Consolidated Balance Sheets Balance Sheet Parenthetical (USD $)
In Thousands, except Share data, unless otherwise specified
Mar. 31, 2014
Dec. 31, 2013
Preferred Stock, Par or Stated Value Per Share $ 0.0001 $ 0.0001
Preferred Stock, Shares Authorized 10,000,000 10,000,000
Preferred Stock, Shares Issued 0 0
Preferred Stock, Shares Outstanding 0 0
Valuation Allowances and Reserves, Balance $ 766 $ 805
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 27,763,181 33,421,033
Common Stock, Shares, Outstanding 27,763,181 33,421,033
Common Class A [Member]
   
Par value of authorized shares $ 0.0001 $ 0.0001
Shares authorized for issuance 750,000,000 750,000,000
Shares issued and outstanding 40,051,054 28,777,653
Common Stock, Shares, Outstanding 40,051,054 28,777,653