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
	(In millions)
Assets
Recoverable pension and postretirement costs:
Pension	$	2,420		$	2,208
Postretirement costs	426			778
Asset retirement obligation	424			420
Recoverable Michigan income taxes	304			324
Recoverable income taxes related to securitized regulatory assets	226			316
Cost to achieve Performance Excellence Process	96			116
Accrued PSCR/GCR revenue	87			147
Other recoverable income taxes	76			81
Choice incentive mechanism	66			166
Unamortized loss on reacquired debt	63			64
Deferred environmental costs	58			49
Recoverable restoration expense	49			58
Recoverable revenue decoupling	28			18
Enterprise Business Systems costs	16			18
Other	78			90
	4,417			4,853
Less amount included in current assets	(182		)	(314		)
	$	4,235		$	4,539
Securitized regulatory assets	$	413		$	577

	2012			2011
	(In millions)
Liabilities
Asset removal costs	$	439		$	419
Renewable energy	230			192
Refundable revenue decoupling/deferred gain	127			127
Negative pension offset	105			120
Refundable income taxes	56			66
Over recovery of Securitization	54			53
Refundable uncollectible expense	37			31
Energy Optimization	34			34
Accrued PSCR/GCR refund	16			26
Fermi 2 refueling outage	12			23
Low Income Energy Efficiency Fund	—			26
Other	10			9
	1,120			1,126
Less amount included in current liabilities	(89		)	(107		)
	$	1,031		$	1,019