Employee Benefits

6 Months Ended

Jun. 30, 2017

Retirement Benefits [Abstract]

Employee Benefits

EMPLOYEE BENEFITS

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,	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	891			992			461			379
Net periodic benefit cost	$	1,958		$	2,290		$	96		$	2,065

	Pension Plan						Postretirement Benefit Plan
Six Months Ended June 30,	2017			2016			2017			2016
Net periodic benefit cost
Service cost	$	3,427		$	3,246		$	1,010		$	1,864
Interest cost	3,530			3,326			964			1,508
Expected return on plan assets	(4,824		)	(3,976		)	—			—
Amortization of prior service credit	—			—			(2,704		)	—
Amortization of net loss	1,782			1,984			922			758
Net periodic benefit cost	$	3,915		$	4,580		$	192		$	4,130

Employer Contributions

We previously disclosed in our Annual Report on Form 10-K for the year ended December 31, 2016 that we expected to contribute $6,400 to the pension plan in 2017. For the six-month period ended June 30, 2017, we contributed $3,196 to the pension plan.