Electricity
Derivative [Line Items]
Number of units	13,667,643
Oil
Derivative [Line Items]
Number of units	27,048,000
Foreign currency exchange contracts
Derivative [Line Items]
Derivative fair value	80,737,962

Financial_and_Other_Derivative7

Financial and Other Derivative Instruments (Details Textuals) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Letters of credit that could be used to offset net derivative liabilities	$0	$7,000,000
Letters of credit received that could be used to offset net derivative assets	1,000,000	5,000,000
Cash collateral posted, net of cash collateral received	85,000,000	61,000,000
Derivative Asset, Collateral, Obligation to Return Cash, Offset	1,000,000	0
Collateral adjustment	46,000,000	19,000,000
Cash collateral received	3,000,000	2,000,000
Cash collateral paid	43,000,000	44,000,000
Additional collateral, aggregate fair value	416,000,000
Derivative net liability position aggregate fair value	726,000,000
Collateral already posted fair value	4,000,000
Derivative net asset position, fair value	630,000,000
Remaining amount of offsets to derivative net liability positions for hard and soft trigger provisions	$92,000,000

LongTerm_Debt_Debt_Issuances_D

Long-Term Debt (Debt Issuances) (Details) (USD $)	Mar. 31, 2015
Debt Instrument [Line Items]
Face amount	$500,000,000
DTE Electric | Mortgages | March 3.70% Mortgage Bonds Maturing 2045
Debt Instrument [Line Items]
Interest Rate	3.70%
Face amount	$500,000,000

LongTerm_Debt_Debt_Redemptions

Long-Term Debt (Debt Redemptions) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015
Debt Instrument [Line Items]
Debt redemption amount	$117
Securitization Bonds | DTE Electric | March 2015 Securitization Bonds 6.62% due 2015 [Member]
Debt Instrument [Line Items]
Interest Rate	6.62%
Debt redemption amount	105
Mortgages | DTE Electric | 7.904% Mortgage Bonds Due 2015
Debt Instrument [Line Items]
Interest Rate	7.90%
Debt redemption amount	10
Other Long Term Debt | Various Other Long Term Debt Due 2015
Debt Instrument [Line Items]
Debt redemption amount	$2

ShortTerm_Credit_Arrangements_2

Short-Term Credit Arrangements and Borrowings (Details) (USD $)	Mar. 31, 2015
Availability under combined facilities
Maximum borrowing capacity	$2,025,000,000
Amounts outstanding	255,000,000
Net availability	1,770,000,000
DTE Energy
Availability under combined facilities
Maximum borrowing capacity	1,425,000,000
Amounts outstanding	255,000,000
Net availability	1,170,000,000
DTE Electric
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Amounts outstanding	0
Net availability	300,000,000
DTE Gas
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Amounts outstanding	0
Net availability	300,000,000
Letter of Credit
Availability under combined facilities
Amounts outstanding	255,000,000
Letter of Credit | DTE Energy
Availability under combined facilities
Amounts outstanding	255,000,000
Letter of Credit | DTE Electric
Availability under combined facilities
Amounts outstanding	0
Letter of Credit | DTE Gas
Availability under combined facilities
Amounts outstanding	0
Letter of Credit | Unsecured letter of credit facility, expiring in February 2017
Availability under combined facilities
Maximum borrowing capacity	100,000,000
Letter of Credit | Unsecured letter of credit facility, expiring in February 2017 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	100,000,000
Letter of Credit | Unsecured letter of credit facility, expiring in February 2017 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Letter of Credit | Unsecured letter of credit facility, expiring in February 2017 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Letter of Credit | Unsecured letter of credit facility, expiring in August 2015
Availability under combined facilities
Maximum borrowing capacity	125,000,000
Letter of Credit | Unsecured letter of credit facility, expiring in August 2015 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	125,000,000
Letter of Credit | Unsecured letter of credit facility, expiring in August 2015 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Letter of Credit | Unsecured letter of credit facility, expiring in August 2015 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Revolving Credit Facility | Unsecured revolving credit facility, expiring April 2018
Availability under combined facilities
Maximum borrowing capacity	1,800,000,000
Revolving Credit Facility | Unsecured revolving credit facility, expiring April 2018 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	1,200,000,000
Revolving Credit Facility | Unsecured revolving credit facility, expiring April 2018 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Revolving Credit Facility | Unsecured revolving credit facility, expiring April 2018 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	$300,000,000

