Short-Term Credit Arrangements and Borrowings (Details)	Mar. 31, 2018 USD ($)
Availability under combined facilities
Maximum borrowing capacity	$ 2,120,000,000
Amounts outstanding	856,000,000
Net availability	1,264,000,000
DTE Electric
Availability under combined facilities
Maximum borrowing capacity	400,000,000
Amounts outstanding	380,000,000
Net availability	20,000,000
DTE Gas
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Amounts outstanding	255,000,000
Net availability	45,000,000
DTE Energy
Availability under combined facilities
Maximum borrowing capacity	1,420,000,000
Amounts outstanding	221,000,000
Net availability	1,199,000,000
Letter of credit
Availability under combined facilities
Amounts outstanding	221,000,000
Letter of credit | DTE Electric
Availability under combined facilities
Amounts outstanding	0
Letter of credit | DTE Gas
Availability under combined facilities
Amounts outstanding	0
Letter of credit | DTE Energy
Availability under combined facilities
Amounts outstanding	221,000,000
Letter of credit | Unsecured letter of credit facility, expiring in February 2019
Availability under combined facilities
Maximum borrowing capacity	150,000,000
Letter of credit | Unsecured letter of credit facility, expiring in February 2019 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Letter of credit | Unsecured letter of credit facility, expiring in February 2019 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Letter of credit | Unsecured letter of credit facility, expiring in February 2019 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	150,000,000
Letter of credit | Unsecured letter of credit facility, expiring in September 2019
Availability under combined facilities
Maximum borrowing capacity	70,000,000
Letter of credit | Unsecured letter of credit facility, expiring in September 2019 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Letter of credit | Unsecured letter of credit facility, expiring in September 2019 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Letter of credit | Unsecured letter of credit facility, expiring in September 2019 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	70,000,000
Revolving credit facility | Unsecured revolving credit facility, expiring April 2022
Availability under combined facilities
Maximum borrowing capacity	1,900,000,000
Revolving credit facility | Unsecured revolving credit facility, expiring April 2022 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	400,000,000
Revolving credit facility | Unsecured revolving credit facility, expiring April 2022 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Revolving credit facility | Unsecured revolving credit facility, expiring April 2022 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	1,200,000,000
Commercial paper issuances
Availability under combined facilities
Amounts outstanding	635,000,000
Commercial paper issuances | DTE Electric
Availability under combined facilities
Amounts outstanding	380,000,000
Commercial paper issuances | DTE Gas
Availability under combined facilities
Amounts outstanding	255,000,000
Commercial paper issuances | DTE Energy
Availability under combined facilities
Amounts outstanding	$ 0