v2.4.1.9

FAIR VALUE MEASUREMENTS (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Fair value measurements
Investments in securities	$ 9,998us-gaap_InvestmentsFairValueDisclosure	$ 39,997us-gaap_InvestmentsFairValueDisclosure
Total
Fair value measurements
Total financial assets	64,007us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember	168,736us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
Total | Government securities money market
Fair value measurements
Cash and cash equivalents	54,009us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember	128,739us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
Total | U.S. treasury bills
Fair value measurements
Investments in securities	9,998us-gaap_InvestmentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_USTreasuryBillSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember	39,997us-gaap_InvestmentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_USTreasuryBillSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_EstimateOfFairValueFairValueDisclosureMember
Level 2
Fair value measurements
Total financial assets	64,007us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	168,736us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Level 2 | Government securities money market
Fair value measurements
Cash and cash equivalents	54,009us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	128,739us-gaap_CashAndCashEquivalentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_MoneyMarketFundsMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Level 2 | U.S. treasury bills
Fair value measurements
Investments in securities	9,998us-gaap_InvestmentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_USTreasuryBillSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member	39,997us-gaap_InvestmentsFairValueDisclosure / us-gaap_FairValueByAssetClassAxis = us-gaap_USTreasuryBillSecuritiesMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member
Level 3
Fair value measurements
Total financial assets	$ 0us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member

X

- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ 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 (a)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Available-for-Sale Securities

-URI http://asc.fasb.org/extlink&oid=6505594



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Trading Securities

-URI http://asc.fasb.org/extlink&oid=6526789



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Subparagraph a, f, g

-Article 7



Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 35

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=27723805&loc=d3e24584-111560

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