Nuclear Operations (Details) - DTE Electric $ in Millions		4 Months Ended	12 Months Ended
	May 16, 2014 kWh	May 15, 2014 $ / MWh	Dec. 31, 2017 USD ($)
Entity Information [Line Items]
Policy waiting period			84 days
Insurance coverage for extra expense when power plant unavailable			$ 490
Period of coverage of policy for extra expenses			3 years
Primary coverage for stabilization, decontamination, debris removal, repair and/or replacement of property, and decommissioning			$ 1,500
Excess coverage for stabilization, decontamination, debris removal, repair and/or replacement of property, and decommissioning			1,250
Combined coverage limit for total property damage			2,750
Total limit for property damage for non-nuclear events			2,000
Limit of coverage for aggregate extra expenses for non-nuclear events			$ 328
Period of coverage for extra expenses			2 years
Time period for TRIA after the first loss from terrorism			1 year
NEIL policies against terrorism loss, amount made available to all insured entities (up to)			$ 3,200
Maximum assessment if loss amount exceeds funds available			47
Public liability insurance for a nuclear incident			450
One industry aggregate limit of coverage arising from terrorist act outside scope of TRIA			300
Maximum deferred premium charges that could be levied against each licensed nuclear facility			127
Limit of deferred premium charges per year per facility			$ 19
Company obligated to pay DOE fee of Fermi 2 electricity generated and sold | $ / MWh		1
New DOE fee for Fermi 2 electricity generated and sold | kWh	0