Regulatory assets and liabilities consist of the following (dollars in millions):



		Weighted Average Remaining Life ⁽¹⁾	As of December 31,
			2012					2011
			Current			Noncurrent		Current			Noncurrent
Regulatory assets:
	Price risk management ⁽²⁾	2 years	$	123		$	71	$	194		$	172
	Pension and other postretirement plans ⁽²⁾	⁽³⁾	—			321		—			295
	Deferred income taxes ⁽²⁾	⁽⁴⁾	—			80		—			87
	Deferred broker settlements ⁽²⁾	1 year	20			1		11			—
	Debt issuance costs ⁽²⁾	7 years	—			22		—			28
	Deferred capital projects	⁽⁵⁾	—			16		—			—
	Other ⁽⁶⁾	Various	1			13		11			12
	Total regulatory assets		$	144		$	524	$	216		$	594
Regulatory liabilities:
	Asset retirement removal costs ⁽⁷⁾	⁽⁴⁾	$	—		$	692	$	—		$	637
	Asset retirement obligations ⁽⁷⁾	⁽⁴⁾	—			39		—			36
	Power cost adjustment mechanism	1 year	6			—		—			10
	Other	Various	6			34		6			37
	Total regulatory liabilities		$	12	⁽⁸⁾	$	765	$	6	⁽⁸⁾	$	720


(1)	As of December 31, 2012.


(2)	Does not include a return on investment.


(3)	Recovery expected over the average service life of employees. For additional information, see Note 2, Summary of Significant Accounting Policies.


(4)	Recovery expected over the estimated lives of the assets.


(5)	Recovery period not yet determined.


(6)	Of the total other unamortized regulatory asset balances, a return is recorded on $15 million and $21 million as of December 31, 2012 and 2011, respectively.


(7)	Included in rate base for ratemaking purposes.


(8)	Included in Accrued expenses and other current liabilities on the consolidated balance sheets.