DTE Electric 10-Q 27 Oct 20 2020 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	9 Months Ended
	Sep. 30, 2020shares
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	1-11607
Entity Registrant Name	DTE Energy Co
Entity Incorporation, State or Country Code	MI
Entity Tax Identification Number	38-3217752
Entity Address, Address Line One	One Energy Plaza
Entity Address, City or Town	Detroit
Entity Address, State or Province	MI
Entity Address, Postal Zip Code	48226-1279
City Area Code	313
Local Phone Number	235-4000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	193,559,593
Entity Central Index Key	0000936340
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false
DTE Electric
Entity File Number	1-2198
Entity Registrant Name	DTE Electric Co
Entity Incorporation, State or Country Code	MI
Entity Tax Identification Number	38-0478650
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	138,632,324
Entity Central Index Key	0000028385
Common stock, without par value
Title of 12(b) Security	Common stock, without par value
Trading Symbol	DTE
Security Exchange Name	NYSE
2016 Series B 5.375% Junior Subordinated Debentures due 2076
Title of 12(b) Security	2016 Series B 5.375% Junior Subordinated Debentures due 2076
Trading Symbol	DTJ
Security Exchange Name	NYSE
2016 Series F 6.00% Junior Subordinated Debentures due 2076
Title of 12(b) Security	2016 Series F 6.00% Junior Subordinated Debentures due 2076
Trading Symbol	DTY
Security Exchange Name	NYSE
2017 Series E 5.25% Junior Subordinated Debentures due 2077
Title of 12(b) Security	2017 Series E 5.25% Junior Subordinated Debentures due 2077
Trading Symbol	DTW
Security Exchange Name	NYSE
2019 6.25% Corporate Units
Title of 12(b) Security	2019 6.25% Corporate Units
Trading Symbol	DTP
Security Exchange Name	NYSE
2020 Series G 4.375% Junior Subordinated Debentures due 2080
Title of 12(b) Security	2020 Series G 4.375% Junior Subordinated Debentures due 2080
Trading Symbol	DTB
Security Exchange Name	NYSE

Consolidated Statements of Oper

Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating Revenues
Utility operations	$ 1,844	$ 1,656	$ 5,119	$ 4,937
Non-utility operations	1,440	1,463	3,770	4,584
Operating Revenues	3,284	3,119	8,889	9,521
Operating Expenses
Fuel, purchased power, and gas — utility	455	400	1,296	1,342
Fuel, purchased power, and gas — non-utility	1,180	1,257	2,937	3,900
Operation and maintenance	588	588	1,731	1,739
Depreciation and amortization	356	322	1,059	923
Taxes other than income	103	101	306	311
Asset (gains) losses and impairments, net	(6)	1	39	14
Operating Expenses	2,676	2,669	7,368	8,229
Operating Income	608	450	1,521	1,292
Other (Income) and Deductions
Interest expense	178	162	532	468
Interest income	(15)	(4)	(31)	(11)
Non-operating retirement benefits, net	5	9	20	28
Other income	(120)	(98)	(286)	(259)
Other expenses	20	17	72	40
Other (Income) and Deductions	68	86	307	266
Income Before Income Taxes	540	364	1,214	1,026
Income Tax Expense	63	47	118	122
Net Income	477	317	1,096	904
Less: Net Income (Loss) Attributable to Noncontrolling Interests	1	(2)	3	2
Net Income Attributable to DTE Energy Company/DTE Electric Company	$ 476	$ 319	$ 1,093	$ 902
Basic Earnings per Common Share
Net Income Attributable to DTE Energy Company (in dollars per share)	$ 2.47	$ 1.74	$ 5.67	$ 4.93
Diluted Earnings per Common Share
Net Income Attributable to DTE Energy Company (in dollars per share)	$ 2.46	$ 1.73	$ 5.66	$ 4.91
Weighted Average Common Shares Outstanding
Basic (in shares)	193	183	192	183
Diluted (in shares)	193	184	193	184
DTE Electric
Operating Revenues
Utility operations	$ 1,690	$ 1,519	$ 4,211	$ 3,944
Operating Expenses
Fuel, purchased power, and gas — utility	451	399	1,090	1,067
Operation and maintenance	361	356	1,074	1,048
Depreciation and amortization	258	244	768	694
Taxes other than income	79	80	220	233
Asset (gains) losses and impairments, net	0	0	41	13
Operating Expenses	1,149	1,079	3,193	3,055
Operating Income	541	440	1,018	889
Other (Income) and Deductions
Interest expense	83	80	249	234
Interest income	0	0	(2)	(1)
Other income	(18)	(20)	(68)	(78)
Other expenses	18	14	66	34
Other (Income) and Deductions	83	74	245	189
Income Before Income Taxes	458	366	773	700
Income Tax Expense	58	59	96	113
Net Income Attributable to DTE Energy Company/DTE Electric Company	$ 400	$ 307	$ 677	$ 587

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net Income	$ 477	$ 317	$ 1,096	$ 904
Net Income	476	319	1,093	902
Other comprehensive income (loss), net of tax:
Benefit obligations, net of taxes of $1, $2, $3, and $4, respectively	2	4	7	11
Net unrealized gains (losses) on derivatives, net of taxes of $—, $(1), $1, and $(4), respectively	1	(4)	3	(13)
Foreign currency translation	0	0	0	1
Other comprehensive income (loss)	3	0	10	(1)
Comprehensive income	480	317	1,106	903
Less: Comprehensive income (loss) attributable to noncontrolling interests	1	(2)	3	2
Comprehensive Income Attributable to DTE Energy Company/DTE Electric Company	479	319	1,103	901
DTE Electric
Net Income	400	307	677	587
Other comprehensive income (loss), net of tax:
Other comprehensive income (loss)	0	0	0	0
Comprehensive Income Attributable to DTE Energy Company/DTE Electric Company	$ 400	$ 307	$ 677	$ 587

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Unaudited) (Parentheticals) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Tax effect on benefit obligation	$ 1	$ 2	$ 3	$ 4
Tax effect on net unrealized gains (losses) on derivatives during the period	$ 0	$ (1)	$ 1	$ (4)

Consolidated Statements of Fina

Consolidated Statements of Financial Position (Unaudited) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 945	$ 93
Restricted cash	17	0
Accounts receivable (less allowance for doubtful accounts)
Customer	1,419	1,642
Other	140	245
Inventories
Fuel and gas	412	373
Materials and supplies	403	386
Derivative assets	65	133
Regulatory assets	125	5
Other	295	209
Total Current Assets	3,821	3,086
Investments
Nuclear decommissioning trust funds	1,664	1,661
Investments in equity method investees	1,865	1,862
Other	186	265
Total Investments	3,715	3,788
Property
Property, plant, and equipment	37,256	35,072
Accumulated depreciation and amortization	(10,097)	(9,755)
Property, plant, and equipment, net	27,159	25,317
Other Assets
Goodwill	2,465	2,464
Regulatory assets	4,187	4,171
Intangible assets	2,358	2,393
Notes receivable	255	202
Derivative assets	29	41
Prepaid postretirement costs	125	69
Operating lease right-of-use assets	157	169
Other	168	182
Total Other Assets	9,744	9,691
Total Assets	44,439	41,882
Accounts payable
Accounts payable	964	1,076
Accrued interest	167	147
Dividends payable	196	195
Short-term borrowings	988	828
Current portion long-term debt, including finance leases	467	687
Derivative liabilities	60	83
Regulatory liabilities	34	65
Short-term borrowings
Operating lease liabilities	32	33
Acquisition related deferred payment	0	379
Other	509	504
Total Current Liabilities	3,417	3,997
Long-Term Debt (net of current portion)
Mortgage bonds, notes, and other	17,052	14,778
Junior subordinated debentures	1,146	1,146
Finance lease liabilities	21	11
Total Long-Term Debt (net of current portion)	18,219	15,935
Other Liabilities
Deferred income taxes	2,736	2,315
Regulatory liabilities	3,129	3,264
Asset retirement obligations	2,794	2,672
Unamortized investment tax credit	163	166
Derivative liabilities	44	86
Accrued pension liability	682	808
Nuclear decommissioning	251	249
Operating lease liabilities	116	127
Other	400	427
Total Other Liabilities	10,315	10,114
Commitments and Contingencies (Notes 6 and 13)
Equity
Common stock	5,369	5,233
Retained earnings	7,092	6,587
Accumulated other comprehensive income (loss)	(138)	(148)
Total DTE Energy/DTE Electric Company Equity	12,323	11,672
Noncontrolling interests	165	164
Total Equity	12,488	11,836
Total Liabilities and Equity	44,439	41,882
DTE Electric
Current Assets
Cash and cash equivalents	189	12
Accounts receivable (less allowance for doubtful accounts)
Customer	784	729
Affiliates	1	25
Other	81	41
Inventories
Fuel and gas	204	187
Materials and supplies	293	280
Regulatory assets	123	5
Prepaid property tax	115	52
Other	25	26
Total Current Assets	1,815	1,357
Investments
Nuclear decommissioning trust funds	1,664	1,661
Other	38	38
Total Investments	1,702	1,699
Property
Property, plant, and equipment	25,585	24,279
Accumulated depreciation and amortization	(6,895)	(6,706)
Property, plant, and equipment, net	18,690	17,573
Other Assets
Regulatory assets	3,500	3,448
Intangible assets	11	15
Prepaid postretirement costs — affiliates	266	266
Operating lease right-of-use assets	78	87
Other	137	143
Total Other Assets	3,992	3,959
Total Assets	26,199	24,588
Accounts payable
Affiliates	65	59
Other	392	406
Accrued interest	79	84
Current portion long-term debt, including finance leases	466	636
Regulatory liabilities	12	40
Short-term borrowings
Affiliates	104	97
Other	200	354
Operating lease liabilities	12	12
Other	167	155
Total Current Liabilities	1,497	1,843
Long-Term Debt (net of current portion)
Mortgage bonds, notes, and other	7,773	6,548
Finance lease liabilities	14	4
Total Long-Term Debt (net of current portion)	7,787	6,552
Other Liabilities
Deferred income taxes	2,489	2,355
Regulatory liabilities	2,441	2,546
Asset retirement obligations	2,564	2,447
Unamortized investment tax credit	163	166
Nuclear decommissioning	251	249
Accrued pension liability — affiliates	637	717
Accrued postretirement liability — affiliates	332	367
Operating lease liabilities	59	67
Other	111	84
Total Other Liabilities	9,047	8,998
Commitments and Contingencies (Notes 6 and 13)
Equity
Common stock	5,211	4,811
Retained earnings	2,657	2,384
Total DTE Energy/DTE Electric Company Equity	7,868	7,195
Total Liabilities and Equity	$ 26,199	$ 24,588

Consolidated Statements of Fi_2

Consolidated Statements of Financial Position (Unaudited) (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Allowance for doubtful accounts	$ 87	$ 91
Shareholder’s Equity
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	193,559,593	192,208,533
Common stock, shares outstanding (in shares)	193,559,593	192,208,533
DTE Electric
Allowance for doubtful accounts	$ 49	$ 46
Shareholder’s Equity
Par value (in dollars per share)	$ 10	$ 10
Common stock, shares authorized (in shares)	400,000,000	400,000,000
Common stock, shares issued (in shares)	138,632,324	138,632,324
Common stock, shares outstanding (in shares)	138,632,324	138,632,324

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating Activities
Net Income	$ 1,096	$ 904
Net Income	1,093	902
Adjustments to reconcile Net Income to Net cash from operating activities:
Depreciation and amortization	1,059	923
Nuclear fuel amortization	22	45
Allowance for equity funds used during construction	(19)	(18)
Deferred income taxes	350	285
Equity earnings of equity method investees	(96)	(77)
Dividends from equity method investees	122	129
Asset (gains) losses and impairments, net	44	14
Changes in assets and liabilities:
Accounts receivable, net	343	188
Inventories	(54)	5
Prepaid postretirement benefit costs	(56)	(29)
Accounts payable	(80)	(291)
Accrued pension liability	(126)	(179)
Derivative assets and liabilities	15	8
Regulatory assets and liabilities	(30)	203
Other current and noncurrent assets and liabilities	191	(209)
Net cash from operating activities	2,781	1,901
Investing Activities
Plant and equipment expenditures — utility	(2,362)	(1,982)
Plant and equipment expenditures — non-utility	(526)	(177)
Acquisitions related to business combinations, net of cash acquired	(126)	(174)
Proceeds from sale of assets	7	0
Proceeds from sale of nuclear decommissioning trust fund assets	2,054	594
Investment in nuclear decommissioning trust funds	(2,051)	(599)
Distributions from equity method investees	6	9
Contributions to equity method investees	(32)	(128)
Notes receivable	(58)	(81)
Other	(5)	(20)
Net cash used for investing activities	(3,093)	(2,558)
Financing Activities
Issuance of long-term debt, net of issuance costs	2,724	1,433
Redemption of long-term debt	(682)	0
Short-term borrowings, net	160	115
Dividends paid on common stock	(574)	(518)
Contributions from noncontrolling interests, principally REF entities	25	23
Distributions to noncontrolling interests	(27)	(44)
Purchases of noncontrolling interest, principally SGG	0	(300)
Acquisition related deferred payment	(380)	0
Other	(65)	(52)
Net cash from financing activities	1,181	657
Net Increase in Cash, Cash Equivalents, and Restricted Cash	869	0
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	93	76
Cash, Cash Equivalents, and Restricted Cash at End of Period	962	76
Supplemental disclosure of non-cash investing and financing activities
Plant and equipment expenditures in accounts payable	282	292
DTE Electric
Operating Activities
Net Income	677	587
Adjustments to reconcile Net Income to Net cash from operating activities:
Depreciation and amortization	768	694
Nuclear fuel amortization	22	45
Allowance for equity funds used during construction	(18)	(17)
Deferred income taxes	74	66
Asset (gains) losses and impairments, net	41	13
Changes in assets and liabilities:
Accounts receivable, net	(71)	(20)
Inventories	(30)	(14)
Accounts payable	37	(15)
Accrued pension liability — affiliates	(80)	(107)
Accrued postretirement liability — affiliates	(35)	(16)
Regulatory assets and liabilities	(79)	178
Other current and noncurrent assets and liabilities	(20)	(237)
Net cash from operating activities	1,286	1,157
Investing Activities
Plant and equipment expenditures	(1,981)	(1,611)
Proceeds from sale of nuclear decommissioning trust fund assets	2,054	594
Investment in nuclear decommissioning trust funds	(2,051)	(599)
Other	(14)	(19)
Net cash used for investing activities	(1,992)	(1,635)
Financing Activities
Issuance of long-term debt, net of issuance costs	1,683	643
Redemption of long-term debt	(632)	0
Capital contribution by parent company	400	0
Short-term borrowings, net — affiliate	7	(4)
Short-term borrowings, net — other	(154)	233
Dividends paid on common stock	(404)	(370)
Other	(17)	(16)
Net cash from financing activities	883	486
Net Increase in Cash, Cash Equivalents, and Restricted Cash	177	8
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	12	18
Cash, Cash Equivalents, and Restricted Cash at End of Period	189	26
Supplemental disclosure of non-cash investing and financing activities
Plant and equipment expenditures in accounts payable	$ 141	$ 168

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Millions	Total	Implementation of ASU	Common Stock	Retained Earnings	Retained EarningsImplementation of ASU	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss)Implementation of ASU	Noncontrolling Interests	DTE Electric	DTE ElectricCommon Stock	DTE ElectricAdditional Paid-in Capital	DTE ElectricRetained Earnings
Beginning Balance (in shares) at Dec. 31, 2018			181,925,000							138,632,000
Beginning Balance at Dec. 31, 2018	$ 10,717	$ 0	$ 4,245	$ 6,112	$ 25	$ (120)	$ (25)	$ 480
Beginning Balance at Dec. 31, 2018									$ 6,793	$ 1,386	$ 3,245	$ 2,162
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income									147			147
Net Income (Loss)	408			401				7
Dividends declared on common stock	(173)			(173)					(124)			(124)
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	2					2
Stock-based compensation, net distributions to (contributions from) noncontrolling interests, and other (in shares)			472,000
Stock-based compensation, net (distributions to) contributions from noncontrolling interests, and other	(34)		$ (21)	(1)				(12)
Ending Balance (in shares) at Mar. 31, 2019			183,212,000							138,632,000
Ending Balance at Mar. 31, 2019	11,020		$ 4,324	6,364		(143)		475
Ending Balance at Mar. 31, 2019									6,816	$ 1,386	3,245	2,185
Beginning Balance (in shares) at Dec. 31, 2018			181,925,000							138,632,000
Beginning Balance at Dec. 31, 2018	10,717	0	$ 4,245	6,112	25	(120)	(25)	480
Beginning Balance at Dec. 31, 2018									6,793	$ 1,386	3,245	2,162
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	902								587
Net Income (Loss)	904
Other comprehensive income (loss), net of tax	(1)								0
Ending Balance (in shares) at Sep. 30, 2019			183,397,000							138,632,000
Ending Balance at Sep. 30, 2019	10,904		$ 4,370	6,516		(146)		164
Ending Balance at Sep. 30, 2019									7,010	$ 1,386	3,245	2,379
Beginning Balance (in shares) at Dec. 31, 2018			181,925,000							138,632,000
Beginning Balance at Dec. 31, 2018	$ 10,717	$ 0	$ 4,245	6,112	$ 25	(120)	$ (25)	480
Beginning Balance at Dec. 31, 2018									$ 6,793	$ 1,386	3,245	2,162
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Implementation of ASU	us-gaap:AccountingStandardsUpdate201802Member
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
Beginning Balance (in shares) at Mar. 31, 2019			183,212,000							138,632,000
Beginning Balance at Mar. 31, 2019	11,020		$ 4,324	6,364		(143)		475
Beginning Balance at Mar. 31, 2019									6,816	$ 1,386	3,245	2,185
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income									133			133
Net Income (Loss)	179			182				(3)
Dividends declared on common stock	(347)			(347)					(123)			(123)
Other comprehensive income (loss), net of tax	(3)					(3)
Purchase of noncontrolling interests, principally SGG	(300)		$ (3)					(297)
Stock-based compensation, net distributions to (contributions from) noncontrolling interests, and other (in shares)			90,000
Stock-based compensation, net (distributions to) contributions from noncontrolling interests, and other	20		$ 23	(1)				(2)
Ending Balance (in shares) at Jun. 30, 2019			183,302,000							138,632,000
Ending Balance at Jun. 30, 2019	10,569		$ 4,344	6,198		(146)		173
Ending Balance at Jun. 30, 2019									6,826	$ 1,386	3,245	2,195
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	319								307			307
Net Income (Loss)	317			319				(2)
Dividends declared on common stock									(123)			(123)
Other comprehensive income (loss), net of tax	0								0
Stock-based compensation, net distributions to (contributions from) noncontrolling interests, and other (in shares)			95,000
Stock-based compensation, net (distributions to) contributions from noncontrolling interests, and other	18		$ 26	(1)				(7)
Ending Balance (in shares) at Sep. 30, 2019			183,397,000							138,632,000
Ending Balance at Sep. 30, 2019	$ 10,904		$ 4,370	6,516		(146)		164
Ending Balance at Sep. 30, 2019									$ 7,010	$ 1,386	3,245	2,379
Beginning Balance (in shares) at Dec. 31, 2019	192,208,533		192,209,000						138,632,324	138,632,000
Beginning Balance at Dec. 31, 2019	$ 11,836		$ 5,233	6,587		(148)		164
Beginning Balance at Dec. 31, 2019	11,672								$ 7,195	$ 1,386	3,425	2,384
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income									94			94
Net Income (Loss)	342			340				2
Dividends declared on common stock	(195)			(195)					(135)			(135)
Other comprehensive income (loss), net of tax	3					3
Stock-based compensation, net distributions to (contributions from) noncontrolling interests, and other (in shares)			403,000
Stock-based compensation, net (distributions to) contributions from noncontrolling interests, and other	2		$ 2
Ending Balance (in shares) at Mar. 31, 2020			192,612,000							138,632,000
Ending Balance at Mar. 31, 2020	$ 11,988		$ 5,235	6,732		(145)		166
Ending Balance at Mar. 31, 2020									$ 7,154	$ 1,386	3,425	2,343
Beginning Balance (in shares) at Dec. 31, 2019	192,208,533		192,209,000						138,632,324	138,632,000
Beginning Balance at Dec. 31, 2019	$ 11,836		$ 5,233	6,587		(148)		164
Beginning Balance at Dec. 31, 2019	11,672								$ 7,195	$ 1,386	3,425	2,384
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	1,093								677
Net Income (Loss)	1,096
Other comprehensive income (loss), net of tax	$ 10								$ 0
Ending Balance (in shares) at Sep. 30, 2020	193,559,593		193,560,000						138,632,324	138,632,000
Ending Balance at Sep. 30, 2020	$ 12,488		$ 5,369	7,092		(138)		165
Ending Balance at Sep. 30, 2020	12,323								$ 7,868	$ 1,386	3,825	2,657
Beginning Balance (in shares) at Mar. 31, 2020			192,612,000							138,632,000
Beginning Balance at Mar. 31, 2020	11,988		$ 5,235	6,732		(145)		166
Beginning Balance at Mar. 31, 2020									7,154	$ 1,386	3,425	2,343
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income									183			183
Net Income (Loss)	277			277
Dividends declared on common stock	(390)			(390)					(134)			(134)
Other comprehensive income (loss), net of tax	4					4
Stock-based compensation, net distributions to (contributions from) noncontrolling interests, and other (in shares)			39,000
Stock-based compensation, net (distributions to) contributions from noncontrolling interests, and other	13		$ 12	(1)				2
Ending Balance (in shares) at Jun. 30, 2020			192,651,000							138,632,000
Ending Balance at Jun. 30, 2020	11,892		$ 5,247	6,618		(141)		168
Ending Balance at Jun. 30, 2020									7,203	$ 1,386	3,425	2,392
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	476								400			400
Net Income (Loss)	477			476				1
Dividends declared on common stock									(135)			(135)
Capital contribution by parent company									400		400
Issuance of common stock (in shares)			98,000
Issuance of common stock	11		$ 11
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	3					3			$ 0
Stock-based compensation, net distributions to (contributions from) noncontrolling interests, and other (in shares)			117,000
Stock-based compensation, net (distributions to) contributions from noncontrolling interests, and other	$ 23		$ 29	(2)				(4)
Ending Balance (in shares) at Sep. 30, 2020	193,559,593		193,560,000						138,632,324	138,632,000
Ending Balance at Sep. 30, 2020	$ 12,488		$ 5,369	$ 7,092		$ (138)		$ 165
Ending Balance at Sep. 30, 2020	$ 12,323								$ 7,868	$ 1,386	$ 3,825	$ 2,657

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Equity (Unaudited) (Parenthetical) - $ / shares	3 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019
Statement of Stockholders' Equity [Abstract]
Dividends declared on common stock (in dollars per share)	$ 2.03	$ 1.01	$ 1.89	$ 0.95

