Short-Term Credit Arrangements and Borrowings (Tables)

12 Months Ended

Dec. 31, 2012

Short-term Debt [Abstract]

Schedule of Short-term Debt [Table Text Block]

	DTE Energy		DTE Electric		DTE Gas		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 December 31, 2012	$	1,275	$	300	$	400	$	1,975
Amounts outstanding at December 31, 2012:
Commercial paper issuances	—		130		110		240
Letters of credit	175		—		—		175
	175		130		110		415
Net availability at December 31, 2012	$	1,100	$	170	$	290	$	1,560