DTE Electric 10-K 13 Feb 15 2014 FY Annual report Financial data

Document_Entity_Information_Do

Document Entity Information Document (USD $)	12 Months Ended
	Dec. 31, 2014	Jun. 30, 2014
Document and Entity Information [Abstract]
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-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding	138,632,324
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float		$0

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Statement [Abstract]
Operating Revenues	$5,282	$5,197	$5,291
Operating Expenses
Fuel and purchased power	1,706	1,668	1,758
Operation and maintenance	1,331	1,376	1,429
Depreciation and amortization	927	896	822
Taxes other than income	267	260	256
Asset (gains) losses and impairments, net	-1	-3	-2
Total operating expenses	4,230	4,197	4,263
Operating Income	1,052	1,000	1,028
Other (Income) and Deductions
Interest expense	250	268	272
Interest income	-1	0	-1
Other income	-62	-54	-53
Other expenses	35	45	42
Total Other (Income) and Deductions	222	259	260
Income Before Income Taxes	830	741	768
Income Tax Expense	298	254	282
Net Income	$532	$487	$486

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net Income	$532	$487	$486
Other comprehensive income (loss), net of tax:
Benefit obligations, net of tax of $(4), $4 and $(1), respectively	-10	5	-2
Net unrealized gains on investments during the period, net of taxes of $—, $— and $—, respectively	0	1	0
Other comprehensive income (loss)	-10	6	-2
Comprehensive income	$522	$493	$484

Consolidated_Statements_of_Com1

Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Tax effect on benefit obligations	($4)	$4	($1)
Tax effect on unrealized gains	$0	$0	$0

Consolidated_Statements_of_Fin

Consolidated Statements of Financial Position (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Current Assets
Cash and cash equivalents	$14	$27
Restricted cash, principally Securitization	96	100
Accounts receivable (less allowance for doubtful accounts of $29 and $28, respectively)
Customer	688	723
Affiliates	31	24
Other	15	24
Inventories
Fuel	269	188
Materials and supplies	231	215
Notes receivable
Affiliates	8	200
Other	8	2
Regulatory assets	46	13
Other	75	68
Total Current Assets	1,481	1,584
Investments
Nuclear decommissioning trust funds	1,241	1,191
Other	172	160
Total Investments	1,413	1,351
Property
Property, plant and equipment	19,805	18,730
Less accumulated depreciation and amortization	-7,216	-6,951
Property, plant and equipment, net	12,589	11,779
Other Assets
Regulatory assets	2,913	2,275
Securitized regulatory assets	34	231
Intangible assets	37	41
Other	182	149
Total Noncurrent Assets	3,166	2,696
Total Assets	18,649	17,410
Accounts payable
Affiliates	60	60
Other	366	424
Accrued interest	58	61
Current portion long-term debt, including capital leases	118	504
Regulatory liabilities	150	278
Deferred income taxes	0	91
Short-term borrowings
Affiliates	84	58
Other	50	0
Other	151	177
Total Current Liabilities	1,037	1,653
Long-Term Debt (net of current portion)
Mortgage bonds, notes and other	5,144	4,540
Securitization bonds	0	105
Capital lease obligations	0	4
Total Long-Term Debt (net of current portion)	5,144	4,649
Other Liabilities
Deferred income taxes	3,188	2,807
Regulatory liabilities	245	386
Asset retirement obligations	1,796	1,667
Unamortized investment tax credit	36	41
Nuclear decommissioning	182	178
Accrued pension liability — affiliates	1,200	705
Accrued postretirement liability — affiliates	520	369
Other	105	101
Total Noncurrent Liabilities	7,272	6,254
Commitments and Contingencies (Notes 7 and 15)
Shareholder’s Equity
Common stock, $10 par value, 400,000,000 shares authorized, and 138,632,324 shares issued and outstanding	3,786	3,596
Retained earnings	1,436	1,274
Accumulated other comprehensive loss	-26	-16
Total Shareholder's Equity	5,196	4,854
Total Liabilities and Shareholder’s Equity	$18,649	$17,410

Consolidated_Statements_of_Fin1

Consolidated Statements of Financial Position (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified
Current Assets
Allowance for doubtful accounts	$29	$28
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 (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Activities
Net Income	$532	$487	$486
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	927	896	822
Nuclear fuel amortization	48	38	29
Allowance for equity funds used during construction	-21	-14	-12
Deferred income taxes	297	108	-52
Asset (gains) losses and impairments, net	-1	-3	-2
Changes in assets and liabilities:
Accounts receivable, net	33	-30	24
Inventories	-97	36	7
Accounts payable	11	-23	-64
Regulatory assets and liabilities	-926	1,029	286
Accrued pension liability — affiliates	495	-663	137
Accrued postretirement liability — affiliates	151	-417	-221
Other assets	-25	0	30
Other liabilities	-40	44	42
Net cash from operating activities	1,384	1,488	1,512
Investing Activities
Plant and equipment expenditures	-1,561	-1,325	-1,230
Notes receivable from affiliate	192	-200	26
Proceeds from sale of nuclear decommissioning trust fund assets	1,146	1,118	759
Investment in nuclear decommissioning trust funds	-1,156	-1,134	-764
Other	-10	-31	-21
Net cash used for investing activities	-1,389	-1,572	-1,230
Financing Activities
Issuance of long-term debt, net of issuance costs	942	768	496
Redemption of long-term debt	-837	-590	-587
Capital contribution by parent company	190	400	0
Short-term borrowings, net — other	50	-130	130
Short-term borrowings, net — affiliate	26	-22	16
Dividends on common stock	-370	-342	-317
Other	-9	-3	-3
Net cash from (used for) financing activities	-8	81	-265
Net Increase (Decrease) in Cash and Cash Equivalents	-13	-3	17
Cash and Cash Equivalents at Beginning of the Period	27	30	13
Cash and Cash Equivalents at End of the Period	14	27	30
Supplemental disclosure of cash information
Cash paid (received) for: Interest (net of interest capitalized)	240	256	280
Cash paid (received) for: Income taxes	4	183	223
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Plant and equipment expenditures in accounts payable	$162	$231	$144

Consolidated_Statements_of_Cha

Consolidated Statements of Changes in Equity (USD $)	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Accumulated Defined Benefit Plans Adjustment	Accumulated Net Unrealized Investment Gain (Loss)
In Millions, except Share data, unless otherwise specified
Beginning balance at Dec. 31, 2011	$4,136	$1,386	$1,810	$960	($20)
Beginning Balance (in shares) at Dec. 31, 2011		138,632,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	486			486
Dividends declared on common stock	-317			-317
Other Comprehensive Income (Loss), Net of Tax	-2					-2
Ending balance at Dec. 31, 2012	4,303	1,386	1,810	1,129	-22
Ending Balance (in shares) at Dec. 31, 2012		138,632,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	487			487
Dividends declared on common stock	-342			-342
Other Comprehensive Income (Loss), Net of Tax	6					5	1
Capital contribution by parent company	400		400
Ending balance at Dec. 31, 2013	4,854	1,386	2,210	1,274	-16
Ending Balance (in shares) at Dec. 31, 2013	138,632,324	138,632,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	532			532
Dividends declared on common stock	-370			-370
Other Comprehensive Income (Loss), Net of Tax	-10					-10
Capital contribution by parent company	190		190
Ending balance at Dec. 31, 2014	$5,196	$1,386	$2,400	$1,436	($26)
Ending Balance (in shares) at Dec. 31, 2014	138,632,324	138,632,000

Organization_and_Basis_of_Pres

Organization and Basis of Presentation (Notes)	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	ORGANIZATION AND BASIS OF PRESENTATION
	Corporate Structure
	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 Electric is regulated by the MPSC and the FERC. In addition, we are regulated by other federal and state regulatory agencies including the NRC, the EPA and the MDEQ.
	References in this Report to “we,” “us,” “our” or “Company” are to DTE Electric and its subsidiaries, collectively.
	Basis of Presentation
	The accompanying Consolidated Financial Statements are prepared using accounting principles generally accepted in the United States of America. These accounting principles require management to use estimates and assumptions that impact reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from the Company’s estimates.
	Principles of Consolidation
	The Company consolidates all majority-owned subsidiaries and investments in entities in which it has controlling influence. Non-majority owned investments are accounted for using the equity method when the Company is able to influence the operating policies of the investee. When the Company does not influence the operating policies of an investee, the cost method is used. These Consolidated Financial Statements also reflect the Company’s proportionate interests in certain jointly owned utility plants. The Company eliminates all intercompany balances and transactions.
	The Company evaluates whether an entity is a VIE whenever reconsideration events occur. The Company consolidates VIEs for which it is the primary beneficiary. If the Company is not the primary beneficiary and an ownership interest is held, the VIE is accounted for under the equity method of accounting. When assessing the determination of the primary beneficiary, the Company considers all relevant facts and circumstances, including: the power, through voting or similar rights, to direct the activities of the VIE that most significantly impact the VIE’s economic performance and the obligation to absorb the expected losses and/or the right to receive the expected returns of the VIE. The Company performs ongoing reassessments of all VIEs to determine if the primary beneficiary status has changed.
	The Company has variable interests in VIEs through certain of its long-term purchase contracts. As of December 31, 2014, the carrying amount of assets and liabilities in the Consolidated Statements of Financial Position that relate to its variable interests under long-term purchase contracts are predominately related to working capital accounts and generally represent the amounts owed by the Company for the deliveries associated with the current billing cycle under the contracts. The Company has not provided any significant form of financial support associated with these long-term contracts. There is no significant potential exposure to loss as a result of its variable interests through these long-term purchase contracts.
	In 2001, DTE Electric financed a regulatory asset related to Fermi 2 and certain other regulatory assets through the sale of rate reduction bonds by a wholly-owned special purpose entity, Securitization. DTE Electric performs servicing activities including billing and collecting surcharge revenue for Securitization. This entity is a VIE and is consolidated by the Company. The maximum risk exposure related to Securitization is reflected on the Company’s Consolidated Statements of Financial Position.
	The following table summarizes the major balance sheet items at December 31, 2014 and 2013 restricted for Securitization that are either (1) assets that can be used only to settle their obligations related to Securitization or (2) liabilities for which creditors do not have recourse to the general credit of the primary beneficiary.
		December 31,
		2014		2013
		(In millions)
	ASSETS
	Restricted cash	$	96	$	100
	Accounts receivable	26		34
	Securitized regulatory assets	34		231
	Other current and long-term assets	1		4
		$	157	$	369
	LIABILITIES
	Accounts payable and accrued current liabilities	$	3	$	7
	Current portion long-term debt, including capital leases	105		196
	Current regulatory liabilities	32		43
	Securitization bonds	—		105
	Other current and long-term liabilities	9		8
		$	149	$	359

Significant_Accounting_Policie

Significant Accounting Policies (Note)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES
	Revenues
	Revenues from the sale and delivery of electricity are recognized as services are provided. The Company records revenues for electricity provided but unbilled at the end of each month. Rates for DTE Electric include provisions to adjust billings for fluctuations in fuel and purchased power costs, and certain other costs. Revenues are adjusted for differences between actual costs subject to reconciliation and the amounts billed in current rates. Under or over recovered revenues related to these cost recovery mechanisms are recorded on the Consolidated Statements of Financial Position and are recovered or returned to customers through adjustments to the billing factors.
	See Note 7, "Regulatory Matters", for further discussion of recovery mechanisms authorized by the MPSC.
	Accounting for ISO Transactions
	DTE Electric participates in the energy market through MISO. MISO requires that we submit hourly day-ahead, real- time and FTR bids and offers for energy at locations across the MISO region. DTE Electric accounts for MISO transactions on a net hourly basis in each of the day-ahead, real-time and FTR markets and net transactions across all MISO energy market locations. In any single hour DTE Electric records net purchases in Fuel and purchased power and net sales in Operating revenues on the Consolidated Statements of Operations. DTE Electric records accruals for future net purchases adjustments based on historical experience, and reconciles accruals to actual costs when invoices are received from MISO.
	Changes in Accumulated Other Comprehensive Loss
	Comprehensive income (loss) is the change in common shareholder’s equity during a period from transactions and events from non-owner sources, including net income. The amounts recorded to accumulated other comprehensive loss include unrealized gains and losses on available-for-sale securities and changes in benefit obligations, consisting of deferred actuarial losses, and prior service costs.
	The following table summarizes the changes in Accumulated other comprehensive loss by component for the years ended December 31, 2014 and 2013:
		Changes in Accumulated Other Comprehensive Loss by Component (a)
		Net Unrealized Gain/(Loss) on Investments		Benefit Obligations (b)			Total
		(In millions)
	Balance, January 1, 2013	$	—	$	(22	)	$	(22	)
	Other comprehensive income before reclassifications	1		3			4
	Amounts reclassified from accumulated other comprehensive income	—		2			2
	Net current-period other comprehensive income	1		5			6
	Balance, December 31, 2013	$	1	$	(17	)	$	(16	)
	Other comprehensive loss before reclassifications	—		(12		)	(12		)
	Amounts reclassified from accumulated other comprehensive income	—		2			2
	Net current-period other comprehensive loss	—		(10		)	(10		)
	Balance, December 31, 2014	$	1	$	(27	)	$	(26	)
	________________________________________
	(a)	All amounts are net of tax.
	(b)	The amounts reclassified from accumulated other comprehensive income (loss) are included in the computation of the net periodic pension and other postretirement benefit costs (see Note 16 to the Consolidated Financial Statements "Retirement Benefits and Trusteed Assets").
	Cash, Cash Equivalents and Restricted Cash
	Cash and cash equivalents include cash on hand, cash in banks and temporary investments purchased with remaining maturities of three months or less. Restricted cash consists of funds held to satisfy requirements of certain debt agreements, related to Securitization bonds. Restricted cash designated for interest and principal payments within one year is classified as a current asset.
	Receivables
	Accounts receivable are primarily composed of trade receivables and unbilled revenue. Our accounts receivable are stated at net realizable value.
	The allowance for doubtful accounts is generally calculated using the aging approach that utilizes rates developed in reserve studies. DTE Electric establishes an allowance for uncollectible accounts based on historical losses and management’s assessment of existing economic conditions, customer trends, and other factors. Customer accounts are generally considered delinquent if the amount billed is not received by the due date, which is typically in 21 days, however, factors such as assistance programs may delay aggressive action. We assess late payment fees on trade receivables based on past-due terms with customers. Customer accounts are written off when collection efforts have been exhausted. The time period for write-off is 150 days after service has been terminated.
	Unbilled revenues of $250 million and $280 million are included in customer accounts receivable at December 31, 2014 and 2013, respectively.
	Notes Receivable
	Notes receivable, or financing receivables, are primarily comprised of loans and are typically considered delinquent when payment is not received for periods ranging from 60 to 120 days. The Company ceases accruing interest (nonaccrual status), considers a note receivable impaired, and establishes an allowance for credit loss when it is probable that all principal and interest amounts due will not be collected in accordance with the contractual terms of the note receivable. Cash payments received on nonaccrual status notes receivable, that do not bring the account contractually current, are first applied to contractually owed past due interest, with any remainder applied to principal. Accrual of interest is generally resumed when the note receivable becomes contractually current.
	In determining the allowance for credit losses for notes receivable, we consider the historical payment experience and other factors that are expected to have a specific impact on the counterparty’s ability to pay. In addition, the Company monitors the credit ratings of the counterparties from which we have notes receivable.
	Inventories
	The Company generally values inventory at average cost.
	Property, Retirement and Maintenance, and Depreciation, Depletion and Amortization
	Property is stated at cost and includes construction-related labor, materials, overheads and AFUDC. The cost of properties retired is charged to accumulated depreciation. Expenditures for maintenance and repairs are charged to expense when incurred, except for Fermi 2.
	Utility property is depreciated over its estimated useful life using straight-line rates approved by the MPSC.
	Depreciation and amortization expense also includes the amortization of certain regulatory assets.
	Approximately $16 million and $26 million of expenses related to Fermi 2 refueling outages were accrued at December 31, 2014 and 2013, respectively. Amounts are accrued on a pro-rata basis, generally over an 18-month period, that coincides with scheduled refueling outages at Fermi 2. This accrual of outage costs matches the regulatory recovery of these costs in rates set by the MPSC. See Note 7 to the Consolidated Financial Statements, "Regulatory Matters".
	The cost of nuclear fuel is capitalized. The amortization of nuclear fuel is included within Fuel and purchased power in the Consolidated Statements of Operations and is recorded using the units-of-production method.
	Long-Lived Assets
	Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. If the carrying amount of the asset exceeds the expected discounted future cash flows generated by the asset, an impairment loss is recognized resulting in the asset being written down to its estimated fair value. Assets to be disposed of are reported at the lower of the carrying amount or fair value, less costs to sell.
	Intangible Assets
	The Company has certain intangible assets relating to emission allowances and renewable energy credits as shown below:
		December 31,
		2014		2013
		(In millions)
	Emission allowances	$	1	$	2
	Renewable energy credits	45		51
		46		53
	Less current intangible assets	9		12
		$	37	$	41
	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.
	Excise and Sales Taxes
	The Company records the billing of excise and sales taxes as a receivable with an offsetting payable to the applicable taxing authority, with no net impact on the Consolidated Statements of Operations.
	Deferred Debt Costs
	The costs related to the issuance of long-term debt are deferred and amortized over the life of each debt issue. In accordance with MPSC regulations, the unamortized discount, premium and expense related to debt redeemed with a refinancing are amortized over the life of the replacement issue.
	Investments in Debt and Equity Securities
	The Company generally classifies investments in debt and equity securities as either trading or available-for-sale and has recorded such investments at market value with unrealized gains or losses included in earnings or in other comprehensive income or loss, respectively. Changes in the fair value of Fermi 2 nuclear decommissioning investments are recorded as adjustments to regulatory assets or liabilities, due to a recovery mechanism from customers. The Company’s equity investments are reviewed for impairment each reporting period. If the assessment indicates that the impairment is other than temporary, a loss is recognized resulting in the equity investment being written down to its estimated fair value. See Note 9 to the Consolidated Financial Statements, "Fair Value".
	Stock-Based Compensation
	The Company received an allocation of costs from DTE Energy associated with stock-based compensation. Our allocation for 2014, 2013 and 2012 for stock-based compensation expense was approximately $62 million, $58 million and $42 million, respectively.
	Government Grants
	Grants are recognized when there is reasonable assurance that the grant will be received and that any conditions associated with the grant will be met. When grants are received related to Property, plant and equipment, the Company reduces the cost of the assets on the Consolidated Statements of Financial Position, resulting in lower depreciation expense over the life of the associated asset. Grants received related to expenses are reflected as a reduction of the associated expense in the period in which the expense is incurred.
Other Accounting Policies
See the following notes for other accounting policies impacting the Company’s Consolidated Financial Statements:
Note		Title
6		Asset Retirement Obligations
7		Regulatory Matters
8		Income Taxes
9		Fair Value
10		Financial and Other Derivative Instruments

New_Accounting_Pronouncements_

New Accounting Pronouncements (Notes)	12 Months Ended
	Dec. 31, 2014
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements	NEW ACCOUNTING PRONOUNCEMENTS
	In May 2014, the FASB issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers. The objectives of this ASU are to improve upon revenue recognition requirements by providing a single comprehensive model to determine the measurement of revenue and timing of recognition. The core principle is that an entity will recognize revenue to depict the transfer of goods or services to customers at an amount that the entity expects to be entitled to in exchange for those goods or services. This ASU also requires expanded qualitative and quantitative disclosures regarding the nature, amount, timing, and uncertainty of revenues and cash flows arising from contracts with customers. The revenue standard is effective for the first interim period within annual reporting periods beginning after December 15, 2016 and is to be applied retrospectively. Early adoption is not permitted. The Company is currently assessing the impact of this ASU on its Consolidated Financial Statements.

Property_Plant_and_Equipment_N

Property, Plant and Equipment (Notes)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	PROPERTY, PLANT AND EQUIPMENT
	Summary of property by classification as of December 31:
		December 31,
		2014			2013
		(In millions)
	Property, Plant and Equipment
	Generation	$	11,641		$	11,127
	Distribution	8,164			7,603
	Total	19,805			18,730
	Less Accumulated Depreciation and Amortization
	Generation	(4,149		)	(4,004		)
	Distribution	(3,067		)	(2,947		)
	Total	(7,216		)	(6,951		)
	Net Property, Plant and Equipment	$	12,589		$	11,779
	AFUDC capitalized was approximately $32 million and $21 million for the years ended December 31, 2014 and 2013, respectively.
	The composite depreciation rate for DTE Electric was approximately 3.4% in 2014 and 2013 and 3.3% in 2012.
	The average estimated useful life for our generation and distribution property was 40 years and 41 years, respectively, at December 31, 2014.
	Capitalized software costs are classified as Property, plant and equipment and the related amortization is included in Accumulated depreciation and amortization on the Consolidated Statements of Financial Position. The Company capitalizes the costs associated with computer software it develops or obtains for use in its business. The Company amortizes capitalized software costs on a straight-line basis over the expected period of benefit, ranging from 5 to 15 years.
	Capitalized software costs amortization expense was $71 million in 2014, $64 million in 2013 and $62 million in 2012. The gross carrying amount and accumulated amortization of capitalized software costs at December 31, 2014 were $590 million and $293 million, respectively. The gross carrying amount and accumulated amortization of capitalized software costs at December 31, 2013 were $521 million and $269 million, respectively.
	Gross property under capital leases was $9 million at December 31, 2014 and 2013. Accumulated amortization of property under capital leases was $5 million and $1 million at December 31, 2014 and 2013, respectively.

Jointly_Owned_Utility_Plant_No

Jointly Owned Utility Plant (Notes)	12 Months Ended
	Dec. 31, 2014
Jointly Owned Utility Plant, Net Ownership Amount [Abstract]
Jointly Owned Utility Plant	JOINTLY OWNED UTILITY PLANT
	DTE Electric has joint ownership interest in two power plants, Belle River and Ludington Hydroelectric Pumped Storage. DTE Electric’s share of direct expenses of the jointly owned plants are included in Fuel and purchased power and Operation and maintenance expenses in the Consolidated Statements of Operations. Ownership information of the two utility plants as of December 31, 2014 was as follows:
		Belle River			Ludington
					Hydroelectric
					Pumped Storage
	In-service date	1984-1985			1973
	Total plant capacity	1,270		MW	1,872		MW
	Ownership interest	(a)			49		%
	Investment in property, plant and equipment (in millions)	$	1,742		$	412
	Accumulated depreciation (in millions)	$	993		$	175
	_________________________________
	(a)	DTE Electric’s ownership interest is 63% in Unit No. 1, 81% of the facilities applicable to Belle River used jointly by the Belle River and St. Clair Power Plants and 75% in common facilities used at Unit No. 2.
	Belle River
	The Michigan Public Power Agency (MPPA) has an ownership interest in Belle River Unit No. 1 and other related facilities. The MPPA is entitled to 19% of the total capacity and energy of the plant and is responsible for the same percentage of the plant’s operation, maintenance and capital improvement costs.
	Ludington Hydroelectric Pumped Storage
	Consumers Energy Company has an ownership interest in the Ludington Hydroelectric Pumped Storage Plant. Consumers Energy is entitled to 51% of the total capacity and energy of the plant and is responsible for the same percentage of the plant’s operation, maintenance and capital improvement costs.

