Short-Term Credit Arrangements and Borrowings (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012
Line Of Credit Facility [Line Items]
Line of Credit Facility, Amount Outstanding	$ 261
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	1,975
Commercial paper issuances	39
Line of Credit, Current	222
Net availability at June 30, 2012	1,714
Unsecured letter of credit facility, expiring in May 2013 [Member]
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	50
Unsecured letter of credit facility, expiring in August 2015 [Member]
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	125
Unsecured revolving credit facility, expiring October 2016 [Member]
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	1,800
DTE Energy [Member]
Line Of Credit Facility [Line Items]
Line of Credit Facility, Amount Outstanding	261
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	1,275
Commercial paper issuances	39
Line of Credit, Current	222
Net availability at June 30, 2012	1,014
DTE Energy [Member] | Unsecured letter of credit facility, expiring in May 2013 [Member]
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	50
DTE Energy [Member] | Unsecured letter of credit facility, expiring in August 2015 [Member]
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	125
DTE Energy [Member] | Unsecured revolving credit facility, expiring October 2016 [Member]
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	1,100
Detroit Edison [Member]
Line Of Credit Facility [Line Items]
Line of Credit Facility, Amount Outstanding	0
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	300
Commercial paper issuances	0
Line of Credit, Current	0
Net availability at June 30, 2012	300
Detroit Edison [Member] | Unsecured letter of credit facility, expiring in May 2013 [Member]
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	0
Detroit Edison [Member] | Unsecured letter of credit facility, expiring in August 2015 [Member]
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	0
Detroit Edison [Member] | Unsecured revolving credit facility, expiring October 2016 [Member]
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	300
MichCon [Member]
Line Of Credit Facility [Line Items]
Line of Credit Facility, Amount Outstanding	0
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	400
Commercial paper issuances	0
Line of Credit, Current	0
Net availability at June 30, 2012	400
MichCon [Member] | Unsecured letter of credit facility, expiring in May 2013 [Member]
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	0
MichCon [Member] | Unsecured letter of credit facility, expiring in August 2015 [Member]
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	0
MichCon [Member] | Unsecured revolving credit facility, expiring October 2016 [Member]
Availability Under Combined Facilities
Total credit facilities at June 30, 2012	$ 400