DTE Electric 10-Q 26 Apr 16 2016 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	3 Months Ended
	Mar. 31, 2016shares
Entity Registrant Name	DTE ENERGY CO
Entity Central Index Key	936,340
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding	179,435,404
DTE Electric
Entity Registrant Name	DTE ELECTRIC CO
Entity Central Index Key	28,385
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding	138,632,324

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Utility operations	$ 1,664	$ 1,841
Non-utility operations	902	1,143
Operating Revenues	2,566	2,984
Operating Expenses
Fuel, purchased power, and gas — utility	565	693
Fuel, purchased power, and gas — non-utility	776	1,005
Operation and maintenance	516	526
Depreciation and amortization	229	209
Taxes other than income	99	100
Asset (gains) losses and impairments, net	0	(10)
Operating Expenses	2,185	2,523
Operating Income	381	461
Other (Income) and Deductions
Interest expense	113	110
Interest income	(11)	(4)
Other income	(52)	(51)
Other expenses	8	10
Total Other (Income) and Deductions	58	65
Income Before Income Taxes	323	396
Income Tax Expense	83	122
Net Income	240	274
Less: Net Income (Loss) Attributable to Noncontrolling Interests	(7)	1
Net Income (Loss) Attributable to DTE Energy Company/DTE Electric	$ 247	$ 273
Basic Earnings per Common Share
Net Income Attributable to DTE Energy Company (in dollars per share)	$ 1.38	$ 1.53
Diluted Earnings per Common Share
Net Income Attributable to DTE Energy Company (in dollars per share)	$ 1.37	$ 1.53
Weighted Average Common Shares Outstanding
Basic (in shares)	179	178
Diluted (in shares)	180	178
Dividends Declared per Common Share (in dollars per share)	$ 0.73	$ 0.69
DTE Electric
Utility operations	$ 1,153	$ 1,203
Operating Expenses
Fuel and purchased power — utility	335	390
Operation and maintenance	324	317
Depreciation and amortization	176	155
Taxes other than income	73	73
Operating Expenses	908	935
Operating Income	245	268
Other (Income) and Deductions
Interest expense	65	63
Interest income	(8)	0
Other income	(16)	(15)
Other expenses	7	9
Total Other (Income) and Deductions	48	57
Income Before Income Taxes	197	211
Income Tax Expense	70	74
Net Income (Loss) Attributable to DTE Energy Company/DTE Electric	$ 127	$ 137

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Net Income	$ 240	$ 274
Net Income (Loss)	247	273
Other comprehensive income (loss), net of tax:
Benefit obligations, net of taxes of $2 and $2, respectively	3	3
Foreign currency translation	2	(3)
Other comprehensive income	5	0
Comprehensive income	245	274
Less comprehensive income (loss) attributable to noncontrolling interests	(7)	1
Comprehensive income attributable to DTE Energy Company/DTE Electric	252	273
DTE Electric
Net Income (Loss)	127	137
Other comprehensive income (loss), net of tax:
Transfer of benefit obligations, net of taxes of $18 in 2015	0	28
Comprehensive income attributable to DTE Energy Company/DTE Electric	$ 127	$ 165

Consolidated Statements of Com4

Consolidated Statements of Comprehensive Income (Parentheticals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Tax effect on benefit obligation	$ 2	$ 2
DTE Electric
Tax effect on benefit obligation - transfer		$ 18

Consolidated Statements of Fina

Consolidated Statements of Financial Position (Unaudited) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Current Assets
Cash and cash equivalents	$ 35	$ 37
Restricted cash	23	23
Accounts receivable (less allowance for doubtful accounts)
Customer	1,185	1,276
Other	80	72
Inventories
Fuel and gas	351	480
Materials and supplies	309	323
Notes receivable
Derivative assets	109	129
Regulatory assets	36	32
Other	234	203
Total Current Assets	2,362	2,575
Investments
Nuclear decommissioning trust funds	1,246	1,236
Investments in equity method investees	542	514
Other	191	186
Total Investments	1,979	1,936
Property
Property, plant, and equipment	28,273	28,121
Less accumulated depreciation and amortization	(10,146)	(10,087)
Property, plant and equipment, net	18,127	18,034
Other Assets
Goodwill	2,018	2,018
Regulatory assets	3,699	3,692
Intangible assets	90	89
Notes receivable	79	85
Derivative assets	53	54
Other	157	179
Total Noncurrent Assets	6,096	6,117
Total Assets	28,564	28,662
Accounts payable
Accounts payable	649	809
Accrued interest	119	89
Dividends payable	131	131
Short-term borrowings	365	499
Current portion long-term debt, including capital leases	462	473
Derivative liabilities	67	57
Gas inventory equalization	87	0
Regulatory liabilities	30	41
Short-term borrowings
Other	299	429
Total Current Liabilities	2,209	2,528
Long-Term Debt (net of current portion)
Mortgage bonds, notes, and other	8,266	8,265
Junior subordinated debentures	480	480
Capital lease obligations	12	15
Total Long-Term Debt (net of current portion)	8,758	8,760
Other Liabilities
Deferred income taxes	4,006	3,923
Regulatory liabilities	585	569
Asset retirement obligations	2,227	2,194
Unamortized investment tax credit	60	62
Derivative liabilities	96	86
Accrued pension liability	1,130	1,133
Accrued postretirement liability	199	228
Nuclear decommissioning	179	177
Other	205	207
Total Noncurrent Liabilities	$ 8,687	$ 8,579
Commitments and Contingencies
Equity
Common stock	$ 4,118	$ 4,123
Retained earnings	4,909	4,794
Accumulated other comprehensive income (loss)	(140)	(145)
Total DTE Energy Company Equity	8,887	8,772
Noncontrolling interests	23	23
Total Equity	8,910	8,795
Total Liabilities and Equity	28,564	28,662
DTE Electric
Current Assets
Cash and cash equivalents	17	15
Accounts receivable (less allowance for doubtful accounts)
Customer	618	657
Affiliates	8	14
Other	43	40
Inventories
Fuel and gas	232	271
Materials and supplies	259	251
Notes receivable
Other	5	0
Regulatory assets	25	17
Prepaid property tax	84	44
Other	31	22
Total Current Assets	1,322	1,331
Investments
Nuclear decommissioning trust funds	1,246	1,236
Other	34	35
Total Investments	1,280	1,271
Property
Property, plant, and equipment	21,476	21,391
Less accumulated depreciation and amortization	(7,681)	(7,646)
Property, plant and equipment, net	13,795	13,745
Other Assets
Regulatory assets	2,981	2,969
Intangible assets	38	34
Prepaid postretirement costs — affiliates	24	24
Other	119	144
Total Noncurrent Assets	3,162	3,171
Total Assets	19,559	19,518
Accounts payable
Affiliates	56	40
Other	288	329
Accrued interest	66	62
Current portion long-term debt, including capital leases	148	157
Regulatory liabilities	27	19
Short-term borrowings
Affiliates	97	75
Other	211	272
Other	122	138
Total Current Liabilities	1,015	1,092
Long-Term Debt (net of current portion)
Mortgage bonds, notes, and other	5,438	5,437
Capital lease obligations	12	15
Total Long-Term Debt (net of current portion)	5,450	5,452
Other Liabilities
Deferred income taxes	3,566	3,498
Regulatory liabilities	213	199
Asset retirement obligations	2,049	2,020
Unamortized investment tax credit	56	58
Nuclear decommissioning	179	177
Accrued pension liability — affiliates	979	976
Accrued postretirement liability — affiliates	288	307
Other	69	66
Total Noncurrent Liabilities	$ 7,399	$ 7,301
Commitments and Contingencies
Equity
Common stock	$ 4,086	$ 4,086
Retained earnings	1,607	1,585
Accumulated other comprehensive income (loss)	2	2
Total DTE Energy Company Equity	5,695	5,673
Total Liabilities and Equity	$ 19,559	$ 19,518

Consolidated Statements of Fin6

Consolidated Statements of Financial Position (Unaudited) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Allowance for doubtful accounts	$ 42	$ 49
Shareholder’s Equity
Common stock, par value (in dollars per share)
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	179,435,404	179,470,213
Common stock, shares outstanding (in shares)	179,435,404	179,470,213
DTE Electric
Allowance for doubtful accounts	$ 26	$ 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 Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating Activities
Net Income	$ 240	$ 274
Net Income (Loss)	247	273
Adjustments to reconcile Net Income to net cash from operating activities:
Depreciation and amortization	229	209
Nuclear fuel amortization	15	13
Allowance for equity funds used during construction	(5)	(5)
Deferred income taxes	80	84
Equity earnings of equity method investees	(15)	(16)
Dividends from equity method investees	18	16
Asset (gains) losses and impairments, net	0	(10)
Changes in assets and liabilities:
Accounts receivable, net	97	(8)
Inventories	143	172
Accounts payable	(93)	(123)
Gas inventory equalization	87	130
Accrued pension liability	(3)	2
Accrued postretirement liability	(29)	(135)
Derivative assets and liabilities	40	49
Regulatory assets and liabilities	34	(4)
Other current and noncurrent assets and liabilities	(97)	99
Net cash from operating activities	741	747
Investing Activities
Plant and equipment expenditures — utility	(394)	(366)
Plant and equipment expenditures — non-utility	(30)	(39)
Acquisition	0	(240)
Proceeds from sale of assets	0	13
Restricted cash for debt redemption, principally Securitization, net	0	96
Proceeds from sale of nuclear decommissioning trust fund assets	260	246
Investment in nuclear decommissioning trust funds	(262)	(250)
Distributions from equity method investees	3	3
Contributions to equity method investees	(26)	(22)
Other	12	3
Net cash used for investing activities	(437)	(556)
Financing Activities
Issuance of long-term debt, net of issuance costs	0	495
Redemption of long-term debt	(11)	(117)
Short-term borrowings, net	(134)	(398)
Issuance of common stock	0	9
Repurchase of common stock	(33)	0
Dividends on common stock	(131)	(122)
Other	3	(7)
Net cash from (used for) financing activities	(306)	(140)
Net Increase (Decrease) in Cash and Cash Equivalents	(2)	51
Cash and Cash Equivalents at Beginning of Period	37	48
Cash and Cash Equivalents at End of Period	35	99
Supplemental disclosure of non-cash investing and financing activities
Plant and equipment expenditures in accounts payable	134	186
DTE Electric
Operating Activities
Net Income (Loss)	127	137
Adjustments to reconcile Net Income to net cash from operating activities:
Depreciation and amortization	176	155
Nuclear fuel amortization	15	13
Allowance for equity funds used during construction	(4)	(5)
Deferred income taxes	70	76
Changes in assets and liabilities:
Accounts receivable, net	57	(3)
Inventories	31	2
Accounts payable	25	(8)
Accrued pension liability — affiliates	3	(88)
Accrued postretirement liability — affiliates	(19)	(128)
Regulatory assets and liabilities	40	(43)
Other current and noncurrent assets and liabilities	(68)	65
Net cash from operating activities	453	173
Investing Activities
Plant and equipment expenditures	(315)	(311)
Acquisition	0	(240)
Proceeds from sale of assets	6	0
Restricted cash for debt redemption, principally Securitization, net	0	96
Notes receivable from affiliate	0	8
Proceeds from sale of nuclear decommissioning trust fund assets	260	246
Investment in nuclear decommissioning trust funds	(262)	(250)
Transfer of Rabbi Trust assets to affiliate	0	137
Other	14	2
Net cash used for investing activities	(297)	(312)
Financing Activities
Issuance of long-term debt, net of issuance costs	0	496
Redemption of long-term debt	(10)	(115)
Short-term borrowings, net — affiliate	22	(49)
Short-term borrowings, net — other	(61)	(50)
Dividends on common stock	(105)	(99)
Other	0	(4)
Net cash from (used for) financing activities	(154)	179
Net Increase (Decrease) in Cash and Cash Equivalents	2	40
Cash and Cash Equivalents at Beginning of Period	15	14
Cash and Cash Equivalents at End of Period	17	54
Supplemental disclosure of non-cash investing and financing activities
Plant and equipment expenditures in accounts payable	$ 100	$ 154

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity (Unaudited) - 3 months ended Mar. 31, 2016 - USD ($) $ in Millions	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Non-Controlling Interests	DTE Electric	DTE ElectricCommon Stock	DTE ElectricAdditional Paid-in Capital	DTE ElectricRetained Earnings	DTE ElectricAccumulated Other Comprehensive Income (Loss)
Beginning Balance, shares at Dec. 31, 2015	179,470,213	179,470,000				138,632,324	138,632,000
Beginning Balance at Dec. 31, 2015	$ 8,795	$ 4,123	$ 4,794	$ (145)	$ 23
Beginning Balance at Dec. 31, 2015	8,772					$ 5,673	$ 1,386	$ 2,700	$ 1,585	$ 2
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	240		247		(7)
Net Income (Loss)	247					127			127
Dividends declared on common stock	(131)		(131)			$ (105)			(105)
Repurchase of common stock, Shares		(394,000)
Repurchase of common stock	(33)	$ (33)
Benefit obligations, net of tax	3			3
Foreign currency translation	2			2
Stock-based compensation, net contributions from noncontrolling interests, and other, Shares		359,000
Stock-based compensation, net contributions from noncontrolling interests, and other	$ 34	$ 28	(1)		7
Ending Balance, shares at Mar. 31, 2016	179,435,404	179,435,000				138,632,324	138,632,000
Ending Balance at Mar. 31, 2016	$ 8,910	$ 4,118	$ 4,909	$ (140)	$ 23
Ending Balance at Mar. 31, 2016	$ 8,887					$ 5,695	$ 1,386	$ 2,700	$ 1,607	$ 2

Organization and Basis of Prese

Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	ORGANIZATION AND BASIS OF PRESENTATION Corporate Structure DTE Energy owns the following businesses: • DTE Electric is a public utility engaged in the generation, purchase, distribution, and sale of electricity to approximately 2.2 million customers in southeastern Michigan; • DTE Gas is a public utility engaged in the purchase, storage, transportation, distribution, and sale of natural gas to approximately 1.2 million customers throughout Michigan and the sale of storage and transportation capacity; and • Other businesses involved in 1) natural gas pipelines, gathering, and storage; 2) power and industrial projects; and 3) energy marketing and trading operations. DTE Electric and DTE Gas are regulated by the MPSC. Certain activities of DTE Electric and DTE Gas, as well as various other aspects of businesses under DTE Energy are regulated by the FERC. In addition, the Registrants are regulated by other federal and state regulatory agencies including the NRC, the EPA, the MDEQ, and the CFTC. Basis of Presentation The Consolidated Financial Statements should be read in conjunction with the Combined Notes to Consolidated Financial Statements included in the combined DTE Energy and DTE Electric 2015 Annual Report on Form 10-K. The accompanying Consolidated Financial Statements of the Registrants are prepared using accounting principles generally accepted in the United States of America. These accounting principles require management to use estimates and assumptions that impact reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from the Registrants' estimates. The Consolidated Financial Statements are unaudited but, in the Registrants' opinions include all adjustments necessary to present a fair statement of the results for the interim periods. All adjustments are of a normal recurring nature, except as otherwise disclosed in these Consolidated Financial Statements and Combined Notes to Consolidated Financial Statements. Financial results for this interim period are not necessarily indicative of results that may be expected for any other interim period or for the fiscal year ending December 31, 2016 . The information in these combined notes relates to each of the Registrants as noted in the Index of Combined Notes to Consolidated Financial Statements. However, DTE Electric does not make any representation as to information related solely to DTE Energy or the subsidiaries of DTE Energy other than itself. Certain prior year balances for the Registrants were reclassified to match the current year's Consolidated Financial Statements presentation. Such revisions include amounts reclassified to separate Operating Revenues and Fuel, purchased power, and gas between Utility operations and Non-utility operations and from Operations and maintenance to Fuel, purchased power, and gas — non-utility related to the Power and Industrial Projects segment. The reclassifications did not affect DTE Energy's Net Income for the prior periods, as such, they are not deemed material to the previously issued Consolidated Financial Statements. For reclassifications of debt issuance costs arising from ASU 2015-03, see Note 3 to the Consolidated Financial Statements, " New Accounting Pronouncements ." Principles of Consolidation The Registrants consolidate all majority-owned subsidiaries and investments in entities in which they have controlling influence. Non-majority owned investments are accounted for using the equity method when the Registrants are able to significantly influence the operating policies of the investee. When the Registrants do not influence the operating policies of an investee, the cost method is used. These Consolidated Financial Statements also reflect the Registrants' proportionate interests in certain jointly-owned utility plants. The Registrants eliminate all intercompany balances and transactions. The Registrants evaluate whether an entity is a VIE whenever reconsideration events occur. The Registrants consolidate VIEs for which they are the primary beneficiary. If a Registrant is not the primary beneficiary and an ownership interest is held, the VIE is accounted for under the equity method of accounting. When assessing the determination of the primary beneficiary, a Registrant considers all relevant facts and circumstances, including: the power, through voting or similar rights, to direct the activities of the VIE that most significantly impact the VIE's economic performance and the obligation to absorb the expected losses and/or the right to receive the expected returns of the VIE. The Registrants perform ongoing reassessments of all VIEs to determine if the primary beneficiary status has changed. Legal entities within DTE Energy's Power and Industrial Projects segment enter into long-term contractual arrangements with customers to supply energy-related products or services. The entities are generally designed to pass-through the commodity risk associated with these contracts to the customers, with DTE Energy retaining operational and customer default risk. These entities generally are VIEs and consolidated when DTE Energy is the primary beneficiary. In addition, DTE Energy has interests in certain VIEs through which control of all significant activities is shared with partners, and therefore are accounted for under the equity method. DTE Energy has variable interests in VIEs through certain of its long-term purchase and sale contracts. DTE Electric has variable interests in VIEs through certain of its long-term purchase contracts. As of March 31, 2016 , the carrying amount of assets and liabilities in DTE Energy's Consolidated Statements of Financial Position that relate to its variable interests under long-term purchase and sale contracts are predominantly related to working capital accounts and generally represent the amounts owed by or to DTE Energy for the deliveries associated with the current billing cycle under the contracts. As of March 31, 2016 , the carrying amount of assets and liabilities in DTE Electric's Consolidated Statements of Financial Position that relate to its variable interests under long-term purchase contracts are predominantly related to working capital accounts and generally represent the amounts owed by DTE Electric for the deliveries associated with the current billing cycle under the contracts. The Registrants have not provided any significant form of financial support associated with these long-term contracts. There is no significant potential exposure to loss as a result of DTE Energy's variable interests through these long-term purchase and sale contracts. In addition, there is no significant potential exposure to loss as a result of DTE Electric's variable interests through these long-term purchase contracts. The maximum risk exposure for consolidated VIEs is reflected on the Registrants' Consolidated Statements of Financial Position. For non-consolidated VIEs, the maximum risk exposure is generally limited to its investment, notes receivable, and future funding commitments. The following table summarizes the major Consolidated Statements of Financial Position items for consolidated VIEs as of March 31, 2016 and December 31, 2015 . All assets and liabilities of a consolidated VIE are presented where it has been determined that a consolidated VIE has either (1) assets that can be used only to settle obligations of the VIE or (2) liabilities for which creditors do not have recourse to the general credit of the primary beneficiary. VIEs, in which DTE Energy holds a majority voting interest and is the primary beneficiary, that meet the definition of a business and whose assets can be used for purposes other than the settlement of the VIE's obligations have been excluded from the table below. March 31, 2016 December 31, 2015 (In millions) ASSETS Cash and cash equivalents $ 9 $ 14 Restricted cash 7 8 Accounts receivable 14 18 Inventories 70 82 Property, plant, and equipment, net 62 66 Other current and long-term assets 3 4 $ 165 $ 192 LIABILITIES Accounts payable and accrued current liabilities $ 8 $ 13 Current portion long-term debt, including capital leases 7 8 Mortgage bonds, notes, and other 8 10 Other current and long-term liabilities 6 6 $ 29 $ 37 Amounts for DTE Energy's non-consolidated VIEs as of March 31, 2016 and December 31, 2015 are as follows: March 31, 2016 December 31, 2015 (In millions) Investment in equity method investees $ 194 $ 136 Notes receivable $ 15 $ 15 Future funding commitments $ 9 $ —

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES Other Income Other income for the Registrants is recognized for non-operating income such as equity earnings, allowance for equity funds used during construction, and contract services. DTE Energy's Power and Industrial Projects segment also recognizes Other income in connection with the sale of membership interests in reduced emissions fuel facilities to investors. In exchange for the cash received, the investors will receive a portion of the economic attributes of the facilities, including income tax attributes. The transactions are not treated as a sale of membership interests for financial reporting purposes. Other income is considered earned when refined coal is produced and tax credits are generated. Power and Industrial Projects recognized approximately $19 million of Other income for the three months ended March 31, 2016 and 2015, respectively . Changes in Accumulated Other Comprehensive Income (Loss) For the three months ended March 31, 2016 and 2015 , reclassifications out of Accumulated other comprehensive income (loss) for the Registrants were not material. Changes in Accumulated other comprehensive income (loss) are presented in DTE Energy's Consolidated Statements of Changes in Equity and DTE Electric's Consolidated Statements of Changes in Shareholder's Equity. Income Taxes The effective tax rate and unrecognized tax benefits of the Registrants are as follows: Effective Tax Rate Unrecognized Tax Benefits Three Months Ended March 31, March 31, 2016 2015 2016 (In millions) DTE Energy 26 % 31 % $ 3 DTE Electric 36 % 35 % $ 4 The 5% decrease in DTE Energy's effective tax rate for the three months ended March 31, 2016 is primarily due to higher production tax credits in 2016. DTE Energy had $2 million of unrecognized tax benefits that, if recognized, would favorably impact its effective tax rate. DTE Electric had $3 million of unrecognized tax benefits that, if recognized, would favorably impact its effective tax rate. The Registrants do not anticipate any material changes to the unrecognized tax benefits in the next twelve months. DTE Electric had income tax receivables with DTE Energy of $6 million at March 31, 2016 and December 31, 2015 , respectively. Unrecognized Compensation Costs As of March 31, 2016 , DTE Energy had $82 million of total unrecognized compensation cost related to non-vested stock incentive plan arrangements. That cost is expected to be recognized over a weighted-average period of 1.79 years . Allocated Stock-Based Compensation DTE Electric received an allocation of costs from DTE Energy associated with stock-based compensation of $10 million and $4 million for the three months ended March 31, 2016 and 2015, respectively .

