Benefit Plans and Other Postretirement Benefits (Tables)

12 Months Ended

Dec. 31, 2014

Benefit Plans and Other Postretirement Benefits [Abstract]

Projected Benefit Payments for the Pension and Postretirement Benefit Plans

The following table lists PSCo’s projected benefit payments for the pension and postretirement benefit plans:

(Thousands of Dollars)	Projected Pension Benefit Payments		Gross Projected Postretirement Health Care Benefit Payments		Expected Medicare Part D Subsidies		Net Projected Postretirement Health Care Benefit Payments
2015	$	74,237	$	32,300	$	2,532	$	29,768
2016	77,804		32,991		2,692		30,299
2017	77,126		33,328		2,863		30,465
2018	80,003		34,146		3,033		31,113
2019	82,472		34,053		3,192		30,861
2020-2024	423,835		165,560		18,053		147,507

Pension Plans

Benefit Plans and Other Postretirement Benefits [Abstract]

Target Asset Allocations and Plan Assets Measured at Fair Value

The following table presents the target pension asset allocations for PSCo at Dec. 31 for the upcoming year:

	2014		2013
Domestic and international equity securities	32	%	29	%
Long-duration fixed income and interest rate swap securities	35		36
Short-to-intermediate term fixed income securities	12		14
Alternative investments	18		19
Cash	3		2
Total	100	%	100	%

The following tables present, for each of the fair value hierarchy levels, PSCo’s pension plan assets that are measured at fair value as of Dec. 31, 2014 and 2013:

	Dec. 31, 2014
(Thousands of Dollars)	Level 1		Level 2			Level 3		Total
Cash equivalents	$	82,486	$	—		$	—	$	82,486
Derivatives	—		508			—		508
Government securities	—		180,912			—		180,912
Corporate bonds	—		115,593			—		115,593
Asset-backed securities	—		1,360			—		1,360
Mortgage-backed securities	—		3,997			—		3,997
Common stock	37,067		—			—		37,067
Private equity investments	—		—			50,210		50,210
Commingled funds	—		629,439			—		629,439
Real estate	—		—			18,410		18,410
Securities lending collateral obligation and other	—		(16,117		)	—		(16,117		)
Total	$	119,553	$	915,692		$	68,620	$	1,103,865

	Dec. 31, 2013
(Thousands of Dollars)	Level 1		Level 2		Level 3		Total
Cash equivalents	$	42,721	$	—	$	—	$	42,721
Derivatives	—		14,755		—		14,755
Government securities	—		125,891		—		125,891
Corporate bonds	—		183,078		—		183,078
Asset-backed securities	—		2,356		—		2,356
Mortgage-backed securities	—		5,267		—		5,267
Common stock	34,742		—		—		34,742
Private equity investments	—		—		49,022		49,022
Commingled funds	—		582,722		—		582,722
Real estate	—		—		15,556		15,556
Securities lending collateral obligation and other	—		10,947		—		10,947
Total	$	77,463	$	925,016	$	64,578	$	1,067,057

Changes in Level 3 Plan Assets

The following tables present the changes in PSCo’s Level 3 pension plan assets for the years ended Dec. 31, 2014, 2013 and 2012:

(Thousands of Dollars)	Jan. 1, 2014		Net Realized Gains (Losses)		Net Unrealized Gains (Losses)			Purchases, Issuances and Settlements, Net			Transfers Out of Level 3		Dec. 31, 2014
Private equity investments	$	49,022	$	8,495	$	(4,299	)	$	(3,008	)	$	—	$	50,210
Real estate	15,556		1,180		(302		)	1,976			—		18,410
Total	$	64,578	$	9,675	$	(4,601	)	$	(1,032	)	$	—	$	68,620

