Consolidated Balance Sheets Balance Sheet Parenthetical (USD $)
In Thousands, except Share data, unless otherwise specified
Sep. 30, 2013
Dec. 31, 2012
Preferred Stock, Par or Stated Value Per Share $ 0.0001 $ 0.0001
Preferred Stock, Shares Authorized 10,000,000 0
Preferred Stock, Shares Issued 0 0
Preferred Stock, Shares Outstanding 0 0
Series B Preferred Stock [Member]
   
Preferred Stock, Par or Stated Value Per Share $ 0.0001 $ 0.0001
Preferred Stock, Shares Authorized 0 7,000,000
Preferred Stock, Shares Issued 0 6,585,153
Preferred Stock, Shares Outstanding 0 6,585,153
Preferred Stock, Liquidation Preference, Value $ 15,080 $ 15,080
Series A Preferred Stock [Member]
   
Preferred Stock, Par or Stated Value Per Share $ 0.0001 $ 0.0001
Preferred Stock, Shares Authorized 0 10,831,164
Preferred Stock, Shares Issued 0 10,831,164
Preferred Stock, Shares Outstanding 0 10,831,164
Preferred Stock, Liquidation Preference, Value $ 5,091 $ 5,091
Common Class B [Member]
   
Par value of authorized shares $ 0.0001 $ 0.0001
Shares authorized for issuance 75,000,000 75,000,000
Shares issued and outstanding 49,722,528 34,317,137
Common Stock, Shares, Outstanding 49,722,528 34,317,137
Common Class A [Member]
   
Par value of authorized shares $ 0.0001 $ 0.0001
Shares authorized for issuance 750,000,000 75,000,000
Shares issued and outstanding 9,430,000 0
Common Stock, Shares, Outstanding 9,430,000 0