Fair Value Measurements and Derivatives - Effects of Foreign Currency Which Was not Designated As Cash Flow Hedge (Details 10) - USD ($) $ in Thousands  | 
3 Months Ended | 9 Months Ended | ||
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Sep. 30, 2015  | 
Sep. 30, 2014  | 
Sep. 30, 2015  | 
Sep. 30, 2014  | 
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| Not Designated as Hedging Instrument | Foreign Currency Collar | ||||
| Derivative Instruments Gain Loss [Line Items] | ||||
| Gain (loss) recognized in other income (expense) | $ 955 | $ (18,648) | ||
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- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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- Details 
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- Details 
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