New Accounting Pronouncements

New Accounting Pronouncements	3 Months Ended
	Mar. 31, 2016
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements	NEW ACCOUNTING PRONOUNCEMENTS Recently Adopted Pronouncements In February 2015, the FASB issued ASU No. 2015-02, Amendments to the Consolidation Analysis , which changes the analysis that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. The ASU affects (1) limited partnerships and similar legal entities, (2) evaluating fees paid to a decision maker or a service provider as a variable interest, (3) the effect of fee arrangements on the primary beneficiary determination, (4) the effect of related parties on the primary beneficiary determination, and (5) certain investment funds. It is effective for the Registrants for the first interim period within annual reporting periods beginning after December 15, 2015. The Registrants adopted this ASU at January 1, 2016. The implementation of this guidance is reflected in Note 1 of the Consolidated Financial Statements, " Organization and Basis of Presentation ." Certain entities are now deemed to be VIEs and are included in DTE Energy's non-consolidated VIE table. This implementation did not have a significant impact on the Registrants' Consolidated Financial Statements. In April 2015, the FASB issued ASU No. 2015-03, Simplifying the Presentation of Debt Issuance Costs . This ASU requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. This ASU is effective for reporting periods beginning after December 15, 2015, and interim periods therein. It is to be applied retrospectively. The Registrants adopted this ASU at January 1, 2016. The effect of the adoption decreased assets and liabilities on DTE Energy’s and DTE Electric’s Consolidated Statements of Financial Position by $75 million and $36 million , respectively, at December 31, 2015. In May 2015, the FASB issued ASU 2015-07, Fair Value Measurement (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent). This guidance removes the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share (or its equivalent) practical expedient. The guidance applies to investments for which there is not a readily determinable fair value (market quote) or the investment is in a mutual fund without a publicly available net asset value. It is effective for the Registrants for the first interim period within annual reporting periods beginning after December 15, 2015. It is to be applied retrospectively. The Registrants adopted this ASU at January 1, 2016. The implementation of this guidance is reflected in Note 6 of the Consolidated Financial Statements, " Fair Value ." This implementation did not have a significant impact on the Registrants' Consolidated Financial Statements. Recently Issued Pronouncements In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers. The objectives of this ASU are to improve upon revenue recognition requirements by providing a single comprehensive model to determine the measurement of revenue and timing of recognition. The core principle is that an entity will recognize revenue to depict the transfer of goods or services to customers at an amount that the entity expects to be entitled to in exchange for those goods or services. This ASU also requires expanded qualitative and quantitative disclosures regarding the nature, amount, timing, and uncertainty of revenues and cash flows arising from contracts with customers. In July 2015, the FASB deferred implementation of the revenue standard to be effective for the first interim period within annual reporting periods beginning after December 15, 2017. The standard is to be applied retrospectively and early adoption is permitted in the preceding year. In March 2016, the FASB issued an ASU that amends and clarifies the implementation guidance on principal versus agent considerations for reporting revenue gross rather than net. In April 2016, the FASB issued an ASU that amends and clarifies the identification of performance obligations and accounting for licenses of intellectual property. Both ASUs issued in 2016 have the same deferred effective date. The Registrants are currently assessing the impact of these ASUs on their Consolidated Financial Statements. In July 2015, the FASB issued ASU No. 2015-11, Inventory (Topic 330), Simplifying the Measurement of Inventory . The ASU replaces the current lower of cost or market test with a lower of cost or net realizable value test when cost is determined on a first-in, first-out or average cost basis. The standard is effective for public entities for annual reporting periods beginning after December 15, 2016, and interim periods therein. It is to be applied prospectively and early adoption is permitted. The ASU will not have a significant impact on the Registrants' Consolidated Financial Statements. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments — Overall: Recognition and Measurement of Financial Assets and Financial Liabilities. The new guidance is intended to improve the recognition and measurement of financial instruments. The ASU primarily impacts accounting for equity investments in unconsolidated entities (other than those accounted for using the equity method of accounting) and financial liabilities under the fair value option. Under the new guidance, equity investments will generally be measured at fair value, with subsequent changes in fair value recognized in net income. The ASU is effective for fiscal years and interim periods within those years beginning after December 15, 2017. Upon adoption, entities will be required to make a cumulative-effect adjustment to the Statements of Financial Position as of the beginning of the first reporting period in which the guidance is effective. Changes to the accounting for equity securities without a readily determinable fair value will be applied prospectively. The Registrants are currently assessing the impact of this ASU on their Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), a replacement of Leases (Topic 840) . This guidance requires a lessee to account for leases as finance or operating leases. Both leases will result in the lessee recognizing a right-of-use asset and a corresponding lease liability on its balance sheet, with differing methodology for income statement recognition. For lessors, the standard modifies the classification criteria and the accounting for sales-type and direct financing leases. Entities will classify leases to determine how to recognize lease-related revenue and expense. This ASU is effective for public entities for fiscal years, and interim periods within those years, beginning after December 15, 2018, and early adoption is permitted. A modified retrospective approach is required for leases existing or entered into after the beginning of the earliest comparative period in the Consolidated Financial Statements. The Registrants are currently assessing the impact of this ASU on their Consolidated Financial Statements. In March 2016, the FASB issued ASU No. 2016-09, Compensation — Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The ASU simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the Statements of Cash Flows. Under the new standard, income tax benefits and deficiencies are to be recognized in the income statement and the tax effects of exercised or vested awards should be treated as discrete items in the reporting period in which they occur. This provision is to be applied prospectively. Excess tax benefits should be recognized regardless of whether the benefit reduces taxes payable in the current period, along with any valuation allowance, on a modified retrospective basis as a cumulative-effect adjustment to the retained earnings as of the date of adoption. Excess tax benefits should be classified along with other income tax cash flows as an operating activity. This provision can be applied prospectively or retrospectively for all periods presented. The standard is effective for public entities for annual reporting periods beginning after December 15, 2016, and interim periods therein. Early adoption is permitted. DTE Energy is currently assessing the impact of this ASU on its Consolidated Financial Statements.

Regulatory Matters

Regulatory Matters	3 Months Ended
	Mar. 31, 2016
Public Utilities, General Disclosures [Abstract]
Regulatory Matters	REGULATORY MATTERS 2014 Electric Rate Case Filing DTE Electric filed a rate case with the MPSC on December 19, 2014 requesting an increase in base rates of $370 million based on a projected twelve-month period ending June 30, 2016. The requested increase in base rates is due primarily to an increase in net plant resulting from infrastructure investments, plant acquisitions, environmental compliance, and reliability improvement projects. The rate filing also included projected changes in sales, working capital, operation and maintenance expenses, return on equity, and capital structure. On July 1, 2015, DTE Electric realized an annual revenue increase of $230 million consisting of $190 million of self-implemented base rate increase related to the December 19, 2014 rate request and $40 million associated with the required elimination of a credit surcharge. On December 11, 2015, the MPSC issued an order approving an annual revenue increase of $238 million for service rendered on or after December 17, 2015. The rate order also provided for a return on equity of 10.3% on a capital structure of 50% debt and 50% equity. On December 22, 2015, DTE Electric and other intervenors petitioned the MPSC for a rehearing and clarification of several issues related to the December 11, 2015 MPSC rate order. On February 23, 2016, the MPSC issued a final rehearing order in this case that adjusted the annual revenue increase to $243 million for service rendered on or after March 1, 2016. 2016 Electric Rate Case Filing DTE Electric filed a rate case with the MPSC on February 1, 2016 requesting an increase in base rates of $344 million based on a projected twelve-month period ending July 31, 2017. The requested increase in base rates is due primarily to an increase in net plant resulting from infrastructure investments, environmental compliance, and reliability improvement projects. The rate filing also includes projected changes in sales, operation and maintenance expenses, and working capital. The rate filing also requests an increase in return on equity from 10.3% to 10.5% on a capital structure of 50% equity and 50% debt. DTE Electric anticipates self-implementing a rate increase in August 2016 with an MPSC order expected by February 2017. 2015 DTE Gas Rate Case Filing DTE Gas filed a rate case with the MPSC on December 18, 2015 requesting an increase in base rates of $183 million , inclusive of $41 million of existing IRM surcharges which are expected to be converted into base rates, based on a projected twelve-month period ending October 31, 2017. The requested increase in base rates is due primarily to an increase in net plant, inclusive of IRM capital investments being recovered through approved IRM surcharge filings. The rate filing also includes projected changes in sales, operation and maintenance expenses, and working capital. The rate filing also requests an increase in return on equity from 10.5% to 10.75% on a capital structure of 52% equity and 48% debt. DTE Gas anticipates self-implementing a rate increase in November 2016 with an MPSC order expected by December 2016. Concurrent with the MPSC order in this rate case, the existing IRM surcharge being billed will be terminated. However, DTE Gas requested to implement a new IRM surcharge of approximately $9 million to become effective in January 2017.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE DTE Energy reports both basic and diluted earnings per share. The calculation of diluted earnings per share assumes the issuance of potentially dilutive common shares outstanding during the period from the exercise of stock options. A reconciliation of both calculations is presented in the following table: Three Months Ended March 31, 2016 2015 (In millions, except per share amounts) Basic Earnings per Share Net Income Attributable to DTE Energy Company $ 247 $ 273 Average number of common shares outstanding 179 178 Dividends declared — common shares $ 131 $ 123 Dividends declared — net restricted shares — 1 Total distributed earnings $ 131 $ 124 Net Income less distributed earnings $ 116 $ 149 Distributed (dividends per common share) $ 0.73 $ 0.69 Undistributed 0.65 0.84 Total Basic Earnings per Common Share $ 1.38 $ 1.53 Diluted Earnings per Share Net Income Attributable to DTE Energy Company $ 247 $ 273 Average number of common shares outstanding 180 178 Dividends declared — common shares $ 131 $ 123 Dividends declared — net restricted shares — 1 Total distributed earnings $ 131 $ 124 Net Income less distributed earnings $ 116 $ 149 Distributed (dividends per common share) $ 0.73 $ 0.69 Undistributed 0.64 0.84 Total Diluted Earnings per Common Share $ 1.37 $ 1.53

Fair Value

Fair Value	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value	FAIR VALUE Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date in a principal or most advantageous market. Fair value is a market-based measurement that is determined based on inputs, which refer broadly to assumptions that market participants use in pricing assets or liabilities. These inputs can be readily observable, market corroborated, or generally unobservable inputs. The Registrants make certain assumptions they believe that market participants would use in pricing assets or liabilities, including assumptions about risk, and the risks inherent in the inputs to valuation techniques. Credit risk of the Registrants and their counterparties is incorporated in the valuation of assets and liabilities through the use of credit reserves, the impact of which was immaterial at March 31, 2016 and December 31, 2015 . The Registrants believe they use valuation techniques that maximize the use of observable market-based inputs and minimize the use of unobservable inputs. A fair value hierarchy has been established that prioritizes the inputs to valuation techniques used to measure fair value in three broad levels. The fair value hierarchy gives the highest priority to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). In some cases, the inputs used to measure fair value might fall in different levels of the fair value hierarchy. All assets and liabilities are required to be classified in their entirety based on the lowest level of input that is significant to the fair value measurement in its entirety. Assessing the significance of a particular input may require judgment considering factors specific to the asset or liability, and may affect the valuation of the asset or liability and its placement within the fair value hierarchy. The Registrants classify fair value balances based on the fair value hierarchy defined as follows: • Level 1 — Consists of unadjusted quoted prices in active markets for identical assets or liabilities that the Registrants have the ability to access as of the reporting date. • Level 2 — Consists of inputs other than quoted prices included within Level 1 that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data. • Level 3 — Consists of unobservable inputs for assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost-benefit constraints. The following table presents assets and liabilities for DTE Energy measured and recorded at fair value on a recurring basis as of March 31, 2016 and December 31, 2015 : March 31, 2016 December 31, 2015 Level Level Level Other Netting Net Balance Level Level Level Other Netting Net Balance (In millions) Assets: Cash equivalents (c) $ 11 $ 3 $ — $ — $ — $ 14 $ 13 $ 3 $ — $ — $ — $ 16 Nuclear decommissioning trusts 752 491 — 3 — 1,246 759 473 — 4 — 1,236 Other investments (d) 154 — — — — 154 149 — — — — 149 Derivative assets: Commodity Contracts: Natural Gas 133 89 76 — (216 ) 82 193 91 103 — (285 ) 102 Electricity — 305 72 — (299 ) 78 — 239 68 — (232 ) 75 Other 3 — 1 — (3 ) 1 2 — 3 — (2 ) 3 Foreign currency exchange contracts — 6 — — (5 ) 1 — 12 — — (9 ) 3 Total derivative assets 136 400 149 — (523 ) 162 195 342 174 — (528 ) 183 Total $ 1,053 $ 894 $ 149 $ 3 $ (523 ) $ 1,576 $ 1,116 $ 818 $ 174 $ 4 $ (528 ) $ 1,584 Liabilities: Derivative liabilities: Commodity Contracts: Natural Gas $ (188 ) $ (52 ) $ (110 ) $ — $ 258 $ (92 ) $ (218 ) $ (57 ) $ (108 ) $ — $ 294 $ (89 ) Electricity — (308 ) (88 ) — 327 (69 ) — (243 ) (62 ) — 253 (52 ) Other (5 ) — (8 ) — 12 (1 ) (2 ) — (8 ) — 8 (2 ) Foreign currency exchange contracts — (4 ) — — 3 (1 ) — (7 ) — — 7 — Total derivative liabilities (193 ) (364 ) (206 ) — 600 (163 ) (220 ) (307 ) (178 ) — 562 (143 ) Total $ (193 ) $ (364 ) $ (206 ) $ — $ 600 $ (163 ) $ (220 ) $ (307 ) $ (178 ) $ — $ 562 $ (143 ) Net Assets (Liabilities) at the end of the period $ 860 $ 530 $ (57 ) $ 3 $ 77 $ 1,413 $ 896 $ 511 $ (4 ) $ 4 $ 34 $ 1,441 Assets: Current $ 118 $ 325 $ 98 $ — $ (418 ) $ 123 $ 174 $ 284 $ 128 $ — $ (441 ) $ 145 Noncurrent 935 569 51 3 (105 ) 1,453 942 534 46 4 (87 ) 1,439 Total Assets $ 1,053 $ 894 $ 149 $ 3 $ (523 ) $ 1,576 $ 1,116 $ 818 $ 174 $ 4 $ (528 ) $ 1,584 Liabilities: Current $ (150 ) $ (296 ) $ (99 ) $ — $ 478 $ (67 ) $ (174 ) $ (260 ) $ (87 ) $ — $ 464 $ (57 ) Noncurrent (43 ) (68 ) (107 ) — 122 (96 ) (46 ) (47 ) (91 ) — 98 (86 ) Total Liabilities $ (193 ) $ (364 ) $ (206 ) $ — $ 600 $ (163 ) $ (220 ) $ (307 ) $ (178 ) $ — $ 562 $ (143 ) Net Assets (Liabilities) at the end of the period $ 860 $ 530 $ (57 ) $ 3 $ 77 $ 1,413 $ 896 $ 511 $ (4 ) $ 4 $ 34 $ 1,441 _______________________________________ (a) Amounts represent assets valued at NAV as a practical expedient for fair value. (b) Amounts represent the impact of master netting agreements that allow DTE Energy to net gain and loss positions and cash collateral held or placed with the same counterparties. (c) At March 31, 2016 , available-for-sale securities of $14 million included $7 million and $7 million of cash equivalents included in Restricted cash and Other investments on DTE Energy's Consolidated Statements of Financial Position, respectively. At December 31, 2015 , available-for-sale securities of $16 million , included $8 million and $8 million of cash equivalents included in Restricted cash and Other investments on DTE Energy's Consolidated Statements of Financial Position, respectively. (d) Excludes cash surrender value of life insurance investments. The following table presents assets for DTE Electric measured and recorded at fair value on a recurring basis as of March 31, 2016 and December 31, 2015 : March 31, 2016 December 31, 2015 Level 1 Level 2 Level 3 Other Net Balance Level 1 Level 2 Level 3 Other Net Balance (In millions) Assets: Cash equivalents (b) $ 4 $ 3 $ — $ — $ 7 $ 5 $ 3 $ — $ — $ 8 Nuclear decommissioning trusts 752 491 — 3 1,246 759 473 — 4 1,236 Other investments 8 — — — 8 8 — — — 8 Derivative assets — FTRs — — 1 — 1 — — 3 — 3 Total $ 764 $ 494 $ 1 $ 3 $ 1,262 $ 772 $ 476 $ 3 $ 4 $ 1,255 Assets: Current $ 4 $ 3 $ 1 $ — $ 8 $ 5 $ 3 $ 3 $ — $ 11 Noncurrent 760 491 — 3 1,254 767 473 — 4 1,244 Total Assets $ 764 $ 494 $ 1 $ 3 $ 1,262 $ 772 $ 476 $ 3 $ 4 $ 1,255 _______________________________________ (a) Amounts represent assets valued at NAV as a practical expedient for fair value. (b) At March 31, 2016 , available-for-sale securities of $7 million consisted of cash equivalents included in Other investments on DTE Electric's Consolidated Statements of Financial Position. At December 31, 2015 , available-for-sale securities of $8 million consisted of cash equivalents included in Other investments on DTE Electric's Consolidated Statements of Financial Position. 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 and commingled funds. Exchange-traded debt and equity securities held directly are valued using quoted market prices in actively traded markets. Non-exchange-traded fixed income securities are valued based upon quotations available from brokers or pricing services. The institutional mutual funds hold exchange-traded equity or debt securities (exchange and non-exchange traded) and are valued based on publicly available NAVs. The commingled funds hold exchange-traded equity or debt securities (exchange and non-exchange traded) and are valued based on a calculated NAV as a practical expedient. A primary price source is identified by asset type, class, or issue for each security. The trustee monitors prices supplied by pricing services and may use a supplemental price source or change the primary price source of a given security if the trustee determines that another price source is considered to be preferable. The Registrants have obtained an understanding of how these prices are derived, including the nature and observability of the inputs used in deriving such prices. Additionally, the Registrants selectively corroborate the fair value of securities by comparison of market-based price sources. Investment policies and procedures are determined by DTE Energy's Trust Investments Department which reports to DTE Energy's Vice President and Treasurer. Derivative Assets and Liabilities Derivative assets and liabilities are comprised of physical and financial derivative contracts, including futures, forwards, options, and swaps that are both exchange-traded and over-the-counter traded contracts. Various inputs are used to value derivatives depending on the type of contract and availability of market data. Exchange-traded derivative contracts are valued using quoted prices in active markets. The Registrants consider the following criteria in determining whether a market is considered active: frequency in which pricing information is updated, variability in pricing between sources or over time, and the availability of public information. Other derivative contracts are valued based upon a variety of inputs including commodity market prices, broker quotes, interest rates, credit ratings, default rates, market-based seasonality, and basis differential factors. The Registrants monitor the prices that are supplied by brokers and pricing services and may use a supplemental price source or change the primary price source of an index if prices become unavailable or another price source is determined to be more representative of fair value. The Registrants have obtained an understanding of how these prices are derived. Additionally, the Registrants selectively corroborate the fair value of their transactions by comparison of market-based price sources. Mathematical valuation models are used for derivatives for which external market data is not readily observable, such as contracts which extend beyond the actively traded reporting period. The Registrants have established a Risk Management Committee whose responsibilities include directly or indirectly ensuring all valuation methods are applied in accordance with predefined policies. The development and maintenance of the Registrants' forward price curves has been assigned to DTE Energy's Risk Management Department, which is separate and distinct from the trading functions within DTE Energy. The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for DTE Energy for the three months ended March 31, 2016 and 2015 : Three Months Ended March 31, 2016 Three Months Ended March 31, 2015 Natural Gas Electricity Other Total Natural Gas Electricity Other Total (In millions) Net Assets (Liabilities) as of December 31 $ (5 ) $ 6 $ (5 ) $ (4 ) $ 30 $ (5 ) $ (1 ) $ 24 Transfers into Level 3 from Level 2 — — — — — — (1 ) (1 ) Transfers from Level 3 into Level 2 (1 ) — — (1 ) — — — — Total gains (losses): Included in earnings (20 ) (58 ) (1 ) (79 ) (29 ) 7 (2 ) (24 ) Recorded in Regulatory assets — — (2 ) (2 ) — — (2 ) (2 ) Purchases, issuances, and settlements: Settlements (8 ) 36 1 29 (1 ) (9 ) 1 (9 ) Net Assets (Liabilities) as of March 31 $ (34 ) $ (16 ) $ (7 ) $ (57 ) $ — $ (7 ) $ (5 ) $ (12 ) The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31, 2016 and 2015 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations $ (72 ) $ (3 ) $ (1 ) $ (76 ) $ (91 ) $ (3 ) $ (2 ) $ (96 ) The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for DTE Electric for the three months ended March 31, 2016 and 2015 : Three Months Ended March 31, 2016 2015 (In millions) Net Assets as of December 31 $ 3 $ 3 Change in fair value recorded in Regulatory assets (2 ) (2 ) Purchases, issuances, and settlements: Settlements — — Net Assets as of March 31 $ 1 $ 1 The amount of total gains (losses) included in Regulatory assets attributed to the change in unrealized gains (losses) related to assets held at March 31, 2016 and 2015 and reflected in DTE Electric's Consolidated Statements of Financial Position $ — $ — Derivatives are transferred between levels primarily due to changes in the source data used to construct price curves as a result of changes in market liquidity. Transfers in and transfers out are reflected as if they had occurred at the beginning of the period. There were no transfers between Levels 1 and 2 for the Registrants during the three months ended March 31, 2016 and 2015 , and there were no transfers from or into Level 3 for DTE Electric during the same periods. The following tables present the unobservable inputs related to DTE Energy's Level 3 assets and liabilities as of March 31, 2016 and December 31, 2015 : March 31, 2016 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 76 $ (110 ) Discounted Cash Flow Forward basis price (per MMBtu) $ (1.21 ) — $ 3.62 /MMBtu $ (0.12 )/MMBtu Electricity $ 72 $ (88 ) Discounted Cash Flow Forward basis price (per MWh) $ (14 ) — $ 13 /MWh $ 1 /MWh December 31, 2015 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 103 $ (108 ) Discounted Cash Flow Forward basis price (per MMBtu) $ (1.50 ) — $ 2.77 /MMBtu $ (0.19 )/MMBtu Electricity $ 68 $ (62 ) Discounted Cash Flow Forward basis price (per MWh) $ (11 ) — $ 14 /MWh $ 2 /MWh The unobservable inputs used in the fair value measurement of the electricity and natural gas commodity types consist of inputs that are less observable due in part to lack of available broker quotes, supported by little, if any, market activity at the measurement date or are based on internally developed models. Certain basis prices (i.e., the difference in pricing between two locations) included in the valuation of natural gas and electricity contracts were deemed unobservable. The inputs listed above would have a direct impact on the fair values of the above security types if they were adjusted. A significant increase (decrease) in the basis price would result in a higher (lower) fair value for long positions, with offsetting impacts to short positions. Fair Value of Financial Instruments The fair value of financial instruments included in the table below is determined by using quoted market prices when available. When quoted prices are not available, pricing services may be used to determine the fair value with reference to observable interest rate indexes. The Registrants have obtained an understanding of how the fair values are derived. The Registrants also selectively corroborate the fair value of their transactions by comparison of market-based price sources. Discounted cash flow analyses based upon estimated current borrowing rates are also used to determine fair value when quoted market prices are not available. The fair values of notes receivable, excluding capital leases, are generally estimated using discounted cash flow techniques that incorporate market interest rates as well as assumptions about the remaining life of the loans and credit risk. Depending on the information available, other valuation techniques may be used that rely on internal assumptions and models. Valuation policies and procedures for the Registrants are determined by DTE Energy's Treasury Department which reports to DTE Energy's Vice President and Treasurer. The following table presents the carrying amount and fair value of financial instruments for DTE Energy as of March 31, 2016 and December 31, 2015 : March 31, 2016 December 31, 2015 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 $ 32 $ — $ — $ 32 $ 32 $ — $ — $ 32 Dividends payable $ 131 $ 131 $ — $ — $ 131 $ 131 $ — $ — Short-term borrowings $ 365 $ — $ 365 $ — $ 499 $ — $ 499 $ — Long-term debt, excluding capital leases $ 9,201 $ 495 $ 8,353 $ 1,299 $ 9,210 $ 496 $ 8,136 $ 1,203 The following table presents the carrying amount and fair value of financial instruments for DTE Electric as of March 31, 2016 and December 31, 2015 : March 31, 2016 December 31, 2015 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 $ 5 $ — $ — $ 5 $ 5 $ — $ — $ 5 Short-term borrowings — affiliates $ 97 $ — $ — $ 97 $ 75 $ — $ — $ 75 Short-term borrowings — other $ 211 $ — $ 211 $ — 272 $ — $ 272 $ — Long-term debt, excluding capital leases $ 5,579 $ — $ 5,501 $ 717 $ 5,588 $ — $ 5,432 $ 545 For further fair value information on financial and derivative instruments see Note 7 to the Consolidated Financial Statements, " Financial and Other Derivative Instruments ." Nuclear Decommissioning Trust Funds DTE Electric has a legal obligation to decommission its nuclear power plants following the expiration of its operating licenses. This obligation is reflected as an ARO on DTE Electric's Consolidated Statements of Financial Position. Rates approved by the MPSC provide for the recovery of decommissioning costs of Fermi 2 and the disposal of low-level radioactive waste. DTE Electric is continuing to fund FERC jurisdictional amounts for decommissioning even though explicit provisions are not included in FERC rates. The following table summarizes DTE Electric's fair value of the nuclear decommissioning trust fund assets: March 31, 2016 December 31, 2015 (In millions) Fermi 2 $ 1,220 $ 1,211 Fermi 1 3 3 Low-level radioactive waste 23 22 Total $ 1,246 $ 1,236 The costs of securities sold are determined on the basis of specific identification. The following table sets forth DTE Electric's gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds: Three Months Ended March 31, 2016 2015 (In millions) Realized gains $ 9 $ 9 Realized losses $ (15 ) $ (7 ) Proceeds from sales of securities $ 260 $ 246 Realized gains and losses from the sale of securities for Fermi 2 are recorded to the Regulatory asset and Nuclear decommissioning liability. Realized gains and losses from the sale of securities for low-level radioactive waste funds are recorded to the Nuclear decommissioning liability. The following table sets forth DTE Electric's fair value and unrealized gains and losses for the nuclear decommissioning trust funds: March 31, 2016 December 31, 2015 Fair Unrealized Unrealized Fair Unrealized Unrealized (In millions) Equity securities $ 728 $ 199 $ (68 ) $ 731 $ 195 $ (68 ) Debt securities 512 24 (2 ) 499 16 (4 ) Cash and cash equivalents 6 — — 6 — — $ 1,246 $ 223 $ (70 ) $ 1,236 $ 211 $ (72 ) The debt securities at March 31, 2016 and December 31, 2015 had an average maturity of approximately 6 years , respectively. Securities held in the Nuclear decommissioning trust funds are classified as available-for-sale. As DTE Electric does not have the ability to hold impaired investments for a period of time sufficient to allow for the anticipated recovery of market value, all unrealized losses are considered to be other-than-temporary impairments. Unrealized losses incurred by the Fermi 2 trust are recognized as a Regulatory asset and Nuclear decommissioning liability. Unrealized losses on the low-level radioactive waste funds are recognized as a Nuclear decommissioning liability. Other Securities At March 31, 2016 and December 31, 2015 , the Registrants' securities were comprised primarily of money market and equity securities. There were no unrealized losses on available-for-sale securities which were reclassified out of Other comprehensive income (loss) and realized into Net Income for DTE Energy or DTE Electric during the three months ended March 31, 2016 and 2015 . Gains related to trading securities held at March 31, 2016 and March 31, 2015 were $5 million and $1 million , respectively, for the Registrants. The trading gains or losses related to the Rabbi Trust assets, included in Other investments at DTE Energy, are allocated from DTE Energy to DTE Electric.

