FAIR VALUE OF CERTAIN FINANCIAL ASSETS AND LIABILITIES (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Level 1
Fair value of certain assets
Cash	$ 174,404	$ 196,090
Assets measured at fair value	863,338	303,018
Level 1 \| Money market funds
Fair value of certain assets
Assets measured at fair value	688,934	106,928
Level 2
Fair value of certain assets
Foreign currency derivatives		(252)
Assets measured at fair value	2,116,933	887,217
Level 2 \| Commercial paper
Fair value of certain assets
Assets measured at fair value	365,364	19,482
Level 2 \| Municipal securities
Fair value of certain assets
Assets measured at fair value	662,874	854,787
Level 2 \| U.S. government agency securities
Fair value of certain assets
Assets measured at fair value	925,811	9,199
Level 2 \| Variable rate demand notes
Fair value of certain assets
Assets measured at fair value	3,901	4,001
Level 2 \| U.S. Treasuries
Fair value of certain assets
Assets measured at fair value	74,981
Level 2 \| Certificates of deposit
Fair value of certain assets
Assets measured at fair value	84,002
Level 3
Fair value of certain assets
Foreign currency derivatives	(139)
Assets measured at fair value	3,296	4,160
Level 3 \| Auction rate securities
Fair value of certain assets
Assets measured at fair value	3,246	3,910
Level 3 \| Put options
Fair value of certain assets
Assets measured at fair value	189	250
Total fair value
Fair value of certain assets
Cash	174,404	196,090
Foreign currency derivatives	(139)	(252)
Assets measured at fair value	2,983,567	1,194,395
Total fair value \| Money market funds
Fair value of certain assets
Assets measured at fair value	688,934	106,928
Total fair value \| Commercial paper
Fair value of certain assets
Assets measured at fair value	365,364	19,482
Total fair value \| Municipal securities
Fair value of certain assets
Assets measured at fair value	662,874	854,787
Total fair value \| U.S. government agency securities
Fair value of certain assets
Assets measured at fair value	925,811	9,199
Total fair value \| Variable rate demand notes
Fair value of certain assets
Assets measured at fair value	3,901	4,001
Total fair value \| Auction rate securities
Fair value of certain assets
Assets measured at fair value	3,246	3,910
Total fair value \| Put options
Fair value of certain assets
Assets measured at fair value	189	$ 250
Total fair value \| U.S. Treasuries
Fair value of certain assets
Assets measured at fair value	74,981
Total fair value \| Certificates of deposit
Fair value of certain assets
Assets measured at fair value	$ 84,002

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

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

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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

-Glossary Cash

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

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

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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.

+ References

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

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No definition available.

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