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INVESTMENTS (Narrative) (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019 | Dec. 31, 2019 | Dec. 31, 2018
Schedule of Investments [Line Items] |  |  |  |  |  |
Net unrealized gain on available-for-sale debt securities, net of tax | $ 28,724 | $ 7,484 | $ 28,724 | $ 7,484 | $ 3,250 | $ (17,826)
Deferred tax assets, unrealized losses on available for sale securities | $ 7,900 |  | $ 7,900 |  | $ 890 |
Unrealized Loss as a Percent of Fair Value | 1.00% |  | 1.00% |  | 1.00% |
Security pledged as collateral, amortized cost | $ 597,700 |  | $ 597,700 |  | $ 709,000 |
Security pledged as collateral, fair value | 622,600 |  | 622,600 |  | $ 712,400 |
Unrealized gain (loss), change in fair value of bank stock equity securities | $ 0 | $ 22 | $ 0 | $ (62) |  |

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- Definition Amount, after tax, of accumulated unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e681-108580 + Details
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- Definition Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from unrealized losses on available-for-sale securities. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32621-109319 + Details
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- Definition Fair value of financial instrument held by the entity for its own account (proprietary securities) for trading or investment purposes that are carried at fair value and pledged to counterparties as collateral for financing transactions. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -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 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=66007379&loc=d3e113888-111728 + Details
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