v3.26.1
Fair Value Of Financial Instruments (Fair Value of Assets and Liabilities Measured on Recurring Basis) (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned $ 1,699,070 $ 1,427,835
Available-for-sale securities 1,529,505 1,593,390
Financial instruments sold, but not yet purchased, at fair value 962,970 793,626
U.S. Government Agency Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale securities 2,395  
Corporate Fixed Income Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale securities 336,461  
State and Municipal Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale securities 2,320  
Agency Mortgage-Backed Securities [Member] | Agency Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale securities 1,109,680 1,101,412
Agency Mortgage-Backed Securities [Member] | Commercial [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale securities 1,269 2,113
Agency Mortgage-Backed Securities [Member] | Non-Agency [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale securities 133 152
Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale securities 1,529,505 1,593,390
Investments 85,274 81,825
Derivative contracts, Assets 70,457 [1] 71,297 [2]
Cash equivalents measured at NAV 3,168 2,340
Total Assets 3,387,474 3,176,687
Financial instruments sold, but not yet purchased, at fair value 962,970 793,626
Derivative contracts, Liabilities 70,466 [3] 71,311 [4]
Total Liabilities 1,033,436 864,937
Fair Value, Recurring [Member] | U.S. Government Agency Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 240,600 174,478
Available-for-sale securities 2,395 2,381
Fair Value, Recurring [Member] | Asset-Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 206,923 143,723
Available-for-sale securities 77,247 109,256
Fair Value, Recurring [Member] | Corporate Fixed Income Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 307,044 295,570
Available-for-sale securities 336,461 375,750
Financial instruments sold, but not yet purchased, at fair value 141,150 145,582
Fair Value, Recurring [Member] | Corporate Equity Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 47,009 55,312
Investments 34,219 34,937
Financial instruments sold, but not yet purchased, at fair value 4,362 16,363
Fair Value, Recurring [Member] | State and Municipal Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 275,626 174,579
Available-for-sale securities 2,320 2,326
Fair Value, Recurring [Member] | Auction Rate Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 184 551
Fair Value, Recurring [Member] | Other Investment [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 14,905 [5] 13,560 [6]
Fair Value, Recurring [Member] | Investments in Funds and Partnerships Measured at NAV [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 35,966 32,777
Fair Value, Recurring [Member] | Assets At Fair Value On Recurring Basis Before Cash Equivalents Measured at NAV [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Total Assets 3,384,306 3,174,347
Fair Value, Recurring [Member] | U.S. Government Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 32,340 5,196
Financial instruments sold, but not yet purchased, at fair value 661,011 475,449
Fair Value, Recurring [Member] | Agency Mortgage-Backed Securities [Member] | Agency Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 515,218 515,634
Available-for-sale securities 1,109,680 1,101,412
Financial instruments sold, but not yet purchased, at fair value 156,073 154,983
Fair Value, Recurring [Member] | Agency Mortgage-Backed Securities [Member] | Commercial [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale securities 1,269 2,113
Fair Value, Recurring [Member] | Agency Mortgage-Backed Securities [Member] | Non-Agency [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale securities 133 152
Sovereign Debt [Member] | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 1,699,070 1,427,835
Other [Member] | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 74,310 [7] 63,343 [8]
Syndicated Loans [Member] | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments sold, but not yet purchased, at fair value 374 [9] 1,249 [10]
Level 1 [Member] | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 10,671 15,490
Total Assets 89,140 76,401
Financial instruments sold, but not yet purchased, at fair value 665,373 491,699
Total Liabilities 665,373 491,699
Level 1 [Member] | Fair Value, Recurring [Member] | Corporate Fixed Income Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 106 517
Level 1 [Member] | Fair Value, Recurring [Member] | Corporate Equity Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 46,023 55,198
Investments 10,671 15,490
Financial instruments sold, but not yet purchased, at fair value 4,362 16,250
