Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total		Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning balance at Dec. 31, 2015	$ 240,201		$ 3	$ 448,069	$ (206,540)	$ (1,331)
Beginning balance, shares at Dec. 31, 2015			31,837,144
Issuance of common stock under employee equity plans, net of repurchases	590			590
Issuance of common stock under employee equity plans, net of repurchases, shares			215,958
Issuance of holdback shares in connection with acquisitions, shares			206,499
Stock-based compensation	15,655			15,655
Income tax deficiencies from employee stock option exercises	(4)			(4)
Shares withheld for tax withholding on vesting of restricted stock units	(2,352)			(2,352)
Components of other comprehensive income (loss), net of tax
Change in unrealized gain (loss) on investments	169					169
Change in unrealized gain (loss) on hedging instruments	916					916
Net income (loss)	(24,007)				(24,007)
Comprehensive income (loss)	(22,922)
Ending balance at Mar. 31, 2016	231,168		$ 3	461,958	(230,547)	(246)
Ending balance, shares at Mar. 31, 2016			32,259,601
Beginning balance at Dec. 31, 2016	231,963	[1]	$ 3	510,257	(276,819)	(1,478)
Beginning balance, shares at Dec. 31, 2016			33,088,990
Cumulative effect of a change in accounting principle	14			2,601	(2,587)
Issuance of common stock under employee equity plans, net of repurchases	7,149			7,149
Issuance of common stock under employee equity plans, net of repurchases, shares			365,552
Stock-based compensation	13,610			13,610
Shares withheld for tax withholding on vesting of restricted stock units	(4,632)			(4,632)
Components of other comprehensive income (loss), net of tax
Change in unrealized gain (loss) on investments	28					28
Change in unrealized gain (loss) on hedging instruments	1,729					1,729
Net income (loss)	23,083				23,083
Comprehensive income (loss)	24,840
Ending balance at Mar. 31, 2017	$ 272,944		$ 3	$ 528,985	$ (256,323)	$ 279
Ending balance, shares at Mar. 31, 2017			33,454,542

[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.