Asset_Retirement_Obligations_N

Asset Retirement Obligations (Notes)	12 Months Ended
	Dec. 31, 2014
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	ASSET RETIREMENT OBLIGATIONS
	The Company has a legal retirement obligation for the decommissioning costs for its Fermi 1 and Fermi 2 nuclear plants, dismantlement of facilities located on leased property and various other operations. The Company has conditional retirement obligations for asbestos and PCB removal at certain of its power plants and various distribution equipment. The Company recognizes such obligations as liabilities at fair market value when they are incurred, which generally is at the time the associated assets are placed in service. Fair value is measured using expected future cash outflows discounted at our credit-adjusted risk-free rate. The Company recognizes regulatory assets or liabilities for timing differences in expense recognition for legal asset retirement costs that are currently recovered in rates.
	If a reasonable estimate of fair value cannot be made in the period in which the retirement obligation is incurred, such as for assets with indeterminate lives, the liability is recognized when a reasonable estimate of fair value can be made. Substations, manholes and certain other distribution assets have an indeterminate life. Therefore, no liability has been recorded for these assets.
	A reconciliation of the asset retirement obligations for 2014 follows:
		(In millions)
	Asset retirement obligations at December 31, 2013	$	1,667
	Accretion	103
	Liabilities incurred	9
	Liabilities settled	(6		)
	Revision in estimated cash flows	23
	Asset retirement obligations at December 31, 2014	$	1,796
	Approximately $1.7 billion of the asset retirement obligations represent nuclear decommissioning liabilities that are funded through a surcharge to electric customers over the life of the Fermi 2 nuclear plant. The NRC has jurisdiction over the decommissioning of nuclear power plants and requires minimum decommissioning funding based upon a formula. The MPSC and FERC regulate the recovery of costs of decommissioning nuclear power plants and both require the use of external trust funds to finance the decommissioning of Fermi 2. 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 Company believes the MPSC and FERC collections will be adequate to fund the estimated cost of decommissioning. The decommissioning assets, anticipated earnings thereon and future revenues from decommissioning collections will be used to decommission Fermi 2. The Company expects the liabilities to be reduced to zero at the conclusion of the decommissioning activities. If amounts remain in the trust funds for Fermi 2 following the completion of the decommissioning activities, those amounts will be disbursed based on rulings by the MPSC and FERC.
	A portion of the funds recovered through the Fermi 2 decommissioning surcharge and deposited in external trust accounts is designated for the removal of non-radioactive assets and returning the site to greenfield. This removal and greenfielding is not considered a legal liability. Therefore, it is not included in the asset retirement obligation, but is reflected as the Nuclear decommissioning liability. The decommissioning of Fermi 1 is funded by DTE Electric. Contributions to the Fermi 1 trust are discretionary. See Note 9 to the Consolidated Financial Statements, "Fair Value", for additional discussion of Nuclear decommissioning trust fund assets.

Regulatory_Matters_Notes

Regulatory Matters (Notes)	12 Months Ended
	Dec. 31, 2014
Regulatory Assets and Liabilities Disclosure [Abstract]
Regulatory Matters	REGULATORY MATTERS
	Regulation
	DTE Electric is subject to the regulatory jurisdiction of the MPSC, which issues orders pertaining to rates, recovery of certain costs, including the costs of generating facilities and regulatory assets, conditions of service, accounting and operating-related matters. DTE Electric is also regulated by the FERC with respect to financing authorization and wholesale electric activities. Regulation results in differences in the application of generally accepted accounting principles between regulated and non-regulated businesses.
	The Company is unable to predict the outcome of the unresolved regulatory matters discussed herein. Resolution of these matters is dependent upon future MPSC orders and appeals, which may materially impact the financial position, results of operations and cash flows of the Company.
	Regulatory Assets and Liabilities
	DTE Electric is required to record regulatory assets and liabilities for certain transactions that would have been treated as revenue or expense in non-regulated businesses. Continued applicability of regulatory accounting treatment requires that rates be designed to recover specific costs of providing regulated services and be charged to and collected from customers. Future regulatory changes or changes in the competitive environment could result in the discontinuance of this accounting treatment for regulatory assets and liabilities for some or all of our businesses and may require the write-off of the portion of any regulatory asset or liability that was no longer probable of recovery through regulated rates. Management believes that currently available facts support the continued use of regulatory assets and liabilities and that all regulatory assets and liabilities are recoverable or refundable in the current regulatory environment.
	The following are balances and a brief description of the regulatory assets and liabilities at December 31:
		2014			2013
		(In millions)
	Assets
	Recoverable pension and other postretirement costs:
	Pension	$	1,743		$	1,257
	Other postretirement costs	191			—
	Asset retirement obligation	448			394
	Recoverable Michigan income taxes	220			237
	Other recoverable income taxes	66			71
	Cost to achieve Performance Excellence Process	46			64
	Unamortized loss on reacquired debt	44			38
	Accrued PSCR revenue	34			—
	Recoverable income taxes related to securitized regulatory assets	19			126
	Removal costs asset	15			—
	Transitional Reconciliation Mechanism	14			—
	Other	119			101
		2,959			2,288
	Less amount included in current assets	(46		)	(13		)
		$	2,913		$	2,275
	Securitized regulatory assets	$	34		$	231
		2014			2013
		(In millions)
	Liabilities
	Renewable energy	$	227		$	277
	Over recovery of Securitization	71			72
	Refundable revenue decoupling / deferred gain	63			127
	Fermi 2 refueling outage	16			26
	Energy optimization	14			25
	Accrued PSCR refund	—			53
	Refundable other postretirement costs	—			48
	Removal costs liability	—			33
	Other	4			3
		395			664
	Less amount included in current liabilities	(150		)	(278		)
		$	245		$	386
	As noted below, regulatory assets for which costs have been incurred have been included (or are expected to be included, for costs incurred subsequent to the most recently approved rate case) in DTE Electric's rate base, thereby providing a return on invested costs (except as noted). Certain other regulatory assets are not included in rate base but accrue recoverable carrying charges until surcharges to collect the assets are billed. Certain regulatory assets do not result from cash expenditures and therefore do not represent investments included in rate base or have offsetting liabilities that reduce rate base.
	ASSETS
	•	Recoverable pension and other postretirement costs — Accounting rules for pension and other postretirement benefit costs require, among other things, the recognition in other comprehensive income of the actuarial gains or losses and the prior service costs that arise during the period but that are not immediately recognized as components of net periodic benefit costs. The Company records the impact of actuarial gains and losses and prior service costs as a regulatory asset since the traditional rate setting process allows for the recovery of pension and other postretirement costs. The asset will reverse as the deferred items are amortized and recognized as components of net periodic benefit costs. (a)
	•	Asset retirement obligation — This obligation is primarily for Fermi 2 decommissioning costs. The asset captures the timing differences between expense recognition and current recovery in rates and will reverse over the remaining life of the related plant. (a)
	•	Recoverable Michigan income taxes — In July 2007, the MBT was enacted by the State of Michigan. A State deferred tax liability was established, and an offsetting regulatory asset was recorded as the impact of the deferred tax liability will be reflected in rates as the related taxable temporary difference reverses and flows through current income tax expense. In May 2011, the MBT was repealed and the MCIT was enacted. The regulatory asset was remeasured to reflect the impact of the MCIT tax rate. (a)
	•	Other recoverable income taxes — Income taxes receivable from DTE Electric customers representing the difference in property-related deferred income taxes and amounts previously reflected in DTE Electric's rates. This asset will reverse over the remaining life of the related plant. (a)
	•	Cost to achieve Performance Excellence Process (PEP) — The MPSC authorized the deferral of costs to implement the PEP. These costs consist of employee severance, project management and consultant support. These costs are amortized over a ten-year period beginning with the year subsequent to the year the costs were deferred.
	•	Unamortized loss on reacquired debt — The unamortized discount, premium and expense related to debt redeemed with a refinancing are deferred, amortized and recovered over the life of the replacement issue.
	•	Accrued PSCR revenue — Receivable for the temporary under-recovery of and carrying costs on fuel and purchased power costs incurred by DTE Electric which are recoverable through the PSCR mechanism.
	•	Recoverable income taxes related to securitized regulatory assets — Receivable for the recovery of income taxes to be paid on the non-bypassable securitization bond surcharge. A non-bypassable securitization tax surcharge, which ended in December 2014, was in place to recover the income tax over a fourteen-year period. (a)
	•	Removal costs asset — Receivable for the recovery of asset removal expenditures in excess of amounts collected from customers.
	•	Transitional Reconciliation Mechanism (TRM) — The MPSC approved the recovery of the deferred net incremental revenue requirement associated with the transition of PLD customers to DTE Electric's distribution system, effective July 1, 2014. Annual reconciliations will be filed and surcharges will be implemented to recover approved amounts. (a)
	•	Securitized regulatory assets — The net book balance of the Fermi 2 nuclear plant was written off in 1998 and an equivalent regulatory asset was established. In 2001, the Fermi 2 regulatory asset and certain other regulatory assets were securitized pursuant to PA 142 and an MPSC order. A non-bypassable securitization bond surcharge, which ended in December 2014, was in place to recover the securitized regulatory asset over a fourteen-year period.
	_________________________________
	(a)	Regulatory assets not earning a return or accruing carrying charges.
	LIABILITIES
	•	Renewable energy — Amounts collected in rates in excess of renewable energy expenditures.
	•	Over recovery of Securitization — Over recovery of securitization bond expenses.
	•	Refundable revenue decoupling / deferred gain — Amounts were originally accrued as refundable to DTE Electric customers for the change in revenue resulting from the difference between actual average sales per customer compared to the base level of average sales per customer established by the MPSC. In 2012, the Michigan Court of Appeals issued a decision reversing the MPSC's decision to authorize a RDM for DTE Electric. The revenue decoupling liability was reversed and, after receiving an order from the MPSC to defer the resulting gain for future amortization, DTE Electric created a regulatory liability representing its obligation to refund the gain. The deferred gain is being amortized into earnings in 2014 and 2015.
	•	Fermi 2 refueling outage — Accrued liability for refueling outage at Fermi 2 pursuant to MPSC authorization.
	•	Energy optimization (EO) — Amounts collected in rates in excess of energy optimization expenditures.
	•	Accrued PSCR refund — Liability for the temporary over-recovery of and a return on power supply costs and transmission costs incurred by DTE Electric which are recoverable through the PSCR mechanism.
•	Refundable other postretirement costs — Accounting rules for other postretirement benefit costs require, among other things, the recognition in other comprehensive income of the actuarial gains or losses and the prior service costs or credits that arise during the period but that are not immediately recognized as components of net periodic benefit costs. DTE Electric records the favorable impact of actuarial gains or losses and prior service credits as a regulatory liability since the impact will reduce expense in a future rate setting process as the deferred items are recognized as a component of net periodic benefit costs.
•	Removal costs liability — The amount collected from customers for the funding of future asset removal activities.
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 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.
2010 Electric Rate Case Filing - Court of Appeals Decision
In July 2013, the MCOA issued a decision relating to an appeal of the October 2011 MPSC order in DTE Electric's October 2010 rate case filing. The MCOA found that the record of evidence in the 2010 rate case order was insufficient to support the MPSC's authorization to recover costs for the AMI program and remanded this matter to the MPSC. The MPSC had approved an approximately $11 million rate increase related to the AMI program in the October 2011 order. DTE Electric is currently operating its AMI program pursuant to the MPSC's approval set forth in the October 2011 order. In August 2013, the MPSC reopened the 2010 electric rate case for the limited purpose of addressing the MCOA's opinion on AMI. On November 6, 2014, the MPSC issued an order affirming the recovery of costs associated with the AMI program.
Customer360 Accounting Authority
In July 2014, DTE Electric filed an application for accounting authority to defer certain costs associated with implementing Customer360, which is an integrated software application that enables improved interface among customer service, billing, meter reading, credit and collections, device management, account management, and retail access. The estimated implementation cost of Customer360 is approximately $215 million and DTE Electric proposed an amortization period of 15 years. On September 26, 2014, the MPSC approved the accounting request.
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 the Company's $127 million regulatory liability associated with the operation of the RDM. The approved application provided for the amortization of the regulatory liability to income, at a monthly rate of approximately $10.6 million, beginning January 2014. On April 1, 2014, the MPSC approved DTE Electric's accounting application to suspend the amortization of the RDM regulatory liability as of June 30, 2014 and to complete the amortization over the period January 2015 to June 2015. If DTE Electric's base rates are increased prior to July 1, 2015, the Company will cease amortization and refund to customers the remaining unamortized balance of the regulatory liability.
Transition of PLD Customers to DTE Electric's Distribution System
On July 19, 2013, DTE Electric filed its TRM application proposing a transitional tariff option for certain former PLD customers and a modified line extension provision. The application also proposed a recovery mechanism for the deferred net incremental revenue requirement associated with the transition. The net incremental revenue requirement includes costs to install meters and attach customers; system and customer facility upgrades and repairs; and the difference between DTE Electric's tariff rates and any transitional rates approved in the future. On May 13, 2014, the MPSC approved the TRM as requested and also ordered DTE Electric to include in the TRM the PLD transmission delivery service costs incurred while DTE Electric is temporarily relying upon PLD to operate and maintain PLD's system during the system conversion period. The meter installation phase of the transition was completed in June 2014. On July 1, 2014, former PLD customers became customers of DTE Electric.
PSCR Proceedings
The PSCR process is designed to allow DTE Electric to recover all of its power supply costs if incurred under reasonable and prudent policies and practices. DTE Electric's power supply costs include fuel and related transportation costs, purchased and net interchange power costs, nitrogen oxide and sulfur dioxide emission allowances costs, urea costs, transmission costs and MISO costs. The MPSC reviews these costs, policies and practices for prudence in annual plan and reconciliation filings.
2012 PSCR Year — In March 2013, DTE Electric filed the 2012 PSCR reconciliation calculating a net under-recovery of approximately $87 million that includes an under-recovery of approximately $148 million for the 2011 PSCR year. The reconciliation includes purchased power costs related to the manual shutdown of our Fermi 2 nuclear power plant in June 2012 caused by the failure of one of the plant's two non-safety related feed-water pumps. The plant was restarted on July 30, 2012, which restored production to 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 our customers. Certain intervenors in the reconciliation case have challenged the recovery of up to $32 million of the Fermi 2 related purchased power costs. Resolution of this matter is expected in 2015.

Income_Taxes_Notes

Income Taxes (Notes)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES
	Income Tax Summary
	We are part of the consolidated federal income tax return of DTE Energy. The federal income tax expense for DTE Electric is determined on an individual company basis with no allocation of tax expenses or benefits from other affiliates of DTE Energy. We had an income tax receivable from DTE Energy of $29 million and $23 million at December 31, 2014 and 2013, respectively.
	Total income tax expense varied from the statutory federal income tax rate for the following reasons:
		Year Ended December 31,
		2014			2013			2012
		(In millions)
	Income before income taxes	$	830		$	741		$	768
	Income tax expense at 35% statutory rate	$	291		$	260		$	269
	Production tax credits	(22		)	(15		)	(5		)
	Investment tax credits	(5		)	(5		)	(6		)
	Depreciation	3			3			3
	AFUDC - Equity	(7		)	(5		)	(4		)
	Employee Stock Ownership Plan dividends	(3		)	(2		)	(3		)
	Domestic production activities deduction	(2		)	(18		)	(16		)
	State and other income taxes, net of federal benefit	43			41			40
	Other, net	—			(5		)	4
	Income tax expense	$	298		$	254		$	282
	Effective income tax rate	35.9		%	34.3		%	36.7		%
	Components of income tax expense  were as follows:
		Year Ended December 31,
		2014			2013			2012
		(In millions)
	Current income tax expense (benefit)
	Federal	$	(19	)	$	123		$	267
	State and other income tax	20			23			67
	Total current income taxes	1			146			334
	Deferred income tax expense (benefit)
	Federal	251			68			(47		)
	State and other income tax	46			40			(5		)
	Total deferred income taxes	297			108			(52		)
	Total	$	298		$	254		$	282
	Deferred tax assets and liabilities are recognized for the estimated future tax effect of temporary differences between the tax basis of assets or liabilities and the reported amounts in the financial statements. Deferred tax assets and liabilities are classified as current or noncurrent according to the classification of the related assets or liabilities. Deferred tax assets and liabilities not related to assets or liabilities are classified according to the expected reversal date of the temporary differences. Consistent with rate making treatment, deferred taxes are offset in the table below for temporary differences which have related regulatory assets and liabilities.
	Deferred tax assets (liabilities) were comprised of the following at December 31:
		2014			2013
		(In millions)
	Property, plant and equipment	$	(3,152	)	$	(2,807	)
	Securitized regulatory assets	(3		)	(130		)
	Pension and benefits	(43		)	27
	Other	12			12
		$	(3,186	)	$	(2,898	)
	Current deferred income tax assets (liabilities)	$	2		$	(91	)
	Long-term deferred income tax liabilities	(3,188		)	(2,807		)
		$	(3,186	)	$	(2,898	)
	Deferred income tax assets	$	357		$	420
	Deferred income tax liabilities	(3,543		)	(3,318		)
		$	(3,186	)	$	(2,898	)
	The above table excludes unamortized investment tax credits that are shown separately on the Consolidated Statements of Financial Position. Investment tax credits are deferred and amortized to income over the average life of the related property.
	Uncertain Tax Positions
	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:
		2014			2013			2012
		(In millions)
	Balance at January 1	$	4		$	4		$	59
	Reductions for tax positions of prior years	—			—			(3		)
	Settlements	—			—			(52		)
	Balance at December 31	$	4		$	4		$	4
	The Company had $2 million of unrecognized tax benefits at December 31, 2014 and 2013 that, if recognized, would favorably impact our effective tax rate. The Company does not anticipate any material decrease in unrecognized tax benefits in the next twelve months.
	The Company recognizes interest and penalties pertaining to income taxes in Interest expense and Other expenses, respectively, on its Consolidated Statements of Operations. Accrued interest pertaining to income taxes totaled $1 million at December 31, 2014 and 2013, respectively. The Company had no accrued penalties pertaining to income taxes. The Company recognized a nominal amount of interest expense (income) related to income taxes in 2014 and 2013 and $(3) million in 2012.
	In 2014, DTE Energy and its subsidiaries settled a federal tax audit for the 2012 tax year. DTE Energy's federal income tax returns for years 2013 and subsequent years remain subject to examination by the IRS. DTE Energy's MBT and MCIT returns for the year 2008 and subsequent years remain subject to examination by the State of Michigan. DTE Energy also files tax returns in numerous state and local jurisdictions with varying statutes of limitation.

Fair_Value_Notes

Fair Value (Notes)	12 Months Ended
	Dec. 31, 2014
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 Company makes certain assumptions it believes that market participants would use in pricing assets or liabilities, including assumptions about risk, and the risks inherent in the inputs to valuation techniques. Credit risk of the Company and its counterparties is incorporated in the valuation of assets and liabilities through the use of credit reserves, the impact of which was immaterial at December 31, 2014 and 2013. The Company believes it uses valuation techniques that maximize the use of observable market-based inputs and minimize the use of unobservable inputs.
	A fair value hierarchy has been established, that prioritizes the inputs to valuation techniques used to measure fair value in three broad levels. The fair value hierarchy gives the highest priority to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). In some cases, the inputs used to measure fair value might fall in different levels of the fair value hierarchy. All assets and liabilities are required to be classified in their entirety based on the lowest level of input that is significant to the fair value measurement in its entirety. Assessing the significance of a particular input may require judgment considering factors specific to the asset or liability, and may affect the valuation of the asset or liability and its placement within the fair value hierarchy. The Company classifies fair value balances based on the fair value hierarchy defined as follows:
	•Level 1 — Consists of unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access as of the reporting date.
	•Level 2 — Consists of inputs other than quoted prices included within Level 1 that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data.
	•Level 3 — Consists of unobservable inputs for assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost-benefit constraints.
	The following table presents assets measured and recorded at fair value on a recurring basis as of December 31, 2014 and 2013:
		December 31, 2014											December 31, 2013
		Level 1			Level 2			Level 3			Net Balance		Level 1		Level 2			Level 3		Net Balance
		(In millions)
	Assets:
	Cash equivalents (a)	$	5		$	99		$	—		$	104	$	2	$	114		$	—	$	116
	Nuclear decommissioning trusts	792			449			—			1,241		779		412			—		1,191
	Other investments (b)	97			50			—			147		91		44			—		135
	Derivative assets — FTRs	—			—			3			3		—		—			3		3
	Total	$	894		$	598		$	3		$	1,495	$	872	$	570		$	3	$	1,445
	Assets:
	Current	$	5		$	99		$	3		$	107	$	2	$	114		$	3	$	119
	Noncurrent	889			499			—			1,388		870		456			—		1,326
	Total Assets	$	894		$	598		$	3		$	1,495	$	872	$	570		$	3	$	1,445
	_______________________________________
	(a)	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 the Consolidated Statements of Financial Position. At December 31, 2013, available-for-sale securities of $116 million, included $100 million and $16 million of cash equivalents included in Restricted cash and Other investments, respectively, on the Consolidated Statements of Financial Position.
	(b)	Available-for-sale equity securities at December 31, 2014 and 2013 of $8 million and $7 million, respectively, are included in Other investments on the 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 Company has obtained an understanding of how these prices are derived, including the nature and observability of the inputs used in deriving such prices. Additionally, the Company selectively corroborates the fair value of securities by comparison of market-based price sources. Investment policies and procedures are determined by the Company's Trust Investments Department which reports to the Company's Vice President and Treasurer.
	Derivative Assets and Liabilities
	Derivative assets and liabilities are comprised of physical and financial derivative contracts, including futures, forwards, options and swaps that are both exchange-traded and over-the-counter traded contracts. Various inputs are used to value derivatives depending on the type of contract and availability of market data. Exchange-traded derivative contracts are valued using quoted prices in active markets. The Company considers the following criteria in determining whether a market is considered active: frequency in which pricing information is updated, variability in pricing between sources or over time and the availability of public information. Other derivative contracts are valued based upon a variety of inputs including commodity market prices, broker quotes, interest rates, credit ratings, default rates, market-based seasonality and basis differential factors. The Company monitors the prices that are supplied by brokers and pricing services and may use a supplemental price source or change the primary price source of an index if prices become unavailable or another price source is determined to be more representative of fair value. The Company has obtained an understanding of how these prices are derived. Additionally, the Company selectively corroborates the fair value of its transactions by comparison of market-based price sources. Mathematical valuation models are used for derivatives for which external market data is not readily observable, such as contracts which extend beyond the actively traded reporting period. The Company has established a Risk Management Committee whose responsibilities include directly or indirectly ensuring all valuation methods are applied in accordance with predefined policies. The development and maintenance of our forward price curves has been assigned to our Risk Management Department, which is separate and distinct from the trading functions within the Company.
	The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for the years ended December 31, 2014 and 2013:
		Year Ended December 31,
		2014			2013
		(In millions)
	Net Assets as of beginning of period	$	3		1
	Change in fair value recorded in regulatory assets/liabilities	8			5
	Purchases, issuances and settlements:
	Settlements	(8		)	(3		)
	Net Assets as of December 31,	$	3		$	3
	The amount of total gains (losses) included in regulatory assets and liabilities attributed to the change in unrealized gains (losses) related to regulatory assets and liabilities held at December 31, 2014 and 2013	$	3		$	2
	No transfers between Levels 1, 2 or 3 occurred in the years ended December 31, 2014 and 2013.
	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 Company has obtained an understanding of how the fair values are derived. The Company also selectively corroborates the fair value of its transactions by comparison of market-based price sources. Discounted cash flow analyses based upon estimated current borrowing rates are also used to determine fair value when quoted market prices are not available. The fair values of notes receivable, excluding capital leases, are estimated using discounted cash flow techniques that incorporate market interest rates as well as assumptions about the remaining life of the loans and credit risk. Depending on the information available, other valuation techniques may be used that rely on internal assumptions and models. Valuation policies and procedures are determined by the Company's Treasury Department which reports to the Company's Vice President and Treasurer.
	The following table presents the carrying amount and fair value of financial instruments as of December 31, 2014 and 2013:
		December 31, 2014											December 31, 2013
		Carrying			Fair Value								Carrying		Fair Value
		Amount			Level 1			Level 2			Level 3		Amount		Level 1			Level 2		Level 3
		(In millions)
	Notes receivable, excluding capital leases	$	12		$	—		$	—		$	12	$	10	$	—		$	—	$	10
	Notes receivable — affiliates	$	8		$	—		$	—		$	8	$	200	$	—		$	—	$	200
	Short-term borrowings — affiliates	$	84		$	—		$	—		$	84	$	58	$	—		$	—	$	58
	Short-term borrowings — other	$	50		$	—		$	50		$	—	$	—	$	—		$	—	$	—
	Long-term debt, excluding capital leases	$	5,259		$	—		$	5,341		$	496	$	5,146	$	—		$	5,253	$	136
	Nuclear Decommissioning Trust Funds
	DTE Electric has a legal obligation to decommission its nuclear power plants following the expiration of their operating licenses. This obligation is reflected as an asset retirement obligation on the Consolidated Statements of Financial Position. Rates approved by the MPSC provide for the recovery of decommissioning costs of Fermi 2 and the disposal of low-level radioactive waste. DTE Electric is continuing to fund FERC jurisdictional amounts for decommissioning even though explicit provisions are not included in FERC rates. See Note 6 to the Consolidated Financial Statements, "Asset Retirement Obligations".
	The following table summarizes the fair value of the nuclear decommissioning trust fund assets:
		December 31,
		2014			2013
		(In millions)
	Fermi 2	$	1,221		$	1,172
	Fermi 1	3			3
	Low-level radioactive waste	17			16
	Total	$	1,241		$	1,191
	The costs of securities sold are determined on the basis of specific identification. The following table sets forth the gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds:
		Year Ended December 31,
	2014			2013			2012
	(In millions)
Realized gains	$	54		$	83		$	37
Realized losses	$	(33	)	$	(41	)	$	(31	)
Proceeds from sales of securities	$	1,146		$	1,118		$	759
Realized gains and losses from the sale of securities for the Fermi 2 and the low level radioactive waste funds are recorded to the Regulatory asset and Nuclear decommissioning liability. The following table sets forth the fair value and unrealized gains for the nuclear decommissioning trust funds:
	December 31, 2014									31-Dec-13
	Fair			Unrealized			Unrealized			Fair		Unrealized		Unrealized
	Value			Gains			Losses			Value		Gains		Losses
	(In millions)
Equity securities	$	756		$	204		$	(39	)	$	730	$	201	$	(25	)
Debt securities	474			21			(2		)	442		12		(6		)
Cash and cash equivalents	11			—			—			19		—		—
	$	1,241		$	225		$	(41	)	$	1,191	$	213	$	(31	)
At December 31, 2014, investments in the nuclear decommissioning trust funds consisted of approximately 61% in publicly traded equity securities, 38% in fixed debt instruments and 1% in cash equivalents. At December 31, 2013, investments in the nuclear decommissioning trust funds consisted of approximately 61% in publicly traded equity securities, 37% in fixed debt instruments and 2% in cash equivalents.
The debt securities at December 31, 2014 and 2013 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 December 31, 2014 and 2013, these securities are comprised primarily of money-market and equity securities. During the years ended December 31, 2014 and 2013, no amounts of unrealized losses on available-for-sale securities were reclassified out of other comprehensive income and realized into net income for the periods. Gains related to trading securities held at December 31, 2014, 2013, and 2012 were $12 million, $19 million and $9 million, respectively.

