Consolidated Statements of Changes in Stockholders' Equity (USD $) In Thousands, except Share data	Total USD ($)	Common Stock Outstanding [Member]	Common Stock [Member] USD ($)	Additional Paid-In Capital [Member] USD ($)	Retained Earnings (Deficit) [Member] USD ($)	Treasury Stock [Member] USD ($)	Accumulated Other Comprehensive Loss [Member] USD ($)
Balance, beginning at Dec. 31, 2011	$ 134,172		$ 394	$ 99,060	$ 60,054	$ (11,793)	$ (13,543)
Balance, Shares beginning at Dec. 31, 2011		37,907,575
Stock-based compensation	2,389			2,389
Issuance of common stock	46			46
Issuance of common stock, Shares		4,499
Exercise of stock options	916		2	914
Exercise of stock options, Shares	155,708	155,708
Exercise of warrants, Shares		52
Acquisition of treasury stock	(28,125)					(28,125)
Acquisition of treasury stock, Shares		(2,432,477)
Other comprehensive income (loss), net	(27,907)						(27,907)
Net income (loss)	110,038				110,038
Balance, ending at Dec. 31, 2012	191,529		396	102,409	170,092	(39,918)	(41,450)
Balance, Shares ending at Dec. 31, 2012		35,635,357
Stock-based compensation	2,213			2,213
Exercise of stock options	4,546		6	4,540
Exercise of stock options, Shares	579,476	579,476
Exercise of warrants	7,064		4	7,060
Exercise of warrants, Shares		448,281
Acquisition of treasury stock	(51,000)		0			(51,000)
Acquisition of treasury stock, Shares	(2,614,748)	(2,614,748)
Other comprehensive income (loss), net	(8,608)						(8,608)
Net income (loss)	(64,203)				(64,203)
Balance, ending at Dec. 31, 2013	81,541		406	116,222	105,889	(90,918)	(50,058)
Balance, Shares ending at Dec. 31, 2013	34,048,366	34,048,366
Stock-based compensation	2,072			2,072
Exercise of stock options	106		0	106
Exercise of stock options, Shares	6,795	6,795
Exercise of warrants	19		0	19
Exercise of warrants, Shares		1,307
Acquisition of treasury stock			0
Other comprehensive income (loss), net	14,992						14,992
Net income (loss)	(117,232)				(117,232)
Balance, ending at Dec. 31, 2014	$ (18,502)		$ 406	$ 118,419	$ (11,343)	$ (90,918)	$ (35,066)
Balance, Shares ending at Dec. 31, 2014	34,056,468	34,056,468