THE COMPANY AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Net income (loss) (per share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Net income	$ 38,429	$ 48,620	$ 16,526	$ 37,843	$ 87,049	$ 54,369
Basic and diluted shares:
Weighted average ordinary shares outstanding (in shares)	54,707		52,615		54,469	52,219
Effect of dilutive shares (in shares)	1,773		1,851		1,711	1,930
Shares used to compute diluted net income per share (in shares)	56,480		54,466		56,180	54,149
Net income per share - basic (in USD per share)	$ 0.70		$ 0.31		$ 1.60	$ 1.04
Net income per share - diluted (in USD per share)	$ 0.68		$ 0.30		$ 1.55	$ 1.00
Share options and restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0		200		0	200