(Thousands of Dollars)	Jan. 1, 2013		Net Realized Gains (Losses)			Net Unrealized Gains (Losses)			Purchases, Issuances and Settlements, Net			Transfers Out of Level 3 (a)			Dec. 31, 2013
Asset-backed securities	$	4,604	$	—		$	—		$	—		$	(4,604	)	$	—
Mortgage-backed securities	12,058		—			—			—			(12,058		)	—
Private equity investments	47,056		7,074			(4,027		)	(1,081		)	—			49,022
Real estate	19,273		(870		)	3,769			3,048			(9,664		)	15,556
Total	$	82,991	$	6,204		$	(258	)	$	1,967		$	(26,326	)	$	64,578

^(a)  Transfers out of Level 3 into Level 2 were principally due to diminished use of unobservable inputs that were previously significant to these fair value measurements and were subsequently sold during 2013.

(Thousands of Dollars)	Jan. 1, 2012		Net Realized Gains (Losses)		Net Unrealized Gains (Losses)			Purchases, Issuances, and Settlements, Net			Transfers Out of Level 3		Dec. 31, 2012
Asset-backed securities	$	9,824	$	1,175	$	(1,597	)	$	(4,798	)	$	—	$	4,604
Mortgage-backed securities	23,614		550		(625		)	(11,481		)	—		12,058
Private equity investments	49,489		5,206		(7,001		)	(638		)	—		47,056
Real estate	11,230		6		1,843			6,194			—		19,273
Total	$	94,157	$	6,937	$	(7,380	)	$	(10,723	)	$	—	$	82,991

Change in Projected Benefit Obligation

Benefit Obligations — A comparison of the actuarially computed pension benefit obligation and plan assets for PSCo is presented in the following table:

(Thousands of Dollars)	2014			2013
Accumulated Benefit Obligation at Dec. 31	$	1,249,739		$	1,134,184
Change in Projected Benefit Obligation:
Obligation at Jan. 1	$	1,152,836		$	1,194,371
Service cost	23,939			25,206
Interest cost	53,277			46,160
Transfer (to) from other plan	(13,404		)	11,306
Actuarial loss (gain)	133,215			(49,384		)
Benefit payments	(71,906		)	(74,823		)
Obligation at Dec. 31	$	1,277,957		$	1,152,836

Change in Fair Value of Plan Assets

(Thousands of Dollars)	2014			2013
Change in Fair Value of Plan Assets:
Fair value of plan assets at Jan. 1	$	1,067,057		$	1,055,308
Actual return on plan assets	84,871			30,684
Employer contributions	35,156			44,582
Transfer (to) from other plan	(11,313		)	11,306
Benefit payments	(71,906		)	(74,823		)
Fair value of plan assets at Dec. 31	$	1,103,865		$	1,067,057

Funded Status of Plans

(Thousands of Dollars)	2014			2013
Funded Status of Plans at Dec. 31:
Funded status (a)	$	(174,092	)	$	(85,779	)

^(a)  Amounts are recognized in noncurrent liabilities on PSCo’s consolidated balance sheets.

Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost

(Thousands of Dollars)	2014			2013
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost:
Net loss	$	530,674		$	450,202
Prior service credit	(18,708		)	(21,800		)
Total	$	511,966		$	428,402

Amounts Not Yet Recognized as Components of Net Periodic Benefit Costs Recorded on the Balance Sheet Based Upon Expected Recovery in Rates

(Thousands of Dollars)	2014		2013
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost Have Been Recorded as Follows Based Upon Expected Recovery in Rates:
Current regulatory assets	$	31,774	$	36,271
Noncurrent regulatory assets	480,192		392,131
Total	$	511,966	$	428,402

Schedule of Assumptions Used

	2014		2013		2012
Significant Assumptions Used to Measure Costs:
Discount rate	4.75	%	4.00	%	5.00	%
Expected average long-term increase in compensation level	3.75		3.75		4.00
Expected average long-term rate of return on assets	6.81		6.47		6.65

Measurement date Dec. 31, 2014 Dec. 31, 2013

	2014		2013
Significant Assumptions Used to Measure Benefit Obligations:
Discount rate for year-end valuation	4.11	%	4.75	%
Expected average long-term increase in compensation level	3.75		3.75
Mortality table	RP 2014		RP 2000

