Borrowings and Other Financing Instruments (Tables)

9 Months Ended

Sep. 30, 2013

Borrowings and Other Financing Instruments [Abstract]

Committed Credit Facility Available

At Sept. 30, 2013, SPS had the following committed credit facility available (in millions):

Credit Facility (a)		Drawn		Available
$	300.0	$	—	$	300.0

^(a)  Credit facility expires in July 2017.

Money Pool

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 Sept. 30, 2013			Twelve Months Ended Dec. 31, 2012
Borrowing limit	$	100		$	100
Amount outstanding at period end	80			—
Average amount outstanding	66			10
Maximum amount outstanding	99			63
Weighted average interest rate, computed on a daily basis	0.28		%	0.33		%
Weighted average interest rate at period end	0.26			N/A

Commercial Paper

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 Sept. 30, 2013			Twelve Months Ended Dec. 31, 2012
Borrowing limit	$	300		$	300
Amount outstanding at period end	—			9
Average amount outstanding	33			18
Maximum amount outstanding	140			106
Weighted average interest rate, computed on a daily basis	0.28		%	0.39		%
Weighted average interest rate at period end	N/A			0.36