DTE Energy (DTE) 10-Q 27 Apr 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	3 Months Ended
	Mar. 31, 2021shares
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	1-11607
Entity Registrant Name	DTE Energy Co
Entity Incorporation, State or Country Code	MI
Entity Tax Identification Number	38-3217752
Entity Address, Address Line One	One Energy Plaza
Entity Address, City or Town	Detroit
Entity Address, State or Province	MI
Entity Address, Postal Zip Code	48226-1279
City Area Code	313
Local Phone Number	235-4000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	193,727,361
Entity Central Index Key	0000936340
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false
DTE Electric
Entity File Number	1-2198
Entity Registrant Name	DTE Electric Co
Entity Incorporation, State or Country Code	MI
Entity Tax Identification Number	38-0478650
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	138,632,324
Entity Central Index Key	0000028385
Common stock, without par value
Title of 12(b) Security	Common stock, without par value
Trading Symbol	DTE
Security Exchange Name	NYSE
2016 Series B 5.375% Junior Subordinated Debentures due 2076
Title of 12(b) Security	2016 Series B 5.375% Junior Subordinated Debentures due 2076
Trading Symbol	DTJ
Security Exchange Name	NYSE
2016 Series F 6.00% Junior Subordinated Debentures due 2076
Title of 12(b) Security	2016 Series F 6.00% Junior Subordinated Debentures due 2076
Trading Symbol	DTY
Security Exchange Name	NYSE
2017 Series E 5.25% Junior Subordinated Debentures due 2077
Title of 12(b) Security	2017 Series E 5.25% Junior Subordinated Debentures due 2077
Trading Symbol	DTW
Security Exchange Name	NYSE
2019 6.25% Corporate Units
Title of 12(b) Security	2019 6.25% Corporate Units
Trading Symbol	DTP
Security Exchange Name	NYSE
2020 Series G 4.375% Junior Subordinated Debentures due 2080
Title of 12(b) Security	2020 Series G 4.375% Junior Subordinated Debentures due 2080
Trading Symbol	DTB
Security Exchange Name	NYSE

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating Revenues
Utility operations	$ 1,953	$ 1,733
Non-utility operations	1,825	1,289
Operating Revenues	3,778	3,022
Operating Expenses
Fuel, purchased power, and gas — utility	544	467
Fuel, purchased power, gas, and other — non-utility	1,600	968
Operation and maintenance	608	579
Depreciation and amortization	368	353
Taxes other than income	122	119
Asset (gains) losses and impairments, net	(1)	(10)
Operating Expenses	3,241	2,476
Operating Income	537	546
Other (Income) and Deductions
Interest expense	181	175
Interest income	(7)	(10)
Non-operating retirement benefits, net	4	9
Other income	(76)	(65)
Other expenses	10	46
Other (Income) and Deductions	112	155
Income Before Income Taxes	425	391
Income Tax Expense	28	49
Net Income	397	342
Less: Net Income Attributable to Noncontrolling Interests	0	2
Net Income Attributable to DTE Energy Company/DTE Electric Company	$ 397	$ 340
Basic Earnings per Common Share
Net Income Attributable to DTE Energy Company (in dollars per share)	$ 2.05	$ 1.77
Diluted Earnings per Common Share
Net Income Attributable to DTE Energy Company (in dollars per share)	$ 2.05	$ 1.76
Weighted Average Common Shares Outstanding
Basic (in shares)	194	192
Diluted (in shares)	194	192
DTE Electric
Operating Revenues
Utility operations	$ 1,360	$ 1,212
Operating Expenses
Fuel, purchased power, and gas — utility	362	297
Operation and maintenance	357	360
Depreciation and amortization	260	258
Taxes other than income	82	83
Operating Expenses	1,061	998
Operating Income	299	214
Other (Income) and Deductions
Interest expense	82	81
Interest income	0	(2)
Other income	(19)	(13)
Other expenses	8	41
Other (Income) and Deductions	71	107
Income Before Income Taxes	228	107
Income Tax Expense	20	13
Net Income Attributable to DTE Energy Company/DTE Electric Company	$ 208	$ 94

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net Income	$ 397	$ 342
Net Income	397	340
Other comprehensive income (loss), net of tax:
Benefit obligations, net of taxes of $1 for both periods	2	3
Net unrealized gains (losses) on derivatives, net of taxes of $— for both periods	1	1
Foreign currency translation	0	(1)
Other comprehensive income	3	3
Comprehensive income	400	345
Less: Comprehensive income attributable to noncontrolling interests	0	2
Comprehensive Income Attributable to DTE Energy Company/DTE Electric Company	400	343
DTE Electric
Net Income	208	94
Other comprehensive income (loss), net of tax:
Other comprehensive income	0	0
Comprehensive Income Attributable to DTE Energy Company/DTE Electric Company	$ 208	$ 94

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Unaudited) (Parentheticals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Tax effect on benefit obligations	$ 1	$ 1
Tax effect on net unrealized gains (losses) on derivatives during the period	$ 0	$ 0

Consolidated Statements of Fina

Consolidated Statements of Financial Position (Unaudited) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Current Assets
Cash and cash equivalents	$ 1,568	$ 514
Restricted cash	2	2
Accounts receivable (less allowance for doubtful accounts)
Customer	1,553	1,665
Other	132	127
Inventories
Fuel and gas	204	335
Materials, supplies, and other	460	381
Derivative assets	73	116
Regulatory assets	117	129
Other	267	229
Total Current Assets	4,376	3,498
Investments
Nuclear decommissioning trust funds	1,924	1,855
Investments in equity method investees	1,856	1,868
Other	197	196
Total Investments	3,977	3,919
Property
Property, plant, and equipment	38,430	37,997
Accumulated depreciation and amortization	(10,158)	(10,028)
Property, plant, and equipment, net	28,272	27,969
Other Assets
Goodwill	2,466	2,466
Regulatory assets	4,070	4,128
Intangible assets	2,318	2,339
Notes receivable	304	280
Derivative assets	37	40
Prepaid postretirement costs	576	561
Operating lease right-of-use assets	145	152
Other	158	144
Total Other Assets	10,074	10,110
Total Assets	46,699	45,496
Accounts payable
Accounts payable	955	1,029
Accrued interest	169	158
Dividends payable	210	210
Short-term borrowings	52	38
Current portion long-term debt, including finance leases	469	469
Derivative liabilities	89	68
Gas inventory equalization	68	0
Regulatory liabilities	29	39
Short-term borrowings
Operating lease liabilities	33	33
Other	521	647
Total Current Liabilities	2,595	2,691
Long-Term Debt (net of current portion)
Mortgage bonds, notes, and other	18,796	17,802
Junior subordinated debentures	1,175	1,175
Finance lease liabilities	22	24
Total Long-Term Debt (net of current portion)	19,993	19,001
Other Liabilities
Deferred income taxes	2,894	2,822
Regulatory liabilities	3,416	3,363
Asset retirement obligations	2,879	2,839
Unamortized investment tax credit	160	162
Derivative liabilities	119	60
Accrued pension liability	773	797
Accrued postretirement liability	404	407
Nuclear decommissioning	295	283
Operating lease liabilities	105	111
Other	352	371
Total Other Liabilities	11,397	11,215
Commitments and Contingencies (Notes 6 and 13)
Equity
Common stock	5,344	5,406
Retained earnings	7,342	7,156
Accumulated other comprehensive loss	(134)	(137)
Total DTE Energy/DTE Electric Company Equity	12,552	12,425
Noncontrolling interests	162	164
Total Equity	12,714	12,589
Total Liabilities and Equity	46,699	45,496
DTE Electric
Current Assets
Cash and cash equivalents	878	16
Accounts receivable (less allowance for doubtful accounts)
Customer	664	763
Affiliates	5	13
Other	55	62
Inventories
Fuel and gas	137	187
Materials, supplies, and other	318	292
Regulatory assets	106	123
Other	122	71
Total Current Assets	2,285	1,527
Investments
Nuclear decommissioning trust funds	1,924	1,855
Other	44	42
Total Investments	1,968	1,897
Property
Property, plant, and equipment	26,481	26,171
Accumulated depreciation and amortization	(7,112)	(7,050)
Property, plant, and equipment, net	19,369	19,121
Other Assets
Regulatory assets	3,404	3,440
Intangible assets	6	11
Prepaid postretirement costs — affiliates	343	335
Operating lease right-of-use assets	73	75
Other	115	107
Total Other Assets	3,941	3,968
Total Assets	27,563	26,513
Accounts payable
Affiliates	70	62
Other	361	410
Accrued interest	79	91
Current portion long-term debt, including finance leases	468	468
Regulatory liabilities	24	18
Short-term borrowings
Affiliates	78	101
Operating lease liabilities	11	11
Other	169	219
Total Current Liabilities	1,260	1,380
Long-Term Debt (net of current portion)
Mortgage bonds, notes, and other	8,764	7,774
Finance lease liabilities	11	13
Total Long-Term Debt (net of current portion)	8,775	7,787
Other Liabilities
Deferred income taxes	2,560	2,525
Regulatory liabilities	2,485	2,432
Asset retirement obligations	2,645	2,607
Unamortized investment tax credit	160	162
Nuclear decommissioning	295	283
Accrued pension liability — affiliates	719	731
Accrued postretirement liability — affiliates	382	384
Operating lease liabilities	54	56
Other	97	96
Total Other Liabilities	9,397	9,276
Commitments and Contingencies (Notes 6 and 13)
Equity
Common stock	5,447	5,447
Retained earnings	2,684	2,623
Total DTE Energy/DTE Electric Company Equity	8,131	8,070
Total Liabilities and Equity	$ 27,563	$ 26,513

Consolidated Statements of Fi_2

Consolidated Statements of Financial Position (Unaudited) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Current Assets
Allowance for doubtful accounts	$ 123	$ 104
Shareholder’s Equity
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	193,727,361	193,770,617
Common stock, shares outstanding (in shares)	193,727,361	193,770,617
DTE Electric
Current Assets
Allowance for doubtful accounts	$ 59	$ 57
Shareholder’s Equity
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, 2021	Mar. 31, 2020
Operating Activities
Net Income	$ 397	$ 342
Net Income	397	340
Adjustments to reconcile Net Income to Net cash from operating activities:
Depreciation and amortization	368	353
Nuclear fuel amortization	15	13
Allowance for equity funds used during construction	(7)	(6)
Deferred income taxes	41	213
Equity earnings of equity method investees	(32)	(29)
Dividends from equity method investees	42	39
Asset (gains) losses and impairments, net	1	(6)
Changes in assets and liabilities:
Accounts receivable, net	107	151
Inventories	52	55
Prepaid postretirement benefit costs	(15)	(14)
Accounts payable	(20)	(24)
Gas inventory equalization	68	62
Accrued pension liability	(24)	(13)
Accrued postretirement liability	(3)	0
Derivative assets and liabilities	126	(30)
Regulatory assets and liabilities	128	(149)
Other current and noncurrent assets and liabilities	(187)	104
Net cash from operating activities	1,057	1,061
Investing Activities
Plant and equipment expenditures — utility	(630)	(993)
Plant and equipment expenditures — non-utility	(39)	(195)
Acquisitions related to business combinations, net of cash acquired	0	(128)
Proceeds from sale of assets	1	4
Proceeds from sale of nuclear decommissioning trust fund assets	271	439
Investment in nuclear decommissioning trust funds	(273)	(438)
Distributions from equity method investees	4	1
Contributions to equity method investees	(2)	(15)
Notes receivable	(27)	(14)
Other	(10)	(3)
Net cash used for investing activities	(705)	(1,342)
Financing Activities
Issuance of long-term debt, net of issuance costs	989	1,092
Redemption of long-term debt	0	(300)
Short-term borrowings, net	14	303
Repurchase of common stock	(54)	0
Dividends paid on common stock	(210)	(195)
Contributions from noncontrolling interests, principally REF entities	12	10
Distributions to noncontrolling interests	(14)	(10)
Other	(35)	(36)
Net cash from financing activities	702	864
Net Increase in Cash, Cash Equivalents, and Restricted Cash	1,054	583
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	516	93
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,570	676
Supplemental disclosure of non-cash investing and financing activities
Plant and equipment expenditures in accounts payable	208	285
DTE Electric
Operating Activities
Net Income	208	94
Adjustments to reconcile Net Income to Net cash from operating activities:
Depreciation and amortization	260	258
Nuclear fuel amortization	15	13
Allowance for equity funds used during construction	(6)	(6)
Deferred income taxes	15	7
Changes in assets and liabilities:
Accounts receivable, net	114	54
Inventories	24	(18)
Accounts payable	(8)	106
Prepaid postretirement benefit costs — affiliates	(8)	0
Accrued pension liability — affiliates	(12)	(6)
Accrued postretirement liability — affiliates	(2)	(8)
Regulatory assets and liabilities	121	(152)
Other current and noncurrent assets and liabilities	(150)	132
Net cash from operating activities	571	474
Investing Activities
Plant and equipment expenditures	(502)	(871)
Proceeds from sale of nuclear decommissioning trust fund assets	271	439
Investment in nuclear decommissioning trust funds	(273)	(438)
Other	(9)	(2)
Net cash used for investing activities	(513)	(872)
Financing Activities
Issuance of long-term debt, net of issuance costs	989	1,092
Redemption of long-term debt	0	(300)
Short-term borrowings, net — affiliate	(23)	42
Short-term borrowings, net — other	0	(283)
Dividends paid on common stock	(147)	(135)
Other	(15)	(17)
Net cash from financing activities	804	399
Net Increase in Cash, Cash Equivalents, and Restricted Cash	862	1
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	16	12
Cash, Cash Equivalents, and Restricted Cash at End of Period	878	13
Supplemental disclosure of non-cash investing and financing activities
Plant and equipment expenditures in accounts payable	$ 141	$ 138

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Millions	Total	Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	DTE Electric	DTE ElectricCommon Stock	DTE ElectricAdditional Paid-in Capital	DTE ElectricRetained Earnings
Beginning Balance (in shares) at Dec. 31, 2019		192,209,000					138,632,000
Beginning Balance at Dec. 31, 2019	$ 11,836	$ 5,233	$ 6,587	$ (148)	$ 164
Beginning Balance at Dec. 31, 2019						$ 7,195	$ 1,386	$ 3,425	$ 2,384
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	342		340		2
Net Income	340					94			94
Dividends declared on common stock	(195)		(195)			(135)			(135)
Other comprehensive income, net of tax	3			3		0
Stock-based compensation, net distributions to noncontrolling interests, and other (in shares)		403,000
Stock-based compensation, net distributions to noncontrolling interests, and other	2	$ 2
Ending Balance (in shares) at Mar. 31, 2020		192,612,000					138,632,000
Ending Balance at Mar. 31, 2020	$ 11,988	$ 5,235	6,732	(145)	166
Ending Balance at Mar. 31, 2020						$ 7,154	$ 1,386	3,425	2,343
Beginning Balance (in shares) at Dec. 31, 2020	193,770,617	193,771,000				138,632,324	138,632,000
Beginning Balance at Dec. 31, 2020	$ 12,589	$ 5,406	7,156	(137)	164
Beginning Balance at Dec. 31, 2020	12,425					$ 8,070	$ 1,386	4,061	2,623
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	397		397
Net Income	397					208			208
Dividends declared on common stock	(210)		(210)			(147)			(147)
Repurchase of common stock (in shares)		(430,000)
Repurchase of common stock	(54)	$ (54)
Other comprehensive income, net of tax	3			3		$ 0
Stock-based compensation, net distributions to noncontrolling interests, and other (in shares)		386,000
Stock-based compensation, net distributions to noncontrolling interests, and other	$ (11)	$ (8)	(1)		(2)
Ending Balance (in shares) at Mar. 31, 2021	193,727,361	193,727,000				138,632,324	138,632,000
Ending Balance at Mar. 31, 2021	$ 12,714	$ 5,344	$ 7,342	$ (134)	$ 162
Ending Balance at Mar. 31, 2021	$ 12,552					$ 8,131	$ 1,386	$ 4,061	$ 2,684

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Stockholders' Equity [Abstract]
Dividends declared on common stock (in dollars per share)	$ 1.09	$ 1.01

Organization and Basis of Prese

Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2021
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 1.3 million customers throughout Michigan and the sale of storage and transportation capacity; and • Other businesses primarily involved in 1) services related to the gathering, transportation, and storage of natural gas; 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, EGLE, and for DTE Energy, the CFTC and CARB. 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 2020 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, 2021. 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. 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 equity investment is valued at cost minus any impairments, if applicable. 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 generally accounted for under the equity method. DTE Energy currently owns an 85% interest in SGG, which owns and operates midstream natural gas assets. SGG has contracts through which certain construction risk was designed to pass-through to the customers, with DTE Energy retaining operational and customer default risk. SGG is a VIE with DTE Energy as the primary beneficiary. The Registrants have variable interests in NEXUS, which include DTE Energy's 50% ownership interest and DTE Electric's transportation services contract. NEXUS is a joint venture which owns a 256-mile pipeline to transport Utica and Marcellus shale gas to Ohio, Michigan, and Ontario market centers. NEXUS also owns Generation Pipeline, LLC, a 25-mile regulated pipeline system located in northern Ohio. NEXUS is a VIE as it has insufficient equity at risk to finance its activities. The Registrants are not the primary beneficiaries, as the power to direct significant activities is shared between the owners of the equity interests. DTE Energy accounts for its ownership interest in NEXUS under the equity method. The Registrants hold ownership interests in certain limited partnerships. The limited partnerships include investment funds which support regional development and economic growth, and an operational business providing energy-related products. These entities are generally VIEs as a result of certain characteristics of the limited partnership voting rights. The ownership interests are accounted for under the equity method as the Registrants are not the primary beneficiaries. 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, including the transportation services contract with NEXUS. As of March 31, 2021, 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, 2021, 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 material 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 material 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 and, for DTE Energy, in Note 13 to the Consolidated Financial Statements, "Commitments and Contingencies," related to the REF guarantees and indemnities. For non-consolidated VIEs, the maximum risk exposure of the Registrants is generally limited to their investment, notes receivable, future funding commitments, and amounts which DTE Energy has loaned or guaranteed. See Note 13 to the Consolidated Financial Statements, "Commitments and Contingencies," for further discussion of the NEXUS guarantee arrangements and credit agreement related to Brilliant Energy, LLC, a non-consolidated VIE and customer of DTE Energy Trading. The following table summarizes the major Consolidated Statements of Financial Position items for consolidated VIEs as of March 31, 2021 and December 31, 2020. 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. Amounts for DTE Energy's consolidated VIEs are as follows: March 31, 2021 December 31, 2020 SGG (a) Other Total SGG (a) Other Total (In millions) ASSETS Cash and cash equivalents $ 21 $ 23 $ 44 $ 34 $ 20 $ 54 Accounts receivable 9 22 31 8 28 36 Inventories — 52 52 — 107 107 Property, plant, and equipment, net 400 19 419 402 23 425 Goodwill 25 — 25 25 — 25 Intangible assets 524 — 524 527 — 527 Other current and long-term assets 1 47 48 2 33 35 $ 980 $ 163 $ 1,143 $ 998 $ 211 $ 1,209 LIABILITIES Accounts payable and accrued current liabilities $ — $ 19 $ 19 $ — $ 22 $ 22 Short-term borrowings — 52 52 — 38 38 Other current and long-term liabilities 7 4 11 7 4 11 $ 7 $ 75 $ 82 $ 7 $ 64 $ 71 _____________________________________ (a) Amounts shown are 100% of SGG's assets and liabilities, of which DTE Energy owns 85% at March 31, 2021 and December 31, 2020. Amounts for DTE Energy's non-consolidated VIEs are as follows: March 31, 2021 December 31, 2020 (In millions) Investments in equity method investees $ 1,496 $ 1,507 Notes receivable $ 48 $ 47 Future funding commitments $ 22 $ 26

