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BORROWINGS, Contractual Maturity on Borrowings (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2016 | Dec. 31, 2015
Debt Instrument [Line Items] |  |
Carrying value | $ 248,370 | $ 403,446
Weighted-average rate at period end | 1.70% |
Weighted-average interest rate on borrowings during period | 1.46% | 0.82%
Federal Home Loan Bank Overnight Advance [Member] |  |
Debt Instrument [Line Items] |  |
Carrying value | $ 146,200 | $ 301,300
Federal Home Loan Bank Overnight Advance [Member] | January 3, 2017 [Member] |  |
Debt Instrument [Line Items] |  |
Carrying value | $ 146,200 |
Weighted-average rate at period end | 0.74% |
Subordinated Debt Held By Unconsolidated Subsidiary Trust [Member] |  |
Debt Instrument [Line Items] |  |
Carrying value | $ 102,170 | $ 102,146
Subordinated Debt Held By Unconsolidated Subsidiary Trust [Member] | July 31, 2031 [Member] |  |
Debt Instrument [Line Items] |  |
Carrying value | $ 24,850 |
Weighted-average rate at period end | 4.47% |
Subordinated Debt Held By Unconsolidated Subsidiary Trust [Member] | December 15, 2036 [Member] |  |
Debt Instrument [Line Items] |  |
Carrying value | $ 77,320 |
Weighted-average rate at period end | 2.61% |

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- Definition The average effective interest rate during the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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