Short-Term Credit Arrangements and Borrowings (Tables)

6 Months Ended

Jun. 30, 2011

Short-Term Credit Arrangements and Borrowings (Tables) [Abstract]

Availability under combined facilities

(in Millions)	DTE Energy		Detroit Edison		MichCon		Total
Unsecured revolving credit facility, expiring August 2012	$	538	$	212	$	250	$	1,000
Unsecured revolving credit facility, expiring August 2013		562		63		175		800
Unsecured letter of credit facility, expiring in May 2013		50		—		—		50
Unsecured letter of credit facility, expiring in August 2015		125		—		—		125
Total credit facilities at June 30, 2011	$	1,275	$	275	$	425	$	1,975
Amounts outstanding at June 30, 2011:
Commercial paper issuances		44		107		—		151
Letters of credit outstanding at June 30, 2011		119		—		—		119
		163		107		—		270
Net availability at June 30, 2011	$	1,112	$	168	$	425	$	1,705