Short-Term Credit Arrangements and Borrowings (Details)	Mar. 31, 2021 USD ($)
Availability under combined facilities
Maximum borrowing capacity	$ 2,848,000,000
Amounts outstanding	264,000,000
Net availability	2,584,000,000
DTE Electric
Availability under combined facilities
Maximum borrowing capacity	700,000,000
Amounts outstanding	0
Net availability	700,000,000
DTE Gas
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Amounts outstanding	0
Net availability	300,000,000
DTE Energy
Availability under combined facilities
Maximum borrowing capacity	1,848,000,000
Amounts outstanding	264,000,000
Net availability	1,584,000,000
Letters of credit
Availability under combined facilities
Amounts outstanding	212,000,000
Letters of credit | DTE Electric
Availability under combined facilities
Amounts outstanding	0
Letters of credit | DTE Gas
Availability under combined facilities
Amounts outstanding	0
Letters of credit | DTE Energy
Availability under combined facilities
Amounts outstanding	212,000,000
Revolver borrowings
Availability under combined facilities
Amounts outstanding	52,000,000
Revolver borrowings | DTE Electric
Availability under combined facilities
Amounts outstanding	0
Revolver borrowings | DTE Gas
Availability under combined facilities
Amounts outstanding	0
Revolver borrowings | DTE Energy
Availability under combined facilities
Amounts outstanding	52,000,000
Unsecured letter of credit facility, expiring in February 2023 | Letters of credit
Availability under combined facilities
Maximum borrowing capacity	150,000,000
Unsecured letter of credit facility, expiring in February 2023 | Letters of credit | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured letter of credit facility, expiring in February 2023 | Letters of credit | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured letter of credit facility, expiring in February 2023 | Letters of credit | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	150,000,000
Unsecured letter of credit facility, expiring in August 2021 | Letters of credit
Availability under combined facilities
Maximum borrowing capacity	110,000,000
Unsecured letter of credit facility, expiring in August 2021 | Letters of credit | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured letter of credit facility, expiring in August 2021 | Letters of credit | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured letter of credit facility, expiring in August 2021 | Letters of credit | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	110,000,000
Unsecured term loan, expiring in November 2021 | Unsecured term loan
Availability under combined facilities
Maximum borrowing capacity	200,000,000
Unsecured term loan, expiring in November 2021 | Unsecured term loan | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	200,000,000
Amounts outstanding	0
Unsecured term loan, expiring in November 2021 | Unsecured term loan | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured term loan, expiring in November 2021 | Unsecured term loan | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured Canadian revolving credit facility, expiring May 2023 | Revolver borrowings
Availability under combined facilities
Maximum borrowing capacity	88,000,000
Unsecured Canadian revolving credit facility, expiring May 2023 | Revolver borrowings | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured Canadian revolving credit facility, expiring May 2023 | Revolver borrowings | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Unsecured Canadian revolving credit facility, expiring May 2023 | Revolver borrowings | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	88,000,000
Unsecured revolving credit facility, expiring April 2025 | Revolver borrowings
Availability under combined facilities
Maximum borrowing capacity	2,300,000,000
Unsecured revolving credit facility, expiring April 2025 | Revolver borrowings | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	500,000,000
Unsecured revolving credit facility, expiring April 2025 | Revolver borrowings | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Unsecured revolving credit facility, expiring April 2025 | Revolver borrowings | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	1,500,000,000
Unsecured revolving credit facility, expiring April 2024 | Revolver borrowings
Availability under combined facilities
Maximum borrowing capacity	102,000,000
Unsecured revolving credit facility, expiring April 2024 | Revolver borrowings | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	22,000,000
Unsecured revolving credit facility, expiring April 2024 | Revolver borrowings | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	13,000,000
Unsecured revolving credit facility, expiring April 2024 | Revolver borrowings | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	$ 67,000,000