Organization and Basis of Prese

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 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, the EGLE, and for DTE Energy, the CFTC. Basis of Presentation The Consolidated Financial Statements should be read in conjunction with the Combined Notes to Consolidated Financial Statements included in the combined DTE Energy and DTE Electric 2019 Annual Report on Form 10-K. The accompanying Consolidated Financial Statements of the Registrants are prepared using accounting principles generally accepted in the United States of America. These accounting principles require management to use estimates and assumptions that impact reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from the Registrants' estimates. The Consolidated Financial Statements are unaudited but, in the Registrants' opinions, include all adjustments necessary to present a fair statement of the results for the interim periods. All adjustments are of a normal recurring nature, except as otherwise disclosed in these Consolidated Financial Statements and Combined Notes to Consolidated Financial Statements. Financial results for this interim period are not necessarily indicative of results that may be expected for any other interim period or for the fiscal year ending December 31, 2020. The information in these combined notes relates to each of the Registrants as noted in the Index of Combined Notes to Consolidated Financial Statements. However, DTE Electric does not make any representation as to information related solely to DTE Energy or the subsidiaries of DTE Energy other than itself. Certain prior year balances for DTE Electric were reclassified to match 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 cost method is used. These Consolidated Financial Statements also reflect the Registrants' proportionate interests in certain jointly-owned utility plants. The Registrants eliminate all intercompany balances and transactions. The Registrants evaluate whether an entity is a VIE whenever reconsideration events occur. The Registrants consolidate VIEs for which they are the primary beneficiary. If a Registrant is not the primary beneficiary and an ownership interest is held, the VIE is accounted for under the equity method of accounting. When assessing the determination of the primary beneficiary, a Registrant considers all relevant facts and circumstances, including: the power, through voting or similar rights, to direct the activities of the VIE that most significantly impact the VIE's economic performance and the obligation to absorb the expected losses and/or the right to receive the expected returns of the VIE. The Registrants perform ongoing reassessments of all VIEs to determine if the primary beneficiary status has changed. Legal entities within DTE Energy's Power and Industrial Projects segment enter into long-term contractual arrangements with customers to supply energy-related products or services. The entities are generally designed to pass-through the commodity risk associated with these contracts to the customers, with DTE Energy retaining operational and customer default risk. These entities generally are VIEs and consolidated when DTE Energy is the primary beneficiary. In addition, DTE Energy has interests in certain VIEs through which control of all significant activities is shared with partners, and therefore are 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 is 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 23-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 September 30, 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 September 30, 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 13 to the Consolidated Financial Statements, "Commitments and Contingencies," related to the REF guarantees and indemnities. For non-consolidated VIEs, the maximum risk exposure of the Registrants is generally limited to their investment, notes receivable, future funding commitments, and amounts which DTE Energy has guaranteed. See Note 13 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 September 30, 2020 and December 31, 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: September 30, 2020 December 31, 2019 SGG (a) Other Total SGG (a) Other Total (In millions) ASSETS Cash and cash equivalents $ 33 $ 22 $ 55 $ 16 $ 11 $ 27 Accounts receivable 7 18 25 8 19 27 Inventories — 102 102 — 74 74 Property, plant, and equipment, net 404 25 429 410 33 443 Goodwill 25 — 25 25 — 25 Intangible assets 531 — 531 542 — 542 Other current and long-term assets 1 19 20 2 — 2 $ 1,001 $ 186 $ 1,187 $ 1,003 $ 137 $ 1,140 LIABILITIES Accounts payable and accrued current liabilities $ — $ 19 $ 19 $ 2 $ 13 $ 15 Short-term borrowings — 21 21 — — — Other current and long-term liabilities 6 4 10 7 7 14 $ 6 $ 44 $ 50 $ 9 $ 20 $ 29 _____________________________________ (a) Amounts shown are 100% of SGG's assets and liabilities, of which DTE Energy owns 85% at September 30, 2020 and December 31, 2019. Amounts for DTE Energy's non-consolidated VIEs are as follows: September 30, 2020 December 31, 2019 (In millions) Investments in equity method investees $ 1,505 $ 1,503 Notes receivable $ 40 $ 21 Future funding commitments $ 36 $ 63

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES Other Income The following is a summary of DTE Energy's Other income: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Equity earnings of equity method investees $ 37 $ 34 $ 96 $ 77 Income from REF entities 43 40 95 96 Gains from equity and fixed income securities 2 3 24 27 Contract services 7 7 20 21 Gas Storage and Pipelines post-acquisition settlement 20 — 20 — Allowance for equity funds used during construction 6 5 19 18 Other 5 9 12 20 $ 120 $ 98 $ 286 $ 259 The following is a summary of DTE Electric's Other income: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Gains from equity and fixed income securities allocated from DTE Energy $ 2 $ 3 $ 24 $ 27 Contract services 7 7 20 23 Allowance for equity funds used during construction 6 5 18 17 Other 3 5 6 11 $ 18 $ 20 $ 68 $ 78 Changes in Accumulated Other Comprehensive Income (Loss) Comprehensive income (loss) is the change in common shareholders' equity during a period from transactions and events from non-owner sources, including Net Income. The amounts recorded to Accumulated other comprehensive income (loss) for DTE Energy include changes in benefit obligations, consisting of deferred actuarial losses and prior service costs, unrealized gains and losses from derivatives accounted for as cash flow hedges, and foreign currency translation adjustments. DTE Energy releases income tax effects from accumulated other comprehensive income when the circumstances upon which they are premised cease to exist. Changes in Accumulated other comprehensive income (loss) are presented in DTE Energy's Consolidated Statements of Changes in Equity and DTE Electric's Consolidated Statements of Changes in Shareholder's Equity. For the three and nine months ended September 30, 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 three and nine months ended September 30, 2019, reclassifications out of Accumulated other comprehensive income (loss) not relating to the adoption of this standard were not material. Income Taxes The interim effective tax rates of the Registrants are as follows: Effective Tax Rate Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 DTE Energy 12 % 13 % 10 % 12 % DTE Electric 13 % 16 % 12 % 16 % These tax rates are affected by estimated annual permanent items, including AFUDC equity, production tax credits, and other flow-through items, as well as discrete items that may occur in any given period, but are not consistent from period to period. The 1% decrease in DTE Energy's effective tax rate for the three months ended September 30, 2020 was primarily due to higher amortization of the TCJA regulatory liability of 2%, partially offset by a decrease in annual production tax credits of 1%. The 2% decrease in DTE Energy's effective tax rate for the nine months ended September 30, 2020 was primarily due to the carryback of the 2018 net operating loss due to the CARES Act of 3% and higher amortization of the TCJA regulatory liability of 2%, partially offset by a decrease in production tax credits and other of 3%. Refer below for additional information regarding the CARES Act and related tax impacts. The 3% decrease in DTE Electric's effective tax rate for the three months ended September 30, 2020 was primarily due to higher amortization of the TCJA regulatory liability of 3%. The 4% decrease in DTE Electric's effective tax rate for the nine months ended September 30, 2020 was primarily due to higher amortization of the TCJA regulatory liability of 3% and an increase in annual production tax credits of 1%. DTE Electric had an income tax payable with DTE Energy of $5 million and an income tax receivable with DTE Energy of $14 million at September 30, 2020 and December 31, 2019, respectively. In March 2020, the "Coronavirus Aid, Relief, and Economic Security Act" (CARES Act) was signed into law and included several significant changes to the Internal Revenue Code. The CARES Act includes 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. During the third quarter 2020, DTE Energy received $220 million of refunds from the U.S. Treasury, 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 nine months ended September 30, 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 nine months ended September 30, 2020. The Registrants have also deferred employer payroll taxes of $32 million, of which $17 million was attributable to DTE Electric, increasing the amount of Other Liabilities - Other on the Registrants' Consolidated Statements of Financial Position as of September 30, 2020. Unrecognized Compensation Costs As of September 30, 2020, DTE Energy had $84 million of total unrecognized compensation cost related to non-vested stock incentive plan arrangements. That cost is expected to be recognized over a weighted-average period of 1.41 years. Allocated Stock-Based Compensation DTE Electric received an allocation of costs from DTE Energy associated with stock-based compensation of $12 million and $9 million for the three months ended September 30, 2020 and 2019, respectively, while such allocation was $28 million and $33 million for the nine months ended September 30, 2020 and 2019, respectively. Cash, Cash Equivalents, and Restricted Cash Cash and cash equivalents include cash on hand, cash in banks, and temporary investments purchased with remaining maturities of three months or less. Restricted cash consists of funds held in separate bank accounts to satisfy contractual obligations to fund certain construction projects and guarantee performance. Restricted cash designated for payments within one year is classified as a Current Asset. Financing Receivables 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 September 30, 2020. DTE Energy DTE Electric Year of origination 2020 2019 2018 and prior Total 2020 and prior (In millions) Notes receivable Internal grade 1 $ — $ 18 $ 9 $ 27 $ 18 Internal grade 2 60 19 6 85 — Total notes receivable (a) $ 60 $ 37 $ 15 $ 112 $ 18 Net investment in leases Net investment in leases, internal grade 1 $ 8 $ — $ 40 $ 48 $ — Net investment in leases, internal grade 2 132 — 1 133 — Total net investment in leases (a) $ 140 $ — $ 41 $ 181 $ — _______________________________________ (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, or financing receivables, 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, or financing receivables, for DTE Electric are primarily comprised of loans. Notes receivable are typically considered delinquent when payment is not received for periods ranging from 60 to 120 days. The Registrants cease accruing interest (nonaccrual status), consider a note receivable impaired, and establish an allowance for credit loss when it is probable that all principal and interest amounts due will not be collected in accordance with the contractual terms of the note receivable. In determining the allowance for credit losses for notes receivable, the Registrants consider the historical payment experience and other factors that are expected to have a specific impact on the counterparty's ability to pay including existing and future economic conditions. DTE Energy has off balance sheet exposure in the form of a revolving credit facility. Refer to Note 13, "Commitments and Contingencies," for additional information. In determining the level of credit reserve needed, DTE considers the likelihood of funding in addition to the other factors noted above. A reserve may be established when it is likely that funding will occur. Cash payments received on nonaccrual status notes receivable, that do not bring the account contractually current, are first applied to the contractually owed past due interest, with any remainder applied to principal. Accrual of interest is generally resumed when the note receivable becomes contractually current. The following table presents a roll-forward of the activity for the Registrants' financing receivables credit loss reserves as of September 30, 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 73 2 75 47 Write-offs charged against allowance (117) (3) (120) (68) Recoveries of amounts previously written off 41 — 41 24 Ending reserve balance, September 30, 2020 $ 84 $ 3 $ 87 $ 49 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 September 30, 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, DTE Electric and DTE Gas deferred $5 million and $1 million of uncollectible expense as Regulatory assets, respectively, for the nine months ended September 30, 2020. For the three months ended September 30, 2020, DTE Electric and DTE Gas, both reversed $1 million of previously deferred uncollectible expense. Refer to Note 6 to the Consolidated Financial Statements, "Regulatory Matters," for further information regarding the order. For DTE Energy, uncollectible expense was $22 million and $70 million for the three and nine months ended September 30, 2020, respectively, which is primarily comprised of the current period provision for allowance for doubtful accounts adjusted for regulatory deferrals. DTE Energy uncollectible expense was $28 million and $81 million for the three and nine months ended September 30, 2019, respectively. For DTE Electric, uncollectible expense was $16 million and $42 million for the three and nine months ended September 30, 2020, respectively, which is primarily comprised of the current period provision adjusted for regulatory deferrals. DTE Electric uncollectible expense was $17 million and $47 million for the three and nine months ended September 30, 2019, respectively.

New Accounting Pronouncements

New Accounting Pronouncements	9 Months Ended
	Sep. 30, 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 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 8 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 (Subtopic 715-20): Disclosure Framework - Changes to the Disclosure requirements for employers that sponsor defined benefit pension or other postretirement 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 required disclosures for this ASU will be reflected in the 2020 year-end financial statements. 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 . 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

Acquisitions	9 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Acquisitions	ACQUISITIONS 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 Acquisitions Effective September 12, 2019, DTE Sustainable Generation closed on the purchase of an 89 MW renewable energy project 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. 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 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 $1 million and $5 million was recorded for the three and nine months ended September 30, 2020, 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. The acquired assets are part of DTE Energy's non-utility Gas Storage and Pipelines segment. The acquisition was accounted for using the acquisition method of accounting for business combinations. The allocation of the purchase price included in the Consolidated Statements of Financial Position is preliminary and may be revised up to one year from the date of acquisition due to adjustments in the estimated fair value of the assets acquired and the liabilities assumed. The purchase price is subject to resolution of any indemnification claims that might be deducted from the remaining $14 million of cash consideration paid and held in escrow. The excess purchase price over the fair value of net assets acquired was classified as goodwill. As of September 30, 2020, total goodwill was approximately $172 million, including $1 million resulting from working capital adjustments recorded during the nine months ended September 30, 2020. DTE Energy cannot estimate the potential for any further revisions to the purchase price allocation for the remainder of 2020. The factors contributing to the recognition of goodwill are 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 expected to be deductible for income tax purposes. The preliminary allocation of the purchase price is 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 preliminary purchase price allocation, inclusive of purchase accounting adjustments, are as follows: (In millions) Assets Cash $ 62 Accounts receivable 31 Property, plant, and equipment, net 1,035 Goodwill 172 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. 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 were included in Operation and maintenance in DTE Energy's 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.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE Disaggregation of Revenue The following is a summary of revenues disaggregated by segment for DTE Energy: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Electric (a) Residential $ 900 $ 791 $ 2,169 $ 1,839 Commercial 498 515 1,313 1,358 Industrial 157 175 434 497 Other (b) 138 39 305 251 Total Electric operating revenues (c) $ 1,693 $ 1,520 $ 4,221 $ 3,945 Gas Gas sales $ 92 $ 87 $ 655 $ 727 End User Transportation 34 35 154 157 Intermediate Transportation 15 15 57 57 Other (b) 32 18 98 102 Total Gas operating revenues (d) $ 173 $ 155 $ 964 $ 1,043 Other segment operating revenues Gas Storage and Pipelines (e) $ 204 $ 126 $ 546 $ 363 Power and Industrial Projects (f) $ 324 $ 406 $ 850 $ 1,196 Energy Trading (g) $ 1,061 $ 1,105 $ 2,714 $ 3,519 _______________________________________ (a) Revenues generally represent those of DTE Electric, except $3 million and $10 million of Other revenues related to DTE Sustainable Generation for the three and nine months ended September 30, 2020, respectively. (b) Includes revenue adjustments related to various regulatory mechanisms. (c) Includes $8 million and $5 million of other revenues outside the scope of topic 606 for the three months ended September 30, 2020 and 2019, and $18 million and $14 million for the nine months ended September 30, 2020 and 2019, respectively. (d) Includes $2 million under Alternative Revenue Programs for the nine months ended September 30, 2020 and $2 million and $7 million of other revenues for the three and nine months ended September 30, 2020, respectively, which are all outside the scope of Topic 606. For prior period, revenues include $2 million and $6 million of other revenues for the three and nine months ended September 30, 2019, respectively, which are all outside the scope of Topic 606. (e) Includes revenues outside the scope of Topic 606 primarily related to $2 million of contracts accounted for as leases for the three months ended September 30, 2020 and 2019, and $7 million for the nine months ended September 30, 2020 and 2019. (f) Includes revenues outside the scope of Topic 606 primarily related to $26 million and $33 million of contracts accounted for as leases for the three months ended September 30, 2020 and 2019, respectively, and $74 million and $94 million for the nine months ended September 30, 2020 and 2019, respectively. (g) Includes revenues outside the scope of Topic 606 primarily related to $731 million and $791 million of derivatives for the three months ended September 30, 2020 and 2019, respectively, and $1.8 billion and $2.6 billion of derivatives for the nine months ended September 30, 2020 and 2019, respectively. 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 39 Revenue recognized that was included in the deferred revenue balance at the beginning of the period (42) Ending Balance, September 30, 2020 $ 72 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) 2020 $ 7 2021 36 2022 7 2023 3 2024 7 2025 and thereafter 12 $ 72 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) 2020 $ 72 $ 2 2021 350 8 2022 294 7 2023 231 7 2024 142 8 2025 and thereafter 580 — $ 1,669 $ 32

Regulatory Matters

Regulatory Matters	9 Months Ended
	Sep. 30, 2020
Public Utilities, General Disclosures [Abstract]
Regulatory Matters	REGULATORY MATTERS 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. Refer to Note 2 to the Consolidated Financial Statements, "Significant Accounting Policies" for the impact to uncollectible expense for the period. 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 do not plan to make a filing in response to this order, and 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 is primarily due to an increase in net plant resulting from 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 nine months ended September 30, 2020. 2020 Accounting Applications On July 9, 2020, the MPSC approved DTE Electric's request to accelerate amortization of the regulatory liability for non-plant-related 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 regulatory 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 is proposing to accrue 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. If approved by the end of 2020, the regulatory liability will be recognized at that time. Amortization of the regulatory liability would be used to offset the cost of service related to new plant in 2022. The regulatory liability would be amortized beginning January 1, 2022 through the earlier of new base rates or December 31, 2022. The one-time accounting treatment would not impact customer rates and would allow DTE Electric to further defer its next rate case filing from March 2021 to May 2021. Additionally, as noted in Note 2 to the Consolidated Financial Statements, "Significant Accounting Policies," DTE Electric has deferred $5 million of uncollectible expense as Regulatory assets for the nine months ended September 30, 2020 as a result of the MPSC's COVID-19 response order discussed above. If the October 26th accounting application is approved, DTE Electric would voluntarily forgo this deferral and record as expense. This action would apply only to DTE Electric in 2020 and the deferral of uncollectible expense would resume beginning in January 2021. 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 is primarily due to an increase in net plant resulting from infrastructure investments and operating and maintenance expenses. The rate filing also requests an increase in return on equity from 10.0% to 10.5% and includes projected changes in sales and working capital.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 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 and performance shares do not receive cash dividends; as such, these awards are not considered participating securities. The following is a reconciliation of DTE Energy's basic and diluted income per share calculation: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions, except per share amounts) Basic Earnings per Share Net Income Attributable to DTE Energy Company $ 476 $ 319 $ 1,093 $ 902 Less: Allocation of earnings to net restricted stock awards 1 1 2 2 Net income available to common shareholders — basic $ 475 $ 318 $ 1,091 $ 900 Average number of common shares outstanding — basic 193 183 192 183 Basic Earnings per Common Share $ 2.47 $ 1.74 $ 5.67 $ 4.93 Diluted Earnings per Share Net Income Attributable to DTE Energy Company $ 476 $ 319 $ 1,093 $ 902 Less: Allocation of earnings to net restricted stock awards 1 1 2 2 Net income available to common shareholders — diluted $ 475 $ 318 $ 1,091 $ 900 Average number of common shares outstanding — basic 193 183 192 183 Incremental shares attributable to: Average dilutive equity units, performance share awards, and stock options — 1 1 1 Average number of common shares outstanding — diluted 193 184 193 184 Diluted Earnings per Common Share (a) $ 2.46 $ 1.73 $ 5.66 $ 4.91 _______________________________________ (a) Equity Units excluded from the calculation of diluted EPS were approximately 10.3 million for the three and nine months ended September 30, 2020, as the dilutive stock price threshold was not met.

