Borrowings and Other Financing Instruments (Tables)

3 Months Ended

Mar. 31, 2013

Borrowings and Other Financing Instruments [Abstract]

At March 31, 2013, SPS had the following committed credit facility available (in millions):

Credit Facility (a)				Drawn (b)				Available
$	300.0			$	16.0			$	284.0

(a)	Credit facility expires in July 2017.

(b)	Includes outstanding commercial paper.

Money Pool [Member]

Borrowings and Other Financing Instruments [Abstract]

Short-Term Borrowings

Money Pool — Xcel Energy Inc. and its utility subsidiaries have established a money pool arrangement that allows for short-term investments in and borrowings between the utility subsidiaries. Xcel Energy Inc. may make investments in the utility subsidiaries at market-based interest rates; however, the money pool arrangement does not allow the utility subsidiaries to make investments in Xcel Energy Inc. Money pool borrowings for SPS were as follows:

(Amounts in Millions, Except Interest Rates)	Three Months Ended March 31, 2013			Twelve Months Ended Dec. 31, 2012
Borrowing limit	$	100		$	100
Amount outstanding at period end		20			-
Average amount outstanding		2			10
Maximum amount outstanding		30			63
Weighted average interest rate, computed on a daily basis		0.34	%		0.33	%
Weighted average interest rate at period end		0.34			N/A

Commercial Paper [Member]

Borrowings and Other Financing Instruments [Abstract]

Short-Term Borrowings

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

(Amounts in Millions, Except Interest Rates)	Three Months Ended March 31, 2013			Twelve Months Ended Dec. 31, 2012
Borrowing limit	$	300		$	300
Amount outstanding at period end		16			9
Average amount outstanding		28			18
Maximum amount outstanding		49			106
Weighted average interest rate, computed on a daily basis		0.34	%		0.39	%
Weighted average interest rate at period end		0.34			0.36