| Goodwill (Schedule of Changes in the Carrying Amount of Goodwill) (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
|---|---|---|---|
| Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014 | |
| Goodwill [Abstract]. | |||
| Goodwill as of January 1 | $ 383,853 | $ 1,323,502 | |
| Goodwill impairment charges | (942,408) | $ (102,470) | |
| Goodwill acquired | 5,400 | ||
| Translation differences | 1,700 | (2,700) | |
| Goodwill as of December 31 | $ 385,629 | $ 383,853 | $ 1,323,502 | 
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- References No definition available. 
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- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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