Short-Term Credit Arrangements and Borrowings (Details)	Jun. 30, 2015 USD ($)
Availability under combined facilities
Maximum borrowing capacity	$ 2,125,000,000
Amounts outstanding	170,000,000
Net availability	1,955,000,000
DTE Energy
Availability under combined facilities
Maximum borrowing capacity	1,425,000,000
Amounts outstanding	170,000,000
Net availability	1,255,000,000
DTE Electric
Availability under combined facilities
Maximum borrowing capacity	400,000,000
Amounts outstanding	0
Net availability	400,000,000
DTE Gas
Availability under combined facilities
Maximum borrowing capacity	300,000,000
Amounts outstanding	0
Net availability	300,000,000
Letter of Credit
Availability under combined facilities
Amounts outstanding	170,000,000
Letter of Credit | DTE Energy
Availability under combined facilities
Amounts outstanding	170,000,000
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 | Unsecured letter of credit facility, expiring in February 2017
Availability under combined facilities
Maximum borrowing capacity	100,000,000
Letter of Credit | Unsecured letter of credit facility, expiring in February 2017 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	100,000,000
Letter of Credit | Unsecured letter of credit facility, expiring in February 2017 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Letter of Credit | Unsecured letter of credit facility, expiring in February 2017 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Letter of Credit | Unsecured letter of credit facility, expiring in August 2015
Availability under combined facilities
Maximum borrowing capacity	125,000,000
Letter of Credit | Unsecured letter of credit facility, expiring in August 2015 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	125,000,000
Letter of Credit | Unsecured letter of credit facility, expiring in August 2015 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	0
Letter of Credit | Unsecured letter of credit facility, expiring in August 2015 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	0
Revolving Credit Facility | Unsecured revolving credit facility, expiring April 2020
Availability under combined facilities
Maximum borrowing capacity	1,900,000,000
Revolving Credit Facility | Unsecured revolving credit facility, expiring April 2020 | DTE Energy
Availability under combined facilities
Maximum borrowing capacity	1,200,000,000
Revolving Credit Facility | Unsecured revolving credit facility, expiring April 2020 | DTE Electric
Availability under combined facilities
Maximum borrowing capacity	400,000,000
Revolving Credit Facility | Unsecured revolving credit facility, expiring April 2020 | DTE Gas
Availability under combined facilities
Maximum borrowing capacity	$ 300,000,000