Pension And Other Postretirement Benefits (Tables)

12 Months Ended

Dec. 31, 2017

Defined Benefit Plan Disclosure [Line Items]

Asset Mix Policy of Funds:



	Defined Benefit Pension Plan		Postretirement Benefit Plan
Asset Category	Minimum	Maximum	Minimum	Maximum
Domestic Equities	16%	36%	0%	55%
International Equities	8%	18%	0%	25%
Fixed Income	39%	51%	20%	100%
Diversified Credit	0%	13%	0%	0%
Real Estate	0%	13%	0%	0%
Short-Term Investments	0%	10%	0%	10%

As of December 31, 2016, the asset mix and acceptable minimum and maximum ranges established by the policy for the pension and other postretirement benefit plans were as follows:

Asset Mix Policy of Funds:



	Defined Benefit Pension Plan		Postretirement Benefit Plan
Asset Category	Minimum	Maximum	Minimum	Maximum
Domestic Equities	25%	45%	35%	55%
International Equities	15%	25%	15%	25%
Fixed Income	23%	37%	20%	50%
Real Estate/Private Equity/Hedge Funds	0%	15%	0%	0%
Short-Term Investments	0%	10%	0%	10%

Pension Plan and Postretirement Plan Asset Mix at December 31, 2017 and December 31, 2016:



	Defined Benefit Pension Assets		December 31, 2017		Postretirement Benefit Plan Assets		December 31, 2017
Asset Class (in millions)	Asset Value		% of Total Assets		Asset Value		% of Total Assets
Domestic Equities	$	698.2	32.3	%	$	96.0	36.6	%
International Equities	351.0		16.2	%	39.8		15.2	%
Fixed Income	977.6		45.3	%	117.5		44.8	%
Real Estate	49.9		2.3	%	—		—
Cash/Other	83.3		3.9	%	9.2		3.4	%
Total	$	2,160.0	100.0	%	$	262.5	100.0	%

	Defined Benefit Pension Assets		December 31, 2016		Postretirement Benefit Plan Assets		December 31, 2016
Asset Class (in millions)	Asset Value		% of Total Assets		Asset Value		% of Total Assets
Domestic Equities	$	755.2	43.1	%	$	97.9	42.3	%
International Equities	339.9		19.4	%	41.8		18.0	%
Fixed Income	565.8		32.3	%	87.0		37.6	%
Real Estate/Private Equity/Hedge Funds	74.8		4.3	%	—		—
Cash/Other	15.2		0.9	%	4.7		2.1	%
Total	$	1,750.9	100.0	%	$	231.4	100.0	%

Schedule Of Fair Value and Changes In The Fair Value Of The Plan Assets

Fair Value Measurements at December 31, 2017:



(in millions)	December 31, 2017			Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Pension plan assets:
Cash	$	9.7		$	9.7	$	—	$	—
Equity securities
U.S. equities	0.3			0.3		—		—
Fixed income securities
Government	143.4			—		143.4		—
Corporate	332.6			—		332.6		—
Mutual Funds
U.S. multi-strategy	231.5			231.5		—		—
International equities	85.8			85.8		—		—
Fixed income	242.3			242.3		—		—
Private equity limited partnerships
U.S. multi-strategy ⁽¹⁾	26.7			—		—		26.7
International multi-strategy ⁽²⁾	19.1			—		—		19.1
Distressed opportunities	3.2			—		—		3.2
Real estate	49.9			—		—		49.9
Commingled funds⁽³⁾
Short-term money markets	34.1
U.S. equities	466.6
International equities	265.1
Fixed income	244.9
Pension plan assets subtotal	2,155.2			569.6		476.0		98.9
Other postretirement benefit plan assets:
Mutual funds
U.S. equities	83.8			83.8		—		—
International equities	39.8			39.8		—		—
Fixed income	117.3			117.3		—		—
Commingled funds⁽³⁾
Short-term money markets	9.4
U.S. equities	12.2
Other postretirement benefit plan assets subtotal	262.5			240.9		—		—
Due to brokers, net ⁽⁴⁾	(2.5		)
Accrued income/dividends	7.3
Total pension and other postretirement benefit plan assets	$	2,422.5		$	810.5	$	476.0	$	98.9

⁽¹⁾ This class includes limited partnerships/fund of funds that invest in a diverse portfolio of private equity strategies, including buy-outs, venture capital, growth capital, special situations and secondary markets, primarily inside the United States.

⁽²⁾ This class includes limited partnerships/fund of funds that invest in diverse portfolio of private equity strategies, including buy-outs, venture capital, growth capital, special situations and secondary markets, primarily outside the United States.