ShortTerm_Credit_Arrangements_3

Short-Term Credit Arrangements and Borrowings (Details Textuals) (USD $)	1 Months Ended
	Apr. 24, 2015	Mar. 31, 2015	Dec. 31, 2014
Short-term Debt [Line Items]
Maximum borrowing capacity, line of credit		$2,025,000,000
Other outstanding letters of credit		255,000,000
Letter of Credit
Short-term Debt [Line Items]
Other outstanding letters of credit		255,000,000
DTE Energy
Short-term Debt [Line Items]
Ratio of indebtedness to net capital		0.5
Maximum borrowing capacity, line of credit		1,425,000,000
Other outstanding letters of credit		255,000,000
DTE Energy | Letter of Credit
Short-term Debt [Line Items]
Other outstanding letters of credit		255,000,000
DTE Energy | Demand Financing Agreement
Short-term Debt [Line Items]
Maximum borrowing capacity, financing agreement		100,000,000
Maximum additional margin financing		50,000,000
Amount outstanding		74,000,000	37,000,000
DTE Energy | Demand Financing Agreement Plus Letter of Credit
Short-term Debt [Line Items]
Maximum borrowing capacity, financing agreement		150,000,000
DTE Electric
Short-term Debt [Line Items]
Ratio of indebtedness to net capital		0.52
Maximum borrowing capacity, line of credit		300,000,000
Other outstanding letters of credit		0
DTE Electric | Letter of Credit
Short-term Debt [Line Items]
Other outstanding letters of credit		0
DTE Gas
Short-term Debt [Line Items]
Ratio of indebtedness to net capital		0.47
Maximum borrowing capacity, line of credit		300,000,000
Other outstanding letters of credit		0
DTE Gas | Letter of Credit
Short-term Debt [Line Items]
Other outstanding letters of credit		0
Unsecured letter of credit facility, expiring in February 2017 | Letter of Credit
Short-term Debt [Line Items]
Maximum borrowing capacity, line of credit		100,000,000
Unsecured letter of credit facility, expiring in February 2017 | DTE Energy | Letter of Credit
Short-term Debt [Line Items]
Maximum borrowing capacity, line of credit		100,000,000
Unsecured letter of credit facility, expiring in February 2017 | DTE Electric | Letter of Credit
Short-term Debt [Line Items]
Maximum borrowing capacity, line of credit		0
Unsecured letter of credit facility, expiring in February 2017 | DTE Gas | Letter of Credit
Short-term Debt [Line Items]
Maximum borrowing capacity, line of credit		0
Unsecured revolving credit facility, expiring April 2020 | Revolving Credit Facility | Subsequent Event
Short-term Debt [Line Items]
Term of revolving credit agreement	5 years
Unsecured revolving credit facility, expiring April 2020 | DTE Electric | Revolving Credit Facility | Subsequent Event
Short-term Debt [Line Items]
Maximum borrowing capacity, line of credit	400,000,000
Unsecured revolving credit facility, expiring April 2018 | Revolving Credit Facility
Short-term Debt [Line Items]
Maximum borrowing capacity, line of credit		1,800,000,000
Unsecured revolving credit facility, expiring April 2018 | DTE Energy | Revolving Credit Facility
Short-term Debt [Line Items]
Maximum borrowing capacity, line of credit		1,200,000,000
Unsecured revolving credit facility, expiring April 2018 | DTE Electric | Revolving Credit Facility
Short-term Debt [Line Items]
Maximum borrowing capacity, line of credit		300,000,000
Unsecured revolving credit facility, expiring April 2018 | DTE Gas | Revolving Credit Facility
Short-term Debt [Line Items]
Maximum borrowing capacity, line of credit		300,000,000
Other outstanding letters of credit [Member] | DTE Energy | Letter of Credit
Short-term Debt [Line Items]
Other outstanding letters of credit		35,000,000
Demand Financing Agreement | DTE Energy | Letter of Credit
Short-term Debt [Line Items]
Maximum borrowing capacity, financing agreement		$50,000,000
Maximum
Short-term Debt [Line Items]
Ratio of indebtedness to net capital		0.65

