Contractual interest rate for funds borrowed, under the debt agreement.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentRedemptionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=123467658&loc=d3e12355-112629

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 50
-Section 40
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=123467658&loc=d3e12317-112629

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585

+ Details

Name:	us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585

+ Details

Name:	us-gaap_RepaymentsOfLongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Long-Term Debt (Schedule of Debt Redeemed) (Details) - USD ($) $ in Millions	1 Months Ended					2 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2021	Jul. 31, 2021	Jun. 30, 2021	May 31, 2021	Apr. 30, 2021	Aug. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Debt Instrument, Redemption [Line Items]
Amount						$ 2,600			$ 3,242	$ 682
Loss on extinguishment of debt							$ 376	$ 0	384	0
Junior Subordinated Debentures \| 5.375% Junior Subordinated Debentures maturing in 2076
Debt Instrument, Redemption [Line Items]
Interest rate			5.375%
Amount			$ 300
Loss on extinguishment of debt			$ 8
Senior Notes
Debt Instrument, Redemption [Line Items]
Amount							$ 2,600
Senior Notes \| 3.30% Senior Notes maturing in 2022
Debt Instrument, Redemption [Line Items]
Interest rate		3.30%
Amount		$ 300
Senior Notes \| 2.60% Senior Notes maturing in 2022
Debt Instrument, Redemption [Line Items]
Interest rate		2.60%
Amount		$ 300
Senior Notes \| 3.70% Senior Notes maturing in 2023
Debt Instrument, Redemption [Line Items]
Interest rate		3.70%
Amount		$ 600
Senior Notes \| 3.85% Senior Notes maturing in 2023
Debt Instrument, Redemption [Line Items]
Interest rate	3.85%	3.85%				3.85%
Amount	$ 165	$ 135
Senior Notes \| 3.50% Senior Notes maturing in 2024
Debt Instrument, Redemption [Line Items]
Interest rate		3.50%
Amount		$ 350
Senior Notes \| 3.80% Senior Notes maturing in 2027
Debt Instrument, Redemption [Line Items]
Interest rate		3.80%
Amount		$ 350
Senior Notes \| 3.40% Senior Notes maturing in 2029
Debt Instrument, Redemption [Line Items]
Interest rate		3.40%
Amount		$ 21
Senior Notes \| 6.375% Senior Notes maturing in 2033
Debt Instrument, Redemption [Line Items]
Interest rate	6.375%	6.375%				6.375%
Amount	$ 209	$ 191
DTE Electric
Debt Instrument, Redemption [Line Items]
Amount									$ 321	$ 632
DTE Electric \| Mortgage Bonds \| 3.90% Mortgage bonds maturing in 2021
Debt Instrument, Redemption [Line Items]
Interest rate					3.90%
Amount					$ 250
DTE Electric \| Mortgage Bonds \| 7.00% Mortgage Bonds maturing in 2021
Debt Instrument, Redemption [Line Items]
Interest rate				7.00%
Amount				$ 33
DTE Electric \| Mortgage Bonds \| 6.90% Senior Notes Due In 2021
Debt Instrument, Redemption [Line Items]
Interest rate	6.90%					6.90%
Amount	$ 38