DTE Electric 10-K 19 Feb 21 2020 FY Annual report Financial data

Document and Entity Information

Document and Entity Information Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2020	Jan. 29, 2021	Jun. 30, 2020
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
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 Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 20.5
Entity Common Stock, Shares Outstanding		193,773,687
Documents Incorporated by Reference	Certain information in DTE Energy's definitive Proxy Statement for its 2021 Annual Meeting of Common Shareholders to be held May 20, 2021, which will be filed with the Securities and Exchange Commission pursuant to Regulation 14A, not later than 120 days after the end of the registrant’s fiscal year covered by this report on Form 10-K, is incorporated herein by reference to Part III (Items 10, 11, 12, 13, and 14) of this Form 10-K. This combined Form 10-K is filed separately by two registrants: DTE Energy and DTE Electric. Information contained herein relating to any individual registrant is filed by such registrant solely on its own behalf. DTE Electric makes no representation as to information relating exclusively to DTE Energy. DTE Electric, an indirect wholly-owned subsidiary of DTE Energy, meets the conditions set forth in General Instructions I(1)(a) and (b) of Form 10-K and is therefore filing this form with the reduced disclosure format specified in General Instruction I(2) of Form 10-K.
Entity Central Index Key	0000936340
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Common stock, without par value
Entity Information [Line Items]
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
Entity Information [Line Items]
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
Entity Information [Line Items]
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
Entity Information [Line Items]
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
Entity Information [Line Items]
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
Entity Information [Line Items]
Title of 12(b) Security	2020 Series G 4.375% Junior Subordinated Debentures due 2080
Trading Symbol	DTB
Security Exchange Name	NYSE
DTE Electric
Entity Information [Line Items]
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 Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		138,362,324
Entity Central Index Key	0000028385

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Revenues
Utility operations	$ 6,845	$ 6,638	$ 6,670
Non-utility operations	5,332	6,031	7,542
Operating Revenues	12,177	12,669	14,212
Operating Expenses
Fuel, purchased power, and gas — utility	1,719	1,798	1,981
Fuel, purchased power, gas, and other — non-utility	4,141	5,053	6,630
Operation and maintenance	2,443	2,419	2,451
Depreciation and amortization	1,443	1,263	1,124
Taxes other than income	410	414	405
Asset (gains) losses and impairments, net	35	15	27
Operating Expenses	10,191	10,962	12,618
Operating Income	1,986	1,707	1,594
Other (Income) and Deductions
Interest expense	720	641	559
Interest income	(38)	(17)	(12)
Non-operating retirement benefits, net	50	39	37
Other income	(388)	(350)	(333)
Other expenses	104	70	127
Other (Income) and Deductions	448	383	378
Income Before Income Taxes	1,538	1,324	1,216
Income Tax Expense	167	152	98
Net Income	1,371	1,172	1,118
Less: Net Income (Loss) Attributable to Noncontrolling Interests	3	3	(2)
Net Income Attributable to DTE Energy Company/DTE Electric Company	$ 1,368	$ 1,169	$ 1,120
Basic Earnings per Common Share
Net income attributable to DTE Energy Company (in dollars per share)	$ 7.09	$ 6.32	$ 6.18
Diluted Earnings per Common Share
Net income attributable to DTE Energy Company (in dollars per share)	$ 7.08	$ 6.31	$ 6.17
Weighted Average Common Shares Outstanding
Basic (in shares)	193	185	181
Diluted (in shares)	193	185	181
DTE Electric
Operating Revenues
Utility operations	$ 5,506	$ 5,224	$ 5,298
Operating Revenues	5,506	5,224
Operating Expenses
Fuel, purchased power, and gas — utility	1,397	1,390	1,552
Operation and maintenance	1,505	1,452	1,470
Depreciation and amortization	1,043	946	836
Taxes other than income	296	310	307
Asset (gains) losses and impairments, net	41	13	(1)
Operating Expenses	4,282	4,111	4,164
Operating Income	1,224	1,113	1,134
Other (Income) and Deductions
Interest expense	331	313	283
Interest income	(2)	(2)	0
Non-operating retirement benefits, net	(1)	(1)	0
Other income	(87)	(107)	(83)
Other expenses	96	56	77
Other (Income) and Deductions	337	259	277
Income Before Income Taxes	887	854	857
Income Tax Expense	109	138	193
Net Income Attributable to DTE Energy Company/DTE Electric Company	$ 778	$ 716	$ 664

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net Income	$ 1,371	$ 1,172	$ 1,118
Net Income	1,368	1,169	1,120
Other comprehensive income (loss), net of tax:
Benefit obligations, net of taxes of $3, $2, and $2, respectively	8	8	8
Net unrealized gains (losses) on derivatives, net of taxes of $1, $(4), and $—, respectively	2	(12)
Net unrealized gains (losses) on derivatives, net of taxes of $1, $(4), and $—, respectively			(1)
Foreign currency translation	1	1	(2)
Other comprehensive income (loss)	11	(3)	5
Comprehensive income	1,382	1,169	1,123
Less: Comprehensive income (loss) attributable to noncontrolling interests	3	3	(2)
Comprehensive Income Attributable to DTE Energy Company/DTE Electric Company	1,379	1,166	1,125
DTE Electric
Net Income	778	716	664
Other comprehensive income (loss), net of tax:
Other comprehensive income (loss)	0	0	0
Comprehensive Income Attributable to DTE Energy Company/DTE Electric Company	$ 778	$ 716	$ 664

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Tax effect on benefit obligation	$ 3	$ 2	$ 2
Tax effect on net unrealized gains (losses) on derivatives during the period	$ 1	$ (4)
Tax effect on net unrealized gains (losses) on derivatives during the period			$ 0

Consolidated Statements of Fina

Consolidated Statements of Financial Position - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 514	$ 93
Restricted cash	2	0
Accounts receivable (less allowance for doubtful accounts)
Customer	1,665	1,642
Other	127	245
Inventories
Fuel and gas	335	373
Materials, supplies, and other	381	386
Derivative assets	116	133
Regulatory assets	129	5
Other	229	209
Total Current Assets	3,498	3,086
Investments
Nuclear decommissioning trust funds	1,855	1,661
Investments in equity method investees	1,868	1,862
Other	196	265
Total Investments	3,919	3,788
Property
Property, plant, and equipment	37,997	35,072
Accumulated depreciation and amortization	(10,028)	(9,755)
Property, plant and equipment, net	27,969	25,317
Other Assets
Goodwill	2,466	2,464
Regulatory assets	4,128	4,171
Intangible assets	2,339	2,393
Notes receivable	280	202
Derivative assets	40	41
Prepaid postretirement costs	561	454
Operating lease right-of-use assets	152	169
Other	144	183
Total Other Assets	10,110	10,077
Total Assets	45,496	42,268
Current Liabilities
Accounts payable	1,029	1,076
Accounts payable
Accrued interest	158	147
Dividends payable	210	195
Short-term borrowings	38	828
Current portion long-term debt, including finance leases	469	687
Derivative liabilities	68	83
Regulatory liabilities	39	65
Short-term borrowings
Operating lease liabilities	33	33
Acquisition related deferred payment	0	379
Other	647	504
Total Current Liabilities	2,691	3,997
Long-Term Debt (net of current portion)
Mortgage bonds, notes, and other	17,802	14,778
Junior subordinated debentures	1,175	1,146
Finance lease obligations	24	11
Total Long-Term Debt (net of current portion)	19,001	15,935
Other Liabilities
Deferred income taxes	2,822	2,315
Regulatory liabilities	3,363	3,264
Asset retirement obligations	2,839	2,672
Unamortized investment tax credit	162	166
Derivative liabilities	60	86
Accrued pension liability	797	808
Accrued postretirement liability	407	385
Nuclear decommissioning	283	249
Operating lease liability	111	127
Other	371	428
Total Other Liabilities	11,215	10,500
Commitments and Contingencies (Notes 10 and 19)
Equity
Common stock	5,406	5,233
Retained earnings	7,156	6,587
Accumulated other comprehensive loss	(137)	(148)
Total DTE Energy Company/DTE Electric Company Equity	12,425	11,672
Noncontrolling interests	164	164
Total Equity	12,589	11,836
Total Liabilities and Equity	45,496	42,268
DTE Electric
Current Assets
Cash and cash equivalents	16	12
Accounts receivable (less allowance for doubtful accounts)
Customer	763	729
Affiliates	13	25
Other	62	41
Inventories
Fuel and gas	187	187
Materials, supplies, and other	292	280
Regulatory assets	123	5
Other	71	78
Total Current Assets	1,527	1,357
Investments
Nuclear decommissioning trust funds	1,855	1,661
Other	42	38
Total Investments	1,897	1,699
Property
Property, plant, and equipment	26,171	24,279
Accumulated depreciation and amortization	(7,050)	(6,706)
Property, plant and equipment, net	19,121	17,573
Other Assets
Regulatory assets	3,440	3,448
Intangible assets	11	15
Prepaid postretirement costs — affiliates	335	266
Operating lease right-of-use assets	75	87
Other	107	143
Total Other Assets	3,968	3,959
Total Assets	26,513	24,588
Accounts payable
Affiliates	62	59
Other	410	406
Accrued interest	91	84
Current portion long-term debt, including finance leases	468	636
Regulatory liabilities	18	40
Short-term borrowings
Affiliates	101	97
Other	0	354
Operating lease liabilities	11	12
Other	219	155
Total Current Liabilities	1,380	1,843
Long-Term Debt (net of current portion)
Mortgage bonds, notes, and other	7,774	6,548
Finance lease obligations	13	4
Total Long-Term Debt (net of current portion)	7,787	6,552
Other Liabilities
Deferred income taxes	2,525	2,355
Regulatory liabilities	2,432	2,546
Asset retirement obligations	2,607	2,447
Unamortized investment tax credit	162	166
Nuclear decommissioning	283	249
Accrued pension liability — affiliates	731	717
Accrued postretirement liability — affiliates	384	367
Operating lease liability	56	67
Other	96	84
Total Other Liabilities	9,276	8,998
Commitments and Contingencies (Notes 10 and 19)
Equity
Common stock	5,447	4,811
Retained earnings	2,623	2,384
Total DTE Energy Company/DTE Electric Company Equity	8,070	7,195
Total Liabilities and Equity	$ 26,513	$ 24,588

Consolidated Statements of Fi_2

Consolidated Statements of Financial Position (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current Assets:
Allowance for doubtful accounts	$ 104	$ 91
Stockholders' Equity:
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	193,770,617	192,208,533
Common stock, shares outstanding (in shares)	193,770,617	192,208,533
DTE Electric
Current Assets:
Allowance for doubtful accounts	$ 57	$ 46
Stockholders' Equity:
Common stock, par value (in dollars per share)	$ 10	$ 10
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	138,632,324	138,632,324
Common stock, shares outstanding (in shares)	138,632,324	138,632,324

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Activities
Net Income		$ 1,371	$ 1,172	$ 1,118
Net Income		1,368	1,169	1,120
Adjustments to reconcile Net Income to Net cash from operating activities:
Depreciation and amortization		1,443	1,263	1,124
Nuclear fuel amortization		37	60	45
Allowance for equity funds used during construction		(25)	(24)	(28)
Deferred income taxes		407	329	114
Equity earnings of equity method investees		(132)	(111)	(132)
Dividends from equity method investees		142	160	74
Asset (gains) losses and impairments, net		47	14	29
Changes in assets and liabilities:
Accounts receivable, net		111	49	(44)
Inventories		45	59	(32)
Prepaid postretirement benefit costs		(107)	(24)	(45)
Accounts payable		0	(288)	146
Accrued pension liability		(11)	(29)	(87)
Accrued postretirement liability		22	0	(61)
Derivative assets and liabilities		(23)	(28)	31
Regulatory assets and liabilities		104	160	15
Other current and noncurrent assets and liabilities		266	(113)	413
Net cash from operating activities		3,697	2,649	2,680
Investing Activities
Plant and equipment expenditures — utility		(3,241)	(2,724)	(2,439)
Plant and equipment expenditures — non-utility		(616)	(273)	(274)
Acquisitions related to business combinations, net of cash acquired		(126)	(2,470)	0
Proceeds from sale of assets		13	0	0
Proceeds from sale of nuclear decommissioning trust fund assets		2,350	788	1,203
Investment in nuclear decommissioning trust funds		(2,350)	(794)	(1,188)
Distributions from equity method investees		24	10	9
Contributions to equity method investees		(37)	(149)	(637)
Notes receivable		(85)	(98)
Notes receivable				2
Other		(2)	(22)	(23)
Net cash used for investing activities		(4,070)	(5,732)	(3,347)
Financing Activities
Issuance of long-term debt, net of issuance costs		3,692	2,506	1,432
Redemption of long-term debt		(882)	(821)	(105)
Issuance of equity units, net of issuance costs		0	1,265	0
Short-term borrowings, net		(790)		(12)
Short-term borrowings, net			219
Issuance of common stock		2	1,023	0
Dividends paid on common stock		(760)	(692)	(620)
Contributions from noncontrolling interests, principally REF entities		36	38	53
Distributions to noncontrolling interests		(39)	(59)	(48)
Purchases of noncontrolling interest, principally SGG		0	(300)	0
Acquisition related deferred payment, excluding accretion		(380)	0	0
Other		(83)	(79)	(46)
Net cash from financing activities		796	3,100	654
Net Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash		423	17	(13)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period		93	76	89
Cash, Cash Equivalents, and Restricted Cash at End of Period		516	93	76
Supplemental disclosure of cash information
Cash paid (received) for: Interest, net of interest capitalized		679	595	572
Cash paid (received) for: Income taxes	[1]	(360)	18	(26)
Supplemental disclosure of non-cash investing and financing activities
Plant and equipment expenditures in accounts payable		266	311	307
Premium on equity units		0	150	0
DTE Electric
Operating Activities
Net Income		778	716	664
Adjustments to reconcile Net Income to Net cash from operating activities:
Depreciation and amortization		1,043	946	836
Nuclear fuel amortization		37	60	45
Allowance for equity funds used during construction		(23)	(22)	(19)
Deferred income taxes		89	97	189
Asset (gains) losses and impairments, net		41	13	0
Changes in assets and liabilities:
Accounts receivable, net		(42)	20	33
Inventories		(12)	(17)	15
Prepaid postretirement benefit costs — affiliates		(69)	(77)	(76)
Accounts payable		20	(57)	54
Accrued pension liability — affiliates		14	(1)	(93)
Accrued postretirement liability — affiliates		17	89	(33)
Regulatory assets and liabilities		55	139	4
Other current and noncurrent assets and liabilities		(43)	(197)	101
Net cash from operating activities		1,905	1,709	1,720
Investing Activities
Plant and equipment expenditures		(2,674)	(2,200)	(1,989)
Proceeds from sale of nuclear decommissioning trust fund assets		2,350	788	1,203
Investment in nuclear decommissioning trust funds		(2,350)	(794)	(1,188)
Notes receivable and other		(8)	(21)	(15)
Net cash used for investing activities		(2,682)	(2,227)	(1,989)
Financing Activities
Issuance of long-term debt, net of issuance costs		1,683	643	519
Redemption of long-term debt		(632)	0	0
Capital contribution by parent company		636	180	325
Short-term borrowings, net — affiliate		4	(4)	(15)
Short-term borrowings, net — other		(354)	205	(89)
Dividends paid on common stock		(539)	(494)	(461)
Other		(17)	(18)	(7)
Net cash from financing activities		781	512	272
Net Increase (Decrease) in Cash, Cash Equivalents, and Restricted Cash		4	(6)	3
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period		12	18	15
Cash, Cash Equivalents, and Restricted Cash at End of Period		16	12	18
Supplemental disclosure of cash information
Cash paid (received) for: Interest, net of interest capitalized		315	295	283
Cash paid (received) for: Income taxes		14	46	0
Supplemental disclosure of non-cash investing and financing activities
Plant and equipment expenditures in accounts payable		$ 174	$ 192	$ 181
[1]	2020 cash received primarily relates to AMT credit and other refunds, of which a portion was accelerated due to and CARES Act. See Note 11 to the Consolidated Financial Statements, "Income Taxes," for additional information.

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Retained Earnings	Retained EarningsCumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss)Cumulative Effect, Period of Adoption, Adjustment	Noncontrolling Interests	DTE Electric	DTE ElectricCumulative Effect, Period of Adoption, Adjustment	DTE ElectricCommon Stock	DTE ElectricAdditional Paid-in Capital	DTE ElectricRetained Earnings	DTE ElectricRetained EarningsCumulative Effect, Period of Adoption, Adjustment	DTE ElectricAccumulated Other Comprehensive Income (Loss)	DTE ElectricAccumulated Other Comprehensive Income (Loss)Cumulative Effect, Period of Adoption, Adjustment
Beginning balance (in shares) at Dec. 31, 2017			179,387,000								138,632,000
Beginning balance at Dec. 31, 2017	$ 9,990	$ 0	$ 3,989	$ 5,643	$ 5	$ (120)	$ (5)	$ 478
Beginning balance at Dec. 31, 2017									$ 6,265	$ 0	$ 1,386	$ 2,920	$ 1,956	$ 3	$ 3	$ (3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	1,118			1,120				(2)
Net Income	1,120								664				664
Dividends declared on common stock	(653)			(653)					(461)				(461)
Issuance of common stock (in shares)			255,000
Issuance of common stock	26		$ 26
Contribution of common stock to pension plan (in shares)			1,751,000
Contribution of common stock to pension plan	175		$ 175
Other comprehensive income (loss), net of tax	5					5			0
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other (in shares)			532,000
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other	56		$ 55	(3)				4
Capital contribution by parent company									325			325
Ending balance (in shares) at Dec. 31, 2018			181,925,000								138,632,000
Ending balance at Dec. 31, 2018	10,717		$ 4,245	6,112		(120)		480
Ending balance at Dec. 31, 2018									6,793		$ 1,386	3,245	2,162		0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Implementation of ASU 2018-02	0			25		(25)
Net Income (Loss)	1,172			1,169				3
Net Income	1,169								716				716
Dividends declared on common stock	(714)			(714)					(494)				(494)
Issuance of common stock (in shares)			8,634,000
Issuance of common stock	1,014		$ 1,014
Premium on equity units	(150)		(150)
Issuance costs of equity units	(30)		$ (30)
Contribution of common stock to pension plan (in shares)			815,000
Contribution of common stock to pension plan	100		$ 100
Other comprehensive income (loss), net of tax	(3)					(3)			0
Purchase of noncontrolling interests, principally SGG	(300)		$ (3)					(297)
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other (in shares)			835,000
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other	$ 30		$ 57	(5)				(22)
Capital contribution by parent company									$ 180			180
Ending balance (in shares) at Dec. 31, 2019	192,208,533		192,209,000						138,632,324		138,632,000
Ending balance at Dec. 31, 2019	$ 11,836		$ 5,233	6,587		(148)		164
Ending balance at Dec. 31, 2019	11,672								$ 7,195		$ 1,386	3,425	2,384		0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	1,371			1,368				3
Net Income	1,368								778				778
Dividends declared on common stock	(796)			(796)					(539)				(539)
Issuance of common stock (in shares)			192,000
Issuance of common stock	22		$ 22
Contribution of common stock to pension plan (in shares)			694,000
Contribution of common stock to pension plan	82		$ 82
Other comprehensive income (loss), net of tax	11					11			0
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other (in shares)			676,000
Stock-based compensation, net contributions from (distributions to) noncontrolling interests, and other	$ 63		$ 69	(3)				(3)
Capital contribution by parent company									$ 636			636
Ending balance (in shares) at Dec. 31, 2020	193,770,617		193,771,000						138,632,324		138,632,000
Ending balance at Dec. 31, 2020	$ 12,589		$ 5,406	$ 7,156		$ (137)		$ 164
Ending balance at Dec. 31, 2020	$ 12,425								$ 8,070		$ 1,386	$ 4,061	$ 2,623		$ 0

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Equity (Parenthetical) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Dividends declared on common stock (in dollars per share)	$ 4.12	$ 3.85	$ 3.60

Organization and Basis of Prese

Organization and Basis of Presentation	12 Months Ended
	Dec. 31, 2020
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 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 information in these combined notes relates to each of the Registrants as noted in the Index of Combined Notes to Consolidated Financial Statements. However, DTE Electric does not make any representation as to information related solely to DTE Energy or the subsidiaries of DTE Energy other than itself. Certain prior year balances for the Registrants were reclassified to match the current year's Consolidated Financial Statements presentation. 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, which was acquired in September 2019. 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 December 31, 2020, 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 December 31, 2020, 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 19 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 guaranteed. See Note 19 to the Consolidated Financial Statements, "Commitments and Contingencies," for further discussion of the NEXUS guarantee arrangements. The following table summarizes the major Consolidated Statements of Financial Position items for consolidated VIEs as of December 31, 2020 and 2019. 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: December 31, 2020 December 31, 2019 SGG (a) Other Total SGG (a) Other Total (In millions) ASSETS Cash and cash equivalents $ 34 $ 20 $ 54 $ 16 $ 11 $ 27 Accounts receivable 8 28 36 8 19 27 Inventories — 107 107 — 74 74 Property, plant, and equipment, net 402 23 425 410 33 443 Goodwill 25 — 25 25 — 25 Intangible assets 527 — 527 542 — 542 Other current and long-term assets 2 33 35 2 — 2 $ 998 $ 211 $ 1,209 $ 1,003 $ 137 $ 1,140 LIABILITIES Accounts payable and accrued current liabilities $ — $ 22 $ 22 $ 2 $ 13 $ 15 Short-term borrowings — 38 38 — — — Other current and long-term liabilities 7 4 11 7 7 14 $ 7 $ 64 $ 71 $ 9 $ 20 $ 29 _____________________________________ (a) Amounts shown are 100% of SGG's assets and liabilities, of which DTE Energy owns 85% at December 31, 2020 and 2019. Amounts for DTE Energy's non-consolidated VIEs are as follows: December 31, 2020 2019 (In millions) Investments in equity method investees $ 1,507 $ 1,503 Notes receivable $ 47 $ 21 Future funding commitments $ 26 $ 63 Equity Method Investments Investments in non-consolidated affiliates that are not controlled by the Registrants, but over which they have significant influence, are accounted for using the equity method. Certain of the equity method investees are also considered VIEs and disclosed in the non-consolidated VIEs table above. At December 31, 2020 and 2019, DTE Energy's share of the underlying equity in the net assets of the investees exceeded the carrying amounts of Investments in equity method investees by $80 million and $74 million, respectively. The difference is being amortized over the life of the underlying assets. As of December 31, 2020 and 2019, DTE Energy's consolidated retained earnings balance includes undistributed earnings from equity method investments of $109 million and $129 million, respectively. DTE Energy equity method investees are described below: Investments % Owned Segment 2020 2019 2020 2019 Description (In millions) Significant Equity Method Investees Gas Storage and Pipelines NEXUS Pipeline $ 1,349 $ 1,345 50% 50% 256-mile pipeline to transport Utica and Marcellus shale gas to Ohio, Michigan, and Ontario market centers. Also includes Generation Pipeline, a 25-mile pipeline located in northern Ohio Vector Pipeline 134 131 40% 40% 348-mile pipeline connecting Chicago, Michigan, and Ontario market centers Millennium Pipeline 208 209 26% 26% 263-mile pipeline serving markets in the Northeast 1,691 1,685 Other Equity Method Investees Other Segments 177 177 $ 1,868 $ 1,862 The balances in Other Equity Method Investees are individually insignificant and are primarily from the Power and Industrial Projects segment. These investments are comprised of projects that deliver energy and utility-type products and services to industrial customers, sell electricity from renewable energy projects under long-term power purchase agreements, and produce and sell metallurgical coke. For further information by segment, see Note 23 to the Consolidated Financial Statements, "Segment and Related Information." The following table presents summarized financial information of subsidiaries not consolidated and 50 percent or less owned by DTE Energy. The amounts included in the table below represents 100% of the results of continuing operations of such entities accounted for under the equity method of accounting. Summarized balance sheet data is as follows: December 31, 2020 2019 (In millions) Current Assets $ 351 $ 374 Non-current assets $ 5,235 $ 5,260 Current Liabilities $ 319 $ 414 Non-current liabilities $ 686 $ 698 Summarized income statement data is as follows: December 31, 2020 2019 2018 (In millions) Operating Revenues $ 1,227 $ 1,210 $ 883 Operating Expenses $ 847 $ 853 $ 622 Net Income $ 395 $ 313 $ 365

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES Other Income Other income for the Registrants is recognized for non-operating income such as equity earnings of equity method investees, allowance for equity funds used during construction, contract services, and gains from trading securities, primarily from those held in DTE Energy's rabbi trust. DTE Energy's Power and Industrial Projects segment also recognizes Other income in connection with the sale of membership interests in reduced emissions fuel facilities to investors. In exchange for the cash received, the investors receive a portion of the economic attributes of the facilities, including income tax attributes. The transactions are not treated as a sale of membership interests for financial reporting purposes. Other income related to fixed non-refundable cash payments received from investors for which the earnings process is not contingent upon production of refined coal is recognized on a straight-line basis over the non-cancelable contract term as the economic benefit from the ownership of the facility is transferred to investors. Other income related to cash payments that is contingent upon production of refined coal is considered earned and recognized when the contingency regarding the timing and amount of payment is resolved, generally as refined coal is produced and tax credits are generated. The following is a summary of DTE Energy's Other income: 2020 2019 2018 (In millions) Income from REF entities $ 139 $ 130 $ 98 Equity earnings of equity method investees 132 111 132 Gains from rabbi trust securities (a) 28 37 6 Contract services 28 29 51 Allowance for equity funds used during construction 25 24 28 Gas Storage and Pipelines post-acquisition settlement 20 — — Other 16 19 18 $ 388 $ 350 $ 333 _______________________________________ (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: 2020 2019 2018 (In millions) Gains from rabbi trust securities allocated from DTE Energy (a) $ 28 $ 37 $ 6 Contract services 28 32 51 Allowance for equity funds used during construction 23 22 19 Other 8 16 7 $ 87 $ 107 $ 83 _______________________________________ (a) Losses from rabbi trust securities are recorded separately to Other expenses on the Consolidated Statements of Operations. For information on equity earnings of equity method investees by segment, see Note 23 to the Consolidated Financial Statements, "Segment and Related Information." Accounting for ISO Transactions DTE Electric participates in the energy market through MISO. MISO requires that DTE Electric submit hourly day-ahead, real-time, and FTR bids and offers for energy at locations across the MISO region. DTE Electric accounts for MISO transactions on a net hourly basis in each of the day-ahead, real-time, and FTR markets. In any single hour, transactions in each of the MISO energy markets are netted based on MWh to determine if DTE Electric is in a net sale or purchase position. Net purchases are recorded in Fuel, purchased power, and gas — utility and net sales are recorded in Operating Revenues — Utility operations on the Registrants' Consolidated Statements of Operations. The Energy Trading segment participates in the energy markets through various ISOs and RTOs. These markets require that Energy Trading submits hourly day-ahead, real-time bids and offers for energy at locations across each region. Energy Trading submits bids in the annual and monthly auction revenue rights and FTR auctions to the RTOs. Energy Trading accounts for these transactions on a net hourly basis for the day-ahead, real-time, and FTR markets. These transactions are related to trading contracts which, if derivatives, are presented on a net basis in Operating Revenues — Non-utility operations, and if non-derivatives, the realized gains and losses for sales are recorded in Operating Revenues — Non-utility operations and purchases are recorded in Fuel, purchased power, gas, and other — non-utility in the DTE Energy Consolidated Statements of Operations. DTE Electric and Energy Trading record accruals for future net purchases adjustments based on historical experience and reconcile accruals to actual costs when invoices are received from MISO and other ISOs and RTOs. Derivatives Energy Trading classifies derivative transactions as revenue or expense based on the intent of the transaction (buy or sell). Revenues are recorded on a gross or net basis within the income statement depending upon whether it represents a non-trading activity or trading activity, respectively. For additional information, refer to Note 14 to the Consolidated Financial Statements, "Financial and Other Derivative Instruments". 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 year ended December 31, 2020, reclassifications out of Accumulated other comprehensive income (loss) were not material. On January 1, 2019, DTE Energy reclassified $25 million of stranded tax effects resulting from the TCJA from Accumulated other comprehensive income (loss) to Retained Earnings. The reclassification was recorded upon adoption of ASU No. 2018-02, Income Statement — Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income . For the year ended December 31, 2019, reclassifications out of Accumulated other comprehensive income (loss) not relating to the adoption of this standard were not material. The following table summarizes the changes in DTE Energy's Accumulated other comprehensive income (loss) by component (a) for the years ended December 31, 2020 and 2019: Net Unrealized Gain (Loss) on Derivatives Benefit Obligations (b) Foreign Currency Translation Total (In millions) Balance, December 31, 2018 $ (11) $ (102) $ (7) $ (120) Other comprehensive income (loss) before reclassifications (14) (7) 1 (20) Amounts reclassified from Accumulated other comprehensive income (loss) 2 15 — 17 Net current-period Other comprehensive income (loss) (12) 8 1 (3) Implementation of ASU 2018-02 (2) (23) — (25) Balance, December 31, 2019 $ (25) $ (117) $ (6) $ (148) Other comprehensive income (loss) before reclassifications (3) (2) 1 (4) Amounts reclassified from Accumulated other comprehensive income (loss) 5 10 — 15 Net current-period Other comprehensive income 2 8 1 11 Balance, December 31, 2020 $ (23) $ (109) $ (5) $ (137) ______________________________________ (a) All amounts are net of tax, except for Foreign currency translation. (b) The amounts reclassified from Accumulated other comprehensive income (loss) are included in the computation of the net periodic pension and other postretirement benefit costs (see Note 21 to the Consolidated Financial Statements, "Retirement Benefits and Trusteed Assets"). Cash, Cash Equivalents, and Restricted Cash Cash and cash equivalents include cash on hand, cash in banks, and temporary investments purchased with remaining maturities of three months or less. Restricted cash consists of funds held 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. DTE Energy unbilled revenues of $944 million and $855 million at December 31, 2020 and 2019, respectively, include $260 million and $263 million of DTE Electric unbilled revenues, respectively, included in Customer Accounts receivable. 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 December 31, 2020. DTE Energy DTE Electric Year of origination 2020 2019 2018 and prior Total 2020 and prior (In millions) Notes receivable Internal grade 1 $ — $ 14 $ 10 $ 24 $ 14 Internal grade 2 68 43 6 117 2 Total notes receivable (a) $ 68 $ 57 $ 16 $ 141 $ 16 Net investment in leases Net investment in leases, internal grade 1 $ 6 $ — $ 39 $ 45 $ — Net investment in leases, internal grade 2 131 — 1 132 — Total net investment in leases (a) $ 137 $ — $ 40 $ 177 $ — _______________________________________ (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 Current Assets — Other and 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 19, "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 table presents a roll-forward of the activity for the Registrants' financing receivables credit loss reserves as of December 31, 2020. 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 100 3 103 61 Write-offs charged against allowance (136) (4) (140) (80) Recoveries of amounts previously written off 50 — 50 30 Ending reserve balance, December 31, 2020 $ 101 $ 3 $ 104 $ 57 The Registrants have been monitoring the impacts from the COVID-19 pandemic on our customers and various counterparties. For DTE Electric and DTE Gas, the allowance for doubtful accounts has been increased to account for additional risk related to the pandemic. As of December 31, 2020, the impact of these increases has not been material. In April 2020, the MPSC issued an order in response to the COVID-19 pandemic and authorized the deferral of certain uncollectible expense that is in excess of the amount used to set current rates. As a result of the order, the Registrants began deferring uncollectible expense as Regulatory assets, including $2 million at DTE Gas for the year ended December 31, 2020. For DTE Electric, deferrals recorded throughout the year were reversed and recorded to expense as a result of the MPSC approval of DTE Electric's one-time accounting application in December 2020. Refer to Note 10 to the Consolidated Financial Statements, "Regulatory Matters," for further information. For DTE Energy, uncollectible expense was $103 million, $111 million, and $140 million for the years ended December 31, 2020, 2019, and 2018, respectively, which is primarily comprised of the current period provision for allowance for doubtful accounts adjusted for regulatory deferrals at DTE Gas. For DTE Electric, uncollectible expense was $62 million, $65 million, and $85 million for the years ended December 31, 2020, 2019, and 2018, respectively, which is primarily comprised of the current period provision for allowance for doubtful accounts. There are no material amounts of past due financing receivables for the Registrants as of December 31, 2020. Inventories Inventory related to utility and non-utility operations is valued at the lower of cost or net realizable value, where cost is generally valued using average cost. DTE Gas' natural gas inventory of $40 million as of December 31, 2020 and 2019 is determined using the last-in, first-out (LIFO) method. The replacement cost of gas in inventory exceeded the LIFO cost by $62 million and $49 million at December 31, 2020 and 2019, respectively. Property, Retirement and Maintenance, and Depreciation and Amortization Property is stated at cost and includes construction-related labor, materials, overheads, and AFUDC for utility property. The cost of utility properties retired is charged to accumulated depreciation. Expenditures for maintenance and repairs are charged to expense when incurred. Utility property at DTE Electric and DTE Gas is depreciated over its estimated useful life using straight-line rates approved by the MPSC. DTE Energy's non-utility property is depreciated over its estimated useful life using the straight-line method. Depreciation and amortization expense also includes the amortization of certain regulatory assets for the Registrants. The cost of nuclear fuel is capitalized. The amortization of nuclear fuel is included within Fuel, purchased power, and gas — utility in the DTE Energy Consolidated Statements of Operations, and Fuel and purchased power in the DTE Electric Consolidated Statements of Operations, and is recorded using the units-of-production method. See Note 7 to the Consolidated Financial Statements, "Property, Plant, and Equipment." Long-Lived Assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. If the carrying amount of the asset exceeds the expected undiscounted future cash flows generated by the asset, an impairment loss is recognized resulting in the asset being written down to its estimated fair value. Assets to be disposed of are reported at the lower of the carrying amount or fair value, less costs to sell. Intangible Assets The Registrants have certain Intangible assets as shown below: December 31, 2020 December 31, 2019 Useful Lives Gross Carrying Value Accumulated Amortization Net Carrying Value Gross Carrying Value Accumulated Amortization Net Carrying Value (In millions) Intangible assets subject to amortization Customer relationships 25 to 40 years (a) $ 2,252 $ (121) $ 2,131 $ 2,252 $ (66) $ 2,186 Contract intangibles 6 to 26 years 289 (92) 197 268 (76) 192 2,541 (213) 2,328 2,520 (142) 2,378 DTE Electric renewable energy credits (b) 8 — 8 15 — 15 DTE Electric zonal resource credits (c) 3 — 3 — — — DTE Electric Long-term intangible assets 11 — 11 15 — 15 DTE Energy Long-term intangible assets $ 2,552 $ (213) $ 2,339 $ 2,535 $ (142) $ 2,393 ______________________________________ (a) The useful lives of the customer relationship intangible assets are based on the number of years in which the assets are expected to economically contribute to the business. The expected economic benefit incorporates existing customer contracts and expected renewal rates based on the estimated volume and production lives of gas resources in the region. (b) Renewable energy credits are charged to expense, using average cost, as the credits are consumed in the operation of the business. (c) Zonal resource credits are amortized on a straight-line basis over the period that they are in effect. The following table summarizes DTE Energy's estimated customer relationship and contract intangible amortization expense expected to be recognized during each year through 2025: 2021 2022 2023 2024 2025 (In millions) Estimated amortization expense $ 73 $ 73 $ 73 $ 73 $ 73 DTE Energy amortizes customer relationship and contract intangible assets on a straight-line basis over the expected period of benefit. DTE Energy's Intangible assets amortization expense was $71 million in 2020, $33 million in 2019, and $27 million in 2018. Excise and Sales Taxes The Registrants record the billing of excise and sales taxes as a receivable with an offsetting payable to the applicable taxing authority, with no net impact on the Registrants’ Consolidated Statements of Operations. Deferred Debt Costs The costs related to the issuance of long-term debt are deferred and amortized over the life of each debt issue. The deferred amounts are included as a direct deduction from the carrying amount of each debt issue in Mortgage bonds, notes, and other and Junior subordinated debentures on DTE Energy's Consolidated Statements of Financial Position and in Mortgage bonds, notes, and other on DTE Electric's Consolidated Statements of Financial Position. In accordance with MPSC regulations applicable to DTE Energy’s electric and gas utilities, the unamortized discount, premium, and expense related to utility debt redeemed with a refinancing are amortized over the life of the replacement issue. Discount, premium, and expense on early redemptions of debt associated with DTE Energy's non-utility operations are charged to earnings. Investments in Debt and Equity Securities The Registrants generally record investments in debt and equity securities at market value with unrealized gains or losses included in earnings. Changes in the fair value of Fermi 2 nuclear decommissioning investments are recorded as adjustments to Regulatory assets or liabilities, due to a recovery mechanism from customers. The Registrants' equity investments are reviewed for impairment each reporting period. If the assessment indicates that an impairment exists, a loss is recognized resulting in the equity investment being written down to its estimated fair value. See Note 13 of the Consolidated Financial Statements, "Fair Value." DTE Energy Foundation DTE Energy's contributions to the DTE Energy Foundation were $20 million and $22 million for the years ended December 31, 2020 and December 31, 2018, respectively. There were no charitable contributions made to the DTE Energy Foundation for the year ended December 31, 2019. The DTE Energy Foundation is a non-consolidated not-for-profit private foundation, the purpose of which is to contribute to and assist charitable organizations. Other Accounting Policies See the following notes for other accounting policies impacting the Registrants’ Consolidated Financial Statements: Note Title 5 Revenue 7 Property, Plant, and Equipment 9 Asset Retirement Obligations 10 Regulatory Matters 11 Income Taxes 13 Fair Value 14 Financial and Other Derivative Instruments 18 Leases 21 Retirement Benefits and Trusteed Assets 22 Stock-Based Compensation

New Accounting Pronouncements

New Accounting Pronouncements	12 Months Ended
	Dec. 31, 2020
Accounting Standards Update and Change in Accounting Principle [Abstract]
New Accounting Pronouncements	NEW ACCOUNTING PRONOUNCEMENTS Recently Adopted Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , as amended. The amendments in this update have replaced the previous incurred loss impairment methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information, including forecasts, to develop credit loss estimates. The ASU requires entities to use the new methodology to measure impairment of financial instruments, including accounts receivable, and may result in earlier recognition of credit losses than under previous generally accepted accounting principles. Entities must apply the new guidance as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The Registrants adopted the standard effective January 1, 2020. The adoption of the ASU did not have an impact on the Registrants' financial position or results of operations. Additional required disclosures have been included in Note 2 to the Consolidated Financial Statements, “Significant Accounting Policies.” In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . The guidance removes Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation to determine the amount of goodwill impairment. Under the ASU, a goodwill impairment will be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The Registrants adopted the ASU effective January 1, 2020. The adoption of the ASU did not have an impact on the Registrants' Consolidated Financial Statements. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurements (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement . The amendments in this update modify the disclosure requirements on fair value measurements in Topic 820. The Registrants adopted the ASU effective January 1, 2020. The Registrants have updated Note 13 to the Consolidated Financial Statements, "Fair Value," to incorporate the disclosure changes required by the ASU. In August 2018, the FASB issued ASU No. 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract . The amendments in this update align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The Registrants adopted the standard effective January 1, 2020 using the prospective approach. The adoption of the ASU did not have an impact on the Registrants’ Consolidated Financial Statements. On a prospective basis, costs within the scope of this amendment will be accounted for consistent with any underlying service contracts. Capitalized implementation costs will be reflected in Other noncurrent assets on the Consolidated Statements of Financial Position and amortization of these costs will be reflected in Operation and maintenance within the Consolidated Statements of Operations. Cash flow activity will be reflected in the Other current and noncurrent assets and liabilities line within the Operating Activities section of the Consolidated Statements of Cash Flows. In August 2018, the FASB issued ASU No. 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20): Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans . The amendments in this update modify the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The Registrants adopted the ASU effective January 1, 2020. The Registrants have updated Note 21 to the Consolidated Financial Statements, "Retirement Benefits and Trusteed Assets," to incorporate the disclosure changes required by the ASU. In October 2018, the FASB issued ASU No. 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities . The amendments in this update modify the requirements for determining whether fees paid to a decision maker or service provider are variable interests and require reporting entities to consider indirect interests held through related parties under common control on a proportional basis. The Registrants adopted the ASU effective January 1, 2020. The adoption of the ASU did not have a significant impact on the Registrants’ Consolidated Financial Statements. Recently Issued 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 ASU is effective for the Registrants for fiscal years beginning after December 15, 2020. The Registrants will adopt the ASU on its effective date using a modified retrospective approach. The ASU will 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. The amendments in this update provide optional expedients and exceptions for applying GAAP to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The optional expedients are effective for the modification of existing contracts or new arrangements executed March 12, 2020 through December 31, 2022. The Registrants are currently assessing the impact of this standard on their 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 ASU is effective for the Registrants for fiscal years beginning after December 15, 2021, and interim periods therein. Early adoption is permitted. The ASU will not have a significant impact on the Registrants' Consolidated Financial Statements.

Acquisitions and Dispositions

Acquisitions and Dispositions	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Acquisitions and Dispositions	ACQUISITIONS AND DISPOSITIONS Power and Industrial Projects Segment Acquisition On February 18, 2020, DTE Energy closed on the purchase of an 8 MW combined heat and power generation facility from South Jersey Industries (“SJI”) that provides electricity and hot and chilled water to a hotel and casino in Atlantic City, New Jersey. Direct transaction costs primarily related to advisory fees were immaterial and are included in Operation and maintenance in DTE Energy's Consolidated Statements of Operations. The fair value of consideration provided for the acquisition was approximately $95 million paid in cash. The acquisition was accounted for using the acquisition method of accounting for business combinations. Accordingly, the cost was allocated to the underlying net assets based on their respective fair values as shown below: (In millions) Contract intangibles $ 17 Property, plant, and equipment, net 76 Working capital 2 Total $ 95 The intangible assets recorded pertain to existing customer contracts and were estimated by applying the income approach, based on discounted projected cash flows attributable to the existing agreements. The contract intangible assets are amortized on a straight-line basis over a period of 13 years, which is based on the number of years the assets are expected to economically contribute to the business. The pro forma financial information has not been presented for DTE Energy because the effects of the acquisition were not material to the Consolidated Statements of Operations. Electric Segment Acquisition Effective September 12, 2019, DTE Sustainable Generation closed on the purchase of 89 MW of renewable energy projects located in Michigan from Heritage Sustainable Energy in support of DTE Energy's renewable energy goals. Direct transaction costs primarily related to advisory fees were immaterial and were included in Operation and maintenance in DTE Energy's Consolidated Statements of Operations for the period incurred. The fair value of consideration provided for the acquisition was approximately $175 million, paid in cash. The acquisition was accounted for using the acquisition method of accounting for business combinations. Accordingly, the cost was allocated to the underlying net assets based on their respective fair values as shown below: (In millions) Contract intangibles $ 109 Property, plant, and equipment, net 60 Working capital 6 Total $ 175 The intangible assets recorded pertain to existing customer contracts and were estimated by applying the income approach, based on discounted projected cash flows attributable to the existing agreements. The contract intangible assets are amortized on a straight-line basis with useful lives ranging from 11 years to 13 years, which is based on the remaining number of years the assets are expected to economically contribute to the business. The pro forma financial information has not been presented for DTE Energy because the effects of the acquisition were not material to the Consolidated Statements of Operations. In conjunction with the above acquisition, DTE Sustainable Generation closed on a purchase and sale agreement with Heritage Sustainable Energy in January 2020 to acquire an additional renewable energy project for approximately $33 million paid in cash. The acquired projects are non-utility operations and related revenues are classified accordingly as Operating Revenues - Non-utility operations within DTE Energy's Consolidated Statements of Operations and the Electric segment results of operations. Refer to Note 23 to the Consolidated Financial Statements, "Segment and Related Information." Gas Storage and Pipelines Segment Acquisition On December 4, 2019, DTE Energy closed on the purchase of midstream natural gas assets in support of its strategy to continue to grow and earn competitive returns for shareholders. DTE Energy purchased 100 percent of M5 Louisiana Gathering, LLC and its wholly owned subsidiaries from Momentum Midstream and Indigo Natural Resources. The acquisition includes the Blue Union and LEAP assets which provide natural gas gathering and other midstream services to producers located primarily in Louisiana. The acquired assets are part of DTE Energy's non-utility Gas Storage and Pipelines segment. The fair value of the consideration provided for the entities acquired was $2.74 billion and included $2.36 billion paid in cash and an estimated $380 million of contingent consideration to be paid upon completion of the LEAP gathering pipeline. A liability for the contingent consideration payment was recorded upon acquisition and adjusted each period for accretion. Refer to the Acquisition related deferred payment line in the Consolidated Statements of Financial Position for the liability balance for the respective reporting periods. Accretion expense of $5 million and $1 million was recorded for the years ended December 31, 2020 and 2019, respectively. In July 2020, the LEAP gathering pipeline achieved the final milestone of its construction and consideration of $385 million was paid on July 27, 2020 in two equal installments. The acquisition was financed through the issuance of Equity Units, common stock, and Senior Notes. See Note 15 to the Consolidated Financial Statements, "Long-Term Debt," for more information. The acquisition was accounted for using the acquisition method of accounting for business combinations. The excess purchase price over the fair value of net assets acquired was classified as goodwill. The factors contributing to the recognition of goodwill were based on various strategic benefits that are expected to be realized from the Blue Union and LEAP acquisition. The acquisition will provide DTE Energy with a platform for midstream growth and access to further investment opportunities in the Haynesville basin. The goodwill is being deducted for income tax purposes. December 3, 2020 marked the expiration of the one-year period from the acquisition to revise the fair value of assets acquired and liabilities assumed. As a result of purchase accounting adjustments through December 3, 2020, approximately $2 million of additional goodwill was recognized. The purchase price is no longer subject to resolution of any indemnification claims and all cash consideration paid and held in escrow has been released. The final allocation of the purchase price was based on estimated fair values of the Blue Union and LEAP assets acquired and liabilities assumed at the date of acquisition, December 4, 2019. The components of the final purchase price allocation, inclusive of purchase accounting adjustments, are as follows: (In millions) Assets Cash $ 62 Accounts receivable 31 Property, plant, and equipment, net 1,034 Goodwill 173 Customer relationship intangibles 1,473 Other current assets 1 $ 2,774 Liabilities Accounts payable $ 26 Acquisition related deferred payment 380 Other current liabilities 2 Asset retirement obligations 9 $ 417 Total cash consideration $ 2,357 The intangible assets recorded as a result of the acquisition pertain to existing customer relationships, which were valued at approximately $1.47 billion as of the acquisition date. The fair value of the intangible assets acquired was estimated by applying the income approach. The income approach is based upon discounted projected future cash flows attributable to the existing contracts and agreements. The fair value measurement is based on significant unobservable inputs, including management estimates and assumptions, and thus represents a Level 3 measurement, pursuant to the applicable accounting guidance. Key estimates and inputs include revenue and expense projections and discount rates based on the risks associated with the entities. The intangible assets are amortized on a straight-line basis over a period of 40 years, which is based on the number of years the assets are expected to economically contribute to the business. The expected economic benefit incorporates existing customer contracts with a weighted average amortization life of 13 years and expected renewal rates, based on the estimated volume and production lives of gas resources in the region. See Note 2 to the Consolidated Financial Statements, "Significant Accounting Policies," for more information. DTE Energy incurred $18 million of direct transaction costs for the year ended December 31, 2019. These costs were primarily related to advisory fees and included in Operation and maintenance in DTE Energy's 2019 Consolidated Statements of Operations. Additionally, DTE Energy incurred $49 million of issuance costs related to the acquisition financing, of which $10 million were included in Mortgage bonds, notes, and other, and $39 million were included in Common Stock in DTE Energy's Consolidated Statements of Financial Position. DTE Energy's 2019 Consolidated Statements of Operations included Operating Revenues — Non-utility operations of $15 million and Net Income of $3 million associated with the acquired entities for the one-month period following the acquisition date, excluding the $18 million transaction costs described above. The pro forma financial information was not presented for DTE Energy because the effects of the acquisition were not material to the Consolidated Statements of Operations. 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	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE Significant Accounting Policy Upon the adoption of Topic 606, revenue is measured based upon the consideration specified in a contract with a customer at the time when performance obligations are satisfied. Under Topic 606, a performance obligation is a promise in a contract to transfer a distinct good or service or a series of distinct goods or services to the customer. The Registrants recognize revenue when performance obligations are satisfied by transferring control over a product or service to a customer. The Registrants have determined control to be transferred when the product is delivered or the service is provided to the customer. For the years ended December 31, 2020, 2019, and 2018, recognition of revenue for the Registrants subsequent to the adoption of Topic 606 is substantially similar in amount and approach to that prior to adoption. Rates for DTE Electric and DTE Gas include provisions to adjust billings for fluctuations in fuel and purchased power costs, cost of natural gas, and certain other costs. Revenues are adjusted for differences between actual costs subject to reconciliation and the amounts billed in current rates. Under or over recovered revenues related to these cost recovery mechanisms are included in Regulatory assets or liabilities on the Registrants' Consolidated Statements of Financial Position and are recovered or returned to customers through adjustments to the billing factors. For discussion of derivative contracts, see Note 14 to the Consolidated Financial Statements, "Financial and Other Derivative Instruments." Disaggregation of Revenue The following is a summary of revenues disaggregated by segment for DTE Energy: 2020 2019 2018 (In millions) Electric (a) Residential $ 2,825 $ 2,427 $ 2,494 Commercial 1,739 1,795 1,794 Industrial 592 659 690 Other (b) 364 348 320 Total Electric operating revenues (c) $ 5,520 $ 5,229 $ 5,298 Gas Gas sales $ 971 $ 1,043 $ 1,055 End User Transportation 218 219 232 Intermediate Transportation 79 78 58 Other (b) 146 142 91 Total Gas operating revenues (d) $ 1,414 $ 1,482 $ 1,436 Other segment operating revenues Gas Storage and Pipelines (e) $ 754 $ 501 $ 485 Power and Industrial Projects (f) $ 1,224 $ 1,560 $ 2,204 Energy Trading (g) $ 3,863 $ 4,610 $ 5,557 _______________________________________ (a) Revenues generally represent those of DTE Electric, except $14 million and $5 million of Other revenues related to DTE Sustainable Generation for the years ended December 31, 2020 and 2019, respectively. (b) Includes revenue adjustments related to various regulatory mechanisms. (c) Includes $26 million, $22 million, and $21 million under Alternative Revenue Programs and $22 million, $19 million, and $20 million of other revenues, which are both outside the scope of Topic 606, for the years ended December 31, 2020, 2019, and 2018, respectively. (d) Includes $10 million, $8 million, and $2 million under Alternative Revenue Programs and $8 million, $7 million, and $7 million of other revenues, which are both outside the scope of Topic 606, for the years ended December 31, 2020, 2019, and 2018, respectively. (e) Includes revenues outside the scope of Topic 606 primarily related to $9 million of contracts accounted for as leases for each of the years ended December 31, 2020 and 2019. (f) Includes revenues outside the scope of Topic 606 primarily related to $99 million, $121 million, and $125 million of contracts accounted for as leases for the years ended December 31, 2020, 2019, and 2018, respectively. (g) Includes revenues outside the scope of Topic 606 primarily related to $2.7 billion, $3.4 billion, and $4.5 billion of derivatives for the years ended December 31, 2020, 2019, and 2018, respectively. Nature of Goods and Services The following is a description of principal activities, separated by reportable segments, from which DTE Energy generates revenue. For more detailed information about reportable segments, see Note 23 to the Consolidated Financial Statements, “Segment and Related Information.” The Registrants have contracts with customers which may contain more than one performance obligation. When more than one performance obligation exists in a contract, the consideration under the contract is allocated to the performance obligations based on the relative standalone selling price. DTE Energy generally determines standalone selling prices based on the prices charged to customers or the use of the adjusted market assessment approach. The adjusted market assessment approach involves the evaluation of the market in which DTE Energy sells goods or services and estimating the price that a customer in that market would be willing to pay. Under Topic 606, when a customer simultaneously receives and consumes the product or service provided, revenue is considered to be recognized over time. Alternatively, if it is determined that the criteria for recognition of revenue over time is not met, the revenue is considered to be recognized at a point in time. Electric Electric consists principally of DTE Electric. Electric revenues are primarily comprised of the supply and delivery of electricity, and related capacity. Revenues are primarily associated with cancellable contracts, with the exception of certain long-term contracts with commercial and industrial customers. Revenues, including estimated unbilled amounts, are generally recognized over time based upon volumes delivered or through the passage of time ratably based upon providing a stand-ready service. The Registrants have determined that the above methods represent a faithful depiction of the transfer of control to the customer. Unbilled revenues are typically determined utilizing approved tariff rates and estimated meter volumes. Estimated unbilled amounts recognized in revenue are subject to adjustment in the following reporting period as actual volumes by customer class are known. Revenues are typically subject to tariff rates based upon customer class and type of service and are billed and received monthly. Tariff rates are determined by the MPSC on a per unit or monthly basis. Gas Gas consists principally of DTE Gas. Gas revenues are primarily comprised of the supply and delivery of natural gas, and other services including storage, transportation, and appliance maintenance. Revenues are primarily associated with cancellable contracts with the exception of certain long-term contracts with commercial and industrial customers. Revenues, including estimated unbilled amounts, are generally recognized over time based upon volumes delivered or through the passage of time ratably based upon providing a stand-ready service. DTE Energy has determined that the above methods represent a faithful depiction of the transfer of control to the customer. Unbilled revenues are typically determined using both estimated meter volumes and estimated usage based upon the number of unbilled days and historical temperatures. Estimated unbilled amounts recognized in revenue are subject to adjustment in the following reporting period as actual volumes by customer class and service type are known. Revenues are typically subject to tariff rates or other rates subject to regulatory oversight and are billed and received monthly. Tariff rates are determined by the MPSC on a per unit or monthly basis. Gas Storage and Pipelines Gas Storage and Pipelines revenues generally consist of services related to the gathering, transportation, and storage of natural gas. Contracts are primarily long-term in nature. Revenues, including estimated unbilled amounts, are generally recognized over time based upon services provided or through the passage of time ratably based upon providing a stand-ready service. Unbilled amounts are generally determined using estimated volumes based on preliminary meter data and contracted rates and typically result in minor adjustments in the following reporting period. DTE Energy has determined that the above methods represent a faithful depiction of the transfer of control to the customer. Revenues are typically billed and received monthly. Pricing for such revenues may consist of demand rates, commodity rates, transportation rates, and other associated fees. Consideration may consist of both fixed and variable components and may be subject to minimum volume commitments. Generally, uncertainties in the variable consideration components are resolved and revenues are known at the time of recognition. Power and Industrial Projects Power and Industrial Projects revenues include contracts accounted for as leases which are outside of the scope of Topic 606. For performance obligations within the scope of Topic 606, the timing of revenue recognition is dependent upon when control over the associated product or service is transferred. Revenues at Power and Industrial Projects, within the scope of Topic 606, generally consist of sales of refined coal, coal, blast furnace coke, coke oven gas, electricity, equipment maintenance services, and other energy related products and services. Revenues, including estimated unbilled amounts, for the sale of blast furnace coke are generally recognized at a point in time when the product is delivered, which represents the transfer of control to the customer. Other revenues are generally recognized over time based upon services provided or through the passage of time ratably based upon providing a stand-ready service. DTE Energy has determined that the above methods represent a faithful depiction of the transfer of control to the customer. Market based pricing structures exist in such contracts including adjustments for consumer price or other indices. Consideration may consist of both fixed and variable components. Generally, uncertainties in the variable consideration components are resolved and revenues are known at the time of recognition. Billing terms vary and are generally monthly with payment terms typically within 30 days following billing. Energy Trading Energy Trading revenues consist primarily of derivative contracts outside of the scope of Topic 606. For performance obligations within the scope of Topic 606, the timing of revenue recognition is dependent upon when control over the associated product or service is transferred. Revenues, including estimated unbilled amounts, within the scope of Topic 606 arising from the sale of natural gas, electricity, power capacity, and other energy related products are generally recognized over time based upon volumes delivered or through the passage of time ratably based upon providing a stand-ready service. DTE Energy has determined that the above methods represent a faithful depiction of the transfer of control to the customer. Revenues are known at the time of recognition. Payment for the aforementioned revenues is generally due from customers in the month following delivery. Revenues associated with RECs are recognized at a point in time when control of the RECs are transferred to the customer which is deemed to be when the subject RECs are entered for transfer to the customer in the applicable regulatory tracking system. Revenues associated with RECs under a wholesale full requirements power contract are deferred until control has been transferred. The deferred revenues represent a contract liability for which payment has been received and the amounts have been estimated using the adjusted market assessment approach. With the exception of RECs, generally all other performance obligations associated with wholesale full requirements power contracts are satisfied over time in conjunction with the delivery of power. At the time power is delivered, DTE Energy may not have control over the RECs as the RECs are not self-generated and may not yet have been procured resulting in deferred revenues. Deferred Revenue The following is a summary of deferred revenue activity: DTE Energy (In millions) Beginning Balance, January 1, 2020 $ 75 Increases due to cash received or receivable, excluding amounts recognized as revenue during the period 55 Revenue recognized that was included in the deferred revenue balance at the beginning of the period (43) Ending Balance, December 31, 2020 $ 87 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 $ 59 2022 7 2023 3 2024 3 2025 7 2026 and thereafter 8 $ 87 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 $ 285 $ 8 2022 323 7 2023 263 7 2024 158 7 2025 113 1 2026 and thereafter 501 — $ 1,643 $ 30

