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

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

Name:	us-gaap_EffectiveIncomeTaxRateContinuingOperations
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration