CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (PARENTHETICAL) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Stockholders' Equity [Abstract]
Unrealized gain (loss) on marketable securities, tax (benefit)	$ 15,313	$ 1,551	$ (7,621)
Currency translation adjustment, tax (benefit)	$ 34,268	$ 60,418	$ 55,597

Amount of tax expense (benefit), after reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=66004124&loc=d3e640-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66004124&loc=SL7669646-108580

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration