Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2014

Pension Plans

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net 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 September 30,						Nine months ended September 30,
(in thousands)	2014			2013			2014			2013
Components of net periodic benefit cost:
Service cost	$	1,902		$	1,326		$	5,157		$	3,980
Interest cost	1,157			1,093			3,974			3,269
Expected long-term return on assets	(1,157		)	(1,321		)	(4,067		)	(3,966		)
Actuarial loss	1,296			1,760			4,115			5,417
Prior service cost amortization	63			62			177			185
Settlement charge	370			18			4,043			161
Net periodic expense	$	3,631		$	2,938		$	13,399		$	9,046

Postretirement Benefit Plans

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Benefit Costs

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

	Three months ended September 30,						Nine months ended September 30,
(in thousands)	2014			2013			2014			2013
Components of net periodic benefit cost:
Service cost	$	87		$	111		$	206		$	334
Interest cost	137			175			587			526
Expected long-term return on assets	(246		)	(212		)	(1,016		)	(638		)
Actuarial gain	(151		)	—			(572		)	—
Transition amortization	9			63			39			189
Net periodic (income) expense	$	(164	)	$	137		$	(756	)	$	411