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES Other Income The following is a summary of DTE Energy's Other income: Three Months Ended March 31, 2021 2020 (In millions) Equity earnings of equity method investees $ 32 $ 29 Income from REF entities 24 23 Contract services 8 7 Allowance for equity funds used during construction 7 6 Gains from rabbi trust securities (a) 2 — Other 3 — $ 76 $ 65 _______________________________________ (a) Losses from rabbi trust securities are recorded separately to Other expenses on the Consolidated Statements of Operations. The following is a summary of DTE Electric's Other income: Three Months Ended March 31, 2021 2020 (In millions) Contract services 8 7 Allowance for equity funds used during construction 6 6 Gains from rabbi trust securities allocated from DTE Energy (a) $ 2 $ — Other 3 — $ 19 $ 13 _______________________________________ (a) Losses from rabbi trust securities are recorded separately to Other expenses on the Consolidated Statements of Operations. Changes in Accumulated Other Comprehensive Income (Loss) Comprehensive income (loss) is the change in common shareholders' equity during a period from transactions and events from non-owner sources, including Net Income. The amounts recorded to Accumulated other comprehensive income (loss) for DTE Energy include changes in benefit obligations, consisting of deferred actuarial losses and prior service costs, unrealized gains and losses from derivatives accounted for as cash flow hedges, and foreign currency translation adjustments. DTE Energy releases income tax effects from accumulated other comprehensive income when the circumstances upon which they are premised cease to exist. 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. For the three months ended March 31, 2021 and 2020, reclassifications out of Accumulated other comprehensive income (loss) were not material. Income Taxes The interim effective tax rates of the Registrants are as follows: Effective Tax Rate Three Months Ended March 31, 2021 2020 DTE Energy 7 % 13 % DTE Electric 9 % 12 % These tax rates are affected by estimated annual permanent items, including AFUDC equity, production tax credits, and other flow-through items, as well as discrete items that may occur in any given period, but are not consistent from period to period. The 6% decrease in DTE Energy's effective tax rate for the three months ended March 31, 2021 was primarily due to an increase in production tax credits of 3% and higher amortization of the TCJA regulatory liability of 2%. The 3% decrease in DTE Electric's effective tax rate for the three months ended March 31, 2021 was primarily due to an increase in production tax credits of 2% and higher amortization of the TCJA regulatory liability of 1%. DTE Electric had income tax receivables with DTE Energy of $3 million and $8 million at March 31, 2021 and December 31, 2020, respectively. Unrecognized Compensation Costs As of March 31, 2021, DTE Energy had $111 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 1.85 years. Allocated Stock-Based Compensation DTE Electric received an allocation of costs from DTE Energy associated with stock-based compensation of $14 million and $9 million for the three months ended March 31, 2021 and 2020, respectively. Cash, Cash Equivalents, and Restricted Cash Cash and cash equivalents include cash on hand, cash in banks, and temporary investments purchased with remaining maturities of three months or less. Restricted cash consists of funds held in separate bank accounts to satisfy contractual obligations and guarantee performance. Restricted cash designated for payments within one year is classified as a Current Asset. Financing Receivables Financing receivables are primarily composed of trade receivables, notes receivable, and unbilled revenue. The Registrant's financing receivables are stated at net realizable value. The Registrants monitor the credit quality of their financing receivables on a regular basis by reviewing credit quality indicators and monitoring for trigger events, such as a credit rating downgrade or bankruptcy. Credit quality indicators include, but are not limited to, ratings by credit agencies where available, collection history, collateral, counterparty financial statements and other internal metrics. Utilizing such data, the Registrants have determined three internal grades of credit quality. Internal grade 1 includes financing receivables for counterparties where credit rating agencies have ranked the counterparty as investment grade. To the extent credit ratings are not available, the Registrants utilize other credit quality indicators to determine the level of risk associated with the financing receivable. Internal grade 1 may include financing receivables for counterparties for which credit rating agencies have ranked the counterparty as below investment grade; however, due to favorable information on other credit quality indicators, the Registrants have determined the risk level to be similar to that of an investment grade counterparty. Internal grade 2 includes financing receivables for counterparties with limited credit information and those with a higher risk profile based upon credit quality indicators. Internal grade 3 reflects financing receivables for which the counterparties have the greatest level of risk, including those in bankruptcy status. The following represents the Registrants' financing receivables by year of origination, classified by internal grade of credit risk. The related credit quality indicators and risk ratings utilized to develop the internal grades have been updated through March 31, 2021. DTE Energy DTE Electric Year of origination 2021 2020 2019 and Prior Total 2021 and Prior (In millions) Notes receivable Internal grade 1 $ — $ — $ 23 $ 23 $ 14 Internal grade 2 1 64 52 117 2 Total notes receivable (a) $ 1 $ 64 $ 75 $ 140 $ 16 Net investment in leases Net investment in leases, internal grade 1 $ — $ 4 $ 39 $ 43 $ — Net investment in leases, internal grade 2 — 161 1 162 — Total net investment in leases (a) $ — $ 165 $ 40 $ 205 $ — _______________________________________ (a) For DTE Energy, included in Current Assets — Other and Other Assets — Notes Receivable on the Consolidated Statements of Financial Position. For DTE Electric, included in Other Assets — Other on the Consolidated Statements of Financial Position. The allowance for doubtful accounts on accounts receivable for the utility entities is generally calculated using an aging approach that utilizes rates developed in reserve studies. DTE Electric and DTE Gas establish an allowance for uncollectible accounts based on historical losses and management's assessment of existing and future economic conditions, customer trends and other factors. Customer accounts are generally considered delinquent if the amount billed is not received by the due date, which is typically in 21 days, however, factors such as assistance programs may delay aggressive action. DTE Electric and DTE Gas generally assess late payment fees on trade receivables based on past-due terms with customers. Customer accounts are written off when collection efforts have been exhausted. The time period for write-off is 150 days after service has been terminated. The customer allowance for doubtful accounts for non-utility businesses and other receivables for both utility and non-utility businesses is generally calculated based on specific review of probable future collections based on receivable balances generally in excess of 30 days. Existing and future economic conditions, customer trends and other factors are also considered. Receivables are written off on a specific identification basis and determined based upon the specific circumstances of the associated receivable. Notes receivable for DTE Energy are primarily comprised of finance lease receivables and loans that are included in Notes Receivable and Other current assets on DTE Energy's Consolidated Statements of Financial Position. Notes receivable for DTE Electric are primarily comprised of loans. Notes receivable are typically considered delinquent when payment is not received for periods ranging from 60 to 120 days. The Registrants cease accruing interest (nonaccrual status), consider a note receivable impaired, and establish an allowance for credit loss when it is probable that all principal and interest amounts due will not be collected in accordance with the contractual terms of the note receivable. In determining the allowance for credit losses for notes receivable, the Registrants consider the historical payment experience and other factors that are expected to have a specific impact on the counterparty's ability to pay including existing and future economic conditions. DTE Energy has off balance sheet exposure in the form of a revolving credit facility. Refer to Note 13, "Commitments and Contingencies," for additional information. In determining the level of credit reserve needed, DTE considers the likelihood of funding in addition to the other factors noted above. A reserve may be established when it is likely that funding will occur. Cash payments received on nonaccrual status notes receivable, that do not bring the account contractually current, are first applied to the contractually owed past due interest, with any remainder applied to principal. Accrual of interest is generally resumed when the note receivable becomes contractually current. The following tables present a roll-forward of the activity for the Registrants' financing receivables credit loss reserves: DTE Energy DTE Electric Trade accounts receivable Other receivables Total Trade and other accounts receivable (In millions) Beginning reserve balance, January 1, 2021 $ 101 $ 3 $ 104 $ 57 Current period provision 30 — 30 12 Write-offs charged against allowance (36) — (36) (24) Recoveries of amounts previously written off 25 — 25 14 Ending reserve balance, March 31, 2021 $ 120 $ 3 $ 123 $ 59 DTE Energy DTE Electric Trade accounts receivable Other receivables Total Trade and other accounts receivable (In millions) Beginning reserve balance, January 1, 2020 $ 87 $ 4 $ 91 $ 46 Current period provision 34 1 35 17 Write-offs charged against allowance (51) (1) (52) (30) Recoveries of amounts previously written off 16 — 16 10 Ending reserve balance, March 31, 2020 $ 86 $ 4 $ 90 $ 43 Uncollectible expense for the Registrants is primarily comprised of the current period provision for allowance for doubtful accounts. For DTE Energy, uncollectible expense was $31 million and $33 million for the three months ended March 31, 2021 and 2020, respectively. For DTE Electric, uncollectible expense was $11 million and $17 million for the three months ended March 31, 2021 and 2020, respectively. There are no material amounts of past due financing receivables for the Registrants as of March 31, 2021.

New Accounting Pronouncements

New Accounting Pronouncements	3 Months Ended
	Mar. 31, 2021
Accounting Standards Update and Change in Accounting Principle [Abstract]
New Accounting Pronouncements	NEW ACCOUNTING PRONOUNCEMENTS Recently Adopted Pronouncements In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes . The amendments in this update simplify the accounting for income taxes by removing certain exceptions, and clarifying certain requirements regarding franchise taxes, goodwill, consolidated tax expenses, and annual effective tax rate calculations. The Registrants adopted the ASU effective January 1, 2021 using the modified retrospective and prospective approaches, where applicable. The adoption of the ASU did not have a significant impact on the Registrants' Consolidated Financial Statements. In August 2020, the FASB issued ASU No. 2020-06, Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity's Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity's Own Equity. The amendments in this update simplify the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts indexed to and potentially settled in an entity's own equity. The Registrants adopted the ASU effective January 1, 2021 using the modified retrospective approach. The adoption of the ASU did not have a significant impact on the Registrants' Consolidated Financial Statements. In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848) - Facilitation of the Effects of Reference Rate Reform on Financial Reporting, as amended

Dispositions

Dispositions	3 Months Ended
	Mar. 31, 2021
Discontinued Operations and Disposal Groups [Abstract]
Dispositions	DISPOSITIONS DTE Midstream Spin-off On October 27, 2020, DTE Energy announced that its Board of Directors has authorized management to pursue a plan to spin-off the DTE Midstream business. DTE Energy expects to complete the separation by mid-year 2021, subject to final approval by its Board of Directors, the Form 10 registration statement being declared effective by the Securities and Exchange Commission, regulatory approvals, and satisfaction of other conditions. DTE Energy shareholder approval is not required to effect the separation transaction. Upon closing of the transaction, DTE Energy shareholders will own shares of both DTE Energy and the new midstream company ("DT Midstream"). The planned separation transaction is intended to be a tax-free spin-off for DTE Energy and its shareholders for U.S. federal income tax purposes. There can be no assurance that any separation transaction will ultimately occur or, if one does occur, of its terms or timing.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE Disaggregation of Revenue The following is a summary of revenues disaggregated by segment for DTE Energy: Three Months Ended March 31, 2021 2020 (In millions) Electric (a) Residential $ 672 $ 599 Commercial 451 426 Industrial 159 156 Other (b) 82 35 Total Electric operating revenues (c) $ 1,364 $ 1,216 Gas Gas sales $ 461 $ 394 End User Transportation 85 77 Intermediate Transportation 26 26 Other (b) 40 43 Total Gas operating revenues (d) $ 612 $ 540 Other segment operating revenues Gas Storage and Pipelines (e) $ 197 $ 170 Power and Industrial Projects (f) $ 366 $ 407 Energy Trading (g) $ 1,439 $ 913 _______________________________________ (a) Revenues generally represent those of DTE Electric, except $4 million of Other revenues related to DTE Sustainable Generation for the three months ended March 31, 2021 and 2020. (b) Includes revenue adjustments related to various regulatory mechanisms. (c) Includes $3 million and $4 million of Other revenues for the three months ended March 31, 2021 and 2020, respectively, which are outside the scope of Topic 606. (d) Includes $2 million under Alternative Revenue Programs for the three months ended March 31, 2020 and $2 million of Other revenues for both the three months ended March 31, 2021 and 2020, which are all outside the scope of Topic 606. (e) Includes revenues outside the scope of Topic 606 primarily related to $2 million of contracts accounted for as leases for the three months ended March 31, 2021 and 2020. (f) Includes revenues outside the scope of Topic 606 primarily related to $21 million and $27 million of contracts accounted for as leases for the three months ended March 31, 2021 and 2020, respectively. (g) Includes revenues outside the scope of Topic 606 primarily related to $1.1 billion and $637 million of derivatives for the three months ended March 31, 2021 and 2020, respectively. Deferred Revenue The following is a summary of deferred revenue activity: DTE Energy (In millions) Beginning Balance, January 1, 2021 $ 87 Increases due to cash received or receivable, excluding amounts recognized as revenue during the period 21 Revenue recognized that was included in the deferred revenue balance at the beginning of the period (13) Ending Balance, March 31, 2021 $ 95 The deferred revenues at DTE Energy generally represent amounts paid by or receivable from customers for which the associated performance obligation has not yet been satisfied. Deferred revenues include amounts associated with REC performance obligations under certain wholesale full requirements power contracts. Deferred revenues associated with RECs are recognized as revenue when control of the RECs has transferred. Other performance obligations associated with deferred revenues include providing products and services related to customer prepayments. Deferred revenues associated with these products and services are recognized when control has transferred to the customer. The following table represents deferred revenue amounts for DTE Energy that are expected to be recognized as revenue in future periods: DTE Energy (In millions) 2021 $ 60 2022 13 2023 3 2024 3 2025 7 2026 and thereafter 9 $ 95 Transaction Price Allocated to the Remaining Performance Obligations In accordance with optional exemptions available under Topic 606, the Registrants did not disclose the value of unsatisfied performance obligations for (1) contracts with an original expected length of one year or less, (2) with the exception of fixed consideration, contracts for which revenue is recognized at the amount to which the Registrants have the right to invoice for goods provided and services performed, and (3) contracts for which variable consideration relates entirely to an unsatisfied performance obligation. Such contracts consist of varying types of performance obligations across the segments, including the supply and delivery of energy related products and services. Contracts with variable volumes and/or variable pricing, including those with pricing provisions tied to a consumer price or other index, have also been excluded as the related consideration under the contract is variable at inception of the contract. Contract lengths vary from cancellable to multi-year. The Registrants expect to recognize revenue for the following amounts related to fixed consideration associated with remaining performance obligations in each of the future periods noted: DTE Energy DTE Electric (In millions) 2021 $ 221 $ 6 2022 373 7 2023 302 7 2024 191 7 2025 120 1 2026 and thereafter 502 — $ 1,709 $ 28

Regulatory Matters

Regulatory Matters	3 Months Ended
	Mar. 31, 2021
Public Utilities, General Disclosures [Abstract]
Regulatory Matters	REGULATORY MATTERS 2020-2021 Accounting Applications On July 9, 2020, the MPSC approved DTE Electric's request to accelerate amortization of the portion of its refundable federal income taxes regulatory liability related to non-plant accumulated deferred income tax balances that resulted from the TCJA. DTE Electric was authorized to increase amortization by $102 million beginning in May 2021, which would fully amortize this portion of the liability by the end of 2021 instead of April 2033. The accelerated amortization would not impact customer rates and would allow DTE Electric to defer its next rate case filing previously set for July 2020 to March 2021. On February 26, 2021, DTE Electric filed an additional application requesting a delay in the accelerated amortization approved in the 2020 application. DTE Electric requested delaying the start of amortization from May 2021 to December 1, 2021, which would fully amortize these balances by the end of 2022 and allow DTE Electric to further defer its next rate case filing to October 2021 or later. The accounting application was approved by the MPSC on April 8, 2021. 2021 Securitization Filing On March 26, 2021, DTE Electric filed an application requesting a financing order approving the securitization of $184 million of qualified costs related to the net book value of the River Rouge generation plant and tree trimming surge program costs. The filing requests collection of these qualifying costs from DTE Electric's customers. A final MPSC order is expected by the end of June 2021. 2021 Gas Rate Case Filing DTE Gas filed a rate case with the MPSC on February 12, 2021 requesting an increase in base rates of $195 million based on a projected twelve-month period ending December 31, 2022. The requested increase in base rates is primarily due to an increase in net plant resulting from infrastructure investments and operating and maintenance expenses. The rate filing also requested an increase in return on equity from 9.9% to 10.25% and includes projected changes in sales and working capital. A final MPSC order in this case is expected by December 2021.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE Basic earnings per share is calculated by dividing the net income, adjusted for income allocated to participating securities, by the weighted average number of common shares outstanding during the period. Diluted earnings per share reflect the dilution that would occur if any potentially dilutive instruments were exercised or converted into common shares. DTE Energy’s participating securities are restricted shares under the stock incentive program that contain rights to receive non-forfeitable dividends. Equity units and performance shares do not receive cash dividends; as such, these awards are not considered participating securities. The following is a reconciliation of DTE Energy's basic and diluted income per share calculation: Three Months Ended March 31, 2021 2020 (In millions, except per share amounts) Basic Earnings per Share Net Income Attributable to DTE Energy Company $ 397 $ 340 Less: Allocation of earnings to net restricted stock awards — 1 Net income available to common shareholders — basic $ 397 $ 339 Average number of common shares outstanding — basic 194 192 Basic Earnings per Common Share $ 2.05 $ 1.77 Diluted Earnings per Share Net Income Attributable to DTE Energy Company $ 397 $ 340 Less: Allocation of earnings to net restricted stock awards — 1 Net income available to common shareholders — diluted $ 397 $ 339 Average number of common shares outstanding — diluted 194 192 Diluted Earnings per Common Share (a) $ 2.05 $ 1.76 _______________________________________ (a) Equity Units excluded from the calculation of diluted EPS were approximately 10.3 million for both the three months ended March 31, 2021 and 2020, as the dilutive stock price threshold was not met.

Fair Value

Fair Value	3 Months Ended
	Mar. 31, 2021
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, 2021 and December 31, 2020. 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: March 31, 2021 December 31, 2020 Level Level Level Other (a) Netting (b) Net Balance Level Level Level Other (a) Netting (b) Net Balance (In millions) Assets Cash equivalents (c) $ 1,500 $ — $ — $ — $ — $ 1,500 $ 438 $ — $ — $ — $ — $ 438 Nuclear decommissioning trusts Equity securities 999 — — 205 — 1,204 947 — — 222 — 1,169 Fixed income securities 107 385 — 86 — 578 102 371 — 82 — 555 Private equity and other — — — 122 — 122 — — — 104 — 104 Cash equivalents 20 — — — — 20 27 — — — — 27 Other investments (d) Equity securities 58 — — — — 58 55 — — — — 55 Fixed income securities 7 — — — — 7 8 — — — — 8 Cash equivalents 98 — — — — 98 97 — — — — 97 Derivative assets Commodity contracts (e) Natural gas 49 72 42 — (106) 57 99 74 60 — (156) 77 Electricity — 118 20 — (100) 38 — 128 52 — (120) 60 Environmental & Other — 258 1 — (244) 15 — 150 4 — (135) 19 Total derivative assets 49 448 63 — (450) 110 99 352 116 — (411) 156 Total $ 2,838 $ 833 $ 63 $ 413 $ (450) $ 3,697 $ 1,773 $ 723 $ 116 $ 408 $ (411) $ 2,609 Liabilities Derivative liabilities Commodity contracts (e) Natural gas $ (36) $ (79) $ (131) $ — $ 108 $ (138) $ (88) $ (59) $ (76) $ — $ 151 $ (72) Electricity — (111) (39) — 98 (52) — (126) (42) — 125 (43) Environmental & Other — (250) — — 238 (12) — (137) — — 129 (8) Foreign currency exchange contracts — (6) — — — (6) — (5) — — (5) Total $ (36) $ (446) $ (170) $ — $ 444 $ (208) $ (88) $ (327) $ (118) $ — $ 405 $ (128) Net Assets (Liabilities) at end of period $ 2,802 $ 387 $ (107) $ 413 $ (6) $ 3,489 $ 1,685 $ 396 $ (2) $ 408 $ (6) $ 2,481 Assets Current $ 1,545 $ 282 $ 44 $ — $ (298) $ 1,573 $ 532 $ 260 $ 92 $ — $ (330) $ 554 Noncurrent 1,293 551 19 413 (152) 2,124 1,241 463 24 408 (81) 2,055 Total Assets $ 2,838 $ 833 $ 63 $ 413 $ (450) $ 3,697 $ 1,773 $ 723 $ 116 $ 408 $ (411) $ 2,609 Liabilities Current $ (34) $ (252) $ (83) $ — $ 280 $ (89) $ (84) $ (223) $ (79) $ — $ 318 $ (68) Noncurrent (2) (194) (87) — 164 (119) (4) (104) (39) — 87 (60) Total Liabilities $ (36) $ (446) $ (170) $ — $ 444 $ (208) $ (88) $ (327) $ (118) $ — $ 405 $ (128) Net Assets (Liabilities) at end of period $ 2,802 $ 387 $ (107) $ 413 $ (6) $ 3,489 $ 1,685 $ 396 $ (2) $ 408 $ (6) $ 2,481 _______________________________________ (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) Amounts consisted of $1 million and $2 million of cash equivalents included in Restricted cash on DTE Energy's Consolidated Statements of Financial Position at March 31, 2021 and December 31, 2020, respectively. All other amounts are included in Cash and cash equivalents on the Consolidated Statements of Financial Position. (d) Excludes cash surrender value of life insurance investments. (e) For contracts with a clearing agent, DTE Energy nets all activity across commodities. This can result in some individual commodities having a contra balance. The following table presents assets for DTE Electric measured and recorded at fair value on a recurring basis as of: March 31, 2021 December 31, 2020 Level 1 Level 2 Level 3 Other (a) Net Balance Level 1 Level 2 Level 3 Other (a) Net Balance (In millions) Assets Cash equivalents (b) $ 864 $ — $ — $ — $ 864 $ 4 $ — $ — $ — $ 4 Nuclear decommissioning trusts Equity securities 999 — — 205 1,204 947 — — 222 1,169 Fixed income securities 107 385 — 86 578 102 371 — 82 555 Private equity and other — — — 122 122 — — — 104 104 Cash equivalents 20 — — — 20 27 — — — 27 Other investments Equity securities 17 — — — 17 16 — — — 16 Cash equivalents 11 — — — 11 11 — — — 11 Derivative assets — FTRs — — 1 — 1 — — 4 — 4 Total $ 2,018 $ 385 $ 1 $ 413 $ 2,817 $ 1,107 $ 371 $ 4 $ 408 $ 1,890 Assets Current $ 864 $ — $ 1 $ — $ 865 $ 4 $ — $ 4 $ — $ 8 Noncurrent 1,154 385 — 413 1,952 1,103 371 — 408 1,882 Total Assets $ 2,018 $ 385 $ 1 $ 413 $ 2,817 $ 1,107 $ 371 $ 4 $ 408 $ 1,890 _______________________________________ (a) Amounts represent assets valued at NAV as a practical expedient for fair value. (b) Amounts are included in Cash and cash equivalents 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 commingled funds. Exchange-traded debt and equity securities held directly, as well as publicly-traded commingled funds, 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. Non-publicly traded commingled funds holding exchange-traded equity or debt securities are valued based on stated NAVs. There are no significant restrictions for these funds and investments may be redeemed with 7 to 65 days notice depending on the fund. There is no intention to sell the investment in these commingled funds. Private equity and other assets include a diversified group of funds that are classified as NAV assets. These funds primarily invest in private equity partnerships, as well as real estate and private debt. Distributions are received through the liquidation of the underlying fund assets over the life of the funds. There are generally no redemption rights. The limited partner must hold the fund for its life or find a third-party buyer, which may need to be approved by the general partner. The funds are established with varied contractual durations generally in the range of 7 years to 12 years. The fund life can often be extended by several years by the general partner, and further extended with the approval of the limited partners. Unfunded commitments related to these investments totaled $178 million and $183 million as of March 31, 2021 and December 31, 2020, respectively. For pricing the nuclear decommissioning trusts and other investments, 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 source of a given security if the trustee determines that another price source is considered 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. 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: Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Natural Gas Electricity Other Total Natural Gas Electricity Other Total (In millions) Net Assets (Liabilities) as of January 1 $ (16) $ 10 $ 4 $ (2) $ (15) $ 16 $ 3 $ 4 Transfers from Level 3 into Level 2 — — — — (1) — — (1) Total gains (losses) Included in earnings (67) 26 — (41) 24 20 — 44 Recorded in Regulatory liabilities — — (1) (1) — — (2) (2) Purchases, issuances, and settlements Settlements (6) (55) (2) (63) — (21) — (21) Net Assets (Liabilities) as of March 31 $ (89) $ (19) $ 1 $ (107) $ 8 $ 15 $ 1 $ 24 Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31 (a) $ (93) $ (7) $ — $ (100) $ 19 $ 21 $ — $ 40 _______________________________________ (a) Amounts are reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, gas, and other — non-utility in DTE Energy's Consolidated Statements of Operations. 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: Three Months Ended March 31, 2021 2020 (In millions) Net Assets as of January 1 $ 4 $ 3 Change in fair value recorded in Regulatory liabilities (1) (2) Purchases, issuances, and settlements Settlements (2) — Net Assets as of March 31 $ 1 $ 1 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 from or into Level 3 for DTE Electric during the three months ended March 31, 2021 and 2020. The following tables present the unobservable inputs related to DTE Energy's Level 3 assets and liabilities: March 31, 2021 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 42 $ (131) Discounted Cash Flow Forward basis price (per MMBtu) $ (1.10) — $ 2.45 /MMBtu $ (0.10) /MMBtu Electricity $ 20 $ (39) Discounted Cash Flow Forward basis price (per MWh) $ (9) — $ 6 /MWh $ (1) /MWh December 31, 2020 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 60 $ (76) Discounted Cash Flow Forward basis price (per MMBtu) $ (0.86) — $ 2.50 /MMBtu $ (0.07) /MMBtu Electricity $ 52 $ (42) Discounted Cash Flow Forward basis price (per MWh) $ (9) — $ 6 /MWh $ — /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 weighted average price for unobservable inputs was calculated using the average of forward price curves for natural gas and electricity and the absolute value of monthly volumes. The inputs listed above would have had 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 have resulted in a higher (lower) fair value for long positions, with offsetting impacts to short positions. Fair Value of Financial Instruments The following table presents the carrying amount and fair value of financial instruments for DTE Energy: March 31, 2021 December 31, 2020 Carrying Fair Value Carrying Fair Value Amount Level 1 Level 2 Level 3 Amount Level 1 Level 2 Level 3 (In millions) Notes receivable (a) , excluding lessor finance leases $ 140 $ — $ — $ 140 $ 141 $ — $ — $ 141 Short-term borrowings $ 52 $ — $ 52 $ — $ 38 $ — $ 38 $ — Notes payable (b) $ 6 $ — $ 6 $ 19 $ — $ — $ 19 Long-term debt (c) $ 20,432 $ 2,537 $ 17,950 $ 1,496 $ 19,439 $ 2,547 $ 18,230 $ 1,397 _______________________________________ (a) Current portion included in Current Assets — Other on DTE Energy's Consolidated Statements of Financial Position. (b) Included in Current Liabilities — Other and Other Liabilities — Other on DTE Energy's Consolidated Statements of Financial Position. (c) Includes debt due within one year, unamortized debt discounts, and issuance costs. Excludes finance lease obligations. The following table presents the carrying amount and fair value of financial instruments for DTE Electric: March 31, 2021 December 31, 2020 Carrying Fair Value Carrying Fair Value Amount Level 1 Level 2 Level 3 Amount Level 1 Level 2 Level 3 (In millions) Notes receivable (a) $ 16 $ — $ — $ 16 $ 16 $ — $ — $ 16 Short-term borrowings — affiliates $ 78 $ — $ — $ 78 $ 101 $ — $ — $ 101 Notes payable (b) $ 4 $ — $ — $ 4 $ 17 $ — $ — $ 17 Long-term debt (c) $ 9,226 $ — $ 9,756 $ 340 $ 8,236 $ — $ 9,579 $ 379 _______________________________________ (a) Included in Other Assets — Other on DTE Electric's Consolidated Statements of Financial Position. (b) Included in Current Liabilities — Other and Other Liabilities — Other on DTE Electric's Consolidated Statements of Financial Position. (c) Includes debt due within one year, unamortized debt discounts, and issuance costs. Excludes finance lease obligations. For further fair value information on financial and derivative instruments, see Note 9 to the Consolidated Financial Statements, "Financial and Other Derivative Instruments." Nuclear Decommissioning Trust Funds DTE Electric has a legal obligation to decommission its nuclear power plants following the expiration of its operating licenses. This obligation is reflected as an Asset retirement obligation 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. The following table summarizes DTE Electric's fair value of the nuclear decommissioning trust fund assets: March 31, 2021 December 31, 2020 (In millions) Fermi 2 $ 1,909 $ 1,841 Fermi 1 3 3 Low-level radioactive waste 12 11 $ 1,924 $ 1,855 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, 2021 2020 (In millions) Realized gains $ 24 $ 31 Realized losses $ (2) $ (16) Proceeds from sale of securities $ 271 $ 439 Realized gains and losses from the sale of securities and unrealized gains and losses incurred by the Fermi 2 trust are recorded to Regulatory assets and the Nuclear decommissioning liability. Realized gains and losses from the sale of securities and unrealized gains and losses on the 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, 2021 December 31, 2020 Fair Unrealized Unrealized Fair Unrealized Unrealized (In millions) Equity securities $ 1,204 $ 504 $ (6) $ 1,169 $ 481 $ (6) Fixed income securities 578 18 (6) 555 20 (1) Private equity and other 122 12 — 104 — — Cash equivalents 20 — — 27 — — $ 1,924 $ 534 $ (12) $ 1,855 $ 501 $ (7) The following table summarizes the fair value of the fixed income securities held in nuclear decommissioning trust funds by contractual maturity: March 31, 2021 (In millions) Due within one year $ 18 Due after one through five years 127 Due after five through ten years 109 Due after ten years 238 $ 492 Fixed income securities held in nuclear decommissioning trust funds include $86 million of non-publicly traded commingled funds that do not have a contractual maturity date. Other Securities At March 31, 2021 and December 31, 2020, the Registrants' securities included in Other investments on the Consolidated Statements of Financial Position were comprised primarily of investments within DTE Energy's rabbi trust. The rabbi trust was established to fund certain non-qualified pension benefits, and therefore changes in market value are recognized in earnings. Gains and losses are allocated from DTE Energy to DTE Electric and are included in Other Income or Other Expense, respectively, in the Registrants' Consolidated Statements of Operations. The following table summarizes the Registrant's gains (losses) related to the trust: Three Months Ended March 31, 2021 2020 (In millions) Gains (losses) related to equity securities $ 2 $ (23) Gains (losses) related to fixed income securities — (8) $ 2 $ (31)

