Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (17,624)		$ (6,195)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	800		626
Stock-based compensation	6,666		2,853
Amortization of acquired intangible assets	204
Amortization of premiums/accretion of discounts on short-term investments	109		186
Changes in operating assets and liabilities:
Accounts receivable, net	15,870		11,277
Inventory	(181)		13
Prepaid expenses and other assets	110		(598)
Accounts payable	(592)		(1,006)
Accrued compensation and benefits	(598)		802
Accrued and other liabilities	269		(714)
Severance pay (net)	188		111
Deferred revenue	(2,025)		358
Deferred tax assets	(19)		(12)
Other	(1)		(8)
Net cash provided by operating activities	3,176		7,693
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of short-term investments	(10,206)		(18,400)
Proceeds from sales/maturities of short-term investments	13,585		17,631
Acquisitions, net of cash acquired	(12,083)
Purchase of property and equipment	(1,718)		(511)
Change in restricted cash			(5)
Net cash used in investing activities	(10,422)		(1,285)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock, net of repurchases	1,289		628
Net cash used provided by financing activities	1,289		628
Effect of exchange rate changes on cash and cash equivalents			(83)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(5,957)		6,953
CASH AND CASH EQUIVALENTS - Beginning of period	76,704	[1]	59,201
CASH AND CASH EQUIVALENTS - End of period	70,747		66,154
NONCASH INVESTING AND FINANCING ACTIVITIES:
Vesting of restricted and early exercised stock options	200		200
Common stock issued in connection with acquisitions	$ 24,164

[1] The Condensed Consolidated Balance Sheet as of December 31, 2013 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.