Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017		Sep. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income (loss)	$ 19,223		$ (60,461)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	7,780		5,107
Stock-based compensation	36,588		45,736
Amortization of acquired intangibles	582		1,056
Loss on disposals	48		267
Amortization of premiums/accretion of discounts on short-term investments	56		144
Excess tax deficiencies from share-based compensation			29
Gain on sale of business	(35,871)		0
Other	(1,090)		(265)
Changes in operating assets and liabilities:
Accounts receivable, net	2,767		15,349
Inventory	61		40
Prepaid expenses and other assets	(794)		549
Accounts payable	(628)		(2,089)
Accrued compensation and benefits	3,981		(2,360)
Accrued and other liabilities	4,936		515
Severance pay (net)	256		315
Deferred revenue	13,253		9,893
Deferred tax assets	(1,682)		(183)
Net cash provided by operating activities	49,466		13,642
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sales/maturities of short-term investments	66,463		54,916
Purchase of short-term investments	(91,878)		(107,403)
Proceeds from sale of business	35,015		0
Net purchases of property and equipment	(9,835)		(13,953)
Change in restricted cash	(302)		10
Net cash used in investing activities	(537)		(66,430)
CASH FLOWS FROM FINANCING ACTIVITIES:
Settlement of holdback liability	0		(7,157)
Proceeds from issuance of common stock, net of repurchases	14,790		8,106
Shares withheld for tax withholding on vesting of restricted stock units	(8,217)		(6,520)
Offering costs relating to follow-on public offering	0		(112)
Excess tax deficiencies from share-based compensation	0		(29)
Net cash provided by (used in) financing activities	6,573		(5,712)
Effect of exchange rate changes on cash and cash equivalents	1,090		265
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	56,592		(58,235)
CASH AND CASH EQUIVALENTS - Beginning of period	107,343	[1]	168,252
CASH AND CASH EQUIVALENTS - End of period	163,935		110,017
NONCASH INVESTING AND FINANCING ACTIVITIES:
Property and equipment acquired but not yet paid	$ 3,120		$ 295

[1] The Condensed Consolidated Balance Sheet as of December 31, 2016 has been derived from the audited consolidated financial statements at that date but does not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements.