Borrowings and Other Financing Instruments (Tables)

12 Months Ended

Dec. 31, 2016

Borrowings and Other Financing Instruments [Abstract]

Credit Facilities

At Dec. 31, 2016, PSCo had the following committed credit facility available (in millions):

Credit Facility (a)		Drawn(b)		Available
$	700	$	132	$	568

^(a)  This credit facility matures in June 2021.

^(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, 2016
Borrowing limit	$	250
Amount outstanding at period end	—
Average amount outstanding	56
Maximum amount outstanding	141
Weighted average interest rate, computed on a daily basis	0.78		%
Weighted average interest rate at period end	N/A

(Amounts in Millions, Except Interest Rates)	Twelve Months Ended Dec. 31, 2016			Twelve Months Ended Dec. 31, 2015			Twelve Months Ended Dec. 31, 2014
Borrowing limit	$	250		$	250		$	250
Amount outstanding at period end	—			—			—
Average amount outstanding	21			1			4
Maximum amount outstanding	141			34			97
Weighted average interest rate, computed on a daily basis	0.73		%	0.41		%	0.25		%
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, 2016
Borrowing limit	$	700
Amount outstanding at period end	129
Average amount outstanding	33
Maximum amount outstanding	151
Weighted average interest rate, computed on a daily basis	0.78		%
Weighted average interest rate at period end	0.95

(Amounts in Millions, Except Interest Rates)	Twelve Months Ended Dec. 31, 2016			Twelve Months Ended Dec. 31, 2015			Twelve Months Ended Dec. 31, 2014
Borrowing limit	$	700		$	700		$	700
Amount outstanding at period end	129			14			382
Average amount outstanding	24			95			167
Maximum amount outstanding	154			449			393
Weighted average interest rate, computed on a daily basis	0.70		%	0.51		%	0.31		%
Weighted average interest rate at period end	0.95			0.60			0.65