Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2016

Pension Plans

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Periodic Benefit Costs

The components of net periodic benefit cost for Energen’s defined benefit non-contributory pension plan and certain nonqualified supplemental pension plans were as follows:

	Three months ended June 30,				Six months ended June 30,
(in thousands)	2016		2015		2016		2015
Components of net periodic benefit cost:
Interest cost	$	—	$	204	—		408
Actuarial loss	—		184		—		369
Settlement charge	—		701		3,325		3,363
Net periodic expense	$	—	$	1,089	$	3,325	$	4,140

Postretirement Benefit Plans

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Periodic Benefit Costs

The components of net periodic postretirement benefit expense for Energen’s postretirement benefit plan were as follows:

	Three months ended June 30,						Six months ended June 30,
(in thousands)	2016			2015			2016			2015
Components of net periodic benefit cost:
Service cost	$	24		$	98		$	47		$	196
Interest cost	52			117			118			233
Expected long-term return on assets	(69		)	(114		)	(180		)	(229		)
Prior service cost amortization	(113		)	—			(238		)	—
Settlement charge	—			—			45			—
Curtailment gain	—			—			(816		)	—
Net periodic (income) expense	$	(106	)	$	101		$	(1,024	)	$	200