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FAIR VALUE MEASUREMENTS (Details 3) - USD ($) $ in Thousands | Dec. 31, 2017 | Dec. 31, 2016
--- | --- | ---
Assets, Fair Value Disclosure [Abstract] |  |  |
Held-to-maturity Securities |  | $ 497,688 | $ 487,076
Loans and Leases Receivable, Net Amount |  | 6,294,910 | 5,938,039
Securities held to maturity, fair value |  | 494,194 | 485,650
Federal Home Loan Bank Stock |  | 11,597 | 11,497
Bank Owned Life Insurance |  | 151,528 | 144,503
Liabilities, Fair Value Disclosure [Abstract] |  |  |
Advances from Federal Home Loan Banks |  | 53,264 | 50,819
Junior subordinated debentures |  | 73,073 | 73,107
Subordinated Debt |  | 34,682 | 34,635
Deposits [Member] |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |
Financial Liabilities Book Value | [1] | 6,084,952 | 5,763,101
Accrued Liabilities, Fair Value Disclosure | [1] | 6,084,952 | 5,763,101
Bank Time Deposits [Member] |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |
Financial Liabilities Book Value | [2] | 644,301 | 649,152
Accrued Liabilities, Fair Value Disclosure | [2] | 639,060 | 647,038
Federal Home Loan Bank Advances [Member] |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |
Advances from Federal Home Loan Banks | [2] | 53,264 | 50,819
Federal Home Loan Bank Borrowings, Fair Value Disclosure | [2] | 52,111 | 50,898
Customer Repurchase Agreements [Member] |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |
Customer Repurchase Agreements and other short-term borrowings | [2] | 162,679 | 176,913
Accrued Liabilities, Fair Value Disclosure | [2] | 162,679 | 176,913
Junior Subordinated Debt [Member] |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |
Junior subordinated debentures | [3] | 73,073 | 73,107
Accrued Liabilities, Fair Value Disclosure | [3] | 74,680 | 72,510
Subordinated Debt [Member] |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |
Subordinated Debt | [2] | 34,682 | 34,635
Accrued Liabilities, Fair Value Disclosure | [2] | 32,707 | 34,241
Significant Other Observable Inputs (Level 2) [Member] | Deposits [Member] |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |
Accrued Liabilities, Fair Value Disclosure | [1] | 6,084,952 | 5,763,101
Significant Other Observable Inputs (Level 2) [Member] | Bank Time Deposits [Member] |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |
Accrued Liabilities, Fair Value Disclosure | [2] | 639,060 | 647,038
Significant Other Observable Inputs (Level 2) [Member] | Federal Home Loan Bank Advances [Member] |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |
Federal Home Loan Bank Borrowings, Fair Value Disclosure | [2] | 52,111 |
Accrued Liabilities, Fair Value Disclosure | [2] |  | 50,898
Significant Other Observable Inputs (Level 2) [Member] | Junior Subordinated Debt [Member] |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |
Accrued Liabilities, Fair Value Disclosure | [3] | 74,680 | 72,510
Significant Unobservable Inputs (Level 3) [Member] | Customer Repurchase Agreements [Member] |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |
Accrued Liabilities, Fair Value Disclosure | [2] | 162,679 | 176,913
Significant Unobservable Inputs (Level 3) [Member] | Subordinated Debt [Member] |  |  |
Liabilities, Fair Value Disclosure [Abstract] |  |  |
Accrued Liabilities, Fair Value Disclosure | [2] | 32,707 | 34,241
US Treasury Securities [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Held-to-maturity Securities | [4] | 1,006 | 1,007
Securities held to maturity, fair value | [4] | 1,035 | 1,054
US Treasury Securities [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Securities held to maturity, fair value | [4] | 1,035 | 1,054
Agency mortgage-backed securities |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Held-to-maturity Securities | [4] | 204,768 | 156,088
Securities held to maturity, fair value | [4] | 205,823 | 157,504
Agency mortgage-backed securities | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Securities held to maturity, fair value | [4] | 205,823 | 157,504
Agency collateralized mortgage obligations |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Held-to-maturity Securities | [4] | 262,998 | 297,445
Securities held to maturity, fair value | [4] | 258,408 | 294,650
Agency collateralized mortgage obligations | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Securities held to maturity, fair value | [4] | 258,408 | 294,650
Single issuer trust preferred securities issued by banks and insurers |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Held-to-maturity Securities | [4] | 1,500 | 1,500
Securities held to maturity, fair value | [4] | 1,529 | 1,544
