CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2015	$ 298,980	$ 215	$ 221,487	$ 76,946	$ 332
Balance (in shares) at Dec. 31, 2015		21,570,746
Increase (Decrease) in Stockholders' Equity
Net Income	40,103			40,103
Other comprehensive income (loss)	(3,053)				(3,053)
Share-based compensation expense	2,729		2,729
Issuance of restricted stock, net (in shares)		296,236
Issuance of common stock	119,383	$ 58	119,325
Issuance of common stock (in shares)		5,815,051
Warrants exercised	379	$ 0	379
Warrants exercised (in shares)		0
Restricted stock surrendered and canceled	(126)	$ 0	(126)
Repurchase of common stock (in shares)		0
Exercise of stock options, net	1,345	$ 1	1,344
Exercise of stock options (in shares)		116,250
Balance at Dec. 31, 2016	459,740	$ 274	345,138	117,049	(2,721)
Balance (in shares) at Dec. 31, 2016		27,798,283
Increase (Decrease) in Stockholders' Equity
Net Income	60,100			60,100
Other comprehensive income (loss)	3,136				3,136
Share-based compensation expense	5,809		5,809
Issuance of restricted stock, net	0
Issuance of restricted stock, net (in shares)		166,397
Issuance of common stock	709,377	$ 181	709,196
Issuance of common stock (in shares)		17,954,274
Goodwill adjustment	500		500
Restricted stock surrendered and canceled	(1,258)		(1,258)
Repurchase of common stock (in shares)		(21,537)
Exercise of stock options, net	4,592	$ 3	4,589
Exercise of stock options (in shares)		347,633
Balance at Dec. 31, 2017	$ 1,241,996	$ 458	1,063,974	177,149	415
Balance (in shares) at Dec. 31, 2017	46,245,050	46,245,050
Increase (Decrease) in Stockholders' Equity
Net Income	$ 123,340			123,340
Other comprehensive income (loss)	(6,098)				(6,098)
Share-based compensation expense	9,033		9,033
Issuance of restricted stock, net	0
Issuance of restricted stock, net (in shares)		270,571
Issuance of common stock	601,171	$ 158	601,013
Issuance of common stock (in shares)		15,758,039
Goodwill adjustment	0
Restricted stock surrendered and canceled	(1,669)		(1,669)
Repurchase of common stock (in shares)		(33,148)
Exercise of stock options, net	1,924	$ 1	1,923
Exercise of stock options (in shares)		240,243
Reclassification of certain tax effects of the Tax Cuts and Jobs Act	0			(82)	82
Balance at Dec. 31, 2018	$ 1,969,697	$ 617	$ 1,674,274	$ 300,407	$ (5,601)
Balance (in shares) at Dec. 31, 2018	62,480,755	62,480,755