Financial_and_Other_Derivative

Financial and Other Derivative Instruments (Notes)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial and Other Derivative Instruments	FINANCIAL AND OTHER DERIVATIVE INSTRUMENTS
	The Company recognizes all derivatives at their fair value as Derivative assets or liabilities on the Consolidated Statements of Financial Position unless they qualify for certain scope exceptions, including the normal purchases and normal sales exception. Further, derivatives that qualify and are designated for hedge accounting are classified as either hedges of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge), or as hedges of the fair value of a recognized asset or liability or of an unrecognized firm commitment (fair value hedge). For cash flow hedges, the portion of the derivative gain or loss that is effective in offsetting the change in the value of the underlying exposure is deferred in Accumulated other comprehensive income and later reclassified into earnings when the underlying transaction occurs. Gains or losses from the ineffective portion of cash flow hedges are recognized in earnings immediately. For fair value hedges, changes in fair values for the derivative and hedged item are recognized in earnings each period. For derivatives that do not qualify or are not designated for hedge accounting, changes in fair value are recognized in earnings each period.
	The Company's primary market risk exposure is associated with commodity prices, credit and interest rates. The Company has risk management policies to monitor and manage market risks. The Company uses derivative instruments to manage some of the exposure. DTE Electric generates, purchases, distributes and sells electricity. DTE Electric uses forward energy contracts to manage changes in the price of electricity and fuel. Substantially all of these contracts meet the normal purchases and sales exemption and are therefore accounted for under the accrual method. Other derivative contracts are MTM and recoverable through the PSCR mechanism when settled. This results in the deferral of unrealized gains and losses as Regulatory assets or liabilities until realized.
	The following table presents the fair value of derivative instruments as of December 31, 2014 and 2013:
		December 31,
		2014		2013
		(In millions)
	FTRs — Other current assets	$	3	$	3
	Total derivatives not designated as hedging instrument	$	3	$	3

LongTerm_Debt_Notes

Long-Term Debt (Notes)	12 Months Ended
	Dec. 31, 2014
Long-term Debt, Unclassified [Abstract]
Long-term Debt	LONG-TERM DEBT
	The Company's long-term debt outstanding and weighted average interest rates (a) of debt outstanding at December 31 were:
		2014				2013
		(In millions)
	Taxable Debt, Principally Secured
	4.5% due 2016 to 2044	$	4,824			$	4,286
	Tax- Exempt Revenue Bonds (b)
	5.2% due 2020 to 2030	330				558
		5,154				4,844
	Less amount due within one year	(10		)		(304		)
		$	5,144			$	4,540
	Securitization Bonds
	6.6% due 2015	$	105			$	302
	Less amount due within one year	(105		)		(197		)
		$	—			$	105
	_________________________________
	(a)	Weighted average interest rates as of December 31, 2014 are shown below the description of each category of debt.
	(b)	Tax-Exempt Revenue Bonds are issued by a public body that loans the proceeds to DTE Electric on terms substantially mirroring the Revenue Bonds.
	Debt Issuances
	In 2014, the following debt was issued:
	Month		Type		Interest Rate			Maturity	Amount
									(In millions)
	June		Mortgage Bonds (a)		3.77	%		2026	$	100
	June		Mortgage Bonds (a)		4.6	%		2044	150
	July		Mortgage Bonds (a)		3.375	%		2025	350
	July		Mortgage Bonds (a)		4.3	%		2044	350
									$	950
	_____________________________
	(a)	Proceeds were used for the redemption of long-term debt, repayment of short-term borrowings and general corporate purposes.
	Debt Redemptions
	In 2014, the following debt was redeemed:
	Month		Type		Interest Rate			Maturity	Amount
									(In millions)
	March		Mortgage Bonds		Various			2014	$	13
	March		Securitization Bonds		6.62	%		2014	100
	April		Tax Exempt Revenue Bonds (a)		2.35	%		2024	31
	April		Tax Exempt Revenue Bonds (a)		4.65	%		2028	32
	June		Tax Exempt Revenue Bonds (a)		4.875	%		2029	36
	June		Tax Exempt Revenue Bonds (a)		6	%		2036	69
	July		Senior Notes		4.8	%		2015	200
	August		Tax Exempt Revenue Bonds (a)		5.25	%		2029	60
	August		Senior Notes		5.4	%		2014	200
	September		Securitization Bonds		6.62	%		2014	96
									$	837
	_____________________________
	(a)	Tax Exempt Revenue Bonds are issued by a public body that loans the proceeds to DTE Electric on terms substantially mirroring the Revenue Bonds.
	The following table shows the scheduled debt maturities, excluding any unamortized discount or premium on debt:
															2020 and
		2015				2016			2017		2018		2019		Thereafter		Total
		(In millions)
	Amount to mature	$	115			$	151		$	—	$	300	$	—	$	4,704	$	5,270
	Cross Default Provisions
	Substantially all of the net properties of DTE Electric are subject to the lien of its mortgage. Should DTE Electric fail to timely pay its indebtedness under this mortgage, such failure may create cross defaults in the indebtedness of DTE Energy.

Preferred_and_Preference_Secur

Preferred and Preference Securities (Notes)	12 Months Ended
	Dec. 31, 2014
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred and Preference Securities	PREFERRED AND PREFERENCE SECURITIES
	At December 31, 2014, DTE Electric had approximately 6.75 million shares of preferred stock with a par value of $100 per share and 30 million shares of preference stock with a par value of $1 per share authorized, with no shares issued.

ShortTerm_Credit_Arrangements_

Short-Term Credit Arrangements and Borrowings (Notes)	12 Months Ended
	Dec. 31, 2014
Short-term Debt [Abstract]
Short-Term Credit Arrangements and Borrowings	SHORT-TERM CREDIT ARRANGEMENTS AND BORROWINGS
	DTE Electric has a $300 million unsecured revolving credit agreement that can be used for general corporate borrowings, but is intended to provide liquidity support for the Company's commercial paper program. Borrowings under the facility are available at prevailing short-term interest rates. The facility will expire in April 2018. At December 31, 2014, there was $50 million outstanding against the facility, while there were no amounts outstanding against the facility at December 31, 2013.
	The agreement requires the Company to maintain a total funded debt to capitalization ratio of no more than 0.65 to 1. At December 31, 2014, the total funded debt to total capitalization ratio for DTE Electric was 0.51 to 1 and is in compliance with this financial covenant.
	The weighted average interest rates for short-term borrowings was 0.5% and zero at December 31, 2014 and 2013, respectively.

Operating_Leases_Notes

Operating Leases (Notes)	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Operating Leases	OPERATING LEASES
	Lessee — The Company leases various assets under operating leases, including coal railcars, computers, vehicles and other equipment. The lease arrangements expire at various dates through 2046.
	Future minimum lease payments under non-cancelable leases at December 31, 2014 were:
		Operating
		Leases
		(In millions)
	2015	$	28
	2016	22
	2017	18
	2018	15
	2019	10
	Thereafter	40
	Total minimum lease payments	$	133
	Rental expense for operating leases was $26 million in 2014, $28 million in 2013, and $29 million in 2012.

Commitments_and_Contingencies_

Commitments and Contingencies (Notes)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES
	Environmental
	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. The Company estimates DTE Electric will make 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), requires further reductions of sulfur dioxide and nitrogen oxides emissions effective in January 2015. DTE Electric expects to meet its obligations under CSAPR beginning in 2015.
	The Mercury and Air Toxics Standard (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, with a potential extension to April 2016. DTE Electric has requested and been granted compliance date extensions for all relevant units to April 2016. DTE Electric has tested technologies to determine technological and economic feasibility as MATS compliance alternatives to Flue Gas Desulfurization (FGD) systems. Implementation of Dry Sorbent Injection (DSI) and Activated Carbon Injection (ACI) technologies will allow several units that would not have been economical for FGD installations to continue operation in compliance with MATS. In 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, 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 will engage with the EPA and other stakeholders in commenting on this rule. 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. On August 23, 2011, the U.S. District Court judge granted DTE Energy's motion for summary judgment in the civil case, dismissing the case and entering judgment in favor of DTE Energy and DTE Electric. 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.
	DTE Energy and Electric believes 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 Company cannot predict the financial impact or outcome of this matter, or the timing of its resolution.
	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 Electric facilities in southwest Detroit and areas of Wayne County. Preliminary modeling runs by the MDEQ suggest that emission reductions may be required by significant sources of sulfur dioxide emissions in these areas, including DTE Electric power plants. The state implementation plan process is in the information gathering stage, and DTE Electric is unable to estimate any required emissions reductions at this time.
	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. We are currently evaluating the compliance options and working with the State of Michigan on evaluating whether any controls are needed. These evaluations/studies may require modifications to some existing intake structures. It is not possible to quantify the impact of this rulemaking at this time.
	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, the Company is also in the process of cleaning up other contaminated sites, including the area surrounding an ash landfill, electrical distribution substations, electric generating power plants, and underground and aboveground storage tank locations. The findings of these investigations indicated that the estimated cost to remediate these sites is expected to be incurred over the next several years. At December 31, 2014 and 2013, the Company had $10 million and $8 million accrued for remediation, respectively. Any change in assumptions, such as remediation techniques, nature and extent of contamination and regulatory requirements, could impact the estimate of remedial action costs for the sites and affect the Company’s financial position and cash flows. The Company believes the likelihood of a material change to the accrued amount is remote based on current knowledge of the conditions at each site.
	In December 2014, the EPA released a pre-publication version of a rule to regulate coal ash. This rule is based on the continued listing of ash as a non-hazardous waste, and relies on various self-implementation design and performance standards. The rule is still being evaluated and it is not possible to quantify its impact at this time. DTE Electric owns and operates three permitted engineered ash storage facilities to dispose of fly ash from coal fired power plants and operates a number of smaller impoundments at its power plants.
	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. The 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 $35 million per event if the loss associated with any one event at any nuclear plant should exceed the accumulated funds available to NEIL.
	Public Liability Insurance
	As required by federal law, DTE Electric maintains $375 million of public liability insurance for a nuclear incident. For liabilities arising from a terrorist act outside the scope of TRIA, the policy is subject to one industry aggregate limit of $300 million. Further, under the Price-Anderson Amendments Act of 2005, deferred premium charges up to $127 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 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 initial dry cask loading campaign planned for 2014 has been completed. The dry cask storage facility is expected to provide sufficient spent fuel storage capability for the life of the plant as defined by the original operating license.
	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.
	Guarantees
	In certain limited circumstances, the Company enters into contractual guarantees. The Company may guarantee another entity’s obligation in the event it fails to perform. The Company may provide guarantees in certain indemnification agreements. Finally, the Company may provide indirect guarantees for the indebtedness of others.
	Labor Contracts
	There are several bargaining units for the Company'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 December 31, 2014, the Company was party to numerous long-term purchase commitments relating to a variety of goods and services required for the Company’s business. These agreements primarily consist of fuel supply commitments and renewable energy contracts. The Company estimates that these commitments will be approximately $2.4 billion from 2015 through 2033 as detailed in the following table:
		(In millions)
	2015	$	496
	2016	330
	2017	278
	2018	125
	2019	106
	2020 and thereafter	1,063
		$	2,398
	The Company also estimates that 2015 capital expenditures will be approximately $1.9 billion. The Company has made certain commitments in connection with expected capital expenditures.
	Bankruptcies
	The Company purchases and sells electricity from and to governmental entities and numerous companies operating in the steel, automotive, energy, retail and other industries. Certain of its customers have filed for bankruptcy protection under the U.S. Bankruptcy Code. The Company regularly reviews contingent matters relating to these customers and its purchase and sale contracts and records provisions for amounts considered at risk of probable loss. The Company believes its accrued amounts are adequate for probable loss.
	Other Contingencies
	The Company is involved in certain other legal, regulatory, administrative and environmental proceedings before various courts, arbitration panels and governmental agencies concerning claims arising in the ordinary course of business. These proceedings include certain contract disputes, additional environmental reviews and investigations, audits, inquiries from various regulators, and pending judicial matters. The Company cannot predict the final disposition of such proceedings. The Company regularly reviews legal matters and records provisions for claims that it can estimate and are considered probable of loss. The resolution of these pending proceedings is not expected to have a material effect on the Company’s operations or financial statements in the periods they are resolved.
	For a discussion of contingencies related to regulatory matters see Note 7 to the Consolidated Financial Statements, "Regulatory Matters".

