Significant Accounting Policies (Schedule of Other Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Other Nonoperating Income, by Component [Line Items]
Income from REF investees	$ 75	$ 83	$ 78
Equity in earnings of equity method investees	68	66	48
Contract services	21	27	23
Allowance for equity funds used during construction	21	21	21
Gains from trading securities	15	1	14
Total other income	7	11	12
Other nonoperating income - total	207	209	196
DTE Electric
Schedule of Other Nonoperating Income, by Component [Line Items]
Equity in earnings of equity method investees	2	2	1
Contract services	20	27	22
Allowance for equity funds used during construction	18	20	21
Gains from trading securities	15	1	14
Total other income	6	10	4
Other nonoperating income - total	$ 61	$ 60	$ 62