Earnings Per Share - Schedule of Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basic earnings per share
Net Income	$ 42,865	$ 29,202	$ 22,141
Total weighted average common stock outstanding	42,613,086	36,872,007	33,495,827
Net income per share	$ 1.01	$ 0.79	$ 0.66
Diluted earnings per share
Net income	$ 42,865	$ 29,202	$ 22,141
Total weighted average common stock outstanding	42,613,086	36,872,007	33,495,827
Add: Dilutive effect of employee restricted stock and stock options (See Note J)	737,000	636,000	248,000
Total weighted average diluted stock outstanding	43,350,314	37,508,046	33,744,171
Net income per share	$ 0.99	$ 0.78	$ 0.66