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 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 September 30, 2020 and December 31, 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) : September 30, 2020 December 31, 2019 Level Level Level Other (b) Netting (c) Net Balance Level Level Level Other (b) Netting (c) Net Balance (In millions) Assets Cash equivalents (d) $ 567 $ — $ — $ — $ — $ 567 $ 15 $ — $ — $ — $ — $ 15 Nuclear decommissioning trusts Equity securities 872 — — 141 — 1,013 1,046 — — — — 1,046 Fixed income securities 122 325 — 80 — 527 160 378 — — — 538 Private equity and other — — — 78 — 78 — — — 43 — 43 Cash equivalents 46 — — — — 46 34 — — — — 34 Other investments (e) Equity securities 49 — — — — 49 140 — — — — 140 Fixed income securities 6 — — — — 6 79 — — — — 79 Cash equivalents 98 — — — — 98 4 — — — — 4 Derivative assets Commodity contracts (f) Natural gas 126 72 42 — (194) 46 205 76 74 — (266) 89 Electricity — 103 34 — (106) 31 — 223 83 — (225) 81 Environmental & Other — 194 7 — (186) 15 — 110 3 — (110) 3 Foreign currency exchange contracts — 2 — — — 2 — 1 — — — 1 Total derivative assets 126 371 83 — (486) 94 205 410 160 — (601) 174 Total $ 1,886 $ 696 $ 83 $ 299 $ (486) $ 2,478 $ 1,683 $ 788 $ 160 $ 43 $ (601) $ 2,073 Liabilities Derivative liabilities Commodity contracts (f) Natural gas $ (118) $ (66) $ (81) $ — $ 185 $ (80) $ (221) $ (41) $ (89) $ — $ 266 $ (85) Electricity — (97) (29) — 104 (22) — (231) (67) — 225 (73) Environmental & Other (3) (168) — — 171 — — (121) — — 110 (11) Foreign currency exchange contracts — (2) — — — (2) — — — — — — Total $ (121) $ (333) $ (110) $ — $ 460 $ (104) $ (221) $ (393) $ (156) $ — $ 601 $ (169) Net Assets (Liabilities) at end of period $ 1,765 $ 363 $ (27) $ 299 $ (26) $ 2,374 $ 1,462 $ 395 $ 4 $ 43 $ — $ 1,904 Assets Current $ 679 $ 273 $ 59 $ — $ (379) $ 632 $ 218 $ 320 $ 123 $ — $ (513) $ 148 Noncurrent 1,207 423 24 299 (107) 1,846 1,465 468 37 43 (88) 1,925 Total Assets $ 1,886 $ 696 $ 83 $ 299 $ (486) $ 2,478 $ 1,683 $ 788 $ 160 $ 43 $ (601) $ 2,073 Liabilities Current $ (112) $ (243) $ (66) $ — $ 361 $ (60) $ (211) $ (300) $ (85) $ — $ 513 $ (83) Noncurrent (9) (90) (44) — 99 (44) (10) (93) (71) — 88 (86) Total Liabilities $ (121) $ (333) $ (110) $ — $ 460 $ (104) $ (221) $ (393) $ (156) $ — $ 601 $ (169) Net Assets (Liabilities) at end of period $ 1,765 $ 363 $ (27) $ 299 $ (26) $ 2,374 $ 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 September 30, 2020, the $567 million consisted of $565 million and $2 million of cash equivalents included in Cash and cash equivalents and Restricted cash on DTE Energy's Consolidated Statements of Financial Position, respectively. 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 on DTE Energy's Consolidated Statements of Financial Position, respectively. (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: September 30, 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) $ 175 $ — $ — $ — $ 175 $ 11 $ — $ — $ — $ 11 Nuclear decommissioning trusts Equity securities 872 — — 141 1,013 1,046 — — — 1,046 Fixed income securities 122 325 — 80 527 160 378 — — 538 Private equity and other — — — 78 78 — — — 43 43 Cash equivalents 46 — — — 46 34 — — — 34 Other investments Equity securities 14 — — — 14 13 — — — 13 Cash equivalents 11 — — — 11 — — — — — Derivative assets — FTRs — — 7 — 7 — — 3 — 3 Total $ 1,240 $ 325 $ 7 $ 299 $ 1,871 $ 1,264 $ 378 $ 3 $ 43 $ 1,688 Assets Current $ 175 $ — $ 7 $ — $ 182 $ 11 $ — $ 3 $ — $ 14 Noncurrent 1,065 325 — 299 1,689 1,253 378 — 43 1,674 Total Assets $ 1,240 $ 325 $ 7 $ 299 $ 1,871 $ 1,264 $ 378 $ 3 $ 43 $ 1,688 _______________________________________ (a) Amounts represent assets valued at NAV as a practical expedient for fair value. (b) At September 30, 2020, the $175 million of cash equivalents was included in Cash and cash equivalents on DTE Electric's Consolidated Statements of Financial Position. At December 31, 2019, the $11 million of cash equivalents was 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 $192 million and $151 million as of September 30, 2020 and December 31, 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: Three Months Ended September 30, 2020 Three Months Ended September 30, 2019 Natural Gas Electricity Other Total Natural Gas Electricity Other Total (In millions) Net Assets (Liabilities) as of June 30 $ 20 $ 16 $ 10 $ 46 $ (10) $ 10 $ 9 $ 9 Transfers from Level 3 into Level 2 (1) — — (1) — — — — Total gains (losses) Included in earnings (80) 37 1 (42) (35) 37 — 2 Recorded in Regulatory liabilities — — 9 9 — — (3) (3) Purchases, issuances, and settlements Settlements 22 (48) (13) (39) 4 (39) (1) (36) Net Assets (Liabilities) as of September 30 $ (39) $ 5 $ 7 $ (27) $ (41) $ 8 $ 5 $ (28) Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2020 and 2019 (a) $ (57) $ 11 $ (1) $ (47) $ (36) $ 15 $ (1) $ (22) _______________________________________ (a) Amounts are reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations. Nine Months Ended September 30, 2020 Nine Months Ended September 30, 2019 Natural Gas Electricity Other Total Natural Gas Electricity Other Total (In millions) Net Assets (Liabilities) as of December 31 $ (15) $ 16 $ 3 $ 4 $ (49) $ (2) $ 7 $ (44) Transfers from Level 3 into Level 2 (5) — — (5) — — — — Total gains (losses) Included in earnings (44) 90 (7) 39 (4) 47 (1) 42 Recorded in Regulatory liabilities — — 21 21 — — 3 3 Purchases, issuances, and settlements Settlements 25 (101) (10) (86) 12 (37) (4) (29) Net Assets (Liabilities) as of September 30 $ (39) $ 5 $ 7 $ (27) $ (41) $ 8 $ 5 $ (28) Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2020 and 2019 (a) $ (20) $ 53 $ (17) $ 16 $ (20) $ 32 $ (6) $ 6 _______________________________________ (a) Amounts are reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations. The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for DTE Electric: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Net Assets as of beginning of period $ 10 $ 9 $ 3 $ 6 Change in fair value recorded in Regulatory liabilities 9 (3) 21 3 Purchases, issuances, and settlements Settlements (12) (1) (17) (4) Net Assets as of September 30 $ 7 $ 5 $ 7 $ 5 The amount of total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets held at September 30, 2020 and 2019 and reflected in DTE Electric's Consolidated Statements of Financial Position $ — $ (1) $ 7 $ 5 Derivatives are transferred between levels primarily due to changes in the source data used to construct price curves as a result of changes in market liquidity. Transfers in and transfers out are reflected as if they had occurred at the beginning of the period. There were no transfers from or into Level 3 for DTE Electric during the three and nine months ended September 30, 2020 and 2019. The following tables present the unobservable inputs related to DTE Energy's Level 3 assets and liabilities: September 30, 2020 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 42 $ (81) Discounted Cash Flow Forward basis price (per MMBtu) $ (1.10) — $ 2.30 /MMBtu $ (0.06) /MMBtu Electricity $ 34 $ (29) Discounted Cash Flow Forward basis price (per MWh) $ (9) — $ 6 /MWh $ (1) /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: September 30, 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) , excluding lessor finance leases $ 112 $ — $ — $ 112 $ 184 $ — $ — $ 184 Short-term borrowings $ 988 $ — $ 988 $ — $ 828 $ — $ 828 $ — Notes payable — Other (b) $ 19 $ — $ — $ 19 $ 25 $ — $ — $ 25 Long-term debt (c) $ 18,660 $ 2,398 $ 17,213 $ 1,406 $ 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: September 30, 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) $ 18 $ — $ — $ 18 $ 9 $ — $ — $ 9 Short-term borrowings — affiliates $ 104 $ — $ — $ 104 $ 97 $ — $ — $ 97 Short-term borrowings — other $ 200 $ — $ 200 $ — $ 354 $ — $ 354 $ — Notes payable — Other (b) $ 17 $ — $ — $ 17 $ 21 $ — $ — $ 21 Long-term debt (c) $ 8,235 $ — $ 9,565 $ 194 $ 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 9 to the Consolidated Financial Statements, "Financial and Other Derivative Instruments." Nuclear Decommissioning Trust Funds DTE Electric has a legal obligation to decommission its nuclear power plants following the expiration of its operating licenses. This obligation is reflected as an Asset retirement obligation on DTE Electric's Consolidated Statements of Financial Position. Rates approved by the MPSC provide for the recovery of decommissioning costs of Fermi 2 and the disposal of low-level radioactive waste. The following table summarizes DTE Electric's fair value of the nuclear decommissioning trust fund assets: September 30, 2020 December 31, 2019 (In millions) Fermi 2 $ 1,652 $ 1,650 Fermi 1 3 3 Low-level radioactive waste 9 8 $ 1,664 $ 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: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Realized gains $ 38 $ 15 $ 172 $ 43 Realized losses $ (11) $ (8) $ (103) $ (25) Proceeds from sale of securities $ 816 $ 198 $ 2,054 $ 594 Realized gains and losses from the sale of securities and unrealized gains and losses incurred by the Fermi 2 trust are recorded to the Regulatory asset and 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: September 30, 2020 December 31, 2019 Fair Unrealized Unrealized Fair Unrealized Unrealized (In millions) Equity securities $ 1,013 $ 325 $ (28) $ 1,046 $ 396 $ (39) Fixed income securities 527 16 (1) 538 24 (1) Private equity and other 78 — — 43 — — Cash equivalents 46 — — 34 — — $ 1,664 $ 341 $ (29) $ 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: September 30, 2020 (In millions) Due within one year $ 92 Due after one through five years 82 Due after five through ten years 79 Due after ten years 194 $ 447 Fixed income securities held in nuclear decommissioning trust funds include $80 million of non-publicly traded commingled funds that do not have a contractual maturity date. Other Securities At September 30, 2020 and December 31, 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: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Gains (losses) related to equity securities $ 2 $ 1 $ (4) $ 18 Gains (losses) related to fixed income securities — 2 (3) 9 $ 2 $ 3 $ (7) $ 27

Financial and Other Derivative

Financial and Other Derivative Instruments	9 Months Ended
	Sep. 30, 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, certain environmental contracts, and natural gas storage assets. DTE Electric — DTE Electric generates, purchases, distributes, and sells electricity. DTE Electric uses forward contracts to manage changes in the price of electricity and fuel. Substantially all of these contracts meet the normal purchases and normal sales exception and are therefore accounted for under the accrual method. Other derivative contracts are MTM and recoverable through the PSCR mechanism when settled. This results in the deferral of unrealized gains and losses as Regulatory assets or liabilities until realized. DTE Gas — DTE Gas purchases, stores, transports, distributes, and sells natural gas, and buys and sells transportation and storage capacity. DTE Gas has fixed-priced contracts for portions of its expected natural gas supply requirements through March 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 September 30, 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: September 30, 2020 December 31, 2019 Derivative Derivative Liabilities Derivative Derivative Liabilities (In millions) Derivatives designated as hedging instruments Foreign currency exchange contracts $ — $ (1) $ — $ — Derivatives not designated as hedging instruments Commodity contracts Natural gas $ 240 $ (265) $ 355 $ (351) Electricity 137 (126) 306 (298) Environmental & Other 201 (171) 113 (121) Foreign currency exchange contracts 2 (1) 1 — Total derivatives not designated as hedging instruments $ 580 $ (563) $ 775 $ (770) Current $ 444 $ (421) $ 646 $ (596) Noncurrent 136 (143) 129 (174) Total derivatives $ 580 $ (564) $ 775 $ (770) The following table presents the fair value of derivative instruments for DTE Electric: September 30, 2020 December 31, 2019 (In millions) FTRs — Other current assets $ 7 $ 3 Total derivatives not designated as hedging instruments $ 7 $ 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 $5 million and $6 million outstanding at September 30, 2020 and December 31, 2019, respectively, which could be used to offset net Derivative liabilities. Letters of credit received from third parties which could be used to offset net Derivative assets were $1 million and $4 million at September 30, 2020 and December 31, 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: September 30, 2020 December 31, 2019 (In millions) Cash collateral netted against Derivative assets $ (26) $ — Cash collateral recorded in Accounts receivable (a) 12 13 Cash collateral recorded in Accounts payable (a) (2) (3) Total net cash collateral posted (received) $ (16) $ 10 _______________________________________ (a) Amounts are recorded net by counterparty. The following table presents the netting offsets of Derivative assets and liabilities for DTE Energy: September 30, 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 $ 240 $ (194) $ 46 $ 355 $ (266) $ 89 Electricity 137 (106) 31 306 (225) 81 Environmental & Other 201 (186) 15 113 (110) 3 Foreign currency exchange contracts 2 — 2 1 — 1 Total derivative assets $ 580 $ (486) $ 94 $ 775 $ (601) $ 174 Derivative liabilities Commodity contracts Natural gas $ (265) $ 185 $ (80) $ (351) $ 266 $ (85) Electricity (126) 104 (22) (298) 225 (73) Environmental & Other (171) 171 — (121) 110 (11) Foreign currency exchange contracts (2) — (2) — — — Total derivative liabilities $ (564) $ 460 $ (104) $ (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: September 30, 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 $ 444 $ 136 $ (421) $ (143) $ 646 $ 129 $ (596) $ (174) Counterparty netting (361) (99) 361 99 (513) (88) 513 88 Collateral adjustment (18) (8) — — — — — — Total derivatives as reported $ 65 $ 29 $ (60) $ (44) $ 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 the Three Months Ended September 30, Gain (Loss) Recognized in Income on Derivatives for the Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Commodity contracts Natural gas Operating Revenues — Non-utility operations $ (27) $ (5) $ (63) $ 4 Natural gas Fuel, purchased power, and gas — non-utility (51) (47) 28 (7) Electricity Operating Revenues — Non-utility operations 33 54 75 21 Environmental & Other Operating Revenues — Non-utility operations 2 (11) (40) (11) Foreign currency exchange contracts Operating Revenues — Non-utility operations (2) 1 — (2) Total $ (45) $ (8) $ — $ 5 Revenues and energy costs related to trading contracts are presented on a net basis in DTE Energy's Consolidated Statements of Operations. Commodity derivatives used for trading purposes, and financial non-trading commodity derivatives, are accounted for using the MTM method with unrealized and realized gains and losses recorded in Operating Revenues — Non-utility operations. Non-trading physical commodity sale and purchase derivative contracts are generally accounted for using the MTM method with unrealized and realized gains and losses for sales recorded in Operating Revenues — Non-utility operations and purchases recorded in Fuel, purchased power, and gas — non-utility. The following represents the cumulative gross volume of DTE Energy's derivative contracts outstanding as of September 30, 2020: Commodity Number of Units Natural gas (MMBtu) 1,739,656,507 Electricity (MWh) 28,258,929 Foreign currency exchange (CAD) 154,336,963 Renewable Energy Certificates (MWh) 7,893,076 Carbon emissions (Metric Ton) 16,451,411 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 September 30, 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 $377 million. As of September 30, 2020, DTE Energy had $472 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 $445 million. The net remaining amount of $27 million is derived from the $377 million noted above.

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Long-Term Debt	LONG-TERM DEBT 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 $ 2,750 _______________________________________ (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. In March 2020, DTE Energy entered into a $200 million unsecured term loan with a maturity date of March 2022 and terms consistent with DTE Energy’s unsecured revolving credit agreements. The purpose of the loan was to enhance liquidity and reduce reliance on the commercial paper market. The loan was subject to terminate if no amounts were drawn by August 27, 2020. No amounts were drawn, therefore the loan terminated per the agreement. In October 2020, DTE Energy issued $230 million of 4.375% Junior Subordinated Debentures due October 15, 2080. Proceeds have been used for the redemption of DTE Energy's $200 million 2012 Series C 5.25% Junior Subordinated Debentures due December 1, 2062. Remaining proceeds will be used for general corporate purposes. In October 2020, DTE Energy also issued $750 million of 0.55% Senior Notes due November 1, 2022. Proceeds have been used for the repayment of DTE Energy's $500 million unsecured term loan expiring March 2021 and DTE Energy's $167 million unsecured term loan expiring June 2021. Remaining proceeds will be used for general corporate purposes. Refer to Note 11 to the Consolidated Financial Statements, "Short-term Credit Arrangements and Borrowings", for additional information regarding the term loans. 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 $ 682 As noted above, on October 22, 2020, DTE Energy also optionally redeemed its $200 million 2012 Series C 5.25% Junior Subordinated Debentures originally due December 1, 2062.

Short-Term Credit Arrangements

Short-Term Credit Arrangements and Borrowings	9 Months Ended
	Sep. 30, 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 have entered into a series of unsecured term loans to raise additional liquidity, including terms consistent with the unsecured revolving credit agreements. In March 2020, DTE Energy entered into a $500 million unsecured term loan expiring in March 2021, of which the full $500 million was drawn. In April 2020, DTE Electric entered into a $200 million unsecured term loan, of which the full $200 million was drawn, and a $200 million unsecured term loan, of which no amount has been drawn. Additionally, in April 2020, DTE Gas entered into a $100 million unsecured term loan, of which the full $100 million was drawn. All three loans expire in April 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$28 million outstanding as of September 30, 2020. The revolving credit agreement expires in May 2023 and has terms consistent with DTE Energy's unsecured revolving credit agreements. In June 2020, DTE Energy entered into a $167 million unsecured term loan expiring in June 2021, of which the full amount was drawn in September 2020. 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 September 30, 2020, the total funded debt to total capitalization ratios for DTE Energy, DTE Electric, and DTE Gas were 0.60 to 1, 0.52 to 1, and 0.49 to 1, respectively, and were in compliance with this financial covenant. The availability under these facilities as of September 30, 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 March 2021 500 — — 500 Unsecured term loans, expiring in April 2021 — 400 100 500 Unsecured term loan, expiring in June 2021 167 — — 167 Unsecured Canadian revolving credit facility, expiring May 2023 83 — — 83 Unsecured revolving credit facility, expiring April 2024 1,500 500 300 2,300 2,510 900 400 3,810 Amounts outstanding at September 30, 2020 Letters of credit 212 — — 212 Unsecured term loan 667 200 100 967 Revolver borrowings 21 — — 21 900 200 100 1,200 Net availability at September 30, 2020 $ 1,610 $ 700 $ 300 $ 2,610 DTE Energy has $59 million of other outstanding letters of credit which are used for various corporate purposes and are not included in the facilities described above. These letters of credit include a $50 million uncommitted letter of credit facility entered into by DTE Energy in July 2020, of which the full amount has been drawn. The facility expires in July 2021 with an automatic renewal provision. In October 2020, DTE Energy repaid several of its unsecured term loans. As noted in Note 10 to the Consolidated Financial Statements, "Long-term Debt", DTE Energy used proceeds from the issuance of long-term debt to repay its $500 million term loan expiring March 2021 and $167 million term loan expiring June 2021. In October 2020, DTE Gas also repaid its $100 million term loan expiring April 2021. 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 September 30, 2020, the capacity under the facilities was $300 million. The amount outstanding under the agreements was $43 million and $114 million at September 30, 2020 and December 31, 2019, respectively, and was fully offset by the posted collateral.

Leases

Leases	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Leases	LEASES Lessor During the second quarter 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 finances leases of $8 million and selling profit of $11 million. During the first quarter 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. The components of DTE Energy’s net investment in finance leases for remaining periods were as follows: DTE Energy September 30, 2020 (In millions) 2020 $ 8 2021 24 2022 20 2023 19 2024 19 2025 and Thereafter 273 Total minimum future lease receipts 363 Residual value of leased pipeline 19 Less unearned income 201 Net investment in finance lease 181 Less current portion 10 $ 171 Interest income recognized under finance leases was $4 million and $2 million for the three months ended September 30, 2020 and 2019, respectively, and $12 million and $4 million for the nine months ended September 30, 2020 and 2019, respectively. DTE Energy’s lease income associated with operating leases was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Fixed payments $ 17 $ 17 $ 50 $ 51 Variable payments 43 40 82 92 $ 60 $ 57 $ 132 $ 143
Leases	LEASES Lessor During the second quarter 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 finances leases of $8 million and selling profit of $11 million. During the first quarter 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. The components of DTE Energy’s net investment in finance leases for remaining periods were as follows: DTE Energy September 30, 2020 (In millions) 2020 $ 8 2021 24 2022 20 2023 19 2024 19 2025 and Thereafter 273 Total minimum future lease receipts 363 Residual value of leased pipeline 19 Less unearned income 201 Net investment in finance lease 181 Less current portion 10 $ 171 Interest income recognized under finance leases was $4 million and $2 million for the three months ended September 30, 2020 and 2019, respectively, and $12 million and $4 million for the nine months ended September 30, 2020 and 2019, respectively. DTE Energy’s lease income associated with operating leases was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Fixed payments $ 17 $ 17 $ 50 $ 51 Variable payments 43 40 82 92 $ 60 $ 57 $ 132 $ 143
Leases	LEASES Lessor During the second quarter 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 finances leases of $8 million and selling profit of $11 million. During the first quarter 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. The components of DTE Energy’s net investment in finance leases for remaining periods were as follows: DTE Energy September 30, 2020 (In millions) 2020 $ 8 2021 24 2022 20 2023 19 2024 19 2025 and Thereafter 273 Total minimum future lease receipts 363 Residual value of leased pipeline 19 Less unearned income 201 Net investment in finance lease 181 Less current portion 10 $ 171 Interest income recognized under finance leases was $4 million and $2 million for the three months ended September 30, 2020 and 2019, respectively, and $12 million and $4 million for the nine months ended September 30, 2020 and 2019, respectively. DTE Energy’s lease income associated with operating leases was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Fixed payments $ 17 $ 17 $ 50 $ 51 Variable payments 43 40 82 92 $ 60 $ 57 $ 132 $ 143

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 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 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. As of September 30, 2020, an additional $5 million remains accrued for the settlement. The U.S. District Court is still reviewing the Sierra Club Consent Decree and a final decision is expected in the fourth quarter of 2020. The Registrants do not expect the final settlement to have a material financial impact. 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 commitments for its electric utility operations to reduce carbon emissions 32% by the early 2020s, 50% by 2030, and 80% by 2040 from the 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 above ground storage tank locations. The findings of these investigations indicated that the estimated cost to remediate these sites is expected to be incurred over the next several years. At September 30, 2020 and December 31, 2019, DTE Electric had $6 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, and September 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. DTE Electric has estimated the impact of the current rule to be $629 million of capital expenditures. 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 March 3, 2020, an additional proposed revision to the CCR Rule 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 the final September 28, 2020 rule and the proposed CCR rule, including the alternative liner system demonstration for our clay lined impoundments, 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 November 2015, the EPA finalized the ELG Rule for the steam electric power generating industry which requires additional controls to be installed between 2018 and 2023. 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. 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 flue gas desulfurization (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 August 31, 2020, the EPA released the final version of 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 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 September 30, 2020 and December 31, 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 a finding of violation 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. EES Coke evaluated the EPA's alleged violations and believes that the permits approved by EGLE complied with the Clean Air Act. Discussions with the EPA are ongoing. At the present time, DTE Energy cannot predict the outcome or financial impact of this FOV. 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 SO 2 emission reductions that, in combination with other non-DTE Energy sources' emission reduction strategies, will help the state attain the standard and sustain its attainment. 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. SIP submittal and EPA approval describing the control strategy and timeline for demonstrating compliance with the new SO 2 standard is the next step in the process and is expected to be completed in 2020. DTE Energy is unable to determine the full impact of the SIP strategy. 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 September 30, 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 September 30, 2020 was $543 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 $226 million and $360 million at September 30, 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 in 2033. The amount of each guarantee decreases annually as payments are made by NEXUS to each of the aforementioned counterparties. NEXUS is also party to certain 15-year capacity agreements for the transportation of natural gas with Vector, 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 September 30, 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 September 30, 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 September 30, 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 September 30, 2020 is $52 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 Utility capital expenditures, expenditures for non-utility businesses, and contributions to equity method investees will be approximately $4.5 billion and $2.6 billion in 2020 for DTE Energy and DTE Electric, respectively. The Registrants have made certain commitments in connection with the estimated 2020 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 three and nine months ended September 30, 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 three and nine months ended September 30, 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. 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 September 30, 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 6 and 9 to the Consolidated Financial Statements, "Regulatory Matters" and "Financial and Other Derivative Instruments," respectively.

Retirement Benefits and Trustee

Retirement Benefits and Trusteed Assets	9 Months Ended
	Sep. 30, 2020
Retirement Benefits [Abstract]
Retirement Benefits and Trusteed Assets	RETIREMENT BENEFITS AND TRUSTEED ASSETS The following tables detail the components of net periodic benefit costs (credits) for pension benefits and other postretirement benefits for DTE Energy: Pension Benefits Other Postretirement Benefits Three Months Ended September 30, 2020 2019 2020 2019 (In millions) Service cost $ 25 $ 21 $ 7 $ 5 Interest cost 46 55 14 18 Expected return on plan assets (84) (82) (32) (30) Amortization of: Net actuarial loss 43 33 4 3 Prior service credit — — (5) (3) Settlements 2 — — — Net periodic benefit cost (credit) $ 32 $ 27 $ (12) $ (7) Pension Benefits Other Postretirement Benefits Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Service cost $ 74 $ 63 $ 20 $ 16 Interest cost 139 164 42 53 Expected return on plan assets (250) (244) (96) (92) Amortization of: Net actuarial loss 129 99 12 9 Prior service credit — — (15) (7) Settlements 2 — — — Net periodic benefit cost (credit) $ 94 $ 82 $ (37) $ (21) DTE Electric participates in various plans that provide pension and other postretirement benefits for DTE Energy and its affiliates. The plans are sponsored by DTE Energy's subsidiary, DTE Energy Corporate Services, LLC. DTE Electric accounts for its participation in DTE Energy's qualified and non-qualified pension plans by applying multiemployer accounting. DTE Electric accounts for its participation in other postretirement benefit plans by applying multiple-employer accounting. Within multiemployer and multiple-employer plans, participants pool plan assets for investment purposes and to reduce the cost of plan administration. The primary difference between plan types is assets contributed in multiemployer plans can be used to provide benefits for all participating employers, while assets contributed within a multiple-employer plan are restricted for use by the contributing employer. As a result of multiemployer accounting treatment, capitalized costs associated with these plans are reflected in Property, plant, and equipment in DTE Electric's Consolidated Statements of Financial Position. The same capitalized costs are reflected as Regulatory assets and liabilities in DTE Energy's Consolidated Statements of Financial Position. In addition, the service cost and non-service cost components are presented in Operation and maintenance in DTE Electric's Consolidated Statements of Operations. The same non-service cost components are presented in Other (Income) and Deductions — Non-operating retirement benefits, net in DTE Energy's Consolidated Statements of Operations. Plan participants of all plans are solely DTE Energy and affiliate participants. DTE Energy's subsidiaries are responsible for their share of qualified and non-qualified pension benefit costs. DTE Electric's allocated portion of pension benefit costs included in capital expenditures and operating and maintenance expense were $28 million and $23 million for the three months ended September 30, 2020 and 2019, respectively, and $79 million and $68 million for the nine months ended September 30, 2020 and 2019, respectively. These amounts include recognized contractual termination benefit charges, curtailment gains, and settlement charges. The following tables detail the components of net periodic benefit costs (credits) for other postretirement benefits for DTE Electric: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) (In millions) Service cost $ 5 $ 4 $ 15 $ 12 Interest cost 11 13 32 40 Expected return on plan assets (21) (21) (65) (63) Amortization of: Net actuarial loss 2 1 8 3 Prior service credit (3) (1) (10) (5) Net periodic benefit credit $ (6) $ (4) $ (20) $ (13) Pension and Other Postretirement Contributions For the nine months ended September 30, 2020, DTE Energy made contributions of $84 million to its qualified pension plans, including $82 million of common stock and $2 million of cash contributions. 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. DTE Energy is currently assessing whether any additional contributions will be made to its pension plans in 2020. If any further contributions are made, they are not expected to be material to the Consolidated Financial Statements. No contributions are anticipated for DTE Energy's postretirement benefit plans in 2020.

