Combined Consolidated Statements of Financial Condition (Parenthetical) (USD $)
Jun. 30, 2012
Dec. 31, 2011
Class A Common Stock
   
Common stock, par value $ 0.01 $ 0.01
Common stock, shares authorized 300,000,000 300,000,000
Common stock, shares issued 13,583,873 13,583,873
Common stock, shares outstanding 13,583,873 13,583,873
Class B Common Stock
   
Common stock, par value $ 0.01 $ 0.01
Common stock, shares authorized 2,000 2,000
Common stock, shares issued 1,000 1,000
Common stock, shares outstanding 1,000 1,000