Employee Benefits

9 Months Ended

Sep. 30, 2013

Employee Benefits

11. Employee Benefits

Retirement Plans.

The components of net periodic benefit cost related to U.S. pension benefits are as follows:

	Threemonthsended September30,							Ninemonthsended September30,
	2013			2012			2013					2012
	(in thousands)							(in thousands)
Service cost	$	828		$	795		$		2,528		$		2,385
Interest cost		1,384			1,394				4,179				4,185
Expected return on plan assets		(1,654	)		(1,464	)			(4,959	)			(4,455	)
Amortization of prior service cost		880			683				2,745				2,048
Net periodic benefit cost	$	1,438		$	1,408		$		4,493		$		4,163

We made contributions of $4.8 million and $6.8 million to our pension plan in the nine months ended September30, 2013 and 2012, respectively.

The components of net periodic benefit cost related to other post-retirement benefits are as follows:

	Threemonthsended September30,					Ninemonthsended September30,
	2013		2012		2013				2012
	(in thousands)					(in thousands)
Service cost	$	130	$	127	$		420	$		383
Interest cost		285		305			870			915
Amortization of prior service cost		161		150			525			450
Net periodic benefit cost	$	576	$	582	$		1,815	$		1,748