Financial and Other Derivative

Financial and Other Derivative Instruments	3 Months Ended
	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial and Other Derivative Instruments	FINANCIAL AND OTHER DERIVATIVE INSTRUMENTSThe 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 derivative gain or loss is deferred in Accumulated other comprehensive income (loss) and later reclassified into earnings when the underlying transaction occurs. 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 environmental contracts, forwards, futures, options, swaps, and foreign currency exchange contracts. Items not classified as derivatives include natural gas and environmental inventory, pipeline transportation contracts, certain environmental contracts, and natural gas storage assets. DTE Electric — DTE Electric generates, purchases, distributes, and sells electricity. DTE Electric uses forward 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 buys and sells transportation and storage capacity. DTE Gas has fixed-priced contracts for portions of its expected natural gas supply requirements through March 2024. Substantially all of these contracts meet the normal purchases and normal sales exception and are therefore accounted for under the accrual method. 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 gathering, 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, renewable 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, 2021 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 for DTE Energy: March 31, 2021 December 31, 2020 Derivative Derivative Liabilities Derivative Derivative Liabilities (In millions) Derivatives designated as hedging instruments Foreign currency exchange contracts $ — $ (4) $ — $ (4) Derivatives not designated as hedging instruments Commodity contracts Natural gas $ 163 $ (246) $ 233 $ (223) Electricity 138 (150) 180 (168) Environmental & Other 259 (250) 154 (137) Foreign currency exchange contracts — (2) — (1) Total derivatives not designated as hedging instruments $ 560 $ (648) $ 567 $ (529) Current $ 371 $ (369) $ 446 $ (386) Noncurrent 189 (283) 121 (147) Total derivatives $ 560 $ (652) $ 567 $ (533) The following table presents the fair value of derivative instruments for DTE Electric: March 31, 2021 December 31, 2020 (In millions) FTRs — Other current assets $ 1 $ 4 Total derivatives not designated as hedging instruments $ 1 $ 4 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 $5 million and $7 million outstanding at March 31, 2021 and December 31, 2020, 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 $14 million and $9 million at March 31, 2021 and December 31, 2020, 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. The following table presents net cash collateral offsetting arrangements for DTE Energy: March 31, 2021 December 31, 2020 (In millions) Cash collateral netted against Derivative assets $ (18) $ (12) Cash collateral netted against Derivative liabilities 12 6 Cash collateral recorded in Accounts receivable (a) 13 14 Cash collateral recorded in Accounts payable (a) (3) (1) Total net cash collateral posted (received) $ 4 $ 7 _______________________________________ (a) Amounts are recorded net by counterparty. The following table presents the netting offsets of Derivative assets and liabilities for DTE Energy: March 31, 2021 December 31, 2020 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 $ 163 $ (106) $ 57 $ 233 $ (156) $ 77 Electricity 138 (100) 38 180 (120) 60 Environmental & Other 259 (244) 15 154 (135) 19 Foreign currency exchange contracts — — — — — — Total derivative assets $ 560 $ (450) $ 110 $ 567 $ (411) $ 156 Derivative liabilities Commodity contracts Natural gas $ (246) $ 108 $ (138) $ (223) $ 151 $ (72) Electricity (150) 98 (52) (168) 125 (43) Environmental & Other (250) 238 (12) (137) 129 (8) Foreign currency exchange contracts (6) — (6) (5) — (5) Total derivative liabilities $ (652) $ 444 $ (208) $ (533) $ 405 $ (128) 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: March 31, 2021 December 31, 2020 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Current Noncurrent Current Noncurrent Current Noncurrent Current Noncurrent (In millions) Total fair value of derivatives $ 371 $ 189 $ (369) $ (283) $ 446 $ 121 $ (386) $ (147) Counterparty netting (280) (152) 280 152 (318) (81) 318 81 Collateral adjustment (18) — — 12 (12) — — 6 Total derivatives as reported $ 73 $ 37 $ (89) $ (119) $ 116 $ 40 $ (68) $ (60) The effect of derivatives not designated as hedging instruments on DTE Energy's Consolidated Statements of Operations is as follows: Location of Gain (Loss) Recognized in Income on Derivatives Gain (Loss) Recognized in Income on Derivatives for the Three Months Ended March 31, 2021 2020 (In millions) Commodity contracts Natural gas Operating Revenues — Non-utility operations $ (43) $ (11) Natural gas Fuel, purchased power, gas, and other — non-utility (55) 36 Electricity Operating Revenues — Non-utility operations 33 1 Environmental & Other Operating Revenues — Non-utility operations (32) 21 Foreign currency exchange contracts Operating Revenues — Non-utility operations (2) 5 Total $ (99) $ 52 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, gas, and other — non-utility. The following represents the cumulative gross volume of DTE Energy's derivative contracts outstanding as of March 31, 2021: Commodity Number of Units Natural gas (MMBtu) 1,877,516,146 Electricity (MWh) 34,963,827 Foreign currency exchange ($ CAD) 135,478,800 Renewable Energy Certificates (MWh) 11,304,487 Carbon emissions (Metric Tons) 11,696,283 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, environmental, and coal) and the provisions and maturities of the underlying transactions. As of March 31, 2021, 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 $506 million. As of March 31, 2021, DTE Energy had $500 million of derivatives in net liability positions, for which hard triggers exist. There is no collateral that has been posted against such liabilities, including cash and letters of credit. Associated derivative net asset positions for which contractual offset exists were $450 million. The net remaining amount of $50 million is derived from the $506 million noted above.

Long-Term Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Long-Term Debt	LONG-TERM DEBT Debt Issuances In 2021, the following debt was issued: Company Month Type Interest Rate Maturity Date Amount (In millions) DTE Electric March Mortgage bonds (a) 1.90% 2028 $ 575 DTE Electric March Mortgage bonds (a) 3.25% 2051 425 $ 1,000 _______________________________________ (a) Bonds were issued as Green Bonds and the proceeds will be used to finance qualified expenditures for solar and wind energy, payments under power purchase agreements for solar and wind energy, and energy optimization programs. Debt Redemptions

Short-Term Credit Arrangements

Short-Term Credit Arrangements and Borrowings	3 Months Ended
	Mar. 31, 2021
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. DTE Energy also has other facilities to support letter of credit issuance. The unsecured revolving credit 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 finance 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, 2021, the total funded debt to total capitalization ratios for DTE Energy, DTE Electric, and DTE Gas were 0.60 to 1, 0.53 to 1, and 0.47 to 1, respectively, and were in compliance with this financial covenant. The availability under these facilities as of March 31, 2021 is shown in the following table: DTE Energy DTE Electric DTE Gas Total (In millions) Unsecured letter of credit facility, expiring in February 2023 $ 150 $ — $ — $ 150 Unsecured letter of credit facility, expiring in August 2021 110 — — 110 Unsecured term loan, expiring in November 2021 (a) — 200 — 200 Unsecured Canadian revolving credit facility, expiring May 2023 88 — — 88 Unsecured revolving credit facility, expiring April 2025 (b) 1,500 500 300 2,300 1,848 700 300 2,848 Amounts outstanding at March 31, 2021 Letters of credit 212 — — 212 Revolver borrowings 52 — — 52 264 — — 264 Net availability at March 31, 2021 $ 1,584 $ 700 $ 300 $ 2,584 _______________________________________ (a) No amounts have been drawn as of March 31, 2021 and the loan will terminate if nothing is drawn by April 30, 2021. Commitment fees are not material. (b) Total availability of $102 million expires in April 2024, including $67 million at DTE Energy, $22 million at DTE Electric, and $13 million at DTE Gas. All other availability expires in April 2025. DTE Energy has $59 million of other outstanding letters of credit which are used for various corporate purposes and are not included in the facilities described above. These letters of credit include a $50 million uncommitted letter of credit facility entered into by DTE Energy in July 2020, of which the full amount has been drawn. The facility expires in July 2021 with an automatic renewal provision. In conjunction with maintaining certain exchange-traded risk management positions, DTE Energy may be required to post collateral with its clearing agents. DTE Energy has demand financing agreements with its clearing agents, including an agreement for up to $100 million with an indefinite term and an agreement for up to $150 million currently contracted through 2022 and subject to renewal. The $100 million 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. Both agreements allow the right of setoff with posted collateral. At March 31, 2021, the capacity under the facilities was $300 million. The amounts outstanding under the agreements were $74 million and $49 million at March 31, 2021 and December 31, 2020, respectively, and were fully offset by the posted collateral.

