Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings (Accumulated Deficit)
Beginning Balance at Dec. 31, 2017	$ 193,458	$ 116	$ 279,111	$ (1,452)	$ (84,317)
Shares issued from option exercise	708	0	708	0	0
Purchase of treasury shares	290	0	0	(290)	0
Issuance of restricted stock	0	1	(1)	0	0
Amortization of share-based compensation	1,485	0	1,485	0	0
Net Income (Loss)	8,466	0	0	0	8,466
Ending Balance at Mar. 31, 2018	203,827	117	281,303	(1,742)	(75,851)
Beginning Balance at Dec. 31, 2017	193,458	116	279,111	(1,452)	(84,317)
Net Income (Loss)	10,787
Ending Balance at Jun. 30, 2018	207,441	117	282,726	(1,870)	(73,532)
Beginning Balance at Mar. 31, 2018	203,827	117	281,303	(1,742)	(75,851)
Purchase of treasury shares	128	0	0	(128)	0
Issuance of restricted stock	0	0	0	0	0
Amortization of share-based compensation	1,423	0	1,423	0	0
Net Income (Loss)	2,319	0	0	0	2,319
Ending Balance at Jun. 30, 2018	207,441	117	282,726	(1,870)	(73,532)
Beginning Balance at Dec. 31, 2018	274,827	118	286,281	(1,870)	(9,702)
Purchase of treasury shares	260	0	0	(260)	0
Issuance of restricted stock	0	0	0	0	0
Amortization of share-based compensation	1,849	0	1,849	0	0
Net Income (Loss)	16,053	0	0	0	16,053
Ending Balance at Mar. 31, 2019	292,469	118	288,130	(2,130)	6,351
Beginning Balance at Dec. 31, 2018	274,827	118	286,281	(1,870)	(9,702)
Net Income (Loss)	80,757
Ending Balance at Jun. 30, 2019	358,884	118	289,899	(2,188)	71,055
Beginning Balance at Mar. 31, 2019	292,469	118	288,130	(2,130)	6,351
Purchase of treasury shares	58	0	0	(58)	0
Issuance of restricted stock	0	0	0	0	0
Amortization of share-based compensation	1,769	0	1,769	0	0
Net Income (Loss)	64,704	0	0	0	64,704
Ending Balance at Jun. 30, 2019	$ 358,884	$ 118	$ 289,899	$ (2,188)	$ 71,055