Financial and Other Derivative Instruments (Details 2)	Mar. 31, 2012 dte.volumes
Natural Gas [Member]
Derivative [Line Items]
Investment Contract Volume	714,004,821
Electricity [Member]
Derivative [Line Items]
Investment Contract Volume	53,173,797
Foreign currency exchange contracts [Member]
Derivative [Line Items]
Investment Contract Volume	31,220,488

The volume of a commodity or material specified in an investment contract.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 12

Name:	invest_InvestmentContractVolume
Namespace Prefix:	invest_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	instant