| UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS UNAUDITED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | |
|---|---|---|
| Mar. 31, 2015 | Mar. 31, 2014 | |
| Statement of Comprehensive Income [Abstract] | ||
| Other comprehensive income (loss), Unrealized Holding Gain (Loss) on Securities Arising During the Period, tax | $ 0us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax | $ 0us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax | 
| Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax | $ 0us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax | $ 0us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTranslationAdjustmentTax | 
| X | ||||||||||
| 
- Definition Amount of tax expense (benefit), after 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Definition Amount of tax expense (benefit) before reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
 | 
| X | ||||||||||
| 
- Details 
 |