SHARE INCENTIVE PLANS: (Shares reserved, ESPP assumptions) (Details) - shares	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Ordinary shares reserved for future issuance under equity incentive plans
Shares outstanding	1,522,515
Common stock, capital shares reserved for future issuance	8,865,789
Restricted Stock Units (RSUs) [Member]
Ordinary shares reserved for future issuance under equity incentive plans
Restricted share units outstanding	3,092,935		3,324,519
Employee Stock [Member]
Ordinary shares reserved for future issuance under equity incentive plans
Shares authorized for future issuance	3,724,647
Weighted average assumptions
Dividend yield (as a percent)	0.00%	0.00%
Expected volatility (as a percent)	25.30%	37.60%
Risk-free interest rate (as a percent)	0.91%	0.46%
Expected life (in years)	6 months	6 months
Global plan [Member]
Ordinary shares reserved for future issuance under equity incentive plans
Shares authorized for future issuance	525,692