Financial and Other Derivative

Financial and Other Derivative Instruments	3 Months Ended
	Mar. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial and Other Derivative Instruments	FINANCIAL AND OTHER DERIVATIVE INSTRUMENTS The Registrants recognize all derivatives at their fair value as Derivative assets or liabilities on their respective Consolidated Statements of Financial Position unless they qualify for certain scope exceptions, including the normal purchases and normal sales exception. Further, derivatives that qualify and are designated for hedge accounting are classified as either hedges of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge); or as hedges of the fair value of a recognized asset or liability or of an unrecognized firm commitment (fair value hedge). For cash flow hedges, the portion of the derivative gain or loss that is effective in offsetting the change in the value of the underlying exposure is deferred in Accumulated other comprehensive income (loss) and later reclassified into earnings when the underlying transaction occurs. Gains or losses from the ineffective portion of cash flow hedges are recognized in earnings immediately. For fair value hedges, changes in fair values for the derivative and hedged item are recognized in earnings each period. For derivatives that do not qualify or are not designated for hedge accounting, changes in fair value are recognized in earnings each period. The Registrants’ primary market risk exposure is associated with commodity prices, credit, and interest rates. The Registrants have risk management policies to monitor and manage market risks. The Registrants use derivative instruments to manage some of the exposure. DTE Energy uses derivative instruments for trading purposes in its Energy Trading segment. Contracts classified as derivative instruments include electricity, natural gas, oil, certain coal forwards, futures, options, swaps, and foreign currency exchange contracts. Items not classified as derivatives include natural gas inventory, pipeline transportation contracts, renewable energy credits, and natural gas storage assets. DTE Electric — DTE Electric generates, purchases, distributes, and sells electricity. DTE Electric uses forward energy contracts to manage changes in the price of electricity and fuel. Substantially all of these contracts meet the normal purchases and normal sales exception and are therefore accounted for under the accrual method. Other derivative contracts are MTM and recoverable through the PSCR mechanism when settled. This results in the deferral of unrealized gains and losses as Regulatory assets or liabilities until realized. DTE Gas — DTE Gas purchases, stores, transports, distributes and sells natural gas, and sells storage and transportation capacity. DTE Gas has fixed-priced contracts for portions of its expected natural gas supply requirements through March 2019. Substantially all of these contracts meet the normal purchases and normal sales exception and are therefore accounted for under the accrual method. DTE Gas may also sell forward transportation and storage capacity contracts. Forward transportation and storage contracts are generally not derivatives and are therefore accounted for under the accrual method. Gas Storage and Pipelines — This segment is primarily engaged in services related to the transportation and storage of natural gas. Primarily fixed-priced contracts are used in the marketing and management of transportation and storage services. Generally these contracts are not derivatives and are therefore accounted for under the accrual method. Power and Industrial Projects — This segment manages and operates energy and pulverized coal projects, a coke battery, reduced emissions fuel projects, landfill gas recovery, and power generation assets. Primarily fixed-price contracts are used in the marketing and management of the segment assets. These contracts are generally not derivatives and are therefore accounted for under the accrual method. Energy Trading — Commodity Price Risk — Energy Trading markets and trades electricity, natural gas physical products, and energy financial instruments, and provides energy and asset management services utilizing energy commodity derivative instruments. Forwards, futures, options, and swap agreements are used to manage exposure to the risk of market price and volume fluctuations in its operations. These derivatives are accounted for by recording changes in fair value to earnings unless hedge accounting criteria are met. Energy Trading — Foreign Currency Exchange Risk — Energy Trading has foreign currency exchange forward contracts to economically hedge fixed Canadian dollar commitments existing under natural gas and power purchase and sale contracts and natural gas transportation contracts. Energy Trading enters into these contracts to mitigate price volatility with respect to fluctuations of the Canadian dollar relative to the U.S. dollar. These derivatives are accounted for by recording changes in fair value to earnings unless hedge accounting criteria are met. Corporate and Other — Interest Rate Risk — DTE Energy may use interest rate swaps, treasury locks, and other derivatives to hedge the risk associated with interest rate market volatility. Credit Risk — DTE Energy maintains credit policies that significantly minimize overall credit risk. These policies include an evaluation of potential customers’ and counterparties’ financial condition, including the viability of underlying productive assets, credit rating, collateral requirements, or other credit enhancements such as letters of credit or guarantees. DTE Energy generally uses standardized agreements that allow the netting of positive and negative transactions associated with a single counterparty. DTE Energy maintains a provision for credit losses based on factors surrounding the credit risk of its customers, historical trends, and other information. Based on DTE Energy's credit policies and its March 31, 2016 provision for credit losses, DTE Energy’s exposure to counterparty nonperformance is not expected to have a material adverse effect on DTE Energy's Consolidated Financial Statements. Derivative Activities DTE Energy manages its MTM risk on a portfolio basis based upon the delivery period of its contracts and the individual components of the risks within each contract. Accordingly, it records and manages the energy purchase and sale obligations under its contracts in separate components based on the commodity (e.g. electricity or natural gas), the product (e.g. electricity for delivery during peak or off-peak hours), the delivery location (e.g. by region), the risk profile (e.g. forward or option), and the delivery period (e.g. by month and year). The following describes the categories of activities represented by their operating characteristics and key risks: • Asset Optimization — Represents derivative activity associated with assets owned and contracted by DTE Energy, including forward natural gas purchases and sales, natural gas transportation, and storage capacity. Changes in the value of derivatives in this category typically economically offset changes in the value of underlying non-derivative positions, which do not qualify for fair value accounting. The difference in accounting treatment of derivatives in this category and the underlying non-derivative positions can result in significant earnings volatility. • Marketing and Origination — Represents derivative activity transacted by originating substantially hedged positions with wholesale energy marketers, producers, end-users, utilities, retail aggregators, and alternative energy suppliers. • Fundamentals Based Trading — Represents derivative activity transacted with the intent of taking a view, capturing market price changes, or putting capital at risk. This activity is speculative in nature as opposed to hedging an existing exposure. • Other — Includes derivative activity at DTE Electric related to FTRs. Changes in the value of derivative contracts at DTE Electric are recorded as Derivative assets or liabilities, with an offset to Regulatory assets or liabilities as the settlement value of these contracts will be included in the PSCR mechanism when realized. The following table presents the fair value of derivative instruments as of March 31, 2016 and December 31, 2015 for DTE Energy: March 31, 2016 December 31, 2015 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities (In millions) Derivatives not designated as hedging instruments: Foreign currency exchange contracts $ 6 $ (4 ) $ 12 $ (7 ) Commodity Contracts: Natural Gas 298 (350 ) 387 (383 ) Electricity 377 (396 ) 307 (305 ) Other 4 (13 ) 5 (10 ) Total derivatives not designated as hedging instruments: $ 685 $ (763 ) $ 711 $ (705 ) Current $ 527 $ (545 ) $ 570 $ (521 ) Noncurrent 158 (218 ) 141 (184 ) Total derivatives $ 685 $ (763 ) $ 711 $ (705 ) The following table presents the fair value of derivative instruments as of March 31, 2016 and December 31, 2015 for DTE Electric: March 31, 2016 December 31, 2015 (In millions) FTRs — Other current assets $ 1 $ 3 Total derivatives not designated as hedging instrument $ 1 $ 3 Certain of DTE Energy's derivative positions are subject to netting arrangements which provide for offsetting of asset and liability positions as well as related cash collateral. Such netting arrangements generally do not have restrictions. Under such netting arrangements, DTE Energy offsets the fair value of derivative instruments with cash collateral received or paid for those contracts executed with the same counterparty, which reduces DTE Energy's Total Assets and Liabilities. Cash collateral is allocated between the fair value of derivative instruments and customer accounts receivable and payable with the same counterparty on a pro-rata basis to the extent there is exposure. Any cash collateral remaining, after the exposure is netted to zero, is reflected in Accounts receivable and Accounts payable as collateral paid or received, respectively. DTE Energy also provides and receives collateral in the form of letters of credit which can be offset against net Derivative assets and liabilities as well as Accounts receivable and payable. DTE Energy had issued letters of credit of approximately $2 million and $7 million outstanding at March 31, 2016 and December 31, 2015 , respectively, which could be used to offset net Derivative liabilities. Letters of credit received from third parties which could be used to offset net Derivative assets were $2 million at March 31, 2016 and December 31, 2015 , respectively. Such balances of letters of credit are excluded from the tables below and are not netted with the recognized assets and liabilities in DTE Energy's Consolidated Statements of Financial Position. For contracts with certain clearing agents the fair value of derivative instruments is netted against realized positions with the net balance reflected as either 1) a Derivative asset or liability or 2) an Account receivable or payable. Other than certain clearing agents, Accounts receivable and Accounts payable that are subject to netting arrangements have not been offset against the fair value of Derivative assets and liabilities. Certain contracts that have netting arrangements have not been offset in DTE Energy's Consolidated Statements of Financial Position. The impact of netting these derivative instruments and cash collateral related to such contracts is not material. Only the gross amounts for these derivative instruments are included in the table below. For DTE Energy, the total cash collateral posted, net of cash collateral received, was $79 million and $37 million as of March 31, 2016 and December 31, 2015 , respectively. DTE Energy had $7 million of cash collateral related to unrealized positions to net against Derivative assets while Derivative liabilities are shown net of cash collateral of $84 million as of March 31, 2016 . DTE Energy had $2 million of cash collateral related to unrealized positions to net against Derivative assets while Derivative liabilities are shown net of cash collateral of $36 million as of December 31, 2015 . DTE Energy recorded cash collateral paid of $5 million and cash collateral received of $3 million not related to unrealized derivative positions as of March 31, 2016 . DTE Energy recorded cash collateral paid of $6 million and cash collateral received of $3 million not related to unrealized derivative positions as of December 31, 2015 . These amounts are included in Accounts receivable and Accounts payable and are recorded net by counterparty. The following table presents the netting offsets of Derivative assets and liabilities for DTE Energy at March 31, 2016 and December 31, 2015 : March 31, 2016 December 31, 2015 Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Consolidated Statements of Financial Position Net Amounts of Assets (Liabilities) Presented in the Consolidated Statements of Financial Position Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Consolidated Statements of Financial Position Net Amounts of Assets (Liabilities) Presented in the Consolidated Statements of Financial Position (In millions) Derivative assets: Commodity Contracts: Natural Gas $ 298 $ (216 ) $ 82 $ 387 $ (285 ) $ 102 Electricity 377 (299 ) 78 307 (232 ) 75 Other 4 (3 ) 1 5 (2 ) 3 Foreign currency exchange contracts 6 (5 ) 1 12 (9 ) 3 Total derivative assets $ 685 $ (523 ) $ 162 $ 711 $ (528 ) $ 183 Derivative liabilities: Commodity Contracts: Natural Gas $ (350 ) $ 258 $ (92 ) $ (383 ) $ 294 $ (89 ) Electricity (396 ) 327 (69 ) (305 ) 253 (52 ) Other (13 ) 12 (1 ) (10 ) 8 (2 ) Foreign currency exchange contracts (4 ) 3 (1 ) (7 ) 7 — Total derivative liabilities $ (763 ) $ 600 $ (163 ) $ (705 ) $ 562 $ (143 ) The following table presents the netting offsets of Derivative assets and liabilities showing the reconciliation of derivative instruments to DTE Energy's Consolidated Statements of Financial Position at March 31, 2016 and December 31, 2015 : March 31, 2016 December 31, 2015 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Current Noncurrent Current Noncurrent Current Noncurrent Current Noncurrent (In millions) Total fair value of derivatives $ 527 $ 158 $ (545 ) $ (218 ) $ 570 $ 141 $ (521 ) $ (184 ) Counterparty netting (415 ) (101 ) 415 101 (441 ) (85 ) 441 85 Collateral adjustment (3 ) (4 ) 63 21 — (2 ) 23 13 Total derivatives as reported $ 109 $ 53 $ (67 ) $ (96 ) $ 129 $ 54 $ (57 ) $ (86 ) The effect of derivatives not designated as hedging instruments on DTE Energy's Consolidated Statements of Operations for the three months ended March 31, 2016 and 2015 for DTE Energy is as follows: Derivatives not Designated as Hedging Instruments Location of Gain Gain (Loss) Recognized in Income on Derivatives for the Three Months Ended March 31, 2016 2015 (In millions) Foreign currency exchange contracts Operating Revenues — Non-utility operations $ (5 ) $ 1 Commodity Contracts: Natural Gas Operating Revenues — Non-utility operations (56 ) (126 ) Natural Gas Fuel, purchased power, and gas — non-utility 41 21 Electricity Operating Revenues — Non-utility operations (24 ) 31 Other Operating Revenues — Non-utility operations (2 ) (2 ) Total $ (46 ) $ (75 ) Revenues and energy costs related to trading contracts are presented on a net basis in DTE Energy's Consolidated Statements of Operations. Commodity derivatives used for trading purposes, and financial non-trading commodity derivatives, are accounted for using the MTM method with unrealized and realized gains and losses recorded in Operating Revenues — Non-utility operations. Non-trading physical commodity sale and purchase derivative contracts are generally accounted for using the MTM method with unrealized and realized gains and losses for sales recorded in Operating Revenues — Non-utility operations and purchases recorded in Fuel, purchased power, and gas — non-utility. The following represents the cumulative gross volume of DTE Energy's derivative contracts outstanding as of March 31, 2016 : Commodity Number of Units Natural Gas (MMBtu) 1,864,037,929 Electricity (MWh) 31,063,981 Oil (Gallons) 19,992,000 Foreign Currency Exchange (Canadian dollars) 84,218,522 Various subsidiaries of DTE Energy have entered into contracts which contain ratings triggers and are guaranteed by DTE Energy. These contracts contain provisions which allow the counterparties to require that DTE Energy post cash or letters of credit as collateral in the event that DTE Energy’s credit rating is downgraded below investment grade. Certain of these provisions (known as “hard triggers”) state specific circumstances under which DTE Energy can be required to post collateral upon the occurrence of a credit downgrade, while other provisions (known as “soft triggers”) are not as specific. For contracts with soft triggers, it is difficult to estimate the amount of collateral which may be requested by counterparties and/or which DTE Energy may ultimately be required to post. The amount of such collateral which could be requested fluctuates based on commodity prices (primarily natural gas, power, and coal) and the provisions and maturities of the underlying transactions. As of March 31, 2016 , DTE Energy's contractual obligation to post collateral in the form of cash or letters of credit in the event of a downgrade to below investment grade, under both hard trigger and soft trigger provisions, was approximately $437 million . As of March 31, 2016 , DTE Energy had approximately $639 million of derivatives in net liability positions, for which hard triggers exist. Collateral of approximately $2 million has been posted against such liabilities, including cash and letters of credit. Associated derivative net asset positions for which contractual offset exists were approximately $491 million . The net remaining amount of approximately $146 million is derived from the $437 million noted above.

