BUSINESS COMBINATION: (Details) - USD ($)			1 Months Ended
	Feb. 23, 2016	Nov. 17, 2015	Sep. 30, 2015	Mar. 31, 2017	Mar. 31, 2016
Business Acquisition [Line Items]
Effective date of acquisition	Feb. 23, 2016
Name of acquired entity	EZchip
Date of acquisition agreement		Nov. 17, 2015	Sep. 30, 2015
Cash acquired					$ 87,500
Consideration transferred	$ 693,700,000
EZchip purchase price (in USD per share)	$ 25.50
Current liabilities	$ 10,253,000
Share-based compensation expense	$ 22,200,000
Award requisite service period (in years)	2 years 3 months 1 day
Debt instrument, face amount	$ 280,000,000
Debt instrument, maturity date	Feb. 21, 2019
Employee Stock Option [Member]
Business Acquisition [Line Items]
Share price (in USD per share)	$ 46.40			$ 50.95
EZchip [Member]
Business Acquisition [Line Items]
Cash acquired	$ 782,209,000
Cash payment for all outstanding common stock of EZchip at $25.50 per share	$ 781,237,000
EZchip purchase price (in USD per share)	$ 25.50
Cash acquired from acquisition	$ 87,545,000
EZchip [Member] | Restricted Stock Units (RSUs) [Member]
Business Acquisition [Line Items]
Fair value of awards attributable to pre-acquisition services, component of purchase price	$ 1,000,000
Conversion of stock, shares converted	891,822
EZchip [Member] | Acquisition-related EZchip [Member]
Business Acquisition [Line Items]
Equity interest issued or issuable, number of shares	499,894