CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (loss) [Member]	Common Stock Held in Treasury [Member]
Balance, beginning at Dec. 31, 2010	$ 162,851	$ 384	$ 95,585	$ 72,157	$ (5,275)
Balance, shares beginning at Dec. 31, 2010		38,401,985
Forfeiture of restricted units
Forfeiture of restricted units, shares		(3,465)
Stock-based compensation	1,140		1,140
Issuance of new stock	1,563	10	1,553
Issuance of new stock, shares		950,000
Exercise of stock options	32		32
Exercise of stock options, shares		5,486
Comprehensive (loss):
Net income (loss)	(1,912)			(1,912)
Fair valuation of derivatives	(10,213)				(10,213)
Reclassification to net loss from accumulated other comprehensive gain related to hedge derivatives	(11,478)				(11,478)
Foreign currency translation adjustments	18,083				18,083
Unrealized (loss) on investments	(119)				(119)
Total comprehensive income (loss)	(5,639)
Balance, ending at Sep. 30, 2011	159,947	394	98,310	70,245	(9,002)
Balance, shares ending at Sep. 30, 2011		39,354,006
Balance, beginning at Jun. 30, 2011	189,814	394	97,987	126,255	(34,822)
Balance, shares beginning at Jun. 30, 2011		39,357,471
Forfeiture of restricted units
Forfeiture of restricted units, shares		(3,465)
Stock-based compensation	323		323
Comprehensive (loss):
Net income (loss)	(56,010)			(56,010)
Fair valuation of derivatives	(16,289)				(16,289)
Reclassification to net loss from accumulated other comprehensive gain related to hedge derivatives	(1,536)				(1,536)
Foreign currency translation adjustments	43,081				43,801
Unrealized (loss) on investments	(156)				(156)
Total comprehensive income (loss)	(30,190)
Balance, ending at Sep. 30, 2011	159,947	394	98,310	70,245	(9,002)
Balance, shares ending at Sep. 30, 2011		39,354,006
Balance, beginning at Dec. 31, 2011	166,670	394	98,929	93,950	(14,810)	(11,793)
Balance, shares beginning at Dec. 31, 2011	37,907,575	37,907,575
Stock-based compensation	1,450		1,450
Issuance of new stock	46		46
Issuance of new stock, shares		4,499
Exercise of stock options	410	1	409
Exercise of stock options, shares		69,737
Acquisition of treasury stock	(22,937)					(22,937)
Acquisition of treasury stock, shares		(2,026,886)
Comprehensive (loss):
Net income (loss)	68,015			68,015
Fair valuation of derivatives	3,374				3,374
Reclassification to net loss from accumulated other comprehensive gain related to hedge derivatives	4,312				4,312
Foreign currency translation adjustments	(14,017)				(14,017)
Unrealized (loss) on investments	61				61
Total comprehensive income (loss)	61,745
Balance, ending at Sep. 30, 2012	207,384	395	100,834	161,965	(21,080)	(34,730)
Balance, shares ending at Sep. 30, 2012	35,954,925	35,954,925
Balance, beginning at Jun. 30, 2012	170,548	395	100,027	113,553	(14,699)	(28,728)
Balance, shares beginning at Jun. 30, 2012		36,353,545
Stock-based compensation	535		535
Issuance of new stock	20		20
Issuance of new stock, shares		2,031
Exercise of stock options	252		252
Exercise of stock options, shares		42,982
Acquisition of treasury stock	(6,002)					(6,002)
Acquisition of treasury stock, shares		(443,633)
Comprehensive (loss):
Net income (loss)	48,412			48,412
Fair valuation of derivatives	4,019				4,019
Reclassification to net loss from accumulated other comprehensive gain related to hedge derivatives	2,783				2,783
Foreign currency translation adjustments	(13,271)				(13,271)
Unrealized (loss) on investments	88				88
Total comprehensive income (loss)	42,031
Balance, ending at Sep. 30, 2012	$ 207,384	$ 395	$ 100,834	$ 161,965	$ (21,080)	$ (34,730)
Balance, shares ending at Sep. 30, 2012	35,954,925	35,954,925