Summary of Significant Accounting Policies - Schedule of Reclassifications Out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Amortization of employee benefit plan items:
Prior service cost	$ (25)	$ 53
Settlement expense	1,510	762
Actuarial loss	1,007	1,153
Total before tax	2,492	1,968
Income tax benefit	(1,019)	(728)
Amount reclassified out of accumulated other comprehensive loss	$ 1,473	$ 1,240