Leases

Leases	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Leases	LEASES Lessor During the first quarter 2021, DTE Energy completed construction of and began operating certain energy infrastructure assets for a large industrial customer under a long-term agreement, where the assets will transfer to the customer at the end of the contract term in 2040. DTE Energy has accounted for a portion of the agreement as a finance lease arrangement, recognizing an additional net investment of $31 million. The components of DTE Energy’s net investment in finance leases for remaining periods were as follows: DTE Energy March 31, 2021 (In millions) 2021 $ 19 2022 22 2023 22 2024 22 2025 22 2026 and Thereafter 292 Total minimum future lease receipts 399 Residual value of leased pipeline 17 Less unearned income 211 Net investment in finance lease 205 Less current portion 9 $ 196 Interest income recognized under finance leases was $4 million for the three months ended March 31, 2021 and 2020. DTE Energy’s lease income associated with operating leases was as follows: Three Months Ended March 31, 2021 2020 (In millions) Fixed payments (a) $ 17 $ 16 Variable payments (a) 17 23 $ 34 $ 39 _______________________________________ (a) Includes $24 million and $29 million of lease payments reported in Operating Revenues on DTE Energy's Consolidated Statements of Operations for the three months ended March 31, 2021 and 2020, respectively, and $10 million of lease payments reported in Other income for both periods.
Leases	LEASES Lessor During the first quarter 2021, DTE Energy completed construction of and began operating certain energy infrastructure assets for a large industrial customer under a long-term agreement, where the assets will transfer to the customer at the end of the contract term in 2040. DTE Energy has accounted for a portion of the agreement as a finance lease arrangement, recognizing an additional net investment of $31 million. The components of DTE Energy’s net investment in finance leases for remaining periods were as follows: DTE Energy March 31, 2021 (In millions) 2021 $ 19 2022 22 2023 22 2024 22 2025 22 2026 and Thereafter 292 Total minimum future lease receipts 399 Residual value of leased pipeline 17 Less unearned income 211 Net investment in finance lease 205 Less current portion 9 $ 196 Interest income recognized under finance leases was $4 million for the three months ended March 31, 2021 and 2020. DTE Energy’s lease income associated with operating leases was as follows: Three Months Ended March 31, 2021 2020 (In millions) Fixed payments (a) $ 17 $ 16 Variable payments (a) 17 23 $ 34 $ 39 _______________________________________ (a) Includes $24 million and $29 million of lease payments reported in Operating Revenues on DTE Energy's Consolidated Statements of Operations for the three months ended March 31, 2021 and 2020, respectively, and $10 million of lease payments reported in Other income for both periods.
Leases	LEASES Lessor During the first quarter 2021, DTE Energy completed construction of and began operating certain energy infrastructure assets for a large industrial customer under a long-term agreement, where the assets will transfer to the customer at the end of the contract term in 2040. DTE Energy has accounted for a portion of the agreement as a finance lease arrangement, recognizing an additional net investment of $31 million. The components of DTE Energy’s net investment in finance leases for remaining periods were as follows: DTE Energy March 31, 2021 (In millions) 2021 $ 19 2022 22 2023 22 2024 22 2025 22 2026 and Thereafter 292 Total minimum future lease receipts 399 Residual value of leased pipeline 17 Less unearned income 211 Net investment in finance lease 205 Less current portion 9 $ 196 Interest income recognized under finance leases was $4 million for the three months ended March 31, 2021 and 2020. DTE Energy’s lease income associated with operating leases was as follows: Three Months Ended March 31, 2021 2020 (In millions) Fixed payments (a) $ 17 $ 16 Variable payments (a) 17 23 $ 34 $ 39 _______________________________________ (a) Includes $24 million and $29 million of lease payments reported in Operating Revenues on DTE Energy's Consolidated Statements of Operations for the three months ended March 31, 2021 and 2020, respectively, and $10 million of lease payments reported in Other income for both periods.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
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 SO 2 and NO X . The EPA and the State of Michigan have also 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 SO 2 , NO X , mercury, and other emissions. Additional rulemakings may occur over the next few years which could require additional controls for SO 2 , NO X , and other hazardous air pollutants. The EPA proposed revised air quality standards for ground level ozone in November 2014 and specifically requested comments on the form and level of the ozone standards. The standards were finalized in October 2015. The State of Michigan recommended to the EPA in October 2016 which areas of the state are not attaining the new standard. On April 30, 2018, the EPA finalized the State of Michigan's recommended marginal non-attainment designation for southeast Michigan. The State is required to develop and implement a plan to address the southeast Michigan ozone non-attainment area by 2021. The Registrants cannot predict the scope and associated financial impact of the State's plan to address the ozone non-attainment area at this time. The EPA has implemented 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, in 2015 the EPA finalized performance standards for emissions of carbon dioxide from new and existing fossil-fuel fired EGUs. The performance standards for existing EGUs, known as the EPA Clean Power Plan, were challenged by petitioners and stayed by the U.S. Supreme Court in February 2016 pending final review by the courts. On October 10, 2017, the EPA, under a new administration, proposed to rescind the Clean Power Plan, and in August 2018, the EPA proposed revised emission guidelines for GHGs from existing EGUs. On June 19, 2019, the EPA Administrator officially repealed the Clean Power Plan and finalized its replacement, named the ACE rule. The ACE rule was vacated and remanded back to the EPA in a D.C. Circuit Court decision on January 19, 2021. The next steps taken by the EPA with respect to regulation of GHGs from EGUs is uncertain. Regardless of future rules, DTE Energy remains committed for its electric utility operations to reduce carbon emissions 32% by 2023, 50% by 2030, and 80% by 2040 from 2005 carbon emissions levels, and its goal of net zero emissions for its electric utility operations by 2050. In addition to the GHG standards for existing EGUs, in December 2018, the EPA issued proposed revisions to the carbon dioxide performance standards for new, modified, or reconstructed fossil-fuel fired 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. 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 has spent approximately $2.4 billion. DTE Electric does not anticipate additional capital expenditures for air pollution requirements through 2025, subject to the results of future rulemakings. Water — In response to an EPA regulation, DTE Electric was required to examine alternatives for reducing the environmental impacts of the cooling water intake structures at several of its facilities. Based on the results of completed studies and expected future studies, DTE Electric may be required to install technologies to reduce the impacts of the water intake structures. A final rule became effective in October 2014. The final rule requires studies to be completed and submitted as part of the NPDES permit application process to determine the type of technology needed to reduce impacts to fish. DTE Electric has initiated the process of completing the required studies. Final compliance for the installation of any required technology will be determined by the state on a case by case, site specific basis. DTE Electric is currently evaluating the compliance options and working with the State of Michigan on evaluating whether any controls are needed. These evaluations/studies may require modifications to some existing intake structures. It is not possible to quantify the impact of this rulemaking at this time. Contaminated and Other Sites — Prior to the construction of major interstate natural gas pipelines, gas for heating and other uses was manufactured locally from processes involving coal, coke, or oil. The facilities, which produced gas, have been designated as MGP sites. DTE Electric conducted remedial investigations at contaminated sites, including three former MGP sites. Cleanup of one of the MGP sites is complete, and the site is closed. The investigations have revealed contamination related to the by-products of gas manufacturing at each MGP site. In addition to the MGP sites, DTE Electric is also in the process of cleaning up other contaminated sites, including the area surrounding an ash landfill, electrical distribution substations, electric generating power plants, and underground and above ground storage tank locations. The findings of these investigations indicated that the estimated cost to remediate these sites is expected to be incurred over the next several years. At March 31, 2021 and December 31, 2020, DTE Electric had $10 million, accrued for remediation. These costs are not discounted to their present value. Any change in assumptions, such as remediation techniques, nature and extent of contamination, and regulatory requirements, could impact the estimate of remedial action costs for the sites and affect DTE Electric’s financial position and cash flows. DTE Electric believes the likelihood of a material change to the accrued amount is remote based on current knowledge of the conditions at each site. 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, and was revised in October 2016, July 2018, September 2020, and November 2020. The rule is based on the continued listing of coal ash as a non-hazardous waste and relies on various self-implementation design and performance standards. DTE Electric owns and operates three permitted engineered coal ash storage facilities to dispose of coal ash from coal-fired power plants and operates a number of smaller impoundments at its power plants subject to certain provisions in the CCR rule. At certain facilities, the rule currently requires ongoing sampling and testing of monitoring wells, compliance with groundwater standards, and the closure of basins at the end of the useful life of the associated power plant. On September 28, 2020, the CCR rule "A Holistic Approach to Closure Part A: Deadline to Initiate Closure and Enhancing Public Access to Information" became effective and establishes April 11, 2021 as the new deadline for all unlined impoundments (including units previously classified as "clay-lined") to initiate closure. Additionally, the rule amends certain reporting requirements and CCR website requirements. On November 12, 2020, an additional revision to the CCR Rule "A Holistic Approach to Closure Part B: Alternate Demonstration for Unlined Surface Impoundments" was published in the Federal Register that provides a process to determine if certain unlined impoundments consist of an alternative liner system that may be as protective as the current liners specified in the CCR rule, and therefore may continue to operate. DTE Electric has submitted applications to the EPA that support continued use of all impoundments through their active lives. The forced closure date of April 11, 2021 is effectively delayed while the EPA's review looks to extend beyond this date. At the State level, legislation was signed by the Governor in December 2018 and provides for further regulation of the CCR program in Michigan. Additionally, the bill provides the basis of a CCR program that EGLE has submitted to the EPA for approval to fully regulate the CCR program in Michigan in lieu of a Federal permit program. In October 2020, the EPA published in the Federal Register the final version of the ELG Reconsideration Rule which updates the 2015 ELG Rule (2015 Rule). The Reconsideration Rule re-establishes the technology-based effluent limitations guidelines and standards applicable to flue gas desulfurization (FGD) wastewater and bottom ash transport water. The EPA set the applicability dates for bottom ash transport water and FGD wastewater retrofits to be "as soon as possible" beginning October 13, 2021 and no later than December 31, 2025. Compliance schedules for individual facilities and individual waste streams are determined through issuance of new NPDES permits by the State of Michigan. The State of Michigan has issued a NPDES permit for the Belle River Power Plant establishing a compliance deadline of December 31, 2021 based on the 2015 Rule. Due to completion of the Reconsideration Rule in 2020, the compliance deadlines within the NPDES permit for Belle River Power Plant will be revised accordingly. No new permits that would require ELG compliance have been issued for other facilities, consequently no compliance timelines have been established. On April 12, 2017, the EPA granted a petition for reconsideration of the 2015 ELG Rule. The EPA also signed an administrative stay of the 2015 ELG Rule’s compliance deadlines for fly ash transport water, bottom ash transport water, and FGD wastewater, among others. On June 6, 2017, the EPA published in the Federal Register a proposed rule (Postponement Rule) to postpone certain applicable deadlines within the 2015 ELG rule. The Postponement Rule was published on September 18, 2017. The Postponement Rule nullified the administrative stay but also extended the earliest compliance deadlines for only FGD wastewater and bottom ash transport water until November 1, 2020 in order for the EPA to propose and finalize a new ruling. On October 13, 2020, the EPA finalized the ELG Reconsideration Rule which revised the regulations from the 2015 ELG rule. The Reconsideration Rule revises requirements for two specific waste streams produced by steam electric power plants: FGD wastewater and bottom ash transport water. The Reconsideration Rule also provides additional compliance opportunities by finalizing low utilization and cessation of coal burning subcategories. The Reconsideration Rule provides new opportunities for DTE Electric to evaluate existing ELG compliance strategies and make any necessary adjustments to ensure full compliance with the ELGs in a cost-effective manner. DTE Electric is currently evaluating compliance strategies, technologies and system designs for both FGD wastewater and bottom ash transport water system to achieve compliance with the final rule. DTE Electric has estimated the impact of the CCR and ELG rules to be $697 million of capital expenditures, including $552 million for 2021 through 2025. DTE Gas Air — In June 2020, DTE Energy expanded its net zero goal to include its gas utility operations by committing to reduce greenhouse gas emissions to net zero by 2050 from procurement of natural gas through delivery. As part of DTE Energy's 2050 net zero commitment, DTE Gas launched its CleanVision Natural Gas Balance program in January 2021 that offers customers a way to reduce their carbon footprint using carbon offsets and renewable natural gas. The carbon offset program is focused on protecting Michigan forests that naturally absorb carbon dioxide. Contaminated and Other Sites — DTE Gas owns or previously owned, 14 former MGP sites. Investigations have revealed contamination related to the by-products of gas manufacturing at each site. Cleanup of eight of the MGP sites is complete, and the sites are closed. DTE Gas has also completed partial closure of four additional sites. Cleanup activities associated with the remaining sites will continue over the next several years. The MPSC has established a cost deferral and rate recovery mechanism for investigation and remediation costs incurred at former MGP sites. In addition to the MGP sites, DTE Gas is also in the process of cleaning up other contaminated sites, including gate stations, gas pipeline releases, and underground storage tank locations. As of March 31, 2021 and December 31, 2020, DTE Gas had $24 million, accrued for remediation. These costs are not discounted to their present value. Any change in assumptions, such as remediation techniques, nature and extent of contamination, and regulatory requirements, could impact the estimate of remedial action costs for the sites and affect DTE Gas' financial position and cash flows. DTE Gas anticipates the cost amortization methodology approved by the MPSC, which allows for amortization of the MGP costs over a ten-year period beginning with the year subsequent to the year the MGP costs were incurred, will prevent the associated investigation and remediation costs from having a material adverse impact on DTE Gas' results of operations. Non-utility DTE Energy's non-utility businesses are subject to a number of environmental laws and regulations dealing with the protection of the environment from various pollutants. In March 2019, the EPA issued an FOV to EES Coke, the Michigan coke battery facility that is a wholly-owned subsidiary of DTE Energy, alleging that the 2008 and 2014 permits issued by EGLE did not comply with the Clean Air Act. In September 2020, the EPA issued another FOV alleging EES Coke's 2018 and 2019 SO2 emissions exceeded projections and hence violated non-attainment new source review requirements. EES Coke evaluated the EPA's alleged violations and believes that the permits approved by EGLE complied with the Clean Air Act. EES Coke also responded to the EPA's September 2020 allegations demonstrating its actual emissions are compliant with non-attainment new source review requirements. Discussions with the EPA are ongoing. At the present time, DTE Energy cannot predict the outcome or financial impact of this FOV. In January 2021, DTE Midstream announced a goal to achieve net zero greenhouse gas emissions by 2050, including a 30% reduction in carbon emissions in the next decade. To achieve this goal, DTE Midstream plans comprehensive integration of carbon capture strategies to reduce carbon emissions in its operations. Other In 2010, the EPA finalized a new one-hour SO 2 ambient air quality standard that requires states to submit plans and associated timelines for non-attainment areas that demonstrate attainment with the new SO 2 standard in phases. Phase 1 addresses non-attainment areas designated based on ambient monitoring data. Phase 2 addresses non-attainment areas with large sources of SO 2 and modeled concentrations exceeding the National Ambient Air Quality Standards for SO 2 . Phase 3 addresses smaller sources of SO 2 with modeled or monitored exceedances of the new SO 2 standard. Michigan's Phase 1 non-attainment area includes DTE Energy facilities in southwest Detroit and areas of Wayne County. Modeling runs by EGLE suggest that emission reductions may be required by significant sources of SO 2 emissions in these areas, including DTE Electric power plants and DTE Energy's Michigan coke battery facility. As part Michigan's SIP process, DTE Energy has worked with EGLE to develop air permits reflecting significant SO 2 emission reductions that, in combination with other non-DTE Energy sources' emission reduction strategies, will help the state attain the standard and sustain its attainment. The Michigan SIP was completed and submitted to the EPA on May 31, 2016 and supplemented on June 30, 2016. On March 19, 2021, the EPA published in the Federal Register partial approval and partial disapproval of Michigan's Detroit SO2 non-attainment area plan. The partial disapproval does not appear to impact DTE's sources and further discussions are underway with the EPA to finalize the plan. Since several non-DTE Energy sources are also part of the proposed compliance plan, DTE Energy is unable to determine the full impact of any further emissions reductions that may be required from DTE's facilities at this time. Michigan's Phase 2 non-attainment area includes DTE Electric facilities in St. Clair County. EGLE has not made a final determination on SIP strategy for this area, pending the EPA's review of a clean data determination request. Until agency plans are final, DTE Energy is unable to determine the impacts. 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, 2021 was approximately $400 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, 2021 was $631 million. Payments under these guarantees are considered remote. NEXUS Guarantees NEXUS is party to certain 15-year capacity agreements for the transportation of natural gas with DTE Gas and Texas Eastern Transmission, LP, an unrelated third party. In conjunction with these agreements, DTE Energy provided certain guarantees on behalf of NEXUS to DTE Gas and Texas Eastern Transmission, LP, with maximum potential payments totaling $209 million and $335 million at March 31, 2021, respectively; each representing 50% of all payment obligations due and payable by NEXUS. Each guarantee terminates at the earlier of (i) such time as all of the guaranteed obligations have been fully performed, or (ii) two months following the end of the primary term of the capacity agreements in 2033. The amount of each guarantee decreases annually as payments are made by NEXUS to each of the aforementioned counterparties. NEXUS is also party to certain 15-year capacity agreements for the transportation of natural gas with Vector Pipeline L.P. ("Vector"), a 40% owned equity method investee of DTE Energy. Pursuant to the terms of those agreements, in October 2018, DTE Energy executed a guarantee agreement with Vector, with a maximum potential payment totaling $7 million at March 31, 2021, representing 50% of the first-year payment obligations due and payable by NEXUS. The guarantee terminates at the earlier of (i) such time as all of the guaranteed obligations have been fully performed or (ii) 15 years from the date DTE Energy entered into the guarantee. Should NEXUS fail to perform under the terms of these agreements, DTE Energy is required to perform on its behalf. Payments under these guarantees are 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 $50 million at March 31, 2021. Payments under these guarantees are considered remote. The Registrants are 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, 2021, DTE Energy had $129 million of performance bonds outstanding, including $73 million for DTE Electric. In the event that such bonds are called for nonperformance, the Registrants would be obligated to reimburse the issuer of the performance bond. The Registrants are 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. Vector Line of Credit In July 2019, DTE Energy, as lender, entered into a revolving term credit facility with Vector, as borrower, in the amount of C$70 million. The credit facility was executed in response to the passage of Canadian regulations requiring oil and gas pipelines to demonstrate their financial ability to respond to a catastrophic event and exists for the sole purpose of satisfying these regulations. Vector may only draw upon the facility if the funds are required to respond to a catastrophic event. The maximum potential payment under the line of credit at March 31, 2021 is $56 million. The funding of a loan under the terms of the credit facility is considered remote. Labor Contracts There are several bargaining units for DTE Energy subsidiaries' approximate 5,200 represented employees, including DTE Electric's approximately 2,800 represented employees. This represents 49% and 57% of DTE Energy's and DTE Electric's total employees, respectively. The majority of the represented employees are under contracts that expire in 2021 and 2022. Purchase Commitments Utility capital expenditures, expenditures for non-utility businesses, and contributions to equity method investees will be approximately $4.2 billion and $3.0 billion in 2021 for DTE Energy and DTE Electric, respectively. The Registrants have made certain commitments in connection with the estimated 2021 annual capital expenditures and contributions to equity method investees. Bankruptcies DTE Energy Trading is the sole supplier of power for Brilliant Energy, LLC ("Brilliant"), a load serving entity and competitive retailer in ERCOT. In this role, DTE Energy Trading schedules and delivers power to ERCOT for Brilliant’s load obligations to its customers. Related costs for power delivery and ancillary services are passed through to Brilliant. On March 16, 2021, Brilliant filed a voluntary petition for bankruptcy protection under Chapter 7 of the Bankruptcy Code. In light of the events related to Brilliant, DTE Energy Trading ceased accruing revenues from Brilliant and related receivables of $48 million were not recorded as collectability was no longer deemed probable. As of March 31, 2021, DTE Energy Trading had recorded accounts receivable of $12 million related to pre-petition contracts with Brilliant, which have been fully reserved. On March 19, 2021, the bankruptcy court authorized a Trustee to continue managing Brilliant’s business to preserve any remaining value for their creditors and begin an orderly wind-down of Brilliant’s operations. On April 5, 2021, the bankruptcy court also authorized the Trustee to enter into a credit agreement with DTE Energy Trading for up to $14 million in post-petition secured financing. DTE Energy Trading expects to recover some accounts receivable from these arrangements, but is unable to approximate an amount at this time. DTE Energy does not believe there is any additional risk related to Brilliant that is significant to the Consolidated Financial Statements and will continue to monitor results from the wind-down of Brilliant's operations and bankruptcy proceedings. COVID-19 Pandemic DTE Energy is actively monitoring the impact of the COVID-19 pandemic on supply chains, markets, counterparties, and customers, and any related impacts on operating costs, customer demand, and recoverability of assets that could materially impact the Registrants' financial results. In 2021, the COVID-19 pandemic has continued to impact DTE Electric sales volumes. As many businesses continue to operate remotely, related sales volumes have shifted from commercial and industrial customers to residential customers. This shift has contributed to a net reduction in DTE Electric sales compared to historical volumes prior to the pandemic, but this impact has been offset by favorable rate mix. COVID-19 has also resulted in some incremental costs at our utilities related to personal protective equipment and other health and safety-related matters. For non-utility businesses, COVID-19 has primarily impacted volumes for certain companies within the Power and Industrial Projects segment. For the three months ended March 31, 2021, the impact of these items on the Registrants' Consolidated Financial Statement was not significant. In consideration of the above factors and all other current and expected impacts to the Registrants' performance and cash flows resulting from the COVID-19 pandemic, there have been no material adjustments or reserves deemed necessary to the Consolidated Financial Statements as of March 31, 2021. The Registrants cannot predict the future impacts of the COVID-19 pandemic on the Consolidated Financial Statements, as developments involving COVID-19 and its related effects on economic and operating conditions remain highly uncertain. 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 6 and 9 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, 2021
Retirement Benefits [Abstract]
Retirement Benefits and Trusteed Assets	RETIREMENT BENEFITS AND TRUSTEED ASSETS The following tables detail the components of net periodic benefit costs (credits) for pension benefits and other postretirement benefits for DTE Energy: Pension Benefits Other Postretirement Benefits Three Months Ended March 31, 2021 2020 2021 2020 (In millions) Service cost $ 27 $ 25 $ 8 $ 6 Interest cost 39 46 11 14 Expected return on plan assets (84) (83) (32) (32) Amortization of: Net actuarial loss 49 43 3 5 Prior service credit — — (5) (5) Net periodic benefit cost (credit) $ 31 $ 31 $ (15) $ (12) DTE Electric participates in various plans that provide pension and other postretirement benefits for DTE Energy and its affiliates. The plans are primarily sponsored by DTE Energy's subsidiary, DTE Energy Corporate Services, LLC. DTE Electric accounts for its participation in DTE Energy's qualified and non-qualified pension plans by applying multiemployer accounting. DTE Electric accounts for its participation in other postretirement benefit plans by applying multiple-employer accounting. Within multiemployer and multiple-employer plans, participants pool plan assets for investment purposes and to reduce the cost of plan administration. The primary difference between plan types is assets contributed in multiemployer plans can be used to provide benefits for all participating employers, while assets contributed within a multiple-employer plan are restricted for use by the contributing employer. As a result of multiemployer accounting treatment, capitalized costs associated with these plans are reflected in Property, plant, and equipment in DTE Electric's Consolidated Statements of Financial Position. The same capitalized costs are reflected as Regulatory assets and liabilities in DTE Energy's Consolidated Statements of Financial Position. In addition, the service cost and non-service cost components are presented in Operation and maintenance in DTE Electric's Consolidated Statements of Operations. The same non-service cost components are presented in Other (Income) and Deductions — Non-operating retirement benefits, net in DTE Energy's Consolidated Statements of Operations. Plan participants of all plans are solely DTE Energy and affiliate participants. DTE Energy's subsidiaries are responsible for their share of qualified and non-qualified pension benefit costs. DTE Electric's allocated portion of pension benefit costs included in capital expenditures and operating and maintenance expense was $26 million for both the three months ended March 31, 2021 and 2020. These amounts include recognized contractual termination benefit charges, curtailment gains, and settlement charges. The following tables detail the components of net periodic benefit costs (credits) for other postretirement benefits for DTE Electric: Three Months Ended March 31, 2021 2020 (In millions) Service cost $ 6 $ 5 Interest cost 8 11 Expected return on plan assets (22) (22) Amortization of: Net actuarial loss 3 3 Prior service credit (3) (4) Net periodic benefit credit $ (8) $ (7) Pension and Other Postretirement Contributions At the discretion of management and depending upon financial market conditions, DTE Energy anticipates making up to $107 million in contributions to the qualified pension plans in 2021, including up to $100 million of equity contributions to the qualified pension plans at DTE Electric. No contributions are anticipated for DTE Energy's postretirement benefit plans in 2021.

Segment and Related Information

Segment and Related Information	3 Months Ended
	Mar. 31, 2021
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 1.3 million residential, commercial, and industrial customers throughout Michigan and the sale of storage and transportation capacity. Gas Storage and Pipelines is primarily engaged in services related to the gathering, transportation, and storage of natural gas. 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 and pipeline-quality gas from renewable energy projects. Energy Trading consists of energy marketing and trading operations. Corporate and Other includes various holding company activities, holds certain non-utility debt, and holds certain investments, including funds supporting regional development and economic growth. 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 also 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, 2021 2020 (In millions) Electric $ 16 $ 15 Gas 4 4 Gas Storage and Pipelines 5 4 Power and Industrial Projects 162 94 Energy Trading 13 6 Corporate and Other 1 1 $ 201 $ 124 Financial data of DTE Energy's business segments follows: Three Months Ended March 31, 2021 2020 (In millions) Operating Revenues — Utility operations Electric $ 1,360 $ 1,212 Gas 612 540 Operating Revenues — Non-utility operations Electric 4 4 Gas Storage and Pipelines 197 170 Power and Industrial Projects 366 307 Energy Trading 1,439 913 Corporate and Other 1 — Reconciliation and Eliminations (201) (124) Total $ 3,778 $ 3,022 Three Months Ended March 31, 2021 2020 (In millions) Net Income (Loss) Attributable to DTE Energy by Segment: Electric $ 208 $ 94 Gas 169 121 Gas Storage and Pipelines 79 72 Power and Industrial Projects 28 30 Energy Trading (55) 34 Corporate and Other (32) (11) Net Income Attributable to DTE Energy Company $ 397 $ 340

