Benefit Plans and Other Postretirement Benefits (Tables)

12 Months Ended

Dec. 31, 2015

Benefit Plans and Other Postretirement Benefits [Abstract]

Projected Benefit Payments for the Pension and Postretirement Benefit Plans

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

(Thousands of Dollars)	ProjectedPension BenefitPayments		Gross Projected Postretirement Health Care BenefitPayments		ExpectedMedicare Part DSubsidies		Net Projected Postretirement Health Care BenefitPayments
2016	$	11,278	$	1,443	$	8	$	1,435
2017	11,893		1,324		6		1,318
2018	11,746		1,278		5		1,273
2019	12,920		1,244		4		1,240
2020	13,404		1,203		4		1,199
2021-2025	62,859		5,200		19		5,181

Contributions to Multiemployer Plans

Contributions to multiemployer plans were as follows for the years ended Dec. 31, 2015, 2014 and 2013. There were no significant changes to the nature or magnitude of the participation of NSP-Wisconsin in multiemployer plans for the years presented:

(Thousands of Dollars)	2015		2014		2013
Multiemployer plan contributions:
Pension	$	944	$	156	$	130
Total	$	944	$	156	$	130

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 NSP-Wisconsin at Dec. 31 for the upcoming year:

	2015		2014
Domestic and international equity securities	41	%	39	%
Long-duration fixed income and interest rate swap securities	23		23
Short-to-intermediate fixed income securities	14		14
Alternative investments	20		22
Cash	2		2
Total	100	%	100	%

The following tables present, for each of the fair value hierarchy levels, NSP-Wisconsin’s pension plan assets that are measured at fair value as of Dec. 31, 2015 and 2014:

	Dec. 31, 2015
(Thousands of Dollars)	Level 1		Level 2		Level 3		Total
Cash equivalents	$	6,005	$	—	$	—	$	6,005
Derivatives	—		89		—		89
Government securities	—		13,048		—		13,048
Corporate bonds	—		10,454		—		10,454
Asset-backed securities	—		101		—		101
Common stock	4,213		—		—		4,213
Private equity investments	—		—		5,967		5,967
Commingled funds	—		76,817		—		76,817
Real estate	—		—		2,413		2,413
Other	—		207		—		207
Total	$	10,218	$	100,716	$	8,380	$	119,314

	Dec. 31, 2014
(Thousands of Dollars)	Level 1		Level 2			Level 3		Total
Cash equivalents	$	7,910	$	—		$	—	$	7,910
Derivatives	—		28			—		28
Government securities	—		16,084			—		16,084
Corporate bonds	—		13,231			—		13,231
Asset-backed securities	—		162			—		162
Mortgage-backed securities	—		475			—		475
Common stock	4,424		—			—		4,424
Private equity investments	—		—			7,078		7,078
Commingled funds	—		81,806			—		81,806
Real estate	—		—			2,510		2,510
Securities lending collateral obligation and other	—		(995		)	—		(995		)
Total	$	12,334	$	110,791		$	9,588	$	132,713

Changes in Level 3 Plan Assets

The following tables present the changes in NSP-Wisconsin’s Level 3 pension plan assets for the years ended Dec. 31, 2015, 2014 and 2013:

(Thousands of Dollars)	Jan. 1, 2015		Net Realized Gains (Losses)		Net Unrealized Gains (Losses)			Purchases, Issuances and Settlements, Net			Transfer Out of Level 3		Dec. 31, 2015
Private equity investments	$	7,078	$	1,326	$	(1,836	)	$	(601	)	$	—	$	5,967
Real estate	2,510		334		(556		)	125			—		2,413
Total	$	9,588	$	1,660	$	(2,392	)	$	(476	)	$	—	$	8,380

(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	$	7,502	$	1,197	$	(1,197	)	$	(424	)	$	—	$	7,078
Real estate	2,299		166		(234		)	279			—		2,510
Total	$	9,801	$	1,363	$	(1,431	)	$	(145	)	$	—	$	9,588

