Credit Quality Assessment (Troubled Debt Restructured Loans for Specific Segments of the Loan Portfolio) (Detail) - Troubled Debt Restructuring - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2015	Dec. 31, 2014
Financing Receivable Modifications [Line Items]
Restructured accruing	$ 1,115	$ 1,359
Restructured non-accruing	1,182	284
Balance	2,297	1,643
Specific allowance	421	99
Restructured and subsequently defaulted	0	0
Commercial
Financing Receivable Modifications [Line Items]
Restructured accruing	875	75
Restructured non-accruing	543	92
Balance	1,418	167
Specific allowance	272	99
Restructured and subsequently defaulted	0	0
All Other
Financing Receivable Modifications [Line Items]
Restructured accruing	0	0
Restructured non-accruing	0	0
Balance	0	0
Specific allowance	0	0
Restructured and subsequently defaulted	0	0
Commercial Portfolio Segment \| Commercial Acquisition, Development and Construction
Financing Receivable Modifications [Line Items]
Restructured accruing	0	0
Restructured non-accruing	0	192
Balance	0	192
Specific allowance	0	0
Restructured and subsequently defaulted	0	0
Commercial Portfolio Segment \| Commercial Investor Real Estate
Financing Receivable Modifications [Line Items]
Restructured accruing	0	1,284
Restructured non-accruing	0	0
Balance	0	1,284
Specific allowance	0	0
Restructured and subsequently defaulted	0	0
Commercial Portfolio Segment \| Commercial Owner Occupied Real Estate
Financing Receivable Modifications [Line Items]
Restructured accruing	240	0
Restructured non-accruing	639	0
Balance	879	0
Specific allowance	149	0
Restructured and subsequently defaulted	$ 0	$ 0

- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

No definition available.

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- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months.

+ References

No definition available.

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- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which restructured accruing.

+ References

No definition available.

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- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which restructured non accruing.

+ References

No definition available.

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- Definition

Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for specific allowance.

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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

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