Commitments_and_Contingencies_

Commitments and Contingencies (Details Textuals) (USD $)	3 Months Ended	0 Months Ended	4 Months Ended
	Mar. 31, 2015	16-May-14	15-May-14	Dec. 31, 2010	Dec. 31, 2014
		kWh	kWh	dte_instances
Loss Contingencies [Line Items]
Number of NOVs				2
Possible environmental capital expenditures to comply with requirements	$1,000,000
Estimated maximum spend to upgrade treatment technology to biological treatment to meet future requirements	15,000,000
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
Commitment amount	8,200,000,000
Future commitments	2,600,000,000
Represented employees
Loss Contingencies [Line Items]
Entity number of employees	4,900
Synthetic Fuel
Loss Contingencies [Line Items]
Maximum potential liability	850,000,000
Emissions
Loss Contingencies [Line Items]
Maximum potential liability	192,000,000
Other Guarantees
Loss Contingencies [Line Items]
Maximum potential liability	63,000,000
Performance Surety Bonds
Loss Contingencies [Line Items]
Performance bonds outstanding	49,000,000
DTE Electric
Loss Contingencies [Line Items]
Environmental capital expenditures through prior year end	2,200,000,000
Environmental capital expenditures in current year	100,000,000
Environmental capital expenditures in future years	30,000,000
EPA is alleging detroit edison power plants violated new source performance standards	5
Number of NOVs/FOVs currently being discussed with the EPA	2
Time period to complete studies on cooling water intake structures impacts on fish - EPA ruling	3 years
Number of former MGP sites	3
Accrual for environmental loss contingencies, gross	9,000,000				10,000,000
Insurance coverage for extra expense when to necessitate power plant when unavailable	490,000,000
Waiting period of policy	84 days
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
Total limit for property damage for non-nuclear events	2,000,000,000
Limit for property damage for non-nuclear events aggregate of extra expenses	328,000,000
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	43,000,000
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 levied against each licensed nuclear facility	127,000,000
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
Commitment amount	2,400,000,000
Future commitments	1,900,000,000
DTE Electric | Represented employees
Loss Contingencies [Line Items]
Entity number of employees	2,600
DTE Gas
Loss Contingencies [Line Items]
Number of former MGP sites	14
Accrual for environmental loss contingencies, gross	$23,000,000				$24,000,000
Period gas utility can amortize MGP costs	10 years
DTE Gas | Cleanup completed and site closed
Loss Contingencies [Line Items]
Number of former MGP sites	4
DTE Gas | Complete closure expected by end of fiscal year
Loss Contingencies [Line Items]
Number of former MGP sites	2

Retirement_Benefits_and_Truste2

Retirement Benefits and Trusteed Assets (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service Cost	$25	$21
Interest Cost	53	53
Expected Return on Plan Assets	-74	-68
Amortization of Net Actuarial Losses	51	38
Amortization of Prior Service Cost (Credit)	0	0
Net Periodic Benefit Cost (Credit)	55	44
Pension Benefits | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service Cost	20	17
Interest Cost	40	40
Expected Return on Plan Assets	-53	-48
Amortization of Net Actuarial Losses	38	27
Amortization of Prior Service Cost (Credit)	0	0
Net Periodic Benefit Cost (Credit)	45	36
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service Cost	9	9
Interest Cost	20	23
Expected Return on Plan Assets	-33	-31
Amortization of Net Actuarial Losses	11	5
Amortization of Prior Service Cost (Credit)	-31	-36
Net Periodic Benefit Cost (Credit)	-24	-30
Other Postretirement Benefits | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service Cost	7	7
Interest Cost	16	17
Expected Return on Plan Assets	-23	-21
Amortization of Net Actuarial Losses	8	3
Amortization of Prior Service Cost (Credit)	-24	-27
Net Periodic Benefit Cost (Credit)	($16)	($21)

Retirement_Benefits_and_Truste3

Retirement Benefits and Trusteed Assets Retirement Benefits and Trusteed Assets (VEBA Trust) (Details) (USD $)	3 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contribution of common stock to VEBA Trust	$117
Other Postretirement Benefits
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contribution of common stock to VEBA Trust	117
VEBA Trust [Member] | Other Postretirement Benefits
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contributions to Master VEBA Trust, Number of shares	1,427,835
Price Per Share	$81.91
Contribution of common stock to VEBA Trust	$117

Retirement_Benefits_and_Truste4

Retirement Benefits and Trusteed Assets (Details Textuals) (USD $)	3 Months Ended	1 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Apr. 24, 2015
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Estimated Future Employer Contributions in Current Fiscal Year	$150
Pension Benefits | Subsequent Event
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Contributions by Employer		25
Pension Benefits | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Estimated Future Employer Contributions in Current Fiscal Year	120
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Estimated Future Employer Contributions in Current Fiscal Year	80
Other Postretirement Benefits | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Estimated Future Employer Contributions in Current Fiscal Year	$60

