INCOME TAXES - Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
U.S. statutory income tax rate	(35.00%)	(35.00%)	(35.00%)
State income taxes, net of federal benefit	(1.20%)	0.00%	0.00%
Foreign income taxes	0.50%	7.90%	3.60%
Foreign tax audit	0.00%	5.20%	0.00%
Acquisition costs	6.00%	0.00%	0.00%
Foreign deemed dividends	3.80%	5.00%	1.70%
Stock-based compensation	(26.80%)	38.90%	14.40%
Tax credits	33.30%	(11.60%)	(3.30%)
Uncertain tax positions	1.20%	0.00%	0.00%
NOL and credit limitations	18.90%	0.00%	0.00%
Valuation allowance	(29.00%)	1.90%	24.30%
Goodwill amortization	1.70%	6.70%	2.20%
Meals and entertainment	0.50%	1.40%	0.80%
Tax reform	(8.80%)	0.00%	0.00%
Other, net	0.60%	1.60%	(2.00%)
Effective income tax rate	(34.30%)	22.00%	6.70%