DEFERRED CONTRACT COSTS AND DEFERRED REVENUE (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Capitalized Contract Cost, Net [Abstract]
Deferred contract costs, current and noncurrent, as of the beginning of period	$ 29,384	$ 25,947	$ 28,049	$ 27,080
Capitalized commissions during the period	7,123	3,104	15,165	8,039
Amortized deferred contract costs during the period	(3,585)	(3,144)	(10,292)	(9,212)
Deferred contract costs, current and noncurrent, as of the end of period	32,922	25,907	32,922	25,907
Change in Contract with Customer, Liability [Abstract]
Deferred revenue, current and noncurrent, as of the beginning of period	218,506	204,845	235,498	196,706
Billings, net	68,309	51,262	207,751	195,143
Revenue recognized	(82,518)	(69,182)	(238,952)	(204,924)
Deferred revenue, current and noncurrent, as of the end of period	204,297	$ 186,925	204,297	$ 186,925
Deferred revenue, current	179,512		179,512		$ 205,771
Deferred revenue, noncurrent	$ 24,785		$ 24,785		$ 29,727