INVESTMENTS (Narrative) (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 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	$ 29,310	$ 3,912	$ 29,310	$ 3,912	$ 3,250	$ (17,826)
Deferred tax assets, unrealized losses on available for sale securities	$ 8,000		$ 8,000		890
Unrealized Loss as a Percent of Fair Value	1.00%		1.00%
Security pledged as collateral, amortized cost	$ 624,900		$ 624,900		709,000
Security pledged as collateral, fair value	650,200		650,200		$ 712,400
Unrealized loss, change in fair value of bank stock equity securities	$ 0	$ 159	$ 0	$ 84

Security Owned and Pledged as Collateral, Amortized Cost

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- Definition

Unrealized Loss as a Percent of Fair Value

+ References

No definition available.

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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

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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

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- Definition

Amount of unrealized gain (loss) on investment in marketable security.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(7)(c))
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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

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
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