Employee Benefit Plans (Tables)

6 Months Ended

Jun. 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 June 30,						Six months ended June 30,
(in thousands)	2014			2013			2014			2013
Components of net periodic benefit cost:
Service cost	$	1,621		$	1,327		$	3,256		$	2,654
Interest cost	1,404			1,088			2,817			2,176
Expected long-term return on assets	(1,449		)	(1,323		)	(2,909		)	(2,645		)
Actuarial loss	1,407			1,823			2,819			3,657
Prior service cost amortization	57			62			114			123
Settlement charge	115			—			3,673			144
Net periodic expense	$	3,155		$	2,977		$	9,770		$	6,109

The components of net periodic benefit cost for Alagasco’s two defined benefit non-contributory pension plans and allocated costs from the Energen nonqualified supplemental pension plans were as follows:

	Three months ended June 30,						Six months ended June 30,
(in thousands)	2014			2013			2014			2013
Components of net periodic benefit cost:
Service cost	$	1,696		$	2,176		$	3,393		$	4,352
Interest cost	1,439			1,612			2,878			3,225
Expected long-term return on assets	(1,679		)	(2,315		)	(3,359		)	(4,632		)
Actuarial loss	1,110			1,937			2,220			3,878
Prior service cost amortization	71			72			143			144
Net periodic expense	$	2,637		$	3,482		$	5,275		$	6,967

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 plans were as follows:

	Three months ended June 30,						Six months ended June 30,
(in thousands)	2014			2013			2014			2013
Components of net periodic benefit cost:
Service cost	$	59		$	112		$	119		$	223
Interest cost	224			176			450			351
Expected long-term return on assets	(383		)	(214		)	(770		)	(426		)
Actuarial loss	(209		)	—			(421		)	—
Transition amortization	15			63			30			126
Net periodic (income) expense	$	(294	)	$	137		$	(592	)	$	274

Alabama Gas Corporation | Postretirement Benefit Plans

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Benefit Costs

The components of net periodic postretirement benefit (income) expense for Alagasco’s postretirement benefit plans were as follows:

	Three months ended June 30,						Six months ended June 30,
(in thousands)	2014			2013			2014			2013
Components of net periodic benefit cost:
Service cost	$	132		$	314		$	265		$	629
Interest cost	614			664			1,227			1,328
Expected long-term return on assets	(1,172		)	(994		)	(2,343		)	(1,989		)
Actuarial loss	(388		)	—			(777		)	—
Transition amortization	17			251			34			502
Net periodic (income) expense	$	(797	)	$	235		$	(1,594	)	$	470