Benefit Plans and Other Postretirement Benefits (Tables)

12 Months Ended

Dec. 31, 2016

Benefit Plans and Other Postretirement Benefits [Abstract]

Projected Benefit Payments for the Pension and Postretirement Benefit Plans

The following table lists Xcel Energy’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
2017	$	276,123	$	49,245	$	2,245	$	47,000
2018	260,252		48,322		2,371		45,951
2019	266,823		47,497		2,485		45,012
2020	270,677		47,640		2,575		45,065
2021	270,119		46,865		2,672		44,193
2022-2026	1,321,308		215,956		14,750		201,206

Contributions to Multiemployer Plans

There were no other significant changes to the nature or magnitude of the participation of NSP-Minnesota and NSP-Wisconsin in multiemployer plans for the years presented:

(Thousands of Dollars)	2016		2015		2014
Multiemployer pension contributions:
NSP-Minnesota	$	13,843	$	17,223	$	20,254
NSP-Wisconsin	707		944		156
Total	$	14,550	$	18,167	$	20,410
Multiemployer other postretirement benefit contributions:
NSP-Minnesota	$	86	$	135	$	273
Total	$	86	$	135	$	273

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 Xcel Energy at Dec. 31 for the upcoming year:

	2016		2015
Domestic and international equity securities	38	%	39	%
Long-duration fixed income and interest rate swap securities	27		27
Short-to-intermediate fixed income securities	16		13
Alternative investments	17		19
Cash	2		2
Total	100	%	100	%

The following tables present, for each of the fair value hierarchy levels, Xcel Energy’s pension plan assets that are measured at fair value as of Dec. 31, 2016 and 2015:

	Dec. 31, 2016
(Thousands of Dollars)	Level 1		Level 2		Level 3		Investments Measured at NAV (a)		Total
Cash equivalents	$	112,515	$	—	$	—	$	—	$	112,515
Commingled funds:
U.S. equity funds	—		—		—		490,919		490,919
Non U.S. equity funds	—		—		—		368,866		368,866
U.S. corporate bond funds	—		—		—		268,017		268,017
Emerging market equity funds	—		—		—		194,495		194,495
Emerging market debt funds	—		—		—		163,586		163,586
Commodity funds	—		—		—		21,275		21,275
Private equity investments	—		—		—		100,877		100,877
Real estate	—		—		—		183,608		183,608
Other commingled funds	—		—		—		210,252		210,252
Debt securities:
Government securities	—		363,386		—		—		363,386
U.S. corporate bonds	—		238,077		—		—		238,077
Non U.S. corporate bonds	—		38,218		—		—		38,218
Mortgage-backed securities	—		6,119		—		—		6,119
Asset-backed securities	—		2,898		—		—		2,898
Equity securities:
U.S. equities	89,467		—		—		—		89,467
Other	—		3,238		—		—		3,238
Total	$	201,982	$	651,936	$	—	$	2,001,895	$	2,855,813

^(a)  Based on the requirements of ASU No. 2015-07, investments measured at fair value using a NAV methodology have not been classified in the fair value hierarchy. See Note 2 for further information on the adoption of ASU No. 2015-07.

	Dec. 31, 2015
(Thousands of Dollars)	Level 1		Level 2		Level 3		Investments Measured at NAV (a)		Total
Cash equivalents	$	178,884	$	—	$	—	$	—	$	178,884
Derivatives	—		2,850		—		—		2,850
Commingled funds:
U.S. equity funds	—		—		—		392,738		392,738
Non U.S. equity funds	—		—		—		377,334		377,334
U.S. corporate bond funds	—		—		—		237,370		237,370
Emerging market equity funds	—		—		—		172,116		172,116
Emerging market debt funds	—		—		—		166,222		166,222
Commodity funds	—		—		—		52,132		52,132
Private equity investments	—		—		—		126,396		126,396
Real estate	—		—		—		200,835		200,835
Other commingled funds	—		—		—		216,254		216,254
Debt securities:
Government securities	—		412,932		—		—		412,932
U.S. corporate bonds	—		213,972		—		—		213,972
Non U.S. corporate bonds	—		34,467		—		—		34,467
Asset-backed securities	—		2,446		—		—		2,446
Equity securities:
U.S. equities	93,831		—		—		—		93,831
Other	—		3,001		—		—		3,001
Total	$	272,715	$	669,668	$	—	$	1,941,397	$	2,883,780

^(a)  Based on the requirements of ASU No. 2015-07, investments measured at fair value using a NAV methodology have not been classified in the fair value hierarchy. See Note 2 for further information on the adoption of ASU No. 2015-07.