(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	$	749	$	—		$	—		$	—		$	(749	)	$	—
Mortgage-backed securities	2,128		—			—			—			(2,128		)	—
Private equity investments	8,545		1,083			(1,960		)	(166		)	—			7,502
Real estate	3,472		(129		)	247			450			(1,741		)	2,299
Total	$	14,894	$	954		$	(1,713	)	$	284		$	(4,618	)	$	9,801

Change in Projected Benefit Obligation

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

(Thousands of Dollars)	2015			2014
Accumulated Benefit Obligation at Dec. 31	$	140,917		$	153,590
Change in Projected Benefit Obligation:
Obligation at Jan. 1	$	165,669		$	163,930
Service cost	4,759			4,527
Interest cost	6,520			7,257
Actuarial (gain) loss	(11,159		)	9,126
Benefit payments	(13,244		)	(19,171		)
Obligation at Dec. 31	$	152,545		$	165,669

Change in Fair Value of Plan Assets

(Thousands of Dollars)	2015			2014
Change in Fair Value of Plan Assets:
Fair value of plan assets at Jan. 1	$	132,713		$	136,935
Actual (loss) return on plan assets	(5,087		)	6,916
Employer contributions	4,932			8,033
Benefit payments	(13,244		)	(19,171		)
Fair value of plan assets at Dec. 31	$	119,314		$	132,713

Funded Status of Plans

(Thousands of Dollars)	2015			2014
Funded Status of Plans at Dec. 31:
Funded status (a)	$	(33,231	)	$	(32,956	)

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

Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost

(Thousands of Dollars)	2015		2014
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost:
Net loss	$	86,614	$	90,007
Prior service cost	556		667
Total	$	87,170	$	90,674

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)	2015		2014
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	$	6,300	$	6,728
Noncurrent regulatory assets	80,870		83,946
Total	$	87,170	$	90,674

Schedule of Assumptions Used

Measurement date Dec. 31, 2015 Dec. 31, 2014

	2015		2014
Significant Assumptions Used to Measure Benefit Obligations:
Discount rate for year-end valuation	4.66	%	4.11	%
Expected average long-term increase in compensation level	4.00		3.75
Mortality table	RP 2014		RP 2014

	2015		2014		2013
Significant Assumptions Used to Measure Costs:
Discount rate	4.11	%	4.75	%	4.00	%
Expected average long-term increase in compensation level	3.75		3.75		3.75
Expected average long-term rate of return on assets	7.25		7.25		7.25

Components of Net Periodic Benefit Costs

Benefit Costs —The components of NSP-Wisconsin’s net periodic pension cost were:

(Thousands of Dollars)	2015			2014			2013
Service cost	$	4,759		$	4,527		$	5,682
Interest cost	6,520			7,257			6,924
Expected return on plan assets	(9,483		)	(9,642		)	(9,995		)
Amortization of prior service cost	111			111			417
Amortization of net loss	6,804			6,617			7,924
Net periodic pension cost	$	8,711		$	8,870		$	10,952

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 NSP-Wisconsin at Dec. 31 for the upcoming year:

	2015		2014
Domestic and international equity securities	25	%	25	%
Short-to-intermediate fixed income securities	57		57
Alternative investments	13		13
Cash	5		5
Total	100	%	100	%

The following tables present, for each of the fair value hierarchy levels, NSP-Wisconsin’s proportionate allocation of the total postretirement benefit plan assets that are measured at fair value as of Dec. 31, 2015 and 2014:

	Dec. 31, 2015
(Thousands of Dollars)	Level 1		Level 2		Level 3		Total
Cash equivalents	$	18	$	—	$	—	$	18
Government securities	—		37		—		37
Insurance contracts	—		44		—		44
Corporate bonds	—		68		—		68
Asset-backed securities	—		27		—		27
Mortgage-backed securities	—		33		—		33
Commingled funds	—		191		—		191
Total	$	18	$	400	$	—	$	418

