Employee Benefits (Tables)

6 Months Ended

Jun. 30, 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 June 30,	2014			2013			2014		2013
Net periodic benefit cost
Service cost	$	1,303		$	1,868		$	924	$	752
Interest cost	1,468			1,326			586		423
Expected return on plan assets	(1,739		)	(1,550		)	—		—
Amortization of net loss	544			1,105			224		138
Net periodic benefit cost	$	1,576		$	2,749		$	1,734	$	1,313

	Pension Plan						Postretirement Benefit Plan
Six Months Ended June 30,	2014			2013			2014		2013
Net periodic benefit cost
Service cost	$	2,606		$	3,150		$	1,848	$	1,505
Interest cost	2,936			2,587			1,172		847
Expected return on plan assets	(3,478		)	(2,886		)	—		—
Amortization of net loss	1,088			2,211			448		274
Net periodic benefit cost	$	3,152		$	5,062		$	3,468	$	2,626