Regulatory Assets and Liabilities

12 Months Ended

Dec. 31, 2012

Regulatory Assets and Liabilities Disclosure [Abstract]

Our primary regulator, the PSCW, considers our regulatory assets and liabilities in two categories, escrowed and deferred. In escrow accounting we expense amounts that are included in rates. If actual costs exceed or are less than the amounts that are allowed in rates, the difference in cost is escrowed on the balance sheet as a regulatory asset or regulatory liability and the escrowed balance is considered in setting future rates. Under deferred cost accounting, we defer amounts to our balance sheet based upon orders or correspondence with our regulators. These deferred costs will be considered in future rate setting proceedings. As of December 31, 2012 and 2011, we had approximately $6.6 million and $11.0 million, respectively, of net regulatory assets that were not earning a return.

In December 2012, the PSCW issued a rate order effective January 1, 2013 that, among other things, reaffirmed our accounting for the regulatory assets and liabilities identified below.

Our regulatory assets and liabilities as of December 31 consist of:



	2012		2011
	(Millions of Dollars)
Regulatory Assets
Deferred unrecognized pension costs	$	731.5	$	647.8
Deferred income tax related	176.5		121.2
Escrowed electric transmission costs	114.1		118.3
Escrowed conservation	73.5		31.5
Deferred unrecognized OPEB costs	61.6		102.9
Deferred plant related -- capital lease	66.6		73.2
Deferred environmental costs	47.4		48.5
Other, net	109.1		122.3
Total regulatory assets	$	1,380.3	$	1,265.7

Regulatory Liabilities
Deferred cost of removal obligations	$	725.0	$	728.2
Escrowed bad debt costs	81.1		69.0
Other, net	62.2		118.7
Total regulatory liabilities	$	868.3	$	915.9

Regulatory assets and liabilities that are expected to be amortized within one year are recorded as current on the balance sheet.