Retirement_Benefits_and_Truste

Retirement Benefits and Trusteed Assets (Notes)	12 Months Ended
	Dec. 31, 2014
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Retirement Benefits and Trusteed Assets	RETIREMENT BENEFITS AND TRUSTEED ASSETS
	Pension Plan Benefits
	DTE Electric participates in various plans that provide pension and other postretirement benefits for DTE Energy and its affiliates. The plans are sponsored by DTE Energy Corporate Services, LLC (LLC), a subsidiary of DTE Energy. DTE Electric is allocated net periodic benefit costs for its share of the amounts of the combined plans.
	Effective January 1, 2012 for non-represented employees and in March 2013 for the majority of represented employees, the Company discontinued offering a defined benefit retirement plan to newly hired employees. In its place, the Company will annually contribute an amount equivalent to 4% of an employee's eligible pay to the employee's defined contribution retirement savings plan.
	The Company’s policy is to fund pension costs by contributing amounts consistent with the provisions of the Pension Protection Act of 2006 and additional amounts when it deems appropriate. The Company contributed $145 million to its qualified pension plans in 2014. At the discretion of management, and depending upon financial market conditions, the Company anticipates making up to $145 million in contributions to the pension plans in 2015.
	Net pension cost includes the following components:
		2014			2013			2012
		(In millions)
	Service cost	$	64		$	73		$	64
	Interest cost	162			146			155
	Expected return on plan assets	(194		)	(184		)	(166		)
	Amortization of:
	Net loss	110			148			124
	Prior service cost	2			1			1
	Settlements	—			—			2
	Net pension cost	$	144		$	184		$	180
		2014			2013
		(In millions)
	Other changes in plan assets and benefit obligations recognized in Regulatory assets and Other comprehensive income
	Net actuarial (gain) loss	$	614		$	(418	)
	Amortization of net actuarial loss	(110		)	(148		)
	Prior service cost	(2		)	—
	Amortization of prior service cost	(2		)	(1		)
	Total recognized in Regulatory assets and Other comprehensive income	$	500		$	(567	)
	Total recognized in net periodic pension cost, Regulatory assets and Other comprehensive income	$	644		$	(383	)
	Estimated amounts to be amortized from Regulatory assets and Accumulated other comprehensive income into net periodic benefit cost during next fiscal year
	Net actuarial loss	$	149		$	106
	Prior service cost	$	1		$	1
	The following table reconciles the obligations, assets and funded status of the plan as well as the amount recognized as prepaid pension cost or pension liability in the Consolidated Statements of Financial Position at December 31:
		2014			2013
		(In millions)
	Accumulated benefit obligation, end of year	$	3,712		$	3,111
	Change in projected benefit obligation
	Projected benefit obligation, beginning of year	$	3,341		$	3,585
	Service cost	64			73
	Interest cost	162			146
	Plan amendments	(2		)	—
	Actuarial (gain) loss	634			(286		)
	Benefits paid	(181		)	(177		)
	Projected benefit obligation, end of year	$	4,018		$	3,341
	Change in plan assets
	Plan assets at fair value, beginning of year	$	2,632		$	2,211
	Actual return on plan assets	212			316
	Company contributions	149			282
	Benefits paid	(181		)	(177		)
	Plan assets at fair value, end of year	$	2,812		$	2,632
	Funded status of the plan	$	(1,206	)	$	(709	)
	Amount recorded as:
	Current liabilities	$	(6	)	$	(4	)
	Noncurrent liabilities	(1,200		)	(705		)
		$	(1,206	)	$	(709	)
	Amounts recognized in Regulatory assets (see Note 7 - "Regulatory Matters")
	Net actuarial loss	$	1,738		$	1,248
	Prior service cost	5			9
		$	1,743		$	1,257
	At December 31, 2014, the benefits related to the Company’s qualified and nonqualified pension plans expected to be paid in each of the next five years and in the aggregate for the five fiscal years thereafter are as follows:
		(In millions)
	2015	$	210
	2016	216
	2017	223
	2018	233
	2019	239
	2020 - 2024	1,264
	Total	$	2,385
Assumptions used in determining the projected benefit obligation and net pension costs are listed below:
	2014		2013	2012
Projected benefit obligation
Discount rate	4.12%		4.95%	4.15%
Rate of compensation increase	4.65%		4.20%	4.20%
Net pension costs
Discount rate	4.95%		4.15%	5.00%
Rate of compensation increase	4.20%		4.20%	4.20%
Expected long-term rate of return on plan assets	7.75%		8.25%	8.25%
The Company employs a formal process in determining the long-term rate of return for various asset classes. Management reviews historic financial market risks and returns and long-term historic relationships between the asset classes of equities, fixed income and other assets, consistent with the widely accepted capital market principle that asset classes with higher volatility generate a greater return over the long-term. Current market factors such as inflation, interest rates, asset class risks and asset class returns are evaluated and considered before long-term capital market assumptions are determined. The long-term portfolio return is also established employing a consistent formal process, with due consideration of diversification, active investment management and rebalancing. Peer data is reviewed to check for reasonableness. As a result of this process, the Company has long-term rate of return assumptions for its pension plans of 7.75% and other postretirement benefit plans of 8.00%, for 2015. The Company believes these rates are a reasonable assumption for the long-term rate of return on its plan assets for 2015 given its investment strategy.
The Company employs a total return investment approach whereby a mix of equities, fixed income and other investments are used to maximize the long-term return on plan assets consistent with prudent levels of risk, with consideration given to the liquidity needs of the plan. Risk tolerance is established through consideration of future plan cash flows, plan funded status and corporate financial considerations. The investment portfolio contains a diversified blend of equity, fixed income and other investments. Furthermore, equity investments are diversified across U.S. and non-U.S. stocks, growth and value stocks and large and small market capitalizations. Fixed income securities generally include market and long duration bonds of companies from diversified industries, mortgage-backed securities, non-US securities, bank loans and U.S. Treasuries. Other assets such as private markets and hedge funds are used to enhance long-term returns while improving portfolio diversification. Derivatives may be utilized in a risk controlled manner, to potentially increase the portfolio beyond the market value of invested assets and/or reduce portfolio investment risk. Investment risk is measured and monitored on an ongoing basis through annual liability measurements, periodic asset/liability studies, and quarterly investment portfolio reviews.
Target allocations for pension plan assets as of December 31, 2014 are listed below:
U.S. Large Cap Equity Securities	22	%
U.S. Small Cap and Mid Cap Equity Securities	5
Non U.S. Equity Securities	20
Fixed Income Securities	25
Hedge Funds and Similar Investments	20
Private Equity and Other	8
	100	%
Fair Value Measurements for pension plan assets at December 31, 2014 and 2013 (a):
	December 31, 2014												December 31, 2013
	Level 1			Level 2			Level 3			Total			Level 1			Level 2			Level 3		Total
	(In millions)
Asset category:
Short-term investments (b)	$	33		$	—		$	—		$	33		$	15		$	—		$	—	$	15
Equity securities
U.S. large cap (c)	638			—			—			638			639			—			—		639
U.S. small/mid cap (d)	162			—			—			162			160			—			—		160
Non U.S. (e)	378			157			—			535			440			94			—		534
Fixed income securities (f)	5			758			—			763			11			623			—		634
Hedge funds and similar investments (g)	163			68			315			546			193			50			285		528
Private equity and other (h)	—			—			135			135			—			—			122		122
Securities lending (i)	(136		)	(36		)	—			(172		)	—			—			—		—
Securities lending collateral (i)	136			36			—			172			—			—			—		—
Total	$	1,379		$	983		$	450		$	2,812		$	1,458		$	767		$	407	$	2,632
_______________________________________
(a)	For a description of levels within the fair value hierarchy see Note 9 to the Consolidated financial Statements, "Fair Value".
(b)	This category predominantly represents certain short-term fixed income securities and money market investments that are managed in separate accounts or commingled funds. Pricing for investments in this category are obtained from quoted prices in actively traded markets or valuations from brokers or pricing services.
(c)	This category comprises both actively and not actively managed portfolios that track the S&P 500 low cost equity index funds. Investments in this category are exchange-traded securities whereby unadjusted quote prices can be obtained. Exchange-traded securities held in a commingled fund are classified as Level 2 assets.
(d)	This category represents portfolios of small and medium capitalization domestic equities. Investments in this category are exchange-traded securities whereby unadjusted quote prices can be obtained. Exchange-traded securities held in a commingled fund are classified as Level 2 assets.
(e)	This category primarily consists of portfolios of non-U.S. developed and emerging market equities. Investments in this category are exchange-traded securities whereby unadjusted quote prices can be obtained. Exchange-traded securities held in a commingled fund are classified as Level 2 assets.
(f)	This category includes corporate bonds from diversified industries, U.S. Treasuries, and mortgage-backed securities. Pricing for investments in this category is obtained from quoted prices in actively traded markets and quotations from broker or pricing services. Non-exchange traded securities and exchange-traded securities held in commingled funds are classified as Level 2 assets.
(g)	This category utilizes a diversified group of strategies that attempt to capture financial market inefficiencies and includes publicly traded debt and equity, publicly traded mutual funds, commingled and limited partnership funds and non-exchange traded securities. Pricing for Level 1 and Level 2 assets in this category is obtained from quoted prices in actively traded markets and quoted prices from broker or pricing services. Non-exchange traded securities held in commingled funds are classified as Level 2 assets. Valuations for some Level 3 assets in this category may be based on limited observable inputs as there may be little, if any, publicly available pricing.
(h)	This category includes a diversified group of funds and strategies that primarily invests in private equity partnerships. This category also includes investments in timber and private mezzanine debt. Pricing for investments in this category is based on limited observable inputs as there is little, if any, publicly available pricing. Valuations for assets in this category may be based on discounted cash flow analyses, relevant publicly-traded comparables and comparable transactions.
(i)	In 2014, DTE Electric began a securities lending program with a third party agent. The program allows the agent to lend certain securities from the Company's pension trusts to selected entities against receipt of collateral (in the form of cash) as provided for and determined in accordance with its securities lending agency agreement.
The pension trust holds debt and equity securities directly and indirectly through commingled funds and institutional mutual funds. Exchange-traded debt and equity securities held directly are valued using quoted market prices in actively traded markets. The commingled funds and institutional mutual funds hold exchange-traded equity or debt securities and are valued based on NAV. Non-exchange traded fixed income securities are valued by the trustee 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 challenges an assigned price and determines that another price source is considered to be preferable. DTE Electric has obtained an understanding of how these prices are derived, including the nature and observability of the inputs used in deriving such prices. Additionally, DTE Electric selectively corroborates the fair values of securities by comparison of market-based price sources.
Fair Value Measurements Using Significant Unobservable Inputs (Level 3):
	Year Ended December 31, 2014									Year Ended December 31, 2013
	Hedge Funds			Private						Hedge Funds			Private
	and Similar			Equity						and Similar			Equity
	Investments			and Other			Total			Investments			and Other			Total
	(In millions)
Beginning Balance at January 1	$	285		$	122		$	407		$	238		$	125		363
Total realized/unrealized gains (losses)	15			12			27			29			2			31
Purchases, sales and settlements:
Purchases	16			22			38			18			15			33
Sales	(1		)	(21		)	(22		)	—			(20		)	(20		)
Ending Balance at December 31	$	315		$	135		$	450		$	285		$	122		$	407
The amount of total gains for the period attributable to the change in unrealized gains or losses related to assets still held at the end of the period	$	15		$	8		$	23		$	27		$	2		$	29
There were no transfers between Level 3 and Level 2 and there were no significant transfers between Level 2 and Level 1 in the years ended December 31, 2014 and 2013.
Other Postretirement Benefits
The Company participates in defined benefit plans sponsored by the LLC that provide certain other postretirement health care and life insurance benefits for employees who are eligible for these benefits. The Company’s policy is to fund certain trusts to meet its other postretirement benefit obligations. Separate qualified VEBA and other benefit trusts exist. The Company made no contributions to these trusts for its defined benefit other postretirement medical and life insurance benefit plans during 2014. At the discretion of management, the Company anticipates making up to $175 million of contributions to the trusts in 2015.
Starting in 2012, in lieu of offering future employees defined benefit post-employment health care and life insurance benefits, the Company allocates a fixed amount per year to an account in a defined contribution VEBA for each employee. These accounts are managed either by the Company (for non-represented and certain represented groups), or by the Utility Workers of America (UWUA) for Local 223 employees. The contributions to the VEBA for these accounts were $2 million in 2014, $1 million in 2013, and less than $1 million in 2012.
Beginning in 2013, the Company replaced the defined benefit employer-sponsored retiree medical, prescription drug and dental coverage with a notional allocation to a Retiree Reimbursement Account. This change applies to both current and future Medicare eligible non-represented and future represented retirees, spouses, surviving spouses or same sex domestic partners when the youngest of the retiree's covered household turns age 65. The amount of the annual allocation to each participant is determined by the employee's retirement date: for employees who retired on or before January 1, 2013, the base allocation is $3,500, which increased to $3,570 in 2014 and for employees who retire after January 1, 2013, the base allocation is $3,250 which increased to $3,315 in 2014. The amount of the allocation will increase each year at the lower of the rate of medical inflation or 2%.
Net other postretirement cost includes the following components:
	2014			2013			2012
	(In millions)
Service cost	$	26		$	35		$	51
Interest cost	68			67			91
Expected return on plan assets	(85		)	(74		)	(61		)
Amortization of:
Net loss	14			47			58
Prior service credit	(109		)	(100		)	(14		)
Net other postretirement cost (credit)	$	(86	)	$	(25	)	$	125
	2014			2013
	(In millions)
Other changes in plan assets and APBO recognized in Regulatory assets (liabilities) and Other comprehensive income
Net actuarial gain	$	144		$	(258	)
Amortization of net actuarial loss	(14		)	(47		)
Prior service credit	—			(159		)
Amortization of prior service credit	109			100
Total recognized in Regulatory assets (liabilities) and Other comprehensive income	$	239		$	(364	)
Total recognized in net periodic benefit cost, Regulatory assets (liabilities) and Other comprehensive income	$	153		$	(389	)
Estimated amounts to be amortized from Regulatory assets (liabilities) and Accumulated other comprehensive income into net periodic benefit cost during next fiscal year
Net actuarial loss	$	31		$	15
Prior service credit	$	(94	)	$	(109	)
The following table reconciles the obligations, assets and funded status of the plans including amounts recorded as Accrued postretirement liability - affiliates in the Consolidated Statements of Financial Position at December 31:
	2014			2013
	(In millions)
Change in accumulated postretirement benefit obligation
Accumulated postretirement benefit obligation, beginning of year	$	1,430		$	1,752
Service cost	26			35
Interest cost	68			67
Plan amendments	—			(159		)
Actuarial (gain) loss	100			(200		)
Medicare Part D subsidy	—			1
Benefits paid	(66		)	(66		)
Accumulated postretirement benefit obligation, end of year	$	1,558		$	1,430
Change in plan assets
Plan assets at fair value, beginning of year	$	1,061		$	756
Actual return on plan assets	41			131
Company contributions	—			239
Benefits paid	(64		)	(65		)
Plan assets at fair value, end of year	$	1,038		$	1,061
Funded status, end of year	$	(520	)	$	(369	)
Amount recorded as:
Noncurrent liabilities	$	(520	)	$	(369	)
Amounts recognized in Regulatory assets (liabilities) (see Note 7 - "Regulatory Matters")
Net actuarial loss	$	385		$	255
Prior service cost	(194		)	(303		)
	$	191		$	(48	)
At December 31, 2014, the benefits expected to be paid, including prescription drug benefits, in each of the next five years and in the aggregate for the five fiscal years thereafter are as follows:
	(In millions)
2015	$	77
2016	82
2017	85
2018	89
2019	93
2020 - 2024	505
Total	$	931
Assumptions used in determining the accumulated postretirement benefit obligation and net other postretirement benefit costs are listed below:
	2014		2013	2012
Accumulated postretirement benefit obligation
Discount rate	4.10%		4.95%	4.15%
Health care trend rate pre- and post- 65	7.50 / 6.50%		7.50 / 6.50%	7.00%
Ultimate health care trend rate	4.50%		4.50%	5.00%
Year in which ultimate reached pre- and post- 65	2025 / 2024		2025 / 2024	2021
Other postretirement benefit costs
Discount rate (prior to interim remeasurement)	4.95%		4.15%	5.00%
Discount rate (post interim remeasurement)	N/A		4.30%	N/A
Expected long-term rate of return on plan assets	8.00%		8.25%	8.25%
Health care trend rate pre- and post- 65	7.50 / 6.50%		7.00%	7.00%
Ultimate health care trend rate	4.50%		5.00%	5.00%
Year in which ultimate reached pre- and post- 65	2025 / 2024		2021	2020
A one percentage-point increase in health care cost trend rates would have increased the total service cost and interest cost components of benefit costs by $5 million in 2014 and increased the accumulated benefit obligation by $89 million at December 31, 2014. A one percentage-point decrease in the health care cost trend rates would have decreased the total service and interest cost components of benefit costs by $4 million in 2014 and would have decreased the accumulated benefit obligation by $77 million at December 31, 2014.
The process used in determining the long-term rate of return for assets and the investment approach for the other postretirement benefits plans is similar to those previously described for its pension plans.
Target allocations for other postretirement benefit plan assets as of December 31, 2014 are listed below:
U.S. Large Cap Equity Securities	17	%
U.S. Small Cap and Mid Cap Equity Securities	4
Non U.S. Equity Securities	20
Fixed Income Securities	25
Hedge Funds and Similar Investments	20
Private Equity and Other	14
	100	%
Fair Value Measurements for other postretirement benefit plan assets at December 31, 2014 and 2013 (a):
	December 31, 2014												December 31, 2013
	Level 1			Level 2			Level 3			Total			Level 1			Level 2			Level 3		Total
Asset category:	(In millions)
Short-term investments (b)	$	4		$	—		$	—		$	4		$	3		$	—		$	—	$	3
Equity securities
U.S. large cap (c)	179			—			—			179			208			—			—		208
U.S. small/mid cap (d)	102			—			—			102			103			—			—		103
Non U.S. (e)	151			39			—			190			197			5			—		202
Fixed income securities (f)	11			243			—			254			12			243			—		255
Hedge funds and similar investments (g)	73			31			114			218			91			17			111		219
Private equity and other (h)	—			—			91			91			—			—			71		71
Securities lending (i)	(98		)	(11		)	—			(109		)	—			—			—		—
Securities lending collateral (i)	98			11			—			109			—			—			—		—
Total	$	520		$	313		$	205		$	1,038		$	614		$	265		$	182	$	1,061
_______________________________________
(a)	For a description of levels within the fair value hierarchy see Note 9 to the Consolidated Financial Statements, "Fair Value".
(b)	This category predominantly represents certain short-term fixed income securities and money market investments that are managed in separate accounts or commingled funds. Pricing for investments in this category are obtained from quoted prices in actively traded markets or valuations from brokers or pricing services.
(c)	This category comprises both actively and not actively managed portfolios that track the S&P 500 low cost equity index funds. Investments in this category are exchange-traded securities whereby unadjusted quote prices can be obtained. Exchange-traded securities held in a commingled fund are classified as Level 2 assets.
(d)	This category represents portfolios of small and medium capitalization domestic equities. Investments in this category are exchange-traded securities whereby unadjusted quote prices can be obtained. Exchange-traded securities held in a commingled fund are classified as Level 2 assets.
(e)	This category primarily consists of portfolios of non-U.S. developed and emerging market equities. Investments in this category are exchange-traded securities whereby unadjusted quote prices can be obtained. Exchange-traded securities held in a commingled fund are classified as Level 2 assets.
(f)	This category includes corporate bonds from diversified industries, U.S. Treasuries, bank loans and mortgage backed securities. Pricing for investments in this category is obtained from quoted prices in actively traded markets and quotations from broker or pricing services. Non-exchange traded securities and exchange-traded securities held in commingled funds are classified as Level 2 assets.
(g)	This category utilizes a diversified group of strategies that attempt to capture financial market inefficiencies and includes publicly traded debt and equity, publicly traded mutual funds, commingled and limited partnership funds and non-exchange traded securities. Pricing for Level 1 and Level 2 assets in this category is obtained from quoted prices in actively traded markets and quoted prices from broker or pricing services. Non-exchange traded securities held in commingled funds are classified as Level 2 assets. Valuations for some Level 3 assets in this category may be based on limited observable inputs as there may be little, if any, publicly available pricing.
(h)	This category includes a diversified group of funds and strategies that primarily invests in private equity partnerships. This category also includes investments in timber and private mezzanine debt. Pricing for investments in this category is based on limited observable inputs as there is little, if any, publicly available pricing. Valuations for assets in this category may be based on discounted cash flow analyses, relevant publicly-traded comparables and comparable transactions.
(i)	In 2014, DTE Electric began a securities lending program with a third party agent. The program allows the agent to lend certain securities from the Company's VEBA trust to selected entities against receipt of collateral (in the form of cash) as provided for and determined in accordance with its securities lending agency agreement.
The VEBA trust holds debt and equity securities directly and indirectly through commingled funds and institutional mutual funds. Exchange-traded debt and equity securities held directly are valued using quoted market prices in actively traded markets. The commingled funds and institutional mutual funds hold exchange-traded equity or debt securities and are valued based on NAV. Non-exchange traded fixed income securities are valued by the trustee 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 trustees monitor 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 challenges an assigned price and determines that another price source is considered to be preferable. DTE Electric has obtained an understanding of how these prices are derived, including the nature and observability of the inputs used in deriving such prices. Additionally, DTE Electric selectively corroborates the fair values of securities by comparison of market-based price sources.
Fair Value Measurements Using Significant Unobservable Inputs (Level 3):
	Year Ended December 31, 2014									Year Ended December 31, 2013
	Hedge Funds and Similar Investments			Private Equity and Other			Total			Hedge Funds and Similar Investments			Private Equity and Other			Total
	(In millions)
Beginning Balance at January 1	$	111		$	71		$	182		$	78		$	57		$	135
Total realized/unrealized gains (losses)	5			6			11			10			7			17
Purchases, sales and settlements:
Purchases	4			22			26			23			14			37
Sales	(6		)	(8		)	(14		)	—			(7		)	(7		)
Ending Balance at December 31	$	114		$	91		$	205		$	111		$	71		$	182
The amount of total gains for the period attributable to the change in unrealized gains or losses related to assets still held at the end of the period	$	5		$	5		$	10		$	10		$	6		$	16
There were no transfers between Level 3 and Level 2 and there were no significant transfers between Level 2 and Level 1 in the years ended December 31, 2014 and 2013.
Interim Re-Measurement of Other Postretirement Benefit Obligation
In March 2013, the Company reached an agreement on a new four-year labor contract with certain represented employees. As a term of the agreement, the Company replaced the defined benefit employer-sponsored retiree medical, prescription drug and dental coverage for future Medicare eligible retirees and their covered dependents with an allocation to a Retiree Reimbursement Account, when the youngest of the retiree's covered household turns age 65. The amount of the allocation is $3,250 per year for each eligible participant, which increased to $3,315 in 2014. The amount of the allocation will increase each year at the lower of the rate of medical inflation or 2%. The modification in retiree health coverage will reduce future other postretirement benefit costs.
Based on the impact of such benefit cost savings on the Consolidated Financial Statements, the Company re-measured its retiree health plan as of March 31, 2013. In performing the re-measurement, the Company updated its significant actuarial assumptions, including an adjustment to the discount rate from 4.15% at December 31, 2012 to 4.30% at March 31, 2013. Plan assets were also updated to reflect fair value as of the re-measurement date. Beginning April 2013, net other postretirement benefit costs were recorded based on the updated actuarial assumptions and benefit changes resulting from the new labor contract.
Defined Contribution Plans
The Company also sponsors defined contribution retirement savings plans. Participation in one of these plans is available to substantially all represented and non-represented employees. The Company matches employee contributions up to certain predefined limits based upon eligible compensation, the employee’s contribution rate and, in some cases, years of credit service. The cost of these plans was $24 million, $21 million and $19 million in each of the years ended December 31, 2014, 2013 and 2012, respectively.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS
	The Company has agreements with affiliated companies to sell energy for resale, purchase power, provide fuel supply services, and provide power plant operation and maintenance services. The Company has agreements with certain DTE Energy affiliates where we charge them for their use of the shared capital assets of the Company. A shared services company accumulates various corporate support services expenses and charges various subsidiaries of DTE Energy, including DTE Electric. DTE Electric records federal, state and local income taxes payable to or receivable from DTE Energy based on its federal, state and local tax provisions.
	The following is a summary of transactions with affiliated companies:
		2014			2013			2012
	Revenues	(In millions)
	Energy sales	$	2		$	2		$	2
	Other services	$	5		$	7		$	11
	Shared capital assets	$	26		$	23		$	26
	Costs
	Fuel and purchased power	$	4		$	4		$	5
	Other services and interest	$	(1	)	$	(1	)	$	1
	Corporate expenses (net)	$	304		$	334		$	322
	Other
	Dividends declared	$	370		$	342		$	317
	Dividends paid	$	370		$	342		$	317
	Capital contribution from DTE Energy	$	190		$	400		$	—
	DTE Electric's Accounts receivable and Accounts payable related to Affiliates are payable upon demand and are generally settled in cash within a monthly business cycle. Notes receivable and Short-term borrowings related to Affiliates are subject to a credit agreement with DTE Energy whereby short-term excess cash or cash shortfalls are remitted to or funded by DTE Energy. This credit arrangement involves the charge and payment of interest at market-based rates. Refer to the Consolidated Statements of Financial Position for affiliate balances at December 31, 2014 and 2013.
	There were no charitable contributions to the DTE Energy Foundation for the years ended December 31, 2014 and December 31, 2012, while there were $18 million in contributions for the year ended December 31, 2013. The DTE Energy Foundation is a non-consolidated not-for-profit private foundation, the purpose of which is to contribute and assist charitable organizations.

Supplementary_Quarterly_Financ

Supplementary Quarterly Financial Information (Unaudited) (Notes)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Supplementary Quarterly Financial Information (Unaudited)	SUPPLEMENTARY QUARTERLY FINANCIAL INFORMATION (UNAUDITED)
		First		Second		Third		Fourth		Total
		Quarter		Quarter		Quarter		Quarter		Year to Date
		(In millions)
	2014
	Operating Revenues	$	1,410	$	1,281	$	1,357	$	1,234	$	5,282
	Operating Income	$	271	$	259	$	272	$	250	$	1,052
	Net Income	$	137	$	130	$	136	$	129	$	532
	2013
	Operating Revenues	$	1,219	$	1,265	$	1,457	$	1,256	$	5,197
	Operating Income	$	235	$	202	$	338	$	225	$	1,000
	Net Income	$	116	$	90	$	180	$	101	$	487

Subsequent_Event_Notes

Subsequent Event (Notes)	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Event	SUBSEQUENT EVENT
	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 for a total purchase price of approximately $240 million paid in cash. This facility will serve to meet the needs of approximately 260,000 additional households during peak demand. DTE Electric closed on the acquisition on January 21, 2015.
	Effective upon closing, DTE Electric obtained control over and applied acquisition accounting to the acquired business. Due to the limited time since the acquisition date, the initial accounting for the business combination is incomplete. As a result, DTE Electric is unable to provide amounts recognized as of the acquisition date for major classes of assets and liabilities acquired. DTE Electric will include required information in the Quarterly Report on Form 10-Q for the period ending March 31, 2015.

Valuation_and_Qualifying_Accou

Valuation and Qualifying Accounts (Notes)	12 Months Ended
	Dec. 31, 2014
Valuation and Qualifying Accounts [Abstract]
Schedule II Valuation and Qualifying Accounts	Schedule II — Valuation and Qualifying Accounts
		Year Ended December 31,
		2014			2013			2012
		(In millions)
	Allowance for Doubtful Accounts (shown as deduction from Accounts Receivable in the Consolidated Statements of Financial Position)
	Balance at Beginning of Period	$	28		$	35		$	80
	Additions:
	Charged to costs and expenses	50			52			40
	Charged to other accounts (a)	10			11			7
	Deductions (b)	(59		)	(70		)	(92		)
	Balance at End of Period	$	29		$	28		$	35
	_______________________________________
	(a)	Collection of accounts previously written off.
	(b)	Uncollectible accounts written off.

