Short-Term Credit Arrangements and Borrowings (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	$ 1,975
Amounts Outstanding
Commercial paper issuances	313
Letters of credit	284
Total Amounts Outstanding	597
Net availability at March 31, 2012	1,378
Unsecured letter of credit facility, expiring in May 2013 [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	50
Unsecured letter of credit facility, expiring in August 2015 [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	125
Unsecured revolving credit facility, expiring October 2016 [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	1,800
DTE Energy [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	1,275
Amounts Outstanding
Commercial paper issuances	267
Letters of credit	284
Total Amounts Outstanding	551
Net availability at March 31, 2012	724
DTE Energy [Member] | Unsecured letter of credit facility, expiring in May 2013 [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	50
DTE Energy [Member] | Unsecured letter of credit facility, expiring in August 2015 [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	125
DTE Energy [Member] | Unsecured revolving credit facility, expiring October 2016 [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	1,100
Detroit Edison [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	300
Amounts Outstanding
Commercial paper issuances	22
Letters of credit	0
Total Amounts Outstanding	22
Net availability at March 31, 2012	278
Detroit Edison [Member] | Unsecured letter of credit facility, expiring in May 2013 [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	0
Detroit Edison [Member] | Unsecured letter of credit facility, expiring in August 2015 [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	0
Detroit Edison [Member] | Unsecured revolving credit facility, expiring October 2016 [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	300
MichCon [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	400
Amounts Outstanding
Commercial paper issuances	24
Letters of credit	0
Total Amounts Outstanding	24
Net availability at March 31, 2012	376
MichCon [Member] | Unsecured letter of credit facility, expiring in May 2013 [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	0
MichCon [Member] | Unsecured letter of credit facility, expiring in August 2015 [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	0
MichCon [Member] | Unsecured revolving credit facility, expiring October 2016 [Member]
Availability Under Combined Facilities
Total credit facilities at March 31, 2012	$ 400