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	GOODWILL DTE Energy has goodwill resulting from business combinations. The following is the summary of change in the carrying amount of goodwill for the years ended December 31: 2020 2019 (In millions) Balance as of January 1 $ 2,464 $ 2,293 Goodwill attributable to Gas Storage and Pipelines 2019 acquisition of Blue Union and LEAP 2 171 Balance at December 31 $ 2,466 $ 2,464

Property, Plant, and Equipment

Property, Plant, and Equipment	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment	PROPERTY, PLANT, AND EQUIPMENT The following is a summary of Property, plant, and equipment by classification as of December 31: 2020 2019 Property, plant, and equipment (In millions) DTE Electric Zero carbon generation Nuclear $ 3,295 $ 3,022 Renewables 1,817 1,362 Fossil and other generation 8,031 7,644 Distribution 10,354 9,715 Other 2,674 2,536 Total DTE Electric 26,171 24,279 DTE Gas Distribution 4,517 4,164 Storage 576 570 Transmission and other 1,341 1,244 Total DTE Gas 6,434 5,978 Non-utility and other Gas Storage and Pipelines 3,981 3,524 Power and Industrial Projects 1,194 1,108 Other 217 183 Non-utility and other 5,392 4,815 Total DTE Energy 37,997 35,072 Accumulated depreciation and amortization DTE Electric Zero carbon generation Nuclear (373) (344) Renewables (295) (243) Fossil and other generation (3,014) (2,873) Distribution (2,686) (2,553) Other (682) (693) Total DTE Electric (7,050) (6,706) DTE Gas Distribution (1,215) (1,334) Storage (146) (172) Transmission and other (403) (409) Total DTE Gas (1,764) (1,915) Non-utility and other Gas Storage and Pipelines (511) (459) Power and Industrial Projects (619) (604) Other (84) (71) Non-utility and other (1,214) (1,134) Total DTE Energy (10,028) (9,755) Net DTE Energy Property, plant, and equipment $ 27,969 $ 25,317 Net DTE Electric Property, plant, and equipment $ 19,121 $ 17,573 AFUDC and Capitalized Interest AFUDC represents the cost of financing construction projects for regulated businesses, including the estimated cost of debt and authorized return-on-equity. The debt component is recorded as a reduction to interest expense and the equity component is recorded as other income. Non-regulated businesses record capitalized interest as a reduction to interest expense. The AFUDC and capitalized interest rates were as follows for the years ended December 31: 2020 2019 2018 DTE Electric AFUDC 5.47 % 5.43 % 5.41 % DTE Gas AFUDC 5.56 % 5.56 % 5.71 % Non-regulated businesses capitalized interest 3.90 % 4.00 % 4.00 % The following is a summary of AFUDC and interest capitalized for the years ended December 31: 2020 2019 2018 DTE Energy (In millions) Allowance for debt funds used during construction and interest capitalized $ 22 $ 15 $ 15 Allowance for equity funds used during construction 25 24 28 Total $ 47 $ 39 $ 43 2020 2019 2018 DTE Electric (In millions) Allowance for debt funds used during construction $ 10 $ 10 $ 9 Allowance for equity funds used during construction 23 22 19 Total $ 33 $ 32 $ 28 Depreciation and Amortization The composite depreciation rate for DTE Electric was approximately 4.2%, 4.0%, and 3.7% in 2020, 2019 and 2018, respectively. The composite depreciation rate for DTE Gas was 2.8% for all periods. The average estimated useful life for each major class of utility Property, plant, and equipment as of December 31, 2020 follows: Estimated Useful Lives in Years Utility Generation Distribution Storage DTE Electric 32 38 N/A DTE Gas N/A 49 58 The estimated useful lives for DTE Electric's Other utility assets range from 3 to 80 years, while the estimated useful lives for DTE Gas' Transmission and other utility assets range from 3 to 80 years. The estimated useful lives for major classes of DTE Energy's non-utility assets and facilities range from 3 to 70 years. The following is a summary of Depreciation and amortization expense for DTE Energy: 2020 2019 2018 (In millions) Property, plant, and equipment $ 1,120 $ 997 $ 878 Regulatory assets and liabilities 245 227 212 Intangible assets 71 33 27 Other 7 6 7 $ 1,443 $ 1,263 $ 1,124 The following is a summary of Depreciation and amortization expense for DTE Electric: 2020 2019 2018 (In millions) Property, plant, and equipment $ 831 $ 748 $ 652 Regulatory assets and liabilities 207 193 179 Other 5 5 5 $ 1,043 $ 946 $ 836 Capitalized Software Capitalized software costs are classified as Property, plant, and equipment and the related amortization is included in accumulated depreciation and amortization on the Registrants' Consolidated Financial Statements. The Registrants capitalize the costs associated with computer software developed or obtained for use in their businesses. The Registrants amortize capitalized software costs on a straight-line basis over the expected period of benefit, ranging from 3 to 15 years for DTE Energy and 3 to 15 years for DTE Electric. The following balances for capitalized software relate to DTE Energy: Year Ended December 31, 2020 2019 2018 (In millions) Amortization expense of capitalized software $ 129 $ 123 $ 108 Gross carrying value of capitalized software $ 866 $ 906 Accumulated amortization of capitalized software $ 432 $ 520 The following balances for capitalized software relate to DTE Electric: Year Ended December 31, 2020 2019 2018 (In millions) Amortization expense of capitalized software $ 118 $ 112 $ 101 Gross carrying value of capitalized software $ 756 $ 811 Accumulated amortization of capitalized software $ 363 $ 462

Jointly-Owned Utility Plant

Jointly-Owned Utility Plant	12 Months Ended
	Dec. 31, 2020
Jointly Owned Utility Plant, Net Ownership Amount [Abstract]
Jointly-Owned Utility Plant	JOINTLY-OWNED UTILITY PLANT DTE Electric has joint ownership interest in two power plants, Belle River and Ludington Hydroelectric Pumped Storage. DTE Electric’s share of direct expenses of the jointly-owned plants are included in Fuel, purchased power, and gas — utility and Operation and maintenance expenses in the DTE Energy Consolidated Statements of Operations and Fuel and purchased power — utility and Operation and maintenance expenses in the DTE Electric Consolidated Statements of Operations. DTE Electric's ownership information of the two utility plants as of December 31, 2020 was as follows: Belle River Ludington In-service date 1984-1985 1973 Total plant capacity 1,270 MW 2,220 MW Ownership interest 81% 49% Investment in Property, plant, and equipment (in millions) $ 1,932 $ 609 Accumulated depreciation (in millions) $ 945 $ 181 Belle River The Michigan Public Power Agency (MPPA) has ownership interests in Belle River Unit No. 1 and other related facilities. The MPPA is entitled to 19% of the total capacity and energy of the plant and is responsible for the same percentage of the plant’s operation, maintenance, and capital improvement costs. Ludington Hydroelectric Pumped Storage Consumers Energy Company has an ownership interest in the Ludington Hydroelectric Pumped Storage Plant. Consumers Energy is entitled to 51% of the total capacity and energy of the plant and is responsible for the same percentage of the plant’s operation, maintenance, and capital improvement costs.

Asset Retirement Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2020
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	ASSET RETIREMENT OBLIGATIONS DTE Electric has a legal retirement obligation for the decommissioning costs for its Fermi 1 and Fermi 2 nuclear plants, dismantlement of facilities located on leased property, and various other operations. DTE Electric has conditional retirement obligations for asbestos and PCB removal at certain of its power plants and various distribution equipment. DTE Gas has conditional retirement obligations for gas pipelines, certain service centers, compressor and gate stations. The Registrants recognize such obligations as liabilities at fair market value when they are incurred, which generally is at the time the associated assets are placed in service. Fair value is measured using expected future cash outflows discounted at the Registrants' credit-adjusted risk-free rate. For its utility operations, the Registrants recognize in the Consolidated Statements of Operations removal costs in accordance with regulatory treatment. Any differences between costs recognized related to asset retirement and those reflected in rates are recognized as either a Regulatory asset or liability on the Consolidated Statements of Financial Position. If a reasonable estimate of fair value cannot be made in the period in which the retirement obligation is incurred, such as for assets with indeterminate lives, the liability is recognized when a reasonable estimate of fair value can be made. Natural gas storage system and certain other distribution assets for DTE Gas and substations, manholes, and certain other distribution assets for DTE Electric have an indeterminate life. Therefore, no liability has been recorded for these assets. Changes to asset retirement obligations for 2020, 2019, and 2018 were as follows: 2020 2019 2018 DTE Energy (In millions) Asset retirement obligations at January 1 $ 2,672 $ 2,469 $ 2,320 Accretion 157 149 140 Liabilities incurred 25 20 27 Liabilities settled (14) (17) (16) Revision in estimated cash flows (1) 51 (2) Asset retirement obligations at December 31 $ 2,839 $ 2,672 $ 2,469 2020 2019 2018 DTE Electric (In millions) Asset retirement obligations at January 1 $ 2,447 $ 2,271 $ 2,125 Accretion 145 138 129 Liabilities incurred 18 1 27 Liabilities settled (8) (14) (8) Revision in estimated cash flows 5 51 (2) Asset retirement obligations at December 31 $ 2,607 $ 2,447 $ 2,271 Approximately $2.2 billion of the asset retirement obligations represent nuclear decommissioning liabilities that are funded through a surcharge to electric customers over the life of the Fermi 2 nuclear plant. The NRC has jurisdiction over the decommissioning of nuclear power plants and requires minimum decommissioning funding based upon a formula. The MPSC and FERC regulate the recovery of costs of decommissioning nuclear power plants and both require the use of external trust funds to finance the decommissioning of Fermi 2. Rates approved by the MPSC provide for the recovery of decommissioning costs of Fermi 2 and the disposal of low-level radioactive waste. DTE Electric believes the MPSC collections will be adequate to fund the estimated cost of decommissioning. The decommissioning assets, anticipated earnings thereon, and future revenues from decommissioning collections will be used to decommission Fermi 2. DTE Electric expects the liabilities to be reduced to zero at the conclusion of the decommissioning activities. If amounts remain in the trust funds for Fermi 2 following the completion of the decommissioning activities, those amounts will be disbursed based on rulings by the MPSC and FERC. A portion of the funds recovered through the Fermi 2 decommissioning surcharge and deposited in external trust accounts is designated for the removal of non-radioactive assets and returning the site to greenfield. This removal and greenfielding is not considered a legal liability. Therefore, it is not included in the asset retirement obligation, but is reflected as the Nuclear decommissioning liability. The decommissioning of Fermi 1 is funded by DTE Electric. Contributions to the Fermi 1 trust are discretionary. For additional discussion of Nuclear decommissioning trust fund assets, see Note 13 to the Consolidated Financial Statements, "Fair Value."

Regulatory Matters

Regulatory Matters	12 Months Ended
	Dec. 31, 2020
Regulatory Assets and Liabilities Disclosure [Abstract]
Regulatory Matters	REGULATORY MATTERS Regulation DTE Electric and DTE Gas are subject to the regulatory jurisdiction of the MPSC, which issues orders pertaining to rates, recovery of certain costs, including the costs of generating facilities and regulatory assets, conditions of service, accounting, and operating-related matters. DTE Electric is also regulated by the FERC with respect to financing authorization, wholesale electric market activities, certain affiliate transactions, the acquisition and disposition of certain generation and other facilities, and, in conjunction with the NERC, compliance with mandatory reliability standards. Regulation results in differences in the application of generally accepted accounting principles between regulated and non-regulated businesses. The Registrants are unable to predict the outcome of any unresolved regulatory matters discussed herein. Resolution of these matters is dependent upon future MPSC and FERC orders and appeals, which may materially impact the Consolidated Financial Statements of the Registrants. Regulatory Assets and Liabilities DTE Electric and DTE Gas are required to record Regulatory assets and liabilities for certain transactions that would have been treated as revenue or expense in non-regulated businesses. Continued applicability of regulatory accounting treatment requires that rates be designed to recover specific costs of providing regulated services and be charged to and collected from customers. Future regulatory changes could result in the discontinuance of this accounting treatment for Regulatory assets and liabilities for some or all of the Registrants' businesses and may require the write-off of the portion of any Regulatory asset or liability that was no longer probable of recovery through regulated rates. Management believes that currently available facts support the continued use of Regulatory assets and liabilities and that all Regulatory assets and liabilities are recoverable or refundable in the current regulatory environment. The following are balances and a brief description of the Registrants' Regulatory assets and liabilities at December 31: DTE Energy DTE Electric 2020 2019 2020 2019 Assets (In millions) Recoverable pension and other postretirement costs Pension $ 1,938 $ 1,983 $ 1,477 $ 1,497 Other postretirement costs 165 201 108 131 Recoverable undepreciated costs on retiring plants 664 657 664 657 Fermi 2 asset retirement obligation 645 669 645 669 Recoverable Michigan income taxes 176 189 142 152 Enhanced Tree Trimming Program deferred costs 119 43 119 43 Accrued PSCR revenue 100 3 100 3 Recoverable income taxes related to AFUDC equity 64 56 54 47 Energy Waste Reduction incentive 62 54 49 43 Deferred environmental costs 57 66 — — Unamortized loss on reacquired debt 55 56 41 40 Nuclear Performance Evaluation and Review Committee Tracker 55 48 55 48 Customer360 deferred costs 51 55 51 55 Non-service pension and other postretirement costs 21 15 — — Other recoverable income taxes 19 20 19 20 Transitional Reconciliation Mechanism 11 10 11 10 Other 55 51 28 38 4,257 4,176 3,563 3,453 Less amount included in Current Assets (129) (5) (123) (5) $ 4,128 $ 4,171 $ 3,440 $ 3,448 DTE Energy DTE Electric 2020 2019 2020 2019 Liabilities (In millions) Refundable federal income taxes $ 2,255 $ 2,359 $ 1,827 $ 1,911 Removal costs liability 831 700 410 483 Negative other postretirement offset 122 93 86 69 Non-service pension and other postretirement costs 78 46 36 21 COVID-19 voluntary refund 30 — 30 — Renewable energy 21 54 21 54 Accrued GCR refund 20 23 — — Other 45 54 40 48 3,402 3,329 2,450 2,586 Less amount included in Current Liabilities (39) (65) (18) (40) $ 3,363 $ 3,264 $ 2,432 $ 2,546 As noted below, certain Regulatory assets for which costs have been incurred have been included (or are expected to be included, for costs incurred subsequent to the most recently approved rate case) in DTE Electric's or DTE Gas' rate base, thereby providing a return on invested costs (except as noted). Certain other regulatory assets are not included in rate base but accrue recoverable carrying charges until surcharges to collect the assets are billed. Certain Regulatory assets do not result from cash expenditures and therefore do not represent investments included in rate base or have offsetting liabilities that reduce rate base. ASSETS • Recoverable pension and other postretirement costs — Accounting standards for pension and other postretirement benefit costs require, among other things, the recognition in Other comprehensive income of the actuarial gains or losses and the prior service costs that arise during the period but are not immediately recognized as components of net periodic benefit costs. DTE Electric and DTE Gas record the impact of actuarial gains or losses and prior service costs as Regulatory assets since the traditional rate setting process allows for the recovery of pension and other postretirement costs. The asset will reverse as the deferred items are amortized and recognized as components of net periodic benefit costs. (a) • Recoverable undepreciated costs on retiring plants — Deferral of estimated remaining balances associated with coal power plants expected to be retired by the end of 2022. • Fermi 2 asset retirement obligation — This obligation is for Fermi 2 decommissioning costs. The asset captures the timing differences between expense recognition and current recovery in rates and will reverse over the remaining life of the related plant. (a) • Recoverable Michigan income taxes — The State of Michigan enacted a corporate income tax resulting in the establishment of state deferred tax liabilities for DTE Energy's utilities. Offsetting Regulatory assets were also recorded as the impacts of the deferred tax liabilities will be reflected in rates as the related taxable temporary differences reverse and flow through current income tax expense. • Enhanced Tree Trimming Program deferred costs — The MPSC approved the deferral of costs for a tree trimming surge through 2022, aimed at reducing the number and duration of customer interruptions. Recovery of these costs and related amortization will be determined at a future rate proceeding. • Accrued PSCR revenue — Receivable for the temporary under-recovery of and carrying costs on fuel and purchased power costs incurred by DTE Electric which are recoverable through the PSCR mechanism. • Recoverable income taxes related to AFUDC equity — Accounting standards for income taxes require recognition of a deferred tax liability for the equity component of AFUDC. A Regulatory asset is required for the future increase in taxes payable related to the equity component of AFUDC that will be recovered from customers through future rates over the remaining life of the related plant. • Energy Waste Reduction incentive — DTE Electric and DTE Gas operate MPSC approved energy waste reduction programs designed to reduce overall energy usage by their customers. The utilities are eligible to earn an incentive by exceeding statutory savings targets. The utilities have consistently exceeded the savings targets and recognize the incentive as a Regulatory asset in the period earned. (a) • Deferred environmental costs — The MPSC approved the deferral of investigation and remediation costs associated with DTE Gas' former MGP sites. Amortization of deferred costs is over a ten-year period beginning in the year after costs were incurred, with recovery (net of any insurance proceeds) through base rate filings. (a) • Unamortized loss on reacquired debt — The unamortized discount, premium, and expense related to debt redeemed with a refinancing are deferred, amortized, and recovered over the life of the replacement issue. • Nuclear Performance Evaluation and Review Committee Tracker — Deferral and amortization of certain costs associated with oversight and review of DTE Electric's nuclear power generation program, including safety and regulatory compliance, nuclear leadership, nuclear facilities, as well as operation and financial performance, pursuant to the MPSC authorization. Deferrals are amortized over a five-year period with recovery through base rate filings. • Customer360 deferred costs — The MPSC approved the deferral and amortization of certain costs associated with implementing Customer360, an integrated software application that enables improved interface among customer service, billing, meter reading, credit and collections, device management, account management, and retail access. Amortization of deferred costs over a 15-year amortization period began after the billing system was put into operation during the second quarter of 2017. The deferred costs are recorded as Regulatory Assets at DTE Electric and DTE Gas receives an intercompany charge for their proportionate share of amortization expense. • Non-service pension and other postretirement costs — Upon adoption of ASU 2017-07 on January 1, 2018, certain non-service pension and other postretirement costs are no longer capitalized into Property, Plant & Equipment. Such costs may be recorded to Regulatory assets for ratemaking purposes and recovered as amortization expense based on the composite depreciation rate for plant-in-service. • Other recoverable income taxes — Income taxes receivable from DTE Electric's customers representing the difference in property-related deferred income taxes and amounts previously reflected in DTE Electric's rates. This asset will reverse over the remaining life of the related plant. • Transitional Reconciliation Mechanism — The MPSC approved the recovery of the deferred net incremental revenue requirement associated with the transition of PLD customers to DTE Electric's distribution system, effective July 1, 2014. Annual reconciliations are filed and surcharges are implemented to recover approved amounts. ________________________________________________ (a) Regulatory assets not earning a return or accruing carrying charges. LIABILITIES • Refundable federal income taxes — In December 2017, the TCJA was enacted and reduced the corporate income tax rate, effective January 1, 2018. DTE Electric and DTE Gas remeasured deferred taxes, resulting in a reduction to deferred tax liabilities, to reflect the impact of the TCJA on the cumulative temporary differences expected to reverse after the effective date. Regulatory liabilities were also recorded to offset the impact of the deferred tax remeasurement reflected in rates. • Removal costs liability — The amounts collected from customers in excess of the estimated cost of future asset removal activities. Cost of removal is included within depreciation rates approved by the MPSC. In 2019, the MPSC approved a settlement agreement in DTE Gas' depreciation case to increase depreciation rates effective following an order in the next general rate case. The new depreciation rates became effective October 1, 2020. In connection with the settlement agreement and the new rates, DTE Gas also re-measured the amount of historical depreciation expense that had been allocated between accumulated depreciation and cost of removal. The reallocation was performed to provide a more accurate estimate of DTE Gas' reserve balances on assets under the group depreciation methodology. Based upon the reallocation, it was determined that the amounts collected for asset removal expenditures, as a component of depreciation, further exceeded actual asset removal expenditures. Accordingly, DTE Gas reallocated amounts from accumulated depreciation to the removal cost regulatory balance, resulting in an increase to the Removal cost liability as of December 31, 2020. • Negative other postretirement offset — DTE Electric and DTE Gas' negative other postretirement costs are not included as a reduction to their authorized rates; therefore, DTE Electric and DTE Gas are accruing a Regulatory liability to eliminate the impact on earnings of the negative other postretirement expense accrual. The Regulatory liabilities will reverse to the extent DTE Electric and DTE Gas' other postretirement expense is positive in future years. • Non-service pension and other postretirement costs — Upon adoption of ASU 2017-07 on January 1, 2018, certain non-service pension and other postretirement cost activity is no longer credited to Property, Plant & Equipment. Such costs may be recorded to regulatory liabilities for ratemaking purposes and refunded through credits to amortization expense based on the composite depreciation rate for plant-in-service. • COVID-19 voluntary refund — The one-time refund obligation owed to DTE Electric customers due to certain sales increases driven by the COVID-19 pandemic. Refer to the "2020 Accounting Applications" section below for additional information related to the voluntary refund. • Renewable energy — Amounts collected in rates in excess of renewable energy expenditures. • Accrued GCR refund — Liability for the temporary over-recovery of and a return on gas costs incurred by DTE Gas which are recoverable through the GCR mechanism. 2020 COVID-19 Response In response to the COVID-19 pandemic, the MPSC issued an order on April 15, 2020 to provide guidance and direction to utilities and other stakeholders on topics including customer protections and affordability, utility accounting, regulatory activities, energy assistance, and energy waste reduction and demand response continuity. The order authorizes the deferral of uncollectible expense that is in excess of the amount used to set current rates effective March 24, 2020, the date of Michigan's executive order to "Stay Home, Stay Safe". The Registrants implemented the deferral in the second quarter 2020, and there is currently no expiration for the ability to defer these costs. With the approval of DTE Electric's October 26, 2020 accounting application as noted below, DTE Electric voluntarily reversed its 2020 deferral and recorded as expense, with deferrals resuming in January 2021. DTE Gas deferred $2 million of uncollectible expense as Regulatory assets through December 31, 2020 as a result of the MPSC's COVID-19 response order. On July 23, 2020, the MPSC further ordered that utilities seeking to recover COVID-19 related expenses beyond uncollectible expense may make an informational filing no later than November 2, 2020. The Registrants did not make a filing, but will continue to monitor MPSC activities involving COVID-19. 2019 Electric Rate Case Filing DTE Electric filed a rate case with the MPSC on July 8, 2019 requesting an increase in base rates of $351 million based on a projected twelve-month period ending April 30, 2021. The requested increase in base rates was primarily due to an increase in net plant resulting from distribution infrastructure and generation investments. The rate filing also requested an increase in return on equity from 10.0% to 10.5% and included projected changes in sales and operating and maintenance expenses. On May 8, 2020, the MPSC issued an order approving an annual revenue increase of $188 million for services rendered on or after May 15, 2020 and a return on equity of 9.9%. The order also disallowed $41 million of capital expenditures related to incentive compensation previously recorded during 2018-2020. The disallowance was recorded during the second quarter 2020 and is included in Asset (gains) losses and impairment, net on the Consolidated Statements of Operations for the year ended December 31, 2020. 2020 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 will increase amortization by $102 million beginning in May 2021, which will fully amortize this portion of the liability by the end of 2021 instead of April 2033. The accelerated amortization will not impact customer rates and will allow DTE Electric to defer its next rate case filing previously set for July 2020 to at least March 2021. On October 26, 2020, DTE Electric filed an application with the MPSC requesting accounting authority for a one-time regulatory liability. DTE Electric proposed accruing a $30 million voluntary refund obligation due to certain sales increases resulting from the unusual and unprecedented electricity usage patterns driven by the COVID-19 pandemic. On December 9, 2020, the MPSC approved DTE Electric's request. Accordingly, DTE Electric recorded a regulatory liability and reduction to Operating revenues of $30 million. Amortization of the regulatory liability will be used to offset the cost of service related to new plant in 2022. The regulatory liability will be amortized beginning January 1, 2022 through the earlier of new base rates or December 31, 2022. The one-time accounting treatment does not impact customer rates and will allow DTE Electric to further defer its next rate case filing from March 2021 to May 2021. Additionally, as noted above, DTE Electric began deferring uncollectible expense in the second quarter 2020 as a result of the MPSC's COVID-19 response order. With the approval of the October 26th accounting application, DTE Electric voluntarily reversed this deferral and recorded as expense. This action only applies to DTE Electric in 2020 and the deferral of uncollectible expense will resume beginning in January 2021, as approved by the MPSC on its December 9, 2020 order. 2019 Gas Rate Case Filing DTE Gas filed a rate case with the MPSC on November 25, 2019 requesting an increase in base rates of $204 million based on a projected twelve-month period ending September 30, 2021. The requested increase in base rates was 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 10.0% to 10.5% and included projected changes in sales and working capital. On July 17, 2020, DTE Gas reached a settlement with all intervening parties in the case and filed a settlement agreement authorizing the company to increase base rates by $110 million, reflecting a return on equity of 9.9%. The resulting rates are a net increase to customers of $51 million as an existing Infrastructure Recovery Mechanism (IRM) surcharge will be rolled into the new base rates. The settlement agreement also approved a $20 million annual increase to the amortization of the portion of the Refundable federal income taxes regulatory liability related to non-plant accumulated deferred income tax balances resulting from the TCJA. This increased amortization will cease upon DTE Gas receiving its next rate order. The MPSC approved the settlement agreement on August 20, 2020 and DTE Gas implemented the increases to rates and amortization effective October 1, 2020. In addition, the settlement agreement disallowed capitalized expenditures related to incentive compensation, consistent with the MPSC order issued for DTE Electric on May 8, 2020. In anticipation of this result, DTE Gas recorded a disallowance of $14 million during the second quarter 2020, which is included in Asset (gains) losses and impairment, net on the Consolidated Statements of Operations for the year ended December 31, 2020. 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.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES Income Tax Summary DTE Energy files a consolidated federal income tax return. DTE Electric is a part of the consolidated federal income tax return of DTE Energy. DTE Energy and its subsidiaries file consolidated and/or separate company income tax returns in various states and localities, including a consolidated return in the State of Michigan. DTE Electric is part of the Michigan consolidated income tax return of DTE Energy. The federal, state and local income tax expense for DTE Electric is determined on an individual company basis with no allocation of tax expenses or benefits from other affiliates of DTE Energy. DTE Electric had income tax receivables with DTE Energy of $8 million and $14 million at December 31, 2020 and 2019, respectively. The Registrants' total Income Tax Expense varied from the statutory federal income tax rate for the following reasons: 2020 2019 2018 DTE Energy (In millions) Income Before Income Taxes $ 1,538 $ 1,324 $ 1,216 Income tax expense at 21% statutory rate $ 323 $ 278 $ 255 State and local income taxes, net of federal benefit 81 48 60 Production tax credits (121) (128) (223) TCJA regulatory liability amortization (76) (38) — Net operating loss carryback (34) — — AFUDC equity (4) (4) (14) Employee Stock Ownership Plan dividends (4) (3) (3) Investment tax credits (4) (4) (4) Stock based compensation (3) (7) (3) Enactment of the Tax Cuts and Jobs Act — — 21 Noncontrolling interests 1 — 2 Depreciation 2 2 2 Other, net 6 8 5 Income Tax Expense $ 167 $ 152 $ 98 Effective income tax rate 10.9 % 11.5 % 8.1 % 2020 2019 2018 DTE Electric (In millions) Income Before Income Taxes $ 887 $ 854 $ 857 Income tax expense at 21% statutory rate $ 186 $ 179 $ 180 State and local income taxes, net of federal benefit 50 49 49 TCJA regulatory liability amortization (62) (35) — Production tax credits (55) (45) (35) Investment tax credits (4) (4) (3) AFUDC equity (4) (4) (3) Employee Stock Ownership Plan dividends (2) (2) (2) Enactment of the Tax Cuts and Jobs Act — — 7 Depreciation 2 2 2 Other, net (2) (2) (2) Income Tax Expense $ 109 $ 138 $ 193 Effective income tax rate 12.3 % 16.2 % 22.5 % Components of the Registrants' Income Tax Expense were as follows: 2020 2019 2018 DTE Energy (In millions) Current income tax expense (benefit) Federal $ (247) $ (184) $ (17) State and other income tax 7 7 1 Total current income taxes (240) (177) (16) Deferred income tax expense Federal 310 275 38 State and other income tax 97 54 76 Total deferred income taxes 407 329 114 $ 167 $ 152 $ 98 2020 2019 2018 DTE Electric (In millions) Current income tax expense Federal $ 15 $ 25 $ — State and other income tax 5 16 4 Total current income taxes 20 41 4 Deferred income tax expense Federal 30 51 131 State and other income tax 59 46 58 Total deferred income taxes 89 97 189 $ 109 $ 138 $ 193 Deferred tax assets and liabilities are recognized for the estimated future tax effect of temporary differences between the tax basis of assets or liabilities and the reported amounts in the Registrant's Consolidated Financial Statements. Consistent with the original establishment of these deferred tax liabilities (assets), recognition of these non-cash transactions are not reflected in the Consolidated Statements of Cash Flows. The Registrants' deferred tax assets (liabilities) were comprised of the following at December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Property, plant, and equipment $ (4,032) $ (3,755) $ (3,099) $ (2,956) Regulatory assets and liabilities (108) (47) (53) 4 Tax credit carry-forwards 1,144 1,161 278 252 Pension and benefits 321 300 264 258 Federal net operating loss carry-forward 265 276 — — State and local net operating loss carry-forwards 155 117 — — Investments in equity method investees (667) (465) — — Other 141 138 85 87 (2,781) (2,275) (2,525) (2,355) Less valuation allowance (41) (40) — — Long-term deferred income tax liabilities $ (2,822) $ (2,315) $ (2,525) $ (2,355) Deferred income tax assets $ 2,241 $ 2,264 $ 883 $ 865 Deferred income tax liabilities (5,063) (4,579) (3,408) (3,220) $ (2,822) $ (2,315) $ (2,525) $ (2,355) Tax credit carry-forwards for DTE Energy include $1.1 billion of general business credits that expire from 2032 through 2040. No valuation allowance is required for the tax credits carry-forward deferred tax asset. DTE Energy has a pre-tax federal net operating loss carry-forward of $1.3 billion as of December 31, 2020. The net operating loss carry-forwards generated in 2015 and 2016 will expire from 2035 through 2036, and the net operating loss carry-forward generated in 2018 and subsequent years will be carried forward indefinitely. No valuation allowance is required for the federal net operating loss deferred tax asset. DTE Energy has state and local deferred tax assets related to net operating loss carry-forwards of $155 million and $117 million at December 31, 2020 and 2019, respectively. The state and local net operating loss carry-forwards expire from 2021 through 2040. DTE Energy has recorded valuation allowances at December 31, 2020 and 2019 of approximately $41 million and $40 million, respectively, which are primarily related to these deferred tax assets. In assessing the realizability of deferred tax assets, DTE Energy considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Tax credit carry-forwards for DTE Electric include $278 million of general business credits that expire from 2036 through 2040. No valuation allowance is required for the tax credits carry-forward deferred tax asset. DTE Electric has no state and local deferred tax assets related to net operating loss carry-forwards at December 31, 2020 or December 31, 2019. The above tables exclude unamortized investment tax credits that are shown separately on the Registrants' Consolidated Statements of Financial Position. Investment tax credits are deferred and amortized to income over the average life of the related property. CARES Act To assist individuals and employers with the impacts of the COVID-19 pandemic, the CARES Act was signed into law in March 2020. The CARES Act included certain tax relief provisions applicable to the Registrants including a) the immediate refund of the corporate AMT credit, b) the ability to carryback net operating losses five years for tax years 2018 through 2020, c) the employee retention credit, and d) delayed payment of employer payroll taxes. As a result of these provisions, DTE Energy received $220 million of refunds from the U.S. Treasury during the year ended December 31, 2020, including $153 million for the immediate refund of the 2018 remaining AMT credit balance and $67 million as a result of carrying back the 2018 net operating loss to 2013. In addition, the carryback of the 2018 net operating loss to 2013 resulted in a $34 million reduction in Income Tax Expense for the year ended December 31, 2020 due primarily to the difference in rates between the two years (35% in 2013 and 21% in 2018). During the second quarter 2020, the Registrants filed a claim for employee retention credits of $6 million, of which $3 million is attributable to DTE Electric. These amounts are included in Taxes other than income in the Consolidated Statements of Operations for the year ended December 31, 2020. The Registrants have also deferred employer payroll taxes of $44 million, of which $23 million is attributable to DTE Electric, increasing the amount of Current Liabilities - Other and Other Liabilities - Other on the Registrants' Consolidated Statements of Financial Position as of December 31, 2020. Uncertain Tax Positions A reconciliation of the beginning and ending amount of unrecognized tax benefits for the Registrants is as follows: 2020 2019 2018 DTE Energy (In millions) Balance at January 1 $ 10 $ 10 $ 10 Additions for tax positions of prior years — — — Balance at December 31 $ 10 $ 10 $ 10 2020 2019 2018 DTE Electric (In millions) Balance at January 1 $ 13 $ 13 $ 13 Additions for tax positions of prior years — — — Balance at December 31 $ 13 $ 13 $ 13 DTE Energy had $8 million of unrecognized tax benefits at December 31, 2020 and 2019 that, if recognized, would favorably impact its effective tax rate. DTE Electric had $10 million of unrecognized tax benefits at December 31, 2020 and 2019 that, if recognized, would favorably impact its effective tax rate. The Registrants do not anticipate any material decrease in unrecognized tax benefits in the next twelve months. The Registrants recognize interest and penalties pertaining to income taxes in Interest expense and Other expenses, respectively, on their Consolidated Statements of Operations. Accrued interest pertaining to income taxes for DTE Energy totaled $5 million and $4 million at December 31, 2020 and 2019, respectively. DTE Energy recognized interest expense related to income taxes of $1 million in 2020, 2019, and 2018. DTE Energy has not accrued any penalties pertaining to income taxes. Accrued interest pertaining to income taxes for DTE Electric totaled $6 million at December 31, 2020 and 2019. DTE Electric recognized interest expense related to income taxes of a nominal amount in 2020 and $1 million in 2019 and 2018. DTE Electric has not accrued any penalties pertaining to income taxes. In 2020, DTE Energy, including DTE Electric, settled a federal tax audit for the 2018 tax year. DTE Energy's federal income tax returns for 2019 and subsequent years remain subject to examination by the IRS. DTE Energy's Michigan Business Tax returns for the years 2008-2011 and Michigan Corporate Income Tax returns for the year 2015 and subsequent years remain subject to examination by the State of Michigan. DTE Energy also files tax returns in numerous state and local jurisdictions with varying statutes of limitation.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2020
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, performance shares, and stock options do not receive cash dividends; as such, these awards are not considered participating securities. For additional information, see Notes 15 and 22 to the Consolidated Financial Statements, "Long-Term Debt" and "Stock-Based Compensation," respectively. The following is a reconciliation of DTE Energy's basic and diluted income per share calculation for the years ended December 31: 2020 2019 2018 (In millions, except per share amounts) Basic Earnings per Share Net Income Attributable to DTE Energy Company $ 1,368 $ 1,169 $ 1,120 Less: Allocation of earnings to net restricted stock awards (2) (2) (2) Net income available to common shareholders — basic $ 1,366 $ 1,167 $ 1,118 Average number of common shares outstanding — basic 193 185 181 Basic Earnings per Common Share $ 7.09 $ 6.32 $ 6.18 Diluted Earnings per Share Net Income Attributable to DTE Energy Company $ 1,368 $ 1,169 $ 1,120 Less: Allocation of earnings to net restricted stock awards (2) (2) (2) Net income available to common shareholders — diluted $ 1,366 $ 1,167 $ 1,118 Average number of common shares outstanding - diluted 193 185 181 Diluted Earnings per Common Share (a) $ 7.08 $ 6.31 $ 6.17 _______________________________________ (a) Equity Units excluded from the calculation of diluted EPS were approximately 10.3 million for the years ended December 31, 2020 and 2019, respectively, and 6.3 million for the year ended December 31, 2018, as the dilutive stock price threshold was not met. For more information, see Note 15 to the Consolidated Financial Statements, "Long-Term Debt."

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2020
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 December 31, 2020 and 2019. 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 (a) : December 31, 2020 December 31, 2019 Level 1 Level 2 Level 3 Other (b) Netting (c) Net Balance Level 1 Level 2 Level 3 Other (b) Netting (c) Net Balance (In millions) Assets Cash equivalents (d) $ 438 $ — $ — $ — $ — $ 438 $ 15 $ — $ — $ — $ — $ 15 Nuclear decommissioning trusts Equity securities 947 — — 222 — 1,169 1,046 — — — — 1,046 Fixed income securities 102 371 — 82 — 555 160 378 — — — 538 Private equity and other — — — 104 — 104 — — — 43 — 43 Cash equivalents 27 — — — — 27 34 — — — — 34 Other investments (e) Equity securities 55 — — — — 55 140 — — — — 140 Fixed income securities 8 — — — — 8 79 — — — — 79 Cash equivalents 97 — — — — 97 4 — — — — 4 Derivative assets Commodity contracts (f) Natural gas 99 74 60 — (156) 77 205 76 74 — (266) 89 Electricity — 128 52 — (120) 60 — 223 83 — (225) 81 Environmental & Other — 150 4 — (135) 19 — 110 3 — (110) 3 Foreign currency exchange contracts — — — — — — — 1 — — — 1 Total derivative assets 99 352 116 — (411) 156 205 410 160 — (601) 174 Total $ 1,773 $ 723 $ 116 $ 408 $ (411) $ 2,609 $ 1,683 $ 788 $ 160 $ 43 $ (601) $ 2,073 Liabilities Derivative liabilities Commodity contracts (f) Natural gas $ (88) $ (59) $ (76) $ — $ 151 $ (72) $ (221) $ (41) $ (89) $ — $ 266 $ (85) Electricity — (126) (42) — 125 (43) — (231) (67) — 225 (73) Environmental & Other — (137) — — 129 (8) — (121) — — 110 (11) Foreign currency exchange contracts — (5) — — — (5) — — — — — — Total $ (88) $ (327) $ (118) $ — $ 405 $ (128) $ (221) $ (393) $ (156) $ — $ 601 $ (169) Net Assets (Liabilities) at end of period $ 1,685 $ 396 $ (2) $ 408 $ (6) $ 2,481 $ 1,462 $ 395 $ 4 $ 43 $ — $ 1,904 Assets Current $ 532 $ 260 $ 92 $ — $ (330) $ 554 $ 218 $ 320 $ 123 $ — $ (513) $ 148 Noncurrent 1,241 463 24 408 (81) 2,055 1,465 468 37 43 (88) 1,925 Total Assets $ 1,773 $ 723 $ 116 $ 408 $ (411) $ 2,609 $ 1,683 $ 788 $ 160 $ 43 $ (601) $ 2,073 Liabilities Current $ (84) $ (223) $ (79) $ — $ 318 $ (68) $ (211) $ (300) $ (85) $ — $ 513 $ (83) Noncurrent (4) (104) (39) — 87 (60) (10) (93) (71) — 88 (86) Total Liabilities $ (88) $ (327) $ (118) $ — $ 405 $ (128) $ (221) $ (393) $ (156) $ — $ 601 $ (169) Net Assets (Liabilities) at end of period $ 1,685 $ 396 $ (2) $ 408 $ (6) $ 2,481 $ 1,462 $ 395 $ 4 $ 43 $ — $ 1,904 _______________________________________ (a) See footnotes on following page. _______________________________________ (b) Amounts represent assets valued at NAV as a practical expedient for fair value. (c) 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. (d) At December 31, 2020, the $438 million consisted of $436 million and $2 million of cash equivalents included in Cash and cash equivalents and Restricted cash, respectively, on DTE Energy's Consolidated Statements of Financial Position. At December 31, 2019, the $15 million consisted of $4 million and $11 million of cash equivalents included in Cash and cash equivalents and Other investments, respectively, on DTE Energy's Consolidated Statements of Financial Position. (e) Excludes cash surrender value of life insurance investments. (f) 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: December 31, 2020 December 31, 2019 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) $ 4 $ — $ — $ — $ 4 $ 11 $ — $ — $ — $ 11 Nuclear decommissioning trusts Equity securities 947 — — 222 1,169 1,046 — — — 1,046 Fixed income securities 102 371 — 82 555 160 378 — — 538 Private equity and other — — — 104 104 — — — 43 43 Cash equivalents 27 — — — 27 34 — — — 34 Other investments Equity securities 16 — — — 16 13 — — — 13 Fixed income securities 11 — — — 11 — — — — — Derivative assets — FTRs — — 4 — 4 — — 3 — 3 Total $ 1,107 $ 371 $ 4 $ 408 $ 1,890 $ 1,264 $ 378 $ 3 $ 43 $ 1,688 Assets Current $ 4 $ — $ 4 $ — $ 8 $ 11 $ — $ 3 $ — $ 14 Noncurrent 1,103 371 — 408 1,882 1,253 378 — 43 1,674 Total Assets $ 1,107 $ 371 $ 4 $ 408 $ 1,890 $ 1,264 $ 378 $ 3 $ 43 $ 1,688 _______________________________________ (a) Amounts represent assets valued at NAV as a practical expedient for fair value. (b) At December 31, 2020, the $4 million consisted of cash equivalents included in Cash and cash equivalents on DTE Electric's Consolidated Statements of Financial Position. At December 31, 2019, the $11 million consisted of cash equivalents included in Other investments on DTE Electric's Consolidated Statements of Financial Position. Cash Equivalents Cash equivalents include investments with maturities of three months or less when purchased. The cash equivalents shown in the fair value table are comprised of short-term investments and money market funds. Nuclear Decommissioning Trusts and Other Investments The nuclear decommissioning trusts and other investments hold debt and equity securities directly and indirectly through 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 $183 million and $151 million as of December 31, 2020 and 2019, 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: Year Ended December 31, 2020 Year Ended December 31, 2019 Natural Gas Electricity Other Total Natural Gas Electricity Other Total (In millions) Net Assets (Liabilities) as of January 1 $ (15) $ 16 $ 3 $ 4 $ (49) $ (2) $ 7 $ (44) Transfers from Level 3 into Level 2 (2) — — (2) — — — — Total gains (losses) Included in earnings (75) 113 (7) 31 15 77 (1) 91 Recorded in Regulatory liabilities — — 20 20 — — 2 2 Purchases, issuances, and settlements: Settlements 76 (119) (12) (55) 19 (59) (5) (45) Net Assets (Liabilities) as of December 31 $ (16) $ 10 $ 4 $ (2) $ (15) $ 16 $ 3 $ 4 Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31 (a) $ (4) $ 70 $ (70) $ (4) $ (1) $ 59 $ (38) $ 20 Total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31 $ — $ — $ 4 $ 4 $ — $ — $ 3 $ 3 _______________________________________ (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: Year Ended December 31, 2020 2019 (In millions) Net Assets as of January 1 $ 3 $ 6 Change in fair value recorded in Regulatory liabilities 20 2 Purchases, issuances, and settlements: Settlements (19) (5) Net Assets as of December 31 $ 4 $ 3 Total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31 $ 4 $ 3 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 years ended December 31, 2020 and 2019. The following tables present the unobservable inputs related to DTE Energy's Level 3 assets and liabilities: 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 December 31, 2019 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 74 $ (89) Discounted Cash Flow Forward basis price (per MMBtu) $ (1.78) — $ 5.78 /MMBtu $ (0.09) /MMBtu Electricity $ 83 $ (67) Discounted Cash Flow Forward basis price (per MWh) $ (10) — $ 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: December 31, 2020 December 31, 2019 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 $ 141 $ — $ — $ 141 $ 184 $ — $ — $ 184 Short-term borrowings $ 38 $ — $ 38 $ — $ 828 $ — $ 828 $ — Notes payable (b) $ 19 $ — $ — $ 19 $ 25 $ — $ — $ 25 Long-term debt (c) $ 19,439 $ 2,547 $ 18,230 $ 1,397 $ 16,606 $ 2,572 $ 14,207 $ 1,252 _______________________________________ (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: December 31, 2020 December 31, 2019 Carrying Fair Value Carrying Fair Value Amount Level 1 Level 2 Level 3 Amount Level 1 Level 2 Level 3 (In millions) Notes receivable — Other (a) $ 16 $ — $ — $ 16 $ 9 $ — $ — $ 9 Short-term borrowings — affiliates $ 101 $ — $ — $ 101 $ 97 $ — $ — $ 97 Short-term borrowings — other $ — $ — $ — $ — 354 $ — $ 354 $ — Notes payable (b) $ 17 $ — $ — $ 17 $ 21 $ — $ — $ 21 Long-term debt (c) $ 8,236 $ — $ 9,579 $ 379 $ 7,180 $ — $ 7,916 $ 173 _______________________________________ (a) Included in Current Assets — Other and 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 14 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. See Note 9 to the Consolidated Financial Statements, "Asset Retirement Obligations." The following table summarizes DTE Electric's fair value of the nuclear decommissioning trust fund assets: December 31, 2020 2019 (In millions) Fermi 2 $ 1,841 $ 1,650 Fermi 1 3 3 Low-level radioactive waste 11 8 $ 1,855 $ 1,661 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: Year Ended December 31, 2020 2019 2018 (In millions) Realized gains $ 192 $ 56 $ 65 Realized losses $ (111) $ (31) $ (42) Proceeds from sale of securities $ 2,350 $ 788 $ 1,203 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: December 31, 2020 December 31, 2019 Fair Unrealized Unrealized Losses Fair Unrealized Unrealized Losses (In millions) Equity securities $ 1,169 $ 481 $ (6) $ 1,046 $ 396 $ (39) Fixed income securities 555 20 (1) 538 24 (1) Private equity and other 104 — — 43 — — Cash equivalents 27 — — 34 — — $ 1,855 $ 501 $ (7) $ 1,661 $ 420 $ (40) The following table summarizes the fair value of the fixed income securities held in nuclear decommissioning trust funds by contractual maturity: December 31, 2020 (In millions) Due within one year $ 51 Due after one through five years 101 Due after five through ten years 89 Due after ten years 232 $ 473 Fixed income securities held in nuclear decommissioning trust funds include $82 million of non-publicly traded commingled funds that do not have a contractual maturity date. Other Securities At December 31, 2020 and 2019, 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 DTE Energy's gains (losses) related to the trust: Year Ended December 31, 2020 2019 2018 (In millions) Gains (losses) related to equity securities $ (1) $ 27 $ (8) Gains (losses) related to fixed income securities (2) 10 (3) $ (3) $ 37 $ (11)

Financial and Other Derivative

Financial and Other Derivative Instruments	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Financial and Other Derivative Instruments	FINANCIAL AND OTHER DERIVATIVE INSTRUMENTS The Registrants recognize all derivatives at their fair value as Derivative assets or liabilities on their respective Consolidated Statements of Financial Position unless they qualify for certain scope exceptions, including the normal purchases and normal sales exception. Further, derivatives that qualify and are designated for hedge accounting are classified as either hedges of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge); or as hedges of the fair value of a recognized asset or liability or of an unrecognized firm commitment (fair value hedge). For cash flow hedges, the 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, some 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 2023. 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 December 31, 2020 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: December 31, 2020 December 31, 2019 Derivative Derivative Derivative Derivative (In millions) Derivatives designated as hedging instruments Foreign currency exchange contracts $ — $ (4) $ — $ — Derivatives not designated as hedging instruments Commodity contracts Natural gas $ 233 $ (223) $ 355 $ (351) Electricity 180 (168) 306 (298) Environmental & Other 154 (137) 113 (121) Foreign currency exchange contracts — (1) 1 — Total derivatives not designated as hedging instruments $ 567 $ (529) $ 775 $ (770) Current $ 446 $ (386) $ 646 $ (596) Noncurrent 121 (147) 129 (174) Total derivatives $ 567 $ (533) $ 775 $ (770) The following table presents the fair value of derivative instruments for DTE Electric: December 31, 2020 2019 (In millions) FTRs — Other current assets $ 4 $ 3 Total derivatives not designated as hedging instruments $ 4 $ 3 Certain of DTE Energy's derivative positions are subject to netting arrangements which provide for offsetting of asset and liability positions as well as related cash collateral. Such netting arrangements generally do not have restrictions. Under such netting arrangements, DTE Energy offsets the fair value of derivative instruments with cash collateral received or paid for those contracts executed with the same counterparty, which reduces DTE Energy's Total Assets and Liabilities. Cash collateral is allocated between the fair value of derivative instruments and customer accounts receivable and payable with the same counterparty on a pro-rata basis to the extent there is exposure. Any cash collateral remaining, after the exposure is netted to zero, is reflected in Accounts receivable and Accounts payable as collateral paid or received, respectively. DTE Energy also provides and receives collateral in the form of letters of credit which can be offset against net Derivative assets and liabilities as well as Accounts receivable and payable. DTE Energy had issued letters of credit of $7 million outstanding at December 31, 2020 and $6 million at December 31, 2019, 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 $9 million and $4 million at December 31, 2020 and 2019, 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: December 31, 2020 2019 (In millions) Cash collateral netted against Derivative assets $ (12) $ — Cash collateral netted against Derivative liabilities 6 — Cash collateral recorded in Accounts receivable (a) 14 13 Cash collateral recorded in Accounts payable (a) (1) (3) Total net cash collateral posted (received) $ 7 $ 10 _______________________________________ (a) Amounts are recorded net by counterparty. The following table presents the netting offsets of Derivative assets and liabilities for DTE Energy: December 31, 2020 December 31, 2019 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 $ 233 $ (156) $ 77 $ 355 $ (266) $ 89 Electricity 180 (120) 60 306 (225) 81 Environmental & Other 154 (135) 19 113 (110) 3 Foreign currency exchange contracts — — — 1 — 1 Total derivative assets $ 567 $ (411) $ 156 $ 775 $ (601) $ 174 Derivative liabilities Commodity contracts Natural gas $ (223) $ 151 $ (72) $ (351) $ 266 $ (85) Electricity (168) 125 (43) (298) 225 (73) Environmental & Other (137) 129 (8) (121) 110 (11) Interest rate contracts — — — — — — Foreign currency exchange contracts (5) — (5) — — — Total derivative liabilities $ (533) $ 405 $ (128) $ (770) $ 601 $ (169) 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: December 31, 2020 December 31, 2019 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Current Noncurrent Current Noncurrent Current Noncurrent Current Noncurrent (In millions) Total fair value of derivatives $ 446 $ 121 $ (386) $ (147) $ 646 $ 129 $ (596) $ (174) Counterparty netting (318) (81) 318 81 (513) (88) 513 88 Collateral adjustment (12) — — 6 — — — — Total derivatives as reported $ 116 $ 40 $ (68) $ (60) $ 133 $ 41 $ (83) $ (86) 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 Years Ended December 31, 2020 2019 2018 (In millions) Commodity contracts Natural gas Operating Revenues — Non-utility operations $ (70) $ 44 $ (42) Natural gas Fuel, purchased power, gas, and other — non-utility 20 (5) (94) Electricity Operating Revenues — Non-utility operations 91 44 49 Environmental & Other Operating Revenues — Non-utility operations (118) (26) (1) Foreign currency exchange contracts Operating Revenues — Non-utility operations (6) (2) 7 Total $ (83) $ 55 $ (81) 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 December 31, 2020: Commodity Number of Units Natural gas (MMBtu) 1,757,668,006 Electricity (MWh) 29,383,355 Foreign currency exchange ($ CAD) 144,655,453 Renewable Energy Certificates (MWh) 9,221,803 Carbon emissions (Metric Ton) 12,495,202 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 December 31, 2020, 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 $428 million. As of December 31, 2020, DTE Energy had $451 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 $401 million. The net remaining amount of $50 million is derived from the $428 million noted above.

