Consolidated Statements Of Stockholders' Equity - USD ($) $ in Thousands		Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Earnings (Loss) [Member]
BALANCE at Dec. 31, 2012		$ 908,424	$ 11	$ 879,303	$ 260	$ 28,850
BALANCE, shares at Dec. 31, 2012			108,647,201
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock in connection with follow-on offering, net of offering costs		1,348,059	$ 1	1,348,058
Issuance of common stock in connection with follow-on offering, net of offering costs, shares			6,188,340
Issuance of common stock upon exercise of employee stock options		32,824		32,824
Issuance of common stock upon exercise of employee stock options, shares			3,659,817
Issuance of common stock upon vesting of restricted stock units, shares			1,154,252
Issuance of common stock in connection with employee stock purchase plan		24,589		24,589
Issuance of common stock in connection with employee stock purchase plan, shares			217,743
Issuance of common stock related to acquisitions, net of reacquired shares		40,834		40,834
Issuance of common stock related to acquisitions, net of reacquired shares, shares			487,958
Vesting of early exercised stock options		937		937
Repurchase of unvested early exercised stock options, shares			(3,562)
Stock-based compensation		203,149		203,149
Excess income tax benefit from stock-based compensation		43,755		43,755
Change in other comprehensive income		54			54
Net loss attributable to common stockholders		26,769				26,769
BALANCE at Dec. 31, 2013		2,629,394	$ 12	2,573,449	314	55,619
BALANCE, shares at Dec. 31, 2013			120,351,749
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of employee stock options		33,577	$ 1	33,576
Issuance of common stock upon exercise of employee stock options, shares			2,371,271
Issuance of common stock upon vesting of restricted stock units, shares			1,628,389
Issuance of common stock in connection with employee stock purchase plan		32,816		32,816
Issuance of common stock in connection with employee stock purchase plan, shares			261,108
Issuance of common stock related to acquisitions, net of reacquired shares		64,207		64,207
Issuance of common stock related to acquisitions, net of reacquired shares, shares			430,584
Repurchase of unvested early exercised stock options, shares			(1,151)
Stock-based compensation		330,346		330,346
Equity component of convertible senior notes, net		236,752		236,752
Purchase of convertible note hedges		(247,969)		(247,969)
Issuance of warrants		167,296		167,296
Other equity		348		348
Excess income tax benefit from stock-based compensation		94,884		94,884
Change in other comprehensive income		(512)			(512)
Net loss attributable to common stockholders		(15,747)				(15,747)
BALANCE at Dec. 31, 2014		3,325,392	$ 13	3,285,705	(198)	39,872
BALANCE, shares at Dec. 31, 2014			125,041,950
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative-effect adjustment on other derivatives as of January 1, 2015	[1]	(2,800)				(2,800)
Issuance of common stock upon exercise of employee stock options		$ 21,686		21,686
Issuance of common stock upon exercise of employee stock options, shares		871,712	871,712
Issuance of common stock upon vesting of restricted stock units, shares			2,220,663
Issuance of common stock in connection with employee stock purchase plan		$ 49,296		49,296
Issuance of common stock in connection with employee stock purchase plan, shares			296,411
Issuance of common stock related to acquisitions, net of reacquired shares		714,653		714,653
Issuance of common stock related to acquisitions, net of reacquired shares, shares			3,618,344
Repurchase of unvested early exercised stock options, shares			(185)
Stock-based compensation		511,661		511,661
Other equity		5,577		5,577
Change in other comprehensive income		9,322			9,322
Net loss attributable to common stockholders		(166,144)				(166,144)
BALANCE at Dec. 31, 2015		$ 4,468,643	$ 13	$ 4,588,578	$ 9,124	$ (129,072)
BALANCE, shares at Dec. 31, 2015			132,048,895

[1] In the fourth quarter of 2015, we adopted new authoritative accounting guidance on determining whether the host contract in a hybrid financial instrument issued in the form of a share is more akin to debt or to equity on a modified retrospective approach. As a result, we have recorded a cumulative-effect adjustment of $2.8 million to Accumulated earnings (deficit) in the first quarter of 2015 with a corresponding increase of $2.8 million to Other long-term liability. In addition, we recorded an adjustment of $6.9 million to Accumulated earnings (deficit) with a corresponding increase of $6.9 million to Other long-term liability in the third quarter of 2015.