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v3.25.0.1

Shareholders' Equity - Narrative (Details) - USD ($) $ / shares in Units, shares in Thousands | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Dec. 31, 2024 | Jun. 30, 2024 | Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 29, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Weighted average fair value of stock options granted (in USD per share) |  |  | $ 23.07 | $ 15.70 | $ 17.95 |
(Decrease) increase in stock-based compensation from change in management's estimate |  |  | $ 11,181,000 | $ (6,941,000) | $ (4,915,000) |
Unvested employee stock options outstanding (in shares) | 6,755 |  | 6,755 |  |  |
Unrecognized compensation cost from employee stock options | $ 67,910,000 |  | $ 67,910,000 |  |  |
Weighted average period for recognition of unrecognized compensation cost |  |  | 2 years 1 month 6 days |  |  |
Options outstanding weighted average remaining contractual life, years |  |  | 6 years 2 months 12 days |  |  |
Total intrinsic value of options exercised |  |  | $ 54,101,000 | $ 34,499,000 |  |
Aggregate intrinsic value of options exercisable | 203,313,000 |  | 203,313,000 |  |  |
Total intrinsic value of options outstanding | $ 324,138,000 |  | $ 324,138,000 |  |  |
Share price of SEI common stock (in USD per share) |  |  |  |  |  | $ 82.48
Dividends declared per common share (in USD per share) | $ 0.49 | $ 0.46 | $ 0.95 | $ 0.89 | $ 0.83 |
Cash dividends declared |  |  | $ (123,119,000) | $ (117,894,000) | $ (112,429,000) |
Common Stock Buyback |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Remaining stock repurchase authorization amount | $ 169,600,000 |  | $ 169,600,000 |  |  |
Employee Stock Purchase Plan |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Employee stock purchase plan, employee eligible percentage on offerings of common stock |  |  | 85.00% |  |  |
Shares reserved under the plan (in shares) | 15,652 |  | 15,652 |  |  |
Issuance of common stock under the employee stock purchase plan (in shares) |  |  | 12,558 |  |  |
Employee stock purchase plan |  |  | $ 0 | $ 0 | $ 0 |
Restricted Stock Units (RSUs) |  |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |
Weighted average period for recognition of unrecognized compensation cost |  |  | 1 year 10 months 24 days |  |  |
Unrecognized compensation cost from employee stock options | $ 52,685,000 |  | $ 52,685,000 |  |  |

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