Components of Net Periodic Benefit Costs

Benefit Costs —The components of PSCo’s net periodic pension cost were:

(Thousands of Dollars)	2014			2013			2012
Service cost	$	23,939		$	25,206		$	22,719
Interest cost	53,277			46,160			51,192
Expected return on plan assets	(70,709		)	(63,821		)	(65,302		)
Amortization of prior service (credit) cost	(3,092		)	(1,064		)	228
Amortization of net loss	33,892			43,418			34,332
Net periodic pension cost	$	37,307		$	49,899		$	43,169

Postretirement Benefit Plan

Benefit Plans and Other Postretirement Benefits [Abstract]

Target Asset Allocations and Plan Assets Measured at Fair Value

The following table presents the target postretirement asset allocations for Xcel Energy Inc. and PSCo at Dec. 31 for the upcoming year:

	2014		2013
Domestic and international equity securities	25	%	41	%
Short-to-intermediate fixed income securities	57		40
Alternative investments	13		13
Cash	5		6
Total	100	%	100	%

The following tables present, for each of the fair value hierarchy levels, PSCo’s proportionate allocation of the total postretirement benefit plan assets that are measured at fair value as of Dec. 31, 2014 and 2013:

	Dec. 31, 2014
(Thousands of Dollars)	Level 1		Level 2			Level 3		Total
Cash equivalents (a)	$	23,566	$	—		$	—	$	23,566
Derivatives	—		166			—		166
Government securities	—		43,494			—		43,494
Insurance contracts	—		45,075			—		45,075
Corporate bonds	—		48,527			—		48,527
Asset-backed securities	—		3,240			—		3,240
Mortgage-backed securities	—		10,071			—		10,071
Commingled funds	—		252,790			—		252,790
Other	—		(1,647		)	—		(1,647		)
Total	$	23,566	$	401,716		$	—	$	425,282

	Dec. 31, 2013
(Thousands of Dollars)	Level 1		Level 2			Level 3		Total
Cash equivalents (a)	$	18,202	$	—		$	—	$	18,202
Derivatives	—		(370		)	—		(370		)
Government securities	—		52,028			—		52,028
Insurance contracts	—		47,029			—		47,029
Corporate bonds	—		46,186			—		46,186
Asset-backed securities	—		2,991			—		2,991
Mortgage-backed securities	—		21,593			—		21,593
Commingled funds	—		265,620			—		265,620
Other	—		(15,086		)	—		(15,086		)
Total	$	18,202	$	419,991		$	—	$	438,193

^(a)  Includes restricted cash of $0.9 million and $0.6 million at Dec. 31, 2014 and 2013, respectively.

Changes in Level 3 Plan Assets

For the year ended Dec. 31, 2014 there were no assets transferred in or out of Level 3. The following tables present the changes in PSCo’s Level 3 postretirement benefit plan assets for the years ended Dec. 31, 2013 and 2012:

(Thousands of Dollars)	Jan. 1, 2013		Net Realized Gains (Losses)		Net Unrealized Gains (Losses)		Purchases, Issuances and Settlements, Net		Transfers Out of Level 3 (a)			Dec. 31, 2013
Asset-backed securities	$	670	$	—	$	—	$	—	$	(670	)	$	—
Mortgage-backed securities	35,394		—		—		—		(35,394		)	—
Total	$	36,064	$	—	$	—	$	—	$	(36,064	)	$	—

^(a)  Transfers out of Level 3 into Level 2 were principally due to diminished use of unobservable inputs that were previously significant to these fair value measurements and were subsequently sold during 2013.