Segment and Related Information

Segment and Related Information	9 Months Ended
	Sep. 30, 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 energy-related investments. The federal income tax provisions or benefits of DTE Energy’s subsidiaries are determined on an individual company basis and recognize the tax benefit of tax credits and net operating losses, if applicable. The state and local income tax provisions of the utility subsidiaries are determined on an individual company basis and recognize the tax benefit of various tax credits and net operating losses, if applicable. The subsidiaries record federal, state, and local income taxes payable to or receivable from DTE Energy based on the federal, state, and local tax provisions of each company. Inter-segment billing for goods and services exchanged between segments is based upon tariffed or market-based prices of the provider and primarily consists of the sale of reduced emissions fuel, power sales, and natural gas sales in the following segments: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Electric $ 16 $ 16 $ 46 $ 43 Gas 4 3 12 8 Gas Storage and Pipelines 8 11 17 17 Power and Industrial Projects 134 160 308 462 Energy Trading 9 4 23 16 Corporate and Other 1 1 2 2 $ 172 $ 195 $ 408 $ 548 Financial data of DTE Energy's business segments follows: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Operating Revenues — Utility operations Electric $ 1,690 $ 1,520 $ 4,211 $ 3,945 Gas 173 155 964 1,043 Operating Revenues — Non-utility operations Electric 3 — 10 — Gas Storage and Pipelines 204 126 546 363 Power and Industrial Projects 324 406 850 1,196 Energy Trading 1,061 1,105 2,714 3,519 Corporate and Other 1 2 2 3 Reconciliation and Eliminations (172) (195) (408) (548) Total $ 3,284 $ 3,119 $ 8,889 $ 9,521 Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Net Income (Loss) Attributable to DTE Energy by Segment: Electric $ 398 $ 307 $ 675 $ 587 Gas (20) (38) 102 121 Gas Storage and Pipelines 104 60 246 158 Power and Industrial Projects 47 49 102 104 Energy Trading (28) (14) 5 12 Corporate and Other (25) (45) (37) (80) Net Income Attributable to DTE Energy Company $ 476 $ 319 $ 1,093 $ 902

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 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: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Operating Revenues — Utility operations DTE Gas $ 8 $ 8 $ 24 $ 24 Fuel, purchased power, and gas — utility DTE Electric $ 2 $ 2 $ 6 $ 6 DTE Gas $ 2 $ 2 $ 14 $ 15 Fuel, purchased power, and gas — non-utility DTE Energy Trading $ 7 $ 2 $ 20 $ 5 Other related party transactions with equity method investees include transactions with Vector Pipeline and Millennium Pipeline. These transactions were not material for the three and nine months ended September 30, 2020 and 2019 .

Subsequent Event

Subsequent Event	9 Months Ended
	Sep. 30, 2020
Subsequent Events [Abstract]
Subsequent Event	SUBSEQUENT EVENTOn 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. The planned separation transaction is intended to be a tax-free spin to DTE Energy 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.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Consolidated Financial Statements should be read in conjunction with the Combined Notes to Consolidated Financial Statements included in the combined DTE Energy and DTE Electric 2019 Annual Report on Form 10-K. The accompanying Consolidated Financial Statements of the Registrants are prepared using accounting principles generally accepted in the United States of America. These accounting principles require management to use estimates and assumptions that impact reported amounts of assets, liabilities, revenues and expenses, and the disclosure of contingent assets and liabilities. Actual results may differ from the Registrants' estimates. The Consolidated Financial Statements are unaudited but, in the Registrants' opinions, include all adjustments necessary to present a fair statement of the results for the interim periods. All adjustments are of a normal recurring nature, except as otherwise disclosed in these Consolidated Financial Statements and Combined Notes to Consolidated Financial Statements. Financial results for this interim period are not necessarily indicative of results that may be expected for any other interim period or for the fiscal year ending December 31, 2020. 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 DTE Electric 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 cost method is used. These Consolidated Financial Statements also reflect the Registrants' proportionate interests in certain jointly-owned utility plants. The Registrants eliminate all intercompany balances and transactions. The Registrants evaluate whether an entity is a VIE whenever reconsideration events occur. The Registrants consolidate VIEs for which they are the primary beneficiary. If a Registrant is not the primary beneficiary and an ownership interest is held, the VIE is accounted for under the equity method of accounting. When assessing the determination of the primary beneficiary, a Registrant considers all relevant facts and circumstances, including: the power, through voting or similar rights, to direct the activities of the VIE that most significantly impact the VIE's economic performance and the obligation to absorb the expected losses and/or the right to receive the expected returns of the VIE. The Registrants perform ongoing reassessments of all VIEs to determine if the primary beneficiary status has changed. Legal entities within DTE Energy's Power and Industrial Projects segment enter into long-term contractual arrangements with customers to supply energy-related products or services. The entities are generally designed to pass-through the commodity risk associated with these contracts to the customers, with DTE Energy retaining operational and customer default risk. These entities generally are VIEs and consolidated when DTE Energy is the primary beneficiary. In addition, DTE Energy has interests in certain VIEs through which control of all significant activities is shared with partners, and therefore are 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 is 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 23-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 September 30, 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 September 30, 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 13 to the Consolidated Financial Statements, "Commitments and Contingencies," related to the REF guarantees and indemnities. For non-consolidated VIEs, the maximum risk exposure of the Registrants is generally limited to their investment, notes receivable, future funding commitments, and amounts which DTE Energy has guaranteed. See Note 13 to the Consolidated Financial Statements, "Commitments and Contingencies," for further discussion of the NEXUS guarantee arrangements.
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 to fund certain construction projects and guarantee performance. Restricted cash designated for payments within one year is classified as a Current Asset.
Financing Receivables	Financing Receivables 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 September 30, 2020. DTE Energy DTE Electric Year of origination 2020 2019 2018 and prior Total 2020 and prior (In millions) Notes receivable Internal grade 1 $ — $ 18 $ 9 $ 27 $ 18 Internal grade 2 60 19 6 85 — Total notes receivable (a) $ 60 $ 37 $ 15 $ 112 $ 18 Net investment in leases Net investment in leases, internal grade 1 $ 8 $ — $ 40 $ 48 $ — Net investment in leases, internal grade 2 132 — 1 133 — Total net investment in leases (a) $ 140 $ — $ 41 $ 181 $ — _______________________________________ (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, or financing receivables, 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, or financing receivables, for DTE Electric are primarily comprised of loans. Notes receivable are typically considered delinquent when payment is not received for periods ranging from 60 to 120 days. The Registrants cease accruing interest (nonaccrual status), consider a note receivable impaired, and establish an allowance for credit loss when it is probable that all principal and interest amounts due will not be collected in accordance with the contractual terms of the note receivable. In determining the allowance for credit losses for notes receivable, the Registrants consider the historical payment experience and other factors that are expected to have a specific impact on the counterparty's ability to pay including existing and future economic conditions. DTE Energy has off balance sheet exposure in the form of a revolving credit facility. Refer to Note 13, "Commitments and Contingencies," for additional information. In determining the level of credit reserve needed, DTE considers the likelihood of funding in addition to the other factors noted above. A reserve may be established when it is likely that funding will occur. Cash payments received on nonaccrual status notes receivable, that do not bring the account contractually current, are first applied to the contractually owed past due interest, with any remainder applied to principal. Accrual of interest is generally resumed when the note receivable becomes contractually current.
Recently Adopted and Recently Issued Pronouncements	Recently Adopted Pronouncements In 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 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 8 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 (Subtopic 715-20): Disclosure Framework - Changes to the Disclosure requirements for employers that sponsor defined benefit pension or other postretirement 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 required disclosures for this ASU will be reflected in the 2020 year-end financial statements. 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 . 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.
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 September 30, 2020 and December 31, 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 $192 million and $151 million as of September 30, 2020 and December 31, 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	The Registrants recognize all derivatives at their fair value as Derivative assets or liabilities on their respective Consolidated Statements of Financial Position unless they qualify for certain scope exceptions, including the normal purchases and normal sales exception. Further, derivatives that qualify and are designated for hedge accounting are classified as either hedges of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge); or as hedges of the fair value of a recognized asset or liability or of an unrecognized firm commitment (fair value hedge). For cash flow hedges, the derivative gain or loss is deferred in Accumulated other comprehensive income (loss) and later reclassified into earnings when the underlying transaction occurs. For fair value hedges, changes in fair values for the derivative and hedged item are recognized in earnings each period. For derivatives that do not qualify or are not designated for hedge accounting, changes in fair value are recognized in earnings each period. The Registrants' primary market risk exposure is associated with commodity prices, credit, and interest rates. The Registrants have risk management policies to monitor and manage market risks. The Registrants use derivative instruments to manage some of the exposure. DTE Energy uses derivative instruments for trading purposes in its Energy Trading segment. Contracts classified as derivative instruments include electricity, natural gas, oil, certain environmental contracts, forwards, futures, options, swaps, and foreign currency exchange contracts. Items not classified as derivatives include natural gas and environmental inventory, pipeline transportation contracts, certain environmental contracts, and natural gas storage assets. DTE Electric — DTE Electric generates, purchases, distributes, and sells electricity. DTE Electric uses forward contracts to manage changes in the price of electricity and fuel. Substantially all of these contracts meet the normal purchases and normal sales exception and are therefore accounted for under the accrual method. Other derivative contracts are MTM and recoverable through the PSCR mechanism when settled. This results in the deferral of unrealized gains and losses as Regulatory assets or liabilities until realized. DTE Gas — DTE Gas purchases, stores, transports, distributes, and sells natural gas, and buys and sells transportation and storage capacity. DTE Gas has fixed-priced contracts for portions of its expected natural gas supply requirements through March 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 September 30, 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.
Derivatives, Offsetting Fair Value Amounts	Certain of DTE Energy's derivative positions are subject to netting arrangements which provide for offsetting of asset and liability positions as well as related cash collateral. Such netting arrangements generally do not have restrictions. Under such netting arrangements, DTE Energy offsets the fair value of derivative instruments with cash collateral received or paid for those contracts executed with the same counterparty, which reduces DTE Energy's Total Assets and Liabilities. Cash collateral is allocated between the fair value of derivative instruments and customer accounts receivable and payable with the same counterparty on a pro-rata basis to the extent there is exposure. Any cash collateral remaining, after the exposure is netted to zero, is reflected in Accounts receivable and Accounts payable as collateral paid or received, respectively. DTE Energy also provides and receives collateral in the form of letters of credit which can be offset against net Derivative assets and liabilities as well as Accounts receivable and payable. DTE Energy had issued letters of credit of $5 million and $6 million outstanding at September 30, 2020 and December 31, 2019, respectively, which could be used to offset net Derivative liabilities. Letters of credit received from third parties which could be used to offset net Derivative assets were $1 million and $4 million at September 30, 2020 and December 31, 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, Derivatives Not Designated or Qualifying as Hedges	Revenues and energy costs related to trading contracts are presented on a net basis in DTE Energy's Consolidated Statements of Operations. Commodity derivatives used for trading purposes, and financial non-trading commodity derivatives, are accounted for using the MTM method with unrealized and realized gains and losses recorded in Operating Revenues — Non-utility operations. Non-trading physical commodity sale and purchase derivative contracts are generally accounted for using the MTM method with unrealized and realized gains and losses for sales recorded in Operating Revenues — Non-utility operations and purchases recorded in Fuel, purchased power, and gas — non-utility.
Income Tax	The federal income tax provisions or benefits of DTE Energy’s subsidiaries are determined on an individual company basis and recognize the tax benefit of tax credits and net operating losses, if applicable. The state and local income tax provisions of the utility subsidiaries are determined on an individual company basis and recognize the tax benefit of various tax credits and net operating losses, if applicable. The subsidiaries record federal, state, and local income taxes payable to or receivable from DTE Energy based on the federal, state, and local tax provisions of each company.

Organization and Basis of Pre_2

Organization and Basis of Presentation (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2020 and December 31, 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: September 30, 2020 December 31, 2019 SGG (a) Other Total SGG (a) Other Total (In millions) ASSETS Cash and cash equivalents $ 33 $ 22 $ 55 $ 16 $ 11 $ 27 Accounts receivable 7 18 25 8 19 27 Inventories — 102 102 — 74 74 Property, plant, and equipment, net 404 25 429 410 33 443 Goodwill 25 — 25 25 — 25 Intangible assets 531 — 531 542 — 542 Other current and long-term assets 1 19 20 2 — 2 $ 1,001 $ 186 $ 1,187 $ 1,003 $ 137 $ 1,140 LIABILITIES Accounts payable and accrued current liabilities $ — $ 19 $ 19 $ 2 $ 13 $ 15 Short-term borrowings — 21 21 — — — Other current and long-term liabilities 6 4 10 7 7 14 $ 6 $ 44 $ 50 $ 9 $ 20 $ 29 _____________________________________ (a) Amounts shown are 100% of SGG's assets and liabilities, of which DTE Energy owns 85% at September 30, 2020 and December 31, 2019.
Summary of Amounts for Non-Consolidated Variable Interest Entities	Amounts for DTE Energy's non-consolidated VIEs are as follows: September 30, 2020 December 31, 2019 (In millions) Investments in equity method investees $ 1,505 $ 1,503 Notes receivable $ 40 $ 21 Future funding commitments $ 36 $ 63

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Schedule of Other Income	The following is a summary of DTE Energy's Other income: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Equity earnings of equity method investees $ 37 $ 34 $ 96 $ 77 Income from REF entities 43 40 95 96 Gains from equity and fixed income securities 2 3 24 27 Contract services 7 7 20 21 Gas Storage and Pipelines post-acquisition settlement 20 — 20 — Allowance for equity funds used during construction 6 5 19 18 Other 5 9 12 20 $ 120 $ 98 $ 286 $ 259 The following is a summary of DTE Electric's Other income: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Gains from equity and fixed income securities allocated from DTE Energy $ 2 $ 3 $ 24 $ 27 Contract services 7 7 20 23 Allowance for equity funds used during construction 6 5 18 17 Other 3 5 6 11 $ 18 $ 20 $ 68 $ 78
Schedule of Effective Tax Rates	The interim effective tax rates of the Registrants are as follows: Effective Tax Rate Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 DTE Energy 12 % 13 % 10 % 12 % DTE Electric 13 % 16 % 12 % 16 %
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 September 30, 2020. DTE Energy DTE Electric Year of origination 2020 2019 2018 and prior Total 2020 and prior (In millions) Notes receivable Internal grade 1 $ — $ 18 $ 9 $ 27 $ 18 Internal grade 2 60 19 6 85 — Total notes receivable (a) $ 60 $ 37 $ 15 $ 112 $ 18 Net investment in leases Net investment in leases, internal grade 1 $ 8 $ — $ 40 $ 48 $ — Net investment in leases, internal grade 2 132 — 1 133 — Total net investment in leases (a) $ 140 $ — $ 41 $ 181 $ — _______________________________________ (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 September 30, 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 73 2 75 47 Write-offs charged against allowance (117) (3) (120) (68) Recoveries of amounts previously written off 41 — 41 24 Ending reserve balance, September 30, 2020 $ 84 $ 3 $ 87 $ 49

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Schedule of Final 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 1,035 Goodwill 172 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)	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following is a summary of revenues disaggregated by segment for DTE Energy: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Electric (a) Residential $ 900 $ 791 $ 2,169 $ 1,839 Commercial 498 515 1,313 1,358 Industrial 157 175 434 497 Other (b) 138 39 305 251 Total Electric operating revenues (c) $ 1,693 $ 1,520 $ 4,221 $ 3,945 Gas Gas sales $ 92 $ 87 $ 655 $ 727 End User Transportation 34 35 154 157 Intermediate Transportation 15 15 57 57 Other (b) 32 18 98 102 Total Gas operating revenues (d) $ 173 $ 155 $ 964 $ 1,043 Other segment operating revenues Gas Storage and Pipelines (e) $ 204 $ 126 $ 546 $ 363 Power and Industrial Projects (f) $ 324 $ 406 $ 850 $ 1,196 Energy Trading (g) $ 1,061 $ 1,105 $ 2,714 $ 3,519 _______________________________________ (a) Revenues generally represent those of DTE Electric, except $3 million and $10 million of Other revenues related to DTE Sustainable Generation for the three and nine months ended September 30, 2020, respectively. (b) Includes revenue adjustments related to various regulatory mechanisms. (c) Includes $8 million and $5 million of other revenues outside the scope of topic 606 for the three months ended September 30, 2020 and 2019, and $18 million and $14 million for the nine months ended September 30, 2020 and 2019, respectively. (d) Includes $2 million under Alternative Revenue Programs for the nine months ended September 30, 2020 and $2 million and $7 million of other revenues for the three and nine months ended September 30, 2020, respectively, which are all outside the scope of Topic 606. For prior period, revenues include $2 million and $6 million of other revenues for the three and nine months ended September 30, 2019, respectively, which are all outside the scope of Topic 606. (e) Includes revenues outside the scope of Topic 606 primarily related to $2 million of contracts accounted for as leases for the three months ended September 30, 2020 and 2019, and $7 million for the nine months ended September 30, 2020 and 2019. (f) Includes revenues outside the scope of Topic 606 primarily related to $26 million and $33 million of contracts accounted for as leases for the three months ended September 30, 2020 and 2019, respectively, and $74 million and $94 million for the nine months ended September 30, 2020 and 2019, respectively. (g) Includes revenues outside the scope of Topic 606 primarily related to $731 million and $791 million of derivatives for the three months ended September 30, 2020 and 2019, respectively, and $1.8 billion and $2.6 billion of derivatives for the nine months ended September 30, 2020 and 2019, 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 39 Revenue recognized that was included in the deferred revenue balance at the beginning of the period (42) Ending Balance, September 30, 2020 $ 72
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) 2020 $ 7 2021 36 2022 7 2023 3 2024 7 2025 and thereafter 12 $ 72 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) 2020 $ 72 $ 2 2021 350 8 2022 294 7 2023 231 7 2024 142 8 2025 and thereafter 580 — $ 1,669 $ 32

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 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: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions, except per share amounts) Basic Earnings per Share Net Income Attributable to DTE Energy Company $ 476 $ 319 $ 1,093 $ 902 Less: Allocation of earnings to net restricted stock awards 1 1 2 2 Net income available to common shareholders — basic $ 475 $ 318 $ 1,091 $ 900 Average number of common shares outstanding — basic 193 183 192 183 Basic Earnings per Common Share $ 2.47 $ 1.74 $ 5.67 $ 4.93 Diluted Earnings per Share Net Income Attributable to DTE Energy Company $ 476 $ 319 $ 1,093 $ 902 Less: Allocation of earnings to net restricted stock awards 1 1 2 2 Net income available to common shareholders — diluted $ 475 $ 318 $ 1,091 $ 900 Average number of common shares outstanding — basic 193 183 192 183 Incremental shares attributable to: Average dilutive equity units, performance share awards, and stock options — 1 1 1 Average number of common shares outstanding — diluted 193 184 193 184 Diluted Earnings per Common Share (a) $ 2.46 $ 1.73 $ 5.66 $ 4.91 _______________________________________ (a) Equity Units excluded from the calculation of diluted EPS were approximately 10.3 million for the three and nine months ended September 30, 2020, as the dilutive stock price threshold was not met.

