ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Realized gain/losses reclassified from AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Realized (Gains)/Losses Reclassified from Accumulated Other Comprehensive Income
Cost of revenues	$ 464,125	$ 388,573	$ 300,450
General and administrative	79,473	68,870	52,170
Sales and marketing	162,726	148,553	150,457
Research and development	414,875	360,344	365,878
Interest and other, net	16,009	137	(4,822)
Net income (loss)	(205,095)	(134,258)	$ 19,425
Realized (Gains)/Losses Reclassified from Accumulated Other Comprehensive Income
Realized (Gains)/Losses Reclassified from Accumulated Other Comprehensive Income
Net income (loss)	(2,126)	4,803
Realized (Gains)/Losses Reclassified from Accumulated Other Comprehensive Income \| Unrealized Gains (Losses) on Derivatives Designated as Hedging Instruments
Realized (Gains)/Losses Reclassified from Accumulated Other Comprehensive Income
Cost of revenues and Operating expenses:	(2,072)
Cost of revenues	(85)
General and administrative	(161)
Sales and marketing	(163)
Research and development	(1,663)
Realized (Gains)/Losses Reclassified from Accumulated Other Comprehensive Income \| Realized (gains)/losses on derivatives designated as hedging instruments
Realized (Gains)/Losses Reclassified from Accumulated Other Comprehensive Income
Cost of revenues and Operating expenses:		4,787
Cost of revenues		206
General and administrative		472
Sales and marketing		384
Research and development		3,725
Realized (Gains)/Losses Reclassified from Accumulated Other Comprehensive Income \| Realized losses on available-for-sale securities
Realized (Gains)/Losses Reclassified from Accumulated Other Comprehensive Income
Interest and other, net	$ 54	$ (16)

The aggregate cost of goods produced and sold and services rendered during the reporting period.

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