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FAIR VALUES OF FINANCIAL INSTRUMENTS - Reconciliation of Assets Measured at Fair Value on Recurring Basis (Detail) - Recurring - Significant Unobservable Inputs (Level 3) - U.S. government agency and U.S. government sponsored enterprise residential mortgage-backed securities - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 945	$ 19,233
Total gains (losses) (realized/unrealized):
Included in earnings—fair value adjustment	0	(1,391)
Sales, settlements, and other	(2)	(715)
Balance at end of period	$ 943	$ 17,127

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- Definition

Fair Value Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Fair Value Adjustment Including in Earnings

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- Definition

Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales And Settlements

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- Definition

Fair Value Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Total Gains (Losses) [Abstract]

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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- Definition

Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258

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