Earnings Per Share - Schedule of Earnings Per Share, Basic and Diluted (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	$ 8,082	$ 7,187	$ 14,697	$ 15,130	$ (804)	$ 17,369	$ 9,193	$ 7,151	$ 45,096	$ 32,909	$ 36,952
Basic earnings per share - weighted average shares outstanding	31,268	31,901	31,859	31,662	31,597	31,571	31,501	31,290	31,671	31,491	31,128
Restricted stock units and stock options - dilutive shares									529	670	467
Convertible senior notes - dilutive shares									0	0	103
Warrants - dilutive shares									0	1	92
Diluted earnings per share - weighted average shares outstanding	31,645	32,408	32,437	32,317	31,597	32,170	32,146	32,058	32,200	32,162	31,790
Basic	$ 0.26	$ 0.23	$ 0.46	$ 0.48	$ (0.03)	$ 0.55	$ 0.29	$ 0.23	$ 1.42	$ 1.05	$ 1.19
Diluted	$ 0.26	$ 0.22	$ 0.45	$ 0.47	$ (0.03)	$ 0.54	$ 0.29	$ 0.22	$ 1.40	$ 1.02	$ 1.16