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis	The following table presents assets and liabilities for DTE Energy measured and recorded at fair value on a recurring basis (a) : September 30, 2020 December 31, 2019 Level Level Level Other (b) Netting (c) Net Balance Level Level Level Other (b) Netting (c) Net Balance (In millions) Assets Cash equivalents (d) $ 567 $ — $ — $ — $ — $ 567 $ 15 $ — $ — $ — $ — $ 15 Nuclear decommissioning trusts Equity securities 872 — — 141 — 1,013 1,046 — — — — 1,046 Fixed income securities 122 325 — 80 — 527 160 378 — — — 538 Private equity and other — — — 78 — 78 — — — 43 — 43 Cash equivalents 46 — — — — 46 34 — — — — 34 Other investments (e) Equity securities 49 — — — — 49 140 — — — — 140 Fixed income securities 6 — — — — 6 79 — — — — 79 Cash equivalents 98 — — — — 98 4 — — — — 4 Derivative assets Commodity contracts (f) Natural gas 126 72 42 — (194) 46 205 76 74 — (266) 89 Electricity — 103 34 — (106) 31 — 223 83 — (225) 81 Environmental & Other — 194 7 — (186) 15 — 110 3 — (110) 3 Foreign currency exchange contracts — 2 — — — 2 — 1 — — — 1 Total derivative assets 126 371 83 — (486) 94 205 410 160 — (601) 174 Total $ 1,886 $ 696 $ 83 $ 299 $ (486) $ 2,478 $ 1,683 $ 788 $ 160 $ 43 $ (601) $ 2,073 Liabilities Derivative liabilities Commodity contracts (f) Natural gas $ (118) $ (66) $ (81) $ — $ 185 $ (80) $ (221) $ (41) $ (89) $ — $ 266 $ (85) Electricity — (97) (29) — 104 (22) — (231) (67) — 225 (73) Environmental & Other (3) (168) — — 171 — — (121) — — 110 (11) Foreign currency exchange contracts — (2) — — — (2) — — — — — — Total $ (121) $ (333) $ (110) $ — $ 460 $ (104) $ (221) $ (393) $ (156) $ — $ 601 $ (169) Net Assets (Liabilities) at end of period $ 1,765 $ 363 $ (27) $ 299 $ (26) $ 2,374 $ 1,462 $ 395 $ 4 $ 43 $ — $ 1,904 Assets Current $ 679 $ 273 $ 59 $ — $ (379) $ 632 $ 218 $ 320 $ 123 $ — $ (513) $ 148 Noncurrent 1,207 423 24 299 (107) 1,846 1,465 468 37 43 (88) 1,925 Total Assets $ 1,886 $ 696 $ 83 $ 299 $ (486) $ 2,478 $ 1,683 $ 788 $ 160 $ 43 $ (601) $ 2,073 Liabilities Current $ (112) $ (243) $ (66) $ — $ 361 $ (60) $ (211) $ (300) $ (85) $ — $ 513 $ (83) Noncurrent (9) (90) (44) — 99 (44) (10) (93) (71) — 88 (86) Total Liabilities $ (121) $ (333) $ (110) $ — $ 460 $ (104) $ (221) $ (393) $ (156) $ — $ 601 $ (169) Net Assets (Liabilities) at end of period $ 1,765 $ 363 $ (27) $ 299 $ (26) $ 2,374 $ 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 September 30, 2020, the $567 million consisted of $565 million and $2 million of cash equivalents included in Cash and cash equivalents and Restricted cash on DTE Energy's Consolidated Statements of Financial Position, respectively. 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 on DTE Energy's Consolidated Statements of Financial Position, respectively. (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: September 30, 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) $ 175 $ — $ — $ — $ 175 $ 11 $ — $ — $ — $ 11 Nuclear decommissioning trusts Equity securities 872 — — 141 1,013 1,046 — — — 1,046 Fixed income securities 122 325 — 80 527 160 378 — — 538 Private equity and other — — — 78 78 — — — 43 43 Cash equivalents 46 — — — 46 34 — — — 34 Other investments Equity securities 14 — — — 14 13 — — — 13 Cash equivalents 11 — — — 11 — — — — — Derivative assets — FTRs — — 7 — 7 — — 3 — 3 Total $ 1,240 $ 325 $ 7 $ 299 $ 1,871 $ 1,264 $ 378 $ 3 $ 43 $ 1,688 Assets Current $ 175 $ — $ 7 $ — $ 182 $ 11 $ — $ 3 $ — $ 14 Noncurrent 1,065 325 — 299 1,689 1,253 378 — 43 1,674 Total Assets $ 1,240 $ 325 $ 7 $ 299 $ 1,871 $ 1,264 $ 378 $ 3 $ 43 $ 1,688 _______________________________________ (a) Amounts represent assets valued at NAV as a practical expedient for fair value. (b) At September 30, 2020, the $175 million of cash equivalents was included in Cash and cash equivalents on DTE Electric's Consolidated Statements of Financial Position. At December 31, 2019, the $11 million of cash equivalents was 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: Three Months Ended September 30, 2020 Three Months Ended September 30, 2019 Natural Gas Electricity Other Total Natural Gas Electricity Other Total (In millions) Net Assets (Liabilities) as of June 30 $ 20 $ 16 $ 10 $ 46 $ (10) $ 10 $ 9 $ 9 Transfers from Level 3 into Level 2 (1) — — (1) — — — — Total gains (losses) Included in earnings (80) 37 1 (42) (35) 37 — 2 Recorded in Regulatory liabilities — — 9 9 — — (3) (3) Purchases, issuances, and settlements Settlements 22 (48) (13) (39) 4 (39) (1) (36) Net Assets (Liabilities) as of September 30 $ (39) $ 5 $ 7 $ (27) $ (41) $ 8 $ 5 $ (28) Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2020 and 2019 (a) $ (57) $ 11 $ (1) $ (47) $ (36) $ 15 $ (1) $ (22) _______________________________________ (a) Amounts are reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations. Nine Months Ended September 30, 2020 Nine Months Ended September 30, 2019 Natural Gas Electricity Other Total Natural Gas Electricity Other Total (In millions) Net Assets (Liabilities) as of December 31 $ (15) $ 16 $ 3 $ 4 $ (49) $ (2) $ 7 $ (44) Transfers from Level 3 into Level 2 (5) — — (5) — — — — Total gains (losses) Included in earnings (44) 90 (7) 39 (4) 47 (1) 42 Recorded in Regulatory liabilities — — 21 21 — — 3 3 Purchases, issuances, and settlements Settlements 25 (101) (10) (86) 12 (37) (4) (29) Net Assets (Liabilities) as of September 30 $ (39) $ 5 $ 7 $ (27) $ (41) $ 8 $ 5 $ (28) Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2020 and 2019 (a) $ (20) $ 53 $ (17) $ 16 $ (20) $ 32 $ (6) $ 6 _______________________________________ (a) Amounts are reflected in Operating Revenues — Non-utility operations and Fuel, purchased power, and gas — non-utility in DTE Energy's Consolidated Statements of Operations. The following table presents the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis for DTE Electric: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Net Assets as of beginning of period $ 10 $ 9 $ 3 $ 6 Change in fair value recorded in Regulatory liabilities 9 (3) 21 3 Purchases, issuances, and settlements Settlements (12) (1) (17) (4) Net Assets as of September 30 $ 7 $ 5 $ 7 $ 5 The amount of total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets held at September 30, 2020 and 2019 and reflected in DTE Electric's Consolidated Statements of Financial Position $ — $ (1) $ 7 $ 5
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: September 30, 2020 Commodity Contracts Derivative Assets Derivative Liabilities Valuation Techniques Unobservable Input Range Weighted Average (In millions) Natural Gas $ 42 $ (81) Discounted Cash Flow Forward basis price (per MMBtu) $ (1.10) — $ 2.30 /MMBtu $ (0.06) /MMBtu Electricity $ 34 $ (29) Discounted Cash Flow Forward basis price (per MWh) $ (9) — $ 6 /MWh $ (1) /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: September 30, 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) , excluding lessor finance leases $ 112 $ — $ — $ 112 $ 184 $ — $ — $ 184 Short-term borrowings $ 988 $ — $ 988 $ — $ 828 $ — $ 828 $ — Notes payable — Other (b) $ 19 $ — $ — $ 19 $ 25 $ — $ — $ 25 Long-term debt (c) $ 18,660 $ 2,398 $ 17,213 $ 1,406 $ 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: September 30, 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) $ 18 $ — $ — $ 18 $ 9 $ — $ — $ 9 Short-term borrowings — affiliates $ 104 $ — $ — $ 104 $ 97 $ — $ — $ 97 Short-term borrowings — other $ 200 $ — $ 200 $ — $ 354 $ — $ 354 $ — Notes payable — Other (b) $ 17 $ — $ — $ 17 $ 21 $ — $ — $ 21 Long-term debt (c) $ 8,235 $ — $ 9,565 $ 194 $ 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: September 30, 2020 December 31, 2019 (In millions) Fermi 2 $ 1,652 $ 1,650 Fermi 1 3 3 Low-level radioactive waste 9 8 $ 1,664 $ 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: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Realized gains $ 38 $ 15 $ 172 $ 43 Realized losses $ (11) $ (8) $ (103) $ (25) Proceeds from sale of securities $ 816 $ 198 $ 2,054 $ 594
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: September 30, 2020 December 31, 2019 Fair Unrealized Unrealized Fair Unrealized Unrealized (In millions) Equity securities $ 1,013 $ 325 $ (28) $ 1,046 $ 396 $ (39) Fixed income securities 527 16 (1) 538 24 (1) Private equity and other 78 — — 43 — — Cash equivalents 46 — — 34 — — $ 1,664 $ 341 $ (29) $ 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: September 30, 2020 (In millions) Due within one year $ 92 Due after one through five years 82 Due after five through ten years 79 Due after ten years 194 $ 447
Summary of Gains (Losses) Related to the Trust	The following table summarizes DTE Energy's gains (losses) related to the trust: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Gains (losses) related to equity securities $ 2 $ 1 $ (4) $ 18 Gains (losses) related to fixed income securities — 2 (3) 9 $ 2 $ 3 $ (7) $ 27

Financial and Other Derivativ_2

Financial and Other Derivative Instruments (Tables)	9 Months Ended
	Sep. 30, 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: September 30, 2020 December 31, 2019 Derivative Derivative Liabilities Derivative Derivative Liabilities (In millions) Derivatives designated as hedging instruments Foreign currency exchange contracts $ — $ (1) $ — $ — Derivatives not designated as hedging instruments Commodity contracts Natural gas $ 240 $ (265) $ 355 $ (351) Electricity 137 (126) 306 (298) Environmental & Other 201 (171) 113 (121) Foreign currency exchange contracts 2 (1) 1 — Total derivatives not designated as hedging instruments $ 580 $ (563) $ 775 $ (770) Current $ 444 $ (421) $ 646 $ (596) Noncurrent 136 (143) 129 (174) Total derivatives $ 580 $ (564) $ 775 $ (770) The following table presents the fair value of derivative instruments for DTE Electric: September 30, 2020 December 31, 2019 (In millions) FTRs — Other current assets $ 7 $ 3 Total derivatives not designated as hedging instruments $ 7 $ 3
Netting Offsets of Derivative Assets	The following table presents net cash collateral offsetting arrangements for DTE Energy: September 30, 2020 December 31, 2019 (In millions) Cash collateral netted against Derivative assets $ (26) $ — Cash collateral recorded in Accounts receivable (a) 12 13 Cash collateral recorded in Accounts payable (a) (2) (3) Total net cash collateral posted (received) $ (16) $ 10 _______________________________________ (a) Amounts are recorded net by counterparty. The following table presents the netting offsets of Derivative assets and liabilities for DTE Energy: September 30, 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 $ 240 $ (194) $ 46 $ 355 $ (266) $ 89 Electricity 137 (106) 31 306 (225) 81 Environmental & Other 201 (186) 15 113 (110) 3 Foreign currency exchange contracts 2 — 2 1 — 1 Total derivative assets $ 580 $ (486) $ 94 $ 775 $ (601) $ 174 Derivative liabilities Commodity contracts Natural gas $ (265) $ 185 $ (80) $ (351) $ 266 $ (85) Electricity (126) 104 (22) (298) 225 (73) Environmental & Other (171) 171 — (121) 110 (11) Foreign currency exchange contracts (2) — (2) — — — Total derivative liabilities $ (564) $ 460 $ (104) $ (770) $ 601 $ (169)
Netting Offsets of Derivative Liabilities	The following table presents net cash collateral offsetting arrangements for DTE Energy: September 30, 2020 December 31, 2019 (In millions) Cash collateral netted against Derivative assets $ (26) $ — Cash collateral recorded in Accounts receivable (a) 12 13 Cash collateral recorded in Accounts payable (a) (2) (3) Total net cash collateral posted (received) $ (16) $ 10 _______________________________________ (a) Amounts are recorded net by counterparty. The following table presents the netting offsets of Derivative assets and liabilities for DTE Energy: September 30, 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 $ 240 $ (194) $ 46 $ 355 $ (266) $ 89 Electricity 137 (106) 31 306 (225) 81 Environmental & Other 201 (186) 15 113 (110) 3 Foreign currency exchange contracts 2 — 2 1 — 1 Total derivative assets $ 580 $ (486) $ 94 $ 775 $ (601) $ 174 Derivative liabilities Commodity contracts Natural gas $ (265) $ 185 $ (80) $ (351) $ 266 $ (85) Electricity (126) 104 (22) (298) 225 (73) Environmental & Other (171) 171 — (121) 110 (11) Foreign currency exchange contracts (2) — (2) — — — Total derivative liabilities $ (564) $ 460 $ (104) $ (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: September 30, 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 $ 444 $ 136 $ (421) $ (143) $ 646 $ 129 $ (596) $ (174) Counterparty netting (361) (99) 361 99 (513) (88) 513 88 Collateral adjustment (18) (8) — — — — — — Total derivatives as reported $ 65 $ 29 $ (60) $ (44) $ 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 the Three Months Ended September 30, Gain (Loss) Recognized in Income on Derivatives for the Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Commodity contracts Natural gas Operating Revenues — Non-utility operations $ (27) $ (5) $ (63) $ 4 Natural gas Fuel, purchased power, and gas — non-utility (51) (47) 28 (7) Electricity Operating Revenues — Non-utility operations 33 54 75 21 Environmental & Other Operating Revenues — Non-utility operations 2 (11) (40) (11) Foreign currency exchange contracts Operating Revenues — Non-utility operations (2) 1 — (2) Total $ (45) $ (8) $ — $ 5
Volume of Commodity Contracts	The following represents the cumulative gross volume of DTE Energy's derivative contracts outstanding as of September 30, 2020: Commodity Number of Units Natural gas (MMBtu) 1,739,656,507 Electricity (MWh) 28,258,929 Foreign currency exchange (CAD) 154,336,963 Renewable Energy Certificates (MWh) 7,893,076 Carbon emissions (Metric Ton) 16,451,411

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
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 $ 2,750 _______________________________________ (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.
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 $ 682

Short-Term Credit Arrangement_2

Short-Term Credit Arrangements and Borrowings (Tables)	9 Months Ended
	Sep. 30, 2020
Short-term Debt [Abstract]
Schedule of Line of Credit Facilities	The availability under these facilities as of September 30, 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 March 2021 500 — — 500 Unsecured term loans, expiring in April 2021 — 400 100 500 Unsecured term loan, expiring in June 2021 167 — — 167 Unsecured Canadian revolving credit facility, expiring May 2023 83 — — 83 Unsecured revolving credit facility, expiring April 2024 1,500 500 300 2,300 2,510 900 400 3,810 Amounts outstanding at September 30, 2020 Letters of credit 212 — — 212 Unsecured term loan 667 200 100 967 Revolver borrowings 21 — — 21 900 200 100 1,200 Net availability at September 30, 2020 $ 1,610 $ 700 $ 300 $ 2,610

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Components of Net Investment in Finance Leases	The components of DTE Energy’s net investment in finance leases for remaining periods were as follows: DTE Energy September 30, 2020 (In millions) 2020 $ 8 2021 24 2022 20 2023 19 2024 19 2025 and Thereafter 273 Total minimum future lease receipts 363 Residual value of leased pipeline 19 Less unearned income 201 Net investment in finance lease 181 Less current portion 10 $ 171
Schedule of Lease Income Associated with Operating Leases	DTE Energy’s lease income associated with operating leases was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Fixed payments $ 17 $ 17 $ 50 $ 51 Variable payments 43 40 82 92 $ 60 $ 57 $ 132 $ 143

Retirement Benefits and Trust_2

Retirement Benefits and Trusteed Assets (Tables)	9 Months Ended
	Sep. 30, 2020
Retirement Benefits [Abstract]
Schedule of Net Periodic Benefit Costs (Credits)	The following tables detail the components of net periodic benefit costs (credits) for pension benefits and other postretirement benefits for DTE Energy: Pension Benefits Other Postretirement Benefits Three Months Ended September 30, 2020 2019 2020 2019 (In millions) Service cost $ 25 $ 21 $ 7 $ 5 Interest cost 46 55 14 18 Expected return on plan assets (84) (82) (32) (30) Amortization of: Net actuarial loss 43 33 4 3 Prior service credit — — (5) (3) Settlements 2 — — — Net periodic benefit cost (credit) $ 32 $ 27 $ (12) $ (7) Pension Benefits Other Postretirement Benefits Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Service cost $ 74 $ 63 $ 20 $ 16 Interest cost 139 164 42 53 Expected return on plan assets (250) (244) (96) (92) Amortization of: Net actuarial loss 129 99 12 9 Prior service credit — — (15) (7) Settlements 2 — — — Net periodic benefit cost (credit) $ 94 $ 82 $ (37) $ (21) The following tables detail the components of net periodic benefit costs (credits) for other postretirement benefits for DTE Electric: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) (In millions) Service cost $ 5 $ 4 $ 15 $ 12 Interest cost 11 13 32 40 Expected return on plan assets (21) (21) (65) (63) Amortization of: Net actuarial loss 2 1 8 3 Prior service credit (3) (1) (10) (5) Net periodic benefit credit $ (6) $ (4) $ (20) $ (13)
Schedule of the Contribution of Common Stock to the DTE Energy Company Affiliates Employee Benefit Plans Master Trust	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

Segment and Related Informati_2

Segment and Related Information (Tables)	9 Months Ended
	Sep. 30, 2020
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	Inter-segment billing for goods and services exchanged between segments is based upon tariffed or market-based prices of the provider and primarily consists of the sale of reduced emissions fuel, power sales, and natural gas sales in the following segments: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Electric $ 16 $ 16 $ 46 $ 43 Gas 4 3 12 8 Gas Storage and Pipelines 8 11 17 17 Power and Industrial Projects 134 160 308 462 Energy Trading 9 4 23 16 Corporate and Other 1 1 2 2 $ 172 $ 195 $ 408 $ 548 Financial data of DTE Energy's business segments follows: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Operating Revenues — Utility operations Electric $ 1,690 $ 1,520 $ 4,211 $ 3,945 Gas 173 155 964 1,043 Operating Revenues — Non-utility operations Electric 3 — 10 — Gas Storage and Pipelines 204 126 546 363 Power and Industrial Projects 324 406 850 1,196 Energy Trading 1,061 1,105 2,714 3,519 Corporate and Other 1 2 2 3 Reconciliation and Eliminations (172) (195) (408) (548) Total $ 3,284 $ 3,119 $ 8,889 $ 9,521 Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Net Income (Loss) Attributable to DTE Energy by Segment: Electric $ 398 $ 307 $ 675 $ 587 Gas (20) (38) 102 121 Gas Storage and Pipelines 104 60 246 158 Power and Industrial Projects 47 49 102 104 Energy Trading (28) (14) 5 12 Corporate and Other (25) (45) (37) (80) Net Income Attributable to DTE Energy Company $ 476 $ 319 $ 1,093 $ 902

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2020
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	The following table summarizes the amounts resulting from these transactions included in the Consolidated Statements of Operations: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (In millions) Operating Revenues — Utility operations DTE Gas $ 8 $ 8 $ 24 $ 24 Fuel, purchased power, and gas — utility DTE Electric $ 2 $ 2 $ 6 $ 6 DTE Gas $ 2 $ 2 $ 14 $ 15 Fuel, purchased power, and gas — non-utility DTE Energy Trading $ 7 $ 2 $ 20 $ 5

Organization and Basis of Pre_3

Organization and Basis of Presentation (Details Textuals) customer in Millions	Sep. 30, 2020USD ($)customer
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Number of electric utility customers | customer	2.2
Number of gas utility customers | customer	1.3
Significant potential exposure | $	$ 0
DTE Electric
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Significant 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]
Percent of assets 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	9 Months Ended
	Dec. 31, 2019	Sep. 30, 2020
ASSETS
Cash and cash equivalents	$ 93	$ 945
Accounts receivable	1,642	1,419
Property, plant, and equipment, net	25,317	27,159
Goodwill	2,464	2,465
Total Assets	41,882	44,439
LIABILITIES
Short-term borrowings	828	988
Total
ASSETS
Cash and cash equivalents	27	55
Accounts receivable	27	25
Inventories	74	102
Property, plant, and equipment, net	443	429
Goodwill	25	25
Intangible assets	542	531
Other current and long-term assets	2	20
Total Assets	1,140	1,187
LIABILITIES
Accounts payable and accrued current liabilities	15	19
Short-term borrowings	0	21
Other current and long-term liabilities	14	10
Total liabilities	29	50
SGG
ASSETS
Cash and cash equivalents	16	33
Accounts receivable	8	7
Inventories	0	0
Property, plant, and equipment, net	410	404
Goodwill	25	25
Intangible assets	542	531
Other current and long-term assets	2	1
Total Assets	1,003	1,001
LIABILITIES
Accounts payable and accrued current liabilities	2	0
Short-term borrowings	0	0
Other current and long-term liabilities	7	6
Total liabilities	$ 9	$ 6
VIE ownership and non-ownership percentage		100.00%
VIE ownership percentage	85.00%	85.00%
Other
ASSETS
Cash and cash equivalents	$ 11	$ 22
Accounts receivable	19	18
Inventories	74	102
Property, plant, and equipment, net	33	25
Goodwill	0	0
Intangible assets	0	0
Other current and long-term assets	0	19
Total Assets	137	186
LIABILITIES
Accounts payable and accrued current liabilities	13	19
Short-term borrowings	0	21
Other current and long-term liabilities	7	4
Total liabilities	$ 20	$ 44

Organization and Basis of Pre_5

Organization and Basis of Presentation (Non-Consolidated Variable Interest Entities) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Investments in equity method investees	$ 1,865	$ 1,862
Notes receivable	255	202
Variable interest entity, non-consolidated
Variable Interest Entity [Line Items]
Investments in equity method investees	1,505	1,503
Notes receivable	40	21
Future funding commitments	$ 36	$ 63

Significant Accounting Polici_4

Significant Accounting Policies (Other Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Schedule of Other Nonoperating Income, by Component [Line Items]
Equity earnings of equity method investees	$ 37	$ 34	$ 96	$ 77
Income from REF entities	43	40	95	96
Gains from equity and fixed income securities	2	3	24	27
Contract services	7	7	20	21
Gas Storage and Pipelines post-acquisition settlement	20	0	20	0
Allowance for equity funds used during construction	6	5	19	18
Other	5	9	12	20
Total other income	120	98	286	259
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Gains from equity and fixed income securities	2	3	24	27
Contract services	7	7	20	23
Allowance for equity funds used during construction	6	5	18	17
Other	3	5	6	11
Total other income	$ 18	$ 20	$ 68	$ 78

Significant Accounting Polici_5

Significant Accounting Policies (Details Textuals) - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019
Significant Accounting Policies [Line Items]
Reclassification of income tax effects	$ 12,488	$ 11,892	$ 10,904	$ 12,488	$ 10,904	$ 11,836	$ 10,717	$ 11,988	$ 10,569	$ 11,020
Implementation of ASU						us-gaap:AccountingStandardsUpdate201802Member	us-gaap:AccountingStandardsUpdate201802Member
Effective tax rate increase (decrease)	(1.00%)			(2.00%)
Amortization of TCJA regulatory liability	2.00%			2.00%
Annual production tax credit increase (decrease)	(1.00%)			(3.00%)
Carryback of 2018 net operating loss due to the CARES Act				3.00%
Unrecognized compensation cost	$ 84			$ 84
Recognition period (in years)				1 year 4 months 28 days
Uncollectible expense adjusted for regulatory deferrals	22		28	$ 70	81
CARES Act
Significant Accounting Policies [Line Items]
Reduction in Income Tax Expense due to carryback of 2018 net operating loss to 2013				34
Claim for employee retention credits		6
Deferral of employer payroll taxes				$ 32
CARES Act, AMT Credit Refund
Significant Accounting Policies [Line Items]
AMT credit received from U.S. Treasury	220
Immediate Refund of 2018 Remaining AMT Credit Balance
Significant Accounting Policies [Line Items]
AMT credit received from U.S. Treasury	153
Immediate Refund of AMT Credit Generated by Carrying Back 2018 Net Operating Loss to 2013
Significant Accounting Policies [Line Items]
AMT credit received from U.S. Treasury	$ 67
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
Unbilled Revenues
Significant Accounting Policies [Line Items]
Specific review of probable future collections based on receivable balances, threshold duration				30 days
DTE Electric and DTE Gas
Significant Accounting Policies [Line Items]
Receivables due date				21 days
Threshold period past due for write-off of trade accounts receivable				150 days
DTE Electric
Significant Accounting Policies [Line Items]
Effective tax rate increase (decrease)	(3.00%)			(4.00%)
Amortization of TCJA regulatory liability	3.00%			3.00%
Annual production tax credit increase (decrease)				1.00%
Uncollectible expense adjusted for regulatory deferrals	$ 16		17	$ 42	47
DTE Electric | COVID-19 Pandemic
Significant Accounting Policies [Line Items]
Uncollectible expense deferred as a Regulatory asset	(1)			5
DTE Electric | CARES Act
Significant Accounting Policies [Line Items]
Claim for employee retention credits		3
Deferral of employer payroll taxes				17
DTE Electric | DTE Energy
Significant Accounting Policies [Line Items]
Income tax payable	5			5
Income tax receivable						$ 14
Allocated costs	12		9	28	33
DTE Gas | COVID-19 Pandemic
Significant Accounting Policies [Line Items]
Uncollectible expense deferred as a Regulatory asset	(1)			1
Accumulated Other Comprehensive Income (Loss)
Significant Accounting Policies [Line Items]
Reclassification of income tax effects	(138)	(141)	(146)	(138)	(146)	(148)	$ (120)	(145)	(146)	(143)
Retained Earnings
Significant Accounting Policies [Line Items]
Reclassification of income tax effects	$ 7,092	$ 6,618	$ 6,516	$ 7,092	$ 6,516	$ 6,587	6,112	$ 6,732	$ 6,198	$ 6,364
Implementation of ASU
Significant Accounting Policies [Line Items]
Reclassification of income tax effects							0
Implementation of ASU | Accumulated Other Comprehensive Income (Loss)
Significant Accounting Policies [Line Items]
Reclassification of income tax effects							(25)
Implementation of ASU | Retained Earnings
Significant Accounting Policies [Line Items]
Reclassification of income tax effects							25
ASU No. 2018-02 | Implementation of ASU | Accumulated Other Comprehensive Income (Loss)
Significant Accounting Policies [Line Items]
Reclassification of income tax effects							(25)
ASU No. 2018-02 | Implementation of ASU | Retained Earnings
Significant Accounting Policies [Line Items]
Reclassification of income tax effects							$ 25

