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LONG-TERM BORROWINGS - Schedule of Junior Subordinated Debt Trusts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 74	$ 73
Trust Preferred Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 77
Rate Reset Factor [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) [Member]
Common Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 3
F.N.B. Statutory Trust II
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 22
Interest Rate	5.63%
Rate Reset Factor [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) [Member]
Rate Reset Factor	1.65%
F.N.B. Statutory Trust II | Trust Preferred Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 22
F.N.B. Statutory Trust II | Common Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	1
Yadkin Valley Statutory Trust I
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 23
Interest Rate	5.30%
Rate Reset Factor [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) [Member]
Rate Reset Factor	1.32%
Yadkin Valley Statutory Trust I | Trust Preferred Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 25
Yadkin Valley Statutory Trust I | Common Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	1
FNB Financial Services Capital Trust I
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 24
Interest Rate	5.41%
Rate Reset Factor [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) [Member]
Rate Reset Factor	1.46%
FNB Financial Services Capital Trust I | Trust Preferred Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 25
FNB Financial Services Capital Trust I | Common Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	1
Patapsco Statutory Trust I
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 5
Interest Rate	5.46%
Rate Reset Factor [Extensible Enumeration]	Secured Overnight Financing Rate (SOFR) [Member]
Rate Reset Factor	1.48%
Patapsco Statutory Trust I | Trust Preferred Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 5
Patapsco Statutory Trust I | Common Securities
Subordinated Borrowing [Line Items]
Junior subordinated debt	$ 0

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Including the current and noncurrent portions, the carrying value of junior subordinated long-term debt owed to unconsolidated subsidiary trusts as of the balance sheet date. Such debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets and was initially scheduled to be repaid after one year or beyond the normal operating cycle if longer.

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