(Thousands of Dollars)	Jan. 1, 2012		Net Realized Gains (Losses)			Net Unrealized Gains (Losses)			Purchases, Issuances, and Settlements, Net			Transfers Out of Level 3		Dec. 31, 2012
Asset-backed securities	$	6,941	$	(293	)	$	1,669		$	(7,647	)	$	—	$	670
Mortgage-backed securities	24,038		(641		)	3,429			8,568			—		35,394
Private equity investments	479		—			(65		)	(414		)	—		—
Real estate	144		—			35			(179		)	—		—
Total	$	31,602	$	(934	)	$	5,068		$	328		$	—	$	36,064

Change in Projected Benefit Obligation

Benefit Obligations — A comparison of the actuarially computed benefit obligation and plan assets for PSCo is presented in the following table:

(Thousands of Dollars)	2014			2013
Change in Projected Benefit Obligation:
Obligation at Jan. 1	$	508,971		$	599,831
Service cost	1,915			2,564
Interest cost	23,704			22,210
Medicare subsidy reimbursements	1,753			923
Plan amendments	—			(14,571		)
Plan participants’ contributions	4,625			4,589
Actuarial gain	(63,130		)	(76,889		)
Benefit payments	(34,085		)	(29,686		)
Obligation at Dec. 31	$	443,753		$	508,971

Change in Fair Value of Plan Assets

(Thousands of Dollars)	2014			2013
Change in Fair Value of Plan Assets:
Fair value of plan assets at Jan. 1	$	438,193		$	425,917
Actual return on plan assets	11,060			30,390
Plan participants’ contributions	4,625			4,589
Employer contributions	5,489			6,983
Benefit payments	(34,085		)	(29,686		)
Fair value of plan assets at Dec. 31	$	425,282		$	438,193

Funded Status of Plans

(Thousands of Dollars)	2014			2013
Funded Status at Dec. 31:
Funded status (a)	$	(18,471	)	$	(70,778	)

^(a)  Amounts are recognized in noncurrent liabilities on PSCo’s consolidated balance sheets.

Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost

(Thousands of Dollars)	2014			2013
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost:
Net loss	$	56,823		$	107,232
Prior service credit	(40,189		)	(46,436		)
Total	$	16,634		$	60,796

Amounts Not Yet Recognized as Components of Net Periodic Benefit Costs Recorded on the Balance Sheet Based Upon Expected Recovery in Rates

(Thousands of Dollars)	2014		2013
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost Have Been Recorded as Follows Based Upon Expected Recovery in Rates:
Current regulatory assets	$	—	$	8,798
Noncurrent regulatory assets	16,634		51,998
Total	$	16,634	$	60,796

Schedule of Assumptions Used

	2014		2013		2012
Significant Assumptions Used to Measure Costs:
Discount rate	4.82	%	4.10	%	5.00	%
Expected average long-term rate of return on assets	7.18		7.11		6.75

Measurement date Dec. 31, 2014 Dec. 31, 2013

	2014		2013
Significant Assumptions Used to Measure Benefit Obligations:
Discount rate for year-end valuation	4.08	%	4.82	%
Mortality table	RP 2014		RP 2000
Health care costs trend rate — initial	6.50	%	7.00	%

Effects of One-Percent Change in Assumed Health Care Cost Trend Rate

A one-percent change in the assumed health care cost trend rate would have the following effects on PSCo:

	One-Percentage Point
(Thousands of Dollars)	Increase		Decrease
APBO	$	45,581	$	(38,371	)
Service and interest components	3,028		(2,488		)

Components of Net Periodic Benefit Costs

Benefit Costs — The components of PSCo’s net periodic postretirement benefit costs were:

(Thousands of Dollars)	2014			2013			2012
Service cost	$	1,915		$	2,564		$	2,825
Interest cost	23,704			22,210			24,527
Expected return on plan assets	(30,214		)	(29,227		)	(25,056		)
Amortization of transition obligation	—			785			11,004
Amortization of prior service credit	(6,247		)	(7,666		)	(5,150		)
Amortization of net loss	6,434			13,699			10,930
Net periodic postretirement benefit (credit) cost	(4,408		)	2,365			19,080
Additional cost recognized due to effects of regulation	—			—			3,891
Net benefit (credit) cost recognized for financial reporting	$	(4,408	)	$	2,365		$	22,971