Regulatory Assets and Liabilities (Tables)

12 Months Ended

Dec. 31, 2012

Regulatory Assets and Liabilities [Abstract]

Regulatory Assets

The components of regulatory assets shown on the consolidated balance sheets of NSP-Wisconsin at Dec. 31, 2012 and Dec. 31, 2011 are:

	See		Remaining
(Thousands of Dollars)	Notes		Amortization Period	Dec. 31, 2012				Dec. 31, 2011
Regulatory Assets				Current		Noncurrent		Current		Noncurrent
Environmental remediation costs		1, 11	Various	$	2,521	$	109,162	$	-	$	108,181
Pension and retiree medical obligations (a)		7	Various		7,328		104,426		8,197		98,045
Recoverable deferred taxeson AFUDC
recorded in plant		1	Plant lives		-		10,458		-		9,630
Losses on reacquired debt		4	Term of related debt		800		6,538		843		7,338
State commission adjustments		1	Plant lives		339		7,533		277		4,506
Contract valuation adjustments (b)		1, 9	Term of related contract		11		-		2,515		-
Conservation programs		1	Less than one year		691		-		2,301		-
Deferred income tax adjustment		1, 6	Typically plant lives		-		1,974		-		1,868
Recoverable purchased natural gas costs			Less than one year		358		-		-		-
Other			Various		-		368		-		342
Total regulatory assets				$	12,048	$	240,459	$	14,133	$	229,910

(a) Includes the non-qualified pension plan.

(b) Includes valuation adjustments on natural gas commodity purchases.

Regulatory Liabilities

The components of regulatory liabilities shown on the consolidated balance sheets of NSP-Wisconsin at Dec. 31, 2012 and Dec. 31, 2011 are:

	See		Remaining
(Thousands of Dollars)	Notes		Amortization Period	Dec. 31, 2012				Dec. 31, 2011
Regulatory Liabilities				Current		Noncurrent		Current		Noncurrent
Plant removal costs		11	Plant lives	$	-	$	113,949	$	-	$	108,850
DOE settlement		11	Less than one year		5,628		-		14,484		-
Investment tax credit deferrals		1, 6	Various		-		9,626		-		9,525
Conservation programs		1	Less than one year		73		-		-		-
Deferred electric energy costs		1	Less than one year		134		-		1,869		-
Other			Various		251		171		256		812
Total regulatory liabilities				$	6,086	$	123,746	$	16,609	$	119,187