STOCKHOLDERS' EQUITY - Summary of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Equity [Abstract]
Foreign currency translation	$ (53,824)	$ (66,192)
Unrealized gain on marketable securities	1,054	1,239
Other	7,735	7,419
Total accumulated other comprehensive loss	$ (45,035)	$ (57,534)

Accumulated adjustment, net of tax, that results from the process of translating subsidiary financial statements and foreign equity investments into the reporting currency from the functional currency of the reporting entity, net of reclassification of realized foreign currency translation gains or losses.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e681-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
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-URI http://asc.fasb.org/extlink&oid=6450520&loc=d3e32583-110901

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