Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (117,232)us-gaap_NetIncomeLoss	$ (64,203)us-gaap_NetIncomeLoss	$ 110,038us-gaap_NetIncomeLoss
Other comprehensive income (loss)
Foreign currency translation adjustments	21,775	(13,727)	(37,737)
Derivative adjustments
Fair valuation of derivatives	(69)	7,497	5,237
Reclassification adjustment for loss (gain) on derivatives included in net income (loss)	(6,033)	(2,984)	4,608
Investment adjustments
Unrealized gain (loss) on investments	1,201	606	(15)
Reclassification adjustment for gain on investments included in net income (loss)	(1,882)
Net current-period other comprehensive income (loss)	14,992	(8,608)	(27,907)
Total comprehensive income (loss)	$ (102,240)us-gaap_ComprehensiveIncomeNetOfTax	$ (72,811)us-gaap_ComprehensiveIncomeNetOfTax	$ 82,131us-gaap_ComprehensiveIncomeNetOfTax

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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