Regulatory Assets, Liabilities, And Balancing Accounts (Tables)

12 Months Ended

Dec. 31, 2011

Regulatory Assets, Liabilities, And Balancing Accounts [Abstract]

Long-Term Regulatory Assets

	Balance at December 31,
(in millions)	2011		2010
Pension benefits	$	2,899	$	1,759
Deferred income taxes		1,444		1,250
Utility retained generation		613		666
Environmental compliance costs		520		450
Price risk management		339		424
Electromechanical meters		247		-
Unamortized loss, net of gain, on reacquired debt		163		181
Energy recovery bonds		-		735
Other		281		381
Total long-term regulatory assets	$	6,506	$	5,846

Long-Term Regulatory Liabilities

	Balance at December 31,
(in millions)	2011		2010
Cost of removal obligation	$	3,460	$	3,229
Recoveries in excess of ARO		611		600
Public purpose programs		499		573
Other		163		123
Total long-term regulatory liabilities	$	4,733	$	4,525

Current Regulatory Balancing Accounts, Net

	Receivable (Payable)
	Balance at December 31,
(in millions)	2011		2010
Utility generation	$	241	$	303
Distribution revenue adjustment mechanism		223		145
Public purpose programs		97		164
Hazardous substance		57		38
Gas fixed cost		16		56
Energy procurement		(48)		(25)
Energy recovery bonds		(105)		(34)
Other		227		202
Total regulatory balancing accounts, net	$	708	$	849