Regulatory Assets, Liabilities, And Balancing Accounts (Tables)

3 Months Ended

Mar. 31, 2012

Regulatory Assets, Liabilities, And Balancing Accounts [Abstract]

Long-Term Regulatory Assets

	Balance at
(in millions)	March 31, 2012		December 31, 2011
Pension benefits	$	2,939	$	2,899
Deferred income taxes		1,483		1,444
Utility retained generation		598		613
Environmental compliance costs		535		520
Price risk management		354		339
Electromechanical meters		234		247
Unamortized loss, net of gain, on reacquired debt		157		163
Other		265		281
Total long-term regulatory assets	$	6,565	$	6,506

Long-Term Regulatory Liabilities

	Balance at
(in millions)	March 31, 2012		December 31, 2011
Cost of removal obligations		$ 3,524		$ 3,460
Recoveries in excess of AROs		707		611
Public purpose programs		526		499
Other		170		163
Total long-term regulatory liabilities		$ 4,927		$ 4,733

Current Regulatory Balancing Accounts, Net

	Receivable (Payable)
	Balance at
(in millions)	March 31, 2012			December 31, 2011
Distribution revenue adjustment mechanism		$ 422			$ 223
Utility generation		412			241
Public purpose programs		96			97
Hazardous substance		56			57
Gas fixed cost		(101	)		16
Energy recovery bonds		(108	)		(105	)
Energy procurement		(129	)		(48	)
Other		136			227
Total regulatory balancing accounts, net		$ 784			$ 708