Significant Accounting Policies (Financing Receivables Classified by Internal Grade of Credit Risk) (Details) $ in Millions	Jun. 30, 2023 USD ($)
Notes receivable
Financing receivables by year of origination
2023	$ 17
2022	70
2021 and Prior	24
Total	111
Notes receivable | DTE Electric
Financing receivables by year of origination
Total	2
Notes receivable | Internal grade 1
Financing receivables by year of origination
2023	0
2022	0
2021 and Prior	6
Total	6
Notes receivable | Internal grade 1 | DTE Electric
Financing receivables by year of origination
Total	2
Notes receivable | Internal grade 2
Financing receivables by year of origination
2023	17
2022	70
2021 and Prior	18
Total	105
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	67
2021 and Prior	224
Total	291
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
2023	0
2022	0
2021 and Prior	37
Total	37
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
2023	0
2022	67
2021 and Prior	187
Total	254
Net investment in leases | Internal grade 2 | DTE Electric
Financing receivables by year of origination
Total	$ 0