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2020
Long-term Debt, Unclassified [Abstract]
Long-Term Debt	LONG-TERM DEBT Long-Term Debt DTE Energy's long-term debt outstanding and weighted average interest rates of debt outstanding at December 31 were: Interest Rate (a) Maturity Date 2020 2019 (In millions) Mortgage bonds, notes, and other DTE Energy Debt, Unsecured 2.7% 2022 — 2033 $ 8,175 $ 6,625 DTE Electric Taxable Debt, Principally Secured 3.9% 2021 — 2050 8,030 6,930 DTE Electric Tax-Exempt Revenue Bonds (b) 4.1% 2021 — 2030 278 310 DTE Gas Taxable Debt, Principally Secured 4% 2023 — 2050 1,910 1,710 18,393 15,575 Unamortized debt discount (25) (24) Unamortized debt issuance costs (104) (91) Long-term debt due within one year (462) (682) $ 17,802 $ 14,778 Junior Subordinated Debentures Subordinated Debentures 5.3% 2076 — 2080 $ 1,210 $ 1,180 Unamortized debt issuance costs (35) (34) $ 1,175 $ 1,146 _______________________________________ (a) Weighted average interest rate as of December 31, 2020. (b) DTE Electric Tax-Exempt Revenue Bonds are issued by a public body that loans the proceeds to DTE Electric on terms substantially mirroring the Revenue Bonds. DTE Electric's long-term debt outstanding and weighted average interest rates of debt outstanding at December 31 were: Interest Rate (a) Maturity Date 2020 2019 (In millions) Mortgage bonds, notes, and other Taxable Debt, Principally Secured 3.9% 2021 — 2050 $ 8,030 $ 6,930 Tax-Exempt Revenue Bonds (b) 4.1% 2021 — 2030 278 310 8,308 7,240 Unamortized debt discount (16) (15) Unamortized debt issuance costs (56) (45) Long-term debt due within one year (462) (632) $ 7,774 $ 6,548 _______________________________________ (a) Weighted average interest rate as of December 31, 2020. (b) Tax-Exempt Revenue Bonds are issued by a public body that loans the proceeds to DTE Electric on terms substantially mirroring the Revenue Bonds. Debt Issuances In 2020, the following debt was issued: Company Month Type Interest Rate Maturity Date Amount (In millions) DTE Electric February Mortgage Bonds (a) 2.25% 2030 $ 600 DTE Electric February Mortgage Bonds (a) 2.95% 2050 500 DTE Electric April Mortgage Bonds (b) 2.63% 2031 600 DTE Energy August Senior Notes (c) 1.05% 2025 800 DTE Gas August Mortgage Bonds (d) 2.35% 2030 125 DTE Gas August Mortgage Bonds (d) 3.20% 2050 125 DTE Energy October Junior Subordinated Debentures (e) 4.38% 2080 230 DTE Energy October Senior Notes (f) 0.55% 2022 750 $ 3,730 _______________________________________ (a) Proceeds used for the repayment of $300 million of DTE Electric's 2010 Series A 4.89% Senior Notes due 2020, repayment of short-term borrowings, capital expenditures, and for other general corporate purposes. (b) Proceeds used for the repayment of $300 million of DTE Electric's 2010 Series B 3.45% Senior Notes due 2020, repayment of $32 million of DTE Electric's 2008 Series KT Variable Rate Senior Notes due 2020, repayment of short-term borrowings, capital expenditures, and for other general corporate purposes. (c) Proceeds used for the repayment of short-term borrowings and for general corporate purposes. (d) Proceeds used for the repayment of $50 million of DTE Gas's 2008 Series I 6.36% Senior Notes due 2020 and for general corporate purposes, including capital expenditures. (e) Proceeds used for the repayment of $200 million of DTE Energy's 2012 Series C 5.25% Junior Subordinated Debentures due 2062 and for general corporate purposes. (f) Proceeds used for the repayment of DTE Energy's $500 million unsecured term loan expiring March 2021, repayment of DTE Energy's $167 million unsecured term loan expiring June 2021, and general corporate purposes. Debt Redemptions In 2020, the following debt was redeemed: Company Month Type Interest Rate Maturity Date Amount (In millions) DTE Electric March Senior Notes 4.89% 2020 $ 300 DTE Electric July Senior Notes 5.63% 2020 32 DTE Electric July Senior Notes 3.45% 2020 300 DTE Gas September Senior Notes 6.36% 2020 50 DTE Energy October Junior Subordinated Debentures 5.25% 2062 200 $ 882 The following table shows the Registrants' scheduled debt maturities, excluding any unamortized discount on debt: 2021 2022 2023 2024 2025 2026 and Thereafter Total (In millions) DTE Energy (a) $ 462 $ 3,466 $ 1,177 $ 1,425 $ 1,220 $ 11,853 $ 19,603 DTE Electric $ 462 $ 316 $ 202 $ 400 $ 350 $ 6,578 $ 8,308 _______________________________________ (a) Amounts include DTE Electric's scheduled debt maturities. Junior Subordinated Debentures DTE Energy has the right to defer interest payments on the Junior Subordinated Debentures. Should DTE Energy exercise this right, it cannot declare or pay dividends on, or redeem, purchase or acquire, any of its capital stock during the deferral period. Any deferred interest payments will bear additional interest at the rate associated with the related debt issue. As of December 31, 2020, no interest payments have been deferred on the Junior Subordinated Debentures. Cross Default Provisions Substantially all of the net utility properties of DTE Electric and DTE Gas are subject to the lien of mortgages. Should DTE Electric or DTE Gas fail to timely pay their indebtedness under these mortgages, such failure may create cross defaults in the indebtedness of DTE Energy. Gas Storage and Pipelines Segment Acquisition Financing In December 2019, DTE Energy closed on the purchase of midstream natural gas assets. The acquisition was financed through the issuance of Equity Units, Senior Notes, and common stock. See Note 4 to the Consolidated Financial Statements, "Acquisitions and Dispositions," for more information on the acquisition. In November 2019, DTE issued $1.3 billion of Equity Units. Each Equity Unit has a stated amount of $50 and was initially issued in the form of a Corporate Unit, comprised of (i) a forward purchase contract to buy DTE Energy common stock (stock purchase contract) and (ii) a 1/20 undivided beneficial ownership interest in a $1,000 principal amount of DTE Energy’s 2019 Series F 2.25% RSNs due 2025. The RSN debt instruments and the stock purchase contract equity instruments are deemed to be separate instruments as the investor may trade the RSNs separately from the stock purchase contracts and may also settle the stock purchase contracts separately. The Corporate Units are listed on the New York Stock Exchange under the symbol DTP. The stock purchase contract obligates the holder to purchase from DTE Energy on the settlement date, November 1, 2022, for a price of $50 per stock purchase contract, the following number of shares of DTE Energy’s common stock, subject to anti-dilution adjustments: • if the AMV of DTE Energy’s common stock, which is the average volume-weighted average price of DTE Energy’s common stock for the trading days during the 20 consecutive scheduled trading day period ending on the third scheduled trading day immediately preceding the stock purchase contract settlement date, is equal to or greater than $157.50, 0.3175 shares of common stock; • if the AMV is less than $157.50 but greater than $126.00, a number of shares of common stock equal to $50 divided by the AMV; and • if the AMV is less than or equal to $126.00, 0.3968 shares of common stock. The RSNs bear interest at a rate of 2.25% per year, payable quarterly, and mature on November 1, 2025. The RSNs will be remarketed in 2022. If this remarketing is successful, the interest rate on the RSNs will be reset, and interest thereafter will be payable semi-annually at the reset rate. If there is no successful remarketing, the interest rate on the RSNs will not be reset. The holders of the RSNs would have the right to put the RSNs to DTE Energy at a price equal to 100% of the principal amount, and the proceeds of the put right would be deemed to have been applied against the holders’ obligation under the stock purchase contracts. DTE Energy may also redeem, in whole or in part, the RSNs in the event of a failed final remarketing. The present value of the future contract adjustment payments of $150 million was recorded as a reduction of shareholders’ equity, offset by the stock purchase contract liability. The stock purchase contract liability is included in Current Liabilities — Other and Other Liabilities — Other on DTE Energy’s Consolidated Statements of Financial Position. On February 1, 2020, DTE Energy began paying the stock purchase contract holders quarterly contract adjustment payments at a rate of 4% per year of the stated amount of $50 per Equity Unit, or $2 per year. Interest payments on the RSNs are being recorded as interest expense and stock purchase contract payments are being charged against the liability. Accretion of the stock purchase contract liability is recorded as imputed interest expense. The treasury stock method is used to compute diluted EPS for the stock purchase contract. Under the treasury stock method, the stock purchase contract will only have a dilutive effect when the settlement rate is based on the market value of DTE’s common stock that is greater than $157.50 (the threshold appreciation price). At December 31, 2020, the stock purchase price contract was anti-dilutive and, therefore, not included in the computation of diluted earnings per share. If payments for the stock purchase contract are deferred, DTE Energy may not make any cash distributions related to its capital stock, including dividends, redemptions, repurchases, liquidation payments or guarantee payments. Also, during the deferral period, DTE Energy may not make any payments on or redeem or repurchase any debt securities that are equal in right of payment with, or subordinated to, the RSNs. Until settlement of the stock purchase contracts, the shares of stock underlying each contract are not outstanding. Under the terms of the stock purchase contracts, assuming no anti-dilution or other adjustments, DTE Energy will issue between 8.3 million and 10.3 million shares of its common stock in November 2022. A total of 13 million shares of DTE Energy’s common stock have been reserved for issuance in connection with the stock purchase contracts. Selected information about DTE Energy’s Equity Units is presented below: Issuance Date Units Issued Total Net Proceeds Total Long-Term Debt RSN Annual Interest Rate Stock Purchase Contract Annual Rate Stock Purchase Settlement Date Stock Purchase Contract Liability (a) RSN Maturity Date (In millions, except interest rates) 11/1/19 26 $ 1,268 $ 1,300 2.25% 4.0% 11/1/2022 $ 150 11/1/2025 _______________________________________

Preferred and Preference Securi

Preferred and Preference Securities	12 Months Ended
	Dec. 31, 2020
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred and Preference Securities	PREFERRED AND PREFERENCE SECURITIES As of December 31, 2020, the amount of authorized and unissued stock is as follows: Company Type of Stock Par Value Shares Authorized DTE Energy Preferred $ — 5,000,000 DTE Electric Preferred $ 100 6,747,484 DTE Electric Preference $ 1 30,000,000 DTE Gas Preferred $ 1 7,000,000 DTE Gas Preference $ 1 4,000,000

Short-Term Credit Arrangements

Short-Term Credit Arrangements and Borrowings	12 Months Ended
	Dec. 31, 2020
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. During 2020, the Registrants entered into a series of unsecured term loans to raise additional liquidity, including terms consistent with the unsecured revolving credit agreements. Several of these term loans were entered into and subsequently repaid in 2020. One unsecured term loan remains as of December 31, 2020, a $200 million loan entered into by DTE Electric in November 2020 with a maturity date in November 2021. Through December 31, 2020, no amounts have been drawn and commitment fees have not been material. The loan will terminate if no amounts are drawn by April 30, 2021. In May 2020, DTE Lake Erie Generation, Inc., an indirect wholly-owned subsidiary of DTE Energy, entered into a C$110 million unsecured revolving credit agreement to fund construction of on-site electric generation and related infrastructure projects at a Canadian integrated steel manufacturing facility in Ontario, Canada. The revolving credit agreement is guaranteed by DTE Energy and there was C$49 million outstanding as of December 31, 2020. The revolving credit agreement expires in May 2023 and has terms consistent with DTE Energy's unsecured revolving credit agreements. 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 December 31, 2020, the total funded debt to total capitalization ratios for DTE Energy, DTE Electric, and DTE Gas were 0.59 to 1, 0.51 to 1, and 0.48 to 1, respectively, and were in compliance with this financial covenant. The availability under the facilities in place at December 31, 2020 is shown in the following table: DTE Energy DTE Electric DTE Gas Total (In millions) Unsecured letter of credit facility, expiring in February 2021 $ 150 $ — $ — $ 150 Unsecured letter of credit facility, expiring in August 2021 110 — — 110 Unsecured term loan, expiring in November 2021 — 200 — 200 Unsecured Canadian revolving credit facility, expiring May 2023 86 — — 86 Unsecured revolving credit facility, expiring April 2024 1,500 500 300 2,300 1,846 700 300 2,846 Amounts outstanding at December 31, 2020 Letters of credit 193 — — 193 Revolver borrowings 38 — — 38 231 — — 231 Net availability at December 31, 2020 $ 1,615 $ 700 $ 300 $ 2,615 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. For DTE Energy, the weighted average interest rate for short-term borrowings was 1.1% and 2.0% at December 31, 2020 and 2019, respectively. For DTE Electric, the weighted average interest rate for short-term borrowings was 1.9% at December 31, 2019. There were no short-term borrowings outstanding as of December 31, 2020. 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 December 31, 2020, the capacity under these facilities was $300 million. The amount outstanding under these agreements was $49 million and $114 million at December 31, 2020 and 2019, respectively, and was fully offset by the posted collateral. Dividend Restrictions Certain of DTE Energy’s credit facilities contain a provision requiring DTE Energy to maintain a total funded debt to capitalization ratio, as defined in the agreements, of no more than 0.65 to 1, which has the effect of limiting the amount of dividends DTE Energy can pay in order to maintain compliance with this provision. At December 31, 2020, the effect of this provision was a restriction on dividend payments to no more than $2.8 billion of DTE Energy's Retained earnings of $7.2 billion. There are no other effective limitations with respect to DTE Energy’s ability to pay dividends.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	LEASES Lessee Leases at DTE Energy are primarily comprised of various forms of equipment, computer hardware, coal railcars, production facilities, buildings, and certain easement leases with terms ranging from approximately 2 to 40 years. Leases at DTE Electric are primarily comprised of various forms of equipment, computer hardware, coal railcars, and certain easement leases with terms ranging from approximately 2 to 40 years. A lease is deemed to exist when the Registrants have the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration paid. The right to control is deemed to occur when the Registrants have the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. Lease liabilities are determined utilizing a discount rate to determine the present values of lease payments. Topic 842 requires the use of the rate implicit in the lease when it is readily determinable. When the rate implicit in the lease is not readily determinable, the incremental borrowing rate is used. The Registrants have determined their respective incremental borrowing rates based upon the rate of interest that would have been paid on a collateralized basis over similar tenors to that of the leases. The incremental borrowing rates for DTE Electric and DTE Gas have been determined utilizing respective secured borrowing rates for first mortgage bonds with like tenors of remaining lease terms. Incremental borrowing rates for non-utility entities have been determined utilizing an implied secured borrowing rate based upon an unsecured rate for a similar tenor of remaining lease terms, which is then adjusted for the estimated impact of collateral. Certain leases of the Registrants contain escalation clauses whereby the payments are adjusted for consumer price or labor indices. DTE Energy has leases with non-index based escalation clauses for fixed dollar or percentage increases. DTE Electric has leases with non-index based escalation clauses for fixed dollar increases. DTE Energy also has leases with variable payments based upon usage of, or revenues associated with, the leased assets. DTE Electric also has leases with variable payments based upon the usage of the leased assets. Certain leases of easements and coal railcars contain provisions whereby the Registrants have the option to terminate the lease agreement by giving notice of such termination during the time frames specified in the respective lease. The Registrants have considered such provisions in the determination of the lease term when it is reasonably certain that the lease would be terminated. The Registrants have certain leases which contain purchase options. Based upon the nature of the leased property and terms of the purchase options, the Registrants have determined it is not reasonably certain that such purchase options will be utilized. Thus, the impact of the purchase options has not been included in the determination of right-of-use assets and lease liabilities for the subject leases. The Registrants have certain leases which contain renewal options. Where the renewal options were deemed reasonably certain to occur, the impacts of such options were included in the determination of the right of use assets and lease liabilities. The Registrants have agreements with lease and non-lease components, which are generally accounted for separately. Consideration in a lease is allocated between lease and non-lease components based upon the estimated relative standalone prices. The Registrants have certain coal railcar leases for which non-lease and lease components are accounted for as a single lease component, as permitted under Topic 842. The following is a summary of the components of lease cost for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Operating lease cost $ 39 $ 41 $ 14 $ 17 Finance lease cost: Amortization of right-of-use assets 5 4 4 4 Interest of lease liabilities — — — — Total finance lease cost 5 4 4 4 Variable lease cost 10 10 — — Short-term lease cost 12 10 6 3 $ 66 $ 65 $ 24 $ 24 The Registrants have elected not to apply the recognition requirements of Topic 842 to leases with a term of 12 months or less. DTE Energy and DTE Electric record operating, variable, and short-term lease costs as Operating Expenses on the Consolidated Statements of Operations, except for certain amounts that may be capitalized to other assets. The following is a summary of other information related to leases for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Supplemental Cash Flows Information Cash paid for amounts included in the measurement of these liabilities: Operating cash flows for finance leases $ 3 $ 5 $ 2 $ 5 Operating cash flows for operating leases $ 40 $ 40 $ 14 $ 16 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 18 $ 68 $ — $ 27 Finance leases $ 19 $ 8 $ 14 $ — Weighted Average Remaining Lease Term (Years) Operating leases 9.3 9.7 10.4 10.6 Finance leases 7.6 9.1 3.1 2.0 Weighted Average Discount Rate Operating leases 3.4 % 3.5 % 3.3 % 3.3 % Finance leases 2.0 % 3.1 % 1.0 % 3.1 % The Registrants' future minimum lease payments under leases for remaining periods as of December 31, 2020 are as follows: DTE Energy DTE Electric Operating Leases Finance Leases Operating Leases Finance Leases (In millions) 2021 $ 37 $ 8 $ 13 $ 6 2022 31 8 12 6 2023 22 8 10 6 2024 13 2 8 1 2025 8 1 6 — 2026 and thereafter 61 7 32 — Total future minimum lease payments 172 34 81 19 Imputed interest (28) (3) (14) — Lease liabilities $ 144 $ 31 $ 67 $ 19 Finance leases reported on the Consolidated Statements of Financial Position are as follows for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Right-of-use assets, within Property, plant, and equipment, net $ 29 $ 15 $ 16 $ 7 Current lease liabilities, within Current Liabilities — Other $ 7 $ 4 $ 6 $ 3 Long-term lease liabilities $ 24 $ 11 $ 13 $ 4 Lessor During 2020, DTE Energy executed a sale of membership interests in the REF business accounted for as a finance lease arrangement with a term of less than 2 years, resulting in a net investment in finance leases of $8 million and selling profit of $11 million. Also in 2020, 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 a net investment of $133 million. DTE Energy leases a portion of its pipeline system to the Vector Pipeline through a finance lease contract that has been renewed through 2025, with additional renewal options reasonably certain to be exercised through 2040. DTE Energy owns a 40% interest in the Vector Pipeline. DTE Energy's net investment in finance leases relating to Vector Pipeline was $39 million at December 31, 2020, and is included in the finance leases table below. DTE Energy also leases various assets under operating leases for a pipeline, energy facilities and related equipment. Such leases are comprised of both fixed payments and variable payments which are contingent on volumes, with terms ranging from 2 to 24 years. Generally, the operating leases do not have renewal provisions or options to purchase the assets at the end of the lease. The operating leases generally do not have termination for convenience provisions. Termination may be allowed under specific circumstances stated in the lease contract, such as under an event of default. Certain of the finance and operating leases have lease terms that extend to the end of the estimated economic life of the leased assets, thereby resulting in no residual value. Any remaining residual values under the finance and operating leases are expected to be recovered through rates, renewals or new lease contracts. Residual values have been determined using the estimated economic life of the leased assets. The finance and operating leases do not contain residual value guarantees. Certain of the operating leases have both lease and non-lease components. The lease and non-lease components are allocated based upon estimated relative standalone selling prices. A lease is deemed to exist when the Registrants have provided other parties with the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration received. The right to control is deemed to occur when the Registrants have provided other parties with the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. DTE Energy’s lease income associated with operating leases was as follows for the years ended December 31: 2020 2019 (In millions) Fixed payments (a) $ 66 $ 65 Variable payments (a) 124 128 $ 190 $ 193 _______________________________________ (a) Includes $108 million and $130 million of lease payments reported in Operating Revenues and $82 million and $63 million of lease payments reported in Other income on DTE Energy's Consolidated Statements of Operations as of December 31, 2020 and 2019, respectively. DTE Energy’s minimum future rental revenues under operating leases for remaining periods as of December 31, 2020 are as follows: DTE Energy (In millions) 2021 $ 62 2022 22 2023 22 2024 22 2025 19 2026 and thereafter 175 $ 322 Depreciation expense associated with DTE Energy's property under operating leases was $27 million and $26 million for the years ended December 31, 2020 and 2019, respectively. The following is a summary of property under operating leases for DTE Energy as of December 31: 2020 2019 (In millions) Gross property under operating leases $ 447 $ 445 Accumulated amortization of property under operating leases $ 197 $ 173 The components of DTE Energy’s net investment in finance leases for remaining periods as of December 31, 2020 are as follows: DTE Energy (In millions) 2021 $ 24 2022 20 2023 19 2024 19 2025 19 2026 and thereafter 253 Total minimum future lease receipts 354 Residual value of leased pipeline 17 Less unearned income 193 Net investment in finance lease 178 Less current portion 9 $ 169 Interest income recognized under finance leases was $16 million and $5 million for the years ended December 31, 2020 and 2019, respectively, including $4 million relating to Vector Pipeline for both periods.
Leases	LEASES Lessee Leases at DTE Energy are primarily comprised of various forms of equipment, computer hardware, coal railcars, production facilities, buildings, and certain easement leases with terms ranging from approximately 2 to 40 years. Leases at DTE Electric are primarily comprised of various forms of equipment, computer hardware, coal railcars, and certain easement leases with terms ranging from approximately 2 to 40 years. A lease is deemed to exist when the Registrants have the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration paid. The right to control is deemed to occur when the Registrants have the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. Lease liabilities are determined utilizing a discount rate to determine the present values of lease payments. Topic 842 requires the use of the rate implicit in the lease when it is readily determinable. When the rate implicit in the lease is not readily determinable, the incremental borrowing rate is used. The Registrants have determined their respective incremental borrowing rates based upon the rate of interest that would have been paid on a collateralized basis over similar tenors to that of the leases. The incremental borrowing rates for DTE Electric and DTE Gas have been determined utilizing respective secured borrowing rates for first mortgage bonds with like tenors of remaining lease terms. Incremental borrowing rates for non-utility entities have been determined utilizing an implied secured borrowing rate based upon an unsecured rate for a similar tenor of remaining lease terms, which is then adjusted for the estimated impact of collateral. Certain leases of the Registrants contain escalation clauses whereby the payments are adjusted for consumer price or labor indices. DTE Energy has leases with non-index based escalation clauses for fixed dollar or percentage increases. DTE Electric has leases with non-index based escalation clauses for fixed dollar increases. DTE Energy also has leases with variable payments based upon usage of, or revenues associated with, the leased assets. DTE Electric also has leases with variable payments based upon the usage of the leased assets. Certain leases of easements and coal railcars contain provisions whereby the Registrants have the option to terminate the lease agreement by giving notice of such termination during the time frames specified in the respective lease. The Registrants have considered such provisions in the determination of the lease term when it is reasonably certain that the lease would be terminated. The Registrants have certain leases which contain purchase options. Based upon the nature of the leased property and terms of the purchase options, the Registrants have determined it is not reasonably certain that such purchase options will be utilized. Thus, the impact of the purchase options has not been included in the determination of right-of-use assets and lease liabilities for the subject leases. The Registrants have certain leases which contain renewal options. Where the renewal options were deemed reasonably certain to occur, the impacts of such options were included in the determination of the right of use assets and lease liabilities. The Registrants have agreements with lease and non-lease components, which are generally accounted for separately. Consideration in a lease is allocated between lease and non-lease components based upon the estimated relative standalone prices. The Registrants have certain coal railcar leases for which non-lease and lease components are accounted for as a single lease component, as permitted under Topic 842. The following is a summary of the components of lease cost for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Operating lease cost $ 39 $ 41 $ 14 $ 17 Finance lease cost: Amortization of right-of-use assets 5 4 4 4 Interest of lease liabilities — — — — Total finance lease cost 5 4 4 4 Variable lease cost 10 10 — — Short-term lease cost 12 10 6 3 $ 66 $ 65 $ 24 $ 24 The Registrants have elected not to apply the recognition requirements of Topic 842 to leases with a term of 12 months or less. DTE Energy and DTE Electric record operating, variable, and short-term lease costs as Operating Expenses on the Consolidated Statements of Operations, except for certain amounts that may be capitalized to other assets. The following is a summary of other information related to leases for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Supplemental Cash Flows Information Cash paid for amounts included in the measurement of these liabilities: Operating cash flows for finance leases $ 3 $ 5 $ 2 $ 5 Operating cash flows for operating leases $ 40 $ 40 $ 14 $ 16 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 18 $ 68 $ — $ 27 Finance leases $ 19 $ 8 $ 14 $ — Weighted Average Remaining Lease Term (Years) Operating leases 9.3 9.7 10.4 10.6 Finance leases 7.6 9.1 3.1 2.0 Weighted Average Discount Rate Operating leases 3.4 % 3.5 % 3.3 % 3.3 % Finance leases 2.0 % 3.1 % 1.0 % 3.1 % The Registrants' future minimum lease payments under leases for remaining periods as of December 31, 2020 are as follows: DTE Energy DTE Electric Operating Leases Finance Leases Operating Leases Finance Leases (In millions) 2021 $ 37 $ 8 $ 13 $ 6 2022 31 8 12 6 2023 22 8 10 6 2024 13 2 8 1 2025 8 1 6 — 2026 and thereafter 61 7 32 — Total future minimum lease payments 172 34 81 19 Imputed interest (28) (3) (14) — Lease liabilities $ 144 $ 31 $ 67 $ 19 Finance leases reported on the Consolidated Statements of Financial Position are as follows for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Right-of-use assets, within Property, plant, and equipment, net $ 29 $ 15 $ 16 $ 7 Current lease liabilities, within Current Liabilities — Other $ 7 $ 4 $ 6 $ 3 Long-term lease liabilities $ 24 $ 11 $ 13 $ 4 Lessor During 2020, DTE Energy executed a sale of membership interests in the REF business accounted for as a finance lease arrangement with a term of less than 2 years, resulting in a net investment in finance leases of $8 million and selling profit of $11 million. Also in 2020, 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 a net investment of $133 million. DTE Energy leases a portion of its pipeline system to the Vector Pipeline through a finance lease contract that has been renewed through 2025, with additional renewal options reasonably certain to be exercised through 2040. DTE Energy owns a 40% interest in the Vector Pipeline. DTE Energy's net investment in finance leases relating to Vector Pipeline was $39 million at December 31, 2020, and is included in the finance leases table below. DTE Energy also leases various assets under operating leases for a pipeline, energy facilities and related equipment. Such leases are comprised of both fixed payments and variable payments which are contingent on volumes, with terms ranging from 2 to 24 years. Generally, the operating leases do not have renewal provisions or options to purchase the assets at the end of the lease. The operating leases generally do not have termination for convenience provisions. Termination may be allowed under specific circumstances stated in the lease contract, such as under an event of default. Certain of the finance and operating leases have lease terms that extend to the end of the estimated economic life of the leased assets, thereby resulting in no residual value. Any remaining residual values under the finance and operating leases are expected to be recovered through rates, renewals or new lease contracts. Residual values have been determined using the estimated economic life of the leased assets. The finance and operating leases do not contain residual value guarantees. Certain of the operating leases have both lease and non-lease components. The lease and non-lease components are allocated based upon estimated relative standalone selling prices. A lease is deemed to exist when the Registrants have provided other parties with the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration received. The right to control is deemed to occur when the Registrants have provided other parties with the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. DTE Energy’s lease income associated with operating leases was as follows for the years ended December 31: 2020 2019 (In millions) Fixed payments (a) $ 66 $ 65 Variable payments (a) 124 128 $ 190 $ 193 _______________________________________ (a) Includes $108 million and $130 million of lease payments reported in Operating Revenues and $82 million and $63 million of lease payments reported in Other income on DTE Energy's Consolidated Statements of Operations as of December 31, 2020 and 2019, respectively. DTE Energy’s minimum future rental revenues under operating leases for remaining periods as of December 31, 2020 are as follows: DTE Energy (In millions) 2021 $ 62 2022 22 2023 22 2024 22 2025 19 2026 and thereafter 175 $ 322 Depreciation expense associated with DTE Energy's property under operating leases was $27 million and $26 million for the years ended December 31, 2020 and 2019, respectively. The following is a summary of property under operating leases for DTE Energy as of December 31: 2020 2019 (In millions) Gross property under operating leases $ 447 $ 445 Accumulated amortization of property under operating leases $ 197 $ 173 The components of DTE Energy’s net investment in finance leases for remaining periods as of December 31, 2020 are as follows: DTE Energy (In millions) 2021 $ 24 2022 20 2023 19 2024 19 2025 19 2026 and thereafter 253 Total minimum future lease receipts 354 Residual value of leased pipeline 17 Less unearned income 193 Net investment in finance lease 178 Less current portion 9 $ 169 Interest income recognized under finance leases was $16 million and $5 million for the years ended December 31, 2020 and 2019, respectively, including $4 million relating to Vector Pipeline for both periods.
Leases	LEASES Lessee Leases at DTE Energy are primarily comprised of various forms of equipment, computer hardware, coal railcars, production facilities, buildings, and certain easement leases with terms ranging from approximately 2 to 40 years. Leases at DTE Electric are primarily comprised of various forms of equipment, computer hardware, coal railcars, and certain easement leases with terms ranging from approximately 2 to 40 years. A lease is deemed to exist when the Registrants have the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration paid. The right to control is deemed to occur when the Registrants have the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. Lease liabilities are determined utilizing a discount rate to determine the present values of lease payments. Topic 842 requires the use of the rate implicit in the lease when it is readily determinable. When the rate implicit in the lease is not readily determinable, the incremental borrowing rate is used. The Registrants have determined their respective incremental borrowing rates based upon the rate of interest that would have been paid on a collateralized basis over similar tenors to that of the leases. The incremental borrowing rates for DTE Electric and DTE Gas have been determined utilizing respective secured borrowing rates for first mortgage bonds with like tenors of remaining lease terms. Incremental borrowing rates for non-utility entities have been determined utilizing an implied secured borrowing rate based upon an unsecured rate for a similar tenor of remaining lease terms, which is then adjusted for the estimated impact of collateral. Certain leases of the Registrants contain escalation clauses whereby the payments are adjusted for consumer price or labor indices. DTE Energy has leases with non-index based escalation clauses for fixed dollar or percentage increases. DTE Electric has leases with non-index based escalation clauses for fixed dollar increases. DTE Energy also has leases with variable payments based upon usage of, or revenues associated with, the leased assets. DTE Electric also has leases with variable payments based upon the usage of the leased assets. Certain leases of easements and coal railcars contain provisions whereby the Registrants have the option to terminate the lease agreement by giving notice of such termination during the time frames specified in the respective lease. The Registrants have considered such provisions in the determination of the lease term when it is reasonably certain that the lease would be terminated. The Registrants have certain leases which contain purchase options. Based upon the nature of the leased property and terms of the purchase options, the Registrants have determined it is not reasonably certain that such purchase options will be utilized. Thus, the impact of the purchase options has not been included in the determination of right-of-use assets and lease liabilities for the subject leases. The Registrants have certain leases which contain renewal options. Where the renewal options were deemed reasonably certain to occur, the impacts of such options were included in the determination of the right of use assets and lease liabilities. The Registrants have agreements with lease and non-lease components, which are generally accounted for separately. Consideration in a lease is allocated between lease and non-lease components based upon the estimated relative standalone prices. The Registrants have certain coal railcar leases for which non-lease and lease components are accounted for as a single lease component, as permitted under Topic 842. The following is a summary of the components of lease cost for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Operating lease cost $ 39 $ 41 $ 14 $ 17 Finance lease cost: Amortization of right-of-use assets 5 4 4 4 Interest of lease liabilities — — — — Total finance lease cost 5 4 4 4 Variable lease cost 10 10 — — Short-term lease cost 12 10 6 3 $ 66 $ 65 $ 24 $ 24 The Registrants have elected not to apply the recognition requirements of Topic 842 to leases with a term of 12 months or less. DTE Energy and DTE Electric record operating, variable, and short-term lease costs as Operating Expenses on the Consolidated Statements of Operations, except for certain amounts that may be capitalized to other assets. The following is a summary of other information related to leases for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Supplemental Cash Flows Information Cash paid for amounts included in the measurement of these liabilities: Operating cash flows for finance leases $ 3 $ 5 $ 2 $ 5 Operating cash flows for operating leases $ 40 $ 40 $ 14 $ 16 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 18 $ 68 $ — $ 27 Finance leases $ 19 $ 8 $ 14 $ — Weighted Average Remaining Lease Term (Years) Operating leases 9.3 9.7 10.4 10.6 Finance leases 7.6 9.1 3.1 2.0 Weighted Average Discount Rate Operating leases 3.4 % 3.5 % 3.3 % 3.3 % Finance leases 2.0 % 3.1 % 1.0 % 3.1 % The Registrants' future minimum lease payments under leases for remaining periods as of December 31, 2020 are as follows: DTE Energy DTE Electric Operating Leases Finance Leases Operating Leases Finance Leases (In millions) 2021 $ 37 $ 8 $ 13 $ 6 2022 31 8 12 6 2023 22 8 10 6 2024 13 2 8 1 2025 8 1 6 — 2026 and thereafter 61 7 32 — Total future minimum lease payments 172 34 81 19 Imputed interest (28) (3) (14) — Lease liabilities $ 144 $ 31 $ 67 $ 19 Finance leases reported on the Consolidated Statements of Financial Position are as follows for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Right-of-use assets, within Property, plant, and equipment, net $ 29 $ 15 $ 16 $ 7 Current lease liabilities, within Current Liabilities — Other $ 7 $ 4 $ 6 $ 3 Long-term lease liabilities $ 24 $ 11 $ 13 $ 4 Lessor During 2020, DTE Energy executed a sale of membership interests in the REF business accounted for as a finance lease arrangement with a term of less than 2 years, resulting in a net investment in finance leases of $8 million and selling profit of $11 million. Also in 2020, 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 a net investment of $133 million. DTE Energy leases a portion of its pipeline system to the Vector Pipeline through a finance lease contract that has been renewed through 2025, with additional renewal options reasonably certain to be exercised through 2040. DTE Energy owns a 40% interest in the Vector Pipeline. DTE Energy's net investment in finance leases relating to Vector Pipeline was $39 million at December 31, 2020, and is included in the finance leases table below. DTE Energy also leases various assets under operating leases for a pipeline, energy facilities and related equipment. Such leases are comprised of both fixed payments and variable payments which are contingent on volumes, with terms ranging from 2 to 24 years. Generally, the operating leases do not have renewal provisions or options to purchase the assets at the end of the lease. The operating leases generally do not have termination for convenience provisions. Termination may be allowed under specific circumstances stated in the lease contract, such as under an event of default. Certain of the finance and operating leases have lease terms that extend to the end of the estimated economic life of the leased assets, thereby resulting in no residual value. Any remaining residual values under the finance and operating leases are expected to be recovered through rates, renewals or new lease contracts. Residual values have been determined using the estimated economic life of the leased assets. The finance and operating leases do not contain residual value guarantees. Certain of the operating leases have both lease and non-lease components. The lease and non-lease components are allocated based upon estimated relative standalone selling prices. A lease is deemed to exist when the Registrants have provided other parties with the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration received. The right to control is deemed to occur when the Registrants have provided other parties with the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. DTE Energy’s lease income associated with operating leases was as follows for the years ended December 31: 2020 2019 (In millions) Fixed payments (a) $ 66 $ 65 Variable payments (a) 124 128 $ 190 $ 193 _______________________________________ (a) Includes $108 million and $130 million of lease payments reported in Operating Revenues and $82 million and $63 million of lease payments reported in Other income on DTE Energy's Consolidated Statements of Operations as of December 31, 2020 and 2019, respectively. DTE Energy’s minimum future rental revenues under operating leases for remaining periods as of December 31, 2020 are as follows: DTE Energy (In millions) 2021 $ 62 2022 22 2023 22 2024 22 2025 19 2026 and thereafter 175 $ 322 Depreciation expense associated with DTE Energy's property under operating leases was $27 million and $26 million for the years ended December 31, 2020 and 2019, respectively. The following is a summary of property under operating leases for DTE Energy as of December 31: 2020 2019 (In millions) Gross property under operating leases $ 447 $ 445 Accumulated amortization of property under operating leases $ 197 $ 173 The components of DTE Energy’s net investment in finance leases for remaining periods as of December 31, 2020 are as follows: DTE Energy (In millions) 2021 $ 24 2022 20 2023 19 2024 19 2025 19 2026 and thereafter 253 Total minimum future lease receipts 354 Residual value of leased pipeline 17 Less unearned income 193 Net investment in finance lease 178 Less current portion 9 $ 169 Interest income recognized under finance leases was $16 million and $5 million for the years ended December 31, 2020 and 2019, respectively, including $4 million relating to Vector Pipeline for both periods.
Leases	LEASES Lessee Leases at DTE Energy are primarily comprised of various forms of equipment, computer hardware, coal railcars, production facilities, buildings, and certain easement leases with terms ranging from approximately 2 to 40 years. Leases at DTE Electric are primarily comprised of various forms of equipment, computer hardware, coal railcars, and certain easement leases with terms ranging from approximately 2 to 40 years. A lease is deemed to exist when the Registrants have the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration paid. The right to control is deemed to occur when the Registrants have the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. Lease liabilities are determined utilizing a discount rate to determine the present values of lease payments. Topic 842 requires the use of the rate implicit in the lease when it is readily determinable. When the rate implicit in the lease is not readily determinable, the incremental borrowing rate is used. The Registrants have determined their respective incremental borrowing rates based upon the rate of interest that would have been paid on a collateralized basis over similar tenors to that of the leases. The incremental borrowing rates for DTE Electric and DTE Gas have been determined utilizing respective secured borrowing rates for first mortgage bonds with like tenors of remaining lease terms. Incremental borrowing rates for non-utility entities have been determined utilizing an implied secured borrowing rate based upon an unsecured rate for a similar tenor of remaining lease terms, which is then adjusted for the estimated impact of collateral. Certain leases of the Registrants contain escalation clauses whereby the payments are adjusted for consumer price or labor indices. DTE Energy has leases with non-index based escalation clauses for fixed dollar or percentage increases. DTE Electric has leases with non-index based escalation clauses for fixed dollar increases. DTE Energy also has leases with variable payments based upon usage of, or revenues associated with, the leased assets. DTE Electric also has leases with variable payments based upon the usage of the leased assets. Certain leases of easements and coal railcars contain provisions whereby the Registrants have the option to terminate the lease agreement by giving notice of such termination during the time frames specified in the respective lease. The Registrants have considered such provisions in the determination of the lease term when it is reasonably certain that the lease would be terminated. The Registrants have certain leases which contain purchase options. Based upon the nature of the leased property and terms of the purchase options, the Registrants have determined it is not reasonably certain that such purchase options will be utilized. Thus, the impact of the purchase options has not been included in the determination of right-of-use assets and lease liabilities for the subject leases. The Registrants have certain leases which contain renewal options. Where the renewal options were deemed reasonably certain to occur, the impacts of such options were included in the determination of the right of use assets and lease liabilities. The Registrants have agreements with lease and non-lease components, which are generally accounted for separately. Consideration in a lease is allocated between lease and non-lease components based upon the estimated relative standalone prices. The Registrants have certain coal railcar leases for which non-lease and lease components are accounted for as a single lease component, as permitted under Topic 842. The following is a summary of the components of lease cost for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Operating lease cost $ 39 $ 41 $ 14 $ 17 Finance lease cost: Amortization of right-of-use assets 5 4 4 4 Interest of lease liabilities — — — — Total finance lease cost 5 4 4 4 Variable lease cost 10 10 — — Short-term lease cost 12 10 6 3 $ 66 $ 65 $ 24 $ 24 The Registrants have elected not to apply the recognition requirements of Topic 842 to leases with a term of 12 months or less. DTE Energy and DTE Electric record operating, variable, and short-term lease costs as Operating Expenses on the Consolidated Statements of Operations, except for certain amounts that may be capitalized to other assets. The following is a summary of other information related to leases for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Supplemental Cash Flows Information Cash paid for amounts included in the measurement of these liabilities: Operating cash flows for finance leases $ 3 $ 5 $ 2 $ 5 Operating cash flows for operating leases $ 40 $ 40 $ 14 $ 16 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 18 $ 68 $ — $ 27 Finance leases $ 19 $ 8 $ 14 $ — Weighted Average Remaining Lease Term (Years) Operating leases 9.3 9.7 10.4 10.6 Finance leases 7.6 9.1 3.1 2.0 Weighted Average Discount Rate Operating leases 3.4 % 3.5 % 3.3 % 3.3 % Finance leases 2.0 % 3.1 % 1.0 % 3.1 % The Registrants' future minimum lease payments under leases for remaining periods as of December 31, 2020 are as follows: DTE Energy DTE Electric Operating Leases Finance Leases Operating Leases Finance Leases (In millions) 2021 $ 37 $ 8 $ 13 $ 6 2022 31 8 12 6 2023 22 8 10 6 2024 13 2 8 1 2025 8 1 6 — 2026 and thereafter 61 7 32 — Total future minimum lease payments 172 34 81 19 Imputed interest (28) (3) (14) — Lease liabilities $ 144 $ 31 $ 67 $ 19 Finance leases reported on the Consolidated Statements of Financial Position are as follows for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Right-of-use assets, within Property, plant, and equipment, net $ 29 $ 15 $ 16 $ 7 Current lease liabilities, within Current Liabilities — Other $ 7 $ 4 $ 6 $ 3 Long-term lease liabilities $ 24 $ 11 $ 13 $ 4 Lessor During 2020, DTE Energy executed a sale of membership interests in the REF business accounted for as a finance lease arrangement with a term of less than 2 years, resulting in a net investment in finance leases of $8 million and selling profit of $11 million. Also in 2020, 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 a net investment of $133 million. DTE Energy leases a portion of its pipeline system to the Vector Pipeline through a finance lease contract that has been renewed through 2025, with additional renewal options reasonably certain to be exercised through 2040. DTE Energy owns a 40% interest in the Vector Pipeline. DTE Energy's net investment in finance leases relating to Vector Pipeline was $39 million at December 31, 2020, and is included in the finance leases table below. DTE Energy also leases various assets under operating leases for a pipeline, energy facilities and related equipment. Such leases are comprised of both fixed payments and variable payments which are contingent on volumes, with terms ranging from 2 to 24 years. Generally, the operating leases do not have renewal provisions or options to purchase the assets at the end of the lease. The operating leases generally do not have termination for convenience provisions. Termination may be allowed under specific circumstances stated in the lease contract, such as under an event of default. Certain of the finance and operating leases have lease terms that extend to the end of the estimated economic life of the leased assets, thereby resulting in no residual value. Any remaining residual values under the finance and operating leases are expected to be recovered through rates, renewals or new lease contracts. Residual values have been determined using the estimated economic life of the leased assets. The finance and operating leases do not contain residual value guarantees. Certain of the operating leases have both lease and non-lease components. The lease and non-lease components are allocated based upon estimated relative standalone selling prices. A lease is deemed to exist when the Registrants have provided other parties with the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration received. The right to control is deemed to occur when the Registrants have provided other parties with the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. DTE Energy’s lease income associated with operating leases was as follows for the years ended December 31: 2020 2019 (In millions) Fixed payments (a) $ 66 $ 65 Variable payments (a) 124 128 $ 190 $ 193 _______________________________________ (a) Includes $108 million and $130 million of lease payments reported in Operating Revenues and $82 million and $63 million of lease payments reported in Other income on DTE Energy's Consolidated Statements of Operations as of December 31, 2020 and 2019, respectively. DTE Energy’s minimum future rental revenues under operating leases for remaining periods as of December 31, 2020 are as follows: DTE Energy (In millions) 2021 $ 62 2022 22 2023 22 2024 22 2025 19 2026 and thereafter 175 $ 322 Depreciation expense associated with DTE Energy's property under operating leases was $27 million and $26 million for the years ended December 31, 2020 and 2019, respectively. The following is a summary of property under operating leases for DTE Energy as of December 31: 2020 2019 (In millions) Gross property under operating leases $ 447 $ 445 Accumulated amortization of property under operating leases $ 197 $ 173 The components of DTE Energy’s net investment in finance leases for remaining periods as of December 31, 2020 are as follows: DTE Energy (In millions) 2021 $ 24 2022 20 2023 19 2024 19 2025 19 2026 and thereafter 253 Total minimum future lease receipts 354 Residual value of leased pipeline 17 Less unearned income 193 Net investment in finance lease 178 Less current portion 9 $ 169 Interest income recognized under finance leases was $16 million and $5 million for the years ended December 31, 2020 and 2019, respectively, including $4 million relating to Vector Pipeline for both periods.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
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. In July 2009, the Registrants received a NOV/FOV from the EPA alleging, among other things, that five DTE Electric power plants violated New Source Performance standards, Prevention of Significant Deterioration requirements, and operating permit requirements under the Clean Air Act. In June 2010, the EPA issued a NOV/FOV making similar allegations related to a project and outage at Unit 2 of the Monroe Power Plant. In March 2013, DTE Energy received a supplemental NOV from the EPA relating to the July 2009 NOV/FOV. The supplemental NOV alleged additional violations relating to the New Source Review provisions under the Clean Air Act, among other things. In August 2010, the U.S. Department of Justice, at the request of the EPA, brought a civil suit in the U.S. District Court for the Eastern District of Michigan against DTE Energy and DTE Electric, related to the June 2010 NOV/FOV and the outage work performed at Unit 2 of the Monroe Power Plant. In August 2011, the U.S. District Court judge granted DTE Energy's motion for summary judgment in the civil case, dismissing the case and entering judgment in favor of DTE Energy and DTE Electric. In October 2011, the EPA filed a Notice of Appeal to the Court of Appeals for the Sixth Circuit. In March 2013, the Court of Appeals remanded the case to the U.S. District Court for review of the procedural component of the New Source Review notification requirements. In September 2013, the EPA filed a motion seeking leave to amend their complaint regarding the June 2010 NOV/FOV adding additional claims related to outage work performed at the Trenton Channel and Belle River Power Plants as well as additional claims related to work performed at the Monroe Power Plant. In March 2014, the U.S. District Court judge again granted DTE Energy's motion for summary judgment dismissing the civil case related to Monroe Unit 2. In April 2014, the U.S. District Court judge granted motions filed by the EPA and the Sierra Club to amend their New Source Review complaint adding additional claims for Monroe Units 1, 2, and 3, Belle River Units 1 and 2, and Trenton Channel Unit 9. In October 2014, the EPA and the U.S. Department of Justice filed a notice of appeal of the U.S. District Court judge's dismissal of the Monroe Unit 2 case. The amended New Source Review claims were all stayed pending resolution of the appeal by the Court of Appeals for the Sixth Circuit. On January 10, 2017, a divided panel of the Court reversed the decision of the U.S. District Court. On May 8, 2017, DTE Energy and DTE Electric filed a motion to stay the mandate pending filing of a petition for writ of certiorari with the U.S. Supreme Court. The Sixth Circuit granted the motion on May 16, 2017, staying the claims in the U.S. District Court until the U.S. Supreme Court disposes of the case. DTE Electric and DTE Energy filed a petition for writ of certiorari on July 31, 2017. On December 11, 2017, the U.S. Supreme Court denied certiorari. As a result of the Supreme Court electing not to review the matter, the case was sent back to the U.S. District Court for further proceedings and on June 14, 2018 the case was stayed pending settlement negotiations. In May 2020, the Registrants, the United States, and the Sierra Club reached a settlement, which was memorialized in the form of a Consent Decree and a separate settlement agreement (Separate Agreement) between the Registrants and Sierra Club. The Consent Decree was submitted and received by the U.S. District Court and the public comment period ended on June 14, 2020. The Consent Decree was entered with the U.S. District Court with an effective date of July 23, 2020 and DTE Electric subsequently paid a civil penalty of $2 million. Sierra Club submitted the Separate Agreement for entry by the U.S. District Court on May 22, 2020; however, the United States opposed the entry of the Separate Agreement. After reviewing the matter, the U.S. District Court determined that the Separate Agreement is a private settlement agreement and therefore, it should not be incorporated into the Consent Decree or entered by the Court. Based on this, Sierra Club voluntarily withdrew its initial complaint in the case, acknowledging that it has resolved the matter privately with DTE Electric by way of the Separate Agreement. On December 3, 2020, the U.S. District Court entered an Opinion and Order Granting Intervenor's Motion for Voluntary Dismissal. As of December 31, 2020, $5 million remains accrued for the settlement with spend expected to begin in early 2021. The Separate Agreement also requires DTE to contribute at least $2 million to community based environmental projects, no later than June 30, 2021. The Registrants believe that the plants and generating units identified by the EPA and the Sierra Club have complied with all applicable federal environmental regulations. DTE Electric is required to retire, repower, refuel, or retrofit units at four power plants by the dates set forth in the Consent Decree and implement a supplemental environmental project. The Registrants do not expect the outcome of this matter to have a material impact on their Consolidated Financial Statements. 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 requires the state of Michigan to submit a plan in 2022 that includes GHG standards for existing coal-fired power plant units in Michigan. These final rules do not impact DTE Energy's commitment for its electric utility operations to reduce carbon emissions 32% by 2023, 50% by 2030, and 80% by 2040 from 2005 carbon emissions levels, or 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 aboveground storage tank locations. The findings of these investigations indicated that the estimated cost to remediate these sites is expected to be incurred over the next several years. At December 31, 2020 and 2019, DTE Electric had $10 million and $8 million, respectively, 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 is currently evaluating both final rules to determine any changes to DTE Electric's plans in the operation and closure of coal ash impoundments. 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 (Final Rule) which updates the 2015 ELG Rule (2015 Rule). The Final Rule 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 Final 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 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 $721 million of capital expenditures, including $601 million 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. In addition, DTE Gas committed to partner with customers to help them reduce GHG emissions through energy efficiency and participation in a voluntary emissions offset program. Further details of the DTE Gas net zero goal will emerge as the company evaluates strategies and technologies for reducing emissions. 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 December 31, 2020 and 2019, DTE Gas had $24 million and $25 million, respectively, 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 of the SIP process, DTE Energy has worked with EGLE to develop air permits reflecting significant SO2 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. Since several non-DTE Energy sources are also part of the proposed compliance plan, DTE Energy is unable to determine the full impact of the final required emissions reductions on 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 December 31, 2020 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 December 31, 2020 was $581 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 December 31, 2020, 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. 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, an 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 December 31, 2020, 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 December 31, 2020. 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 December 31, 2020, DTE Energy had $125 million of performance bonds outstanding, including $69 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 December 31, 2020 is $55 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 approximate 2,800 represented employees. The majority of the represented employees are under contracts that expire in 2021 and 2022. Purchase Commitments As of December 31, 2020, the Registrants were party to numerous long-term purchase commitments relating to a variety of goods and services required for their businesses. These agreements primarily consist of fuel supply commitments and renewable energy contracts for the Registrants, as well as energy trading contracts for DTE Energy. The Registrants estimate the following commitments from 2021 through 2051 for DTE Energy, and 2021 through 2051 for DTE Electric, as detailed in the following table: DTE Energy DTE Electric (In millions) 2021 $ 2,998 $ 1,132 2022 1,142 246 2023 804 226 2024 520 159 2025 397 209 2026 and thereafter 1,634 969 $ 7,495 $ 2,941 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's Power and Industrial Projects segment holds ownership interests in, and operates, five generating plants that sell electric output from renewable sources under long-term power purchase agreements with PG&E. PG&E filed for Chapter 11 bankruptcy protection on January 29, 2019. PG&E emerged from Chapter 11 bankruptcy effective July 1, 2020. DTE's renewable power purchase agreements were assumed under PG&E's Reorganization Plan and payment has been received for all past due receivables related to these agreements. 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. Impacts from the COVID-19 pandemic for the year ended December 31, 2020 include a reduction in DTE Electric sales volumes from commercial and industrial customers and an increase in residential customer sales volumes. This shift contributed to a net reduction in DTE Electric sales volumes for the year ended December 31, 2020, but the impact to earnings has been mitigated by favorable rate mix. Operation and maintenance expense has also been impacted by COVID-19, primarily at DTE Electric, due to higher costs for personal protective equipment and other health and safety-related costs, including shift premiums and related expenses associated with the sequestration of certain employees critical to continued operations. The Registrants implemented certain cost savings initiatives to offset some of these impacts, to the extent they did not affect safety or reliability of service. Impacts from the COVID-19 pandemic did not have a material effect on the Registrants' capital spending. For non-utility businesses, COVID-19 has primarily impacted the Power and Industrial Projects segment, contributing to lower production in the REF business and lower demand in the Steel business. These impacts were most significant in March and April 2020 when government orders to cease non-essential business activity resulted in temporary shut-down of certain operations. While these impacts have adversely affected Operating revenues and Other income from REF entities, Net income has not been significantly impacted due to related decreases in Operating expenses. Finally, as discussed in Note 2, "Significant Accounting Policies", the allowance for doubtful accounts was increased at our utilities due to additional risk relating to COVID-19. However, the impact of these increases has not been material. 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 December 31, 2020. 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 10 and 14 to the Consolidated Financial Statements, "Regulatory Matters" and "Financial and Other Derivative Instruments," respectively.

Nuclear Operations

Nuclear Operations	12 Months Ended
	Dec. 31, 2020
Nuclear Operations [Abstract]
Nuclear Operations	NUCLEAR OPERATIONS Property Insurance DTE Electric maintains property insurance policies specifically for the Fermi 2 plant. These policies cover such items as replacement power and property damage. NEIL is the primary supplier of the insurance policies. DTE Electric maintains a policy for extra expenses, including replacement power costs necessitated by Fermi 2’s unavailability due to an insured event. This policy has a 12-week waiting period and provides an aggregate $490 million of coverage over a three-year period. DTE Electric has $1.5 billion in primary coverage and $1.25 billion of excess coverage for stabilization, decontamination, debris removal, repair and/or replacement of property, and decommissioning. The combined coverage limit for total property damage is $2.75 billion. The total limit for property damage for non-nuclear events is $1.8 billion and an aggregate of $328 million of coverage for extra expenses over a two-year period. On December 20, 2019, the Terrorism Risk Insurance Program Reauthorization Act of 2019 was signed, extending TRIA through December 31, 2027. For multiple terrorism losses caused by acts of terrorism not covered under the TRIA occurring within one year after the first loss from terrorism, the NEIL policies would make available to all insured entities up to $3.2 billion, plus any amounts recovered from reinsurance, government indemnity, or other sources to cover losses. Under NEIL policies, DTE Electric could be liable for maximum assessments of up to $43 million per event if the loss associated with any one event at any nuclear plant should exceed the accumulated funds available to NEIL. Public Liability Insurance As required by federal law, DTE Electric maintains $450 million of public liability insurance for a nuclear incident. For liabilities arising from a terrorist act outside the scope of TRIA, the policy is subject to one industry aggregate limit of $300 million. Further, under the Price-Anderson Amendments Act of 2005, deferred premium charges up to $138 million could be levied against each licensed nuclear facility, but not more than $20 million per year per facility. Thus, deferred premium charges could be levied against all owners of licensed nuclear facilities in the event of a nuclear incident at any of these facilities. Nuclear Fuel Disposal Costs In accordance with the Federal Nuclear Waste Policy Act of 1982, DTE Electric has a contract with the DOE for the future storage and disposal of spent nuclear fuel from Fermi 2 that required DTE Electric to pay the DOE a fee of 1 mill per kWh of Fermi 2 electricity generated and sold. The fee was a component of nuclear fuel expense. The 1 mill per kWh DOE fee was reduced to zero effective May 16, 2014. The DOE's Yucca Mountain Nuclear Waste Repository program for the acceptance and disposal of spent nuclear fuel was terminated in 2011. DTE Electric is a party in the litigation against the DOE for both past and future costs associated with the DOE's failure to accept spent nuclear fuel under the timetable set forth in the Federal Nuclear Waste Policy Act of 1982. In July 2012, DTE Electric executed a settlement agreement with the federal government for costs associated with the DOE's delay in acceptance of spent nuclear fuel from Fermi 2 for permanent storage. The settlement agreement, including extensions, provides for a claims process and payment of delay-related costs experienced by DTE Electric through 2019. DTE Electric's claims are being settled and paid on a timely basis. The settlement proceeds reduce the cost of the dry cask storage facility assets and provide reimbursement for related operating expenses. DTE Electric currently employs a spent nuclear fuel storage strategy utilizing a fuel pool and a dry cask storage facility. The spent nuclear fuel storage strategy is expected to provide sufficient spent fuel storage capability for the life of the plant as defined by DTE Electric's operating license agreement. The federal government continues to maintain its legal obligation to accept spent nuclear fuel from Fermi 2 for permanent storage. Issues relating to long-term waste disposal policy and to the disposition of funds contributed by DTE Electric ratepayers to the federal waste fund await future governmental action.