Significant_Accounting_Policie1

Significant Accounting Policies Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
	The accompanying Consolidated Financial Statements are prepared using accounting principles generally accepted in the United States of America. These accounting principles require management to use estimates and assumptions that impact reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from the Company’s estimates.
Principles of Consolidation	Principles of Consolidation
	The Company consolidates all majority-owned subsidiaries and investments in entities in which it has controlling influence. Non-majority owned investments are accounted for using the equity method when the Company is able to influence the operating policies of the investee. When the Company does not influence the operating policies of an investee, the cost method is used. These Consolidated Financial Statements also reflect the Company’s proportionate interests in certain jointly owned utility plants. The Company eliminates all intercompany balances and transactions.
	The Company evaluates whether an entity is a VIE whenever reconsideration events occur. The Company consolidates VIEs for which it is the primary beneficiary. If the Company is not the primary beneficiary and an ownership interest is held, the VIE is accounted for under the equity method of accounting. When assessing the determination of the primary beneficiary, the Company considers all relevant facts and circumstances, including: the power, through voting or similar rights, to direct the activities of the VIE that most significantly impact the VIE’s economic performance and the obligation to absorb the expected losses and/or the right to receive the expected returns of the VIE. The Company performs ongoing reassessments of all VIEs to determine if the primary beneficiary status has changed.
	The Company has variable interests in VIEs through certain of its long-term purchase contracts. As of December 31, 2014, the carrying amount of assets and liabilities in the Consolidated Statements of Financial Position that relate to its variable interests under long-term purchase contracts are predominately related to working capital accounts and generally represent the amounts owed by the Company for the deliveries associated with the current billing cycle under the contracts. The Company has not provided any significant form of financial support associated with these long-term contracts. There is no significant potential exposure to loss as a result of its variable interests through these long-term purchase contracts.
	In 2001, DTE Electric financed a regulatory asset related to Fermi 2 and certain other regulatory assets through the sale of rate reduction bonds by a wholly-owned special purpose entity, Securitization. DTE Electric performs servicing activities including billing and collecting surcharge revenue for Securitization. This entity is a VIE and is consolidated by the Company. The maximum risk exposure related to Securitization is reflected on the Company’s Consolidated Statements of Financial Position.
Revenues	Revenues
	Revenues from the sale and delivery of electricity are recognized as services are provided. The Company records revenues for electricity provided but unbilled at the end of each month. Rates for DTE Electric include provisions to adjust billings for fluctuations in fuel and purchased power costs, and certain other costs. Revenues are adjusted for differences between actual costs subject to reconciliation and the amounts billed in current rates. Under or over recovered revenues related to these cost recovery mechanisms are recorded on the Consolidated Statements of Financial Position and are recovered or returned to customers through adjustments to the billing factors.
	See Note 7, "Regulatory Matters", for further discussion of recovery mechanisms authorized by the MPSC.
Accounting for ISO Transactions	Accounting for ISO Transactions
	DTE Electric participates in the energy market through MISO. MISO requires that we submit hourly day-ahead, real- time and FTR bids and offers for energy at locations across the MISO region. DTE Electric accounts for MISO transactions on a net hourly basis in each of the day-ahead, real-time and FTR markets and net transactions across all MISO energy market locations. In any single hour DTE Electric records net purchases in Fuel and purchased power and net sales in Operating revenues on the Consolidated Statements of Operations. DTE Electric records accruals for future net purchases adjustments based on historical experience, and reconciles accruals to actual costs when invoices are received from MISO.
Changes in Accumulated Other Comprehensive Loss	Changes in Accumulated Other Comprehensive Loss
	Comprehensive income (loss) is the change in common shareholder’s equity during a period from transactions and events from non-owner sources, including net income. The amounts recorded to accumulated other comprehensive loss include unrealized gains and losses on available-for-sale securities and changes in benefit obligations, consisting of deferred actuarial losses, and prior service costs.
Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash
	Cash and cash equivalents include cash on hand, cash in banks and temporary investments purchased with remaining maturities of three months or less. Restricted cash consists of funds held to satisfy requirements of certain debt agreements, related to Securitization bonds. Restricted cash designated for interest and principal payments within one year is classified as a current asset.
Receivables	Receivables
	Accounts receivable are primarily composed of trade receivables and unbilled revenue. Our accounts receivable are stated at net realizable value.
	The allowance for doubtful accounts is generally calculated using the aging approach that utilizes rates developed in reserve studies. DTE Electric establishes an allowance for uncollectible accounts based on historical losses and management’s assessment of existing economic conditions, customer trends, and other factors. Customer accounts are generally considered delinquent if the amount billed is not received by the due date, which is typically in 21 days, however, factors such as assistance programs may delay aggressive action. We assess late payment fees on trade receivables based on past-due terms with customers. Customer accounts are written off when collection efforts have been exhausted. The time period for write-off is 150 days after service has been terminated.
	Unbilled revenues of $250 million and $280 million are included in customer accounts receivable at December 31, 2014 and 2013, respectively.
	Notes Receivable
	Notes receivable, or financing receivables, are primarily comprised of loans and are typically considered delinquent when payment is not received for periods ranging from 60 to 120 days. The Company ceases accruing interest (nonaccrual status), considers a note receivable impaired, and establishes an allowance for credit loss when it is probable that all principal and interest amounts due will not be collected in accordance with the contractual terms of the note receivable. Cash payments received on nonaccrual status notes receivable, that do not bring the account contractually current, are first applied to contractually owed past due interest, with any remainder applied to principal. Accrual of interest is generally resumed when the note receivable becomes contractually current.
	In determining the allowance for credit losses for notes receivable, we consider the historical payment experience and other factors that are expected to have a specific impact on the counterparty’s ability to pay. In addition, the Company monitors the credit ratings of the counterparties from which we have notes receivable.
Inventories	Inventories
	The Company generally values inventory at average cost.
Property, Retirement, and Maintenance, and Depreciation, Depletion and Amortization	Property, Retirement and Maintenance, and Depreciation, Depletion and Amortization
	Property is stated at cost and includes construction-related labor, materials, overheads and AFUDC. The cost of properties retired is charged to accumulated depreciation. Expenditures for maintenance and repairs are charged to expense when incurred, except for Fermi 2.
	Utility property is depreciated over its estimated useful life using straight-line rates approved by the MPSC.
	Depreciation and amortization expense also includes the amortization of certain regulatory assets.
	Approximately $16 million and $26 million of expenses related to Fermi 2 refueling outages were accrued at December 31, 2014 and 2013, respectively. Amounts are accrued on a pro-rata basis, generally over an 18-month period, that coincides with scheduled refueling outages at Fermi 2. This accrual of outage costs matches the regulatory recovery of these costs in rates set by the MPSC. See Note 7 to the Consolidated Financial Statements, "Regulatory Matters".
	The cost of nuclear fuel is capitalized. The amortization of nuclear fuel is included within Fuel and purchased power in the Consolidated Statements of Operations and is recorded using the units-of-production method.
	Capitalized software costs are classified as Property, plant and equipment and the related amortization is included in Accumulated depreciation and amortization on the Consolidated Statements of Financial Position. The Company capitalizes the costs associated with computer software it develops or obtains for use in its business. The Company amortizes capitalized software costs on a straight-line basis over the expected period of benefit
Long-Lived Assets	Long-Lived Assets
	Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. If the carrying amount of the asset exceeds the expected discounted future cash flows generated by the asset, an impairment loss is recognized resulting in the asset being written down to its estimated fair value. Assets to be disposed of are reported at the lower of the carrying amount or fair value, less costs to sell.
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.
Excise and Sales Taxes	Excise and Sales Taxes
	The Company records the billing of excise and sales taxes as a receivable with an offsetting payable to the applicable taxing authority, with no net impact on the Consolidated Statements of Operations.
	Deferred tax assets and liabilities are recognized for the estimated future tax effect of temporary differences between the tax basis of assets or liabilities and the reported amounts in the financial statements. Deferred tax assets and liabilities are classified as current or noncurrent according to the classification of the related assets or liabilities. Deferred tax assets and liabilities not related to assets or liabilities are classified according to the expected reversal date of the temporary differences. Consistent with rate making treatment, deferred taxes are offset in the table below for temporary differences which have related regulatory assets and liabilities.
Deferred Debt Costs	Deferred Debt Costs
	The costs related to the issuance of long-term debt are deferred and amortized over the life of each debt issue. In accordance with MPSC regulations, the unamortized discount, premium and expense related to debt redeemed with a refinancing are amortized over the life of the replacement issue.
Investments in Debt and Equity Securities	Investments in Debt and Equity Securities
	The Company generally classifies investments in debt and equity securities as either trading or available-for-sale and has recorded such investments at market value with unrealized gains or losses included in earnings or in other comprehensive income or loss, respectively. Changes in the fair value of Fermi 2 nuclear decommissioning investments are recorded as adjustments to regulatory assets or liabilities, due to a recovery mechanism from customers. The Company’s equity investments are reviewed for impairment each reporting period. If the assessment indicates that the impairment is other than temporary, a loss is recognized resulting in the equity investment being written down to its estimated fair value. See Note 9 to the Consolidated Financial Statements, "Fair Value".
Government Grants	Government Grants
	Grants are recognized when there is reasonable assurance that the grant will be received and that any conditions associated with the grant will be met. When grants are received related to Property, plant and equipment, the Company reduces the cost of the assets on the Consolidated Statements of Financial Position, resulting in lower depreciation expense over the life of the associated asset. Grants received related to expenses are reflected as a reduction of the associated expense in the period in which the expense is incurred.
Asset Retirement Obligations	The Company has a legal retirement obligation for the decommissioning costs for its Fermi 1 and Fermi 2 nuclear plants, dismantlement of facilities located on leased property and various other operations. The Company has conditional retirement obligations for asbestos and PCB removal at certain of its power plants and various distribution equipment. The Company recognizes such obligations as liabilities at fair market value when they are incurred, which generally is at the time the associated assets are placed in service. Fair value is measured using expected future cash outflows discounted at our credit-adjusted risk-free rate. The Company recognizes regulatory assets or liabilities for timing differences in expense recognition for legal asset retirement costs that are currently recovered in rates.
	If a reasonable estimate of fair value cannot be made in the period in which the retirement obligation is incurred, such as for assets with indeterminate lives, the liability is recognized when a reasonable estimate of fair value can be made. Substations, manholes and certain other distribution assets have an indeterminate life. Therefore, no liability has been recorded for these assets.
Regulatory Matters	DTE Electric is required to record regulatory assets and liabilities for certain transactions that would have been treated as revenue or expense in non-regulated businesses. Continued applicability of regulatory accounting treatment requires that rates be designed to recover specific costs of providing regulated services and be charged to and collected from customers. Future regulatory changes or changes in the competitive environment could result in the discontinuance of this accounting treatment for regulatory assets and liabilities for some or all of our businesses and may require the write-off of the portion of any regulatory asset or liability that was no longer probable of recovery through regulated rates. Management believes that currently available facts support the continued use of regulatory assets and liabilities and that all regulatory assets and liabilities are recoverable or refundable in the current regulatory environment.
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 Company makes certain assumptions it believes that market participants would use in pricing assets or liabilities, including assumptions about risk, and the risks inherent in the inputs to valuation techniques. Credit risk of the Company and its counterparties is incorporated in the valuation of assets and liabilities through the use of credit reserves, the impact of which was immaterial at December 31, 2014 and 2013. The Company believes it uses valuation techniques that maximize the use of observable market-based inputs and minimize the use of unobservable inputs.
	A fair value hierarchy has been established, that prioritizes the inputs to valuation techniques used to measure fair value in three broad levels. The fair value hierarchy gives the highest priority to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). In some cases, the inputs used to measure fair value might fall in different levels of the fair value hierarchy. All assets and liabilities are required to be classified in their entirety based on the lowest level of input that is significant to the fair value measurement in its entirety. Assessing the significance of a particular input may require judgment considering factors specific to the asset or liability, and may affect the valuation of the asset or liability and its placement within the fair value hierarchy. The Company classifies fair value balances based on the fair value hierarchy defined as follows:
	•Level 1 — Consists of unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access as of the reporting date.
	•Level 2 — Consists of inputs other than quoted prices included within Level 1 that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data.
	•Level 3 — Consists of unobservable inputs for assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost-benefit constraints.
Nuclear Decommissioning Trust and Other Investments	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 Company has obtained an understanding of how these prices are derived, including the nature and observability of the inputs used in deriving such prices. Additionally, the Company selectively corroborates the fair value of securities by comparison of market-based price sources. Investment policies and procedures are determined by the Company's Trust Investments Department which reports to the Company's Vice President and Treasurer.
Derivatives Reporting of Derivative Activity	The Company considers the following criteria in determining whether a market is considered active: frequency in which pricing information is updated, variability in pricing between sources or over time and the availability of public information. Other derivative contracts are valued based upon a variety of inputs including commodity market prices, broker quotes, interest rates, credit ratings, default rates, market-based seasonality and basis differential factors. The Company monitors the prices that are supplied by brokers and pricing services and may use a supplemental price source or change the primary price source of an index if prices become unavailable or another price source is determined to be more representative of fair value. The Company has obtained an understanding of how these prices are derived. Additionally, the Company selectively corroborates the fair value of its transactions by comparison of market-based price sources. Mathematical valuation models are used for derivatives for which external market data is not readily observable, such as contracts which extend beyond the actively traded reporting period. The Company has established a Risk Management Committee whose responsibilities include directly or indirectly ensuring all valuation methods are applied in accordance with predefined policies. The development and maintenance of our forward price curves has been assigned to our Risk Management Department, which is separate and distinct from the trading functions within the Company.
Fair Value 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 Company has obtained an understanding of how the fair values are derived. The Company also selectively corroborates the fair value of its transactions by comparison of market-based price sources. Discounted cash flow analyses based upon estimated current borrowing rates are also used to determine fair value when quoted market prices are not available. The fair values of notes receivable, excluding capital leases, are estimated using discounted cash flow techniques that incorporate market interest rates as well as assumptions about the remaining life of the loans and credit risk. Depending on the information available, other valuation techniques may be used that rely on internal assumptions and models. Valuation policies and procedures are determined by the Company's Treasury Department which reports to the Company's Vice President and Treasurer.
Derivatives	The Company recognizes all derivatives at their fair value as Derivative assets or liabilities on the Consolidated Statements of Financial Position unless they qualify for certain scope exceptions, including the normal purchases and normal sales exception. Further, derivatives that qualify and are designated for hedge accounting are classified as either hedges of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge), or as hedges of the fair value of a recognized asset or liability or of an unrecognized firm commitment (fair value hedge). For cash flow hedges, the portion of the derivative gain or loss that is effective in offsetting the change in the value of the underlying exposure is deferred in Accumulated other comprehensive income and later reclassified into earnings when the underlying transaction occurs. Gains or losses from the ineffective portion of cash flow hedges are recognized in earnings immediately. For fair value hedges, changes in fair values for the derivative and hedged item are recognized in earnings each period. For derivatives that do not qualify or are not designated for hedge accounting, changes in fair value are recognized in earnings each period.
	The Company's primary market risk exposure is associated with commodity prices, credit and interest rates. The Company has risk management policies to monitor and manage market risks. The Company uses derivative instruments to manage some of the exposure. DTE Electric generates, purchases, distributes and sells electricity. DTE Electric uses forward energy contracts to manage changes in the price of electricity and fuel. Substantially all of these contracts meet the normal purchases and sales exemption and are therefore accounted for under the accrual method. Other derivative contracts are MTM and recoverable through the PSCR mechanism when settled. This results in the deferral of unrealized gains and losses as Regulatory assets or liabilities until realized.

Organization_and_Basis_of_Pres1

Organization and Basis of Presentation (Tables)	12 Months Ended
	Dec. 31, 2014
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Schedule of Variable Interest Entities	The following table summarizes the major balance sheet items at December 31, 2014 and 2013 restricted for Securitization that are either (1) assets that can be used only to settle their obligations related to Securitization or (2) liabilities for which creditors do not have recourse to the general credit of the primary beneficiary.
		December 31,
		2014		2013
		(In millions)
	ASSETS
	Restricted cash	$	96	$	100
	Accounts receivable	26		34
	Securitized regulatory assets	34		231
	Other current and long-term assets	1		4
		$	157	$	369
	LIABILITIES
	Accounts payable and accrued current liabilities	$	3	$	7
	Current portion long-term debt, including capital leases	105		196
	Current regulatory liabilities	32		43
	Securitization bonds	—		105
	Other current and long-term liabilities	9		8
		$	149	$	359

Significant_Accounting_Policie2

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes the changes in Accumulated other comprehensive loss by component for the years ended December 31, 2014 and 2013:
		Changes in Accumulated Other Comprehensive Loss by Component (a)
		Net Unrealized Gain/(Loss) on Investments		Benefit Obligations (b)			Total
		(In millions)
	Balance, January 1, 2013	$	—	$	(22	)	$	(22	)
	Other comprehensive income before reclassifications	1		3			4
	Amounts reclassified from accumulated other comprehensive income	—		2			2
	Net current-period other comprehensive income	1		5			6
	Balance, December 31, 2013	$	1	$	(17	)	$	(16	)
	Other comprehensive loss before reclassifications	—		(12		)	(12		)
	Amounts reclassified from accumulated other comprehensive income	—		2			2
	Net current-period other comprehensive loss	—		(10		)	(10		)
	Balance, December 31, 2014	$	1	$	(27	)	$	(26	)
	________________________________________
	(a)	All amounts are net of tax.
	(b)	The amounts reclassified from accumulated other comprehensive income (loss) are included in the computation of the net periodic pension and other postretirement benefit costs (see Note 16 to the Consolidated Financial Statements "Retirement Benefits and Trusteed Assets").
Schedule of Finite-Lived Intangible Assets	The Company has certain intangible assets relating to emission allowances and renewable energy credits as shown below:
		December 31,
		2014		2013
		(In millions)
	Emission allowances	$	1	$	2
	Renewable energy credits	45		51
		46		53
	Less current intangible assets	9		12
		$	37	$	41

Property_Plant_and_Equipment_T

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	Summary of property by classification as of December 31:
		December 31,
		2014			2013
		(In millions)
	Property, Plant and Equipment
	Generation	$	11,641		$	11,127
	Distribution	8,164			7,603
	Total	19,805			18,730
	Less Accumulated Depreciation and Amortization
	Generation	(4,149		)	(4,004		)
	Distribution	(3,067		)	(2,947		)
	Total	(7,216		)	(6,951		)
	Net Property, Plant and Equipment	$	12,589		$	11,779

Jointly_Owned_Utility_Plant_Ta

Jointly Owned Utility Plant (Tables)	12 Months Ended
	Dec. 31, 2014
Jointly Owned Utility Plant, Net Ownership Amount [Abstract]
Schedule of Jointly Owned Utility Plants	Ownership information of the two utility plants as of December 31, 2014 was as follows:
		Belle River			Ludington
					Hydroelectric
					Pumped Storage
	In-service date	1984-1985			1973
	Total plant capacity	1,270		MW	1,872		MW
	Ownership interest	(a)			49		%
	Investment in property, plant and equipment (in millions)	$	1,742		$	412
	Accumulated depreciation (in millions)	$	993		$	175
	_________________________________
	(a)	DTE Electric’s ownership interest is 63% in Unit No. 1, 81% of the facilities applicable to Belle River used jointly by the Belle River and St. Clair Power Plants and 75% in common facilities used at Unit No. 2.

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2014
Asset Retirement Obligation Disclosure [Abstract]
Schedule of Change in Asset Retirement Obligation	A reconciliation of the asset retirement obligations for 2014 follows:
		(In millions)
	Asset retirement obligations at December 31, 2013	$	1,667
	Accretion	103
	Liabilities incurred	9
	Liabilities settled	(6		)
	Revision in estimated cash flows	23
	Asset retirement obligations at December 31, 2014	$	1,796

Regulatory_Matters_Tables

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2014
Regulatory Assets and Liabilities Disclosure [Abstract]
Schedule of Regulatory Assets	The following are balances and a brief description of the regulatory assets and liabilities at December 31:
		2014			2013
		(In millions)
	Assets
	Recoverable pension and other postretirement costs:
	Pension	$	1,743		$	1,257
	Other postretirement costs	191			—
	Asset retirement obligation	448			394
	Recoverable Michigan income taxes	220			237
	Other recoverable income taxes	66			71
	Cost to achieve Performance Excellence Process	46			64
	Unamortized loss on reacquired debt	44			38
	Accrued PSCR revenue	34			—
	Recoverable income taxes related to securitized regulatory assets	19			126
	Removal costs asset	15			—
	Transitional Reconciliation Mechanism	14			—
	Other	119			101
		2,959			2,288
	Less amount included in current assets	(46		)	(13		)
		$	2,913		$	2,275
	Securitized regulatory assets	$	34		$	231
Schedule of Regulatory Liabilities
		2014			2013
		(In millions)
	Liabilities
	Renewable energy	$	227		$	277
	Over recovery of Securitization	71			72
	Refundable revenue decoupling / deferred gain	63			127
	Fermi 2 refueling outage	16			26
	Energy optimization	14			25
	Accrued PSCR refund	—			53
	Refundable other postretirement costs	—			48
	Removal costs liability	—			33
	Other	4			3
		395			664
	Less amount included in current liabilities	(150		)	(278		)
		$	245		$	386

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation	Total income tax expense varied from the statutory federal income tax rate for the following reasons:
		Year Ended December 31,
		2014			2013			2012
		(In millions)
	Income before income taxes	$	830		$	741		$	768
	Income tax expense at 35% statutory rate	$	291		$	260		$	269
	Production tax credits	(22		)	(15		)	(5		)
	Investment tax credits	(5		)	(5		)	(6		)
	Depreciation	3			3			3
	AFUDC - Equity	(7		)	(5		)	(4		)
	Employee Stock Ownership Plan dividends	(3		)	(2		)	(3		)
	Domestic production activities deduction	(2		)	(18		)	(16		)
	State and other income taxes, net of federal benefit	43			41			40
	Other, net	—			(5		)	4
	Income tax expense	$	298		$	254		$	282
	Effective income tax rate	35.9		%	34.3		%	36.7		%
Schedule of Components of Income Tax Expense (Benefit)	Components of income tax expense  were as follows:
		Year Ended December 31,
		2014			2013			2012
		(In millions)
	Current income tax expense (benefit)
	Federal	$	(19	)	$	123		$	267
	State and other income tax	20			23			67
	Total current income taxes	1			146			334
	Deferred income tax expense (benefit)
	Federal	251			68			(47		)
	State and other income tax	46			40			(5		)
	Total deferred income taxes	297			108			(52		)
	Total	$	298		$	254		$	282
Schedule of Deferred Tax Assets and Liabilities	Deferred tax assets (liabilities) were comprised of the following at December 31:
		2014			2013
		(In millions)
	Property, plant and equipment	$	(3,152	)	$	(2,807	)
	Securitized regulatory assets	(3		)	(130		)
	Pension and benefits	(43		)	27
	Other	12			12
		$	(3,186	)	$	(2,898	)
	Current deferred income tax assets (liabilities)	$	2		$	(91	)
	Long-term deferred income tax liabilities	(3,188		)	(2,807		)
		$	(3,186	)	$	(2,898	)
	Deferred income tax assets	$	357		$	420
	Deferred income tax liabilities	(3,543		)	(3,318		)
		$	(3,186	)	$	(2,898	)
Schedule of Unrecognized Tax Benefits Roll Forward	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows:
		2014			2013			2012
		(In millions)
	Balance at January 1	$	4		$	4		$	59
	Reductions for tax positions of prior years	—			—			(3		)
	Settlements	—			—			(52		)
	Balance at December 31	$	4		$	4		$	4

Fair_Value_Tables

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis	The following table presents assets measured and recorded at fair value on a recurring basis as of December 31, 2014 and 2013:
		December 31, 2014											December 31, 2013
		Level 1			Level 2			Level 3			Net Balance		Level 1		Level 2			Level 3		Net Balance
		(In millions)
	Assets:
	Cash equivalents (a)	$	5		$	99		$	—		$	104	$	2	$	114		$	—	$	116
	Nuclear decommissioning trusts	792			449			—			1,241		779		412			—		1,191
	Other investments (b)	97			50			—			147		91		44			—		135
	Derivative assets — FTRs	—			—			3			3		—		—			3		3
	Total	$	894		$	598		$	3		$	1,495	$	872	$	570		$	3	$	1,445
	Assets:
	Current	$	5		$	99		$	3		$	107	$	2	$	114		$	3	$	119
	Noncurrent	889			499			—			1,388		870		456			—		1,326
	Total Assets	$	894		$	598		$	3		$	1,495	$	872	$	570		$	3	$	1,445
	_______________________________________
	(a)	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 the Consolidated Statements of Financial Position. At December 31, 2013, available-for-sale securities of $116 million, included $100 million and $16 million of cash equivalents included in Restricted cash and Other investments, respectively, on the Consolidated Statements of Financial Position.
	(b)	Available-for-sale equity securities at December 31, 2014 and 2013 of $8 million and $7 million, respectively, are included in Other investments on the Consolidated Statements of Financial Position.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation	The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for the years ended December 31, 2014 and 2013:
		Year Ended December 31,
		2014			2013
		(In millions)
	Net Assets as of beginning of period	$	3		1
	Change in fair value recorded in regulatory assets/liabilities	8			5
	Purchases, issuances and settlements:
	Settlements	(8		)	(3		)
	Net Assets as of December 31,	$	3		$	3
	The amount of total gains (losses) included in regulatory assets and liabilities attributed to the change in unrealized gains (losses) related to regulatory assets and liabilities held at December 31, 2014 and 2013	$	3		$	2
Fair Value, by Balance Sheet Grouping	The following table presents the carrying amount and fair value of financial instruments as of December 31, 2014 and 2013:
		December 31, 2014											December 31, 2013
		Carrying			Fair Value								Carrying		Fair Value
		Amount			Level 1			Level 2			Level 3		Amount		Level 1			Level 2		Level 3
		(In millions)
	Notes receivable, excluding capital leases	$	12		$	—		$	—		$	12	$	10	$	—		$	—	$	10
	Notes receivable — affiliates	$	8		$	—		$	—		$	8	$	200	$	—		$	—	$	200
	Short-term borrowings — affiliates	$	84		$	—		$	—		$	84	$	58	$	—		$	—	$	58
	Short-term borrowings — other	$	50		$	—		$	50		$	—	$	—	$	—		$	—	$	—
	Long-term debt, excluding capital leases	$	5,259		$	—		$	5,341		$	496	$	5,146	$	—		$	5,253	$	136
Fair Value of Nuclear Decommissioning Trust Fund Assets	The following table summarizes the fair value of the nuclear decommissioning trust fund assets:
		December 31,
		2014			2013
		(In millions)
	Fermi 2	$	1,221		$	1,172
	Fermi 1	3			3
	Low-level radioactive waste	17			16
	Total	$	1,241		$	1,191
Schedule of Realized Gain (Loss)	The following table sets forth the gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds:
		Year Ended December 31,
		2014			2013			2012
		(In millions)
	Realized gains	$	54		$	83		$	37
	Realized losses	$	(33	)	$	(41	)	$	(31	)
	Proceeds from sales of securities	$	1,146		$	1,118		$	759
Fair Value and Unrealized Gains for Nuclear Decommissioning Trust Fund	The following table sets forth the fair value and unrealized gains for the nuclear decommissioning trust funds:
		December 31, 2014									31-Dec-13
		Fair			Unrealized			Unrealized			Fair		Unrealized		Unrealized
		Value			Gains			Losses			Value		Gains		Losses
		(In millions)
	Equity securities	$	756		$	204		$	(39	)	$	730	$	201	$	(25	)
	Debt securities	474			21			(2		)	442		12		(6		)
	Cash and cash equivalents	11			—			—			19		—		—
		$	1,241		$	225		$	(41	)	$	1,191	$	213	$	(31	)

