FAIR VALUE MEASUREMENTS AND FINANCIAL INSTRUMENTS (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Assets:
Marketable securities	$ 233,523	$ 160,648
Fair value on a recurring basis
Assets:
Total Assets	567,801	780,563
Liabilities:
Contingent consideration arrangement	(31,858)	(30,140)
Fair value on a recurring basis \| Money market funds
Assets:
Cash equivalents:	207,014	174,720
Fair value on a recurring basis \| Commercial paper
Assets:
Cash equivalents:	76,789	388,801
Fair value on a recurring basis \| Time deposits
Assets:
Cash equivalents:	32,457	42,914
Fair value on a recurring basis \| Corporate debt securities
Assets:
Marketable securities	232,917	159,197
Fair value on a recurring basis \| Equity security
Assets:
Marketable securities	606	1,451
Long-term investments:	11,388	7,410
Fair value on a recurring basis \| Auction rate security
Assets:
Long-term investments:	6,630	6,070
Fair value on a recurring basis \| Quoted Market Prices in Active Markets for Identical Assets (Level 1)
Assets:
Total Assets	219,008	183,581
Fair value on a recurring basis \| Quoted Market Prices in Active Markets for Identical Assets (Level 1) \| Money market funds
Assets:
Cash equivalents:	207,014	174,720
Fair value on a recurring basis \| Quoted Market Prices in Active Markets for Identical Assets (Level 1) \| Equity security
Assets:
Marketable securities	606	1,451
Long-term investments:	11,388	7,410
Fair value on a recurring basis \| Significant Other Observable Inputs (Level 2)
Assets:
Total Assets	342,163	590,912
Fair value on a recurring basis \| Significant Other Observable Inputs (Level 2) \| Commercial paper
Assets:
Cash equivalents:	76,789	388,801
Fair value on a recurring basis \| Significant Other Observable Inputs (Level 2) \| Time deposits
Assets:
Cash equivalents:	32,457	42,914
Fair value on a recurring basis \| Significant Other Observable Inputs (Level 2) \| Corporate debt securities
Assets:
Marketable securities	232,917	159,197
Fair value on a recurring basis \| Significant Unobservable Inputs (Level 3)
Assets:
Total Assets	6,630	6,070
Liabilities:
Contingent consideration arrangement	(31,858)	(30,140)
Fair value on a recurring basis \| Significant Unobservable Inputs (Level 3) \| Auction rate security
Assets:
Long-term investments:	$ 6,630	$ 6,070

Fair value, as of the balance sheet date, of potential cash payments under the contingent consideration arrangement.

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

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

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Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

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Investments in debt and equity securities which are categorized neither as held-to-maturity nor trading and which are intended to be sold or mature more than one year from the balance sheet date or operating cycle, if longer. Such securities are reported at fair value; unrealized gains (losses) related to Available-for-sale Securities are excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain (loss) of an Available-for-sale security that is designated as being hedged in a fair value hedge is recognized in earnings during the period of the hedge, as are other than temporary declines in fair value below the cost basis for investments in equity securities and debt securities that an entity intends to sell or it is more likely than not that it will be required to sell before the recovery of its amortized cost basis. Other than temporary declines in fair value below the cost basis for debt securities categorized as Available-for-sale that an entity does not intend to sell and for which it is not more likely than not that the entity will be required to sell before the recovery of its amortized cost basis are bifurcated into credit losses and losses related to all other factors. Other than temporary declines in fair value below cost basis related to credit losses are recognized in earnings, and losses related to all other factors are recognized in other comprehensive income.

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-Publisher FASB

-Name Accounting Standards Codification

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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.

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-Glossary Cash

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-Glossary Cash Equivalents

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