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MARKETABLE SECURITIES - Sale of Securities (Details) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2018 | Sep. 30, 2017 | Sep. 30, 2018 | Sep. 30, 2017
Sale of Marketable Securities [Abstract] |  |  |  |
Proceeds | $ 102,356 | $ 199,974 | $ 111,813 | $ 214,736
Gross gains | 4 | 0 | 4 | 38
Gross losses | $ (3) | 0 | (54) | (13)
Debt Securities, Held-to-maturity, Sale, Excluding Other-than-temporary Impairment [Abstract] |  |  |  |
Proceeds from sales |  | 0 | $ 0 | 923
Amortized cost |  | 0 |  | 907
Gross realized gains |  | 0 |  | 16
Tax expense related to securities gains/losses |  | $ 0 |  | $ (4)

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- Definition Held-to-maturity Securities, Sold Security, Amortized Cost + References No definition available. + Details
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- Definition Held-to-maturity Securities, Sold Security, Tax Expense (Benefit) On Realized Gain (Loss) + References No definition available. + Details
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- Definition Marketable Securities, Gross Realized Gains + References No definition available. + Details
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- Definition Marketable Securities, Gross Realized Losses + References No definition available. + Details
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- Definition Proceeds from the Sale of Marketable Securities + References No definition available. + Details
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- Definition Sale Of Marketable Securities [Abstract] + References No definition available. + Details
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- Definition Amount of gain (loss) on sale of investment in debt security measured at amortized cost (held-to-maturity), including other-than-temporary impairment (OTTI). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27405-111563 + Details
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- Definition The cash inflow associated with the sale of securities that had been designated as held-to-maturity. Excludes proceeds from maturities, prepayments and calls by the issuer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=109979856&loc=d3e26853-111562 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 12 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585 + Details
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