Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Schedule of Other Income

The following is a summary of DTE Energy's Other income:

	2020		2019		2018
	(In millions)
Income from REF entities	$	139	$	130	$	98
Equity earnings of equity method investees	132		111		132
Gains from rabbi trust securities(a)	28		37		6
Contract services	28		29		51
Allowance for equity funds used during construction	25		24		28
Gas Storage and Pipelines post-acquisition settlement	20		—		—
Other	16		19		18
	$	388	$	350	$	333

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(a)Losses from rabbi trust securities are recorded separately to Other expenses on the Consolidated Statements of Operations.

The following is a summary of DTE Electric's Other income:

	2020		2019		2018
	(In millions)
Gains from rabbi trust securities allocated from DTE Energy(a)	$	28	$	37	$	6
Contract services	28		32		51
Allowance for equity funds used during construction	23		22		19
Other	8		16		7
	$	87	$	107	$	83

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(a)Losses from rabbi trust securities are recorded separately to Other expenses on the Consolidated Statements of Operations.

Schedule of Accumulated Other Comprehensive Income (Loss)

The following table summarizes the changes in DTE Energy's Accumulated other comprehensive income (loss) by component(a) for the years ended December 31, 2020 and 2019:

	Net Unrealized Gain (Loss) on Derivatives		Benefit Obligations(b)		Foreign Currency Translation		Total
	(In millions)
Balance, December 31, 2018	$	(11)	$	(102)	$	(7)	$	(120)
Other comprehensive income (loss) before reclassifications	(14)		(7)		1		(20)
Amounts reclassified from Accumulated other comprehensive income (loss)	2		15		—		17
Net current-period Other comprehensive income (loss)	(12)		8		1		(3)
Implementation of ASU 2018-02	(2)		(23)		—		(25)
Balance, December 31, 2019	$	(25)	$	(117)	$	(6)	$	(148)
Other comprehensive income (loss) before reclassifications	(3)		(2)		1		(4)
Amounts reclassified from Accumulated other comprehensive income (loss)	5		10		—		15
Net current-period Other comprehensive income	2		8		1		11
Balance, December 31, 2020	$	(23)	$	(109)	$	(5)	$	(137)

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(a)All amounts are net of tax, except for Foreign currency translation.

(b)The amounts reclassified from Accumulated other comprehensive income (loss) are included in the computation of the net periodic pension and other postretirement benefit costs (see Note 21 to the Consolidated Financial Statements, "Retirement Benefits and Trusteed Assets").

Schedule of Financing Receivables Classified by Internal Grade of Credit Risk

The following represents the Registrants' financing receivables by year of origination, classified by internal grade of credit risk. The related credit quality indicators and risk ratings utilized to develop the internal grades have been updated through December 31, 2020.

	DTE Energy								DTE Electric
	Year of origination
	2020		2019		2018 and prior		Total		2020 and prior
	(In millions)
Notes receivable
Internal grade 1	$	—	$	14	$	10	$	24	$	14
Internal grade 2	68		43		6		117		2
Total notes receivable(a)	$	68	$	57	$	16	$	141	$	16
Net investment in leases
Net investment in leases, internal grade 1	$	6	$	—	$	39	$	45	$	—
Net investment in leases, internal grade 2	131		—		1		132		—
Total net investment in leases(a)	$	137	$	—	$	40	$	177	$	—

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(a)For DTE Energy, included in Current Assets — Other and Other Assets — Notes Receivable on the Consolidated Statements of Financial Position. For DTE Electric, included in Current Assets — Other and Other Assets — Other on the Consolidated Statements of Financial Position.

Schedule of Roll-Forward of Activity for Financing Receivables Credit Loss Reserves

The following table presents a roll-forward of the activity for the Registrants' financing receivables credit loss reserves as of December 31, 2020.

