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Financial Instruments -Recurring Basis (Details) - USD ($) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014 | Mar. 31, 2014
Key inputs used in investor option liability valuation |  |  |  |
Impairment loss for available-for-sale investments | $ 4,800,000 | $ 0 | $ 0 |
Loss on fair value change of investor option liability |  |  | (46,972,000) |
Financial instruments measured on a recurring basis |  |  |  |
Key inputs used in investor option liability valuation |  |  |  |
Impairment loss for available-for-sale investments | $ 4,800,000 | $ 0 | 0 |
Financial instruments measured on a recurring basis | Investor option liability |  |  |  |
Key inputs used in investor option liability valuation |  |  |  |
Investor option liability |  |  |  | $ 76,500,000
Loss on fair value change of investor option liability |  |  | $ (47,000,000) |
Financial instruments measured on a recurring basis | Significant Unobservable Inputs (Level 3) | Alibaba |  |  |  |
Key inputs used in investor option liability valuation |  |  |  |
Percentage of ownership interest in subsidiary to be reached if fully exercised | 30.00% |  |  |

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- Definition Amount of gain (loss) recognized on the income statement for financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
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- Definition Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
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- Definition The amount by which the fair value of an investment in debt and equity securities categorized as Available-for-sale is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27161-111563 + Details
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