Employee Benefits (Tables)

3 Months Ended

Mar. 31, 2015

Compensation and Retirement Disclosure [Abstract]

Net Periodic Benefit Cost

The components of the net periodic benefit cost for our pension and postretirement benefit plans are as follows:

	Pension Plan						Postretirement Benefit Plan
Three Months Ended March 31,	2015			2014			2015		2014
Net periodic benefit cost
Service cost	$	1,669		$	1,303		$	1,305	$	924
Interest cost	1,500			1,468			713		586
Expected return on plan assets	(1,950		)	(1,739		)	—		—
Amortization of net loss	1,136			544			731		224
Net periodic benefit cost	$	2,355		$	1,576		$	2,749	$	1,734