GEOGRAPHIC INFORMATION - Revenue by geographic region (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) segment	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment	1
Revenues by geographic region
Total revenue	$ 1,330,576	$ 1,088,743	$ 863,893
United States
Revenues by geographic region
Total revenue	515,292	402,840	327,528
China
Revenues by geographic region
Total revenue	372,041	258,451	172,405
Europe
Revenues by geographic region
Total revenue	169,594	174,892	176,937
Other Americas
Revenues by geographic region
Total revenue	123,956	128,077	92,449
Other Asia
Revenues by geographic region
Total revenue	$ 149,693	$ 124,483	$ 94,574