CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 67,527	$ 68,044
Adjustments to reconcile net profit to net cash provided by operating activities:
Deferred taxes	297	17,496
Depreciation and amortization	8,638	9,130
Stock-based compensation	24,474	19,438
Excess tax benefit from share-based payment arrangements	(6,207)	(16,161)
Other non-cash operating activities	6,162	5,095
Changes in assets and liabilities, net of acquired assets and liabilities:
Accounts receivable	(22,904)	(21,407)
Inventories	(510)	855
Prepaid expenses and other assets	(4,786)	(2,806)
Accounts payable	4,902	(9)
Accrued and other long-term liabilities	8,259	1,343
Deferred revenues	12,733	6,705
Net cash provided by operating activities	98,585	87,723
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property, plant and equipment	(26,172)	(9,960)
Purchase of marketable securities	(195,399)	(232,178)
Proceeds from maturities of marketable securities	148,685	92,005
Proceeds from sales of marketable securities	12,518	32,683
Other investing activities	46	(133)
Net cash used in investing activities	(60,322)	(117,583)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock	6,036	12,622
Common stock repurchases	(50,781)	(49,000)
Equity forward contract related to accelerated share repurchase	(21,000)	(21,000)
Excess tax benefit from share-based payment arrangements	6,207	16,161
Employees’ taxes paid upon the vesting of restricted stock units	(15,389)	(4,650)
Net cash used in financing activities	(74,927)	(45,867)
Effect of foreign exchange rate changes on cash and cash equivalents	(1,454)	245
Net decrease in cash and cash equivalents	(38,118)	(75,482)
Cash and cash equivalents, beginning of the period	199,871	$ 242,953
Cash and cash equivalents, end of the period	$ 161,753