FAIR VALUE OF CERTAIN FINANCIAL ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Total fair value
Fair value of certain assets
Cash	$ 194,242	$ 196,090
Foreign currency derivatives	(570)	(252)
Assets measured at fair value	2,819,260	1,194,395
Money market funds \| Total fair value
Fair value of certain assets
Assets measured at fair value	624,007	106,928
Commercial paper \| Total fair value
Fair value of certain assets
Assets measured at fair value	361,833	19,482
Municipal securities \| Total fair value
Fair value of certain assets
Assets measured at fair value	670,186	854,787
U.S. government agency securities \| Total fair value
Fair value of certain assets
Assets measured at fair value	740,525	9,199
Variable rate demand notes \| Total fair value
Fair value of certain assets
Assets measured at fair value		4,001
Auction rate securities \| Total fair value
Fair value of certain assets
Assets measured at fair value	1,487	3,910
Put options \| Total fair value
Fair value of certain assets
Assets measured at fair value	48	250
U.S. Treasuries \| Total fair value
Fair value of certain assets
Assets measured at fair value	111,993
Certificates of deposit \| Total fair value
Fair value of certain assets
Assets measured at fair value	115,509
Level 1
Fair value of certain assets
Cash	194,242	196,090
Assets measured at fair value	818,249	303,018
Level 1 \| Money market funds
Fair value of certain assets
Assets measured at fair value	624,007	106,928
Level 2
Fair value of certain assets
Foreign currency derivatives	(570)	(252)
Assets measured at fair value	1,999,476	887,217
Level 2 \| Commercial paper
Fair value of certain assets
Assets measured at fair value	361,833	19,482
Level 2 \| Municipal securities
Fair value of certain assets
Assets measured at fair value	670,186	854,787
Level 2 \| U.S. government agency securities
Fair value of certain assets
Assets measured at fair value	740,525	9,199
Level 2 \| Variable rate demand notes
Fair value of certain assets
Assets measured at fair value		4,001
Level 2 \| U.S. Treasuries
Fair value of certain assets
Assets measured at fair value	111,993
Level 2 \| Certificates of deposit
Fair value of certain assets
Assets measured at fair value	115,509
Level 3
Fair value of certain assets
Assets measured at fair value	1,535	4,160
Level 3 \| Auction rate securities
Fair value of certain assets
Assets measured at fair value	1,487	3,910
Level 3 \| Put options
Fair value of certain assets
Assets measured at fair value	$ 48	$ 250

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

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

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Amount 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. Excludes cash and cash equivalents within disposal group and discontinued operation.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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No definition available.

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