Borrowings and Other Financing Instruments (Tables)

12 Months Ended

Dec. 31, 2015

Borrowings and Other Financing Instruments [Abstract]

Credit Facilities

At Dec. 31, 2015, PSCo had the following committed credit facility available (in millions):

Credit Facility (a)		Drawn(b)		Available
$	700	$	18	$	682

^(a)  This credit facility matures in October 2019.

^(b)  Includes outstanding commercial paper and letters of credit.

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 PSCo were as follows:

(Amounts in Millions, Except Interest Rates)	Three Months Ended Dec. 31, 2015
Borrowing limit	$	250
Amount outstanding at period end	—
Average amount outstanding	4
Maximum amount outstanding	34
Weighted average interest rate, computed on a daily basis	0.36		%
Weighted average interest rate at period end	N/A

(Amounts in Millions, Except Interest Rates)	Twelve Months Ended Dec. 31, 2015			Twelve Months Ended Dec. 31, 2014			Twelve Months Ended Dec. 31, 2013
Borrowing limit	$	250		$	250		$	250
Amount outstanding at period end	—			—			—
Average amount outstanding	1			4			—
Maximum amount outstanding	34			97			12
Weighted average interest rate, computed on a daily basis	0.41		%	0.25		%	0.36		%
Weighted average interest rate at period end	N/A			N/A			N/A

Commercial Paper

Borrowings and Other Financing Instruments [Abstract]

Short-Term Borrowings

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

(Amounts in Millions, Except Interest Rates)	Three Months Ended Dec. 31, 2014
Borrowing limit	$	700
Amount outstanding at period end	14
Average amount outstanding	14
Maximum amount outstanding	68
Weighted average interest rate, computed on a daily basis	0.50		%
Weighted average interest rate at period end	0.60

(Amounts in Millions, Except Interest Rates)	Twelve Months Ended Dec. 31, 2015			Twelve Months Ended Dec. 31, 2014			Twelve Months Ended Dec. 31, 2013
Borrowing limit	$	700		$	700		$	700
Amount outstanding at period end	14			382			—
Average amount outstanding	95			167			38
Maximum amount outstanding	449			393			332
Weighted average interest rate, computed on a daily basis	0.51		%	0.31		%	0.34		%
Weighted average interest rate at period end	0.60			0.65			N/A