Significant Accounting Polici_6

Significant Accounting Policies (Income Taxes) (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Schedule of Income Taxes [Line Items]
Effective Tax Rate	12.00%	13.00%	10.00%	12.00%
DTE Electric
Schedule of Income Taxes [Line Items]
Effective Tax Rate	13.00%	16.00%	12.00%	16.00%

Significant Accounting Polici_7

Significant Accounting Policies (Financing Receivables Classified by Internal Grade of Credit Risk) (Details) $ in Millions	Sep. 30, 2020USD ($)
Notes receivable
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 60
2019	37
2018 and prior	15
Total	112
Notes receivable | Internal grade 1
Financing Receivable, Credit Quality Indicator [Line Items]
2020	0
2019	18
2018 and prior	9
Total	27
Notes receivable | Internal grade 2
Financing Receivable, Credit Quality Indicator [Line Items]
2020	60
2019	19
2018 and prior	6
Total	85
Net investment in leases
Financing Receivable, Credit Quality Indicator [Line Items]
2020	140
2019	0
2018 and prior	41
Total	181
Net investment in leases | Internal grade 1
Financing Receivable, Credit Quality Indicator [Line Items]
2020	8
2019	0
2018 and prior	40
Total	48
Net investment in leases | Internal grade 2
Financing Receivable, Credit Quality Indicator [Line Items]
2020	132
2019	0
2018 and prior	1
Total	133
DTE Electric | Notes receivable
Financing Receivable, Credit Quality Indicator [Line Items]
Total	18
DTE Electric | Notes receivable | Internal grade 1
Financing Receivable, Credit Quality Indicator [Line Items]
Total	18
DTE Electric | Notes receivable | Internal grade 2
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0
DTE Electric | Net investment in leases
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0
DTE Electric | Net investment in leases | Internal grade 1
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0
DTE Electric | Net investment in leases | Internal grade 2
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 0

Significant Accounting Polici_8

Significant Accounting Policies (Roll-Forward of Activity for Financing Receivables Credit Loss Reserves) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020USD ($)
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 91
Current period provision	75
Write-offs charged against allowance	(120)
Recoveries of amounts previously written off	41
Ending balance	87
Trade accounts receivable
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	87
Current period provision	73
Write-offs charged against allowance	(117)
Recoveries of amounts previously written off	41
Ending balance	84
Other receivables
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	4
Current period provision	2
Write-offs charged against allowance	(3)
Recoveries of amounts previously written off	0
Ending balance	3
DTE Electric
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	46
Current period provision	47
Write-offs charged against allowance	(68)
Recoveries of amounts previously written off	24
Ending balance	$ 49

Acquisitions (Details Textuals)

Acquisitions (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 ($)

Sep. 30, 2020USD ($)

Jun. 30, 2020USD ($)

Mar. 31, 2020USD ($)

Sep. 30, 2019USD ($)

Jun. 30, 2019USD ($)

Mar. 31, 2019USD ($)

Sep. 30, 2020USD ($)

Sep. 30, 2019USD ($)

Business Acquisition [Line Items]

Consideration paid for entity acquired, paid in cash

$ 126

$ 174

Goodwill

$ 2,464

$ 2,465

2,465

Operating Revenues — Non-utility operations

1,440

$ 1,463

3,770

4,584

Net Income

477

$ 277

$ 342

$ 317

$ 179

$ 408

1,096

$ 904

Power and Industrial Projects | South Jersey Industries, Combined Heat and Power Generation Facility

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

Power and Industrial Projects | South Jersey Industries, Combined Heat and Power Generation Facility | Contract intangibles

Business Acquisition [Line Items]

Intangible assets, amortization period

13 years

Intangible assets recorded as a result of acquisition

$ 17

Electric | Heritage Sustainable Energy, Renewable Energy Project | DTE Sustainable Generation

Business Acquisition [Line Items]

Amount of power associated with purchase of renewable energy project | MW

89

Total consideration provided for acquired entity

$ 175

Electric | Heritage Sustainable Energy, Renewable Energy Project | DTE Sustainable Generation | Contract intangibles

Business Acquisition [Line Items]

Intangible assets recorded as a result of acquisition

$ 109

Electric | Heritage Sustainable Energy, Renewable Energy Project | DTE Sustainable Generation | Contract intangibles | Minimum

Business Acquisition [Line Items]

Intangible assets, amortization period

11 years

Electric | Heritage Sustainable Energy, Renewable Energy Project | DTE Sustainable Generation | Contract intangibles | Maximum

Business Acquisition [Line Items]

Intangible assets, amortization period

13 years

Electric | Heritage Sustainable Energy, Additional Renewable Energy Project | DTE Sustainable Generation

Business Acquisition [Line Items]

Consideration paid for entity acquired, paid in cash

$ 33

Gas Storage and Pipelines | Blue Union and LEAP

Business Acquisition [Line Items]

Consideration paid for entity acquired, paid in cash

$ 2,360

Total consideration provided for acquired entity

$ 2,740

Percent of assets acquired

100.00%

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

Remaining cash consideration paid and held in escrow

14

Goodwill

$ 172

$ 172

172

Goodwill, working capital adjustments

$ 1

Direct transaction costs incurred

18

Issuance costs related to acquisition financing

49

Operating Revenues — Non-utility operations

15

Net Income

3

Gas Storage and Pipelines | Blue Union and LEAP | Mortgage bonds, notes, and other

Business Acquisition [Line Items]

Issuance costs related to acquisition financing

10

Gas Storage and Pipelines | Blue Union and LEAP | Common Stock

Business Acquisition [Line Items]

Issuance costs related to acquisition financing

$ 39

Gas Storage and Pipelines | Blue Union and LEAP | 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 (Purchase Price Al

Acquisitions (Purchase Price Allocation - Power and Industrial Segment Acquisition) (Details) - Power and Industrial Projects - South Jersey Industries, Combined Heat and Power Generation Facility $ 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 (Purchase Price _2

Acquisitions (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 (Purchase Price _3

Acquisitions (Purchase Price Allocation - Gas Storage and Pipelines Segment Acquisition) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019	Dec. 04, 2019
Assets
Goodwill	$ 2,465	$ 2,464
Gas Storage and Pipelines | Blue Union and LEAP
Assets
Cash			$ 62
Accounts receivable			31
Property, plant, and equipment, net			1,035
Goodwill	$ 172		172
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		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Revenues	$ 3,284	$ 3,119	$ 8,889	$ 9,521
Lease revenue outside scope of Topic 606	60	57	132	143
Electric
Disaggregation of Revenue [Line Items]
Revenues	1,693	1,520	4,221	3,945
Other revenues outside scope of topic 606	8	5	18	14
Electric | Residential
Disaggregation of Revenue [Line Items]
Revenues	900	791	2,169	1,839
Electric | Commercial
Disaggregation of Revenue [Line Items]
Revenues	498	515	1,313	1,358
Electric | Industrial
Disaggregation of Revenue [Line Items]
Revenues	157	175	434	497
Electric | Other
Disaggregation of Revenue [Line Items]
Revenues	138	39	305	251
Electric | Other | DTE Sustainable Generation
Disaggregation of Revenue [Line Items]
Revenues	3		10
Gas
Disaggregation of Revenue [Line Items]
Revenues	173	155	964	1,043
Other revenues outside scope of topic 606	2	2	7	6
Alternative Revenue Program revenues outside scope of Topic 606			2
Gas | Other
Disaggregation of Revenue [Line Items]
Revenues	32	18	98	102
Gas | Gas sales
Disaggregation of Revenue [Line Items]
Revenues	92	87	655	727
Gas | End User Transportation
Disaggregation of Revenue [Line Items]
Revenues	34	35	154	157
Gas | Intermediate Transportation
Disaggregation of Revenue [Line Items]
Revenues	15	15	57	57
Gas Storage and Pipelines
Disaggregation of Revenue [Line Items]
Revenues	204	126	546	363
Lease revenue outside scope of Topic 606	2	2	7	7
Power and Industrial Projects
Disaggregation of Revenue [Line Items]
Revenues	324	406	850	1,196
Lease revenue outside scope of Topic 606	26	33	74	94
Energy Trading
Disaggregation of Revenue [Line Items]
Revenues	1,061	1,105	2,714	3,519
Gain (loss) on derivative outside scope of Topic 606	$ 731	$ 791	$ 1,800	$ 2,600

Revenue (Deferred Revenue) (Det

Revenue (Deferred Revenue) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020USD ($)
Contract Liability [Roll Forward]
Beginning Balance	$ 75
Increases due to cash received or receivable, excluding amounts recognized as revenue during the period	39
Revenue recognized that was included in the deferred revenue balance at the beginning of the period	(42)
Ending Balance	$ 72

Revenue (Expected Recognition o

Revenue (Expected Recognition of Deferred Revenue) (Details) $ in Millions	Sep. 30, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 72
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 7
Remaining performance obligation, expected timing of satisfaction	3 months
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	$ 36
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	$ 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	$ 12
Remaining performance obligation, expected timing of satisfaction

Revenue (Expected Timing of Per

Revenue (Expected Timing of Performance Obligation Satisfaction) (Details) $ in Millions	Sep. 30, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 72
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 7
Remaining performance obligation, expected timing of satisfaction	3 months
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	$ 36
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	$ 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	$ 12
Remaining performance obligation, expected timing of satisfaction
Fixed-price Contract
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 1,669
Fixed-price Contract | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	32
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 72
Remaining performance obligation, expected timing of satisfaction	3 months
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 2
Remaining performance obligation, expected timing of satisfaction	3 months
Fixed-price Contract | 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	$ 350
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | 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
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 294
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 7
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 231
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 7
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 142
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 8
Remaining performance obligation, expected timing of satisfaction	1 year
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 580
Remaining performance obligation, expected timing of satisfaction
Fixed-price Contract | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | DTE Electric
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 0
Remaining performance obligation, expected timing of satisfaction

Regulatory Matters (Details Tex

Regulatory Matters (Details Textuals) - USD ($) $ in Millions	Jul. 17, 2020	May 08, 2020	Nov. 25, 2019	Jul. 08, 2019	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2020	Dec. 31, 2020	Jul. 09, 2020
DTE Electric | COVID-19 Pandemic
Public Utilities, General Disclosures [Line Items]
Uncollectible expense deferred as a Regulatory asset					$ (1)		$ 5
DTE Electric | COVID-19 Pandemic | Forecast
Public Utilities, General Disclosures [Line Items]
Proposed regulatory liability								$ 30
DTE Electric | MPSC | 2019 Electric Rate Case Filing
Public Utilities, General Disclosures [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 Gas | COVID-19 Pandemic
Public Utilities, General Disclosures [Line Items]
Uncollectible expense deferred as a Regulatory asset					$ (1)		$ 1
DTE Gas | MPSC | 2019 Gas Rate Case Filing
Public Utilities, General Disclosures [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

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Basic Earnings per Share
Net Income Attributable to DTE Energy Company	$ 476	$ 319	$ 1,093	$ 902
Less: Allocation of earnings to net restricted stock awards	1	1	2	2
Net income available to common shareholders — basic	$ 475	$ 318	$ 1,091	$ 900
Average number of common shares outstanding — basic (in shares)	193	183	192	183
Basic Earnings per Common Share (in dollars per share)	$ 2.47	$ 1.74	$ 5.67	$ 4.93
Diluted Earnings per Share
Net Income Attributable to DTE Energy Company	$ 476	$ 319	$ 1,093	$ 902
Less: Allocation of earnings to net restricted stock awards	1	1	2	2
Net income available to common shareholders — diluted	$ 475	$ 318	$ 1,091	$ 900
Average number of common shares outstanding — basic (in shares)	193	183	192	183
Incremental shares attributable to:
Average dilutive equity units, performance share awards, and stock options (in shares)	0	1	1	1
Average number of common shares outstanding — diluted (in shares)	193	184	193	184
Diluted Earnings per Common Share (in dollars per share)	$ 2.46	$ 1.73	$ 5.66	$ 4.91
Antidilutive securities excluded from computation of earnings per share (in shares)	10.3		10.3

Fair Value (Assets and Liabilit

Fair Value (Assets and Liabilities Recorded at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivative assets
Derivative assets, gross	$ 580	$ 775
Derivative asset, netting	(486)	(601)
Derivative assets, net	94	174
Derivative liabilities
Derivative liabilities, gross	(564)	(770)
Derivative liability, netting	460	601
Derivative liabilities, net	(104)	(169)
Current liabilities
Derivative liabilities
Derivative liabilities, gross	(421)	(596)
Noncurrent liabilities
Derivative liabilities
Derivative liabilities, gross	(143)	(174)
Natural gas
Derivative assets
Derivative assets, gross	240	355
Derivative asset, netting	(194)	(266)
Derivative assets, net	46	89
Derivative liabilities
Derivative liabilities, gross	(265)	(351)
Derivative liability, netting	185	266
Derivative liabilities, net	(80)	(85)
Electricity
Derivative assets
Derivative assets, gross	137	306
Derivative asset, netting	(106)	(225)
Derivative assets, net	31	81
Derivative liabilities
Derivative liabilities, gross	(126)	(298)
Derivative liability, netting	104	225
Derivative liabilities, net	(22)	(73)
Environmental & Other
Derivative assets
Derivative assets, gross	201	113
Derivative asset, netting	(186)	(110)
Derivative assets, net	15	3
Derivative liabilities
Derivative liabilities, gross	(171)	(121)
Derivative liability, netting	171	110
Derivative liabilities, net	0	(11)
Foreign currency exchange contracts
Derivative assets
Derivative assets, gross	2	1
Derivative asset, netting	0	0
Derivative assets, net	2	1
Derivative liabilities
Derivative liabilities, gross	(2)	0
Derivative liability, netting	0	0
Derivative liabilities, net	(2)	0
Recurring
Assets
Cash equivalents	567	15
Derivative assets
Derivative asset, netting	(486)	(601)
Derivative assets, net	94	174
Total assets	2,478	2,073
Derivative liabilities
Derivative liability, netting	460	601
Derivative liabilities, net	(104)	(169)
Net Assets (Liabilities) at end of period	2,374	1,904
Net Assets at end of period, netting	(26)	0
Recurring | DTE Electric
Assets
Cash equivalents	175	11
Derivative assets
Total assets	1,871	1,688
Recurring | Current assets
Derivative assets
Derivative asset, netting	(379)	(513)
Total assets	632	148
Recurring | Current assets | DTE Electric
Derivative assets
Total assets	182	14
Recurring | Noncurrent assets
Derivative assets
Derivative asset, netting	(107)	(88)
Total assets	1,846	1,925
Recurring | Noncurrent assets | DTE Electric
Derivative assets
Total assets	1,689	1,674
Recurring | Current liabilities
Derivative liabilities
Derivative liability, netting	361	513
Derivative liabilities, net	(60)	(83)
Recurring | Noncurrent liabilities
Derivative liabilities
Derivative liability, netting	99	88
Derivative liabilities, net	(44)	(86)
Recurring | Cash and cash equivalents
Assets
Cash equivalents	565	4
Recurring | Cash and cash equivalents | DTE Electric
Assets
Cash equivalents	175
Recurring | Restricted cash
Assets
Cash equivalents	2
Recurring | Other
Assets
Cash equivalents		11
Recurring | Other | DTE Electric
Assets
Cash equivalents		11
Recurring | Natural gas
Derivative assets
Derivative asset, netting	(194)	(266)
Derivative assets, net	46	89
Derivative liabilities
Derivative liability, netting	185	266
Derivative liabilities, net	(80)	(85)
Recurring | Electricity
Derivative assets
Derivative asset, netting	(106)	(225)
Derivative assets, net	31	81
Derivative liabilities
Derivative liability, netting	104	225
Derivative liabilities, net	(22)	(73)
Recurring | Environmental & Other
Derivative assets
Derivative asset, netting	(186)	(110)
Derivative assets, net	15	3
Derivative liabilities
Derivative liability, netting	171	110
Derivative liabilities, net	0	(11)
Recurring | Foreign currency exchange contracts
Derivative assets
Derivative asset, netting	0	0
Derivative assets, net	2	1
Derivative liabilities
Derivative liability, netting	0	0
Derivative liabilities, net	(2)	0
Recurring | Derivative assets — FTRs | DTE Electric
Derivative assets
Derivative assets, net	7	3
Recurring | Cash equivalents
Assets
Nuclear decommissioning trusts	46	34
Other investments	98	4
Recurring | Cash equivalents | DTE Electric
Assets
Nuclear decommissioning trusts	46	34
Other investments	11	0
Recurring | Private equity and other
Assets
Nuclear decommissioning trusts	78	43
Recurring | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	78	43
Recurring | Equity securities
Assets
Nuclear decommissioning trusts	1,013	1,046
Other investments	49	140
Recurring | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	1,013	1,046
Other investments	14	13
Recurring | Fixed income securities
Assets
Nuclear decommissioning trusts	527	538
Other investments	6	79
Recurring | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	527	538
Recurring | Level 1
Assets
Cash equivalents	567	15
Derivative assets
Derivative assets, gross	126	205
Total assets	1,886	1,683
Derivative liabilities
Derivative liabilities, gross	(121)	(221)
Net Assets (Liabilities) at end of period	1,765	1,462
Recurring | Level 1 | DTE Electric
Assets
Cash equivalents	175	11
Derivative assets
Total assets	1,240	1,264
Recurring | Level 1 | Current assets
Derivative assets
Total assets	679	218
Recurring | Level 1 | Current assets | DTE Electric
Derivative assets
Total assets	175	11
Recurring | Level 1 | Noncurrent assets
Derivative assets
Total assets	1,207	1,465
Recurring | Level 1 | Noncurrent assets | DTE Electric
Derivative assets
Total assets	1,065	1,253
Recurring | Level 1 | Current liabilities
Derivative liabilities
Derivative liabilities, gross	(112)	(211)
Recurring | Level 1 | Noncurrent liabilities
Derivative liabilities
Derivative liabilities, gross	(9)	(10)
Recurring | Level 1 | Natural gas
Derivative assets
Derivative assets, gross	126	205
Derivative liabilities
Derivative liabilities, gross	(118)	(221)
Recurring | Level 1 | Electricity
Derivative assets
Derivative assets, gross	0	0
Derivative liabilities
Derivative liabilities, gross	0	0
Recurring | Level 1 | Environmental & Other
Derivative assets
Derivative assets, gross	0	0
Derivative liabilities
Derivative liabilities, gross	(3)	0
Recurring | Level 1 | Foreign currency exchange contracts
Derivative assets
Derivative assets, gross	0	0
Derivative liabilities
Derivative liabilities, gross	0	0
Recurring | Level 1 | Derivative assets — FTRs | DTE Electric
Derivative assets
Derivative assets, net	0	0
Recurring | Level 1 | Cash equivalents
Assets
Nuclear decommissioning trusts	46	34
Other investments	98	4
Recurring | Level 1 | Cash equivalents | DTE Electric
Assets
Nuclear decommissioning trusts	46	34
Other investments	11	0
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	872	1,046
Other investments	49	140
Recurring | Level 1 | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	872	1,046
Other investments	14	13
Recurring | Level 1 | Fixed income securities
Assets
Nuclear decommissioning trusts	122	160
Other investments	6	79
Recurring | Level 1 | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	122	160
Recurring | Level 2
Assets
Cash equivalents	0	0
Derivative assets
Derivative assets, gross	371	410
Total assets	696	788
Derivative liabilities
Derivative liabilities, gross	(333)	(393)
Net Assets (Liabilities) at end of period	363	395
Recurring | Level 2 | DTE Electric
Assets
Cash equivalents	0	0
Derivative assets
Total assets	325	378
Recurring | Level 2 | Current assets
Derivative assets
Total assets	273	320
Recurring | Level 2 | Current assets | DTE Electric
Derivative assets
Total assets	0	0
Recurring | Level 2 | Noncurrent assets
Derivative assets
Total assets	423	468
Recurring | Level 2 | Noncurrent assets | DTE Electric
Derivative assets
Total assets	325	378
Recurring | Level 2 | Current liabilities
Derivative liabilities
Derivative liabilities, gross	(243)	(300)
Recurring | Level 2 | Noncurrent liabilities
Derivative liabilities
Derivative liabilities, gross	(90)	(93)
Recurring | Level 2 | Natural gas
Derivative assets
Derivative assets, gross	72	76
Derivative liabilities
Derivative liabilities, gross	(66)	(41)
Recurring | Level 2 | Electricity
Derivative assets
Derivative assets, gross	103	223
Derivative liabilities
Derivative liabilities, gross	(97)	(231)
Recurring | Level 2 | Environmental & Other
Derivative assets
Derivative assets, gross	194	110
Derivative liabilities
Derivative liabilities, gross	(168)	(121)
Recurring | Level 2 | Foreign currency exchange contracts
Derivative assets
Derivative assets, gross	2	1
Derivative liabilities
Derivative liabilities, gross	(2)	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
Other investments	0	0
Recurring | Level 2 | Private equity and other
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 2 | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 2 | Equity securities
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 2 | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 2 | Fixed income securities
Assets
Nuclear decommissioning trusts	325	378
Other investments	0	0
Recurring | Level 2 | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	325	378
Recurring | Level 3
Assets
Cash equivalents	0	0
Derivative assets
Derivative assets, gross	83	160
Total assets	83	160
Derivative liabilities
Derivative liabilities, gross	(110)	(156)
Net Assets (Liabilities) at end of period	(27)	4
Recurring | Level 3 | DTE Electric
Assets
Cash equivalents	0	0
Derivative assets
Total assets	7	3
Recurring | Level 3 | Current assets
Derivative assets
Total assets	59	123
Recurring | Level 3 | Current assets | DTE Electric
Derivative assets
Total assets	7	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
Derivative liabilities
Derivative liabilities, gross	(66)	(85)
Recurring | Level 3 | Noncurrent liabilities
Derivative liabilities
Derivative liabilities, gross	(44)	(71)
Recurring | Level 3 | Natural gas
Derivative assets
Derivative assets, gross	42	74
Derivative liabilities
Derivative liabilities, gross	(81)	(89)
Recurring | Level 3 | Electricity
Derivative assets
Derivative assets, gross	34	83
Derivative liabilities
Derivative liabilities, gross	(29)	(67)
Recurring | Level 3 | Environmental & Other
Derivative assets
Derivative assets, gross	7	3
Derivative liabilities
Derivative liabilities, gross	0	0
Recurring | Level 3 | Foreign currency exchange contracts
Derivative assets
Derivative assets, gross	0	0
Derivative liabilities
Derivative liabilities, gross	0	0
Recurring | Level 3 | Derivative assets — FTRs | DTE Electric
Derivative assets
Derivative assets, net	7	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
Other investments	0	0
Recurring | Level 3 | Private equity and other
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 3 | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Recurring | Level 3 | Equity securities
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 3 | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 3 | Fixed income securities
Assets
Nuclear decommissioning trusts	0	0
Other investments	0	0
Recurring | Level 3 | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	0	0
Recurring | Other
Derivative assets
Total assets	299	43
Derivative liabilities
Net Assets (Liabilities) at end of period	299	43
Recurring | Other | DTE Electric
Derivative assets
Total assets	299	43
Recurring | Other | Noncurrent assets
Derivative assets
Total assets	299	43
Recurring | Other | Noncurrent assets | DTE Electric
Derivative assets
Total assets	299	43
Recurring | Other | Private equity and other
Assets
Nuclear decommissioning trusts	78	43
Recurring | Other | Private equity and other | DTE Electric
Assets
Nuclear decommissioning trusts	78	$ 43
Recurring | Other | Equity securities
Assets
Nuclear decommissioning trusts	141
Recurring | Other | Equity securities | DTE Electric
Assets
Nuclear decommissioning trusts	141
Recurring | Other | Fixed income securities
Assets
Nuclear decommissioning trusts	80
Recurring | Other | Fixed income securities | DTE Electric
Assets
Nuclear decommissioning trusts	$ 80

