BORROWED FUNDS - Narrative (Details) - USD ($)				11 Months Ended	12 Months Ended
	Jan. 01, 2022	Dec. 03, 2020	Jun. 13, 2016	Dec. 14, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 15, 2022
Repurchase Agreement Counterparty [Line Items]
Stock in Federal Home Loan Bank of Pittsburgh, at cost					$ 15,398,000	$ 24,116,000
Securities sold under agreements to repurchase					0	0
Collateralized borrowings					586,000,000	38,300,000
Receipts from Bank Term Funding Program					$ 565,000,000	0	$ 0
SOFR
Repurchase Agreement Counterparty [Line Items]
Variable interest rate percentage					2.41%
Trusts
Repurchase Agreement Counterparty [Line Items]
Trust common securities owned	$ 800,000
Aggregate principal amount of Pooled Floating Rate Securities	12,500,000
Floating rate common securities issued	400,000
Federal Reserve Bank of Philadelphia
Repurchase Agreement Counterparty [Line Items]
Advances from the FHLB					$ 0
Borrowed funds						0
Federal Reserve Bank of Philadelphia | Asset Pledged as Collateral
Repurchase Agreement Counterparty [Line Items]
Loans and securities pledged as collateral					2,100,000,000	700,000,000
FHLB advances
Repurchase Agreement Counterparty [Line Items]
Stock in Federal Home Loan Bank of Pittsburgh, at cost					15,400,000	24,100,000
Dividends from the FHLB					$ 1,100,000	300,000
Junior Subordinated Debt
Repurchase Agreement Counterparty [Line Items]
Interest rate on unsecured debt percent					7.80%
Junior Subordinated Debt | SOFR
Repurchase Agreement Counterparty [Line Items]
Variable interest rate percentage					2.41%
Junior Subordinated Debt | Trusts
Repurchase Agreement Counterparty [Line Items]
Trust capital securities issued	11,800,000
Trust capital securities issued net	23,600,000
Senior Notes | 4.50% Senior Unsecured Notes Mature on 2026
Repurchase Agreement Counterparty [Line Items]
Interest rate on unsecured debt percent			4.50%
Debt instrument, face amount			$ 100,000,000
Senior unsecured notes, percentage of principle amount to be redeemed percent			100.00%
Senior Notes | 4.50% Senior Unsecured Notes Mature on 2026 | LIBOR
Repurchase Agreement Counterparty [Line Items]
Variable interest rate percentage			3.30%
Senior Notes 2030
Repurchase Agreement Counterparty [Line Items]
Interest rate on unsecured debt percent		2.75%
Debt instrument, face amount		$ 150,000,000
Redemption price, percentage		100.00%
Debt issuance costs, gross					$ 148,400,000	148,200,000
Senior Notes 2030 | SOFR
Repurchase Agreement Counterparty [Line Items]
Variable interest rate percentage		2.485%
Senior Notes 2025
Repurchase Agreement Counterparty [Line Items]
Debt instrument, face amount	$ 30,000,000
Senior Notes 2025 | LIBOR
Repurchase Agreement Counterparty [Line Items]
Variable interest rate percentage	3.068%
Senior Notes 2027
Repurchase Agreement Counterparty [Line Items]
Variable interest rate percentage				4.25%
Interest rate on unsecured debt percent								7.70%
Debt instrument, face amount	$ 70,000,000
Carrying value of securities purchased under agreements					$ 70,000,000	$ 70,000,000
Senior Notes 2027 | SOFR
Repurchase Agreement Counterparty [Line Items]
Variable interest rate percentage	2.31%