	DTE Energy						DTE Electric
	Trade accounts receivable		Other receivables		Total		Trade and other accounts receivable
	(In millions)
Beginning reserve balance, January 1, 2020	$	87	$	4	$	91	$	46
Current period provision	100		3		103		61
Write-offs charged against allowance	(136)		(4)		(140)		(80)
Recoveries of amounts previously written off	50		—		50		30
Ending reserve balance, December 31, 2020	$	101	$	3	$	104	$	57

Schedule of Finite-Lived Intangible Assets

The Registrants have certain Intangible assets as shown below:

		December 31, 2020						December 31, 2019
	Useful Lives	Gross Carrying Value		Accumulated Amortization		Net Carrying Value		Gross Carrying Value		Accumulated Amortization		Net Carrying Value
		(In millions)
Intangible assets subject to amortization
Customer relationships	25 to 40 years(a)	$	2,252	$	(121)	$	2,131	$	2,252	$	(66)	$	2,186
Contract intangibles	6 to 26 years	289		(92)		197		268		(76)		192
		2,541		(213)		2,328		2,520		(142)		2,378
DTE Electric renewable energy credits	(b)	8		—		8		15		—		15
DTE Electric zonal resource credits	(c)	3		—		3		—		—		—
DTE Electric Long-term intangible assets		11		—		11		15		—		15
DTE Energy Long-term intangible assets		$	2,552	$	(213)	$	2,339	$	2,535	$	(142)	$	2,393

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(a)The useful lives of the customer relationship intangible assets are based on the number of years in which the assets are expected to economically contribute to the business. The expected economic benefit incorporates existing customer contracts and expected renewal rates based on the estimated volume and production lives of gas resources in the region.

(b)Renewable energy credits are charged to expense, using average cost, as the credits are consumed in the operation of the business.

(c)Zonal resource credits are amortized on a straight-line basis over the period that they are in effect.

Schedule of Indefinite-Lived Intangible Assets

The Registrants have certain Intangible assets as shown below:

		December 31, 2020						December 31, 2019
	Useful Lives	Gross Carrying Value		Accumulated Amortization		Net Carrying Value		Gross Carrying Value		Accumulated Amortization		Net Carrying Value
		(In millions)
Intangible assets subject to amortization
Customer relationships	25 to 40 years(a)	$	2,252	$	(121)	$	2,131	$	2,252	$	(66)	$	2,186
Contract intangibles	6 to 26 years	289		(92)		197		268		(76)		192
		2,541		(213)		2,328		2,520		(142)		2,378
DTE Electric renewable energy credits	(b)	8		—		8		15		—		15
DTE Electric zonal resource credits	(c)	3		—		3		—		—		—
DTE Electric Long-term intangible assets		11		—		11		15		—		15
DTE Energy Long-term intangible assets		$	2,552	$	(213)	$	2,339	$	2,535	$	(142)	$	2,393

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(a)The useful lives of the customer relationship intangible assets are based on the number of years in which the assets are expected to economically contribute to the business. The expected economic benefit incorporates existing customer contracts and expected renewal rates based on the estimated volume and production lives of gas resources in the region.

(b)Renewable energy credits are charged to expense, using average cost, as the credits are consumed in the operation of the business.

(c)Zonal resource credits are amortized on a straight-line basis over the period that they are in effect.

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense

The following table summarizes DTE Energy's estimated customer relationship and contract intangible amortization expense expected to be recognized during each year through 2025:

	2021		2022		2023		2024		2025
	(In millions)
Estimated amortization expense	$	73	$	73	$	73	$	73	$	73

Schedule of Accounting Policies

See the following notes for other accounting policies impacting the Registrants’ Consolidated Financial Statements:

Note	Title
5	Revenue
7	Property, Plant, and Equipment
9	Asset Retirement Obligations
10	Regulatory Matters
11	Income Taxes
13	Fair Value
14	Financial and Other Derivative Instruments
18	Leases
21	Retirement Benefits and Trusteed Assets
22	Stock-Based Compensation