Retirement Benefits and Trustee

Retirement Benefits and Trusteed Assets	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Retirement Benefits and Trusteed Assets	RETIREMENT BENEFITS AND TRUSTEED ASSETS DTE Energy's subsidiary, DTE Energy Corporate Services, LLC, sponsors defined benefit pension plans and other postretirement plans covering certain employees of the Registrants. The table below represents the pension and other postretirement benefit plans of each Registrant at December 31, 2020: Registrants DTE Energy DTE Electric Qualified Pension Plans DTE Energy Company Retirement Plan X X DTE Gas Company Retirement Plan for Employees Covered by Collective Bargaining Agreements X Shenango Inc. Pension Plan (a) X Non-qualified Pension Plans DTE Energy Company Supplemental Retirement Plan (b) X X DTE Energy Company Executive Supplemental Retirement Plan (b) X X DTE Energy Company Supplemental Severance Benefit Plan X Other Postretirement Benefit Plans The DTE Energy Company Comprehensive Non-Health Welfare Plan X X The DTE Energy Company Comprehensive Retiree Group Health Care Plan X X DTE Supplemental Retiree Benefit Plan X X DTE Energy Company Retiree Reimbursement Arrangement Plan X X _____________________________________ (a) Sponsored by Shenango, LLC (b) Sponsored by DTE Energy Company DTE Electric participates in various plans that provide pension and other postretirement benefits for DTE Energy and its affiliates. The plans are sponsored by the 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. Pension Plan Benefits DTE Energy has qualified defined benefit retirement plans for eligible represented and non-represented employees. The plans are noncontributory and provide traditional retirement benefits based on the employee's years of benefit service, average final compensation, and age at retirement. In addition, certain represented and non-represented employees are covered under cash balance provisions that determine benefits on annual employer contributions and interest credits. DTE Energy also maintains supplemental non-qualified, noncontributory, retirement benefit plans for certain management employees. These plans provide for benefits that supplement those provided by DTE Energy’s other retirement plans. Net pension cost for DTE Energy includes the following components: 2020 2019 2018 (In millions) Service cost $ 99 $ 84 $ 99 Interest cost 186 219 202 Expected return on plan assets (334) (325) (329) Amortization of: Net actuarial loss 171 131 176 Prior service cost 1 1 — Settlements 25 2 — Net pension cost $ 148 $ 112 $ 148 2020 2019 (In millions) Other changes in plan assets and benefit obligations recognized in Regulatory assets and Other comprehensive income (loss) Net actuarial loss $ 137 $ 156 Amortization of net actuarial loss (193) (133) Amortization of prior service cost (1) (1) Total recognized in Regulatory assets and Other comprehensive income (loss) $ (57) $ 22 Total recognized in net periodic pension cost, Regulatory assets, and Other comprehensive income (loss) $ 91 $ 134 The following table reconciles the obligations, assets, and funded status of the plans as well as the amounts recognized as prepaid pension cost or pension liability in DTE Energy's Consolidated Statements of Financial Position at December 31: DTE Energy 2020 2019 (In millions) Accumulated benefit obligation, end of year $ 5,843 $ 5,387 Change in projected benefit obligation Projected benefit obligation, beginning of year $ 5,810 $ 5,124 Service cost 99 84 Interest cost 186 219 Actuarial loss 619 719 Special termination benefits 3 — Benefits paid (353) (336) Settlements (60) — Projected benefit obligation, end of year $ 6,304 $ 5,810 Change in plan assets Plan assets at fair value, beginning of year $ 4,993 $ 4,273 Actual return on plan assets 815 888 Company contributions 102 168 Benefits paid (353) (336) Settlements (60) — Plan assets at fair value, end of year $ 5,497 $ 4,993 Funded status $ (807) $ (817) Amount recorded as: Current liabilities $ (10) $ (9) Noncurrent liabilities (797) (808) $ (807) $ (817) Amounts recognized in Accumulated other comprehensive income (loss), pre-tax Net actuarial loss $ 142 $ 153 Prior service cost 3 4 $ 145 $ 157 Amounts recognized in Regulatory assets (a) Net actuarial loss $ 1,949 $ 1,995 Prior service credit (11) (12) $ 1,938 $ 1,983 ______________________________________ (a) See Note 10 to the Consolidated Financial Statements, "Regulatory Matters." The increases in DTE Energy's pension benefit obligation for the years ended December 31, 2020 and 2019 were primarily due to actuarial loss in both periods, which was primarily driven by decreases in discount rates. The increase in the pension benefit obligation in 2020 was partially offset by a one-time settlement described below. In December 2020, a DTE Energy non-regulated qualified pension plan used plan assets to purchase an annuity contract from a third-party insurance company. The annuity contract will be used to settle the benefit obligations for certain plan participants. The transaction resulted in a $60 million reduction to the plan's projected benefit obligation and plan assets, as well as a one-time settlement charge of $22 million. The settlement charge is a component of net pension cost and is included in Non-operating retirement benefits, net in DTE Energy's Consolidated Statements of Operations for the year ended December 31, 2020. The Registrants' policy is to fund pension costs by contributing amounts consistent with the provisions of the Pension Protection Act of 2006, and additional amounts when it deems appropriate. The following table provides contributions to the qualified pension plans in: 2020 2019 2018 (In millions) DTE Energy $ 92 $ 150 $ 175 DTE Electric $ 60 $ 100 $ 175 DTE Energy's contributions of $92 million in 2020 included $82 million of common stock and $10 million of cash. Details of the contribution of common stock to the DTE Energy Company Affiliates Employee Benefit Plans Master Trust are as follows: Date Number of Shares Price per Share Amount (In millions) September 8, 2020 694,444 $118.08 $ 82 The above contribution was made on behalf of DTE Electric and DTE Gas, for which DTE Electric and DTE Gas paid DTE Energy cash consideration of $60 million and $22 million, respectively, in September 2020. 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. 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 were $106 million, $93 million, and $120 million for the years ended December 31, 2020, 2019, and 2018, respectively. These amounts include recognized contractual termination benefit charges, curtailment gains, and settlement charges. At December 31, 2020, the benefits related to DTE Energy's qualified and non-qualified pension plans expected to be paid in each of the next five years and in the aggregate for the five fiscal years thereafter are as follows: (In millions) 2021 $ 352 2022 363 2023 368 2024 352 2025 360 2026-2030 1,757 Total $ 3,552 Assumptions used in determining the projected benefit obligation and net pension costs of DTE Energy are: 2020 2019 2018 Projected benefit obligation Discount rate 2.57% 3.28% 4.40% Rate of compensation increase 3.80% 3.85% 3.85% Cash balance interest crediting rate 2.00% 3.30% 3.70% Net pension costs Discount rate 3.28% 4.40% 3.70% Rate of compensation increase 3.85% 3.85% 3.85% Expected long-term rate of return on plan assets 7.10% 7.30% 7.50% Cash balance interest crediting rate 3.30% 3.70% 3.70% DTE Energy employs a formal process in determining the long-term rate of return for various asset classes. Management reviews historic financial market risks and returns and long-term historic relationships between the asset classes of equities, fixed income, and other assets, consistent with the widely accepted capital market principle that asset classes with higher volatility generate a greater return over the long-term. Current market factors such as inflation, interest rates, asset class risks, and asset class returns are evaluated and considered before long-term capital market assumptions are determined. The long-term portfolio return is also established employing a consistent formal process, with due consideration of diversification, active investment management, and rebalancing. Peer data is reviewed to check for reasonableness. As a result of this process, the Registrants have long-term rate of return assumptions for the pension plans of 7.00% and other postretirement benefit plans of 6.70% for 2021. The Registrants believe these rates are a reasonable assumption for the long-term rate of return on plan assets for 2021 given the current investment strategy. The DTE Energy Company Affiliates Employee Benefit Plans Master Trust employs a liability driven investment program whereby the characteristics of plan liabilities are considered when determining investment policy. Risk tolerance is established through consideration of future plan cash flows, plan funded status, and corporate financial considerations. The investment portfolio contains a diversified blend of equity, fixed income, and other investments. Furthermore, equity investments are diversified across U.S. and non-U.S. stocks and large and small market capitalizations. Fixed income investments generally include U.S. Treasuries, other governmental debt, diversified corporate bonds, bank loans, and mortgage-backed securities. Other investments are used to enhance long-term returns while improving portfolio diversification. Derivatives may be utilized in a risk controlled manner, to potentially increase the portfolio beyond the market value of invested assets and/or reduce portfolio investment risk. Investment risk is measured and monitored on an ongoing basis through annual liability measurements, periodic asset/liability studies, and quarterly investment portfolio reviews. Target allocations for DTE Energy's pension plan assets as of December 31, 2020 are listed below: U.S. Large Capitalization (Cap) Equity Securities 18 % U.S. Small Cap and Mid Cap Equity Securities 3 Non-U.S. Equity Securities 16 Fixed Income Securities 38 Hedge Funds and Similar Investments 14 Private Equity and Other 11 100 % The following tables provide the fair value measurement amounts for DTE Energy's pension plan assets at December 31, 2020 and 2019 (a) : December 31, 2020 December 31, 2019 Level 1 Level 2 Other (b) Total Level 1 Level 2 Other (b) Total DTE Energy asset category: (In millions) Short-term Investments (c) $ 92 $ — $ — $ 92 $ 99 $ — $ — $ 99 Equity Securities Domestic (d) 167 — 1,093 1,260 172 — 870 1,042 International (e) 100 — 791 891 387 — 322 709 Fixed Income Securities Governmental (f) 459 95 — 554 569 — — 569 Corporate (g) — 1,404 — 1,404 — 1,452 — 1,452 Hedge Funds and Similar Investments (h) 238 61 411 710 169 — 502 671 Private Equity and Other (i) — — 586 586 — — 451 451 DTE Energy Total $ 1,056 $ 1,560 $ 2,881 $ 5,497 $ 1,396 $ 1,452 $ 2,145 $ 4,993 _______________________________________ (a) For a description of levels within the fair value hierarchy, see Note 13 to the Consolidated Financial Statements, "Fair Value." (b) Amounts represent assets valued at NAV as a practical expedient for fair value. (c) This category predominantly represents certain short-term fixed income securities and money market investments that are managed in separate accounts or commingled funds. Pricing for investments in this category are obtained from quoted prices in actively traded markets. (d) This category represents portfolios of large, medium and small capitalization domestic equities. Investments in this category include exchange-traded securities for which unadjusted quoted prices can be obtained and exchange-traded securities held in a commingled fund classified as NAV assets. (e) This category primarily consists of portfolios of non-U.S. developed and emerging market equities. Investments in this category include exchange-traded securities for which unadjusted quoted prices can be obtained and exchange-traded securities held in a commingled fund classified as NAV assets. (f) This category includes U.S. Treasuries, bonds, and other governmental debt. Pricing for investments in this category is obtained from quoted prices in actively traded markets and quotations from broker or pricing services. (g) This category primarily consists of corporate bonds from diversified industries, bank loans, and mortgage backed securities. Pricing for investments in this category is obtained from quotations from broker or pricing services. (h) This category utilizes a diversified group of strategies that attempt to capture financial market inefficiencies and includes publicly traded mutual funds, commingled funds and limited partnership funds. Pricing for mutual funds in this category is obtained from quoted prices in actively traded markets. Commingled funds and limited partnership funds are classified as NAV assets. (i) This category includes a diversified group of funds and strategies that primarily invests in private equity partnerships. This category also includes investments in real estate and private debt. All pricing for investments in this category are classified as NAV assets. The pension trust holds debt and equity securities directly and indirectly through commingled funds. Exchange-traded debt and equity securities held directly are valued using quoted market prices in actively traded markets. The commingled funds hold exchange-traded equity or debt securities and are valued based on stated NAVs. Non-exchange traded fixed income securities are valued by the trustee based upon quotations available from brokers or pricing services. A primary price source is identified by asset type, class, or issue for each security. The trustee monitors prices supplied by pricing services and may use a supplemental price source or change the primary price source of a given security if the trustee challenges an assigned price and determines that another price source is considered preferable. DTE Energy has obtained an understanding of how these prices are derived, including the nature and observability of the inputs used in deriving such prices. Other Postretirement Benefits The Registrants participate in defined benefit plans sponsored by the LLC that provide certain other postretirement health care and life insurance benefits for employees who are eligible for these benefits. The Registrants' policy is to fund certain trusts to meet its other postretirement benefit obligations. DTE Energy did not make any contributions to these trusts during 2020 and does not anticipate making any contributions to the trusts in 2021. DTE Energy and DTE Electric offer a defined contribution VEBA for eligible represented and non-represented employees, in lieu of defined benefit post-employment health care benefits. The Registrants allocate a fixed amount per year to an account in a defined contribution VEBA for each employee. These accounts are managed either by the Registrant (for non-represented and certain represented groups) or by the Utility Workers of America for Local 223 employees. DTE Energy contributions to the VEBA for these accounts were $15 million in 2020, $13 million in 2019, and $11 million in 2018, including DTE Electric contributions of $7 million in 2020, and $6 million in 2019, and $5 million in 2018. The Registrants also contribute a fixed amount to a Retiree Reimbursement Account, for certain non-represented and represented retirees, spouses, and surviving spouses when the youngest of the retiree's covered household becomes eligible for Medicare Part A based on age. The amount of the annual allocation to each participant is determined by the employee's retirement date and increases each year for each eligible participant at the lower of the rate of medical inflation or 2%. Net other postretirement credit for DTE Energy includes the following components: 2020 2019 2018 (In millions) Service cost $ 26 $ 22 $ 27 Interest cost 56 70 69 Expected return on plan assets (128) (96) (143) Amortization of: Net actuarial loss 16 12 11 Prior service credit (19) (9) — Net other postretirement credit $ (49) $ (1) $ (36) 2020 2019 (In millions) Other changes in plan assets and accumulated postretirement benefit obligation recognized in Regulatory assets and Other comprehensive income (loss) Net actuarial (gain) loss $ (38) $ 34 Amortization of net actuarial loss (16) (12) Prior service credit — (53) Amortization of prior service credit 19 9 Total recognized in Regulatory assets and Other comprehensive income (loss) $ (35) $ (22) Total recognized in net periodic benefit cost, Regulatory assets, and Other comprehensive income (loss) $ (84) $ (23) Net other postretirement credit for DTE Electric includes the following components: 2020 2019 2018 (In millions) Service cost $ 20 $ 16 $ 20 Interest cost 43 53 53 Expected return on plan assets (87) (65) (98) Amortization of: Net actuarial loss 11 5 8 Prior service credit (14) (7) — Net other postretirement cost (credit) $ (27) $ 2 $ (17) 2020 2019 (In millions) Other changes in plan assets and accumulated postretirement benefit obligation recognized in Regulatory assets Net actuarial (gain) loss $ (26) $ 41 Amortization of net actuarial loss (11) (5) Prior service credit — (33) Amortization of prior service credit 14 7 Total recognized in Regulatory assets $ (23) $ 10 Total recognized in net periodic benefit cost and Regulatory assets $ (50) $ 12 The following table reconciles the obligations, assets, and funded status of the plans including amounts recorded as Accrued postretirement liability in the Registrants' Consolidated Statements of Financial Position at December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Change in accumulated postretirement benefit obligation Accumulated postretirement benefit obligation, beginning of year $ 1,751 $ 1,645 $ 1,337 $ 1,247 Service cost 26 22 20 16 Interest cost 56 70 43 53 Plan amendments — (53) — (33) Actuarial loss 54 153 31 118 Benefits paid (80) (86) (62) (64) Accumulated postretirement benefit obligation, end of year $ 1,807 $ 1,751 $ 1,369 $ 1,337 Change in plan assets Plan assets at fair value, beginning of year $ 1,819 $ 1,689 $ 1,236 $ 1,158 Actual return on plan assets 220 215 145 141 Benefits paid (79) (85) (61) (63) Plan assets at fair value, end of year $ 1,960 $ 1,819 $ 1,320 $ 1,236 Funded status $ 153 $ 68 $ (49) $ (101) Amount recorded as: (a) Noncurrent assets $ 561 $ 454 $ 335 $ 266 Current liabilities (1) (1) — — Noncurrent liabilities (407) (385) (384) (367) $ 153 $ 68 $ (49) $ (101) Amounts recognized in Accumulated other comprehensive income (loss), pre-tax Net actuarial gain $ (7) $ (8) $ — $ — $ (7) $ (8) $ — $ — Amounts recognized in Regulatory assets (b) Net actuarial loss $ 234 $ 289 $ 156 $ 193 Prior service credit (69) (88) (48) (62) $ 165 $ 201 $ 108 $ 131 ______________________________________ (a) Prior year balances for DTE Energy were recast to be consistent with the current year gross presentation of Noncurrent assets and Noncurrent liabilities. (b) See Note 10 to the Consolidated Financial Statements, "Regulatory Matters." The increases in the Registrants' other postretirement benefit obligation for the years ended December 31, 2020 and 2019 were primarily due to actuarial loss in both periods, which was primarily driven by decreases in discount rates and partially offset by favorable changes in healthcare cost assumptions. The increase in the other postretirement benefit obligation in 2019 was also partially offset by plan amendments. The following table reflects other postretirement benefit plans with accumulated postretirement benefit obligations in excess of plan assets as of December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Accumulated postretirement benefit obligation $ 878 $ 840 $ 826 $ 795 Fair value of plan assets 470 454 442 428 Accumulated postretirement benefit obligation in excess of plan assets $ 408 $ 386 $ 384 $ 367 At December 31, 2020, the benefits expected to be paid, including prescription drug benefits, in each of the next five years and in the aggregate for the five fiscal years thereafter for the Registrants are as follows: DTE Energy DTE Electric (In millions) 2021 $ 82 $ 62 2022 87 66 2023 91 69 2024 92 70 2025 95 72 2026-2030 497 376 Total $ 944 $ 715 Assumptions used in determining the accumulated postretirement benefit obligation and net other postretirement benefit costs of the Registrants are: 2020 2019 2018 Accumulated postretirement benefit obligation Discount rate 2.58% 3.29% 4.40% Health care trend rate pre- and post- 65 6.75 / 7.25% 6.75 / 7.25% 6.75 / 7.25% Ultimate health care trend rate 4.50% 4.50% 4.50% Year in which ultimate reached pre- and post- 65 2033 2032 2031 Other postretirement benefit costs Discount rate 3.29% 4.40% 3.70% Expected long-term rate of return on plan assets 7.20% 7.30% 7.75% Health care trend rate pre- and post- 65 6.75 / 7.25% 6.75 / 7.25% 6.75 / 7.25% Ultimate health care trend rate 4.50% 4.50% 4.50% Year in which ultimate reached pre- and post- 65 2032 2031 2030 The process used in determining the long-term rate of return on assets for the other postretirement benefit plans is similar to that previously described for the pension plans. The DTE Energy Company Master VEBA Trust employs a liability driven investment program whereby the characteristics of plan liabilities are considered when determining investment policy. Risk tolerance is established through consideration of future plan cash flows, plan funded status, and corporate financial considerations. The investment portfolio contains a diversified blend of equity, fixed income, and other investments. Furthermore, equity investments are diversified across U.S. and non-U.S. stocks and large and small market capitalizations. Fixed income investments generally include U.S. Treasuries, other governmental debt, diversified corporate bonds, bank loans, and mortgage-backed securities. Other investments are used to enhance long-term returns while improving portfolio diversification. Derivatives may be utilized in a risk controlled manner to potentially increase the portfolio beyond the market value of invested assets and/or reduce portfolio investment risk. Investment risk is measured and monitored on an ongoing basis through annual liability measurements, periodic asset/liability studies, and quarterly investment portfolio reviews. Target allocations for the Registrants' other postretirement benefit plan assets as of December 31, 2020 are listed below: U.S. Large Cap Equity Securities 11 % U.S. Small Cap and Mid Cap Equity Securities 2 Non-U.S. Equity Securities 10 Fixed Income Securities 52 Hedge Funds and Similar Investments 11 Private Equity and Other 14 100 % The following tables provide the fair value measurement amounts for the Registrants' other postretirement benefit plan assets at December 31, 2020 and 2019 (a) : December 31, 2020 December 31, 2019 Level 1 Level 2 Other (b) Total Level 1 Level 2 Other (b) Total (In millions) DTE Energy asset category: Short-term Investments (c) $ 21 $ — $ — $ 21 $ 80 $ — $ — $ 80 Equity Securities Domestic (d) 51 — 200 251 51 — 273 324 International (e) 23 — 178 201 182 — 89 271 Fixed Income Securities Governmental (f) 40 45 — 85 74 — — 74 Corporate (g) — 477 379 856 — 256 251 507 Hedge Funds and Similar Investments (h) 61 17 124 202 71 — 182 253 Private Equity and Other (i) — — 344 344 — — 310 310 DTE Energy Total $ 196 $ 539 $ 1,225 $ 1,960 $ 458 $ 256 $ 1,105 $ 1,819 DTE Electric asset category: Short-term Investments (c) $ 14 $ — $ — $ 14 $ 55 $ — $ — $ 55 Equity Securities Domestic (d) 33 — 131 164 34 — 185 219 International (e) 16 — 117 133 124 — 60 184 Fixed Income Securities Governmental (f) 24 31 — 55 48 — — 48 Corporate (g) — 321 263 584 — 168 176 344 Hedge Funds and Similar Investments (h) 41 11 83 135 49 — 123 172 Private Equity and Other (i) — — 235 235 — — 214 214 DTE Electric Total $ 128 $ 363 $ 829 $ 1,320 $ 310 $ 168 $ 758 $ 1,236 _______________________________________ (a) For a description of levels within the fair value hierarchy see Note 13 to the Consolidated Financial Statements, "Fair Value." (b) Amounts represent assets valued at NAV as a practical expedient for fair value. (c) This category predominantly represents certain short-term fixed income securities and money market investments that are managed in separate accounts or commingled funds. Pricing for investments in this category are obtained from quoted prices in actively traded markets. (d) This category represents portfolios of large, medium and small capitalization domestic equities. Investments in this category include exchange-traded securities for which unadjusted quoted prices can be obtained and exchange-traded securities held in a commingled fund classified as NAV assets. (e) This category primarily consists of portfolios of non-U.S. developed and emerging market equities. Investments in this category include exchange-traded securities for which unadjusted quoted prices can be obtained and exchange-traded securities held in a commingled fund classified as NAV assets. (f) This category includes U.S. Treasuries, bonds and other governmental debt. Pricing for investments in this category is obtained from quoted prices in actively traded markets and quotations from broker or pricing services. (g) This category primarily consists of corporate bonds from diversified industries, bank loans, and mortgage backed securities. Pricing for investments in this category is obtained from quotations from broker or pricing services. Non-exchange traded securities and exchange-traded securities held in commingled funds are classified as NAV assets. (h) This category utilizes a diversified group of strategies that attempt to capture financial market inefficiencies and includes publicly traded mutual funds, commingled funds and limited partnership funds. Pricing for mutual funds in this category is obtained from quoted prices in actively traded markets. Commingled funds and limited partnership funds are classified as NAV assets. (i) This category includes a diversified group of funds and strategies that primarily invests in private equity partnerships. This category also includes investments in real estate and private debt. All investments in this category are classified as NAV assets. The DTE Energy Company Master VEBA Trust holds debt and equity securities directly and indirectly through commingled funds. Exchange-traded debt and equity securities held directly are valued using quoted market prices in actively traded markets. The commingled funds hold exchange-traded equity or debt securities and are valued based on NAVs. Non-exchange traded fixed income securities are valued by the trustee based upon quotations available from brokers or pricing services. A primary price source is identified by asset type, class, or issue for each security. The trustee monitors prices supplied by pricing services and may use a supplemental price source or change the primary price source of a given security if the trustee challenges an assigned price and determines that another price source is considered 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. Defined Contribution Plans The Registrants also sponsor defined contribution retirement savings plans. Participation in one of these plans is available to substantially all represented and non-represented employees. For substantially all employees, the Registrants match employee contributions up to certain predefined limits based upon eligible compensation and the employee’s contribution rate. Additionally, for eligible represented and non-represented employees who do not participate in the Pension Plans, the Registrants annually contribute an amount equivalent to 4% (8% for certain DTE Gas represented employees) of an employee's eligible pay to the employee's defined contribution retirement savings plan. For DTE Energy, the cost of these plans was $73 million, $65 million, and $61 million for the years ended December 31, 2020, 2019, and 2018, respectively. For DTE Electric, the cost of these plans was $34 million, $31 million, and $29 million for the years ended December 31, 2020, 2019, and 2018, respectively.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement, Noncash Expense [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION DTE Energy’s stock incentive program permits the grant of incentive stock options, non-qualifying stock options, stock awards, performance shares, and performance units to employees and members of its Board of Directors. As a result of a stock award, a settlement of an award of performance shares, or by exercise of a participant’s stock option, DTE Energy may deliver common stock from its authorized but unissued common stock and/or from outstanding common stock acquired by or on behalf of DTE Energy in the name of the participant. Key provisions of the stock incentive program are: • Authorized limit is 16,500,000 shares of common stock; • Prohibits the grant of a stock option with an exercise price that is less than the fair market value of DTE Energy’s stock on the date of the grant; and • Imposes the following award limits to a single participant in a single calendar year, (1) options for more than 500,000 shares of common stock; (2) stock awards for more than 150,000 shares of common stock; (3) performance share awards for more than 300,000 shares of common stock (based on the maximum payout under the award); or (4) more than 1,000,000 performance units, which have a face amount of $1.00 each. DTE Energy records compensation expense at fair value over the vesting period for all awards it grants. The following table summarizes the components of stock-based compensation for DTE Energy: 2020 2019 2018 (In millions) Stock-based compensation expense $ 63 $ 71 $ 64 Tax benefit $ 12 $ 13 $ 13 Stock-based compensation cost capitalized in Property, plant, and equipment (a) $ — $ 16 $ 11 _______________________________________ (a) In DTE Electric's May 2020 rate order, the MPSC disallowed certain capital expenditures related to incentive compensation. Therefore, beginning in 2020, no stock-based compensation cost will be capitalized in Property, plant, and equipment. Refer to Note 10 to the Consolidated Financial Statements, "Regulatory Matters," for further information. Restricted Stock Awards Stock awards granted under the plan are restricted for varying periods, generally for three years. Participants have all rights of a shareholder with respect to a stock award, including the right to receive dividends and vote the shares. Prior to vesting in stock awards, the participant: (i) may not sell, transfer, pledge, exchange, or otherwise dispose of shares; (ii) shall not retain custody of the share certificates; and (iii) will deliver to DTE Energy a stock power with respect to each stock award upon request. The stock awards are recorded at cost that approximates fair value on the date of grant. The cost is amortized to compensation expense over the vesting period. The fair value of awards vested were not material for the years ended December 31, 2020, 2019, and 2018. Compensation cost charged against income was $13 million for the year ended December 31, 2020, and $11 million for the years ended December 31, 2019 and 2018, respectively. Performance Share Awards Performance shares awarded under the plan are for a specified number of shares of DTE Energy common stock that entitle the holder to receive a cash payment, shares of DTE Energy common stock, or a combination thereof. The final value of the award is determined by the achievement of certain performance objectives and market conditions. The awards vest at the end of a specified period, usually three years. Awards granted in 2020, 2019, and 2018 were primarily deemed to be equity awards. The DTE Energy stock price and number of probable shares attributable to market conditions for such equity awards are fair valued only at the grant date. DTE Energy accounts for performance share awards by accruing compensation expense over the vesting period based on: (i) the number of shares expected to be paid which is based on the probable achievement of performance objectives; and (ii) the closing stock price market value. The settlement of the award is based on the closing price at the settlement date. DTE Energy recorded activity relating to performance share awards as follows: 2020 2019 2018 (In millions, except per share amounts) Weighted average grant date fair value of awards granted (per share) $ 129.68 $ 115.85 $ 105.64 Awards settled in cash (a) $ 21 $ 19 $ 13 Awards settled in stock (a) $ 53 $ 79 $ 39 Compensation expense $ 50 $ 60 $ 53 _______________________________________ (a) Sum of awards settled in cash and stock approximates the intrinsic value of the awards. During the vesting period, the recipient of a performance share award has no shareholder rights. During the period beginning on the date the performance shares are awarded and ending on the certification date of the performance objectives, the number of performance shares awarded will be increased, assuming full dividend reinvestment at the fair market value on the dividend payment date. The cumulative number of performance shares will be adjusted to determine the final payment based on the performance objectives achieved. Performance share awards are nontransferable and are subject to risk of forfeiture. The following table summarizes DTE Energy’s performance share activity for the period ended December 31, 2020: Performance Shares Weighted Average Balance at December 31, 2019 1,226,031 $ 107.35 Grants 383,813 $ 129.68 Forfeitures (43,768) $ 116.94 Payouts (438,639) $ 99.22 Balance at December 31, 2020 1,127,437 $ 117.06 Unrecognized Compensation Costs As of December 31, 2020, DTE Energy's total unrecognized compensation cost related to non-vested stock incentive plan arrangements and the weighted average recognition period was as follows: Unrecognized Weighted Average (In millions) (In years) Stock awards $ 19 1.60 Performance shares 49 1.04 $ 68 1.19 Allocated Stock-Based Compensation DTE Electric received an allocation of costs from DTE Energy associated with stock-based compensation. DTE Electric's allocation for 2020, 2019, and 2018 for stock-based compensation expense was $37 million, $43 million, and $38 million, respectively.

Segment and Related Information

Segment and Related Information	12 Months Ended
	Dec. 31, 2020
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: Year Ended December 31, 2020 2019 2018 (In millions) Electric (a) $ 61 $ 56 $ 52 Gas 16 12 12 Gas Storage and Pipelines 26 27 36 Power and Industrial Projects 464 596 642 Energy Trading 31 22 27 Corporate and Other 2 2 2 $ 600 $ 715 $ 771 _______________________________________ (a) Inter-segment billing for the Electric segment includes $2 million relating to Non-utility operations for the year ended December 31, 2020. Financial data of DTE Energy's business segments follows: Electric Gas Gas Storage and Pipelines Power and Industrial Projects Energy Trading Corporate and Other Reclassifications Total (In millions) 2020 Operating Revenues — Utility operations $ 5,506 1,414 — — — — (75) $ 6,845 Operating Revenues — Non-utility operations $ 14 — 754 1,224 3,863 2 (525) $ 5,332 Depreciation and amortization $ 1,057 157 151 72 5 1 — $ 1,443 Interest expense $ 337 80 113 37 6 331 (184) $ 720 Interest income $ (4) (5) (9) (22) (2) (180) 184 $ (38) Equity in earnings of equity method investees $ — 1 106 17 — 8 — $ 132 Income Tax Expense (Benefit) $ 108 48 116 (40) 12 (77) — $ 167 Net Income (Loss) Attributable to DTE Energy Company $ 777 186 315 134 36 (80) — $ 1,368 Investment in equity method investees $ 6 12 1,691 125 — 34 — $ 1,868 Capital expenditures and acquisitions $ 2,701 574 517 186 5 — — $ 3,983 Goodwill $ 1,208 743 472 26 17 — — $ 2,466 Total Assets $ 26,588 6,339 5,068 696 807 8,071 (2,073) $ 45,496 Electric Gas Gas Storage and Pipelines Power and Industrial Projects Energy Trading Corporate and Other Reclassifications Total (In millions) 2019 Operating Revenues — Utility operations $ 5,224 1,482 — — — — (68) $ 6,638 Operating Revenues — Non-utility operations $ 5 — 501 1,560 4,610 2 (647) $ 6,031 Depreciation and amortization $ 949 144 94 69 6 1 — $ 1,263 Interest expense $ 315 78 73 33 8 266 (132) $ 641 Interest income $ (2) (6) (8) (9) (4) (120) 132 $ (17) Equity in earnings of equity method investees $ 1 2 97 14 — (3) — $ 111 Income Tax Expense (Benefit) $ 137 62 74 (63) 17 (75) — $ 152 Net Income (Loss) Attributable to DTE Energy Company $ 714 185 204 133 49 (116) — $ 1,169 Investment in equity method investees $ 5 11 1,685 130 — 31 — $ 1,862 Capital expenditures and acquisitions $ 2,368 530 2,510 54 5 — — $ 5,467 Goodwill $ 1,208 743 470 26 17 — — $ 2,464 Total Assets $ 24,617 5,717 4,832 537 798 7,610 (1,843) $ 42,268 Electric Gas Gas Storage and Pipelines Power and Industrial Projects Energy Trading Corporate and Other Reclassifications Total (In millions) 2018 Operating Revenues — Utility operations $ 5,298 1,436 — — — — (64) $ 6,670 Operating Revenues — Non-utility operations $ — — 485 2,204 5,557 3 (707) $ 7,542 Depreciation and amortization $ 836 133 82 67 5 1 — $ 1,124 Interest expense $ 283 70 68 31 6 220 (119) $ 559 Interest income $ — (6) (9) (9) (3) (104) 119 $ (12) Equity in earnings of equity method investees $ — 2 123 3 — 4 — $ 132 Income Tax Expense (Benefit) $ 193 67 68 (195) 13 (48) — $ 98 Net Income (Loss) Attributable to DTE Energy Company $ 664 150 235 161 39 (129) — $ 1,120 Investment in equity method investees $ 7 12 1,585 134 — 33 — $ 1,771 Capital expenditures and acquisitions $ 1,979 460 176 91 5 2 — $ 2,713 Goodwill $ 1,208 743 299 26 17 — — $ 2,293 Total Assets $ 22,501 5,378 3,161 495 909 6,153 (2,309) $ 36,288

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	RELATED PARTY TRANSACTIONS DTE Energy enters into related party transactions with certain equity method investees, primarily NEXUS. DTE Gas is party to a 15-year capacity lease agreement with NEXUS for the transportation of natural gas. Under the lease agreement, DTE Gas provides firm pipeline capacity in the DTE Gas system in order for NEXUS to provide service to its customers from an interconnect between NEXUS and DTE Gas. DTE Gas charges NEXUS a fixed daily pipeline reservation charge for this capacity. DTE Electric and DTE Gas are also party to respective 20-year and 15-year service agreements with NEXUS for the transportation of natural gas. Under the service agreements, NEXUS provides firm pipeline capacity to transport natural gas to DTE Electric and to service DTE Gas customers. DTE Electric and DTE Gas incur a firm daily pipeline reservation charge, which is recovered through the respective PSCR and GCR mechanisms. DTE Energy Trading also enters into related party transactions with NEXUS for the transportation of natural gas. The following table summarizes the amounts resulting from these transactions included in the Consolidated Statements of Operations for the years ended December 31: 2020 2019 2018 (In millions) Operating Revenues — Utility operations DTE Gas $ 32 $ 32 $ 6 Fuel, purchased power, and gas — utility DTE Electric $ 8 $ 8 $ 1 DTE Gas $ 21 $ 22 $ 1 Fuel, purchased power, gas, and other — non-utility DTE Energy Trading $ 27 $ 13 $ 1 Other related party transactions with equity method investees include transactions with Vector Pipeline and Millennium Pipeline. Refer to Note 18 to the Consolidated Financial Statements, "Leases," for lease activity related to Vector Pipeline. Other transactions relating to Vector Pipeline and Millennium Pipeline were not material for the years ended December 31, 2020, 2019, and 2018. DTE Electric has agreements with affiliated companies to sell energy for resale, purchase fuel and power, provide fuel supply services, and provide power plant operation and maintenance services. DTE Electric has agreements with certain DTE Energy affiliates where it charges the affiliates for their use of the shared capital assets of DTE Electric. A shared services company accumulates various corporate support expenses and charges various subsidiaries of DTE Energy, including DTE Electric. DTE Electric records federal, state, and local income taxes payable to or receivable from DTE Energy based on its federal, state, and local tax provisions. The following is a summary of DTE Electric's transactions with affiliated companies: 2020 2019 2018 (In millions) Revenues and Other Income Energy sales $ 8 $ 10 $ 9 Other services $ 2 $ 5 $ 4 Shared capital assets $ 51 $ 47 $ 43 Costs Fuel and purchased power $ 16 $ 9 $ 7 Other services and interest $ 1 $ 23 $ 33 Corporate expenses $ 367 $ 372 $ 377 Other Dividends declared $ 539 $ 494 $ 461 Dividends paid $ 539 $ 494 $ 461 Capital contribution from DTE Energy $ 636 $ 180 $ 325 DTE Electric's Accounts receivable and Accounts payable related to Affiliates are payable upon demand and are generally settled in cash within a monthly business cycle. Notes receivable and Short-term borrowings related to Affiliates are subject to a credit agreement with DTE Energy whereby short-term excess cash or cash shortfalls are remitted to or funded by DTE Energy. This credit arrangement involves the charge and payment of interest at market-based rates. Refer to DTE Electric's Consolidated Statements of Financial Position for affiliate balances at December 31, 2020 and 2019. There were $20 million in charitable contributions made by DTE Electric to the DTE Energy Foundation for the year ended December 31, 2020 and no contributions for the years ended December 31, 2019, and 2018. The DTE Energy Foundation is a non-consolidated not-for-profit private foundation, the purpose of which is to contribute and assist charitable organizations. See the following notes for other related party transactions impacting DTE Electric’s Consolidated Financial Statements: Note Title 1 Organization and Basis of Presentation 21 Retirement Benefits and Trusteed Assets 22 Stock-Based Compensation

Supplementary Quarterly Financi

Supplementary Quarterly Financial Information (Unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Supplementary Quarterly Financial Information (Unaudited)	SUPPLEMENTARY QUARTERLY FINANCIAL INFORMATION (UNAUDITED) DTE Energy The sum of quarterly earnings per share may not equal year-end amounts, since quarterly computations are based on weighted average common shares outstanding during each quarter. First Second Third Fourth Year (In millions, except per share amounts) 2020 Operating Revenues $ 3,022 $ 2,583 $ 3,284 $ 3,288 $ 12,177 Operating Income $ 546 $ 367 $ 608 $ 465 $ 1,986 Net Income Attributable to DTE Energy Company $ 340 $ 277 $ 476 $ 275 $ 1,368 Basic Earnings per Share $ 1.77 $ 1.44 $ 2.47 $ 1.42 $ 7.09 Diluted Earnings per Share $ 1.76 $ 1.44 $ 2.46 $ 1.42 $ 7.08 2019 Operating Revenues $ 3,514 $ 2,888 $ 3,119 $ 3,148 $ 12,669 Operating Income $ 542 $ 300 $ 450 $ 415 $ 1,707 Net Income Attributable to DTE Energy Company $ 401 $ 182 $ 319 $ 267 $ 1,169 Basic Earnings per Share $ 2.20 $ 0.99 $ 1.74 $ 1.40 $ 6.32 Diluted Earnings per Share $ 2.19 $ 0.99 $ 1.73 $ 1.40 $ 6.31 DTE Electric First Second Third Fourth Year (In millions) 2020 Operating Revenues $ 1,212 $ 1,309 $ 1,690 $ 1,295 $ 5,506 Operating Income $ 214 $ 263 $ 541 $ 206 $ 1,224 Net Income $ 94 $ 183 $ 400 $ 101 $ 778 2019 Operating Revenues $ 1,235 $ 1,190 $ 1,519 $ 1,280 $ 5,224 Operating Income $ 226 $ 223 $ 440 $ 224 $ 1,113 Net Income $ 147 $ 133 $ 307 $ 129 $ 716

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	DTE Energy Company Schedule II — Valuation and Qualifying Accounts Year Ending December 31, 2020 2019 2018 (In millions) Allowance for Doubtful Accounts (shown as deduction from Accounts receivable in DTE Energy's Consolidated Statements of Financial Position) Balance at Beginning of Period $ 91 $ 91 $ 49 Additions: Charged to costs and expenses 103 111 140 Charged to other accounts (a) 50 56 55 Deductions (b) (140) (167) (153) Balance at End of Period $ 104 $ 91 $ 91 _______________________________________ (a) Collection of accounts previously written off. (b) Uncollectible accounts written off. DTE Electric Company Schedule II — Valuation and Qualifying Accounts Year Ending December 31, 2020 2019 2018 (In millions) Allowance for Doubtful Accounts (shown as deduction from Accounts receivable in DTE Electric's Consolidated Statements of Financial Position) Balance at Beginning of Period $ 46 $ 53 $ 31 Additions: Charged to costs and expenses 61 65 85 Charged to other accounts (a) 30 36 36 Deductions (b) (80) (108) (99) Balance at End of Period $ 57 $ 46 $ 53 _______________________________________ (a) Collection of accounts previously written off. (b) Uncollectible accounts written off.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying Consolidated Financial Statements of the Registrants are prepared using accounting principles generally accepted in the United States of America. These accounting principles require management to use estimates and assumptions that impact reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from the Registrants' estimates. 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.
Reclassification	Certain prior year balances for the Registrants were reclassified to match the current year's Consolidated Financial Statements presentation.
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, which was acquired in September 2019. 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 December 31, 2020, 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 December 31, 2020, 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 19 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 guaranteed. See Note 19 to the Consolidated Financial Statements, "Commitments and Contingencies," for further discussion of the NEXUS guarantee arrangements.
Other Income	Other Income Other income for the Registrants is recognized for non-operating income such as equity earnings of equity method investees, allowance for equity funds used during construction, contract services, and gains from trading securities, primarily from those held in DTE Energy's rabbi trust. DTE Energy's Power and Industrial Projects segment also recognizes Other income in connection with the sale of membership interests in reduced emissions fuel facilities to investors. In exchange for the cash received, the investors receive a portion of the economic attributes of the facilities, including income tax attributes. The transactions are not treated as a sale of membership interests for financial reporting purposes. Other income related to fixed non-refundable cash payments received from investors for which the earnings process is not contingent upon production of refined coal is recognized on a straight-line basis over the non-cancelable contract term as the economic benefit from the ownership of the facility is transferred to investors. Other income related to cash payments that is contingent upon production of refined coal is considered earned and recognized when the contingency regarding the timing and amount of payment is resolved, generally as refined coal is produced and tax credits are generated.
Accounting for ISO Transactions	Accounting for ISO Transactions DTE Electric participates in the energy market through MISO. MISO requires that DTE Electric submit hourly day-ahead, real-time, and FTR bids and offers for energy at locations across the MISO region. DTE Electric accounts for MISO transactions on a net hourly basis in each of the day-ahead, real-time, and FTR markets. In any single hour, transactions in each of the MISO energy markets are netted based on MWh to determine if DTE Electric is in a net sale or purchase position. Net purchases are recorded in Fuel, purchased power, and gas — utility and net sales are recorded in Operating Revenues — Utility operations on the Registrants' Consolidated Statements of Operations. The Energy Trading segment participates in the energy markets through various ISOs and RTOs. These markets require that Energy Trading submits hourly day-ahead, real-time bids and offers for energy at locations across each region. Energy Trading submits bids in the annual and monthly auction revenue rights and FTR auctions to the RTOs. Energy Trading accounts for these transactions on a net hourly basis for the day-ahead, real-time, and FTR markets. These transactions are related to trading contracts which, if derivatives, are presented on a net basis in Operating Revenues — Non-utility operations, and if non-derivatives, the realized gains and losses for sales are recorded in Operating Revenues — Non-utility operations and purchases are recorded in Fuel, purchased power, gas, and other — non-utility in the DTE Energy Consolidated Statements of Operations. DTE Electric and Energy Trading record accruals for future net purchases adjustments based on historical experience and reconcile accruals to actual costs when invoices are received from MISO and other ISOs and RTOs.
Derivatives	DerivativesEnergy Trading classifies derivative transactions as revenue or expense based on the intent of the transaction (buy or sell). Revenues are recorded on a gross or net basis within the income statement depending upon whether it represents a non-trading activity or trading activity, respectively. 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, some 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 2023. 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 December 31, 2020 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.
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. DTE Energy unbilled revenues of $944 million and $855 million at December 31, 2020 and 2019, respectively, include $260 million and $263 million of DTE Electric unbilled revenues, respectively, included in Customer Accounts receivable. 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 December 31, 2020. DTE Energy DTE Electric Year of origination 2020 2019 2018 and prior Total 2020 and prior (In millions) Notes receivable Internal grade 1 $ — $ 14 $ 10 $ 24 $ 14 Internal grade 2 68 43 6 117 2 Total notes receivable (a) $ 68 $ 57 $ 16 $ 141 $ 16 Net investment in leases Net investment in leases, internal grade 1 $ 6 $ — $ 39 $ 45 $ — Net investment in leases, internal grade 2 131 — 1 132 — Total net investment in leases (a) $ 137 $ — $ 40 $ 177 $ — _______________________________________ (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 Current Assets — Other and 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 19, "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 table presents a roll-forward of the activity for the Registrants' financing receivables credit loss reserves as of December 31, 2020. 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 100 3 103 61 Write-offs charged against allowance (136) (4) (140) (80) Recoveries of amounts previously written off 50 — 50 30 Ending reserve balance, December 31, 2020 $ 101 $ 3 $ 104 $ 57 The Registrants have been monitoring the impacts from the COVID-19 pandemic on our customers and various counterparties. For DTE Electric and DTE Gas, the allowance for doubtful accounts has been increased to account for additional risk related to the pandemic. As of December 31, 2020, the impact of these increases has not been material. In April 2020, the MPSC issued an order in response to the COVID-19 pandemic and authorized the deferral of certain uncollectible expense that is in excess of the amount used to set current rates. As a result of the order, the Registrants began deferring uncollectible expense as Regulatory assets, including $2 million at DTE Gas for the year ended December 31, 2020. For DTE Electric, deferrals recorded throughout the year were reversed and recorded to expense as a result of the MPSC approval of DTE Electric's one-time accounting application in December 2020. Refer to Note 10 to the Consolidated Financial Statements, "Regulatory Matters," for further information. For DTE Energy, uncollectible expense was $103 million, $111 million, and $140 million for the years ended December 31, 2020, 2019, and 2018, respectively, which is primarily comprised of the current period provision for allowance for doubtful accounts adjusted for regulatory deferrals at DTE Gas. For DTE Electric, uncollectible expense was $62 million, $65 million, and $85 million for the years ended December 31, 2020, 2019, and 2018, respectively, which is primarily comprised of the current period provision for allowance for doubtful accounts. There are no material amounts of past due financing receivables for the Registrants as of December 31, 2020.
Inventories	Inventories Inventory related to utility and non-utility operations is valued at the lower of cost or net realizable value, where cost is generally valued using average cost.
Property, Retirement and Maintenance, and Depreciation and Amortization	Property, Retirement and Maintenance, and Depreciation and Amortization Property is stated at cost and includes construction-related labor, materials, overheads, and AFUDC for utility property. The cost of utility properties retired is charged to accumulated depreciation. Expenditures for maintenance and repairs are charged to expense when incurred. Utility property at DTE Electric and DTE Gas is depreciated over its estimated useful life using straight-line rates approved by the MPSC. DTE Energy's non-utility property is depreciated over its estimated useful life using the straight-line method. Depreciation and amortization expense also includes the amortization of certain regulatory assets for the Registrants. The cost of nuclear fuel is capitalized. The amortization of nuclear fuel is included within Fuel, purchased power, and gas — utility in the DTE Energy Consolidated Statements of Operations, and Fuel and purchased power in the DTE Electric Consolidated Statements of Operations, and is recorded using the units-of-production method.
Long-Lived Assets	Long-Lived Assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. If the carrying amount of the asset exceeds the expected undiscounted future cash flows generated by the asset, an impairment loss is recognized resulting in the asset being written down to its estimated fair value. Assets to be disposed of are reported at the lower of the carrying amount or fair value, less costs to sell.
Intangible Assets	DTE Energy amortizes customer relationship and contract intangible assets on a straight-line basis over the expected period of benefit.
Excise and Sales Taxes and Income Taxes	Excise and Sales Taxes The Registrants record the billing of excise and sales taxes as a receivable with an offsetting payable to the applicable taxing authority, with no net impact on the Registrants’ Consolidated Statements of Operations.
Deferred Debt Costs	Deferred Debt Costs The costs related to the issuance of long-term debt are deferred and amortized over the life of each debt issue. The deferred amounts are included as a direct deduction from the carrying amount of each debt issue in Mortgage bonds, notes, and other and Junior subordinated debentures on DTE Energy's Consolidated Statements of Financial Position and in Mortgage bonds, notes, and other on DTE Electric's Consolidated Statements of Financial Position. In accordance with MPSC regulations applicable to DTE Energy’s electric and gas utilities, the unamortized discount, premium, and expense related to utility debt redeemed with a refinancing are amortized over the life of the replacement issue. Discount, premium, and expense on early redemptions of debt associated with DTE Energy's non-utility operations are charged to earnings.
Investments in Debt and Equity Securities	Investments in Debt and Equity SecuritiesThe Registrants generally record investments in debt and equity securities at market value with unrealized gains or losses included in earnings. Changes in the fair value of Fermi 2 nuclear decommissioning investments are recorded as adjustments to Regulatory assets or liabilities, due to a recovery mechanism from customers. The Registrants' equity investments are reviewed for impairment each reporting period. If the assessment indicates that an impairment exists, a loss is recognized resulting in the equity investment being written down to its estimated fair value.
DTE Energy Foundation	DTE Energy Foundation DTE Energy's contributions to the DTE Energy Foundation were $20 million and $22 million for the years ended December 31, 2020 and December 31, 2018, respectively. There were no charitable contributions made to the DTE Energy Foundation for the year ended December 31, 2019. The DTE Energy Foundation is a non-consolidated not-for-profit private foundation, the purpose of which is to contribute to and assist charitable organizations.
New Accounting Pronouncements	Recently Adopted Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , as amended. The amendments in this update have replaced the previous incurred loss impairment methodology with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information, including forecasts, to develop credit loss estimates. The ASU requires entities to use the new methodology to measure impairment of financial instruments, including accounts receivable, and may result in earlier recognition of credit losses than under previous generally accepted accounting principles. Entities must apply the new guidance as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The Registrants adopted the standard effective January 1, 2020. The adoption of the ASU did not have an impact on the Registrants' financial position or results of operations. Additional required disclosures have been included in Note 2 to the Consolidated Financial Statements, “Significant Accounting Policies.” In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . The guidance removes Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation to determine the amount of goodwill impairment. Under the ASU, a goodwill impairment will be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The Registrants adopted the ASU effective January 1, 2020. The adoption of the ASU did not have an impact on the Registrants' Consolidated Financial Statements. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurements (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement . The amendments in this update modify the disclosure requirements on fair value measurements in Topic 820. The Registrants adopted the ASU effective January 1, 2020. The Registrants have updated Note 13 to the Consolidated Financial Statements, "Fair Value," to incorporate the disclosure changes required by the ASU. In August 2018, the FASB issued ASU No. 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract . The amendments in this update align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The Registrants adopted the standard effective January 1, 2020 using the prospective approach. The adoption of the ASU did not have an impact on the Registrants’ Consolidated Financial Statements. On a prospective basis, costs within the scope of this amendment will be accounted for consistent with any underlying service contracts. Capitalized implementation costs will be reflected in Other noncurrent assets on the Consolidated Statements of Financial Position and amortization of these costs will be reflected in Operation and maintenance within the Consolidated Statements of Operations. Cash flow activity will be reflected in the Other current and noncurrent assets and liabilities line within the Operating Activities section of the Consolidated Statements of Cash Flows. In August 2018, the FASB issued ASU No. 2018-14, Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20): Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans . The amendments in this update modify the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The Registrants adopted the ASU effective January 1, 2020. The Registrants have updated Note 21 to the Consolidated Financial Statements, "Retirement Benefits and Trusteed Assets," to incorporate the disclosure changes required by the ASU. In October 2018, the FASB issued ASU No. 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities . The amendments in this update modify the requirements for determining whether fees paid to a decision maker or service provider are variable interests and require reporting entities to consider indirect interests held through related parties under common control on a proportional basis. The Registrants adopted the ASU effective January 1, 2020. The adoption of the ASU did not have a significant impact on the Registrants’ Consolidated Financial Statements. Recently Issued 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 ASU is effective for the Registrants for fiscal years beginning after December 15, 2020. The Registrants will adopt the ASU on its effective date using a modified retrospective approach. The ASU will 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. The amendments in this update provide optional expedients and exceptions for applying GAAP to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The optional expedients are effective for the modification of existing contracts or new arrangements executed March 12, 2020 through December 31, 2022. The Registrants are currently assessing the impact of this standard on their 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 ASU is effective for the Registrants for fiscal years beginning after December 15, 2021, and interim periods therein. Early adoption is permitted. The ASU will not have a significant impact on the Registrants' Consolidated Financial Statements.
Revenue	Upon the adoption of Topic 606, revenue is measured based upon the consideration specified in a contract with a customer at the time when performance obligations are satisfied. Under Topic 606, a performance obligation is a promise in a contract to transfer a distinct good or service or a series of distinct goods or services to the customer. The Registrants recognize revenue when performance obligations are satisfied by transferring control over a product or service to a customer. The Registrants have determined control to be transferred when the product is delivered or the service is provided to the customer. For the years ended December 31, 2020, 2019, and 2018, recognition of revenue for the Registrants subsequent to the adoption of Topic 606 is substantially similar in amount and approach to that prior to adoption. Rates for DTE Electric and DTE Gas include provisions to adjust billings for fluctuations in fuel and purchased power costs, cost of natural gas, and certain other costs. Revenues are adjusted for differences between actual costs subject to reconciliation and the amounts billed in current rates. Under or over recovered revenues related to these cost recovery mechanisms are included in Regulatory assets or liabilities on the Registrants' Consolidated Statements of Financial Position and are recovered or returned to customers through adjustments to the billing factors.
Asset Retirement Obligations	DTE Electric has a legal retirement obligation for the decommissioning costs for its Fermi 1 and Fermi 2 nuclear plants, dismantlement of facilities located on leased property, and various other operations. DTE Electric has conditional retirement obligations for asbestos and PCB removal at certain of its power plants and various distribution equipment. DTE Gas has conditional retirement obligations for gas pipelines, certain service centers, compressor and gate stations. The Registrants recognize such obligations as liabilities at fair market value when they are incurred, which generally is at the time the associated assets are placed in service. Fair value is measured using expected future cash outflows discounted at the Registrants' credit-adjusted risk-free rate. For its utility operations, the Registrants recognize in the Consolidated Statements of Operations removal costs in accordance with regulatory treatment. Any differences between costs recognized related to asset retirement and those reflected in rates are recognized as either a Regulatory asset or liability on the Consolidated Statements of Financial Position. If a reasonable estimate of fair value cannot be made in the period in which the retirement obligation is incurred, such as for assets with indeterminate lives, the liability is recognized when a reasonable estimate of fair value can be made. Natural gas storage system and certain other distribution assets for DTE Gas and substations, manholes, and certain other distribution assets for DTE Electric have an indeterminate life. Therefore, no liability has been recorded for these assets.
Regulatory Assets and Liabilities	Regulatory Assets and Liabilities DTE Electric and DTE Gas are required to record Regulatory assets and liabilities for certain transactions that would have been treated as revenue or expense in non-regulated businesses. Continued applicability of regulatory accounting treatment requires that rates be designed to recover specific costs of providing regulated services and be charged to and collected from customers. Future regulatory changes could result in the discontinuance of this accounting treatment for Regulatory assets and liabilities for some or all of the Registrants' businesses and may require the write-off of the portion of any Regulatory asset or liability that was no longer probable of recovery through regulated rates. Management believes that currently available facts support the continued use of Regulatory assets and liabilities and that all Regulatory assets and liabilities are recoverable or refundable in the current regulatory environment.
Fair Value Measurement	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date in a principal or most advantageous market. Fair value is a market-based measurement that is determined based on inputs, which refer broadly to assumptions that market participants use in pricing assets or liabilities. These inputs can be readily observable, market corroborated, or generally unobservable inputs. The 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 December 31, 2020 and 2019. 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 $183 million and $151 million as of December 31, 2020 and 2019, 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, 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 $7 million outstanding at December 31, 2020 and $6 million at December 31, 2019, 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 $9 million and $4 million at December 31, 2020 and 2019, 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.
Lessee	Lessee Leases at DTE Energy are primarily comprised of various forms of equipment, computer hardware, coal railcars, production facilities, buildings, and certain easement leases with terms ranging from approximately 2 to 40 years. Leases at DTE Electric are primarily comprised of various forms of equipment, computer hardware, coal railcars, and certain easement leases with terms ranging from approximately 2 to 40 years. A lease is deemed to exist when the Registrants have the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration paid. The right to control is deemed to occur when the Registrants have the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets. Lease liabilities are determined utilizing a discount rate to determine the present values of lease payments. Topic 842 requires the use of the rate implicit in the lease when it is readily determinable. When the rate implicit in the lease is not readily determinable, the incremental borrowing rate is used. The Registrants have determined their respective incremental borrowing rates based upon the rate of interest that would have been paid on a collateralized basis over similar tenors to that of the leases. The incremental borrowing rates for DTE Electric and DTE Gas have been determined utilizing respective secured borrowing rates for first mortgage bonds with like tenors of remaining lease terms. Incremental borrowing rates for non-utility entities have been determined utilizing an implied secured borrowing rate based upon an unsecured rate for a similar tenor of remaining lease terms, which is then adjusted for the estimated impact of collateral. Certain leases of the Registrants contain escalation clauses whereby the payments are adjusted for consumer price or labor indices. DTE Energy has leases with non-index based escalation clauses for fixed dollar or percentage increases. DTE Electric has leases with non-index based escalation clauses for fixed dollar increases. DTE Energy also has leases with variable payments based upon usage of, or revenues associated with, the leased assets. DTE Electric also has leases with variable payments based upon the usage of the leased assets. Certain leases of easements and coal railcars contain provisions whereby the Registrants have the option to terminate the lease agreement by giving notice of such termination during the time frames specified in the respective lease. The Registrants have considered such provisions in the determination of the lease term when it is reasonably certain that the lease would be terminated. The Registrants have certain leases which contain purchase options. Based upon the nature of the leased property and terms of the purchase options, the Registrants have determined it is not reasonably certain that such purchase options will be utilized. Thus, the impact of the purchase options has not been included in the determination of right-of-use assets and lease liabilities for the subject leases. The Registrants have certain leases which contain renewal options. Where the renewal options were deemed reasonably certain to occur, the impacts of such options were included in the determination of the right of use assets and lease liabilities. The Registrants have agreements with lease and non-lease components, which are generally accounted for separately. Consideration in a lease is allocated between lease and non-lease components based upon the estimated relative standalone prices. The Registrants have certain coal railcar leases for which non-lease and lease components are accounted for as a single lease component, as permitted under Topic 842.
Lessor	Lessor During 2020, DTE Energy executed a sale of membership interests in the REF business accounted for as a finance lease arrangement with a term of less than 2 years, resulting in a net investment in finance leases of $8 million and selling profit of $11 million. Also in 2020, 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 a net investment of $133 million. DTE Energy leases a portion of its pipeline system to the Vector Pipeline through a finance lease contract that has been renewed through 2025, with additional renewal options reasonably certain to be exercised through 2040. DTE Energy owns a 40% interest in the Vector Pipeline. DTE Energy's net investment in finance leases relating to Vector Pipeline was $39 million at December 31, 2020, and is included in the finance leases table below. DTE Energy also leases various assets under operating leases for a pipeline, energy facilities and related equipment. Such leases are comprised of both fixed payments and variable payments which are contingent on volumes, with terms ranging from 2 to 24 years. Generally, the operating leases do not have renewal provisions or options to purchase the assets at the end of the lease. The operating leases generally do not have termination for convenience provisions. Termination may be allowed under specific circumstances stated in the lease contract, such as under an event of default. Certain of the finance and operating leases have lease terms that extend to the end of the estimated economic life of the leased assets, thereby resulting in no residual value. Any remaining residual values under the finance and operating leases are expected to be recovered through rates, renewals or new lease contracts. Residual values have been determined using the estimated economic life of the leased assets. The finance and operating leases do not contain residual value guarantees. Certain of the operating leases have both lease and non-lease components. The lease and non-lease components are allocated based upon estimated relative standalone selling prices. A lease is deemed to exist when the Registrants have provided other parties with the right to control the use of identified property, plant or equipment, as conveyed through a contract, for a certain period of time and consideration received. The right to control is deemed to occur when the Registrants have provided other parties with the right to obtain substantially all of the economic benefits of the identified assets and the right to direct the use of such assets.
Stock-Based Compensation	DTE Energy records compensation expense at fair value over the vesting period for all awards it grants.

