Consolidated Statements of Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Treasury Stock	Capital in Excess of Par Value	Retained Deficit	Accumulated Other Comprehensive Loss (note 14)
Balance, value at Dec. 31, 2011	$ 27,780	$ 203	$ 0	$ 310,985	$ (155,036)	$ (128,372)
Balance, shares at Dec. 31, 2011		20,342,342	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	6,966				6,966
Other comprehensive income (loss)	(12,668)					(12,668)
Stock compensation expense (note 12)	3,321			3,321
Stock issued, value	(923)	6		(929)
Stock issued, shares		493,147
Purchase of treasury shares, shares	0
Balance value at Dec. 31, 2012	24,476	209	0	313,377	(148,070)	(141,040)
Balance, shares at Dec. 31, 2012		20,835,489	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	28,459				28,459
Other comprehensive income (loss)	67,880					67,880
Stock compensation expense (note 12)	5,063			5,063
Stock issued, value	4,931	4		4,927
Stock issued, shares		480,991
Purchase of treasury shares, shares	0
Balance value at Dec. 31, 2013	130,809	213	0	323,367	(119,611)	(73,160)
Balance, shares at Dec. 31, 2013		21,316,480	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,963				4,963
Other comprehensive income (loss)	(65,287)					(65,287)
Stock compensation expense (note 12)	3,932			3,932
Stock issued, value	4,097	5		4,092
Stock issued, shares		527,371
Purchase of treasury shares, value	(1,060)		(1,060)
Purchase of treasury shares, shares	34,985		34,985
Balance value at Dec. 31, 2014	$ 77,454	$ 218	$ (1,060)	$ 331,391	$ (114,648)	$ (138,447)
Balance, shares at Dec. 31, 2014		21,843,851	34,985