⁽³⁾This class of investments is measured at fair value using the net asset value per share and has not been classified in the fair value hierarchy.

⁽⁴⁾ This class represents pending trades with brokers.

The table below sets forth a summary of changes in the fair value of the Plan’s Level 3 assets for the year ended December 31, 2017:



	Balance at January 1, 2017		Total gains or losses (unrealized / realized)			Purchases		(Sales)			Balance at December 31, 2017
Fixed income securities
Other fixed income	$	0.1	$	(0.1	)	$	—	$	—		$	—
Private equity limited partnerships
U.S. multi-strategy	34.8		2.1			0.9		(11.1		)	26.7
International multi-strategy	24.9		1.1			0.1		(7.0		)	19.1
Distressed opportunities	4.1		0.4			—		(1.3		)	3.2
Real estate	9.2		(0.6		)	42.1		(0.8		)	49.9
Total	$	73.1	$	2.9		$	43.1	$	(20.2	)	$	98.9

The table below sets forth a summary of unfunded commitments, redemption frequency and redemption notice periods for certain investments that are measured at fair value using the net asset value per share for the year ended December 31, 2017:



(in millions)	Fair Value		Redemption Frequency	Redemption Notice Period
Commingled Funds
Short-term money markets	$	43.5	Daily	1 day
U.S. equities	478.8		Monthly	3 days
International equities	265.1		Monthly	10-30 days
Fixed income	244.9		Monthly	3 days
Total	$	1,032.3

Fair Value Measurements at December 31, 2016:



(in millions)	December 31, 2016			Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Pension plan assets:
Cash	$	1.9		$	1.9	$	—	$	—
Fixed income securities
Government	42.2			—		42.2		—
Corporate	104.1			—		104.1		—
Other fixed income	0.1			—		—		0.1
Mutual Funds
U.S. multi-strategy	283.2			283.2		—		—
International equities	116.6			116.6		—		—
Fixed income	135.6			135.6		—		—
Private equity limited partnerships
U.S. multi-strategy ⁽¹⁾	34.8			—		—		34.8
International multi-strategy ⁽²⁾	24.9			—		—		24.9
Distressed opportunities	4.1			—		—		4.1
Real Estate	9.2			—		—		9.2
Commingled funds⁽³⁾
Short-term money markets	16.6
U.S. equities	472.0
International equities	223.2
Fixed income	280.7
Pension plan assets subtotal	1,749.2			537.3		146.3		73.1
Other postretirement benefit plan assets:
Mutual funds
U.S. equities	85.4			85.4		—		—
International equities	41.8			41.8		—		—
Fixed income	86.8			86.8		—		—
Commingled funds⁽³⁾
Short-term money markets	9.5
U.S. equities	12.5
Other postretirement benefit plan assets subtotal	236.0			214.0		—		—
Due to brokers, net ⁽⁴⁾	(5.0		)
Receivables/payables	2.1
Total pension and other postretirement benefit plan assets	$	1,982.3		$	751.3	$	146.3	$	73.1

⁽²⁾ This class includes limited partnerships/fund of funds that invest in a diverse portfolio of private equity strategies, including buy-outs, venture capital, growth capital, special situations and secondary markets, primarily outside the United States.

⁽³⁾ This class of investments is measured at fair value using the net asset value per share and has not been classified in the fair value hierarchy.

⁽⁴⁾ This class represents pending trades with brokers.

The table below sets forth a summary of changes in the fair value of the Plan’s Level 3 assets for the year ended December 31, 2016:



	Balance at January 1, 2016		Total gains or losses (unrealized / realized)			Purchases		(Sales)			Balance at December 31, 2016
Fixed income securities
Other fixed income	$	0.1	$	—		$	—	$	—		$	0.1
Private equity limited partnerships
U.S. multi-strategy	46.4		2.1			0.8		(14.5		)	34.8
International multi-strategy	29.3		2.0			1.0		(7.4		)	24.9
Distress opportunities	5.9		(0.4		)	0.1		(1.5		)	4.1
Real estate	13.6		0.1			0.1		(4.6		)	9.2
Total	$	95.3	$	3.8		$	2.0	$	(28.0	)	$	73.1



(in millions)	Fair Value		Redemption Frequency	Redemption Notice Period
Commingled Funds
Short-term money markets	$	26.1	Daily	1 day
U.S. equities	484.5		Monthly	3 days
International equities	223.2		Monthly	14-30 days
Fixed income	280.7		Monthly	3 days
Total	$	1,014.5

