v3.26.3
REVENUE RECOGNITION = Disaggregation of Revenue (Details) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Disaggregation of Revenue [Line Items]        
Total revenue $ 376,183 $ 339,778 $ 1,133,502 $ 994,639
Services transferred at a point in time        
Disaggregation of Revenue [Line Items]        
Total revenue 321,052 296,116 977,162 873,162
Services transferred over time        
Disaggregation of Revenue [Line Items]        
Total revenue 55,131 43,662 156,340 121,477
Transaction and clearing fees        
Disaggregation of Revenue [Line Items]        
Total revenue 316,420 292,814 963,714 868,257
Access fees        
Disaggregation of Revenue [Line Items]        
Total revenue 36,949 27,096 105,247 77,285
Market data fees        
Disaggregation of Revenue [Line Items]        
Total revenue 13,877 10,730 39,038 30,625
Other revenue        
Disaggregation of Revenue [Line Items]        
Total revenue 8,937 9,138 25,503 18,472
Corporate & Other        
Disaggregation of Revenue [Line Items]        
Total revenue 292 313 833 852
Corporate & Other | Services transferred at a point in time        
Disaggregation of Revenue [Line Items]        
Total revenue 0 0 0 0
Corporate & Other | Services transferred over time        
Disaggregation of Revenue [Line Items]        
Total revenue 292 313 833 852
Corporate & Other | Transaction and clearing fees        
Disaggregation of Revenue [Line Items]        
Total revenue 0 0 0 0
Corporate & Other | Access fees        
Disaggregation of Revenue [Line Items]        
Total revenue (57) (57) (171) (171)
Corporate & Other | Market data fees        
Disaggregation of Revenue [Line Items]        
Total revenue (8) (8) (23) (23)
Corporate & Other | Other revenue        
Disaggregation of Revenue [Line Items]        
Total revenue 357 378 1,027 1,046
Options | Operating Segments        
Disaggregation of Revenue [Line Items]        
Total revenue 317,286 276,540 939,232 799,393
Options | Operating Segments | Services transferred at a point in time        
Disaggregation of Revenue [Line Items]        
Total revenue 276,704 246,661 825,068 714,048
Options | Operating Segments | Services transferred over time        
Disaggregation of Revenue [Line Items]        
Total revenue 40,582 29,879 114,164 85,345
Options | Operating Segments | Transaction and clearing fees        
Disaggregation of Revenue [Line Items]        
Total revenue 274,261 245,406 817,720 712,330
Options | Operating Segments | Access fees        
Disaggregation of Revenue [Line Items]        
Total revenue 32,689 23,076 92,563 65,668
Options | Operating Segments | Market data fees        
Disaggregation of Revenue [Line Items]        
Total revenue 10,211 7,011 28,689 20,087
Options | Operating Segments | Other revenue        
Disaggregation of Revenue [Line Items]        
Total revenue 125 1,047 260 1,308
Equities | Operating Segments        
Disaggregation of Revenue [Line Items]        
Total revenue 28,694 38,028 103,238 118,466
Equities | Operating Segments | Services transferred at a point in time        
Disaggregation of Revenue [Line Items]        
Total revenue 22,789 31,899 85,686 100,545
Equities | Operating Segments | Services transferred over time        
Disaggregation of Revenue [Line Items]        
Total revenue 5,905 6,129 17,552 17,921
Equities | Operating Segments | Transaction and clearing fees        
Disaggregation of Revenue [Line Items]        
Total revenue 22,788 31,899 85,633 100,545
Equities | Operating Segments | Access fees        
Disaggregation of Revenue [Line Items]        
Total revenue 3,824 3,761 11,488 10,915
Equities | Operating Segments | Market data fees        
Disaggregation of Revenue [Line Items]        
Total revenue 2,082 2,368 6,064 7,006
Equities | Operating Segments | Other revenue        
Disaggregation of Revenue [Line Items]        
Total revenue 0 0 53 0
Futures | Operating Segments        
Disaggregation of Revenue [Line Items]        
Total revenue 23,772 19,364 72,672 67,278
Futures | Operating Segments | Services transferred at a point in time        
Disaggregation of Revenue [Line Items]        
Total revenue 19,355 15,632 60,352 55,881
Futures | Operating Segments | Services transferred over time        
Disaggregation of Revenue [Line Items]        
Total revenue 4,417 3,732 12,320 11,397
Futures | Operating Segments | Transaction and clearing fees        
Disaggregation of Revenue [Line Items]        
Total revenue 19,300 15,424 60,164 55,184
Futures | Operating Segments | Access fees        
Disaggregation of Revenue [Line Items]        
Total revenue 455 275 1,251 751
Futures | Operating Segments | Market data fees        
Disaggregation of Revenue [Line Items]        
Total revenue 1,512 1,279 4,068 3,315
Futures | Operating Segments | Other revenue        
Disaggregation of Revenue [Line Items]        
Total revenue 2,505 2,386 7,189 8,028
International | Operating Segments        
Disaggregation of Revenue [Line Items]        
Total revenue 6,139 5,533 17,527 8,650
International | Operating Segments | Services transferred at a point in time        
Disaggregation of Revenue [Line Items]        
Total revenue 2,204 1,924 6,056 2,688
International | Operating Segments | Services transferred over time        
Disaggregation of Revenue [Line Items]        
Total revenue 3,935 3,609 11,471 5,962
International | Operating Segments | Transaction and clearing fees        
Disaggregation of Revenue [Line Items]        
Total revenue 71 85 197 198
International | Operating Segments | Access fees        
Disaggregation of Revenue [Line Items]        
Total revenue 38 41 116 122
International | Operating Segments | Market data fees        
Disaggregation of Revenue [Line Items]        
Total revenue 80 80 240 240
International | Operating Segments | Other revenue        
Disaggregation of Revenue [Line Items]        
Total revenue $ 5,950 $ 5,327 $ 16,974 $ 8,090