Significant Accounting Policies (Financing Receivables Classified by Internal Grade of Credit Risk) (Details) $ in Millions	Mar. 31, 2024 USD ($)
Notes receivable
Financing receivables by year of origination
2024	$ 364
2023	23
2022 and Prior	30
Total	417
Notes receivable | DTE Electric
Financing receivables by year of origination
Total	16
Notes receivable | Internal grade 1
Financing receivables by year of origination
2024	0
2023	15
2022 and Prior	4
Total	19
Notes receivable | Internal grade 1 | DTE Electric
Financing receivables by year of origination
Total	15
Notes receivable | Internal grade 2
Financing receivables by year of origination
2024	364
2023	8
2022 and Prior	26
Total	398
Notes receivable | Internal grade 2 | DTE Electric
Financing receivables by year of origination
Total	1
Net investment in leases
Financing receivables by year of origination
2024	122
2023	0
2022 and Prior	283
Total	405
Net investment in leases | DTE Electric
Financing receivables by year of origination
Total	0
Net investment in leases | Internal grade 1
Financing receivables by year of origination
2024	0
2023	0
2022 and Prior	36
Total	36
Net investment in leases | Internal grade 1 | DTE Electric
Financing receivables by year of origination
Total	0
Net investment in leases | Internal grade 2
Financing receivables by year of origination
2024	122
2023	0
2022 and Prior	247
Total	369
Net investment in leases | Internal grade 2 | DTE Electric
Financing receivables by year of origination
Total	$ 0