Organization and Basis of Pre_2

Organization and Basis of Presentation (Tables)	12 Months Ended
	Dec. 31, 2020
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 December 31, 2020 and 2019. 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: December 31, 2020 December 31, 2019 SGG (a) Other Total SGG (a) Other Total (In millions) ASSETS Cash and cash equivalents $ 34 $ 20 $ 54 $ 16 $ 11 $ 27 Accounts receivable 8 28 36 8 19 27 Inventories — 107 107 — 74 74 Property, plant, and equipment, net 402 23 425 410 33 443 Goodwill 25 — 25 25 — 25 Intangible assets 527 — 527 542 — 542 Other current and long-term assets 2 33 35 2 — 2 $ 998 $ 211 $ 1,209 $ 1,003 $ 137 $ 1,140 LIABILITIES Accounts payable and accrued current liabilities $ — $ 22 $ 22 $ 2 $ 13 $ 15 Short-term borrowings — 38 38 — — — Other current and long-term liabilities 7 4 11 7 7 14 $ 7 $ 64 $ 71 $ 9 $ 20 $ 29 _____________________________________ (a) Amounts shown are 100% of SGG's assets and liabilities, of which DTE Energy owns 85% at December 31, 2020 and 2019.
Summary of Amounts For Nonconsolidated Variable Interest Entities	Amounts for DTE Energy's non-consolidated VIEs are as follows: December 31, 2020 2019 (In millions) Investments in equity method investees $ 1,507 $ 1,503 Notes receivable $ 47 $ 21 Future funding commitments $ 26 $ 63
Equity Method Investments	DTE Energy equity method investees are described below: Investments % Owned Segment 2020 2019 2020 2019 Description (In millions) Significant Equity Method Investees Gas Storage and Pipelines NEXUS Pipeline $ 1,349 $ 1,345 50% 50% 256-mile pipeline to transport Utica and Marcellus shale gas to Ohio, Michigan, and Ontario market centers. Also includes Generation Pipeline, a 25-mile pipeline located in northern Ohio Vector Pipeline 134 131 40% 40% 348-mile pipeline connecting Chicago, Michigan, and Ontario market centers Millennium Pipeline 208 209 26% 26% 263-mile pipeline serving markets in the Northeast 1,691 1,685 Other Equity Method Investees Other Segments 177 177 $ 1,868 $ 1,862 Summarized balance sheet data is as follows: December 31, 2020 2019 (In millions) Current Assets $ 351 $ 374 Non-current assets $ 5,235 $ 5,260 Current Liabilities $ 319 $ 414 Non-current liabilities $ 686 $ 698 Summarized income statement data is as follows: December 31, 2020 2019 2018 (In millions) Operating Revenues $ 1,227 $ 1,210 $ 883 Operating Expenses $ 847 $ 853 $ 622 Net Income $ 395 $ 313 $ 365

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of Other Income	The following is a summary of DTE Energy's Other income: 2020 2019 2018 (In millions) Income from REF entities $ 139 $ 130 $ 98 Equity earnings of equity method investees 132 111 132 Gains from rabbi trust securities (a) 28 37 6 Contract services 28 29 51 Allowance for equity funds used during construction 25 24 28 Gas Storage and Pipelines post-acquisition settlement 20 — — Other 16 19 18 $ 388 $ 350 $ 333 _______________________________________ (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: 2020 2019 2018 (In millions) Gains from rabbi trust securities allocated from DTE Energy (a) $ 28 $ 37 $ 6 Contract services 28 32 51 Allowance for equity funds used during construction 23 22 19 Other 8 16 7 $ 87 $ 107 $ 83 _______________________________________ (a) Losses from rabbi trust securities are recorded separately to Other expenses on the Consolidated Statements of Operations.
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes the changes in DTE Energy's Accumulated other comprehensive income (loss) by component (a) for the years ended December 31, 2020 and 2019: Net Unrealized Gain (Loss) on Derivatives Benefit Obligations (b) Foreign Currency Translation Total (In millions) Balance, December 31, 2018 $ (11) $ (102) $ (7) $ (120) Other comprehensive income (loss) before reclassifications (14) (7) 1 (20) Amounts reclassified from Accumulated other comprehensive income (loss) 2 15 — 17 Net current-period Other comprehensive income (loss) (12) 8 1 (3) Implementation of ASU 2018-02 (2) (23) — (25) Balance, December 31, 2019 $ (25) $ (117) $ (6) $ (148) Other comprehensive income (loss) before reclassifications (3) (2) 1 (4) Amounts reclassified from Accumulated other comprehensive income (loss) 5 10 — 15 Net current-period Other comprehensive income 2 8 1 11 Balance, December 31, 2020 $ (23) $ (109) $ (5) $ (137) ______________________________________ (a) All amounts are net of tax, except for Foreign currency translation. (b) The amounts reclassified from Accumulated other comprehensive income (loss) are included in the computation of the net periodic pension and other postretirement benefit costs (see Note 21 to the Consolidated Financial Statements, "Retirement Benefits and Trusteed Assets").
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 December 31, 2020. DTE Energy DTE Electric Year of origination 2020 2019 2018 and prior Total 2020 and prior (In millions) Notes receivable Internal grade 1 $ — $ 14 $ 10 $ 24 $ 14 Internal grade 2 68 43 6 117 2 Total notes receivable (a) $ 68 $ 57 $ 16 $ 141 $ 16 Net investment in leases Net investment in leases, internal grade 1 $ 6 $ — $ 39 $ 45 $ — Net investment in leases, internal grade 2 131 — 1 132 — Total net investment in leases (a) $ 137 $ — $ 40 $ 177 $ — _______________________________________ (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 Current Assets — Other and Other Assets — Other on the Consolidated Statements of Financial Position.
Schedule of Roll-Forward of Activity for Financing Receivables Credit Loss Reserves	The following table presents a roll-forward of the activity for the Registrants' financing receivables credit loss reserves as of December 31, 2020. 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 100 3 103 61 Write-offs charged against allowance (136) (4) (140) (80) Recoveries of amounts previously written off 50 — 50 30 Ending reserve balance, December 31, 2020 $ 101 $ 3 $ 104 $ 57
Schedule of Finite-Lived Intangible Assets	The Registrants have certain Intangible assets as shown below: December 31, 2020 December 31, 2019 Useful Lives Gross Carrying Value Accumulated Amortization Net Carrying Value Gross Carrying Value Accumulated Amortization Net Carrying Value (In millions) Intangible assets subject to amortization Customer relationships 25 to 40 years (a) $ 2,252 $ (121) $ 2,131 $ 2,252 $ (66) $ 2,186 Contract intangibles 6 to 26 years 289 (92) 197 268 (76) 192 2,541 (213) 2,328 2,520 (142) 2,378 DTE Electric renewable energy credits (b) 8 — 8 15 — 15 DTE Electric zonal resource credits (c) 3 — 3 — — — DTE Electric Long-term intangible assets 11 — 11 15 — 15 DTE Energy Long-term intangible assets $ 2,552 $ (213) $ 2,339 $ 2,535 $ (142) $ 2,393 ______________________________________ (a) The useful lives of the customer relationship intangible assets are based on the number of years in which the assets are expected to economically contribute to the business. The expected economic benefit incorporates existing customer contracts and expected renewal rates based on the estimated volume and production lives of gas resources in the region. (b) Renewable energy credits are charged to expense, using average cost, as the credits are consumed in the operation of the business. (c) Zonal resource credits are amortized on a straight-line basis over the period that they are in effect.
Schedule of Indefinite-Lived Intangible Assets	The Registrants have certain Intangible assets as shown below: December 31, 2020 December 31, 2019 Useful Lives Gross Carrying Value Accumulated Amortization Net Carrying Value Gross Carrying Value Accumulated Amortization Net Carrying Value (In millions) Intangible assets subject to amortization Customer relationships 25 to 40 years (a) $ 2,252 $ (121) $ 2,131 $ 2,252 $ (66) $ 2,186 Contract intangibles 6 to 26 years 289 (92) 197 268 (76) 192 2,541 (213) 2,328 2,520 (142) 2,378 DTE Electric renewable energy credits (b) 8 — 8 15 — 15 DTE Electric zonal resource credits (c) 3 — 3 — — — DTE Electric Long-term intangible assets 11 — 11 15 — 15 DTE Energy Long-term intangible assets $ 2,552 $ (213) $ 2,339 $ 2,535 $ (142) $ 2,393 ______________________________________ (a) The useful lives of the customer relationship intangible assets are based on the number of years in which the assets are expected to economically contribute to the business. The expected economic benefit incorporates existing customer contracts and expected renewal rates based on the estimated volume and production lives of gas resources in the region. (b) Renewable energy credits are charged to expense, using average cost, as the credits are consumed in the operation of the business. (c) Zonal resource credits are amortized on a straight-line basis over the period that they are in effect.
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The following table summarizes DTE Energy's estimated customer relationship and contract intangible amortization expense expected to be recognized during each year through 2025: 2021 2022 2023 2024 2025 (In millions) Estimated amortization expense $ 73 $ 73 $ 73 $ 73 $ 73
Schedule of Accounting Policies	See the following notes for other accounting policies impacting the Registrants’ Consolidated Financial Statements: Note Title 5 Revenue 7 Property, Plant, and Equipment 9 Asset Retirement Obligations 10 Regulatory Matters 11 Income Taxes 13 Fair Value 14 Financial and Other Derivative Instruments 18 Leases 21 Retirement Benefits and Trusteed Assets 22 Stock-Based Compensation

Acquisitions and Dispositions (

Acquisitions and Dispositions (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Schedule of Purchase Price Allocation	The acquisition was accounted for using the acquisition method of accounting for business combinations. Accordingly, the cost was allocated to the underlying net assets based on their respective fair values as shown below: (In millions) Contract intangibles $ 17 Property, plant, and equipment, net 76 Working capital 2 Total $ 95 The acquisition was accounted for using the acquisition method of accounting for business combinations. Accordingly, the cost was allocated to the underlying net assets based on their respective fair values as shown below: (In millions) Contract intangibles $ 109 Property, plant, and equipment, net 60 Working capital 6 Total $ 175 (In millions) Assets Cash $ 62 Accounts receivable 31 Property, plant, and equipment, net 1,034 Goodwill 173 Customer relationship intangibles 1,473 Other current assets 1 $ 2,774 Liabilities Accounts payable $ 26 Acquisition related deferred payment 380 Other current liabilities 2 Asset retirement obligations 9 $ 417 Total cash consideration $ 2,357

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following is a summary of revenues disaggregated by segment for DTE Energy: 2020 2019 2018 (In millions) Electric (a) Residential $ 2,825 $ 2,427 $ 2,494 Commercial 1,739 1,795 1,794 Industrial 592 659 690 Other (b) 364 348 320 Total Electric operating revenues (c) $ 5,520 $ 5,229 $ 5,298 Gas Gas sales $ 971 $ 1,043 $ 1,055 End User Transportation 218 219 232 Intermediate Transportation 79 78 58 Other (b) 146 142 91 Total Gas operating revenues (d) $ 1,414 $ 1,482 $ 1,436 Other segment operating revenues Gas Storage and Pipelines (e) $ 754 $ 501 $ 485 Power and Industrial Projects (f) $ 1,224 $ 1,560 $ 2,204 Energy Trading (g) $ 3,863 $ 4,610 $ 5,557 _______________________________________ (a) Revenues generally represent those of DTE Electric, except $14 million and $5 million of Other revenues related to DTE Sustainable Generation for the years ended December 31, 2020 and 2019, respectively. (b) Includes revenue adjustments related to various regulatory mechanisms. (c) Includes $26 million, $22 million, and $21 million under Alternative Revenue Programs and $22 million, $19 million, and $20 million of other revenues, which are both outside the scope of Topic 606, for the years ended December 31, 2020, 2019, and 2018, respectively. (d) Includes $10 million, $8 million, and $2 million under Alternative Revenue Programs and $8 million, $7 million, and $7 million of other revenues, which are both outside the scope of Topic 606, for the years ended December 31, 2020, 2019, and 2018, respectively. (e) Includes revenues outside the scope of Topic 606 primarily related to $9 million of contracts accounted for as leases for each of the years ended December 31, 2020 and 2019. (f) Includes revenues outside the scope of Topic 606 primarily related to $99 million, $121 million, and $125 million of contracts accounted for as leases for the years ended December 31, 2020, 2019, and 2018, respectively. (g) Includes revenues outside the scope of Topic 606 primarily related to $2.7 billion, $3.4 billion, and $4.5 billion of derivatives for the years ended December 31, 2020, 2019, and 2018, respectively.
Summary of Deferred Revenue Activity	The following is a summary of deferred revenue activity: DTE Energy (In millions) Beginning Balance, January 1, 2020 $ 75 Increases due to cash received or receivable, excluding amounts recognized as revenue during the period 55 Revenue recognized that was included in the deferred revenue balance at the beginning of the period (43) Ending Balance, December 31, 2020 $ 87
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 $ 59 2022 7 2023 3 2024 3 2025 7 2026 and thereafter 8 $ 87 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 $ 285 $ 8 2022 323 7 2023 263 7 2024 158 7 2025 113 1 2026 and thereafter 501 — $ 1,643 $ 30

Goodwill (Tables)

Goodwill (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following is the summary of change in the carrying amount of goodwill for the years ended December 31: 2020 2019 (In millions) Balance as of January 1 $ 2,464 $ 2,293 Goodwill attributable to Gas Storage and Pipelines 2019 acquisition of Blue Union and LEAP 2 171 Balance at December 31 $ 2,466 $ 2,464

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
PP&E by Classification, Summary of Depreciation and Amortization	The following is a summary of Property, plant, and equipment by classification as of December 31: 2020 2019 Property, plant, and equipment (In millions) DTE Electric Zero carbon generation Nuclear $ 3,295 $ 3,022 Renewables 1,817 1,362 Fossil and other generation 8,031 7,644 Distribution 10,354 9,715 Other 2,674 2,536 Total DTE Electric 26,171 24,279 DTE Gas Distribution 4,517 4,164 Storage 576 570 Transmission and other 1,341 1,244 Total DTE Gas 6,434 5,978 Non-utility and other Gas Storage and Pipelines 3,981 3,524 Power and Industrial Projects 1,194 1,108 Other 217 183 Non-utility and other 5,392 4,815 Total DTE Energy 37,997 35,072 Accumulated depreciation and amortization DTE Electric Zero carbon generation Nuclear (373) (344) Renewables (295) (243) Fossil and other generation (3,014) (2,873) Distribution (2,686) (2,553) Other (682) (693) Total DTE Electric (7,050) (6,706) DTE Gas Distribution (1,215) (1,334) Storage (146) (172) Transmission and other (403) (409) Total DTE Gas (1,764) (1,915) Non-utility and other Gas Storage and Pipelines (511) (459) Power and Industrial Projects (619) (604) Other (84) (71) Non-utility and other (1,214) (1,134) Total DTE Energy (10,028) (9,755) Net DTE Energy Property, plant, and equipment $ 27,969 $ 25,317 Net DTE Electric Property, plant, and equipment $ 19,121 $ 17,573 The following is a summary of Depreciation and amortization expense for DTE Energy: 2020 2019 2018 (In millions) Property, plant, and equipment $ 1,120 $ 997 $ 878 Regulatory assets and liabilities 245 227 212 Intangible assets 71 33 27 Other 7 6 7 $ 1,443 $ 1,263 $ 1,124 The following is a summary of Depreciation and amortization expense for DTE Electric: 2020 2019 2018 (In millions) Property, plant, and equipment $ 831 $ 748 $ 652 Regulatory assets and liabilities 207 193 179 Other 5 5 5 $ 1,043 $ 946 $ 836
Schedule of AFUDC and Capitalized Interest Rates	The AFUDC and capitalized interest rates were as follows for the years ended December 31: 2020 2019 2018 DTE Electric AFUDC 5.47 % 5.43 % 5.41 % DTE Gas AFUDC 5.56 % 5.56 % 5.71 % Non-regulated businesses capitalized interest 3.90 % 4.00 % 4.00 %
Schedule of AFUDC and Interest Capitalized	The following is a summary of AFUDC and interest capitalized for the years ended December 31: 2020 2019 2018 DTE Energy (In millions) Allowance for debt funds used during construction and interest capitalized $ 22 $ 15 $ 15 Allowance for equity funds used during construction 25 24 28 Total $ 47 $ 39 $ 43 2020 2019 2018 DTE Electric (In millions) Allowance for debt funds used during construction $ 10 $ 10 $ 9 Allowance for equity funds used during construction 23 22 19 Total $ 33 $ 32 $ 28
Schedule of Utility Property, Plant, and Equipment	The average estimated useful life for each major class of utility Property, plant, and equipment as of December 31, 2020 follows: Estimated Useful Lives in Years Utility Generation Distribution Storage DTE Electric 32 38 N/A DTE Gas N/A 49 58
Schedule of Capitalized Software	The following balances for capitalized software relate to DTE Energy: Year Ended December 31, 2020 2019 2018 (In millions) Amortization expense of capitalized software $ 129 $ 123 $ 108 Gross carrying value of capitalized software $ 866 $ 906 Accumulated amortization of capitalized software $ 432 $ 520 The following balances for capitalized software relate to DTE Electric: Year Ended December 31, 2020 2019 2018 (In millions) Amortization expense of capitalized software $ 118 $ 112 $ 101 Gross carrying value of capitalized software $ 756 $ 811 Accumulated amortization of capitalized software $ 363 $ 462

Jointly-Owned Utility Plant (Ta

Jointly-Owned Utility Plant (Tables)	12 Months Ended
	Dec. 31, 2020
Jointly Owned Utility Plant, Net Ownership Amount [Abstract]
Schedule of Jointly-Owned Utility Plants	DTE Electric's ownership information of the two utility plants as of December 31, 2020 was as follows: Belle River Ludington In-service date 1984-1985 1973 Total plant capacity 1,270 MW 2,220 MW Ownership interest 81% 49% Investment in Property, plant, and equipment (in millions) $ 1,932 $ 609 Accumulated depreciation (in millions) $ 945 $ 181

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2020
Asset Retirement Obligation Disclosure [Abstract]
Schedule of Change in Asset Retirement Obligations	Changes to asset retirement obligations for 2020, 2019, and 2018 were as follows: 2020 2019 2018 DTE Energy (In millions) Asset retirement obligations at January 1 $ 2,672 $ 2,469 $ 2,320 Accretion 157 149 140 Liabilities incurred 25 20 27 Liabilities settled (14) (17) (16) Revision in estimated cash flows (1) 51 (2) Asset retirement obligations at December 31 $ 2,839 $ 2,672 $ 2,469 2020 2019 2018 DTE Electric (In millions) Asset retirement obligations at January 1 $ 2,447 $ 2,271 $ 2,125 Accretion 145 138 129 Liabilities incurred 18 1 27 Liabilities settled (8) (14) (8) Revision in estimated cash flows 5 51 (2) Asset retirement obligations at December 31 $ 2,607 $ 2,447 $ 2,271

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
	Dec. 31, 2020
Regulatory Assets and Liabilities Disclosure [Abstract]
Schedule of Regulatory Assets	The following are balances and a brief description of the Registrants' Regulatory assets and liabilities at December 31: DTE Energy DTE Electric 2020 2019 2020 2019 Assets (In millions) Recoverable pension and other postretirement costs Pension $ 1,938 $ 1,983 $ 1,477 $ 1,497 Other postretirement costs 165 201 108 131 Recoverable undepreciated costs on retiring plants 664 657 664 657 Fermi 2 asset retirement obligation 645 669 645 669 Recoverable Michigan income taxes 176 189 142 152 Enhanced Tree Trimming Program deferred costs 119 43 119 43 Accrued PSCR revenue 100 3 100 3 Recoverable income taxes related to AFUDC equity 64 56 54 47 Energy Waste Reduction incentive 62 54 49 43 Deferred environmental costs 57 66 — — Unamortized loss on reacquired debt 55 56 41 40 Nuclear Performance Evaluation and Review Committee Tracker 55 48 55 48 Customer360 deferred costs 51 55 51 55 Non-service pension and other postretirement costs 21 15 — — Other recoverable income taxes 19 20 19 20 Transitional Reconciliation Mechanism 11 10 11 10 Other 55 51 28 38 4,257 4,176 3,563 3,453 Less amount included in Current Assets (129) (5) (123) (5) $ 4,128 $ 4,171 $ 3,440 $ 3,448
Schedule of Regulatory Liabilities	DTE Energy DTE Electric 2020 2019 2020 2019 Liabilities (In millions) Refundable federal income taxes $ 2,255 $ 2,359 $ 1,827 $ 1,911 Removal costs liability 831 700 410 483 Negative other postretirement offset 122 93 86 69 Non-service pension and other postretirement costs 78 46 36 21 COVID-19 voluntary refund 30 — 30 — Renewable energy 21 54 21 54 Accrued GCR refund 20 23 — — Other 45 54 40 48 3,402 3,329 2,450 2,586 Less amount included in Current Liabilities (39) (65) (18) (40) $ 3,363 $ 3,264 $ 2,432 $ 2,546

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation	The Registrants' total Income Tax Expense varied from the statutory federal income tax rate for the following reasons: 2020 2019 2018 DTE Energy (In millions) Income Before Income Taxes $ 1,538 $ 1,324 $ 1,216 Income tax expense at 21% statutory rate $ 323 $ 278 $ 255 State and local income taxes, net of federal benefit 81 48 60 Production tax credits (121) (128) (223) TCJA regulatory liability amortization (76) (38) — Net operating loss carryback (34) — — AFUDC equity (4) (4) (14) Employee Stock Ownership Plan dividends (4) (3) (3) Investment tax credits (4) (4) (4) Stock based compensation (3) (7) (3) Enactment of the Tax Cuts and Jobs Act — — 21 Noncontrolling interests 1 — 2 Depreciation 2 2 2 Other, net 6 8 5 Income Tax Expense $ 167 $ 152 $ 98 Effective income tax rate 10.9 % 11.5 % 8.1 % 2020 2019 2018 DTE Electric (In millions) Income Before Income Taxes $ 887 $ 854 $ 857 Income tax expense at 21% statutory rate $ 186 $ 179 $ 180 State and local income taxes, net of federal benefit 50 49 49 TCJA regulatory liability amortization (62) (35) — Production tax credits (55) (45) (35) Investment tax credits (4) (4) (3) AFUDC equity (4) (4) (3) Employee Stock Ownership Plan dividends (2) (2) (2) Enactment of the Tax Cuts and Jobs Act — — 7 Depreciation 2 2 2 Other, net (2) (2) (2) Income Tax Expense $ 109 $ 138 $ 193 Effective income tax rate 12.3 % 16.2 % 22.5 %
Schedule of Components of Income Tax Expense (Benefit)	Components of the Registrants' Income Tax Expense were as follows: 2020 2019 2018 DTE Energy (In millions) Current income tax expense (benefit) Federal $ (247) $ (184) $ (17) State and other income tax 7 7 1 Total current income taxes (240) (177) (16) Deferred income tax expense Federal 310 275 38 State and other income tax 97 54 76 Total deferred income taxes 407 329 114 $ 167 $ 152 $ 98 2020 2019 2018 DTE Electric (In millions) Current income tax expense Federal $ 15 $ 25 $ — State and other income tax 5 16 4 Total current income taxes 20 41 4 Deferred income tax expense Federal 30 51 131 State and other income tax 59 46 58 Total deferred income taxes 89 97 189 $ 109 $ 138 $ 193
Schedule of Deferred Tax Assets and Liabilities	The Registrants' deferred tax assets (liabilities) were comprised of the following at December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Property, plant, and equipment $ (4,032) $ (3,755) $ (3,099) $ (2,956) Regulatory assets and liabilities (108) (47) (53) 4 Tax credit carry-forwards 1,144 1,161 278 252 Pension and benefits 321 300 264 258 Federal net operating loss carry-forward 265 276 — — State and local net operating loss carry-forwards 155 117 — — Investments in equity method investees (667) (465) — — Other 141 138 85 87 (2,781) (2,275) (2,525) (2,355) Less valuation allowance (41) (40) — — Long-term deferred income tax liabilities $ (2,822) $ (2,315) $ (2,525) $ (2,355) Deferred income tax assets $ 2,241 $ 2,264 $ 883 $ 865 Deferred income tax liabilities (5,063) (4,579) (3,408) (3,220) $ (2,822) $ (2,315) $ (2,525) $ (2,355)
Schedule of Unrecognized Tax Benefits Roll Forward	A reconciliation of the beginning and ending amount of unrecognized tax benefits for the Registrants is as follows: 2020 2019 2018 DTE Energy (In millions) Balance at January 1 $ 10 $ 10 $ 10 Additions for tax positions of prior years — — — Balance at December 31 $ 10 $ 10 $ 10 2020 2019 2018 DTE Electric (In millions) Balance at January 1 $ 13 $ 13 $ 13 Additions for tax positions of prior years — — — Balance at December 31 $ 13 $ 13 $ 13

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
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 for the years ended December 31: 2020 2019 2018 (In millions, except per share amounts) Basic Earnings per Share Net Income Attributable to DTE Energy Company $ 1,368 $ 1,169 $ 1,120 Less: Allocation of earnings to net restricted stock awards (2) (2) (2) Net income available to common shareholders — basic $ 1,366 $ 1,167 $ 1,118 Average number of common shares outstanding — basic 193 185 181 Basic Earnings per Common Share $ 7.09 $ 6.32 $ 6.18 Diluted Earnings per Share Net Income Attributable to DTE Energy Company $ 1,368 $ 1,169 $ 1,120 Less: Allocation of earnings to net restricted stock awards (2) (2) (2) Net income available to common shareholders — diluted $ 1,366 $ 1,167 $ 1,118 Average number of common shares outstanding - diluted 193 185 181 Diluted Earnings per Common Share (a) $ 7.08 $ 6.31 $ 6.17 _______________________________________ (a) Equity Units excluded from the calculation of diluted EPS were approximately 10.3 million for the years ended December 31, 2020 and 2019, respectively, and 6.3 million for the year ended December 31, 2018, as the dilutive stock price threshold was not met. For more information, see Note 15 to the Consolidated Financial Statements, "Long-Term Debt."

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Assets and Liabilities 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 (a) : December 31, 2020 December 31, 2019 Level 1 Level 2 Level 3 Other (b) Netting (c) Net Balance Level 1 Level 2 Level 3 Other (b) Netting (c) Net Balance (In millions) Assets Cash equivalents (d) $ 438 $ — $ — $ — $ — $ 438 $ 15 $ — $ — $ — $ — $ 15 Nuclear decommissioning trusts Equity securities 947 — — 222 — 1,169 1,046 — — — — 1,046 Fixed income securities 102 371 — 82 — 555 160 378 — — — 538 Private equity and other — — — 104 — 104 — — — 43 — 43 Cash equivalents 27 — — — — 27 34 — — — — 34 Other investments (e) Equity securities 55 — — — — 55 140 — — — — 140 Fixed income securities 8 — — — — 8 79 — — — — 79 Cash equivalents 97 — — — — 97 4 — — — — 4 Derivative assets Commodity contracts (f) Natural gas 99 74 60 — (156) 77 205 76 74 — (266) 89 Electricity — 128 52 — (120) 60 — 223 83 — (225) 81 Environmental & Other — 150 4 — (135) 19 — 110 3 — (110) 3 Foreign currency exchange contracts — — — — — — — 1 — — — 1 Total derivative assets 99 352 116 — (411) 156 205 410 160 — (601) 174 Total $ 1,773 $ 723 $ 116 $ 408 $ (411) $ 2,609 $ 1,683 $ 788 $ 160 $ 43 $ (601) $ 2,073 Liabilities Derivative liabilities Commodity contracts (f) Natural gas $ (88) $ (59) $ (76) $ — $ 151 $ (72) $ (221) $ (41) $ (89) $ — $ 266 $ (85) Electricity — (126) (42) — 125 (43) — (231) (67) — 225 (73) Environmental & Other — (137) — — 129 (8) — (121) — — 110 (11) Foreign currency exchange contracts — (5) — — — (5) — — — — — — Total $ (88) $ (327) $ (118) $ — $ 405 $ (128) $ (221) $ (393) $ (156) $ — $ 601 $ (169) Net Assets (Liabilities) at end of period $ 1,685 $ 396 $ (2) $ 408 $ (6) $ 2,481 $ 1,462 $ 395 $ 4 $ 43 $ — $ 1,904 Assets Current $ 532 $ 260 $ 92 $ — $ (330) $ 554 $ 218 $ 320 $ 123 $ — $ (513) $ 148 Noncurrent 1,241 463 24 408 (81) 2,055 1,465 468 37 43 (88) 1,925 Total Assets $ 1,773 $ 723 $ 116 $ 408 $ (411) $ 2,609 $ 1,683 $ 788 $ 160 $ 43 $ (601) $ 2,073 Liabilities Current $ (84) $ (223) $ (79) $ — $ 318 $ (68) $ (211) $ (300) $ (85) $ — $ 513 $ (83) Noncurrent (4) (104) (39) — 87 (60) (10) (93) (71) — 88 (86) Total Liabilities $ (88) $ (327) $ (118) $ — $ 405 $ (128) $ (221) $ (393) $ (156) $ — $ 601 $ (169) Net Assets (Liabilities) at end of period $ 1,685 $ 396 $ (2) $ 408 $ (6) $ 2,481 $ 1,462 $ 395 $ 4 $ 43 $ — $ 1,904 _______________________________________ (a) See footnotes on following page. _______________________________________ (b) Amounts represent assets valued at NAV as a practical expedient for fair value. (c) 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. (d) At December 31, 2020, the $438 million consisted of $436 million and $2 million of cash equivalents included in Cash and cash equivalents and Restricted cash, respectively, on DTE Energy's Consolidated Statements of Financial Position. At December 31, 2019, the $15 million consisted of $4 million and $11 million of cash equivalents included in Cash and cash equivalents and Other investments, respectively, on DTE Energy's Consolidated Statements of Financial Position. (e) Excludes cash surrender value of life insurance investments. (f) 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: December 31, 2020 December 31, 2019 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) $ 4 $ — $ — $ — $ 4 $ 11 $ — $ — $ — $ 11 Nuclear decommissioning trusts Equity securities 947 — — 222 1,169 1,046 — — — 1,046 Fixed income securities 102 371 — 82 555 160 378 — — 538 Private equity and other — — — 104 104 — — — 43 43 Cash equivalents 27 — — — 27 34 — — — 34 Other investments Equity securities 16 — — — 16 13 — — — 13 Fixed income securities 11 — — — 11 — — — — — Derivative assets — FTRs — — 4 — 4 — — 3 — 3 Total $ 1,107 $ 371 $ 4 $ 408 $ 1,890 $ 1,264 $ 378 $ 3 $ 43 $ 1,688 Assets Current $ 4 $ — $ 4 $ — $ 8 $ 11 $ — $ 3 $ — $ 14 Noncurrent 1,103 371 — 408 1,882 1,253 378 — 43 1,674 Total Assets $ 1,107 $ 371 $ 4 $ 408 $ 1,890 $ 1,264 $ 378 $ 3 $ 43 $ 1,688 _______________________________________ (a) Amounts represent assets valued at NAV as a practical expedient for fair value. (b) At December 31, 2020, the $4 million consisted of cash equivalents included in Cash and cash equivalents on DTE Electric's Consolidated Statements of Financial Position. At December 31, 2019, the $11 million consisted of cash equivalents included in Other investments 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: Year Ended December 31, 2020 Year Ended December 31, 2019 Natural Gas Electricity Other Total Natural Gas Electricity Other Total (In millions) Net Assets (Liabilities) as of January 1 $ (15) $ 16 $ 3 $ 4 $ (49) $ (2) $ 7 $ (44) Transfers from Level 3 into Level 2 (2) — — (2) — — — — Total gains (losses) Included in earnings (75) 113 (7) 31 15 77 (1) 91 Recorded in Regulatory liabilities — — 20 20 — — 2 2 Purchases, issuances, and settlements: Settlements 76 (119) (12) (55) 19 (59) (5) (45) Net Assets (Liabilities) as of December 31 $ (16) $ 10 $ 4 $ (2) $ (15) $ 16 $ 3 $ 4 Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31 (a) $ (4) $ 70 $ (70) $ (4) $ (1) $ 59 $ (38) $ 20 Total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31 $ — $ — $ 4 $ 4 $ — $ — $ 3 $ 3 _______________________________________ (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: Year Ended December 31, 2020 2019 (In millions) Net Assets as of January 1 $ 3 $ 6 Change in fair value recorded in Regulatory liabilities 20 2 Purchases, issuances, and settlements: Settlements (19) (5) Net Assets as of December 31 $ 4 $ 3 Total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31 $ 4 $ 3
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: 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 December 31, 2019 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 74 $ (89) Discounted Cash Flow Forward basis price (per MMBtu) $ (1.78) — $ 5.78 /MMBtu $ (0.09) /MMBtu Electricity $ 83 $ (67) Discounted Cash Flow Forward basis price (per MWh) $ (10) — $ 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: December 31, 2020 December 31, 2019 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 $ 141 $ — $ — $ 141 $ 184 $ — $ — $ 184 Short-term borrowings $ 38 $ — $ 38 $ — $ 828 $ — $ 828 $ — Notes payable (b) $ 19 $ — $ — $ 19 $ 25 $ — $ — $ 25 Long-term debt (c) $ 19,439 $ 2,547 $ 18,230 $ 1,397 $ 16,606 $ 2,572 $ 14,207 $ 1,252 _______________________________________ (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: December 31, 2020 December 31, 2019 Carrying Fair Value Carrying Fair Value Amount Level 1 Level 2 Level 3 Amount Level 1 Level 2 Level 3 (In millions) Notes receivable — Other (a) $ 16 $ — $ — $ 16 $ 9 $ — $ — $ 9 Short-term borrowings — affiliates $ 101 $ — $ — $ 101 $ 97 $ — $ — $ 97 Short-term borrowings — other $ — $ — $ — $ — 354 $ — $ 354 $ — Notes payable (b) $ 17 $ — $ — $ 17 $ 21 $ — $ — $ 21 Long-term debt (c) $ 8,236 $ — $ 9,579 $ 379 $ 7,180 $ — $ 7,916 $ 173 _______________________________________ (a) Included in Current Assets — Other and 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: December 31, 2020 2019 (In millions) Fermi 2 $ 1,841 $ 1,650 Fermi 1 3 3 Low-level radioactive waste 11 8 $ 1,855 $ 1,661
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: Year Ended December 31, 2020 2019 2018 (In millions) Realized gains $ 192 $ 56 $ 65 Realized losses $ (111) $ (31) $ (42) Proceeds from sale of securities $ 2,350 $ 788 $ 1,203
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: December 31, 2020 December 31, 2019 Fair Unrealized Unrealized Losses Fair Unrealized Unrealized Losses (In millions) Equity securities $ 1,169 $ 481 $ (6) $ 1,046 $ 396 $ (39) Fixed income securities 555 20 (1) 538 24 (1) Private equity and other 104 — — 43 — — Cash equivalents 27 — — 34 — — $ 1,855 $ 501 $ (7) $ 1,661 $ 420 $ (40)
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: December 31, 2020 (In millions) Due within one year $ 51 Due after one through five years 101 Due after five through ten years 89 Due after ten years 232 $ 473
Summary of Gains (Losses) Related to the Trust	The following table summarizes DTE Energy's gains (losses) related to the trust: Year Ended December 31, 2020 2019 2018 (In millions) Gains (losses) related to equity securities $ (1) $ 27 $ (8) Gains (losses) related to fixed income securities (2) 10 (3) $ (3) $ 37 $ (11)

Financial and Other Derivativ_2

Financial and Other Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
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: December 31, 2020 December 31, 2019 Derivative Derivative Derivative Derivative (In millions) Derivatives designated as hedging instruments Foreign currency exchange contracts $ — $ (4) $ — $ — Derivatives not designated as hedging instruments Commodity contracts Natural gas $ 233 $ (223) $ 355 $ (351) Electricity 180 (168) 306 (298) Environmental & Other 154 (137) 113 (121) Foreign currency exchange contracts — (1) 1 — Total derivatives not designated as hedging instruments $ 567 $ (529) $ 775 $ (770) Current $ 446 $ (386) $ 646 $ (596) Noncurrent 121 (147) 129 (174) Total derivatives $ 567 $ (533) $ 775 $ (770) The following table presents the fair value of derivative instruments for DTE Electric: December 31, 2020 2019 (In millions) FTRs — Other current assets $ 4 $ 3 Total derivatives not designated as hedging instruments $ 4 $ 3
Offsetting Assets	The following table presents net cash collateral offsetting arrangements for DTE Energy: December 31, 2020 2019 (In millions) Cash collateral netted against Derivative assets $ (12) $ — Cash collateral netted against Derivative liabilities 6 — Cash collateral recorded in Accounts receivable (a) 14 13 Cash collateral recorded in Accounts payable (a) (1) (3) Total net cash collateral posted (received) $ 7 $ 10 _______________________________________ (a) Amounts are recorded net by counterparty. The following table presents the netting offsets of Derivative assets and liabilities for DTE Energy: December 31, 2020 December 31, 2019 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 $ 233 $ (156) $ 77 $ 355 $ (266) $ 89 Electricity 180 (120) 60 306 (225) 81 Environmental & Other 154 (135) 19 113 (110) 3 Foreign currency exchange contracts — — — 1 — 1 Total derivative assets $ 567 $ (411) $ 156 $ 775 $ (601) $ 174 Derivative liabilities Commodity contracts Natural gas $ (223) $ 151 $ (72) $ (351) $ 266 $ (85) Electricity (168) 125 (43) (298) 225 (73) Environmental & Other (137) 129 (8) (121) 110 (11) Interest rate contracts — — — — — — Foreign currency exchange contracts (5) — (5) — — — Total derivative liabilities $ (533) $ 405 $ (128) $ (770) $ 601 $ (169)
Offsetting Liabilities	The following table presents net cash collateral offsetting arrangements for DTE Energy: December 31, 2020 2019 (In millions) Cash collateral netted against Derivative assets $ (12) $ — Cash collateral netted against Derivative liabilities 6 — Cash collateral recorded in Accounts receivable (a) 14 13 Cash collateral recorded in Accounts payable (a) (1) (3) Total net cash collateral posted (received) $ 7 $ 10 _______________________________________ (a) Amounts are recorded net by counterparty. The following table presents the netting offsets of Derivative assets and liabilities for DTE Energy: December 31, 2020 December 31, 2019 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 $ 233 $ (156) $ 77 $ 355 $ (266) $ 89 Electricity 180 (120) 60 306 (225) 81 Environmental & Other 154 (135) 19 113 (110) 3 Foreign currency exchange contracts — — — 1 — 1 Total derivative assets $ 567 $ (411) $ 156 $ 775 $ (601) $ 174 Derivative liabilities Commodity contracts Natural gas $ (223) $ 151 $ (72) $ (351) $ 266 $ (85) Electricity (168) 125 (43) (298) 225 (73) Environmental & Other (137) 129 (8) (121) 110 (11) Interest rate contracts — — — — — — Foreign currency exchange contracts (5) — (5) — — — Total derivative liabilities $ (533) $ 405 $ (128) $ (770) $ 601 $ (169)
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: December 31, 2020 December 31, 2019 Derivative Assets Derivative Liabilities Derivative Assets Derivative Liabilities Current Noncurrent Current Noncurrent Current Noncurrent Current Noncurrent (In millions) Total fair value of derivatives $ 446 $ 121 $ (386) $ (147) $ 646 $ 129 $ (596) $ (174) Counterparty netting (318) (81) 318 81 (513) (88) 513 88 Collateral adjustment (12) — — 6 — — — — Total derivatives as reported $ 116 $ 40 $ (68) $ (60) $ 133 $ 41 $ (83) $ (86)
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 Years Ended December 31, 2020 2019 2018 (In millions) Commodity contracts Natural gas Operating Revenues — Non-utility operations $ (70) $ 44 $ (42) Natural gas Fuel, purchased power, gas, and other — non-utility 20 (5) (94) Electricity Operating Revenues — Non-utility operations 91 44 49 Environmental & Other Operating Revenues — Non-utility operations (118) (26) (1) Foreign currency exchange contracts Operating Revenues — Non-utility operations (6) (2) 7 Total $ (83) $ 55 $ (81)
Volume of Commodity Contracts	The following represents the cumulative gross volume of DTE Energy's derivative contracts outstanding as of December 31, 2020: Commodity Number of Units Natural gas (MMBtu) 1,757,668,006 Electricity (MWh) 29,383,355 Foreign currency exchange ($ CAD) 144,655,453 Renewable Energy Certificates (MWh) 9,221,803 Carbon emissions (Metric Ton) 12,495,202

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Long-term Debt, Unclassified [Abstract]
Schedule of Long-term Debt Instruments	DTE Energy's long-term debt outstanding and weighted average interest rates of debt outstanding at December 31 were: Interest Rate (a) Maturity Date 2020 2019 (In millions) Mortgage bonds, notes, and other DTE Energy Debt, Unsecured 2.7% 2022 — 2033 $ 8,175 $ 6,625 DTE Electric Taxable Debt, Principally Secured 3.9% 2021 — 2050 8,030 6,930 DTE Electric Tax-Exempt Revenue Bonds (b) 4.1% 2021 — 2030 278 310 DTE Gas Taxable Debt, Principally Secured 4% 2023 — 2050 1,910 1,710 18,393 15,575 Unamortized debt discount (25) (24) Unamortized debt issuance costs (104) (91) Long-term debt due within one year (462) (682) $ 17,802 $ 14,778 Junior Subordinated Debentures Subordinated Debentures 5.3% 2076 — 2080 $ 1,210 $ 1,180 Unamortized debt issuance costs (35) (34) $ 1,175 $ 1,146 _______________________________________ (a) Weighted average interest rate as of December 31, 2020. (b) DTE Electric Tax-Exempt Revenue Bonds are issued by a public body that loans the proceeds to DTE Electric on terms substantially mirroring the Revenue Bonds. DTE Electric's long-term debt outstanding and weighted average interest rates of debt outstanding at December 31 were: Interest Rate (a) Maturity Date 2020 2019 (In millions) Mortgage bonds, notes, and other Taxable Debt, Principally Secured 3.9% 2021 — 2050 $ 8,030 $ 6,930 Tax-Exempt Revenue Bonds (b) 4.1% 2021 — 2030 278 310 8,308 7,240 Unamortized debt discount (16) (15) Unamortized debt issuance costs (56) (45) Long-term debt due within one year (462) (632) $ 7,774 $ 6,548 _______________________________________ (a) Weighted average interest rate as of December 31, 2020. (b) Tax-Exempt Revenue Bonds are issued by a public body that loans the proceeds to DTE Electric on terms substantially mirroring the Revenue Bonds. Selected information about DTE Energy’s Equity Units is presented below: Issuance Date Units Issued Total Net Proceeds Total Long-Term Debt RSN Annual Interest Rate Stock Purchase Contract Annual Rate Stock Purchase Settlement Date Stock Purchase Contract Liability (a) RSN Maturity Date (In millions, except interest rates) 11/1/19 26 $ 1,268 $ 1,300 2.25% 4.0% 11/1/2022 $ 150 11/1/2025 _______________________________________
Schedule of Issued Debt	In 2020, the following debt was issued: Company Month Type Interest Rate Maturity Date Amount (In millions) DTE Electric February Mortgage Bonds (a) 2.25% 2030 $ 600 DTE Electric February Mortgage Bonds (a) 2.95% 2050 500 DTE Electric April Mortgage Bonds (b) 2.63% 2031 600 DTE Energy August Senior Notes (c) 1.05% 2025 800 DTE Gas August Mortgage Bonds (d) 2.35% 2030 125 DTE Gas August Mortgage Bonds (d) 3.20% 2050 125 DTE Energy October Junior Subordinated Debentures (e) 4.38% 2080 230 DTE Energy October Senior Notes (f) 0.55% 2022 750 $ 3,730 _______________________________________ (a) Proceeds used for the repayment of $300 million of DTE Electric's 2010 Series A 4.89% Senior Notes due 2020, repayment of short-term borrowings, capital expenditures, and for other general corporate purposes. (b) Proceeds used for the repayment of $300 million of DTE Electric's 2010 Series B 3.45% Senior Notes due 2020, repayment of $32 million of DTE Electric's 2008 Series KT Variable Rate Senior Notes due 2020, repayment of short-term borrowings, capital expenditures, and for other general corporate purposes. (c) Proceeds used for the repayment of short-term borrowings and for general corporate purposes. (d) Proceeds used for the repayment of $50 million of DTE Gas's 2008 Series I 6.36% Senior Notes due 2020 and for general corporate purposes, including capital expenditures. (e) Proceeds used for the repayment of $200 million of DTE Energy's 2012 Series C 5.25% Junior Subordinated Debentures due 2062 and for general corporate purposes.
Schedule of Debt Redeemed	In 2020, the following debt was redeemed: Company Month Type Interest Rate Maturity Date Amount (In millions) DTE Electric March Senior Notes 4.89% 2020 $ 300 DTE Electric July Senior Notes 5.63% 2020 32 DTE Electric July Senior Notes 3.45% 2020 300 DTE Gas September Senior Notes 6.36% 2020 50 DTE Energy October Junior Subordinated Debentures 5.25% 2062 200 $ 882
Schedule of Maturities of Long-term Debt	The following table shows the Registrants' scheduled debt maturities, excluding any unamortized discount on debt: 2021 2022 2023 2024 2025 2026 and Thereafter Total (In millions) DTE Energy (a) $ 462 $ 3,466 $ 1,177 $ 1,425 $ 1,220 $ 11,853 $ 19,603 DTE Electric $ 462 $ 316 $ 202 $ 400 $ 350 $ 6,578 $ 8,308 _______________________________________ (a) Amounts include DTE Electric's scheduled debt maturities.