Fair Value (Details Textuals)

Fair Value (Details Textuals) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Nuclear decommissioning trust fund | Fixed income securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities with no contractual maturity date	$ 80
Equity or debt securities | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, redemption notice period	7 days
Equity or debt securities | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, redemption notice period	65 days
Private equity and other
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unfunded commitments related to investments classified as NAV assets	$ 192	$ 151
Private equity and other | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments classified as NAV assets, general contractual durations	7 years
Private equity and other | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments classified as NAV assets, general contractual durations	12 years

Fair Value (Reconciliation of L

Fair Value (Reconciliation of Level 3 Assets and Liabilities at Fair Value on a Recurring Basis) (Details) - Recurring - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	$ 46	$ 9	$ 4	$ (44)
Transfers from Level 3 into Level 2	(1)	0	(5)	0
Total gains (losses)
Included in earnings	(42)	2	39	42
Recorded in/Change in fair value recorded in Regulatory liabilities	9	(3)	21	3
Purchases, issuances, and settlements
Settlements	(39)	(36)	(86)	(29)
Net Assets (Liabilities) as of end of period	(27)	(28)	(27)	(28)
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2020 and 2019	(47)	(22)	16	6
DTE Electric
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	10	9	3	6
Total gains (losses)
Recorded in/Change in fair value recorded in Regulatory liabilities	9	(3)	21	3
Purchases, issuances, and settlements
Settlements	(12)	(1)	(17)	(4)
Net Assets (Liabilities) as of end of period	7	5	7	5
The amount of total gains (losses) included in Regulatory liabilities attributed to the change in unrealized gains (losses) related to assets held at September 30, 2020 and 2019 and reflected in DTE Electric's Consolidated Statements of Financial Position	0	(1)	7	5
Natural gas
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	20	(10)	(15)	(49)
Transfers from Level 3 into Level 2	(1)	0	(5)	0
Total gains (losses)
Included in earnings	(80)	(35)	(44)	(4)
Recorded in/Change in fair value recorded in Regulatory liabilities	0	0	0	0
Purchases, issuances, and settlements
Settlements	22	4	25	12
Net Assets (Liabilities) as of end of period	(39)	(41)	(39)	(41)
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2020 and 2019	(57)	(36)	(20)	(20)
Electricity
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	16	10	16	(2)
Transfers from Level 3 into Level 2	0	0	0	0
Total gains (losses)
Included in earnings	37	37	90	47
Recorded in/Change in fair value recorded in Regulatory liabilities	0	0	0	0
Purchases, issuances, and settlements
Settlements	(48)	(39)	(101)	(37)
Net Assets (Liabilities) as of end of period	5	8	5	8
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2020 and 2019	11	15	53	32
Other
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Net Assets (Liabilities) as of beginning of period	10	9	3	7
Transfers from Level 3 into Level 2	0	0	0	0
Total gains (losses)
Included in earnings	1	0	(7)	(1)
Recorded in/Change in fair value recorded in Regulatory liabilities	9	(3)	21	3
Purchases, issuances, and settlements
Settlements	(13)	(1)	(10)	(4)
Net Assets (Liabilities) as of end of period	7	5	7	5
Total gains (losses) included in Net Income attributed to the change in unrealized gains (losses) related to assets and liabilities held at September 30, 2020 and 2019	$ (1)	$ (1)	$ (17)	$ (6)

Fair Value (Unobservable Inputs

Fair Value (Unobservable Inputs related to Level 3 Assets and Liabilities) (Details) $ in Millions	Sep. 30, 2020USD ($)MWhMMBTU	Dec. 31, 2019USD ($)MMBTUMWh
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	$ 580	$ 775
Derivative Liabilities	(564)	(770)
Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	83	160
Derivative Liabilities	(110)	(156)
Natural gas
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	240	355
Derivative Liabilities	(265)	(351)
Natural gas | Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	42	74
Derivative Liabilities	(81)	(89)
Electricity
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	137	306
Derivative Liabilities	(126)	(298)
Electricity | Recurring | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Derivative Assets	34	83
Derivative Liabilities	$ (29)	$ (67)
Forward basis price | Natural gas | Minimum | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | MMBTU	(1.10)	(1.78)
Forward basis price | Natural gas | Maximum | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | MMBTU	2.30	5.78
Forward basis price | Natural gas | Weighted Average | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | MMBTU	(0.06)	(0.09)
Forward basis price | Electricity | Minimum | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | MWh	(9)	(10)
Forward basis price | Electricity | Maximum | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | MWh	6	6
Forward basis price | Electricity | Weighted Average | Discounted Cash Flow | Level 3
Unobservable Inputs Valuation Techniques [Line Items]
Forward basis price | MWh	(1)	0

Fair Value (Fair Value of Finan

Fair Value (Fair Value of Financial Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Carrying amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other	$ 112	$ 184
Short-term borrowings	988	828
Notes payable — Other	19	25
Long-term debt	18,660	16,606
Carrying amount | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other	18	9
Short-term borrowings	200	354
Notes payable — Other	17	21
Long-term debt	8,235	7,180
Carrying amount | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	104	97
Fair value | Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other	0	0
Short-term borrowings	0	0
Notes payable — Other	0	0
Long-term debt	2,398	2,572
Fair value | Level 1 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other	0	0
Short-term borrowings	0	0
Notes payable — Other	0	0
Long-term debt	0	0
Fair value | Level 1 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0	0
Fair value | Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other	0	0
Short-term borrowings	988	828
Notes payable — Other	0	0
Long-term debt	17,213	14,207
Fair value | Level 2 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other	0	0
Short-term borrowings	200	354
Notes payable — Other	0	0
Long-term debt	9,565	7,916
Fair value | Level 2 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	0	0
Fair value | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other	112	184
Short-term borrowings	0	0
Notes payable — Other	19	25
Long-term debt	1,406	1,252
Fair value | Level 3 | DTE Electric
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable — Other	18	9
Short-term borrowings	0	0
Notes payable — Other	17	21
Long-term debt	194	173
Fair value | Level 3 | DTE Electric | Affiliates
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short-term borrowings	$ 104	$ 97

Fair Value (Fair Value of Nucle

Fair Value (Fair Value of Nuclear Decommissioning Trust Fund Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	$ 1,664	$ 1,661
DTE Electric
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	1,664	1,661
DTE Electric | Nuclear decommissioning trust fund
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	1,664	1,661
DTE Electric | Nuclear decommissioning trust fund | Fermi 2
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	1,652	1,650
DTE Electric | Nuclear decommissioning trust fund | Fermi 1
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	3	3
DTE Electric | Nuclear decommissioning trust fund | Low-level radioactive waste
Debt Securities, Available-for-sale [Line Items]
Nuclear decommissioning trust funds	$ 9	$ 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 trust fund - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Debt Securities, Available-for-sale [Line Items]
Realized gains	$ 38	$ 15	$ 172	$ 43
Realized losses	(11)	(8)	(103)	(25)
Proceeds from sale of securities	$ 816	$ 198	$ 2,054	$ 594

Fair Value (Fair Value and Unre

Fair Value (Fair Value and Unrealized Gains and Losses for the Nuclear Decommissioning Trust Funds) (Details) - DTE Electric - Nuclear decommissioning trust fund - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 1,664	$ 1,661
Fixed income securities, fair value	527	538
Private equity and other, fair value	78	43
Cash equivalents, fair value	46	34
Unrealized Gains	341	420
Fixed income securities, unrealized gains	16	24
Unrealized Losses	(29)	(40)
Fixed income securities, unrealized losses	(1)	(1)
Equity securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	1,013	1,046
Unrealized Gains	325	396
Unrealized Losses	$ (28)	$ (39)

Fair Value (Fair Value of Fixed

Fair Value (Fair Value of Fixed Income Securities Held in Nuclear Decommissioning Trust Funds (Details) - Fixed income securities - Nuclear decommissioning trust fund $ in Millions	Sep. 30, 2020USD ($)
Debt Securities, Available-for-sale [Line Items]
Due within one year	$ 92
Due after one through five years	82
Due after five through ten years	79
Due after ten years	194
Available-for-sale securities total	$ 447

Fair Value (Gains (Losses) Rela

Fair Value (Gains (Losses) Related to the Trust) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Rabbi Trust
Schedule of Investments [Line Items]
Gains (losses) related to the Trust	$ 2	$ 3	$ (7)	$ 27
Equity securities
Schedule of Investments [Line Items]
Gains (losses) related to the Trust	2	1	(4)	18
Fixed income securities
Schedule of Investments [Line Items]
Gains (losses) related to the Trust	$ 0	$ 2	$ (3)	$ 9

Financial and Other Derivativ_3

Financial and Other Derivative Instruments (Fair Value of Derivative Instruments) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 580	$ 775
Derivative Liabilities	(564)	(770)
Current derivative assets
Derivatives, Fair Value [Line Items]
Derivative Assets	444	646
Current derivative liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(421)	(596)
Noncurrent derivative assets
Derivatives, Fair Value [Line Items]
Derivative Assets	136	129
Noncurrent derivative liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities	(143)	(174)
Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	2	1
Derivative Liabilities	(2)	0
Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	240	355
Derivative Liabilities	(265)	(351)
Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	137	306
Derivative Liabilities	(126)	(298)
Environmental & Other
Derivatives, Fair Value [Line Items]
Derivative Assets	201	113
Derivative Liabilities	(171)	(121)
Derivatives designated as hedging instruments | Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	0	0
Derivative Liabilities	(1)	0
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets	580	775
Derivative Liabilities	(563)	(770)
Derivatives not designated as hedging instruments | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative Assets	7	3
Derivatives not designated as hedging instruments | Foreign currency exchange contracts
Derivatives, Fair Value [Line Items]
Derivative Assets	2	1
Derivative Liabilities	(1)	0
Derivatives not designated as hedging instruments | Natural gas
Derivatives, Fair Value [Line Items]
Derivative Assets	240	355
Derivative Liabilities	(265)	(351)
Derivatives not designated as hedging instruments | Electricity
Derivatives, Fair Value [Line Items]
Derivative Assets	137	306
Derivative Liabilities	(126)	(298)
Derivatives not designated as hedging instruments | Environmental & Other
Derivatives, Fair Value [Line Items]
Derivative Assets	201	113
Derivative Liabilities	(171)	(121)
Derivatives not designated as hedging instruments | FTRs — Other current assets | DTE Electric
Derivatives, Fair Value [Line Items]
Derivative Assets	$ 7	$ 3

Financial and Other Derivativ_4

Financial and Other Derivative Instruments (Details Textuals) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Letters of credit that could be used to offset net derivative liabilities	$ 5,000,000	$ 6,000,000
Letters of credit received that could be used to offset net derivative assets	1,000,000	$ 4,000,000
Contractual obligation to post collateral in event of downgrade to below investment grade	377,000,000
Derivative net liability position aggregate fair value	472,000,000
Collateral already posted fair value	0
Derivative net asset position, fair value	445,000,000
Remaining amount of offsets to derivative net liability positions for hard and soft trigger provisions	$ 27,000,000

Financial and Other Derivativ_5

Financial and Other Derivative Instruments (Net Cash Collateral Offsetting Arrangements) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Cash collateral netted against Derivative assets	$ (26)	$ 0
Cash collateral recorded in Accounts receivable	12	13
Cash collateral recorded in Accounts payable	(2)	(3)
Total net cash collateral posted (received)	$ (16)	$ 10

Financial and Other Derivativ_6

Financial and Other Derivative Instruments (Netting Offsets of Derivative Assets and Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	$ 580	$ 775
Gross Amounts Offset in the Consolidated Statements of Financial Position	(486)	(601)
Derivative assets, net	94	174
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(564)	(770)
Gross Amounts Offset in the Consolidated Statements of Financial Position	460	601
Derivative liabilities, net	(104)	(169)
Natural gas
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	240	355
Gross Amounts Offset in the Consolidated Statements of Financial Position	(194)	(266)
Derivative assets, net	46	89
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(265)	(351)
Gross Amounts Offset in the Consolidated Statements of Financial Position	185	266
Derivative liabilities, net	(80)	(85)
Electricity
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	137	306
Gross Amounts Offset in the Consolidated Statements of Financial Position	(106)	(225)
Derivative assets, net	31	81
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(126)	(298)
Gross Amounts Offset in the Consolidated Statements of Financial Position	104	225
Derivative liabilities, net	(22)	(73)
Environmental & Other
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	201	113
Gross Amounts Offset in the Consolidated Statements of Financial Position	(186)	(110)
Derivative assets, net	15	3
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(171)	(121)
Gross Amounts Offset in the Consolidated Statements of Financial Position	171	110
Derivative liabilities, net	0	(11)
Foreign currency exchange contracts
Derivative assets
Gross Amounts of Recognized Assets (Liabilities)	2	1
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Derivative assets, net	2	1
Derivative liabilities
Gross Amounts of Recognized Assets (Liabilities)	(2)	0
Gross Amounts Offset in the Consolidated Statements of Financial Position	0	0
Derivative liabilities, net	$ (2)	$ 0

Financial and Other Derivativ_7

Financial and Other Derivative Instruments (Netting Offsets Reconciliation to Balance Sheet) (Details) - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Derivative Assets
Derivative Assets	$ 580	$ 775
Collateral adjustment	(26)	0
Derivative assets, current	65	133
Derivative assets, noncurrent	29	41
Derivative Liabilities
Derivative Liabilities	(564)	(770)
Derivative liabilities, current	(60)	(83)
Derivative liabilities, noncurrent	(44)	(86)
Current derivative assets
Derivative Assets
Derivative Assets	444	646
Counterparty netting	(361)	(513)
Collateral adjustment	(18)	0
Derivative assets, current	65	133
Noncurrent derivative assets
Derivative Assets
Derivative Assets	136	129
Counterparty netting	(99)	(88)
Collateral adjustment	(8)	0
Derivative assets, noncurrent	29	41
Current derivative liabilities
Derivative Liabilities
Derivative Liabilities	(421)	(596)
Counterparty netting	361	513
Collateral adjustment	0	0
Derivative liabilities, current	(60)	(83)
Noncurrent derivative liabilities
Derivative Liabilities
Derivative Liabilities	(143)	(174)
Counterparty netting	99	88
Collateral adjustment	0	0
Derivative liabilities, noncurrent	$ (44)	$ (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	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ (45)	$ (8)	$ 0	$ 5
Natural gas | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(27)	(5)	(63)	4
Natural gas | Fuel, purchased power, and gas — non-utility
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	(51)	(47)	28	(7)
Electricity | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	33	54	75	21
Environmental & Other | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	2	(11)	(40)	(11)
Foreign currency exchange contracts | Operating Revenues — Non-utility operations
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Income on Derivatives	$ (2)	$ 1	$ 0	$ (2)

Financial and Other Derivativ_9

Financial and Other Derivative Instruments (Cumulative Gross Volume of Derivative Contracts Outstanding) (Details)	9 Months Ended
	Sep. 30, 2020CAD ($)MWhMMBTUT
Natural gas (MMBtu)
Derivative [Line Items]
Commodity, energy measures | MMBTU	1,739,656,507
Electricity (MWh)
Derivative [Line Items]
Commodity, energy measures	28,258,929
Foreign currency exchange (CAD)
Derivative [Line Items]
Commodity, monetary measure | $	$ 154,336,963
Renewable Energy Certificates (MWh)
Derivative [Line Items]
Commodity, energy measures	7,893,076
Carbon emissions (Metric Ton)
Derivative [Line Items]
Commodity, mass measure | T	16,451,411

Long-Term Debt (Schedule of Iss

Long-Term Debt (Schedule of Issued Debt) (Details)	9 Months Ended
	Sep. 30, 2020USD ($)
Debt Instrument [Line Items]
Debt issued	$ 2,750,000,000
Repayment of debt	$ 682,000,000
Senior Notes | August 2020 1.05% Mortgage Bonds Maturing 2025
Debt Instrument [Line Items]
Interest rate	1.05%
Debt issued	$ 800,000,000
DTE Electric | Mortgage Bonds | February 2020 2.25% Mortgage Bonds Maturing 2030
Debt Instrument [Line Items]
Interest rate	2.25%
Debt issued	$ 600,000,000
DTE Electric | Mortgage Bonds | February 2020 2.95% Mortgage Bonds Maturing 2050
Debt Instrument [Line Items]
Interest rate	2.95%
Debt issued	$ 500,000,000
DTE Electric | Mortgage Bonds | April 2020 2.63% Mortgage Bonds Maturing 2031
Debt Instrument [Line Items]
Interest rate	2.63%
Debt issued	$ 600,000,000
DTE Electric | Senior Notes | 4.89% Senior Notes Maturing 2020
Debt Instrument [Line Items]
Interest rate	4.89%
Repayment of debt	$ 300,000,000
DTE Electric | Senior Notes | 2010 Series B 3.45% Senior Notes Due 2020
Debt Instrument [Line Items]
Interest rate	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 Electric | Senior Notes | 6.36% Senior Notes Maturing 2020
Debt Instrument [Line Items]
Interest rate	6.36%
Repayment of debt	$ 50,000,000
DTE Gas | Mortgage Bonds | August 2020 2.35% Mortgage Bonds Maturing 2030
Debt Instrument [Line Items]
Interest rate	2.35%
Debt issued	$ 125,000,000
DTE Gas | Mortgage Bonds | August 2020 3.20% Mortgage Bonds Maturing 2050
Debt Instrument [Line Items]
Interest rate	3.20%
Debt issued	$ 125,000,000
DTE Gas | Senior Notes | 6.36% Senior Notes Maturing 2020
Debt Instrument [Line Items]
Interest rate	6.36%
Repayment of debt	$ 50,000,000

Long-Term Debt (Details Textual

Long-Term Debt (Details Textuals) - USD ($)	Oct. 22, 2020	Oct. 27, 2020	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Mar. 31, 2020
Debt Instrument [Line Items]
Face amount of loan			$ 2,750,000,000	$ 2,750,000,000
Amount drawn down on loan				2,724,000,000	$ 1,433,000,000
Repayment of debt				$ 682,000,000
Unsecured Term Loan Maturing in March 2022 | Unsecured term loan
Debt Instrument [Line Items]
Face amount of loan							$ 200,000,000
Amount drawn down on loan			$ 0
October 2020 4.375% Junior Subordinated Debentures Due 2080 | Junior Subordinated Debentures | Subsequent Event
Debt Instrument [Line Items]
Face amount of loan		$ 230,000,000
Interest rate		4.375%
Series C, 2012, 5.25% Junior Subordinated Debentures Due 2062 [Member] | Junior Subordinated Debentures | Subsequent Event
Debt Instrument [Line Items]
Interest rate	5.25%
Repayment of debt	$ 200,000,000
October 2020 0.55% Senior Notes Maturing 2022 | Senior Notes | Subsequent Event
Debt Instrument [Line Items]
Face amount of loan		$ 750,000,000
Interest rate		0.55%
Unsecured term loan, expiring March 2021 | Unsecured term loan
Debt Instrument [Line Items]
Face amount of loan							$ 500,000,000
Unsecured term loan, expiring March 2021 | Unsecured term loan | Subsequent Event
Debt Instrument [Line Items]
Repayment of debt		$ 500,000,000
Unsecured term loan, expiring June 2021 | Unsecured term loan
Debt Instrument [Line Items]
Face amount of loan						$ 167,000,000
Unsecured term loan, expiring June 2021 | Unsecured term loan | Subsequent Event
Debt Instrument [Line Items]
Repayment of debt		$ 167,000,000

Long-Term Debt (Schedule of Deb

Long-Term Debt (Schedule of Debt Redeemed) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020USD ($)
Debt Instrument, Redemption [Line Items]
Debt redeemed	$ 682
DTE Electric | Senior Notes | 4.89% Senior Notes Maturing 2020
Debt Instrument, Redemption [Line Items]
Interest rate	4.89%
Debt redeemed	$ 300
DTE Electric | Senior Notes | 5.63% Senior Notes Maturing 2020
Debt Instrument, Redemption [Line Items]
Interest rate	5.63%
Debt redeemed	$ 32
DTE Electric | Senior Notes | 3.45% Senior Notes Maturing 2020
Debt Instrument, Redemption [Line Items]
Interest rate	3.45%
Debt redeemed	$ 300
DTE Electric | Senior Notes | 6.36% Senior Notes Maturing 2020
Debt Instrument, Redemption [Line Items]
Interest rate	6.36%
Debt redeemed	$ 50

