Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2015

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Benefit Costs

Components of the net periodic pension and postretirement benefit cost for the three and six months ended June 30, 2015 and 2014, respectively, are as follows:

	Three months ended June 30,						Six months ended June 30,
	2015			2014			2015			2014
Service cost	$	237		$	128		$	474		$	255
Interest cost	1,795			1,740			3,590			3,480
Expected return on assets	(2,317		)	(2,095		)	(4,634		)	(4,190		)
Amortization of prior service cost	94			70			188			141
Amortization of actuarial loss	929			345			1,857			690
Curtailment charge	$	3,080		$	—		$	3,080		$	—
Net periodic pension and postretirement benefit cost	$	3,818		$	188		$	4,555		$	376
Contributions paid	$	—		$	—		$	—		$	—