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2016
Long-term Debt, Unclassified [Abstract]
Long-term Debt	LONG-TERM DEBT Debt Redemptions In 2016 , the following debt was redeemed: Company Month Type Interest Rate Maturity Amount (In millions) DTE Electric March Mortgage Bonds 7.904% 2016 $ 10 DTE Energy Various Other Long-Term Debt Various 2016 1 $ 11

Short-Term Credit Arrangements

Short-Term Credit Arrangements and Borrowings	3 Months Ended
	Mar. 31, 2016
Short-term Debt [Abstract]
Short-Term Credit Arrangements and Borrowings	SHORT-TERM CREDIT ARRANGEMENTS AND BORROWINGS DTE Energy, DTE Electric and DTE Gas, have unsecured revolving credit agreements that can be used for general corporate borrowings, but are intended to provide liquidity support for each of the companies’ commercial paper programs. Borrowings under the revolvers are available at prevailing short-term interest rates. Additionally, DTE Energy has other facilities to support letter of credit issuance. In April 2016, DTE Energy, DTE Electric, and DTE Gas exercised the extension features in their revolving credit agreements to add one year to the existing maturities. Each of these revolvers' expirations were extended from April 2020 to April 2021. The agreements require DTE Energy, DTE Electric, and DTE Gas to maintain a total funded debt to capitalization ratio of no more than 0.65 to 1. In the agreements, “total funded debt” means all indebtedness of each respective company and their consolidated subsidiaries, including capital lease obligations, hedge agreements, and guarantees of third parties’ debt, but excluding contingent obligations, nonrecourse and junior subordinated debt, and certain equity-linked securities and, except for calculations at the end of the second quarter, certain DTE Gas short-term debt. “Capitalization” means the sum of (a) total funded debt plus (b) “consolidated net worth,” which is equal to consolidated total equity of each respective company and their consolidated subsidiaries (excluding pension effects under certain FASB statements), as determined in accordance with accounting principles generally accepted in the United States of America. At March 31, 2016 , the total funded debt to total capitalization ratios for DTE Energy, DTE Electric, and DTE Gas were 0.50 to 1, 0.51 to 1, and 0.47 to 1, respectively, and were in compliance with this financial covenant. The availability under the facilities in place at March 31, 2016 is shown in the following table: DTE Energy DTE Electric DTE Gas Total (In millions) Unsecured letter of credit facility, expiring in February 2017 $ 100 $ — $ — $ 100 Unsecured letter of credit facility, expiring in September 2017 70 — — 70 Unsecured revolving credit facility, expiring April 2020 1,200 400 300 1,900 1,370 400 300 2,070 Amounts outstanding at March 31, 2016 Commercial paper issuances 71 211 83 365 Letters of credit 167 — — 167 238 211 83 532 Net availability at March 31, 2016 $ 1,132 $ 189 $ 217 $ 1,538 DTE Energy has other outstanding letters of credit which are not included in the above described facilities totaling approximately $17 million which are used for various corporate purposes. In conjunction with maintaining certain exchange traded risk management positions, DTE Energy may be required to post collateral with its clearing agent. DTE Energy has a demand financing agreement for up to $100 million with its clearing agent. The agreement, as amended, also allows for up to $50 million of additional margin financing provided that DTE Energy posts a letter of credit for the incremental amount and allows the right of setoff with posted collateral. At March 31, 2016 , a $35 million letter of credit was in place, raising the capacity under this facility to $135 million . The $35 million letter of credit is included in the table above. The amount outstanding under this agreement was $106 million and $103 million at March 31, 2016 and December 31, 2015 , respectively, and was fully offset by the posted collateral.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Environmental DTE Electric Air — DTE Electric is subject to the EPA ozone and fine particulate transport and acid rain regulations that limit power plant emissions of sulfur dioxide and nitrogen oxides. The EPA and the State of Michigan have issued emission reduction regulations relating to ozone, fine particulate, regional haze, mercury, and other air pollution. These rules have led to controls on fossil-fueled power plants to reduce nitrogen oxide, sulfur dioxide, mercury and other emissions. Additional rulemakings are expected over the next few years which could require additional controls for sulfur dioxide, nitrogen oxides, and hazardous air pollutants. The Mercury and Air Toxics Standards (MATS) rule, formerly known as the Electric Generating Unit Maximum Achievable Control Technology (EGU MACT) Rule was finalized in December 2011. The MATS rule required reductions of mercury and other hazardous air pollutants beginning in April 2015. DTE Electric requested and was granted compliance date extensions for all relevant units to April 2016. In November 2014, the U.S. 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. In June 2015, the U.S. Supreme Court reversed the decision of the Court of Appeals for the D.C. District and remanded the MATS rule to the Court of Appeals for further consideration based on their decision that the EPA must consider costs prior to deciding to regulate under the provisions of the Clean Air Act. Subsequently, in December 2015, the Court of Appeals ordered a remand of the MATS rule back to the EPA without staying the rule. DTE Electric does not expect this decision to have a material effect on its compliance plans 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. In August 2011, the U.S. District Court judge granted DTE Energy's motion for summary judgment in the civil case, dismissing the case and entering judgment in favor of DTE Energy and DTE Electric. In October 2011, the EPA caused to be filed a Notice of Appeal to the 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 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, and Trenton Channel Unit 9. In October 2014, the EPA and the U.S. Department of Justice filed a notice of appeal of the U.S. District Court judge's dismissal of the Monroe Unit 2 case. The amended New Source Review claims are all stayed until the appeal is resolved by the Court of Appeals for the Sixth Circuit. Oral arguments for the appeal occurred in December 2015. The Registrants believe that the plants and generating units identified by the EPA and the Sierra Club have complied with all applicable federal environmental regulations. Depending upon the outcome of discussions with the EPA regarding the two NOVs/FOVs, DTE Electric could be required to install additional pollution control equipment at some or all of the power plants in question, implement early retirement of facilities where control equipment is not economical, engage in supplemental environmental programs, and/or pay fines. The Registrants cannot predict the financial impact or outcome of this matter, or the timing of its resolution. The EPA is implementing regulatory actions under the Clean Air Act to address emissions of GHGs from the utility sector and other sectors of the economy. Among these actions, the EPA finalized performance standards for emissions of carbon dioxide from new and existing electric generating units (EGUs). The carbon standards for new sources are not expected to have a material impact on DTE Electric, since DTE Electric has no plans to build new coal-fired generation and any potential new gas generation will be able to comply with the standards. In February 2016, the U.S. Supreme Court granted petitioners' requests for a stay of the carbon rules for existing EGUs (also known as the EPA Clean Power Plan) pending final review by the courts. The Clean Power Plan has no legal effect while the stay is in place. It is not possible to determine the potential impact of the EPA Clean Power Plan on existing sources at this time. Pending or future legislation or other regulatory actions could have a material impact on DTE Electric's operations and financial position and the rates charged to its customers. Impacts include expenditures for environmental equipment beyond what is currently planned, financing costs related to additional capital expenditures, the purchase of emission credits from market sources, higher costs of purchased power, and the retirement of facilities where control equipment is not economical. DTE Electric would seek to recover these incremental costs through increased rates charged to its utility customers, as authorized by the MPSC. To comply with air pollution requirements, DTE Electric spent approximately $2.3 billion through 2015 . DTE Electric estimates making capital expenditures of approximately $45 million in 2016 . Coal Combustion Residuals and Effluent Limitations Guidelines — A final EPA rule for the disposal of coal combustion residuals, commonly known as coal ash, became effective in October 2015. DTE Electric owns and operates three permitted engineered coal ash storage facilities to dispose of coal ash from coal-fired power plants and operates a number of smaller impoundments at its power plants. At certain facilities, the rule requires the installation of monitoring wells, compliance with groundwater standards, and the closure of basins at the end of the useful life of the associated power plant. At other facilities, the rule requires ash laden waters be moved from earthen basins to steel and concrete tanks. In November 2015, the EPA finalized effluent limitations guidelines for the steam electric power generating industry which may require additional controls to be installed between 2018 and 2023. Compliance schedules for individual facilities and individual waste streams are determined through issuance of new wastewater permits by the State of Michigan. No new permits have been issued, consequently no compliance timelines have been established. Certain effluent limitations guidelines requirements will be required to be performed in conjunction with the coal combustion residuals requirements. Costs associated with the building of new facilities over the next seven years to comply with coal combustion residuals requirements and effluent limitations guidelines are estimated to be approximately $290 million . Non-utility DTE Energy's non-utility businesses are subject to a number of environmental laws and regulations dealing with the protection of the environment from various pollutants. The Shenango coke battery received two NOVs from the Pennsylvania Department of Environmental Protection (PADEP) in 2010 alleging violations of the permit for the Pennsylvania coke battery facility in connection with coal pile storm water runoff. DTE Energy settled the alleged violations by implementing best management practices to address the issues and repair/upgrade its wastewater treatment plant. DTE Energy received a construction permit to upgrade its existing waste water treatment system. Due to the December 2015 decision to close the Shenango coke battery in January 2016, DTE Energy will not proceed with the upgrade to its wastewater treatment system. The decision to close the Shenango facility has prompted the PADEP, the EPA, and the Allegheny County, PA Health Department to submit demand letters under the 2012 consent decree for stipulated penalties related to water and air matters since 2012. The stipulated penalties totaling $534,000 have been assessed to the facility of which $189,000 remains unpaid as of March 31, 2016. DTE Energy is currently working with the respective regulatory agencies to settle all matters. Nuclear Operations Nuclear Fuel Disposal Costs DTE Electric currently employs a spent nuclear fuel storage strategy utilizing a fuel pool and a newly completed dry cask storage facility. The dry cask storage facility is expected to provide sufficient spent fuel storage capability for the life of the plant as defined by the original operating license. The federal government continues to maintain its legal obligation to accept spent nuclear fuel from Fermi 2 for permanent storage. Issues relating to long-term waste disposal policy and to the disposition of funds contributed by DTE Electric ratepayers to the federal waste fund await future governmental action. Synthetic Fuel Guarantees DTE Energy discontinued the operations of its synthetic fuel production facilities throughout the United States as of December 31, 2007. DTE Energy provided certain guarantees and indemnities in conjunction with the sales of interests in its synfuel facilities. The guarantees cover potential commercial, environmental, oil price, and tax-related obligations that will survive until 90 days after expiration of all applicable statutes of limitations. DTE Energy estimates that its maximum potential liability under these guarantees at March 31, 2016 is approximately $850 million . Payment under these guarantees is considered remote. REF Guarantees DTE Energy has provided certain guarantees and indemnities in conjunction with the sales of interests in or lease of its REF facilities. The guarantees cover potential commercial, environmental, and tax-related obligations that will survive until 90 days after expiration of all applicable statutes of limitations. DTE Energy estimates that its maximum potential liability under these guarantees at March 31, 2016 is approximately $270 million . Payment under these guarantees is considered remote. Other Guarantees In certain limited circumstances, the Registrants enter into contractual guarantees. The Registrants may guarantee another entity’s obligation in the event it fails to perform and may provide guarantees in certain indemnification agreements. Finally, the Registrants may provide indirect guarantees for the indebtedness of others. DTE Energy’s guarantees are not individually material with maximum potential payments totaling $56 million at March 31, 2016 . Payment under these guarantees is considered remote. DTE Energy is periodically required to obtain performance surety bonds in support of obligations to various governmental entities and other companies in connection with its operations. As of March 31, 2016 , DTE Energy had approximately $56 million of performance bonds outstanding. In the event that such bonds are called for nonperformance, DTE Energy would be obligated to reimburse the issuer of the performance bond. DTE Energy is released from the performance bonds as the contractual performance is completed and does not believe that a material amount of any currently outstanding performance bonds will be called. Bankruptcies Certain of the Registrants' customers and suppliers have filed for bankruptcy protection under the U.S. Bankruptcy Code. The Registrants regularly review contingent matters relating to these customers and suppliers and their purchase and sale contracts, and record provisions for amounts considered at risk of probable loss in the allowance for doubtful accounts. The Registrants believe their accrued amounts are adequate for probable loss. Other Contingencies The Registrants are involved in certain other legal, regulatory, administrative, and environmental proceedings before various courts, arbitration panels, and governmental agencies concerning claims arising in the ordinary course of business. These proceedings include certain contract disputes, additional environmental reviews and investigations, audits, inquiries from various regulators, and pending judicial matters. The Registrants cannot predict the final disposition of such proceedings. The Registrants regularly review legal matters and record provisions for claims that they can estimate and are considered probable of loss. The resolution of these pending proceedings is not expected to have a material effect on the Registrants' Consolidated Financial Statements in the periods they are resolved. For a discussion of contingencies related to regulatory matters and derivatives see Notes 4 and 7 to the Consolidated Financial Statements, " Regulatory Matters " and " Financial and Other Derivative Instruments ," respectively.

Retirement Benefits and Trustee

Retirement Benefits and Trusteed Assets	3 Months Ended
	Mar. 31, 2016
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Retirement Benefits and Trusteed Assets	RETIREMENT BENEFITS AND TRUSTEED ASSETS The following table details the components of net periodic benefit costs for pension benefits and other postretirement benefits for DTE Energy: Pension Benefits Other Postretirement Benefits 2016 2015 2016 2015 Three Months Ended March 31, (In millions) Service cost $ 23 $ 25 $ 6 $ 9 Interest cost 54 53 20 20 Expected return on plan assets (77 ) (74 ) (32 ) (33 ) Amortization of: Net actuarial loss 40 51 8 11 Prior service credit — — (30 ) (31 ) Net periodic benefit cost (credit) $ 40 $ 55 $ (28 ) $ (24 ) The following table details the components of net periodic benefit costs for pension benefits and other postretirement benefits for DTE Electric: Pension Benefits Other Postretirement Benefits 2016 2015 2016 2015 Three Months Ended March 31, (In millions) Service cost $ 18 $ 20 $ 5 $ 7 Interest cost 41 40 15 16 Expected return on plan assets (55 ) (53 ) (23 ) (23 ) Amortization of: Net actuarial loss 29 38 6 8 Prior service credit — — (22 ) (24 ) Net periodic benefit cost (credit) $ 33 $ 45 $ (19 ) $ (16 ) Pension and Other Postretirement Contributions At the discretion of management, DTE Energy may make contributions up to $175 million , including contributions from DTE Electric of $145 million , to its pension plans in 2016. At the discretion of management, DTE Energy may make up to $20 million , through contributions from DTE Gas, to its other postretirement benefit plans in 2016 .

Segment and Related Information

Segment and Related Information	3 Months Ended
	Mar. 31, 2016
Segment Reporting [Abstract]
Segment and Related Information	SEGMENT AND RELATED INFORMATION DTE Energy sets strategic goals, allocates resources, and evaluates performance based on the following structure: Electric segment consists principally of DTE Electric, which is engaged in the generation, purchase, distribution, and sale of electricity to approximately 2.2 million residential, commercial, and industrial customers in southeastern Michigan. Gas segment consists principally of DTE Gas, which is engaged in the purchase, storage, transportation, distribution, and sale of natural gas to approximately 1.2 million residential, commercial, and industrial customers throughout Michigan and the sale of storage and transportation capacity. Gas Storage and Pipelines consists of natural gas pipeline, gathering, and storage businesses. Power and Industrial Projects is comprised primarily of projects that deliver energy and utility-type products and services to industrial, commercial, and institutional customers, produce reduced emissions fuel, and sell electricity from renewable energy projects. Energy Trading consists of energy marketing and trading operations. Corporate and Other includes various holding company activities, and holds certain non-utility debt and energy-related investments. The federal income tax provisions or benefits of DTE Energy’s subsidiaries are determined on an individual company basis and recognize the tax benefit of tax credits and net operating losses, if applicable. The state and local income tax provisions of the utility subsidiaries are determined on an individual company basis and recognize the tax benefit of various tax credits and net operating losses, if applicable. The subsidiaries record federal, state, and local income taxes payable to or receivable from DTE Energy based on the federal, state, and local tax provisions of each company. Inter-segment billing for goods and services exchanged between segments is based upon tariffed or market-based prices of the provider and primarily consists of the sale of reduced emissions fuel, power sales, and natural gas sales in the following segments: Three Months Ended March 31, 2016 2015 (In millions) Inter-segment Revenues Electric $ 9 $ 9 Gas — 1 Gas Storage and Pipelines 2 1 Power and Industrial Projects 148 180 Energy Trading 10 9 Corporate and Other — 1 $ 169 $ 201 Financial data of the DTE Energy business segments follows: Three Months Ended March 31, 2016 2015 (In millions) Operating Revenues — Utility operations Electric $ 1,153 $ 1,203 Gas 520 647 Operating Revenues — Non-utility operations Gas Storage and Pipelines 67 57 Power and Industrial Projects 446 567 Energy Trading 549 711 Corporate and Other — — Reconciliation and Eliminations (169 ) (201 ) Total $ 2,566 $ 2,984 Net Income (Loss) Attributable to DTE Energy by Segment: Electric $ 127 $ 136 Gas 87 111 Gas Storage and Pipelines 30 27 Power and Industrial Projects 17 33 Energy Trading (7 ) (9 ) Corporate and Other (7 ) (25 ) Net Income Attributable to DTE Energy Company $ 247 $ 273