Preferred and Preference Secu_2

Preferred and Preference Securities (Tables)	12 Months Ended
	Dec. 31, 2020
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Schedule of Preferred and Preference Securities	As of December 31, 2020, the amount of authorized and unissued stock is as follows: Company Type of Stock Par Value Shares Authorized DTE Energy Preferred $ — 5,000,000 DTE Electric Preferred $ 100 6,747,484 DTE Electric Preference $ 1 30,000,000 DTE Gas Preferred $ 1 7,000,000 DTE Gas Preference $ 1 4,000,000

Short-Term Credit Arrangement_2

Short-Term Credit Arrangements and Borrowings (Tables)	12 Months Ended
	Dec. 31, 2020
Short-term Debt [Abstract]
Schedule of Line of Credit Facilities	The availability under the facilities in place at December 31, 2020 is shown in the following table: DTE Energy DTE Electric DTE Gas Total (In millions) Unsecured letter of credit facility, expiring in February 2021 $ 150 $ — $ — $ 150 Unsecured letter of credit facility, expiring in August 2021 110 — — 110 Unsecured term loan, expiring in November 2021 — 200 — 200 Unsecured Canadian revolving credit facility, expiring May 2023 86 — — 86 Unsecured revolving credit facility, expiring April 2024 1,500 500 300 2,300 1,846 700 300 2,846 Amounts outstanding at December 31, 2020 Letters of credit 193 — — 193 Revolver borrowings 38 — — 38 231 — — 231 Net availability at December 31, 2020 $ 1,615 $ 700 $ 300 $ 2,615

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Components of Lease Cost and Other Information Related to Leases	The following is a summary of the components of lease cost for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Operating lease cost $ 39 $ 41 $ 14 $ 17 Finance lease cost: Amortization of right-of-use assets 5 4 4 4 Interest of lease liabilities — — — — Total finance lease cost 5 4 4 4 Variable lease cost 10 10 — — Short-term lease cost 12 10 6 3 $ 66 $ 65 $ 24 $ 24 The following is a summary of other information related to leases for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Supplemental Cash Flows Information Cash paid for amounts included in the measurement of these liabilities: Operating cash flows for finance leases $ 3 $ 5 $ 2 $ 5 Operating cash flows for operating leases $ 40 $ 40 $ 14 $ 16 Right-of-use assets obtained in exchange for lease obligations: Operating leases $ 18 $ 68 $ — $ 27 Finance leases $ 19 $ 8 $ 14 $ — Weighted Average Remaining Lease Term (Years) Operating leases 9.3 9.7 10.4 10.6 Finance leases 7.6 9.1 3.1 2.0 Weighted Average Discount Rate Operating leases 3.4 % 3.5 % 3.3 % 3.3 % Finance leases 2.0 % 3.1 % 1.0 % 3.1 %
Schedule of Maturities of Operating Leases	The Registrants' future minimum lease payments under leases for remaining periods as of December 31, 2020 are as follows: DTE Energy DTE Electric Operating Leases Finance Leases Operating Leases Finance Leases (In millions) 2021 $ 37 $ 8 $ 13 $ 6 2022 31 8 12 6 2023 22 8 10 6 2024 13 2 8 1 2025 8 1 6 — 2026 and thereafter 61 7 32 — Total future minimum lease payments 172 34 81 19 Imputed interest (28) (3) (14) — Lease liabilities $ 144 $ 31 $ 67 $ 19
Schedule of Maturities of Finance Leases	The Registrants' future minimum lease payments under leases for remaining periods as of December 31, 2020 are as follows: DTE Energy DTE Electric Operating Leases Finance Leases Operating Leases Finance Leases (In millions) 2021 $ 37 $ 8 $ 13 $ 6 2022 31 8 12 6 2023 22 8 10 6 2024 13 2 8 1 2025 8 1 6 — 2026 and thereafter 61 7 32 — Total future minimum lease payments 172 34 81 19 Imputed interest (28) (3) (14) — Lease liabilities $ 144 $ 31 $ 67 $ 19
Schedule of Finance Leases Reported on Consolidated Statement of Financial Position	Finance leases reported on the Consolidated Statements of Financial Position are as follows for the years ended December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Right-of-use assets, within Property, plant, and equipment, net $ 29 $ 15 $ 16 $ 7 Current lease liabilities, within Current Liabilities — Other $ 7 $ 4 $ 6 $ 3 Long-term lease liabilities $ 24 $ 11 $ 13 $ 4
Schedule of Lease Income Associated with Operating Leases	DTE Energy’s lease income associated with operating leases was as follows for the years ended December 31: 2020 2019 (In millions) Fixed payments (a) $ 66 $ 65 Variable payments (a) 124 128 $ 190 $ 193 _______________________________________ (a) Includes $108 million and $130 million of lease payments reported in Operating Revenues and $82 million and $63 million of lease payments reported in Other income on DTE Energy's Consolidated Statements of Operations as of December 31, 2020 and 2019, respectively.
Schedule of Minimum Future Rental Revenues under Operating Leases	DTE Energy’s minimum future rental revenues under operating leases for remaining periods as of December 31, 2020 are as follows: DTE Energy (In millions) 2021 $ 62 2022 22 2023 22 2024 22 2025 19 2026 and thereafter 175 $ 322
Schedule of Property under Operating Leases	The following is a summary of property under operating leases for DTE Energy as of December 31: 2020 2019 (In millions) Gross property under operating leases $ 447 $ 445 Accumulated amortization of property under operating leases $ 197 $ 173
Components of Net Investment in Finance Leases	The components of DTE Energy’s net investment in finance leases for remaining periods as of December 31, 2020 are as follows: DTE Energy (In millions) 2021 $ 24 2022 20 2023 19 2024 19 2025 19 2026 and thereafter 253 Total minimum future lease receipts 354 Residual value of leased pipeline 17 Less unearned income 193 Net investment in finance lease 178 Less current portion 9 $ 169

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Schedule of Long-term Purchase Commitments	The Registrants estimate the following commitments from 2021 through 2051 for DTE Energy, and 2021 through 2051 for DTE Electric, as detailed in the following table: DTE Energy DTE Electric (In millions) 2021 $ 2,998 $ 1,132 2022 1,142 246 2023 804 226 2024 520 159 2025 397 209 2026 and thereafter 1,634 969 $ 7,495 $ 2,941

Retirement Benefits and Trust_2

Retirement Benefits and Trusteed Assets (Tables)	12 Months Ended
	Dec. 31, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Defined Benefit Plans Disclosures	The table below represents the pension and other postretirement benefit plans of each Registrant at December 31, 2020: Registrants DTE Energy DTE Electric Qualified Pension Plans DTE Energy Company Retirement Plan X X DTE Gas Company Retirement Plan for Employees Covered by Collective Bargaining Agreements X Shenango Inc. Pension Plan (a) X Non-qualified Pension Plans DTE Energy Company Supplemental Retirement Plan (b) X X DTE Energy Company Executive Supplemental Retirement Plan (b) X X DTE Energy Company Supplemental Severance Benefit Plan X Other Postretirement Benefit Plans The DTE Energy Company Comprehensive Non-Health Welfare Plan X X The DTE Energy Company Comprehensive Retiree Group Health Care Plan X X DTE Supplemental Retiree Benefit Plan X X DTE Energy Company Retiree Reimbursement Arrangement Plan X X _____________________________________ (a) Sponsored by Shenango, LLC (b) Sponsored by DTE Energy Company
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Defined Benefit Plans Disclosures	The following table reconciles the obligations, assets, and funded status of the plans as well as the amounts recognized as prepaid pension cost or pension liability in DTE Energy's Consolidated Statements of Financial Position at December 31: DTE Energy 2020 2019 (In millions) Accumulated benefit obligation, end of year $ 5,843 $ 5,387 Change in projected benefit obligation Projected benefit obligation, beginning of year $ 5,810 $ 5,124 Service cost 99 84 Interest cost 186 219 Actuarial loss 619 719 Special termination benefits 3 — Benefits paid (353) (336) Settlements (60) — Projected benefit obligation, end of year $ 6,304 $ 5,810 Change in plan assets Plan assets at fair value, beginning of year $ 4,993 $ 4,273 Actual return on plan assets 815 888 Company contributions 102 168 Benefits paid (353) (336) Settlements (60) — Plan assets at fair value, end of year $ 5,497 $ 4,993 Funded status $ (807) $ (817) Amount recorded as: Current liabilities $ (10) $ (9) Noncurrent liabilities (797) (808) $ (807) $ (817) Amounts recognized in Accumulated other comprehensive income (loss), pre-tax Net actuarial loss $ 142 $ 153 Prior service cost 3 4 $ 145 $ 157 Amounts recognized in Regulatory assets (a) Net actuarial loss $ 1,949 $ 1,995 Prior service credit (11) (12) $ 1,938 $ 1,983 ______________________________________ (a) See Note 10 to the Consolidated Financial Statements, "Regulatory Matters." 2020 2019 2018 (In millions) DTE Energy $ 92 $ 150 $ 175 DTE Electric $ 60 $ 100 $ 175 DTE Energy's contributions of $92 million in 2020 included $82 million of common stock and $10 million of cash. Details of the contribution of common stock to the DTE Energy Company Affiliates Employee Benefit Plans Master Trust are as follows: Date Number of Shares Price per Share Amount (In millions) September 8, 2020 694,444 $118.08 $ 82
Schedule of Net Benefit Costs	Net pension cost for DTE Energy includes the following components: 2020 2019 2018 (In millions) Service cost $ 99 $ 84 $ 99 Interest cost 186 219 202 Expected return on plan assets (334) (325) (329) Amortization of: Net actuarial loss 171 131 176 Prior service cost 1 1 — Settlements 25 2 — Net pension cost $ 148 $ 112 $ 148
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	2020 2019 (In millions) Other changes in plan assets and benefit obligations recognized in Regulatory assets and Other comprehensive income (loss) Net actuarial loss $ 137 $ 156 Amortization of net actuarial loss (193) (133) Amortization of prior service cost (1) (1) Total recognized in Regulatory assets and Other comprehensive income (loss) $ (57) $ 22 Total recognized in net periodic pension cost, Regulatory assets, and Other comprehensive income (loss) $ 91 $ 134
Schedule of Expected Benefit Payments	At December 31, 2020, the benefits related to DTE Energy's qualified and non-qualified pension plans expected to be paid in each of the next five years and in the aggregate for the five fiscal years thereafter are as follows: (In millions) 2021 $ 352 2022 363 2023 368 2024 352 2025 360 2026-2030 1,757 Total $ 3,552
Schedule of Assumptions Used	Assumptions used in determining the projected benefit obligation and net pension costs of DTE Energy are: 2020 2019 2018 Projected benefit obligation Discount rate 2.57% 3.28% 4.40% Rate of compensation increase 3.80% 3.85% 3.85% Cash balance interest crediting rate 2.00% 3.30% 3.70% Net pension costs Discount rate 3.28% 4.40% 3.70% Rate of compensation increase 3.85% 3.85% 3.85% Expected long-term rate of return on plan assets 7.10% 7.30% 7.50% Cash balance interest crediting rate 3.30% 3.70% 3.70%
Schedule of Allocation of Plan Assets	Target allocations for DTE Energy's pension plan assets as of December 31, 2020 are listed below: U.S. Large Capitalization (Cap) Equity Securities 18 % U.S. Small Cap and Mid Cap Equity Securities 3 Non-U.S. Equity Securities 16 Fixed Income Securities 38 Hedge Funds and Similar Investments 14 Private Equity and Other 11 100 % The following tables provide the fair value measurement amounts for DTE Energy's pension plan assets at December 31, 2020 and 2019 (a) : December 31, 2020 December 31, 2019 Level 1 Level 2 Other (b) Total Level 1 Level 2 Other (b) Total DTE Energy asset category: (In millions) Short-term Investments (c) $ 92 $ — $ — $ 92 $ 99 $ — $ — $ 99 Equity Securities Domestic (d) 167 — 1,093 1,260 172 — 870 1,042 International (e) 100 — 791 891 387 — 322 709 Fixed Income Securities Governmental (f) 459 95 — 554 569 — — 569 Corporate (g) — 1,404 — 1,404 — 1,452 — 1,452 Hedge Funds and Similar Investments (h) 238 61 411 710 169 — 502 671 Private Equity and Other (i) — — 586 586 — — 451 451 DTE Energy Total $ 1,056 $ 1,560 $ 2,881 $ 5,497 $ 1,396 $ 1,452 $ 2,145 $ 4,993 _______________________________________ (a) For a description of levels within the fair value hierarchy, see Note 13 to the Consolidated Financial Statements, "Fair Value." (b) Amounts represent assets valued at NAV as a practical expedient for fair value. (c) This category predominantly represents certain short-term fixed income securities and money market investments that are managed in separate accounts or commingled funds. Pricing for investments in this category are obtained from quoted prices in actively traded markets. (d) This category represents portfolios of large, medium and small capitalization domestic equities. Investments in this category include exchange-traded securities for which unadjusted quoted prices can be obtained and exchange-traded securities held in a commingled fund classified as NAV assets. (e) This category primarily consists of portfolios of non-U.S. developed and emerging market equities. Investments in this category include exchange-traded securities for which unadjusted quoted prices can be obtained and exchange-traded securities held in a commingled fund classified as NAV assets. (f) This category includes U.S. Treasuries, bonds, and other governmental debt. Pricing for investments in this category is obtained from quoted prices in actively traded markets and quotations from broker or pricing services. (g) This category primarily consists of corporate bonds from diversified industries, bank loans, and mortgage backed securities. Pricing for investments in this category is obtained from quotations from broker or pricing services. (h) This category utilizes a diversified group of strategies that attempt to capture financial market inefficiencies and includes publicly traded mutual funds, commingled funds and limited partnership funds. Pricing for mutual funds in this category is obtained from quoted prices in actively traded markets. Commingled funds and limited partnership funds are classified as NAV assets. (i) This category includes a diversified group of funds and strategies that primarily invests in private equity partnerships. This category also includes investments in real estate and private debt. All pricing for investments in this category are classified as NAV assets.
Other postretirement benefit plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Schedule of Defined Benefit Plans Disclosures	The following table reconciles the obligations, assets, and funded status of the plans including amounts recorded as Accrued postretirement liability in the Registrants' Consolidated Statements of Financial Position at December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Change in accumulated postretirement benefit obligation Accumulated postretirement benefit obligation, beginning of year $ 1,751 $ 1,645 $ 1,337 $ 1,247 Service cost 26 22 20 16 Interest cost 56 70 43 53 Plan amendments — (53) — (33) Actuarial loss 54 153 31 118 Benefits paid (80) (86) (62) (64) Accumulated postretirement benefit obligation, end of year $ 1,807 $ 1,751 $ 1,369 $ 1,337 Change in plan assets Plan assets at fair value, beginning of year $ 1,819 $ 1,689 $ 1,236 $ 1,158 Actual return on plan assets 220 215 145 141 Benefits paid (79) (85) (61) (63) Plan assets at fair value, end of year $ 1,960 $ 1,819 $ 1,320 $ 1,236 Funded status $ 153 $ 68 $ (49) $ (101) Amount recorded as: (a) Noncurrent assets $ 561 $ 454 $ 335 $ 266 Current liabilities (1) (1) — — Noncurrent liabilities (407) (385) (384) (367) $ 153 $ 68 $ (49) $ (101) Amounts recognized in Accumulated other comprehensive income (loss), pre-tax Net actuarial gain $ (7) $ (8) $ — $ — $ (7) $ (8) $ — $ — Amounts recognized in Regulatory assets (b) Net actuarial loss $ 234 $ 289 $ 156 $ 193 Prior service credit (69) (88) (48) (62) $ 165 $ 201 $ 108 $ 131 ______________________________________ (a) Prior year balances for DTE Energy were recast to be consistent with the current year gross presentation of Noncurrent assets and Noncurrent liabilities. (b) See Note 10 to the Consolidated Financial Statements, "Regulatory Matters."
Schedule of Net Benefit Costs	Net other postretirement credit for DTE Energy includes the following components: 2020 2019 2018 (In millions) Service cost $ 26 $ 22 $ 27 Interest cost 56 70 69 Expected return on plan assets (128) (96) (143) Amortization of: Net actuarial loss 16 12 11 Prior service credit (19) (9) — Net other postretirement credit $ (49) $ (1) $ (36) Net other postretirement credit for DTE Electric includes the following components: 2020 2019 2018 (In millions) Service cost $ 20 $ 16 $ 20 Interest cost 43 53 53 Expected return on plan assets (87) (65) (98) Amortization of: Net actuarial loss 11 5 8 Prior service credit (14) (7) — Net other postretirement cost (credit) $ (27) $ 2 $ (17)
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	2020 2019 (In millions) Other changes in plan assets and accumulated postretirement benefit obligation recognized in Regulatory assets and Other comprehensive income (loss) Net actuarial (gain) loss $ (38) $ 34 Amortization of net actuarial loss (16) (12) Prior service credit — (53) Amortization of prior service credit 19 9 Total recognized in Regulatory assets and Other comprehensive income (loss) $ (35) $ (22) Total recognized in net periodic benefit cost, Regulatory assets, and Other comprehensive income (loss) $ (84) $ (23) 2020 2019 (In millions) Other changes in plan assets and accumulated postretirement benefit obligation recognized in Regulatory assets Net actuarial (gain) loss $ (26) $ 41 Amortization of net actuarial loss (11) (5) Prior service credit — (33) Amortization of prior service credit 14 7 Total recognized in Regulatory assets $ (23) $ 10 Total recognized in net periodic benefit cost and Regulatory assets $ (50) $ 12
Schedule of Expected Benefit Payments	At December 31, 2020, the benefits expected to be paid, including prescription drug benefits, in each of the next five years and in the aggregate for the five fiscal years thereafter for the Registrants are as follows: DTE Energy DTE Electric (In millions) 2021 $ 82 $ 62 2022 87 66 2023 91 69 2024 92 70 2025 95 72 2026-2030 497 376 Total $ 944 $ 715
Schedule of Assumptions Used	Assumptions used in determining the accumulated postretirement benefit obligation and net other postretirement benefit costs of the Registrants are: 2020 2019 2018 Accumulated postretirement benefit obligation Discount rate 2.58% 3.29% 4.40% Health care trend rate pre- and post- 65 6.75 / 7.25% 6.75 / 7.25% 6.75 / 7.25% Ultimate health care trend rate 4.50% 4.50% 4.50% Year in which ultimate reached pre- and post- 65 2033 2032 2031 Other postretirement benefit costs Discount rate 3.29% 4.40% 3.70% Expected long-term rate of return on plan assets 7.20% 7.30% 7.75% Health care trend rate pre- and post- 65 6.75 / 7.25% 6.75 / 7.25% 6.75 / 7.25% Ultimate health care trend rate 4.50% 4.50% 4.50% Year in which ultimate reached pre- and post- 65 2032 2031 2030
Schedule of Allocation of Plan Assets	Target allocations for the Registrants' other postretirement benefit plan assets as of December 31, 2020 are listed below: U.S. Large Cap Equity Securities 11 % U.S. Small Cap and Mid Cap Equity Securities 2 Non-U.S. Equity Securities 10 Fixed Income Securities 52 Hedge Funds and Similar Investments 11 Private Equity and Other 14 100 % The following tables provide the fair value measurement amounts for the Registrants' other postretirement benefit plan assets at December 31, 2020 and 2019 (a) : December 31, 2020 December 31, 2019 Level 1 Level 2 Other (b) Total Level 1 Level 2 Other (b) Total (In millions) DTE Energy asset category: Short-term Investments (c) $ 21 $ — $ — $ 21 $ 80 $ — $ — $ 80 Equity Securities Domestic (d) 51 — 200 251 51 — 273 324 International (e) 23 — 178 201 182 — 89 271 Fixed Income Securities Governmental (f) 40 45 — 85 74 — — 74 Corporate (g) — 477 379 856 — 256 251 507 Hedge Funds and Similar Investments (h) 61 17 124 202 71 — 182 253 Private Equity and Other (i) — — 344 344 — — 310 310 DTE Energy Total $ 196 $ 539 $ 1,225 $ 1,960 $ 458 $ 256 $ 1,105 $ 1,819 DTE Electric asset category: Short-term Investments (c) $ 14 $ — $ — $ 14 $ 55 $ — $ — $ 55 Equity Securities Domestic (d) 33 — 131 164 34 — 185 219 International (e) 16 — 117 133 124 — 60 184 Fixed Income Securities Governmental (f) 24 31 — 55 48 — — 48 Corporate (g) — 321 263 584 — 168 176 344 Hedge Funds and Similar Investments (h) 41 11 83 135 49 — 123 172 Private Equity and Other (i) — — 235 235 — — 214 214 DTE Electric Total $ 128 $ 363 $ 829 $ 1,320 $ 310 $ 168 $ 758 $ 1,236 _______________________________________ (a) For a description of levels within the fair value hierarchy see Note 13 to the Consolidated Financial Statements, "Fair Value." (b) Amounts represent assets valued at NAV as a practical expedient for fair value. (c) This category predominantly represents certain short-term fixed income securities and money market investments that are managed in separate accounts or commingled funds. Pricing for investments in this category are obtained from quoted prices in actively traded markets. (d) This category represents portfolios of large, medium and small capitalization domestic equities. Investments in this category include exchange-traded securities for which unadjusted quoted prices can be obtained and exchange-traded securities held in a commingled fund classified as NAV assets. (e) This category primarily consists of portfolios of non-U.S. developed and emerging market equities. Investments in this category include exchange-traded securities for which unadjusted quoted prices can be obtained and exchange-traded securities held in a commingled fund classified as NAV assets. (f) This category includes U.S. Treasuries, bonds and other governmental debt. Pricing for investments in this category is obtained from quoted prices in actively traded markets and quotations from broker or pricing services. (g) This category primarily consists of corporate bonds from diversified industries, bank loans, and mortgage backed securities. Pricing for investments in this category is obtained from quotations from broker or pricing services. Non-exchange traded securities and exchange-traded securities held in commingled funds are classified as NAV assets. (h) This category utilizes a diversified group of strategies that attempt to capture financial market inefficiencies and includes publicly traded mutual funds, commingled funds and limited partnership funds. Pricing for mutual funds in this category is obtained from quoted prices in actively traded markets. Commingled funds and limited partnership funds are classified as NAV assets. (i) This category includes a diversified group of funds and strategies that primarily invests in private equity partnerships. This category also includes investments in real estate and private debt. All investments in this category are classified as NAV assets.
Schedule of Accumulated Benefit Obligations in Excess of Plan Assets	The following table reflects other postretirement benefit plans with accumulated postretirement benefit obligations in excess of plan assets as of December 31: DTE Energy DTE Electric 2020 2019 2020 2019 (In millions) Accumulated postretirement benefit obligation $ 878 $ 840 $ 826 $ 795 Fair value of plan assets 470 454 442 428 Accumulated postretirement benefit obligation in excess of plan assets $ 408 $ 386 $ 384 $ 367

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement, Noncash Expense [Abstract]
Schedule of Components of Stock-Based Compensation	The following table summarizes the components of stock-based compensation for DTE Energy: 2020 2019 2018 (In millions) Stock-based compensation expense $ 63 $ 71 $ 64 Tax benefit $ 12 $ 13 $ 13 Stock-based compensation cost capitalized in Property, plant, and equipment (a) $ — $ 16 $ 11 _______________________________________ (a) In DTE Electric's May 2020 rate order, the MPSC disallowed certain capital expenditures related to incentive compensation. Therefore, beginning in 2020, no stock-based compensation cost will be capitalized in Property, plant, and equipment. Refer to Note 10 to the Consolidated Financial Statements, "Regulatory Matters," for further information.
Schedule of Activity Relating to Performance Share Awards	DTE Energy recorded activity relating to performance share awards as follows: 2020 2019 2018 (In millions, except per share amounts) Weighted average grant date fair value of awards granted (per share) $ 129.68 $ 115.85 $ 105.64 Awards settled in cash (a) $ 21 $ 19 $ 13 Awards settled in stock (a) $ 53 $ 79 $ 39 Compensation expense $ 50 $ 60 $ 53 _______________________________________ (a) Sum of awards settled in cash and stock approximates the intrinsic value of the awards.
Schedule of Stock-based Compensation, Performance Shares Activity Rollforward	The following table summarizes DTE Energy’s performance share activity for the period ended December 31, 2020: Performance Shares Weighted Average Balance at December 31, 2019 1,226,031 $ 107.35 Grants 383,813 $ 129.68 Forfeitures (43,768) $ 116.94 Payouts (438,639) $ 99.22 Balance at December 31, 2020 1,127,437 $ 117.06
Schedule of Unrecognized Compensation Cost, Non-Vested Awards	As of December 31, 2020, DTE Energy's total unrecognized compensation cost related to non-vested stock incentive plan arrangements and the weighted average recognition period was as follows: Unrecognized Weighted Average (In millions) (In years) Stock awards $ 19 1.60 Performance shares 49 1.04 $ 68 1.19

Segment and Related Informati_2

Segment and Related Information (Tables)	12 Months Ended
	Dec. 31, 2020
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: Year Ended December 31, 2020 2019 2018 (In millions) Electric (a) $ 61 $ 56 $ 52 Gas 16 12 12 Gas Storage and Pipelines 26 27 36 Power and Industrial Projects 464 596 642 Energy Trading 31 22 27 Corporate and Other 2 2 2 $ 600 $ 715 $ 771 _______________________________________ (a) Inter-segment billing for the Electric segment includes $2 million relating to Non-utility operations for the year ended December 31, 2020. Financial data of DTE Energy's business segments follows: Electric Gas Gas Storage and Pipelines Power and Industrial Projects Energy Trading Corporate and Other Reclassifications Total (In millions) 2020 Operating Revenues — Utility operations $ 5,506 1,414 — — — — (75) $ 6,845 Operating Revenues — Non-utility operations $ 14 — 754 1,224 3,863 2 (525) $ 5,332 Depreciation and amortization $ 1,057 157 151 72 5 1 — $ 1,443 Interest expense $ 337 80 113 37 6 331 (184) $ 720 Interest income $ (4) (5) (9) (22) (2) (180) 184 $ (38) Equity in earnings of equity method investees $ — 1 106 17 — 8 — $ 132 Income Tax Expense (Benefit) $ 108 48 116 (40) 12 (77) — $ 167 Net Income (Loss) Attributable to DTE Energy Company $ 777 186 315 134 36 (80) — $ 1,368 Investment in equity method investees $ 6 12 1,691 125 — 34 — $ 1,868 Capital expenditures and acquisitions $ 2,701 574 517 186 5 — — $ 3,983 Goodwill $ 1,208 743 472 26 17 — — $ 2,466 Total Assets $ 26,588 6,339 5,068 696 807 8,071 (2,073) $ 45,496 Electric Gas Gas Storage and Pipelines Power and Industrial Projects Energy Trading Corporate and Other Reclassifications Total (In millions) 2019 Operating Revenues — Utility operations $ 5,224 1,482 — — — — (68) $ 6,638 Operating Revenues — Non-utility operations $ 5 — 501 1,560 4,610 2 (647) $ 6,031 Depreciation and amortization $ 949 144 94 69 6 1 — $ 1,263 Interest expense $ 315 78 73 33 8 266 (132) $ 641 Interest income $ (2) (6) (8) (9) (4) (120) 132 $ (17) Equity in earnings of equity method investees $ 1 2 97 14 — (3) — $ 111 Income Tax Expense (Benefit) $ 137 62 74 (63) 17 (75) — $ 152 Net Income (Loss) Attributable to DTE Energy Company $ 714 185 204 133 49 (116) — $ 1,169 Investment in equity method investees $ 5 11 1,685 130 — 31 — $ 1,862 Capital expenditures and acquisitions $ 2,368 530 2,510 54 5 — — $ 5,467 Goodwill $ 1,208 743 470 26 17 — — $ 2,464 Total Assets $ 24,617 5,717 4,832 537 798 7,610 (1,843) $ 42,268 Electric Gas Gas Storage and Pipelines Power and Industrial Projects Energy Trading Corporate and Other Reclassifications Total (In millions) 2018 Operating Revenues — Utility operations $ 5,298 1,436 — — — — (64) $ 6,670 Operating Revenues — Non-utility operations $ — — 485 2,204 5,557 3 (707) $ 7,542 Depreciation and amortization $ 836 133 82 67 5 1 — $ 1,124 Interest expense $ 283 70 68 31 6 220 (119) $ 559 Interest income $ — (6) (9) (9) (3) (104) 119 $ (12) Equity in earnings of equity method investees $ — 2 123 3 — 4 — $ 132 Income Tax Expense (Benefit) $ 193 67 68 (195) 13 (48) — $ 98 Net Income (Loss) Attributable to DTE Energy Company $ 664 150 235 161 39 (129) — $ 1,120 Investment in equity method investees $ 7 12 1,585 134 — 33 — $ 1,771 Capital expenditures and acquisitions $ 1,979 460 176 91 5 2 — $ 2,713 Goodwill $ 1,208 743 299 26 17 — — $ 2,293 Total Assets $ 22,501 5,378 3,161 495 909 6,153 (2,309) $ 36,288

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Summary of Related Party Transactions	The following table summarizes the amounts resulting from these transactions included in the Consolidated Statements of Operations for the years ended December 31: 2020 2019 2018 (In millions) Operating Revenues — Utility operations DTE Gas $ 32 $ 32 $ 6 Fuel, purchased power, and gas — utility DTE Electric $ 8 $ 8 $ 1 DTE Gas $ 21 $ 22 $ 1 Fuel, purchased power, gas, and other — non-utility DTE Energy Trading $ 27 $ 13 $ 1 The following is a summary of DTE Electric's transactions with affiliated companies: 2020 2019 2018 (In millions) Revenues and Other Income Energy sales $ 8 $ 10 $ 9 Other services $ 2 $ 5 $ 4 Shared capital assets $ 51 $ 47 $ 43 Costs Fuel and purchased power $ 16 $ 9 $ 7 Other services and interest $ 1 $ 23 $ 33 Corporate expenses $ 367 $ 372 $ 377 Other Dividends declared $ 539 $ 494 $ 461 Dividends paid $ 539 $ 494 $ 461 Capital contribution from DTE Energy $ 636 $ 180 $ 325 See the following notes for other related party transactions impacting DTE Electric’s Consolidated Financial Statements: Note Title 1 Organization and Basis of Presentation 21 Retirement Benefits and Trusteed Assets 22 Stock-Based Compensation

Supplementary Quarterly Finan_2

Supplementary Quarterly Financial Information (Unaudited ) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	DTE Energy The sum of quarterly earnings per share may not equal year-end amounts, since quarterly computations are based on weighted average common shares outstanding during each quarter. First Second Third Fourth Year (In millions, except per share amounts) 2020 Operating Revenues $ 3,022 $ 2,583 $ 3,284 $ 3,288 $ 12,177 Operating Income $ 546 $ 367 $ 608 $ 465 $ 1,986 Net Income Attributable to DTE Energy Company $ 340 $ 277 $ 476 $ 275 $ 1,368 Basic Earnings per Share $ 1.77 $ 1.44 $ 2.47 $ 1.42 $ 7.09 Diluted Earnings per Share $ 1.76 $ 1.44 $ 2.46 $ 1.42 $ 7.08 2019 Operating Revenues $ 3,514 $ 2,888 $ 3,119 $ 3,148 $ 12,669 Operating Income $ 542 $ 300 $ 450 $ 415 $ 1,707 Net Income Attributable to DTE Energy Company $ 401 $ 182 $ 319 $ 267 $ 1,169 Basic Earnings per Share $ 2.20 $ 0.99 $ 1.74 $ 1.40 $ 6.32 Diluted Earnings per Share $ 2.19 $ 0.99 $ 1.73 $ 1.40 $ 6.31 DTE Electric First Second Third Fourth Year (In millions) 2020 Operating Revenues $ 1,212 $ 1,309 $ 1,690 $ 1,295 $ 5,506 Operating Income $ 214 $ 263 $ 541 $ 206 $ 1,224 Net Income $ 94 $ 183 $ 400 $ 101 $ 778 2019 Operating Revenues $ 1,235 $ 1,190 $ 1,519 $ 1,280 $ 5,224 Operating Income $ 226 $ 223 $ 440 $ 224 $ 1,113 Net Income $ 147 $ 133 $ 307 $ 129 $ 716

Organization and Basis of Pre_3

Organization and Basis of Presentation (Details Textuals) customer in Millions, $ in Millions	Dec. 31, 2020USD ($)customer	Dec. 31, 2019USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of electric utility customers | customer	2.2
Number of gas utility customers | customer	1.3
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Material potential exposure	$ 0
Amount in excess of carrying amount	80	$ 74
Undistributed earnings from equity method investees	109	$ 129
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%
SGG | Midstream Natural Gas Assets
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Percentage of voting interests acquired	85.00%

Organization and Basis of Pre_4

Organization and Basis of Presentation (Consolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	8 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
ASSETS
Cash and cash equivalents	$ 93	$ 514	$ 93
Accounts receivable	1,642	1,665	1,642
Property, plant, and equipment, net	25,317	27,969	25,317
Goodwill	2,464	2,466	2,464	$ 2,293
Intangible assets	2,378	2,328	2,378
Total Assets	42,268	45,496	42,268	$ 36,288
LIABILITIES
Short-term borrowings	828	38	828
Total
ASSETS
Cash and cash equivalents	27	54	27
Accounts receivable	27	36	27
Inventories	74	107	74
Property, plant, and equipment, net	443	425	443
Goodwill	25	25	25
Intangible assets	542	527	542
Other current and long-term assets	2	35	2
Total Assets	1,140	1,209	1,140
LIABILITIES
Accounts payable and accrued current liabilities	15	22	15
Short-term borrowings	0	38	0
Other current and long-term liabilities	14	11	14
Total liabilities	29	71	29
SGG
ASSETS
Cash and cash equivalents	16	34	16
Accounts receivable	8	8	8
Inventories	0	0	0
Property, plant, and equipment, net	410	402	410
Goodwill	25	25	25
Intangible assets	542	527	542
Other current and long-term assets	2	2	2
Total Assets	1,003	998	1,003
LIABILITIES
Accounts payable and accrued current liabilities	2	0	2
Short-term borrowings	0	0	0
Other current and long-term liabilities	7	7	7
Total liabilities	$ 9	$ 7	$ 9
VIE ownership and non-ownership percentage		100.00%	100.00%
VIE ownership percentage	85.00%	85.00%
Other
ASSETS
Cash and cash equivalents	$ 11	$ 20	$ 11
Accounts receivable	19	28	19
Inventories	74	107	74
Property, plant, and equipment, net	33	23	33
Goodwill	0	0	0
Intangible assets	0	0	0
Other current and long-term assets	0	33	0
Total Assets	137	211	137
LIABILITIES
Accounts payable and accrued current liabilities	13	22	13
Short-term borrowings	0	38	0
Other current and long-term liabilities	7	4	7
Total liabilities	$ 20	$ 64	$ 20

Organization and Basis of Pre_5

Organization and Basis of Presentation (Non-Consolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Variable Interest Entity [Line Items]
Investments in equity method investees	$ 1,868	$ 1,862	$ 1,771
Notes receivable	280	202
Variable interest entity, nonconsolidated
Variable Interest Entity [Line Items]
Investments in equity method investees	1,507	1,503
Notes receivable	47	21
Future funding commitments	$ 26	$ 63

Organization and Basis of Pre_6

Organization and Basis of Presentation (Equity Method Investees) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Investments	$ 1,868	$ 1,862	$ 1,771
NEXUS Pipeline
Schedule of Equity Method Investments [Line Items]
% Owned	50.00%
Gas Storage and Pipelines
Schedule of Equity Method Investments [Line Items]
Investments	$ 1,691	1,685
Gas Storage and Pipelines | NEXUS Pipeline
Schedule of Equity Method Investments [Line Items]
Investments	$ 1,349	$ 1,345
% Owned	50.00%	50.00%
Gas Storage and Pipelines | Vector Pipeline
Schedule of Equity Method Investments [Line Items]
Investments	$ 134	$ 131
% Owned	40.00%	40.00%
Gas Storage and Pipelines | Millennium Pipeline
Schedule of Equity Method Investments [Line Items]
Investments	$ 208	$ 209
% Owned	26.00%	26.00%
Other Segments
Schedule of Equity Method Investments [Line Items]
Investments	$ 177	$ 177

Organization and Basis of Pre_7

Organization and Basis of Presentation (Summarized Balance Sheet Data) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Current Assets	$ 3,498	$ 3,086
Current Liabilities	2,691	3,997
Equity method investment, nonconsolidated investee or group of investees
Schedule of Equity Method Investments [Line Items]
Current Assets	351	374
Non-current assets	5,235	5,260
Current Liabilities	319	414
Non-current liabilities	$ 686	$ 698

Organization and Basis of Pre_8

Organization and Basis of Presentation (Summarized Income Statement Data) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Operating Revenues	$ 3,288	$ 3,284	$ 2,583	$ 3,022	$ 3,148	$ 3,119	$ 2,888	$ 3,514	$ 12,177	$ 12,669	$ 14,212
Operating Expenses									10,191	10,962	12,618
Net Income									1,371	1,172	1,118
Equity method investment, nonconsolidated investee or group of investees
Schedule of Equity Method Investments [Line Items]
Operating Revenues									1,227	1,210	883
Operating Expenses									847	853	622
Net Income									$ 395	$ 313	$ 365

Significant Accounting Polici_4

Significant Accounting Policies (Schedule of Other Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Other Nonoperating Income, by Component [Line Items]
Income from REF entities	$ 139	$ 130	$ 98
Equity in earnings of equity method investees	132	111	132
Gains from rabbi trust securities	28	37	6
Contract services	28	29	51
Allowance for equity funds used during construction	25	24	28
Gas Storage and Pipelines post-acquisition settlement	20	0	0
Other	16	19	18
Other income	388	350	333
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Gains from rabbi trust securities	28	37	6
Contract services	28	32	51
Allowance for equity funds used during construction	23	22	19
Other	8	16	7
Other income	$ 87	$ 107	$ 83

Significant Accounting Polici_5

Significant Accounting Policies (Details Textuals) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Significant Accounting Policies [Line Items]
Reclassification of stranded tax effects resulting from the TCJA		$ 0
Unbilled revenues	$ 1,665,000,000	1,642,000,000
Specific review of probable future collections based on receivable balances, threshold duration	30 days
Uncollectible expense adjusted for regulatory deferrals	$ 103,000,000	111,000,000	$ 140,000,000
Past due financing receivables	0
Intangible assets amortization expense	71,000,000	33,000,000	27,000,000
Excise and sales taxes net impact on statement of operations	0
Charitable contributions	20,000,000	0	22,000,000
Retained Earnings
Significant Accounting Policies [Line Items]
Reclassification of stranded tax effects resulting from the TCJA		25,000,000
Accumulated Other Comprehensive Income (Loss)
Significant Accounting Policies [Line Items]
Reclassification of stranded tax effects resulting from the TCJA		(25,000,000)
Natural gas inventory
Significant Accounting Policies [Line Items]
LIFO inventory amount	40,000,000	40,000,000
Excess of replacement costs over stated LIFO value	$ 62,000,000	49,000,000
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]
Unbilled revenues	$ 763,000,000	729,000,000
Uncollectible expense adjusted for regulatory deferrals	62,000,000	65,000,000	$ 85,000,000
DTE Gas | COVID-19 Pandemic
Significant Accounting Policies [Line Items]
Uncollectible expense deferred as a Regulatory asset	2,000,000
Unbilled revenues
Significant Accounting Policies [Line Items]
Unbilled revenues	944,000,000	855,000,000
Unbilled revenues | DTE Electric
Significant Accounting Policies [Line Items]
Unbilled revenues	$ 260,000,000	$ 263,000,000

Significant Accounting Polici_6

Significant Accounting Policies (Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 11,836	$ 10,717	$ 9,990
Other comprehensive income (loss)	11	(3)	5
Implementation of ASU 2018-02		0
Ending balance	12,589	11,836	10,717
AOCI including portion attributable to noncontrolling interest
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(148)	(120)
Other comprehensive income (loss) before reclassifications	(4)	(20)
Amounts reclassified from Accumulated other comprehensive income (loss)	15	17
Other comprehensive income (loss)	11	(3)
Implementation of ASU 2018-02		(25)
Ending balance	(137)	(148)	(120)
Net Unrealized Gain (Loss) on Derivatives
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance		(11)
Ending balance			(11)
Net Unrealized Gain (Loss) on Derivatives
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(25)
Other comprehensive income (loss) before reclassifications	(3)	(14)
Amounts reclassified from Accumulated other comprehensive income (loss)	5	2
Other comprehensive income (loss)	2	(12)
Implementation of ASU 2018-02		(2)
Ending balance	(23)	(25)
Benefit Obligations
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(117)	(102)
Other comprehensive income (loss) before reclassifications	(2)	(7)
Amounts reclassified from Accumulated other comprehensive income (loss)	10	15
Other comprehensive income (loss)	8	8
Implementation of ASU 2018-02		(23)
Ending balance	(109)	(117)	(102)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(6)	(7)
Other comprehensive income (loss) before reclassifications	1	1
Amounts reclassified from Accumulated other comprehensive income (loss)	0	0
Other comprehensive income (loss)	1	1
Implementation of ASU 2018-02		0
Ending balance	$ (5)	$ (6)	$ (7)

Significant Accounting Polici_7

Significant Accounting Policies (Financing Receivables Classified by Internal Grade of Credit Risk) (Details) $ in Millions	Dec. 31, 2020USD ($)
Notes receivable
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 68
2019	57
2018 and prior	16
Total	141
Notes receivable | DTE Electric
Financing Receivable, Credit Quality Indicator [Line Items]
Total	16
Notes receivable | Internal grade 1
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	14
2018 and prior	10
Total	24
Notes receivable | Internal grade 1 | DTE Electric
Financing Receivable, Credit Quality Indicator [Line Items]
Total	14
Notes receivable | Internal grade 2
Financing Receivable, Credit Quality Indicator [Line Items]
2020	68
2019	43
2018 and prior	6
Total	117
Notes receivable | Internal grade 2 | DTE Electric
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2
Net investment in leases
Financing Receivable, Credit Quality Indicator [Line Items]
2020	137
2019	0
2018 and prior	40
Total	177
Net investment in leases | DTE Electric
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0
Net investment in leases | Internal grade 1
Financing Receivable, Credit Quality Indicator [Line Items]
2020	6
2019	0
2018 and prior	39
Total	45
Net investment in leases | Internal grade 1 | DTE Electric
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0
Net investment in leases | Internal grade 2
Financing Receivable, Credit Quality Indicator [Line Items]
2020	131
2019	0
2018 and prior	1
Total	132
Net investment in leases | Internal grade 2 | DTE Electric
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) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 91
Current period provision	103
Write-offs charged against allowance	(140)
Recoveries of amounts previously written off	50
Ending balance	104
DTE Electric
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	46
Current period provision	61
Write-offs charged against allowance	(80)
Recoveries of amounts previously written off	30
Ending balance	57
Trade accounts receivable
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	87
Current period provision	100
Write-offs charged against allowance	(136)
Recoveries of amounts previously written off	50
Ending balance	101
Other receivables
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	4
Current period provision	3
Write-offs charged against allowance	(4)
Recoveries of amounts previously written off	0
Ending balance	$ 3

Significant Accounting Polici_9

Significant Accounting Policies (Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying value	$ 2,541	$ 2,520
Accumulated Amortization	(213)	(142)
Finite-lived intangible assets, net carrying value	2,328	2,378
Intangible assets, gross carrying value	2,552	2,535
Intangible assets, net carrying value	2,339	2,393
DTE Electric
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net carrying value	11	15
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	11	15
DTE Electric renewable energy credits | DTE Electric
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	8	15
DTE Electric zonal resource credits | DTE Electric
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	3	0
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying value	2,252	2,252
Accumulated Amortization	(121)	(66)
Finite-lived intangible assets, net carrying value	$ 2,131	2,186
Customer relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful Lives	25 years
Customer relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful Lives	40 years
Contract intangibles
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross carrying value	$ 289	268
Accumulated Amortization	(92)	(76)
Finite-lived intangible assets, net carrying value	$ 197	$ 192
Contract intangibles | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful Lives	6 years
Contract intangibles | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful Lives	26 years

Significant Accounting Polic_10

Significant Accounting Policies (Future Amortization Expense Intangible Assets) (Details) $ in Millions	Dec. 31, 2020USD ($)
Estimated amortization expense
2021	$ 73
2022	73
2023	73
2024	73
2025	$ 73

Acquisitions and Dispositions_2

Acquisitions and Dispositions (Details Textuals) $ in Millions	Jul. 27, 2020USD ($)installment	Feb. 18, 2020USD ($)MW	Dec. 04, 2019USD ($)	Sep. 12, 2019USD ($)MW	Jan. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Business Acquisition [Line Items]
Operating Revenues — Non-utility operations							$ 5,332	$ 6,031	$ 7,542
Net Income							$ 1,371	1,172	$ 1,118
Contract intangibles | Minimum
Business Acquisition [Line Items]
Intangible assets, amortization period							6 years
Contract intangibles | Maximum
Business Acquisition [Line Items]
Intangible assets, amortization period							26 years
Customer relationships | Minimum
Business Acquisition [Line Items]
Intangible assets, amortization period							25 years
Customer relationships | Maximum
Business Acquisition [Line Items]
Intangible assets, amortization period							40 years
South Jersey Industries, Combined Heat and Power Generation Facility | Power and Industrial Projects
Business Acquisition [Line Items]
Amount of power associated with purchase of renewable energy project | MW		8
Consideration paid for entity acquired, paid in cash		$ 95
South Jersey Industries, Combined Heat and Power Generation Facility | Power and Industrial Projects | Contract intangibles
Business Acquisition [Line Items]
Intangible assets, amortization period		13 years
Intangible assets recorded as a result of acquisition		$ 17
Heritage Sustainable Energy, Renewable Energy Project | Electric | DTE Sustainable Generation
Business Acquisition [Line Items]
Amount of power associated with purchase of renewable energy project | MW				89
Consideration paid for entity acquired, paid in cash				$ 175
Heritage Sustainable Energy, Renewable Energy Project | Electric | DTE Sustainable Generation | Contract intangibles
Business Acquisition [Line Items]
Intangible assets recorded as a result of acquisition				$ 109
Heritage Sustainable Energy, Renewable Energy Project | Electric | DTE Sustainable Generation | Contract intangibles | Minimum
Business Acquisition [Line Items]
Intangible assets, amortization period				11 years
Heritage Sustainable Energy, Renewable Energy Project | Electric | DTE Sustainable Generation | Contract intangibles | Maximum
Business Acquisition [Line Items]
Intangible assets, amortization period				13 years
Heritage Sustainable Energy, Additional Renewable Energy Project | Electric | DTE Sustainable Generation
Business Acquisition [Line Items]
Consideration paid for entity acquired, paid in cash					$ 33
Blue Union and LEAP | Gas Storage and Pipelines
Business Acquisition [Line Items]
Consideration paid for entity acquired, paid in cash			$ 2,360
Percent of assets acquired			100.00%
Total consideration provided for acquired entity			$ 2,740
Contingent consideration to be paid upon completion			$ 380
Accretion expense related to liability for contingent consideration payment						$ 1	$ 5
Payment of consideration upon achievement of final milestone	$ 385
Number of equal payment installments made upon achievement of final milestone | installment	2
Goodwill, working capital adjustments							$ 2
Direct transaction costs incurred						18		18
Issuance costs related to acquisition financing						49		49
Operating Revenues — Non-utility operations						15
Net Income						3
Blue Union and LEAP | Gas Storage and Pipelines | Mortgage bonds, notes, and other
Business Acquisition [Line Items]
Issuance costs related to acquisition financing						10		10
Blue Union and LEAP | Gas Storage and Pipelines | Common Stock
Business Acquisition [Line Items]
Issuance costs related to acquisition financing						$ 39		$ 39
Blue Union and LEAP | Gas Storage and Pipelines | Customer relationships
Business Acquisition [Line Items]
Intangible assets, amortization period			40 years
Intangible assets recorded as a result of acquisition			$ 1,473
Existing intangible asset weighted-average amortization life			13 years

Acquisitions and Dispositions_3

Acquisitions and Dispositions (Purchase Price Allocation - Power and Industrial Segment Acquisition) (Details) - South Jersey Industries, Combined Heat and Power Generation Facility - Power and Industrial Projects $ in Millions	Feb. 18, 2020USD ($)
Business Acquisition [Line Items]
Property, plant, and equipment, net	$ 76
Working capital	2
Total	95
Contract intangibles
Business Acquisition [Line Items]
Contract intangibles	$ 17

Acquisitions and Dispositions_4

Acquisitions and Dispositions (Purchase Price Allocation - Electric Segment Acquisition) (Details) - DTE Sustainable Generation - Electric - Heritage Sustainable Energy, Renewable Energy Project $ in Millions	Sep. 12, 2019USD ($)
Business Acquisition [Line Items]
Property, plant, and equipment, net	$ 60
Working capital	6
Total	175
Contract intangibles
Business Acquisition [Line Items]
Contract intangibles	$ 109

Acquisitions and Dispositions_5

Acquisitions and Dispositions (Purchase Price Allocation - Gas Storage and Pipelines Segment Acquisition) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 04, 2019	Dec. 31, 2018
Assets
Goodwill	$ 2,466	$ 2,464		$ 2,293
Gas Storage and Pipelines | Blue Union and LEAP
Assets
Cash			$ 62
Accounts receivable			31
Property, plant, and equipment, net			1,034
Goodwill			173
Other current assets			1
Total assets			2,774
Liabilities
Accounts payable			26
Acquisition related deferred payment			380
Other current liabilities			2
Asset retirement obligations			9
Total liabilities			417
Total cash consideration			2,357
Gas Storage and Pipelines | Customer relationships | Blue Union and LEAP
Assets
Customer relationship intangibles			$ 1,473

Revenue (Disaggregation of Reve

Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 3,288	$ 3,284	$ 2,583	$ 3,022	$ 3,148	$ 3,119	$ 2,888	$ 3,514	$ 12,177	$ 12,669	$ 14,212
Lease revenue outside scope of Topic 606									190	193
Electric
Disaggregation of Revenue [Line Items]
Revenues									5,520	5,229	5,298
Alternative Revenue Program revenues outside scope of Topic 606									26	22	21
Other revenues outside scope of topic 606									22	19	20
Electric | Residential
Disaggregation of Revenue [Line Items]
Revenues									2,825	2,427	2,494
Electric | Commercial
Disaggregation of Revenue [Line Items]
Revenues									1,739	1,795	1,794
Electric | Industrial
Disaggregation of Revenue [Line Items]
Revenues									592	659	690
Electric | Other
Disaggregation of Revenue [Line Items]
Revenues									364	348	320
Electric | Other | DTE Sustainable Generation
Disaggregation of Revenue [Line Items]
Revenues									14	5
Gas
Disaggregation of Revenue [Line Items]
Revenues									1,414	1,482	1,436
Alternative Revenue Program revenues outside scope of Topic 606									10	8	2
Other revenues outside scope of topic 606									8	7	7
Gas | Other
Disaggregation of Revenue [Line Items]
Revenues									146	142	91
Gas | Gas sales
Disaggregation of Revenue [Line Items]
Revenues									971	1,043	1,055
Gas | End User Transportation
Disaggregation of Revenue [Line Items]
Revenues									218	219	232
Gas | Intermediate Transportation
Disaggregation of Revenue [Line Items]
Revenues									79	78	58
Gas Storage and Pipelines
Disaggregation of Revenue [Line Items]
Revenues									754	501	485
Lease revenue outside scope of Topic 606									9	9
Power and Industrial Projects
Disaggregation of Revenue [Line Items]
Revenues									1,224	1,560	2,204
Lease revenue outside scope of Topic 606									99	121
Lease revenue outside scope of Topic 606											125
Energy Trading
Disaggregation of Revenue [Line Items]
Revenues									3,863	4,610	5,557
Gain (loss) on derivative outside scope of Topic 606									$ 2,700	$ 3,400	$ 4,500

Revenue (Details Textuals)

Revenue (Details Textuals)	12 Months Ended
	Dec. 31, 2020
Power and Industrial Projects
Revenue from External Customer [Line Items]
Payment terms	30 days

Revenue (Deferred Revenue) (Det

Revenue (Deferred Revenue) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Contract Liability [Roll Forward]
Beginning Balance	$ 75
Increases due to cash received or receivable, excluding amounts recognized as revenue during the period	55
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(43)
Ending Balance	$ 87

Revenue (Expected Recognition o

Revenue (Expected Recognition of Deferred Revenue) (Details) $ in Millions	Dec. 31, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 87
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 59
Remaining performance obligation, expected timing of satisfaction	1 year
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	$ 7
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	$ 8
Remaining performance obligation, expected timing of satisfaction

Revenue (Expected Recognition_2

Revenue (Expected Recognition of Deferred Revenue for fixed consideration) (Details) $ in Millions	Dec. 31, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 87
Fixed Consideration
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	1,643
Fixed Consideration | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	30
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 59
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Fixed Consideration
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 285
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Fixed Consideration | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 8
Remaining performance obligation, expected timing of satisfaction	1 year
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	$ 7
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Fixed Consideration
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 323
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Fixed Consideration | 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
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]: 2023-01-01 | Fixed Consideration
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 263
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Fixed Consideration | 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
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]: 2024-01-01 | Fixed Consideration
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 158
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Fixed Consideration | 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
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]: 2025-01-01 | Fixed Consideration
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 113
Remaining performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | Fixed Consideration | 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
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	$ 8
Remaining performance obligation, expected timing of satisfaction
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | Fixed Consideration
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 501
Remaining performance obligation, expected timing of satisfaction
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | Fixed Consideration | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 0
Remaining performance obligation, expected timing of satisfaction

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill [Roll Forward]
Balance as of January 1	$ 2,464	$ 2,293
Goodwill attributable to Gas Storage and Pipelines 2019 acquisition of Blue Union and LEAP	2	171
Balance at December 31	$ 2,466	$ 2,464

Property, Plant, and Equipmen_2

Property, Plant, and Equipment (Summary of Property by Classification) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	$ 37,997	$ 35,072
Accumulated depreciation and amortization	(10,028)	(9,755)
Net property, plant, and equipment	27,969	25,317
Gas Storage and Pipelines
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	3,981	3,524
Accumulated depreciation and amortization	(511)	(459)
Power and Industrial Projects
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	1,194	1,108
Accumulated depreciation and amortization	(619)	(604)
Other
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	217	183
Accumulated depreciation and amortization	(84)	(71)
Non-utility and other
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	5,392	4,815
Accumulated depreciation and amortization	(1,214)	(1,134)
DTE Electric
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	26,171	24,279
Accumulated depreciation and amortization	(7,050)	(6,706)
Net property, plant, and equipment	19,121	17,573
DTE Electric | Nuclear
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	3,295	3,022
Accumulated depreciation and amortization	(373)	(344)
DTE Electric | Renewables
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	1,817	1,362
Accumulated depreciation and amortization	(295)	(243)
DTE Electric | Fossil and other generation
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	8,031	7,644
Accumulated depreciation and amortization	(3,014)	(2,873)
DTE Electric | Distribution
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	10,354	9,715
Accumulated depreciation and amortization	(2,686)	(2,553)
DTE Electric | Other
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	2,674	2,536
Accumulated depreciation and amortization	(682)	(693)
DTE Gas
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	6,434	5,978
Accumulated depreciation and amortization	(1,764)	(1,915)
DTE Gas | Distribution
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	4,517	4,164
Accumulated depreciation and amortization	(1,215)	(1,334)
DTE Gas | Storage
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	576	570
Accumulated depreciation and amortization	(146)	(172)
DTE Gas | Transmission and other
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	1,341	1,244
Accumulated depreciation and amortization	$ (403)	$ (409)

Property, Plant, and Equipmen_3

Property, Plant, and Equipment (Schedule of AFUDC and Capitalized Interest Rates (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant, and Equipment [Line Items]
Non-regulated businesses capitalized interest	3.90%	4.00%	4.00%
DTE Electric
Property, Plant, and Equipment [Line Items]
AFUDC	5.47%	5.43%	5.41%
DTE Gas
Property, Plant, and Equipment [Line Items]
AFUDC	5.56%	5.56%	5.71%

Property, Plant, and Equipmen_4

Property, Plant, and Equipment (Schedule of AFUDC and Interest Capitalized) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Allowance for debt funds used during construction and interest capitalized	$ 22	$ 15	$ 15
Allowance for equity funds used during construction	25	24	28
Total	47	39	43
DTE Electric
Property, Plant, and Equipment [Line Items]
Allowance for debt funds used during construction	10	10	9
Allowance for equity funds used during construction	23	22	19
Total	$ 33	$ 32	$ 28

Property, Plant, and Equipmen_5

Property, Plant, and Equipment (Details Textuals)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Minimum | Non-utility
Public Utility Property, Plant, and Equipment [Line Items]
Property plant and equipment, useful life	3 years
Minimum | Capitalized software
Public Utility Property, Plant, and Equipment [Line Items]
Property plant and equipment, useful life	3 years
Maximum | Non-utility
Public Utility Property, Plant, and Equipment [Line Items]
Property plant and equipment, useful life	70 years
Maximum | Capitalized software
Public Utility Property, Plant, and Equipment [Line Items]
Property plant and equipment, useful life	15 years
DTE Electric | Minimum | Other
Public Utility Property, Plant, and Equipment [Line Items]
Property plant and equipment, useful life	3 years
DTE Electric | Minimum | Capitalized software
Public Utility Property, Plant, and Equipment [Line Items]
Property plant and equipment, useful life	3 years
DTE Electric | Maximum | Other
Public Utility Property, Plant, and Equipment [Line Items]
Property plant and equipment, useful life	80 years
DTE Electric | Maximum | Capitalized software
Public Utility Property, Plant, and Equipment [Line Items]
Property plant and equipment, useful life	15 years
DTE Gas | Minimum | Transmission and other
Public Utility Property, Plant, and Equipment [Line Items]
Property plant and equipment, useful life	3 years
DTE Gas | Maximum | Transmission and other
Public Utility Property, Plant, and Equipment [Line Items]
Property plant and equipment, useful life	80 years
DTE Electric
Public Utility Property, Plant, and Equipment [Line Items]
Composite depreciation rate for plants in service	4.20%	4.00%	3.70%
DTE Gas
Public Utility Property, Plant, and Equipment [Line Items]
Composite depreciation rate for plants in service	2.80%	2.80%	2.80%

Property, Plant, and Equipmen_6

Property, Plant, and Equipment (Average Estimated Useful Life of Each Major Class) (Details)	12 Months Ended
	Dec. 31, 2020
DTE Electric
Public Utility Property, Plant, and Equipment [Line Items]
Useful Life - Generation	32 years
Useful Life - Distribution	38 years
DTE Gas
Public Utility Property, Plant, and Equipment [Line Items]
Useful Life - Distribution	49 years
Useful Life - Storage	58 years

Property, Plant, and Equipmen_7

Property, Plant, and Equipment (Depreciation and Amortization) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	$ 1,120	$ 997	$ 878
Regulatory assets and liabilities	245	227	212
Intangible assets	71	33	27
Other	7	6	7
Depreciation and amortization	1,443	1,263	1,124
DTE Electric
Property, Plant, and Equipment [Line Items]
Property, plant, and equipment	831	748	652
Regulatory assets and liabilities	207	193	179
Other	5	5	5
Depreciation and amortization	$ 1,043	$ 946	$ 836

Property, Plant, and Equipmen_8

Property, Plant, and Equipment (Capitalized Software) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant, and Equipment [Line Items]
Amortization expense of capitalized software	$ 129	$ 123	$ 108
Gross carrying value of capitalized software	866	906
Accumulated amortization of capitalized software	432	520
DTE Electric
Property, Plant, and Equipment [Line Items]
Amortization expense of capitalized software	118	112	$ 101
Gross carrying value of capitalized software	756	811
Accumulated amortization of capitalized software	$ 363	$ 462

Jointly-Owned Utility Plant (De

Jointly-Owned Utility Plant (Details Textuals)	Dec. 31, 2020plant
Belle River Unit 1
Jointly-Owned Utility Plant Interests [Line Items]
Percent of the total capacity and energy of the plant	19.00%
Ludington Hydroelectric Pumped Storage
Jointly-Owned Utility Plant Interests [Line Items]
Percent of the total capacity and energy of the plant	51.00%
DTE Electric
Jointly-Owned Utility Plant Interests [Line Items]
Number of power plants owned	2

Jointly-Owned Utility Plant (Ow

Jointly-Owned Utility Plant (Ownership Information) (Details) - DTE Electric $ in Millions	Dec. 31, 2020USD ($)MW
Belle River
Jointly-Owned Utility Plant Interests [Line Items]
Total plant capacity | MW	1,270,000
Ownership interest	81.00%
Investment in Property, plant, and equipment (in millions)	$ 1,932
Accumulated depreciation (in millions)	$ 945
Ludington Hydroelectric Pumped Storage
Jointly-Owned Utility Plant Interests [Line Items]
Total plant capacity | MW	2,220,000
Ownership interest	49.00%
Investment in Property, plant, and equipment (in millions)	$ 609
Accumulated depreciation (in millions)	$ 181

