Annual report pursuant to Section 13 and 15(d)

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

v3.19.1
Intangible Assets (Intangible Assets Subject To Amortization) (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 9 years 10 months 4 days  
Gross Carrying Amount $ 184,845 $ 217,550
Accumulated Amortization $ 111,781 113,939
Technology    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 7 years 9 months 60 days  
Gross Carrying Amount $ 25,563 25,563
Accumulated Amortization $ 22,187 19,020
Relationships with financial advisors    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 14 years 3 months 30 days  
Gross Carrying Amount $ 126,122 117,995
Accumulated Amortization $ 59,584 49,925
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 3,613
Covenants not-to-compete    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 3 years 10 months  
Gross Carrying Amount $ 6,964 6,421
Accumulated Amortization $ 6,258 5,732
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 $ 2,029 2,029
Trade names    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 7 years 8 months 12 days  
Gross Carrying Amount $ 16,916 16,910
Accumulated Amortization 14,472 12,245
Renewal revenue (1)    
Indefinite-lived Intangible Assets [Line Items]    
Gross Carrying Amount 0 41,381
Accumulated Amortization $ 0 17,737
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 $ 124 124
Other    
Indefinite-lived Intangible Assets [Line Items]    
Weighted-Average Estimated Useful Life 6 years  
Gross Carrying Amount $ 67 67
Accumulated Amortization $ 67 $ 67