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Sale of a Majority Interest of Insurance Business (Details) - USD ($) $ in Thousands |  | 12 Months Ended
--- | --- | ---
Jan. 01, 2018 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |
Gain on sale of majority interest of insurance business |  | $ 0 | $ 0 | $ 1,873
Percentage of equity owned |  | 100.00% |  |
New Partnership |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |
Percentage of equity owned | 30.00% |  |  |
S&T Evergreen Insurance LLC | Subsidiaries |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |
Percentage of ownership in subsidiary sold | 70.00% |  |  |
Gain on sale of majority interest of insurance business | $ 1,900 |  |  |

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