FAIR VALUE OF FINANCIAL INSTRUMENTS (Assets and Liabilities Measured on a Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—trading	$ 25,268	$ 28,694
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	2,287,993	2,789,031
Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Held-for-sale, Fair Value Disclosure	51,697	51,779
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	2,287,993	2,789,031
Total assets	2,363,152	2,853,326
Junior subordinated debentures net of unamortized deferred issuance costs at fair value	66,284	74,857
Total liabilities	112,266	112,192
Recurring [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	23,809	19,339
Derivative liabilities	45,938	37,150
Recurring [Member] | Interest rate lock and forward sale commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	338	142
Derivative liabilities	25	118
Recurring [Member] | Loan Participations and Assignments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	19	67
Recurring [Member] | Trust Preferred Securities Subject to Mandatory Redemption
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—trading	25,268	28,694
Recurring [Member] | U.S. Government and agency obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	34,327	55,108
Recurring [Member] | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	123,598	261,209
Recurring [Member] | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	91,018	121,853
Recurring [Member] | Mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	1,819,452	2,139,336
Recurring [Member] | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	219,598	211,525
Recurring [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Held-for-sale, Fair Value Disclosure	11,634	2,305
Recurring [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	552	553
Recurring [Member] | SBA Servicing Asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
SBA servicing asset	717	835
Recurring [Member] | Investment in Limited Partnerships
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in limited partnerships	12,841	12,427
Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	0	0
Total assets	552	553
Junior subordinated debentures net of unamortized deferred issuance costs at fair value	0	0
Total liabilities	0	0
Recurring [Member] | Level 1 [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Recurring [Member] | Level 1 [Member] | Interest rate lock and forward sale commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Recurring [Member] | Level 1 [Member] | Loan Participations and Assignments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0	0
Recurring [Member] | Level 1 [Member] | Trust Preferred Securities Subject to Mandatory Redemption
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—trading	0	0
Recurring [Member] | Level 1 [Member] | U.S. Government and agency obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	0	0
Recurring [Member] | Level 1 [Member] | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	0	0
Recurring [Member] | Level 1 [Member] | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	0	0
Recurring [Member] | Level 1 [Member] | Mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	0	0
Recurring [Member] | Level 1 [Member] | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	0	0
Recurring [Member] | Level 1 [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Held-for-sale, Fair Value Disclosure	0	0
Recurring [Member] | Level 1 [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	552	553
Recurring [Member] | Level 1 [Member] | SBA Servicing Asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
SBA servicing asset	0	0
Recurring [Member] | Level 1 [Member] | Investment in Limited Partnerships
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in limited partnerships	0	0
Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	2,287,993	2,789,031
Total assets	2,323,672	2,810,736
Junior subordinated debentures net of unamortized deferred issuance costs at fair value	0	0
Total liabilities	45,957	37,293
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	23,809	19,339
Derivative liabilities	45,938	37,150
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Interest rate lock and forward sale commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	236	61
Derivative liabilities	0	76
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Loan Participations and Assignments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	19	67
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Trust Preferred Securities Subject to Mandatory Redemption
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—trading	0	0
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government and agency obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	34,327	55,108
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	123,598	261,209
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	91,018	121,853
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	1,819,452	2,139,336
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	219,598	211,525
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Held-for-sale, Fair Value Disclosure	11,634	2,305
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	0	0
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | SBA Servicing Asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
SBA servicing asset	0	0
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Investment in Limited Partnerships
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in limited partnerships	0	0
Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential Mortgage
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Held-For-Sale, Fair Value Disclosure, Unpaid Principal Balance	11,500	2,200
Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	0	0
Total assets	38,928	42,037
Junior subordinated debentures net of unamortized deferred issuance costs at fair value	66,284	74,857
Total liabilities	66,309	74,899
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Interest rate swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Interest rate lock and forward sale commitments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	102
Derivative liabilities	25	42
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Loan Participations and Assignments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Trust Preferred Securities Subject to Mandatory Redemption
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—trading	25,268	28,694
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government and agency obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities—available-for-sale, net of allowance for credit losses of $750 and none, respectively; amortized cost $2,774,972 and $3,218,777, respectively	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans Held-for-sale, Fair Value Disclosure	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities	0	0
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | SBA Servicing Asset
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
SBA servicing asset	717	835
Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Investment in Limited Partnerships
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in limited partnerships	$ 12,841	$ 12,427