Schedule Of Reconciliation Of The Plan Funded Status

The following table provides a reconciliation of the plans’ funded status and amounts reflected in NiSource’s Consolidated Balance Sheets at December 31 based on a December 31 measurement date:



	Pension Benefits						Other Postretirement Benefits
(in millions)	2017			2016			2017			2016
Change in projected benefit obligation ⁽¹⁾
Benefit obligation at beginning of year	$	2,165.8		$	2,206.7		$	529.0		$	525.8
Service cost	30.0			30.7			4.8			5.0
Interest cost	68.3			89.7			17.8			22.0
Plan participants’ contributions	—			—			5.7			5.9
Plan amendments	0.9			—			1.6			7.5
Actuarial (gain) loss	98.3			(2.7		)	36.2			1.0
Settlement loss	1.6			—			—			—
Benefits paid	(172.3		)	(158.6		)	(39.3		)	(38.9		)
Estimated benefits paid by incurred subsidy	—			—			0.5			0.7
Projected benefit obligation at end of year	$	2,192.6		$	2,165.8		$	556.3		$	529.0
Change in plan assets
Fair value of plan assets at beginning of year	$	1,750.9		$	1,747.1		$	231.4		$	225.9
Actual return on plan assets	299.1			159.1			33.1			13.0
Employer contributions	282.3			3.3			31.6			25.5
Plan participants’ contributions	—			—			5.7			5.9
Benefits paid	(172.3		)	(158.6		)	(39.3		)	(38.9		)
Fair value of plan assets at end of year	$	2,160.0		$	1,750.9		$	262.5		$	231.4
Funded Status at end of year	$	(32.6	)	$	(414.9	)	$	(293.8	)	$	(297.6	)
Amounts recognized in the statement of financial position consist of:
Noncurrent assets	9.8			—			—			—
Current liabilities	(2.8		)	(2.9		)	(0.7		)	(0.7		)
Noncurrent liabilities	(39.6		)	(412.0		)	(293.1		)	(296.9		)
Net amount recognized at end of year ⁽²⁾	$	(32.6	)	$	(414.9	)	$	(293.8	)	$	(297.6	)
Amounts recognized in accumulated other comprehensive income or regulatory asset/liability ⁽³⁾
Unrecognized prior service credit	$	2.5		$	1.0		$	(23.1	)	$	(29.2	)
Unrecognized actuarial loss	692.9			835.5			84.2			68.3
Net amount recognized at end of year	$	695.4		$	836.5		$	61.1		$	39.1

⁽¹⁾ The change in benefit obligation for Pension Benefits represents the change in Projected Benefit Obligation while the change in benefit obligation for Other Postretirement Benefits represents the change in accumulated postretirement benefit obligation.

⁽²⁾ NiSource recognizes in its Consolidated Balance Sheets the underfunded and overfunded status of its various defined benefit postretirement plans, measured as the difference between the fair value of the plan assets and the benefit obligation.

⁽³⁾ NiSource determined that for certain rate-regulated subsidiaries the future recovery of pension and other postretirement benefits costs is probable. These rate-regulated subsidiaries recorded regulatory assets and liabilities of $733.5 million and $0.1 million, respectively, as of December 31, 2017, and $847.5 million and $0.3 million, respectively, as of December 31, 2016 that would otherwise have been recorded to accumulated other comprehensive loss.

Schedule of Benefit Obligations in Excess of Fair Value of Plan Assets

Information for pension plans with an accumulated benefit obligation in excess of plan assets:



	December 31,
	2017			2016
Accumulated Benefit Obligation	$	1,502.5		$	2,148.9
Funded Status
Projected Benefit Obligation	1,524.7			2,165.8
Fair Value of Plan Assets	1,482.3			1,750.9
Funded Status of Underfunded Pension Plans at End of Year	$	(42.4	)	$	(414.9	)

Information for pension plans with plan assets in excess of the accumulated benefit obligation:



	December 31,
	2017		2016
Accumulated Benefit Obligation	$	667.9	$	—
Funded Status
Projected Benefit Obligation	667.9		—
Fair Value of Plan Assets	677.7		—
Funded Status of Overfunded Pension Plans at End of Year	$	9.8	$	—

Schedule Of Significant Actuarial Assumptions In Determining Funded Status Plan

The following table provides the key assumptions that were used to calculate the pension and other postretirement benefits obligations for NiSource’s various plans as of December 31:



