Parties-in-Interest Transactions (Details) - EBP 002 - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
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| EBP, Related Party and Party-in-Interest Transactions [Line Items] | ||
| Administrative expenses | $ 377,571 | |
| Investments, at fair value: | 585,743,136 | $ 520,560,705 |
| EBP, Trustee | ||
| EBP, Related Party and Party-in-Interest Transactions [Line Items] | ||
| Administrative expenses | $ 327,702 | |
| F.N.B. Corporation Common Stock Fund | ||
| EBP, Related Party and Party-in-Interest Transactions [Line Items] | ||
| Number of shares | 6,851,760 | 8,074,783 |
| Investments, at fair value: | $ 117,175,933 | $ 119,355,214 |
| F.N.B. Corporation common stock dividends received | $ 3,541,879 | |
| F.N.B. Corporation common stock shares purchased by the Plan | 677,323 | |
| F.N.B. Corporation aggregate cost of purchased common stock | $ 9,870,154 | |
| F.N.B. Corporation common stock shares sold by the Plan | 1,763,507 | |
| F.N.B. Corporation proceeds from sale of common stock | $ 22,162,206 | |
| In-kind shares of F.N.B. Corporation stock distributed | 136,839 |
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- Definition EBP, Investment, Paid In Kind, Number of Shares No definition available.
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- Definition Amount of decrease in net asset available for benefit from administrative expense incurred by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of increase in net asset available for benefit from dividend income on investment held by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Cost of investment, excluding plan interest in master trust, acquired by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Fair value of investment, excluding plan interest in master trust, held by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Includes, but is not limited to, derivative, investment measured at net asset value per share as practical expedient, and insurance contract not meeting fully-benefit responsive investment criteria. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Number of shares or units of investment held by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Number of shares or units of investment purchased by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Number of shares or units of investment sold by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount of selling price for investment, excluding plan interest in master trust, sold by employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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