Significant Accounting Policies (Financing Receivables Classified by Internal Grade of Credit Risk) (Details) $ in Millions	Dec. 31, 2021 USD ($)
Notes receivable
Financing Receivable, Credit Quality Indicator [Line Items]
2021	$ 16
2020	107
2019 and prior	27
Total	150
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]
2021	0
2020	0
2019 and prior	21
Total	21
Notes receivable | Internal grade 1 | DTE Electric
Financing Receivable, Credit Quality Indicator [Line Items]
Total	14
Notes receivable | Internal grade 2
Financing Receivable, Credit Quality Indicator [Line Items]
2021	16
2020	107
2019 and prior	6
Total	129
Notes receivable | Internal grade 2 | DTE Electric
Financing Receivable, Credit Quality Indicator [Line Items]
Total	3
Net investment in leases
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0
2020	160
2019 and prior	39
Total	199
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]
2021	0
2020	1
2019 and prior	38
Total	39
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]
2021	0
2020	159
2019 and prior	1
Total	160
Net investment in leases | Internal grade 2 | DTE Electric
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 0