Financial_and_Other_Derivative1

Financial and Other Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair value of derivative instruments	The following table presents the fair value of derivative instruments as of December 31, 2014 and 2013:
		December 31,
		2014		2013
		(In millions)
	FTRs — Other current assets	$	3	$	3
	Total derivatives not designated as hedging instrument	$	3	$	3

LongTerm_Debt_Tables

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2014
Long-term Debt, Unclassified [Abstract]
Schedule of Long-term Debt Instruments	The Company's long-term debt outstanding and weighted average interest rates (a) of debt outstanding at December 31 were:
		2014				2013
		(In millions)
	Taxable Debt, Principally Secured
	4.5% due 2016 to 2044	$	4,824			$	4,286
	Tax- Exempt Revenue Bonds (b)
	5.2% due 2020 to 2030	330				558
		5,154				4,844
	Less amount due within one year	(10		)		(304		)
		$	5,144			$	4,540
	Securitization Bonds
	6.6% due 2015	$	105			$	302
	Less amount due within one year	(105		)		(197		)
		$	—			$	105
	_________________________________
	(a)	Weighted average interest rates as of December 31, 2014 are shown below the description of each category of debt.
	(b)	Tax-Exempt Revenue Bonds are issued by a public body that loans the proceeds to DTE Electric on terms substantially mirroring the Revenue Bonds.
Schedule of Issued Debt	In 2014, the following debt was issued:
	Month		Type		Interest Rate			Maturity	Amount
									(In millions)
	June		Mortgage Bonds (a)		3.77	%		2026	$	100
	June		Mortgage Bonds (a)		4.6	%		2044	150
	July		Mortgage Bonds (a)		3.375	%		2025	350
	July		Mortgage Bonds (a)		4.3	%		2044	350
									$	950
	_____________________________
	(a)	Proceeds were used for the redemption of long-term debt, repayment of short-term borrowings and general corporate purposes.
Debt Instrument Redemption	In 2014, the following debt was redeemed:
	Month		Type		Interest Rate			Maturity	Amount
									(In millions)
	March		Mortgage Bonds		Various			2014	$	13
	March		Securitization Bonds		6.62	%		2014	100
	April		Tax Exempt Revenue Bonds (a)		2.35	%		2024	31
	April		Tax Exempt Revenue Bonds (a)		4.65	%		2028	32
	June		Tax Exempt Revenue Bonds (a)		4.875	%		2029	36
	June		Tax Exempt Revenue Bonds (a)		6	%		2036	69
	July		Senior Notes		4.8	%		2015	200
	August		Tax Exempt Revenue Bonds (a)		5.25	%		2029	60
	August		Senior Notes		5.4	%		2014	200
	September		Securitization Bonds		6.62	%		2014	96
									$	837
	_____________________________
	(a)	Tax Exempt Revenue Bonds are issued by a public body that loans the proceeds to DTE Electric on terms substantially mirroring the Revenue Bonds.
Schedule of Maturities of Long-term Debt	The following table shows the scheduled debt maturities, excluding any unamortized discount or premium on debt:
															2020 and
		2015				2016			2017		2018		2019		Thereafter		Total
		(In millions)
	Amount to mature	$	115			$	151		$	—	$	300	$	—	$	4,704	$	5,270

Operating_Leases_Tables

Operating Leases (Tables)	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	Future minimum lease payments under non-cancelable leases at December 31, 2014 were:
		Operating
		Leases
		(In millions)
	2015	$	28
	2016	22
	2017	18
	2018	15
	2019	10
	Thereafter	40
	Total minimum lease payments	$	133

Commitments_and_Contingencies_1

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of Long-term Purchase Commitment	The Company estimates that these commitments will be approximately $2.4 billion from 2015 through 2033 as detailed in the following table:
		(In millions)
	2015	$	496
	2016	330
	2017	278
	2018	125
	2019	106
	2020 and thereafter	1,063
		$	2,398

Retirement_Benefits_and_Truste1

Retirement Benefits and Trusteed Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Net Benefit Costs	Net pension cost includes the following components:
		2014			2013			2012
		(In millions)
	Service cost	$	64		$	73		$	64
	Interest cost	162			146			155
	Expected return on plan assets	(194		)	(184		)	(166		)
	Amortization of:
	Net loss	110			148			124
	Prior service cost	2			1			1
	Settlements	—			—			2
	Net pension cost	$	144		$	184		$	180
Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss)
		2014			2013
		(In millions)
	Other changes in plan assets and benefit obligations recognized in Regulatory assets and Other comprehensive income
	Net actuarial (gain) loss	$	614		$	(418	)
	Amortization of net actuarial loss	(110		)	(148		)
	Prior service cost	(2		)	—
	Amortization of prior service cost	(2		)	(1		)
	Total recognized in Regulatory assets and Other comprehensive income	$	500		$	(567	)
	Total recognized in net periodic pension cost, Regulatory assets and Other comprehensive income	$	644		$	(383	)
	Estimated amounts to be amortized from Regulatory assets and Accumulated other comprehensive income into net periodic benefit cost during next fiscal year
	Net actuarial loss	$	149		$	106
	Prior service cost	$	1		$	1
Schedule of Defined Benefit Plans Disclosures	The following table reconciles the obligations, assets and funded status of the plan as well as the amount recognized as prepaid pension cost or pension liability in the Consolidated Statements of Financial Position at December 31:
		2014			2013
		(In millions)
	Accumulated benefit obligation, end of year	$	3,712		$	3,111
	Change in projected benefit obligation
	Projected benefit obligation, beginning of year	$	3,341		$	3,585
	Service cost	64			73
	Interest cost	162			146
	Plan amendments	(2		)	—
	Actuarial (gain) loss	634			(286		)
	Benefits paid	(181		)	(177		)
	Projected benefit obligation, end of year	$	4,018		$	3,341
	Change in plan assets
	Plan assets at fair value, beginning of year	$	2,632		$	2,211
	Actual return on plan assets	212			316
	Company contributions	149			282
	Benefits paid	(181		)	(177		)
	Plan assets at fair value, end of year	$	2,812		$	2,632
	Funded status of the plan	$	(1,206	)	$	(709	)
	Amount recorded as:
	Current liabilities	$	(6	)	$	(4	)
	Noncurrent liabilities	(1,200		)	(705		)
		$	(1,206	)	$	(709	)
	Amounts recognized in Regulatory assets (see Note 7 - "Regulatory Matters")
	Net actuarial loss	$	1,738		$	1,248
	Prior service cost	5			9
		$	1,743		$	1,257
Schedule of Expected Benefit Payments	At December 31, 2014, the benefits related to the Company’s qualified and nonqualified pension plans expected to be paid in each of the next five years and in the aggregate for the five fiscal years thereafter are as follows:
		(In millions)
	2015	$	210
	2016	216
	2017	223
	2018	233
	2019	239
	2020 - 2024	1,264
	Total	$	2,385
Schedule of Assumptions Used	Assumptions used in determining the projected benefit obligation and net pension costs are listed below:
		2014		2013	2012
	Projected benefit obligation
	Discount rate	4.12%		4.95%	4.15%
	Rate of compensation increase	4.65%		4.20%	4.20%
	Net pension costs
	Discount rate	4.95%		4.15%	5.00%
	Rate of compensation increase	4.20%		4.20%	4.20%
	Expected long-term rate of return on plan assets	7.75%		8.25%	8.25%
Schedule of Allocation of Plan Assets	Fair Value Measurements for pension plan assets at December 31, 2014 and 2013 (a):
		December 31, 2014												December 31, 2013
		Level 1			Level 2			Level 3			Total			Level 1			Level 2			Level 3		Total
		(In millions)
	Asset category:
	Short-term investments (b)	$	33		$	—		$	—		$	33		$	15		$	—		$	—	$	15
	Equity securities
	U.S. large cap (c)	638			—			—			638			639			—			—		639
	U.S. small/mid cap (d)	162			—			—			162			160			—			—		160
	Non U.S. (e)	378			157			—			535			440			94			—		534
	Fixed income securities (f)	5			758			—			763			11			623			—		634
	Hedge funds and similar investments (g)	163			68			315			546			193			50			285		528
	Private equity and other (h)	—			—			135			135			—			—			122		122
	Securities lending (i)	(136		)	(36		)	—			(172		)	—			—			—		—
	Securities lending collateral (i)	136			36			—			172			—			—			—		—
	Total	$	1,379		$	983		$	450		$	2,812		$	1,458		$	767		$	407	$	2,632
	_______________________________________
	(a)	For a description of levels within the fair value hierarchy see Note 9 to the Consolidated financial Statements, "Fair Value".
	(b)	This category predominantly represents certain short-term fixed income securities and money market investments that are managed in separate accounts or commingled funds. Pricing for investments in this category are obtained from quoted prices in actively traded markets or valuations from brokers or pricing services.
	(c)	This category comprises both actively and not actively managed portfolios that track the S&P 500 low cost equity index funds. Investments in this category are exchange-traded securities whereby unadjusted quote prices can be obtained. Exchange-traded securities held in a commingled fund are classified as Level 2 assets.
	(d)	This category represents portfolios of small and medium capitalization domestic equities. Investments in this category are exchange-traded securities whereby unadjusted quote prices can be obtained. Exchange-traded securities held in a commingled fund are classified as Level 2 assets.
	(e)	This category primarily consists of portfolios of non-U.S. developed and emerging market equities. Investments in this category are exchange-traded securities whereby unadjusted quote prices can be obtained. Exchange-traded securities held in a commingled fund are classified as Level 2 assets.
	(f)	This category includes corporate bonds from diversified industries, U.S. Treasuries, and mortgage-backed securities. Pricing for investments in this category is obtained from quoted prices in actively traded markets and quotations from broker or pricing services. Non-exchange traded securities and exchange-traded securities held in commingled funds are classified as Level 2 assets.
	(g)	This category utilizes a diversified group of strategies that attempt to capture financial market inefficiencies and includes publicly traded debt and equity, publicly traded mutual funds, commingled and limited partnership funds and non-exchange traded securities. Pricing for Level 1 and Level 2 assets in this category is obtained from quoted prices in actively traded markets and quoted prices from broker or pricing services. Non-exchange traded securities held in commingled funds are classified as Level 2 assets. Valuations for some Level 3 assets in this category may be based on limited observable inputs as there may be little, if any, publicly available pricing.
	(h)	This category includes a diversified group of funds and strategies that primarily invests in private equity partnerships. This category also includes investments in timber and private mezzanine debt. Pricing for investments in this category is based on limited observable inputs as there is little, if any, publicly available pricing. Valuations for assets in this category may be based on discounted cash flow analyses, relevant publicly-traded comparables and comparable transactions.
	(i)	In 2014, DTE Electric began a securities lending program with a third party agent. The program allows the agent to lend certain securities from the Company's pension trusts to selected entities against receipt of collateral (in the form of cash) as provided for and determined in accordance with its securities lending agency agreement.
	Target allocations for pension plan assets as of December 31, 2014 are listed below:
	U.S. Large Cap Equity Securities	22	%
	U.S. Small Cap and Mid Cap Equity Securities	5
	Non U.S. Equity Securities	20
	Fixed Income Securities	25
	Hedge Funds and Similar Investments	20
	Private Equity and Other	8
		100	%
Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets	Fair Value Measurements Using Significant Unobservable Inputs (Level 3):
		Year Ended December 31, 2014									Year Ended December 31, 2013
		Hedge Funds			Private						Hedge Funds			Private
		and Similar			Equity						and Similar			Equity
		Investments			and Other			Total			Investments			and Other			Total
		(In millions)
	Beginning Balance at January 1	$	285		$	122		$	407		$	238		$	125		363
	Total realized/unrealized gains (losses)	15			12			27			29			2			31
	Purchases, sales and settlements:
	Purchases	16			22			38			18			15			33
	Sales	(1		)	(21		)	(22		)	—			(20		)	(20		)
	Ending Balance at December 31	$	315		$	135		$	450		$	285		$	122		$	407
	The amount of total gains for the period attributable to the change in unrealized gains or losses related to assets still held at the end of the period	$	15		$	8		$	23		$	27		$	2		$	29
Other Postretirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Net Benefit Costs	Net other postretirement cost includes the following components:
		2014			2013			2012
		(In millions)
	Service cost	$	26		$	35		$	51
	Interest cost	68			67			91
	Expected return on plan assets	(85		)	(74		)	(61		)
	Amortization of:
	Net loss	14			47			58
	Prior service credit	(109		)	(100		)	(14		)
	Net other postretirement cost (credit)	$	(86	)	$	(25	)	$	125
Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss)
		2014			2013
		(In millions)
	Other changes in plan assets and APBO recognized in Regulatory assets (liabilities) and Other comprehensive income
	Net actuarial gain	$	144		$	(258	)
	Amortization of net actuarial loss	(14		)	(47		)
	Prior service credit	—			(159		)
	Amortization of prior service credit	109			100
	Total recognized in Regulatory assets (liabilities) and Other comprehensive income	$	239		$	(364	)
	Total recognized in net periodic benefit cost, Regulatory assets (liabilities) and Other comprehensive income	$	153		$	(389	)
	Estimated amounts to be amortized from Regulatory assets (liabilities) and Accumulated other comprehensive income into net periodic benefit cost during next fiscal year
	Net actuarial loss	$	31		$	15
	Prior service credit	$	(94	)	$	(109	)
Schedule of Defined Benefit Plans Disclosures	The following table reconciles the obligations, assets and funded status of the plans including amounts recorded as Accrued postretirement liability - affiliates in the Consolidated Statements of Financial Position at December 31:
		2014			2013
		(In millions)
	Change in accumulated postretirement benefit obligation
	Accumulated postretirement benefit obligation, beginning of year	$	1,430		$	1,752
	Service cost	26			35
	Interest cost	68			67
	Plan amendments	—			(159		)
	Actuarial (gain) loss	100			(200		)
	Medicare Part D subsidy	—			1
	Benefits paid	(66		)	(66		)
	Accumulated postretirement benefit obligation, end of year	$	1,558		$	1,430
	Change in plan assets
	Plan assets at fair value, beginning of year	$	1,061		$	756
	Actual return on plan assets	41			131
	Company contributions	—			239
	Benefits paid	(64		)	(65		)
	Plan assets at fair value, end of year	$	1,038		$	1,061
	Funded status, end of year	$	(520	)	$	(369	)
	Amount recorded as:
	Noncurrent liabilities	$	(520	)	$	(369	)
	Amounts recognized in Regulatory assets (liabilities) (see Note 7 - "Regulatory Matters")
	Net actuarial loss	$	385		$	255
	Prior service cost	(194		)	(303		)
		$	191		$	(48	)
Schedule of Expected Benefit Payments	At December 31, 2014, the benefits expected to be paid, including prescription drug benefits, in each of the next five years and in the aggregate for the five fiscal years thereafter are as follows:
		(In millions)
	2015	$	77
	2016	82
	2017	85
	2018	89
	2019	93
	2020 - 2024	505
	Total	$	931
Schedule of Assumptions Used	Assumptions used in determining the accumulated postretirement benefit obligation and net other postretirement benefit costs are listed below:
		2014		2013	2012
	Accumulated postretirement benefit obligation
	Discount rate	4.10%		4.95%	4.15%
	Health care trend rate pre- and post- 65	7.50 / 6.50%		7.50 / 6.50%	7.00%
	Ultimate health care trend rate	4.50%		4.50%	5.00%
	Year in which ultimate reached pre- and post- 65	2025 / 2024		2025 / 2024	2021
	Other postretirement benefit costs
	Discount rate (prior to interim remeasurement)	4.95%		4.15%	5.00%
	Discount rate (post interim remeasurement)	N/A		4.30%	N/A
	Expected long-term rate of return on plan assets	8.00%		8.25%	8.25%
	Health care trend rate pre- and post- 65	7.50 / 6.50%		7.00%	7.00%
	Ultimate health care trend rate	4.50%		5.00%	5.00%
	Year in which ultimate reached pre- and post- 65	2025 / 2024		2021	2020
Schedule of Allocation of Plan Assets	Target allocations for other postretirement benefit plan assets as of December 31, 2014 are listed below:
	U.S. Large Cap Equity Securities	17	%
	U.S. Small Cap and Mid Cap Equity Securities	4
	Non U.S. Equity Securities	20
	Fixed Income Securities	25
	Hedge Funds and Similar Investments	20
	Private Equity and Other	14
		100	%
	Fair Value Measurements for other postretirement benefit plan assets at December 31, 2014 and 2013 (a):
		December 31, 2014												December 31, 2013
		Level 1			Level 2			Level 3			Total			Level 1			Level 2			Level 3		Total
	Asset category:	(In millions)
	Short-term investments (b)	$	4		$	—		$	—		$	4		$	3		$	—		$	—	$	3
	Equity securities
	U.S. large cap (c)	179			—			—			179			208			—			—		208
	U.S. small/mid cap (d)	102			—			—			102			103			—			—		103
	Non U.S. (e)	151			39			—			190			197			5			—		202
	Fixed income securities (f)	11			243			—			254			12			243			—		255
	Hedge funds and similar investments (g)	73			31			114			218			91			17			111		219
	Private equity and other (h)	—			—			91			91			—			—			71		71
	Securities lending (i)	(98		)	(11		)	—			(109		)	—			—			—		—
	Securities lending collateral (i)	98			11			—			109			—			—			—		—
	Total	$	520		$	313		$	205		$	1,038		$	614		$	265		$	182	$	1,061
	_______________________________________
	(a)	For a description of levels within the fair value hierarchy see Note 9 to the Consolidated Financial Statements, "Fair Value".
	(b)	This category predominantly represents certain short-term fixed income securities and money market investments that are managed in separate accounts or commingled funds. Pricing for investments in this category are obtained from quoted prices in actively traded markets or valuations from brokers or pricing services.
	(c)	This category comprises both actively and not actively managed portfolios that track the S&P 500 low cost equity index funds. Investments in this category are exchange-traded securities whereby unadjusted quote prices can be obtained. Exchange-traded securities held in a commingled fund are classified as Level 2 assets.
	(d)	This category represents portfolios of small and medium capitalization domestic equities. Investments in this category are exchange-traded securities whereby unadjusted quote prices can be obtained. Exchange-traded securities held in a commingled fund are classified as Level 2 assets.
	(e)	This category primarily consists of portfolios of non-U.S. developed and emerging market equities. Investments in this category are exchange-traded securities whereby unadjusted quote prices can be obtained. Exchange-traded securities held in a commingled fund are classified as Level 2 assets.
	(f)	This category includes corporate bonds from diversified industries, U.S. Treasuries, bank loans and mortgage backed securities. Pricing for investments in this category is obtained from quoted prices in actively traded markets and quotations from broker or pricing services. Non-exchange traded securities and exchange-traded securities held in commingled funds are classified as Level 2 assets.
	(g)	This category utilizes a diversified group of strategies that attempt to capture financial market inefficiencies and includes publicly traded debt and equity, publicly traded mutual funds, commingled and limited partnership funds and non-exchange traded securities. Pricing for Level 1 and Level 2 assets in this category is obtained from quoted prices in actively traded markets and quoted prices from broker or pricing services. Non-exchange traded securities held in commingled funds are classified as Level 2 assets. Valuations for some Level 3 assets in this category may be based on limited observable inputs as there may be little, if any, publicly available pricing.
	(h)	This category includes a diversified group of funds and strategies that primarily invests in private equity partnerships. This category also includes investments in timber and private mezzanine debt. Pricing for investments in this category is based on limited observable inputs as there is little, if any, publicly available pricing. Valuations for assets in this category may be based on discounted cash flow analyses, relevant publicly-traded comparables and comparable transactions.
	(i)	In 2014, DTE Electric began a securities lending program with a third party agent. The program allows the agent to lend certain securities from the Company's VEBA trust to selected entities against receipt of collateral (in the form of cash) as provided for and determined in accordance with its securities lending agency agreement.
Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets	Fair Value Measurements Using Significant Unobservable Inputs (Level 3):
		Year Ended December 31, 2014									Year Ended December 31, 2013
		Hedge Funds and Similar Investments			Private Equity and Other			Total			Hedge Funds and Similar Investments			Private Equity and Other			Total
		(In millions)
	Beginning Balance at January 1	$	111		$	71		$	182		$	78		$	57		$	135
	Total realized/unrealized gains (losses)	5			6			11			10			7			17
	Purchases, sales and settlements:
	Purchases	4			22			26			23			14			37
	Sales	(6		)	(8		)	(14		)	—			(7		)	(7		)
	Ending Balance at December 31	$	114		$	91		$	205		$	111		$	71		$	182
	The amount of total gains for the period attributable to the change in unrealized gains or losses related to assets still held at the end of the period	$	5		$	5		$	10		$	10		$	6		$	16

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	The following is a summary of transactions with affiliated companies:
		2014			2013			2012
	Revenues	(In millions)
	Energy sales	$	2		$	2		$	2
	Other services	$	5		$	7		$	11
	Shared capital assets	$	26		$	23		$	26
	Costs
	Fuel and purchased power	$	4		$	4		$	5
	Other services and interest	$	(1	)	$	(1	)	$	1
	Corporate expenses (net)	$	304		$	334		$	322
	Other
	Dividends declared	$	370		$	342		$	317
	Dividends paid	$	370		$	342		$	317
	Capital contribution from DTE Energy	$	190		$	400		$	—

Supplementary_Quarterly_Financ1

Supplementary Quarterly Financial Information (Unaudited ) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information
		First		Second		Third		Fourth		Total
		Quarter		Quarter		Quarter		Quarter		Year to Date
		(In millions)
	2014
	Operating Revenues	$	1,410	$	1,281	$	1,357	$	1,234	$	5,282
	Operating Income	$	271	$	259	$	272	$	250	$	1,052
	Net Income	$	137	$	130	$	136	$	129	$	532
	2013
	Operating Revenues	$	1,219	$	1,265	$	1,457	$	1,256	$	5,197
	Operating Income	$	235	$	202	$	338	$	225	$	1,000
	Net Income	$	116	$	90	$	180	$	101	$	487

Valuation_and_Qualifying_Accou1

Valuation and Qualifying Accounts Valuation and Qualifying Accounts (Tables)	12 Months Ended
	Dec. 31, 2014
Valuation and Qualifying Accounts [Abstract]
Summary of Valuation Allowance
		Year Ended December 31,
		2014			2013			2012
		(In millions)
	Allowance for Doubtful Accounts (shown as deduction from Accounts Receivable in the Consolidated Statements of Financial Position)
	Balance at Beginning of Period	$	28		$	35		$	80
	Additions:
	Charged to costs and expenses	50			52			40
	Charged to other accounts (a)	10			11			7
	Deductions (b)	(59		)	(70		)	(92		)
	Balance at End of Period	$	29		$	28		$	35
	_______________________________________
	(a)	Collection of accounts previously written off.
	(b)	Uncollectible accounts written off.