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
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 2020 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, 2021. 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.
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 equity investment is valued at cost minus any impairments, if applicable. 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 generally accounted for under the equity method. DTE Energy currently owns an 85% interest in SGG, which owns and operates midstream natural gas assets. SGG has contracts through which certain construction risk was designed to pass-through to the customers, with DTE Energy retaining operational and customer default risk. SGG is a VIE with DTE Energy as the primary beneficiary. The Registrants have variable interests in NEXUS, which include DTE Energy's 50% ownership interest and DTE Electric's transportation services contract. NEXUS is a joint venture which owns a 256-mile pipeline to transport Utica and Marcellus shale gas to Ohio, Michigan, and Ontario market centers. NEXUS also owns Generation Pipeline, LLC, a 25-mile regulated pipeline system located in northern Ohio. NEXUS is a VIE as it has insufficient equity at risk to finance its activities. The Registrants are not the primary beneficiaries, as the power to direct significant activities is shared between the owners of the equity interests. DTE Energy accounts for its ownership interest in NEXUS under the equity method. The Registrants hold ownership interests in certain limited partnerships. The limited partnerships include investment funds which support regional development and economic growth, and an operational business providing energy-related products. These entities are generally VIEs as a result of certain characteristics of the limited partnership voting rights. The ownership interests are accounted for under the equity method as the Registrants are not the primary beneficiaries. 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, including the transportation services contract with NEXUS. As of March 31, 2021, 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, 2021, 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 material 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 material 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 and, for DTE Energy, in Note 13 to the Consolidated Financial Statements, "Commitments and Contingencies," related to the REF guarantees and indemnities. For non-consolidated VIEs, the maximum risk exposure of the Registrants is generally limited to their investment, notes receivable, future funding commitments, and amounts which DTE Energy has loaned or guaranteed. See Note 13 to the Consolidated Financial Statements, "Commitments and Contingencies," for further discussion of the NEXUS guarantee arrangements and credit agreement related to Brilliant Energy, LLC, a non-consolidated VIE and customer of DTE Energy Trading.
Changes in Accumulated Other Comprehensive Income (Loss)	Changes in Accumulated Other Comprehensive Income (Loss) Comprehensive income (loss) is the change in common shareholders' equity during a period from transactions and events from non-owner sources, including Net Income. The amounts recorded to Accumulated other comprehensive income (loss) for DTE Energy include changes in benefit obligations, consisting of deferred actuarial losses and prior service costs, unrealized gains and losses from derivatives accounted for as cash flow hedges, and foreign currency translation adjustments. DTE Energy releases income tax effects from accumulated other comprehensive income when the circumstances upon which they are premised cease to exist.
Cash, Cash Equivalents, and Restricted Cash	Cash, Cash Equivalents, and Restricted Cash Cash and cash equivalents include cash on hand, cash in banks, and temporary investments purchased with remaining maturities of three months or less. Restricted cash consists of funds held in separate bank accounts to satisfy contractual obligations and guarantee performance. Restricted cash designated for payments within one year is classified as a Current Asset.
Financing Receivables	Financing Receivables Financing receivables are primarily composed of trade receivables, notes receivable, and unbilled revenue. The Registrant's financing receivables are stated at net realizable value. The Registrants monitor the credit quality of their financing receivables on a regular basis by reviewing credit quality indicators and monitoring for trigger events, such as a credit rating downgrade or bankruptcy. Credit quality indicators include, but are not limited to, ratings by credit agencies where available, collection history, collateral, counterparty financial statements and other internal metrics. Utilizing such data, the Registrants have determined three internal grades of credit quality. Internal grade 1 includes financing receivables for counterparties where credit rating agencies have ranked the counterparty as investment grade. To the extent credit ratings are not available, the Registrants utilize other credit quality indicators to determine the level of risk associated with the financing receivable. Internal grade 1 may include financing receivables for counterparties for which credit rating agencies have ranked the counterparty as below investment grade; however, due to favorable information on other credit quality indicators, the Registrants have determined the risk level to be similar to that of an investment grade counterparty. Internal grade 2 includes financing receivables for counterparties with limited credit information and those with a higher risk profile based upon credit quality indicators. Internal grade 3 reflects financing receivables for which the counterparties have the greatest level of risk, including those in bankruptcy status. The following represents the Registrants' financing receivables by year of origination, classified by internal grade of credit risk. The related credit quality indicators and risk ratings utilized to develop the internal grades have been updated through March 31, 2021. DTE Energy DTE Electric Year of origination 2021 2020 2019 and Prior Total 2021 and Prior (In millions) Notes receivable Internal grade 1 $ — $ — $ 23 $ 23 $ 14 Internal grade 2 1 64 52 117 2 Total notes receivable (a) $ 1 $ 64 $ 75 $ 140 $ 16 Net investment in leases Net investment in leases, internal grade 1 $ — $ 4 $ 39 $ 43 $ — Net investment in leases, internal grade 2 — 161 1 162 — Total net investment in leases (a) $ — $ 165 $ 40 $ 205 $ — _______________________________________ (a) For DTE Energy, included in Current Assets — Other and Other Assets — Notes Receivable on the Consolidated Statements of Financial Position. For DTE Electric, included in Other Assets — Other on the Consolidated Statements of Financial Position. The allowance for doubtful accounts on accounts receivable for the utility entities is generally calculated using an aging approach that utilizes rates developed in reserve studies. DTE Electric and DTE Gas establish an allowance for uncollectible accounts based on historical losses and management's assessment of existing and future economic conditions, customer trends and other factors. Customer accounts are generally considered delinquent if the amount billed is not received by the due date, which is typically in 21 days, however, factors such as assistance programs may delay aggressive action. DTE Electric and DTE Gas generally assess late payment fees on trade receivables based on past-due terms with customers. Customer accounts are written off when collection efforts have been exhausted. The time period for write-off is 150 days after service has been terminated. The customer allowance for doubtful accounts for non-utility businesses and other receivables for both utility and non-utility businesses is generally calculated based on specific review of probable future collections based on receivable balances generally in excess of 30 days. Existing and future economic conditions, customer trends and other factors are also considered. Receivables are written off on a specific identification basis and determined based upon the specific circumstances of the associated receivable. Notes receivable for DTE Energy are primarily comprised of finance lease receivables and loans that are included in Notes Receivable and Other current assets on DTE Energy's Consolidated Statements of Financial Position. Notes receivable for DTE Electric are primarily comprised of loans. Notes receivable are typically considered delinquent when payment is not received for periods ranging from 60 to 120 days. The Registrants cease accruing interest (nonaccrual status), consider a note receivable impaired, and establish an allowance for credit loss when it is probable that all principal and interest amounts due will not be collected in accordance with the contractual terms of the note receivable. In determining the allowance for credit losses for notes receivable, the Registrants consider the historical payment experience and other factors that are expected to have a specific impact on the counterparty's ability to pay including existing and future economic conditions. DTE Energy has off balance sheet exposure in the form of a revolving credit facility. Refer to Note 13, "Commitments and Contingencies," for additional information. In determining the level of credit reserve needed, DTE considers the likelihood of funding in addition to the other factors noted above. A reserve may be established when it is likely that funding will occur. Cash payments received on nonaccrual status notes receivable, that do not bring the account contractually current, are first applied to the contractually owed past due interest, with any remainder applied to principal. Accrual of interest is generally resumed when the note receivable becomes contractually current.
Recently Adopted and Recently Issued Pronouncements	Recently Adopted Pronouncements In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes . The amendments in this update simplify the accounting for income taxes by removing certain exceptions, and clarifying certain requirements regarding franchise taxes, goodwill, consolidated tax expenses, and annual effective tax rate calculations. The Registrants adopted the ASU effective January 1, 2021 using the modified retrospective and prospective approaches, where applicable. The adoption of the ASU did not have a significant impact on the Registrants' Consolidated Financial Statements. In August 2020, the FASB issued ASU No. 2020-06, Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity's Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity's Own Equity. The amendments in this update simplify the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts indexed to and potentially settled in an entity's own equity. The Registrants adopted the ASU effective January 1, 2021 using the modified retrospective approach. The adoption of the ASU did not have a significant impact on the Registrants' Consolidated Financial Statements. In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848) - Facilitation of the Effects of Reference Rate Reform on Financial Reporting, as amended
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, 2021 and December 31, 2020. 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 commingled funds. Exchange-traded debt and equity securities held directly, as well as publicly-traded commingled funds, 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. Non-publicly traded commingled funds holding exchange-traded equity or debt securities are valued based on stated NAVs. There are no significant restrictions for these funds and investments may be redeemed with 7 to 65 days notice depending on the fund. There is no intention to sell the investment in these commingled funds. Private equity and other assets include a diversified group of funds that are classified as NAV assets. These funds primarily invest in private equity partnerships, as well as real estate and private debt. Distributions are received through the liquidation of the underlying fund assets over the life of the funds. There are generally no redemption rights. The limited partner must hold the fund for its life or find a third-party buyer, which may need to be approved by the general partner. The funds are established with varied contractual durations generally in the range of 7 years to 12 years. The fund life can often be extended by several years by the general partner, and further extended with the approval of the limited partners. Unfunded commitments related to these investments totaled $178 million and $183 million as of March 31, 2021 and December 31, 2020, respectively. For pricing the nuclear decommissioning trusts and other investments, 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 source of a given security if the trustee determines that another price source is considered 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.
Derivative Assets and Liabilities	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.
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 derivative gain or loss is deferred in Accumulated other comprehensive income (loss) and later reclassified into earnings when the underlying transaction occurs. 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 environmental contracts, forwards, futures, options, swaps, and foreign currency exchange contracts. Items not classified as derivatives include natural gas and environmental inventory, pipeline transportation contracts, certain environmental contracts, and natural gas storage assets. DTE Electric — DTE Electric generates, purchases, distributes, and sells electricity. DTE Electric uses forward 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 buys and sells transportation and storage capacity. DTE Gas has fixed-priced contracts for portions of its expected natural gas supply requirements through March 2024. Substantially all of these contracts meet the normal purchases and normal sales exception and are therefore accounted for under the accrual method. 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 gathering, 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, renewable 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, 2021 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.
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 $5 million and $7 million outstanding at March 31, 2021 and December 31, 2020, 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 $14 million and $9 million at March 31, 2021 and December 31, 2020, 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.
Derivatives, Methods of Accounting	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, gas, and other — 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 also 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 Pre_2

Organization and Basis of Presentation (Tables)	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [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, 2021 and December 31, 2020. 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. Amounts for DTE Energy's consolidated VIEs are as follows: March 31, 2021 December 31, 2020 SGG (a) Other Total SGG (a) Other Total (In millions) ASSETS Cash and cash equivalents $ 21 $ 23 $ 44 $ 34 $ 20 $ 54 Accounts receivable 9 22 31 8 28 36 Inventories — 52 52 — 107 107 Property, plant, and equipment, net 400 19 419 402 23 425 Goodwill 25 — 25 25 — 25 Intangible assets 524 — 524 527 — 527 Other current and long-term assets 1 47 48 2 33 35 $ 980 $ 163 $ 1,143 $ 998 $ 211 $ 1,209 LIABILITIES Accounts payable and accrued current liabilities $ — $ 19 $ 19 $ — $ 22 $ 22 Short-term borrowings — 52 52 — 38 38 Other current and long-term liabilities 7 4 11 7 4 11 $ 7 $ 75 $ 82 $ 7 $ 64 $ 71 _____________________________________ (a) Amounts shown are 100% of SGG's assets and liabilities, of which DTE Energy owns 85% at March 31, 2021 and December 31, 2020.
Summary of Amounts for Non-Consolidated Variable Interest Entities	Amounts for DTE Energy's non-consolidated VIEs are as follows: March 31, 2021 December 31, 2020 (In millions) Investments in equity method investees $ 1,496 $ 1,507 Notes receivable $ 48 $ 47 Future funding commitments $ 22 $ 26

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Schedule of Other Income	The following is a summary of DTE Energy's Other income: Three Months Ended March 31, 2021 2020 (In millions) Equity earnings of equity method investees $ 32 $ 29 Income from REF entities 24 23 Contract services 8 7 Allowance for equity funds used during construction 7 6 Gains from rabbi trust securities (a) 2 — Other 3 — $ 76 $ 65 _______________________________________ (a) Losses from rabbi trust securities are recorded separately to Other expenses on the Consolidated Statements of Operations. The following is a summary of DTE Electric's Other income: Three Months Ended March 31, 2021 2020 (In millions) Contract services 8 7 Allowance for equity funds used during construction 6 6 Gains from rabbi trust securities allocated from DTE Energy (a) $ 2 $ — Other 3 — $ 19 $ 13 _______________________________________ (a) Losses from rabbi trust securities are recorded separately to Other expenses on the Consolidated Statements of Operations.
Schedule of Effective Tax Rates	The interim effective tax rates of the Registrants are as follows: Effective Tax Rate Three Months Ended March 31, 2021 2020 DTE Energy 7 % 13 % DTE Electric 9 % 12 %
Schedule of Financing Receivables Classified by Internal Grade of Credit Risk	The following represents the Registrants' financing receivables by year of origination, classified by internal grade of credit risk. The related credit quality indicators and risk ratings utilized to develop the internal grades have been updated through March 31, 2021. DTE Energy DTE Electric Year of origination 2021 2020 2019 and Prior Total 2021 and Prior (In millions) Notes receivable Internal grade 1 $ — $ — $ 23 $ 23 $ 14 Internal grade 2 1 64 52 117 2 Total notes receivable (a) $ 1 $ 64 $ 75 $ 140 $ 16 Net investment in leases Net investment in leases, internal grade 1 $ — $ 4 $ 39 $ 43 $ — Net investment in leases, internal grade 2 — 161 1 162 — Total net investment in leases (a) $ — $ 165 $ 40 $ 205 $ — _______________________________________ (a) For DTE Energy, included in Current Assets — Other and Other Assets — Notes Receivable on the Consolidated Statements of Financial Position. For DTE Electric, included in Other Assets — Other on the Consolidated Statements of Financial Position.
Schedule of Roll-Forward of Activity for Financing Receivables Credit Loss Reserves	The following tables present a roll-forward of the activity for the Registrants' financing receivables credit loss reserves: DTE Energy DTE Electric Trade accounts receivable Other receivables Total Trade and other accounts receivable (In millions) Beginning reserve balance, January 1, 2021 $ 101 $ 3 $ 104 $ 57 Current period provision 30 — 30 12 Write-offs charged against allowance (36) — (36) (24) Recoveries of amounts previously written off 25 — 25 14 Ending reserve balance, March 31, 2021 $ 120 $ 3 $ 123 $ 59 DTE Energy DTE Electric Trade accounts receivable Other receivables Total Trade and other accounts receivable (In millions) Beginning reserve balance, January 1, 2020 $ 87 $ 4 $ 91 $ 46 Current period provision 34 1 35 17 Write-offs charged against allowance (51) (1) (52) (30) Recoveries of amounts previously written off 16 — 16 10 Ending reserve balance, March 31, 2020 $ 86 $ 4 $ 90 $ 43

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following is a summary of revenues disaggregated by segment for DTE Energy: Three Months Ended March 31, 2021 2020 (In millions) Electric (a) Residential $ 672 $ 599 Commercial 451 426 Industrial 159 156 Other (b) 82 35 Total Electric operating revenues (c) $ 1,364 $ 1,216 Gas Gas sales $ 461 $ 394 End User Transportation 85 77 Intermediate Transportation 26 26 Other (b) 40 43 Total Gas operating revenues (d) $ 612 $ 540 Other segment operating revenues Gas Storage and Pipelines (e) $ 197 $ 170 Power and Industrial Projects (f) $ 366 $ 407 Energy Trading (g) $ 1,439 $ 913 _______________________________________ (a) Revenues generally represent those of DTE Electric, except $4 million of Other revenues related to DTE Sustainable Generation for the three months ended March 31, 2021 and 2020. (b) Includes revenue adjustments related to various regulatory mechanisms. (c) Includes $3 million and $4 million of Other revenues for the three months ended March 31, 2021 and 2020, respectively, which are outside the scope of Topic 606. (d) Includes $2 million under Alternative Revenue Programs for the three months ended March 31, 2020 and $2 million of Other revenues for both the three months ended March 31, 2021 and 2020, which are all outside the scope of Topic 606. (e) Includes revenues outside the scope of Topic 606 primarily related to $2 million of contracts accounted for as leases for the three months ended March 31, 2021 and 2020. (f) Includes revenues outside the scope of Topic 606 primarily related to $21 million and $27 million of contracts accounted for as leases for the three months ended March 31, 2021 and 2020, respectively. (g) Includes revenues outside the scope of Topic 606 primarily related to $1.1 billion and $637 million of derivatives for the three months ended March 31, 2021 and 2020, respectively.
Summary of Deferred Revenue Activity	The following is a summary of deferred revenue activity: DTE Energy (In millions) Beginning Balance, January 1, 2021 $ 87 Increases due to cash received or receivable, excluding amounts recognized as revenue during the period 21 Revenue recognized that was included in the deferred revenue balance at the beginning of the period (13) Ending Balance, March 31, 2021 $ 95
Deferred Revenue Amounts Expected to be Recognized as Revenue in Future Periods	The following table represents deferred revenue amounts for DTE Energy that are expected to be recognized as revenue in future periods: DTE Energy (In millions) 2021 $ 60 2022 13 2023 3 2024 3 2025 7 2026 and thereafter 9 $ 95 The Registrants expect to recognize revenue for the following amounts related to fixed consideration associated with remaining performance obligations in each of the future periods noted: DTE Energy DTE Electric (In millions) 2021 $ 221 $ 6 2022 373 7 2023 302 7 2024 191 7 2025 120 1 2026 and thereafter 502 — $ 1,709 $ 28

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following is a reconciliation of DTE Energy's basic and diluted income per share calculation: Three Months Ended March 31, 2021 2020 (In millions, except per share amounts) Basic Earnings per Share Net Income Attributable to DTE Energy Company $ 397 $ 340 Less: Allocation of earnings to net restricted stock awards — 1 Net income available to common shareholders — basic $ 397 $ 339 Average number of common shares outstanding — basic 194 192 Basic Earnings per Common Share $ 2.05 $ 1.77 Diluted Earnings per Share Net Income Attributable to DTE Energy Company $ 397 $ 340 Less: Allocation of earnings to net restricted stock awards — 1 Net income available to common shareholders — diluted $ 397 $ 339 Average number of common shares outstanding — diluted 194 192 Diluted Earnings per Common Share (a) $ 2.05 $ 1.76 _______________________________________ (a) Equity Units excluded from the calculation of diluted EPS were approximately 10.3 million for both the three months ended March 31, 2021 and 2020, as the dilutive stock price threshold was not met.

Fair Value (Tables)

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2021
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: March 31, 2021 December 31, 2020 Level Level Level Other (a) Netting (b) Net Balance Level Level Level Other (a) Netting (b) Net Balance (In millions) Assets Cash equivalents (c) $ 1,500 $ — $ — $ — $ — $ 1,500 $ 438 $ — $ — $ — $ — $ 438 Nuclear decommissioning trusts Equity securities 999 — — 205 — 1,204 947 — — 222 — 1,169 Fixed income securities 107 385 — 86 — 578 102 371 — 82 — 555 Private equity and other — — — 122 — 122 — — — 104 — 104 Cash equivalents 20 — — — — 20 27 — — — — 27 Other investments (d) Equity securities 58 — — — — 58 55 — — — — 55 Fixed income securities 7 — — — — 7 8 — — — — 8 Cash equivalents 98 — — — — 98 97 — — — — 97 Derivative assets Commodity contracts (e) Natural gas 49 72 42 — (106) 57 99 74 60 — (156) 77 Electricity — 118 20 — (100) 38 — 128 52 — (120) 60 Environmental & Other — 258 1 — (244) 15 — 150 4 — (135) 19 Total derivative assets 49 448 63 — (450) 110 99 352 116 — (411) 156 Total $ 2,838 $ 833 $ 63 $ 413 $ (450) $ 3,697 $ 1,773 $ 723 $ 116 $ 408 $ (411) $ 2,609 Liabilities Derivative liabilities Commodity contracts (e) Natural gas $ (36) $ (79) $ (131) $ — $ 108 $ (138) $ (88) $ (59) $ (76) $ — $ 151 $ (72) Electricity — (111) (39) — 98 (52) — (126) (42) — 125 (43) Environmental & Other — (250) — — 238 (12) — (137) — — 129 (8) Foreign currency exchange contracts — (6) — — — (6) — (5) — — (5) Total $ (36) $ (446) $ (170) $ — $ 444 $ (208) $ (88) $ (327) $ (118) $ — $ 405 $ (128) Net Assets (Liabilities) at end of period $ 2,802 $ 387 $ (107) $ 413 $ (6) $ 3,489 $ 1,685 $ 396 $ (2) $ 408 $ (6) $ 2,481 Assets Current $ 1,545 $ 282 $ 44 $ — $ (298) $ 1,573 $ 532 $ 260 $ 92 $ — $ (330) $ 554 Noncurrent 1,293 551 19 413 (152) 2,124 1,241 463 24 408 (81) 2,055 Total Assets $ 2,838 $ 833 $ 63 $ 413 $ (450) $ 3,697 $ 1,773 $ 723 $ 116 $ 408 $ (411) $ 2,609 Liabilities Current $ (34) $ (252) $ (83) $ — $ 280 $ (89) $ (84) $ (223) $ (79) $ — $ 318 $ (68) Noncurrent (2) (194) (87) — 164 (119) (4) (104) (39) — 87 (60) Total Liabilities $ (36) $ (446) $ (170) $ — $ 444 $ (208) $ (88) $ (327) $ (118) $ — $ 405 $ (128) Net Assets (Liabilities) at end of period $ 2,802 $ 387 $ (107) $ 413 $ (6) $ 3,489 $ 1,685 $ 396 $ (2) $ 408 $ (6) $ 2,481 _______________________________________ (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) Amounts consisted of $1 million and $2 million of cash equivalents included in Restricted cash on DTE Energy's Consolidated Statements of Financial Position at March 31, 2021 and December 31, 2020, respectively. All other amounts are included in Cash and cash equivalents on the Consolidated Statements of Financial Position. (d) Excludes cash surrender value of life insurance investments. (e) For contracts with a clearing agent, DTE Energy nets all activity across commodities. This can result in some individual commodities having a contra balance. The following table presents assets for DTE Electric measured and recorded at fair value on a recurring basis as of: March 31, 2021 December 31, 2020 Level 1 Level 2 Level 3 Other (a) Net Balance Level 1 Level 2 Level 3 Other (a) Net Balance (In millions) Assets Cash equivalents (b) $ 864 $ — $ — $ — $ 864 $ 4 $ — $ — $ — $ 4 Nuclear decommissioning trusts Equity securities 999 — — 205 1,204 947 — — 222 1,169 Fixed income securities 107 385 — 86 578 102 371 — 82 555 Private equity and other — — — 122 122 — — — 104 104 Cash equivalents 20 — — — 20 27 — — — 27 Other investments Equity securities 17 — — — 17 16 — — — 16 Cash equivalents 11 — — — 11 11 — — — 11 Derivative assets — FTRs — — 1 — 1 — — 4 — 4 Total $ 2,018 $ 385 $ 1 $ 413 $ 2,817 $ 1,107 $ 371 $ 4 $ 408 $ 1,890 Assets Current $ 864 $ — $ 1 $ — $ 865 $ 4 $ — $ 4 $ — $ 8 Noncurrent 1,154 385 — 413 1,952 1,103 371 — 408 1,882 Total Assets $ 2,018 $ 385 $ 1 $ 413 $ 2,817 $ 1,107 $ 371 $ 4 $ 408 $ 1,890 _______________________________________ (a) Amounts represent assets valued at NAV as a practical expedient for fair value. (b) Amounts are included in Cash and cash equivalents on DTE Electric's Consolidated Statements of Financial Position.
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: Three Months Ended March 31, 2021 Three Months Ended March 31, 2020 Natural Gas Electricity Other Total Natural Gas Electricity Other Total (In millions) Net Assets (Liabilities) as of January 1 $ (16) $ 10 $ 4 $ (2) $ (15) $ 16 $ 3 $ 4 Transfers from Level 3 into Level 2 — — — — (1) — — (1) Total gains (losses) Included in earnings (67) 26 — (41) 24 20 — 44 Recorded in Regulatory liabilities — — (1) (1) — — (2) (2) Purchases, issuances, and settlements Settlements (6) (55) (2) (63) — (21) — (21) Net Assets (Liabilities) as of March 31 $ (89) $ (19) $ 1 $ (107) $ 8 $ 15 $ 1 $ 24 Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31 (a) $ (93) $ (7) $ — $ (100) $ 19 $ 21 $ — $ 40 _______________________________________ (a) Amounts are reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, gas, and other — non-utility in DTE Energy's Consolidated Statements of Operations. 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: Three Months Ended March 31, 2021 2020 (In millions) Net Assets as of January 1 $ 4 $ 3 Change in fair value recorded in Regulatory liabilities (1) (2) Purchases, issuances, and settlements Settlements (2) — Net Assets as of March 31 $ 1 $ 1
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: March 31, 2021 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 42 $ (131) Discounted Cash Flow Forward basis price (per MMBtu) $ (1.10) — $ 2.45 /MMBtu $ (0.10) /MMBtu Electricity $ 20 $ (39) Discounted Cash Flow Forward basis price (per MWh) $ (9) — $ 6 /MWh $ (1) /MWh December 31, 2020 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 60 $ (76) Discounted Cash Flow Forward basis price (per MMBtu) $ (0.86) — $ 2.50 /MMBtu $ (0.07) /MMBtu Electricity $ 52 $ (42) Discounted Cash Flow Forward basis price (per MWh) $ (9) — $ 6 /MWh $ — /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: March 31, 2021 December 31, 2020 Carrying Fair Value Carrying Fair Value Amount Level 1 Level 2 Level 3 Amount Level 1 Level 2 Level 3 (In millions) Notes receivable (a) , excluding lessor finance leases $ 140 $ — $ — $ 140 $ 141 $ — $ — $ 141 Short-term borrowings $ 52 $ — $ 52 $ — $ 38 $ — $ 38 $ — Notes payable (b) $ 6 $ — $ 6 $ 19 $ — $ — $ 19 Long-term debt (c) $ 20,432 $ 2,537 $ 17,950 $ 1,496 $ 19,439 $ 2,547 $ 18,230 $ 1,397 _______________________________________ (a) Current portion included in Current Assets — Other on DTE Energy's Consolidated Statements of Financial Position. (b) Included in Current Liabilities — Other and Other Liabilities — Other on DTE Energy's Consolidated Statements of Financial Position. (c) Includes debt due within one year, unamortized debt discounts, and issuance costs. Excludes finance lease obligations. The following table presents the carrying amount and fair value of financial instruments for DTE Electric: March 31, 2021 December 31, 2020 Carrying Fair Value Carrying Fair Value Amount Level 1 Level 2 Level 3 Amount Level 1 Level 2 Level 3 (In millions) Notes receivable (a) $ 16 $ — $ — $ 16 $ 16 $ — $ — $ 16 Short-term borrowings — affiliates $ 78 $ — $ — $ 78 $ 101 $ — $ — $ 101 Notes payable (b) $ 4 $ — $ — $ 4 $ 17 $ — $ — $ 17 Long-term debt (c) $ 9,226 $ — $ 9,756 $ 340 $ 8,236 $ — $ 9,579 $ 379 _______________________________________ (a) Included in Other Assets — Other on DTE Electric's Consolidated Statements of Financial Position. (b) Included in Current Liabilities — Other and Other Liabilities — Other on DTE Electric's Consolidated Statements of Financial Position. (c) Includes debt due within one year, unamortized debt discounts, and issuance costs. Excludes finance lease obligations.
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, 2021 December 31, 2020 (In millions) Fermi 2 $ 1,909 $ 1,841 Fermi 1 3 3 Low-level radioactive waste 12 11 $ 1,924 $ 1,855
Schedule of Realized Gains and Losses and Proceeds from Sale of Securities by Nuclear Decommissioning Trust Funds	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, 2021 2020 (In millions) Realized gains $ 24 $ 31 Realized losses $ (2) $ (16) Proceeds from sale of securities $ 271 $ 439
Fair Value and Unrealized Gains and Losses for Nuclear Decommissioning Trust Funds	The following table sets forth DTE Electric's fair value and unrealized gains and losses for the nuclear decommissioning trust funds: March 31, 2021 December 31, 2020 Fair Unrealized Unrealized Fair Unrealized Unrealized (In millions) Equity securities $ 1,204 $ 504 $ (6) $ 1,169 $ 481 $ (6) Fixed income securities 578 18 (6) 555 20 (1) Private equity and other 122 12 — 104 — — Cash equivalents 20 — — 27 — — $ 1,924 $ 534 $ (12) $ 1,855 $ 501 $ (7)
Fair Value of the Fixed Income Securities Held in Nuclear Decommissioning Trust Funds	The following table summarizes the fair value of the fixed income securities held in nuclear decommissioning trust funds by contractual maturity: March 31, 2021 (In millions) Due within one year $ 18 Due after one through five years 127 Due after five through ten years 109 Due after ten years 238 $ 492
Summary of Gains (Losses) Related to the Trust	The following table summarizes the Registrant's gains (losses) related to the trust: Three Months Ended March 31, 2021 2020 (In millions) Gains (losses) related to equity securities $ 2 $ (23) Gains (losses) related to fixed income securities — (8) $ 2 $ (31)

