Capital Stock (Tables)

9 Months Ended

Sep. 30, 2012

Capital Stock [Abstract]

Reserved shares of common stock for future issuance

	September 30, 2012		December 31, 2011
Shares reserved for convertible preferred stock		—		13,205,180
Shares reserved for stock options and restricted stock units		7,478,166		5,849,131
Shares reserved for employee stock purchase plan		451,764		—
Shares reserved for warrants		1,333		111,602