Asset Retirement Obligations (R

Asset Retirement Obligations (Rollforward) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations at January 1	$ 2,672	$ 2,469	$ 2,320
Accretion	157	149	140
Liabilities incurred	25	20	27
Liabilities settled	(14)	(17)	(16)
Revision in estimated cash flows	(1)	51	(2)
Asset retirement obligations at December 31	2,839	2,672	2,469
DTE Electric
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations at January 1	2,447	2,271	2,125
Accretion	145	138	129
Liabilities incurred	18	1	27
Liabilities settled	(8)	(14)	(8)
Revision in estimated cash flows	5	51	(2)
Asset retirement obligations at December 31	$ 2,607	$ 2,447	$ 2,271

Asset Retirement Obligations (D

Asset Retirement Obligations (Details Textuals) - Fermi 2	Dec. 31, 2020USD ($)
Asset Retirement Obligations [Line Items]
Nuclear decommissioning liabilities funded through surcharge and included in ARO balance	$ 2,200,000,000
Liabilities balance upon completion of decommissioning	$ 0

Regulatory Matters (Schedule of

Regulatory Matters (Schedule of Regulatory Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Regulatory Assets [Line Items]
Regulatory assets	$ 4,257	$ 4,176
Less amount included in Current Assets	(129)	(5)
Regulatory assets, noncurrent	4,128	4,171
Pension
Regulatory Assets [Line Items]
Regulatory assets	1,938	1,983
Other postretirement costs
Regulatory Assets [Line Items]
Regulatory assets	165	201
Recoverable undepreciated costs on retiring plants
Regulatory Assets [Line Items]
Regulatory assets	664	657
Fermi 2 asset retirement obligation
Regulatory Assets [Line Items]
Regulatory assets	645	669
Recoverable Michigan income taxes
Regulatory Assets [Line Items]
Regulatory assets	176	189
Enhanced Tree Trimming Program deferred costs
Regulatory Assets [Line Items]
Regulatory assets	119	43
Accrued PSCR revenue
Regulatory Assets [Line Items]
Regulatory assets	100	3
Recoverable income taxes related to AFUDC equity
Regulatory Assets [Line Items]
Regulatory assets	64	56
Energy Waste Reduction incentive
Regulatory Assets [Line Items]
Regulatory assets	62	54
Deferred environmental costs
Regulatory Assets [Line Items]
Regulatory assets	57	66
Unamortized loss on reacquired debt
Regulatory Assets [Line Items]
Regulatory assets	55	56
Nuclear Performance Evaluation and Review Committee Tracker
Regulatory Assets [Line Items]
Regulatory assets	55	48
Customer360 deferred costs
Regulatory Assets [Line Items]
Regulatory assets	51	55
Non-service pension and other postretirement costs
Regulatory Assets [Line Items]
Regulatory assets	21	15
Other recoverable income taxes
Regulatory Assets [Line Items]
Regulatory assets	19	20
Transitional Reconciliation Mechanism
Regulatory Assets [Line Items]
Regulatory assets	11	10
Other
Regulatory Assets [Line Items]
Regulatory assets	55	51
DTE Electric
Regulatory Assets [Line Items]
Regulatory assets	3,563	3,453
Less amount included in Current Assets	(123)	(5)
Regulatory assets, noncurrent	3,440	3,448
DTE Electric | Pension
Regulatory Assets [Line Items]
Regulatory assets	1,477	1,497
DTE Electric | Other postretirement costs
Regulatory Assets [Line Items]
Regulatory assets	108	131
DTE Electric | Recoverable undepreciated costs on retiring plants
Regulatory Assets [Line Items]
Regulatory assets	664	657
DTE Electric | Fermi 2 asset retirement obligation
Regulatory Assets [Line Items]
Regulatory assets	645	669
DTE Electric | Recoverable Michigan income taxes
Regulatory Assets [Line Items]
Regulatory assets	142	152
DTE Electric | Enhanced Tree Trimming Program deferred costs
Regulatory Assets [Line Items]
Regulatory assets	119	43
DTE Electric | Accrued PSCR revenue
Regulatory Assets [Line Items]
Regulatory assets	100	3
DTE Electric | Recoverable income taxes related to AFUDC equity
Regulatory Assets [Line Items]
Regulatory assets	54	47
DTE Electric | Energy Waste Reduction incentive
Regulatory Assets [Line Items]
Regulatory assets	49	43
DTE Electric | Deferred environmental costs
Regulatory Assets [Line Items]
Regulatory assets	0	0
DTE Electric | Unamortized loss on reacquired debt
Regulatory Assets [Line Items]
Regulatory assets	41	40
DTE Electric | Nuclear Performance Evaluation and Review Committee Tracker
Regulatory Assets [Line Items]
Regulatory assets	55	48
DTE Electric | Customer360 deferred costs
Regulatory Assets [Line Items]
Regulatory assets	51	55
DTE Electric | Non-service pension and other postretirement costs
Regulatory Assets [Line Items]
Regulatory assets	0	0
DTE Electric | Other recoverable income taxes
Regulatory Assets [Line Items]
Regulatory assets	19	20
DTE Electric | Transitional Reconciliation Mechanism
Regulatory Assets [Line Items]
Regulatory assets	11	10
DTE Electric | Other
Regulatory Assets [Line Items]
Regulatory assets	$ 28	$ 38

Regulatory Matters (Schedule _2

Regulatory Matters (Schedule of Regulatory Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Regulatory Liabilities [Line Items]
Regulatory liabilities	$ 3,402	$ 3,329
Less amount included in Current Liabilities	(39)	(65)
Regulatory liabilities, noncurrent	3,363	3,264
Refundable federal income taxes
Regulatory Liabilities [Line Items]
Regulatory liabilities	2,255	2,359
Removal costs liability
Regulatory Liabilities [Line Items]
Regulatory liabilities	831	700
Negative other postretirement offset
Regulatory Liabilities [Line Items]
Regulatory liabilities	122	93
Non-service pension and other postretirement costs
Regulatory Liabilities [Line Items]
Regulatory liabilities	78	46
COVID-19 voluntary refund
Regulatory Liabilities [Line Items]
Regulatory liabilities	30	0
Renewable energy
Regulatory Liabilities [Line Items]
Regulatory liabilities	21	54
Accrued GCR refund
Regulatory Liabilities [Line Items]
Regulatory liabilities	20	23
Other
Regulatory Liabilities [Line Items]
Regulatory liabilities	45	54
DTE Electric
Regulatory Liabilities [Line Items]
Regulatory liabilities	2,450	2,586
Less amount included in Current Liabilities	(18)	(40)
Regulatory liabilities, noncurrent	2,432	2,546
DTE Electric | Refundable federal income taxes
Regulatory Liabilities [Line Items]
Regulatory liabilities	1,827	1,911
DTE Electric | Removal costs liability
Regulatory Liabilities [Line Items]
Regulatory liabilities	410	483
DTE Electric | Negative other postretirement offset
Regulatory Liabilities [Line Items]
Regulatory liabilities	86	69
DTE Electric | Non-service pension and other postretirement costs
Regulatory Liabilities [Line Items]
Regulatory liabilities	36	21
DTE Electric | COVID-19 voluntary refund
Regulatory Liabilities [Line Items]
Regulatory liabilities	30	0
DTE Electric | Renewable energy
Regulatory Liabilities [Line Items]
Regulatory liabilities	21	54
DTE Electric | Accrued GCR refund
Regulatory Liabilities [Line Items]
Regulatory liabilities	0	0
DTE Electric | Other
Regulatory Liabilities [Line Items]
Regulatory liabilities	$ 40	$ 48

Regulatory Matters (Details Tex

Regulatory Matters (Details Textuals) - USD ($) $ in Millions	Feb. 12, 2021	Jul. 17, 2020	May 08, 2020	Nov. 25, 2019	Jul. 08, 2019	Jun. 30, 2020	Dec. 31, 2020	Dec. 09, 2020	Oct. 26, 2020	Jul. 09, 2020	Dec. 31, 2019
Regulatory Assets [Line Items]
Deferral of investigation and remediation of costs associated with gas utilities former MGP sites							10 years
Regulatory liability							$ 3,402				$ 3,329
DTE Gas | MPSC | 2019 Gas Rate Case Filing
Regulatory Assets [Line Items]
Requested rate increase				$ 204
Return on equity, percent		9.90%		10.00%
Return on equity, requested percent				10.50%
Approved rate increase		$ 110
Disallowed cost, capital expenditures related to incentive compensation						$ 14
Regulatory liability for non-plant-related accumulated deferred income tax balances that resulted from the TCJA, accelerated amortization approved		20
Net increase to customers due to rate increase		$ 51
DTE Gas | MPSC | 2021 Gas Rate Case Filing | Subsequent Event
Regulatory Assets [Line Items]
Requested rate increase	$ 195
Return on equity, percent	9.90%
Return on equity, requested percent	10.25%
DTE Gas | COVID-19 Pandemic
Regulatory Assets [Line Items]
Uncollectible expense deferred as a Regulatory asset							2
DTE Electric
Regulatory Assets [Line Items]
Regulatory liability							$ 2,450				$ 2,586
DTE Electric | MPSC | 2019 Electric Rate Case Filing
Regulatory Assets [Line Items]
Requested rate increase					$ 351
Return on equity, percent			9.90%		10.00%
Return on equity, requested percent					10.50%
Approved rate increase			$ 188
Disallowed cost, capital expenditures related to incentive compensation						$ 41
Regulatory liability for non-plant-related accumulated deferred income tax balances that resulted from the TCJA, accelerated amortization approved										$ 102
DTE Electric | COVID-19 Pandemic
Regulatory Assets [Line Items]
Proposed regulatory liability									$ 30
Regulatory liability								$ 30
Nuclear Performance Evaluation and Review Committee Tracker
Regulatory Assets [Line Items]
Approved amortization period							5 years
Customer360 deferred costs
Regulatory Assets [Line Items]
Approved amortization period							15 years

Income Taxes (Details Textuals)

Income Taxes (Details Textuals) - USD ($)	3 Months Ended	12 Months Ended
	Jun. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Entity Information [Line Items]
Deferred tax asset, general business tax credit carryforwards		$ 1,100,000,000
State and local net operating loss carry-forwards		155,000,000	$ 117,000,000
Valuation allowance		41,000,000	40,000,000
Unrecognized tax benefits that would impact effective tax rate		8,000,000	8,000,000
Interest on income taxes accrued		5,000,000	4,000,000
Interest on income taxes expense		1,000,000	1,000,000	$ 1,000,000
Penalties on income taxes accrued		0	0
CARES Act
Entity Information [Line Items]
Reduction in Income Tax Expense due to carryback of 2018 net operating loss to 2013		34,000,000
Claim for employee retention credits	$ 6,000,000
Deferral of employer payroll taxes		44,000,000
CARES Act, AMT Credit Refund
Entity Information [Line Items]
AMT credit received from U.S. Treasury		220,000,000
Immediate Refund of 2018 Remaining AMT Credit Balance
Entity Information [Line Items]
AMT credit received from U.S. Treasury		153,000,000
Immediate Refund of AMT Credit Generated by Carrying Back 2018 Net Operating Loss to 2013
Entity Information [Line Items]
AMT credit received from U.S. Treasury		67,000,000
Federal
Entity Information [Line Items]
Net operating loss carry-forwards		1,300,000,000
DTE Electric
Entity Information [Line Items]
Income tax receivable from related party		8,000,000	14,000,000
State and local net operating loss carry-forwards		0	0
Valuation allowance		0	0
Unrecognized tax benefits that would impact effective tax rate		10,000,000	10,000,000
Interest on income taxes accrued		6,000,000	6,000,000
Interest on income taxes expense		0	1,000,000	$ 1,000,000
Penalties on income taxes accrued		0	$ 0
DTE Electric | CARES Act
Entity Information [Line Items]
Claim for employee retention credits	$ 3,000,000
Deferral of employer payroll taxes		23,000,000
DTE Electric | General Business Credits
Entity Information [Line Items]
Tax credit carry-forward		$ 278,000,000

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of Income Tax Expense to the Statutory Federal Income Tax Rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income Before Income Taxes	$ 1,538	$ 1,324	$ 1,216
Income tax expense at 21% statutory rate	323	278	255
State and local income taxes, net of federal benefit	81	48	60
Production tax credits	(121)	(128)	(223)
TCJA regulatory liability amortization	(76)	(38)	0
Net operating loss carryback	(34)	0	0
AFUDC equity	(4)	(4)	(14)
Employee Stock Ownership Plan dividends	(4)	(3)	(3)
Investment tax credits	(4)	(4)	(4)
Stock based compensation	(3)	(7)	(3)
Enactment of the Tax Cuts and Jobs Act	0	0	21
Noncontrolling interests	1	0	2
Depreciation	2	2	2
Other, net	6	8	5
Income Tax Expense	$ 167	$ 152	$ 98
Effective income tax rate	10.90%	11.50%	8.10%
DTE Electric
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Income Before Income Taxes	$ 887	$ 854	$ 857
Income tax expense at 21% statutory rate	186	179	180
State and local income taxes, net of federal benefit	50	49	49
Production tax credits	(55)	(45)	(35)
TCJA regulatory liability amortization	(62)	(35)	0
AFUDC equity	(4)	(4)	(3)
Employee Stock Ownership Plan dividends	(2)	(2)	(2)
Investment tax credits	(4)	(4)	(3)
Enactment of the Tax Cuts and Jobs Act	0	0	7
Depreciation	2	2	2
Other, net	(2)	(2)	(2)
Income Tax Expense	$ 109	$ 138	$ 193
Effective income tax rate	12.30%	16.20%	22.50%

Income Taxes (Components of Inc

Income Taxes (Components of Income Tax Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current income tax expense (benefit)
Federal	$ (247)	$ (184)	$ (17)
State and other income tax	7	7	1
Total current income taxes	(240)	(177)	(16)
Deferred income tax expense
Federal	310	275	38
State and other income tax	97	54	76
Total deferred income taxes	407	329	114
Total income tax expense	167	152	98
DTE Electric
Current income tax expense (benefit)
Federal	15	25	0
State and other income tax	5	16	4
Total current income taxes	20	41	4
Deferred income tax expense
Federal	30	51	131
State and other income tax	59	46	58
Total deferred income taxes	89	97	189
Total income tax expense	$ 109	$ 138	$ 193

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets (Liabilities)) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Components of Deferred Tax Assets and Liabilities [Abstract]
Property, plant, and equipment	$ (4,032,000,000)	$ (3,755,000,000)
Regulatory assets and liabilities	(108,000,000)	(47,000,000)
Tax credit carry-forwards	1,144,000,000	1,161,000,000
Pension and benefits	321,000,000	300,000,000
Federal net operating loss carry-forward	265,000,000	276,000,000
State and local net operating loss carry-forwards	155,000,000	117,000,000
Investments in equity method investees	(667,000,000)	(465,000,000)
Other	141,000,000	138,000,000
Deferred tax liabilities, gross	(2,781,000,000)	(2,275,000,000)
Less valuation allowance	(41,000,000)	(40,000,000)
Deferred income tax liabilities	(2,822,000,000)	(2,315,000,000)
Deferred income tax assets	2,241,000,000	2,264,000,000
Deferred income tax liabilities	(5,063,000,000)	(4,579,000,000)
DTE Electric
Components of Deferred Tax Assets and Liabilities [Abstract]
Property, plant, and equipment	(3,099,000,000)	(2,956,000,000)
Regulatory assets and liabilities	(53,000,000)
Regulatory assets and liabilities		4,000,000
Tax credit carry-forwards	278,000,000	252,000,000
Pension and benefits	264,000,000	258,000,000
Federal net operating loss carry-forward	0	0
State and local net operating loss carry-forwards	0	0
Investments in equity method investees	0	0
Other	85,000,000	87,000,000
Deferred tax liabilities, gross	(2,525,000,000)	(2,355,000,000)
Less valuation allowance	0	0
Deferred income tax liabilities	(2,525,000,000)	(2,355,000,000)
Deferred income tax assets	883,000,000	865,000,000
Deferred income tax liabilities	$ (3,408,000,000)	$ (3,220,000,000)

Income Taxes (Reconciliation _2

Income Taxes (Reconciliation of Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, beginning balance	$ 10	$ 10	$ 10
Additions for tax positions of prior years	0	0	0
Unrecognized tax benefits, ending balance	10	10	10
DTE Electric
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits, beginning balance	13	13	13
Additions for tax positions of prior years	0	0	0
Unrecognized tax benefits, ending balance	$ 13	$ 13	$ 13

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Basic Earnings per Share
Net Income Attributable to DTE Energy Company	$ 275	$ 476	$ 277	$ 340	$ 267	$ 319	$ 182	$ 401	$ 1,368	$ 1,169	$ 1,120
Less: Allocation of earnings to net restricted stock awards									(2)	(2)	(2)
Net income available to common shareholders — basic									$ 1,366	$ 1,167	$ 1,118
Average number of common shares outstanding — basic (in shares)									193	185	181
Basic Earnings per Common Share (in dollars per share)	$ 1.42	$ 2.47	$ 1.44	$ 1.77	$ 1.40	$ 1.74	$ 0.99	$ 2.20	$ 7.09	$ 6.32	$ 6.18
Diluted Earnings per Share
Net Income Attributable to DTE Energy Company	$ 275	$ 476	$ 277	$ 340	$ 267	$ 319	$ 182	$ 401	$ 1,368	$ 1,169	$ 1,120
Less: Allocation of earnings to net restricted stock awards									(2)	(2)	(2)
Net income available to common shareholders — diluted									$ 1,366	$ 1,167	$ 1,118
Average number of common shares outstanding — diluted (in shares)									193	185	181
Diluted Earnings per Common Share (in dollars per share)	$ 1.42	$ 2.46	$ 1.44	$ 1.76	$ 1.40	$ 1.73	$ 0.99	$ 2.19	$ 7.08	$ 6.31	$ 6.17
Incremental common shares attributable to dilutive effect of equity units (in shares)									10.3	10.3	6.3

Fair Value (Assets and Liabilit

Fair Value (Assets and Liabilities Recorded at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivative assets
Derivative assets, gross	$ 567	$ 775
Derivative assets, netting	(411)	(601)
Derivative assets, net	156	174
Liabilities
Derivative liabilities, gross	(533)	(770)
Derivative liabilities, netting	405	601
Derivative liabilities, net	(128)	(169)
Current liabilities
Liabilities
Derivative liabilities, gross	(386)	(596)
Noncurrent liabilities
Liabilities
Derivative liabilities, gross	(147)	(174)
Natural Gas
Derivative assets
Derivative assets, gross	233	355
Derivative assets, netting	(156)	(266)
Derivative assets, net	77	89
Liabilities
Derivative liabilities, gross	(223)	(351)
Derivative liabilities, netting	151	266
Derivative liabilities, net	(72)	(85)
Electricity
Derivative assets
Derivative assets, gross	180	306
Derivative assets, netting	(120)	(225)
Derivative assets, net	60	81
Liabilities
Derivative liabilities, gross	(168)	(298)
Derivative liabilities, netting	125	225
Derivative liabilities, net	(43)	(73)
Environmental & Other
Derivative assets
Derivative assets, gross	154	113
Derivative assets, netting	(135)	(110)
Derivative assets, net	19	3
Liabilities
Derivative liabilities, gross	(137)	(121)
Derivative liabilities, netting	129	110
Derivative liabilities, net	(8)	(11)
Foreign currency exchange contracts
Derivative assets
Derivative assets, gross	0	1
Derivative assets, netting	0	0
Derivative assets, net	0	1
Liabilities
Derivative liabilities, gross	(5)	0
Derivative liabilities, netting	0	0
Derivative liabilities, net	(5)	0
Recurring
Assets
Cash equivalents	438	15
Derivative assets
Derivative assets, netting	(411)	(601)
Derivative assets, net	156	174
Total assets	2,609	2,073
Liabilities
Derivative liabilities, netting	405	601
Derivative liabilities, net	(128)	(169)
Net Assets (Liabilities) at end of period	2,481	1,904
Net Assets (Liabilities) at the end of the period, netting	(6)	0
Recurring | DTE Electric
Assets
Cash equivalents	4	11
Derivative assets
Total assets	1,890	1,688
Recurring | Current assets
Derivative assets
Derivative assets, netting	(330)	(513)
Total assets	554	148
Recurring | Current assets | DTE Electric
Derivative assets
Total assets	8	14
Recurring | Noncurrent assets
Derivative assets
Derivative assets, netting	(81)	(88)
Total assets	2,055	1,925
Recurring | Noncurrent assets | DTE Electric
Derivative assets
Total assets	1,882	1,674
Recurring | Current liabilities
Liabilities
Derivative liabilities, netting	318	513
Derivative liabilities, net	(68)	(83)
Recurring | Noncurrent liabilities
Liabilities
Derivative liabilities, netting	87	88
Derivative liabilities, net	(60)	(86)
Recurring | Cash and Cash equivalents
Assets
Cash equivalents	436	4
Recurring | Restricted cash
Assets
Cash equivalents	2
Recurring | Other investments
Assets
Cash equivalents		11
Recurring | Natural Gas
Derivative assets
Derivative assets, netting	(156)	(266)
Derivative assets, net	77	89
Liabilities
Derivative liabilities, netting	151	266
Derivative liabilities, net	(72)	(85)
Recurring | Electricity
Derivative assets
Derivative assets, netting	(120)	(225)
Derivative assets, net	60	81
Liabilities
Derivative liabilities, netting	125	225
Derivative liabilities, net	(43)	(73)
Recurring | Environmental & Other
Derivative assets
Derivative assets, netting	(135)	(110)
Derivative assets, net	19	3
Liabilities
Derivative liabilities, netting	129	110
Derivative liabilities, net	(8)	(11)
Recurring | Foreign currency exchange contracts
Derivative assets
Derivative assets, netting	0	0
Derivative assets, net	0	1
Liabilities
Derivative liabilities, netting	0	0
Derivative liabilities, net	(5)	0
Recurring | Derivative assets — FTRs | DTE Electric
Derivative assets
Derivative assets, net	4	3
Recurring | Cash equivalents
Assets
Nuclear decommissioning trusts	27	34
Other investments	97	4
Recurring | Cash equivalents | DTE Electric
Assets
Nuclear decommissioning trusts	27	34
Recurring | Private equity and other
Assets
Nuclear decommissioning trusts	104	43
Recurring | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	104	43
Recurring | Equity securities
Assets
Nuclear decommissioning trusts	1,169	1,046
Other investments	55	140
Recurring | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	1,169	1,046
Other investments	16	13
Recurring | Fixed income securities
Assets
Nuclear decommissioning trusts	555	538
Other investments	8	79
Recurring | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	555	538
Other investments	11	0
Recurring | Level 1
Assets
Cash equivalents	438	15
Derivative assets
Derivative assets, gross	99	205
Total assets	1,773	1,683
Liabilities
Derivative liabilities, gross	(88)	(221)
Net Assets (Liabilities) at end of period	1,685	1,462
Recurring | Level 1 | DTE Electric
Assets
Cash equivalents	4	11
Derivative assets
Total assets	1,107	1,264
Recurring | Level 1 | Current assets
Derivative assets
Total assets	532	218
Recurring | Level 1 | Current assets | DTE Electric
Derivative assets
Total assets	4	11
Recurring | Level 1 | Noncurrent assets
Derivative assets
Total assets	1,241	1,465
Recurring | Level 1 | Noncurrent assets | DTE Electric
Derivative assets
Total assets	1,103	1,253
Recurring | Level 1 | Current liabilities
Liabilities
Derivative liabilities, gross	(84)	(211)
Recurring | Level 1 | Noncurrent liabilities
Liabilities
Derivative liabilities, gross	(4)	(10)
Recurring | Level 1 | Natural Gas
Derivative assets
Derivative assets, gross	99	205
Liabilities
Derivative liabilities, gross	(88)	(221)
Recurring | Level 1 | Electricity
Derivative assets
Derivative assets, gross	0	0
Liabilities
Derivative liabilities, gross	0	0
Recurring | Level 1 | Environmental & Other
Derivative assets
Derivative assets, gross	0	0
Liabilities
Derivative liabilities, gross	0	0
Recurring | Level 1 | Foreign currency exchange contracts
Derivative assets
Derivative assets, gross	0	0
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	27	34
Other investments	97	4
Recurring | Level 1 | Cash equivalents | DTE Electric
Assets
Nuclear decommissioning trusts	27	34
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	947	1,046
Other investments	55	140
Recurring | Level 1 | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	947	1,046
Other investments	16	13
Recurring | Level 1 | Fixed income securities
Assets
Nuclear decommissioning trusts	102	160
Other investments	8	79
Recurring | Level 1 | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	102	160
Other investments	11	0
Recurring | Level 2
Assets
Cash equivalents	0	0
Derivative assets
Derivative assets, gross	352	410
Total assets	723	788
Liabilities
Derivative liabilities, gross	(327)	(393)
Net Assets (Liabilities) at end of period	396	395
Recurring | Level 2 | DTE Electric
Assets
Cash equivalents	0	0
Derivative assets
Total assets	371	378
Recurring | Level 2 | Current assets
Derivative assets
Total assets	260	320
Recurring | Level 2 | Current assets | DTE Electric
Derivative assets
Total assets	0	0
Recurring | Level 2 | Noncurrent assets
Derivative assets
Total assets	463	468
Recurring | Level 2 | Noncurrent assets | DTE Electric
Derivative assets
Total assets	371	378
Recurring | Level 2 | Current liabilities
Liabilities
Derivative liabilities, gross	(223)	(300)
Recurring | Level 2 | Noncurrent liabilities
Liabilities
Derivative liabilities, gross	(104)	(93)
Recurring | Level 2 | Natural Gas
Derivative assets
Derivative assets, gross	74	76
Liabilities
Derivative liabilities, gross	(59)	(41)
Recurring | Level 2 | Electricity
Derivative assets
Derivative assets, gross	128	223
Liabilities
Derivative liabilities, gross	(126)	(231)
Recurring | Level 2 | Environmental & Other
Derivative assets
Derivative assets, gross	150	110
Liabilities
Derivative liabilities, gross	(137)	(121)
Recurring | Level 2 | Foreign currency exchange contracts
Derivative assets
Derivative assets, gross	0	1
Liabilities
Derivative liabilities, gross	(5)	0
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
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	371	378
Other investments	0	0
Recurring | Level 2 | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	371	378
Other investments	0	0
Recurring | Level 3
Assets
Cash equivalents	0	0
Derivative assets
Derivative assets, gross	116	160
Total assets	116	160
Liabilities
Derivative liabilities, gross	(118)	(156)
Net Assets (Liabilities) at end of period	(2)	4
Recurring | Level 3 | DTE Electric
Assets
Cash equivalents	0	0
Derivative assets
Total assets	4	3
Recurring | Level 3 | Current assets
Derivative assets
Total assets	92	123
Recurring | Level 3 | Current assets | DTE Electric
Derivative assets
Total assets	4	3
Recurring | Level 3 | Noncurrent assets
Derivative assets
Total assets	24	37
Recurring | Level 3 | Noncurrent assets | DTE Electric
Derivative assets
Total assets	0	0
Recurring | Level 3 | Current liabilities
Liabilities
Derivative liabilities, gross	(79)	(85)
Recurring | Level 3 | Noncurrent liabilities
Liabilities
Derivative liabilities, gross	(39)	(71)
Recurring | Level 3 | Natural Gas
Derivative assets
Derivative assets, gross	60	74
Liabilities
Derivative liabilities, gross	(76)	(89)
Recurring | Level 3 | Electricity
Derivative assets
Derivative assets, gross	52	83
Liabilities
Derivative liabilities, gross	(42)	(67)
Recurring | Level 3 | Environmental & Other
Derivative assets
Derivative assets, gross	4	3
Liabilities
Derivative liabilities, gross	0	0
Recurring | Level 3 | Foreign currency exchange contracts
Derivative assets
Derivative assets, gross	0	0
Liabilities
Derivative liabilities, gross	0	0
Recurring | Level 3 | Derivative assets — FTRs | DTE Electric
Derivative assets
Derivative assets, net	4	3
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
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
Other investments	0	0
Recurring | Other
Derivative assets
Total assets	408	43
Liabilities
Net Assets (Liabilities) at end of period	408	43
Recurring | Other | DTE Electric
Derivative assets
Total assets	408	43
Recurring | Other | Noncurrent assets
Derivative assets
Total assets	408	43
Recurring | Other | Noncurrent assets | DTE Electric
Derivative assets
Total assets	408	43
Recurring | Other | Private equity and other
Assets
Nuclear decommissioning trusts	104	43
Recurring | Other | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	104	43
Recurring | Other | Equity securities
Assets
Nuclear decommissioning trusts	222	0
Recurring | Other | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	222	0
Recurring | Other | Fixed income securities
Assets
Nuclear decommissioning trusts	82	0
Recurring | Other | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	$ 82	$ 0

Fair Value (Details Textuals)

Fair Value (Details Textuals) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Nuclear decommissioning trusts | Fixed Income Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities with no contractual maturity date	$ 82
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	$ 183	$ 151
Minimum | Equity or debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, redemption notice period	7 days
Minimum | Private Equity and Other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments classified as NAV assets, general contractual durations	7 years
Maximum | Equity or debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, redemption notice period	65 days
Maximum | Private Equity and Other
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	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of January 1	$ 4	$ (44)
Transfers from Level 3 into Level 2	(2)	0
Total gains (losses)
Included in earnings	31	91
Recorded in Regulatory liabilities	20	2
Purchases, issuances, and settlements:
Settlements	(55)	(45)
Net Assets (Liabilities) as of December 31	(2)	4
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31	(4)	20
Total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31	4	3
Natural Gas
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of January 1	(15)	(49)
Transfers from Level 3 into Level 2	(2)	0
Total gains (losses)
Included in earnings	(75)	15
Recorded in Regulatory liabilities	0	0
Purchases, issuances, and settlements:
Settlements	76	19
Net Assets (Liabilities) as of December 31	(16)	(15)
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31	(4)	(1)
Total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31	0	0
Electricity
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of January 1	16	(2)
Transfers from Level 3 into Level 2	0	0
Total gains (losses)
Included in earnings	113	77
Recorded in Regulatory liabilities	0	0
Purchases, issuances, and settlements:
Settlements	(119)	(59)
Net Assets (Liabilities) as of December 31	10	16
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31	70	59
Total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31	0	0
Other
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of January 1	3	7
Transfers from Level 3 into Level 2	0	0
Total gains (losses)
Included in earnings	(7)	(1)
Recorded in Regulatory liabilities	20	2
Purchases, issuances, and settlements:
Settlements	(12)	(5)
Net Assets (Liabilities) as of December 31	4	3
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31	(70)	(38)
Total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31	4	3
DTE Electric
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of January 1	3	6
Total gains (losses)
Recorded in Regulatory liabilities	20	2
Purchases, issuances, and settlements:
Settlements	(19)	(5)
Net Assets (Liabilities) as of December 31	4	3
Total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets and liabilities held at December 31	$ 4	$ 3

Fair Value (Unobservable Inputs

Fair Value (Unobservable Inputs related to Level 3 Assets and Liabilities) (Details) $ in Millions	Dec. 31, 2020USD ($)$ / MWh$ / MMBTU	Dec. 31, 2019USD ($)$ / MMBTU$ / MWh
Unobservable Input Valuation Techniques [Line Items]
Derivative Assets	$ 567	$ 775
Derivative Liabilities	(533)	(770)
Natural Gas
Unobservable Input Valuation Techniques [Line Items]
Derivative Assets	233	355
Derivative Liabilities	(223)	(351)
Electricity
Unobservable Input Valuation Techniques [Line Items]
Derivative Assets	180	306
Derivative Liabilities	$ (168)	$ (298)
Level 3 | Discounted Cash Flow | Forward basis price | Natural Gas | Minimum
Unobservable Input Valuation Techniques [Line Items]
Forward basis price | $ / MMBTU	(0.86)	(1.78)
Level 3 | Discounted Cash Flow | Forward basis price | Natural Gas | Maximum
Unobservable Input Valuation Techniques [Line Items]
Forward basis price | $ / MMBTU	2.50	5.78
Level 3 | Discounted Cash Flow | Forward basis price | Natural Gas | Weighted Average
Unobservable Input Valuation Techniques [Line Items]
Forward basis price | $ / MMBTU	(0.07)	(0.09)
Level 3 | Discounted Cash Flow | Forward basis price | Electricity | Minimum
Unobservable Input Valuation Techniques [Line Items]
Forward basis price | $ / MWh	(9)	(10)
Level 3 | Discounted Cash Flow | Forward basis price | Electricity | Maximum
Unobservable Input Valuation Techniques [Line Items]
Forward basis price | $ / MWh	6	6
Level 3 | Discounted Cash Flow | Forward basis price | Electricity | Weighted Average
Unobservable Input Valuation Techniques [Line Items]
Forward basis price | $ / MWh	0	0
Recurring | Level 3
Unobservable Input Valuation Techniques [Line Items]
Derivative Assets	$ 116	$ 160
Derivative Liabilities	(118)	(156)
Recurring | Level 3 | Natural Gas
Unobservable Input Valuation Techniques [Line Items]
Derivative Assets	60	74
Derivative Liabilities	(76)	(89)
Recurring | Level 3 | Electricity
Unobservable Input Valuation Techniques [Line Items]
Derivative Assets	52	83
Derivative Liabilities	$ (42)	$ (67)

Fair Value (Fair Value of Finan

Fair Value (Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding lessor finance leases	$ 141	$ 184
Short-term borrowings	38	828
Notes payable	19	25
Long-term debt	19,439	16,606
Carrying Amount | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding lessor finance leases	16	9
Short-term borrowings	0	354
Notes payable	17	21
Long-term debt	8,236	7,180
Carrying Amount | DTE Electric | Affiliated entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	101	97
Fair Value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding lessor finance leases	0	0
Short-term borrowings	0	0
Notes payable	0	0
Long-term debt	2,547	2,572
Fair Value | Level 1 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding lessor finance leases	0	0
Short-term borrowings	0	0
Notes payable	0	0
Long-term debt	0	0
Fair Value | Level 1 | DTE Electric | Affiliated entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0	0
Fair Value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding lessor finance leases	0	0
Short-term borrowings	38	828
Notes payable	0	0
Long-term debt	18,230	14,207
Fair Value | Level 2 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding lessor finance leases	0	0
Short-term borrowings	0	354
Notes payable	0	0
Long-term debt	9,579	7,916
Fair Value | Level 2 | DTE Electric | Affiliated entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0	0
Fair Value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding lessor finance leases	141	184
Short-term borrowings	0	0
Notes payable	19	25
Long-term debt	1,397	1,252
Fair Value | Level 3 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, excluding lessor finance leases	16	9
Short-term borrowings	0	0
Notes payable	17	21
Long-term debt	379	173
Fair Value | Level 3 | DTE Electric | Affiliated entity
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	$ 101	$ 97

Fair Value (Fair Value of Nucle

Fair Value (Fair Value of Nuclear Decommissioning Trust Fund Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	$ 1,855	$ 1,661
DTE Electric
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	1,855	1,661
DTE Electric | Nuclear decommissioning trusts
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	1,855	1,661
DTE Electric | Nuclear decommissioning trusts | Fermi 2
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	1,841	1,650
DTE Electric | Nuclear decommissioning trusts | Fermi 1
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	3	3
DTE Electric | Nuclear decommissioning trusts | Low-level radioactive waste
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	$ 11	$ 8

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 trusts - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Realized gains	$ 192	$ 56	$ 65
Realized losses	(111)	(31)	(42)
Proceeds from sale of securities	$ 2,350	$ 788	$ 1,203

Fair Value (Fair Value and Unre

Fair Value (Fair Value and Unrealized Gains and Losses for the Nuclear Decommissioning Trust Funds) (Details) - DTE Electric - Nuclear decommissioning trusts - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 1,855	$ 1,661
Fixed income securities, fair value	555	538
Private equity and other, fair value	104	43
Cash equivalents, fair value	27	34
Unrealized gains	501	420
Fixed income securities, unrealized gains	20	24
Unrealized losses	(7)	(40)
Fixed income securities, unrealized losses	(1)	(1)
Equity securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	1,169	1,046
Unrealized gains	481	396
Unrealized losses	$ (6)	$ (39)

Fair Value (Fair Value of Fixed

Fair Value (Fair Value of Fixed Income Securities Held in Nuclear Decommissioning Trust Funds (Details) - Nuclear decommissioning trusts - Fixed Income Securities $ in Millions	Dec. 31, 2020USD ($)
Debt Securities, Available-for-sale [Line Items]
Due within one year	$ 51
Due after one through five years	101
Due after five through ten years	89
Due after ten years	232
Fixed income securities total	$ 473

Fair Value (Gains (Losses) Rela

Fair Value (Gains (Losses) Related to the Trust) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Rabbi Trust
Schedule of Investments [Line Items]
Gains (losses) related to the trust	$ (3)	$ 37	$ (11)
Equity securities
Schedule of Investments [Line Items]
Gains (losses) related to the trust	(1)	27	(8)
Fixed Income Securities
Schedule of Investments [Line Items]
Gains (losses) related to the trust	$ (2)	$ 10	$ (3)

Financial and Other Derivativ_3

Financial and Other Derivative Instruments (Fair Value of Derivative Instruments) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 567	$ 775
Derivative Liabilities	(533)	(770)
Current derivative asset
Derivatives, Fair Value [Line Items]
Derivative Assets	446	646
Noncurrent derivative asset
Derivatives, Fair Value [Line Items]
Derivative Assets	121	129
Current derivative liability
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(386)	(596)
Noncurrent derivative liability
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(147)	(174)
Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	0	1
Derivative Liabilities	(5)	0
Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	233	355
Derivative Liabilities	(223)	(351)
Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	180	306
Derivative Liabilities	(168)	(298)
Environmental & Other
Derivatives, Fair Value [Line Items]
Derivative Assets	154	113
Derivative Liabilities	(137)	(121)
Derivatives designated as hedging instruments | Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Derivative Liabilities	(4)	0
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets	567	775
Derivative Liabilities	(529)	(770)
Derivatives not designated as hedging instruments | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative Assets	4	3
Derivatives not designated as hedging instruments | Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	0	1
Derivative Liabilities	(1)	0
Derivatives not designated as hedging instruments | Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	233	355
Derivative Liabilities	(223)	(351)
Derivatives not designated as hedging instruments | Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	180	306
Derivative Liabilities	(168)	(298)
Derivatives not designated as hedging instruments | Environmental & Other
Derivatives, Fair Value [Line Items]
Derivative Assets	154	113
Derivative Liabilities	(137)	(121)
Derivatives not designated as hedging instruments | FTRs — Other current assets | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 4	$ 3

Financial and Other Derivativ_4

Financial and Other Derivative Instruments (Details Textuals) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Letters of credit that could be used to offset net derivative liabilities	$ 7,000,000	$ 6,000,000
Letters of credit that could be used to offset net derivative assets	9,000,000	$ 4,000,000
Additional collateral, aggregate fair value	428,000,000
Derivative net liability position aggregate fair value	451,000,000
Collateral already posted fair value	0
Derivative, net asset position, fair value	401,000,000
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	Dec. 31, 2020	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Cash collateral netted against Derivative assets	$ (12)	$ 0
Cash collateral netted against Derivative liabilities	6	0
Cash collateral recorded in Accounts receivable	14	13
Cash collateral recorded in Accounts payable	(1)	(3)
Total net cash collateral posted (received)	$ 7	$ 10

Financial and Other Derivativ_6

Financial and Other Derivative Instruments (Netting Offsets of Derivative Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	$ 567	$ 775
Gross Amounts Offset in the Consolidated Statements of Financial Position	(411)	(601)
Derivative assets, net	156	174
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(533)	(770)
Gross Amounts Offset in the Consolidated Statements of Financial Position	405	601
Derivative liabilities, net	(128)	(169)
Natural gas
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	233	355
Gross Amounts Offset in the Consolidated Statements of Financial Position	(156)	(266)
Derivative assets, net	77	89
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(223)	(351)
Gross Amounts Offset in the Consolidated Statements of Financial Position	151	266
Derivative liabilities, net	(72)	(85)
Electricity
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	180	306
Gross Amounts Offset in the Consolidated Statements of Financial Position	(120)	(225)
Derivative assets, net	60	81
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(168)	(298)
Gross Amounts Offset in the Consolidated Statements of Financial Position	125	225
Derivative liabilities, net	(43)	(73)
Environmental & Other
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	154	113
Gross Amounts Offset in the Consolidated Statements of Financial Position	(135)	(110)
Derivative assets, net	19	3
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(137)	(121)
Gross Amounts Offset in the Consolidated Statements of Financial Position	129	110
Derivative liabilities, net	(8)	(11)
Interest rate contracts
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	0	0
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Derivative liabilities, net	0	0
Foreign currency exchange contracts
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	0	1
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Derivative assets, net	0	1
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(5)	0
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Derivative liabilities, net	$ (5)	$ 0

Financial and Other Derivativ_7

Financial and Other Derivative Instruments (Netting Offsets Reconciliation to Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivative Assets
Derivative Assets	$ 567	$ 775
Collateral adjustment	(12)	0
Derivative asset, current	116	133
Derivative assets, noncurrent	40	41
Derivative Liabilities
Derivative Liabilities	(533)	(770)
Collateral adjustment	6	0
Derivative liabilities, current	(68)	(83)
Derivative liabilities, noncurrent	(60)	(86)
Current derivative asset
Derivative Assets
Derivative Assets	446	646
Counterparty netting	(318)	(513)
Collateral adjustment	(12)	0
Derivative asset, current	116	133
Noncurrent derivative asset
Derivative Assets
Derivative Assets	121	129
Counterparty netting	(81)	(88)
Collateral adjustment	0	0
Derivative assets, noncurrent	40	41
Current derivative liability
Derivative Liabilities
Derivative Liabilities	(386)	(596)
Counterparty netting	318	513
Collateral adjustment	0	0
Derivative liabilities, current	(68)	(83)
Noncurrent derivative liability
Derivative Liabilities
Derivative Liabilities	(147)	(174)
Counterparty netting	81	88
Collateral adjustment	6	0
Derivative liabilities, noncurrent	$ (60)	$ (86)

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	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ (83)	$ 55	$ (81)
Natural gas | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(70)	44	(42)
Natural gas | Fuel, purchased power, gas, and other — non-utility
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	20	(5)	(94)
Electricity | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	91	44	49
Environmental & Other | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(118)	(26)	(1)
Foreign currency exchange contracts | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ (6)	$ (2)	$ 7

Financial and Other Derivativ_9

Financial and Other Derivative Instruments (Cumulative Gross Volume of Derivative Contracts Outstanding) (Details)	12 Months Ended
	Dec. 31, 2020CAD ($)MMBTUMWhT
Natural gas (MMBtu)
Derivative [Line Items]
Commodity, energy measure | MMBTU	1,757,668,006
Electricity (MWh)
Derivative [Line Items]
Commodity, energy measure	29,383,355
Foreign currency exchange ($ CAD)
Derivative [Line Items]
Commodity, monetary measure | $	$ 144,655,453
Renewable Energy Certificates (MWh)
Derivative [Line Items]
Commodity, energy measure	9,221,803
Carbon emissions (Metric Ton)
Derivative [Line Items]
Commodity, mass measure | T	12,495,202

Long-Term Debt (Long Term Debt

Long-Term Debt (Long Term Debt Outstanding and Weighted Average Interest Rates) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Long-term debt, total	$ 19,603
Unsecured
Debt Instrument [Line Items]
Interest rate	2.70%
Long-term debt, gross	$ 8,175	$ 6,625
Secured Debt, Unsecured Debt, Mortgage Notes and Other Debt
Debt Instrument [Line Items]
Long-term debt, gross	18,393	15,575
Unamortized debt discount	(25)	(24)
Unamortized debt issuance costs	(104)	(91)
Long-term debt due within one year	(462)	(682)
Mortgage bonds, notes, and other	$ 17,802	14,778
Junior Subordinated Debentures
Debt Instrument [Line Items]
Interest rate	5.30%
Long-term debt, gross	$ 1,210	1,180
Unamortized debt issuance costs	(35)	(34)
Long-term debt, total	1,175	1,146
DTE Electric
Debt Instrument [Line Items]
Long-term debt due within one year	(462)	(632)
Mortgage bonds, notes, and other	7,774	6,548
Long-term debt, total	$ 8,308
DTE Electric | Principally Secured
Debt Instrument [Line Items]
Interest rate	3.90%
Long-term debt, gross	$ 8,030	6,930
DTE Electric | Tax-Exempt Revenue Bonds
Debt Instrument [Line Items]
Interest rate	4.10%
Long-term debt, gross	$ 278	310
DTE Electric | Secured Debt, Unsecured Debt, Mortgage Notes and Other Debt
Debt Instrument [Line Items]
Long-term debt, gross	8,308	7,240
Unamortized debt discount	(16)	(15)
Unamortized debt issuance costs	(56)	(45)
Mortgage bonds, notes, and other	$ 7,774	6,548
DTE Gas | Principally Secured
Debt Instrument [Line Items]
Interest rate	4.00%
Long-term debt, gross	$ 1,910	$ 1,710

Long-Term Debt (Debt Issuances)

Long-Term Debt (Debt Issuances) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Oct. 31, 2020	Sep. 30, 2020	Aug. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Mar. 31, 2020	Feb. 29, 2020
Debt Instrument [Line Items]
Amount	$ 3,730,000,000
Unsecured Term Loan, Expiring in March 2021 | Unsecured
Debt Instrument [Line Items]
Repayment of debt	500,000,000
June 2020 Unsecured Term Loan, Expiring June 2021 | Unsecured
Debt Instrument [Line Items]
Repayment of debt	$ 167,000,000
Senior Notes | August 2020 1.05% Senior Notes Maturing In 2025
Debt Instrument [Line Items]
Interest Rate				1.05%
Amount				$ 800,000,000
Senior Notes | October 2020 0.55% Senior Notes Maturing In 2022
Debt Instrument [Line Items]
Interest Rate		0.55%
Amount		$ 750,000,000
Junior Subordinated Debentures | October 2020 4.375% Junior Subordinated Debentures Maturing In 2080
Debt Instrument [Line Items]
Interest Rate		4.38%
Amount		$ 230,000,000
Junior Subordinated Debentures | Series C, 2012, 5.25% Junior Subordinated Debentures Maturing 2062
Debt Instrument [Line Items]
Interest Rate	5.25%	5.25%
Repayment of debt	$ 200,000,000
DTE Electric | Mortgage Bonds | February 2020 2.25% Mortgage Bonds Maturing in 2030
Debt Instrument [Line Items]
Interest Rate								2.25%
Amount								$ 600,000,000
DTE Electric | Mortgage Bonds | February 2020 2.95% Mortgage Bonds Maturing In 2050
Debt Instrument [Line Items]
Interest Rate								2.95%
Amount								$ 500,000,000
DTE Electric | Mortgage Bonds | April 2020 2.63% Mortgage Bonds Maturing in 2031
Debt Instrument [Line Items]
Interest Rate						2.63%
Amount						$ 600,000,000
DTE Electric | Senior Notes | 4.89% Senior Notes Maturing 2020
Debt Instrument [Line Items]
Interest Rate	4.89%						4.89%
Repayment of debt	$ 300,000,000
DTE Electric | Senior Notes | 2010 Series B 3.45% Senior Notes Maturing 2020
Debt Instrument [Line Items]
Interest Rate	3.45%				3.45%
Repayment of debt	$ 300,000,000
DTE Electric | Senior Notes | 2008 Series KT Variable Rate Senior Notes Due 2020
Debt Instrument [Line Items]
Repayment of debt	$ 32,000,000
DTE Gas | Mortgage Bonds | August 2020 2.35% Mortgage Bonds Maturing In 2030
Debt Instrument [Line Items]
Interest Rate				2.35%
Amount				$ 125,000,000
DTE Gas | Mortgage Bonds | August 2020 3.20% Mortgage Bonds Maturing In 2050
Debt Instrument [Line Items]
Interest Rate				3.20%
Amount				$ 125,000,000
DTE Gas | Senior Notes | 2008 Series I 6.36% Senior Notes Maturing 2020
Debt Instrument [Line Items]
Interest Rate	6.36%		6.36%
Repayment of debt	$ 50,000,000

Long-Term Debt (Debt Redemption

Long-Term Debt (Debt Redemptions) (Details) - USD ($) $ in Millions	1 Months Ended				12 Months Ended
	Oct. 31, 2020	Sep. 30, 2020	Jul. 31, 2020	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument, Redemption [Line Items]
Amount					$ 882	$ 821	$ 105
Junior Subordinated Debentures | Series C, 2012, 5.25% Junior Subordinated Debentures Maturing 2062
Debt Instrument, Redemption [Line Items]
Interest Rate	5.25%				5.25%
Amount	$ 200
DTE Electric
Debt Instrument, Redemption [Line Items]
Amount					$ 632	$ 0	$ 0
DTE Electric | Senior Notes | 4.89% Senior Notes Maturing 2020
Debt Instrument, Redemption [Line Items]
Interest Rate				4.89%	4.89%
Amount				$ 300
DTE Electric | Senior Notes | 5.63% Senior Notes Maturing 2020
Debt Instrument, Redemption [Line Items]
Interest Rate			5.63%
Amount			$ 32
DTE Electric | Senior Notes | 2010 Series B 3.45% Senior Notes Maturing 2020
Debt Instrument, Redemption [Line Items]
Interest Rate			3.45%		3.45%
Amount			$ 300
DTE Gas | Senior Notes | 2008 Series I 6.36% Senior Notes Maturing 2020
Debt Instrument, Redemption [Line Items]
Interest Rate		6.36%			6.36%
Amount		$ 50

Long-Term Debt (Scheduled Debt

Long-Term Debt (Scheduled Debt Maturities) (Details) $ in Millions	Dec. 31, 2020USD ($)
Maturities of Long-term Debt [Abstract]
2021	$ 462
2022	3,466
2023	1,177
2024	1,425
2025	1,220
2026 and Thereafter	11,853
Long-term debt, total	19,603
DTE Electric
Maturities of Long-term Debt [Abstract]
2021	462
2022	316
2023	202
2024	400
2025	350
2026 and Thereafter	6,578
Long-term debt, total	$ 8,308

Long-Term Debt (Details Textual

Long-Term Debt (Details Textuals) $ / shares in Units, shares in Millions	Feb. 01, 2020$ / shares	Nov. 01, 2019USD ($)	Nov. 30, 2019USD ($)day$ / shares	Dec. 31, 2019USD ($)	Nov. 30, 2022shares	Dec. 31, 2020USD ($)shares
Debt Instrument [Line Items]
Face amount | $						$ 3,730,000,000
Financial instruments subject to mandatory redemption, settlement terms, share value, amount | $				$ 150,000,000
Equity units subject to mandatory redemption
Debt Instrument [Line Items]
Forward contract indexed to issuer's equity, forward rate per share (in dollars per share)	$ 50		$ 50
Equity units, percentage interest in attached debt instrument			0.005%
Financial instruments subject to mandatory redemption, settlement terms, share value, amount | $			$ 150,000,000
Financial instruments subject to mandatory redemption, contract adjustment rate	4.00%	4.00%
Financial instruments subject to mandatory redemption, contract adjustment rate, annual amount (in dollars per share)	$ 2
Financial instruments subject to mandatory redemption, settlement terms, maximum number of shares (in shares) | shares						13
Equity units subject to mandatory redemption | Minimum | Forecast
Debt Instrument [Line Items]
Financial instruments subject to mandatory redemption, settlement terms, number of shares (in shares) | shares					8.3
Equity units subject to mandatory redemption | Maximum | Forecast
Debt Instrument [Line Items]
Financial instruments subject to mandatory redemption, settlement terms, number of shares (in shares) | shares					10.3
Equal to or greater than $157.50, 0.3175 shares of common stock | Equity units subject to mandatory redemption
Debt Instrument [Line Items]
Number of consecutive scheduled trading days | day			20
Financial instruments subject to mandatory redemption, anti-dilution provision, conversion ratio			0.3175
Equal to or greater than $157.50, 0.3175 shares of common stock | Equity units subject to mandatory redemption | Minimum
Debt Instrument [Line Items]
Financial instruments subject to mandatory redemption, anti-dilution provision, stock price threshold (in dollars per share)			$ 157.50
Less than $157.50, but greater than $126.00, number of shares of common stock equal to $50 divided by the AMV | Equity units subject to mandatory redemption
Debt Instrument [Line Items]
Financial instruments subject to mandatory redemption, anti-dilution provision, conversion ratio			50
Less than $157.50, but greater than $126.00, number of shares of common stock equal to $50 divided by the AMV | Equity units subject to mandatory redemption | Minimum
Debt Instrument [Line Items]
Financial instruments subject to mandatory redemption, anti-dilution provision, stock price threshold (in dollars per share)			$ 126
Less than $157.50, but greater than $126.00, number of shares of common stock equal to $50 divided by the AMV | Equity units subject to mandatory redemption | Maximum
Debt Instrument [Line Items]
Financial instruments subject to mandatory redemption, anti-dilution provision, stock price threshold (in dollars per share)			$ 157.50
Less than or equal to $126.00, 0.3968 shares of common stock | Equity units subject to mandatory redemption
Debt Instrument [Line Items]
Financial instruments subject to mandatory redemption, anti-dilution provision, conversion ratio			0.3968
Less than or equal to $126.00, 0.3968 shares of common stock | Equity units subject to mandatory redemption | Maximum
Debt Instrument [Line Items]
Financial instruments subject to mandatory redemption, anti-dilution provision, stock price threshold (in dollars per share)			$ 126
November 2019 Series F 2.25% RSNs Maturing 2025 | Equity Units
Debt Instrument [Line Items]
Face amount | $		$ 1,300,000,000	$ 1,300,000,000
Interest rate		2.25%	2.25%
November 2019 Series F 2.25% RSNs Maturing 2025 | Unsuccessful remarketing | Equity Units
Debt Instrument [Line Items]
Debt instrument, redemption price, percentage			100.00%

Long-Term Debt (Equity Units) (

Long-Term Debt (Equity Units) (Details) - USD ($) shares in Millions	Feb. 01, 2020	Nov. 01, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Nov. 30, 2019
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Total Net Proceeds		$ 1,268,000,000	$ 0	$ 1,265,000,000	$ 0
Total Long-Term Debt			3,730,000,000
Equity units subject to mandatory redemption
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Units Issued (in shares)		26
Stock Purchase Contract Annual Rate	4.00%	4.00%
Stock Purchase Contract Liability		$ 150,000,000	101,000,000	$ 150,000,000
Payments			$ 49,000,000
November 2019 Equity Units Maturing 2025 | Equity Units
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Total Long-Term Debt		$ 1,300,000,000				$ 1,300,000,000
RSN Annual Interest Rate		2.25%				2.25%

Preferred and Preference Secu_3

Preferred and Preference Securities (Details)	Dec. 31, 2020$ / sharesshares
DTE Electric
Preferred and Preferenced Securities [Line Items]
Preferred stock, par value (in dollars per share) | $ / shares	$ 100
Preferred stock, shares authorized (in shares) | shares	6,747,484
Preference stock, par value (in dollars per share) | $ / shares	$ 1
Preference stock shares authorized (in shares) | shares	30,000,000
DTE Gas
Preferred and Preferenced Securities [Line Items]
Preferred stock, par value (in dollars per share) | $ / shares	$ 1
Preferred stock, shares authorized (in shares) | shares	7,000,000
Preference stock, par value (in dollars per share) | $ / shares	$ 1
Preference stock shares authorized (in shares) | shares	4,000,000
DTE Energy
Preferred and Preferenced Securities [Line Items]
Preferred stock, par value (in dollars per share) | $ / shares	$ 0
Preferred stock, shares authorized (in shares) | shares	5,000,000