Single issuer trust preferred securities issued by banks and insurers | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Securities held to maturity, fair value | [4] | 1,529 | 1,544
Small Business Administration Pooled Securities [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Held-to-maturity Securities | [4] | 27,416 | 31,036
Securities held to maturity, fair value | [4] | 27,399 | 30,898
Small Business Administration Pooled Securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Securities held to maturity, fair value | [4] | 0 | 0
Small Business Administration Pooled Securities [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Securities held to maturity, fair value | [4] | 27,399 | 30,898
Small Business Administration Pooled Securities [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Securities held to maturity, fair value | [4] | 0 | 0
Loans Net Of Allowance For Loan Loses [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Loans and Leases Receivable, Net Amount | [5] | 6,261,343 | 5,904,065
Loans, net of allowance for loan losses | [5] | 6,116,051 | 5,784,778
Loans Net Of Allowance For Loan Loses [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Loans, net of allowance for loan losses | [5] | 6,116,051 | 5,784,778
Investment in Federal Home Loan Bank Stock [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Federal Home Loan Bank Stock | [6] | 11,597 | 11,497
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure | [6] | 11,597 | 11,497
Investment in Federal Home Loan Bank Stock [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure | [6] | 0 | 0
Investment in Federal Home Loan Bank Stock [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure | [6] | 11,597 | 11,497
Investment in Federal Home Loan Bank Stock [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure | [6] | 0 | 0
Cash Surrender Value [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Bank Owned Life Insurance | [7] | 151,528 | 144,503
Cash Surrender Value, Fair Value Disclosure | [7] | 151,528 | 144,503
Cash Surrender Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Cash Surrender Value, Fair Value Disclosure | [7] | 0 | 0
Cash Surrender Value [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Cash Surrender Value, Fair Value Disclosure | [7] | 151,528 | 144,503
Cash Surrender Value [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Assets, Fair Value Disclosure [Abstract] |  |  |
Cash Surrender Value, Fair Value Disclosure | [7] | $ 0 | $ 0
[1] | Fair value of demand deposits, savings and interest checking accounts and money market deposits is the amount payable on demand at the reporting date.
[2] | Fair value was determined by discounting anticipated future cash payments using rates currently available for instruments with similar remaining maturities.
[3] | Fair value was determined based upon market prices of securities with similar terms and maturities.
[4] | The fair values presented are based on quoted market prices, where available. If quoted market prices are not available, fair values are based on quoted market prices of comparable instruments and/or discounted cash flow analysis.
[5] | Fair value is estimated by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and for the same remaining maturities or cash flows. Additionally, this amount excludes collateral dependent impaired loans, which are deemed to be marked to fair value on a nonrecurring basis.
[6] | FHLB stock has no quoted market value and is carried at cost, therefore the carrying amount approximates fair value.
[7] | Cash surrender value of life insurance is recorded at its cash surrender value (or the amount that can be realized upon surrender of the policy), therefore carrying amount approximates fair value.

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- Definition Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822 + Details
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- Definition The carrying amount of a life insurance policy on an officer, executive or employee for which the reporting entity (a bank) is entitled to proceeds from the policy upon death of the insured or surrender of the insurance policy. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.10) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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- Definition Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=75030427&loc=d3e22054-111558 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.6) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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- Definition Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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