Change in Projected Benefit Obligation

A comparison of the actuarially computed pension benefit obligation and plan assets for Xcel Energy is presented in the following table:

(Thousands of Dollars)	2016			2015
Accumulated Benefit Obligation at Dec. 31	$	3,488,758		$	3,368,239
Change in Projected Benefit Obligation:
Obligation at Jan. 1	$	3,567,927		$	3,746,752
Service cost	91,739			99,311
Interest cost	160,102			148,524
Plan amendments	1,922			—
Actuarial loss (gain)	185,469			(169,678		)
Benefit payments	(325,541		)	(256,982		)
Obligation at Dec. 31	$	3,681,618		$	3,567,927

Change in Fair Value of Plan Assets

(Thousands of Dollars)	2016			2015
Change in Fair Value of Plan Assets:
Fair value of plan assets at Jan. 1	$	2,883,780		$	3,083,771
Actual return (loss) on plan assets	172,359			(33,102		)
Employer contributions	125,215			90,093
Benefit payments	(325,541		)	(256,982		)
Fair value of plan assets at Dec. 31	$	2,855,813		$	2,883,780

Funded Status of Plans

(Thousands of Dollars)	2016			2015
Funded Status of Plans at Dec. 31:
Funded status (a)	$	(825,805	)	$	(684,147	)

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

Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost

(Thousands of Dollars)	2016			2015
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost:
Net loss	$	1,835,966		$	1,710,097
Prior service credit	(5,232		)	(9,073		)
Total	$	1,830,734		$	1,701,024

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)	2016		2015
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	$	101,426	$	105,426
Noncurrent regulatory assets	1,649,482		1,520,975
Deferred income taxes	31,032		29,002
Net-of-tax accumulated OCI	48,794		45,621
Total	$	1,830,734	$	1,701,024

Schedule of Assumptions Used

	2016		2015		2014
Significant Assumptions Used to Measure Costs:
Discount rate	4.66	%	4.11	%	4.75	%
Expected average long-term increase in compensation level	4.00		3.75		3.75
Expected average long-term rate of return on assets	6.87		7.09		7.05

Measurement date Dec. 31, 2016 Dec. 31, 2015

	2016		2015
Significant Assumptions Used to Measure Benefit Obligations:
Discount rate for year-end valuation	4.13	%	4.66	%
Expected average long-term increase in compensation level	3.75		4.00
Mortality table	RP-2014		RP-2014

Components of Net Periodic Benefit Costs

The components of Xcel Energy’s net periodic pension cost were:

(Thousands of Dollars)	2016			2015			2014
Service cost	$	91,739		$	99,311		$	88,342
Interest cost	160,102			148,524			156,619
Expected return on plan assets	(210,299		)	(213,890		)	(207,205		)
Amortization of prior service credit	(1,919		)	(1,805		)	(1,746		)
Amortization of net loss	97,539			125,152			116,762
Net periodic pension cost	137,162			157,292			152,772
Costs not recognized due to effects of regulation	(15,459		)	(29,633		)	(26,315		)
Net benefit cost recognized for financial reporting	$	121,703		$	127,659		$	126,457

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 at Dec. 31 for the upcoming year:

	2016		2015
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, Xcel Energy’s postretirement benefit plan assets that are measured at fair value as of Dec. 31, 2016 and 2015:

	Dec. 31, 2016
(Thousands of Dollars)	Level 1		Level 2		Level 3		Investments Measured at NAV (a)		Total
Cash equivalents	$	20,545	$	—	$	—	$	—	$	20,545
Insurance contracts	—		47,233		—		—		47,233
Commingled funds:
U.S. equity funds	—		—		—		54,440		54,440
U.S fixed income funds	—		—		—		27,109		27,109
Emerging market debt funds	—		—		—		30,431		30,431
Other commingled funds	—		—		—		54,957		54,957
Debt securities:
Government securities	—		37,745		—		—		37,745
U.S. corporate bonds	—		62,317		—		—		62,317
Non U.S. corporate bonds	—		17,281		—		—		17,281
Asset-backed securities	—		18,922		—		—		18,922
Mortgage-backed securities	—		28,717		—		—		28,717
Equity securities:
Non U.S. equities	40,960		—		—		—		40,960
Other	—		1,448		—		—		1,448
Total	$	61,505	$	213,663	$	—	$	166,937	$	442,105

^(a)  Based on the requirements of ASU No. 2015-07, investments measured at fair value using a NAV methodology have not been classified in the fair value hierarchy. See Note 2 for further information on the adoption of ASU No. 2015-07.