Short-Term Credit Arrangement_3

Short-Term Credit Arrangements and Borrowings (Details Textuals)	Dec. 31, 2020USD ($)	Dec. 31, 2020CAD ($)	Nov. 30, 2020USD ($)	Jul. 31, 2020USD ($)	May 31, 2020CAD ($)	Dec. 31, 2019USD ($)
Short-term Debt [Line Items]
Face amount	$ 3,730,000,000
Short-term borrowings	38,000,000					$ 828,000,000
Maximum borrowing capacity	2,846,000,000
Other outstanding letters of credit	$ 231,000,000
Weighted average interest rate	1.10%	1.10%				2.00%
Dividend restriction	$ 2,800,000,000
Retained earnings	7,156,000,000					$ 6,587,000,000
Effective limitations	0
Revolving credit facility
Short-term Debt [Line Items]
Other outstanding letters of credit	38,000,000
Letters of credit
Short-term Debt [Line Items]
Other outstanding letters of credit	193,000,000
Unsecured term loan, expiring in November 2021 | Letters of credit
Short-term Debt [Line Items]
Maximum borrowing capacity	200,000,000
Unsecured Canadian revolving credit facility, expiring May 2023 | Revolving credit facility
Short-term Debt [Line Items]
Maximum borrowing capacity	86,000,000
DTE Electric
Short-term Debt [Line Items]
Maximum borrowing capacity	700,000,000
Other outstanding letters of credit	$ 0
Total funded debt to capitalization ratio	0.51	0.51
Weighted average interest rate						1.90%
Retained earnings	$ 2,623,000,000					$ 2,384,000,000
DTE Electric | Revolving credit facility
Short-term Debt [Line Items]
Other outstanding letters of credit	0
DTE Electric | Letters of credit
Short-term Debt [Line Items]
Other outstanding letters of credit	0
DTE Electric | Unsecured term loan, expiring in November 2021 | Unsecured
Short-term Debt [Line Items]
Face amount			$ 200,000,000
Short-term borrowings	0
DTE Electric | Unsecured term loan, expiring in November 2021 | Letters of credit
Short-term Debt [Line Items]
Maximum borrowing capacity	200,000,000
DTE Electric | Unsecured Canadian revolving credit facility, expiring May 2023 | Revolving credit facility
Short-term Debt [Line Items]
Maximum borrowing capacity	0
DTE Gas
Short-term Debt [Line Items]
Maximum borrowing capacity	300,000,000
Other outstanding letters of credit	$ 0
Total funded debt to capitalization ratio	0.48	0.48
DTE Gas | Revolving credit facility
Short-term Debt [Line Items]
Other outstanding letters of credit	$ 0
DTE Gas | Letters of credit
Short-term Debt [Line Items]
Other outstanding letters of credit	0
DTE Gas | Unsecured term loan, expiring in November 2021 | Letters of credit
Short-term Debt [Line Items]
Maximum borrowing capacity	0
DTE Gas | Unsecured Canadian revolving credit facility, expiring May 2023 | Revolving credit facility
Short-term Debt [Line Items]
Maximum borrowing capacity	0
DTE Lake Erie Generation, Inc | Unsecured Canadian revolving credit facility, expiring May 2023 | Revolving credit facility
Short-term Debt [Line Items]
Maximum borrowing capacity					$ 110,000,000
Other outstanding letters of credit		$ 49,000,000
DTE Energy
Short-term Debt [Line Items]
Maximum borrowing capacity	1,846,000,000
Other outstanding letters of credit	$ 231,000,000
Total funded debt to capitalization ratio	0.59	0.59
DTE Energy | Revolving credit facility
Short-term Debt [Line Items]
Other outstanding letters of credit	$ 38,000,000
DTE Energy | Letters of credit
Short-term Debt [Line Items]
Other outstanding letters of credit	193,000,000
DTE Energy | Demand financing agreement
Short-term Debt [Line Items]
Maximum borrowing capacity	300,000,000
Amount outstanding	49,000,000					$ 114,000,000
DTE Energy | Unsecured term loan, expiring in November 2021 | Letters of credit
Short-term Debt [Line Items]
Maximum borrowing capacity	0
DTE Energy | Unsecured Canadian revolving credit facility, expiring May 2023 | Revolving credit facility
Short-term Debt [Line Items]
Maximum borrowing capacity	86,000,000
DTE Energy | Other outstanding letters of credit | Letters of credit
Short-term Debt [Line Items]
Other outstanding letters of credit	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	100,000,000
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	$ 150,000,000
Maximum
Short-term Debt [Line Items]
Total funded debt to capitalization ratio	0.65	0.65

Short-Term Credit Arrangement_4

Short-Term Credit Arrangements and Borrowings (Schedule of Borrowings) (Details) $ in Millions	Dec. 31, 2020USD ($)
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	$ 2,846
Amounts outstanding	231
Net availability	2,615
DTE Electric
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	700
Amounts outstanding	0
Net availability	700
DTE Gas
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	300
Amounts outstanding	0
Net availability	300
DTE Energy
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	1,846
Amounts outstanding	231
Net availability	1,615
Letters of credit
Line Of Credit Facility [Line Items]
Amounts outstanding	193
Letters of credit | DTE Electric
Line Of Credit Facility [Line Items]
Amounts outstanding	0
Letters of credit | DTE Gas
Line Of Credit Facility [Line Items]
Amounts outstanding	0
Letters of credit | DTE Energy
Line Of Credit Facility [Line Items]
Amounts outstanding	193
Letters of credit | Unsecured letter of credit facility, expiring in February 2021
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	150
Letters of credit | Unsecured letter of credit facility, expiring in February 2021 | DTE Electric
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	0
Letters of credit | Unsecured letter of credit facility, expiring in February 2021 | DTE Gas
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	0
Letters of credit | Unsecured letter of credit facility, expiring in February 2021 | DTE Energy
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	150
Letters of credit | Unsecured letter of credit facility, expiring in August 2021
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	110
Letters of credit | Unsecured letter of credit facility, expiring in August 2021 | DTE Electric
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	0
Letters of credit | Unsecured letter of credit facility, expiring in August 2021 | DTE Gas
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	0
Letters of credit | Unsecured letter of credit facility, expiring in August 2021 | DTE Energy
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	110
Letters of credit | Unsecured term loan, expiring in November 2021
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	200
Letters of credit | Unsecured term loan, expiring in November 2021 | DTE Electric
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	200
Letters of credit | Unsecured term loan, expiring in November 2021 | DTE Gas
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	0
Letters of credit | Unsecured term loan, expiring in November 2021 | DTE Energy
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	0
Revolving credit facility
Line Of Credit Facility [Line Items]
Amounts outstanding	38
Revolving credit facility | DTE Electric
Line Of Credit Facility [Line Items]
Amounts outstanding	0
Revolving credit facility | DTE Gas
Line Of Credit Facility [Line Items]
Amounts outstanding	0
Revolving credit facility | DTE Energy
Line Of Credit Facility [Line Items]
Amounts outstanding	38
Revolving credit facility | Unsecured Canadian revolving credit facility, expiring May 2023
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	86
Revolving credit facility | Unsecured Canadian revolving credit facility, expiring May 2023 | DTE Electric
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	0
Revolving credit facility | Unsecured Canadian revolving credit facility, expiring May 2023 | DTE Gas
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	0
Revolving credit facility | Unsecured Canadian revolving credit facility, expiring May 2023 | DTE Energy
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	86
Revolving credit facility | Unsecured revolving credit facility, expiring April 2024
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	2,300
Revolving credit facility | Unsecured revolving credit facility, expiring April 2024 | DTE Electric
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	500
Revolving credit facility | Unsecured revolving credit facility, expiring April 2024 | DTE Gas
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	300
Revolving credit facility | Unsecured revolving credit facility, expiring April 2024 | DTE Energy
Line Of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	$ 1,500

Leases (Details Textuals)

Leases (Details Textuals) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Finance lease agreement, term (less than)	2 years
Net investment in finance lease arrangement	$ 8
Selling profit recognized	11
Net investment in finance lease arrangement	$ 133
Percent ownership interest in Vector Pipeline	40.00%
Net investment in finance leases	$ 178
Depreciation expense associated with property under operating leases	27	$ 26
Interest income recognized under finance leases	16	5
Vector | Equity Method Investee
Lessee, Lease, Description [Line Items]
Net investment in finance leases	39
Interest income recognized under finance leases	$ 4	$ 4
Minimum
Lessee, Lease, Description [Line Items]
Lease terms	2 years
Term of operating lease contracts	2 years
Maximum
Lessee, Lease, Description [Line Items]
Lease terms	40 years
Term of operating lease contracts	24 years
DTE Electric | Minimum
Lessee, Lease, Description [Line Items]
Lease terms	2 years
DTE Electric | Maximum
Lessee, Lease, Description [Line Items]
Lease terms	40 years

Leases (Components of Lease Cos

Leases (Components of Lease Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 39	$ 41
Finance lease cost:
Amortization of right-of-use assets	5	4
Interest of lease liabilities	0	0
Total finance lease cost	5	4
Variable lease cost	10	10
Short-term lease cost	12	10
Total lease cost	66	65
DTE Electric
Lessee, Lease, Description [Line Items]
Operating lease cost	14	17
Finance lease cost:
Amortization of right-of-use assets	4	4
Interest of lease liabilities	0	0
Total finance lease cost	4	4
Variable lease cost	0	0
Short-term lease cost	6	3
Total lease cost	$ 24	$ 24

Leases (Other Information) (Det

Leases (Other Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash paid for amounts included in the measurement of these liabilities:
Operating cash flows for finance leases	$ 3	$ 5
Operating cash flows for operating leases	40	40
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	18	68
Finance leases	$ 19	$ 8
Weighted Average Remaining Lease Term (Years)
Operating leases	9 years 3 months 18 days	9 years 8 months 12 days
Finance leases	7 years 7 months 6 days	9 years 1 month 6 days
Weighted Average Discount Rate
Operating leases	3.40%	3.50%
Finance leases	2.00%	3.10%
DTE Electric
Cash paid for amounts included in the measurement of these liabilities:
Operating cash flows for finance leases	$ 2	$ 5
Operating cash flows for operating leases	14	16
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	0	27
Finance leases	$ 14	$ 0
Weighted Average Remaining Lease Term (Years)
Operating leases	10 years 4 months 24 days	10 years 7 months 6 days
Finance leases	3 years 1 month 6 days	2 years
Weighted Average Discount Rate
Operating leases	3.30%	3.30%
Finance leases	1.00%	3.10%

Leases (Future Minimum Lease Pa

Leases (Future Minimum Lease Payments) (Details) $ in Millions	Dec. 31, 2020USD ($)
Operating Leases
2021	$ 37
2022	31
2023	22
2024	13
2025	8
2026 and thereafter	61
Total future minimum lease payments	172
Imputed interest	(28)
Lease liabilities	144
Finance Leases
2021	8
2022	8
2023	8
2024	2
2025	1
2026 and thereafter	7
Total future minimum lease payments	34
Imputed interest	(3)
Lease liabilities	31
DTE Electric
Operating Leases
2021	13
2022	12
2023	10
2024	8
2025	6
2026 and thereafter	32
Total future minimum lease payments	81
Imputed interest	(14)
Lease liabilities	67
Finance Leases
2021	6
2022	6
2023	6
2024	1
2025	0
2026 and thereafter	0
Total future minimum lease payments	19
Imputed interest	0
Lease liabilities	$ 19

Leases (Finance Leases Reported

Leases (Finance Leases Reported on Consolidated Statements of Financial Position) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet	us-gaap:PropertyPlantAndEquipmentNet
Right-of-use assets, within Property, plant, and equipment, net	$ 29	$ 15
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent
Current lease liabilities, within Current Liabilities — Other	$ 7	$ 4
Long-term lease liabilities	24	11
DTE Electric
Lessee, Lease, Description [Line Items]
Right-of-use assets, within Property, plant, and equipment, net	16	7
Current lease liabilities, within Current Liabilities — Other	6	3
Long-term lease liabilities	$ 13	$ 4

Leases (Lease Income Associated

Leases (Lease Income Associated with Operating Leases) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lessor, Lease, Description [Line Items]
Fixed payments	$ 66	$ 65
Variable payments	124	128
Total lease income under operating leases	190	193
Operating Revenues
Lessor, Lease, Description [Line Items]
Total lease income under operating leases	108	130
Other Income
Lessor, Lease, Description [Line Items]
Total lease income under operating leases	$ 82	$ 63

Leases (Minimum Future Rental R

Leases (Minimum Future Rental Revenues under Operating Leases) (Details) $ in Millions	Dec. 31, 2020USD ($)
Leases [Abstract]
2021	$ 62
2022	22
2023	22
2024	22
2025	19
2026 and thereafter	175
Total minimum future rental revenues under operating leases	$ 322

Leases (Property under Operatin

Leases (Property under Operating Leases) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Lessor, Lease, Description [Line Items]
Gross property under operating leases	$ 37,997	$ 35,072
Accumulated amortization of property under operating leases	10,028	9,755
Property Under Operating Leases
Lessor, Lease, Description [Line Items]
Gross property under operating leases	447	445
Accumulated amortization of property under operating leases	$ 197	$ 173

Leases (Components of Net Inves

Leases (Components of Net Investment in Finance Leases) (Details) $ in Millions	Dec. 31, 2020USD ($)
Leases [Abstract]
2021	$ 24
2022	20
2023	19
2024	19
2025	19
2026 and thereafter	253
Total minimum future lease receipts	354
Residual value of leased pipeline	17
Less unearned income	193
Net investment in finance lease	178
Less current portion	9
Net investment in finance lease, noncurrent	$ 169

Commitments and Contingencies_2

Commitments and Contingencies (Details Textuals)	Jul. 23, 2020USD ($)plant	Jan. 31, 2021	Jun. 30, 2020	Dec. 31, 2020USD ($)employeesitefacilityplant	Dec. 31, 2019USD ($)	Jul. 31, 2019CAD ($)	Jul. 31, 2009plant
Loss Contingencies [Line Items]
Expected minimum contribution for community based environmental projects	$ 2,000,000
Utility capital expenditures, expenditures for non-utility businesses, and contributions to equity method investees estimated for next year				$ 4,200,000,000
Power and Industrial Projects
Loss Contingencies [Line Items]
Number of generating plants operated with ownership interests held | plant				5
Labor force concentration risk | Workforce subject to collective bargaining arrangements
Loss Contingencies [Line Items]
Approximate number of employees | employee				5,200
Synthetic fuel guarantees
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				$ 581,000,000
Other guarantees
Loss Contingencies [Line Items]
Maximum potential liability				50,000,000
Performance surety bonds
Loss Contingencies [Line Items]
Performance bonds outstanding				$ 125,000,000
Reduction of Carbon Emissions by 2023
Loss Contingencies [Line Items]
Goal to reduce carbon emissions, percentage				32.00%
Reduction of Carbon Emissions by 2030
Loss Contingencies [Line Items]
Goal to reduce carbon emissions, percentage				50.00%
Reduction of Carbon Emissions by 2040
Loss Contingencies [Line Items]
Goal to reduce carbon emissions, percentage				80.00%
The Sierra Club
Loss Contingencies [Line Items]
Amount accrued for settlement				$ 5,000,000
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				$ 55,000,000
Vector | NEXUS Pipeline
Loss Contingencies [Line Items]
Maximum potential liability				$ 7,000,000
Percentage of all payment obligations due and payable				50.00%
Guarantee termination, minimum threshold, period following end of primary term of capacity lease agreements				15 years
DTE Electric
Loss Contingencies [Line Items]
Number of power plants allegedly in violation | plant							5
Number of power plants with requirement to retire, repower, refuel or retrofit units | plant	4
Environmental capital expenditures				$ 2,400,000,000
Estimated capital expenditures				$ 0
Number of former MGP sites | site				3
Accrued for remediation related to the sites				$ 10,000,000	$ 8,000,000
Number of permitted engineered coal ash storage facilities owned | facility				3
Utility capital expenditures, expenditures for non-utility businesses, and contributions to equity method investees estimated for next year				$ 3,000,000,000
DTE Electric | Labor force concentration risk | Workforce subject to collective bargaining arrangements
Loss Contingencies [Line Items]
Approximate number of employees | employee				2,800
DTE Electric | Performance surety bonds
Loss Contingencies [Line Items]
Performance bonds outstanding				$ 69,000,000
DTE Electric | Reduction of Carbon Emissions by 2050
Loss Contingencies [Line Items]
Goal of net carbon emissions, percentage				0.00%
DTE Electric | CCR and ELG Rules
Loss Contingencies [Line Items]
Estimated impact of the CCR and ELG rules				$ 721,000,000
Estimated impact of the CCR and ELG rules, through 2025				$ 601,000,000
DTE Electric | The Sierra Club
Loss Contingencies [Line Items]
Civil penalty paid	$ 2,000,000
DTE Gas
Loss Contingencies [Line Items]
Number of former MGP sites | site				14
Accrued for remediation related to the sites				$ 24,000,000	$ 25,000,000
Amortization period for MGP costs (in years)				10 years
DTE Gas | Cleanup completed and site closed
Loss Contingencies [Line Items]
Number of former MGP sites | site				8
DTE Gas | Partial closure completed
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 | Subsequent Event
Loss Contingencies [Line Items]
Goal of net greenhouse gas emissions, percentage		0.00%
DTE Midstream | Reduction of Carbon Emissions in the next decade | Subsequent Event
Loss Contingencies [Line Items]
Goal to reduce carbon emissions, percentage		30.00%
NEXUS | DTE Gas | NEXUS Pipeline
Loss Contingencies [Line Items]
Capacity lease agreement term				15 years
Percentage of all payment obligations due and payable				50.00%
NEXUS | Texas Eastern Transmission, LP | NEXUS Pipeline
Loss Contingencies [Line Items]
Capacity lease agreement term				15 years
Percentage of all payment obligations due and payable				50.00%
NEXUS | Vector | NEXUS Pipeline
Loss Contingencies [Line Items]
Capacity lease agreement term				15 years

Commitments and Contingencies_3

Commitments and Contingencies (Purchase Commitments) (Details) $ in Millions	Dec. 31, 2020USD ($)
Purchase Obligation, Fiscal Year Maturity [Abstract]
2021	$ 2,998
2022	1,142
2023	804
2024	520
2025	397
2026 and thereafter	1,634
Total purchase commitments	7,495
DTE Electric
Purchase Obligation, Fiscal Year Maturity [Abstract]
2021	1,132
2022	246
2023	226
2024	159
2025	209
2026 and thereafter	969
Total purchase commitments	$ 2,941

Nuclear Operations (Details)

Nuclear Operations (Details) - DTE Electric $ in Millions	May 16, 2014kWh	May 15, 2014$ / MWh	Dec. 31, 2020USD ($)
Entity Information [Line Items]
Policy waiting period			84 days
Insurance coverage for extra expense when power plant unavailable			$ 490
Period of coverage of policy for extra expenses			3 years
Primary coverage for stabilization, decontamination, debris removal, repair and/or replacement of property, and decommissioning			$ 1,500
Excess coverage for stabilization, decontamination, debris removal, repair and/or replacement of property, and decommissioning			1,250
Combined coverage limit for total property damage			2,750
Total limit for property damage for non-nuclear events			1,800
Limit of coverage for aggregate extra expenses for non-nuclear events			$ 328
Period of coverage for extra expenses			2 years
Time period for TRIA after the first loss from terrorism			1 year
NEIL policies against terrorism loss, amount made available to all insured entities (up to)			$ 3,200
Maximum assessment if loss amount exceeds funds available			43
Public liability insurance for a nuclear incident			450
One industry aggregate limit of coverage arising from terrorist act outside scope of TRIA			300
Maximum deferred premium charges that could be levied against each licensed nuclear facility			138
Limit of deferred premium charges per year per facility			$ 20
Company obligated to pay DOE fee of Fermi 2 electricity generated and sold (in dollars per MWh) | $ / MWh		1
New DOE fee for Fermi 2 electricity generated and sold (KWh) | kWh	0

Retirement Benefits and Trust_3

Retirement Benefits and Trusteed Assets (Pension Plan - Pension Cost Inclusions) (Details) - Pension plan - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		$ 99	$ 84	$ 99
Interest cost		186	219	202
Expected return on plan assets		(334)	(325)	(329)
Amortization of:
Net actuarial loss		171	131	176
Prior service cost		1	1	0
Settlements	$ 22	25	2	0
Net pension cost/other postretirement cost (credit)		$ 148	$ 112	$ 148

Retirement Benefits and Trust_4

Retirement Benefits and Trusteed Assets (Pension Plan - Other Changes in Plan Assets and Benefit Obligations recognized in Reg Assets and OCI) (Details) - Pension plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Other changes in plan assets and benefit obligations recognized in Regulatory assets and Other comprehensive income (loss)
Net actuarial loss	$ 137	$ 156
Amortization of net actuarial loss	(193)	(133)
Amortization of prior service cost	(1)	(1)
Total recognized in Regulatory assets and Other comprehensive income (loss)	(57)	22
Total recognized in net periodic pension cost, Regulatory assets, and Other comprehensive income (loss)	$ 91	$ 134

Retirement Benefits and Trust_5

Retirement Benefits and Trusteed Assets (Pension Plan - Reconciliation of Obligations, Assets and Funded Status of Plans) (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Amounts recognized in Regulatory assets
Regulatory assets	$ 4,257	$ 4,257	$ 4,176
Pension plan
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Accumulated benefit obligation, end of year	5,843	5,843	5,387
Change in projected benefit obligation
Projected/Accumulated postretirement benefit obligation, beginning of year		5,810	5,124
Service cost		99	84	$ 99
Interest cost		186	219	202
Actuarial loss		619	719
Special termination benefits		3	0
Benefits paid		(353)	(336)
Settlements	(60)	(60)	0
Projected/Accumulated postretirement benefit obligation, end of year	6,304	6,304	5,810	5,124
Change in plan assets
Plan assets at fair value, beginning of year		4,993	4,273
Actual return on plan assets		815	888
Company contributions		102	168
Benefits paid		(353)	(336)
Settlements	(60)	(60)	0
Plan assets at fair value, end of year	5,497	5,497	4,993	$ 4,273
Funded status	(807)	(807)	(817)
Amount recorded as:
Current liabilities	(10)	(10)	(9)
Noncurrent liabilities	(797)	(797)	(808)
Defined benefit plans liabilities	(807)	(807)	(817)
Amounts recognized in Accumulated other comprehensive income (loss), pre-tax
Net actuarial loss	142	142	153
Prior service cost	3	3	4
Amounts recognized in Accumulated other comprehensive income (loss), pre-tax	145	145	157
Amounts recognized in Regulatory assets
Net actuarial loss	1,949	1,949	1,995
Prior service credit	(11)	(11)	(12)
Regulatory assets	$ 1,938	$ 1,938	$ 1,983

Retirement Benefits and Trust_6

Retirement Benefits and Trusteed Assets (Details Textuals) - USD ($) $ in Millions	Sep. 08, 2020	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contribution of common stock to pension plan				$ 82	$ 100	$ 175
Defined contribution plan, cost recognized				$ 73	65	61
Annual contributions per employee, percentage				4.00%
Qualified Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Cash contributions to pension plan				$ 10
DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined contribution plan, cost recognized				$ 34	31	29
DTE Electric | Qualified Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Cash contributions to pension plan			$ 60
DTE Gas
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Annual contributions per employee, percentage				8.00%
DTE Gas | Qualified Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Cash contributions to pension plan			$ 22
Pension plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Reduction to projected benefit obligation due to settlement		$ 60		$ 60	0
Reduction to plan assets due to settlement		60		60	0
Settlement charge		22		25	2	0
Company contributions				$ 102	168
Contribution of common stock to pension plan	$ 82
Expected return on plan assets for next fiscal year				7.00%
Pension plan | Qualified Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions				$ 92	150	175
Contribution of common stock to pension plan				82
Pension plan | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Allocated pension benefit costs				106	93	120
Pension plan | DTE Electric | Qualified Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Company contributions				60	100	175
Pension plan | Maximum | Qualified Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Estimated future employer contributions in next fiscal year		107		107
Pension plan | Maximum | DTE Electric | Qualified Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Estimated future employer contributions in next fiscal year		$ 100		$ 100
Other postretirement benefit plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected return on plan assets for next fiscal year				6.70%
Retiree health care allowance will increase at lower of the rate of medical inflation or a set percentage		2.00%		2.00%
Retiree healthcare plan (VEBA)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined contribution plan, cost recognized				$ 15	13	11
Retiree healthcare plan (VEBA) | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined contribution plan, cost recognized				$ 7	$ 6	$ 5

Retirement Benefits and Trust_7

Retirement Benefits and Trusteed Assets (Pension Plan - Contributions) (Details) - Pension Plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Cash contributions to qualified pension plans	$ 102	$ 168
Qualified Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Cash contributions to qualified pension plans	92	150	$ 175
Qualified Plan | DTE Electric
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Cash contributions to qualified pension plans	$ 60	$ 100	$ 175

Retirement Benefits and Trust_8

Retirement Benefits and Trusteed Assets (Pension Plan - Contributions to DTE Energy Company Affiliates Employee Benefit Plans Master Trust) (Details) - USD ($) $ / shares in Units, $ in Millions	Sep. 08, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Contribution Plan Disclosure [Line Items]
Amount		$ 82	$ 100	$ 175
Pension Plan
Defined Contribution Plan Disclosure [Line Items]
Number of Shares (in shares)	694,444
Price per Share (in dollars per share)	$ 118.08
Amount	$ 82

Retirement Benefits and Trust_9

Retirement Benefits and Trusteed Assets (Pension Plan - Benefits related to Qualified and Nonqualified Pension Plans Expected to be paid in the Next Ten Years) (Details) - Pension plan $ in Millions	Dec. 31, 2020USD ($)
Defined Benefit Plan, Expected Future Benefit Payment [Abstract]
2021	$ 352
2022	363
2023	368
2024	352
2025	360
2026-2030	1,757
Total	$ 3,552

Retirement Benefits and Trus_10

Retirement Benefits and Trusteed Assets (Pension Plan - Assumptions used in Determining the PBO and Net Pension Costs) (Details) - Pension plan	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Projected benefit obligation
Discount rate	2.57%	3.28%	4.40%
Rate of compensation increase	3.80%	3.85%	3.85%
Cash balance interest crediting rate	2.00%	3.30%	3.70%
Net pension costs
Discount rate	3.28%	4.40%	3.70%
Rate of compensation increase	3.85%	3.85%	3.85%
Expected long-term rate of return on plan assets	7.10%	7.30%	7.50%
Cash balance interest crediting rate	3.30%	3.70%	3.70%

Retirement Benefits and Trus_11

Retirement Benefits and Trusteed Assets (Pension Plan - Target Allocations of Plan Assets) (Details) - Pension plan	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage of assets	100.00%
U.S. Large Capitalization (Cap) Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage of assets	18.00%
U.S. Small Cap and Mid Cap Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage of assets	3.00%
Non-U.S. Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage of assets	16.00%
Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage of assets	38.00%
Hedge Funds and Similar Investments
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage of assets	14.00%
Private Equity and Other
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage of assets	11.00%

Retirement Benefits and Trus_12

Retirement Benefits and Trusteed Assets (Pension Plan - Fair Value Measurements) (Details) - Pension Plan - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 5,497	$ 4,993	$ 4,273
Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	92	99
Equity Securities, Domestic
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	1,260	1,042
Equity Securities, International
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	891	709
Fixed Income Securities, Governmental
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	554	569
Fixed Income Securities, Corporate
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	1,404	1,452
Hedge Funds and Similar Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	710	671
Private Equity and Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	586	451
Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	1,056	1,396
Level 1 | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	92	99
Level 1 | Equity Securities, Domestic
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	167	172
Level 1 | Equity Securities, International
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	100	387
Level 1 | Fixed Income Securities, Governmental
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	459	569
Level 1 | Fixed Income Securities, Corporate
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Level 1 | Hedge Funds and Similar Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	238	169
Level 1 | Private Equity and Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	1,560	1,452
Level 2 | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Level 2 | Equity Securities, Domestic
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Level 2 | Equity Securities, International
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Level 2 | Fixed Income Securities, Governmental
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	95	0
Level 2 | Fixed Income Securities, Corporate
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	1,404	1,452
Level 2 | Hedge Funds and Similar Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	61	0
Level 2 | Private Equity and Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	2,881	2,145
Other | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Other | Equity Securities, Domestic
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	1,093	870
Other | Equity Securities, International
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	791	322
Other | Fixed Income Securities, Governmental
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Other | Fixed Income Securities, Corporate
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Other | Hedge Funds and Similar Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	411	502
Other | Private Equity and Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 586	$ 451

Retirement Benefits and Trus_13

Retirement Benefits and Trusteed Assets (OPEB - Postretirement Cost Inclusions) (Details) - Other postretirement benefit plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 26	$ 22	$ 27
Interest cost	56	70	69
Expected return on plan assets	(128)	(96)	(143)
Amortization of:
Net actuarial loss	16	12	11
Prior service credit	(19)	(9)	0
Net pension cost/other postretirement cost (credit)	(49)	(1)	(36)
DTE Electric
Defined Benefit Plan Disclosure [Line Items]
Service cost	20	16	20
Interest cost	43	53	53
Expected return on plan assets	(87)	(65)	(98)
Amortization of:
Net actuarial loss	11	5	8
Prior service credit	(14)	(7)	0
Net pension cost/other postretirement cost (credit)	$ (27)	$ 2	$ (17)

Retirement Benefits and Trus_14

Retirement Benefits and Trusteed Assets (OPEB - Other Changes in Plan Assets and APBO Recognized in Regulatory Assets and OCI) (Details) - Other postretirement benefit plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Other changes in plan assets and accumulated postretirement benefit obligation recognized in Regulatory assets and Other comprehensive income (loss)
Net actuarial (gain) loss	$ (38)	$ 34
Amortization of net actuarial loss	(16)	(12)
Prior service credit (cost)	0	(53)
Amortization of prior service credit	19	9
Total recognized in Regulatory assets and Other comprehensive income (loss)	(35)	(22)
Total recognized in net periodic pension cost, Regulatory assets, and Other comprehensive income (loss)	(84)	(23)
DTE Electric
Other changes in plan assets and accumulated postretirement benefit obligation recognized in Regulatory assets and Other comprehensive income (loss)
Net actuarial (gain) loss	(26)	41
Amortization of net actuarial loss	(11)	(5)
Prior service credit (cost)	0	(33)
Amortization of prior service credit	14	7
Total recognized in Regulatory assets and Other comprehensive income (loss)	(23)	10
Total recognized in net periodic pension cost, Regulatory assets, and Other comprehensive income (loss)	$ (50)	$ 12

Retirement Benefits and Trus_15

Retirement Benefits and Trusteed Assets (OPEB - Reconciliation of Obligations, Assets and Funded Status of Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Amounts recognized in Regulatory assets
Regulatory assets	$ 4,257	$ 4,176
Other postretirement benefit plan
Change in accumulated postretirement benefit obligation
Projected/Accumulated postretirement benefit obligation, beginning of year	1,751	1,645
Service cost	26	22	$ 27
Interest cost	56	70	69
Plan amendments	0	(53)
Actuarial loss	54	153
Benefits paid	(80)	(86)
Projected/Accumulated postretirement benefit obligation, end of year	1,807	1,751	1,645
Change in plan assets
Plan assets at fair value, beginning of year	1,819	1,689
Actual return on plan assets	220	215
Benefits paid	(79)	(85)
Plan assets at fair value, end of year	1,960	1,819	1,689
Funded status	153	68
Amount recorded as:
Noncurrent assets	561	454
Current liabilities	(1)	(1)
Noncurrent liabilities	(407)	(385)
Defined benefit plans assets (liabilities)	153	68
Amounts recognized in Accumulated other comprehensive income (loss), pre-tax
Net actuarial gain	(7)	(8)
Amounts recognized in Accumulated other comprehensive income (loss), pre-tax	(7)	(8)
Amounts recognized in Regulatory assets
Net actuarial loss	234	289
Prior service credit	(69)	(88)
Regulatory assets	165	201
DTE Electric
Amounts recognized in Regulatory assets
Regulatory assets	3,563	3,453
DTE Electric | Other postretirement benefit plan
Change in accumulated postretirement benefit obligation
Projected/Accumulated postretirement benefit obligation, beginning of year	1,337	1,247
Service cost	20	16	20
Interest cost	43	53	53
Plan amendments	0	(33)
Actuarial loss	31	118
Benefits paid	(62)	(64)
Projected/Accumulated postretirement benefit obligation, end of year	1,369	1,337	1,247
Change in plan assets
Plan assets at fair value, beginning of year	1,236	1,158
Actual return on plan assets	145	141
Benefits paid	(61)	(63)
Plan assets at fair value, end of year	1,320	1,236	$ 1,158
Funded status	(49)	(101)
Amount recorded as:
Noncurrent assets	335	266
Current liabilities	0	0
Noncurrent liabilities	(384)	(367)
Defined benefit plans assets (liabilities)	(49)	(101)
Amounts recognized in Accumulated other comprehensive income (loss), pre-tax
Net actuarial gain	0	0
Amounts recognized in Accumulated other comprehensive income (loss), pre-tax	0	0
Amounts recognized in Regulatory assets
Net actuarial loss	156	193
Prior service credit	(48)	(62)
Regulatory assets	$ 108	$ 131

Retirement Benefits and Trus_16

Retirement Benefits and Trusteed Assets (OPEB - Accumulated Postretirement Obligations in Excess of Plan Assets) (Details) - Other postretirement benefit plan - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Accumulated postretirement benefit obligation	$ 878	$ 840
Fair value of plan assets	470	454
Accumulated postretirement benefit obligation in excess of plan assets	408	386
DTE Electric
Defined Benefit Plan Disclosure [Line Items]
Accumulated postretirement benefit obligation	826	795
Fair value of plan assets	442	428
Accumulated postretirement benefit obligation in excess of plan assets	$ 384	$ 367

Retirement Benefits and Trus_17

Retirement Benefits and Trusteed Assets (OPEB - Benefits related to Qualified and Nonqualified Pension Plans Expected to be paid in the Next Ten Years) (Details) - Other postretirement benefit plan $ in Millions	Dec. 31, 2020USD ($)
Defined Benefit Plan Disclosure [Line Items]
2021	$ 82
2022	87
2023	91
2024	92
2025	95
2026-2030	497
Total	944
DTE Electric
Defined Benefit Plan Disclosure [Line Items]
2021	62
2022	66
2023	69
2024	70
2025	72
2026-2030	376
Total	$ 715

Retirement Benefits and Trus_18

Retirement Benefits and Trusteed Assets (OPEB - Assumptions used in Determining the PBO and Net Pension Costs) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated postretirement benefit obligation
Ultimate health care trend rate			4.50%
Other postretirement benefit costs
Ultimate health care trend rate			4.50%
Other postretirement benefit plan
Accumulated postretirement benefit obligation
Discount rate	2.58%	3.29%	4.40%
Health care trend rate pre- 65	6.75%	6.75%	6.75%
Health care trend post- 65	7.25%	7.25%	7.25%
Ultimate health care trend rate	4.50%	4.50%	4.50%
Other postretirement benefit costs
Discount rate	3.29%	4.40%	3.70%
Expected long-term rate of return on plan assets	7.20%	7.30%	7.75%
Health care trend rate pre- 65	6.75%	6.75%	6.75%
Health care trend post- 65	7.25%	7.25%	7.25%
Ultimate health care trend rate	4.50%	4.50%	4.50%

Retirement Benefits and Trus_19

Retirement Benefits and Trusteed Assets (OPEB - Target Allocations of Plan Assets) (Details) - Other postretirement benefit plan	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage of assets	100.00%
U.S. Large Cap Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage of assets	11.00%
U.S. Small Cap and Mid Cap Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage of assets	2.00%
Non-U.S. Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage of assets	10.00%
Fixed Income Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage of assets	52.00%
Hedge Funds and Similar Investments
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage of assets	11.00%
Private Equity and Other
Defined Benefit Plan Disclosure [Line Items]
Target allocation percentage of assets	14.00%

Retirement Benefits and Trus_20

Retirement Benefits and Trusteed Assets (OPEB - Fair Value Measurements) (Details) - Other postretirement benefit plan - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 1,960	$ 1,819	$ 1,689
Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	196	458
Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	539	256
Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	1,225	1,105
Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	21	80
Short-term Investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	21	80
Short-term Investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Short-term Investments | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Equity Securities, Domestic
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	251	324
Equity Securities, Domestic | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	51	51
Equity Securities, Domestic | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Equity Securities, Domestic | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	200	273
Equity Securities, International
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	201	271
Equity Securities, International | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	23	182
Equity Securities, International | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Equity Securities, International | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	178	89
Fixed Income Securities, Governmental
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	85	74
Fixed Income Securities, Governmental | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	40	74
Fixed Income Securities, Governmental | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	45	0
Fixed Income Securities, Governmental | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Fixed Income Securities, Corporate
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	856	507
Fixed Income Securities, Corporate | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Fixed Income Securities, Corporate | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	477	256
Fixed Income Securities, Corporate | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	379	251
Hedge Funds and Similar Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	202	253
Hedge Funds and Similar Investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	61	71
Hedge Funds and Similar Investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	17	0
Hedge Funds and Similar Investments | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	124	182
Private Equity and Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	344	310
Private Equity and Other | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Private Equity and Other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
Private Equity and Other | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	344	310
DTE Electric
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	1,320	1,236	$ 1,158
DTE Electric | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	128	310
DTE Electric | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	363	168
DTE Electric | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	829	758
DTE Electric | Short-term Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	14	55
DTE Electric | Short-term Investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	14	55
DTE Electric | Short-term Investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Short-term Investments | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Equity Securities, Domestic
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	164	219
DTE Electric | Equity Securities, Domestic | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	33	34
DTE Electric | Equity Securities, Domestic | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Equity Securities, Domestic | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	131	185
DTE Electric | Equity Securities, International
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	133	184
DTE Electric | Equity Securities, International | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	16	124
DTE Electric | Equity Securities, International | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Equity Securities, International | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	117	60
DTE Electric | Fixed Income Securities, Governmental
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	55	48
DTE Electric | Fixed Income Securities, Governmental | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	24	48
DTE Electric | Fixed Income Securities, Governmental | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	31	0
DTE Electric | Fixed Income Securities, Governmental | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Fixed Income Securities, Corporate
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	584	344
DTE Electric | Fixed Income Securities, Corporate | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Fixed Income Securities, Corporate | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	321	168
DTE Electric | Fixed Income Securities, Corporate | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	263	176
DTE Electric | Hedge Funds and Similar Investments
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	135	172
DTE Electric | Hedge Funds and Similar Investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	41	49
DTE Electric | Hedge Funds and Similar Investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	11	0
DTE Electric | Hedge Funds and Similar Investments | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	83	123
DTE Electric | Private Equity and Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	235	214
DTE Electric | Private Equity and Other | Level 1
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Private Equity and Other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	0	0
DTE Electric | Private Equity and Other | Other
Defined Benefit Plan Disclosure [Line Items]
Plan assets at fair value	$ 235	$ 214

Stock-Based Compensation (Detai

Stock-Based Compensation (Details Textuals) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized limit of common stock shares (in shares)	16,500,000
Performance units price per unit (in dollars per share)	1
DTE Electric | DTE Energy
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost charged against income (in millions) | $	$ 37	$ 43	$ 38
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum award per employee (in shares)	500,000
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum award per employee (in shares)	150,000
Award vesting period	3 years
Compensation cost charged against income (in millions) | $	$ 13	$ 11	$ 11
Performance Share Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum award per employee (in shares)	300,000
Award vesting period	3 years
Performance Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum award per employee (in shares)	1,000,000

Stock-Based Compensation (Compo

Stock-Based Compensation (Components of Stock Based Compensation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Components of stock based-compensation [Abstract]
Stock-based compensation expense	$ 63	$ 71	$ 64
Tax benefit	12	13	13
Stock-based compensation cost capitalized in Property, plant, and equipment	$ 0	$ 16	$ 11

Stock-Based Compensation (Activ

Stock-Based Compensation (Activity Relating to Performance Share Awards) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Compensation Expense Recorded [Line Items]
Compensation expense	$ 63	$ 71	$ 64
Performance Share Awards
Compensation Expense Recorded [Line Items]
Weighted grant date fair value of awards granted (in dollars per share)	$ 129.68	$ 115.85	$ 105.64
Awards settled in cash	$ 21	$ 19	$ 13
Awards settled in stock	53	79	39
Compensation expense	$ 50	$ 60	$ 53

Stock-Based Compensation (Perfo

Stock-Based Compensation (Performance Share Awards Activity) (Details) - Performance shares - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Performance Shares
Balance at beginning of period (in shares)	1,226,031
Grants (in shares)	383,813
Forfeitures (in shares)	(43,768)
Payouts (in shares)	(438,639)
Balance at end of period (in shares)	1,127,437	1,226,031
Weighted Average Grant Date Fair Value
Balance at beginning of period (in dollars per share)	$ 107.35
Grants (in dollars per share)	129.68	$ 115.85	$ 105.64
Forfeitures (in dollars per share)	116.94
Payouts (in dollars per share)	99.22
Balance at end of period (in dollars per share)	$ 117.06	$ 107.35

Stock-Based Compensation (Unrec

Stock-Based Compensation (Unrecognized Compensation Costs) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Share Based Compensation Unrecognized and Non-Vested Cost [Line Items]
Unrecognized Compensation Cost	$ 68
Weighted Average to be Recognized	1 year 2 months 8 days
Stock awards
Share Based Compensation Unrecognized and Non-Vested Cost [Line Items]
Unrecognized Compensation Cost	$ 19
Weighted Average to be Recognized	1 year 7 months 6 days
Performance shares
Share Based Compensation Unrecognized and Non-Vested Cost [Line Items]
Unrecognized Compensation Cost	$ 49
Weighted Average to be Recognized	1 year 14 days

Segment and Related Informati_3

Segment and Related Information (Details Textuals) customer in Millions	Dec. 31, 2020customer
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								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Operating Revenues	$ (3,288)	$ (3,284)	$ (2,583)	$ (3,022)	$ (3,148)	$ (3,119)	$ (2,888)	$ (3,514)	$ (12,177)	$ (12,669)	$ (14,212)
Operating Revenues — Non-utility operations									(5,332)	(6,031)	(7,542)
Electric
Segment Reporting Information [Line Items]
Operating Revenues									(5,520)	(5,229)	(5,298)
Gas
Segment Reporting Information [Line Items]
Operating Revenues									(1,414)	(1,482)	(1,436)
Gas Storage and Pipelines
Segment Reporting Information [Line Items]
Operating Revenues									(754)	(501)	(485)
Power and Industrial Projects
Segment Reporting Information [Line Items]
Operating Revenues									(1,224)	(1,560)	(2,204)
Energy Trading
Segment Reporting Information [Line Items]
Operating Revenues									(3,863)	(4,610)	(5,557)
Reclassifications and Eliminations
Segment Reporting Information [Line Items]
Operating Revenues									600	715	771
Operating Revenues — Non-utility operations									525	647	707
Reclassifications and Eliminations | Electric
Segment Reporting Information [Line Items]
Operating Revenues									61	56	52
Operating Revenues — Non-utility operations									2
Reclassifications and Eliminations | Gas
Segment Reporting Information [Line Items]
Operating Revenues									16	12	12
Reclassifications and Eliminations | Gas Storage and Pipelines
Segment Reporting Information [Line Items]
Operating Revenues									26	27	36
Reclassifications and Eliminations | Power and Industrial Projects
Segment Reporting Information [Line Items]
Operating Revenues									464	596	642
Reclassifications and Eliminations | Energy Trading
Segment Reporting Information [Line Items]
Operating Revenues									31	22	27
Reclassifications and Eliminations | Corporate and Other
Segment Reporting Information [Line Items]
Operating Revenues									$ 2	$ 2	$ 2

Segment and Related Informati_5

Segment and Related Information (Financial Data - Operating Revenues Including Inter-Segment Revenues) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Operating Revenues — Utility operations									$ 6,845	$ 6,638	$ 6,670
Operating Revenues — Non-utility operations									5,332	6,031	7,542
Depreciation and amortization									1,443	1,263	1,124
Interest expense									720	641	559
Interest income									(38)	(17)	(12)
Equity in earnings of equity method investees									132	111	132
Income Tax Expense (Benefit)									167	152	98
Net Income (Loss) Attributable to DTE Energy Company	$ 275	$ 476	$ 277	$ 340	$ 267	$ 319	$ 182	$ 401	1,368	1,169	1,120
Investments in equity method investees	1,868				1,862				1,868	1,862	1,771
Capital expenditures and acquisitions									3,983	5,467	2,713
Goodwill	2,466				2,464				2,466	2,464	2,293
Total Assets	45,496				42,268				45,496	42,268	36,288
Gas Storage and Pipelines
Segment Reporting Information [Line Items]
Investments in equity method investees	1,691				1,685				1,691	1,685
Operating Segments | Electric
Segment Reporting Information [Line Items]
Operating Revenues — Utility operations									5,506	5,224	5,298
Operating Revenues — Non-utility operations									14	5	0
Depreciation and amortization									1,057	949	836
Interest expense									337	315	283
Interest income									(4)	(2)	0
Equity in earnings of equity method investees									0	1	0
Income Tax Expense (Benefit)									108	137	193
Net Income (Loss) Attributable to DTE Energy Company									777	714	664
Investments in equity method investees	6				5				6	5	7
Capital expenditures and acquisitions									2,701	2,368	1,979
Goodwill	1,208				1,208				1,208	1,208	1,208
Total Assets	26,588				24,617				26,588	24,617	22,501
Operating Segments | Gas
Segment Reporting Information [Line Items]
Operating Revenues — Utility operations									1,414	1,482	1,436
Operating Revenues — Non-utility operations									0	0	0
Depreciation and amortization									157	144	133
Interest expense									80	78	70
Interest income									(5)	(6)	(6)
Equity in earnings of equity method investees									1	2	2
Income Tax Expense (Benefit)									48	62	67
Net Income (Loss) Attributable to DTE Energy Company									186	185	150
Investments in equity method investees	12				11				12	11	12
Capital expenditures and acquisitions									574	530	460
Goodwill	743				743				743	743	743
Total Assets	6,339				5,717				6,339	5,717	5,378
Operating Segments | Gas Storage and Pipelines
Segment Reporting Information [Line Items]
Operating Revenues — Utility operations									0	0	0
Operating Revenues — Non-utility operations									754	501	485
Depreciation and amortization									151	94	82
Interest expense									113	73	68
Interest income									(9)	(8)	(9)
Equity in earnings of equity method investees									106	97	123
Income Tax Expense (Benefit)									116	74	68
Net Income (Loss) Attributable to DTE Energy Company									315	204	235
Investments in equity method investees	1,691				1,685				1,691	1,685	1,585
Capital expenditures and acquisitions									517	2,510	176
Goodwill	472				470				472	470	299
Total Assets	5,068				4,832				5,068	4,832	3,161
Operating Segments | Power and Industrial Projects
Segment Reporting Information [Line Items]
Operating Revenues — Utility operations									0	0	0
Operating Revenues — Non-utility operations									1,224	1,560	2,204
Depreciation and amortization									72	69	67
Interest expense									37	33	31
Interest income									(22)	(9)	(9)
Equity in earnings of equity method investees									17	14	3
Income Tax Expense (Benefit)									(40)	(63)	(195)
Net Income (Loss) Attributable to DTE Energy Company									134	133	161
Investments in equity method investees	125				130				125	130	134
Capital expenditures and acquisitions									186	54	91
Goodwill	26				26				26	26	26
Total Assets	696				537				696	537	495
Operating Segments | Energy Trading
Segment Reporting Information [Line Items]
Operating Revenues — Utility operations									0	0	0
Operating Revenues — Non-utility operations									3,863	4,610	5,557
Depreciation and amortization									5	6	5
Interest expense									6	8	6
Interest income									(2)	(4)	(3)
Equity in earnings of equity method investees									0	0	0
Income Tax Expense (Benefit)									12	17	13
Net Income (Loss) Attributable to DTE Energy Company									36	49	39
Investments in equity method investees	0				0				0	0	0
Capital expenditures and acquisitions									5	5	5
Goodwill	17				17				17	17	17
Total Assets	807				798				807	798	909
Operating Segments | Corporate and Other
Segment Reporting Information [Line Items]
Operating Revenues — Utility operations									0	0	0
Operating Revenues — Non-utility operations									2	2	3
Depreciation and amortization									1	1	1
Interest expense									331	266	220
Interest income									(180)	(120)	(104)
Equity in earnings of equity method investees									8	(3)	4
Income Tax Expense (Benefit)									(77)	(75)	(48)
Net Income (Loss) Attributable to DTE Energy Company									(80)	(116)	(129)
Investments in equity method investees	34				31				34	31	33
Capital expenditures and acquisitions									0	0	2
Goodwill	0				0				0	0	0
Total Assets	8,071				7,610				8,071	7,610	6,153
Reclassifications and Eliminations
Segment Reporting Information [Line Items]
Operating Revenues — Utility operations									(75)	(68)	(64)
Operating Revenues — Non-utility operations									(525)	(647)	(707)
Depreciation and amortization									0	0	0
Interest expense									(184)	(132)	(119)
Interest income									184	132	119
Equity in earnings of equity method investees									0	0	0
Income Tax Expense (Benefit)									0	0	0
Net Income (Loss) Attributable to DTE Energy Company									0	0	0
Investments in equity method investees	0				0				0	0	0
Capital expenditures and acquisitions									0	0	0
Goodwill	0				0				0	0	0
Total Assets	$ (2,073)				$ (1,843)				(2,073)	$ (1,843)	$ (2,309)
Reclassifications and Eliminations | Electric
Segment Reporting Information [Line Items]
Operating Revenues — Non-utility operations									$ (2)

Related Party Transactions (Tra

Related Party Transactions (Transactions with NEXUS) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Operating Revenues — Utility operations	$ 6,845	$ 6,638	$ 6,670
Fuel, purchased power, and gas — utility	1,719	1,798	1,981
Fuel, purchased power, gas, and other — non-utility	4,141	5,053	6,630
DTE Electric
Related Party Transaction [Line Items]
Operating Revenues — Utility operations	5,506	5,224	5,298
Fuel, purchased power, and gas — utility	1,397	1,390	1,552
NEXUS | Equity Method Investee | DTE Gas
Related Party Transaction [Line Items]
Operating Revenues — Utility operations	32	32	6
Fuel, purchased power, and gas — utility	21	22	1
NEXUS | Equity Method Investee | DTE Electric
Related Party Transaction [Line Items]
Fuel, purchased power, and gas — utility	8	8	1
NEXUS | Equity Method Investee | DTE Energy Trading
Related Party Transaction [Line Items]
Fuel, purchased power, gas, and other — non-utility	$ 27	$ 13	$ 1
NEXUS | Capacity Lease Agreement | DTE Gas
Related Party Transaction [Line Items]
Term of agreement	15 years
NEXUS | Service Agreement | DTE Gas
Related Party Transaction [Line Items]
Term of agreement	15 years
NEXUS | Service Agreement | DTE Electric
Related Party Transaction [Line Items]
Term of agreement	20 years

Related Party Transactions (DTE

Related Party Transactions (DTE Electric Transactions with Affiliated Companies) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Dividends declared	$ 796,000,000	$ 714,000,000	$ 653,000,000
Dividends paid	760,000,000	692,000,000	620,000,000
DTE Electric
Related Party Transaction [Line Items]
Other services	2,000,000	5,000,000	4,000,000
Dividends declared	539,000,000	494,000,000	461,000,000
Dividends paid	539,000,000	494,000,000	461,000,000
DTE Electric | Energy sales
Related Party Transaction [Line Items]
Revenues and Other Income	8,000,000	10,000,000	9,000,000
DTE Electric | Shared capital assets
Related Party Transaction [Line Items]
Revenues and Other Income	51,000,000	47,000,000	43,000,000
DTE Electric | Fuel and purchased power
Related Party Transaction [Line Items]
Costs	16,000,000	9,000,000	7,000,000
DTE Electric | Other services and interest
Related Party Transaction [Line Items]
Costs	1,000,000	23,000,000	33,000,000
DTE Electric | Corporate expenses
Related Party Transaction [Line Items]
Costs	367,000,000	372,000,000	377,000,000
DTE Electric | DTE Energy
Related Party Transaction [Line Items]
Dividends declared	539,000,000	494,000,000	461,000,000
Dividends paid	539,000,000	494,000,000	461,000,000
Capital contribution from DTE Energy	636,000,000	180,000,000	325,000,000
DTE Electric | DTE Energy Foundation
Related Party Transaction [Line Items]
Charitable contributions to foundation	$ 20,000,000	$ 0	$ 0

Supplementary Quarterly Finan_3

Supplementary Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Entity Information [Line Items]
Operating Revenues	$ 3,288	$ 3,284	$ 2,583	$ 3,022	$ 3,148	$ 3,119	$ 2,888	$ 3,514	$ 12,177	$ 12,669	$ 14,212
Operating Income	465	608	367	546	415	450	300	542	1,986	1,707	1,594
Net Income	$ 275	$ 476	$ 277	$ 340	$ 267	$ 319	$ 182	$ 401	$ 1,368	$ 1,169	$ 1,120
Basic Earnings per Share (in dollars per share)	$ 1.42	$ 2.47	$ 1.44	$ 1.77	$ 1.40	$ 1.74	$ 0.99	$ 2.20	$ 7.09	$ 6.32	$ 6.18
Diluted Earnings per Share (in dollars per share)	$ 1.42	$ 2.46	$ 1.44	$ 1.76	$ 1.40	$ 1.73	$ 0.99	$ 2.19	$ 7.08	$ 6.31	$ 6.17
DTE Electric
Entity Information [Line Items]
Operating Revenues	$ 1,295	$ 1,690	$ 1,309	$ 1,212	$ 1,280	$ 1,519	$ 1,190	$ 1,235	$ 5,506	$ 5,224
Operating Income	206	541	263	214	224	440	223	226	1,224	1,113	$ 1,134
Net Income	$ 101	$ 400	$ 183	$ 94	$ 129	$ 307	$ 133	$ 147	$ 778	$ 716	$ 664

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Allowance for Doubtful Accounts (shown as deduction from Accounts receivable in DTE Energy's Consolidated Statements of Financial Position)
Balance at Beginning of Period	$ 91
Additions:
Balance at End of Period	104	$ 91
DTE Electric
Allowance for Doubtful Accounts (shown as deduction from Accounts receivable in DTE Energy's Consolidated Statements of Financial Position)
Balance at Beginning of Period	46
Additions:
Balance at End of Period	57	46
Allowance for Doubtful Accounts
Allowance for Doubtful Accounts (shown as deduction from Accounts receivable in DTE Energy's Consolidated Statements of Financial Position)
Balance at Beginning of Period	91	91	$ 49
Additions:
Charged to costs and expenses	103	111	140
Charged to other accounts	50	56	55
Deductions	(140)	(167)	(153)
Balance at End of Period	104	91	91
Allowance for Doubtful Accounts | DTE Electric
Allowance for Doubtful Accounts (shown as deduction from Accounts receivable in DTE Energy's Consolidated Statements of Financial Position)
Balance at Beginning of Period	46	53	31
Additions:
Charged to costs and expenses	61	65	85
Charged to other accounts	30	36	36
Deductions	(80)	(108)	(99)
Balance at End of Period	$ 57	$ 46	$ 53

Uncategorized Items - dte-20201

Label	Element	Value
Accounting Standards Update [Extensible List]	us-gaap_AccountingStandardsUpdateExtensibleList	us-gaap:AccountingStandardsUpdate201601Member