Level 1 [Member] | Fair Value, Recurring [Member] | U.S. Government Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 32,340 5,196
Financial instruments sold, but not yet purchased, at fair value 661,011 475,449
Level 1 [Member] | Sovereign Debt [Member] | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 78,469 60,911
Level 2 [Member] | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale securities 1,529,505 1,593,390
Investments 4,412 1
Derivative contracts, Assets 70,457 [1] 71,297 [2]
Total Assets 3,156,468 2,970,560
Financial instruments sold, but not yet purchased, at fair value 297,223 300,691
Derivative contracts, Liabilities 70,466 [3] 71,311 [4]
Total Liabilities 367,689 372,002
Level 2 [Member] | Fair Value, Recurring [Member] | U.S. Government Agency Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 240,600 174,478
Available-for-sale securities 2,395 2,381
Level 2 [Member] | Fair Value, Recurring [Member] | Asset-Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 206,423 139,683
Available-for-sale securities 77,247 109,256
Level 2 [Member] | Fair Value, Recurring [Member] | Corporate Fixed Income Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 306,938 295,053
Available-for-sale securities 336,461 375,750
Financial instruments sold, but not yet purchased, at fair value 141,150 145,582
Level 2 [Member] | Fair Value, Recurring [Member] | Corporate Equity Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 882 0
Investments 4,412 1
Financial instruments sold, but not yet purchased, at fair value   113
Level 2 [Member] | Fair Value, Recurring [Member] | State and Municipal Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 275,626 174,579
Available-for-sale securities 2,320 2,326
Level 2 [Member] | Fair Value, Recurring [Member] | Agency Mortgage-Backed Securities [Member] | Agency Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 515,218 515,634
Available-for-sale securities 1,109,680 1,101,412
Financial instruments sold, but not yet purchased, at fair value 156,073 154,983
Level 2 [Member] | Fair Value, Recurring [Member] | Agency Mortgage-Backed Securities [Member] | Commercial [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale securities 1,269 2,113
Level 2 [Member] | Fair Value, Recurring [Member] | Agency Mortgage-Backed Securities [Member] | Non-Agency [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale securities 133 152
Level 2 [Member] | Sovereign Debt [Member] | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 1,552,094 1,305,872
Level 2 [Member] | Other [Member] | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 6,407 [7] 6,445 [8]
Financial instruments sold, but not yet purchased, at fair value [10]   13
Level 3 [Member] | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 34,225 33,557
Total Assets 102,732 94,609
Financial instruments sold, but not yet purchased, at fair value 374 1,236
Total Liabilities 374 1,236
Level 3 [Member] | Fair Value, Recurring [Member] | Asset-Backed Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 500 4,040
Level 3 [Member] | Fair Value, Recurring [Member] | Corporate Equity Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 104  
Investments 19,136 19,446
Level 3 [Member] | Fair Value, Recurring [Member] | Auction Rate Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 184 551
Level 3 [Member] | Fair Value, Recurring [Member] | Agency Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments sold, but not yet purchased, at fair value [9] 374  
Level 3 [Member] | Fair Value, Recurring [Member] | Other Investment [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Investments 14,905 [5] 13,560 [6]
Level 3 [Member] | Sovereign Debt [Member] | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned 68,507 61,052
Level 3 [Member] | Other [Member] | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments owned $ 67,903 [7] 56,898 [8]
Level 3 [Member] | Syndicated Loans [Member] | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Financial instruments sold, but not yet purchased, at fair value [10]   $ 1,236
[1] Included in other assets in the consolidated statements of financial condition.
[2] Included in other assets in the consolidated statements of financial condition.
[3] Included in accounts payable and accrued expenses in the consolidated statements of financial condi
[4] Included in accounts payable and accrued expenses in the consolidated statements of financial condition.
[5] Primarily includes private company investments.
[6] Primarily includes private company investments.
[7] Includes syndicated loans, non-agency mortgage-backed securities, and sovereign debt.
[8] Includes syndicated loans, non-agency mortgage-backed securities, and sovereign debt.
[9] Includes syndicated loans.
[10] Includes syndicated loans and state and municipal securities.