Financial and Other Derivative Instruments (Details 4)	Mar. 31, 2013 dte.volumes
Natural Gas [Member]
Derivative [Line Items]
Volume of Commodity Contracts	636,667,880
Electricity [Member]
Derivative [Line Items]
Volume of Commodity Contracts	52,296,934
Foreign currency exchange contracts [Member]
Derivative [Line Items]
Volume of Commodity Contracts	14,158,230