Net Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	9,998	24,781
Net Income	$ 30,998	$ 4,875
Weighted average number of common shares outstanding (for basic calculation)	20,527,000	20,255,000
Dilutive securities	1,024,000	1,145,000
Diluted (in shares)	21,551,000	21,400,000
EPS - basic	$ 1.51	$ 0.24
Diluted (In dollars per share)	$ 1.44	$ 0.23