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Parent Company Condensed Financial Information - Statements of Net Income (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Condensed Income Statements, Captions [Line Items] |  |  |
Total Interest and Dividend Income | $ 515,872 | $ 477,901 | $ 340,751
Interest expense on long-term debt | 1,964 | 1,332 | 411
Income tax benefit | 33,553 | 34,023 | 33,410
Equity in undistributed net income (distribution in excess of net income) of: |  |  |
Net Income | 131,265 | 144,781 | 135,520
S&T |  |  |
Condensed Income Statements, Captions [Line Items] |  |  |
Dividends from subsidiaries | 66,775 | 86,950 | 61,426
Total Interest and Dividend Income | 66,775 | 86,950 | 61,426
Interest expense on long-term debt | 2,180 | 2,372 | 1,545
Other expenses | 4,973 | 4,764 | 4,112
Total expense | 7,153 | 7,136 | 5,657
Income before income tax and undistributed net income of subsidiaries | 59,622 | 79,814 | 55,769
Income tax benefit | (1,309) | (1,478) | (1,208)
Income before undistributed net income of subsidiaries | 60,931 | 81,292 | 56,977
Equity in undistributed net income (distribution in excess of net income) of: |  |  |
Bank subsidiary | 70,823 | 63,337 | 79,566
Nonbank subsidiaries | (489) | 152 | (1,023)
Net Income | $ 131,265 | $ 144,781 | $ 135,520

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