Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net Income	$ 219	$ 136	$ 36,148	$ 18,939
Weighted average number of common shares outstanding (for basic calculation)	20,474	19,984	20,362	19,433
Dilutive securities	1,159	1,122	1,226	1,170
Diluted (in shares)	21,633	21,106	21,588	20,603
EPS - basic	$ 0.01	$ 0.01	$ 1.78	$ 0.97
Diluted (In dollars per share)	$ 0.01	$ 0.01	$ 1.67	$ 0.92