	Dec. 31, 2015
(Thousands of Dollars)	Level 1		Level 2			Level 3		Investments Measured at NAV (a)		Total
Cash equivalents	$	19,638	$	—		$	—	$	—	$	19,638
Insurance contracts	—		47,205			—		—		47,205
Commingled funds:
U.S. equity funds	—		—			—		38,202		38,202
Non U.S. equity funds	—		—			—		33,596		33,596
U.S fixed income funds	—		—			—		24,248		24,248
Emerging market equity funds	—		—			—		11,096		11,096
Emerging market debt funds	—		—			—		35,667		35,667
Other commingled funds	—		—			—		61,973		61,973
Debt securities:
Government securities	—		39,241			—		—		39,241
U.S. corporate bonds	—		59,879			—		—		59,879
Non U.S. corporate bonds	—		12,997			—		—		12,997
Asset-backed securities	—		28,691			—		—		28,691
Mortgage-backed securities	—		35,612			—		—		35,612
Other	—		(412		)	—		—		(412		)
Total	$	19,638	$	223,213		$	—	$	204,782	$	447,633

^(a)  Based on the requirements of ASU No. 2015-07, investments measured at fair value using a NAV methodology have not been classified in the fair value hierarchy. See Note 2 for further information on the adoption of ASU No. 2015-07.

Change in Projected Benefit Obligation

A comparison of the actuarially computed benefit obligation and plan assets for Xcel Energy is presented in the following table:

(Thousands of Dollars)	2016			2015
Change in Projected Benefit Obligation:
Obligation at Jan. 1	$	584,267		$	642,869
Service cost	1,727			2,116
Interest cost	26,107			25,297
Medicare subsidy reimbursements	2,058			1,958
Plan participants’ contributions	6,896			6,718
Actuarial loss (gain)	32,954			(45,793		)
Benefit payments	(50,925		)	(48,898		)
Obligation at Dec. 31	$	603,084		$	584,267

Change in Fair Value of Plan Assets

(Thousands of Dollars)	2016			2015
Change in Fair Value of Plan Assets:
Fair value of plan assets at Jan. 1	$	447,633		$	475,058
Actual return (loss) on plan assets	20,555			(3,570		)
Plan participants’ contributions	6,896			6,718
Employer contributions	17,946			18,325
Benefit payments	(50,925		)	(48,898		)
Fair value of plan assets at Dec. 31	$	442,105		$	447,633

Funded Status of Plans

(Thousands of Dollars)	2016			2015
Funded Status of Plans at Dec. 31:
Funded status	$	(160,979	)	$	(136,634	)
Noncurrent assets	437			1,820
Current liabilities	(6,395		)	(7,495		)
Noncurrent liabilities	(155,021		)	(130,959		)
Net postretirement amounts recognized on consolidated balance sheets	$	(160,979	)	$	(136,634	)

Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost

(Thousands of Dollars)	2016			2015
Amounts Not Yet Recognized as Components of Net Periodic Benefit Cost:
Net loss	$	136,391		$	103,039
Prior service credit	(54,239		)	(64,925		)
Total	$	82,152		$	38,114

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)	2016			2015
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	$	247		$	352
Noncurrent regulatory assets	90,990			50,135
Current regulatory liabilities	(1,004		)	(985		)
Noncurrent regulatory liabilities	(14,221		)	(16,916		)
Deferred income taxes	2,387			2,148
Net-of-tax accumulated OCI	3,753			3,380
Total	$	82,152		$	38,114

Schedule of Assumptions Used

Measurement date Dec. 31, 2016 Dec. 31, 2015

	2016		2015
Significant Assumptions Used to Measure Benefit Obligations:
Discount rate for year-end valuation	4.13	%	4.65	%
Mortality table	RP 2014		RP 2014
Health care costs trend rate — initial	5.50	%	6.00	%

	2016		2015		2014
Significant Assumptions Used to Measure Costs:
Discount rate	4.65	%	4.08	%	4.82	%
Expected average long-term rate of return on assets	5.80		5.80		7.17

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 Xcel Energy:

	One-Percentage Point
(Thousands of Dollars)	Increase		Decrease
APBO	$	57,329	$	(48,831	)
Service and interest components	2,926		(2,477		)

Components of Net Periodic Benefit Costs

The components of Xcel Energy’s net periodic postretirement benefit costs were:

(Thousands of Dollars)	2016			2015			2014
Service cost	$	1,727		$	2,116		$	3,457
Interest cost	26,107			25,297			34,028
Expected return on plan assets	(24,995		)	(26,600		)	(33,954		)
Amortization of prior service credit	(10,686		)	(10,686		)	(10,688		)
Amortization of net loss	4,042			5,404			11,740
Net periodic postretirement benefit (credit) cost	$	(3,805	)	$	(4,469	)	$	4,583