Earning Per Common Share (Schedule of Earnings Per Share, Basic and Diluted) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Numerator for basic and diluted earnings (loss) per common share:
Net income (loss)	$ 289	$ 3,222	$ 3,024	$ (2,422)	$ (40,851)	$ (5,982)	$ (91,996)	$ (2,832)	$ 4,113	$ (141,660)	$ (44,445)
Denominator:
Weighted average shares outstanding (shares)									10,334	10,273	10,254
Denominator for basic earnings per common share (shares)									10,334	10,273	10,254
Effect of dilutive securities:
Other stock compensation plans (shares)									149	0	0
Dilutive potential common shares (shares)									149	0	0
Denominator for diluted earnings per common share - adjusted weighted average shares and assumed conversions (shares)									10,483	10,273	10,254
Basic earnings (loss) per common share (usd per share)	$ 0.03	$ 0.31	$ 0.29	$ (0.23)	$ (3.97)	$ (0.58)	$ (8.96)	$ (0.28)	$ 0.40	$ (13.79)	$ (4.33)
Diluted earnings (loss) per common share (usd per share)	0.03	0.31	0.29	(0.23)	(3.97)	(0.58)	(8.96)	(0.28)	0.39	(13.79)	(4.33)
Dividends paid per common share (usd per share)	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0.04	$ 0.04	$ 0.04	$ 0.00	$ 0.12	$ 0.16
Antidilutive shares excluded from computation of earnings per share (shares)										143	130