Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2010 Redeemable convertible preferred stock
Preferred stock, par value	$ 8.86
Issuance of Series D redeemable convertible preferred stock, issuance costs	$ 286