Preferred Stock and Stockholders' Equity - Preferred Stock and Common Stock Narrative (Details) (USD $) In Thousands, except Share data, unless otherwise specified						0 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Nov. 29, 2010	Dec. 01, 2010 Series A Preferred Stock [Member]	Dec. 01, 2010 Series B Preferred Stock [Member]	Nov. 29, 2010 Preferred Stock [Member]	Nov. 29, 2010 Common Stock [Member]
Class of Stock [Line Items]
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, par value (in usd per share)	$ 0.001	$ 0.001
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0		77,891,000	64,507,000
Conversion of convertible preferred stock to common stock at initial public offering, shares			10.00
Preferred stock outstanding				$ 76,955	$ 72,357
Conversion of Stock, Shares Converted						142,398,000
Common stock, shares outstanding							14,240,000
Common stock, shares authorized	200,000,000	100,000,000
Common stock, par value (in usd per share)	$ 0.001	$ 0.001