Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) (Temporary Equity) - 12 months ended Dec. 31, 2014 - USD ($) shares in Thousands	Convertible preferred stock	Total
Convertible preferred stock balance at Dec. 31, 2013	$ 185,199,000
Convertible preferred stock balance (in shares) at Dec. 31, 2013	27,048
Issuance of convertible preferred stock	$ 55,413,000
Issuance of convertible preferred stock (in shares)	4,349
Issuance costs of Series F Preferred Stock		$ (86,933)
Convertible preferred stock balance at Dec. 31, 2014	$ 240,612,000	$ 240,612
Convertible preferred stock balance (in shares) at Dec. 31, 2014	31,397