Earnings (Loss) Per Share (EPS) - Schedule of Diluted Earnings Per Shares Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Calculation of net income (loss) per share:
Net Income (loss)	$ 7,824	$ (80)	$ 12,653	$ 2,261
Basic weighted average shares outstanding (in shares)	49,547	49,115	49,511	49,083
Basic income (loss) per share (in dollars per share)	$ 0.16	$ 0.00	$ 0.26	$ 0.05
Effect of stock options outstanding:
Basic weighted average shares outstanding (in shares)	49,547	49,115	49,511	49,083
Effect from dilutive shares and options outstanding (in shares)	523	0	518	767
Diluted weighted average shares (in shares)	50,070	49,115	50,029	49,850
Diluted income (loss) per share (in dollars per share)	$ 0.16	$ 0.00	$ 0.25	$ 0.05