Annual report pursuant to section 13 and 15(d)

Shareholder's Equity - Additional Information (Detail)

v2.4.0.6
Shareholder's Equity - Additional Information (Detail) (USD $)
12 Months Ended 1 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Oct. 31, 2011
Mar. 31, 2007
Nov. 30, 2011
Securities America Acquisition [Member]
Apr. 30, 2010
Former Employees [Member]
Apr. 30, 2010
Former Employees [Member]
Reduced Exercise Price [Member]
Apr. 30, 2009
Stock Repurchase Price [Member]
Capital Unit [Line Items]                  
Shares authorized for repurchase         2,500,000        
Shares authorized for additional repurchase       5,000,000          
Shares repurchased, shares 2,981,967                
Shares repurchased, value $ 4,653,000                
Share Price           $ 1.68     $ 0.68
Number of Shares 17,122,332,000         10,713,332,000 2,300,000,000    
Exercise Price               0.96  
Non-cash compensation expense $ 4,744,000 $ 4,014,000 $ 5,439,000       $ 243,000