Financial and Other Derivativ_2

Financial and Other Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value of Derivative Instruments	The following table presents the fair value of derivative instruments for DTE Energy: March 31, 2021 December 31, 2020 Derivative Derivative Liabilities Derivative Derivative Liabilities (In millions) Derivatives designated as hedging instruments Foreign currency exchange contracts $ — $ (4) $ — $ (4) Derivatives not designated as hedging instruments Commodity contracts Natural gas $ 163 $ (246) $ 233 $ (223) Electricity 138 (150) 180 (168) Environmental & Other 259 (250) 154 (137) Foreign currency exchange contracts — (2) — (1) Total derivatives not designated as hedging instruments $ 560 $ (648) $ 567 $ (529) Current $ 371 $ (369) $ 446 $ (386) Noncurrent 189 (283) 121 (147) Total derivatives $ 560 $ (652) $ 567 $ (533) The following table presents the fair value of derivative instruments for DTE Electric: March 31, 2021 December 31, 2020 (In millions) FTRs — Other current assets $ 1 $ 4 Total derivatives not designated as hedging instruments $ 1 $ 4
Offsetting Assets	The following table presents net cash collateral offsetting arrangements for DTE Energy: March 31, 2021 December 31, 2020 (In millions) Cash collateral netted against Derivative assets $ (18) $ (12) Cash collateral netted against Derivative liabilities 12 6 Cash collateral recorded in Accounts receivable (a) 13 14 Cash collateral recorded in Accounts payable (a) (3) (1) Total net cash collateral posted (received) $ 4 $ 7 _______________________________________ (a) Amounts are recorded net by counterparty. The following table presents the netting offsets of Derivative assets and liabilities for DTE Energy: March 31, 2021 December 31, 2020 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 $ 163 $ (106) $ 57 $ 233 $ (156) $ 77 Electricity 138 (100) 38 180 (120) 60 Environmental & Other 259 (244) 15 154 (135) 19 Foreign currency exchange contracts — — — — — — Total derivative assets $ 560 $ (450) $ 110 $ 567 $ (411) $ 156 Derivative liabilities Commodity contracts Natural gas $ (246) $ 108 $ (138) $ (223) $ 151 $ (72) Electricity (150) 98 (52) (168) 125 (43) Environmental & Other (250) 238 (12) (137) 129 (8) Foreign currency exchange contracts (6) — (6) (5) — (5) Total derivative liabilities $ (652) $ 444 $ (208) $ (533) $ 405 $ (128)
Offsetting Liabilities	The following table presents net cash collateral offsetting arrangements for DTE Energy: March 31, 2021 December 31, 2020 (In millions) Cash collateral netted against Derivative assets $ (18) $ (12) Cash collateral netted against Derivative liabilities 12 6 Cash collateral recorded in Accounts receivable (a) 13 14 Cash collateral recorded in Accounts payable (a) (3) (1) Total net cash collateral posted (received) $ 4 $ 7 _______________________________________ (a) Amounts are recorded net by counterparty. The following table presents the netting offsets of Derivative assets and liabilities for DTE Energy: March 31, 2021 December 31, 2020 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 $ 163 $ (106) $ 57 $ 233 $ (156) $ 77 Electricity 138 (100) 38 180 (120) 60 Environmental & Other 259 (244) 15 154 (135) 19 Foreign currency exchange contracts — — — — — — Total derivative assets $ 560 $ (450) $ 110 $ 567 $ (411) $ 156 Derivative liabilities Commodity contracts Natural gas $ (246) $ 108 $ (138) $ (223) $ 151 $ (72) Electricity (150) 98 (52) (168) 125 (43) Environmental & Other (250) 238 (12) (137) 129 (8) Foreign currency exchange contracts (6) — (6) (5) — (5) Total derivative liabilities $ (652) $ 444 $ (208) $ (533) $ 405 $ (128)
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: March 31, 2021 December 31, 2020 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Current Noncurrent Current Noncurrent Current Noncurrent Current Noncurrent (In millions) Total fair value of derivatives $ 371 $ 189 $ (369) $ (283) $ 446 $ 121 $ (386) $ (147) Counterparty netting (280) (152) 280 152 (318) (81) 318 81 Collateral adjustment (18) — — 12 (12) — — 6 Total derivatives as reported $ 73 $ 37 $ (89) $ (119) $ 116 $ 40 $ (68) $ (60)
Gain (Loss) Recognized in Income on Derivatives	The effect of derivatives not designated as hedging instruments on DTE Energy's Consolidated Statements of Operations is as follows: Location of Gain (Loss) Recognized in Income on Derivatives Gain (Loss) Recognized in Income on Derivatives for the Three Months Ended March 31, 2021 2020 (In millions) Commodity contracts Natural gas Operating Revenues — Non-utility operations $ (43) $ (11) Natural gas Fuel, purchased power, gas, and other — non-utility (55) 36 Electricity Operating Revenues — Non-utility operations 33 1 Environmental & Other Operating Revenues — Non-utility operations (32) 21 Foreign currency exchange contracts Operating Revenues — Non-utility operations (2) 5 Total $ (99) $ 52
Volume of Commodity Contracts	The following represents the cumulative gross volume of DTE Energy's derivative contracts outstanding as of March 31, 2021: Commodity Number of Units Natural gas (MMBtu) 1,877,516,146 Electricity (MWh) 34,963,827 Foreign currency exchange ($ CAD) 135,478,800 Renewable Energy Certificates (MWh) 11,304,487 Carbon emissions (Metric Tons) 11,696,283

Long-Term Debt (Tables)

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Schedule of Issued Debt	In 2021, the following debt was issued: Company Month Type Interest Rate Maturity Date Amount (In millions) DTE Electric March Mortgage bonds (a) 1.90% 2028 $ 575 DTE Electric March Mortgage bonds (a) 3.25% 2051 425 $ 1,000 _______________________________________ (a) Bonds were issued as Green Bonds and the proceeds will be used to finance qualified expenditures for solar and wind energy, payments under power purchase agreements for solar and wind energy, and energy optimization programs.

Short-Term Credit Arrangement_2

Short-Term Credit Arrangements and Borrowings (Tables)	3 Months Ended
	Mar. 31, 2021
Short-term Debt [Abstract]
Schedule of Line of Credit Facilities	The availability under these facilities as of March 31, 2021 is shown in the following table: DTE Energy DTE Electric DTE Gas Total (In millions) Unsecured letter of credit facility, expiring in February 2023 $ 150 $ — $ — $ 150 Unsecured letter of credit facility, expiring in August 2021 110 — — 110 Unsecured term loan, expiring in November 2021 (a) — 200 — 200 Unsecured Canadian revolving credit facility, expiring May 2023 88 — — 88 Unsecured revolving credit facility, expiring April 2025 (b) 1,500 500 300 2,300 1,848 700 300 2,848 Amounts outstanding at March 31, 2021 Letters of credit 212 — — 212 Revolver borrowings 52 — — 52 264 — — 264 Net availability at March 31, 2021 $ 1,584 $ 700 $ 300 $ 2,584 _______________________________________ (a) No amounts have been drawn as of March 31, 2021 and the loan will terminate if nothing is drawn by April 30, 2021. Commitment fees are not material. (b) Total availability of $102 million expires in April 2024, including $67 million at DTE Energy, $22 million at DTE Electric, and $13 million at DTE Gas. All other availability expires in April 2025.

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Components of Net Investment in Finance Leases	The components of DTE Energy’s net investment in finance leases for remaining periods were as follows: DTE Energy March 31, 2021 (In millions) 2021 $ 19 2022 22 2023 22 2024 22 2025 22 2026 and Thereafter 292 Total minimum future lease receipts 399 Residual value of leased pipeline 17 Less unearned income 211 Net investment in finance lease 205 Less current portion 9 $ 196
Schedule of Lease Income Associated with Operating Leases	DTE Energy’s lease income associated with operating leases was as follows: Three Months Ended March 31, 2021 2020 (In millions) Fixed payments (a) $ 17 $ 16 Variable payments (a) 17 23 $ 34 $ 39 _______________________________________ (a) Includes $24 million and $29 million of lease payments reported in Operating Revenues on DTE Energy's Consolidated Statements of Operations for the three months ended March 31, 2021 and 2020, respectively, and $10 million of lease payments reported in Other income for both periods.

Retirement Benefits and Trust_2

Retirement Benefits and Trusteed Assets (Tables)	3 Months Ended
	Mar. 31, 2021
Retirement Benefits [Abstract]
Schedule of Net Periodic Benefit Costs (Credits)	The following tables detail the components of net periodic benefit costs (credits) for pension benefits and other postretirement benefits for DTE Energy: Pension Benefits Other Postretirement Benefits Three Months Ended March 31, 2021 2020 2021 2020 (In millions) Service cost $ 27 $ 25 $ 8 $ 6 Interest cost 39 46 11 14 Expected return on plan assets (84) (83) (32) (32) Amortization of: Net actuarial loss 49 43 3 5 Prior service credit — — (5) (5) Net periodic benefit cost (credit) $ 31 $ 31 $ (15) $ (12) The following tables detail the components of net periodic benefit costs (credits) for other postretirement benefits for DTE Electric: Three Months Ended March 31, 2021 2020 (In millions) Service cost $ 6 $ 5 Interest cost 8 11 Expected return on plan assets (22) (22) Amortization of: Net actuarial loss 3 3 Prior service credit (3) (4) Net periodic benefit credit $ (8) $ (7)

Segment and Related Informati_2

Segment and Related Information (Tables)	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Financial Data of Business Segments	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, 2021 2020 (In millions) Electric $ 16 $ 15 Gas 4 4 Gas Storage and Pipelines 5 4 Power and Industrial Projects 162 94 Energy Trading 13 6 Corporate and Other 1 1 $ 201 $ 124 Financial data of DTE Energy's business segments follows: Three Months Ended March 31, 2021 2020 (In millions) Operating Revenues — Utility operations Electric $ 1,360 $ 1,212 Gas 612 540 Operating Revenues — Non-utility operations Electric 4 4 Gas Storage and Pipelines 197 170 Power and Industrial Projects 366 307 Energy Trading 1,439 913 Corporate and Other 1 — Reconciliation and Eliminations (201) (124) Total $ 3,778 $ 3,022 Three Months Ended March 31, 2021 2020 (In millions) Net Income (Loss) Attributable to DTE Energy by Segment: Electric $ 208 $ 94 Gas 169 121 Gas Storage and Pipelines 79 72 Power and Industrial Projects 28 30 Energy Trading (55) 34 Corporate and Other (32) (11) Net Income Attributable to DTE Energy Company $ 397 $ 340

Organization and Basis of Pre_3

Organization and Basis of Presentation (Details Textuals) customer in Millions, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021USD ($)customer	Dec. 31, 2020
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Number of electric utility customers | customer	2.2
Number of gas utility customers | customer	1.3
Material potential exposure | $	$ 0
SGG
Error Corrections and Prior Period Adjustments Restatement [Line Items]
VIE ownership percentage	85.00%	85.00%
DTE Electric
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Material potential exposure | $	$ 0
NEXUS pipeline
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Ownership interest	50.00%

Organization and Basis of Pre_4

Organization and Basis of Presentation (Consolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
ASSETS
Cash and cash equivalents	$ 1,568	$ 514
Accounts receivable	1,553	1,665
Property, plant, and equipment, net	28,272	27,969
Goodwill	2,466	2,466
Total Assets	46,699	45,496
LIABILITIES
Short-term borrowings	52	38
Total
ASSETS
Cash and cash equivalents	44	54
Accounts receivable	31	36
Inventories	52	107
Property, plant, and equipment, net	419	425
Goodwill	25	25
Intangible assets	524	527
Other current and long-term assets	48	35
Total Assets	1,143	1,209
LIABILITIES
Accounts payable and accrued current liabilities	19	22
Short-term borrowings	52	38
Other current and long-term liabilities	11	11
Total liabilities	82	71
SGG
ASSETS
Cash and cash equivalents	21	34
Accounts receivable	9	8
Inventories	0	0
Property, plant, and equipment, net	400	402
Goodwill	25	25
Intangible assets	524	527
Other current and long-term assets	1	2
Total Assets	980	998
LIABILITIES
Accounts payable and accrued current liabilities	0	0
Short-term borrowings	0	0
Other current and long-term liabilities	7	7
Total liabilities	$ 7	$ 7
VIE ownership and non-ownership percentage	100.00%
VIE ownership percentage	85.00%	85.00%
Other
ASSETS
Cash and cash equivalents	$ 23	$ 20
Accounts receivable	22	28
Inventories	52	107
Property, plant, and equipment, net	19	23
Goodwill	0	0
Intangible assets	0	0
Other current and long-term assets	47	33
Total Assets	163	211
LIABILITIES
Accounts payable and accrued current liabilities	19	22
Short-term borrowings	52	38
Other current and long-term liabilities	4	4
Total liabilities	$ 75	$ 64

Organization and Basis of Pre_5

Organization and Basis of Presentation (Non-Consolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
Investments in equity method investees	$ 1,856	$ 1,868
Notes receivable	304	280
Variable interest entity, non-consolidated
Variable Interest Entity [Line Items]
Investments in equity method investees	1,496	1,507
Notes receivable	48	47
Future funding commitments	$ 22	$ 26

Significant Accounting Polici_4

Significant Accounting Policies (Other Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Schedule of Other Nonoperating Income, by Component [Line Items]
Equity earnings of equity method investees	$ 32	$ 29
Income from REF entities	24	23
Contract services	8	7
Gains from rabbi trust securities	2	0
Allowance for equity funds used during construction	7	6
Other	3	0
Total other income	76	65
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Contract services	8	7
Gains from rabbi trust securities	2	0
Allowance for equity funds used during construction	6	6
Other	3	0
Total other income	$ 19	$ 13

Significant Accounting Polici_5

Significant Accounting Policies (Income Taxes) (Details)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Schedule of Income Taxes [Line Items]
Effective Tax Rate	7.00%	13.00%
DTE Electric
Schedule of Income Taxes [Line Items]
Effective Tax Rate	9.00%	12.00%

Significant Accounting Polici_6

Significant Accounting Policies (Details Textuals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Significant Accounting Policies [Line Items]
Effective tax rate decrease	6.00%
Annual production tax credits	3.00%
Amortization of TCJA regulatory liability	2.00%
Unrecognized compensation cost	$ 111
Recognition period (in years)	1 year 10 months 6 days
Specific review of probable future collections based on receivable balances, threshold duration	30 days
Uncollectible expense adjusted for regulatory deferrals	$ 31	$ 33
Past due financing receivables	$ 0
Minimum
Significant Accounting Policies [Line Items]
Notes receivable considered delinquent period	60 days
Maximum
Significant Accounting Policies [Line Items]
Notes receivable considered delinquent period	120 days
DTE Electric and DTE Gas
Significant Accounting Policies [Line Items]
Receivables due date	21 days
Threshold period past due for write-off of trade accounts receivable	150 days
DTE Electric
Significant Accounting Policies [Line Items]
Effective tax rate decrease	3.00%
Annual production tax credits	2.00%
Amortization of TCJA regulatory liability	1.00%
Uncollectible expense adjusted for regulatory deferrals	$ 11	17
DTE Electric | DTE Energy
Significant Accounting Policies [Line Items]
Income tax receivable	3		$ 8
Allocated costs	$ 14	$ 9

Significant Accounting Polici_7

Significant Accounting Policies (Financing Receivables Classified by Internal Grade of Credit Risk) (Details) $ in Millions	Mar. 31, 2021USD ($)
Notes receivable
Financing Receivable, Credit Quality Indicator [Line Items]
2021	$ 1
2020	64
2019 and Prior	75
Total	140
Notes receivable | Internal grade 1
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0
2020	0
2019 and Prior	23
Total	23
Notes receivable | Internal grade 2
Financing Receivable, Credit Quality Indicator [Line Items]
2021	1
2020	64
2019 and Prior	52
Total	117
Net investment in leases
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0
2020	165
2019 and Prior	40
Total	205
Net investment in leases | Internal grade 1
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0
2020	4
2019 and Prior	39
Total	43
Net investment in leases | Internal grade 2
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0
2020	161
2019 and Prior	1
Total	162
DTE Electric | Notes receivable
Financing Receivable, Credit Quality Indicator [Line Items]
Total	16
DTE Electric | Notes receivable | Internal grade 1
Financing Receivable, Credit Quality Indicator [Line Items]
Total	14
DTE Electric | Notes receivable | Internal grade 2
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2
DTE Electric | Net investment in leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0
DTE Electric | Net investment in leases | Internal grade 1
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0
DTE Electric | Net investment in leases | Internal grade 2
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 0

Significant Accounting Polici_8

Significant Accounting Policies (Roll-Forward of Activity for Financing Receivables Credit Loss Reserves) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 104	$ 91
Current period provision	30	35
Write-offs charged against allowance	(36)	(52)
Recoveries of amounts previously written off	25	16
Ending balance	123	90
Trade accounts receivable
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	101	87
Current period provision	30	34
Write-offs charged against allowance	(36)	(51)
Recoveries of amounts previously written off	25	16
Ending balance	120	86
Other receivables
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3	4
Current period provision	0	1
Write-offs charged against allowance	0	(1)
Recoveries of amounts previously written off	0	0
Ending balance	3	4
DTE Electric
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	57	46
Current period provision	12	17
Write-offs charged against allowance	(24)	(30)
Recoveries of amounts previously written off	14	10
Ending balance	$ 59	$ 43

Revenue (Disaggregation of Reve

Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Revenues	$ 3,778	$ 3,022
Lease revenue outside scope of Topic 606	34	39
Electric
Disaggregation of Revenue [Line Items]
Revenues	1,364	1,216
Other revenues outside scope of topic 606	3	4
Electric | Residential
Disaggregation of Revenue [Line Items]
Revenues	672	599
Electric | Commercial
Disaggregation of Revenue [Line Items]
Revenues	451	426
Electric | Industrial
Disaggregation of Revenue [Line Items]
Revenues	159	156
Electric | Other
Disaggregation of Revenue [Line Items]
Revenues	82	35
Electric | Other | DTE Sustainable Generation
Disaggregation of Revenue [Line Items]
Revenues	4	4
Gas
Disaggregation of Revenue [Line Items]
Revenues	612	540
Alternative Revenue Program revenues outside scope of Topic 606		2
Other revenues outside scope of topic 606	2	2
Gas | Other
Disaggregation of Revenue [Line Items]
Revenues	40	43
Gas | Gas sales
Disaggregation of Revenue [Line Items]
Revenues	461	394
Gas | End User Transportation
Disaggregation of Revenue [Line Items]
Revenues	85	77
Gas | Intermediate Transportation
Disaggregation of Revenue [Line Items]
Revenues	26	26
Gas Storage and Pipelines
Disaggregation of Revenue [Line Items]
Revenues	197	170
Lease revenue outside scope of Topic 606	2	2
Power and Industrial Projects
Disaggregation of Revenue [Line Items]
Revenues	366	407
Lease revenue outside scope of Topic 606	21	27
Energy Trading
Disaggregation of Revenue [Line Items]
Revenues	1,439	913
Gain (loss) on derivative outside scope of Topic 606	$ 1,100	$ 637

Revenue (Deferred Revenue) (Det

Revenue (Deferred Revenue) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)
Contract Liability [Roll Forward]
Beginning Balance	$ 87
Increases due to cash received or receivable, excluding amounts recognized as revenue during the period	21
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(13)
Ending Balance	$ 95

Revenue (Expected Recognition o

Revenue (Expected Recognition of Deferred Revenue) (Details) $ in Millions	Mar. 31, 2021USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 95
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 60
Remaining performance obligation, expected timing of satisfaction	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 13
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 3
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 3
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 7
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 9
Remaining performance obligation, expected timing of satisfaction

Revenue (Expected Timing of Per

Revenue (Expected Timing of Performance Obligation Satisfaction) (Details) $ in Millions	Mar. 31, 2021USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 95
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 60
Remaining performance obligation, expected timing of satisfaction	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 13
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 3
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 3
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 7
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 9
Remaining performance obligation, expected timing of satisfaction
Fixed-price Contract
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 1,709
Fixed-price Contract | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	28
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 221
Remaining performance obligation, expected timing of satisfaction	9 months
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 6
Remaining performance obligation, expected timing of satisfaction	9 months
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 373
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 7
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 302
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 7
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 191
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 7
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 120
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 1
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 502
Remaining performance obligation, expected timing of satisfaction
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 0
Remaining performance obligation, expected timing of satisfaction

