Employee Benefits (Tables)

3 Months Ended

Mar. 31, 2014

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,	2014			2013			2014		2013
Net periodic benefit cost
Service cost	$	1,303		$	1,282		$	924	$	753
Interest cost	1,468			1,262			586		424
Expected return on plan assets	(1,739		)	(1,336		)	—		—
Amortization of net loss	544			1,106			224		136
Net periodic benefit cost	$	1,576		$	2,314		$	1,734	$	1,313