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)	17,867
Ending Balance at Sep. 30, 2018	216,204	118	284,406	(1,870)	(66,450)
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)	2,321	0	0	0	2,321
Ending Balance at Jun. 30, 2018	207,443	117	282,726	(1,870)	(73,530)
Issuance of restricted stock	1	1	0	0	0
Amortization of share-based compensation	1,680	0	1,680	0	0
Net Income (Loss)	7,080	0	0	0	7,080
Ending Balance at Sep. 30, 2018	216,204	118	284,406	(1,870)	(66,450)
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)	108,408
Ending Balance at Sep. 30, 2019	388,386	119	291,754	(2,193)	98,706
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
Purchase of treasury shares	(5)	0	0	(5)	0
Issuance of restricted stock	1	1	0	0	0
Amortization of share-based compensation	1,855	0	1,855	0	0
Net Income (Loss)	27,651	0	0	0	27,651
Ending Balance at Sep. 30, 2019	$ 388,386	$ 119	$ 291,754	$ (2,193)	$ 98,706