Annual report pursuant to Section 13 and 15(d)

Intangible Assets (Intangible Assets Subject To Amortization) (Detail)

v3.3.1.900
Intangible Assets (Intangible Assets Subject To Amortization) (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 9 years 8 months 9 days  
Gross Carrying Amount $ 209,840 $ 174,259
Accumulated Amortization $ 71,909 51,258
Technology    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 7 years 10 months 24 days  
Gross Carrying Amount $ 25,563 23,483
Accumulated Amortization $ 12,488 9,223
Relationships With Financial Advisors    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 15 years 2 months 12 days  
Gross Carrying Amount $ 110,671 81,438
Accumulated Amortization $ 32,028 23,704
Vendor Relationships    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 7 years  
Gross Carrying Amount $ 3,613 3,613
Accumulated Amortization $ 3,613 3,458
Covenants Not-to-Compete    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 3 years 10 months 24 days  
Gross Carrying Amount $ 6,035 5,401
Accumulated Amortization $ 3,347 2,100
Customer Accounts    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 8 years 3 months 18 days  
Gross Carrying Amount $ 2,029 2,029
Accumulated Amortization $ 1,765 1,516
Trade names    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 7 years 8 months 12 days  
Gross Carrying Amount $ 16,910 15,154
Accumulated Amortization $ 7,790 2,099
Renewal revenue    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 7 years 10 months 24 days  
Gross Carrying Amount $ 41,381 39,503
Accumulated Amortization $ 7,263 5,563
Relationships With Investment Banking Clients    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 4 years  
Gross Carrying Amount $ 2,586 2,586
Accumulated Amortization $ 2,586 2,586
Leases    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 6 years  
Gross Carrying Amount $ 861 861
Accumulated Amortization $ 861 861
Referral Agreement    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 6 years 7 months 6 days  
Gross Carrying Amount $ 124 124
Accumulated Amortization $ 101 81
Other    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 6 years  
Gross Carrying Amount $ 67 67
Accumulated Amortization $ 67 $ 67