Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net Income	$ 20,077	$ 25,261	$ (74,879)
Pension Adjustments:
Amortization of actuarial loss included in net income, net of tax benefit of $302, $283, and $330 for 2017, 2016, and 2015, respectively	508	479	557
Actuarial (loss) gain arising during the period, net of tax (benefit) expense of $(194), $(413), and $300 for 2017, 2016, and 2015, respectively	(304)	(650)	491
Decrease in net unrealized gains and losses on cash flow hedges, net of tax benefit of $145, $180, and $0 for 2017, 2016, and 2015, respectively	(242)	(305)	0
Other Comprehensive (Loss) Income, Net of Tax	(38)	(476)	1,048
Comprehensive Income (Loss), Net of Tax	$ 20,039	$ 24,785	$ (73,831)