Significant Accounting Policies (Financing Receivables Classified by Internal Grade of Credit Risk) (Details) $ in Millions	Sep. 30, 2022 USD ($)
Notes receivable
Financing Receivable, Credit Quality Indicator [Line Items]
2022	$ 25
2021	3
2020 and Prior	37
Total	65
Notes receivable | DTE Electric
Financing Receivable, Credit Quality Indicator [Line Items]
Total	17
Notes receivable | Internal grade 1
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0
2021	0
2020 and Prior	21
Total	21
Notes receivable | Internal grade 1 | DTE Electric
Financing Receivable, Credit Quality Indicator [Line Items]
Total	17
Notes receivable | Internal grade 2
Financing Receivable, Credit Quality Indicator [Line Items]
2022	25
2021	3
2020 and Prior	16
Total	44
Notes receivable | Internal grade 2 | DTE Electric
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0
Net investment in leases
Financing Receivable, Credit Quality Indicator [Line Items]
2022	64
2021	0
2020 and Prior	227
Total	291
Net investment in leases | DTE Electric
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0
Net investment in leases | Internal grade 1
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0
2021	0
2020 and Prior	38
Total	38
Net investment in leases | Internal grade 1 | DTE Electric
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0
Net investment in leases | Internal grade 2
Financing Receivable, Credit Quality Indicator [Line Items]
2022	64
2021	0
2020 and Prior	189
Total	253
Net investment in leases | Internal grade 2 | DTE Electric
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 0