Significant Accounting Policies (Financing Receivables Classified by Internal Grade of Credit Risk) (Details) $ in Millions	Mar. 31, 2023 USD ($)
Notes receivable
Financing receivables by year of origination
2023	$ 2
2022	45
2021 and Prior	24
Total	71
Notes receivable | DTE Electric
Financing receivables by year of origination
Total	32
Notes receivable | Internal grade 1(a)
Financing receivables by year of origination
2023	0
2022	0
2021 and Prior	6
Total	6
Notes receivable | Internal grade 1(a) | DTE Electric
Financing receivables by year of origination
Total	32
Notes receivable | Internal grade 1(a) | DTE Electric | Affiliates
Financing receivables by year of origination
2023	30
Notes receivable | Internal grade 2
Financing receivables by year of origination
2023	2
2022	45
2021 and Prior	18
Total	65
Notes receivable | Internal grade 2 | DTE Electric
Financing receivables by year of origination
Total	0
Net investment in leases
Financing receivables by year of origination
2023	0
2022	66
2021 and Prior	225
Total	291
Net investment in leases | DTE Electric
Financing receivables by year of origination
Total	0
Net investment in leases | Internal grade 1(a)
Financing receivables by year of origination
2023	0
2022	0
2021 and Prior	37
Total	37
Net investment in leases | Internal grade 1(a) | DTE Electric
Financing receivables by year of origination
Total	0
Net investment in leases | Internal grade 2
Financing receivables by year of origination
2023	0
2022	66
2021 and Prior	188
Total	254
Net investment in leases | Internal grade 2 | DTE Electric
Financing receivables by year of origination
Total	$ 0