THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 707,760	$ 555,450	$ 1,375,372	$ 1,100,092
Direct Revenue
Disaggregation of Revenue [Line Items]
Revenue	694,322	546,741	1,349,503	1,081,565
Indirect Revenue (principally advertising revenue)
Disaggregation of Revenue [Line Items]
Revenue	13,438	8,709	25,869	18,527
Americas | Direct Revenue
Disaggregation of Revenue [Line Items]
Revenue	374,388	298,693	718,650	579,938
Europe | Direct Revenue
Disaggregation of Revenue [Line Items]
Revenue	196,542	154,050	385,601	310,540
APAC and Other | Direct Revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 123,392	$ 93,998	$ 245,252	$ 191,087