Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Basic EPS:
Net Income (Loss)	$ 7,080	$ 12,884	$ 17,867	$ 46,834	$ 71,971
Income, share amounts	11,671	11,531	11,643	11,417
Earnings Per Share, Basic	$ 0.61	$ 1.12	$ 1.53	$ 4.10
Dilutive Securities:
Dilutive RSAs	0	0	0	0
Dilutive RSUs	103	13	99	53
Dilutive Stock Options	18	1	17	9
Diluted EPS:
Net Income (Loss) Available to Common Stockholders, Diluted	$ 7,080	$ 12,884	$ 17,867	$ 46,834
Weighted Average Number of Shares Outstanding, Diluted	11,792	11,545	11,759	11,479
Earnings Per Share, Diluted	$ 0.60	$ 1.12	$ 1.52	$ 4.08
Warrant [Member]
Earnings Per Share (Textual)
Antidilutive shares excluded from EPS, shares	4,300	4,300	4,300	4,300
Stock Options [Member]
Earnings Per Share (Textual)
Antidilutive shares excluded from EPS, shares	500	400	400	300
Restricted Stock Units (RSUs) [Member]
Earnings Per Share (Textual)
Antidilutive shares excluded from EPS, shares	100	200	100	100
Performance Shares [Member]
Earnings Per Share (Textual)
Antidilutive shares excluded from EPS, shares	100		100