BORROWINGS (Additional Information) (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Borrowings [Line Items]
Percentage of principal and accrued interest of retail repurchase agreements collateralized	102.50%
FHLB
Borrowings [Line Items]
Pledged under blanket lien	$ 1,600.0	$ 1,400.0
Line of credit amount available for borrowing	1,600.0	1,400.0
Line Of Credit, Outstanding Amount	765.8	790.0
Residential Portfolio Segment
Borrowings [Line Items]
Pledged under blanket lien	805.7	725.1
HELOC
Borrowings [Line Items]
Pledged under blanket lien	281.0	307.2
Multifamily Loans
Borrowings [Line Items]
Pledged under blanket lien	83.0	60.4
Federal Reserve and Correspondent Banks
Borrowings [Line Items]
Line of credit amount available for borrowing	359.7	369.4
Unsecured line of credit available for borrowing	70.0	70.0
Line Of Credit, Outstanding Amount	0.0	0.0
Commercial Portfolio Segment
Borrowings [Line Items]
Pledged under blanket lien	$ 1,200.0	$ 1,000.0

Represents the Pledged Financial Instruments Percentage Of Principal And Accrued Interest Collateralized.

No definition available.

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- Definition

Represents the Unsecured Line Of Credit Facility Maximum Borrowing Capacity.

+ References

No definition available.

+ Details

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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.

+ Details

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

The carrying amount, as of the date of the latest financial statement presented, of loans receivable which are owned but transferred to serve as collateral for the payment of FHLB debt obligations, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-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=64858031&loc=SL6224234-111729

+ Details

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- Details

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- Details

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- Details

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- Details

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- Details

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