Significant Accounting Polici21

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Consolidated Financial Statements should be read in conjunction with the Combined Notes to Consolidated Financial Statements included in the combined DTE Energy and DTE Electric 2015 Annual Report on Form 10-K. The accompanying Consolidated Financial Statements of the Registrants are prepared using accounting principles generally accepted in the United States of America. These accounting principles require management to use estimates and assumptions that impact reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from the Registrants' estimates. The Consolidated Financial Statements are unaudited but, in the Registrants' opinions include all adjustments necessary to present a fair statement of the results for the interim periods. All adjustments are of a normal recurring nature, except as otherwise disclosed in these Consolidated Financial Statements and Combined Notes to Consolidated Financial Statements. Financial results for this interim period are not necessarily indicative of results that may be expected for any other interim period or for the fiscal year ending December 31, 2016 . The information in these combined notes relates to each of the Registrants as noted in the Index of Combined Notes to Consolidated Financial Statements. However, DTE Electric does not make any representation as to information related solely to DTE Energy or the subsidiaries of DTE Energy other than itself. Certain prior year balances for the Registrants were reclassified to match the current year's Consolidated Financial Statements presentation. Such revisions include amounts reclassified to separate Operating Revenues and Fuel, purchased power, and gas between Utility operations and Non-utility operations and from Operations and maintenance to Fuel, purchased power, and gas — non-utility related to the Power and Industrial Projects segment. The reclassifications did not affect DTE Energy's Net Income for the prior periods, as such, they are not deemed material to the previously issued Consolidated Financial Statements.
Reclassification	Certain prior year balances for the Registrants were reclassified to match the current year's Consolidated Financial Statements presentation. Such revisions include amounts reclassified to separate Operating Revenues and Fuel, purchased power, and gas between Utility operations and Non-utility operations and from Operations and maintenance to Fuel, purchased power, and gas — non-utility related to the Power and Industrial Projects segment. The reclassifications did not affect DTE Energy's Net Income for the prior periods, as such, they are not deemed material to the previously issued Consolidated Financial Statements.
Principles of Consolidation	Principles of Consolidation The Registrants consolidate all majority-owned subsidiaries and investments in entities in which they have controlling influence. Non-majority owned investments are accounted for using the equity method when the Registrants are able to significantly influence the operating policies of the investee. When the Registrants do not influence the operating policies of an investee, the cost method is used. These Consolidated Financial Statements also reflect the Registrants' proportionate interests in certain jointly-owned utility plants. The Registrants eliminate all intercompany balances and transactions. The Registrants evaluate whether an entity is a VIE whenever reconsideration events occur. The Registrants consolidate VIEs for which they are the primary beneficiary. If a Registrant is not the primary beneficiary and an ownership interest is held, the VIE is accounted for under the equity method of accounting. When assessing the determination of the primary beneficiary, a Registrant considers all relevant facts and circumstances, including: the power, through voting or similar rights, to direct the activities of the VIE that most significantly impact the VIE's economic performance and the obligation to absorb the expected losses and/or the right to receive the expected returns of the VIE. The Registrants perform ongoing reassessments of all VIEs to determine if the primary beneficiary status has changed. Legal entities within DTE Energy's Power and Industrial Projects segment enter into long-term contractual arrangements with customers to supply energy-related products or services. The entities are generally designed to pass-through the commodity risk associated with these contracts to the customers, with DTE Energy retaining operational and customer default risk. These entities generally are VIEs and consolidated when DTE Energy is the primary beneficiary. In addition, DTE Energy has interests in certain VIEs through which control of all significant activities is shared with partners, and therefore are accounted for under the equity method. DTE Energy has variable interests in VIEs through certain of its long-term purchase and sale contracts. DTE Electric has variable interests in VIEs through certain of its long-term purchase contracts. As of March 31, 2016 , the carrying amount of assets and liabilities in DTE Energy's Consolidated Statements of Financial Position that relate to its variable interests under long-term purchase and sale contracts are predominantly related to working capital accounts and generally represent the amounts owed by or to DTE Energy for the deliveries associated with the current billing cycle under the contracts. As of March 31, 2016 , the carrying amount of assets and liabilities in DTE Electric's Consolidated Statements of Financial Position that relate to its variable interests under long-term purchase contracts are predominantly related to working capital accounts and generally represent the amounts owed by DTE Electric for the deliveries associated with the current billing cycle under the contracts. The Registrants have not provided any significant form of financial support associated with these long-term contracts. There is no significant potential exposure to loss as a result of DTE Energy's variable interests through these long-term purchase and sale contracts. In addition, there is no significant potential exposure to loss as a result of DTE Electric's variable interests through these long-term purchase contracts. The maximum risk exposure for consolidated VIEs is reflected on the Registrants' Consolidated Statements of Financial Position. For non-consolidated VIEs, the maximum risk exposure is generally limited to its investment, notes receivable, and future funding commitments.
Other Income	Other Income Other income for the Registrants is recognized for non-operating income such as equity earnings, allowance for equity funds used during construction, and contract services. DTE Energy's Power and Industrial Projects segment also recognizes Other income in connection with the sale of membership interests in reduced emissions fuel facilities to investors. In exchange for the cash received, the investors will receive a portion of the economic attributes of the facilities, including income tax attributes. The transactions are not treated as a sale of membership interests for financial reporting purposes. Other income is considered earned when refined coal is produced and tax credits are generated.
Changes in Accumulated Other Comprehensive Income (Loss)	Changes in Accumulated Other Comprehensive Income (Loss) For the three months ended March 31, 2016 and 2015 , reclassifications out of Accumulated other comprehensive income (loss) for the Registrants were not material. Changes in Accumulated other comprehensive income (loss) are presented in DTE Energy's Consolidated Statements of Changes in Equity and DTE Electric's Consolidated Statements of Changes in Shareholder's Equity.
New Accounting Pronouncements	Recently Adopted Pronouncements In February 2015, the FASB issued ASU No. 2015-02, Amendments to the Consolidation Analysis , which changes the analysis that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. The ASU affects (1) limited partnerships and similar legal entities, (2) evaluating fees paid to a decision maker or a service provider as a variable interest, (3) the effect of fee arrangements on the primary beneficiary determination, (4) the effect of related parties on the primary beneficiary determination, and (5) certain investment funds. It is effective for the Registrants for the first interim period within annual reporting periods beginning after December 15, 2015. The Registrants adopted this ASU at January 1, 2016. The implementation of this guidance is reflected in Note 1 of the Consolidated Financial Statements, " Organization and Basis of Presentation ." Certain entities are now deemed to be VIEs and are included in DTE Energy's non-consolidated VIE table. This implementation did not have a significant impact on the Registrants' Consolidated Financial Statements. In April 2015, the FASB issued ASU No. 2015-03, Simplifying the Presentation of Debt Issuance Costs . This ASU requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. This ASU is effective for reporting periods beginning after December 15, 2015, and interim periods therein. It is to be applied retrospectively. The Registrants adopted this ASU at January 1, 2016. The effect of the adoption decreased assets and liabilities on DTE Energy’s and DTE Electric’s Consolidated Statements of Financial Position by $75 million and $36 million , respectively, at December 31, 2015. In May 2015, the FASB issued ASU 2015-07, Fair Value Measurement (Topic 820): Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent). This guidance removes the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share (or its equivalent) practical expedient. The guidance applies to investments for which there is not a readily determinable fair value (market quote) or the investment is in a mutual fund without a publicly available net asset value. It is effective for the Registrants for the first interim period within annual reporting periods beginning after December 15, 2015. It is to be applied retrospectively. The Registrants adopted this ASU at January 1, 2016. The implementation of this guidance is reflected in Note 6 of the Consolidated Financial Statements, " Fair Value ." This implementation did not have a significant impact on the Registrants' Consolidated Financial Statements. Recently Issued Pronouncements In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers. The objectives of this ASU are to improve upon revenue recognition requirements by providing a single comprehensive model to determine the measurement of revenue and timing of recognition. The core principle is that an entity will recognize revenue to depict the transfer of goods or services to customers at an amount that the entity expects to be entitled to in exchange for those goods or services. This ASU also requires expanded qualitative and quantitative disclosures regarding the nature, amount, timing, and uncertainty of revenues and cash flows arising from contracts with customers. In July 2015, the FASB deferred implementation of the revenue standard to be effective for the first interim period within annual reporting periods beginning after December 15, 2017. The standard is to be applied retrospectively and early adoption is permitted in the preceding year. In March 2016, the FASB issued an ASU that amends and clarifies the implementation guidance on principal versus agent considerations for reporting revenue gross rather than net. In April 2016, the FASB issued an ASU that amends and clarifies the identification of performance obligations and accounting for licenses of intellectual property. Both ASUs issued in 2016 have the same deferred effective date. The Registrants are currently assessing the impact of these ASUs on their Consolidated Financial Statements. In July 2015, the FASB issued ASU No. 2015-11, Inventory (Topic 330), Simplifying the Measurement of Inventory . The ASU replaces the current lower of cost or market test with a lower of cost or net realizable value test when cost is determined on a first-in, first-out or average cost basis. The standard is effective for public entities for annual reporting periods beginning after December 15, 2016, and interim periods therein. It is to be applied prospectively and early adoption is permitted. The ASU will not have a significant impact on the Registrants' Consolidated Financial Statements. In January 2016, the FASB issued ASU No. 2016-01, Financial Instruments — Overall: Recognition and Measurement of Financial Assets and Financial Liabilities. The new guidance is intended to improve the recognition and measurement of financial instruments. The ASU primarily impacts accounting for equity investments in unconsolidated entities (other than those accounted for using the equity method of accounting) and financial liabilities under the fair value option. Under the new guidance, equity investments will generally be measured at fair value, with subsequent changes in fair value recognized in net income. The ASU is effective for fiscal years and interim periods within those years beginning after December 15, 2017. Upon adoption, entities will be required to make a cumulative-effect adjustment to the Statements of Financial Position as of the beginning of the first reporting period in which the guidance is effective. Changes to the accounting for equity securities without a readily determinable fair value will be applied prospectively. The Registrants are currently assessing the impact of this ASU on their Consolidated Financial Statements. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), a replacement of Leases (Topic 840) . This guidance requires a lessee to account for leases as finance or operating leases. Both leases will result in the lessee recognizing a right-of-use asset and a corresponding lease liability on its balance sheet, with differing methodology for income statement recognition. For lessors, the standard modifies the classification criteria and the accounting for sales-type and direct financing leases. Entities will classify leases to determine how to recognize lease-related revenue and expense. This ASU is effective for public entities for fiscal years, and interim periods within those years, beginning after December 15, 2018, and early adoption is permitted. A modified retrospective approach is required for leases existing or entered into after the beginning of the earliest comparative period in the Consolidated Financial Statements. The Registrants are currently assessing the impact of this ASU on their Consolidated Financial Statements. In March 2016, the FASB issued ASU No. 2016-09, Compensation — Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. The ASU simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the Statements of Cash Flows. Under the new standard, income tax benefits and deficiencies are to be recognized in the income statement and the tax effects of exercised or vested awards should be treated as discrete items in the reporting period in which they occur. This provision is to be applied prospectively. Excess tax benefits should be recognized regardless of whether the benefit reduces taxes payable in the current period, along with any valuation allowance, on a modified retrospective basis as a cumulative-effect adjustment to the retained earnings as of the date of adoption. Excess tax benefits should be classified along with other income tax cash flows as an operating activity. This provision can be applied prospectively or retrospectively for all periods presented. The standard is effective for public entities for annual reporting periods beginning after December 15, 2016, and interim periods therein. Early adoption is permitted. DTE Energy is currently assessing the impact of this ASU on its Consolidated Financial Statements.
Fair Value Measurement	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date in a principal or most advantageous market. Fair value is a market-based measurement that is determined based on inputs, which refer broadly to assumptions that market participants use in pricing assets or liabilities. These inputs can be readily observable, market corroborated, or generally unobservable inputs. The Registrants make certain assumptions they believe that market participants would use in pricing assets or liabilities, including assumptions about risk, and the risks inherent in the inputs to valuation techniques. Credit risk of the Registrants and their counterparties is incorporated in the valuation of assets and liabilities through the use of credit reserves, the impact of which was immaterial at March 31, 2016 and December 31, 2015 . The Registrants believe they use valuation techniques that maximize the use of observable market-based inputs and minimize the use of unobservable inputs. A fair value hierarchy has been established that prioritizes the inputs to valuation techniques used to measure fair value in three broad levels. The fair value hierarchy gives the highest priority to quoted prices (unadjusted) in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). In some cases, the inputs used to measure fair value might fall in different levels of the fair value hierarchy. All assets and liabilities are required to be classified in their entirety based on the lowest level of input that is significant to the fair value measurement in its entirety. Assessing the significance of a particular input may require judgment considering factors specific to the asset or liability, and may affect the valuation of the asset or liability and its placement within the fair value hierarchy. The Registrants classify fair value balances based on the fair value hierarchy defined as follows: • Level 1 — Consists of unadjusted quoted prices in active markets for identical assets or liabilities that the Registrants have the ability to access as of the reporting date. • Level 2 — Consists of inputs other than quoted prices included within Level 1 that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data. • Level 3 — Consists of unobservable inputs for assets or liabilities whose fair value is estimated based on internally developed models or methodologies using inputs that are generally less readily observable and supported by little, if any, market activity at the measurement date. Unobservable inputs are developed based on the best available information and subject to cost-benefit constraints.
Nuclear Decommissioning Trusts and Other Investments	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 and commingled funds. Exchange-traded debt and equity securities held directly are valued using quoted market prices in actively traded markets. Non-exchange-traded fixed income securities are valued based upon quotations available from brokers or pricing services. The institutional mutual funds hold exchange-traded equity or debt securities (exchange and non-exchange traded) and are valued based on publicly available NAVs. The commingled funds hold exchange-traded equity or debt securities (exchange and non-exchange traded) and are valued based on a calculated NAV as a practical expedient. A primary price source is identified by asset type, class, or issue for each security. The trustee monitors prices supplied by pricing services and may use a supplemental price source or change the primary price source of a given security if the trustee determines that another price source is considered to be preferable. The Registrants have obtained an understanding of how these prices are derived, including the nature and observability of the inputs used in deriving such prices. Additionally, the Registrants selectively corroborate the fair value of securities by comparison of market-based price sources. Investment policies and procedures are determined by DTE Energy's Trust Investments Department which reports to DTE Energy's Vice President and Treasurer.
Derivatives, Reporting of Derivative Activity	Derivative Assets and Liabilities Derivative assets and liabilities are comprised of physical and financial derivative contracts, including futures, forwards, options, and swaps that are both exchange-traded and over-the-counter traded contracts. Various inputs are used to value derivatives depending on the type of contract and availability of market data. Exchange-traded derivative contracts are valued using quoted prices in active markets. The Registrants consider the following criteria in determining whether a market is considered active: frequency in which pricing information is updated, variability in pricing between sources or over time, and the availability of public information. Other derivative contracts are valued based upon a variety of inputs including commodity market prices, broker quotes, interest rates, credit ratings, default rates, market-based seasonality, and basis differential factors. The Registrants monitor the prices that are supplied by brokers and pricing services and may use a supplemental price source or change the primary price source of an index if prices become unavailable or another price source is determined to be more representative of fair value. The Registrants have obtained an understanding of how these prices are derived. Additionally, the Registrants selectively corroborate the fair value of their transactions by comparison of market-based price sources. Mathematical valuation models are used for derivatives for which external market data is not readily observable, such as contracts which extend beyond the actively traded reporting period. The Registrants have established a Risk Management Committee whose responsibilities include directly or indirectly ensuring all valuation methods are applied in accordance with predefined policies. The development and maintenance of the Registrants' forward price curves has been assigned to DTE Energy's Risk Management Department, which is separate and distinct from the trading functions within DTE Energy.
Fair Value Transfer	Derivatives are transferred between levels primarily due to changes in the source data used to construct price curves as a result of changes in market liquidity. Transfers in and transfers out are reflected as if they had occurred at the beginning of the period.
Fair Value of Financial Instruments	The fair value of financial instruments included in the table below is determined by using quoted market prices when available. When quoted prices are not available, pricing services may be used to determine the fair value with reference to observable interest rate indexes. The Registrants have obtained an understanding of how the fair values are derived. The Registrants also selectively corroborate the fair value of their transactions by comparison of market-based price sources. Discounted cash flow analyses based upon estimated current borrowing rates are also used to determine fair value when quoted market prices are not available. The fair values of notes receivable, excluding capital leases, are generally estimated using discounted cash flow techniques that incorporate market interest rates as well as assumptions about the remaining life of the loans and credit risk. Depending on the information available, other valuation techniques may be used that rely on internal assumptions and models. Valuation policies and procedures for the Registrants are determined by DTE Energy's Treasury Department which reports to DTE Energy's Vice President and Treasurer.
Derivatives	The Registrants recognize all derivatives at their fair value as Derivative assets or liabilities on their respective Consolidated Statements of Financial Position unless they qualify for certain scope exceptions, including the normal purchases and normal sales exception. Further, derivatives that qualify and are designated for hedge accounting are classified as either hedges of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge); or as hedges of the fair value of a recognized asset or liability or of an unrecognized firm commitment (fair value hedge). For cash flow hedges, the portion of the derivative gain or loss that is effective in offsetting the change in the value of the underlying exposure is deferred in Accumulated other comprehensive income (loss) and later reclassified into earnings when the underlying transaction occurs. Gains or losses from the ineffective portion of cash flow hedges are recognized in earnings immediately. For fair value hedges, changes in fair values for the derivative and hedged item are recognized in earnings each period. For derivatives that do not qualify or are not designated for hedge accounting, changes in fair value are recognized in earnings each period. The Registrants’ primary market risk exposure is associated with commodity prices, credit, and interest rates. The Registrants have risk management policies to monitor and manage market risks. The Registrants use derivative instruments to manage some of the exposure. DTE Energy uses derivative instruments for trading purposes in its Energy Trading segment. Contracts classified as derivative instruments include electricity, natural gas, oil, certain coal forwards, futures, options, swaps, and foreign currency exchange contracts. Items not classified as derivatives include natural gas inventory, pipeline transportation contracts, renewable energy credits, and natural gas storage assets.
Derivatives, Offsetting Fair Value Amounts	Certain of DTE Energy's derivative positions are subject to netting arrangements which provide for offsetting of asset and liability positions as well as related cash collateral. Such netting arrangements generally do not have restrictions. Under such netting arrangements, DTE Energy offsets the fair value of derivative instruments with cash collateral received or paid for those contracts executed with the same counterparty, which reduces DTE Energy's Total Assets and Liabilities. Cash collateral is allocated between the fair value of derivative instruments and customer accounts receivable and payable with the same counterparty on a pro-rata basis to the extent there is exposure. Any cash collateral remaining, after the exposure is netted to zero, is reflected in Accounts receivable and Accounts payable as collateral paid or received, respectively. DTE Energy also provides and receives collateral in the form of letters of credit which can be offset against net Derivative assets and liabilities as well as Accounts receivable and payable. DTE Energy had issued letters of credit of approximately $2 million and $7 million outstanding at March 31, 2016 and December 31, 2015 , respectively, which could be used to offset net Derivative liabilities. Letters of credit received from third parties which could be used to offset net Derivative assets were $2 million at March 31, 2016 and December 31, 2015 , respectively. Such balances of letters of credit are excluded from the tables below and are not netted with the recognized assets and liabilities in DTE Energy's Consolidated Statements of Financial Position. For contracts with certain clearing agents the fair value of derivative instruments is netted against realized positions with the net balance reflected as either 1) a Derivative asset or liability or 2) an Account receivable or payable. Other than certain clearing agents, Accounts receivable and Accounts payable that are subject to netting arrangements have not been offset against the fair value of Derivative assets and liabilities. Certain contracts that have netting arrangements have not been offset in DTE Energy's Consolidated Statements of Financial Position. The impact of netting these derivative instruments and cash collateral related to such contracts is not material. Only the gross amounts for these derivative instruments are included in the table below.
Derivatives, Methods of Accounting, Derivatives Not Designated or Qualifying as Hedges	Revenues and energy costs related to trading contracts are presented on a net basis in DTE Energy's Consolidated Statements of Operations. Commodity derivatives used for trading purposes, and financial non-trading commodity derivatives, are accounted for using the MTM method with unrealized and realized gains and losses recorded in Operating Revenues — Non-utility operations. Non-trading physical commodity sale and purchase derivative contracts are generally accounted for using the MTM method with unrealized and realized gains and losses for sales recorded in Operating Revenues — Non-utility operations and purchases recorded in Fuel, purchased power, and gas — non-utility.
Income Tax	The federal income tax provisions or benefits of DTE Energy’s subsidiaries are determined on an individual company basis and recognize the tax benefit of tax credits and net operating losses, if applicable. The state and local income tax provisions of the utility subsidiaries are determined on an individual company basis and recognize the tax benefit of various tax credits and net operating losses, if applicable. The subsidiaries record federal, state, and local income taxes payable to or receivable from DTE Energy based on the federal, state, and local tax provisions of each company.

