INVESTMENT SECURITIES - Additional Information (Detail)	12 Months Ended
Dec. 31, 2018 USD ($) position	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Investments, Debt and Equity Securities [Abstract]
Percentage of debt securities considered to be of investment-grade	97.00%
Maximum percentage of any general obligation bonds in one state	9.00%
Number of securities in loss position	1,210
Number of positions	1,500
Other-than-temporary impairments \| $	$ 0	$ 0	$ 0

Debt Securities, Available-for-sale, Qualitative Disclosure, Number of Positions

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- Definition

Maximum percentage of any general obligation bonds in one state

+ References

No definition available.

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- Definition

Percentage of Total Debt Securities

+ References

No definition available.

+ Details

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- Definition

Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563

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- Definition

The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 8A
-URI http://asc.fasb.org/extlink&oid=109979856&loc=SL6284422-111562

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- References

No definition available.

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