Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net Income (Loss) Attributable to Parent	$ 13,354	$ 12,197	$ 14,869	$ 11,203	$ (8,195)	$ 9,279	$ 7,689	$ 6,197	$ 51,623	$ 14,970	$ 23,756
Weighted Average Number Diluted Shares Outstanding Adjustment									99	86	7
Weighted Average Number of Shares Outstanding, Basic									50,652	49,597	48,879
Earnings Per Share, Basic	$ 0.26	$ 0.24	$ 0.29	$ 0.22	$ (0.16)	$ 0.19	$ 0.16	$ 0.13	$ 1.02	$ 0.30	$ 0.49
Weighted Average Number of Shares Outstanding, Diluted									50,751	49,683	48,886
Earnings Per Share, Diluted	$ 0.26	$ 0.24	$ 0.29	$ 0.22	$ (0.16)	$ 0.19	$ 0.16	$ 0.13	$ 1.02	$ 0.30	$ 0.49