Organization and Basis of Pre22

Organization and Basis of Presentation (Tables)	3 Months Ended
	Mar. 31, 2016
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Schedule of Variable Interest Entities	The following table summarizes the major Consolidated Statements of Financial Position items for consolidated VIEs as of March 31, 2016 and December 31, 2015 . All assets and liabilities of a consolidated VIE are presented where it has been determined that a consolidated VIE has either (1) assets that can be used only to settle obligations of the VIE or (2) liabilities for which creditors do not have recourse to the general credit of the primary beneficiary. VIEs, in which DTE Energy holds a majority voting interest and is the primary beneficiary, that meet the definition of a business and whose assets can be used for purposes other than the settlement of the VIE's obligations have been excluded from the table below. March 31, 2016 December 31, 2015 (In millions) ASSETS Cash and cash equivalents $ 9 $ 14 Restricted cash 7 8 Accounts receivable 14 18 Inventories 70 82 Property, plant, and equipment, net 62 66 Other current and long-term assets 3 4 $ 165 $ 192 LIABILITIES Accounts payable and accrued current liabilities $ 8 $ 13 Current portion long-term debt, including capital leases 7 8 Mortgage bonds, notes, and other 8 10 Other current and long-term liabilities 6 6 $ 29 $ 37
Summary of Amounts for Non-Consolidated Variable Interest Entities	Amounts for DTE Energy's non-consolidated VIEs as of March 31, 2016 and December 31, 2015 are as follows: March 31, 2016 December 31, 2015 (In millions) Investment in equity method investees $ 194 $ 136 Notes receivable $ 15 $ 15 Future funding commitments $ 9 $ —

Significant Accounting Polici23

Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2016
Accounting Policies [Abstract]
Schedule of Effective Tax Rate and Unrecognized Tax Benefits	The effective tax rate and unrecognized tax benefits of the Registrants are as follows: Effective Tax Rate Unrecognized Tax Benefits Three Months Ended March 31, March 31, 2016 2015 2016 (In millions) DTE Energy 26 % 31 % $ 3 DTE Electric 36 % 35 % $ 4

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	A reconciliation of both calculations is presented in the following table: Three Months Ended March 31, 2016 2015 (In millions, except per share amounts) Basic Earnings per Share Net Income Attributable to DTE Energy Company $ 247 $ 273 Average number of common shares outstanding 179 178 Dividends declared — common shares $ 131 $ 123 Dividends declared — net restricted shares — 1 Total distributed earnings $ 131 $ 124 Net Income less distributed earnings $ 116 $ 149 Distributed (dividends per common share) $ 0.73 $ 0.69 Undistributed 0.65 0.84 Total Basic Earnings per Common Share $ 1.38 $ 1.53 Diluted Earnings per Share Net Income Attributable to DTE Energy Company $ 247 $ 273 Average number of common shares outstanding 180 178 Dividends declared — common shares $ 131 $ 123 Dividends declared — net restricted shares — 1 Total distributed earnings $ 131 $ 124 Net Income less distributed earnings $ 116 $ 149 Distributed (dividends per common share) $ 0.73 $ 0.69 Undistributed 0.64 0.84 Total Diluted Earnings per Common Share $ 1.37 $ 1.53

Fair Value (Tables)

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Assets and liabilities measured and recorded at fair value on a recurring basis	The following table presents assets and liabilities for DTE Energy measured and recorded at fair value on a recurring basis as of March 31, 2016 and December 31, 2015 : March 31, 2016 December 31, 2015 Level Level Level Other Netting Net Balance Level Level Level Other Netting Net Balance (In millions) Assets: Cash equivalents (c) $ 11 $ 3 $ — $ — $ — $ 14 $ 13 $ 3 $ — $ — $ — $ 16 Nuclear decommissioning trusts 752 491 — 3 — 1,246 759 473 — 4 — 1,236 Other investments (d) 154 — — — — 154 149 — — — — 149 Derivative assets: Commodity Contracts: Natural Gas 133 89 76 — (216 ) 82 193 91 103 — (285 ) 102 Electricity — 305 72 — (299 ) 78 — 239 68 — (232 ) 75 Other 3 — 1 — (3 ) 1 2 — 3 — (2 ) 3 Foreign currency exchange contracts — 6 — — (5 ) 1 — 12 — — (9 ) 3 Total derivative assets 136 400 149 — (523 ) 162 195 342 174 — (528 ) 183 Total $ 1,053 $ 894 $ 149 $ 3 $ (523 ) $ 1,576 $ 1,116 $ 818 $ 174 $ 4 $ (528 ) $ 1,584 Liabilities: Derivative liabilities: Commodity Contracts: Natural Gas $ (188 ) $ (52 ) $ (110 ) $ — $ 258 $ (92 ) $ (218 ) $ (57 ) $ (108 ) $ — $ 294 $ (89 ) Electricity — (308 ) (88 ) — 327 (69 ) — (243 ) (62 ) — 253 (52 ) Other (5 ) — (8 ) — 12 (1 ) (2 ) — (8 ) — 8 (2 ) Foreign currency exchange contracts — (4 ) — — 3 (1 ) — (7 ) — — 7 — Total derivative liabilities (193 ) (364 ) (206 ) — 600 (163 ) (220 ) (307 ) (178 ) — 562 (143 ) Total $ (193 ) $ (364 ) $ (206 ) $ — $ 600 $ (163 ) $ (220 ) $ (307 ) $ (178 ) $ — $ 562 $ (143 ) Net Assets (Liabilities) at the end of the period $ 860 $ 530 $ (57 ) $ 3 $ 77 $ 1,413 $ 896 $ 511 $ (4 ) $ 4 $ 34 $ 1,441 Assets: Current $ 118 $ 325 $ 98 $ — $ (418 ) $ 123 $ 174 $ 284 $ 128 $ — $ (441 ) $ 145 Noncurrent 935 569 51 3 (105 ) 1,453 942 534 46 4 (87 ) 1,439 Total Assets $ 1,053 $ 894 $ 149 $ 3 $ (523 ) $ 1,576 $ 1,116 $ 818 $ 174 $ 4 $ (528 ) $ 1,584 Liabilities: Current $ (150 ) $ (296 ) $ (99 ) $ — $ 478 $ (67 ) $ (174 ) $ (260 ) $ (87 ) $ — $ 464 $ (57 ) Noncurrent (43 ) (68 ) (107 ) — 122 (96 ) (46 ) (47 ) (91 ) — 98 (86 ) Total Liabilities $ (193 ) $ (364 ) $ (206 ) $ — $ 600 $ (163 ) $ (220 ) $ (307 ) $ (178 ) $ — $ 562 $ (143 ) Net Assets (Liabilities) at the end of the period $ 860 $ 530 $ (57 ) $ 3 $ 77 $ 1,413 $ 896 $ 511 $ (4 ) $ 4 $ 34 $ 1,441 _______________________________________ (a) Amounts represent assets valued at NAV as a practical expedient for fair value. (b) Amounts represent the impact of master netting agreements that allow DTE Energy to net gain and loss positions and cash collateral held or placed with the same counterparties. (c) At March 31, 2016 , available-for-sale securities of $14 million included $7 million and $7 million of cash equivalents included in Restricted cash and Other investments on DTE Energy's Consolidated Statements of Financial Position, respectively. At December 31, 2015 , available-for-sale securities of $16 million , included $8 million and $8 million of cash equivalents included in Restricted cash and Other investments on DTE Energy's Consolidated Statements of Financial Position, respectively. (d) Excludes cash surrender value of life insurance investments. The following table presents assets for DTE Electric measured and recorded at fair value on a recurring basis as of March 31, 2016 and December 31, 2015 : March 31, 2016 December 31, 2015 Level 1 Level 2 Level 3 Other Net Balance Level 1 Level 2 Level 3 Other Net Balance (In millions) Assets: Cash equivalents (b) $ 4 $ 3 $ — $ — $ 7 $ 5 $ 3 $ — $ — $ 8 Nuclear decommissioning trusts 752 491 — 3 1,246 759 473 — 4 1,236 Other investments 8 — — — 8 8 — — — 8 Derivative assets — FTRs — — 1 — 1 — — 3 — 3 Total $ 764 $ 494 $ 1 $ 3 $ 1,262 $ 772 $ 476 $ 3 $ 4 $ 1,255 Assets: Current $ 4 $ 3 $ 1 $ — $ 8 $ 5 $ 3 $ 3 $ — $ 11 Noncurrent 760 491 — 3 1,254 767 473 — 4 1,244 Total Assets $ 764 $ 494 $ 1 $ 3 $ 1,262 $ 772 $ 476 $ 3 $ 4 $ 1,255 _______________________________________ (a) Amounts represent assets valued at NAV as a practical expedient for fair value. (b) At March 31, 2016 , available-for-sale securities of $7 million consisted of cash equivalents included in Other investments on DTE Electric's Consolidated Statements of Financial Position. At December 31, 2015 , available-for-sale securities of $8 million consisted of cash equivalents included in Other investments on DTE Electric's Consolidated Statements of Financial Position.
Fair value reconciliation of level 3 assets and liabilities measured at fair value on a recurring basis	The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for DTE Energy for the three months ended March 31, 2016 and 2015 : Three Months Ended March 31, 2016 Three Months Ended March 31, 2015 Natural Gas Electricity Other Total Natural Gas Electricity Other Total (In millions) Net Assets (Liabilities) as of December 31 $ (5 ) $ 6 $ (5 ) $ (4 ) $ 30 $ (5 ) $ (1 ) $ 24 Transfers into Level 3 from Level 2 — — — — — — (1 ) (1 ) Transfers from Level 3 into Level 2 (1 ) — — (1 ) — — — — Total gains (losses): Included in earnings (20 ) (58 ) (1 ) (79 ) (29 ) 7 (2 ) (24 ) Recorded in Regulatory assets — — (2 ) (2 ) — — (2 ) (2 ) Purchases, issuances, and settlements: Settlements (8 ) 36 1 29 (1 ) (9 ) 1 (9 ) Net Assets (Liabilities) as of March 31 $ (34 ) $ (16 ) $ (7 ) $ (57 ) $ — $ (7 ) $ (5 ) $ (12 ) The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31, 2016 and 2015 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations $ (72 ) $ (3 ) $ (1 ) $ (76 ) $ (91 ) $ (3 ) $ (2 ) $ (96 ) The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for DTE Electric for the three months ended March 31, 2016 and 2015 : Three Months Ended March 31, 2016 2015 (In millions) Net Assets as of December 31 $ 3 $ 3 Change in fair value recorded in Regulatory assets (2 ) (2 ) Purchases, issuances, and settlements: Settlements — — Net Assets as of March 31 $ 1 $ 1 The amount of total gains (losses) included in Regulatory assets attributed to the change in unrealized gains (losses) related to assets held at March 31, 2016 and 2015 and reflected in DTE Electric's Consolidated Statements of Financial Position $ — $ —
Unobservable inputs related to Level 3 assets and liabilities	The following tables present the unobservable inputs related to DTE Energy's Level 3 assets and liabilities as of March 31, 2016 and December 31, 2015 : March 31, 2016 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 76 $ (110 ) Discounted Cash Flow Forward basis price (per MMBtu) $ (1.21 ) — $ 3.62 /MMBtu $ (0.12 )/MMBtu Electricity $ 72 $ (88 ) Discounted Cash Flow Forward basis price (per MWh) $ (14 ) — $ 13 /MWh $ 1 /MWh December 31, 2015 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 103 $ (108 ) Discounted Cash Flow Forward basis price (per MMBtu) $ (1.50 ) — $ 2.77 /MMBtu $ (0.19 )/MMBtu Electricity $ 68 $ (62 ) Discounted Cash Flow Forward basis price (per MWh) $ (11 ) — $ 14 /MWh $ 2 /MWh
Carrying amount of fair value of financial instruments	The following table presents the carrying amount and fair value of financial instruments for DTE Energy as of March 31, 2016 and December 31, 2015 : March 31, 2016 December 31, 2015 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 $ 32 $ — $ — $ 32 $ 32 $ — $ — $ 32 Dividends payable $ 131 $ 131 $ — $ — $ 131 $ 131 $ — $ — Short-term borrowings $ 365 $ — $ 365 $ — $ 499 $ — $ 499 $ — Long-term debt, excluding capital leases $ 9,201 $ 495 $ 8,353 $ 1,299 $ 9,210 $ 496 $ 8,136 $ 1,203 The following table presents the carrying amount and fair value of financial instruments for DTE Electric as of March 31, 2016 and December 31, 2015 : March 31, 2016 December 31, 2015 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 $ 5 $ — $ — $ 5 $ 5 $ — $ — $ 5 Short-term borrowings — affiliates $ 97 $ — $ — $ 97 $ 75 $ — $ — $ 75 Short-term borrowings — other $ 211 $ — $ 211 $ — 272 $ — $ 272 $ — Long-term debt, excluding capital leases $ 5,579 $ — $ 5,501 $ 717 $ 5,588 $ — $ 5,432 $ 545
Fair value of nuclear decommissioning trust fund assets	The following table summarizes DTE Electric's fair value of the nuclear decommissioning trust fund assets: March 31, 2016 December 31, 2015 (In millions) Fermi 2 $ 1,220 $ 1,211 Fermi 1 3 3 Low-level radioactive waste 23 22 Total $ 1,246 $ 1,236
Schedule of realized gain (loss)	The following table sets forth DTE Electric's gains and losses and proceeds from the sale of securities by the nuclear decommissioning trust funds: Three Months Ended March 31, 2016 2015 (In millions) Realized gains $ 9 $ 9 Realized losses $ (15 ) $ (7 ) Proceeds from sales of securities $ 260 $ 246
Fair value and unrealized gains and losses for nuclear decommissioning trust fund	The following table sets forth DTE Electric's fair value and unrealized gains and losses for the nuclear decommissioning trust funds: March 31, 2016 December 31, 2015 Fair Unrealized Unrealized Fair Unrealized Unrealized (In millions) Equity securities $ 728 $ 199 $ (68 ) $ 731 $ 195 $ (68 ) Debt securities 512 24 (2 ) 499 16 (4 ) Cash and cash equivalents 6 — — 6 — — $ 1,246 $ 223 $ (70 ) $ 1,236 $ 211 $ (72 )

Financial and Other Derivativ26

Financial and Other Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair value of derivative instruments	The following table presents the fair value of derivative instruments as of March 31, 2016 and December 31, 2015 for DTE Energy: March 31, 2016 December 31, 2015 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities (In millions) Derivatives not designated as hedging instruments: Foreign currency exchange contracts $ 6 $ (4 ) $ 12 $ (7 ) Commodity Contracts: Natural Gas 298 (350 ) 387 (383 ) Electricity 377 (396 ) 307 (305 ) Other 4 (13 ) 5 (10 ) Total derivatives not designated as hedging instruments: $ 685 $ (763 ) $ 711 $ (705 ) Current $ 527 $ (545 ) $ 570 $ (521 ) Noncurrent 158 (218 ) 141 (184 ) Total derivatives $ 685 $ (763 ) $ 711 $ (705 ) The following table presents the fair value of derivative instruments as of March 31, 2016 and December 31, 2015 for DTE Electric: March 31, 2016 December 31, 2015 (In millions) FTRs — Other current assets $ 1 $ 3 Total derivatives not designated as hedging instrument $ 1 $ 3
Netting Offsets of Derivative Assets and Liabilities	The following table presents the netting offsets of Derivative assets and liabilities for DTE Energy at March 31, 2016 and December 31, 2015 : March 31, 2016 December 31, 2015 Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Consolidated Statements of Financial Position Net Amounts of Assets (Liabilities) Presented in the Consolidated Statements of Financial Position Gross Amounts of Recognized Assets (Liabilities) Gross Amounts Offset in the Consolidated Statements of Financial Position Net Amounts of Assets (Liabilities) Presented in the Consolidated Statements of Financial Position (In millions) Derivative assets: Commodity Contracts: Natural Gas $ 298 $ (216 ) $ 82 $ 387 $ (285 ) $ 102 Electricity 377 (299 ) 78 307 (232 ) 75 Other 4 (3 ) 1 5 (2 ) 3 Foreign currency exchange contracts 6 (5 ) 1 12 (9 ) 3 Total derivative assets $ 685 $ (523 ) $ 162 $ 711 $ (528 ) $ 183 Derivative liabilities: Commodity Contracts: Natural Gas $ (350 ) $ 258 $ (92 ) $ (383 ) $ 294 $ (89 ) Electricity (396 ) 327 (69 ) (305 ) 253 (52 ) Other (13 ) 12 (1 ) (10 ) 8 (2 ) Foreign currency exchange contracts (4 ) 3 (1 ) (7 ) 7 — Total derivative liabilities $ (763 ) $ 600 $ (163 ) $ (705 ) $ 562 $ (143 )
Netting Offsets of Derivative Assets and Liabilities Reconciliation to the Statements of Financial Position	The following table presents the netting offsets of Derivative assets and liabilities showing the reconciliation of derivative instruments to DTE Energy's Consolidated Statements of Financial Position at March 31, 2016 and December 31, 2015 : March 31, 2016 December 31, 2015 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Current Noncurrent Current Noncurrent Current Noncurrent Current Noncurrent (In millions) Total fair value of derivatives $ 527 $ 158 $ (545 ) $ (218 ) $ 570 $ 141 $ (521 ) $ (184 ) Counterparty netting (415 ) (101 ) 415 101 (441 ) (85 ) 441 85 Collateral adjustment (3 ) (4 ) 63 21 — (2 ) 23 13 Total derivatives as reported $ 109 $ 53 $ (67 ) $ (96 ) $ 129 $ 54 $ (57 ) $ (86 )
Gain (Loss) Recognized in Income on Derivative	The effect of derivatives not designated as hedging instruments on DTE Energy's Consolidated Statements of Operations for the three months ended March 31, 2016 and 2015 for DTE Energy is as follows: Derivatives not Designated as Hedging Instruments Location of Gain Gain (Loss) Recognized in Income on Derivatives for the Three Months Ended March 31, 2016 2015 (In millions) Foreign currency exchange contracts Operating Revenues — Non-utility operations $ (5 ) $ 1 Commodity Contracts: Natural Gas Operating Revenues — Non-utility operations (56 ) (126 ) Natural Gas Fuel, purchased power, and gas — non-utility 41 21 Electricity Operating Revenues — Non-utility operations (24 ) 31 Other Operating Revenues — Non-utility operations (2 ) (2 ) Total $ (46 ) $ (75 )
Volume of Commodity Contracts	The following represents the cumulative gross volume of DTE Energy's derivative contracts outstanding as of March 31, 2016 : Commodity Number of Units Natural Gas (MMBtu) 1,864,037,929 Electricity (MWh) 31,063,981 Oil (Gallons) 19,992,000 Foreign Currency Exchange (Canadian dollars) 84,218,522

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2016
Long-term Debt, Unclassified [Abstract]
Schedule of Debt Redemptions	In 2016 , the following debt was redeemed: Company Month Type Interest Rate Maturity Amount (In millions) DTE Electric March Mortgage Bonds 7.904% 2016 $ 10 DTE Energy Various Other Long-Term Debt Various 2016 1 $ 11

Short-Term Credit Arrangement28

Short-Term Credit Arrangements and Borrowings (Tables)	3 Months Ended
	Mar. 31, 2016
Short-term Debt [Abstract]
Schedule of Line of Credit Facilities	The availability under the facilities in place at March 31, 2016 is shown in the following table: DTE Energy DTE Electric DTE Gas Total (In millions) Unsecured letter of credit facility, expiring in February 2017 $ 100 $ — $ — $ 100 Unsecured letter of credit facility, expiring in September 2017 70 — — 70 Unsecured revolving credit facility, expiring April 2020 1,200 400 300 1,900 1,370 400 300 2,070 Amounts outstanding at March 31, 2016 Commercial paper issuances 71 211 83 365 Letters of credit 167 — — 167 238 211 83 532 Net availability at March 31, 2016 $ 1,132 $ 189 $ 217 $ 1,538

Retirement Benefits and Trust29

Retirement Benefits and Trusteed Assets (Tables)	3 Months Ended
	Mar. 31, 2016
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]
Schedule of Net Benefit Costs	The following table details the components of net periodic benefit costs for pension benefits and other postretirement benefits for DTE Energy: Pension Benefits Other Postretirement Benefits 2016 2015 2016 2015 Three Months Ended March 31, (In millions) Service cost $ 23 $ 25 $ 6 $ 9 Interest cost 54 53 20 20 Expected return on plan assets (77 ) (74 ) (32 ) (33 ) Amortization of: Net actuarial loss 40 51 8 11 Prior service credit — — (30 ) (31 ) Net periodic benefit cost (credit) $ 40 $ 55 $ (28 ) $ (24 ) The following table details the components of net periodic benefit costs for pension benefits and other postretirement benefits for DTE Electric: Pension Benefits Other Postretirement Benefits 2016 2015 2016 2015 Three Months Ended March 31, (In millions) Service cost $ 18 $ 20 $ 5 $ 7 Interest cost 41 40 15 16 Expected return on plan assets (55 ) (53 ) (23 ) (23 ) Amortization of: Net actuarial loss 29 38 6 8 Prior service credit — — (22 ) (24 ) Net periodic benefit cost (credit) $ 33 $ 45 $ (19 ) $ (16 )