	Pension Benefits				Other Postretirement Benefits
	2017		2016		2017		2016
Weighted-average assumptions to Determine Benefit Obligation
Discount Rate	3.58	%	4.03	%	3.67	%	4.12	%
Rate of Compensation Increases	4.00	%	4.00	%	—		—
Health Care Trend Rates
Trend for Next Year	—		—		8.52	%	8.43	%
Ultimate Trend	—		—		4.50	%	4.50	%
Year Ultimate Trend Reached	—		—		2025		2024

The following table provides the key assumptions that were used to calculate the net periodic benefits cost for NiSource’s various plans:



	Pension Benefits						Other Postretirement Benefits
	2017		2016		2015		2017		2016		2015
Weighted-average Assumptions to Determine Net Periodic Benefit Cost
Discount rate - service cost⁽¹⁾	4.40	%	4.24	%	3.81	%	4.58	%	4.33	%	3.94	%
Discount rate - interest cost⁽¹⁾	3.31	%	4.24	%	3.81	%	3.48	%	4.33	%	3.94	%
Expected Long-Term Rate of Return on Plan Assets	7.25	%	8.00	%	8.30	%	6.99	%	7.85	%	8.15	%
Rate of Compensation Increases	4.00	%	4.00	%	4.00	%	—		—		—

Schedule Of One-Percentage-Point Change In Assumed Health Care Cost Trend Rates

Assumed health care cost trend rates have a significant effect on the amounts reported for the health care plans. A one-percentage-point change in assumed health care cost trend rates would have the following effects:



(in millions)	1% point increase		1% point decrease
Effect on service and interest components of net periodic cost	$	1.1	$	(0.9	)
Effect on accumulated postretirement benefit obligation	29.7		(25.9		)

Schedule Of Expected Payments To Participants In Pension Plan

The expected benefits are estimated based on the same assumptions used to measure NiSource’s benefit obligation at the end of the year and includes benefits attributable to the estimated future service of employees:



(in millions)	Pension Benefits		Other Postretirement Benefits		Federal Subsidy Receipts
Year(s)
2018	$	176.2	$	34.3	$	0.5
2019	173.7		35.3		0.5
2020	172.1		36.3		0.5
2021	172.0		36.9		0.5
2022	171.3		36.9		0.5
2023-2027	784.7		178.9		1.9

Components Of The Plans' Net Periodic Benefits Cost

The following table provides the components of the plans’ actuarially determined net periodic benefits cost for each of the three years ended December 31, 2017, 2016 and 2015:



	Pension Benefits									Other Postretirement Benefits
(in millions)	2017			2016			2015			2017			2016			2015
Components of Net Periodic Benefit Cost
Service cost	$	30.0		$	30.7		$	34.8		$	4.8		$	5.0		$	6.4
Interest cost	68.3			89.7			95.9			17.8			22.0			24.9
Expected return on assets	(123.1		)	(132.9		)	(167.2		)	(15.9		)	(17.2		)	(28.2		)
Amortization of prior service cost (credit)	(0.7		)	(0.2		)	0.1			(4.4		)	(4.9		)	(5.2		)
Recognized actuarial loss	52.9			61.2			59.3			3.0			3.1			3.4
Net Periodic Benefit Costs	27.4			48.5			22.9			5.3			8.0			1.3
Additional loss recognized due to:
Settlement loss	13.7			—			2.5			—			—			—
Total Net Periodic Benefits Cost	$	41.1		$	48.5		$	25.4		$	5.3		$	8.0		$	1.3

Schedule Of Changes In Plan Assets And Projected Benefit Obligations Recognized In Other Comprehensive Income

The following table provides other changes in plan assets and projected benefit obligations recognized in other comprehensive income or regulatory asset or liability:



	Pension Benefits						Other Postretirement Benefits
(in millions)	2017			2016			2017			2016
Other Changes in Plan Assets and Projected Benefit Obligations Recognized in Other Comprehensive Income or Regulatory Asset or Liability
Net prior service cost	$	0.9		$	—		$	1.6		$	7.5
Net actuarial loss (gain)	(76.1		)	(28.9		)	18.9			5.3
Settlements	(13.7		)	—			—			—
Less: amortization of prior service cost	0.7			0.2			4.4			4.9
Less: amortization of net actuarial loss	(52.9		)	(61.2		)	(3.0		)	(3.1		)
Total Recognized in Other Comprehensive Income or Regulatory Asset or Liability	$	(141.1	)	$	(89.9	)	$	21.9		$	14.6
Amount Recognized in Net Periodic Benefits Cost and Other Comprehensive Income or Regulatory Asset or Liability	$	(100.0	)	$	(41.4	)	$	27.2		$	22.6