Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2015	$ 140,316	$ 120,147	$ 353,050	$ 973,538	$ (1,262,859)	$ (43,560)
Increase (Decrease) in Stockholders' Equity (Deficit)
Exercise of stock options and release of unvested shares	(81)	118	(118)		(81)
Net tax effect of stock options exercised and release of unvested shares	(593)		(593)
Stock-based compensation	563		563
Dividends paid ($0.085 for the three months ended March 31, 2016)	(5,285)			(5,285)
Treasury stock issued	40		(222)		262
Net loss	(5,603)			(5,603)
Other comprehensive income	52					52
Balance at Mar. 31, 2016	129,409	120,265	352,680	962,650	(1,262,678)	(43,508)
Balance at Dec. 31, 2016	2,656	120,437	350,245	837,316	(1,259,164)	(46,178)
Increase (Decrease) in Stockholders' Equity (Deficit)
Cumulative effect of accounting change	(164)		709	(873)
Exercise of stock options and release of unvested shares	(15)	38	(38)		(15)
Stock-based compensation	628		628
Treasury stock issued	75		(1,464)		1,539
Net loss	(7,386)			(7,386)
Other comprehensive income	383					383
Balance at Mar. 31, 2017	$ (3,823)	$ 120,475	$ 350,080	$ 829,057	$ (1,257,640)	$ (45,795)