Unaudited Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income
Beginning balance, shares at Dec. 31, 2017		11,167,425
Beginning balance at Dec. 31, 2017	$ 209,197	$ 112	$ 47,079	$ 162,006	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	2,688		2,688
Restricted stock grants, net of forfeitures (in shares)		133,246
Restricted stock grants, net of forfeitures		$ 1	(1)
Common stock dividends	(2,889)			(2,889)
Unrealized gains on marketable securities, net of tax	0
Net income	9,467			9,467
Ending balance, shares at Mar. 31, 2018		11,300,671
Ending balance at Mar. 31, 2018	218,292	$ 113	49,766	168,413	0
Beginning balance, shares at Dec. 31, 2018		21,743,498
Beginning balance at Dec. 31, 2018	1,425,224	$ 217	1,306,653	118,322	32
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	2,854		2,772	82
Exercise of stock options, net (in shares)		51,889
Exercise of stock options, net	(1,699)	$ 1	(1,700)
Restricted stock grants, net of forfeitures (in shares)		121,714
Restricted stock grants, net of forfeitures		$ 1	(1)
Issuance of restricted stock, net (in shares)		6,699
Issuance of restricted stock, net	(3,554)		(3,554)
Common stock dividends	(11,121)			(11,121)
Unrealized gains on marketable securities, net of tax	234				234
Net income	11,500			11,500
Ending balance, shares at Mar. 31, 2019		21,923,800
Ending balance at Mar. 31, 2019	$ 1,423,438	$ 219	$ 1,304,170	$ 118,783	$ 266