Segment and Related Informati30

Segment and Related Information (Tables)	3 Months Ended
	Mar. 31, 2016
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Inter-segment billing for goods and services exchanged between segments is based upon tariffed or market-based prices of the provider and primarily consists of the sale of reduced emissions fuel, power sales, and natural gas sales in the following segments: Three Months Ended March 31, 2016 2015 (In millions) Inter-segment Revenues Electric $ 9 $ 9 Gas — 1 Gas Storage and Pipelines 2 1 Power and Industrial Projects 148 180 Energy Trading 10 9 Corporate and Other — 1 $ 169 $ 201 Financial data of the DTE Energy business segments follows: Three Months Ended March 31, 2016 2015 (In millions) Operating Revenues — Utility operations Electric $ 1,153 $ 1,203 Gas 520 647 Operating Revenues — Non-utility operations Gas Storage and Pipelines 67 57 Power and Industrial Projects 446 567 Energy Trading 549 711 Corporate and Other — — Reconciliation and Eliminations (169 ) (201 ) Total $ 2,566 $ 2,984 Net Income (Loss) Attributable to DTE Energy by Segment: Electric $ 127 $ 136 Gas 87 111 Gas Storage and Pipelines 30 27 Power and Industrial Projects 17 33 Energy Trading (7 ) (9 ) Corporate and Other (7 ) (25 ) Net Income Attributable to DTE Energy Company $ 247 $ 273

Organization and Basis of Pre31

Organization and Basis of Presentation (Details Textuals) customer in Millions	Mar. 31, 2016USD ($)customer
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Number of electric utility customers | customer	2.2
Number of gas utility customers | customer	1.2
Significant Potential Exposure to Loss Due to VIE Long-Term Purchase and Sale Contracts | $	$ 0
DTE Electric
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Significant Potential Exposure to Loss Due to VIE Long-Term Purchase and Sale Contracts | $	$ 0

Organization and Basis of Pre32

Organization and Basis of Presentation (Consolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
ASSETS
Cash and cash equivalents	$ 35	$ 37	$ 99	$ 48
Restricted cash	23	23
Accounts receivable	1,185	1,276
Property, plant, and equipment, net	18,127	18,034
Total Assets	28,564	28,662
LIABILITIES
Current portion long-term debt, including capital leases	462	473
Mortgage bonds, notes, and other	8,266	8,265
Variable Interest Entity, Primary Beneficiary
ASSETS
Cash and cash equivalents	9	14
Restricted cash	7	8
Accounts receivable	14	18
Inventories	70	82
Property, plant, and equipment, net	62	66
Other current and long-term assets	3	4
Total Assets	165	192
LIABILITIES
Accounts payable and accrued current liabilities	8	13
Current portion long-term debt, including capital leases	7	8
Mortgage bonds, notes, and other	8	10
Other current and long-term liabilities	6	6
Total Liabilities	$ 29	$ 37

Organization and Basis of Pre33

Organization and Basis of Presentation (Non Consolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Variable Interest Entity [Line Items]
Notes receivable	$ 79	$ 85
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Investment in equity method investees	194	136
Notes receivable	15	15
Future funding commitments	$ 9	$ 0

Significant Accounting Polici34

Significant Accounting Policies (Details Textuals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Significant Accounting Policies [Line Items]
Other income	$ 52	$ 51
Effective tax rate increase (decrease)	(5.00%)
Unrecognized tax benefits that would impact effective tax rate	$ 2
Unrecognized compensation cost	$ 82
Recognition period (in years)	1 year 9 months 15 days
Power and Industrial Projects
Significant Accounting Policies [Line Items]
Other income	$ 19	19
DTE Electric
Significant Accounting Policies [Line Items]
Other income	16	15
Unrecognized tax benefits that would impact effective tax rate	3
DTE Electric | DTE Energy
Significant Accounting Policies [Line Items]
Income tax receivable	6		$ 6
Allocated Share-based Compensation Expense	$ 10	$ 4

Significant Accounting Polici35

Significant Accounting Policies (Income Taxes) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Schedule of Income Taxes [Line Items]
Effective Tax Rate	26.00%	31.00%
Unrecognized Tax Benefits	$ 3
DTE Electric
Schedule of Income Taxes [Line Items]
Effective Tax Rate	36.00%	35.00%
Unrecognized Tax Benefits	$ 4

New Accounting Pronouncements N

New Accounting Pronouncements New Accounting Pronouncements (Details) - ASU No. 2015-03 $ in Millions	Dec. 31, 2015USD ($)
Liability [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Debt issuance cost	$ 75
Assets
New Accounting Pronouncement, Early Adoption [Line Items]
Debt issuance cost	75
DTE Electric | Liability [Member]
New Accounting Pronouncement, Early Adoption [Line Items]
Debt issuance cost	36
DTE Electric | Assets
New Accounting Pronouncement, Early Adoption [Line Items]
Debt issuance cost	$ 36

Regulatory Matters (Details Tex

Regulatory Matters (Details Textuals) - MPSC - USD ($) $ in Millions	Feb. 23, 2016	Feb. 01, 2016	Dec. 18, 2015	Dec. 11, 2015	Jul. 01, 2015	Dec. 19, 2014	Jan. 31, 2017
Electric Rate Case Filing 2014 | DTE Electric
Public Utilities, General Disclosures [Line Items]
Requested rate increase						$ 370
Rate increase amount					$ 230
Self-implemented base rate increase					190
Required elimination of credit surcharge					$ 40
Annual revenue increase	$ 243			$ 238
Return on equity percent				10.30%
Capital structure debt percent				50.00%
Capital structure equity percent				50.00%
Electric Rate Case Filing 2016 | DTE Electric
Public Utilities, General Disclosures [Line Items]
Requested rate increase		$ 344
Return on equity percent		10.30%
Capital structure debt percent		50.00%
Capital structure equity percent		50.00%
Return on equity requested percent		10.50%
DTE Gas Rate Case Filing 2015 | DTE Gas
Public Utilities, General Disclosures [Line Items]
Requested rate increase			$ 183
Return on equity percent			10.50%
Capital structure debt percent			48.00%
Capital structure equity percent			52.00%
Return on equity requested percent			10.75%
IRM surcharges			$ 41
Scenario, Forecast | DTE Gas Rate Case Filing 2015 | DTE Gas
Public Utilities, General Disclosures [Line Items]
IRM surcharges							$ 9

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Basic Earnings per Share
Net Income (Loss) Attributable to DTE Energy Company	$ 247	$ 273
Average number of common shares outstanding (in shares)	179	178
Dividends declared — common shares	$ 131	$ 123
Dividends declared — net restricted shares	0	1
Total distributed earnings	131	124
Net Income less distributed earnings	$ 116	$ 149
Distributed (dividends per common share) (dollars per share)	$ 0.73	$ 0.69
Undistributed (dollars per share)	0.65	0.84
Total Basic Earnings per Common Share (dollars per share)	$ 1.38	$ 1.53
Diluted Earnings per Share
Net Income (Loss) Attributable to DTE Energy Company	$ 247	$ 273
Average number of common shares outstanding (in shares)	180	178
Dividends declared — common shares	$ 131	$ 123
Dividends declared — net restricted shares	0	1
Total distributed earnings	131	124
Net Income less distributed earnings	$ 116	$ 149
Distributed (dividends per common share) (dollars per share)	$ 0.73	$ 0.69
Undistributed (dollars per share)	0.64	0.84
Total Diluted Earnings per Common Share (dollars per share)	$ 1.37	$ 1.53

Fair Value (Assets and Liabilit

Fair Value (Assets and Liabilities Recorded at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Derivative Assets
Derivative Assets, gross	$ 685	$ 711
Derivative asset, netting	(523)	(528)
Derivative assets, net	162	183
Derivative Liabilities
Derivative Liabilities	(763)	(705)
Derivative liability, netting	600	562
Derivative liabilities, net	(163)	(143)
Current derivative liability
Derivative Liabilities
Derivative Liabilities	(545)	(521)
Noncurrent derivative liability
Derivative Liabilities
Derivative Liabilities	(218)	(184)
Natural Gas
Derivative Assets
Derivative Assets, gross	298	387
Derivative asset, netting	(216)	(285)
Derivative assets, net	82	102
Derivative Liabilities
Derivative Liabilities	(350)	(383)
Derivative liability, netting	258	294
Derivative liabilities, net	(92)	(89)
Electricity
Derivative Assets
Derivative Assets, gross	377	307
Derivative asset, netting	(299)	(232)
Derivative assets, net	78	75
Derivative Liabilities
Derivative Liabilities	(396)	(305)
Derivative liability, netting	327	253
Derivative liabilities, net	(69)	(52)
Other
Derivative Assets
Derivative Assets, gross	4	5
Derivative asset, netting	(3)	(2)
Derivative assets, net	1	3
Derivative Liabilities
Derivative Liabilities	(13)	(10)
Derivative liability, netting	12	8
Derivative liabilities, net	(1)	(2)
Foreign currency exchange contracts
Derivative Assets
Derivative Assets, gross	6	12
Derivative asset, netting	(5)	(9)
Derivative assets, net	1	3
Derivative Liabilities
Derivative Liabilities	(4)	(7)
Derivative liability, netting	3	7
Derivative liabilities, net	(1)	0
Recurring
ASSETS
Cash equivalents	14	16
Nuclear decommissioning trusts	1,246	1,236
Alternative Investments valued at NAV as practical expedient for FV	3	4
Other investments	154	149
Derivative Assets
Derivative asset, netting	(523)	(528)
Derivative assets, net	162	183
Total assets	1,576	1,584
Derivative Liabilities
Derivative liability, netting	600	562
Derivative liabilities, net	(163)	(143)
Net Assets (Liabilities) at the end of the period	1,413	1,441
Net Assets (Liabilities) at the end of the period, netting	77	34
Recurring | Current asset
Derivative Assets
Derivative asset, netting	(418)	(441)
Total assets	123	145
Recurring | Noncurrent asset
ASSETS
Alternative Investments valued at NAV as practical expedient for FV	3	4
Derivative Assets
Derivative asset, netting	(105)	(87)
Total assets	1,453	1,439
Recurring | Current derivative liability
Derivative Liabilities
Derivative liability, netting	478	464
Derivative liabilities, net	(67)	(57)
Recurring | Noncurrent derivative liability
Derivative Liabilities
Derivative liability, netting	122	98
Derivative liabilities, net	(96)	(86)
Recurring | Natural Gas
Derivative Assets
Derivative asset, netting	(216)	(285)
Derivative assets, net	82	102
Derivative Liabilities
Derivative liability, netting	258	294
Derivative liabilities, net	(92)	(89)
Recurring | Electricity
Derivative Assets
Derivative asset, netting	(299)	(232)
Derivative assets, net	78	75
Derivative Liabilities
Derivative liability, netting	327	253
Derivative liabilities, net	(69)	(52)
Recurring | Other
Derivative Assets
Derivative asset, netting	(3)	(2)
Derivative assets, net	1	3
Derivative Liabilities
Derivative liability, netting	12	8
Derivative liabilities, net	(1)	(2)
Recurring | Foreign currency exchange contracts
Derivative Assets
Derivative asset, netting	(5)	(9)
Derivative assets, net	1	3
Derivative Liabilities
Derivative liability, netting	3	7
Derivative liabilities, net	(1)	0
Recurring | Level 1
ASSETS
Cash equivalents	11	13
Nuclear decommissioning trusts	752	759
Other investments	154	149
Derivative Assets
Derivative Assets, gross	136	195
Total assets	1,053	1,116
Derivative Liabilities
Derivative Liabilities	(193)	(220)
Net Assets (Liabilities) at the end of the period	860	896
Recurring | Level 1 | Current asset
Derivative Assets
Total assets	118	174
Recurring | Level 1 | Noncurrent asset
Derivative Assets
Total assets	935	942
Recurring | Level 1 | Current derivative liability
Derivative Liabilities
Derivative Liabilities	(150)	(174)
Recurring | Level 1 | Noncurrent derivative liability
Derivative Liabilities
Derivative Liabilities	(43)	(46)
Recurring | Level 1 | Natural Gas
Derivative Assets
Derivative Assets, gross	133	193
Derivative Liabilities
Derivative Liabilities	(188)	(218)
Recurring | Level 1 | Electricity
Derivative Assets
Derivative Assets, gross	0	0
Derivative Liabilities
Derivative Liabilities	0	0
Recurring | Level 1 | Other
Derivative Assets
Derivative Assets, gross	3	2
Derivative Liabilities
Derivative Liabilities	(5)	(2)
Recurring | Level 1 | Foreign currency exchange contracts
Derivative Assets
Derivative Assets, gross	0	0
Derivative Liabilities
Derivative Liabilities	0	0
Recurring | Level 2
ASSETS
Cash equivalents	3	3
Nuclear decommissioning trusts	491	473
Other investments	0	0
Derivative Assets
Derivative Assets, gross	400	342
Total assets	894	818
Derivative Liabilities
Derivative Liabilities	(364)	(307)
Net Assets (Liabilities) at the end of the period	530	511
Recurring | Level 2 | Current asset
Derivative Assets
Total assets	325	284
Recurring | Level 2 | Noncurrent asset
Derivative Assets
Total assets	569	534
Recurring | Level 2 | Current derivative liability
Derivative Liabilities
Derivative Liabilities	(296)	(260)
Recurring | Level 2 | Noncurrent derivative liability
Derivative Liabilities
Derivative Liabilities	(68)	(47)
Recurring | Level 2 | Natural Gas
Derivative Assets
Derivative Assets, gross	89	91
Derivative Liabilities
Derivative Liabilities	(52)	(57)
Recurring | Level 2 | Electricity
Derivative Assets
Derivative Assets, gross	305	239
Derivative Liabilities
Derivative Liabilities	(308)	(243)
Recurring | Level 2 | Other
Derivative Assets
Derivative Assets, gross	0	0
Derivative Liabilities
Derivative Liabilities	0	0
Recurring | Level 2 | Foreign currency exchange contracts
Derivative Assets
Derivative Assets, gross	6	12
Derivative Liabilities
Derivative Liabilities	(4)	(7)
Recurring | Level 3
ASSETS
Cash equivalents	0	0
Nuclear decommissioning trusts	0	0
Other investments	0	0
Derivative Assets
Derivative Assets, gross	149	174
Total assets	149	174
Derivative Liabilities
Derivative Liabilities	(206)	(178)
Net Assets (Liabilities) at the end of the period	(57)	(4)
Recurring | Level 3 | Current asset
Derivative Assets
Total assets	98	128
Recurring | Level 3 | Noncurrent asset
Derivative Assets
Total assets	51	46
Recurring | Level 3 | Current derivative liability
Derivative Liabilities
Derivative Liabilities	(99)	(87)
Recurring | Level 3 | Noncurrent derivative liability
Derivative Liabilities
Derivative Liabilities	(107)	(91)
Recurring | Level 3 | Natural Gas
Derivative Assets
Derivative Assets, gross	76	103
Derivative Liabilities
Derivative Liabilities	(110)	(108)
Recurring | Level 3 | Electricity
Derivative Assets
Derivative Assets, gross	72	68
Derivative Liabilities
Derivative Liabilities	(88)	(62)
Recurring | Level 3 | Other
Derivative Assets
Derivative Assets, gross	1	3
Derivative Liabilities
Derivative Liabilities	(8)	(8)
Recurring | Level 3 | Foreign currency exchange contracts
Derivative Assets
Derivative Assets, gross	0	0
Derivative Liabilities
Derivative Liabilities	0	0
DTE Electric | Recurring
ASSETS
Cash equivalents	7	8
Nuclear decommissioning trusts	1,246	1,236
Alternative Investments valued at NAV as practical expedient for FV	3	4
Other investments	8	8
Derivative Assets
Total assets	1,262	1,255
DTE Electric | Recurring | Current asset
Derivative Assets
Total assets	8	11
DTE Electric | Recurring | Noncurrent asset
ASSETS
Alternative Investments valued at NAV as practical expedient for FV	3	4
Derivative Assets
Total assets	1,254	1,244
DTE Electric | Recurring | Financial transmission rights
Derivative Assets
Derivative assets, net	1	3
DTE Electric | Recurring | Level 1
ASSETS
Cash equivalents	4	5
Nuclear decommissioning trusts	752	759
Other investments	8	8
Derivative Assets
Total assets	764	772
DTE Electric | Recurring | Level 1 | Current asset
Derivative Assets
Total assets	4	5
DTE Electric | Recurring | Level 1 | Noncurrent asset
Derivative Assets
Total assets	760	767
DTE Electric | Recurring | Level 1 | Financial transmission rights
Derivative Assets
Derivative assets, net	0	0
DTE Electric | Recurring | Level 2
ASSETS
Cash equivalents	3	3
Nuclear decommissioning trusts	491	473
Other investments	0	0
Derivative Assets
Total assets	494	476
DTE Electric | Recurring | Level 2 | Current asset
Derivative Assets
Total assets	3	3
DTE Electric | Recurring | Level 2 | Noncurrent asset
Derivative Assets
Total assets	491	473
DTE Electric | Recurring | Level 2 | Financial transmission rights
Derivative Assets
Derivative assets, net	0	0
DTE Electric | Recurring | Level 3
ASSETS
Cash equivalents	0	0
Nuclear decommissioning trusts	0	0
Other investments	0	0
Derivative Assets
Total assets	1	3
DTE Electric | Recurring | Level 3 | Current asset
Derivative Assets
Total assets	1	3
DTE Electric | Recurring | Level 3 | Noncurrent asset
Derivative Assets
Total assets	0	0
DTE Electric | Recurring | Level 3 | Financial transmission rights
Derivative Assets
Derivative assets, net	1	3
Nuclear decommissioning trust fund | Recurring
ASSETS
Alternative Investments valued at NAV as practical expedient for FV	3	4
Nuclear decommissioning trust fund | DTE Electric | Recurring
ASSETS
Alternative Investments valued at NAV as practical expedient for FV	$ 3	$ 4

Fair Value (Reconciliation of L

Fair Value (Reconciliation of Level 3 Assets and Liabilities at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	$ (4)	$ 24
Transfers into Level 3 from Level 2	0	(1)
Transfers from Level 3 into Level 2	(1)	0
Total gains (losses):
Included in earnings	(79)	(24)
Recorded in Regulatory assets	(2)	(2)
Purchases, issuances, and settlements:
Settlements	29	(9)
Net Assets (Liabilities) as of end of period	(57)	(12)
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31, 2016 and 2015 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	(76)	(96)
DTE Electric
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	3	3
Total gains (losses):
Recorded in Regulatory assets	(2)	(2)
Purchases, issuances, and settlements:
Settlements	0	0
Net Assets (Liabilities) as of end of period	1	1
The amount of total gains (losses) included in Regulatory assets attributed to the change in unrealized gains (losses) related to assets held at March 31, 2016 and 2015 and reflected in DTE Electric's Consolidated Statements of Financial Position	0	0
Natural Gas
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	(5)	30
Transfers into Level 3 from Level 2	0	0
Transfers from Level 3 into Level 2	(1)	0
Total gains (losses):
Included in earnings	(20)	(29)
Recorded in Regulatory assets	0	0
Purchases, issuances, and settlements:
Settlements	(8)	(1)
Net Assets (Liabilities) as of end of period	(34)	0
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31, 2016 and 2015 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	(72)	(91)
Electricity
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	6	(5)
Transfers into Level 3 from Level 2	0	0
Transfers from Level 3 into Level 2	0	0
Total gains (losses):
Included in earnings	(58)	7
Recorded in Regulatory assets	0	0
Purchases, issuances, and settlements:
Settlements	36	(9)
Net Assets (Liabilities) as of end of period	(16)	(7)
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31, 2016 and 2015 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	(3)	(3)
Other
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	(5)	(1)
Transfers into Level 3 from Level 2	0	(1)
Transfers from Level 3 into Level 2	0	0
Total gains (losses):
Included in earnings	(1)	(2)
Recorded in Regulatory assets	(2)	(2)
Purchases, issuances, and settlements:
Settlements	1	1
Net Assets (Liabilities) as of end of period	(7)	(5)
The amount of total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31, 2016 and 2015 and reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations	$ (1)	$ (2)

Fair Value (Unobservable Inputs

Fair Value (Unobservable Inputs related to Level 3 Assets and Liabilities) (Details) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016USD ($)$ / MWh$ / MMBTU	Dec. 31, 2015USD ($)$ / MWh$ / MMBTU
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets, gross	$ 685	$ 711
Derivative Liabilities	(763)	(705)
Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets, gross	149	174
Derivative Liabilities	(206)	(178)
Natural Gas
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets, gross	298	387
Derivative Liabilities	(350)	(383)
Natural Gas | Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets, gross	76	103
Derivative Liabilities	$ (110)	$ (108)
Natural Gas | Minimum | Discounted cash flow valuation technique | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | $ / MMBTU	(1.21)	(1.50)
Natural Gas | Maximum | Discounted cash flow valuation technique | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | $ / MMBTU	3.62	2.77
Natural Gas | Weighted Average | Discounted cash flow valuation technique | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | $ / MMBTU	(0.12)	(0.19)
Electricity
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets, gross	$ 377	$ 307
Derivative Liabilities	(396)	(305)
Electricity | Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets, gross	72	68
Derivative Liabilities	$ (88)	$ (62)
Electricity | Minimum | Discounted cash flow valuation technique | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | $ / MWh	(14)	(11)
Electricity | Maximum | Discounted cash flow valuation technique | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | $ / MWh	13	14
Electricity | Weighted Average | Discounted cash flow valuation technique | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | $ / MWh	1	2

