BORROWINGS - Additional Information (Detail) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Overnight maturities	67.00%	75.70%
FHLB [Member]
Debt Instrument [Line Items]
Credit available with FHLB	$ 7,472,000,000
Credit with FHLB utilized	$ 2,300,000,000
Federal Home Loan Bank advances are scheduled to mature periodically through the year	2021
Minimum [Member] \| FHLB [Member]
Debt Instrument [Line Items]
Effective interest rates	1.39%	0.95%
Maximum [Member] \| FHLB [Member]
Debt Instrument [Line Items]
Effective interest rates	4.19%	4.19%

Amount of advances or credit lines used from the Federal Home Loan Bank (FHLB).

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- Definition

Short-term Advances, Overnight Maturities

+ References

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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

The last year of maturity for the advances from the Federal Home Loan Bank as of the Balance Sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
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- Definition

States the interest rate applicable to Federal Home Loan Bank advances outstanding as of the Balance Sheet date.

+ References

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- Definition

Amount of maximum advances or credit lines available from the Federal Home Loan Bank (FHLB).

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