Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net Income (Loss)	$ 16,861	$ (534)	$ 13,849	$ (4,548)
Other Comprehensive Income (Loss), Net of Tax:
Amortization of actuarial losses	62	157	125	315
Total other comprehensive income, net of tax	62	157	125	315
Total Comprehensive Income (Loss)	$ 16,923	$ (377)	$ 13,974	$ (4,233)