Fair Value (Fair Value of Finan

Fair Value (Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases	$ 32	$ 32
Dividends payable	131	131
Short-term borrowings	365	499
Long-term debt, excluding capital leases	9,201	9,210
Carrying Amount | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases	5	5
Short-term borrowings	211	272
Long-term debt, excluding capital leases	5,579	5,588
Carrying Amount | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	97	75
Fair Value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases	0	0
Dividends payable	131	131
Short-term borrowings	0	0
Long-term debt, excluding capital leases	495	496
Fair Value | Level 1 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases	0	0
Short-term borrowings	0	0
Long-term debt, excluding capital leases	0	0
Fair Value | Level 1 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0	0
Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases	0	0
Dividends payable	0	0
Short-term borrowings	365	499
Long-term debt, excluding capital leases	8,353	8,136
Fair Value | Level 2 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases	0	0
Short-term borrowings	211	272
Long-term debt, excluding capital leases	5,501	5,432
Fair Value | Level 2 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0	0
Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases	32	32
Dividends payable	0	0
Short-term borrowings	0	0
Long-term debt, excluding capital leases	1,299	1,203
Fair Value | Level 3 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding capital leases	5	5
Short-term borrowings	0	0
Long-term debt, excluding capital leases	717	545
Fair Value | Level 3 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	$ 97	$ 75

Fair Value (Fair Value of Nucle

Fair Value (Fair Value of Nuclear Decommissioning Trust Fund Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	$ 1,246	$ 1,236
DTE Electric
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	1,246	1,236
DTE Electric | Fermi 2
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	1,220	1,211
DTE Electric | Fermi 1
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	3	3
DTE Electric | Low-level radioactive waste
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	23	22
DTE Electric | Nuclear decommissioning trust fund
Schedule of Available-for-sale Securities [Line Items]
Nuclear decommissioning trust funds	$ 1,246	$ 1,236

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) - DTE Electric - Nuclear decommissioning trust fund - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Realized gains	$ 9	$ 9
Realized losses	(15)	(7)
Proceeds from sales of securities	$ 260	$ 246

Fair Value (Fair Value and Unre

Fair Value (Fair Value and Unrealized Gains and Losses for the Nuclear Decommissioning Trust Funds) (Details) - DTE Electric - Nuclear decommissioning trust fund - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Equity securities, fair value	$ 728	$ 731
Debt securities, fair value	512	499
Cash and cash equivalents	6	6
Fair Value	1,246	1,236
Equity securities, unrealized gains	199	195
Debt securities, unrealized gains	24	16
Unrealized Gains	223	211
Equity securities, unrealized losses	(68)	(68)
Debt securities, unrealized losses	(2)	(4)
Unrealized Losses	$ (70)	$ (72)

Fair Value (Details Textuals)

Fair Value (Details Textuals) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Fair Value, Option, Quantitative Disclosures [Line Items]
Trading securities realized gain (loss)	$ 5,000,000	$ 1,000,000
Recurring
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash equivalents	14,000,000		$ 16,000,000
Recurring | Restricted assets
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash equivalents	7,000,000		8,000,000
Recurring | Other investments
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash equivalents	7,000,000		8,000,000
DTE Electric
Fair Value, Option, Quantitative Disclosures [Line Items]
Trading securities realized gain (loss)	5,000,000	1,000,000
DTE Electric | Recurring
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash equivalents	7,000,000		8,000,000
DTE Electric | Recurring | Other investments
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash equivalents	7,000,000		8,000,000
Nuclear decommissioning trust fund | DTE Electric
Fair Value, Option, Quantitative Disclosures [Line Items]
Cash equivalents	$ 6,000,000		$ 6,000,000
Average maturity of debt securities (in years)	6 years		6 years
Accumulated Net Unrealized Investment Gain (Loss)
Fair Value, Option, Quantitative Disclosures [Line Items]
Unrealized losses on available for sale securities	$ 0	0
Accumulated Net Unrealized Investment Gain (Loss) | DTE Electric
Fair Value, Option, Quantitative Disclosures [Line Items]
Unrealized losses on available for sale securities	$ 0	$ 0

Financial and Other Derivativ47

Financial and Other Derivative Instruments (Fair Value of Derivative Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 685	$ 711
Derivative Liabilities	(763)	(705)
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Assets	685	711
Derivative Liabilities	(763)	(705)
DTE Electric | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Assets	1	3
Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	6	12
Derivative Liabilities	(4)	(7)
Foreign currency exchange contracts | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Assets	6	12
Derivative Liabilities	(4)	(7)
Natural Gas
Derivatives, Fair Value [Line Items]
Derivative Assets	298	387
Derivative Liabilities	(350)	(383)
Natural Gas | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Assets	298	387
Derivative Liabilities	(350)	(383)
Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	377	307
Derivative Liabilities	(396)	(305)
Electricity | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Assets	377	307
Derivative Liabilities	(396)	(305)
Other
Derivatives, Fair Value [Line Items]
Derivative Assets	4	5
Derivative Liabilities	(13)	(10)
Other | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Assets	4	5
Derivative Liabilities	(13)	(10)
Financial transmission rights | DTE Electric | Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative Assets	1	3
Current derivative asset
Derivatives, Fair Value [Line Items]
Derivative Assets	527	570
Current derivative liability
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(545)	(521)
Noncurrent derivative asset
Derivatives, Fair Value [Line Items]
Derivative Assets	158	141
Noncurrent derivative liability
Derivatives, Fair Value [Line Items]
Derivative Liabilities	$ (218)	$ (184)

Financial and Other Derivativ48

Financial and Other Derivative Instruments (Netting Offsets of Derivative Assets and Liabilities) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Offsetting Assets [Line Items]
Derivative Assets	$ 685	$ 711
Gross Amounts Offset in the Consolidated Statements of Financial Position	(523)	(528)
Net Amounts of Assets Presented in the Consolidated Statements of Financial Position	162	183
Gross Amounts of Recognized (Liabilities)	(763)	(705)
Gross Amounts Offset in the Consolidated Statements of Financial Position	600	562
Net Amounts of (Liabilities) Presented in the Consolidated Statements of Financial Position	(163)	(143)
Natural Gas
Offsetting Assets [Line Items]
Derivative Assets	298	387
Gross Amounts Offset in the Consolidated Statements of Financial Position	(216)	(285)
Net Amounts of Assets Presented in the Consolidated Statements of Financial Position	82	102
Gross Amounts of Recognized (Liabilities)	(350)	(383)
Gross Amounts Offset in the Consolidated Statements of Financial Position	258	294
Net Amounts of (Liabilities) Presented in the Consolidated Statements of Financial Position	(92)	(89)
Electricity
Offsetting Assets [Line Items]
Derivative Assets	377	307
Gross Amounts Offset in the Consolidated Statements of Financial Position	(299)	(232)
Net Amounts of Assets Presented in the Consolidated Statements of Financial Position	78	75
Gross Amounts of Recognized (Liabilities)	(396)	(305)
Gross Amounts Offset in the Consolidated Statements of Financial Position	327	253
Net Amounts of (Liabilities) Presented in the Consolidated Statements of Financial Position	(69)	(52)
Other
Offsetting Assets [Line Items]
Derivative Assets	4	5
Gross Amounts Offset in the Consolidated Statements of Financial Position	(3)	(2)
Net Amounts of Assets Presented in the Consolidated Statements of Financial Position	1	3
Gross Amounts of Recognized (Liabilities)	(13)	(10)
Gross Amounts Offset in the Consolidated Statements of Financial Position	12	8
Net Amounts of (Liabilities) Presented in the Consolidated Statements of Financial Position	(1)	(2)
Foreign currency exchange contracts
Offsetting Assets [Line Items]
Derivative Assets	6	12
Gross Amounts Offset in the Consolidated Statements of Financial Position	(5)	(9)
Net Amounts of Assets Presented in the Consolidated Statements of Financial Position	1	3
Gross Amounts of Recognized (Liabilities)	(4)	(7)
Gross Amounts Offset in the Consolidated Statements of Financial Position	3	7
Net Amounts of (Liabilities) Presented in the Consolidated Statements of Financial Position	$ (1)	$ 0

Financial and Other Derivativ49

Financial and Other Derivative Instruments (Netting Offsets Reconciliation to Balance Sheet) (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Derivative Assets
Derivative Assets, gross	$ 685	$ 711
Collateral adjustment	(7)	(2)
Derivative assets, current	109	129
Derivative assets, noncurrent	53	54
Derivative Liabilities
Derivative Liabilities	(763)	(705)
Collateral adjustment	84	36
Derivative liabilities, current	(67)	(57)
Derivative liabilities, noncurrent	(96)	(86)
Current derivative asset
Derivative Assets
Derivative Assets, gross	527	570
Counterparty netting	(415)	(441)
Collateral adjustment	(3)	0
Noncurrent derivative asset
Derivative Assets
Derivative Assets, gross	158	141
Counterparty netting	(101)	(85)
Collateral adjustment	(4)	(2)
Current derivative liability
Derivative Liabilities
Derivative Liabilities	(545)	(521)
Counterparty netting	415	441
Collateral adjustment	63	23
Noncurrent derivative liability
Derivative Liabilities
Derivative Liabilities	(218)	(184)
Counterparty netting	101	85
Collateral adjustment	$ 21	$ 13

Financial and Other Derivativ50

Financial and Other Derivative Instruments (Effect of Derivatives not Designated as Hedging Instruments on the Consolidated Statement of Operations) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ (46)	$ (75)
Foreign currency exchange contracts | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(5)	1
Natural Gas | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(56)	(126)
Natural Gas | Fuel, purchased power, and gas — non-utility
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	41	21
Electricity | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(24)	31
Other | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ (2)	$ (2)

Financial and Other Derivativ51

Financial and Other Derivative Instruments (Cumulative Gross Volume of Derivative Contracts Outstanding) (Details)	Mar. 31, 2016CADMWhgalMMBTU
Natural Gas (MMBtu)
Derivative [Line Items]
Number of units | MMBTU	1,864,037,929
Electricity (MWh)
Derivative [Line Items]
Number of units | MWh	31,063,981
Oil (Gallons)
Derivative [Line Items]
Number of units | gal	19,992,000
Foreign currency exchange contracts (Canadian dollars)
Derivative [Line Items]
Derivative fair value | CAD	CAD 84,218,522

Financial and Other Derivativ52

Financial and Other Derivative Instruments (Details Textuals) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Letters of credit that could be used to offset net derivative liabilities	$ 2	$ 7
Letters of credit received that could be used to offset net derivative assets	2	2
Cash collateral posted, net of cash collateral received	79	37
Collateral adjustment on derivative assets	7	2
Collateral adjustment on derivative liabilities	84	36
Cash collateral paid	5	6
Cash collateral received	3	$ 3
Additional collateral, aggregate fair value	437
Derivative net liability position aggregate fair value	639
Collateral already posted fair value	2
Derivative net asset position, fair value	491
Remaining amount of offsets to derivative net liability positions for hard and soft trigger provisions	$ 146

Long-Term Debt (Details)

Long-Term Debt (Details) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)
Debt Instrument [Line Items]
Debt redemption amount	$ 11
Mortgages | DTE Electric | March 2016 Mortgage Bonds 7.904%
Debt Instrument [Line Items]
Interest Rate	7.904%
Debt redemption amount	$ 10
Other Long-Term Debt | DTE Energy
Debt Instrument [Line Items]
Debt redemption amount	$ 1

Short-Term Credit Arrangement54

Short-Term Credit Arrangements and Borrowings (Details)	Mar. 31, 2016USD ($)
Availability under combined facilities
Maximum borrowing capacity	$ 2,070,000,000
Amounts outstanding	532,000,000
Net availability	1,538,000,000
DTE Energy
Availability under combined facilities
Maximum borrowing capacity	1,370,000,000
Amounts outstanding	238,000,000
Net availability	1,132,000,000
DTE Electric
Availability under combined facilities
Maximum borrowing capacity	400,000,000
Amounts outstanding	211,000,000
Net availability	189,000,000
DTE Gas
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Amounts outstanding	83,000,000
Net availability	217,000,000
Letter of Credit
Availability under combined facilities
Amounts outstanding	167,000,000
Letter of Credit | DTE Energy
Availability under combined facilities
Amounts outstanding	167,000,000
Letter of Credit | DTE Electric
Availability under combined facilities
Amounts outstanding	0
Letter of Credit | DTE Gas
Availability under combined facilities
Amounts outstanding	0
Letter of Credit | Unsecured letter of credit facility, expiring in February 2017
Availability under combined facilities
Maximum borrowing capacity	100,000,000
Letter of Credit | Unsecured letter of credit facility, expiring in February 2017 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	100,000,000
Letter of Credit | Unsecured letter of credit facility, expiring in February 2017 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Letter of Credit | Unsecured letter of credit facility, expiring in February 2017 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Letter of Credit | Unsecured letter of credit facility, expiring in September 2017
Availability under combined facilities
Maximum borrowing capacity	70,000,000
Letter of Credit | Unsecured letter of credit facility, expiring in September 2017 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	70,000,000
Letter of Credit | Unsecured letter of credit facility, expiring in September 2017 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Letter of Credit | Unsecured letter of credit facility, expiring in September 2017 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Revolving Credit Facility | Unsecured revolving credit facility, expiring April 2020
Availability under combined facilities
Maximum borrowing capacity	1,900,000,000
Revolving Credit Facility | Unsecured revolving credit facility, expiring April 2020 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	1,200,000,000
Revolving Credit Facility | Unsecured revolving credit facility, expiring April 2020 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	400,000,000
Revolving Credit Facility | Unsecured revolving credit facility, expiring April 2020 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Commercial paper issuances
Availability under combined facilities
Amounts outstanding	365,000,000
Commercial paper issuances | DTE Energy
Availability under combined facilities
Amounts outstanding	71,000,000
Commercial paper issuances | DTE Electric
Availability under combined facilities
Amounts outstanding	211,000,000
Commercial paper issuances | DTE Gas
Availability under combined facilities
Amounts outstanding	$ 83,000,000

Short-Term Credit Arrangement55

Short-Term Credit Arrangements and Borrowings (Details Textuals)	Mar. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Short-term Debt [Line Items]
Other outstanding letters of credit	$ 532,000,000
Maximum
Short-term Debt [Line Items]
Ratio of indebtedness to net capital	0.65
DTE Energy
Short-term Debt [Line Items]
Ratio of indebtedness to net capital	0.50
Other outstanding letters of credit	$ 238,000,000
DTE Electric
Short-term Debt [Line Items]
Ratio of indebtedness to net capital	0.51
Other outstanding letters of credit	$ 211,000,000
DTE Gas
Short-term Debt [Line Items]
Ratio of indebtedness to net capital	0.47
Other outstanding letters of credit	$ 83,000,000
Letter of Credit
Short-term Debt [Line Items]
Other outstanding letters of credit	167,000,000
Letter of Credit | DTE Energy
Short-term Debt [Line Items]
Other outstanding letters of credit	167,000,000
Letter of Credit | DTE Electric
Short-term Debt [Line Items]
Other outstanding letters of credit	0
Letter of Credit | DTE Gas
Short-term Debt [Line Items]
Other outstanding letters of credit	0
Demand Financing Agreement | DTE Energy
Short-term Debt [Line Items]
Maximum borrowing capacity, financing agreement	100,000,000
Maximum additional margin financing	50,000,000
Amount outstanding	106,000,000	$ 103,000,000
Demand Financing Agreement Plus Letter of Credit | DTE Energy
Short-term Debt [Line Items]
Maximum borrowing capacity, financing agreement	135,000,000
Other outstanding letters of credit | Letter of Credit | DTE Energy
Short-term Debt [Line Items]
Other outstanding letters of credit	17,000,000
Demand Financing Agreement | Letter of Credit | DTE Energy
Short-term Debt [Line Items]
Maximum borrowing capacity, financing agreement	$ 35,000,000

Commitments and Contingencies (

Commitments and Contingencies (Details Textuals)	3 Months Ended	12 Months Ended
	Mar. 31, 2016USD ($)facilityinstance	Dec. 31, 2015USD ($)	Jul. 31, 2009facility
Loss Contingencies [Line Items]
Number of NOVs/FOVs currently being discussed with the EPA | instance	2
Synthetic Fuel
Loss Contingencies [Line Items]
Number of days after expiration of statutes of limitations	90 days
Maximum potential liability	$ 850,000,000
Emissions
Loss Contingencies [Line Items]
Number of days after expiration of statutes of limitations	90 days
Maximum potential liability	$ 270,000,000
Other Guarantees
Loss Contingencies [Line Items]
Maximum potential liability	56,000,000
Performance Surety Bonds
Loss Contingencies [Line Items]
Performance bonds outstanding	56,000,000
PADEP NOV
Loss Contingencies [Line Items]
Penalties accrued	189,000	$ 534,000
DTE Electric
Loss Contingencies [Line Items]
Number of power plants in violation | facility			5
Environmental capital expenditures through prior year end		$ 2,300,000,000
Estimated environmental capital expenditures in current year	$ 45,000,000
Number of permitted engineered coal ash storage facilities owned | facility	3
Time period to complete studies on cooling water intake structures impacts on fish - EPA ruling (in years)	7 years
Coal Combustion Residual Rule [Member] | DTE Electric
Loss Contingencies [Line Items]
Estimated costs associated with building new facilities	$ 290,000,000

Retirement Benefits and Trust57

Retirement Benefits and Trusteed Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 23	$ 25
Interest cost	54	53
Expected return on plan assets	(77)	(74)
Amortization of net actuarial loss	40	51
Amortization of prior service credit	0	0
Net periodic benefit cost (credit)	40	55
Pension Benefits | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	18	20
Interest cost	41	40
Expected return on plan assets	(55)	(53)
Amortization of net actuarial loss	29	38
Amortization of prior service credit	0	0
Net periodic benefit cost (credit)	33	45
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	6	9
Interest cost	20	20
Expected return on plan assets	(32)	(33)
Amortization of net actuarial loss	8	11
Amortization of prior service credit	(30)	(31)
Net periodic benefit cost (credit)	(28)	(24)
Other Postretirement Benefits | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	5	7
Interest cost	15	16
Expected return on plan assets	(23)	(23)
Amortization of net actuarial loss	6	8
Amortization of prior service credit	(22)	(24)
Net periodic benefit cost (credit)	$ (19)	$ (16)

Retirement Benefits and Trust58

Retirement Benefits and Trusteed Assets (Details Textuals) $ in Millions	3 Months Ended
	Mar. 31, 2016USD ($)
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Maximum contribution amount	$ 175
Pension Benefits | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Maximum contribution amount	145
Qualified Pension Plan | DTE Gas
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Maximum contribution amount	$ 20

Segment and Related Informati59

Segment and Related Information (Details Textuals) customer in Millions	Mar. 31, 2016customer
Segment Reporting [Abstract]
Number of electric utility customers	2.2
Number of gas utility customers	1.2

Segment and Related Informati60

Segment and Related Information (Financial Data - Operating Revenues including Inter-segment Revenues) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting, Revenue Reconciling Item [Line Items]
Utility operations	$ 1,664	$ 1,841
Non-utility operations	902	1,143
Inter-segment Revenues	2,566	2,984
Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Non-utility operations	(169)	(201)
Electric | Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Utility operations	1,153	1,203
Electric | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Non-utility operations	(9)	(9)
Gas | Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Utility operations	520	647
Gas | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Non-utility operations	0	(1)
Gas Storage and Pipelines | Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Non-utility operations	67	57
Gas Storage and Pipelines | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Non-utility operations	(2)	(1)
Power and Industrial Projects | Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Non-utility operations	446	567
Power and Industrial Projects | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Non-utility operations	(148)	(180)
Energy Trading | Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Non-utility operations	549	711
Energy Trading | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Non-utility operations	(10)	(9)
Corporate and Other | Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Non-utility operations	0	0
Corporate and Other | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Non-utility operations	$ 0	$ (1)

Segment and Related Informati61

Segment and Related Information (Financial Data - Net Income (Loss) Attributable to DTE Energy by Segment) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income (Loss) Attributable to DTE Energy Company	$ 247	$ 273
Electric
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income (Loss) Attributable to DTE Energy Company	127	136
Gas
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income (Loss) Attributable to DTE Energy Company	87	111
Gas Storage and Pipelines
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income (Loss) Attributable to DTE Energy Company	30	27
Power and Industrial Projects
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income (Loss) Attributable to DTE Energy Company	17	33
Energy Trading
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income (Loss) Attributable to DTE Energy Company	(7)	(9)
Corporate and Other
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income (Loss) Attributable to DTE Energy Company	$ (7)	$ (25)