Regulatory Matters (Tables)

12 Months Ended

Dec. 31, 2012

Regulatory Assets and Liabilities Disclosure [Abstract]

Schedule of Regulatory Assets and Liabilities [Table Text Block]

The following are balances and a brief description of the regulatory assets and liabilities at December 31:

	2012			2011
Assets	(In millions)
Recoverable pension and postretirement costs:
Pension	$	1,815		$	1,656
Postretirement costs	316			582
Asset retirement obligation	424			420
Recoverable Michigan income taxes	253			270
Recoverable income taxes related to securitized regulatory assets	226			316
Accrued PSCR revenue	87			147
Cost to achieve Performance Excellence Process	82			100
Other recoverable income taxes	76			81
Choice incentive mechanism	66			166
Recoverable restoration expense	49			58
Unamortized loss on reacquired debt	37			36
Enterprise Business Systems costs	16			18
Other	63			40
	3,510			3,890
Less amount included in current assets	(162		)	(272		)
	$	3,348		$	3,618
Securitized regulatory assets	$	413		$	577
Liabilities
Renewable energy	$	230		$	192
Refundable revenue decoupling / deferred gain	127			127
Asset removal costs	81			73
Over recovery of Securitization	54			53
Energy Optimization	26			24
Fermi 2 refueling outage	12			23
Refundable uncollectible expense	10			13
Low Income Energy Efficiency Fund	—			23
Other	9			6
	549			534
Less amount included in current liabilities	(66		)	(80		)
	$	483		$	454