Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017
CASH FLOWS FROM OPERATING ACTIVITIES:
Net (loss) income		$ (32,840)	$ 19,593
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization		6,196	4,943
Amortization of deferred costs		2,311	0
Stock-based compensation		25,950	25,117
Amortization of acquired intangibles		264	449
Amortization of premiums/accretion of discounts on short-term investments		130	(104)
Gain on sale of business			(35,871)
Other adjustments		769	(1,255)
Changes in operating assets and liabilities:
Accounts receivable, net		5,228	3,238
Inventory		351	192
Deferred costs		(10,106)	0
Prepaid expenses and other assets		1,487	(864)
Accounts payable		(695)	(1,901)
Income tax payable		9,696	1,148
Accrued compensation and benefits		(245)	3,626
Accrued and other liabilities		7,157	1,842
Severance pay (net)		712	246
Deferred revenue		18,958	5,132
Deferred tax assets		1,005	(1,593)
Net cash provided by operating activities		36,328	23,938
CASH FLOWS FROM INVESTING ACTIVITIES:
Proceeds from sales/maturities of short-term investments		32,609	50,923
Purchase of short-term investments		(51,253)	(69,451)
Proceeds from sale of business		0	35,015
Net purchases of property and equipment		(3,443)	(6,546)
Net cash (used in) provided by investing activities		(22,087)	9,941
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net of repurchases		9,995	11,725
Shares withheld for tax withholding on vesting of restricted stock units		(6,753)	(6,621)
Net cash provided by financing activities		3,242	5,104
Effect of exchange rate changes on cash, cash equivalents, and restricted cash		(799)	1,255
NET INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH		16,684	40,238
CASH, CASH EQUIVALENTS AND RESTRICTED CASH - Beginning of period	[1]	194,874	109,295
CASH, CASH EQUIVALENTS AND RESTRICTED CASH - End of period	[1]	211,558	149,533
NONCASH INVESTING AND FINANCING ACTIVITIES:
Property and equipment acquired but not yet paid		$ 1,609	$ 2,520

[1] Amounts in As Reported column include cash, cash equivalents and restricted cash as required. Amounts in the As Previously Reported column reflect only cash and cash equivalents.