Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2015

Defined Benefit Plan Disclosure [Line Items]

The following table sets forth the combined funded status of the defined qualified and nonqualified supplemental benefit plans along with the postretirement health care and life insurance benefit plans and their reconciliation with the related amounts in Energen’s consolidated financial statements.



As of December 31, (in thousands)	2015			2014			2015			2014
	Pension						Postretirement Benefits
Accumulated benefit obligation	$	15,729		$	107,669
Benefit obligation:
Balance at beginning of period	$	107,669		$	266,294		$	11,127		$	33,224
Service cost	—			8,329			392			262
Interest cost	816			5,325			466			716
Actuarial (gain) loss	(683		)	9,078			(1,185		)	6,385
Plan amendments	—			—			(4,071		)	—
Curtailment gain	—			(8,496		)	—			—
Transfer in connection with the sale of Alagasco	—			(124,783		)	—			(28,648		)
Termination benefit charge	—			2,477			—			—
Retiree drug subsidy program	—			—			—			48
Benefits paid	(92,073		)	(50,555		)	(241		)	(860		)
Balance at end of period	$	15,729		$	107,669		$	6,488		$	11,127
Plan assets:
Fair value of plan assets at beginning of period	$	67,542		$	193,457		$	10,693		$	55,459
Actual return (loss) on plan assets	(289		)	5,359			(83		)	(331		)
Employer contributions	24,847			19,164			—			21
Transfer in connection with the sale of Alagasco	—			(99,883		)	—			(43,596		)
Benefits paid	(92,073		)	(50,555		)	(241		)	(860		)
Fair value of plan assets at end of period	$	27		$	67,542		$	10,369		$	10,693

Funded status of plans	$	(15,702	)	$	(40,127	)	$	3,881		$	(434	)



Noncurrent assets	$	—		$	—		$	3,881		$	—
Current liabilities	(15,702		)	(24,626		)	—			—
Noncurrent liabilities	—			(15,501		)	—			(434		)
Net asset (liability) recognized	$	(15,702	)	$	(40,127	)	$	3,881		$	(434	)
Amounts recognized to accumulated other comprehensive income:
Prior service credit, net of taxes	$	—		$	—		$	(2,646	)	$	—
Net actuarial loss, net of taxes	2,179			22,246			205			624
Total accumulated other comprehensive income (loss)	$	2,179		$	22,246		$	(2,441	)	$	624

Schedule of Allocation of Plan Assets

The Company’s weighted average plan asset allocations by asset category were as follows:



	Pension						Postretirement Benefits
As of December 31,	Target		2015		2014		Target		2015		2014
Asset category:
Equity securities	—	%	—	%	—	%	56	%	56	%	60	%
Debt securities	—	%	—	%	—	%	44	%	44	%	40	%
Cash and cash equivalents	100	%	100	%	100	%	—	%	—	%	—	%
Total	100	%	100	%	100	%	100	%	100	%	100	%

Schedule of Net Periodic Benefit Cost

The components of net periodic benefit cost from continuing operations were as follows:



Years ended December 31, (in thousands)	2015			2014			2013
Pension Plans
Components of net periodic benefit cost:
Service cost	$	—		$	6,808		$	5,196
Interest cost	816			4,498			4,496
Expected long-term return on assets	—			(4,386		)	(5,225		)
Prior service cost amortization	—			202			246
Actuarial loss amortization	737			4,995			6,919
Termination benefit charge	—			2,477			—
Settlement charge	29,767			4,082			161
Curtailment expense (gain)	—			254			(4		)
Net periodic expense	$	31,320		$	18,930		$	11,789
Postretirement Benefit Plans
Components of net periodic benefit cost:
Service cost	$	392		$	253		$	386
Interest cost	466			661			645
Expected long-term return on assets	(457		)	(1,122		)	(787		)
Actuarial gain amortization	—			(653		)	(28		)
Transition obligation amortization	—			44			229
Net periodic (income) expense	$	401		$	(817	)	$	445

Schedule of Other Changes in Plan Assets and Projected Benefit Obligations Recognized in Other Comprehensive Income

Other changes in plan assets and projected benefit obligations recognized in other comprehensive income were as follows:



Years ended December 31, (in thousands)	2015			2014			2013
Pension Plans
Net actuarial (gain) loss experienced during the year	$	(394	)	$	10,495		$	(14,138	)
Net actuarial loss recognized as expense	(30,478		)	(25,433		)	(8,934		)
Prior service cost recognized as expense	—			(246		)	(311		)
Curtailment loss	—			(8,749		)	—
Total recognized in other comprehensive income (loss)	(30,872		)	(23,933		)	(23,383		)
Postretirement Benefit Plans
Net actuarial (gain) loss experienced during the year	$	(645	)	$	7,649		$	(8,057	)
Prior service credit during the year	(4,071		)	—			—
Net actuarial gain recognized as expense	—			1,908			550
Transition obligation recognized as expense	—			(48		)	(283		)
Total recognized in other comprehensive income (loss)	$	(4,716	)	$	9,509		$	(7,790	)

Schedule of Estimated Amount to be Amortized from Accumulated Other Comprehensive Income

Estimated amounts to be amortized, including settlement charges, from accumulated other comprehensive income into pension cost during 2016 are included in the table below.