	Dec. 31, 2014
(Thousands of Dollars)	Level 1		Level 2			Level 3		Total
Cash equivalents	$	28	$	—		$	—	$	28
Government securities	—		52			—		52
Insurance contracts	—		54			—		54
Corporate bonds	—		59			—		59
Asset-backed securities	—		4			—		4
Mortgage-backed securities	—		12			—		12
Commingled funds	—		304			—		304
Other	—		(1		)	—		(1		)
Total	$	28	$	484		$	—	$	512

Changes in Level 3 Plan Assets

For the year ended Dec. 31, 2015 and 2014 there were no assets transferred in or out of Level 3. The following table presents the changes in NSP-Wisconsin’s Level 3 postretirement benefit plan assets for the year ended 2013:

(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	$	1	$	—	$	—	$	—	$	(1	)	$	—
Mortgage-backed securities	54		—		—		—		(54		)	—
Total	$	55	$	—	$	—	$	—	$	(55	)	$	—

Change in Projected Benefit Obligation

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

(Thousands of Dollars)	2015			2014
Change in Projected Benefit Obligation:
Obligation at Jan. 1	$	16,768		$	17,153
Service cost	29			35
Interest cost	653			791
Medicare subsidy reimbursements	13			2
Plan participants’ contributions	130			284
Actuarial gain	(1,645		)	(38		)
Benefit payments	(1,230		)	(1,459		)
Obligation at Dec. 31	$	14,718		$	16,768

Change in Fair Value of Plan Assets

(Thousands of Dollars)	2015			2014
Change in Fair Value of Plan Assets:
Fair value of plan assets at Jan. 1	$	512		$	746
Actual loss on plan assets	(12		)	(15		)
Plan participants’ contributions	130			284
Employer contributions	1,018			956
Benefit payments	(1,230		)	(1,459		)
Fair value of plan assets at Dec. 31	$	418		$	512

Funded Status of Plans

(Thousands of Dollars)	2015			2014
Funded Status of Plans at Dec. 31:
Funded status	$	(14,300	)	$	(16,256	)
Current liabilities	(1,017		)	(1,022		)
Noncurrent liabilities	(13,283		)	(15,234		)
Net postretirement amounts recognized on consolidated balance sheets	$	(14,300	)	$	(16,256	)

Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost

(Thousands of Dollars)	2015			2014
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost:
Net loss	$	8,402		$	10,461
Prior service credit	(2,485		)	(2,836		)
Total	$	5,917		$	7,625

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)	2015		2014
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	$	99	$	95
Noncurrent regulatory assets	5,818		7,530
Total	$	5,917	$	7,625

Schedule of Assumptions Used

Measurement date Dec. 31, 2015 Dec. 31, 2014

	2015		2014
Significant Assumptions Used to Measure Benefit Obligations:
Discount rate for year-end valuation	4.65	%	4.08	%
Mortality table	RP 2014		RP 2014
Health care costs trend rate — initial	6.00	%	6.50	%

	2015		2014		2013
Significant Assumptions Used to Measure Costs:
Discount rate	4.08	%	4.82	%	4.10	%
Expected average long-term rate of return on assets	5.80		7.08		7.11

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 NSP-Wisconsin:

	One-Percentage Point
(Thousands of Dollars)	Increase		Decrease
APBO	$	1,420	$	(1,208	)
Service and interest components	77		(65		)

Components of Net Periodic Benefit Costs

Benefit Costs — The components of NSP-Wisconsin’s net periodic postretirement benefit costs were:

(Thousands of Dollars)	2015			2014			2013
Service cost	$	29		$	35		$	25
Interest cost	653			791			760
Expected return on plan assets	(30		)	(52		)	(42		)
Amortization of transition obligation	—			—			1
Amortization of prior service credit	(351		)	(351		)	(351		)
Amortization of net loss	456			666			963
Net periodic postretirement benefit cost	$	757		$	1,089		$	1,356