Regulatory Matters (Details Tex

Regulatory Matters (Details Textuals) - MPSC - USD ($) $ in Millions	Feb. 12, 2021	Mar. 26, 2021	Jul. 09, 2020
DTE Electric
Public Utilities, General Disclosures [Line Items]
Regulatory liability for non-plant-related accumulated deferred income tax balances that resulted from the TCJA, accelerated amortization approved			$ 102
Requested securitization of qualified costs		$ 184
DTE Gas | 2021 Gas Rate Case Filing
Public Utilities, General Disclosures [Line Items]
Requested rate increase	$ 195
Return on equity percent	9.90%
Return on equity requested percent	10.25%

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Basic Earnings per Share
Net Income Attributable to DTE Energy Company	$ 397	$ 340
Less: Allocation of earnings to net restricted stock awards	0	1
Net income available to common shareholders — basic	$ 397	$ 339
Average number of common shares outstanding — basic (in shares)	194	192
Basic Earnings per Common Share (in dollars per share)	$ 2.05	$ 1.77
Diluted Earnings per Share
Net Income Attributable to DTE Energy Company	$ 397	$ 340
Less: Allocation of earnings to net restricted stock awards	0	1
Net income available to common shareholders — diluted	$ 397	$ 339
Average number of common shares outstanding — diluted (in shares)	194	192
Diluted Earnings per Common Share (in dollars per share)	$ 2.05	$ 1.76
Antidilutive securities excluded from computation of earnings per share (in shares)	10.3	10.3

Fair Value (Assets and Liabilit

Fair Value (Assets and Liabilities Recorded at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Derivative assets
Derivative assets, gross	$ 560	$ 567
Derivative asset, netting	(450)	(411)
Derivative assets, net	110	156
Derivative liabilities
Derivative liabilities, gross	(652)	(533)
Derivative liability, netting	444	405
Derivative liabilities, net	(208)	(128)
DTE Electric
Assets
Nuclear decommissioning trusts	1,924	1,855
Current liabilities
Derivative liabilities
Derivative liabilities, gross	(369)	(386)
Noncurrent liabilities
Derivative liabilities
Derivative liabilities, gross	(283)	(147)
Natural gas
Derivative assets
Derivative assets, gross	163	233
Derivative asset, netting	(106)	(156)
Derivative assets, net	57	77
Derivative liabilities
Derivative liabilities, gross	(246)	(223)
Derivative liability, netting	108	151
Derivative liabilities, net	(138)	(72)
Electricity
Derivative assets
Derivative assets, gross	138	180
Derivative asset, netting	(100)	(120)
Derivative assets, net	38	60
Derivative liabilities
Derivative liabilities, gross	(150)	(168)
Derivative liability, netting	98	125
Derivative liabilities, net	(52)	(43)
Environmental & Other
Derivative assets
Derivative assets, gross	259	154
Derivative asset, netting	(244)	(135)
Derivative assets, net	15	19
Derivative liabilities
Derivative liabilities, gross	(250)	(137)
Derivative liability, netting	238	129
Derivative liabilities, net	(12)	(8)
Foreign currency exchange contracts
Derivative assets
Derivative assets, gross	0	0
Derivative asset, netting	0	0
Derivative assets, net	0	0
Derivative liabilities
Derivative liabilities, gross	(6)	(5)
Derivative liability, netting	0	0
Derivative liabilities, net	(6)	(5)
Cash equivalents | DTE Electric
Assets
Nuclear decommissioning trusts	20	27
Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	122	104
Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	1,204	1,169
Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	578	555
Recurring
Assets
Cash equivalents	1,500	438
Derivative assets
Derivative asset, netting	(450)	(411)
Derivative assets, net	110	156
Total assets	3,697	2,609
Derivative liabilities
Derivative liability, netting	444	405
Derivative liabilities, net	(208)	(128)
Net Assets (Liabilities) at end of period	3,489	2,481
Net Assets at end of period, netting	(6)	(6)
Recurring | DTE Electric
Assets
Cash equivalents	864	4
Derivative assets
Total assets	2,817	1,890
Recurring | Current assets
Derivative assets
Derivative asset, netting	(298)	(330)
Total assets	1,573	554
Recurring | Current assets | DTE Electric
Derivative assets
Total assets	865	8
Recurring | Noncurrent assets
Derivative assets
Derivative asset, netting	(152)	(81)
Total assets	2,124	2,055
Recurring | Noncurrent assets | DTE Electric
Derivative assets
Total assets	1,952	1,882
Recurring | Current liabilities
Derivative liabilities
Derivative liability, netting	280	318
Derivative liabilities, net	(89)	(68)
Recurring | Noncurrent liabilities
Derivative liabilities
Derivative liability, netting	164	87
Derivative liabilities, net	(119)	(60)
Recurring | Restricted cash
Assets
Cash equivalents	1	2
Recurring | Natural gas
Derivative assets
Derivative asset, netting	(106)	(156)
Derivative assets, net	57	77
Derivative liabilities
Derivative liability, netting	108	151
Derivative liabilities, net	(138)	(72)
Recurring | Electricity
Derivative assets
Derivative asset, netting	(100)	(120)
Derivative assets, net	38	60
Derivative liabilities
Derivative liability, netting	98	125
Derivative liabilities, net	(52)	(43)
Recurring | Environmental & Other
Derivative assets
Derivative asset, netting	(244)	(135)
Derivative assets, net	15	19
Derivative liabilities
Derivative liability, netting	238	129
Derivative liabilities, net	(12)	(8)
Recurring | Foreign currency exchange contracts
Derivative liabilities
Derivative liability, netting	0	0
Derivative liabilities, net	(6)	(5)
Recurring | Derivative assets — FTRs | DTE Electric
Derivative assets
Derivative assets, net	1	4
Recurring | Cash equivalents
Assets
Nuclear decommissioning trusts	20	27
Other investments	98	97
Recurring | Cash equivalents | DTE Electric
Assets
Nuclear decommissioning trusts	20	27
Other investments	11	11
Recurring | Private equity and other
Assets
Nuclear decommissioning trusts	122	104
Recurring | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	122	104
Recurring | Equity securities
Assets
Nuclear decommissioning trusts	1,204	1,169
Other investments	58	55
Recurring | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	1,204	1,169
Other investments	17	16
Recurring | Fixed income securities
Assets
Nuclear decommissioning trusts	578	555
Other investments	7	8
Recurring | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	578	555
Recurring | Level 1
Assets
Cash equivalents	1,500	438
Derivative assets
Derivative assets, gross	49	99
Total assets	2,838	1,773
Derivative liabilities
Derivative liabilities, gross	(36)	(88)
Net Assets (Liabilities) at end of period	2,802	1,685
Recurring | Level 1 | DTE Electric
Assets
Cash equivalents	864	4
Derivative assets
Total assets	2,018	1,107
Recurring | Level 1 | Current assets
Derivative assets
Total assets	1,545	532
Recurring | Level 1 | Current assets | DTE Electric
Derivative assets
Total assets	864	4
Recurring | Level 1 | Noncurrent assets
Derivative assets
Total assets	1,293	1,241
Recurring | Level 1 | Noncurrent assets | DTE Electric
Derivative assets
Total assets	1,154	1,103
Recurring | Level 1 | Current liabilities
Derivative liabilities
Derivative liabilities, gross	(34)	(84)
Recurring | Level 1 | Noncurrent liabilities
Derivative liabilities
Derivative liabilities, gross	(2)	(4)
Recurring | Level 1 | Natural gas
Derivative assets
Derivative assets, gross	49	99
Derivative liabilities
Derivative liabilities, gross	(36)	(88)
Recurring | Level 1 | Electricity
Derivative assets
Derivative assets, gross	0	0
Derivative liabilities
Derivative liabilities, gross	0	0
Recurring | Level 1 | Environmental & Other
Derivative assets
Derivative assets, gross	0	0
Derivative liabilities
Derivative liabilities, gross	0	0
Recurring | Level 1 | Foreign currency exchange contracts
Derivative liabilities
Derivative liabilities, gross	0	0
Recurring | Level 1 | Derivative assets — FTRs | DTE Electric
Derivative assets
Derivative assets, net	0	0
Recurring | Level 1 | Cash equivalents
Assets
Nuclear decommissioning trusts	20	27
Other investments	98	97
Recurring | Level 1 | Cash equivalents | DTE Electric
Assets
Nuclear decommissioning trusts	20	27
Other investments	11	11
Recurring | Level 1 | Private equity and other
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 1 | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 1 | Equity securities
Assets
Nuclear decommissioning trusts	999	947
Other investments	58	55
Recurring | Level 1 | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	999	947
Other investments	17	16
Recurring | Level 1 | Fixed income securities
Assets
Nuclear decommissioning trusts	107	102
Other investments	7	8
Recurring | Level 1 | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	107	102
Recurring | Level 2
Assets
Cash equivalents	0	0
Derivative assets
Derivative assets, gross	448	352
Total assets	833	723
Derivative liabilities
Derivative liabilities, gross	(446)	(327)
Net Assets (Liabilities) at end of period	387	396
Recurring | Level 2 | DTE Electric
Assets
Cash equivalents	0	0
Derivative assets
Total assets	385	371
Recurring | Level 2 | Current assets
Derivative assets
Total assets	282	260
Recurring | Level 2 | Current assets | DTE Electric
Derivative assets
Total assets	0	0
Recurring | Level 2 | Noncurrent assets
Derivative assets
Total assets	551	463
Recurring | Level 2 | Noncurrent assets | DTE Electric
Derivative assets
Total assets	385	371
Recurring | Level 2 | Current liabilities
Derivative liabilities
Derivative liabilities, gross	(252)	(223)
Recurring | Level 2 | Noncurrent liabilities
Derivative liabilities
Derivative liabilities, gross	(194)	(104)
Recurring | Level 2 | Natural gas
Derivative assets
Derivative assets, gross	72	74
Derivative liabilities
Derivative liabilities, gross	(79)	(59)
Recurring | Level 2 | Electricity
Derivative assets
Derivative assets, gross	118	128
Derivative liabilities
Derivative liabilities, gross	(111)	(126)
Recurring | Level 2 | Environmental & Other
Derivative assets
Derivative assets, gross	258	150
Derivative liabilities
Derivative liabilities, gross	(250)	(137)
Recurring | Level 2 | Foreign currency exchange contracts
Derivative liabilities
Derivative liabilities, gross	(6)	(5)
Recurring | Level 2 | Derivative assets — FTRs | DTE Electric
Derivative assets
Derivative assets, net	0	0
Recurring | Level 2 | Cash equivalents
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 2 | Cash equivalents | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 2 | Private equity and other
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 2 | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 2 | Equity securities
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 2 | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 2 | Fixed income securities
Assets
Nuclear decommissioning trusts	385	371
Other investments	0	0
Recurring | Level 2 | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	385	371
Recurring | Level 3
Assets
Cash equivalents	0	0
Derivative assets
Derivative assets, gross	63	116
Total assets	63	116
Derivative liabilities
Derivative liabilities, gross	(170)	(118)
Net Assets (Liabilities) at end of period	(107)	(2)
Recurring | Level 3 | DTE Electric
Assets
Cash equivalents	0	0
Derivative assets
Total assets	1	4
Recurring | Level 3 | Current assets
Derivative assets
Total assets	44	92
Recurring | Level 3 | Current assets | DTE Electric
Derivative assets
Total assets	1	4
Recurring | Level 3 | Noncurrent assets
Derivative assets
Total assets	19	24
Recurring | Level 3 | Noncurrent assets | DTE Electric
Derivative assets
Total assets	0	0
Recurring | Level 3 | Current liabilities
Derivative liabilities
Derivative liabilities, gross	(83)	(79)
Recurring | Level 3 | Noncurrent liabilities
Derivative liabilities
Derivative liabilities, gross	(87)	(39)
Recurring | Level 3 | Natural gas
Derivative assets
Derivative assets, gross	42	60
Derivative liabilities
Derivative liabilities, gross	(131)	(76)
Recurring | Level 3 | Electricity
Derivative assets
Derivative assets, gross	20	52
Derivative liabilities
Derivative liabilities, gross	(39)	(42)
Recurring | Level 3 | Environmental & Other
Derivative assets
Derivative assets, gross	1	4
Derivative liabilities
Derivative liabilities, gross	0	0
Recurring | Level 3 | Foreign currency exchange contracts
Derivative liabilities
Derivative liabilities, gross	0
Recurring | Level 3 | Derivative assets — FTRs | DTE Electric
Derivative assets
Derivative assets, net	1	4
Recurring | Level 3 | Cash equivalents
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 3 | Cash equivalents | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 3 | Private equity and other
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 3 | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 3 | Equity securities
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 3 | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 3 | Fixed income securities
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 3 | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Recurring | Other
Derivative assets
Total assets	413	408
Derivative liabilities
Net Assets (Liabilities) at end of period	413	408
Recurring | Other | DTE Electric
Derivative assets
Total assets	413	408
Recurring | Other | Noncurrent assets
Derivative assets
Total assets	413	408
Recurring | Other | Noncurrent assets | DTE Electric
Derivative assets
Total assets	413	408
Recurring | Other | Private equity and other
Assets
Nuclear decommissioning trusts	122	104
Recurring | Other | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	122	104
Recurring | Other | Equity securities
Assets
Nuclear decommissioning trusts	205	222
Recurring | Other | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	205	222
Recurring | Other | Fixed income securities
Assets
Nuclear decommissioning trusts	86	82
Recurring | Other | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	$ 86	$ 82

Fair Value (Details Textuals)

Fair Value (Details Textuals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Nuclear decommissioning trust fund | Fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities with no contractual maturity date	$ 86
Equity or debt securities | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, redemption notice period	7 days
Equity or debt securities | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, redemption notice period	65 days
Private equity and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unfunded commitments related to investments classified as NAV assets	$ 178	$ 183
Private equity and other | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments classified as NAV assets, general contractual durations	7 years
Private equity and other | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments classified as NAV assets, general contractual durations	12 years

Fair Value (Reconciliation of L

Fair Value (Reconciliation of Level 3 Assets and Liabilities at Fair Value on a Recurring Basis) (Details) - Recurring - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	$ (2)	$ 4
Transfers from Level 3 into Level 2	0	(1)
Total gains (losses)
Included in earnings	(41)	44
Recorded in Regulatory liabilities	(1)	(2)
Purchases, issuances, and settlements
Settlements	(63)	(21)
Net Assets (Liabilities) as of end of period	(107)	24
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31	(100)	40
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	4	3
Total gains (losses)
Recorded in Regulatory liabilities	(1)	(2)
Purchases, issuances, and settlements
Settlements	(2)	0
Net Assets (Liabilities) as of end of period	1	1
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	(16)	(15)
Transfers from Level 3 into Level 2	0	(1)
Total gains (losses)
Included in earnings	(67)	24
Recorded in Regulatory liabilities	0	0
Purchases, issuances, and settlements
Settlements	(6)	0
Net Assets (Liabilities) as of end of period	(89)	8
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31	(93)	19
Electricity
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	10	16
Transfers from Level 3 into Level 2	0	0
Total gains (losses)
Included in earnings	26	20
Recorded in Regulatory liabilities	0	0
Purchases, issuances, and settlements
Settlements	(55)	(21)
Net Assets (Liabilities) as of end of period	(19)	15
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31	(7)	21
Other
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	4	3
Transfers from Level 3 into Level 2	0	0
Total gains (losses)
Included in earnings	0	0
Recorded in Regulatory liabilities	(1)	(2)
Purchases, issuances, and settlements
Settlements	(2)	0
Net Assets (Liabilities) as of end of period	1	1
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at March 31	$ 0	$ 0

Fair Value (Unobservable Inputs

Fair Value (Unobservable Inputs related to Level 3 Assets and Liabilities) (Details) $ in Millions	Mar. 31, 2021USD ($)MWhMMBTU	Dec. 31, 2020USD ($)MWhMMBTU
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	$ 560	$ 567
Derivative Liabilities	(652)	(533)
Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	63	116
Derivative Liabilities	(170)	(118)
Natural gas
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	163	233
Derivative Liabilities	(246)	(223)
Natural gas | Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	42	60
Derivative Liabilities	(131)	(76)
Electricity
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	138	180
Derivative Liabilities	(150)	(168)
Electricity | Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	20	52
Derivative Liabilities	$ (39)	$ (42)
Forward basis price | Natural gas | Minimum | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | MMBTU	(1.10)	(0.86)
Forward basis price | Natural gas | Maximum | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | MMBTU	2.45	2.50
Forward basis price | Natural gas | Weighted Average | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | MMBTU	(0.10)	(0.07)
Forward basis price | Electricity | Minimum | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | MWh	(9)	(9)
Forward basis price | Electricity | Maximum | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | MWh	6	6
Forward basis price | Electricity | Weighted Average | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | MWh	(1)	0

Fair Value (Fair Value of Finan

Fair Value (Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Carrying amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	$ 140	$ 141
Short-term borrowings	52	38
Notes payable	6	19
Long-term debt	20,432	19,439
Carrying amount | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	16	16
Notes payable	4	17
Long-term debt	9,226	8,236
Carrying amount | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	78	101
Fair value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Short-term borrowings	0	0
Notes payable	0	0
Long-term debt	2,537	2,547
Fair value | Level 1 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Notes payable	0	0
Long-term debt	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	0	0
Short-term borrowings	52	38
Notes payable		0
Long-term debt	17,950	18,230
Fair value | Level 2 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	0	0
Notes payable	0	0
Long-term debt	9,756	9,579
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	140	141
Short-term borrowings	0	0
Notes payable	6	19
Long-term debt	1,496	1,397
Fair value | Level 3 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable	16	16
Notes payable	4	17
Long-term debt	340	379
Fair value | Level 3 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	$ 78	$ 101

Fair Value (Fair Value of Nucle

Fair Value (Fair Value of Nuclear Decommissioning Trust Fund Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	$ 1,924	$ 1,855
DTE Electric
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	1,924	1,855
DTE Electric | Nuclear decommissioning trust fund
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	1,924	1,855
DTE Electric | Nuclear decommissioning trust fund | Fermi 2
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	1,909	1,841
DTE Electric | Nuclear decommissioning trust fund | Fermi 1
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	3	3
DTE Electric | Nuclear decommissioning trust fund | Low-level radioactive waste
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	$ 12	$ 11

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, 2021	Mar. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Realized gains	$ 24	$ 31
Realized losses	(2)	(16)
Proceeds from sale of securities	$ 271	$ 439

Fair Value (Fair Value and Unre

Fair Value (Fair Value and Unrealized Gains and Losses for the Nuclear Decommissioning Trust Funds) (Details) - DTE Electric - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 1,924	$ 1,855
Unrealized Gains	534	501
Unrealized Losses	(12)	(7)
Cash equivalents
Debt Securities, Available-for-sale [Line Items]
Fair Value	20	27
Private equity and other
Debt Securities, Available-for-sale [Line Items]
Fair Value	122	104
Unrealized Gains	12	0
Unrealized Losses	0	0
Equity securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	1,204	1,169
Unrealized Gains	504	481
Unrealized Losses	(6)	(6)
Fixed income securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	578	555
Unrealized Gains	18	20
Unrealized Losses	$ (6)	$ (1)

Fair Value (Fair Value of Fixed

Fair Value (Fair Value of Fixed Income Securities Held in Nuclear Decommissioning Trust Funds (Details) - Fixed income securities - Nuclear decommissioning trust fund $ in Millions	Mar. 31, 2021USD ($)
Debt Securities, Available-for-sale [Line Items]
Due within one year	$ 18
Due after one through five years	127
Due after five through ten years	109
Due after ten years	238
Fixed income securities total	$ 492

Fair Value (Gains (Losses) Rela

Fair Value (Gains (Losses) Related to the Trust) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Rabbi Trust
Schedule of Investments [Line Items]
Gains (losses) related to the Trust	$ 2	$ (31)
Equity securities
Schedule of Investments [Line Items]
Gains (losses) related to the Trust	2	(23)
Fixed income securities
Schedule of Investments [Line Items]
Gains (losses) related to the Trust	$ 0	$ (8)

Financial and Other Derivativ_3

Financial and Other Derivative Instruments (Fair Value of Derivative Instruments) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 560	$ 567
Derivative Liabilities	(652)	(533)
Current derivative assets
Derivatives, Fair Value [Line Items]
Derivative Assets	371	446
Current derivative liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(369)	(386)
Noncurrent derivative assets
Derivatives, Fair Value [Line Items]
Derivative Assets	189	121
Noncurrent derivative liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(283)	(147)
Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Derivative Liabilities	(6)	(5)
Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	163	233
Derivative Liabilities	(246)	(223)
Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	138	180
Derivative Liabilities	(150)	(168)
Environmental & Other
Derivatives, Fair Value [Line Items]
Derivative Assets	259	154
Derivative Liabilities	(250)	(137)
Derivatives designated as hedging instruments | Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Derivative Liabilities	(4)	(4)
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets	560	567
Derivative Liabilities	(648)	(529)
Derivatives not designated as hedging instruments | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative Assets	1	4
Derivatives not designated as hedging instruments | Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Derivative Liabilities	(2)	(1)
Derivatives not designated as hedging instruments | Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	163	233
Derivative Liabilities	(246)	(223)
Derivatives not designated as hedging instruments | Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	138	180
Derivative Liabilities	(150)	(168)
Derivatives not designated as hedging instruments | Environmental & Other
Derivatives, Fair Value [Line Items]
Derivative Assets	259	154
Derivative Liabilities	(250)	(137)
Derivatives not designated as hedging instruments | FTRs — Other current assets | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 1	$ 4

Financial and Other Derivativ_4

Financial and Other Derivative Instruments (Details Textuals) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Letters of credit that could be used to offset net derivative liabilities	$ 5,000,000	$ 7,000,000
Letters of credit received that could be used to offset net derivative assets	14,000,000	$ 9,000,000
Contractual obligation to post collateral in event of downgrade to below investment grade	506,000,000
Derivative net liability position aggregate fair value	500,000,000
Collateral already posted fair value	0
Derivative net asset position, fair value	450,000,000
Remaining amount of offsets to derivative net liability positions for hard and soft trigger provisions	$ 50,000,000

Financial and Other Derivativ_5

Financial and Other Derivative Instruments (Net Cash Collateral Offsetting Arrangements) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Cash collateral netted against Derivative assets	$ (18)	$ (12)
Cash collateral netted against Derivative liabilities	12	6
Cash collateral recorded in Accounts receivable	13	14
Cash collateral recorded in Accounts payable	(3)	(1)
Total net cash collateral posted (received)	$ 4	$ 7

