Leases (Narrative) (Detail)	3 Months Ended
Dec. 31, 2019 Office Lease
Lessee Lease Description [Line Items]
Number of leases \| Lease	3
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Lessee, operating lease, renewal term	5 years
Private Banking Office
Lessee Lease Description [Line Items]
Number of office leases included in option to extend	2
Private Banking Office \| Short-term Leases [Member]
Lessee Lease Description [Line Items]
Number of offices	2
Representative Office \| Short-term Leases [Member]
Lessee Lease Description [Line Items]
Number of offices	2
New Castle County, Montchanin, Delaware \| Private Banking Office
Lessee Lease Description [Line Items]
Number of offices	1
Morris County, Morristown, New Jersey \| Private Banking Office
Lessee Lease Description [Line Items]
Number of offices	1
Palm Beach County, Palm Beach, Florida \| Private Banking Office
Lessee Lease Description [Line Items]
Number of offices	1
Palm Beach County, Palm Beach, Florida \| Representative Office
Lessee Lease Description [Line Items]
Number of offices	1
Allentown, Pennsylvania \| Representative Office
Lessee Lease Description [Line Items]
Number of offices	1

Number of leases.

No definition available.

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- Definition

Number of office leases included in option to extend.

+ References

No definition available.

+ Details

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- Definition

Number of offices.

+ 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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Namespace Prefix:	us-gaap_
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- Definition

Indicates (true false) whether lessee has option to extend operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980

+ Details

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- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918673-209980

+ Details

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