Acquisitions and Dispositions (Purchase Price Allocation - Electric Segment Acquisition) (Details) - DTE Sustainable Generation - Electric - Heritage Sustainable Energy, Renewable Energy Project $ in Millions	Sep. 12, 2019 USD ($)
Business Acquisition [Line Items]
Property, plant, and equipment, net	$ 60
Working capital	6
Total	175
Contract intangibles
Business Acquisition [Line Items]
Contract intangibles	$ 109