(in thousands)
Amortization of net actuarial loss	$	3,352

Estimated amounts to be amortized from accumulated other comprehensive income into postretirement benefit cost during 2016 are included in the table below.



(in thousands)
Amortization of prior service credit	$	(515	)

Schedule of Weighted Average Rate Assumptions

The weighted average rate assumptions to determine net periodic benefit costs were as follows:



Years ended December 31,	2015		2014		2013
Pension Plans
Discount rate	0.96	%	3.66	%	3.63	%
Expected long-term return on plan assets	—	%	7.00	%	7.00	%
Rate of compensation increase for pay-related plans	—	%	3.63	%	3.71	%
Postretirement Benefit Plans
Discount rate	4.25	%	4.88	%	4.36	%
Expected long-term return on plan assets	6.20	%	7.00	%	7.00	%
Rate of compensation increase	—	%	3.60	%	3.70	%

The pension benefit obligation as of December 31, 2014 represents the present value of the estimated cost of settling the benefit obligation of the plan. For our defined benefit pension plan, we discounted the estimated termination liability using the one year spot rate of 0.70 percent. For the year ended December 31, 2015, the discount rate shown above represents the weighted average for the nonqualified supplemental retirement plan. The discount rate shown below represents the weighted average for both the defined qualified and nonqualified supplemental retirement plans for the year ended December 31, 2014. For the year ended December 31, 2015, the expected long-term return on plan assets no longer applies for our defined benefit pension plan as the assets of the nonqualified supplemental retirement plan are not considered qualifying assets. As the plans were frozen as of December 31, 2014, the rate of compensation increase no longer applies for any of the plans. The weighted average assumptions used to determine the benefit obligations at the measurement date were as follows:



Years ended December 31,	2015		2014
Pension Plans
Discount rate	3.90	%	0.96	%
Postretirement Benefit Plans
Discount rate	4.70	%	4.25	%

Schedule of Assumed Post-65 Health Care Cost Trend Rates

The assumed post-65 health care cost trend rates used to determine the postretirement benefit obligation at the measurement date were as follows:



As of December 31,	2015		2014
Health care cost trend rate assumed for next year	7.75	%	7.25	%
Rate to which the cost trend rate is assumed to decline	5.00	%	5.00	%
Year that rate reaches ultimate rate	2026		2021

Schedule of Expected Benefit Payments

The following benefit payments, which reflect expected future service, as appropriate, are anticipated to be paid as follows:



(in thousands)	Pension Benefits	Postretirement Benefits
2016	$14,606	$198
2017	$117	$213
2018	$114	$245
2019	$110	$258
2020	$107	$289
2021-2025	$472	$1,769

Pension Benefits

Defined Benefit Plan Disclosure [Line Items]

Schedule of Allocation of Plan Assets

Plan assets included in the funded status of the pension plans were as follows:



	December 31, 2015
(in thousands)	Level 1		Level 2		Total
Cash and cash equivalents	27		$	—	$	27
Total	$	27	$	—	$	27



	December 31, 2014
(in thousands)	Level 1		Level 2		Total
Cash and cash equivalents	$	67,542	$	—	$	67,542
Total	$	67,542	$	—	$	67,542

Postretirement Benefits

Defined Benefit Plan Disclosure [Line Items]

Schedule of Allocation of Plan Assets

Plan assets included in the funded status of the postretirement benefit plans were as follows:



	December 31, 2015
(in thousands)	Level 1		Level 2		Total
United States equities	$	4,185	$	—	$	4,185
Global equities	1,650		—		1,650
Fixed income	—		4,534		4,534
Total	$	5,835	$	4,534	$	10,369



	December 31, 2014
(in thousands)	Level 1		Level 2		Total
United States equities	$	4,715	$	—	$	4,715
Global equities	1,711		—		1,711
Fixed income	—		4,267		4,267
Total	$	6,426	$	4,267	$	10,693

Nonqualified Supplemental Retirement Plans

Defined Benefit Plan Disclosure [Line Items]

Schedule of Allocation of Plan Assets

Other investment assets designated for payment of the nonqualified supplemental retirement plans were as follows:



	December 31, 2015
(in thousands)	Level 1		Level 2		Total
Cash and cash equivalents	$	3,308	$	—	$	3,308
Total	$	3,308	$	—	$	3,308



	December 31, 2014
(in thousands)	Level 1		Level 2		Total
Fixed income	$	—	$	4,255	$	4,255
Cash and cash equivalents	9,929		—		9,929
Total	$	9,929	$	4,255	$	14,184