Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income(loss)
Increase (Decrease) in Stockholders' Equity
Effect of change in accounting principle	$ 177			$ 1,050	$ (873)
Balance at Dec. 31, 2016	2,656	$ 0	$ 12,044	458,638	837,316	$ (1,259,164)	$ (46,178)
Increase (Decrease) in Stockholders' Equity
Exercise of stock options and release of unvested shares	(111)		31	(30)		(112)
Stock-based compensation	2,457			2,457
Treasury stock issued	171			(4,929)		5,100
Net income (loss)	(41,860)				(41,860)
Other comprehensive income (loss)	1,875						1,875
Balance at Dec. 31, 2017	(34,635)	0	12,075	457,186	794,583	(1,254,176)	(44,303)
Increase (Decrease) in Stockholders' Equity
Preferred Stock issued		9,723
Exercise of stock options and release of unvested shares	(115)		78	(159)		(34)
Rounding from reverse stock split	0		(38)	38
Stock-based compensation	(438)			(438)
Treasury stock issued	63			(2,759)		2,822
Net income (loss)	17,550				17,550
Other comprehensive income (loss)	(2,180)						(2,180)
Balance at Dec. 31, 2018	$ (19,184)	$ 9,723	$ 12,115	$ 453,868	$ 812,704	$ (1,251,388)	$ (46,483)