Borrowings and Other Financing Instruments (Tables)

3 Months Ended

Mar. 31, 2013

Borrowings and Other Financing Instruments [Abstract]

Committed Credit Facility Available

At March 31, 2013, NSP-Wisconsin had the following committed credit facility available (in millions of dollars):

Credit Facility(a)		Drawn (b)		Available
$	150.0	$	21.0	$	129.0

(a) Credit facility expires in July 2017.

(b) Includes outstanding commercial paper.

Commercial Paper [Member]

Borrowings and Other Financing Instruments [Abstract]

Short-Term Borrowings

Commercial Paper — NSP-Wisconsin meets its short-term liquidity requirements primarily through the issuance of commercial paper and borrowings under its credit facility. Commercial paper outstanding for NSP-Wisconsin was as follows:

(Amounts in Millions, Except Interest Rates)	Three Months Ended March 31, 2013			Twelve Months Ended Dec. 31, 2012
Borrowing limit	$	150		$	150
Amount outstandingat period end		21			39
Average amount outstanding		24			61
Maximum amount outstanding		46			116
Weighted average interest rate, computed on a daily basis		0.34	%		0.39	%
Weighted average interest rate at period end		0.33			0.40

Intercompany Borrowing Arrangement [Member]

Borrowings and Other Financing Instruments [Abstract]

Short-Term Borrowings

Other Short-Term Borrowings— The following table presents the notes payable of Clearwater Investments, Inc., a NSP-Wisconsin subsidiary, to Xcel Energy Inc.:

(Amounts in Millions, Except Interest Rates)	March 31, 2013			Dec. 31, 2012
Notes payable to affiliates	$	0.6		$	0.6
Weighted average interest rate		0.33	%		0.33	%