StockBased_Compensation_Compon

Stock-Based Compensation (Components of Stock Based Compensation) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Components of stock-based compensation [Abstract]
Stock-based compensation expense	$6	$33
Tax benefit	2	13
Stock-based compensation cost capitalized in property, plant and equipment	$1	$5

StockBased_Compensation_Stock_

Stock-Based Compensation (Stock Option Activity) (Details) (USD $)	3 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2015
Number of Options
Options outstanding at January 1, 2015	444,278
Exercised	-150,317
Forfeited or expired	-3,979
Options outstanding and exercisable at March 31, 2015	289,982
Options exercisable	289,982
Weighted Average Exercise Price
Options outstanding at January 1, 2015	$43.56
Exercised	$45.37
Forfeited or expired	$44.72
Options outstanding and exercisable at March 31, 2015	$42.61
Weighted Average Exercise Price - Options exercisable	$42.61
Aggregate Intrinsic Value - Options outstanding	$12
Aggregate Intrinsic Value - Options exercisable	$12

StockBased_Compensation_Restri

Stock-Based Compensation (Restricted Stock) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015
Restricted Stock (in shares)
Forfeitures	-3,979
Restricted Stock
Restricted Stock (in shares)
Balance at January 1, 2015	416,318
Grants	105,500
Forfeitures	-260
Vested and issued	-141,260
Balance at March 31, 2015	380,298
Weighted Average Grant Date Fair Value (in dollars per share)
Balance at January 1, 2015	62.82
Grants	84.06
Forfeitures	67.23
Vested and issued	53.4
Balance at March 31, 2015	72.2

StockBased_Compensation_Perfor

Stock-Based Compensation (Performance Share Awards Activity) (Details) (Performance Shares, USD $)	3 Months Ended
	Mar. 31, 2015
Performance Shares
Performance Shares (in shares)
Balance at January 1, 2015	1,554,697
Grants	429,151
Forfeitures	-5,021
Payouts	-532,700
Balance at March 31, 2015	1,446,127
Weighted Average Grant Date Fair Value (in dollars per share)
Balance at January 1, 2015	$69.32
Grants	$84.04
Forfeitures	$69.16
Payouts	$0
Balance at March 31, 2015	$75.76

StockBased_Compensation_Detail

Stock-Based Compensation (Details Textuals) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Remaining contractual life for exercisable shares	3 years 3 months 25 days
Intrinsic value	$6,000,000	$5,000,000
Stock option plan expense	0	0
Unrecognized compensation cost	81,000,000
Weighted average period for unrecognized compensation cost to be recognized	1 year 8 months 19 days
DTE Electric | DTE Energy
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation	$4,000,000	$19,000,000

Segment_Information_Financial_

Segment Information (Financial Data - Operating Revenues including inter segment revenues) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	$2,984	$3,930
Operating Segments | Electric
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	1,203	1,412
Operating Segments | Gas
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	647	804
Operating Segments | Gas Storage and Pipelines
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	57	52
Operating Segments | Power and Industrial Projects
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	567	575
Operating Segments | Energy Trading
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	711	1,314
Operating Segments | Corporate and Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	0	0
Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	-201	-227
Reconciliation and Eliminations | Electric
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	-9	-7
Reconciliation and Eliminations | Gas
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	-1	-2
Reconciliation and Eliminations | Gas Storage and Pipelines
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	-1	-1
Reconciliation and Eliminations | Power and Industrial Projects
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	-180	-206
Reconciliation and Eliminations | Energy Trading
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	-9	-9
Reconciliation and Eliminations | Corporate and Other
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	($1)	($2)

Segment_Information_Financial_1

Segment Information (Financial Data - Net Income or Loss) (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	$273	$326
Electric
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	136	136
Gas
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	111	129
Gas Storage and Pipelines
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	27	21
Power and Industrial Projects
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	33	15
Energy Trading
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	-9	42
Corporate and Other
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company/DTE Electric	($25)	($17)

Segment_Information_Details_Te

Segment Information (Details Textuals)	Mar. 31, 2015
	customers
Segment Reporting [Abstract]
Number of electric utility customers	2,100,000
Number of gas utility customers	1,200,000