Financial and Other Derivativ_6

Financial and Other Derivative Instruments (Netting Offsets of Derivative Assets and Liabilities) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	$ 560	$ 567
Gross Amounts Offset in the Consolidated Statements of Financial Position	(450)	(411)
Derivative assets, net	110	156
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(652)	(533)
Gross Amounts Offset in the Consolidated Statements of Financial Position	444	405
Derivative liabilities, net	(208)	(128)
Natural gas
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	163	233
Gross Amounts Offset in the Consolidated Statements of Financial Position	(106)	(156)
Derivative assets, net	57	77
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(246)	(223)
Gross Amounts Offset in the Consolidated Statements of Financial Position	108	151
Derivative liabilities, net	(138)	(72)
Electricity
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	138	180
Gross Amounts Offset in the Consolidated Statements of Financial Position	(100)	(120)
Derivative assets, net	38	60
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(150)	(168)
Gross Amounts Offset in the Consolidated Statements of Financial Position	98	125
Derivative liabilities, net	(52)	(43)
Environmental & Other
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	259	154
Gross Amounts Offset in the Consolidated Statements of Financial Position	(244)	(135)
Derivative assets, net	15	19
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(250)	(137)
Gross Amounts Offset in the Consolidated Statements of Financial Position	238	129
Derivative liabilities, net	(12)	(8)
Foreign currency exchange contracts
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	0	0
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Derivative assets, net	0	0
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(6)	(5)
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Derivative liabilities, net	$ (6)	$ (5)

Financial and Other Derivativ_7

Financial and Other Derivative Instruments (Netting Offsets Reconciliation to Balance Sheet) (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Derivative Assets
Derivative Assets	$ 560	$ 567
Collateral adjustment	(18)	(12)
Derivative assets, current	73	116
Derivative assets, noncurrent	37	40
Derivative Liabilities
Derivative Liabilities	(652)	(533)
Collateral adjustment	12	6
Derivative liabilities, current	(89)	(68)
Derivative liabilities, noncurrent	(119)	(60)
Current derivative assets
Derivative Assets
Derivative Assets	371	446
Counterparty netting	(280)	(318)
Collateral adjustment	(18)	(12)
Derivative assets, current	73	116
Noncurrent derivative assets
Derivative Assets
Derivative Assets	189	121
Counterparty netting	(152)	(81)
Collateral adjustment	0	0
Derivative assets, noncurrent	37	40
Current derivative liabilities
Derivative Liabilities
Derivative Liabilities	(369)	(386)
Counterparty netting	280	318
Collateral adjustment	0	0
Derivative liabilities, current	(89)	(68)
Noncurrent derivative liabilities
Derivative Liabilities
Derivative Liabilities	(283)	(147)
Counterparty netting	152	81
Collateral adjustment	12	6
Derivative liabilities, noncurrent	$ (119)	$ (60)

Financial and Other Derivativ_8

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, 2021	Mar. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ (99)	$ 52
Natural gas | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(43)	(11)
Natural gas | Fuel, purchased power, gas, and other — non-utility
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(55)	36
Electricity | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	33	1
Environmental & Other | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(32)	21
Foreign currency exchange contracts | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ (2)	$ 5

Financial and Other Derivativ_9

Financial and Other Derivative Instruments (Cumulative Gross Volume of Derivative Contracts Outstanding) (Details)	3 Months Ended
	Mar. 31, 2021CAD ($)MWhMMBTUT
Natural gas (MMBtu)
Derivative [Line Items]
Commodity, energy measures | MMBTU	1,877,516,146
Electricity (MWh)
Derivative [Line Items]
Commodity, energy measures	34,963,827
Foreign currency exchange ($ CAD)
Derivative [Line Items]
Commodity, monetary measure | $	$ 135,478,800
Renewable Energy Certificates (MWh)
Derivative [Line Items]
Commodity, energy measures	11,304,487
Carbon emissions (Metric Tons)
Derivative [Line Items]
Commodity, mass measure | T	11,696,283

Long-Term Debt (Schedule of Iss

Long-Term Debt (Schedule of Issued Debt) (Details)	Mar. 31, 2021USD ($)
Debt Instrument [Line Items]
Debt issued	$ 1,000,000,000
DTE Electric | Mortgage Bonds | March 2021 1.9% Mortgage Bonds Maturing in 2028
Debt Instrument [Line Items]
Interest rate	1.90%
Debt issued	$ 575,000,000
DTE Electric | Mortgage Bonds | March 2021 3.25% Mortgage Bonds Maturing In 2051
Debt Instrument [Line Items]
Interest rate	3.25%
Debt issued	$ 425,000,000

Long-Term Debt (Details Textual

Long-Term Debt (Details Textuals) - USD ($) $ in Millions	Apr. 23, 2021	Mar. 31, 2021	Mar. 31, 2020
Debt Instrument [Line Items]
Debt redeemed		$ 0	$ 300
DTE Electric
Debt Instrument [Line Items]
Debt redeemed		$ 0	$ 300
2011 Series B 3.90% General and Refunding Mortgage Bonds | Mortgage Bonds | DTE Electric | Subsequent Event
Debt Instrument [Line Items]
Debt redeemed	$ 250
Interest rate	3.90%

Short-Term Credit Arrangement_3

Short-Term Credit Arrangements and Borrowings (Details Textuals)	Mar. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Jul. 31, 2020USD ($)
Short-term Debt [Line Items]
Amounts outstanding	$ 264,000,000
Maximum borrowing capacity	2,848,000,000
Letters of credit
Short-term Debt [Line Items]
Amounts outstanding	$ 212,000,000
DTE Electric
Short-term Debt [Line Items]
Ratio of indebtedness to net capital	0.53
Amounts outstanding	$ 0
Maximum borrowing capacity	700,000,000
DTE Electric | Letters of credit
Short-term Debt [Line Items]
Amounts outstanding	$ 0
DTE Gas
Short-term Debt [Line Items]
Ratio of indebtedness to net capital	0.47
Amounts outstanding	$ 0
Maximum borrowing capacity	300,000,000
DTE Gas | Letters of credit
Short-term Debt [Line Items]
Amounts outstanding	$ 0
DTE Energy
Short-term Debt [Line Items]
Ratio of indebtedness to net capital	0.60
Amounts outstanding	$ 264,000,000
Maximum borrowing capacity	1,848,000,000
DTE Energy | Letters of credit
Short-term Debt [Line Items]
Amounts outstanding	212,000,000
DTE Energy | Demand financing agreement
Short-term Debt [Line Items]
Maximum borrowing capacity, financing agreement	300,000,000
Amount outstanding	74,000,000	$ 49,000,000
DTE Energy | Other outstanding letters of credit | Letters of credit
Short-term Debt [Line Items]
Amounts outstanding	59,000,000
DTE Energy | Uncommitted letter of credit facility, Expiring July 2021 | Letters of credit
Short-term Debt [Line Items]
Maximum borrowing capacity			$ 50,000,000
DTE Energy | Demand financing agreement, indefinite term | Demand financing agreement
Short-term Debt [Line Items]
Maximum borrowing capacity, financing agreement	100,000,000
Maximum additional margin financing	50,000,000
DTE Energy | Demand financing agreement, expiring in 2022 | Demand financing agreement
Short-term Debt [Line Items]
Maximum borrowing capacity, financing agreement	$ 150,000,000
Maximum
Short-term Debt [Line Items]
Ratio of indebtedness to net capital	0.65

Short-Term Credit Arrangement_4

Short-Term Credit Arrangements and Borrowings (Details)	Mar. 31, 2021USD ($)
Availability under combined facilities
Maximum borrowing capacity	$ 2,848,000,000
Amounts outstanding	264,000,000
Net availability	2,584,000,000
DTE Electric
Availability under combined facilities
Maximum borrowing capacity	700,000,000
Amounts outstanding	0
Net availability	700,000,000
DTE Gas
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Amounts outstanding	0
Net availability	300,000,000
DTE Energy
Availability under combined facilities
Maximum borrowing capacity	1,848,000,000
Amounts outstanding	264,000,000
Net availability	1,584,000,000
Letters of credit
Availability under combined facilities
Amounts outstanding	212,000,000
Letters of credit | DTE Electric
Availability under combined facilities
Amounts outstanding	0
Letters of credit | DTE Gas
Availability under combined facilities
Amounts outstanding	0
Letters of credit | DTE Energy
Availability under combined facilities
Amounts outstanding	212,000,000
Revolver borrowings
Availability under combined facilities
Amounts outstanding	52,000,000
Revolver borrowings | DTE Electric
Availability under combined facilities
Amounts outstanding	0
Revolver borrowings | DTE Gas
Availability under combined facilities
Amounts outstanding	0
Revolver borrowings | DTE Energy
Availability under combined facilities
Amounts outstanding	52,000,000
Unsecured letter of credit facility, expiring in February 2023 | Letters of credit
Availability under combined facilities
Maximum borrowing capacity	150,000,000
Unsecured letter of credit facility, expiring in February 2023 | Letters of credit | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured letter of credit facility, expiring in February 2023 | Letters of credit | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured letter of credit facility, expiring in February 2023 | Letters of credit | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	150,000,000
Unsecured letter of credit facility, expiring in August 2021 | Letters of credit
Availability under combined facilities
Maximum borrowing capacity	110,000,000
Unsecured letter of credit facility, expiring in August 2021 | Letters of credit | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured letter of credit facility, expiring in August 2021 | Letters of credit | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured letter of credit facility, expiring in August 2021 | Letters of credit | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	110,000,000
Unsecured term loan, expiring in November 2021 | Unsecured term loan
Availability under combined facilities
Maximum borrowing capacity	200,000,000
Unsecured term loan, expiring in November 2021 | Unsecured term loan | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	200,000,000
Amounts outstanding	0
Unsecured term loan, expiring in November 2021 | Unsecured term loan | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured term loan, expiring in November 2021 | Unsecured term loan | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured Canadian revolving credit facility, expiring May 2023 | Revolver borrowings
Availability under combined facilities
Maximum borrowing capacity	88,000,000
Unsecured Canadian revolving credit facility, expiring May 2023 | Revolver borrowings | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured Canadian revolving credit facility, expiring May 2023 | Revolver borrowings | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured Canadian revolving credit facility, expiring May 2023 | Revolver borrowings | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	88,000,000
Unsecured revolving credit facility, expiring April 2025 | Revolver borrowings
Availability under combined facilities
Maximum borrowing capacity	2,300,000,000
Unsecured revolving credit facility, expiring April 2025 | Revolver borrowings | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	500,000,000
Unsecured revolving credit facility, expiring April 2025 | Revolver borrowings | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Unsecured revolving credit facility, expiring April 2025 | Revolver borrowings | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	1,500,000,000
Unsecured revolving credit facility, expiring April 2024 | Revolver borrowings
Availability under combined facilities
Maximum borrowing capacity	102,000,000
Unsecured revolving credit facility, expiring April 2024 | Revolver borrowings | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	22,000,000
Unsecured revolving credit facility, expiring April 2024 | Revolver borrowings | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	13,000,000
Unsecured revolving credit facility, expiring April 2024 | Revolver borrowings | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	$ 67,000,000

Leases (Details Textuals)

Leases (Details Textuals) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Leases [Abstract]
Additional net investment in finance leases	$ 31
Interest income recognized under finance leases	$ 4	$ 4

Leases (Components of Net Inves

Leases (Components of Net Investment in Finance Leases) (Details) $ in Millions	Mar. 31, 2021USD ($)
Leases [Abstract]
2021	$ 19
2022	22
2023	22
2024	22
2025	22
2026 and Thereafter	292
Total minimum future lease receipts	399
Residual value of leased pipeline	17
Less unearned income	211
Net investment in finance lease	205
Less current portion	9
Net investment in finance lease, noncurrent	$ 196

Leases (Lease Income Associated

Leases (Lease Income Associated with Operating Leases) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Lessor, Lease, Description [Line Items]
Fixed payment	$ 17	$ 16
Variable payments	17	23
Total lease income under operating leases	34	39
Operating Revenues
Lessor, Lease, Description [Line Items]
Total lease income under operating leases	24	29
Other income
Lessor, Lease, Description [Line Items]
Total lease income under operating leases	$ 10	$ 10

Commitments and Contingencies (

Commitments and Contingencies (Details Textuals)	1 Months Ended		3 Months Ended
	Jan. 31, 2021	Jun. 30, 2020	Mar. 31, 2021USD ($)employeesitefacility	Apr. 05, 2021USD ($)	Dec. 31, 2020USD ($)	Jul. 31, 2019CAD ($)
Loss Contingencies [Line Items]
Estimated capital expenditures and contributions to equity method investees for current fiscal year			$ 4,200,000,000
Allowance for doubtful accounts			$ 123,000,000		$ 104,000,000
Workforce subject to collective bargaining arrangements | Labor force concentration risk
Loss Contingencies [Line Items]
Number of employees | employee			5,200
Percentage of total employees			49.00%
Vector Pipeline
Loss Contingencies [Line Items]
Ownership interest			40.00%
Synthetic fuel
Loss Contingencies [Line Items]
Number of days after expiration of statutes of limitations			90 days
Maximum potential liability			$ 400,000,000
Reduced emissions fuel guarantees
Loss Contingencies [Line Items]
Number of days after expiration of statutes of limitations			90 days
Maximum potential liability			$ 631,000,000
Other guarantees
Loss Contingencies [Line Items]
Maximum potential liability			50,000,000
Performance surety bonds
Loss Contingencies [Line Items]
Performance bonds outstanding			$ 129,000,000
Reduction of Carbon Emissions by 2023
Loss Contingencies [Line Items]
Commitment to reduce carbon emissions, percentage			32.00%
Reduction of Carbon Emissions by 2030
Loss Contingencies [Line Items]
Commitment to reduce carbon emissions, percentage			50.00%
Reduction of Carbon Emissions by 2040
Loss Contingencies [Line Items]
Commitment to reduce carbon emissions, percentage			80.00%
DTE Gas | NEXUS pipeline
Loss Contingencies [Line Items]
Maximum potential liability			$ 209,000,000
Guarantee termination, minimum threshold, period following end of primary term of capacity lease agreements			2 months
Texas Eastern Transmission, LP | NEXUS pipeline
Loss Contingencies [Line Items]
Maximum potential liability			$ 335,000,000
Guarantee termination, minimum threshold, period following end of primary term of capacity lease agreements			2 months
Vector | Revolving Term Credit Facility
Loss Contingencies [Line Items]
Revolving term credit facility amount						$ 70,000,000
Maximum potential payments under line of credit			$ 56,000,000
Vector | NEXUS pipeline
Loss Contingencies [Line Items]
Maximum potential liability			$ 7,000,000
Percentage of payment obligations due			50.00%
Guarantee termination, minimum threshold, period following end of primary term of capacity lease agreements			15 years
DTE Electric
Loss Contingencies [Line Items]
Environmental capital expenditures			$ 2,400,000,000
Estimated environmental capital expenditures			$ 0
Number of former MGP sites | site			3
Accrued for remediation			$ 10,000,000		10,000,000
Number of permitted engineered ash storage facilities owned | facility			3
Estimated capital expenditures and contributions to equity method investees for current fiscal year			$ 3,000,000,000
Allowance for doubtful accounts			$ 59,000,000		57,000,000
DTE Electric | Workforce subject to collective bargaining arrangements | Labor force concentration risk
Loss Contingencies [Line Items]
Number of employees | employee			2,800
Percentage of total employees			57.00%
DTE Electric | Performance surety bonds
Loss Contingencies [Line Items]
Performance bonds outstanding			$ 73,000,000
DTE Electric | Reduction of Carbon Emissions by 2050
Loss Contingencies [Line Items]
Goal of net carbon emissions, percentage			0.00%
DTE Electric | Coal Combustion Residual And Effluent Limitations Guidelines Rules
Loss Contingencies [Line Items]
Estimated impact of the CCR and ELG rules			$ 697,000,000
Estimated impact of the CCR and ELG rules through 2025			$ 552,000,000
DTE Gas
Loss Contingencies [Line Items]
Number of former MGP sites | site			14
Accrued for remediation			$ 24,000,000		$ 24,000,000
Amortization period (in years)			10 years
DTE Gas | Clean up completed and site closed
Loss Contingencies [Line Items]
Number of former MGP sites | site			8
DTE Gas | Partial closure complete
Loss Contingencies [Line Items]
Number of former MGP sites | site			4
DTE Gas | Reduction of Greenhouse Gas Emissions by 2050
Loss Contingencies [Line Items]
Goal of net greenhouse gas emissions, percentage		0.00%
DTE Midstream | Reduction of Greenhouse Gas Emissions by 2050
Loss Contingencies [Line Items]
Goal of net greenhouse gas emissions, percentage	0.00%
DTE Midstream | Reduction of Carbon Emissions in the next decade
Loss Contingencies [Line Items]
Commitment to reduce carbon emissions, percentage	30.00%
NEXUS | DTE Gas | NEXUS pipeline
Loss Contingencies [Line Items]
Agreement term			15 years
Percentage of payment obligations due			50.00%
NEXUS | Texas Eastern Transmission, LP | NEXUS pipeline
Loss Contingencies [Line Items]
Agreement term			15 years
Percentage of payment obligations due			50.00%
NEXUS | Vector | NEXUS pipeline
Loss Contingencies [Line Items]
Agreement term			15 years
DTE Energy Trading | Brilliant
Loss Contingencies [Line Items]
Accounts receivable not recorded as collectability no longer deemed probable			$ 48,000,000
Accounts receivable			12,000,000
Allowance for doubtful accounts			$ 12,000,000
Brilliant | DTE Energy Trading | Subsequent Event
Loss Contingencies [Line Items]
Maximum amount under credit agreement				$ 14,000,000

Retirement Benefits and Trust_3

Retirement Benefits and Trusteed Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 27	$ 25
Interest cost	39	46
Expected return on plan assets	(84)	(83)
Amortization of net actuarial loss	49	43
Amortization of prior service credit	0	0
Net periodic benefit cost (credit)	31	31
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	8	6
Interest cost	11	14
Expected return on plan assets	(32)	(32)
Amortization of net actuarial loss	3	5
Amortization of prior service credit	(5)	(5)
Net periodic benefit cost (credit)	(15)	(12)
Other Postretirement Benefits | DTE Electric
Defined Benefit Plan Disclosure [Line Items]
Service cost	6	5
Interest cost	8	11
Expected return on plan assets	(22)	(22)
Amortization of net actuarial loss	3	3
Amortization of prior service credit	(3)	(4)
Net periodic benefit cost (credit)	$ (8)	$ (7)

Retirement Benefits and Trust_4

Retirement Benefits and Trusteed Assets (Details Textuals) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Pension plans | Qualified Plan | Maximum
Defined Benefit Plan Disclosure [Line Items]
Anticipated contributions, current fiscal year	$ 107,000,000
Postretirement benefit plans
Defined Benefit Plan Disclosure [Line Items]
Anticipated contributions, current fiscal year	0
DTE Electric | Pension plans
Defined Benefit Plan Disclosure [Line Items]
Pension cost	26,000,000	$ 26,000,000
DTE Electric | Pension plans | Qualified Plan | Maximum
Defined Benefit Plan Disclosure [Line Items]
Anticipated contributions, current fiscal year	$ 100,000,000

Segment and Related Informati_3

Segment and Related Information (Details Textuals) customer in Millions	Mar. 31, 2021customer
Segment Reporting [Abstract]
Number of electric utility customers	2.2
Number of gas utility customers	1.3

Segment and Related Informati_4

Segment and Related Information (Financial Data - Inter-segment Billing) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Operating Revenues	$ (3,778)	$ (3,022)
Electric
Segment Reporting Information [Line Items]
Operating Revenues	(1,364)	(1,216)
Gas
Segment Reporting Information [Line Items]
Operating Revenues	(612)	(540)
Gas Storage and Pipelines
Segment Reporting Information [Line Items]
Operating Revenues	(197)	(170)
Power and Industrial Projects
Segment Reporting Information [Line Items]
Operating Revenues	(366)	(407)
Energy Trading
Segment Reporting Information [Line Items]
Operating Revenues	(1,439)	(913)
Reconciliation and Eliminations
Segment Reporting Information [Line Items]
Operating Revenues	201	124
Reconciliation and Eliminations | Electric
Segment Reporting Information [Line Items]
Operating Revenues	16	15
Reconciliation and Eliminations | Gas
Segment Reporting Information [Line Items]
Operating Revenues	4	4
Reconciliation and Eliminations | Gas Storage and Pipelines
Segment Reporting Information [Line Items]
Operating Revenues	5	4
Reconciliation and Eliminations | Power and Industrial Projects
Segment Reporting Information [Line Items]
Operating Revenues	162	94
Reconciliation and Eliminations | Energy Trading
Segment Reporting Information [Line Items]
Operating Revenues	13	6
Reconciliation and Eliminations | Corporate and Other
Segment Reporting Information [Line Items]
Operating Revenues	$ 1	$ 1

Segment and Related Informati_5

Segment and Related Information (Financial Data - Operating Revenues including Inter-segment Revenues) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Utility operations	$ 1,953	$ 1,733
Operating Revenues — Non-utility operations	1,825	1,289
Operating Revenues	3,778	3,022
Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	(201)	(124)
Operating Revenues	(201)	(124)
Electric
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	1,364	1,216
Electric | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Utility operations	1,360	1,212
Operating Revenues — Non-utility operations	4	4
Electric | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(16)	(15)
Gas
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	612	540
Gas | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Utility operations	612	540
Gas | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(4)	(4)
Gas Storage and Pipelines
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	197	170
Gas Storage and Pipelines | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	197	170
Gas Storage and Pipelines | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(5)	(4)
Power and Industrial Projects
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	366	407
Power and Industrial Projects | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	366	307
Power and Industrial Projects | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(162)	(94)
Energy Trading
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	1,439	913
Energy Trading | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	1,439	913
Energy Trading | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(13)	(6)
Corporate and Other | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	1	0
Corporate and Other | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	$ (1)	$ (1)

Segment and Related Informati_6

Segment and Related Information (Financial Data - Net Income (Loss) Attributable to DTE Energy by Segment) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	$ 397	$ 340
Electric
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	208	94
Gas
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	169	121
Gas Storage and Pipelines
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	79	72
Power and Industrial Projects
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	28	30
Energy Trading
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	(55)	34
Corporate and Other
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	$ (32)	$ (11)