Organization_and_Basis_of_Pres2

Organization and Basis of Presentation (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets [Abstract]
Restricted cash	$96	$100
Accounts receivable	688	723
Securitized regulatory assets	34	231
Other current and long-term assets	182	149
Total Assets	18,649	17,410
Liabilities [Abstract]
Current portion long-term debt, including capital leases	118	504
Current regulatory liabilities	150	278
Securitization bonds	0	105
Other current and long-term liabilities	105	101
Variable Interest Entity Securitization [Member]
Assets [Abstract]
Restricted cash	96	100
Accounts receivable	26	34
Securitized regulatory assets	34	231
Other current and long-term assets	1	4
Total Assets	157	369
Liabilities [Abstract]
Accounts payable and accrued current liabilities	3	7
Current portion long-term debt, including capital leases	105	196
Current regulatory liabilities	32	43
Securitization bonds	0	105
Other current and long-term liabilities	9	8
Total Liabilities	$149	$359

Organization_and_Basis_of_Pres3

Organization and Basis of Presentation (Details Textuals) (USD $)	Dec. 31, 2014
	customers
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of electric utility customers	2,100,000
Significant potential exposure to loss due to VIE long-term purchase contracts	$0

Significant_Accounting_Policie3

Significant Accounting Policies Significant Accounting Policies (Accumulated Other Comprehensive Loss) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of the period	($16)	($22)
Other comprehensive income before reclassifications	-12	4
Amounts reclassified from accumulated other comprehensive income	2	2
Net current-period other comprehensive income	-10	6
End of the period	-26	-16
Net Unrealized Gain/(Loss) on Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of the period	1	0
Other comprehensive income before reclassifications	0	1
Amounts reclassified from accumulated other comprehensive income	0	0
Net current-period other comprehensive income	0	1
End of the period	1	1
Benefit Obligations [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of the period	-17	-22
Other comprehensive income before reclassifications	-12	3
Amounts reclassified from accumulated other comprehensive income	2	2
Net current-period other comprehensive income	-10	5
End of the period	($27)	($17)

Significant_Accounting_Policie4

Significant Accounting Policies Significant Accounting Policies (Intangible Assets) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Finite Lived Intangible Assets [Line Items]
Intangible Assets, Gross (Excluding Goodwill)	$46	$53
Intangible Assets, Current	9	12
Finite-Lived Intangible Assets, Net	37	41
Renewable Energy Credits [Member]
Finite Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	45	51
Emission Allowances [Member]
Finite Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	$1	$2

Significant_Accounting_Policie5

Significant Accounting Policies (Details Textuals) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Significant Accounting Policies [Line Items]
Receivables due date	21 days
Threshold period past due for write-off of trade accounts receivable	150 days
Unbilled revenues included in customer accounts receivable	$688,000,000	$723,000,000
Expense related to refueling outages	16,000,000	26,000,000
Period expenses related to refueling outages accrued	18 months
Excise sales tax net impact on the statement operations	0
Unbilled Revenues [Member]
Significant Accounting Policies [Line Items]
Unbilled revenues included in customer accounts receivable	250,000,000	280,000,000
Minimum [Member]
Significant Accounting Policies [Line Items]
Notes receivable considered delinquent period	60 days
Maximum [Member]
Significant Accounting Policies [Line Items]
Notes receivable considered delinquent period	120 days
Parent Company [Member]
Significant Accounting Policies [Line Items]
Allocated share-based compensation expense	$62,000,000	$58,000,000	$42,000,000

Property_Plant_and_Equipment_S

Property, Plant and Equipment (Summary of property by classification) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$12,589	$11,779
Electric Generation Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment - Generation	11,641	11,127
Less Accumulated Depreciation and Amortization - Total	-4,149	-4,004
Electric Transmission and Distribution Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment - Distribution	8,164	7,603
Less Accumulated Depreciation and Amortization - Total	-3,067	-2,947
Electric Generation, Transmission and Distribution Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment - Total	19,805	18,730
Less Accumulated Depreciation and Amortization - Total	($7,216)	($6,951)

Property_Plant_and_Equipment_D

Property, Plant and Equipment (Details Textuals) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Public Utility Property, Plant and Equipment [Line Items]
AFUDC capitalized	$32	$21
Disclosure of composite depreciation rate for plants in service	3.40%	3.40%	3.30%
Public utilities, generation, useful life	40 years
Public utilities, distribution, useful life	41 years
Capitalized computer software amortization	71	64	62
Capitalized computer software gross	590	521
Capitalized computer software accumulated amortization	293	269
Capital leased assets gross	9	9
Capital leased assets, accumulated depreciation	$5	$1
Minimum [Member] | Computer Software, Intangible Asset [Member]
Public Utility Property, Plant and Equipment [Line Items]
Finite-lived intangible asset, useful life	5 years
Maximum [Member] | Computer Software, Intangible Asset [Member]
Public Utility Property, Plant and Equipment [Line Items]
Finite-lived intangible asset, useful life	15 years

Jointly_Owned_Utility_Plant_De

Jointly Owned Utility Plant (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified	MW
Belle River [Member]
Jointly Owned Utility Plant Interests [Line Items]
Total plant capacity	1,270
Investment (in millions)	$1,742
Accumulated depreciation (in millions)	993
Ludington [Member]
Jointly Owned Utility Plant Interests [Line Items]
Total plant capacity	1,872
Ownership interest	49.00%
Investment (in millions)	412
Accumulated depreciation (in millions)	$175

Jointly_Owned_Utility_Plant_De1

Jointly Owned Utility Plant (Details Textuals)	Dec. 31, 2014
	facilities
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, number of plants	2
Belle River Unit 1 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest	63.00%
Belle River Facilities used jointly by Belle River and St. Clair Power Plants [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest	81.00%
Belle River Unit 2 [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest	75.00%
Belle River [Member]
Jointly Owned Utility Plant Interests [Line Items]
Joint owners percentage of the total capacity energy and related responsibilities	19.00%
Ludington [Member]
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest	49.00%
Joint owners percentage of the total capacity energy and related responsibilities	51.00%

Asset_Retirement_Obligations_D

Asset Retirement Obligations (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations, beginning balance	$1,667
Accretion	103
Liabilities incurred	9
Liabilities settled	-6
Revision in estimated cash flows	23
Asset retirement obligations, ending balance	$1,796

Asset_Retirement_Obligations_D1

Asset Retirement Obligations (Details Textuals) (USD $)	12 Months Ended
	Dec. 31, 2014
Asset Retirement Obligations [Line Items]
Asset retirement obligations, liability not recognized	Substations, manholes and certain other distribution assets have an indeterminate life. Therefore, no liability has been recorded for these assets
Liabilities balance upon completion of decommissioning	$0
Fermi 2 [Member]
Asset Retirement Obligations [Line Items]
Nuclear decommissioning liabilities funded through surcharge and included in ARO balance	$1,700,000,000

Regulatory_Matters_Regulatory_

Regulatory Matters (Regulatory Assets) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Regulatory Assets [Line Items]
Regulatory Assets	$2,959	$2,288
Regulatory Assets, Current	-46	-13
Regulatory Assets, Noncurrent	2,913	2,275
Securitized Regulatory Assets, Noncurrent	34	231
Pension Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	1,743	1,257
Postretirement Benefit Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	191	0
Asset Retirement Obligation Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	448	394
Recoverable Michigan Income Taxes [Member]
Regulatory Assets [Line Items]
Regulatory Assets	220	237
Other Recoverabe Income Taxes [Member]
Regulatory Assets [Line Items]
Regulatory Assets	66	71
Cost to Achieve Performance Excellence Process [Member]
Regulatory Assets [Line Items]
Regulatory Assets	46	64
Loss on Reacquired Debt [Member]
Regulatory Assets [Line Items]
Regulatory Assets	44	38
Accrued PSCR Revenue [Member]
Regulatory Assets [Line Items]
Regulatory Assets	34	0
Recoverable Income Taxes related to Securitized Regulatory Assets [Member]
Regulatory Assets [Line Items]
Regulatory Assets	19	126
Unrecovered Removal Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets	15	0
Transitional Recovery Mechanism
Regulatory Assets [Line Items]
Regulatory Assets	14	0
Other Assets [Member]
Regulatory Assets [Line Items]
Regulatory Assets	$119	$101

Regulatory_Matters_Regulatory_1

Regulatory Matters Regulatory Matters (Regulatory Liabilities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2012
In Millions, unless otherwise specified
Regulatory Liabilities [Line Items]
Regulatory Liabilities	$395	$664
Regulatory Liability, Current	-150	-278
Regulatory Liability, Noncurrent	245	386
Renewable Energy [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	227	277
Over Recovery of Securitization [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	71	72
Refundable Revenue Decoupling/ Deferred Gain [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	63	127	127
Fermi 2 Refueling Outage [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	16	26
Energy Optimization [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	14	25
Accrued PSCR refund [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	53
Refundable postretirement costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	48
Removal Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	33
Other Liabilities [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	$4	$3

Regulatory_Matters_Details_Tex

Regulatory Matters (Details Textuals) (USD $)	3 Months Ended	12 Months Ended	0 Months Ended
	Mar. 31, 2013	Dec. 31, 2014	Dec. 19, 2014	Dec. 31, 2013	Jul. 30, 2012	Sep. 26, 2014	Aug. 31, 2013	Jan. 02, 2014	Sep. 30, 2012
Regulatory Assets [Line Items]
Amortization period of cost to achieve deferral		10 years
Time period required by non-bypassable securitization bond surcharge to recover securitized regulatory asset		14 years
Regulatory liabilities		$395,000,000		$664,000,000
PSCR under-recovery from 1 plan year prior	87,000,000
PSCR Under-Recovery from 2 play years prior	148,000,000
Fermi 2 Production Level of Full Capacity					68.00%
Maximum of challenged Fermi 2 outage charges		32,000,000
MPSC [Member]
Regulatory Assets [Line Items]
Public utilities, requested rate increase (decrease)			370,000,000
Rate increase previously authorized by the MPSC challenged by Court of Appeals reopened by the MPSC							11,000,000
Approved recovery amount for customer 360						215,000,000
Approved amortization period for customer 360 recovery		15 years
Refundable Revenue Decoupling/ Deferred Gain [Member]
Regulatory Assets [Line Items]
Regulatory liabilities		63,000,000		127,000,000					127,000,000
Amortization of Deferred Gain Regulatory Liability								$10,600,000

Income_Taxes_Income_Tax_Expens

Income Taxes (Income Tax Expense Reconciled to Federal Income Tax Rate) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income before income taxes	$830	$741	$768
Income tax expense at 35% statutory rate	291	260	269
Production tax credits	-22	-15	-5
Investment tax credits	-5	-5	-6
Depreciation	3	3	3
AFUDC - Equity	-7	-5	-4
Employee Stock Ownership Plan dividends	-3	-2	-3
Domestic production activities deduction	-2	-18	-16
State and other income taxes, net of federal benefit	43	41	40
Other, net	0	-5	4
Income tax expense	$298	$254	$282
Effective income tax rate (as percent)	35.90%	34.30%	36.70%

Income_Taxes_Components_of_Inc

Income Taxes (Components of Income Tax Expense (Benefits)) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current income tax expense (benefit)
Federal	($19)	$123	$267
State and other income tax	20	23	67
Total current income taxes	1	146	334
Deferred income tax expense (benefit)
Federal	251	68	-47
State and other income tax	46	40	-5
Total deferred income taxes	297	108	-52
Income tax expense	$298	$254	$282

Income_Taxes_Deferred_Tax_Asse

Income Taxes (Deferred Tax Assets (Liabilities)) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Components of Deferred Tax Assets and Liabilities [Abstract]
Property, plant and equipment	($3,152)	($2,807)
Securitized regulatory assets	-3	-130
Pension and benefits	-43	27
Deferred Tax Liabilities, Other, net	12	12
Current deferred income tax liabilities	2	-91
Long-term deferred income tax liabilities	-3,188	-2,807
Deferred Tax Assets, Net	357	420
Deferred Tax Liabilities, Net	-3,543	-3,318
Deferred income tax liabilities	($3,186)	($2,898)

Income_Taxes_Reconciliation_of

Income Taxes (Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits, beginning balance	$4	$4	$59
Reductions for tax positions of prior years	0	0	-3
Settlements	0	0	-52
Unrecognized Tax Benefits, ending balance	$4	$4	$4

Income_Taxes_Details_Textuals

Income Taxes (Details Textuals) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Related party tax expense due from affiliates	$29,000,000	$23,000,000
Unrecognized tax benefits that would impact effect tax rate	2,000,000	2,000,000
Interest and income taxes accrued	1,000,000	1,000,000
Income tax penalties accrued	0
Interest on income taxes expense			($3,000,000)

Fair_Value_Assets_and_Liabilit

Fair Value (Assets and Liabilites Recorded at Fair Value on a Recurring Basis) (Details) (Recurring [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	$104	$116
Nuclear decommissioning trusts	1,241	1,191
Other investments	147	135
Assets, Fair Value Disclosure	1,495	1,445
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	5	2
Nuclear decommissioning trusts	792	779
Other investments	97	91
Assets, Fair Value Disclosure	894	872
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	99	114
Nuclear decommissioning trusts	449	412
Other investments	50	44
Assets, Fair Value Disclosure	598	570
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Nuclear decommissioning trusts	0	0
Other investments	0	0
Assets, Fair Value Disclosure	3	3
Current Asset [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	107	119
Current Asset [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	5	2
Current Asset [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	99	114
Current Asset [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	3	3
Noncurrent Asset [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	1,388	1,326
Noncurrent Asset [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	889	870
Noncurrent Asset [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	499	456
Noncurrent Asset [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Financial Transmission Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets - FTRs	3	3
Financial Transmission Rights [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets - FTRs	0	0
Financial Transmission Rights [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets - FTRs	0	0
Financial Transmission Rights [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets - FTRs	$3	$3

Fair_Value_Reconciliation_of_L

Fair Value (Reconciliation of Level 3 Assets and Liabilities at Fair Value on a Recurring Basis) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis
Beginning Balance	$3	$1
Change in fair value recorded in regulatory assets/liabilities	8	5
Settlements	-8	-3
Ending Balance	3	3
The amount of total gains (losses) included in regulatory assets and liabilities attributed to the change in unrealized gains (losses) related to regulatory assets and liabilities held at the end of the period	$3	$2

Fair_Value_Fair_Value_of_Finan

Fair Value (Fair Value of Financial Instruments) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases, fair value	$12	$10
Short-term borrowings, fair value	50	0
Long-term debt, excluding capital leases, fair value	5,259	5,146
Reported Value Measurement [Member] | Affiliated Entity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases, fair value	8	200
Short-term borrowings, fair value	84	58
Estimate of Fair Value Measurement [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases, fair value	0	0
Short-term borrowings, fair value	0	0
Long-term debt, excluding capital leases, fair value	0	0
Estimate of Fair Value Measurement [Member] | Level 1 [Member] | Affiliated Entity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases, fair value	0	0
Short-term borrowings, fair value	0	0
Estimate of Fair Value Measurement [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases, fair value	0	0
Short-term borrowings, fair value	50	0
Long-term debt, excluding capital leases, fair value	5,341	5,253
Estimate of Fair Value Measurement [Member] | Level 2 [Member] | Affiliated Entity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases, fair value	0	0
Short-term borrowings, fair value	0	0
Estimate of Fair Value Measurement [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases, fair value	12	10
Short-term borrowings, fair value	0	0
Long-term debt, excluding capital leases, fair value	496	136
Estimate of Fair Value Measurement [Member] | Level 3 [Member] | Affiliated Entity [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases, fair value	8	200
Short-term borrowings, fair value	$84	$58

Fair_Value_Fair_Value_of_Nucle

Fair Value (Fair Value of Nuclear Decommissioning Trust Fund Assets) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Decommissioning Fund Investments	$1,241	$1,191
Nuclear Decommissioning Trust Fund [Member]
Schedule of Available-for-sale Securities [Line Items]
Decommissioning Fund Investments	1,241	1,191
Fermi 2 [Member]
Schedule of Available-for-sale Securities [Line Items]
Decommissioning Fund Investments	1,221	1,172
Fermi 1 [Member]
Schedule of Available-for-sale Securities [Line Items]
Decommissioning Fund Investments	3	3
Low level radioactive waste [Member]
Schedule of Available-for-sale Securities [Line Items]
Decommissioning Fund Investments	$17	$16

Fair_Value_Gains_and_Losses_an

Fair Value (Gains and Losses and Proceeds from the Sale of Securities by the Nuclear Decommissioning Trust Funds) (Details) (Nuclear Decommissioning Trust Fund [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Nuclear Decommissioning Trust Fund [Member]
Schedule of Available-for-sale Securities [Line Items]
Realized gains	$54	$83	$37
Realized losses	-33	-41	-31
Proceeds from sales of securities	$1,146	$1,118	$759

Fair_Value_Fair_Value_and_Unre

Fair Value (Fair Value and Unrealized Gains for the Nuclear Decommissioning Trust Funds) (Details) (Nuclear Decommissioning Trust Fund [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Nuclear Decommissioning Trust Fund [Member]
Schedule of Available-for-sale Securities [Line Items]
Equity Securities	$756	$730
Equity Securities, Gross Unrealized Gain	204	201
Equity Securities, Gross Unrealized Loss	-39	-25
Debt securities	474	442
Debt Securities Gross Unrealized Gain	21	12
Debt Securities, Gross Unrealized Loss	-2	-6
Cash and cash equivalents	11	19
Nuclear decommissioning trusts	1,241	1,191
Gross Unrealized Gains	225	213
Gross Unrealized Loss	($41)	($31)

Fair_Value_Details_Textuals

Fair Value (Details Textuals) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Option, Quantitative Disclosures [Line Items]
Transfers between levels 1, 2, and 3	$0	$0
Unrealized Losses on Available for Sale Securities	2,000,000	2,000,000
Trading securities realized gain (loss)	12,000,000	19,000,000	9,000,000
Net Unrealized Gain/(Loss) on Investments [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Unrealized Losses on Available for Sale Securities	0	0
Equity Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Nuclear decommissioning trust fund investments	61.00%	61.00%
Debt Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Nuclear decommissioning trust fund investments	38.00%	37.00%
Cash and Cash Equivalents [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Nuclear decommissioning trust fund investments	1.00%	2.00%
Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash and cash equivalents	104,000,000	116,000,000
Restricted Assets [Member] | Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash and cash equivalents	96,000,000	100,000,000
Other Investments [Member] | Recurring [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash and cash equivalents	8,000,000	16,000,000
Other Investments [Member] | Recurring [Member] | Equity Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Available-for-sale securities	8,000,000	7,000,000
Nuclear Decommissioning Trust Fund [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash and cash equivalents	$11,000,000	$19,000,000
Average maturity of debt securities	7 years	7 years

Financial_and_Other_Derivative2

Financial and Other Derivative Instruments (Fair Value of Derivative Instruments) (Details) (Not Designated as Hedging Instrument [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Derivatives, Fair Value [Line Items]
Derivative Asset, Current	$3	$3
Financial Transmission Rights [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Current	$3	$3

LongTerm_Debt_Long_Term_Debt_O

Long-Term Debt (Long Term Debt Outstanding and Weighted Average Interest Rates) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Long-term debt	$5,270
Long Term Debt excluding Securitization, Debentures and Capital Leases	5,154	4,844
Less amount of long-term debt due within one year	-10	-304
Long-term Debt, Excluding Current Maturities	5,144	4,540
Securitization bonds	105	302
Less amount of Securitization Bonds due within one year	-105	-197
Securitization bonds	0	105
Secured Debt [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	4.50%
Debt Instrument, Maturity Date Range, Start	31-Mar-16
Debt Instrument, Maturity Date Range, End	1-Jun-44
Long-term debt	4,824	4,286
Tax Exempt Revenue Bonds [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	5.20%
Debt Instrument, Maturity Date Range, Start	1-Jul-20
Debt Instrument, Maturity Date Range, End	1-Dec-30
Long-term debt	$330	$558
Securitization Bonds [Member]
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	6.60%
Debt Instrument, Maturity Date	15-Mar-15

LongTerm_Debt_Debt_Issuances_D

Long-Term Debt (Debt Issuances) (Details) (USD $)	Dec. 31, 2014
Debt Instrument [Line Items]
Debt face amount	$950,000,000
June 2014 3.77% Mortgage Bonds Maturing in 2026 [Member] | Mortgages [Member]
Debt Instrument [Line Items]
Debt instrument stated interest rate	3.77%
Debt face amount	100,000,000
June 2014 4.60% Mortgage Bonds Maturing in 2044 [Member] | Mortgages [Member]
Debt Instrument [Line Items]
Debt instrument stated interest rate	4.60%
Debt face amount	150,000,000
July 2014 3.375% Mortgage Bonds Maturing in 2025 [Member] | Mortgages [Member]
Debt Instrument [Line Items]
Debt instrument stated interest rate	3.38%
Debt face amount	350,000,000
July 2014 4.30% Mortgage Bonds Maturing in 2044 [Member] | Mortgages [Member]
Debt Instrument [Line Items]
Debt instrument stated interest rate	4.30%
Debt face amount	$350,000,000

LongTerm_Debt_Debt_Redemptions

Long-Term Debt (Debt Redemptions) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Debt Instrument, Redemption [Line Items]
Extinguishment of debt	$837
Mortgages [Member] | March 2014 Mortgage Bonds Various Interest Rates Maturing in 2014 [Member]
Debt Instrument, Redemption [Line Items]
Extinguishment of debt	13
Securitization Bonds [Member] | March 2014 Securitization Bonds 6.62% Maturing in 2014 [Member]
Debt Instrument, Redemption [Line Items]
Debt instrument stated interest rate	6.62%
Extinguishment of debt	100
Securitization Bonds [Member] | September 2014 Securitization Bonds 6.62% Maturing in 2014 [Member]
Debt Instrument, Redemption [Line Items]
Debt instrument stated interest rate	6.62%
Extinguishment of debt	96
Tax Exempt Revenue Bonds [Member] | April 2014 Tax Exempt Revenue Bonds 2.35% Maturing in 2024 [Member]
Debt Instrument, Redemption [Line Items]
Debt instrument stated interest rate	2.35%
Extinguishment of debt	31
Tax Exempt Revenue Bonds [Member] | April 2014 Tax Exempt Revenue Bonds 4.65% Maturing in 2028 [Member]
Debt Instrument, Redemption [Line Items]
Debt instrument stated interest rate	4.65%
Extinguishment of debt	32
Tax Exempt Revenue Bonds [Member] | June 2014 Tax Exempt Revenue Bonds 4.875% Maturing in 2029 [Member]
Debt Instrument, Redemption [Line Items]
Debt instrument stated interest rate	4.88%
Extinguishment of debt	36
Tax Exempt Revenue Bonds [Member] | June 2014 Tax Exempt Revenue Bonds 6.00% Maturing in 2036 [Member]
Debt Instrument, Redemption [Line Items]
Debt instrument stated interest rate	6.00%
Extinguishment of debt	69
Tax Exempt Revenue Bonds [Member] | August 2014 Tax Exempt Revenue Bonds 5.25% Maturing in 2029 [Member]
Debt Instrument, Redemption [Line Items]
Debt instrument stated interest rate	5.25%
Extinguishment of debt	60
Senior Notes [Member] | July 2014 Senior Notes 4.80% Maturing in 2015 [Member]
Debt Instrument, Redemption [Line Items]
Debt instrument stated interest rate	4.80%
Extinguishment of debt	200
Senior Notes [Member] | August 2014 Senior Notes 5.40% Maturing in 2014 [Member]
Debt Instrument, Redemption [Line Items]
Debt instrument stated interest rate	5.40%
Extinguishment of debt	$200

