Significant Accounting Policies (Roll-Forward of Activity for Financing Receivables Credit Loss Reserves) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 104	$ 83
Current period provision	54	105
Write-offs charged against allowance	(127)	(134)
Recoveries of amounts previously written off	61	50
Ending balance	92	104
DTE Electric
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	57	46
Current period provision	36	61
Write-offs charged against allowance	(77)	(80)
Recoveries of amounts previously written off	38	30
Ending balance	54	57
Trade accounts receivable
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	101	79
Current period provision	53	102
Write-offs charged against allowance	(126)	(130)
Recoveries of amounts previously written off	61	50
Ending balance	89	101
Trade accounts receivable | Discontinued operations, spinoff | DT Midstream
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Trade accounts receivable reserve related to discontinued operations			$ 8
Other receivables
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	3	4
Current period provision	1	3
Write-offs charged against allowance	(1)	(4)
Recoveries of amounts previously written off	0	0
Ending balance	$ 3	$ 3