Short-Term Credit Arrangement_3

Short-Term Credit Arrangements and Borrowings (Details Textuals)	1 Months Ended	9 Months Ended
	Oct. 27, 2020USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2020CAD ($)	Jul. 31, 2020USD ($)	Jun. 30, 2020USD ($)	May 31, 2020CAD ($)	Apr. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Short-term Debt [Line Items]
Face amount of loan		$ 2,750,000,000
Amounts drawn		988,000,000							$ 828,000,000
Maximum borrowing capacity		3,810,000,000
Amounts outstanding		1,200,000,000
Debt redeemed		682,000,000
Unsecured term loan
Short-term Debt [Line Items]
Amounts outstanding		967,000,000
Revolving credit facility
Short-term Debt [Line Items]
Amounts outstanding		21,000,000
Letters of credit
Short-term Debt [Line Items]
Amounts outstanding		212,000,000
Unsecured term loan, expiring March 2021 | Unsecured term loan
Short-term Debt [Line Items]
Face amount of loan								$ 500,000,000
Amounts drawn		500,000,000
Maximum borrowing capacity		500,000,000
Unsecured term loan, expiring March 2021 | Unsecured term loan | Subsequent Event
Short-term Debt [Line Items]
Debt redeemed	$ 500,000,000
Unsecured Term Loan, Expiring April 2021 | Unsecured term loan
Short-term Debt [Line Items]
Maximum borrowing capacity		500,000,000
Unsecured Canadian Revolving Credit Facility, Expiring May 2023 | Revolving credit facility
Short-term Debt [Line Items]
Maximum borrowing capacity		83,000,000
Unsecured term loan, expiring June 2021 | Unsecured term loan
Short-term Debt [Line Items]
Face amount of loan					$ 167,000,000
Maximum borrowing capacity		167,000,000
Unsecured term loan, expiring June 2021 | Unsecured term loan | Subsequent Event
Short-term Debt [Line Items]
Debt redeemed	167,000,000
DTE Energy
Short-term Debt [Line Items]
Maximum borrowing capacity		2,510,000,000
Amounts outstanding		$ 900,000,000
Ratio of indebtedness to net capital		0.60	0.60
DTE Energy | Unsecured term loan
Short-term Debt [Line Items]
Amounts outstanding		$ 667,000,000
DTE Energy | Revolving credit facility
Short-term Debt [Line Items]
Amounts outstanding		21,000,000
DTE Energy | Letters of credit
Short-term Debt [Line Items]
Amounts outstanding		212,000,000
DTE Energy | Demand financing agreement
Short-term Debt [Line Items]
Maximum borrowing capacity, financing agreement		300,000,000
Amount outstanding		43,000,000							$ 114,000,000
DTE Energy | Unsecured term loan, expiring March 2021 | Unsecured term loan
Short-term Debt [Line Items]
Maximum borrowing capacity		500,000,000
DTE Energy | Unsecured Term Loan, Expiring April 2021 | Unsecured term loan
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		83,000,000
DTE Energy | Unsecured term loan, expiring June 2021 | Unsecured term loan
Short-term Debt [Line Items]
Maximum borrowing capacity		167,000,000
DTE Energy | Other outstanding letters of credit | Letters of credit
Short-term Debt [Line Items]
Amounts outstanding		59,000,000
DTE Energy | Uncommitted letter of credit facility, Expiring July 2021 | Letters of credit
Short-term Debt [Line Items]
Maximum borrowing capacity				$ 50,000,000
DTE Energy | Demand financing agreement, indefinite term | Demand financing agreement
Short-term Debt [Line Items]
Maximum borrowing capacity, financing agreement		100,000,000
Maximum additional margin financing		50,000,000
DTE Energy | Demand financing agreement, expiring in 2022 | Demand financing agreement
Short-term Debt [Line Items]
Maximum borrowing capacity, financing agreement		$ 150,000,000
Maximum
Short-term Debt [Line Items]
Ratio of indebtedness to net capital		0.65	0.65
DTE Electric
Short-term Debt [Line Items]
Maximum borrowing capacity		$ 900,000,000
Amounts outstanding		$ 200,000,000
Ratio of indebtedness to net capital		0.52	0.52
DTE Electric | Unsecured term loan
Short-term Debt [Line Items]
Amounts outstanding		$ 200,000,000
DTE Electric | Revolving credit facility
Short-term Debt [Line Items]
Amounts outstanding		0
DTE Electric | Letters of credit
Short-term Debt [Line Items]
Amounts outstanding		0
DTE Electric | Unsecured term loan, expiring March 2021 | Unsecured term loan
Short-term Debt [Line Items]
Maximum borrowing capacity		0
DTE Electric | Unsecured Term Loan, Expiring April 2021, Funded | Unsecured term loan
Short-term Debt [Line Items]
Face amount of loan							$ 200,000,000
Amounts drawn		200,000,000
DTE Electric | Unsecured Term Loan, Expiring April 2021, Unfunded | Unsecured term loan
Short-term Debt [Line Items]
Face amount of loan							200,000,000
Amounts drawn		0
DTE Electric | Unsecured Term Loan, Expiring April 2021 | Unsecured term loan
Short-term Debt [Line Items]
Maximum borrowing capacity		400,000,000
DTE Electric | Unsecured Canadian Revolving Credit Facility, Expiring May 2023 | Revolving credit facility
Short-term Debt [Line Items]
Maximum borrowing capacity		0
DTE Electric | Unsecured term loan, expiring June 2021 | Unsecured term loan
Short-term Debt [Line Items]
Maximum borrowing capacity		0
DTE Gas
Short-term Debt [Line Items]
Maximum borrowing capacity		400,000,000
Amounts outstanding		$ 100,000,000
Ratio of indebtedness to net capital		0.49	0.49
DTE Gas | Unsecured term loan
Short-term Debt [Line Items]
Amounts outstanding		$ 100,000,000
DTE Gas | Revolving credit facility
Short-term Debt [Line Items]
Amounts outstanding		0
DTE Gas | Letters of credit
Short-term Debt [Line Items]
Amounts outstanding		0
DTE Gas | Unsecured term loan, expiring March 2021 | Unsecured term loan
Short-term Debt [Line Items]
Maximum borrowing capacity		0
DTE Gas | Unsecured Term Loan, Expiring April 2021 | Unsecured term loan
Short-term Debt [Line Items]
Face amount of loan							100,000,000
Amounts drawn							$ 100,000,000
Maximum borrowing capacity		100,000,000
DTE Gas | Unsecured Term Loan, Expiring April 2021 | Unsecured term loan | Subsequent Event
Short-term Debt [Line Items]
Debt redeemed	$ 100,000,000
DTE Gas | Unsecured Canadian Revolving Credit Facility, Expiring May 2023 | Revolving credit facility
Short-term Debt [Line Items]
Maximum borrowing capacity		0
DTE Gas | Unsecured term loan, expiring June 2021 | Unsecured term loan
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
Amounts outstanding			$ 28,000,000

Short-Term Credit Arrangement_4

Short-Term Credit Arrangements and Borrowings (Details)	Sep. 30, 2020USD ($)
Availability under combined facilities
Maximum borrowing capacity	$ 3,810,000,000
Amounts outstanding	1,200,000,000
Net availability	2,610,000,000
DTE Electric
Availability under combined facilities
Maximum borrowing capacity	900,000,000
Amounts outstanding	200,000,000
Net availability	700,000,000
DTE Gas
Availability under combined facilities
Maximum borrowing capacity	400,000,000
Amounts outstanding	100,000,000
Net availability	300,000,000
DTE Energy
Availability under combined facilities
Maximum borrowing capacity	2,510,000,000
Amounts outstanding	900,000,000
Net availability	1,610,000,000
Letters of credit
Availability under combined facilities
Amounts outstanding	212,000,000
Letters of credit | DTE Electric
Availability under combined facilities
Amounts outstanding	0
Letters of credit | DTE Gas
Availability under combined facilities
Amounts outstanding	0
Letters of credit | DTE Energy
Availability under combined facilities
Amounts outstanding	212,000,000
Unsecured term loan
Availability under combined facilities
Amounts outstanding	967,000,000
Unsecured term loan | DTE Electric
Availability under combined facilities
Amounts outstanding	200,000,000
Unsecured term loan | DTE Gas
Availability under combined facilities
Amounts outstanding	100,000,000
Unsecured term loan | DTE Energy
Availability under combined facilities
Amounts outstanding	667,000,000
Revolver borrowings
Availability under combined facilities
Amounts outstanding	21,000,000
Revolver borrowings | DTE Electric
Availability under combined facilities
Amounts outstanding	0
Revolver borrowings | DTE Gas
Availability under combined facilities
Amounts outstanding	0
Revolver borrowings | DTE Energy
Availability under combined facilities
Amounts outstanding	21,000,000
Unsecured letter of credit facility, expiring in February 2021 | Letters of credit
Availability under combined facilities
Maximum borrowing capacity	150,000,000
Unsecured letter of credit facility, expiring in February 2021 | Letters of credit | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured letter of credit facility, expiring in February 2021 | Letters of credit | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured letter of credit facility, expiring in February 2021 | Letters of credit | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	150,000,000
Unsecured letter of credit facility, expiring in August 2021 | Letters of credit
Availability under combined facilities
Maximum borrowing capacity	110,000,000
Unsecured letter of credit facility, expiring in August 2021 | Letters of credit | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured letter of credit facility, expiring in August 2021 | Letters of credit | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured letter of credit facility, expiring in August 2021 | Letters of credit | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	110,000,000
Unsecured term loan, expiring in March 2021 | Unsecured term loan
Availability under combined facilities
Maximum borrowing capacity	500,000,000
Unsecured term loan, expiring in March 2021 | Unsecured term loan | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured term loan, expiring in March 2021 | Unsecured term loan | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured term loan, expiring in March 2021 | Unsecured term loan | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	500,000,000
Unsecured term loans, expiring in April 2021 | Unsecured term loan
Availability under combined facilities
Maximum borrowing capacity	500,000,000
Unsecured term loans, expiring in April 2021 | Unsecured term loan | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	400,000,000
Unsecured term loans, expiring in April 2021 | Unsecured term loan | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	100,000,000
Unsecured term loans, expiring in April 2021 | Unsecured term loan | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured term loan, expiring in June 2021 | Unsecured term loan
Availability under combined facilities
Maximum borrowing capacity	167,000,000
Unsecured term loan, expiring in June 2021 | Unsecured term loan | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured term loan, expiring in June 2021 | Unsecured term loan | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured term loan, expiring in June 2021 | Unsecured term loan | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	167,000,000
Unsecured Canadian revolving credit facility, expiring May 2023 | Revolver borrowings
Availability under combined facilities
Maximum borrowing capacity	83,000,000
Unsecured Canadian revolving credit facility, expiring May 2023 | Revolver borrowings | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured Canadian revolving credit facility, expiring May 2023 | Revolver borrowings | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured Canadian revolving credit facility, expiring May 2023 | Revolver borrowings | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	83,000,000
Unsecured revolving credit facility, expiring April 2024 | Revolver borrowings
Availability under combined facilities
Maximum borrowing capacity	2,300,000,000
Unsecured revolving credit facility, expiring April 2024 | Revolver borrowings | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	500,000,000
Unsecured revolving credit facility, expiring April 2024 | Revolver borrowings | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Unsecured revolving credit facility, expiring April 2024 | Revolver borrowings | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	$ 1,500,000,000

Leases (Details Textuals)

Leases (Details Textuals) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2020
Leases [Abstract]
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
Interest income recognized under finance leases	$ 4		$ 2	$ 12	$ 4

Leases (Components of Net Inves

Leases (Components of Net Investment in Finance Leases) (Details) $ in Millions	Sep. 30, 2020USD ($)
Leases [Abstract]
2020	$ 8
2021	24
2022	20
2023	19
2024	19
2025 and Thereafter	273
Total minimum future lease receipts	363
Residual value of leased pipeline	19
Less unearned income	201
Net investment in finance lease	181
Less current portion	10
Net investment in finance lease, noncurrent	$ 171

Leases (Lease Income Associated

Leases (Lease Income Associated with Operating Leases) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Fixed payments	$ 17	$ 17	$ 50	$ 51
Variable payments	43	40	82	92
Total lease income under operating leases	$ 60	$ 57	$ 132	$ 143

Commitments and Contingencies (

Commitments and Contingencies (Details Textuals) $ in Millions	Jul. 23, 2020USD ($)	Jun. 30, 2020	Sep. 30, 2020USD ($)employeesitefacilityplant	May 31, 2020plant	Dec. 31, 2019USD ($)	Jul. 31, 2019CAD ($)	Jul. 31, 2009plant
Loss Contingencies [Line Items]
Estimated utility capital expenditures, expenditures for non-utility businesses, and contributions to equity method investees			$ 4,500
Power and Industrial Projects
Loss Contingencies [Line Items]
Number of generating plants operated with ownership interest held | plant			5
Workforce subject to collective bargaining arrangements | Labor force concentration risk
Loss Contingencies [Line Items]
Number of employees | employee			5,200
Synthetic fuel
Loss Contingencies [Line Items]
Number of days after expiration of statutes of limitations			90 days
Maximum potential liability			$ 400
Reduced emissions fuel guarantees
Loss Contingencies [Line Items]
Number of days after expiration of statutes of limitations			90 days
Maximum potential liability			$ 543
Other guarantees
Loss Contingencies [Line Items]
Maximum potential liability			50
Performance surety bonds
Loss Contingencies [Line Items]
Performance bonds outstanding			$ 125
Reduction of Carbon Emissions by Early 2020s
Loss Contingencies [Line Items]
Commitment to reduce carbon emissions, percentage			32.00%
Reduction of Carbon Emissions by 2030
Loss Contingencies [Line Items]
Commitment to reduce carbon emissions, percentage			50.00%
Reduction of Carbon Emissions by 2040
Loss Contingencies [Line Items]
Commitment to reduce carbon emissions, percentage			80.00%
The Sierra Club
Loss Contingencies [Line Items]
Amount accrued for settlement			$ 5
DTE Gas | NEXUS pipeline
Loss Contingencies [Line Items]
Maximum potential liability			$ 226
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			$ 360
Percentage of payment obligations due			50.00%
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			$ 52
Vector | NEXUS pipeline
Loss Contingencies [Line Items]
Maximum potential liability			$ 7
Percentage of payment obligations due			50.00%
Guarantee termination, minimum threshold, period following end of primary term of capacity lease agreements			15 years
DTE Electric
Loss Contingencies [Line Items]
Number of power plants in violation | plant							5
Number of power plants with requirement to retire, repower, refuel or retrofit units | plant				4
Environmental capital expenditures			$ 2,400
Number of former MGP sites | site			3
Accrued for remediation			$ 6		$ 8
Number of permitted engineered ash storage facilities owned | facility			3
Estimated utility capital expenditures, expenditures for non-utility businesses, and contributions to equity method investees			$ 2,600
DTE Electric | Workforce subject to collective bargaining arrangements | Labor force concentration risk
Loss Contingencies [Line Items]
Number of employees | employee			2,800
DTE Electric | Performance surety bonds
Loss Contingencies [Line Items]
Performance bonds outstanding			$ 69
DTE Electric | Reduction of Carbon Emissions by 2050
Loss Contingencies [Line Items]
Goal of net carbon emissions, percentage			0.00%
DTE Electric | Coal Combustion Residual Rule
Loss Contingencies [Line Items]
Estimated impact of the current rule			$ 629
DTE Electric | The Sierra Club
Loss Contingencies [Line Items]
Amount paid related to settlement	$ 2
DTE Gas
Loss Contingencies [Line Items]
Number of former MGP sites | site			14
Accrued for remediation			$ 24		$ 25
Amortization period (in years)			10 years
DTE Gas | Clean up completed and site closed
Loss Contingencies [Line Items]
Number of former MGP sites | site			8
DTE Gas | Partial closure complete
Loss Contingencies [Line Items]
Number of former MGP sites | site			4
DTE Gas | Reduction of Greenhouse Gas Emissions by 2050
Loss Contingencies [Line Items]
Goal of net greenhouse gas emissions, percentage		0.00%
DTE Gas | DTE Gas | NEXUS pipeline
Loss Contingencies [Line Items]
Percentage of payment obligations due			50.00%
NEXUS | DTE Gas | NEXUS pipeline
Loss Contingencies [Line Items]
Agreement term			15 years
NEXUS | Texas Eastern Transmission, LP | NEXUS pipeline
Loss Contingencies [Line Items]
Agreement term			15 years
NEXUS | Vector | NEXUS pipeline
Loss Contingencies [Line Items]
Agreement term			15 years

Retirement Benefits and Trust_3

Retirement Benefits and Trusteed Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 25	$ 21	$ 74	$ 63
Interest cost	46	55	139	164
Expected return on plan assets	(84)	(82)	(250)	(244)
Amortization of net actuarial loss	43	33	129	99
Amortization of prior service credit	0	0	0	0
Settlements	2	0	2	0
Net periodic benefit cost (credit)	32	27	94	82
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	7	5	20	16
Interest cost	14	18	42	53
Expected return on plan assets	(32)	(30)	(96)	(92)
Amortization of net actuarial loss	4	3	12	9
Amortization of prior service credit	(5)	(3)	(15)	(7)
Settlements	0	0	0	0
Net periodic benefit cost (credit)	(12)	(7)	(37)	(21)
Other Postretirement Benefits | DTE Electric
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	4	15	12
Interest cost	11	13	32	40
Expected return on plan assets	(21)	(21)	(65)	(63)
Amortization of net actuarial loss	2	1	8	3
Amortization of prior service credit	(3)	(1)	(10)	(5)
Net periodic benefit cost (credit)	$ (6)	$ (4)	$ (20)	$ (13)

Retirement Benefits and Trust_4

Retirement Benefits and Trusteed Assets (Details Textuals) - USD ($)	Sep. 08, 2020	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Defined Benefit Plan Disclosure [Line Items]
Contribution of common stock to pension plan			$ 82,000,000		$ 100,000,000
Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Cash contribution						$ 2,000,000
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Contribution of common stock to pension plan	$ 82,000,000
Pension Benefits | Qualified Plan
Defined Benefit Plan Disclosure [Line Items]
Contributions by employer						84,000,000
Contribution of common stock to pension plan						82,000,000
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Anticipated contributions, remainder of fiscal year		$ 0	0			0
DTE Electric | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Pension cost			$ 28,000,000	$ 23,000,000		$ 79,000,000	$ 68,000,000
Cash contribution		60,000,000
DTE Gas | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Cash contribution		$ 22,000,000

Retirement Benefits and Trust_5

Retirement Benefits and Trusteed Assets (Contributions to DTE Energy Company Affiliates Employee Benefit Plans Master Trust) (Details) - USD ($) $ / shares in Units, $ in Millions	Sep. 08, 2020	Sep. 30, 2020	Mar. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contribution of common stock to pension plan		$ 82	$ 100
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of Shares (in shares)	694,444
Price per Share (in dollars per share)	$ 118.08
Contribution of common stock to pension plan	$ 82

Segment and Related Informati_3

Segment and Related Information (Details Textuals) customer in Millions	Sep. 30, 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		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Revenues	$ (3,284)	$ (3,119)	$ (8,889)	$ (9,521)
Electric
Segment Reporting Information [Line Items]
Revenues	(1,693)	(1,520)	(4,221)	(3,945)
Gas
Segment Reporting Information [Line Items]
Revenues	(173)	(155)	(964)	(1,043)
Gas Storage and Pipelines
Segment Reporting Information [Line Items]
Revenues	(204)	(126)	(546)	(363)
Power and Industrial Projects
Segment Reporting Information [Line Items]
Revenues	(324)	(406)	(850)	(1,196)
Energy Trading
Segment Reporting Information [Line Items]
Revenues	(1,061)	(1,105)	(2,714)	(3,519)
Reconciliation and Eliminations
Segment Reporting Information [Line Items]
Revenues	172	195	408	548
Reconciliation and Eliminations | Electric
Segment Reporting Information [Line Items]
Revenues	16	16	46	43
Reconciliation and Eliminations | Gas
Segment Reporting Information [Line Items]
Revenues	4	3	12	8
Reconciliation and Eliminations | Gas Storage and Pipelines
Segment Reporting Information [Line Items]
Revenues	8	11	17	17
Reconciliation and Eliminations | Power and Industrial Projects
Segment Reporting Information [Line Items]
Revenues	134	160	308	462
Reconciliation and Eliminations | Energy Trading
Segment Reporting Information [Line Items]
Revenues	9	4	23	16
Reconciliation and Eliminations | Corporate and Other
Segment Reporting Information [Line Items]
Revenues	$ 1	$ 1	$ 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		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Utility operations	$ 1,844	$ 1,656	$ 5,119	$ 4,937
Operating Revenues — Non-utility operations	1,440	1,463	3,770	4,584
Operating Revenues	3,284	3,119	8,889	9,521
Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	(172)	(195)	(408)	(548)
Operating Revenues	(172)	(195)	(408)	(548)
Electric
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	1,693	1,520	4,221	3,945
Electric | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Utility operations	1,690	1,520	4,211	3,945
Operating Revenues — Non-utility operations	3	0	10	0
Electric | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(16)	(16)	(46)	(43)
Gas
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	173	155	964	1,043
Gas | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Utility operations	173	155	964	1,043
Gas | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(4)	(3)	(12)	(8)
Gas Storage and Pipelines
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	204	126	546	363
Gas Storage and Pipelines | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	204	126	546	363
Gas Storage and Pipelines | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(8)	(11)	(17)	(17)
Power and Industrial Projects
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	324	406	850	1,196
Power and Industrial Projects | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	324	406	850	1,196
Power and Industrial Projects | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(134)	(160)	(308)	(462)
Energy Trading
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	1,061	1,105	2,714	3,519
Energy Trading | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	1,061	1,105	2,714	3,519
Energy Trading | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	(9)	(4)	(23)	(16)
Corporate and Other | Operating segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues — Non-utility operations	1	2	2	3
Corporate and Other | Reconciliation and Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Operating Revenues	$ (1)	$ (1)	$ (2)	$ (2)

Segment and Related Informati_6

Segment and Related Information (Financial Data - Net Income (Loss) Attributable to DTE Energy by Segment) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	$ 476	$ 319	$ 1,093	$ 902
Electric
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	398	307	675	587
Gas
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	(20)	(38)	102	121
Gas Storage and Pipelines
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	104	60	246	158
Power and Industrial Projects
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	47	49	102	104
Energy Trading
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	(28)	(14)	5	12
Corporate and Other
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net Income Attributable to DTE Energy Company	$ (25)	$ (45)	$ (37)	$ (80)

Related Party Transactions (Det

Related Party Transactions (Details) - NEXUS - Equity Method Investee	9 Months Ended
	Sep. 30, 2020
DTE Gas | Capacity Lease Agreement
Related Party Transaction [Line Items]
Term of related party agreement	15 years
DTE Gas | Service Agreement
Related Party Transaction [Line Items]
Term of related party agreement	15 years
DTE Electric | Service Agreement
Related Party Transaction [Line Items]
Term of related party agreement	20 years

Related Party Transactions (Sch

Related Party Transactions (Schedule of Related Party Transactions) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Related Party Transaction [Line Items]
Operating Revenues — Utility operations	$ 1,844	$ 1,656	$ 5,119	$ 4,937
Fuel, purchased power, and gas — utility	455	400	1,296	1,342
Fuel, purchased power, and gas — non-utility	1,180	1,257	2,937	3,900
DTE Electric
Related Party Transaction [Line Items]
Operating Revenues — Utility operations	1,690	1,519	4,211	3,944
Fuel, purchased power, and gas — utility	451	399	1,090	1,067
NEXUS | DTE Gas | Equity Method Investee
Related Party Transaction [Line Items]
Operating Revenues — Utility operations	8	8	24	24
Fuel, purchased power, and gas — utility	2	2	14	15
NEXUS | DTE Electric | Equity Method Investee
Related Party Transaction [Line Items]
Fuel, purchased power, and gas — utility	2	2	6	6
NEXUS | DTE Energy Trading | Equity Method Investee
Related Party Transaction [Line Items]
Fuel, purchased power, and gas — non-utility	$ 7	$ 2	$ 20	$ 5