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Business Segment Information - Schedule of Financial Information About Business Segments (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2025 | Sep. 30, 2024 | Sep. 30, 2025 | Sep. 30, 2024
Segment Reporting Information [Line Items] |  |  |  |
Total revenue | $ 578,511 | $ 537,396 | $ 1,689,456 | $ 1,567,961
Operations & services | 212,410 | 199,006 | 626,378 | 585,803
Sales, marketing & client service | 44,446 | 42,408 | 132,723 | 128,311
Technology services & infrastructure | 54,051 | 50,229 | 160,951 | 147,061
Strategic initiatives & new business development | 50,649 | 50,831 | 146,350 | 153,004
Other segment expenses | 14,200 | 13,184 | 38,583 | 38,589
Segment profit (loss) | 202,755 | 181,738 | 584,471 | 515,193
Investment Managers |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Total revenue | 207,050 | 184,607 | 594,165 | 537,128
Operations & services | 89,335 | 82,140 | 263,945 | 241,176
Sales, marketing & client service | 11,240 | 9,515 | 31,573 | 29,236
Technology services & infrastructure | 12,887 | 11,008 | 39,407 | 31,752
Strategic initiatives & new business development | 8,316 | 8,584 | 20,987 | 25,569
Other segment expenses | 4,156 | 2,871 | 8,869 | 7,222
Segment profit (loss) | 81,116 | 70,489 | 229,384 | 202,173
Private Banks |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Total revenue | 143,994 | 138,734 | 423,157 | 401,272
Operations & services | 54,044 | 50,749 | 157,576 | 147,120
Sales, marketing & client service | 10,723 | 9,928 | 29,756 | 31,241
Technology services & infrastructure | 28,809 | 27,754 | 85,412 | 81,540
Strategic initiatives & new business development | 21,305 | 21,317 | 65,185 | 63,437
Other segment expenses | 5,882 | 5,349 | 16,307 | 16,623
Segment profit (loss) | 23,231 | 23,637 | 68,921 | 61,311
Investment Advisors |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Total revenue | 147,465 | 126,836 | 421,234 | 370,141
Operations & services | 46,211 | 40,121 | 130,048 | 118,707
Sales, marketing & client service | 8,819 | 8,122 | 28,251 | 21,175
Technology services & infrastructure | 9,074 | 8,590 | 26,849 | 25,260
Strategic initiatives & new business development | 13,389 | 11,790 | 37,191 | 36,437
Other segment expenses | 1,635 | 1,529 | 5,045 | 4,484
Segment profit (loss) | 68,337 | 56,684 | 193,850 | 164,078
Institutional Investors |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Total revenue | 71,826 | 71,626 | 209,675 | 214,911
Operations & services | 21,010 | 21,217 | 62,401 | 64,048
Sales, marketing & client service | 9,820 | 10,162 | 29,574 | 32,438
Technology services & infrastructure | 1,678 | 1,504 | 4,810 | 4,442
Strategic initiatives & new business development | 4,168 | 3,210 | 8,994 | 10,200
Other segment expenses | 1,392 | 1,758 | 4,016 | 5,258
Segment profit (loss) | 33,758 | 33,775 | 99,880 | 98,525
Investments In New Businesses |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |
Total revenue | 8,176 | 15,593 | 41,225 | 44,509
Operations & services | 1,810 | 4,779 | 12,408 | 14,752
Sales, marketing & client service | 3,844 | 4,681 | 13,569 | 14,221
Technology services & infrastructure | 1,603 | 1,373 | 4,473 | 4,067
Strategic initiatives & new business development | 3,471 | 5,930 | 13,993 | 17,361
Other segment expenses | 1,135 | 1,677 | 4,346 | 5,002
Segment profit (loss) | $ (3,687) | $ (2,847) | $ (7,564) | $ (10,894)

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