Long-Term Debt (Debt Issuances) (Details) - Jun. 30, 2015 - USD ($)	Total
Debt Instrument [Line Items]
Face amount	$ 800,000,000
Senior Notes \| June 3.30% Senior Notes Maturing 2022
Debt Instrument [Line Items]
Interest Rate	3.30%
Face amount	$ 300,000,000
DTE Electric \| Mortgages \| March 3.70% Mortgage Bonds Maturing 2045
Debt Instrument [Line Items]
Interest Rate	3.70%
Face amount	$ 500,000,000

Face (par) amount of debt instrument at time of issuance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant