COMMITMENTS AND CONTINGENCIES (Schedule of Securities Pledged as Collateral) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financial Instruments Owned and Pledged as Collateral [Line Items]
Cash	$ 246,430	$ 116,839
Loans	4,427,325	4,139,672
Total pledged assets	5,732,208	5,300,858
Available-for-sale Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged	734,463	733,995
Held-to-maturity Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged	323,990	310,352
Public deposits
Financial Instruments Owned and Pledged as Collateral [Line Items]
Cash	0	0
Loans	0	0
Total pledged assets	770,154	759,362
Public deposits \| Available-for-sale Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged	455,201	467,266
Public deposits \| Held-to-maturity Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged	314,953	292,096
Repurchase agreements
Financial Instruments Owned and Pledged as Collateral [Line Items]
Cash	0	0
Loans	0	0
Total pledged assets	98,445	86,901
Repurchase agreements \| Available-for-sale Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged	98,445	79,299
Repurchase agreements \| Held-to-maturity Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged	0	7,602
FHLB Advances
Financial Instruments Owned and Pledged as Collateral [Line Items]
Cash	0	0
Loans	4,107,411	3,846,934
Total pledged assets	4,168,540	3,910,746
FHLB Advances \| Available-for-sale Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged	61,129	63,812
FHLB Advances \| Held-to-maturity Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged	0	0
Fed Funds
Financial Instruments Owned and Pledged as Collateral [Line Items]
Cash	0	0
Loans	319,914	292,738
Total pledged assets	319,914	292,738
Fed Funds \| Available-for-sale Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged	0	0
Fed Funds \| Held-to-maturity Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged	0	0
Derivatives
Financial Instruments Owned and Pledged as Collateral [Line Items]
Cash	246,430	116,839
Loans	0	0
Total pledged assets	247,521	118,099
Derivatives \| Available-for-sale Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged	1,091	1,260
Derivatives \| Held-to-maturity Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged	0	0
Other purposes
Financial Instruments Owned and Pledged as Collateral [Line Items]
Cash	0	0
Loans	0	0
Total pledged assets	127,634	133,012
Other purposes \| Available-for-sale Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged	118,597	122,358
Other purposes \| Held-to-maturity Securities
Financial Instruments Owned and Pledged as Collateral [Line Items]
Securities pledged	$ 9,037	$ 10,654

Cash Pledged as Collateral.

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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.

+ References

No definition available.

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- Definition

The carrying amount, as of the date of the latest financial statement presented, of all assets that are pledged as collateral for the payment of the related debt obligation primarily arising from secured borrowings, repurchase agreements or other current or potential obligations, where the secured party does not have the right by contract or custom to sell or re-pledge the collateral and therefore are not reclassified and separately reported in the statement of financial position.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (b)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729

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- Definition

The sum of the carrying amounts, as of the date of the latest financial statement presented, of loans receivable which are owned but transferred to serve as collateral for the payment of related debt obligations, primarily secured borrowings and repurchase agreements, and for which the transferees are not permitted to sell or re-pledge them to an unrelated party.

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- Definition

Sum of the carrying amounts as of the date of the latest financial statement presented of securities which are owned but transferred to another party to serve as collateral to partially or fully secure a debt obligation, repurchase agreement or other current or potential obligation, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party.

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