Benefit Plans

The components of our consolidated net pension costs are set forth in the following table:



	For the Three Months Ended						For the Nine Months Ended
	September 30,						September 30,
	2013			2014			2013			2014
	(Dollars in thousands)						(Dollars in thousands)
Service cost	$	489		$	473		$	1,467		$	1,419
Interest cost	1,985			2,169			5,955			6,507
Expected return on plan assets	(1,706		)	(1,938		)	(5,118		)	(5,814		)
Amortization of prior service cost	6			1			18			3
Net cost	$	774		$	705		$	2,322		$	2,115

The components of our consolidated net postretirement costs are set forth in the following table:



	For the Three Months Ended						For the Nine Months Ended
	September 30,						September 30,
	2013			2014			2013			2014
	(Dollars in thousands)						(Dollars in thousands)
Service cost	$	28		$	19		$	84		$	57
Interest cost	331			352			993			1,056
Curtailment loss	—			—			—			1,048
Amortization of prior service benefit	(50		)	(47		)	(150		)	(141		)
Net cost	$	309		$	324		$	927		$	2,020