Employee Benefits (Tables)

3 Months Ended

Mar. 31, 2017

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,	2017			2016			2017			2016
Net periodic benefit cost
Service cost	$	1,714		$	1,623		$	505		$	932
Interest cost	1,765			1,663			482			754
Expected return on plan assets	(2,412		)	(1,988		)	—			—
Amortization of prior service credit	—			—			(1,352		)	—
Amortization of net loss	890			992			461			379
Net periodic benefit cost	$	1,957		$	2,290		$	96		$	2,065