Regulatory Assets and Liabilities (Tables)

12 Months Ended

Dec. 31, 2012

RegulatoryAssetsAndLiabilitiesDisclosureAbstract

Regulatory Assets And Liabilities Disclosure [Table Text Block]

				2012		2011
				(Thousands of Dollars)
Current regulatory assets:
	Environmental costs			$	1,300	$	2,200
	Fuel recovery				1,249		78
		Total current regulatory assets			2,549		2,278
Noncurrent regulatory assets:
	Environmental costs				739		1,117
	Grossed-up deferred taxes on equity funds used during construction				16,083		17,034
	Levelized depreciation				33,979		33,485
	Asset retirement obligations, net				9,497		7,969
		Total noncurrent regulatory assets			60,298		59,605
			Total regulatory assets	$	62,847	$	61,883
Current regulatory liabilities:
	Fuel recovery			$	-	$	3,562
Noncurrent regulatory liabilities:
	Postretirement benefits				17,395		17,386
			Total regulatory liabilities	$	17,395	$	20,948