Short-Term Credit Arrangements and Borrowings (Tables)

3 Months Ended

Mar. 31, 2012

Short-Term Credit Arrangements and Borrowings [Abstract]

Schedule of Short-term Debt [Table Text Block]

	DTE Energy		Detroit Edison		MichCon		Total
	(In millions)
Unsecured letter of credit facility, expiring in May 2013	$	50	$	—	$	—	$	50
Unsecured letter of credit facility, expiring in August 2015	125		—		—		125
Unsecured revolving credit facility, expiring October 2016	1,100		300		400		1,800
Total credit facilities at March 31, 2012	$	1,275	$	300	$	400	$	1,975
Amounts outstanding at March 31, 2012:
Commercial paper issuances	267		22		24		313
Letters of credit	284		—		—		284
	551		22		24		597
Net availability at March 31, 2012	$	724	$	278	$	376	$	1,378