LongTerm_Debt_Scheduled_Debt_M

Long-Term Debt (Scheduled Debt Maturities) (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Maturities of Long-term Debt [Abstract]
2015	$115
2016	151
2017	0
2018	300
2019	0
2020 and Thereafter	4,704
Long-term Debt	$5,270

Preferred_and_Preference_Secur1

Preferred and Preference Securities (Details Textuals) (USD $)	Dec. 31, 2014
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock, shares authorized (in shares)	6,750,000
Preferred stock, par value (in dollars per share)	$100
Preference stock, shares authorized (in shares)	30,000,000
Preference stock, par value (in dollars per share)	$1
Preferred stock, shares issued (in shares)	0

ShortTerm_Credit_Arrangements_1

Short-Term Credit Arrangements and Borrowings (Details Textuals) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Short-term Debt [Line Items]
Long-term Commercial Paper, Current	$50,000,000	$0
Ratio of Indebtedness to Net Capital	0.51
Short-term Debt, Weighted Average Interest Rate	0.50%	0.00%
Unsecured revolving credit facility expiring April 2018 [Member] | Revolving Credit Facility [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$300,000,000
Maximum [Member]
Short-term Debt [Line Items]
Ratio of Indebtedness to Net Capital	0.65

Operating_Leases_Details

Operating Leases (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2015	$28
2016	22
2017	18
2018	15
2019	10
Thereafter	40
Total minimum lease payments	$133

Operating_Leases_Details_Textu

Operating Leases (Details Textuals) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Leases [Abstract]
Rent expense	$26	$28	$29

Commitments_and_Contingencies_2

Commitments and Contingencies (Purchase Commitments) (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Purchase Obligation, Fiscal Year Maturity [Abstract]
2015	$496
2016	330
2017	278
2018	125
2019	106
2020 and thereafter	1,063
Total Purchase Obligations	$2,398

Commitments_and_Contingencies_3

Commitments and Contingencies (Details Textuals) (USD $)	0 Months Ended	4 Months Ended	8 Months Ended	12 Months Ended
	31-May-14	15-May-14	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013
		kWh	kWh	facilities
			facilities	dte_instances
			dte_instances
Other Commitments [Line Items]
Environmental Capital Expenditures Through Current Year				$2,200,000,000
Estimated capital expenditures in next fiscal year				100,000,000
Environmental Capital Expenditures In Future Years				30,000,000
EPA is Alleging Power Plants Violated New Source Performance Standards			5	5
Number of NOVs/FOVs currently being discussed with the EPA			2	2
EPA Sulfur Dioxide Ambient Air Quality Standard				1 hour
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 remediation related to sites			10,000,000	10,000,000	8,000,000
Number of Permitted Engineered Ash Storage Facilities Owned				3
Waiting Period of Policy				84 days
Insurance Coverage for Extra Expense When to Necessitate Power Plant when Unavailable				490,000,000
Period of Coverage of Policy for Extra Expenses				P3Y
Primary Coverage				1,500,000,000
Coverage for Stabilization Decontamination Debris Removal Repair and Replacement of Property and Decommissioning				1,250,000,000
Combined Coverage Limit for Total Property Damage				2,750,000,000
Insurance Deductible for Nuclear Power Plant			1,000,000	1,000,000
Total Limit for Property Damage for Non-Nuclear Event			2,000,000,000	2,000,000,000
Limit of Coverage for Aggreagate Extra Expenses for Non-Nuclear Events				328,000,000
Limit for Property Damage for Non-Nuclear Events Aggregate of Extra Expenses of Period				2 years
NEIL Policies Against Terroism Loss				3,200,000,000
Amount per Event Loss Associated with Nuclear Power Plants				35,000,000
Maintenance of Public Liability Insurance for Nuclear Power Plants				375,000,000
Aggregate Limit of Liabilities Arises From Terroist Act Outside Scope of Trials Subject to One Industry				300,000,000
Deferred premium charges 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 Sold1		1
New DOE fee for nuclear waste			0
Total Purchase Obligations			2,398,000,000	2,398,000,000
estimated future capital expenditures for next year				$1,900,000,000
Represented Employees [Member]
Other Commitments [Line Items]
Number of Represented Employees			2,600	2,600

Retirement_Benefits_and_Truste2

Retirement Benefits and Trusteed Assets (Pension Plan - Pension Cost Inclusions) (Details) (Pension Plan [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$64	$73	$64
Interest cost	162	146	155
Expected return on plan assets	-194	-184	-166
Amortization of net loss	110	148	124
Amortization of prior service cost (credit)	2	1	1
Settlements	0	0	2
Net pension cost	$144	$184	$180

Retirement_Benefits_and_Truste3

Retirement Benefits and Trusteed Assets (Pension Plan - Other Changes in Plan Assets and Benefit Obligations recognized in Reg Assets and OCI) (Details) (Pension Plan [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Pension Plan [Member]
Other changes in plan assets and benefit obligations recognized in Regulatory assets and Other comprehensive income
Net actuarial (gain) loss	$614	($418)
Amortization of net actuarial loss	-110	-148
Prior service cost	-2	0
Amortization of prior service cost	-2	-1
Total recognized in Regulatory assets and Other comprehensive income	500	-567
Total recognized in net periodic pension cost, Regulatory assets and Other comprehensive income	644	-383
Estimated amounts to be amortized from Regulatory assets and Accumulated other comprehensive income into net periodic benefit cost during next fiscal year
Net actuarial loss	149	106
Prior service cost	$1	$1

Retirement_Benefits_and_Truste4

Retirement Benefits and Trusteed Assets (Pension Plan - Reconciliation of Obligations, Assets and Funded Status of Plans) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change in projected benefit obligation
Plan amendments	($2)	$0
Amounts recognized in Regulatory assets (liabilities) (see Note 7 - Regulatory Matters)
Regulatory Assets	2,959	2,288
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Accumulated benefit obligation, end of year	3,712	3,111
Change in projected benefit obligation
Projected benefit obligation, beginning of year	3,341	3,585
Service cost	64	73	64
Interest cost	162	146	155
Actuarial (gain) loss	634	-286
Benefits paid	-181	-177
Projected benefit obligation, end of year	4,018	3,341	3,585
Change in plan assets
Plan assets at fair value, beginning of year	2,632	2,211
Actual return on plan assets	212	316
Company contributions	149	282
Benefits paid	-181	-177
Plan assets at fair value, end of year	2,812	2,632	2,211
Funded status of the plan	-1,206	-709
Amount recorded as:
Current liabilities	-6	-4
Noncurrent liabilities	-1,200	-705
Pension and Other Postretirement Defined Benefit Plans, Liabilities	-1,206	-709
Amounts recognized in Regulatory assets (liabilities) (see Note 7 - Regulatory Matters)
Net actuarial loss	1,738	1,248
Prior service cost	5	9
Regulatory Assets	$1,743	$1,257

Retirement_Benefits_and_Truste5

Retirement Benefits and Trusteed Assets (Pension Plan - Benefits related to Qualified and Nonqualified Pension Plans Expected to be paid in the Next Ten Years) (Details) (Pension Plan [Member], USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Pension Plan [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	$210
2016	216
2017	223
2018	233
2019	239
2020 - 2024	1,264
Total Defined Benefit Pension Plan Expected Future Payments	$2,385

Retirement_Benefits_and_Truste6

Retirement Benefits and Trusteed Assets (Pension Plan - Assumptions used in Determining the PBO and Net Pension Costs) (Details) (Pension Plan [Member])	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Plan [Member]
Projected benefit obligation
Discount rate	4.12%	4.95%	4.15%
Rate of compensation increase	4.65%	4.20%	4.20%
Net pension costs
Discount rate	4.95%	4.15%	5.00%
Rate of compensation increase	4.20%	4.20%	4.20%
Expected long-term rate of return on plan assets	7.75%	8.25%	8.25%

Retirement_Benefits_and_Truste7

Retirement Benefits and Trusteed Assets (Pension Plan - Target Allocations of Plan Assets) (Details) (Pension Plan [Member])	12 Months Ended
	Dec. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocations for pension plan assets	100.00%
US Large Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocations for pension plan assets	22.00%
US Small Cap and Mid Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocations for pension plan assets	5.00%
Non US Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocations for pension plan assets	20.00%
Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocations for pension plan assets	25.00%
Hedge Funds and Similar Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocations for pension plan assets	20.00%
Private Equity and Other [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocations for pension plan assets	8.00%

Retirement_Benefits_and_Truste8

Retirement Benefits and Trusteed Assets (Pension Plan - Fair Value Measurements) (Details) (Pension Plan [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$2,812	$2,632	$2,211
Short-term Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	33	15
US Large Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	638	639
US Small Cap and Mid Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	162	160
Non US Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	535	534
Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	763	634
Hedge Funds and Similar Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	546	528
Private Equity and Other [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	135	122
Securities Lending [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	-172	0
Securities Lending Collateral [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	172	0
Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1,379	1,458
Level 1 [Member] | Short-term Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	33	15
Level 1 [Member] | US Large Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	638	639
Level 1 [Member] | US Small Cap and Mid Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	162	160
Level 1 [Member] | Non US Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	378	440
Level 1 [Member] | Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	5	11
Level 1 [Member] | Hedge Funds and Similar Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	163	193
Level 1 [Member] | Private Equity and Other [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Level 1 [Member] | Securities Lending [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	-136	0
Level 1 [Member] | Securities Lending Collateral [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	136	0
Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	983	767
Level 2 [Member] | Short-term Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Level 2 [Member] | US Large Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Level 2 [Member] | US Small Cap and Mid Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Level 2 [Member] | Non US Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	157	94
Level 2 [Member] | Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	758	623
Level 2 [Member] | Hedge Funds and Similar Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	68	50
Level 2 [Member] | Private Equity and Other [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Level 2 [Member] | Securities Lending [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	-36	0
Level 2 [Member] | Securities Lending Collateral [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	36	0
Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	450	407	363
Level 3 [Member] | Short-term Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Level 3 [Member] | US Large Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Level 3 [Member] | US Small Cap and Mid Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Level 3 [Member] | Non US Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Level 3 [Member] | Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Level 3 [Member] | Hedge Funds and Similar Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	315	285	238
Level 3 [Member] | Private Equity and Other [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	135	122	125
Level 3 [Member] | Securities Lending [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Level 3 [Member] | Securities Lending Collateral [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$0	$0

Retirement_Benefits_and_Truste9

Retirement Benefits and Trusteed Assets (Pension Plan - Fair Value Measurement using Level 3 Inputs) (Details) (Pension Plan [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Change in plan assets
Plan assets at fair value, beginning of year	$2,632	$2,211
Actual return on plan assets	212	316
Plan assets at fair value, end of year	2,812	2,632
Hedge Funds and Similar Investments [Member]
Change in plan assets
Plan assets at fair value, end of year	546	528
Private Equity and Other [Member]
Change in plan assets
Plan assets at fair value, end of year	135	122
Level 3 [Member]
Change in plan assets
Plan assets at fair value, beginning of year	407	363
Actual return on plan assets	27	31
Purchases	38	33
Sales	-22	-20
Plan assets at fair value, end of year	450	407
The amount of total gains for the period attributable to the change in unrealized gains or losses related to assets still held at the end of the period	23	29
Level 3 [Member] | Hedge Funds and Similar Investments [Member]
Change in plan assets
Plan assets at fair value, beginning of year	285	238
Actual return on plan assets	15	29
Purchases	16	18
Sales	-1	0
Plan assets at fair value, end of year	315	285
The amount of total gains for the period attributable to the change in unrealized gains or losses related to assets still held at the end of the period	15	27
Level 3 [Member] | Private Equity and Other [Member]
Change in plan assets
Plan assets at fair value, beginning of year	122	125
Actual return on plan assets	12	2
Purchases	22	15
Sales	-21	-20
Plan assets at fair value, end of year	135	122
The amount of total gains for the period attributable to the change in unrealized gains or losses related to assets still held at the end of the period	$8	$2

Recovered_Sheet1

Retirement Benefits and Trusteed Assets (OPEB - Postretirement Cost Inclusions) (Details) (Other Postretirement Benefit Plan [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	$26	$35	$51
Interest cost	68	67	91
Expected return on plan assets	-85	-74	-61
Amortization of net loss	14	47	58
Amortization of prior service cost (credit)	-109	-100	-14
Net pension cost	($86)	($25)	$125

Recovered_Sheet2

Retirement Benefits and Trusteed Assets (OPEB - Other Changes in Plan Assets and APBO Recognized in Regulatory Assets and OCI) (Details) (Other Postretirement Benefit Plan [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Other Postretirement Benefit Plan [Member]
Other changes in plan assets and benefit obligations recognized in Regulatory assets and Other comprehensive income
Net actuarial (gain) loss	$144	($258)
Amortization of net actuarial loss	-14	-47
Prior service cost	0	-159
Amortization of prior service cost	109	100
Total recognized in Regulatory assets and Other comprehensive income	239	-364
Total recognized in net periodic pension cost, Regulatory assets and Other comprehensive income	153	-389
Estimated amounts to be amortized from Regulatory assets and Accumulated other comprehensive income into net periodic benefit cost during next fiscal year
Net actuarial loss	31	15
Prior service cost	($94)	($109)

Recovered_Sheet3

Retirement Benefits and Trusteed Assets (OPEB - Reconciliation of Obligations, Assets and Funded Status of Plans) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change in projected benefit obligation
Plan amendments	($2)	$0
Amounts recognized in Regulatory assets (liabilities) (see Note 7 - Regulatory Matters)
Regulatory Liabilities	-395	-664
Other Postretirement Benefit Plan [Member]
Change in projected benefit obligation
Projected benefit obligation, beginning of year	1,430	1,752
Service cost	26	35	51
Interest cost	68	67	91
Plan amendments	0	-159
Actuarial (gain) loss	100	-200
Medicare Part D subsidy	0	1
Benefits paid	-66	-66
Projected benefit obligation, end of year	1,558	1,430	1,752
Change in plan assets
Plan assets at fair value, beginning of year	1,061	756
Actual return on plan assets	41	131
Company contributions	0	239
Benefits paid	-64	-65
Plan assets at fair value, end of year	1,038	1,061	756
Funded status of the plan	-520	-369
Amount recorded as:
Noncurrent liabilities	-520	-369
Amounts recognized in Regulatory assets (liabilities) (see Note 7 - Regulatory Matters)
Net actuarial loss	385	255
Prior service cost	-194	-303
Regulatory Liabilities	$191	($48)

Recovered_Sheet4

Retirement Benefits and Trusteed Assets Retirement Benefits and Trusteed Assets (OPEB - Future Payments) (Details) (Other Postretirement Benefit Plan [Member], USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Other Postretirement Benefit Plan [Member]
Defined Benefit Plan, Expected Future Benefit Payments, Fiscal Year Maturity [Abstract]
2015	$77
2016	82
2017	85
2018	89
2019	93
2020 - 2024	505
Total Expected Future Benefit Payments	$931

Recovered_Sheet5

Retirement Benefits and Trusteed Assets Retirement Benefits and Trusteed Assets (OPEB - Assumptions Used) (Details) (USD $)	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Postretirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.30%	4.95%	4.10%	4.95%	4.15%
Health care trend rate pre 65			7.50%	7.50%
Health care trend rate post 65			6.50%	6.50%
Health care trend rate				7.00%	7.00%
Ultimate health care trend rate				4.50%	5.00%
Year in which ultimate reached pre 65			2025	2025
Year in which ultimate reached post 65			2024	2024
Year in which ultimate reached pre- and post- 65					2021
Discount rate	4.15%	4.30%	4.95%		5.00%
Expected long-term rate of return on plan assets			8.00%	8.25%	8.25%
Health care trend rate pre 65			7.50%
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers into Level 3			$0	$0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3			0	0
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate		4.95%	4.12%	4.95%	4.15%
Discount rate			4.95%	4.15%	5.00%
Expected long-term rate of return on plan assets			7.75%	8.25%	8.25%
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers into Level 3			0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3			$0	$0
Accumulated postretirement obligation [Member] | Other Postretirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Ultimate health care trend rate			4.50%
Other postretirement benefit costs [Member] | Other Postretirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Ultimate health care trend rate			4.50%	5.00%	5.00%
Year in which ultimate reached pre 65			2025
Year in which ultimate reached pre- and post- 65		2021		2021	2020
Health care trend rate post 65			6.50%

Recovered_Sheet6

Retirement Benefits and Trusteed Assets (OPEB - Target Allocations of Plan Assets) (Details) (Other Postretirement Benefit Plan [Member])	12 Months Ended
	Dec. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation Percentage of Assets	1
US Large Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation Percentage of Assets	0.17
US Small Cap and Mid Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation Percentage of Assets	0.04
Non US Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation Percentage of Assets	0.2
Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation Percentage of Assets	0.25
Hedge Funds and Similar Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation Percentage of Assets	0.2
Private Equity and Other [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target Allocation Percentage of Assets	0.14

Recovered_Sheet7

Retirement Benefits and Trusteed Assets (OPEB - Fair Value Measurements) (Details) (Other Postretirement Benefit Plan [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$1,038	$1,061	$756
Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	520	614
Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	313	265
Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	205	182	135
Short-term Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	4	3
Short-term Investments [Member] | Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	4	3
Short-term Investments [Member] | Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Short-term Investments [Member] | Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
US Large Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	179	208
US Large Cap Equity Securities [Member] | Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	179	208
US Large Cap Equity Securities [Member] | Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
US Large Cap Equity Securities [Member] | Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
US Small Cap and Mid Cap Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	102	103
US Small Cap and Mid Cap Equity Securities [Member] | Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	102	103
US Small Cap and Mid Cap Equity Securities [Member] | Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
US Small Cap and Mid Cap Equity Securities [Member] | Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Non US Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	190	202
Non US Equity Securities [Member] | Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	151	197
Non US Equity Securities [Member] | Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	39	5
Non US Equity Securities [Member] | Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	254	255
Fixed Income Securities [Member] | Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	11	12
Fixed Income Securities [Member] | Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	243	243
Fixed Income Securities [Member] | Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Hedge Funds and Similar Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	218	219
Hedge Funds and Similar Investments [Member] | Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	73	91
Hedge Funds and Similar Investments [Member] | Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	31	17
Hedge Funds and Similar Investments [Member] | Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	114	111	78
Private Equity and Other [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	91	71
Private Equity and Other [Member] | Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Private Equity and Other [Member] | Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Private Equity and Other [Member] | Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	91	71	57
Securities Lending [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	-109	0
Securities Lending [Member] | Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	-98	0
Securities Lending [Member] | Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	-11	0
Securities Lending [Member] | Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Securities Lending Collateral [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	109	0
Securities Lending Collateral [Member] | Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	98	0
Securities Lending Collateral [Member] | Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	11	0
Securities Lending Collateral [Member] | Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$0	$0

Recovered_Sheet8

Retirement Benefits and Trusteed Assets (OPEB - Fair Value Measurements using Level 3 Inputs) (Details) (Other Postretirement Benefit Plan [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan assets at fair value, beginning of year	$1,061	$756
Actual return on plan assets	41	131
Plan assets at fair value, end of year	1,038	1,061
Hedge Funds and Similar Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan assets at fair value, end of year	218	219
Private Equity and Other [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan assets at fair value, end of year	91	71
Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan assets at fair value, beginning of year	182	135
Actual return on plan assets	11	17
Purchases	26	37
Sales	-14	-7
Plan assets at fair value, end of year	205	182
The amount of total gains for the period attributable to the change in unrealized gains or losses related to assets still held at the end of the period	10	16
Level 3 [Member] | Hedge Funds and Similar Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan assets at fair value, beginning of year	111	78
Actual return on plan assets	5	10
Purchases	4	23
Sales	-6	0
Plan assets at fair value, end of year	114	111
The amount of total gains for the period attributable to the change in unrealized gains or losses related to assets still held at the end of the period	5	10
Level 3 [Member] | Private Equity and Other [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan assets at fair value, beginning of year	71	57
Actual return on plan assets	6	7
Purchases	22	14
Sales	-8	-7
Plan assets at fair value, end of year	91	71
The amount of total gains for the period attributable to the change in unrealized gains or losses related to assets still held at the end of the period	$5	$6

Recovered_Sheet9

Retirement Benefits and Trusteed Assets (Details Textuals) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined contribution plan, cost recognized (less than $1 million in 2012)	$24,000,000	$21,000,000	$19,000,000
Retiree Health Care Allowance will increase at lower of the rate of medical inflation or a set percentage	2.00%
Qualified Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions	145,000,000
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions	149,000,000	282,000,000
Defined Benefit Plan, Expected Return on Plan Assets	7.75%
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers into Level 3	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3	0	0
Discount rate	4.12%	4.95%	4.15%
Other Postretirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions	0	239,000,000
Defined Benefit Plan, Expected Return on Plan Assets	8.00%
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers into Level 3	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers out of Level 3	0	0
Annual allocation to Retiree Reimbursement Account Per Participant, Retired on or before January 1, 2013	3,570	3,500
Annual allocation to Retiree Reimbursement Account Per Participant, Retired after January 1, 2013	3,315	3,250
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components	5,000,000
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation	89,000,000
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components	4,000,000
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation	77,000,000
Discount rate	4.10%	4.95%	4.15%	4.30%
Retirement Savings Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions to employee savings plan	4.00%
Maximum [Member] | Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	145,000,000
Maximum [Member] | Other Postretirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	175,000,000
Retiree Healthcare Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined contribution plan, cost recognized (less than $1 million in 2012)	$2,000,000	$1,000,000

Related_Party_Transactions_Det

Related Party Transactions (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues [Abstract]
Other services	$5	$7	$11
Other [Abstract]
Dividends declared	370	342	317
Dividends paid	370	342	317
Capital Contribution from DTE Energy	190	400
DTE Energy [Member]
Other [Abstract]
Dividends declared	370	342	317
Dividends paid	370	342	317
Capital Contribution from DTE Energy	190	400	0
Energy Sales [Member]
Revenues [Abstract]
Revenue from Related Parties	2	2	2
Shared Capital Assets [Member]
Revenues [Abstract]
Revenue from Related Parties	26	23	26
Fuel and Power Purchases [Member]
Costs and Expenses [Abstract]
Related Party Transaction, Expenses from Transactions with Related Party	4	4	5
Other Services and Interest [Member]
Costs and Expenses [Abstract]
Related Party Transaction, Expenses from Transactions with Related Party	-1	-1	1
Corporate Expenses, Net [Member]
Costs and Expenses [Abstract]
Related Party Transaction, Expenses from Transactions with Related Party	$304	$334	$322

Related_Party_Transactions_Det1

Related Party Transactions (Details Textuals) (DTE Energy Foundation [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
DTE Energy Foundation [Member]
Related Party Transaction [Line Items]
Charitable Contributions to a Foundation	$0	$18,000,000	$0

Supplementary_Quarterly_Financ2

Supplementary Quarterly Financial Information (Unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Operating Revenues	$1,234	$1,357	$1,281	$1,410	$1,256	$1,457	$1,265	$1,219	$5,282	$5,197	$5,291
Operating Income (Loss)	250	272	259	271	225	338	202	235	1,052	1,000	1,028
Net Income	$129	$136	$130	$137	$101	$180	$90	$116	$532	$487	$486

Subsequent_Event_Details

Subsequent Event (Details) (Subsequent Event [Member], USD $)	0 Months Ended
In Millions, unless otherwise specified	Jan. 21, 2015
Subsequent Event [Member]
Subsequent Event [Line Items]
Payments to acquire business	$240

Valuation_and_Qualifying_Accou2

Valuation and Qualifying Accounts (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$28	$35	$80
Charged to cost and expenses	50	52	40
Charged to other accounts	10	11	7
Deductions	-59	-70	-92
Balance at End of Period	$29	$28	$35