Common Stock Reserved for Issuance (Tables)

6 Months Ended

Jun. 30, 2013

Common Stock Reserved for Issuance

Schedule of shares of common stock reserved for issuance

 As of December 31, 2010, 2011, 2012 and June 30, 2013, the Company had reserved shares of common stock, on an as-if-converted basis, for issuance as follows:

	December 31,
							June 30, 2013
	2010		2011		2012
							(unaudited)
Exercise of stock options to purchase common stock		2,350,977		4,587,344		6,581,481		7,891,581
Issuances of shares available under stock option plans		2,538,359		1,776,912		928,105		3,419,575
Vesting of restricted stock units		—		—		328,466		256,635
Employee stock purchase plan		—		—		—		738,032
Conversion of convertible preferred stock		21,245,808		25,033,684		25,876,142		—
		26,135,144		31,397,940		33,714,194		12,305,823